JP5549293B2 - Fuel injection device - Google Patents

Description

  The present invention relates to a fuel injection device that opens or closes a nozzle needle by controlling a first control valve to increase or decrease a fuel pressure in a control chamber, and particularly from a fuel supply flow path during fuel injection. The present invention relates to a fuel injection device (injector) in which a fuel inflow passage for allowing high-pressure fuel to flow into a control chamber is closed by a second control valve.

[Conventional technology]
Conventionally, as shown in FIG. 10, a nozzle needle that opens and closes a nozzle hole for injecting fuel into a combustion chamber of an internal combustion engine (engine), and a piston 101 that reciprocates in the cylinder hole in conjunction with the nozzle needle, , A housing having a cylinder 103 in which an axially extending cylinder hole is formed, a control member 105 held inside the cylinder hole, and internal fuel pressure in the nozzle needle and piston 101 in the direction of opening the nozzle hole A nozzle chamber for applying an urging force, a control chamber 106 in which the internal fuel pressure applies an urging force in the nozzle hole closing direction to the nozzle needle and the piston 101, and an urging force in the nozzle hole closing direction to the nozzle needle and the piston 101. There has been proposed a fuel injection device (an injector of the prior art 1) provided with a spring (see, for example, Patent Document 1).

  The injector of the prior art 1 includes a fuel supply path for supplying high-pressure fuel to the nozzle chamber from a high-pressure generator that pressurizes the fuel sucked from the fuel tank to increase the pressure, and the high-pressure fuel from the fuel supply path to the control chamber 106. Into the fuel tank, the fuel discharge path for returning the fuel from the control chamber 106 to the fuel tank via the low pressure fuel flow path 107, and the seat surface of the control member 105 (the upper end face in the figure). An electromagnetic control valve that closes and opens the discharge path and an intermediate valve that closes and opens the fuel introduction path by seating on and leaving the seat surface (lower end face in the drawing) of the control member 105 are provided.

The injector according to the related art 1 includes a fuel supply channel for supplying high-pressure fuel from the high-pressure generating unit to the nozzle chamber, and fuel introduction channels 111 to 113 for allowing high-pressure fuel to flow into the control chamber 106 from the fuel supply channel. And fuel outflow passages 117 and 118 for discharging fuel from the control chamber 106 to the low-pressure fuel passage 107.
The cylinder 103 has a cylinder inner wall (inner peripheral surface) that forms radial gaps 114 and 115 between the intermediate valve and the outer peripheral surface of the intermediate valve. Note that the sum of the cross-sectional areas of the radial gap 114 is set smaller than the sum of the cross-sectional areas of the radial gap 115. Further, an out-orifice (main orifice) 116 that restricts the cross-sectional area of the fuel outflow passage 117 is provided on the control chamber side of the fuel outflow passage 117. Further, an out-orifice (sub-orifice) 119 that restricts the cross-sectional area of the fuel outflow passage 118 is provided on the electromagnetic control valve side of the fuel outflow passage 118.

The electromagnetic control valve includes a valve 121 that opens and closes an outflow port (out orifice 119) that discharges (outflows) fuel from the control chamber 106 to the low-pressure fuel flow path 107, and an electromagnetic actuator that drives the valve 121. Further, the intermediate valve has a valve 131 that opens and closes an inflow port (fuel introduction channel 113) through which (introduces) high-pressure fuel from the fuel supply channel to the control chamber 106. Inside the valve 131, a fuel outflow passage 117 that connects the control chamber 106 and the fuel outflow passage 118 is formed.
In the injector of this prior art 1, when the electromagnetic control valve is opened, the fuel introduction flow path 113 is closed by pressing the intermediate valve 131 against the seat surface of the control member 105 by the urging force of the spring 132, When the control valve is closed, the valve 131 of the intermediate valve is separated (lifted) from the seat surface of the control member 105 with the fuel pressure in the fuel introduction passage 113.

Further, as shown in FIG. 11, the nozzle needle, piston 201, cylinder 203, housing 204, control member 205, nozzle chamber, control chamber 206, spring, fuel supply path, fuel introduction path, fuel discharge path, electromagnetic control valve And a fuel injection device (injector of prior art 2) provided with an intermediate valve has been proposed (see, for example, Patent Document 2).
The injector of the prior art 2 includes a fuel supply passage 210 that supplies high-pressure fuel from the high-pressure generator to the nozzle chamber, and a fuel introduction passage 211 that flows high-pressure fuel from the fuel supply passage 210 into the control chamber 206, 212 and a fuel outflow passage 217 for discharging the fuel from the control chamber 206 to the low pressure fuel passage 207.
The piston 201 has a valve guide 222 that forms a sliding clearance 215 with the inner peripheral surface of the valve 231 of the intermediate valve. The cylinder 203 has a cylinder inner wall (inner peripheral surface) that forms a radial gap 213 between the outer peripheral surface of the valve 231 of the intermediate valve.

In the injector according to the related art 2, the control chamber 206 is separated into two control chambers 214 and 216 via a sliding clearance 215. Further, an out orifice 218 that restricts the cross-sectional area of the fuel outflow passage 217 is provided on the electromagnetic control valve side of the fuel outflow passage 217.
The electromagnetic control valve includes a valve 221 that opens and closes an outflow port (out orifice 218) that discharges (outflows) fuel from the control chambers 214 and 216 to the low-pressure fuel flow path 207, and an electromagnetic actuator that drives the valve 221. Yes. The intermediate valve includes a valve 231 that opens and closes an inflow port (fuel introduction flow path 212) through which high pressure fuel flows (introduces) from the fuel supply flow path 210 to the control chambers 214 and 216, and the valve 231 is connected to the control member 205. A spring 232 that biases the sheet surface to be pressed is provided.

Further, as shown in FIG. 12, the nozzle needle 301, piston 302, cylinder 303, housing 304, control member 305, nozzle chamber, control chamber 306, spring 308, fuel supply path, fuel introduction path, fuel discharge path, control A fuel injection device (injector of prior art 3) provided with a valve and an intermediate valve has been proposed (see, for example, Patent Document 3).
The injector of the prior art 3 includes a fuel supply channel 310 that supplies high-pressure fuel from the high-pressure generator to the nozzle chamber, and a fuel introduction channel 311 that flows high-pressure fuel from the fuel supply channel 310 into the control chamber 306. , And fuel outflow passages 317 and 318 for discharging fuel from the control chamber 306 to the low pressure fuel passage 307.

The control member 305 has a block 312 in which a large diameter space is formed and a block 313 in which a small diameter space is formed. The block 312 has an inner wall (inner peripheral surface) that forms a radial gap 314 between the outer peripheral surface of the maximum outer diameter portion 332 of the valve 331 of the intermediate valve. The block 313 has an inner wall (sliding surface) that forms a sliding clearance 315 between the outer peripheral surface of the minimum outer diameter portion 333 of the valve 331 of the intermediate valve. Further, an out orifice 316 that restricts the cross-sectional area of the fuel outflow passage 317 is provided on the control chamber side of the fuel outflow passage 317.
The electromagnetic control valve includes a valve 321 that opens and closes an outflow port (fuel outflow passage 318) that discharges (outflows) fuel from the control chamber 306 to the low-pressure fuel passage 307, and a piezoelectric actuator that drives the valve 321. Yes. The intermediate valve also has a valve 331 that opens and closes an inflow port (fuel introduction flow path 311) through which high pressure fuel flows (introduces) from the fuel supply flow path 310 to the control chamber 306. The valve 331 has a maximum outer diameter portion 332 and a minimum outer diameter portion 333.

[Conventional technical problems]
However, in the injector of the prior art 1, the valve guide for slidably supporting the intermediate valve is not provided, and the intermediate valve reciprocates in the axial direction in the internal space (axial hole) of the cylinder 103. There is a possibility of leaning in between. For example, if the intermediate valve is tilted when the intermediate valve closes the fuel introduction passage 113 when the electromagnetic control valve is opened, the closing timing for closing the fuel introduction passage 113 is delayed. As a result, the flow rate of the fuel flowing out from the fuel introduction passage 113 to the low pressure fuel passage 107 via the fuel outflow passage 118 → the out orifice 119 is increased at the start of fuel injection even though the intermediate valve is installed. Problem occurs.

  Further, in the injector of the prior art 2, the control chamber 206 that applies the oil pressure in the injection hole closing direction to the fuel pressure receiving portion of the piston 201 is provided between the sliding hole wall surface of the intermediate valve and the outer peripheral surface of the valve guide 222. It is separated into two control chambers 214 and 216 with the sliding portion (sliding clearance 215) as a boundary. In this case, when the electromagnetic control valve is opened, the intermediate valve is seated on the lower end surface (seat surface) of the control member 205 and the high-pressure fuel flows from the fuel introduction passages 211 and 212 into the two control chambers 214 and 216. Is cut off, the fuel flows out from the control chamber 216 via the fuel outflow passage 217 to the out orifice 218 into the low pressure fuel passage 207, so that the fuel pressure in the control chamber 216 first decreases. Subsequently, since the fuel flows out from the control chamber 214 through the sliding clearance 215 → the control chamber 216 → the fuel outflow passage 217 → the out orifice 218 into the low pressure fuel passage 207, the fuel pressure in the control chamber 214 is subsequently lowered. . As a result, the fuel pressure in the control chambers 214 and 216 does not drop at a stroke even when the intermediate valve is closed. Therefore, the valve opening response time from the opening of the electromagnetic control valve to the opening of the nozzle needle is long. Become. Therefore, there arises a problem that the valve opening response of the nozzle needle is poor.

  Moreover, in the injector of the prior art 2, since the sliding part (sliding clearance 215) is provided between the two control chambers 214 and 216, there arises a problem that the temperature characteristic of the fuel viscosity is deteriorated. Here, the flow rate of the fuel flowing out from the control chamber 214 via the sliding clearance 215 → the control chamber 216 → the fuel outflow passage 217 → the out orifice 218 into the low pressure fuel passage 207 is the viscosity of the fuel passing through the sliding clearance 215. It has temperature characteristics due to temperature dependence. Accordingly, when the temperature of the fuel increases when passing through the sliding clearance 215, the fuel viscosity changes (lower viscosity) and the flow rate through the orifice passing through the fuel discharge path (particularly the out orifice 218) changes. The fuel outflow rate flowing out of the chamber 214 varies. Therefore, since the valve opening timing of the nozzle needle varies, there arises a problem that the control accuracy of the fuel injection amount deteriorates.

  Further, in the injector of the prior art 3, when the piezo actuator closes the valve 321, the intermediate valve 331 is moved to the lower end surface (seat surface) of the block 313 of the control member 305 by the fuel pressure in the fuel introduction passage 311. The high pressure fuel is introduced into the control chamber 306 from the fuel introduction flow path 311 after being further separated. Here, the valve 331 of the intermediate valve is slidably fitted to the hole wall surface of the block 313 of the control member 305 so that the outer periphery of the minimum outer diameter portion 333 is slidable from the control chamber 306 to the low pressure fuel flow path 307. The fuel that flows out to the inevitably passes through the out orifice 316. As a result, the valve 321 is closed and the valve 331 is opened, and then it is necessary until the high pressure fuel flowing into the control chamber 306 and the fuel pressure in the fuel outflow passage 318 become equal to each other. Pressure recovery time is very long. Therefore, there arises a problem that the valve closing response of the nozzle needle is poor.

Japanese Patent Laid-Open No. 06-108948 German Patent Application No. 102006036843 Special table 2009-528480

  An object of the present invention is to provide a fuel injection device capable of improving the valve opening responsiveness of a needle and the valve closing responsiveness of a needle by moving a valve of a second control valve without tilting with respect to a specified moving direction. Is to provide. Another object of the present invention is to provide a fuel injection device capable of improving the valve opening response of the needle by shortening the period from when the first control valve opens until the needle opens. Another object of the present invention is to provide a fuel injection device capable of improving the valve closing response of the needle by shortening the period from when the first control valve is closed until the needle is closed.

According to the first aspect of the present invention, the first control valve installed in the fuel discharge path having the fuel outflow passage for letting fuel out from the control chamber is configured to open and close the fuel outflow passage. . The second control valve installed in the fuel introduction path having a fuel introduction path for allowing high-pressure fuel to flow into the control chamber from the fuel supply path is configured to open and close the fuel introduction path.
Further, inside the valve of the second control valve, a throttle portion (for example, an out-orifice or a fixed throttle) is provided that communicates the control chamber and the intermediate flow path and restricts the cross-sectional area of the communication flow path. . In addition, the valve (the inner peripheral surface) of the second control valve is provided with a sliding surface that forms a sliding portion with the valve guide of the needle.
In addition, the outer peripheral surface of the valve of the second control valve is provided with an outer surface that faces the peripheral wall surface of the housing (a peripheral wall surface that surrounds the periphery of the valve of the second control valve in the circumferential direction) with a gap therebetween. ing.

First, when the first control valve is opened and the second control valve is closed, a path for bypassing the sliding portion and discharging the fuel from the control chamber (the path of the fuel discharge path) is formed. The valve opening response time, which is a period from when the first control valve is opened to when the needle is opened, can be shortened. Thereby, the valve opening responsiveness of a needle can be improved.
Further, the needle is provided with a valve guide for guiding the valve of the second control valve so as to be slidable in the moving direction (for example, the valve closing direction). For this reason, since the valve of the second control valve can move without tilting with respect to a predetermined movement direction (for example, a direction parallel to the axial direction of the needle), the fuel introduction flow path communicating with the fuel supply path can be quickly opened. Can be closed. Thus, the fuel flowing from the fuel supply path to the control chamber and the intermediate flow path through the fuel introduction flow path can be shut off, so that the fuel pressure in the control chamber can be rapidly lowered. Thereby, the valve opening responsiveness of a needle can be improved.

When the needle is opened, that is, when fuel injection into the combustion chamber of the internal combustion engine is started, the second control valve is closed to close the fuel introduction flow path. Thereby, even if the fuel is discharged from the control chamber through the fuel outflow passage (communication passageway, intermediate passage) by opening the first control valve and opening the fuel outflow passage, the fuel supply The fuel flowing into the control chamber or the fuel outflow channel (intermediate channel) from the path through the fuel introduction channel can be shut off. Therefore, the flow rate of the fuel flowing out from the fuel supply path and the fuel introduction path to the fuel discharge path side through the control chamber or the fuel outflow path (intermediate path) can be reduced.
In addition, when the first control valve is opened and the second control valve is closed, a path for bypassing the sliding portion and discharging the fuel from the control chamber (the path of the fuel discharge path) is formed. In addition, it is possible to suppress the problem that the temperature characteristic of the fuel viscosity deteriorates. Thereby, since the change of the fuel flow rate which passes a throttle part can be suppressed, the dispersion | variation in the fuel flow rate discharged | emitted from a control chamber can be suppressed. Therefore, since the variation in the valve opening timing of the needle can be suppressed, the control accuracy of the fuel injection amount can be improved.

