JP2011202545A - Fuel injection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection device improving the responsiveness of a nozzle needle 60 in closing a valve.SOLUTION: The fuel injection device 100 includes a control body 40 formed with a nozzle 44, the nozzle needle 60 opening and closing the nozzle 44, a pressure control chamber 53 controlling movement of the nozzle needle 60, an inflow passage 52 leading high-pressure fuel into the pressure control chamber 53, an outflow passage 54 letting the fuel in the pressure control chamber 53 flow out, and a floating plate 70 opening and closing the inflow passage 52. In the control body 40, an opening wall face 90, which is pressed by the floating plate 70 and in which an inflow port 52a of the inflow passage 52 is opened, forms an inflow recessed part 94. The inflow recessed part 94 becomes deeper at a position more distant from the inflow port 52a.

Description

  The present invention relates to a fuel injection device that injects high-pressure fuel into a combustion chamber of an internal combustion engine.

  2. Description of the Related Art Conventionally, there has been known a fuel injection device including a valve body in which a high-pressure fuel passage and a pressure control chamber are formed, and a valve member that opens and closes an injection hole by moving in the axial direction inside the valve body. ing. The movement of the valve member is controlled by the fuel pressure in the pressure control chamber. As one type of such a fuel injection device, for example, Patent Document 1 discloses a device that includes a control member that can be displaced in the axial direction of a valve body in a pressure control chamber and that opens and closes an inflow passage. This control member can stop the introduction of the high-pressure fuel into the pressure control chamber by closing the inflow passage. By the operation of the control member, the pressure in the pressure control chamber quickly decreases. Therefore, the valve member controlled by the pressure of the fuel in the pressure control chamber can quickly open the nozzle hole.

JP-A-6-108948

  Now, in the fuel injection device as disclosed in Patent Document 1, the present inventors use a control member to promptly cause pressure recovery in the pressure control chamber after the control member is displaced away from the opening wall surface. The structure which forms an inflow recessed part in the opening wall surface to be pressed corresponded. The inflow recess is formed by recessing the opening wall surface where the inlet of the inflow passage communicating with the pressure control chamber opens to the side opposite to the control member. However, it has been found that when the depth of the inflow recess is uniform, the effect of speeding up the pressure recovery in the pressure control chamber is not sufficiently exhibited. Details will be described below.

  In a state where the opening wall surface is pressed by the control member to close the inflow passage, high-pressure fuel is introduced into the inflow recess. When the depth of the inflow recess is uniform, a predetermined amount of high-pressure fuel is accumulated at each position of the recess. From the above state, when the pressure control chamber is displaced in the axial direction so that the control member is separated from the opening wall surface in order to open the inflow passage, the high-pressure fuel accumulated in the inflow recess starts to be released into the pressure control chamber.

  At a position close to the inlet in the inflow recess, high-pressure fuel introduced from the inlet is likely to be newly supplied. Therefore, the high-pressure fuel supplied from the inlet along with the accumulated high-pressure fuel continues to be released from the position close to the inlet in the inflow recess. On the other hand, high-pressure fuel introduced from the inflow port is hardly newly supplied to a position away from the inflow port in the inflow recess. Therefore, if the accumulated high-pressure fuel is exhausted, the high-pressure fuel is unlikely to continue to be released from a position away from the inlet in the inflow recess.

  As described above, after the displacement of the control member is started, the continuous discharge of the high-pressure fuel from the inflow recess to the pressure control chamber is performed only in a part of the inflow recess. As described above, the flow rate variation of the fuel discharged from the inflow recess to the pressure control chamber is generated, so that the effect of accelerating the pressure recovery in the pressure control chamber has not been exhibited sufficiently. Therefore, the effect of improving the responsiveness of the valve member by advancing the operation of the valve member closing the nozzle hole has not been sufficiently obtained.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a fuel injection device that improves the responsiveness of the valve member when the valve is closed.

  In order to achieve the above object, according to the first aspect of the present invention, a high-pressure fuel passage is formed therein, and an injection hole (44) for injecting the high-pressure fuel into the combustion chamber (22) of the internal combustion engine (20). A valve body (40) formed at the tip, a valve member (60) that moves in the axial direction of the valve body (40) inside the valve body (40) and opens and closes the injection hole (44), Pressure control formed inside the main body (40) on the opposite side of the nozzle hole (44) across the valve member (60) and introducing high-pressure fuel to control the movement of the valve member (60) by the pressure of the fuel A chamber (53), an inflow passage (52) for introducing high-pressure fuel into the pressure control chamber (53), an outflow passage (54) for allowing the fuel in the pressure control chamber (53) to flow out to the outside low-pressure side, A control member that is axially displaceable in the pressure control chamber (53) and opens and closes the inflow passage (52). 70), the control member for closing the inflow passage (52) by opening the inflow passage (52a) of the inflow passage (52) communicating with the pressure control chamber (53). The opening wall surface (90) pressed by (70) is recessed on the side opposite to the control member (70) to form an inflow recess (94), and the inflow recess (94) extends from the inflow port (52a). It is characterized by becoming deeper as it is farther away.

  According to the present invention, in order to close the inflow passage, in a state where the opening wall surface where the inflow opening opens is pressed by the control member, the inflow recess formed by denting the opening wall surface on the side opposite to the control member has a high pressure. Fuel is introduced. The inflow recess is deeper as the position is farther from the inlet. Therefore, the storage capacity in which the high-pressure fuel can be stored in the inflow recess is larger at a position farther from the inlet than at a position near the inlet. From the above state, when the pressure control chamber is displaced in the axial direction so that the control member is separated from the opening wall surface in order to open the inflow passage, the high-pressure fuel accumulated in the inflow recess starts to be released into the pressure control chamber.

  The high pressure fuel introduced from the inflow port is easily supplied to a position near the inflow port in the inflow recess. Therefore, at the position close to the inlet in the inflow recess, even if the storage capacity of the high-pressure fuel is small, the high-pressure fuel is newly supplied from the inlet, so that the fuel discharge is continued. On the other hand, high-pressure fuel introduced from the inflow port is hardly newly supplied to a position away from the inflow port in the inflow recess. However, since the accumulation capacity of the high-pressure fuel is large, the accumulated fuel is continuously discharged from a position away from the inlet in the inflow recess.

  As described above, after the displacement of the control member is started, the continuous discharge of the high-pressure fuel from the inflow recess to the pressure control chamber can be performed over the entire area of the inflow recess. As described above, by reducing the variation in the flow rate of the fuel discharged from the inflow recess to the pressure control chamber, the pressure recovery in the pressure control chamber can occur promptly. Therefore, since the operation of the valve member that closes the nozzle hole is accelerated, a fuel injection device that improves the responsiveness of the valve member can be realized.

  The invention according to claim 2 is characterized in that the depth of the inflow recess (94) gradually increases as the distance from the inflow port (52a) increases. Further, the invention according to claim 3 is characterized in that the inflow recessed portion (94) becomes deeper in steps as the distance from the inflow port (52a) increases. As in these inventions, the storage capacity of the high-pressure fuel increases as the distance from the inlet increases due to the inflow recess that increases in depth as the distance from the inlet increases. In this way, the higher the high-pressure fuel that is introduced from the inlet, the more the high-pressure fuel storage capacity can be increased, thereby reliably reducing the variation in the flow rate of the fuel discharged from the inflow recess. As described above, since the pressure recovery in the pressure control chamber can be further promptly generated, the responsiveness of the valve member can be further improved.

  In the invention according to claim 4, the inflow recess (94) extends annularly in the opening wall surface (90), and the inflow port (52a) opens to the bottom surface portion (94a) of the inflow recess (94). Features. According to the present invention, high-pressure fuel is introduced into the inflow recess extending in an annular shape on the opening wall surface from the inlet opening in the bottom surface. When the control member is separated from the opening wall surface, the high-pressure fuel is discharged from the inflow recess in an annular shape. Since the discharged high-pressure fuel can push the control member over the entire area in the circumferential direction, the control member can be quickly displaced in the pressure control chamber. In addition, since the high-pressure fuel continues to be discharged from the entire annular inflow recess, it is difficult for the control member pushed by the fuel to tilt. Thus, the pressure recovery in the pressure control chamber can be accelerated by smoothly causing the displacement of the control member. Therefore, the responsiveness improvement of the valve member when the valve is closed is further ensured.

  In the fifth aspect of the present invention, the inflow port (252a) is arranged in an annular shape so as to open to the bottom surface portion (294a), and the inflow recess (294) flows in the circumferential direction of the inflow recess (294). It is characterized by becoming deeper toward the intermediate position between the entrances (252a). According to the present invention, in a form in which a plurality of inlets are annularly arranged on the bottom surface of the inflow recess, an intermediate position between the inlets in the circumferential direction of the inflow recess is a place where high-pressure fuel is difficult to be supplied. Therefore, by making the inflow recesses deeper from each of the inflow ports toward the intermediate position between these inflow ports, the intermediate position between the inflow ports becomes the deepest point in the inflow recess, and the high-pressure fuel storage capacity Will increase. As a result, the variation in the flow rate of the fuel discharged from the inflow recess can be reduced, and the pressure recovery in the pressure control chamber can be promptly caused. Therefore, even if a plurality of inflow ports are arranged, the effect of improving the responsiveness of the valve member can be reliably obtained.

