JP6926718B2 - Fuel injection device - Google Patents

Description

The disclosure by this specification relates to a fuel injection device that injects fuel from a injection hole.

Conventionally, a fuel injection device including a needle displaced by the fuel pressure of a chamber provided inside a housing and a valve body for controlling the fuel pressure of the chamber is known. As a kind of such a fuel injection device, for example, the configuration disclosed in Patent Document 1 includes a solenoid valve for controlling the supply of fuel to the chamber and a solenoid valve for controlling the outflow of fuel from the chamber.

U.S. Patent Application Publication No. 2013/0233941

The fuel injection device of Patent Document 1 can switch the displacement speed of the needle by controlling the fuel pressure in the chamber by opening and closing the two solenoid valves individually. However, the fuel injection device of Patent Document 1 is provided with two solenoid valves, so that the size of the fuel injection device can be easily increased.

An object of the present disclosure is to provide a fuel injection device capable of switching the displacement speed of a needle while avoiding an increase in size.

In order to achieve the above object, one disclosed aspect is a control chamber (35) in which a fuel injection hole (38) is formed and filled with fuel, and a high pressure chamber (31a) for supplying fuel to the control chamber. ), A low-pressure chamber (36) through which fuel in the control chamber flows out, and a body (20, 20) internally provided with a first series passage (33) and a second series passage (34) communicating the control chamber and the low pressure chamber. 3 and 20), the driving unit for performing a large second extending action than the first extension operation and the first extension operation (40), is pressed in the direction of closing the injection hole by the fuel pressure in the control chamber, by vacuum in the control chamber The needle (50), which is displaced in the direction of opening the injection hole, and the drive unit are contracted to block the communication between the control chamber and the low pressure chamber by the first series passage, and the first extension operation of the drive unit causes the first series passage. A drive that cuts off the communication between the first valve body (70) that allows communication between the control chamber and the low pressure chamber and the control chamber and the low pressure chamber through the second communication passage while the drive unit is contracted, and performs the second extension operation. by the driving force of the parts it is transmitted through the first valve body, a second valve body (80, 4 8 0) to permit communication between the control chamber and the low pressure chamber by the second communication path comprises, body A supply communication passage (32) that communicates with the high pressure chamber and the control room is further provided inside, and the second valve body communicates with the high pressure chamber and the control room by the supply communication passage with the drive unit contracted. permitting, by the second extension operation of the drive unit, is a fuel injection device you block the communication of the high pressure chamber and the control chamber by the supply communication passage.
Further, one aspect disclosed is a control chamber (35) in which a injection hole (38) for injecting fuel is formed and filled with fuel, a high-pressure chamber (31a) for supplying fuel to the control chamber, and fuel in the control chamber. A body (220) provided inside with a low-pressure chamber (36) through which fuel flows out, and a series of passages (33) and a second passage (34) communicating the control chamber and the low-pressure chamber, and a first extension operation. And the drive unit (40) that performs the second extension operation larger than the first extension operation, and the needle that is pressed in the direction of closing the injection hole by the fuel pressure in the control chamber and displaced in the direction of opening the injection hole by the decompression of the control chamber. (50), the communication between the control chamber and the low pressure chamber by the first series passage is cut off in a state where the drive unit is contracted, and the communication between the control chamber and the low pressure chamber by the first series passage is allowed by the first extension operation of the drive unit. The driving force of the driving unit that performs the second extension operation by blocking the communication between the first valve body (270) and the control chamber and the low pressure chamber by the second connecting passage in a contracted state causes the first valve body. The second valve body is provided with a second valve body (280,580) that allows communication between the control chamber and the low pressure chamber through the second communication passage, and the second valve body is provided with the high pressure chamber and the control chamber. A supply communication passage (284,584) for communication is provided, and the first valve body allows communication between the high pressure chamber and the control room by the supply communication passage in a state where the drive unit is contracted, and the first extension of the drive unit. By operation, it is a fuel injection device that cuts off the communication between the high pressure chamber and the control chamber through the supply communication passage.
Further, one aspect disclosed is a control chamber (35) in which a injection hole (38) for injecting fuel is formed and filled with fuel, a high-pressure chamber (31a) for supplying fuel to the control chamber, and fuel in the control chamber. A body (20, 220, 320) provided inside with a low-pressure chamber (36) through which fuel flows out, and a first series passage (33) and a second series passage (34) communicating the control room and the low pressure chamber. The drive unit (40) that performs the first extension operation and the second extension operation that is larger than the first extension operation, and the direction in which the injection hole is opened by the decompression of the control room, which is pressed in the direction of closing the injection hole by the fuel pressure in the control chamber. With the needle (50) displaced to, and the drive unit contracted, the communication between the control chamber and the low pressure chamber by the first series passage is cut off, and the first extension operation of the drive unit cuts off the communication between the control chamber and the low pressure chamber by the first series passage. The driving force of the first valve body (70, 270) that allows the communication of the fuel and the driving unit that performs the second extension operation by blocking the communication between the control chamber and the low pressure chamber by the second connecting passage while the driving unit is contracted. The body is provided with a second valve body (80, 280, 480, 580) that allows communication between the control chamber and the low pressure chamber by the second communication passage by transmitting the fuel through the first valve body. , An outflow seat surface portion (28) for seating the second valve body in a state where the drive portion is contracted is formed, and an outflow groove portion (28a) connected to the second aisle is formed on the outflow seat surface portion. It is said to be a fuel injection device.
Further, one aspect disclosed is a control chamber (35) in which a injection hole (38) for injecting fuel is formed and filled with fuel, a high-pressure chamber (31a) for supplying fuel to the control chamber, and fuel in the control chamber. A body (20, 220, 320) provided inside with a low-pressure chamber (36) through which fuel flows out, and a first series passage (33) and a second series passage (34) communicating the control room and the low pressure chamber. The drive unit (40) that performs the first extension operation and the second extension operation that is larger than the first extension operation, and the direction in which the injection hole is opened by the decompression of the control room, which is pressed in the direction of closing the injection hole by the fuel pressure in the control chamber. With the needle (50) displaced to, and the drive unit contracted, the communication between the control chamber and low pressure chamber by the first series passage is cut off, and the first extension operation of the drive unit cuts off the communication between the control chamber and low pressure chamber by the first series passage. The driving force of the first valve body (70, 270) that allows the communication of the fuel and the driving unit that performs the second extension operation by blocking the communication between the control chamber and the low pressure chamber by the second connecting passage while the driving unit is contracted. The second valve body (80, 280, 480, 580), which allows communication between the control chamber and the low pressure chamber by the second communication passage, is provided by transmitting the fuel through the first valve body, and the first series is provided. The passage is provided with a first orifice (33a) that limits the flow of fuel flowing from the control chamber to the low pressure chamber, and the second connecting passage is provided with the flow of fuel flowing from the control chamber to the low pressure chamber. A second orifice (34a) is provided to limit the fuel injection device, and the throttle area (So2) of the second orifice is larger than the throttle area (So1) of the first orifice.

In these embodiments, the first extension operation of the drive unit, the first valve body to permit communication between the control chamber and the low pressure chamber by the first communication passage. Further, according to the second extension operation, which is larger than the first extension operation, the second valve body is moved into the control chamber and the low pressure chamber by the second communication passage due to the driving force of the drive unit transmitted through the first valve body. Allow communication.

As described above, according to the control of the magnitude of the extension operation in the drive unit, the implementation and non-execution of the fuel outflow through the second continuous passage can be switched. As a result, the flow rate of fuel flowing out from the control chamber to the low pressure chamber increases or decreases, so that the mode of pressure drop in the control chamber can be changed. As a result, in order to avoid an increase in the size of the fuel injection device, the displacement speed of the needle can be switched even in a configuration in which the first valve body and the second valve body are opened and closed by one drive unit.

The reference numbers in parentheses are merely examples of the correspondence with the specific configuration in the embodiment described later, and do not limit the technical scope at all.

It is a figure which shows the whole structure of the fuel supply system including the fuel injection device and the control device by 1st Embodiment. It is a vertical sectional view of a fuel injection device. It is a vertical cross-sectional view which shows the detailed structure of a pressure control mechanism. It is a figure which shows the detail of the pressure control mechanism in a low speed valve opening mode. It is a figure which shows the detail of the pressure control mechanism in a high-speed valve opening mode. It is a figure which shows the detail of the pressure control mechanism in a valve closing period. It is a vertical sectional view of the fuel injection apparatus according to the 2nd Embodiment. It is a vertical cross-sectional view which shows the detailed structure of a pressure control mechanism. It is a figure which shows the detail of the pressure control mechanism in a low speed valve opening mode. It is a figure which shows the detail of the pressure control mechanism in a high-speed valve opening mode. It is a figure which shows the detail of the pressure control mechanism in the non-injection period. It is a time chart which shows the detail of the operation of the fuel-injection apparatus in fuel-injection including a non-injection period. It is a figure which shows the detail of the pressure control mechanism in a valve closing period. It is a figure which shows the detail of the pressure control mechanism by 3rd Embodiment. It is a figure which shows the detail of the pressure control mechanism by 4th Embodiment. It is a figure which shows the detail of the pressure control mechanism by 5th Embodiment. It is a figure which shows the detail of the pressure control mechanism by 6th Embodiment.

Hereinafter, a plurality of embodiments of the present disclosure will be described with reference to the drawings. By assigning the same reference numerals to the corresponding components in each embodiment, duplicate description may be omitted. When only a part of the configuration is described in each embodiment, the configurations of the other embodiments described above can be applied to the other parts of the configuration. Further, not only the combination of the configurations specified in the description of each embodiment, but also the configurations of a plurality of embodiments can be partially combined even if the combination is not specified. Further, an unspecified combination of the configurations described in the plurality of embodiments and modifications is also disclosed by the following description.

(First Embodiment)
The fuel injection device 10 according to the first embodiment of the present disclosure is used in the fuel supply system 1 shown in FIG. The fuel injection device 10 supplies the fuel stored in the fuel tank 4 to each combustion chamber 2b of a diesel engine (hereinafter, “engine 2”) which is an internal combustion engine. The fuel supply system 1 includes a feed pump 5, a high-pressure fuel pump 6, a common rail 3, a control device 9, and the like together with a fuel injection device 10.