On the other hand, when the first control valve is closed and the second control valve is opened, the first path (the fuel introduction path of the fuel introduction path) allows the high pressure fuel to flow from the fuel supply path to the control chamber via the fuel introduction path and the gap. First path) is formed. That is, when the second control valve is opened, a flow path (path) through which high-pressure fuel flows quickly from the fuel supply path to the control chamber through the fuel introduction path and gap is formed, so the first control valve is closed. The valve closing response time, which is a period from when the valve is turned on until the needle is closed, can be shortened. Thereby, the valve closing response of the needle can be improved.
Further, when the first control valve is closed and the second control valve is opened, the high-pressure fuel is bypassed from the throttle portion and the sliding portion, and the high pressure fuel is supplied from the fuel supply path to the intermediate flow path through the fuel introduction path. A second path to be introduced (second path of the fuel introduction path) is formed. That is, when the second control valve is opened, a flow path (path) through which high-pressure fuel flows quickly from the fuel supply path to the intermediate flow path through the fuel introduction flow path is formed, so the first control valve is closed. Then, the valve closing response time, which is a period required for the fuel pressure in the intermediate flow path to recover, can be shortened. Thereby, the valve closing response of the needle can be improved.
Further, the needle is provided with a valve guide for guiding the valve of the second control valve so as to be slidable in the moving direction (for example, the valve opening direction). For this reason, since the valve of the second control valve can move without tilting with respect to a predetermined movement direction (for example, a direction parallel to the axial direction of the needle), the fuel introduction flow path communicating with the fuel supply path can be quickly opened. It can be opened. As a result, high-pressure fuel can be introduced from the fuel supply path through the fuel introduction flow path to the control chamber and the intermediate flow path at once, so that the fuel pressure in the control chamber can be rapidly increased. Thereby, the valve closing response of the needle can be improved.

According to invention of Claim 2, the needle has a fuel pressure receiving part and an axial direction convex part. Then, the axial convex portion of the needle protrudes in the axial direction toward one end side in the axial direction from the fuel pressure receiving portion that receives the fuel pressure in the control chamber.
Further, the valve has an opposing end face that faces the fuel pressure receiving portion of the needle with a control chamber therebetween. And the axial recessed part extended in an axial direction from this opening side to a back | inner side is formed in the inside of a valve | bulb. On the back side of the axial recess, a bottom portion (closing portion) that closes the back side of the axial recess is provided.
According to the invention described in claim 3, the valve guide is provided on the outer periphery (part) of the axial convex portion of the needle. Further, the sliding surface of the valve is provided on the inner periphery (surface) of the axial recess of the valve of the second control valve. The sliding portion is a minute sliding clearance, and is formed between the outer peripheral surface of the axial convex portion of the needle and the sliding surface of the axial concave portion of the valve.

According to the fourth aspect of the present invention, the communication channel is used as a channel that connects the control chamber and the intermediate channel via the throttle portion.
According to the fifth aspect of the present invention, the communication flow path includes an axial hole extending in the axial direction (straight) of the needle from the tip surface of the axial convex portion of the needle toward the fuel pressure receiving portion, and sliding. A communication port that communicates the outer peripheral surface of the axial convex portion located on the extension line of the portion and the axial hole. This communication port has an opening that opens to face the control chamber on the outer peripheral surface of the axial convex portion of the needle. Further, the axial hole is used as a flow path that connects the communication port and the throttle portion. That is, the throttle part of the communication channel is provided inside the valve of the second control valve, and the axial hole and the communication port of the communication channel are provided inside the axial convex part of the needle.

According to the sixth aspect of the present invention, the first control valve installed in the fuel discharge passage having the fuel outflow passage for letting fuel out from the control chamber is configured to open and close the fuel outflow passage. . The second control valve installed in the fuel introduction path having a fuel introduction path for allowing high-pressure fuel to flow into the control chamber from the fuel supply path is configured to open and close the fuel introduction path.
Further, inside the valve of the second control valve, a throttle portion (for example, an out-orifice or a fixed throttle) is provided that communicates the control chamber and the intermediate flow path and restricts the cross-sectional area of the communication flow path. . In addition, the valve (the inner peripheral surface) of the second control valve is provided with a sliding surface that forms a sliding portion with the valve guide of the housing.
In addition, the outer peripheral surface of the valve of the second control valve is provided with an outer surface that faces the peripheral wall surface of the housing (a peripheral wall surface that surrounds the periphery of the valve of the second control valve in the circumferential direction) with a gap therebetween. ing.
Further, an axial groove extending in the axial direction of the valve is provided on the sliding surface of the valve of the second control valve so as to face the valve guide of the housing with an axial clearance therebetween.

First, when the first control valve is opened and the second control valve is closed, a path for bypassing the sliding portion and discharging the fuel from the control chamber through the communication flow path and the intermediate flow path (fuel Therefore, the valve opening response time, which is the period from when the first control valve is opened to when the needle is opened, can be shortened. Thereby, the valve opening responsiveness of a needle can be improved.
Further, the housing is provided with a valve guide for guiding the valve of the second control valve so as to be slidable in the moving direction (for example, the valve closing direction). For this reason, since the valve of the second control valve can move without tilting with respect to a predetermined movement direction (for example, a direction parallel to the axial direction of the needle), the fuel introduction flow path communicating with the fuel supply path can be quickly opened. Can be closed. Thus, the fuel flowing from the fuel supply path to the control chamber and the intermediate flow path through the fuel introduction flow path can be shut off, so that the fuel pressure in the control chamber can be rapidly lowered. Thereby, the valve opening responsiveness of a needle can be improved.

When the needle is opened, that is, when fuel injection into the combustion chamber of the internal combustion engine is started, the second control valve is closed to close the fuel introduction flow path. Thereby, even if the fuel is discharged from the control chamber through the fuel outflow passage (communication passageway, intermediate passage) by opening the first control valve and opening the fuel outflow passage, the fuel supply The fuel flowing into the control chamber or the fuel outflow channel (intermediate channel) from the path through the fuel introduction channel can be shut off. Therefore, the flow rate of the fuel flowing out from the fuel supply path and the fuel introduction path to the fuel discharge path side through the control chamber or the fuel outflow path (intermediate path) can be reduced.
In addition, when the first control valve is opened and the second control valve is closed, a path for bypassing the sliding portion and discharging the fuel from the control chamber (the path of the fuel discharge path) is formed. In addition, it is possible to suppress the problem that the temperature characteristic of the fuel viscosity deteriorates. Thereby, since the change of the fuel flow rate which passes a throttle part can be suppressed, the dispersion | variation in the fuel flow rate discharged | emitted from a control chamber can be suppressed. Therefore, since the variation in the valve opening timing of the needle can be suppressed, the control accuracy of the fuel injection amount can be improved.

On the other hand, when the first control valve is closed and the second control valve is opened, the first path (the fuel introduction path of the fuel introduction path) allows the high pressure fuel to flow from the fuel supply path to the control chamber via the fuel introduction path and the gap. First path) is formed. That is, when the second control valve is opened, a flow path (path) through which high-pressure fuel flows quickly from the fuel supply path to the control chamber through the fuel introduction path and gap is formed, so the first control valve is closed. The valve closing response time, which is a period from when the valve is turned on until the needle is closed, can be shortened. Thereby, the valve closing response of the needle can be improved.
In addition, when the first control valve is closed and the second control valve is opened, the throttle part and the sliding part are bypassed, the fuel supply path, the axial clearance, and the intermediate flow path from the fuel supply path A second path (a second path of the fuel introduction path) through which high-pressure fuel flows is formed. That is, when the second control valve is opened, a flow path (path) through which high-pressure fuel flows quickly from the fuel supply path to the intermediate flow path through the fuel introduction flow path is formed, so the first control valve is closed. Then, the valve closing response time, which is a period required for the fuel pressure in the intermediate flow path to recover, can be shortened. Thereby, the valve closing response of the needle can be improved.
Further, the housing is provided with a valve guide for guiding the valve of the second control valve so as to be slidable in the moving direction (for example, the valve opening direction). For this reason, since the valve of the second control valve can move without tilting with respect to a predetermined movement direction (for example, a direction parallel to the axial direction of the needle), the fuel introduction flow path communicating with the fuel supply path can be quickly opened. It can be opened. As a result, high-pressure fuel can be introduced from the fuel supply path through the fuel introduction flow path to the control chamber and the intermediate flow path at once, so that the fuel pressure in the control chamber can be rapidly increased. Thereby, the valve closing response of the needle can be improved.

According to the seventh aspect of the present invention, the housing has a first valve body in which a first receiving recess is formed and a second valve body in which a second receiving recess is formed. Further, the valve of the second control valve includes a first body part (first block valve, first cylinder part, minimum outer diameter part), and a second body part (second block valve, second cylinder part, maximum outer diameter). Part). The first body portion of the valve is housed in the first housing recess of the first valve body so as to be slidable back and forth. Further, the second body portion of the valve is accommodated in the second accommodating recess of the second valve body so as to be reciprocally movable.
According to the eighth aspect of the present invention, the valve guide is provided on the inner periphery (part) of the first accommodating recess of the first valve body. Moreover, the sliding surface of the valve is provided on the outer periphery (surface) of the first body part.
The sliding portion has a minute sliding clearance and is formed between the inner peripheral surface of the first receiving recess of the first valve body and the sliding surface of the first body portion of the valve.

According to the ninth aspect of the present invention, the communication flow path includes an axial hole extending in the axial direction of the valve of the second control valve, and a sliding surface of the first body portion provided in the valve of the second control valve. A communication port that communicates with the axial hole is provided. The communication port has an opening that opens at the sliding surface of the first body portion. Then, only when the first control valve is closed and the second control valve is opened, the fuel introduction path or the gap is used as a flow path communicating with the axial hole.
According to the tenth aspect of the present invention, the narrowing portion for reducing the cross-sectional area of the communication channel is formed on the intermediate channel side of the opening of the communication port. And the axial direction hole of a communicating flow path is used as a flow path which connects a control chamber and a throttle part.

According to the eleventh aspect of the present invention, when the first control valve is closed and the second control valve is opened, the fuel introduction path is connected to the control chamber via the fuel introduction path and the gap from the fuel supply path. When the first control valve is closed and the second control valve is opened, the throttle passage and the sliding portion are bypassed, and the fuel supply passage from the fuel supply passage, When the second control valve closes and the second control valve opens when the high-pressure fuel flows into the intermediate flow path through the axial gap, the fuel introduction flow path, the communication port when the second control valve opens And a third path through which high-pressure fuel flows into the control chamber via the axial hole.
As a result, when the first control valve is closed and the second control valve is opened, high-pressure fuel quickly flows from the fuel supply path through the fuel introduction flow path to the control chamber and the intermediate flow path. And the fuel pressure in the intermediate flow path rise rapidly. Accordingly, since the pressure recovery time from when the first control valve is closed until the fuel pressure in the control chamber and the fuel pressure in the intermediate flow path recover to the valve closing pressure of the needle or more can be shortened, the needle closing time is reduced. Valve responsiveness can be improved.

According to the invention described in claim 12, when the first control valve is opened and the second control valve is closed, the fuel discharge path bypasses the sliding portion and communicates from the control chamber. It has a path for discharging the fuel (outside the fuel injection device) through the (axial hole, throttle part) and fuel outflow channel (intermediate channel). In addition, during the period from when the first control valve is opened to when the second control valve is closed, bypassing the throttle part and the sliding part, the communication channel (axial hole, communication port) from the control chamber, You may provide the path | route which discharges fuel through an axial direction groove | channel and a fuel outflow channel (intermediate channel) (outside of a fuel injection device).
As a result, when the first control valve is opened and the second control valve is closed, a path that bypasses the sliding portion and discharges fuel from the control chamber (a path of the fuel discharge path) is formed. Therefore, it is possible to suppress a problem that the temperature characteristic of the fuel viscosity is deteriorated. Thereby, since the change of the fuel flow rate which passes a throttle part can be suppressed, the dispersion | variation in the fuel flow rate discharged | emitted from a control chamber can be suppressed. Therefore, since the variation in the valve opening timing of the needle can be suppressed, the control accuracy of the fuel injection amount can be improved.
According to the thirteenth aspect of the present invention, the flow passage cross-sectional area of the throttle portion is set smaller than the sum of the cross-sectional areas of the axial gaps.

According to the fourteenth aspect of the present invention, the throttle portion that restricts the cross-sectional area of the communication flow path is formed closer to the control chamber than the opening of the communication port. And the axial direction hole of a communicating flow path is used as a flow path which connects a narrowing part and an intermediate flow path.
According to the invention described in claim 15, when the first control valve is closed and the second control valve is opened, the fuel introduction path is connected to the control chamber through the fuel introduction path and the gap from the fuel supply path. When the first control valve is closed and the second control valve is opened, the throttle passage and the sliding portion are bypassed, and the fuel supply passage from the fuel supply passage, When the second path through which the high-pressure fuel flows into the intermediate flow path through the axial gap and the first control valve are closed and the second control valve is opened, the throttle part and the sliding part are bypassed, A third path through which high-pressure fuel flows from the fuel supply path to the intermediate flow path through the fuel introduction flow path, the communication port, and the axial hole is provided.
As a result, when the first control valve is closed and the second control valve is opened, high-pressure fuel quickly flows from the fuel supply path through the fuel introduction flow path to the control chamber and the intermediate flow path. And the fuel pressure in the intermediate flow path rise rapidly. Therefore, the pressure recovery time from when the first control valve is closed and the second control valve is opened to when the fuel pressure in the control chamber and the fuel pressure in the intermediate flow path recover to the valve closing pressure of the needle or higher. Therefore, the valve closing response of the needle can be improved.

According to the invention described in claim 16, when the first control valve is opened and the second control valve is closed, the fuel discharge path bypasses the sliding portion and communicates from the control chamber. (Throttle part, axial hole) and a path for discharging the fuel through the intermediate flow path (outside of the fuel injection device). During the period from when the first control valve is opened to when the second control valve is closed, the throttle and the sliding portion are bypassed, and a gap, a communication channel (communication port, axial hole) is formed from the control chamber. ), A path for discharging the fuel through the intermediate flow path (outside the fuel injection device) may be provided.
As a result, when the first control valve is opened and the second control valve is closed, a path that bypasses the sliding portion and discharges fuel from the control chamber (a path of the fuel discharge path) is formed. Therefore, it is possible to suppress a problem that the temperature characteristic of the fuel viscosity is deteriorated. Thereby, since the change of the fuel flow rate which passes a throttle part can be suppressed, the dispersion | variation in the fuel flow rate discharged | emitted from a control chamber can be suppressed. Therefore, since the variation in the valve opening timing of the needle can be suppressed, the control accuracy of the fuel injection amount can be improved.