  The intermediate position between the inlets does not indicate only the same position from the pair of inlets in the circumferential direction of the inflow recess. This intermediate position may be closer to one of the inlets than the other of the inlets in the region of the inflow recess sandwiched between the pair of inlets.

  The invention according to claim 6 is characterized in that the plurality of inlets (52a) are opened at equal intervals in the circumferential direction of the inflow recess (94). According to the present invention, when a plurality of inlets are opened in the opening wall surface, it is difficult to supply high-pressure fuel at each position of the annular inflow recess by opening these inlets at equal intervals around the center of the opening wall surface. Can correct the imbalance. Therefore, the effect | action which suppresses the flow volume dispersion | variation of the fuel discharge | released from an inflow recessed part becomes still more reliable. Therefore, the responsiveness of the valve member when the valve is closed can be improved reliably.

  In the invention according to claim 7, in the opening wall surface (90), the outlet (54a) of the outflow passage (54) communicating with the pressure control chamber (53) opens on the inner peripheral side of the inflow recess (94). It is characterized by doing. By forming the outlet of the outflow passage communicating with the pressure control chamber on the inner peripheral side of the inlet recess as in the present invention, the inlet recess is expanded in the radial direction without being blocked by the outlet on the opening wall surface. Can be done. More high pressure fuel is introduced into the enlarged inflow recess from the inlet. Therefore, after the control member is separated from the wall surface of the opening, the amount of fuel released from the inflow recess to the pressure control chamber can be increased, so that pressure recovery in the pressure control chamber occurs more promptly. Therefore, the responsiveness of the valve member when the valve is closed can be further improved.

  In the invention according to claim 8, the outflow passage (354a) of the outflow passage (354) communicating with the pressure control chamber (53) is a circular opening located eccentrically on the circular opening wall surface (390). The recess (394) extends along the outer edge of the outlet (354a), and gradually increases in width from both ends (394b) in the extending direction toward the center (394c) where the inlet (352a) opens. The inflow recess (394) is characterized by being deeper from the central part (394c) toward both ends (394b).

  As in the present invention, in the form in which the outlet of the outflow passage communicating with the pressure control chamber is eccentrically positioned on the circular opening wall surface, the inflow recess extends along the outer edge shape of the circular outlet. This inflow recessed part becomes a groove | channel with the width | variety which increases gradually as it goes to the center part which the inflow port opens from the both ends of the extending direction. Therefore, it is difficult to secure a sufficient high-pressure fuel storage capacity at both ends of the inflow recess. Furthermore, if the inflow port is formed at the central portion in the extending direction, it is difficult to supply high-pressure fuel to both ends away from the central portion. Therefore, in the inflow concave portion having the above-described shape, there is a risk that the flow rate variation between the vicinity of the central portion and the vicinity of both end portions is remarkably increased.

  Therefore, the inflow recess, which is a groove having a width gradually increasing from both ends toward the center, becomes deeper from the center where the inflow opening opens toward both ends located away from the inflow. It is better to form deeper as you go. As a result, the storage capacity of the high-pressure fuel that can be accumulated at both ends can be increased, so that it is possible to continuously release the fuel from both ends. Therefore, the effect | action which suppresses the flow volume dispersion | variation from an inflow recessed part to a pressure control chamber is exhibited notably. Therefore, even in the groove-shaped inflow recess that becomes narrower as it approaches the both ends, deepening the recess further away from the inflow port speeds up the pressure recovery in the pressure control chamber, and the valve member is closed when the valve is closed. This can contribute to improved responsiveness.

  Note that the reference numerals and descriptions in parentheses described in the claims and in the above means are examples that clearly show the correspondence with the specific means described in the embodiments described later, and limit the contents of the invention. is not.

It is a lineblock diagram of a fuel supply system provided with a fuel injection device by a first embodiment of the present invention. 1 is a longitudinal sectional view of a fuel injection device according to a first embodiment of the present invention. It is the figure which expanded the vicinity of the characteristic part of the fuel-injection apparatus by 1st embodiment of this invention. It is the figure which expanded further the characteristic part of the fuel-injection apparatus by 1st embodiment of this invention. It is the VV sectional view taken on the line of FIG. It is a figure for demonstrating the correlation with the distance from an inflow port, and a depth about the inflow recessed part of FIG. It is a figure which shows the modification of FIG. It is a figure which shows the modification of FIG. It is the IX-IX sectional view taken on the line of FIG. It is a figure for demonstrating the correlation with the distance from an inflow port, and depth about the inflow recessed part of FIG. It is a figure which shows another modification of FIG. It is the XII-XII sectional view taken on the line of FIG. It is a figure for demonstrating the correlation with the distance from an inflow port, and a depth about the inflow recessed part of FIG. It is a figure which shows another modification of FIG. 6, Comprising: It is a figure for demonstrating the correlation with the distance from an inflow port, and the depth in the inflow recessed part of the form. It is a figure which shows the modification of FIG. 10, Comprising: It is a figure for demonstrating the correlation with the distance from an inflow port, and the depth in the inflow recessed part of the form. It is a figure which shows the modification of FIG. 13, Comprising: It is a figure for demonstrating the correlation with the distance from an inflow port, and the depth in the inflow recessed part of the form.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In addition, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol to the corresponding component in each embodiment.

(First embodiment)
FIG. 1 shows a fuel supply system 10 in which a fuel injection device 100 according to a first embodiment of the present invention is used. The fuel injection device 100 of this embodiment is a so-called direct injection fuel supply system that directly injects fuel into the combustion chamber 22 of the diesel engine 20 that is an internal combustion engine.

  The fuel supply system 10 includes a feed pump 12, a high-pressure fuel pump 13, a common rail 14, an engine control device 17, a fuel injection device 100, and the like.

  The feed pump 12 is an electric pump and is accommodated in the fuel tank 11. The feed pump 12 applies a feed pressure that is higher than the vapor pressure of the fuel to the fuel stored in the fuel tank 11. The feed pump 12 is connected to the high-pressure fuel pump 13 by a fuel pipe 12 a and supplies the high-pressure fuel pump 13 with fuel in a liquid phase state to which a predetermined feed pressure is applied. The fuel pipe 12a is provided with a pressure regulating valve (not shown), and the pressure of the fuel supplied to the high pressure fuel pump 13 is maintained at a predetermined value by the pressure regulating valve.

  The high-pressure fuel pump 13 is attached to a diesel engine and is driven by power from the output shaft of the diesel engine. The high-pressure fuel pump 13 is connected to the common rail 14 by a fuel pipe 13 a, and further applies pressure to the fuel supplied by the feed pump 12 to produce high-pressure fuel to be supplied to the common rail 14. In addition, the high pressure fuel pump 13 has a solenoid valve (not shown) electrically connected to the engine control device 17. The pressure of the fuel supplied from the high-pressure fuel pump 13 to the common rail 14 is controlled to a predetermined pressure by the opening / closing control of the electromagnetic valve by the engine control device 17.

  The common rail 14 is a tubular member made of a metal material such as chromium / molybdenum steel, and has a plurality of branch portions 14a corresponding to the number of cylinders per bank of the diesel engine. Each of the plurality of branch portions 14a is connected to the fuel injection device 100 by a fuel pipe that forms a supply flow path 14d. The fuel injection device 100 and the high-pressure fuel pump 13 are connected by a fuel pipe that forms a return flow path 14f. With the above configuration, the common rail 14 temporarily stores the fuel supplied in a high pressure state by the high-pressure fuel pump 13, and distributes the fuel to the plurality of fuel injection devices 100 via the supply flow path 14d while maintaining the pressure. In addition, the common rail 14 has a common rail sensor 14b at one end of the both ends in the axial direction and a pressure regulator 14c at the other end. The common rail sensor 14 b is electrically connected to the engine control device 17, detects the fuel pressure and temperature, and outputs the detected fuel pressure and temperature to the engine control device 17. The pressure regulator 14c keeps the fuel pressure in the common rail 14 constant, and depressurizes the excess fuel and discharges it to the low pressure side. The surplus fuel that has passed through the pressure regulator 14 c is returned to the fuel tank 11 through a flow path in the fuel pipe 14 e that connects the common rail 14 and the fuel tank 11.