The feed pump 5 is, for example, a trochoidal electric pump. The feed pump 5 is built in the high pressure fuel pump 6. The feed pump 5 pumps light oil as fuel stored in the fuel tank 4 to the high-pressure fuel pump 6. The feed pump 5 may be separate from the high-pressure fuel pump 6 and may be arranged inside, for example, the fuel tank 4.

The high-pressure fuel pump 6 is, for example, a plunger type pump. The high-pressure fuel pump 6 is driven by the output shaft of the engine 2. The high-pressure fuel pump 6 is connected to the common rail 3 by a fuel pipe 6a. The high-pressure fuel pump 6 further boosts the fuel supplied by the feed pump 5 and supplies it to the common rail 3 as high-pressure fuel.

The common rail 3 is connected to a plurality of fuel injection devices 10 via a high-pressure fuel pipe 3b. The common rail 3 is connected to the fuel tank 4 via a surplus fuel pipe 8a. The common rail 3 temporarily stores the high-pressure fuel supplied from the high-pressure fuel pump 6 and distributes the high-pressure fuel to each fuel injection device 10 while maintaining the pressure. The common rail 3 is provided with a pressure sensor 3a and a pressure reducing valve 8. The pressure sensor 3a detects the fuel pressure stored in the common rail 3. When the value detected by the pressure sensor 3a is higher than the target pressure, the pressure reducing valve 8 discharges the surplus fuel to the surplus fuel pipe 8a.

The control device 9 is an electronic control unit including an ECU (Electronic Control Unit) 9a and an EDU (Electronic Driver Unit) 9b. The control device 9 is electrically connected to each fuel injection device 10. The control device 9 controls the injection of fuel by each fuel injection device 10 according to the operating state of the engine 2.

The ECU 9a includes an arithmetic circuit mainly composed of a microcomputer or a microcontroller. The arithmetic circuit includes a processor, RAM, and a rewritable non-volatile memory device. The EDU 9b applies a drive voltage to the drive unit 40 (see FIG. 2) of the fuel injection device 10 based on the command signal input from the ECU 9a.

The fuel injection device 10 is attached to the head member 2a in a state of being inserted into the insertion hole of the head member 2a forming the combustion chamber 2b. The fuel injection device 10 injects the high-pressure fuel supplied through the high-pressure fuel pipe 3b directly from the injection hole 38 toward the combustion chamber 2b. The fuel injection device 10 has a valve structure for controlling the injection of fuel from the injection hole 38. The fuel injection device 10 uses a part of the high-pressure fuel to open and close the injection hole 38. A part of the fuel supplied to the fuel injection device 10 is returned to the fuel tank 4 through the return pipe 8b and the surplus fuel pipe 8a.

As shown in FIGS. 2 and 3, the fuel injection device 10 includes a valve body 20, a nozzle needle 50, a drive unit 40, and a pressure control mechanism 60 having a control valve 70 and a control plate 80.

The valve body 20 is formed by combining a plurality of metal members such as an injector body member 21, an upper valve body member 22, a lower valve body member 23, a nozzle body member 24, a retaining nut 25, and a needle cylinder 26. Inside the valve body 20, a high-pressure fuel passage 31, a high-pressure chamber 31a, a supply communication passage 32, a low-pressure chamber 36, a control chamber 35, a first outflow passage 33, and a second outflow passage 34 are provided. In addition, the valve body 20 is formed with a first seat surface portion 27, a second seat surface portion 28, a third seat surface portion 29, and a jet hole 38.

The high-pressure fuel passage 31 is formed over the injector turbo day member 21, the upper valve body member 22, and the lower valve body member 23. The high-pressure fuel passage 31 is connected to the high-pressure fuel pipe 3b (see FIG. 1). The high-pressure fuel passage 31 supplies the high-pressure fuel supplied from the common rail 3 (see FIG. 1) to the high-pressure chamber 31a through the high-pressure fuel pipe 3b.

The high-pressure chamber 31a is a space formed in a columnar shape on the nozzle body member 24. The nozzle needle 50 and the needle cylinder 26 are housed in the high pressure chamber 31a. The high pressure chamber 31a is connected to the high pressure fuel passage 31. The high pressure chamber 31a is filled with high pressure fuel supplied through the high pressure fuel passage 31. The high-pressure chamber 31a distributes high-pressure fuel to the injection hole 38.

The supply communication passage 32 is a fuel passage that communicates the high pressure chamber 31a and the control chamber 35. An in orifice 32a is formed in the supply passage 32. The flow path area in the in orifice 32a (hereinafter referred to as “throttle area Si1”) is narrower than the flow path area of the portion of the supply communication passage 32 excluding the in orifice 32a. The in orifice 32a limits the flow rate of fuel flowing from the high pressure chamber 31a into the control chamber 35 in a state where the high pressure chamber 31a and the control chamber 35 are connected by the supply communication passage 32.

The low pressure chamber 36 is formed in the injector turbo day member 21. The low pressure chamber 36 is connected to the return pipe 8b (see FIG. 1), and the surplus fuel is circulated to the return pipe 8b. The low pressure chamber 36 is filled with fuel having a lower pressure than the high pressure chamber 31a. The fuel of the control chamber 35 flows out to the low pressure chamber 36.

The control chamber 35 is a columnar space partitioned by an upper valve body member 22, a lower valve body member 23, a needle cylinder 26, a nozzle needle 50, and the like. The control chamber 35 is filled with fuel supplied through the supply passage 32. The control chamber 35 can be connected to the high pressure chamber 31a and the low pressure chamber 36. The control chamber 35 is located between the drive unit 40 and the nozzle needle 50, on the opposite side of the injection hole 38 with the nozzle needle 50 in between. The control chamber 35 is divided into upper and lower parts by a control plate 80 described later. In the control chamber 35, the space formed between the control plate 80 and the drive unit 40 is the valve chamber portion 35b. In the control chamber 35, the space formed between the control plate 80 and the nozzle needle 50 is the main control chamber portion 35a.

Both the first outflow passage 33 and the second outflow passage 34 are formed in the upper valve body member 22. The first outflow passage 33 and the second outflow passage 34 are fuel passages that communicate the control chamber 35 and the low pressure chamber 36. The first outflow passage 33 and the second outflow passage 34 allow the fuel in the control chamber 35 to flow out into the low pressure chamber 36.

The first outflow passage 33 is connected to a pin accommodating hole 22a penetrating the center of the upper valve body member 22 in the axial direction, and extends in an inclined posture with respect to the pin accommodating hole 22a. A first out orifice 33a is formed at the entrance portion of the first outflow path 33 facing the pin accommodating hole 22a. The flow path area in the first out orifice 33a (hereinafter referred to as “squeezing area So1”) is narrower than the flow path area of the portion of the first outflow path 33 excluding the first out orifice 33a. The first out orifice 33a transfers the flow rate of fuel flowing out from the control chamber 35 to the low pressure chamber 36 through the first outflow passage 33 in a state where the control chamber 35 and the low pressure chamber 36 are connected by the pin accommodating hole 22a and the first outflow passage 33. Restrict.

The second outflow passage 34 is provided on the outer peripheral side of the valve chamber portion 35b, and penetrates the upper valve body member 22 in the axial direction. The second outflow passage 34 extends in an inclined posture with respect to the axial direction of the upper valve body member 22. A second out orifice 34a is formed at the entrance portion of the second outflow passage 34 facing the control chamber 35. The flow path area in the second out orifice 34a (hereinafter referred to as “throttle area So2”) is narrower than the flow path area of the portion of the second flow path excluding the second out orifice 34a. The second out orifice 34a limits the flow rate of fuel flowing out from the control chamber 35 to the low pressure chamber 36 through the second outflow passage 34 in a state where the control chamber 35 and the low pressure chamber 36 are connected by the second outflow passage 34. The throttle area So2 of the second out orifice 34a is defined to be larger than the throttle area So1 of the first out orifice 33a.

The first seat surface portion 27 and the second seat surface portion 28 are provided on the upper valve body member 22. The first seat surface portion 27 is provided in an annular shape around the opening of the pin accommodating hole 22a facing the valve chamber portion 35b. The periphery of the first sheet surface portion 27 is recessed with respect to the first sheet surface portion 27. The control valve 70 is taken off and seated on the first seat surface portion 27.

The second seat surface portion 28 is formed on the lower end surface of the upper valve body member 22 facing the lower valve body member 23. The top surface of the control plate 80 is detached and seated on the second seat surface portion 28. The second seat surface portion 28 is formed in an annular shape along the outer edge shape of the top surface of the control plate 80. An upper annular groove 28a is formed on the second seat surface portion 28. The upper annular groove 28a is recessed with respect to the second seat surface portion 28, and extends in an annular shape along the shape of the second seat surface portion 28. The upper annular groove 28a is connected to the second outflow passage 34.

The third seat surface portion 29 is provided on the lower valve body member 23. The third seat surface portion 29 is formed by a stepped surface in the radial direction provided on the inner peripheral wall of the lower valve body member 23. The third seat surface portion 29 faces the second seat surface portion 28 in the axial direction of the lower valve body member 23. The bottom surface of the control plate 80 is detached and seated on the third seat surface portion 29. The third seat surface portion 29 is formed in an annular shape along the outer edge shape of the bottom surface of the control plate 80. A lower annular groove 29a is formed on the third seat surface portion 29. The lower annular groove 29a is recessed with respect to the third seat surface portion 29, and extends in an annular shape along the shape of the third seat surface portion 29. The lower annular groove 29a is connected to the supply passage 32.

The injection hole 38 is formed at the tip end portion in the insertion direction in the valve body 20 inserted into the head member 2a (see FIG. 1). The injection hole 38 is exposed in the combustion chamber 2b (see FIG. 1). The tip of the valve body 20 is formed in a conical or hemispherical shape. A plurality of injection holes 38 are provided radially from the inside to the outside of the valve body 20. Each injection hole 38 injects high-pressure fuel toward the combustion chamber 2b. The high-pressure fuel is atomized by passing through the injection hole 38, and is in a state where it can be easily mixed with air.