According to the seventeenth aspect of the present invention, the first valve body is a cylindrical valve body that surrounds the periphery of the first body portion in the circumferential direction. The second valve body is a cylindrical cylinder that surrounds the control chamber and the second body portion in the circumferential direction. The valve guide is provided on a valve body made of a separate part from the cylinder.
Thereby, a sliding part is formed between the valve guide provided in the valve body other than the cylinder forming the control chamber therein and the sliding surface of the first body part provided in the valve. Therefore, the sliding diameter (D) can be reduced as compared with the type (prior art 3) in which the sliding part is formed between the cylinder forming the control chamber inside and the second body part provided in the valve. it can. And when sliding part length (L) is made equivalent to the prior art 3, L / D ratio becomes large compared with the prior art 3, and it becomes very advantageous with respect to slidability. Thereby, the valve opening responsiveness of a needle and the valve closing responsiveness of a needle can be improved.

Further, the sum of the cross-sectional areas of the axial gaps may be set smaller than the sum of the cross-sectional areas of the communication ports (or the axial holes).
Here, the sum of the cross-sectional areas of the axial clearances <the sum of the cross-sectional areas of the communication ports (or axial holes), and the cross-sectional area of the throttle portion <the sum of the cross-sectional areas of the axial gaps, and communication In the case where a throttle portion that restricts the flow passage cross-sectional area of the communication flow passage is formed on the intermediate flow passage side from the opening portion of the port, the second control valve is closed after the first control valve is opened. Or when the first control valve is closed and the second control valve is opened, bypassing the throttle, and passing from the fuel supply path to the fuel introduction flow path and the axial clearance to the intermediate flow path Fuel flows in.
Further, the sum of the cross-sectional areas of the axial clearances <the sum of the cross-sectional areas of the communication ports (or axial holes), and the cross-sectional area of the throttle portion <the sum of the cross-sectional areas of the axial gaps, and the communication ports In the case where a throttle part for reducing the flow passage cross-sectional area of the communication flow path is formed on the control chamber side of the opening of the first opening, the first control valve is opened until the second control valve is closed Or when the first control valve is closed and the second control valve is opened, the throttle part and the sliding part are bypassed, and the fuel supply path, communication port, axial hole are bypassed from the fuel supply path. Then, the fuel flows into the intermediate flow path.

According to the invention described in claim 18, the sum total of the cross-sectional areas of the sliding portions is set to be smaller than the flow-path cross-sectional area of the throttle portion.
According to the nineteenth aspect of the present invention, the flow path cross-sectional area of the throttle portion is set smaller than the sum of the cross-sectional areas of the gaps.
In these cases, when the first control valve is closed and the second control valve is opened, it bypasses the throttle part and the sliding part, and passes from the fuel supply path to the fuel introduction flow path (the axial clearance). ) Through which the high-pressure fuel flows into the intermediate flow path (second path of the fuel introduction path) is formed.
Further, when the first control valve is opened and the second control valve is closed, at least the sliding portion is bypassed and the fuel is discharged from the control chamber through the communication flow path and the intermediate flow path (fuel A discharge route) is formed.

According to the twentieth aspect, the valve of the second control valve constitutes a valve body that closes and opens the valve hole communicating with the fuel introduction flow path. The second control valve has valve urging means for urging the valve in the valve hole closing direction.
In addition, you may provide the through-hole penetrated in the moving direction to a valve | bulb. You may use this through-hole as an exit throttle flow path which connects a control chamber and a fuel outflow flow path. In this case, the flow rate of the fuel flowing out from the control chamber to the fuel outflow passage when the first control valve is opened can be regulated, and the opening characteristic of the second control valve can be easily set.

1 is a schematic configuration diagram illustrating a common rail fuel injection device (Example 1). FIG. It is sectional drawing which showed the injector (Example 1). It is principal part sectional drawing which showed the intermediate valve periphery part of the injector (Example 1). It is principal part sectional drawing which showed the intermediate valve periphery part of the injector (Example 1). It is principal part sectional drawing which showed the intermediate valve periphery part of the injector (Example 2). (A) is AA sectional drawing of FIG. 5, (b) is the front view which showed the valve | bulb of the intermediate valve (Example 2). It is principal part sectional drawing which showed the intermediate valve periphery part of the injector (Example 2). It is principal part sectional drawing which showed the intermediate valve periphery part of the injector (Example 2). (Example 3) which is the principal part sectional drawing which showed the intermediate valve periphery part of the injector. It is principal part sectional drawing which showed the intermediate valve periphery part of the injector of the prior art 1. FIG. It is principal part sectional drawing which showed the intermediate valve periphery part of the injector of the prior art 2. FIG. It is principal part sectional drawing which showed the intermediate valve periphery part of the injector of the prior art 3. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The present invention aims to improve the valve opening responsiveness of the needle and the valve closing responsiveness of the needle by moving the valve of the second control valve without inclining with respect to the specified moving direction. This is realized by providing a valve guide for guiding the valve in the reciprocating direction (for example, freely reciprocatingly slidable) in a needle or a housing (particularly a part (valve body) other than a cylinder in which a control chamber is formed). .
In addition, the first control valve opens, the second control valve opens for the purpose of improving the valve opening responsiveness of the needle by shortening the period from when the first control valve opens until the needle opens. This is realized by providing a path (fuel discharge path) that discharges fuel from the control chamber by bypassing the sliding part when the control valve is closed.
In addition, the first control valve closes the second control valve for the purpose of improving the valve closing response of the needle by shortening the period from when the first control valve is closed until the needle is closed. When the control valve is opened, the first path (first path of the fuel introduction path) through which high-pressure fuel flows into the control chamber through the gap from the fuel introduction path, and the first control valve are closed, and the second By providing a second path (second path of the fuel introduction path) for allowing high-pressure fuel to flow from the fuel introduction flow path to the intermediate flow path, bypassing the throttle portion and the sliding portion when the control valve is opened It was realized.

[Configuration of Example 1]
1 to 4 show a first embodiment of the present invention, FIG. 1 is a view showing a common rail type fuel injection device, FIG. 2 is a view showing an injector, and FIGS. 3 and 4 are views of the injector. It is the figure which showed the intermediate valve peripheral part.

The fuel supply device for an internal combustion engine of the present embodiment is mounted in an engine room of a vehicle such as an automobile, and is known as a fuel injection system for an internal combustion engine (engine E) such as a diesel engine having a plurality of cylinders. It is constituted by a common rail type fuel injection system (accumulation type fuel injection system).
The common rail fuel injection system includes a feed pump 2 that pumps fuel from a fuel tank 1 that is a fuel supply source, a high-pressure fuel pump 3 that sucks and pressurizes fuel discharged from the feed pump 2, and the high-pressure fuel pump 3. A common rail 4 into which high-pressure fuel discharged from the common rail 4 is introduced, and a plurality (four in this example) of fuel injectors (hereinafter referred to as injectors 5) to which high-pressure fuel is distributed and supplied from each fuel outlet of the common rail 4; The high-pressure fuel accumulated in the common rail 4 is injected and supplied into the combustion chamber of each cylinder of the engine E via each injector 5.

The feed pump 2 is a low-pressure fuel pump that pressurizes and discharges fuel drawn from the fuel tank 1, and is an in-tank electric fuel pump installed in the fuel tank 1.
The high-pressure fuel pump 3 includes a pump drive shaft (camshaft) driven by a crankshaft of the engine E, a pump housing that rotatably supports the camshaft, a plurality of plungers that pressurize and pump fuel, and each plunger And a plurality of cylinders that are inserted and supported so as to be reciprocally slidable. The plunger reciprocates in the plunger sliding hole of the cylinder, so that the fuel sucked into the fuel pressurizing chamber from the feed pump 2 through the electromagnetic valve can be obtained. This is a supply pump that pressurizes and pressurizes.

The solenoid valve of the high-pressure fuel pump 3 controls the amount of fuel discharged from the discharge port (discharge port) of the high-pressure fuel pump 3 by adjusting the amount of fuel drawn from the feed pump 2 into the fuel pressurizing chamber. This is a fuel metering valve.
The common rail 4 is a pressure accumulation container that accumulates high-pressure fuel corresponding to the fuel injection pressure. A pressure limiter (pressure regulator) 6 and a fuel pressure sensor (common rail pressure sensor) 7 are attached to the common rail 4. The high-pressure fuel pump 3 or the common rail 4 constitutes a high-pressure generator that generates high-pressure fuel.

  The plurality of injectors 5 are mounted on the cylinder head of the engine E corresponding to each cylinder. The injector 5 for each cylinder includes a nozzle needle 9 that opens and closes a nozzle hole 8 that injects fuel, a spring 10 that urges the nozzle needle 9 in the nozzle hole closing direction, and a high-pressure fuel from the common rail 4 to the nozzle chamber 11. A fuel supply path for supplying high pressure fuel from the fuel supply path to the control chamber 12, a fuel discharge path for discharging fuel from the control chamber 12 to the outside of the injector (for example, the fuel tank 1), An electromagnetic control valve (first control valve) for opening and closing the fuel discharge path and an intermediate valve (second control valve) for opening and closing the fuel introduction path are provided.

The electromagnetic control valve is seated on and removed from the first seat surface of the valve seat to separate and leave the fuel discharge passage (fuel outflow passage) to open and close the first valve body . It has one valve (ball valve: hereinafter referred to as valve 13).
The intermediate valve is a cylindrical second valve that forms a second valve body that is seated and separated (separated) from the second seat surface of the valve seat to close and open the fuel introduction path (fuel introduction flow path). A block valve having a reverse concave shape in section: hereinafter referred to as a valve 14). A sliding surface is formed on the inner peripheral surface of the valve 14 of the intermediate valve so as to form a sliding portion with the valve guide. The sliding portion is a minute clearance formed between the outer peripheral surface of the valve guide (the outer peripheral portion of the axial convex portion (shaft) 16 of the nozzle needle 9) and the sliding surface of the valve 14 of the intermediate valve. (Hereinafter referred to as sliding clearance 17).

Here, the amount of current supplied to the electromagnetic valve of the high-pressure fuel pump 3 and the amount of current supplied to each electromagnetic control valve of the plurality of injectors 5 are an engine control unit configured to include a pump drive circuit and an injector drive circuit. It is configured to be controlled by (engine control device: hereinafter referred to as ECU).
The ECU includes a CPU that performs control processing and arithmetic processing, a storage device (memory such as ROM and RAM) that stores various programs and control data, an input circuit (input unit), an output circuit (output unit), and the like. A known microcomputer is built in. Here, a pump drive circuit is connected between the output part of the microcomputer and the solenoid valve of the high-pressure fuel pump 3. An injector drive circuit (EDU) is connected between the output unit of the microcomputer and each electromagnetic control valve of the plurality of injectors 5.

The sensor output signals from the common rail pressure sensor 7 attached to the common rail 4 and the sensor output signals from various sensors are A / D converted by the A / D conversion circuit and then input to the microcomputer. It is configured. Here, not only the common rail pressure sensor 7 but also a crank angle sensor, an accelerator opening sensor, a coolant temperature sensor, a fuel temperature sensor, an intake air temperature sensor, and the like are connected to the input portion of the microcomputer.
The microcomputer also has a function as a rotational speed detecting means for detecting the engine rotational speed (NE) by measuring the interval time of the NE signal pulse that is a sensor output signal output from the crank angle sensor. .

In addition, when an ignition switch (not shown) is turned on (IG / ON), the ECU determines the optimum based on the sensor output signals from the common rail pressure sensor 7 and the various sensors described above and the control program stored in the memory. The fuel injection characteristic is calculated, and the amount of current supplied to the solenoid valve of the high-pressure fuel pump 3 (so-called pump drive current), the amount of current supplied to each electromagnetic control valve of the plurality of injectors 5 (so-called injector drive current), etc. It is configured to be electronically controlled.
The optimum fuel injection characteristics are the fuel injection pressure (command injection pressure) into the combustion chamber for each cylinder of the engine E, the fuel injection start timing (command injection timing) of each injector 5, and the valve opening of each injector 5. It is an optimum value such as a period (a command injection period obtained from the fuel injection amount and the command injection pressure).

  The injector 5 mounted corresponding to each cylinder of the engine E includes a housing that slidably supports the nozzle needle 9 and surrounds the periphery of the nozzle chamber 11, the control chamber 12, and the intermediate valve in the circumferential direction. ing. The housing includes an injector body 18 that houses an electromagnetic control valve therein, a valve body 19 that is held by the injector body 18, and a block (orifice) that has a contact surface that is coupled to the coupling end surfaces of the injector body 18 and the valve body 19. Plate) 20, nozzle body 21 having a coupling end surface (contact surface) coupled to the coupling end surface (contact surface) of block 20, and coupling end surface (contact surface) coupled to the coupling end surface (contact surface) of block 20. And a cylinder 22 that slidably supports the nozzle needle 9.

The common rail fuel injection system includes a fuel supply pipe extending from the fuel tank 1, particularly the feed pump 2 to a plurality of injectors 5. The fuel supply pipe includes a low-pressure fuel pipe extending from the feed pump 2 to the intake port of the high-pressure fuel pump 3 and a high-pressure fuel pipe extending from the high-pressure fuel pump 3 through the common rail 4 to the inlet ports 23 of the plurality of injectors 5. ing.
The low-pressure fuel pipe has a supply pipe for supplying low-pressure fuel from the discharge port of the feed pump 2 to the suction port of the high-pressure fuel pump 3. A fuel filter may be installed between the discharge port of the feed pump 2 and the suction port of the high-pressure fuel pump 3.
The high-pressure fuel piping supplies the high-pressure fuel from the discharge port of the high-pressure fuel pump 3 to the inlet port of the common rail 4 and supplies the high-pressure fuel from the outlet ports of the common rail 4 to the inlet ports 23 of the plurality of injectors 5. Supply pipes (fuel distribution pipes, branch pipes) and the like.

The common rail fuel injection system includes a fuel return pipe (fuel return path) extending from the fuel supply device (the high pressure fuel pump 3, the common rail 4 and the plurality of injectors 5) to the fuel tank 1.
The fuel return pipe is an overflow pipe (overflow pipe) that returns the fuel (including leaked fuel) overflowed from the fuel supply device (high pressure fuel pump 3, common rail 4 and plural injectors 5) and surplus fuel to the fuel tank 1. is there.
The overflow pipe is connected to a flow path pipe connecting the leak port of the common rail 4 (overflow port of the pressure regulator 6) and the fuel tank 1, the outlet port (leak port, overflow port) of the plurality of injectors 5, and the junction (flow). And a flow path pipe connecting the leak port (overflow port) of the high-pressure fuel pump 3 and the merge section (merging section with the flow path pipe).