  The fuel injection device 100 is a device that injects high-pressure fuel with an increased pressure supplied through the branch portion 14 a of the common rail 14 from the injection hole 44. Specifically, the fuel injection device 100 is a valve that controls the injection of the high-pressure fuel supplied from the high-pressure fuel pump 13 through the supply flow path 14 d from the injection hole 44 in accordance with a control signal from the engine control device 17. Part 50 is provided. In addition, in this fuel injection device 100, the surplus fuel that is part of the high-pressure fuel supplied from the supply flow path 14d and that has not been injected from the injection hole 44 is supplied to the fuel injection device 100 and the high-pressure fuel pump. 13 is discharged to a return flow path 14 f that communicates with 13 and returned to the high-pressure fuel pump 13. The fuel injection device 100 is inserted and attached to an insertion hole of a head member 21 that is a part of a combustion chamber 22 of the diesel engine 20. A plurality of fuel injection devices 100 are arranged for each combustion chamber 22 of the diesel engine 20, and fuel is injected directly into the combustion chamber 22, specifically at an injection pressure of about 160 to 220 megapascals (MPa). To do.

  The engine control device 17 is configured by a microcomputer or the like. In addition to the common rail sensor 14b described above, the engine control device 17 includes a rotation speed sensor that detects the rotation speed of the diesel engine 20, a throttle sensor that detects the throttle opening, an airflow sensor that detects the intake air intake amount, and a boost pressure. It is electrically connected to various sensors such as a supercharging pressure sensor for detecting, a water temperature sensor for detecting the cooling water temperature, and an oil temperature sensor for detecting the oil temperature of the lubricating oil. Based on information from each of these sensors, the engine control device 17 sends an electrical signal for controlling the opening and closing of the solenoid valve of the high pressure fuel pump 13 and the valve portion 50 of each fuel injection device 100 to the high pressure fuel pump 13. Output to the solenoid valve and each fuel injection device 100.

  Next, the configuration of the fuel injection device 100 will be described with reference to FIGS. 2 and 3.

  The fuel injection device 100 includes a control valve drive unit 30, a control body 40, a nozzle needle 60, and a floating plate 70.

  The control valve drive unit 30 is accommodated in the control body 40. The control valve drive unit 30 includes a terminal 32, a solenoid 31, a stator 36, a mover 35, a spring 34, and a valve seat member 33. The terminal 32 is formed of a metal material having electrical conductivity, and one end of the both ends in the extending direction is exposed to the outside from the control body 40, and the other end is connected to the solenoid 31. Yes. The solenoid 31 is wound in a spiral shape and receives supply of a pulse current from the engine control device 17 via the terminal 32. The solenoid 31 receives this current supply to generate a magnetic field that circulates along the axial direction. The stator 36 is a cylindrical member made of a magnetic material and magnetizes in a magnetic field generated by the solenoid 31. The mover 35 is a two-stage columnar member made of a magnetic material, and is disposed on the axial front end side of the stator 36. The mover 35 is attracted to the proximal side in the axial direction by a magnetized stator 36. The spring 34 is a coil spring in which a metal wire is wound in a circular shape, and biases the mover 35 in a direction in which the mover 35 is separated from the stator 36. The valve seat member 33 forms a pressure control valve 80 together with a later-described control valve seat 47a of the control body 40. The valve seat member 33 is provided on the opposite side of the stator 36 in the axial direction of the mover 35 and is seated on the control valve seat 47a. When the magnetic field is not formed by the solenoid 31, the valve seat member 33 is seated on the control valve seat portion 47 a by the urging force of the spring 34. When a magnetic field is formed by the solenoid 31, the valve seat member 33 is separated from the control valve seat portion 47a.

  The control body 40 has a longitudinal shape including a nozzle body 41, a cylinder 56, an orifice plate 46, a holder 48, and a retaining nut 49, and a passage for high-pressure fuel is formed therein. The nozzle body 41, the orifice plate 46, and the holder 48 are arranged in this order from the tip end side in the axial direction to the head member 21 (see FIG. 1) in which the injection hole 44 is formed. An injection hole 44 for injecting high-pressure fuel into the combustion chamber 22 (see FIG. 1) of the diesel engine 20 is formed at the tip.

  The control body 40 is formed with an inflow passage 52, an outflow passage 54, a pressure control chamber 53, and an opening wall surface 90 exposed to the pressure control chamber 53. One end of the inflow passage 52 communicates with the supply passage 14d (see FIG. 1) connected to the high-pressure fuel pump 13 and the common rail 14, and the other end of the inflow passage 52 communicates with the pressure control chamber 53. The inflow passage 52 has an inlet 52 a that is the other channel end opened to the opening wall surface 90, and introduces high-pressure fuel into the pressure control chamber 53. Further, the outflow passage 54 communicates with the return flow path 14f (see FIG. 1) where one flow path end is connected to the high-pressure fuel pump 13, and the other flow path end communicates with the pressure control chamber 53. In the outflow passage 54, an outlet 54a, which is the other channel end, is opened in the opening wall surface 90, and the fuel in the pressure control chamber 53 flows out to the low pressure side. The pressure control chamber 53 is partitioned by an orifice plate 46, a cylinder 56, and the like. The pressure control chamber 53 is formed inside the control body 40 on the side opposite to the nozzle hole 44 with the nozzle needle 60 interposed therebetween, and introduces high-pressure fuel from the inflow passage 52 and discharges it through the outflow passage 54.

  The nozzle body 41 is a bottomed cylindrical member made of a metal material such as chromium / molybdenum steel. The nozzle body 41 has a nozzle needle housing portion 43, a valve seat portion 45, and an injection hole 44. The nozzle needle accommodating portion 43 is a cylindrical hole that is formed along the axial direction of the nozzle body 41 and accommodates the nozzle needle 60. High-pressure fuel is supplied to the nozzle needle housing portion 43 from the high-pressure fuel pump 13 and the common rail 14 (see FIG. 1). The valve seat portion 45 is formed on the bottom wall of the nozzle needle housing portion 43 and contacts the tip of the nozzle needle 60. The nozzle holes 44 are located on the opposite side of the orifice plate 46 with the valve seat 45 interposed therebetween, and a plurality of the nozzle holes 44 are formed radially from the inside to the outside of the nozzle body 41. By passing through the nozzle hole 44, the high-pressure fuel is atomized and diffused to be easily mixed with air.

  The cylinder 56 is made of a metal material and is a cylindrical member that partitions the pressure control chamber 53 together with the orifice plate 46 and the nozzle needle 60. The cylinder 56 is disposed in the nozzle needle housing portion 43 so as to be coaxial with the nozzle needle housing portion 43. In the cylinder 56, the end surface in the axial direction on the orifice plate 46 side is held by the orifice plate 46.

  The cylinder 56 forms a control wall surface portion 57, a cylinder sliding portion 59, a plate stopper portion 58a, and a needle stopper portion 58b by the inner wall surface. The control wall surface portion 57 is located on the orifice plate 46 side in the axial direction of the cylinder 56 and surrounds the opening wall surface 90. The cylinder sliding portion 59 is located on the opposite side of the orifice plate 46 in the axial direction of the cylinder 56, and slides the nozzle needle 60 along the axial direction. The inner diameter of the cylinder sliding portion 59 is reduced with respect to the inner diameter of the control wall surface portion 57. The plate stopper portion 58 a is a step portion formed by a difference in inner diameter between the cylinder sliding portion 59 and the control wall surface portion 57, and faces the floating plate 70 in the displacement axis direction of the plate 70. The plate stopper portion 58 a regulates the displacement of the floating plate 70 in the direction approaching the nozzle needle 60. The needle stopper portion 58b is formed on the side opposite to the control wall surface portion 57 with respect to the cylinder sliding portion 59 in the displacement axis direction. The needle stopper portion 58 b faces in the direction opposite to the plate stopper portion 58 a in the displacement axis direction, and restricts the displacement of the nozzle needle 60 in the direction approaching the floating plate 70.

  The orifice plate 46 is made of a metal material such as chromium / molybdenum steel and is a columnar member that is held between the nozzle body 41 and the holder 48. The orifice plate 46 forms a control valve seat 47a, an opening wall surface 90, an outflow passage 54, and an inflow passage 52. The control valve seat portion 47 a is formed on the end surface on the holder 48 side of both end surfaces of the orifice plate 46 in the axial direction, and constitutes a pressure control valve 80 together with the valve seat member 33 and the like of the control valve drive unit 30. The opening wall surface 90 is a flat surface formed at the radial center of the end surface of the orifice plate 46 on the nozzle body 41 side. The opening wall surface 90 is surrounded by a cylindrical cylinder 56 and has a circular shape. The outflow passage 54 extends from the radial center of the opening wall surface 90 toward the control valve seat 47a. The outflow passage 54 is inclined with respect to the axial direction of the orifice plate 46. The inflow passage 52 extends from the radially outer side of the outflow passage 54 in the opening wall surface 90 toward the end surface forming the control valve seat portion 47a. The inflow passage 52 is inclined with respect to the axial direction of the orifice plate 46.