The nozzle needle 50 is formed in a cylindrical shape by a metal material. The tip of the nozzle needle 50 on the injection hole 38 side is formed in a conical shape. The nozzle needle 50 is housed in the high-pressure chamber 31a, and receives a force from the high-pressure fuel in the high-pressure chamber 31a in the direction of opening the injection hole 38 (hereinafter, “valve opening direction”). The nozzle needle 50 is formed with a needle pressure receiving portion 51, a spring seat portion 54, and a needle sliding surface 55.

The needle pressure receiving portion 51 is an axial end portion of the nozzle needle 50 facing the control chamber 35. A columnar protrusion 52 is provided at the center of the needle pressure receiving portion 51 in the radial direction. The needle pressure receiving unit 51 receives a force in the direction of closing the injection hole 38 (hereinafter, “valve closing direction”) from the high-pressure fuel filled in the control chamber 35. The nozzle needle 50 is pressed in the valve closing direction by the fuel pressure of the control chamber 35. The nozzle needle 50 is displaced relative to the valve body 20 along the axial direction due to the fluctuation of the fuel pressure in the control chamber 35, and opens and closes the injection hole 38.

The spring seat portion 54 is provided on the nozzle needle 50 in a collar shape. A needle spring 53 is installed between the spring seat portion 54 and the needle cylinder 26 in a state of being compressed in the axial direction. The needle spring 53 is a coil spring formed in a cylindrical spiral shape. The needle spring 53 applies an urging force in the valve closing direction to the spring seat portion 54.

The needle sliding surface 55 is a portion of the outer peripheral wall surface of the nozzle needle 50 that is internally fitted into the needle cylinder 26. The needle sliding surface 55 is slidably supported with respect to the needle cylinder 26. The needle sliding surface 55 forms an oil tightness between the control chamber 35 and the high pressure chamber 31a with the inner peripheral wall surface of the needle cylinder 26.

The nozzle needle 50 described above is pushed up by the fuel in the high pressure chamber 31a due to the decompression of the control chamber 35, and is displaced in the valve opening direction. As a result, the high-pressure fuel filled in the high-pressure chamber 31a is injected from the injection hole 38 toward the combustion chamber 2b (see FIG. 1). On the other hand, according to the pressure recovery of the control chamber 35, the nozzle needle 50 is pushed down in the valve closing direction. As a result, fuel injection from the injection hole 38 is stopped.

The drive unit 40 drives the pressure control mechanism 60. The drive unit 40 is composed of a piezoelectric element laminate, a stress buffer unit 41, a drive transmission pin 42, and the like. The piezoelectric element laminate is, for example, a laminate in which layers called PZT (PbZrTiO3) and thin electrode layers are alternately stacked. The drive voltage output from the control device 9 (see FIG. 1) is input to the piezoelectric element laminate. The piezoelectric element laminate expands and contracts due to the inverse piezoelectric effect, which is a characteristic of the piezo element, based on the input of the drive voltage.

The stress buffer section 41 transmits the expansion and contraction of the piezoelectric element laminate to the drive transmission pin 42, and buffers the stress input to the piezoelectric element laminate. The drive transmission pin 42 is a pressing shaft portion that transmits the extension operation of the piezoelectric element laminate to the pressure control mechanism 60. The drive transmission pin 42 is housed in the pin accommodating hole 22a of the upper valve body member 22. The tip of the drive transmission pin 42 is abutted against the upper end surface of the control valve 70.

The drive unit 40 displaces the drive transmission pin 42 in the direction of protruding into the valve chamber 35b by the piezoelectric element laminate extended by the accumulation of electric charges, and causes the drive transmission pin 42 to shrink due to the contraction of the piezoelectric element laminate due to the discharge of electric charges. It is pulled back to the pin accommodating hole 22a. The magnitude of the extension operation of the drive transmission pin 42 corresponds to the magnitude of the drive energy input to the piezoelectric element laminate, in other words, the amount of electric charge charged to the piezoelectric element laminate. The magnitude of the extension operation of the drive transmission pin 42 in the drive unit 40 can be controlled in multiple stages by the control device 9 (see FIG. 1).

The pressure control mechanism 60 is housed in the control chamber 35. The pressure control mechanism 60 functions as a three-way valve that switches between an inflow state in which fuel flows into the control chamber 35 and an outflow state in which fuel flows out from the control chamber 35 by being pressed by the drive unit 40 in the valve closing direction. Have. The pressure control mechanism 60 includes a first spring 61, a second spring 62, and the like in addition to the control valve 70 and the control plate 80 described above. These configurations are arranged so that they are coaxial with each other.

The control valve 70 is made of a metal material and is formed in a two-stage columnar shape having a small diameter portion 70a and a large diameter portion 70b as a whole. The control valve 70 is housed in the valve chamber portion 35b in a posture in which the large diameter portion 70b is directed toward the drive transmission pin 42. The outer diameter of the large diameter portion 70b is defined to be smaller than the inner diameter of the inner peripheral surface of the upper valve body member 22 that partitions the valve chamber portion 35b. The control valve 70 can be displaced in the axial direction in a state of being substantially non-contact with the inner peripheral surface of the upper valve body member 22. The control valve 70 is formed with a closing portion 71, a pressing portion 72, and a communication groove 73.

The closing portion 71 is formed on the upper end surface of the control valve 70 in the axial direction, which faces the driving portion 40 side. The closing portion 71 is formed in a flat circular flat shape larger than the opening of the pin accommodating hole 22a. The closing portion 71 faces the first seat surface portion 27, and is detached and seated from the first seat surface portion 27 due to the axial displacement of the control valve 70. A drive transmission pin 42 is in contact with the center of the closing portion 71. The extension operation of the drive unit 40 is directly input to the control valve 70 by the drive transmission pin 42.

The pressing portion 72 is formed on the lower end surface of the control valve 70 in the axial direction, which faces the control plate 80. With the drive unit 40 contracted, a slight gap GP is formed between the pressing unit 72 and the control plate 80. The size of the gap GP is, for example, about 10 to 30 μm. The pressing unit 72 abuts on the top surface of the control plate 80 by the extension operation of the drive unit 40, and transmits the driving force of the drive unit 40 to be extended to the control plate 80.

The communication groove 73 is formed on the lower end surface of the control valve 70, for example, in a cross shape. The communication groove 73 is a recess provided on the lower end surface, and extends along the radial direction so as to pass through the center of the lower end surface. The communication groove 73 enables the flow of fuel between the main control chamber portion 35a and the valve chamber portion 35b in a state where the control valve 70 is pressed against the control plate 80.

In the above control valve 70, the closing portion 71 is seated on the first seat surface portion 27 in a state where the driving portion 40 is contracted. As a result, the control valve 70 cuts off the communication between the control chamber 35 and the low pressure chamber 36 by the first outflow passage 33. On the other hand, in the control valve 70, the closing portion 71 is separated from the first seat surface portion 27 by the extension operation of the driving portion 40, and the pressing portion 72 is brought into contact with the control plate 80. As a result, the control valve 70 allows communication between the control chamber 35 and the low pressure chamber 36 by the first outflow passage 33.

The extension operation of the drive unit 40 that opens only the control valve 70 among the control valve 70 and the control plate 80 and allows fuel to flow only to the first outflow passage 33 among the first outflow passage 33 and the second outflow passage 34. Is hereinafter referred to as "first extension operation". The magnitude of the first extension operation is substantially the same as the gap GP between the control valve 70 and the control plate 80.

The control plate 80 is made of a metal material and is formed in a flat disk shape as a whole. The control plate 80 is housed in the control chamber 35 in a substantially coaxial arrangement with the pin housing hole 22a and the control valve 70. The control plate 80 is formed with an upper seating surface 81, an underwearing seating surface 82, and a communication hole 83.

The upper seating surface 81 is formed on the outer edge portion of the top surface of the control plate 80. The upper seating surface 81 has a flat flat surface. The upper seating surface 81 faces the second seat surface portion 28, and is detached and seated with respect to the second seat surface portion 28 due to the displacement of the control plate 80. The upper ring seat surface 81 closes the upper annular groove 28a by seating on the second seat surface portion 28.

The underwear seating surface 82 is formed on the outer edge portion of the bottom surface of the control plate 80. The underwear seating surface 82 has a flat flat surface. The underwear seating surface 82 faces the third seat surface portion 29, and takes off and seats on the third seat surface portion 29 due to the displacement of the control plate 80. The underwear seating surface 82 closes the lower annular groove 29a by seating on the third seat surface portion 29.

The communication hole 83 is provided in the center of the control plate 80 in the radial direction, and is formed by a cylindrical through hole that penetrates the control plate 80 in the axial direction. The communication hole 83 communicates the main control chamber portion 35a and the valve chamber portion 35b with each other. The flow path area of the communication hole 83 is defined to be larger than the total of the drawing areas So1 and So2.

In the above control plate 80, the upper seating surface 81 is seated on the second seat surface portion 28 and the underwear seating surface 82 is separated from the third seat surface portion 29 in a state where the drive unit 40 is contracted. As a result, the control plate 80 allows communication between the high pressure chamber 31a and the control chamber 35 through the supply communication passage 32 while blocking communication between the control chamber 35 and the low pressure chamber 36 through the second outflow passage 34.

Further, in the control plate 80, the driving force of the driving unit 40 accompanying the extension operation is transmitted via the control valve 70, so that the upper seating surface 81 is separated from the second seating surface 28 and the underwearing surface 82. Is seated on the third seat surface portion 29. As a result, the control plate 80 blocks communication between the high pressure chamber 31a and the control chamber 35 through the supply communication passage 32 while allowing communication between the control chamber 35 and the low pressure chamber 36 through the second outflow passage 34.

The extension operation of the drive unit 40 that opens both the control valve 70 and the control plate 80 and brings the control plate 80 into contact with the third seat surface portion 29 is hereinafter referred to as a "second extension operation". The magnitude of the second extension operation is larger than that of the first extension operation. In addition, the difference in the amount of operation between the first extension operation and the second extension operation corresponds to the stroke amount DP of the control plate 80. The stroke amount DP of the control plate 80 has a larger flow path area between the seating surfaces 81 and 82 and the seat surface portions 28 and 29 than the throttle areas Si1 and So2 of the in orifice 32a and the second out orifice 34a. Is set to.