  The injector 5 is a direct injection type fuel injection valve (fuel injection valve of an internal combustion engine) that injects high-pressure fuel accumulated in the common rail 4 directly into the combustion chamber in the form of a mist. The injector 5 includes a nozzle needle 9 that opens and closes a nozzle hole 8 that injects fuel into the combustion chamber of each cylinder of the engine E, and a biasing force (valve closing force: F3) in the nozzle hole closing direction. A spring (valve closing force applying means) 10 for applying pressure, a nozzle chamber 11 for applying an oil pressure in the nozzle hole opening direction (valve opening force: F1) to the nozzle needle 9, and an internal fuel pressure for the nozzle. A control chamber 12 that applies oil pressure (valve closing force: F2) in the nozzle hole closing direction to the needle 9, a fuel supply path that supplies high-pressure fuel from the common rail 4 to the nozzle chamber 11 via the inlet port 23, and this fuel supply A fuel introduction path through which high-pressure fuel flows from the path into the control chamber 12 and a fuel discharge path through which fuel is discharged from the control chamber 12 to the outside of the injector (for example, the fuel tank 1) are provided.

The fuel supply path includes fuel supply passages 24 to 28 that connect the inlet port 23 opened at one end surface (the upper end surface in the drawing) of the injector body 18 of the injector 5 with the nozzle chamber 11.
The fuel introduction path has first to third fuel introduction paths that communicate between the fuel supply paths 24 and 25 and the control chamber 12 when the intermediate valve is opened.
The first fuel introduction flow path (hereinafter referred to as the fuel introduction flow path) is a fuel flow path 31 that communicates with the fuel supply flow paths 24 and 25, and an inlet that forms a second valve hole that narrows the cross-sectional area of the fuel introduction flow path. An orifice 32 and an annular groove 33 communicating with the in-orifice 32 and opening on the second sheet surface of the block 20 are provided.
The second fuel introduction channel (hereinafter referred to as fuel introduction channel) is a clearance 34 that is a minute gap formed between the seat portion (seat surface) of the valve 14 of the intermediate valve and the second seat surface of the block 20. And communicates with the fuel introduction passage (the fuel passage 31, the in-orifice 32, and the annular concave groove 33) when the intermediate valve is opened.
The third fuel introduction flow path (hereinafter referred to as fuel introduction flow path) has a radial gap (hereinafter referred to as gap 35) and a plurality of streak-like concave grooves (hereinafter referred to as fuel flow path 36). When the valve is opened, the fuel introduction flow path (the fuel flow path 31, the in-orifice 32, the annular concave groove 33) and the control chamber 12 are communicated with each other through the clearance 34.

The fuel discharge path has a fuel outflow passage that connects the control chamber 12 and the fuel discharge passage when the electromagnetic control valve is opened. The fuel outflow channel has a communication channel that communicates with the control chamber 12 and an intermediate channel that communicates with the communication channel.
The communication channel includes a communication port 39 that communicates with the control chamber 12, an axial hole 40 that communicates with the communication port 39, a fuel channel 41 that communicates with the axial hole 40, and a fuel channel 41 that communicates with the fuel channel 41. It has a main out orifice (hereinafter referred to as an out orifice 42) that forms a constricted portion that restricts the cross sectional area of the flow channel.
The intermediate channel communicates with the clearance 34 or the out-orifice 42, and has an annular groove 43 opened on the second seat surface of the block 20, a fuel channel 48 that communicates with the annular groove 43, and communicates with the fuel channel 48. In addition, a sub-out orifice (hereinafter referred to as “out-orifice 49”) for reducing the cross-sectional area of the intermediate flow path is provided.
The fuel discharge flow path has fuel flow paths 51 and 52, and communicates the intermediate flow path (fuel flow path 48) and the outlet port of the injector 5. The fuel discharge channel is a low-pressure fuel channel that connects the fuel outflow channel and a fuel supply source (fuel tank 1) that stores fuel.
Details of the fuel supply path, the fuel introduction path, and the fuel discharge path will be described later.

The nozzle needle 9 is seated on and removed from the seat surface of the nozzle body 21 to close and open the plurality of nozzle holes 8.
Further, a conical surface is provided at the tip end portion (the lower end portion in the drawing) of the nozzle needle 9 in the axial direction. An annular edge formed between the conical surface and the circular surface (curved surface) of the nozzle needle 9 functions as a seat portion that liquid-tightly contacts (sits) the seat surface of the nozzle body 21. To do.
Further, an annular step for locking the annular spring seat 53 and an intermediate portion slidably supported in a nozzle hole extending in the axial direction of the nozzle body 21 are provided in the central portion of the nozzle needle 9 in the axial direction. Is provided. In this intermediate portion, four cutting surfaces with the outer periphery being plane-cut are formed, and a gap formed between this cutting surface and the hole wall surface of the nozzle hole is used as a fuel flow path (fuel supply flow path). The arc surface left on the outer periphery is used as the sliding surface. In addition, a needle head 54 that is slidably supported in a cylinder hole extending in the axial direction of the cylinder 22 is provided at the rear end (the upper end in the figure) of the nozzle needle 9 in the axial direction.

Here, a first fuel pressure receiving portion (first pressure receiving surface) that receives the fuel pressure in the control chamber 12 is provided on the control chamber side of the needle head 54 of the nozzle needle 9. Further, a second fuel pressure receiving portion (second pressure receiving surface) that receives the fuel pressure in the nozzle chamber 11 is provided on the nozzle hole side (the nozzle hole side of the cutting surface) of the intermediate portion of the nozzle needle 9.
And the nozzle needle 9 has the axial direction convex part 16 extended straightly in the axial direction. This axial convex portion 16 is the tip end side in the axial direction from the center of the control chamber side end surface (first pressure receiving surface) of the needle head 54 of the nozzle needle 9 (in the orifice 32 side, intermediate valve side, upper side in the figure). Projecting straight toward Moreover, the axial direction convex part 16 is supporting the valve | bulb 14 of the intermediate valve so that reciprocation is possible. That is, the outer peripheral portion of the axial convex portion 16 constitutes a valve guide that guides (supports) the valve 14 of the intermediate valve so as to be able to reciprocate.

Here, a sliding portion (sliding clearance 17) is formed between the outer peripheral portion (valve guide) of the axial convex portion 16 of the nozzle needle 9 and the inner peripheral surface (sliding surface) of the valve 14 of the intermediate valve. doing. Further, a communication port 39 and an axial hole 40 are provided in the axial convex portion 16 of the nozzle needle 9. The communication port 39 is open on the extended line of the sliding portion and on the outer peripheral surface facing the control chamber 12 (the outer peripheral surface of the axial convex portion 16). The axial hole 40 is formed inside the axial convex portion 16.
The details of the axial convex portion 16 of the nozzle needle 9 will be described later.

The spring 10 constitutes a needle urging means that urges the seat portion of the nozzle needle 9 in the direction in which the nozzle portion is pressed against the seat surface of the nozzle body 21 (injection hole closing direction). The spring 10 is installed between a spring seat portion of the cylinder 22 (the lower end surface shown in the drawing of the cylinder 22) and a spring seat portion of the spring seat 53 (the upper end surface shown in the drawing of the spring seat 53). The nozzle chamber 11 is a clearance formed between the outer periphery of the small-diameter portion closer to the nozzle hole than the intermediate portion of the nozzle needle 9 and the nozzle hole wall surface of the nozzle body 21.
The control chamber 12 is surrounded by the first fuel pressure receiving portion of the nozzle needle 9, the intermediate valve, and the hole wall surface of the cylinder hole of the cylinder 22, and so as to surround the periphery of the axial convex portion 16 of the nozzle needle 9 in the circumferential direction. Is a cylindrical space.

  The injector body 18 is used as a holder that holds the electromagnetic control valve on the side connected to the block 20 (the lower end in the figure). The injector body 18 is fastened and fixed to the upper end of the nozzle body 21 by a retaining nut 55 in a state where the block 20 is sandwiched between the injector body 18 and the nozzle body 21. In addition, a coupling end surface (contact surface) that is liquid-tightly coupled to the coupling end surface (contact surface) of the block 20 is provided on the tip end surface (lower end surface in the drawing) of the injector body 18. The injector body 18 has an inlet port 23 connected to each outlet port of the common rail 4 through a supply pipe of a high-pressure fuel pipe, and an outlet connected to the fuel tank 1 through a flow pipe of a fuel return pipe. A port is formed.

Here, the block 20 constitutes a first valve seat that the valve 13 seats when the valve 13 of the electromagnetic control valve is fully closed. The first seat surface of the block 20 is arranged to face the valve 13 with a minute gap (clearance) when the valve 13 of the electromagnetic control valve is fully opened.
The block 20 constitutes a second valve seat on which the valve 14 is seated when the intermediate valve 14 is fully closed. The second seat surface of the block 20 is disposed to face the seal portion (seal surface) of the valve 14 with a minute gap (clearance 34) when the valve 14 of the intermediate valve is fully opened.

On both sides of the block 20 in the axial direction (plate thickness direction), a coupling end surface (contact surface) closely contacting the coupling end surface of the injector body 18, and a coupling end surface (contacting surface) closely contacting the coupling end surface of the nozzle body 21 and the coupling end surface of the cylinder 22 ( A close contact surface).
A flat first sheet surface that is flattened by surface grinding or the like is formed at a portion that is decentered from the central portion of the coupling end surface of the block 20. An annular groove is formed around the first sheet surface.
Further, a flat second sheet surface that is planarized by surface grinding or the like is formed at the center of the coupling end surface of the block 20. An annular groove is formed around the second sheet surface.
A fuel supply channel 26 and fuel channels 31 and 48 are formed inside the block 20. The fuel supply flow path 26 and the fuel flow paths 31 and 48 are inclined with respect to the axial direction of the nozzle needle 9 and extend straight.

On the tip end side (the lower side in the figure) of the nozzle body 21 is provided with an inverted conical seat surface (valve seat) that forms a conical space therein. The seat surface is provided with a plurality of injection holes 8 for injecting high-pressure fuel into the combustion chamber of each cylinder of the engine E. Further, a coupling end surface (contact surface) that is liquid-tightly coupled to the coupling end surface of the block 20 is provided on the rear end surface (the upper end surface in the drawing) of the nozzle body 21 in the axial direction.
A nozzle hole that extends straight from the coupling end surface to the nozzle hole side is formed in the nozzle body 21, that is, on the central axis of the nozzle body 21. A nozzle chamber 11 is provided on the lower side of the nozzle hole in the figure. Further, the upper end side of the nozzle hole in the drawing is opened at the coupling end surface of the nozzle body 21.

A coupling end surface that is liquid-tightly coupled to the coupling end surface of the block 20 is provided on the illustrated upper end surface in the axial direction of the cylinder 22. The cylinder 22 is accommodated in the nozzle hole of the nozzle body 21 so as to be movable (or slidable) with respect to the nozzle body 21. The cylinder 22 is pressed against the coupling end surface of the block 20 by the biasing force of the spring 10. The cylinder 22 has a cylinder inner wall that surrounds the control chamber 12 and the intermediate valve in the circumferential direction.
A cylinder hole extending in the axial direction of the cylinder 22 is formed inside the cylinder 22. The lower side of the cylinder hole in the axial direction is used as a needle sliding hole 56 through which the needle head 54 of the nozzle needle 9 slides. In addition, the upper side of the cylinder hole in the axial direction in the figure (the end surface on the side of the block 20) is used as a valve housing hole (valve housing recess) 57 that houses the valve 14 of the intermediate valve so as to be able to reciprocate. The hole wall surface of the valve housing recess 57 is a circumferential wall surface that surrounds the periphery of the valve 14 of the intermediate valve in the circumferential direction.

Here, the hole diameter (opening cross-sectional area) of the valve housing recess 57 is set larger than the hole diameter (opening cross-sectional area) of the needle sliding hole 56. Thus, an annular step surface (hereinafter referred to as a needle stopper 58) is formed between the needle sliding hole 56 and the valve housing recess 57.
The cylinder 22 constitutes a second valve seat that is seated by the second seal portion (annular opposed end surface) of the valve 14 when the valve 14 of the intermediate valve is fully opened. The needle stopper 58 of the cylinder 22 is a restricting portion that restricts the movement range (particularly the valve fully open position) of the valve 14 of the intermediate valve.

The electromagnetic control valve is installed in the fuel discharge path and constitutes a first control valve that controls opening and closing of the fuel discharge path. This electromagnetic control valve controls switching between a communication state and a shut-off state between the control chamber 12 on the high pressure side and the fuel flow path 48 on the intermediate pressure side and the fuel flow paths 51 and 52 on the low pressure side.
The electromagnetic control valve includes a valve 13 that opens and closes a fuel flow path 48 that discharges (outflows) fuel from the control chamber 12, and an electromagnetic actuator that drives the valve 13.
The electromagnetic actuator includes an injector body 18, a valve body 19 in which fuel flow paths 51 and 52 are formed, a block 20 having a first seat surface at the center of a coupling end surface coupled to the valve body 19, and a valve The armature 60 that drives the block 13 to the side of the block 20 that separates from the first seat surface (the valve opening direction), an electromagnet (solenoid) that generates electromagnetic force that pulls the armature 60, and the valve 13 A spring (valve urging means, first spring) 61 that urges to the side pressed against one seat surface (valve hole closing direction) is provided.

The valve 13 is a hemispherical ball that opens and closes the fuel flow path 48, particularly the out orifice 49 used as the first valve hole, and a contact portion that contacts the bottom surface of the housing recess of the armature 60, and the block 20. A first seat portion that contacts (sits) the valve seat surface.
The electromagnetic control valve closes the fuel flow path 48 when the valve 13 is seated on the first seat surface of the block 20. As a result, the communication state between the control chamber 12 on the high pressure side and the fuel passage 48 on the intermediate pressure side and the fuel passages 51 and 52 on the low pressure side is blocked.
Further, the electromagnetic control valve opens the fuel flow path 48 when the valve 13 is separated (separated) from the first seat surface of the block 20. As a result, the control chamber 12 on the high pressure side, the fuel passage 48 on the intermediate pressure side, and the fuel passages 51 and 52 on the low pressure side communicate with each other.
As a result, the fuel flows out from the control chamber 12 to the fuel passages 51 and 52 through the communication passage, the fuel passage 48 and the out orifice 49.