  The holder 48 is a cylindrical member made of a metal material such as chrome / molybdenum steel, and has vertical holes 48a and 48b formed along the axial direction, and a socket portion 48c. The vertical hole 48 a is a fuel flow path that connects the supply flow path 14 d (see FIG. 1) and the inflow passage 52. On the other hand, the control valve drive unit 30 is accommodated on the orifice plate 46 side of the vertical hole 48b. In addition, a socket portion 48c is formed on the opposite side of the vertical hole 48b from the orifice plate 46 so as to close the opening of the vertical hole 48b. One end of the terminal 32 of the control valve drive unit 30 protrudes inside the socket portion 48c, and can be fitted to a plug portion (not shown) connected to the engine control device 17. According to the connection between the socket portion 48c and a plug portion (not shown), it is possible to supply a pulse current from the engine control device 17 to the control valve drive portion 30.

  The retaining nut 49 is a two-stage cylindrical member made of a metal material. The retaining nut 49 is screwed to the orifice plate 46 side of the holder 48 while accommodating a part of the nozzle body 41 and the orifice plate 46. In addition, the retaining nut 49 forms a stepped portion 49a at the inner peripheral wall portion. The stepped portion 49 a presses the nozzle body 41 and the orifice plate 46 toward the holder 48 by attaching the retaining nut 49 to the holder 48. As a result, the retaining nut 49 sandwiches the nozzle body 41 and the orifice plate 46 together with the holder 48.

  The nozzle needle 60 is formed in a cylindrical shape as a whole by a metal material such as high-speed tool steel, and moves along the axial direction of the control body 40 inside the control body 40. A seat portion 65, a valve pressure receiving surface 61, a needle sliding portion 63, a needle locking portion 68, a return spring 66, and a flange member 67 are provided. The seat portion 65 is formed at an end portion on the opposite side to the pressure control chamber 53 among both end portions of the nozzle needle 60 in the axial direction, and is seated on the valve seat portion 45 of the control body 40. The seat portion 65 constitutes a valve portion 50 for opening and closing the high-pressure fuel injection hole 44 supplied into the nozzle needle housing portion 43 together with the valve seat portion 45. The valve pressure receiving surface 61 is formed by an end portion on the side of the pressure control chamber 53 that is opposite to the seat portion 65 among both end portions in the axial direction of the nozzle needle 60. The valve pressure receiving surface 61 divides the pressure control chamber 53 together with the opening wall surface 90 and the control wall surface portion 57 and receives the fuel pressure in the pressure control chamber 53. Thereby, the movement of the nozzle needle 60 is controlled by the pressure of the fuel in the pressure control chamber 53.

  The needle sliding portion 63 is a portion of the cylindrical outer peripheral wall of the nozzle needle 60 that is located closer to the valve pressure receiving surface 61 than the control wall surface portion 57. The needle sliding portion 63 is slidably supported with respect to a cylinder sliding portion 59 formed by the inner peripheral wall of the cylinder 56. The flange member 67 is an annular member that is fitted on the outer peripheral wall portion of the nozzle needle 60 and is held by the nozzle needle 60. The needle locking portion 68 is formed on the axial sheet portion 65 side with respect to the needle sliding surface 63 and is a step portion formed by increasing the outer diameter of the nozzle needle 60. The needle locking portion 68 forms a surface facing the needle stopper portion 58 b of the cylinder 56 in the moving axis direction of the nozzle needle 60. By the needle locking portion 68 being locked to the needle stopper portion 58b, the movement of the nozzle needle 60 in the direction approaching the floating plate 70 is restricted.

  The nozzle needle 60 is biased toward the valve unit 50 by a return spring 66. The return spring 66 is a coil spring in which a metal wire is wound around. The return spring 66 is seated at one end in the axial direction on the surface of the flange member 67 on the pressure control chamber 53 side and on the other end on the end surface of the cylinder 56 on the valve portion side. The nozzle needle 60 configured as described above reciprocates linearly in the axial direction of the cylinder 56 with respect to the cylinder 56 in accordance with the pressure of the fuel in the pressure control chamber 53 received by the valve pressure receiving surface 61, so that the seat portion 65. Is seated on and separated from the valve seat portion 45, and the valve portion 50 is opened and closed.

  The floating plate 70 is a disk-shaped member made of a metal material, and presses the opening wall surface 90 in order to close the inflow passage 52. The floating plate 70 has a pressing surface 73, a pressing pressure receiving surface 77, a plate locking portion 78, an outer peripheral wall surface 74, and a restriction hole 71. The floating plate 70 is disposed in the pressure control chamber 53 along the axial direction of the cylinder 56 of the control body 40 and can be reciprocally displaced in the axial direction. The direction of the displacement axis of the floating plate 70 that is reciprocally displaced is along the direction of the displacement axis of the nozzle needle 60. Of the both end surfaces of the floating plate 70 in the displacement axis direction, the end surface facing the opening wall surface 90 in the displacement axis direction forms a pressing surface 73. The pressing surface 73 has a circular shape, and comes into contact with the opening wall surface 90 by the reciprocating displacement of the floating plate 70. An end surface of the floating plate 70 that is opposite to the pressing surface 73 in the displacement axis direction forms a pressing pressure receiving surface 77 that faces the valve pressure receiving surface 61 in the displacement axis direction. The pressure receiving surface 77 receives a force in the direction toward the opening wall surface 90 by the fuel in the pressure control chamber 53. A plate locking portion 78 is formed on the outer edge of the pressure receiving surface 77 to face the plate stopper portion 58a of the cylinder 56 in the displacement axis direction. The plate locking portion 78 is locked to the plate stopper portion 58 a, thereby restricting the displacement of the floating plate 70 in the direction approaching the nozzle needle 60.

  The outer peripheral wall surface 74 that continues between the both end faces is located around the displacement axis of the floating plate 70 and is along the displacement axis direction of the plate 70. The outer peripheral wall surface 74 faces the control wall surface portion 57 in a direction orthogonal to the displacement axis. In a state where the floating plate 70 is coaxially positioned with respect to the cylinder 56, the outer peripheral wall surface 74 forms a gap through which fuel can flow with the control wall surface portion 57. Through the gap between the outer peripheral wall surface 74 and the control wall surface portion 57, the fuel that has flowed into the space of the pressure control chamber 53 on the opening wall surface 90 side with respect to the floating plate 70 is separated from the plate 70 on the valve pressure receiving surface 61 side. It circulates in the space of the pressure control chamber 53. In the pressure control chamber 53, a space on the pressing surface 73 side with the floating plate 70 interposed therebetween is referred to as an opening space 53a. In addition, a space on the side opposite to the pressing surface 73 with respect to the floating plate 70 on the side of the pressing pressure receiving surface 77 is referred to as a back pressure space 53b.

  The restriction hole 71 extends from the radial center of the pressure receiving surface 77 of the floating plate 70 toward the outlet 54a. The extending direction of the restriction hole 71 is along the displacement axis direction of the floating plate 70. The restriction hole 71 has one end opened at the central portion in the radial direction of the pressing surface 73 facing the outflow port 54a. The restriction hole 71 communicates the pressure control chamber 53 and the outlet 54a with the pressing surface 73 of the floating plate 70 in contact with the opening wall surface 90, and the fuel from the pressure control chamber 53 to the outlet 54a. Limit circulation.

  The restriction hole 71 includes a throttle part 71 a and a concave part 72. The restricting portion 71 a defines the minimum flow passage area in the restriction hole 71 and defines the amount of fuel flowing through the restriction hole 71. The flow passage area of the throttle portion 71a is smaller than the opening area of the outlet 54a. In addition, the narrowed portion 71 a is closer to the end surface that forms the pressing surface 73 than to form the pressing pressure receiving surface 77 of both end surfaces in the axial direction of the floating plate 70. The recess 72 is a cylindrical hole located on the same axis as the floating plate 70, and is recessed from the pressure receiving surface 77 on the side opposite to the valve pressure receiving surface 61 to partially enlarge the flow passage area of the limiting hole 71. . Due to the recess 72, the opening of the restriction hole 71 in the pressure receiving surface 77 is enlarged.

(Characteristic part)
Next, the characteristic part of the fuel injection device 100 will be described in more detail with reference to FIGS.

  As shown in FIG. 4, the orifice plate 46 has an outflow recess 97 and an inflow recess 94. The outflow recess 97 and the inflow recess 94 are formed by denting the opening wall surface 90 to the side opposite to the pressing surface 73 facing the floating plate 70 in the axial direction. The outflow recess 97 is located on the inner peripheral side of the inflow recess 94 in the circular opening wall surface 90 and is concentric with the center of the opening wall 90. An outflow port 54 a opens in a circular shape at the bottom surface portion 97 a of the outflow recess 97. On the other hand, the inflow recess 94 is a groove that is located radially outside the outflow recess 97 and extends in an annular shape along the outer edge of the outflow recess 97. The inflow recess 94 is concentric with the center of the opening wall surface 90. An inflow port 52a opens in a circular shape in the bottom surface portion 94a of the inflow recess 94.