More specifically, when the stroke amount DP of the control plate 80 is set and the inner diameter of the valve chamber portion 35b is d1, the second seat surface portion 28 and the upper seating surface 81 are seated on the third seat surface portion 29. The minimum flow path area between them is "2π x d1 x DP". Similarly, when the inner diameter of the main control chamber portion 35a is d2, the minimum flow path area between the third seat surface portion 29 and the underwear seating surface 82 is set when the control plate 80 is seated on the second seat surface portion 28. It becomes "2π x d2 x DP". The stroke amount DP is set to So2 <2π × d1 × DP and Si1 <2π × d2 × DP, respectively, so that the flow rates can be defined by the in orifice 32a and the second out orifice 34a, respectively.

The first spring 61 and the second spring 62 are both coil springs formed in a cylindrical spiral shape. The first spring 61 and the second spring 62 are housed in the control chamber 35. The first spring 61 is located on the outer peripheral side of the small diameter portion 70a, and is arranged between the large diameter portion 70b and the control plate 80 in a state of being compressed in the axial direction. The first spring 61 urges the control valve 70 toward the first seat surface portion 27. The second spring 62 is located on the outer peripheral side of the protrusion 52, and is arranged between the control plate 80 and the nozzle needle 50 in a state of being compressed in the axial direction. The second spring 62 urges the control plate 80 toward the second seat surface portion 28. In addition, the second spring 62 urges the control valve 70 toward the second seat surface portion 28 via the control plate 80 and the first spring 61.

The fuel injection device 10 described so far can change the mode of transition of the injection rate in fuel injection. Specifically, the fuel injection device 10 includes fuel injection in a low-speed valve opening mode in which the injection rate is raised as standard, and fuel injection in a high-speed valve opening mode in which the injection rate is raised steeper than in the low-speed valve opening mode. It can be performed. Hereinafter, the details of the operation of fuel injection in the fuel injection device 10 will be described with reference to FIGS. 3 to 6 with reference to FIGS. 2 while comparing the low-speed valve opening mode and the high-speed valve opening mode.

FIG. 3 shows a contracted state of the drive unit 40 without energizing the piezoelectric element laminate. In this state, the control valve 70 seats the closing portion 71 on the first seat surface portion 27 as an initial position by the urging force of the first spring 61 or the like. The control valve 70 at the initial position cuts off the connection between the control chamber 35 and the low pressure chamber 36 by the first outflow passage 33. Similarly, the control plate 80 has the upper seating surface 81 seated on the second seating surface 28 as an initial position due to the pressure difference between the main control chamber portion 35a and the upper annular groove 28a, the urging force of the second spring 62, and the like. There is. The control plate 80 at the initial position cuts off the connection between the control chamber 35 and the low pressure chamber 36 by the second outflow passage 34. As a result, the outflow of fuel from the control chamber 35 to the low pressure chamber 36 is interrupted.

On the other hand, the underwear seating surface 82 of the control plate 80 is separated from the third seat surface portion 29. Therefore, communication between the high pressure chamber 31a and the control chamber 35 through the supply communication passage 32 is allowed, and the fuel pressure in the control chamber 35 is substantially the same as the fuel pressure in the high pressure chamber 31a. The nozzle needle 50 maintains the valve closed state of the injection hole 38 by the oil pressure received from the fuel in the control chamber 35.

In the low-speed valve opening mode shown in FIG. 4, the drive energy (hereinafter, “first drive energy”) that causes the drive unit 40 to perform the first extension operation is input to the piezoelectric element laminate. The drive unit 40 in the low-speed valve opening mode pushes down the control valve 70 by the drive transmission pin 42, and brings the pressed portion 72 of the pushed down control valve 70 into contact with the top surface of the control plate 80. When the closing portion 71 is separated from the first seat surface portion 27 by opening the control valve 70, the valve chamber portion 35b is connected to the low pressure chamber 36 via the pin accommodating hole 22a and the first outflow passage 33. As a result, the fuel in the main control chamber portion 35a moves to the valve chamber portion 35b through the communication hole 83 and the communication groove 73, and can flow out to the low pressure chamber 36 via the first outflow passage 33.

The control plate 80 in the low-speed valve opening mode maintains a state in which the upper seating surface 81 is seated on the second seat surface 28 even when the control valve 70 abuts due to the low pressure of the upper annular groove 28a. Therefore, the communication between the control chamber 35 and the low pressure chamber 36 by the second outflow passage 34 is cut off. Further, the communication state of the high pressure chamber 31a and the control chamber 35 by the supply communication passage 32 is maintained.

In the above low-speed valve opening mode, only the first outflow passage 33 of the first outflow passage 33 and the second outflow passage 34 allows fuel to flow from the control chamber 35 to the low pressure chamber 36. Due to the depressurization of the control chamber 35 due to the fuel outflow controlled by the first out orifice 33a, the oil pressure in the valve closing direction acting on the needle pressure receiving portion 51 is reduced. As a result, the fuel pressure in the control chamber 35 falls below the valve opening pressure, and the nozzle needle 50 starts displacement in the valve opening direction due to the hydraulic pressure of the high-pressure fuel. As a result, the injection hole 38 is opened.

In the high-speed valve opening mode shown in FIG. 5, the drive energy (hereinafter, “second drive energy”) that causes the drive unit 40 to perform the second extension operation is input to the piezoelectric element laminate. The second drive energy is larger than the first drive energy. The drive unit 40 in the high-speed valve opening mode pushes down the control plate 80 together with the control valve 70. According to the displacement of the control plate 80, the upper seating surface 81 is separated from the second seat surface portion 28, and the underwear seating surface 82 is seated on the third seat surface portion 29. As described above, the valve chamber portion 35b is connected to the low pressure chamber 36 via the second outflow passage 34. In addition, the lower annular groove 29a is blocked by the underwear seating surface 82, so that the high pressure chamber 31a and the control chamber 35 are blocked from communicating with each other by the supply communication passage 32. As a result, the supply of fuel from the high pressure chamber 31a to the control chamber 35 is interrupted.

In the above high-speed valve opening mode, both the first outflow passage 33 and the second outflow passage 34 allow fuel to flow from the control chamber 35 to the low pressure chamber 36. As described above, according to the depressurization of the control chamber 35 accompanying the fuel outflow regulated by the out orifices 33a and 34a, the oil pressure in the valve closing direction acting on the needle pressure receiving portion 51 rapidly decreases. As a result, the nozzle needle 50 can be displaced in the valve opening direction at a higher speed than in the low speed valve opening mode.

During the valve closing period shown in FIG. 6, the energization of the piezoelectric element laminate is stopped. When the electric charge stored in the piezoelectric element laminate is released as the energization is stopped, the driving force of the driving unit 40 disappears. As a result, during the valve closing period in the high-speed valve opening mode, the control plate 80 is displaced toward the second seat surface portion 28 due to the hydraulic pressure of the lower annular groove 29a and the urging force of the second spring 62. As a result, the high pressure chamber 31a and the control chamber 35 are connected by the supply passage 32, and the inflow of fuel into the control chamber 35 is started. Further, the communication between the control chamber 35 and the low pressure chamber 36 by the second outflow passage 34 is blocked by the control plate 80. As a result, the outflow of fuel from the control chamber 35 to the low pressure chamber 36 through the second outflow passage 34 is stopped.

In addition, during the valve closing period of each valve opening mode, the control valve 70 is displaced toward the first seat surface portion 27 due to the urging force of the first spring 61, the hydraulic pressure, and the like. The control valve 70 seats the closing portion 71 on the first seat surface portion 27 to block the communication between the control chamber 35 and the low pressure chamber 36. As a result, the outflow of fuel from the control chamber 35 to the low pressure chamber 36 through the first outflow passage 33 is stopped.

As described above, the fuel pressure in the control chamber 35 is restored to the same initial pressure as the high pressure chamber 31a by the fuel supplied through the supply passage 32. As a result, the nozzle needle 50 is pushed down in the valve closing direction by the restoring force of the needle spring 53, the hydraulic pressure, and the like, and the injection hole 38 is closed.

In the first embodiment described so far, the control valve 70 allows the control chamber 35 and the low pressure chamber 36 to communicate with each other by the first extension operation of the drive unit 40. Further, according to the second extension operation, which is larger than the first extension operation, the control plate 80 is moved to the control chamber 35 by the second outflow passage 34 and the low pressure due to the driving force of the drive unit 40 transmitted via the control valve 70. Allows communication of chamber 36.

As described above, according to the control of the magnitude of the extension operation in the drive unit 40, the implementation and non-execution of the fuel outflow through the second outflow passage 34 can be switched. As a result, the flow rate of fuel flowing out from the control chamber 35 to the low pressure chamber 36 increases or decreases, so that the mode of pressure drop in the control chamber 35 can be changed. As a result, in order to avoid an increase in the size of the fuel injection device 10, the displacement speed of the nozzle needle 50 can be switched even if the control valve 70 and the control plate 80 are opened and closed by one drive unit 40. Become.

In addition, in the first embodiment, the second extension operation of the drive unit 40 cuts off the communication between the high pressure chamber 31a and the control chamber 35 through the supply communication passage 32, and the inflow of fuel from the high pressure chamber 31a into the control chamber 35. Is interrupted. Based on the above, the pressure drop in the control chamber 35 due to the second extension operation occurs more rapidly than the pressure drop in the control chamber due to the first extension operation. Therefore, as the operating amount of the drive unit 40 is changed, the displacement speed of the nozzle needle 50 can be switched and the range can be further expanded.

Further, the third seat surface portion 29 of the first embodiment is provided with a lower annular groove 29a connected to the supply communication passage 32. When the control plate 80 is seated on the third seat surface portion 29, the fuel filling the lower annular groove 29a has substantially the same pressure as the high pressure chamber 31a. Therefore, the control plate 80 is pushed up in the direction away from the third seat surface portion 29 due to the fuel pressure difference between the lower annular groove 29a and the control chamber 35. According to the above, since the operation of the control plate 80 that separates from the third seat surface portion 29 during the valve closing period is supported by the fuel in the lower annular groove 29a, the pressure in the control chamber 35 is recovered, and the nozzle needle 50 is closed. Displacement in the valve direction is performed promptly.