Inside the injector body 18 and the valve body 19, fuel flow paths 51 and 52 communicating with the control chamber 12 are formed via a fuel outflow path (communication flow path, intermediate flow path). The fuel flow paths 51 and 52 have valve accommodating chambers for accommodating the valve 13 and the armature 60 so as to be reciprocally movable. A sliding hole in which the armature 60 slides is formed in the valve housing chamber.
The armature 60 has a sliding portion that is slidably supported in the sliding hole of the valve body 19. A housing recess for housing the valve 13 is provided on the distal end side of the axial portion of the armature 60.
The spring 61 is valve closing force applying means for applying an urging force (valve closing force) in the valve hole closing direction to the valve 13.
The solenoid is obtained by winding a coil 63 around an annular space portion of a double cylindrical stator 62, and a supply current amount is supplied from an injector drive circuit of the ECU via a coil lead wire and a terminal connected to the coil 63. Is done.

The intermediate valve is installed in the fuel introduction path and constitutes a second control valve that controls opening and closing of the fuel introduction path. This intermediate valve includes a cylinder 22 used as a valve body having a valve housing recess 57 formed therein, and a valve hole for introducing high-pressure fuel from the fuel supply passages 24 and 25 to the control chamber 12 via the fuel passage 31. And a block valve (second valve: hereinafter referred to as a valve) 14 having a concave cross section that opens and closes the (in-orifice 32).
An annular second seal portion (seal surface) that is seated on the second seat surface of the block 20 when the intermediate valve is closed is provided at one end (upper end in the figure) of the valve 14 of the intermediate valve. .
Here, a coil spring (spool urging means, second spring: hereinafter referred to as a spring 15) that urges the valve 14 toward the side pressing the second seat surface of the block 20 (the valve hole closing direction) may be provided. good.

A control chamber 12 is separated from the other end (lower end in the drawing) of the valve 14 of the intermediate valve with the first fuel pressure receiving portion (first pressure receiving surface) on the upper end side in the axial direction of the nozzle needle 9. Opposing end faces (portions surrounded by the second seal portion) 64 are provided. In the valve 14 of the intermediate valve, there is provided an axial recess 65 that opens at the opposing end face 64 and extends in the axial direction from the opening side to the back side.
The axial recess 65 is a round hole shaped axial hole extending along the axial direction of the nozzle needle 9. Further, on the back side of the axial recess 65, a bottom portion (closing portion) for closing the back side of the axial hole is provided. A bottom surface is formed at the bottom of the axial recess 65 so as to be opposed to the tip surface of the axial protrusion 16 of the nozzle needle 9 with a space (fuel passage 41) therebetween.

Further, a through-hole penetrating in the reciprocating movement direction (plate thickness direction) of the valve 14 is formed in the bottom portion (blocking portion) of the axial recess 65 so as to communicate the illustrated upper end surface and the illustrated lower end surface of the blocking portion. Has been. This through hole is used as the out orifice 42. That is, an out orifice 42 that communicates the control chamber 12 and the fuel flow path 48 is formed inside the valve 14.
A sliding surface (sliding surface of the valve 14) is provided on the inner peripheral surface of the axial recess 65 so as to be supported on the outer periphery of the axial protrusion 16 of the nozzle needle 9 so as to be able to reciprocate. That is, the axial recess 65 is fitted to the outer peripheral portion (valve guide) of the axial protrusion 16 of the nozzle needle 9 so as to be freely slidable.
Further, on the outer periphery of the valve 14, there is provided a facing portion (outer surface) that faces the hole wall surface (circumferential wall surface) of the valve housing recess 57 of the cylinder 22 with a gap 35 therebetween.
Note that, for example, a plurality of streak-shaped notched grooves (fuel flow paths 36) extending radially are formed at the lower edge of the valve 14 in the figure. The fuel flow path 36 forms a communication portion that communicates the gap 35 and the control chamber 12 with the second seat surface of the cylinder 22.

Here, when the intermediate valve is opened, that is, the second seal portion of the valve 14 is separated (separated) from the second seat surface of the block 20, and the illustrated lower end surface (locked portion) of the valve 14 is the cylinder 22. The fuel flow path 31 and the control chamber 12 communicate with each other when abutting against the needle stopper (locking portion) 58. As a result, high-pressure fuel is introduced from the fuel flow path 31 into the control chamber 12 through the clearance 34 and the gap 35.
Further, when the intermediate valve is closed, that is, the second seal portion of the valve 14 is separated (separated) from the needle stopper 58, and the second seal portion of the valve 14 abuts (seats) the second seat surface of the block 20. Then, the communication state between the fuel flow path 31 and the control chamber 12 is interrupted. This eliminates the introduction of high-pressure fuel from the fuel flow path 31 to the control chamber 12.

Next, details of the axial convex portion 16 of the nozzle needle 9 of this embodiment will be described with reference to FIGS.
As described above, the axial projection 16 is provided on the nozzle needle 9. And the axial direction convex part 16 of the nozzle needle 9 has an outer peripheral surface which forms a sliding part between the valves 14 of an intermediate valve. This outer peripheral surface is a sliding surface that guides the valve 14 of the intermediate valve slidably in the reciprocating direction (valve moving direction).
Here, between the sliding surface of the axial convex portion 16 of the nozzle needle 9 and the sliding surface of the axial concave portion 65 of the valve 14, the axial concave portion 65 of the valve 14 is protruded in the axial direction of the nozzle needle 9. A minute gap (sliding clearance 17) necessary for sliding on the outer periphery of the portion 16 is provided.

The axial convex portion 16 of the nozzle needle 9 is a bottomed cylinder that projects along the axial direction of the nozzle needle 9 from the first fuel pressure receiving portion (first pressure receiving surface) of the nozzle needle 9 toward the out orifice 42 side. Shaped protrusion. The axial convex portion 16 communicates with the control chamber 12, extends in the radial direction perpendicular to the axial direction of the nozzle needle 9 (communication port 39), and the distal end surface of the axial convex portion 16. A bag hole-shaped axial recess (axial hole 40) extending in the axial direction of the nozzle needle 9 from the first to the first fuel pressure receiving side is provided.
The communication port 39 is used as a flow path that connects the outer peripheral surface of the axial convex portion 16 located on the extension line of the sliding portion and the axial hole 40. In addition, the communication port 39 has an opening that opens to face the control chamber 12 on the outer peripheral surface of the axial protrusion 16 of the nozzle needle 9.
The axial hole 40 is used as a flow path that connects the communication port 39 and the out orifice 42 via a space (fuel flow path 41) formed inside the valve 14 of the intermediate valve. The axial hole 40 has a bottom surface provided in the vicinity of the first fuel pressure receiving portion of the nozzle needle 9 and an opening portion that opens to face the fuel flow path 41 at the tip surface of the axial convex portion 16 of the nozzle needle 9. doing.

Next, details of the fuel supply path of this embodiment will be described with reference to FIGS.
The fuel supply path has supply piping for supplying high pressure fuel from the common rail 4 to the inlet port 23 of the injector 5, and fuel supply passages 24 to 28 for supplying high pressure fuel from the inlet port 23 to the nozzle chamber 11.
The fuel supply channels 24 to 26 are formed inside the injector body 18 and inside the block 20. The fuel supply channels 24 to 26 are fuel channel holes that communicate the inlet port 23 opened at the upper end surface of each injector body 18 in the figure with the inside of the nozzle hole (cylinder housing chamber) of the nozzle body 21.
The fuel supply channels 27 and 28 are formed inside the nozzle holes of the nozzle body 21. The fuel supply channels 27 and 28 are fuel channel holes that connect the fuel supply channels 24 to 26 and the nozzle chamber 11.

Next, details of the fuel introduction path of this embodiment will be described with reference to FIGS.
The fuel introduction path is such that when the electromagnetic control valve is closed and the intermediate valve is opened, the fuel supply passages 24 and 25 to the fuel passage 31, the in-orifice 32, the annular groove 33, the clearance 34, the gap 35, and the When the first path through which the high-pressure fuel flows into the control chamber 12 via the fuel flow path 36 and the electromagnetic control valve are closed and the intermediate valve is opened, the sliding clearance 17 and the out orifice 42 are bypassed, A second path through which high-pressure fuel flows from the fuel supply channels 24 and 25 to the fuel channel 48 via the fuel channel 31, the in-orifice 32, the annular groove 33, the clearance 34 and the annular groove 43 is provided.

The fuel flow path 31 is formed inside the block 20. The fuel flow path 31 is a fuel flow path hole communicating with the fuel supply flow paths 24 and 25.
The in-orifice 32 is provided inside the block 20, particularly on the downstream side of the fuel introduction channel in the fuel flow direction. The in-orifice 32 communicates the fuel supply passages 24 and 25 with the control chamber 12 and is an inlet orifice (inflow side restrictor, fuel passage hole, small-diameter hole) that restricts the cross-sectional area of the fuel passage 31. It is. The in-orifice 32 may be opened on the second sheet surface of the block 20.
The annular groove 33 is an annular ring groove channel that opens on the second sheet surface of the block 20 and communicates with the in-orifice 32. The gap 35 is a radial gap formed between the outer peripheral surface of the valve 14 of the intermediate valve and the hole wall surface (peripheral wall surface) of the valve accommodating recess 57 of the cylinder 22.

Next, details of the fuel discharge path of this embodiment will be described with reference to FIGS.
When the electromagnetic control valve is opened and the intermediate valve is closed, the fuel discharge path bypasses the sliding clearance 17 and communicates from the control chamber 12 to the communication port 39, the axial hole 40, the fuel flow path 41, and the out. There is a path through which fuel is discharged to the outside of the injector (for example, the fuel tank 1) via the orifice 42, the annular groove 43, the fuel flow path 48, the out orifice 49, and the fuel flow paths 51 and 52. The communication channel is formed inside the axial convex portion 16 of the nozzle needle 9 and the valve 14 of the intermediate valve. The communication channel communicates the control chamber 12 and the fuel channel 48. The communication channel causes the fuel to flow out from the control chamber 12 to the fuel channel 48 through the communication port 39, the axial hole 40, the fuel channel 41, the out orifice 42, and the annular groove 43.

The out orifice 42 is formed inside the valve 14 of the intermediate valve. The out orifice 42 communicates between the control chamber 12 and the fuel flow path 48, and also has a main outlet orifice (throttle part, control chamber side outlet restriction, fuel flow path hole, small diameter) that restricts the cross-sectional area of the communication flow path. Hole).
The fuel flow path 48 is formed inside the block 20. The fuel flow path 48 is a fuel flow path hole that connects the out orifice 42 of the communication flow path and the fuel flow path 51 via the annular concave groove 43.
The out orifice 49 is provided inside the block 20, particularly on the downstream side of the intermediate flow path in the fuel flow direction. The out orifice 49 is a sub outlet orifice (fuel passage hole, small diameter hole) that connects the fuel passage 48 and the fuel passage 51 of the intermediate passage and narrows the cross-sectional area of the fuel passage 48. is there.
The annular concave groove 43 is an annular ring groove flow path that opens at the second sheet surface of the block 20.

The fuel flow paths 51 and 52 are formed inside the injector body 18 and the valve body 19. The fuel flow paths 51 and 52 are fuel flow path holes that connect the fuel flow path 48 and the outlet port.
Then, the fuel that has flowed into the fuel flow paths 51 and 52 from the control chamber 12 through the communication flow path and the intermediate flow path is discharged from the outlet port provided in the injector body 18 to the outside of the injector 5. The outlet port is connected to a flow path pipe for returning the fuel overflowed or discharged from the injector 5 to the fuel tank 1.

The sum of the cross-sectional areas of the sliding clearance 17 is set smaller than the cross-sectional area of the out orifice 42. Further, the cross-sectional area of the out-orifice 42 is set smaller than the cross-sectional area of the out-orifice 49. Further, the cross-sectional area of the out-orifice 49 is set smaller than the cross-sectional area of the in-orifice 32. Further, the flow path cross-sectional areas of the in-orifice 32 and the out-orifices 42 and 49 are set to be smaller than the sum of the cross-sectional areas of the gap 35. That is, the sum total of the cross-sectional areas of the gap 35 is sufficiently larger than the cross-sectional areas of the in-orifice 32 and the out-orifices 42 and 49.
That is, the sum of the sectional areas of the sliding clearance 17 is S1, the sectional area of the out orifice 42 is S2, the sectional area of the out orifice 49 is S3, and the sectional area of the in orifice 32 is S4. When the total cross-sectional area of the gap 35 is S5, the relationship of S1 <S2 <S3 <S4 <S5 is satisfied.

[Operation of Example 1]
Next, the operation of the injector 5 for a diesel engine used in the common rail fuel injection system of this embodiment will be briefly described with reference to FIGS.

The high pressure fuel supplied from the common rail 4 flows into the fuel supply passage 26 from the inlet port 23 of the injector 5 through the fuel supply passages 24 and 25. The high-pressure fuel that has flowed into the fuel supply channel 26 flows into the nozzle chamber 11 from the fuel supply channel 26 through the fuel supply channel 27 → the fuel supply channel 28.
The ECU does not energize the solenoid coil 63 of the electromagnetic control valve. The valve 13 of the electromagnetic control valve is seated on the first seat surface of the block 20 and the out orifice 49 which is the valve hole of the electromagnetic control valve is opened. Block it.

  Thus, when the electromagnetic control valve is closed, the fuel discharge path is closed. That is, when the valve 13 of the electromagnetic control valve is seated on the first seat surface of the block 20 and the communication state between the fuel flow path 48 and the fuel flow paths 51 and 52 is interrupted, the control chamber 12 and Since the outflow of the fuel from the fuel flow path 48 stops, the valve 14 of the intermediate valve lifts (detaches) from the second seat surface of the block 20 due to the fuel pressure in the fuel flow path 31 and serves as the valve hole of the intermediate valve. The in-orifice 32 is opened. That is, the axial recess 65 of the valve 14 of the intermediate valve moves in the valve hole opening direction while being guided by the outer peripheral portion (valve guide) of the axial protrusion 16 of the nozzle needle 9 to open the intermediate valve.

  As described above, when the electromagnetic control valve is closed and the intermediate valve is opened, as shown in FIG. 3, the fuel supply flow paths 24 and 25 to the fuel flow path 31 → the in-orifice 32 → A first path (first path of the fuel introduction path) through which the high-pressure fuel flows into the control chamber 12 through the annular groove 33 → the clearance 34 → the gap 35 → the fuel flow path 36 is formed. As a result, the high-pressure fuel that has flowed into the fuel flow path 31 from the fuel supply flow paths 24 and 25 passes through the fuel flow path 31 through the in-orifice 32 → the annular groove 33 → the clearance 34 → the gap 35 → the fuel flow path 36. It flows into the control room 12.