  Furthermore, the inflow recess 94 becomes deeper as the position is farther from the inflow port 52a along the planar direction of the opening wall surface 90. Hereinafter, the change in the depth of the inflow recess 94 with respect to the distance from the inflow port 52a in the inflow recess 94 will be described. 6 shows the correlation between the distance from the inflow port 52a and the depth when the inflow recess 94 is cut along the profile scanning line PSL1 defined in the circumferential direction of the inflow recess 94 as shown in FIG. Is shown.

  In the bottom surface portion 94a of the inflow recess 94, positions closest to the inflow port 52a are a1 and e1. These positions a1 and e1 are opposed to each other across the inflow port 52a in the circumferential direction of the inflow recess 94. The above-described profile scanning line PSL1 starts at the position a1 and circulates in the inflow recess 94 counterclockwise and reaches the position e1. Points that divide the position a1 to the position e1 at intervals of about 90 degrees are defined as positions b1, c1, and d1. The depth of the inflow recess 94 is shallowest at a position a1 near the inflow port 52a in the inflow recess 94. And let the depth of the inflow recessed part 94 in this position a1 be f1 (refer FIG. 4).

  Along the profile scanning line PSL1, the depth of the inflow recess 94 gradually increases as it moves away from the inflow port 52a until it passes through the position b1 and reaches a position c1 that faces the position a1 and the outflow port 54a. At the position c1 farthest from the inflow port 52a, the depth of the inflow recess 94 is the deepest. The depth of the inflow recess 94 at this position c1 is defined as g1 (see FIG. 4). From this position c1, along the profile scanning line PSL1, passes through the position d1 and reaches the position e1, and the depth of the inflow recess 94 gradually decreases as it approaches the inflow port 52a. The depth of the inflow recess 94 at this position e1 is f1 as in the position a1. It is desirable that the depth g1 at the deepest position c1 in the inflow recess 94 is, for example, about twice the depth f1 at the shallowest positions a1 and e1. However, the depth ratio between the deepest portion and the shallowest portion in the inflow recess 94 is not limited at all.

  Due to the shape of the bottom surface portion 94a of the inflow recess 94 as described above, the storage capacity in which the high pressure fuel can be stored in the inflow recess 94 is a position c1 farther from the inflow port 52a than the positions a1 and e1 close to the inflow port 52a. Become more.

  An operation in which the fuel injection device 100 having the above-described configuration performs fuel injection by opening and closing the valve unit 50 in accordance with a control signal from the engine control device 17 will be described with reference to FIGS.

  In a state where the pressure control valve 80 blocks the outlet 54a and the return flow path 14f (see FIG. 1), the floating plate 70 has the plate locking portion 78 seated on the plate stopper portion 58a. From this state, when the outlet 54 a communicates with the return flow path 14 f by the operation of the pressure control valve 80, the fuel flows out from the pressure control chamber 53 via the outflow passage 54. As a result, the floating plate 70 is sucked toward the opening wall surface 90 due to the reduced pressure in the vicinity of the outlet 54a, and is displaced in a direction in which the plate locking portion 78 is separated from the plate stopper portion 58a. The floating plate 70 having the pressing surface 73 in contact with the opening wall surface 90 by this displacement closes the inflow port 52 a that opens to the opening wall surface 90 by pressing the opening wall surface 90 with the pressing surface 73.

  In order to close the inflow passage 52, in the state where the opening wall surface 90 where the inflow port 52 a is opened is pressed by the floating plate 70, the inflow recess 94 has an annular space together with the pressing surface 73 in contact with the opening wall surface 90. Form. At this time, high-pressure fuel pressurized by the high-pressure fuel pump 13 (see FIG. 1) from the inlet 52a is introduced into the inflow recess 94 through the inlet 52a. As described above, the storage capacity of the high-pressure fuel is increased as the inflow recess 94 is further away from the inflow port 52a. Therefore, more high-pressure fuel is accumulated at the position c1 away from the inlet 52a than at the positions a1 and e1 close to the inlet 52a.

  On the other hand, the fuel in the pressure control chamber 53 is discharged from the outlet 54 a via the restriction hole 71 and the outflow recess 97. When this fuel discharge is continued, the fuel pressure in the pressure control chamber 53 drops to a predetermined pressure. When the pressure in the pressure control chamber 53 further falls below the predetermined pressure, the nozzle needle 60 is pushed up to the pressure control chamber 53 side, the seat portion 65 is separated from the valve seat portion 45, and the valve portion 50 is opened. Let Thereafter, the movement of the nozzle needle 60 toward the pressure control chamber 53 is restricted by the contact of the needle locking portion 68 with the needle stopper portion 58b. By this contact, the opening degree of the valve unit 50 is maximized.

  When the outlet 54a and the return flow path 14f (see FIG. 1) are blocked by closing the pressure control valve 80, the floating plate 70 receives the valve pressure-receiving surface by the pressure of the high-pressure fuel introduced from the inlet 52a. It is pushed to the 61 side and the displacement starts. Thus, when the inside of the pressure control chamber 53 is displaced in the axial direction so that the floating plate 70 is separated from the opening wall surface 90 in order to open the inflow passage 52, the high-pressure fuel accumulated in the inflow recess 94 is transferred to the pressure control chamber 53. Begins to be released inside.

  At this time, high-pressure fuel introduced from the inflow port 52a is likely to be newly supplied to the positions a1 and e1 near the inflow port 52a in the inflow recess 94. Therefore, in the vicinity of the positions a1 and e1 near the inlet 52a in the inflow recess 94, the high-pressure fuel is newly supplied from the inlet 52a even if the storage capacity of the high-pressure fuel is small. The On the other hand, the high pressure fuel introduced from the inflow port 52a is hardly newly supplied to the position c1 in the inflow recess 94 that is away from the inflow port 52a. However, since the high-pressure fuel has a large storage capacity, the stored fuel is continuously discharged from a position away from the inlet 52a in the inflow recess 94. As described above, after the displacement of the floating plate 70 is started, the high-pressure fuel can be continuously discharged from the inflow recess 94 to the pressure control chamber 53 over the entire annular inflow recess 94. Further, since the high-pressure fuel is discharged in an annular shape from the annular inflow recess 94, the released high-pressure fuel pushes the floating plate 70 over the entire area in the circumferential direction and quickly displaces it in the pressure control chamber 53.

  The fuel released from the entire area of the inflow recess 94 into the opening space 53a of the pressure control chamber 53 flows through the restriction hole 71 and the gap between the outer peripheral wall surface 74 and the control wall surface portion 57 and reaches the back pressure space 53b. To do. The nozzle needle 60 is pushed down to the valve portion 50 side by the pressure recovery in the back pressure space 53b. The nozzle needle 60 places the seat portion 65 on the valve seat portion 45 to close the nozzle hole 44 so as to close the valve portion 50.

  In the first embodiment described so far, after the displacement of the floating plate 70 is started, the continuous discharge of the high-pressure fuel is performed over the entire inflow recess 94, so that the inflow recess 94 enters the pressure control chamber 53. Variation in the flow rate of the released fuel is reduced. Thereby, since a large amount of fuel can be supplied into the pressure control chamber 53 in a short time, the pressure recovery in the pressure control chamber 53 can occur promptly. Therefore, the operation of the nozzle needle 60 that closes the nozzle hole 44 is accelerated. Therefore, the fuel injection device 100 with improved responsiveness of the nozzle needle 60 can be realized.

  In addition, in the first embodiment, since the depth of the inflow recess 94 gradually increases as the distance from the inflow port 52a increases (see FIG. 6), the storage capacity of high-pressure fuel increases as the distance from the inflow port 52a increases. Thus, since the high-pressure fuel accumulation capacity can be increased at the position c1 where the high-pressure fuel introduced from the inflow port 52a is difficult to be supplied, the flow rate variation of the fuel discharged from the inflow recess 94 is reliably reduced. As described above, since the pressure recovery in the pressure control chamber can be further promptly generated, the response of the nozzle needle 60 can be further improved.

  Further, in the first embodiment, since the floating plate 70 is pushed over the entire circumferential direction by the fuel released from the entire annular inflow recess 94, the inside of the pressure control chamber 53 can be quickly displaced. In addition, since the inflow recess 94 is annular, it is difficult for the floating plate 70 pushed by the released fuel to tilt. Thus, the pressure recovery in the pressure control chamber 53 can be accelerated by causing the floating plate 70 to move smoothly. Therefore, the responsiveness improvement of the nozzle needle 60 when the valve is closed is further ensured.