In addition, as in the first embodiment, if the lower annular groove 29a has a shape extending along the third seat surface portion 29, the fuel flowing through the supply passage 32 can be supplied from the entire lower annular groove 29a to the control chamber 35. Can flow into. Therefore, even if the stroke amount DP secured on the control plate 80, that is, the gap between the third seat surface portion 29 and the underwear seat surface 82 is small, the fuel in the supply passage 32 is the fuel between the third seat surface portion 29 and the underwear seat surface. It can flow into the control chamber 35 without being substantially narrowed down to the 82. In this way, if the stroke amount DP of the control plate 80 can be shortened and the fuel flow rate flowing into the control chamber 35 can be secured, the drive energy input to the piezoelectric element laminate in the high-speed valve opening mode can be reduced and the speed can be increased. It is possible to achieve both valve closing operation.

Further, if the lower annular groove 29a is formed in an annular shape along the outer edge shape of the underwear seating surface 82 as in the first embodiment, the fuel in the lower annular groove 29a is biased to the control plate 80 in the circumferential direction. A uniform oil pressure that suppresses the pressure can be applied to the underwear seating surface 82. According to the above, the control plate 80 can follow the contracting operation of the drive unit 40, maintain a stable posture without tilting in the axial direction, and can be separated from the third seat surface portion 29.

Further, the second seat surface portion 28 of the first embodiment is provided with an upper annular groove 28a connected to the second outflow passage 34. When the control plate 80 is seated on the second seat surface portion 28, the fuel filling the upper annular groove 28a has substantially the same pressure as the low pressure chamber 36. Therefore, the control plate 80 is pressed against the second seat surface portion 28 due to the difference in fuel pressure between the upper annular groove 28a and the control chamber 35.

According to the above, even if the control valve 70 comes into contact with the control plate 80 in the low-speed valve opening mode, the control plate 80 uses the low pressure of the upper annular groove 28a to provide the upper seating surface 81 to the second seat surface portion 28. It can be kept seated. Therefore, by switching from the first extension operation to the second extension operation, the mode of change in the displacement speed of the nozzle needle 50 and, by extension, the injection rate can be clearly switched.

In addition, if the upper annular groove 28a has a shape extending along the second seat surface portion 28 as in the first embodiment, the fuel in the control chamber 35 flows into the entire upper annular groove 28a and flows out second. It is discharged to the low pressure chamber 36 through the road 34. With such a configuration, even if the gap between the second seat surface portion 28 and the upper seating surface 81 is small, the fuel in the control chamber 35 is substantially throttled between the second seat surface portion 28 and the upper seating surface 81. It can be distributed to the second outflow channel 34 without any problem. In this way, if the fuel flow rate flowing out from the control chamber 35 can be secured while shortening the stroke amount DP of the control plate 80, the drive energy input to the piezoelectric element laminate in the high-speed valve opening mode can be reduced and the speed can be increased. It is possible to achieve both valve opening operation.

Further, in the first embodiment, the upper annular groove 28a is formed in an annular shape along the outer edge shape of the upper seating surface 81. Therefore, the fuel in the upper annular groove 28a can apply an even suction force to the control plate 80 in the circumferential direction, so that the control plate 80 can be seated on the second seat surface portion 28. In addition, the upper annular groove 28a can reduce the bias of the hydraulic pressure, suppress the inclination generated in the control plate 80, and stabilize the displacement of the control plate 80.

Further, in the first embodiment, the throttle area So2 of the second out orifice 34a is defined to be larger than the throttle area So1 of the first out orifice 33a. Therefore, the fuel flow rate flowing out of the control chamber 35 changes remarkably with the switching between the low-speed valve opening mode and the high-speed valve opening mode. According to the above, the valve opening mode, that is, the variable range of the injection rate accompanying the switching of the extension operation of the drive unit 40 can be expanded.

In addition, in the first embodiment, the control valve 70 and the control plate 80 are urged toward the drive transmission pin 42 by the urging forces of the first spring 61 and the second spring 62, respectively. With such a configuration, the control valve 70 and the control plate 80 can accurately follow the expansion / contraction operation of the drive unit 40. Therefore, the operation of the fuel injection device 10 is stabilized.

In the first embodiment, the valve body 20 corresponds to the "bed", the second seat surface portion 28 corresponds to the "outflow seat surface portion", the upper annular groove 28a corresponds to the "outflow groove portion", and the third The seat surface portion 29 corresponds to the “inflow seat surface portion”, and the lower annular groove 29a corresponds to the “inflow groove portion”. Further, the first outflow passage 33 corresponds to the "first series passage", the first out orifice 33a corresponds to the "first orifice", the second outflow passage 34 corresponds to the "second continuous passage", and the second The out orifice 34a corresponds to the "second orifice". Further, the nozzle needle 50 corresponds to the "needle", the second spring 62 corresponds to the "valve elastic member", the control valve 70 corresponds to the "first valve body", and the control plate 80 corresponds to the "second valve". Corresponds to "body".

(Second Embodiment)
The second embodiment shown in FIGS. 7 to 12 is a modification of the first embodiment. In the second embodiment, as shown in FIGS. 7 and 8, the configurations of the valve body 220 and the pressure control mechanism 260 are different from those in the first embodiment. The details of the valve body 220 and the pressure control mechanism 260 will be described below.

The valve body 220 includes a valve body member 222 as a configuration corresponding to the upper valve body member 22 and the lower valve body member 23 (see FIG. 3). The valve body member 222 is provided with a mechanism accommodating hole 260a in addition to the pin accommodating hole 22a, the first seat surface portion 27, and the second seat surface portion 28. The mechanism accommodating hole 260a partitions a two-stage columnar space and accommodates the pressure control mechanism 260. The mechanism accommodating hole 260a forms a part of the high pressure chamber 31a.

The pressure control mechanism 260 includes a control valve 270, an in-control cylinder 280, an out-of-control cylinder 290, a first spring 61, a second spring 62, and the like.

The control valve 270 is formed in a flat columnar shape. The control valve 270 is housed in the mechanism housing hole 260a in a state where it can be displaced in the axial direction. A clearance for flowing fuel is secured between the outer peripheral wall surface of the control valve 270 and the inner peripheral wall surface of the valve body 220. The control valve 270 is formed with a communication passage 274 in addition to the closing portion 71 and the pressing portion 72. The communication passage 274 is formed by a through hole that penetrates the control valve 270 in the axial direction. One end of the communication passage 274 is connected to the main control chamber unit 35a. The other end of the communication passage 274 is connected to a space portion secured around the first seat surface portion 27 in the control chamber 35. The communication passage 274 distributes the fuel of the main control chamber portion 35a toward the pin accommodating hole 22a.

The inner control cylinder 280 is formed in a cylindrical shape as a whole. The inner control cylinder 280 is housed inside the out-of-control cylinder 290. An intermediate chamber portion 263 is partitioned between the cylinder inside the control 280 and the cylinder outside the control 290. The intermediate chamber portion 263 is a cylindrical space and is a part of the high pressure chamber 31a. The intermediate chamber portion 263 is filled with high-pressure fuel and can be connected to the main control chamber portion 35a.

The inner control cylinder 280 is provided with a flange portion 280a protruding outward in the radial direction. The flange portion 280a is formed in an annular shape at one end of the control inner cylinder 280 in the axial direction facing the control valve 270. The outer diameter of the flange portion 280a is defined to be smaller than the inner diameter of the out-of-control cylinder 290. With such a configuration, the inner cylinder 280 can be displaced in the axial direction without sliding the flange 280a to the out-of-control cylinder 290.

In addition to the upper seating surface 81 and the lower seating surface 82, the inner control cylinder 280 is provided with an inflow seat surface portion 285 and a supply communication passage 284. The upper seating surface 81 is formed on the upper end surface of the control inner cylinder 280 in the axial direction, which faces the control valve 270. The upper seating surface 81 is provided on the outer edge portion of the upper end surface formed by the collar portion 280a. The upper seating surface 81 closes the upper annular groove 28a provided in the second seat surface portion 28 by abutting on the second seat surface portion 28. The underwear seating surface 82 is formed on the lower end surface of the control inner cylinder 280 in the axial direction, which faces the injection hole 38 side. The underwear seating surface 82 takes off and seats on the out-of-control cylinder 290 due to the axial displacement of the control inner cylinder 280.

The inflow sheet surface portion 285 has a configuration corresponding to the third sheet surface portion 29 (see FIG. 3) of the first embodiment. The inflow seat surface portion 285 is formed in an annular shape on the inner peripheral side of the upper seating surface 81 among the upper end surfaces of the control inner cylinder 280. The inflow seat surface portion 285 faces the pressing portion 72 of the control valve 270. The pressing portion 72 is detached and seated on the inflow seat surface portion 285. An inflow annular groove 285a is formed in the inflow sheet surface portion 285. The inflow annular groove 285a is recessed with respect to the upper end surface and extends in an annular shape along the shape of the inflow sheet surface portion 285. The inflow annular groove 285a is connected to the supply passage 284. The inflow annular groove 285a is closed by the pressing portion 72 seated on the inflow seat surface portion 285.

The supply communication passage 284 is a fuel passage that communicates the intermediate chamber portion 263 and the main control chamber portion 35a. The supply passage 284 is formed by a through hole penetrating the wall portion of the control inner cylinder 280. The supply passage 284 is provided with an in orifice 284a. In the second embodiment, the entire supply passage 284 is an in orifice 284a. The in orifice 284a limits the flow rate of fuel flowing from the intermediate chamber portion 263 into the main control chamber portion 35a in a state where the intermediate chamber portion 263 and the main control chamber portion 35a are connected. The flow path area of the in orifice 284a corresponds to the throttle area Si1 of the first embodiment.

The out-of-control cylinder 290 is made of a metal material and is formed in a bottomed cylindrical shape. The out-of-control cylinder 290 is urged toward the drive unit 40 by the needle spring 53. The driving force of the driving unit 40 that performs the extension operation is transmitted to the out-of-control cylinder 290 via the control valve 270 and the in-control cylinder 280. The out-of-control cylinder 290 can be displaced by the extension operation of the drive unit 40. Hereinafter, the extension operation for separating the out-of-control cylinder 290 from the second seat surface portion 28 is referred to as a "third extension operation". The third extension operation is a larger extension operation than the second extension operation.