  Further, when the electromagnetic control valve is closed and the intermediate valve is opened, as shown in FIG. 3, the fuel supply passages 24 and 25 bypass the sliding clearance 17 and the out orifice 42. From the fuel flow path 31 to the in-orifice 32 → the annular groove 33 → the clearance 34 → the annular groove 43 to the fuel flow path 48 that is an intermediate flow path (second path of the fuel introduction path) ) Is formed. As a result, the high-pressure fuel that has flowed into the fuel flow path 31 from the fuel supply flow paths 24 and 25 passes through the fuel flow path 31 through the in-orifice 32 → the annular groove 33 → the clearance 34 → the annular groove 43. 48 flows into the interior.

As a result, the nozzle needle 9 receives a valve opening force in the direction to be pushed up by the fuel pressure in the nozzle chamber 11 (the nozzle hole opening direction) and is pushed down by the fuel pressure in the control chamber 12 (the nozzle hole closing direction). The valve closing force will be received.
Here, when the electromagnetic control valve is closed and the intermediate valve is opened, the interior of the nozzle chamber 11 and the interior of the control chamber 12 are filled with high-pressure fuel. That is, the pressure receiving area for receiving the fuel pressure in the control chamber 12 at the first fuel pressure receiving portion of the nozzle needle 9 is larger than the pressure receiving area for receiving the fuel pressure in the nozzle chamber 11 at the second fuel pressure receiving portion of the nozzle needle 9. The spring 10 applies a biasing force (spring load, valve closing force) for biasing the nozzle needle 9 toward the nozzle hole 9 by the spring 10.

  In other words, the nozzle needle 9 has a force (valve opening force: F1) in the direction of pushing up by the fuel pressure in the nozzle chamber 11 (opening valve opening direction: F1) and a direction of pushing down by the fuel pressure in the control chamber 12 (nozzle hole closing). The force (valve closing force: F2) in the valve direction and the force (valve closing force: F3) in the direction of pushing down by the spring load of the spring 10 (valve closing force: F3) act, and F1 <F2 + F3 is established. doing. Therefore, when the ECU does not energize the solenoid coil 63 of the electromagnetic control valve, the electromagnetic control valve is closed, and the intermediate valve is open, the downward force shown in FIG. It will be.

As a result, when the electromagnetic control valve is closed and the intermediate valve is opened, the seat portion of the nozzle needle 9 is pressed against (seats) the seat surface of the nozzle body 21, and the seat portion of the nozzle needle 9 is seated. Closes each nozzle hole 8 of the nozzle body 21.
Therefore, the injector 5 is in a closed state in which the nozzle needle 9 is closed, and fuel is not injected into the combustion chamber of the cylinder of the engine E.
At the stage where the fuel pressure in the control chamber 12 and the fuel pressure in the fuel flow path 48 are balanced, the valve 14 of the intermediate valve moves in the valve hole closing direction regardless of the presence or absence of the spring 15. The second seat surface is seated. As a result, the valve 14 of the intermediate valve closes the in-orifice 32 that is the valve hole of the intermediate valve. That is, the intermediate valve is closed.

  On the other hand, when the injection timing from the injector 5 (fuel injection timing) is reached and the electromagnetic control valve is driven to open by the ECU, that is, when the ECU energizes the solenoid coil 63 of the electromagnetic control valve. The valve 13 is pulled up together with the armature 60 against the urging force (spring load) of the spring 10. As a result, the valve 13 is pulled away from the first seat surface of the block 20 and the valve 13 of the electromagnetic control valve is opened. For this reason, the valve 13 opens the fuel flow path 48 to allow communication between the high pressure side control chamber 12 and the intermediate pressure side fuel flow path 48 and the low pressure side fuel flow paths 51 and 52.

Thus, when the electromagnetic control valve is opened, the fuel discharge path is opened. That is, when the valve 13 of the electromagnetic control valve is separated from the first seat surface of the block 20 and communicates between the fuel flow path 48 and the fuel flow paths 51 and 52, the intermediate flow path (fuel flow path 48) The fuel inside flows out. For this reason, the intermediate valve maintains the closed state.
As described above, when the electromagnetic control valve is opened and the intermediate valve is closed, as shown in FIG. 4, the sliding clearance 17 is bypassed and the communication channel ( Communication port 39 → axial hole 40 → fuel flow path 41 → out orifice 42) → intermediate flow path (annular concave groove 43 → fuel flow path 48 → out orifice 49) through fuel discharge flow path (fuel flow paths 51, 52) ) To discharge the fuel (the path of the fuel discharge path) is formed.
As a result, the fuel in the control chamber 12 flows out to the fuel channel 48 side through the communication channel including the out orifice 42 inside the valve 14 of the intermediate valve, and further from the fuel channel 48 to the fuel channel 51. , 52 flows out to the side, and the fuel pressure in the control chamber 12 decreases. At this time, since the valve 14 of the intermediate valve closes the in-orifice 32, the inflow of high-pressure fuel from the fuel flow path 31 to the control chamber 12 and the communication flow path is blocked. Thereby, the fuel pressure in the control chamber 12 decreases in a short time. That is, the fuel pressure in the control chamber 12 rapidly decreases.

Since the pressure difference between the fuel pressure in the nozzle chamber 11 and the fuel pressure in the control chamber 12 increases, the valve opening force (force in the nozzle hole opening direction) acting on the nozzle needle 9 increases. The biasing force (valve closing force) in the nozzle hole closing direction of the spring 10 becomes larger. When F1> F2 + F3 is established, the nozzle needle 9 is raised (starts lifting) by the valve opening force in the direction of pushing up by the fuel pressure in the nozzle chamber 11 (the injection hole opening direction), and the seat portion of the nozzle needle 9 Moves away from the seat surface of the nozzle body 21 (separates or leaves). As a result, the nozzle needle 9 is opened, and high-pressure fuel supplied from the common rail 4 to the nozzle chamber 11 through the fuel supply path is injected from each injection hole 8.
Accordingly, the injector 5 starts to inject fuel into the combustion chamber of the cylinder of the engine E.

Thereafter, when the valve opening period of the injector 5 (command injection period determined from the fuel injection amount and the command injection pressure) elapses from the injection timing, the solenoid coil 63 of the electromagnetic control valve is turned off, and the armature 60 is sucked. The power to do disappears. Then, the armature 60 moves away from the magnetic pole surface of the stator 62 by the urging force (spring load) of the spring 10.
That is, the spring 10 pushes down the armature 60 by the biasing force, and the valve 13 of the electromagnetic control valve is seated on the first seat surface of the block 20. Thereby, the valve 13 of the electromagnetic control valve is closed.

  Thus, when the electromagnetic control valve is closed, the fuel discharge path is closed. That is, when the valve 13 of the electromagnetic control valve is seated on the first seat surface of the block 20 and the communication state between the fuel flow path 48 and the fuel flow paths 51 and 52 is interrupted, the control chamber 12 and Since the outflow of fuel from the fuel flow path 48 stops, the valve 14 of the intermediate valve is lifted from the second seat surface of the block 20 by the fuel pressure in the fuel flow path 31, and the in-orifice 32 which is the valve hole of the intermediate valve Is released. That is, the axial recess 65 of the valve 14 of the intermediate valve moves in the valve hole opening direction while being guided by the axial protrusion 16 of the nozzle needle 9 to open the intermediate valve.

As described above, when the electromagnetic control valve is closed and the intermediate valve is opened, as shown in FIG. 3, the fuel supply flow paths 24 and 25 to the fuel flow path 31 → the in-orifice 32 → A first path (first path of the fuel introduction path) through which the high-pressure fuel flows into the control chamber 12 through the annular groove 33 → the clearance 34 → the gap 35 → the fuel flow path 36 is formed.
As a result, the fuel outflow from the control chamber 12 and the fuel flow path 48 to the fuel discharge flow paths (fuel flow paths 51 and 52) is stopped, so that the fuel is supplied from the fuel supply flow paths 24 and 25 as shown in FIG. The high pressure fuel flowing into the control chamber 12 through the flow path 31 → the in-orifice 32 → the annular groove 33 → the clearance 34 → the gap 35 → the fuel flow path 36 restores the fuel pressure in the control chamber 12. For this reason, the fuel pressure in the control chamber 12 rises rapidly.

Further, when the electromagnetic control valve is closed and the intermediate valve is opened, as shown in FIG. 3, the fuel supply passages 24 and 25 bypass the sliding clearance 17 and the out orifice 42. From the fuel flow path 31 to the in-orifice 32 → the annular groove 33 → the clearance 34 → the annular groove 43 to the fuel flow path 48 that is an intermediate flow path (second path of the fuel introduction path) ) Is formed.
On the other hand, since the intermediate valve is opened, the clearance between the annular groove 33 and the annular groove 43 is also reduced via the clearance 34 between the second seat surface of the block 20 and the second seal portion of the valve 14. It becomes a communication state. For this reason, the high-pressure fuel flowing into the fuel channel 48 from the fuel supply channels 24, 25 through the fuel channel 31 → the in-orifice 32 → the annular groove 33 → the clearance 34 → the annular groove 43 is supplied to the fuel channel 48. Recover the fuel pressure inside. For this reason, the fuel pressure in the fuel flow path 48 also rises rapidly.

Then, the pressure difference between the fuel pressure in the nozzle chamber 11 and the fuel pressure in the control chamber 12 decreases, and the valve opening force for opening the nozzle needle 9 is less than the urging force of the spring 10 in the nozzle hole closing direction. Then, that is, when the fuel pressure in the control chamber 12 rises rapidly, F1 <F2 + F3 is established, so that the nozzle needle 9 moves in the nozzle hole closing direction, and the seat portion of the nozzle needle 9 becomes the seat of the nozzle body 21. Sit on the face. As a result, the injector 5 returns to the closed state in which the seat portion of the nozzle needle 9 is pressed against the seat surface of the nozzle body 21, the nozzle holes 9 are closed, and the nozzle needle 9 is closed. Therefore, fuel injection from each nozzle hole 8 is completed.
Note that, when the fuel pressure in the control chamber 12 and the fuel pressure in the fuel flow path 48 are balanced, the axial recess 65 of the valve 14 of the intermediate valve becomes the shaft of the nozzle needle 9 regardless of the presence or absence of the spring 15. It moves in the valve hole closing direction while being guided by the outer peripheral portion (valve guide) of the direction convex portion 16 and is seated on the second seat surface of the block 20. As a result, the valve 14 of the intermediate valve closes the in-orifice 32. That is, the intermediate valve is closed.

[Effect of Example 1]
As described above, in the diesel engine injector 5 used in the common rail fuel injection system of this embodiment, the valve 14 of the intermediate valve is connected to the outer peripheral portion (valve guide) of the axial convex portion 16 of the nozzle needle 9. Since it is possible to guide, a radial gap 35 (radial gap: in the actual machine) formed between the outer peripheral surface of the valve 14 of the intermediate valve and the hole wall surface (peripheral wall surface) of the valve accommodating recess 57 of the cylinder 22 (About 0.05 mm on one side) can be further enlarged. Thereby, after the valve 14 of the intermediate valve is separated from the second seat surface of the block 20, the restriction on the flow rate of the high-pressure fuel from the fuel flow path 31 to the control chamber 12 is relaxed. Thereby, by expanding the in-orifice 32, the flow rate of the high-pressure fuel flowing into the control chamber 12 can be significantly increased. As a result, the valve closing speed of the nozzle needle 9 is greatly improved.

  Further, when the electromagnetic control valve is opened and the intermediate valve is closed, the sliding clearance 17 is bypassed, and the communication channel (communication port 39, axial hole 40, fuel channel 41, Out orifice 42) → path for discharging fuel to the fuel discharge passage (fuel passage 51, 52) through the intermediate passage (annular groove 43, fuel passage 48, out orifice 49) (fuel discharge passage) Is formed. For this reason, the valve opening response time, which is a period from when the electromagnetic control valve is opened to when the nozzle needle 9 is opened, can be shortened. Thereby, the valve opening responsiveness of the nozzle needle 9 can be improved.

  Further, the nozzle needle 9 is fitted to the inner circumferential surface (sliding surface) of the axial recess 65 of the valve 14 of the intermediate valve so as to be freely slidable and the valve 14 of the intermediate valve is moved in the valve moving direction (valve hole). A valve guide (outer peripheral portion of the axial convex portion 16) is provided to be slidably guided in the valve closing direction). For this reason, since the valve 14 of the intermediate valve can move without tilting with respect to a specified valve moving direction (a direction parallel to the axial direction (needle moving direction) of the nozzle needle 9), the fuel supply flow path 24, The fuel introduction channel (the fuel channel 31, the in-orifice 32, and the annular groove 33) communicating with 25 can be quickly and reliably closed. As a result, the fuel flowing from the fuel supply passages 24 and 25 through the fuel introduction passage (the fuel passage 31, the in-orifice 32, and the annular concave groove 33) into the control chamber 12 and the intermediate passage (the fuel passage 48). Since it can interrupt | block, the fuel pressure in the control chamber 12 can be dropped rapidly. Thereby, the valve opening responsiveness of the nozzle needle 9 can be improved.

  Further, when the nozzle needle 9 is opened, that is, when fuel injection into the combustion chamber of each cylinder of the engine E is started, the intermediate valve is closed and the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular recess). The groove 33) is closed. As a result, by opening the electromagnetic control valve and opening the fuel outflow passage (communication passage, intermediate passage), the fuel flows from the control chamber 12 through the fuel outflow passage (communication passage, intermediate passage). Is discharged from the fuel supply passages 24, 25 through the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular groove 33), or the intermediate passage (annular passage) of the control chamber 12 or the fuel outflow passage. The fuel flowing into the concave groove 43, the fuel flow path 48, and the out orifice 49) can be shut off. Therefore, the fuel supply passages 24 and 25 and the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular groove 33) to the control chamber 12 or the intermediate passage (the annular groove 43, the fuel flow) of the fuel outflow passage. The flow rate of the fuel flowing out to the fuel discharge flow path (fuel flow paths 51, 52) through the passage 48 and the out orifice 49) can be reduced.

  Further, when the electromagnetic control valve is opened and the intermediate valve is closed, the sliding clearance 17 is bypassed, and the communication channel (communication port 39, axial hole 40, fuel channel 41, Out orifice 42) → A path for discharging fuel to the fuel flow paths 51 and 52 through the intermediate flow path (annular groove 43, fuel flow path 48, out orifice 49) (fuel discharge path) is formed. The problem that the temperature characteristic of fuel viscosity deteriorates can be suppressed. Thereby, since the change of the fuel flow rate which passes the out orifices 42 and 49 can be suppressed, the dispersion | variation in the fuel flow rate discharged | emitted from the control chamber 12 can be suppressed. Therefore, variation in the valve opening timing of the nozzle needle 9 can be suppressed, so that the control accuracy of the fuel injection amount can be improved.