  Furthermore, in the first embodiment, the outlet 54 a is formed on the inner peripheral side of the inflow recess 94 and in the central portion in the radial direction of the opening wall 90, so that the inflow recess 94 is formed on the opening wall 90. It can be enlarged in the radial direction without being obstructed by. More high pressure fuel is introduced into the enlarged inflow recess 94 from the inflow port 52a. Therefore, after the floating plate 70 is separated from the opening wall surface 90, the amount of fuel released from the inflow recess 94 to the pressure control chamber 53 can be increased, so that the pressure recovery in the pressure control chamber 53 is further promptly performed. Arise. Therefore, the responsiveness of the nozzle needle 60 when the valve is closed can be further improved.

  In the first embodiment, the control body 40 is the “valve body” according to the claims, the nozzle needle 60 is the “valve member” according to the claims, and the floating plate 70 is the “control member” according to the claims. Respectively.

(Second embodiment)
The second embodiment of the present invention shown in FIGS. 7 to 10 is a modification of the first embodiment. In the fuel injection device 200 according to the second embodiment, the first orifice plate 246 and the second orifice plate 247 are configured to correspond to the orifice plate 46 of the first embodiment. Further, the fuel injection device 200 of the second embodiment includes a plate spring 276 that biases the floating plate 270 toward the first orifice plate 246 side. Hereinafter, the configuration of the fuel injection device 200 according to the second embodiment will be described in detail.

  The first orifice plate 246 and the second orifice plate 247 are both cylindrical members made of a metal material such as chromium / molybdenum steel. The first orifice plate 246 and the second orifice plate 247 are formed with an outflow passage 254 and an inflow passage 252. In the first orifice plate 246, the outflow passage 254 extends from the center of the opening wall surface 290 to the end surface on the second orifice plate 247 side along the axial direction of the first orifice plate 246. Similar to the outflow passage 254, the inflow passage 252 passes through the plate 246 in the axial direction along the axial direction of the first orifice plate 246. The inflow passages 252 are positioned on the radially outer side of the outflow passages 254, and four inflow passages 252 are formed at equal intervals in the circumferential direction of the outflow passages 254.

  In addition, the first orifice plate 246 has an outflow recess 297 and an inflow recess 294. The outflow recess 297 is located on the inner peripheral side of the inflow recess 294 in the circular opening wall surface 290 and is concentric with the center of the opening wall surface 290. An outflow port 254a opens in a circular shape at the bottom surface portion 297a of the outflow recess 297. On the other hand, the inflow recess 294 is a groove that is located radially outside the outflow recess 297 and extends in an annular shape along the outer edge of the outflow recess 297. The inflow recess 294 is concentric with the center of the opening wall surface 290. Four circular inflow ports 252 a are opened at equal intervals in the circumferential direction of the inflow recess 294 in the bottom surface portion 294 a of the inflow recess 294.

  Further, the inflow recess 294 is deeper from each of the adjacent inflow ports 252a toward the space between the inflow ports 252a. Hereinafter, the change of the depth with respect to the distance from the inflow port 252a in the inflow recessed part 294 is demonstrated. 10 shows the correlation between the distance from the inlet 252a and the depth when the inflow recess 294 is cut along the profile scanning line PSL2 defined in the circumferential direction of the inflow recess 294 as shown in FIG. Is shown.

  Of the four inlets 252a, positions closest to each of a pair of adjacent inlets 252a are a2 and c2. The above-described profile scanning line PSL2 starts from the position a2, circulates the inflow recess 294 counterclockwise, and reaches the position c2. In the circumferential direction of the inflow recess 294, a position that is intermediate between the position a2 and the position c2 is b2. The depth of the inflow recess 294 is shallowest at positions a2 and c2 near the inflow ports 252a in the inflow recess 294. And let the depth of the inflow recessed part 294 in this position a2 and c2 be f2 (refer FIG. 10).

  Along the profile scanning line PSL2, the depth of the inflow recess 294 gradually increases as the distance from the inflow port 252a increases until reaching the position b2. That is, the inflow recess 294 becomes deeper toward the circumferential intermediate position b2 between the inflow ports 252a adjacent to each other in the circumferential direction of the inflow recess 294. As described above, the depth of the inflow recess 294 is deepest at the intermediate position b2 by being deeper from each of the adjacent inflow ports 252a toward the inflow ports 252a. The depth of the inflow recess 294 at this position b2 is defined as g2 (see FIG. 10). The depth of the inflow recess 294 gradually decreases from the position b2 to the position c2 along the profile scanning line PSL2. In the second embodiment, the depth of the position b2 that is the same distance from the pair of inflow ports 252a has been described as the intermediate position between the inflow ports 252a. However, the intermediate position between the inlets 252a where the inflow recesses are deepest may be closer to one of the inlets 252a than the other inlet 252a between the pair of inlets 252a.

  In the second embodiment, the change in the depth of the inflow recess 294 as described above is formed in a region between all the adjacent inflow ports 252a. Due to the shape of the bottom surface portion 294a of the inflow recess 294, the storage capacity in which the high-pressure fuel can be stored in the inflow recess 294 is greater than the positions a2 and c2 close to the inflow port at the intermediate position b2 farther from the inflow port 252a. More.

  Also in the second embodiment described so far, after the displacement of the floating plate 270 is started, the high-pressure fuel is continuously discharged over the entire inflow recess 294, so that the inflow recess 294 enters the pressure control chamber 53. Variation in the flow rate of the released fuel is reduced. Thereby, since a large amount of fuel can be supplied into the pressure control chamber 53 in a short time, the pressure recovery in the pressure control chamber 53 can occur promptly. Therefore, the operation of the nozzle needle 60 that closes the nozzle hole 44 (see FIG. 2) is accelerated. Therefore, the fuel injection device 200 with improved responsiveness of the nozzle needle 60 can be realized.

  In addition, in the second embodiment in which a plurality of inflow ports 252a are opened in the bottom surface portion 294a of the inflow recess 294, a position b2 that is in the middle of the adjacent inflow ports 252a is a place where high-pressure fuel is difficult to be supplied. Therefore, the storage capacity of the high-pressure fuel at the intermediate position b2 can be increased by forming the inflow recesses 294 that are deeper from each of the adjacent inflow ports 252a toward the inflow ports 252a. As a result, the variation in the flow rate of the fuel discharged from the inflow recess 294 can be reduced, and the pressure in the pressure control chamber 53 can be quickly recovered. Therefore, even if the inlet 252a has a plurality of openings, the effect of improving the responsiveness of the nozzle needle 60 can be obtained with certainty.

  Further, as in the second embodiment, when a plurality of inflow ports 252a are opened in the opening wall surface 290, each of the annular inflow recesses 294 is formed by opening the inflow ports 252a at equal intervals around the center of the opening wall surface 290. The imbalance in the difficulty of supplying high-pressure fuel at the location can be corrected. Therefore, the effect | action which suppresses the flow volume dispersion | variation of the fuel discharged | emitted from the inflow recessed part 294 becomes still more reliable. Therefore, the responsiveness of the nozzle needle 60 when the valve is closed can be reliably improved.

  In the second embodiment, the floating plate 270 corresponds to a “control member” recited in the claims.

(Third embodiment)
The third embodiment of the present invention shown in FIGS. 11 to 13 is another modification of the first embodiment. The fuel injection device 300 according to the third embodiment includes an orifice plate 346 corresponding to the orifice plate 46 of the first embodiment. Hereinafter, the configuration of the fuel injection device 300 according to the third embodiment will be described in detail.

  In the orifice plate 346, an outflow passage 354 and an inflow passage 352 are formed. The outflow passage 354 extends from the position eccentric from the radial center of the opening wall surface 390 toward the control valve seat 47a. The outflow passage 354 is inclined with respect to the axial direction of the orifice plate 346. The inflow passage 352 is formed adjacent to the outflow passage 354 in the opening wall surface 390, and is inclined in a direction different from the outflow passage 354 with respect to the axial direction of the orifice plate 346.

  Further, the orifice plate 346 has an outflow recess 397 and an inflow recess 394. The outflow recess 397 and the inflow recess 394 are formed by recessing the opening wall surface 390 on the side opposite to the pressing surface 373 opposed in the axial direction of the floating plate 70. The outflow recess 397 is a circular depression located in the circular opening wall surface 390 that is eccentric from the center of the opening wall surface 390. An outflow port 354 a is opened in a circular shape at the bottom surface portion 397 a of the outflow recess 397. The outlet 354 a is an opening formed eccentrically from the center of the opening wall surface 390, and is located in the radial center of the outflow recess 397. On the other hand, the inflow recess 394 extends along the outer edges of the outflow recess 397 and the outlet 354a. The inflow recess 394 is a groove having a width that gradually increases from both ends 394b in the extending direction toward the center 394c where the inflow port 352a opens.