The out-of-control cylinder 290 is provided with an upper contact surface portion 291, a needle insertion opening 292, and an intermediate seat surface portion 293. The upper contact surface portion 291 is formed by the upper end surface of the out-of-control cylinder 290 facing the second seat surface portion 28. The upper contact surface portion 291 is located on the outer peripheral side of the upper seat surface portion 81, and can be taken off and seated on the second seat surface portion 28. The upper contact surface portion 291 is pressed against the second seat surface portion 28 by the urging force of the needle spring 53 acting on the out-of-control cylinder 290.

The needle insertion opening 292 is a through opening formed in the center of the bottom wall of the out-of-control cylinder 290. The needle insertion opening 292 allows the nozzle needle 50 to be inserted. A flow gap IS2 is provided between the needle insertion opening 292 and the nozzle needle 50. The circulation gap IS2 is a radial gap that serves as a passage for the high-pressure fuel that flows into the intermediate chamber portion 263. The flow path area Si2 of the flow gap IS2 is the area of the annular portion in the cross section, and is larger than the throttle area Si1 of the in orifice 284a.

The intermediate seat surface portion 293 is formed in a portion of the bottom wall of the out-of-control cylinder 290 that surrounds the periphery of the needle insertion opening 292. The intermediate seat surface portion 293 faces the underwear seat surface 82 in the axial direction. By seating the underwear seating surface 82 on the intermediate seat surface portion 293, the intermediate chamber portion 263 is shielded from the main portion of the high pressure chamber 31a. As a result, the supply of high-pressure fuel to the intermediate chamber 263 is stopped. With the drive unit 40 contracted and both the inner control cylinder 280 and the out-of-control cylinder 290 seated on the second seat surface 28, distribution between the intermediate seat surface 293 and the underwear seat 82. There is a gap IS3. The circulation gap IS3 is an axial gap that serves as a passage for the high-pressure fuel that flows into the intermediate chamber portion 263. The flow path area Si3 of the flow gap is the area of the outer peripheral surface of the cylinder having the same inner diameter as the needle insertion opening 292, and is larger than the throttle area Si1 of the in orifice 284a.

The first spring 61 is housed in the main control chamber portion 35a. The first spring 61 is arranged between the control valve 270 and the nozzle needle 50 in a state of being compressed in the axial direction. The second spring 62 is housed in the intermediate chamber portion 263. The second spring 62 is arranged between the flange portion 280a of the inner control cylinder 280 and the bottom wall of the out-of-control cylinder 290 in a state of being compressed in the axial direction.

The fuel injection device 210 having the above configuration can switch between fuel injection in the low-speed valve opening mode and fuel injection in the high-speed valve opening mode, as in the first embodiment. In addition, the fuel injection device 210 can provide an interruption period during which the fuel injection is temporarily interrupted within one injection period. Hereinafter, the details of the operation of fuel injection by the fuel injection device 210 will be described with reference to FIGS. 7 and 7 based on FIGS. 8 to 12.

FIG. 8 shows a pressure control mechanism 260 in a state where the drive unit 40 is contracted. In this state, the control valve 270 has the closing portion 71 seated on the first seat surface portion 27 as an initial position by the urging force of the first spring 61 or the like. The inner control cylinder 280 has the upper seating surface 81 seated on the second seating surface 28 as an initial position by the urging force of the second spring 62 or the like. The out-of-control cylinder 290 has the upper contact surface portion 291 seated on the second seat surface portion 28 as an initial position by the urging force of the needle spring 53 or the like.

On the other hand, the pressing portion 72 of the control valve 270 is separated from the second seat surface portion 28. In addition, the underwear seating surface 82 of the inner control cylinder 280 is separated from the intermediate seating surface portion 293. Therefore, the high-pressure fuel can be supplied to the control chamber 35 through the intermediate chamber portion 263 and the supply passage 284. As a result, the fuel pressure in the control chamber 35 becomes substantially the same as the fuel pressure in the high pressure chamber 31a, so that the nozzle needle 50 maintains the valve closed state of the injection hole 38 by the oil pressure received from the fuel in the control chamber 35.

In the low-speed valve opening mode shown in FIG. 9, the control valve 270 comes into contact with the in-control cylinder 280 fixed to the second seat surface portion 28 at a low pressure of the upper annular groove 28a by the drive transmission pin 42 that performs the first extension operation. It is pushed down to the position. The control valve 270 closes the upper annular groove 28a by the pressing portion 72. As a result, the communication between the intermediate chamber portion 263 and the main control chamber portion 35a by the supply communication passage 284 is cut off, and the supply of fuel to the main control chamber portion 35a is interrupted. Further, the fuel of the main control chamber portion 35a circulates through the communication passage 274, the pin accommodating hole 22a, and the first outflow passage 33 due to the separation of the closing portion 71 from the first seat surface portion 27 by opening the control valve 270. It is discharged to the low pressure chamber 36. Even in the low-speed valve opening mode of the second embodiment, the fuel flow rate flowing out from the control chamber 35 to the low-pressure chamber 36 is defined by the first out orifice 33a. According to the depressurization of the control chamber 35 due to the fuel outflow, the oil pressure in the valve closing direction acting on the needle pressure receiving portion 51 is reduced. As a result, the nozzle needle 50 starts to be displaced in the valve opening direction by the hydraulic pressure of the high-pressure fuel, and the injection hole 38 is opened.

The drive unit 40 in the high-speed valve opening mode shown in FIG. 10 pushes down the control cylinder 280 together with the control valve 270 by the second extension operation. According to the displacement of the in-control cylinder 280, the upper seating surface 81 is separated from the second seat surface portion 28, and the lower seating surface 82 is seated on the intermediate seat surface portion 293. As a result, the main control chamber unit 35a is connected to the low pressure chamber 36 via the second outflow passage 34. In addition, the seating of the underwear seating surface 82 on the intermediate seat surface portion 293 obstructs the fuel flow from the high pressure chamber 31a to the intermediate chamber portion 263, so that the high pressure chamber 31a moves to the control chamber 35 as in the low speed valve opening mode. Fuel supply is virtually non-existent.

In the above high-speed valve opening mode, the fuel in the control chamber 35 flows to the low pressure chamber 36 through both the first outflow passage 33 and the second outflow passage 34. As a result, the fuel pressure in the control chamber 35 drops more rapidly than in the low-speed valve opening mode, and the nozzle needle 50 is displaced in the valve opening direction at a higher speed than in the low-speed valve opening mode.

As shown in FIGS. 11 and 12, the fuel injection device 210 can provide a non-injection period in the middle of fuel injection in, for example, a high-speed valve opening mode (time t3 to t4). In order to realize the non-injection period, the drive energy (hereinafter, “third drive energy”) that causes the drive transmission pin 42 to perform the third extension operation is input to the piezoelectric element laminate. The third drive energy is larger than the second drive energy. According to the third extension operation of the drive unit 40, the out-of-control cylinder 290 separates the upper contact surface portion 291 from the second seat surface portion 28.

Specifically, the second drive energy is once input to the drive unit 40. As a result, the control valve 270 is opened (time t1) and the control cylinder 280 is opened in order, and the control cylinder 280 comes into contact with the out-of-control cylinder 290 and stops (time t2). After that, when the third drive energy is input to the drive unit 40, the out-of-control cylinder 290 is pushed down together with the control valve 270 and the control inner cylinder 280.

According to the above, since both the upper contact surface portion 291 and the upper seating surface 81 are separated from the second seat surface portion 28, the fuel in the high pressure chamber 31a does not pass through the intermediate chamber portion 263 and is in the second seat. It can flow between the surface portion 28, the upper contact surface portion 291 and the upper seating surface 81. Therefore, the fuel in the high pressure chamber 31a flows into the main control chamber portion 35a between the outer peripheral wall of the control valve 270 and the inner peripheral wall of the mechanism accommodating hole 260a, and further through the communication passage 274. In this way, the fuel can flow into the control chamber 35 from the high pressure chamber 31a, and the fuel pressure in the main control chamber 35a is restored. Therefore, the nozzle needle 50 is pushed down in the valve closing direction, and the injection hole is formed. 38 is closed (time t3).

Then, a part of the electric charge accumulated in the piezoelectric element laminate is discharged, and the operating amount of the drive transmission pin 42 is reduced to the equivalent of the second extension operation. As a result, the supply of fuel to the main control chamber unit 35a is stopped, and the outflow of fuel from the main control chamber unit 35a via the first outflow passage 33 and the second outflow passage 34 is restarted. As a result, the nozzle needle 50 starts displacement in the valve opening direction again and restarts fuel injection from the injection hole 38 (time t3). The period up to time t3 is the period of the first injection, and the period after time t4 is the period of the second injection.

During the valve closing period shown in FIG. 13, the driving force of the driving unit 40 disappears due to the stoppage of energization of the piezoelectric element laminated body. The in-control cylinder 280 starts to be displaced toward the second seat surface portion 28 as the driving force disappears (time t5 in FIG. 12). As a result, the in-control cylinder 280 returns to the initial position in which the underwear seating surface 82 is separated from the intermediate seating surface portion 293 and the upper seating surface 81 is seated on the second seating surface portion 28. Further, the control valve 270 returns the pressing portion 72 from the inflow seat surface portion 285 (time t6 in FIG. 12) and returns to the initial position where the closing portion 71 is seated on the first seat surface portion 27. As a result, the outflow of fuel from the control chamber 35 is stopped and the fuel supply to the control chamber 35 is started, so that the nozzle needle 50 is displaced in the valve closing direction and the injection hole 38 is closed. (Fig. 12, time t7).

The second embodiment described so far also has the same effect as that of the first embodiment, and one drive unit 40 controls the opening and closing of the control valve 270 and the control cylinder 280 to switch the displacement speed of the nozzle needle 50. Is possible.