  On the other hand, when the electromagnetic control valve is closed and the intermediate valve is opened, the fuel supply flow path 24, 25 to the fuel introduction flow path (fuel flow path 31, in-orifice 32, annular concave groove 33) → fuel introduction flow A first path (first path of the fuel introduction path) through which high-pressure fuel flows into the control chamber 12 through the path (clearance 34) → the fuel introduction path (gap 35, fuel path 36) is formed. That is, when the intermediate valve is opened, the fuel supply passages 24 and 25 to the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular groove 33), the fuel introduction passage (clearance 34), and the fuel introduction Since a flow path (first path) through which high-pressure fuel quickly flows into the control chamber 12 through the flow paths (gap 35, fuel flow path 36) is formed, the nozzle needle 9 is closed after the electromagnetic control valve is closed. It is possible to shorten the valve closing response time, which is a period until the operation. Thereby, the valve closing response of the nozzle needle 9 can be improved.

  Further, when the electromagnetic control valve is closed and the intermediate valve is opened, the fuel supply passages 24 and 25 bypass the out-orifice 42 and the sliding clearance 17, and the fuel introduction passages (fuel passage 31, In-orifice 32, annular groove 33) → through fuel introduction flow path (clearance 34) → second path through which high-pressure fuel flows into intermediate flow path (annular groove 43, fuel flow path 48) 2 paths) are formed. That is, when the intermediate valve is opened, the fuel supply passages 24 and 25 are passed through the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular concave groove 33) and the fuel introduction passage (the clearance 34). Since a flow path (second path) through which high-pressure fuel flows quickly is formed in the flow path (annular concave groove 43, fuel flow path 48), the intermediate flow path (annular concave groove 43, The valve closing response time, which is a period required until the fuel pressure in the fuel flow path 48) is recovered, can be shortened. Thereby, the valve closing response of the nozzle needle 9 can be improved.

  Further, the nozzle needle 9 is provided with a valve guide (an outer peripheral portion of the axial convex portion 16) for slidably guiding the valve 14 of the intermediate valve in the valve moving direction (valve opening direction). For this reason, since the valve 14 of the intermediate valve can be moved without inclining with respect to a prescribed valve movement direction (a direction parallel to the axial direction of the nozzle needle 9), the fuel communicated with the fuel supply passages 24, 25 The introduction channel (fuel channel 31, in-orifice 32, annular groove 33) can be quickly opened. As a result, the fuel supply passages 24 and 25 to the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular groove 33), the fuel introduction passage (the clearance 34), the fuel introduction passage (the gap 35, the fuel flow). Since the high pressure fuel can be introduced into the control chamber 12 and the intermediate flow path (annular groove 43, fuel flow path 48) at once through the passage 36), the fuel pressure in the control chamber 12 can be rapidly increased. Thereby, the valve closing response of the nozzle needle 9 can be improved.

  Here, the axial guide portion of the nozzle needle 9 is a separate part from the cylinder 22 in which the control chamber 12 is formed. 16 are provided on the outer periphery. Therefore, the gap between the outer peripheral surface (outer surface) of the valve 14 of the intermediate valve and the inner peripheral surface of the valve housing recess 57 of the cylinder 22 (the peripheral wall surface surrounding the outer periphery of the valve 14 of the intermediate valve in the circumferential direction). The (radial gap) 35 can be expanded in the radial direction. Therefore, from the fuel supply flow paths 24 and 25 to the fuel introduction flow path (the fuel flow path 31, the in-orifice 32, the annular concave groove 33), the fuel introduction flow path (clearance 34), and the fuel introduction flow path (gap 35, fuel flow path). Since the inflow flow rate of the high-pressure fuel introduced into the control chamber 12 through 36) can be increased, the valve closing speed of the nozzle needle 9 can be improved. Thereby, the valve closing response of the nozzle needle 9 can be further improved.

[Configuration of Example 2]
FIGS. 5 to 8 show a second embodiment of the present invention, FIG. 5 is a view showing the periphery of the intermediate valve of the injector, and FIG. 6 is a view showing a valve of the intermediate valve. 8 is a view showing the periphery of the intermediate valve of the injector.

As shown in FIG. 5, a space (a part of the control chamber 12) is separated from the control chamber side end surface (the upper end surface in the drawing) of the needle head 54 of the nozzle needle 9 with the valve 14 of the intermediate valve. Opposing end faces 66 are provided.
The nozzle needle 9 is provided with an axial recess 67 that opens at the opposed end surface 66 and extends in the axial direction from the opening side to the back side. The axial recess 67 is a round hole-shaped axial hole extending along the axial direction of the nozzle needle 9. Further, on the back side of the axial recess 67, a bottom portion (closing portion) for closing the back side of the axial hole is provided. A spring seat that supports the illustrated lower end of the spring 15 is provided at the bottom of the axial recess 67.
Here, the control chamber 12 includes a columnar space formed in the axial recess 67 and a columnar space between the valve 14 of the intermediate valve and the opposed end surface 66 of the nozzle needle 9. When the axial recess 67 is not provided, only the cylindrical space between the valve 14 of the intermediate valve and the opposed end surface 66 of the nozzle needle 9 becomes the control chamber 12.

As in the first embodiment, the housing of the injector 5 according to the present embodiment includes an injector body 18, a valve body 19, a block 20, a nozzle body 21, a cylinder 22, and the like.
Here, the block 20 constitutes a first valve body in which a first accommodating recess 44 is formed. The first accommodation recess 44 is open at the center of the second sheet surface of the block 20. In addition, a valve guide that guides the valve 14 of the intermediate valve so as to be slidable in the reciprocating movement direction (valve movement direction) is provided on the inner peripheral portion of the first housing recess 44. In addition, a coupling end surface (contact surface) that is coupled to the cylinder 22 is provided on the lower end surface of the block 20 in the figure.
The annular groove 43 opened on the second sheet surface of the block 20 is formed in an annular shape so as to surround the opening of the first accommodation recess 44. The annular groove 43 is connected to the fuel introduction channel (the fuel channel 31, the in-orifice 32, the annular groove 33) and the communication channel (the axial hole 38, via the clearance 34) when the intermediate valve is opened. The communication port 39 communicates with the out orifice 42).

The cylinder 22 constitutes a second valve body in which a second accommodation recess 45 is formed. The second housing recess 45 has an inner diameter larger than that of the first housing recess 44 and opens at the coupling end surface of the cylinder 22 (the coupling end surface with the block 20, the upper end surface in the drawing). The second accommodation recess 45 is a valve accommodation hole provided on the block 20 side with respect to the control chamber 12. The hole wall surface of the valve housing hole is a peripheral wall surface that surrounds the periphery of the valve 14 of the intermediate valve in the circumferential direction. Further, a coupling end surface (contact surface) that is coupled to the coupling end surface of the block 20 is provided on the upper end surface of the cylinder 22 in the figure.
Here, the first accommodation recess 44 of the block 20 is opened at the coupling end surface of the block 20 so as to communicate with the second accommodation recess 45 of the cylinder 22. Further, the second accommodation recess 45 of the cylinder 22 opens at the coupling end surface of the cylinder 22 so as to communicate with the first accommodation recess 44 of the block 20.

The intermediate valve includes a valve 14 having a convex cross section in which an axial hole 38 and an out orifice 42 are formed, and a side where the valve 14 is pressed against the second seat surface of the block 20 (the valve hole closing direction). A spring 15 for biasing is provided.
The valve 14 of the intermediate valve is a cylindrical first body portion (first block valve, first tube portion, minimum outer diameter portion: hereinafter referred to as a first outer diameter portion) that is housed in the first housing recess 44 of the block 20 so as to be reciprocally slidable. 1 cylindrical portion 71), and a cylindrical second body portion (second block valve, second cylindrical portion, maximum outer diameter portion): A second cylindrical portion 72).

On the outer peripheral surface of the first cylindrical portion 71, a sliding surface that forms a sliding portion with the inner peripheral surface of the first receiving recess 44 of the block 20, and an axial groove extending in the axial direction of the sliding surface An axial concave groove 46 (see FIG. 6) is formed. Here, the sliding portion is the sliding clearance 17 formed between the inner peripheral surface of the first housing recess 44 and the sliding surface of the first cylindrical portion 71.
Further, the axial groove 46 has a groove bottom surface that forms an axial clearance with the inner peripheral surface of the first housing recess 44 of the block 20. The axial clearance is used as a flow path that connects the control chamber 12 and the intermediate flow paths (fuel flow paths 47, 48) via the outer peripheral surface of the first cylindrical portion 71 of the valve 14 of the intermediate valve.

  The second cylindrical portion 72 has an opposing end surface that faces the opposing end surface 66 of the needle head 54 of the nozzle needle 9 with the control chamber 12 therebetween. On the outer peripheral surface of the second cylindrical portion 72, an outer surface facing the inner peripheral surface (peripheral wall surface) of the second accommodating recess 45 of the cylinder 22 with a gap 35 therebetween is formed. The second cylindrical portion 72 has an annular seal portion (step surface, seal surface) that is seated on the second seat surface of the block 20 when the intermediate valve is closed. Note that the outer diameter of the second cylindrical portion 72 is larger than the first cylindrical portion 71 toward the radially outer side.

The spring 15 is installed between the spring seat of the valve 14 (the opposed end surface of the second cylindrical portion 72, the lower end surface of the valve 14 in the drawing) and the spring seat of the nozzle needle 9 (the bottom of the axial recess 67). Yes. As shown in FIGS. 7 and 8, the spring 15 may not be provided.
Here, the gap 35 is a radial gap formed between the inner peripheral surface of the second accommodating recess 45 of the cylinder 22 and the outer peripheral surface of the second cylindrical portion 72 of the valve 14.

Similar to the first embodiment, the fuel supply path includes fuel supply passages 24 to 28 that connect the inlet port 23 and the nozzle chamber 11 to the nozzle chamber 11 from the common rail 4 through the fuel supply passages 24 to 28. This is a route for supplying high-pressure fuel.
The fuel introduction path is a fuel introduction path (fuel path 31, in-orifice 32, annular concave groove 33) communicating with the fuel supply paths 24, 25, and the second cylindrical portion 72 of the valve 14 when the intermediate valve is opened. The fuel flow path 31 via the clearance 34 which is a minute gap (fuel introduction flow path) formed between the seal portion (seal surface) and the second seat surface of the block 20 and the clearance 34 when the intermediate valve is opened. And the control chamber 12 are provided with fuel introduction passages (gap 35, fuel passage 36).

The fuel discharge path includes a communication channel (axial hole 38, communication port 39, out orifice 42) communicating with the control chamber 12, and an intermediate channel (fuel channels 47, 48, out orifice 49) communicating with this communication channel. ), And fuel discharge passages (fuel passages 51 and 52) communicating the intermediate passages (fuel passages 47 and 48, out orifice 49) with the outlet port of the injector 5. The fuel channel 47 has a channel cross-sectional area larger than that of the fuel channel 48, and the channel diameter increases toward the first housing recess 44 side.
Here, the communication flow path and the intermediate flow path constitute a fuel outflow flow path that communicates with the control chamber 12 and communicates between the control chamber 12 and the fuel flow path 51.

The communication channel is formed inside the valve 14 of the intermediate valve. This communication flow path has an axial hole 38 extending in the axial direction of the valve 14 and a communication port 39 that communicates the sliding surface of the first cylindrical portion 71 with the axial hole 38.
The axial hole 38 is used as a flow path that connects the control chamber 12 and the out orifice 42. The axial hole 38 has a bottom surface provided on the intermediate flow path side, and an opening that opens to face the control chamber 12 at the opposite end surface of the second cylindrical portion 72.

The communication port 39 has a sliding side opening that opens at the sliding surface of the first cylindrical portion 71 of the valve 14 of the intermediate valve. The communication port 39 is connected to the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular recess) via the clearance 34 and the annular groove 43 only when the electromagnetic control valve is closed and the intermediate valve is opened. Groove 33) or the gap 35 and the axial hole 38 are used as a flow path (flow path opened at the sliding surface of the valve 14 of the intermediate valve).
Further, inside the valve 14 of the intermediate valve, the control chamber 12 communicates with the intermediate flow path (fuel flow paths 47 and 48, the out orifice 49) and the communication flow path (the axial hole 38 and the communication port 39). An out-orifice (squeezing part) 42 for reducing the cross-sectional area of the channel is formed. The out orifice 42 is formed closer to the intermediate flow path (fuel flow paths 47, 48) than the sliding side opening of the communication port 39.

  Here, the fuel introduction path is such that when the electromagnetic control valve is closed and the intermediate valve is opened, the fuel supply flow paths 24 and 25 to the fuel introduction flow path (the fuel flow path 31, the in-orifice 32, the annular concave groove). 33), a fuel introduction passage (clearance 34), and a first passage through which high-pressure fuel flows into the control chamber 12 via the fuel introduction passage (gap 35, fuel passage 36). Further, when the electromagnetic control valve is closed and the intermediate valve is opened, the fuel supply passages 24 and 25 bypass the sliding clearance 17 and the out orifice 42, and the fuel introduction passages (fuel passage 31, In-orifice 32, annular groove 33), fuel introduction channel (clearance 34), annular groove 43, axial gap (axial groove 46), and high pressure fuel in intermediate channel (fuel channels 47, 48) A second path through which the water flows. Further, when the electromagnetic control valve is closed and the intermediate valve is opened, the fuel supply passages 24 and 25 to the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular concave groove 33), the fuel introduction flow There is a third path through which high-pressure fuel flows into the control chamber 12 via the path (clearance 34), the annular groove 43, the communication port 39, and the axial hole 38.

Further, the fuel discharge path is configured such that when the electromagnetic control valve is opened and the intermediate valve is closed, the sliding clearance 17 is bypassed and the communication channel (axial hole 38, out orifice 42) is bypassed from the control chamber 12. The first flow path for discharging the fuel to the fuel flow paths 51 and 52 through the intermediate flow paths (the fuel flow paths 47 and 48 and the out orifice 49).
If the intermediate valve is open when the electromagnetic control valve is open, the sliding clearance 17 and the out orifice 42 are bypassed during the period from when the electromagnetic control valve opens until the intermediate valve closes. The fuel flows from the control chamber 12 to the fuel flow paths 51 and 52 through the axial hole 38, the communication port 39, the axial clearance (axial recess 46), the intermediate flow path (fuel flow paths 47 and 48, the out orifice 49). You may provide the 2nd path | route which discharges.

The sum of the cross-sectional areas of the sliding clearance 17 is set smaller than the cross-sectional area of the out orifice 42.
Further, the cross-sectional area of the out-orifice 42 is set smaller than the cross-sectional area of the out-orifice 49.
Further, the cross-sectional area of the out-orifice 49 is set smaller than the cross-sectional area of the in-orifice 32.
Further, the flow path cross-sectional areas of the in-orifice 32 and the out-orifices 42 and 49 are set to be smaller than the sum of the cross-sectional areas of the gap 35.
Further, the sum of the cross-sectional areas of the axial gaps (axial recess 46) is set smaller than the sum of the cross-sectional areas of the communication ports 39 of the communication flow path.
The flow passage cross-sectional area of the out orifice 42 is set smaller than the sum of the cross-sectional areas of the axial gaps (axial concave grooves 46).