  Furthermore, the inflow recess 394 becomes deeper as the position is farther from the inflow port 52a along the extending direction. Hereinafter, the change in the depth of the inflow recess 394 with respect to the distance from the inflow port 352a in the inflow recess 394 will be described. FIG. 13 shows the distance and depth from the inlet 352a when the inflow recess 394 is cut along the profile scanning line PSL3 defined along the extending direction of the inflow recess 394 as shown in FIG. Is shown.

  In the bottom surface portion 394a of the inflow recess 394, a position closest to the inflow port 352a is defined as a3. The profile scanning line PSL3 described above starts from the position a3, circulates the inflow recess 394 counterclockwise, and reaches the position c2 which is one of the both end portions 394b. In the extending direction of the inflow recess 394, a position that is intermediate between the position a2 and the position c2 is defined as b3. The depth of the inflow recess 394 is shallowest at a position a3 near the inflow port 352a in the inflow recess 394. And let the depth of the inflow recessed part 394 in this position a3 be f3.

  Along the profile scanning line PSL3, the depth of the inflow recess 394 gradually increases as the distance from the inflow port 352a increases, from the position b3 to the position c3. At the position c3 farthest from the inflow port 352a, the depth of the inflow recess 394 is the deepest. The depth of the inflow recess 394 at this position c3 is defined as g3.

  With the shape of the bottom surface portion 394a of the inflow recess 394 as described above, a storage capacity for storing high-pressure fuel in the vicinity of the position c3 away from the inflow port 352a can be secured.

  As in the third embodiment described so far, even the inflow recess 394 whose width gradually increases from the center portion 394c toward both ends 394b becomes deeper as it goes from the center portion 394c to both ends 394b. It is good to do. As a result, the storage capacity of the high-pressure fuel that can be accumulated at both end portions 394b can be increased, so that continuous fuel discharge from both end portions 394b becomes possible. Therefore, the effect | action which suppresses the flow volume dispersion | variation from the inflow recessed part to the pressure control chamber 53 is exhibited notably. Therefore, even in the groove-like inflow recess 394 that becomes narrower as it approaches the both end portions 394b, the deeper the recess is at a position farther from the inlet 352a, the pressure recovery in the pressure control chamber 53 is accelerated, and the valve is closed. This can contribute to improving the response of the nozzle needle 60 at the time.

(Fourth to seventh embodiments)
The fourth to seventh embodiments of the present invention shown in FIGS. 14 (a) to 14 (d) are further modifications of the first embodiment. In the first embodiment, the depth of the inflow recess 94 gradually increases as the distance from the inflow port 52a increases along the profile scanning line PSL1. However, the correlation between the distance from the inlet 52a and the depth in the inflow recess is not limited to that defined in the first embodiment, and the fourth to seventh described below with reference to FIGS. It may be as in the embodiment.

  In the fourth embodiment shown in FIGS. 14A and 5, the inflow recess 494 is a region from the middle between the position a1 and the position b1 to the middle between the position d1 and the position e1 along the profile scanning line PSL1. It is the deepest. In addition, in the inflow recess 494, reinforcing portions are formed at the positions b1 and d1. The reinforcing portion connects the inner peripheral wall surface and the outer peripheral wall surface of the inflow recess 494 along the radial direction of the inflow recess 494. These reinforcing portions increase the rigidity of the opening wall surface 90 and suppress deformation due to the pressing force of the floating plate 70 (see FIG. 4). Since such a reinforcing portion is formed, the depth of the inflow recess 494 is once shallow at the position b1 and the position d1. As described above, even if the reinforcement for partially shallowing the inflow recess 494 is formed, the flow rate of the fuel discharged from the inflow recess 494 as long as the inflow recess 494 becomes deeper as the distance from the inflow port 52a increases. Can correct the imbalance of variation. Therefore, the inflow recessed part 494 by 4th embodiment can contribute to the response improvement of the nozzle needle 60 (refer FIG. 4) at the time of valve closing.

  In the fifth embodiment shown in FIGS. 14B and 5, the depth of the inflow recess 594 is constant at the shallowest depth f1 in the range from the position a1 to the position b1 along the profile scanning line PSL1. ing. Due to the step formed between the position b1 and the position c1, the depth of the inflow recess 594 is deepest in the vicinity of the position c1. Moreover, the depth of the inflow recessed part 594 is returned to the shallowest depth f1 by the level | step difference formed between the position c1 and the position d1. And between the position d1 and the position e1, the depth of the inflow recessed part 94 is constant with the shallowest depth f1.

  In the sixth embodiment shown in FIG. 14C and FIG. 5, the inflow recess 694 becomes deeper stepwise as the distance from the position a1 increases along the profile scanning line PSL1. Due to the step formed between the position a1 and the position b1 along the profile scanning line PSL1, the inflow recess 694 has an intermediate depth between f1 and g1 in the vicinity of the position b1. In addition, a step is also formed between the position b1 and the position c1, and the inflow recess 694 is deepest in the vicinity of the position c1. Then, due to the steps formed between the position c1 and the position d1 and between the position d1 and the position e1, the inflow recess 694 becomes shallower in steps as the position c1 approaches the position e1.

  As in the fifth and sixth embodiments described above, the inflow recess may become deeper in stages as it moves away from the inflow port 52a. Even with the inflow recess having such a shape, it is possible to increase the storage capacity of the high-pressure fuel at a position where it is difficult to supply the high-pressure fuel introduced from the inflow port 52a. Therefore, the variation in the flow rate of the fuel discharged from the inflow recess is reliably reduced. Therefore, the responsiveness of the nozzle needle 60 (see FIG. 4) can be improved.

  In the seventh embodiment shown in FIGS. 14D and 5, the depth of the inflow recess 794 is proportional to the distance from the inflow port 52a in the range from the position a1 to the position c1 along the profile scanning line PSL1. Thus, the depth f1 changes to the depth g1. In the range from the position c1 to the position e1, the depth g1 changes to the depth f1 along the profile scanning line PSL1 in proportion to the distance from the inflow port 52a. As described above, the depth of the inflow recess 794 may be defined in proportion to the distance from the inflow port 52a.

(Eighth to tenth embodiments)
The eighth to tenth embodiments of the present invention shown in FIGS. 15A to 15C are modifications of the second embodiment. In the second embodiment, the depth of the inflow recess 294 gradually increases as the distance from one of the pair of adjacent inflow ports 252a increases along the profile scanning line PSL2, and is the largest in the middle of the pair of inflow ports 252a. It was deep. However, the correlation between the distance from the inlet 252a and the depth in the inflow recess is not limited to that defined in the second embodiment, and the eighth to tenth described below with reference to FIGS. It may be as in the embodiment.

  In the eighth embodiment shown in FIGS. 15A and 9, the inflow recess 894 has a pair of steps in the vicinity of the position b2. Due to the step formed between the position a2 and the position b2 along the profile scanning line PSL2, the depth of the inflow recess 894 changes from the shallowest depth f2 to the deepest depth g2. Further, the depth of the inflow recess 894 is changed from the deepest depth g2 to the shallowest depth f2 by a step formed between the position b2 and the position c2.

  In the ninth embodiment shown in FIGS. 15B and 9, two steps are formed between the position a2 and the position b2 along the profile scanning line PSL2. Due to these steps, the depth of the inflow recess 994 gradually changes from the shallowest depth f2 to the deepest depth g2 from the position a2 to the position b2. Similarly, two steps are formed between the position b2 and the position c2. As a result, from the position b2 to the position c2, the depth of the inflow recess 994 changes stepwise from the deepest depth g2 to the deepest depth f2.

  As described above, even when the depth of the inflow recess changes depending on the level difference, it is possible to increase the storage capacity of the high-pressure fuel at a position where it is difficult to supply the high-pressure fuel introduced from the inflow port 252a. Therefore, the variation in the flow rate of the fuel discharged from the inflow recess is reliably reduced. Therefore, the responsiveness of the nozzle needle 60 (see FIG. 8) can be improved.

  In the tenth embodiment shown in FIG. 15C and FIG. 9, the depth of the inflow recess 1094 is within a range from the position a2 to the position b2 along the profile scanning line PSL2, and is a distance from the specific inlet 252a. Proportionally, the depth f2 changes to the depth g2. Further, in the range from the position b2 to the position c2, it changes from the depth g2 to the depth f2 along the profile scanning line PSL2 in proportion to the distance from the inflow port 252a. As described above, even when the plurality of inflow ports 252a are open to the opening wall surface 290, the depth of the inflow recess 1094 may be defined in proportion to the distance from the inflow port 252a.

(Eleventh and Twelfth Embodiments)
Each of the eleventh and twelfth embodiments of the present invention shown in FIGS. 16A and 16B is a modification of the third embodiment. In the third embodiment, the depth of the inflow recess 394 gradually increases along the profile scanning line PSL3 as it goes from the central portion 394c where the inflow port 352a opens to either one of the end portions 394b. However, the correlation between the distance from the inlet 352a and the depth in the inflow recess is not limited to that defined in the third embodiment, and the eleventh and the eleventh described below with reference to FIGS. Twelve embodiments may be used.