In addition, in the second embodiment, even in the low speed valve opening mode, the communication between the high pressure chamber 31a and the control chamber 35 through the supply communication passage 284 is cut off. By interrupting the inflow of fuel into the control chamber 35 in this way, the consumption of leaked fuel that is not used for driving the nozzle needle 50 can be reduced. This makes it possible to suppress an increase in the load of the high-pressure fuel pump 6 (FIG. 1), suppress an increase in the fuel temperature, suppress the generation of deposits, and the like.

Further, in the control inner cylinder 280 of the second embodiment, the underwear seating surface 82 is brought into contact with the out-of-control cylinder 290 by the second extension operation of the drive unit 40 to block the inflow of fuel from the high pressure chamber 31a into the control chamber 35. Can be done. In this way, if the configuration is such that the fuel flow from the high pressure chamber 31a to the control chamber 35 can be blocked by the contact between the control inner cylinder 280 and the control outer cylinder 290, the space between the out-of-control cylinder 290 and the control inner cylinder 280 can be blocked. There is no need to use a sliding structure. According to the above, even if the out-of-control cylinder 290, the in-control cylinder 280, and the nozzle needle 50 are stacked in the radial direction, the dimensional accuracy required for each can be relaxed.

Further, in the second embodiment, at least two charge control patterns for switching the valve opening speed of the nozzle needle 50 are set, and further charging is performed during the fuel injection period. According to such control, the nozzle needle 50 is temporarily closed. Then, the nozzle needle 50 opens again due to the discharge of the additionally charged electric charge.

As described above, if the fuel can flow into the control chamber 35 by the third extension operation of the drive unit 40, the injection hole 38 can be temporarily closed. Then, when the drive unit 40 returns to the state of the second extension operation due to the discharge of the electric charge, the nozzle needle 50 is displaced in the direction of opening the injection hole 38 again. As described above, if the non-injection period can be provided, it is possible to increase the pattern of multi-stage injection.

In addition, in the configuration of the second embodiment, the size of the flow gap IS2 between the out-of-control cylinder 290 and the nozzle needle 50 tends to vary due to dimensional tolerances of individual parts, assembly tolerances, and the like. Similarly, the size of the flow gap IS3 between the out-of-control cylinder 290 and the in-control cylinder 280 is likely to vary. Therefore, the flow path areas Si2 and Si3 of the flow gaps IS2 and IS3 are made larger than the throttle area Si1 of the in orifice 284a. According to such a design, the fuel flow rate flowing into the main control chamber 35a via the intermediate chamber 263 is controlled by the in orifice 284a, so that the fuel flow rate is stable. As a result, the behavior of the nozzle needle 50 when the valve is closed is also stabilized.

In the second embodiment, the valve body 220 corresponds to the "body", the control valve 270 corresponds to the "first valve body", the controlled cylinder 280 corresponds to the "second valve body", and is out of control. Cylinder 290 corresponds to a "cylinder". Further, the inflow annular groove 285a corresponds to the "inflow groove portion", and the distribution gaps IS2 and IS3 correspond to the "gap", respectively.

(Third Embodiment)
The third embodiment shown in FIG. 14 is another modification of the first embodiment. The needle cylinder 26 (see FIG. 3) is omitted from the valve body 320 of the third embodiment. In the valve body 320, a needle support member 323 is provided between the lower valve body member 23 and the nozzle body member 24. The needle sliding surface 55 of the nozzle needle 50 is slidably supported by the inner peripheral wall 323a of the needle support member 323. In such a third embodiment, the same effect as that of the first embodiment can be obtained, and the opening and closing of the control valve 70 and the control plate 80 can be controlled by one drive unit 40 to switch the displacement speed of the nozzle needle 50. .. In the third embodiment, the valve body 320 corresponds to the "body".

(Fourth Embodiment)
The fourth embodiment shown in FIG. 15 is still another modification of the first embodiment. From the nozzle needle 50 of the fourth embodiment, the portion corresponding to the protrusion 52 (see FIG. 3) is omitted. On the other hand, the control plate 480 is provided with a cylindrical portion 485. The cylindrical portion 485 projects cylindrically from the main body portion 480a, which has a disk shape on the control plate 480, toward the needle pressure receiving portion 51 of the nozzle needle 50 along the axial direction. The cylindrical portion 485 is arranged on the inner peripheral side of the second spring 62. A communication hole 83 is formed inside the cylindrical portion 485 and the main body portion 480a. The cylindrical portion 485 reduces the volume of the main control chamber portion 35a.

In the fourth embodiment as described above, the same effect as that of the first embodiment can be obtained, and the opening and closing of the control valve 70 and the control plate 480 can be controlled by one drive unit 40 to switch the displacement speed of the nozzle needle 50. Become. In the fourth embodiment, the control plate 480 corresponds to the "second valve body".

(Fifth Embodiment)
The fifth embodiment shown in FIG. 16 is a modification of the second embodiment. In the pressure control mechanism 560 of the fifth embodiment, the control inner cylinder 580 and the out-of-control cylinder 590 have a sliding structure.

The inner cylinder 580 is provided with a collar portion 580a as in the second embodiment. The flange portion 580a is formed with a supply passage 584 and a cylinder sliding surface 585. The supply communication passage 584 communicates the high pressure chamber 31a with the control chamber 35. The supply passage 584 is provided with an in orifice 584a. The cylinder sliding surface 585 is formed by the outer peripheral wall surface of the flange portion 580a. The cylinder sliding surface 585 is fitted inside the inner peripheral wall surface 594 of the out-of-control cylinder 590. The cylinder sliding surface 585 slidably supports the control inner cylinder 580 with respect to the inner peripheral wall surface 594 while forming oiltightness with the inner peripheral wall surface 594. The out-of-control cylinder 590 is formed in a cylindrical shape. From the out-of-control cylinder 590, the configuration corresponding to the needle insertion opening 292 and the intermediate seat surface portion 293 (see FIG. 9) is omitted.

The fifth embodiment also has the same effect as that of the second embodiment, and one drive unit 40 controls the opening and closing of the control valve 270, the in-control cylinder 580, and the out-of-control cylinder 590 to displace the nozzle needle 50. The speed can be switched. In the fifth embodiment, the in-control cylinder 580 corresponds to the "second valve body", and the out-of-control cylinder 590 corresponds to the "cylinder".

(Sixth Embodiment)
The sixth embodiment shown in FIG. 17 is another modification of the second embodiment. In the pressure control mechanism 660 of the sixth embodiment, a third spring 63 is provided in addition to the first spring 61 and the second spring 62.

The third spring 63 is a coil spring formed in a cylindrical spiral shape. The spring constant of the third spring 63 is set higher than the spring constant of the needle spring 53. The third spring 63 is housed in the high pressure chamber 31a. The third spring 63 is arranged between the nozzle body member 24 and the out-of-control cylinder 290 in a state of being compressed in the axial direction. The third spring 63, together with the needle spring 53, urges the out-of-control cylinder 290 toward the second seat surface portion 28.

The sixth embodiment also has the same effect as that of the second embodiment, and one drive unit 40 controls the opening and closing of the control valve 270, the in-control cylinder 280, and the out-of-control cylinder 290 to displace the nozzle needle 50. The speed can be switched. In addition, in the sixth embodiment, most of the function of pressing the out-of-control cylinder 290 against the second seat surface portion 28 is performed by the third spring 63. Therefore, the spring constant of the needle spring 53 can be set lower than that in which the out-of-control cylinder 290 is urged only by the needle spring 53. According to the above, the timing of starting the lift of the nozzle needle 50 can be advanced.

(Other embodiments)
Although the plurality of embodiments of the present disclosure have been described above, the present disclosure is not construed as being limited to the above embodiments, and is applied to various embodiments and combinations without departing from the gist of the present disclosure. can do.

In the above embodiment, the fuel injection in the high-speed valve opening mode and the fuel injection in the low-speed valve opening mode have been described individually. However, each operation of the high-speed valve opening mode and the low-speed valve opening mode may be switched at least once or more by controlling to increase or decrease the driving energy applied to the piezoelectric element laminate during one fuel injection period. For example, switching to the high-speed valve opening mode may be performed after the injection is started in the low-speed valve opening mode. Alternatively, the reverse switching may be performed. Further, even in the fuel injection device according to the second embodiment, the non-injection period may not be provided.

In the first embodiment, the supply passage is closed in the high-speed valve opening mode. Further, in the second embodiment, the supply passage is closed in the low-speed valve opening mode. However, if the amount of leaked fuel is acceptable, the supply passages that supply fuel to the control chamber need not be closed. Further, the shapes of the configurations corresponding to the "first valve body", the "second valve body", and the "cylinder" can be changed as appropriate. In addition, the "first valve body", the "second valve body", and the "cylinder" may each have a configuration in which a plurality of parts are assembled. Further, a member for transmitting a driving force may be interposed between the "first valve body", the "second valve body", and the "cylinder".

The first outflow passage and the second outflow passage in the above embodiment were in the form of merging at least a part of the end portion on the low pressure chamber side. As described above, the first outflow path and the second outflow path may merge with each other on the downstream side (low voltage chamber) side of each orifice section as long as each orifice section having the narrowest flow path area is separate. Further, the first outflow passage and the second outflow passage may be in the form of being separated as a whole as long as a space for forming a flow path between the control chamber and the low pressure chamber can be secured.

In the above embodiment, an annular groove is provided on each seat surface portion. However, such an annular groove may not be provided. Further, a groove having a shape different from that of the annular shape may be formed on each seat surface portion. Further, the configuration corresponding to the first spring and the second spring of the above embodiment may be omitted as appropriate as long as the control valve and the control plate can be reliably moved to the initial positions.

In the above embodiment, the throttle area of the second out orifice is larger than the throttle area of the first out orifice. However, the throttle area of each out orifice may be appropriately adjusted according to the characteristics of the injection rate required for the fuel injection device. Specifically, the throttle area of the first out orifice may be larger than the throttle area of the second out orifice.

The respective operating amounts of the first extension operation, the second extension operation, and the third extension operation in the drive unit of the above embodiment may be appropriately changed as long as the magnitude relationship between them is maintained. Further, in the above embodiment, the piezoelectric element laminate is adopted as the actuator of the drive unit. However, the drive unit may have a configuration having, for example, a magnetic actuator or the like.

In the above embodiment, an example in which the pressure control mechanism and the like of the present disclosure are applied to a fuel injection device that injects light oil as fuel has been described. However, the above pressure control mechanism can also be applied to a fuel injection device that injects a fuel other than light oil, for example, a liquefied gas fuel such as dimethyl ether.

10,210 Fuel injection device, 20,220,320 Valve body (body), 28 Second seat surface (outflow seat surface), 28a Upper annular groove (outflow groove), 29 Third seat surface (inflow seat surface), 29a Lower annular groove (inflow groove), 31a high pressure chamber, 32 supply passage, 33 first outflow passage (first series passage), 33a first out orifice (first orifice), 34 second outflow passage (second passage) , 34a 2nd out orifice (2nd orifice), 35 control chamber, 36 low pressure chamber, 38 injection hole, 40 drive unit, 50 nozzle needle, 62 2nd spring (valve elastic member), 70,270 control valve (1st (One valve body), 80,480 Control plate (second valve body), 280,580 Control inner cylinder (second valve body), 284,584 Supply passage, 284a, 584a in orifice, 285 Inflow seat surface, 285a Inflow Circular groove (inflow groove), 290,590 Out-of-control cylinder (cylinder), IS2, IS3 flow gap, Si1, So1, So2 throttle area, Si2, Si3 flow path area

Claims (17)

A control chamber (35) in which a fuel injection hole (38) is formed and filled with fuel, a high-pressure chamber (31a) for supplying fuel to the control chamber, and a low-pressure chamber (36) from which fuel in the control chamber flows out. ), And a body (20, 320) having a first communication passage (33) and a second communication passage (34) communicating the control chamber and the low pressure chamber inside.
A drive unit (40) that performs a first extension operation and a second extension operation larger than the first extension operation,
A needle (50) that is pressed in the direction of closing the injection hole by the fuel pressure of the control chamber and displaced in the direction of opening the injection hole by the decompression of the control chamber.
In a state where the drive unit is contracted, the communication between the control chamber and the low pressure chamber by the first series passage is cut off, and the first extension operation of the drive unit causes the control chamber and the low pressure chamber by the first series passage. The first valve body (70 ) that allows communication between
In a state where the drive unit is contracted, the communication between the control chamber and the low pressure chamber by the second communication passage is cut off, and the driving force of the drive unit that performs the second extension operation is transmitted via the first valve body. A second valve body (80, 480) that allows communication between the control chamber and the low pressure chamber through the second communication passage is provided .
Inside the body, a supply communication passage (32) that communicates the high pressure chamber and the control chamber is further provided.
The second valve body allows communication between the high pressure chamber and the control chamber through the supply communication passage in a state where the drive unit is contracted, and the second extension operation of the drive unit allows the supply communication passage to communicate with the second valve body. fuel injection device block the communication of the high pressure chamber and the control chamber. The body is formed with an inflow seat surface portion (29) for seating the second valve body in a state where the drive portion performs the second extension operation.
The inflow to the seat surface, the fuel injection device according to claim 1, wherein the supply communication passage and connected inlet groove (29a) is formed. The inflow seat surface portion is formed in an annular shape along the outer edge shape of the second valve body.
The fuel injection device according to claim 2 , wherein the inflow groove portion extends in an annular shape along the shape of the inflow sheet surface portion. A control chamber (35) in which a fuel injection hole (38) is formed and filled with fuel, a high-pressure chamber (31a) for supplying fuel to the control chamber, and a low-pressure chamber (36) from which fuel in the control chamber flows out. ), And a body ( 220) provided inside with a first communication passage (33) and a second communication passage (34) communicating the control chamber and the low pressure chamber.
A drive unit (40) that performs a first extension operation and a second extension operation larger than the first extension operation,
A needle (50) that is pressed in the direction of closing the injection hole by the fuel pressure of the control chamber and displaced in the direction of opening the injection hole by the decompression of the control chamber.
In a state where the drive unit is contracted, the communication between the control chamber and the low pressure chamber by the first series passage is cut off, and the first extension operation of the drive unit causes the control chamber and the low pressure chamber by the first series passage. The first valve body ( 270), which allows communication between the two, and
In a state where the drive unit is contracted, the communication between the control chamber and the low pressure chamber by the second communication passage is cut off, and the driving force of the drive unit that performs the second extension operation is transmitted via the first valve body. A second valve body ( 280,580 ) that allows communication between the control chamber and the low pressure chamber through the second communication passage is provided .
The second valve body is provided with a supply communication passage (284,584) that communicates the high pressure chamber and the control chamber.
The first valve body allows communication between the high pressure chamber and the control chamber through the supply communication passage in a state where the drive unit is contracted, and the first extension operation of the drive unit allows the supply communication passage to communicate with the first valve body. fuel injection device block the communication of the high pressure chamber and the control chamber. A cylinder (290,590) for accommodating the second valve body is further provided.
The fuel injection device according to claim 4 , wherein the second valve body abuts on the cylinder by the second extension operation of the drive unit to block the inflow of fuel from the high pressure chamber to the control chamber. In the cylinder, the driving force of the driving unit that performs the third extension operation larger than the second extension operation is transmitted through the first valve body and the second valve body, so that the high pressure chamber causes the cylinder. The fuel injection device according to claim 5 , which enables the inflow of fuel into the control chamber. The fuel injection device according to claim 5 or 6 , wherein the supply passage is provided with an in orifice (284a, 584a) that limits the flow rate of fuel flowing from the high pressure chamber to the control chamber. The fuel injection device according to claim 7 , wherein the throttle area (Si1) of the in orifice is smaller than the flow path area (Si2) of the flow gap (IS2) provided between the cylinder and the needle. The restriction area of the supply communication passage (Si1) is claim 7 flow passage area (Si3) is smaller than the distribution gap generated between the state where contracting the driver second valve body and the cylinder (IS3) Or the fuel injection device according to 8. The second valve body is formed with an inflow seat surface portion (285) on which the first valve body is seated in a state where the drive unit performs the second extension operation.
The fuel injection device according to any one of claims 4 to 9 , wherein an inflow groove portion (285a) connected to the supply communication passage is formed on the inflow seat surface portion. The inflow seat surface portion is formed in an annular shape along the outer edge shape of the first valve body.
The fuel injection device according to claim 10 , wherein the inflow groove portion extends in an annular shape along the shape of the inflow sheet surface portion. The body is formed with an outflow seat surface portion (28) on which the second valve body is seated in a state where the drive portion is contracted.
The fuel injection device according to any one of claims 1 to 11 , wherein an outflow groove portion (28a) connected to the second continuous passage is formed on the outflow sheet surface portion. A control chamber (35) in which a fuel injection hole (38) is formed and filled with fuel, a high-pressure chamber (31a) for supplying fuel to the control chamber, and a low-pressure chamber (36) from which fuel in the control chamber flows out. ), And a body (20, 220, 320) having a first communication passage (33) and a second communication passage (34) communicating the control chamber and the low pressure chamber inside.
A drive unit (40) that performs a first extension operation and a second extension operation larger than the first extension operation,
A needle (50) that is pressed in the direction of closing the injection hole by the fuel pressure of the control chamber and displaced in the direction of opening the injection hole by the decompression of the control chamber.
In a state where the drive unit is contracted, the communication between the control chamber and the low pressure chamber by the first series passage is cut off, and the first extension operation of the drive unit causes the control chamber and the low pressure chamber by the first series passage. The first valve body (70,270) that allows communication between
In a state where the drive unit is contracted, the communication between the control chamber and the low pressure chamber by the second communication passage is cut off, and the driving force of the drive unit that performs the second extension operation is transmitted via the first valve body. A second valve body (80, 280, 480, 580) that allows communication between the control chamber and the low pressure chamber by the second communication passage is provided .
The body is formed with an outflow seat surface portion (28) on which the second valve body is seated in a state where the drive portion is contracted.
The outlet to the sheet surface, the outflow groove (28a) is a fuel injection system that has been formed that is connected to the second communication passage. The outflow sheet surface portion is formed in an annular shape along the outer edge shape of the second valve body.
The fuel injection device according to claim 12 or 13, wherein the outflow groove portion extends in an annular shape along the shape of the outflow sheet surface portion. The first series passage is provided with a first orifice (33a) that limits the flow rate of fuel flowing from the control chamber to the low pressure chamber.
The second passage is provided with a second orifice (34a) that limits the flow rate of fuel flowing from the control chamber to the low pressure chamber.
The fuel injection device according to any one of claims 1 to 14, wherein the throttle area (So2) of the second orifice is larger than the throttle area (So1) of the first orifice. A control chamber (35) in which a fuel injection hole (38) is formed and filled with fuel, a high-pressure chamber (31a) for supplying fuel to the control chamber, and a low-pressure chamber (36) from which fuel in the control chamber flows out. ), And a body (20, 220, 320) having a first communication passage (33) and a second communication passage (34) communicating the control chamber and the low pressure chamber inside.
A drive unit (40) that performs a first extension operation and a second extension operation larger than the first extension operation,
A needle (50) that is pressed in the direction of closing the injection hole by the fuel pressure of the control chamber and displaced in the direction of opening the injection hole by the decompression of the control chamber.
In a state where the drive unit is contracted, the communication between the control chamber and the low pressure chamber by the first series passage is cut off, and the first extension operation of the drive unit causes the control chamber and the low pressure chamber by the first series passage. The first valve body (70,270) that allows communication between
In a state where the drive unit is contracted, the communication between the control chamber and the low pressure chamber by the second communication passage is cut off, and the driving force of the drive unit that performs the second extension operation is transmitted via the first valve body. A second valve body (80, 280, 480, 580) that allows communication between the control chamber and the low pressure chamber by the second communication passage is provided .
The first series passage is provided with a first orifice (33a) that limits the flow rate of fuel flowing from the control chamber to the low pressure chamber.
The second passage is provided with a second orifice (34a) that limits the flow rate of fuel flowing from the control chamber to the low pressure chamber.
A fuel injection device in which the throttle area (So2) of the second orifice is larger than the throttle area (So1) of the first orifice. The fuel injection device according to any one of claims 1 to 16 , further comprising a valve body elastic member (62) that urges the first valve body and the second valve body toward the drive unit.

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