  In the eleventh embodiment shown in FIGS. 16A and 12, the depth of the inflow recess 1194 is changed from the shallowest depth f3 to the deepest depth by the step formed between the position a3 and the position b3. It has changed to g3. As described above, even in a form in which a step is formed in the bottom surface portion 1197a of the inflow recess 1194, it is possible to secure a storage capacity for storing high-pressure fuel in the vicinity of the position c3 away from the inflow port 352a.

  In the twelfth embodiment shown in FIGS. 16B and 12, the bottom surface portion 1297a of the inflow recess 1294 is inclined from the vicinity of the position a3 to the position c3 along the profile scanning line PSL3. In addition, the inclination from the vicinity of the position a3 to the vicinity of the position b3 is larger than the inclination from the position b3 to the position c3. In this way, in the inflow recess 1294 in which the distance from the inflow port 352a is proportional to the depth, the bottom surface portion 1297a has an inclination angle in the middle if the depth of the position c3 can be maximized. It may be changed. If the inflow recess 1294 has the deepest depth at the position c3 away from the inflow port 352a, a storage capacity for storing high-pressure fuel in the vicinity of the position c3 can be secured.

  As in the eleventh and twelfth embodiments described above, in the form in which the storage capacity of the high-pressure fuel that can be stored in the both end portions 394b is increased, it is possible to continuously release the fuel from the both end portions 394b. . Therefore, the effect | action which suppresses the flow volume dispersion | variation from the inflow recessed part to the pressure control chamber 53 is exhibited notably. Therefore, even in the groove-like inflow recess 394 that becomes narrower as it approaches the both end portions 394b, the deeper the recess is at a position farther from the inlet 352a, the pressure recovery in the pressure control chamber 53 is accelerated, and the valve is closed. This can contribute to improving the response of the nozzle needle 60 (see FIG. 11).

(Other embodiments)
As mentioned above, although several embodiment by this invention was described, this invention is limited to these embodiment and is not interpreted and can be applied to various embodiment in the range which does not deviate from the summary.

  In the said embodiment, the example which applied this invention to the fuel-injection apparatus whose shape of an inflow recessed part is a ring shape or a crescent moon was demonstrated. However, the shape of the inflow recess is not limited to the shape described in the above embodiment. In the first and third embodiments, only one inflow port is opened at the bottom surface of the inflow recess. Moreover, in said 2nd embodiment etc., four inflow ports were formed in the bottom face part of the inflow port part at equal intervals. Thus, the number of openings of the inflow port on the opening wall surface is not limited. In addition, the opening of the inflow port is not limited to the bottom surface portion of the inflow recess, and the opening may extend to the inner peripheral surface or the outer peripheral wall surface of the inflow recess.

  In the above-described embodiment, a mechanism for driving the mover 35 by the electromagnetic force of the solenoid 31 is used as the drive unit that opens and closes the pressure control valve 80 that controls the pressure of the fuel in the pressure control chamber 53. However, as long as it is a drive unit that can move according to a control signal from the engine control device 17 and can open and close the pressure control valve 80, a form using, for example, a piezo element other than a form using a solenoid may be used.

  In the above, the example which applied this invention to the fuel-injection apparatus used for the diesel engine 20 which injects a fuel directly to the combustion chamber 22 was demonstrated. However, the present invention is not limited to the diesel engine 20 and may be applied to a fuel injection device used for an internal combustion engine such as an Otto cycle engine. In addition, the fuel injected by the fuel injection device is not limited to light oil but may be gasoline, liquefied petroleum gas, or the like. Furthermore, the present invention may be applied to a fuel injection device that injects fuel toward a combustion chamber of an engine that burns fuel such as an external combustion engine.

DESCRIPTION OF SYMBOLS 10 Fuel supply system, 11 Fuel tank, 12 Feed pump, 12a, 13a, 14e Fuel piping, 13 High pressure fuel pump, 14 Common rail, 14a Branch part, 14b Common rail sensor, 14c Pressure regulator, 14d Supply flow path, 14f Return flow path , 17 engine control device, 20 diesel engine, 21 head member, 22 combustion chamber, 30 control valve drive unit, 31 solenoid, 32 terminal, 33 valve seat member, 34 spring, 35 mover, 36 stator, 40 control body ( Valve body), 41 nozzle body, 43 nozzle needle housing portion, 44 nozzle hole, 45 valve seat portion, 46,346 orifice plate, 246 first orifice plate, 247 second orifice plate, 47a control valve seat portion, 48 holder, 48a, 48b Vertical hole, 48c Socket part, 49 Retaining nut, 49a Step part, 50 Valve part, 52, 252, 352 Inflow passage, 52a, 252a, 352a Inlet, 53 Pressure control chamber, 53a Open space, 53b Back pressure space , 54, 254, 354 Outlet passage, 54a, 254a, 354a Outlet, 56 cylinder, 57 Control wall surface part, 58a Plate stopper part, 58b Needle stopper part, 59 Cylinder sliding part, 60 Nozzle needle (valve member), 61 Valve pressure receiving surface, 63 Needle sliding portion, 65 Seat portion, 66 Return spring, 67 Needle member, 68 Needle locking portion, 70, 270 Floating plate (control member), 71 Restriction hole, 71a Restriction portion, 72 Recessed portion, 73 , 373 Pressing surface, 74 Outer peripheral wall surface, 276 Plates Ring, 77 Pressure receiving surface, 78 Plate locking part, 80 Pressure control valve, 90, 290, 390 Open wall surface, 94, 294, 394, 494, 594, 694, 794, 894, 994, 1094, 1194, 1294 Inflow Recessed portion, 94a, 294a, 394a, 1194a, 1294a Bottom surface portion, 394b end portion, 394c central portion, 97, 297, 397 Outflow recessed portion, 97a, 297a, 397a Bottom surface portion, 100, 200, 300 Fuel injector

Claims (8)

A valve body (40) in which a passage for the high-pressure fuel is formed, and a nozzle hole (44) for injecting the high-pressure fuel into the combustion chamber (22) of the internal combustion engine (20) is formed at the tip;
A valve member (60) that moves in the axial direction of the valve body (40) in the valve body (40) to open and close the nozzle hole (44);
The valve body (40) is formed on the opposite side of the nozzle hole (44) across the valve member (60), and the high-pressure fuel is introduced to control the movement of the valve member (60). A pressure control chamber (53) controlled by the pressure of
An inflow passage (52) for introducing the high-pressure fuel into the pressure control chamber (53);
An outflow passage (54) for allowing the fuel in the pressure control chamber (53) to flow out to the external low pressure side;
A fuel injection device (100) comprising: a control member (70) that is displaceable in the axial direction in the pressure control chamber (53) and opens and closes the inflow passage (52);
An opening wall surface (90) pressed by the control member (70) to open the inlet (52a) of the inflow passage (52) communicating with the pressure control chamber (53) and close the inflow passage (52). Forms an inflow recess (94) by recessing on the opposite side of the control member (70),
The fuel injection device (100), wherein the inflow recess (94) is deeper as the position is farther from the inlet (52a).   The fuel injection device (100) according to claim 1, wherein the depth of the inflow recess (94) gradually increases as the distance from the inflow port (52a) increases.   The fuel injection device (500) according to claim 1, wherein the inflow recess (594) deepens stepwise as the distance from the inflow port (52a) increases. The inflow recess (94) extends annularly in the opening wall surface (90),
The fuel injection device (100) according to any one of claims 1 to 3, wherein the inflow port (52a) opens to a bottom surface portion (94a) of the inflow recess (94). The inflow port (252a) is annularly arranged so as to open a plurality of openings in the bottom surface portion (294a)
The fuel injection device (200) according to claim 4, wherein the inflow recess (294) becomes deeper toward an intermediate position between the inflow ports (252a) in the circumferential direction of the inflow recess (294). .   The fuel injection device (200) according to claim 5, wherein the plurality of inflow ports (252a) are opened at equal intervals in the circumferential direction of the inflow recess (294).   In the opening wall surface (90), an outflow port (54a) of the outflow passage (54) communicating with the pressure control chamber (53) opens on the inner peripheral side of the inflow recess (94). The fuel injection device (100) according to any one of claims 4 to 6. The outlet (354a) of the outflow passage (354) communicating with the pressure control chamber (53) is a circular opening located eccentrically on the circular opening wall surface (390),
The inflow recess (394) extends along the outer edge of the outlet (354a), and from both ends (394b) in the extending direction toward the center (394c) where the inlet (352a) opens. A groove with a gradually increasing width,
The fuel injection device (300) according to any one of claims 1 to 3, wherein the inflow recess (394) becomes deeper from the central portion (394c) toward the both end portions (394b). .

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