[Operation of Example 2]
Next, the operation of the diesel engine injector 5 used in the common rail fuel injection system of this embodiment will be briefly described with reference to FIGS.

First, when the electromagnetic control valve is opened and the intermediate valve is closed, as shown in FIG. 7, the sliding clearance 17 is bypassed and the communication channel (axial hole 38, A first path (a first path of the fuel discharge path) is formed through which fuel is discharged to the fuel flow paths 51 and 52 via the out orifice 42) and the intermediate flow paths (fuel flow paths 47 and 48, the out orifice 49).
That is, when the electromagnetic control valve is opened, the fuel outflow channel (communication channel, intermediate channel) is opened. Thereby, the fuel in the intermediate flow path (fuel flow paths 47, 48, out orifice 49) flows out to the fuel discharge flow path (fuel flow paths 51, 52) side. For this reason, the intermediate valve maintains the closed state.

Subsequently, the fuel in the control chamber 12 flows out to the intermediate channel side through the communication channel including the throttle portion (out orifice 42) formed inside the valve 14 of the intermediate valve, so that the inside of the control chamber 12 The fuel pressure will decrease. At this time, since the intermediate valve closes the fuel introduction passage (the fuel passage 31, the in-orifice 32, and the annular groove 33), the high-pressure fuel flows from the fuel introduction passage into the control chamber 12 or the intermediate passage. Is cut off. Thereby, the fuel pressure in the control chamber 12 decreases in a short time. That is, the fuel pressure in the control chamber 12 rapidly decreases.
If the intermediate valve is open when the electromagnetic control valve is opened, the sliding clearance 17 and the out orifice 42 are bypassed during the period from when the electromagnetic control valve is opened until the intermediate valve is closed. Then, fuel passes from the control chamber 12 through the communication flow path (axial hole 38, communication port 39), the axial clearance (axial recess 46), and the intermediate flow path (fuel flow paths 47, 48, out orifice 49). You may form the 2nd path | route (2nd path | route of a fuel discharge path | route) which discharges fuel to the flow paths 51 and 52. FIG.

That is, when the electromagnetic control valve is opened, the fuel outflow channel (communication channel, intermediate channel) is opened. As a result, the fuel in the control chamber 12 bypasses the throttle portion (out orifice 42), passes through the gap 35, the clearance 34, the annular groove 43, and the axial gap (axial groove 46) as an intermediate flow path. It flows out to the (fuel flow paths 47, 48, out orifice 49) side. Further, the fuel flowing in from the fuel introduction flow path (the fuel flow path 31, the in-orifice 32, the annular groove 33) also bypasses the throttle portion (the out-orifice 42), and the clearance 34, the annular groove 43, and the axial clearance. It flows out to the intermediate flow path (fuel flow paths 47, 48, out orifice 49) through the (axial groove 46). Thereby, the fuel pressure in the control chamber 12 decreases in a short time. That is, the fuel pressure in the control chamber 12 rapidly decreases.
And since the pressure difference between the fuel pressure in the nozzle chamber 11 and the fuel pressure in the control chamber 12 increases, the valve opening force (force in the nozzle hole opening direction) acting on the nozzle needle 9 increases, and the spring When it becomes larger than the urging force (valve closing force) in the nozzle hole closing direction, the nozzle needle 9 opens. As a result, the high-pressure fuel supplied from the common rail 4 to the nozzle chamber 11 via the fuel supply path (fuel supply flow path) is injected from the injection hole 8 into the combustion chamber for each cylinder of the engine E. That is, fuel injection into the combustion chamber for each cylinder of the engine E is started.

  On the other hand, when the electromagnetic control valve is closed and the intermediate valve is opened, as shown in FIG. 8, the fuel supply passages 24 and 25 to the fuel introduction passages (fuel passage 31, in-orifice 32, A first path (first path of the fuel introduction path) through which high-pressure fuel flows into the control chamber 12 through the annular groove 33), the fuel introduction path (clearance 34), and the fuel introduction path (gap 35, fuel path 36). ) Is formed. Further, when the electromagnetic control valve is closed and the intermediate valve is opened, the fuel supply passages 24 and 25 bypass the sliding clearance 17 and the out orifice 42, and the fuel introduction passages (fuel passage 31). , The in-orifice 32, the annular groove 33), the fuel introduction passage (clearance 34), the annular groove 43, the axial clearance (axial recess 46), and the intermediate passage (fuel passages 47, 48) with high pressure. A second path (second path of the fuel introduction path) through which the fuel flows is formed. Further, when the electromagnetic control valve is closed and the intermediate valve is opened, the fuel supply passages 24 and 25 to the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular concave groove 33), the fuel introduction flow A third path (a third path of the fuel introduction path) through which high-pressure fuel flows into the control chamber 12 through the path (clearance 34), the annular groove 43, the communication port 39, and the axial hole 38 is formed.

  That is, when the electromagnetic control valve is closed, the fuel outflow channel (communication channel, intermediate channel) is closed. As a result, the outflow of fuel from the control chamber 12 and the intermediate flow path (the fuel flow paths 47 and 48, the out orifice 49) stops, so that the fuel pressure in the intermediate flow path (the fuel flow paths 47 and 48) and the control chamber The pressure difference with the fuel pressure in 12 becomes small. For this reason, the valve 14 of the intermediate valve is lifted downward in the figure by the fuel pressure in the fuel introduction passage (the fuel passage 31, the in-orifice 32, and the annular concave groove 33). That is, the valve 14 of the intermediate valve moves in the valve hole opening direction while being guided by the inner peripheral portion (valve guide) of the first receiving recess 44 of the block 20. Then, since the seal portion of the valve 14 of the intermediate valve is detached from the second seat surface of the block 20, the intermediate valve is opened.

Then, when the electromagnetic control valve is closed and the intermediate valve is opened, as shown in FIG. 8, fuel is introduced from the fuel introduction passage (the fuel passage 31, the in-orifice 32, and the annular groove 33). High-pressure fuel flows into the control chamber 12 through the flow path (clearance 34) and the fuel introduction flow path (gap 35, fuel flow path 36). Further, the fuel introduction flow path (fuel flow path 31, in-orifice 32, annular groove 33) through the fuel introduction flow path (clearance 34), the annular groove 43, the communication port 39, and the axial hole 38 inside the control chamber 12. High pressure fuel flows into the tank. Thereby, the fuel pressure in the control chamber 12 rises in a short time. That is, the fuel pressure in the control chamber 12 rises rapidly. Further, bypassing the out-orifice 42 and the sliding clearance 17, the fuel introduction channel (the fuel channel 31, the in-orifice 32, the annular groove 33) to the fuel introduction channel (clearance 34), the annular groove 43, the shaft The high-pressure fuel flowing into the intermediate flow path (fuel flow paths 47, 48) through the directional gap (axial recess 46) quickly recovers the fuel pressure in the intermediate flow paths (fuel flow paths 47, 48).
When the fuel pressure in the control chamber 12 and the fuel pressure in the fuel flow paths 47 and 48 are balanced, the valve 14 of the intermediate valve is moved into the first housing recess 44 of the block 20 by the biasing force of the spring 15. It moves in the valve-closing direction while being guided by the peripheral portion (valve guide) and is seated on the second seat surface of the block 20. As a result, the valve 14 of the intermediate valve closes the in-orifice 32. That is, the intermediate valve is closed.

[Effect of Example 2]
As described above, in the injector 5 for a diesel engine used in the common rail fuel injection system of the present embodiment, the intermediate flow path (fuel flow paths 47, 48) side from the sliding side opening of the communication port 39. An out-orifice 42 is provided at the end. As a result, when the electromagnetic control valve is opened and the intermediate valve is closed, the sliding clearance 17 is bypassed and the communication flow path (the axial hole 38, the out orifice 42) is passed from the control chamber 12 to the intermediate flow path. A first path (first path of the fuel discharge path) for discharging the fuel to the fuel discharge path (fuel flow paths 51, 52) via the (fuel paths 47, 48) is formed. For this reason, the valve opening response time, which is a period from when the electromagnetic control valve is opened to when the nozzle needle 9 is opened, can be shortened. Thereby, the valve opening responsiveness of the nozzle needle 9 can be improved.

  If the intermediate valve is open when the electromagnetic control valve is opened, the sliding clearance 17 and the out orifice 42 are bypassed during the period from when the electromagnetic control valve is opened until the intermediate valve is closed. Then, the fuel is discharged from the control chamber 12 through the communication flow path (axial hole 38, communication port 39) → the axial clearance (axial recess 46) → the intermediate flow path (fuel flow paths 47, 48, out orifice 49). You may form the 2nd path | route (2nd path | route of a fuel discharge path) which discharges a fuel to a flow path (fuel flow paths 51 and 52). In this case, a communication channel (axial hole 38, communication port 39), an axial gap (axial groove 46), and an intermediate channel (fuel channels 47, 48, out orifice 49) are connected from the control chamber 12. As a result, a flow path (second path) through which fuel quickly flows out to the fuel discharge flow path (fuel flow paths 51, 52) is formed, so that the fuel pressure in the control chamber 12 can be rapidly lowered. Thereby, the valve opening responsiveness of the nozzle needle 9 can be improved.

  Further, the block 20 is fitted to the outer peripheral surface (sliding surface) of the first cylindrical portion 71 of the valve 14 of the intermediate valve so as to be slidable back and forth, and the valve 14 of the intermediate valve is moved in the valve moving direction (valve closing). A valve guide (inner peripheral portion of the first receiving recess 44) is provided to be slidably guided in the valve direction). For this reason, since the valve 14 of the intermediate valve can move without tilting with respect to a specified valve moving direction (a direction parallel to the axial direction (needle moving direction) of the nozzle needle 9), the fuel supply flow path 24, The fuel introduction channel (the fuel channel 31, the in-orifice 32, and the annular groove 33) communicating with 25 can be quickly and reliably closed. As a result, the fuel flows into the control chamber 12 and the intermediate flow paths (fuel flow paths 47, 48) from the fuel supply flow paths 24, 25 through the fuel introduction flow paths (fuel flow path 31, in-orifice 32, annular groove 33). Since the fuel can be shut off, the fuel pressure in the control chamber 12 can be rapidly lowered. Thereby, the valve opening responsiveness of the nozzle needle 9 can be improved.

  Further, when the nozzle needle 9 is opened, that is, when fuel injection into the combustion chamber of each cylinder of the engine E is started, the intermediate valve is closed and the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular recess). The groove 33) is closed. As a result, by opening the electromagnetic control valve and opening the fuel outflow passage (communication passage, intermediate passage), the fuel flows from the control chamber 12 through the fuel outflow passage (communication passage, intermediate passage). Is discharged from the fuel supply passages 24, 25 through the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular concave groove 33), or the intermediate passage (fuel) of the control chamber 12 or the fuel outflow passage. The fuel flowing into the flow paths 47, 48) can be shut off. Therefore, the fuel supply passages 24 and 25 and the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular concave groove 33) to the control passage 12 or the intermediate passage (the fuel passage 47, 48) of the fuel outflow passage. It is possible to reduce the flow rate of the fuel flowing out to the fuel discharge flow path (fuel flow paths 51, 52) side through the above.

  Further, when the electromagnetic control valve is opened and the intermediate valve is closed, the sliding clearance 17 is bypassed and the communication flow path (the axial hole 38, the out orifice 42) is passed from the control chamber 12 to the intermediate flow path ( Since the first path (first path of the fuel discharge path) for discharging the fuel is formed in the fuel discharge path (fuel paths 51 and 52) through the fuel paths 47 and 48 and the out orifice 49), the fuel viscosity It is possible to suppress a problem that the temperature characteristics of the battery deteriorate. Thereby, since the change of the fuel flow rate which passes the out orifices 42 and 49 can be suppressed, the dispersion | variation in the fuel flow rate discharged | emitted from the control chamber 12 can be suppressed. Therefore, variation in the valve opening timing of the nozzle needle 9 can be suppressed, so that the control accuracy of the fuel injection amount can be improved.

  On the other hand, when the electromagnetic control valve is closed and the intermediate valve is opened, the fuel supply flow path 24, 25 to the fuel introduction flow path (fuel flow path 31, in-orifice 32, annular concave groove 33) → fuel introduction flow A first path (first path of the fuel introduction path) through which high-pressure fuel flows into the control chamber 12 through the path (clearance 34) → the fuel introduction path (gap 35, fuel path 36) is formed. That is, when the intermediate valve is opened, the fuel supply passages 24 and 25 to the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular groove 33), the fuel introduction passage (clearance 34), and the fuel introduction Since a flow path (first path) through which high-pressure fuel quickly flows into the control chamber 12 through the flow paths (gap 35, fuel flow path 36) is formed, the nozzle needle 9 is closed after the electromagnetic control valve is closed. It is possible to shorten the valve closing response time, which is a period until the operation. Thereby, the valve closing response of the nozzle needle 9 can be improved.

  Further, when the electromagnetic control valve is closed and the intermediate valve is opened, the fuel supply flow paths 24 and 25 to the fuel introduction flow path (fuel flow path 31, in-orifice 32, annular concave groove 33) → fuel introduction flow A third path (a third path of the fuel introduction path) through which high-pressure fuel flows into the control chamber 12 is formed via the path (clearance 34) → the annular groove 43 → the communication channel (communication port 39, axial hole 38). The That is, when the intermediate valve is opened, the fuel supply passages 24 and 25 to the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular concave groove 33), the fuel introduction passage (clearance 34), the annular concave portion. Since a flow path (third path) through which high-pressure fuel flows quickly into the control chamber 12 through the groove 43 and the communication flow path (communication port 39, axial hole 38) is formed, the nozzle is closed after the electromagnetic control valve is closed. The valve closing response time, which is a period until the needle 9 is closed, can be shortened. Thereby, the valve closing response of the nozzle needle 9 can be improved.

  Further, when the electromagnetic control valve is closed and the intermediate valve is opened, the fuel supply passages 24 and 25 bypass the out-orifice 42 and the sliding clearance 17, and the fuel introduction passages (fuel passage 31, In-orifice 32, annular groove 33) → fuel introduction flow path (clearance 34) → annular groove 43 → axial gap (axial groove 46) and high pressure fuel to intermediate flow path (fuel flow paths 47, 48) A second path (second path of the fuel introduction path) is formed. That is, when the intermediate valve is opened, the fuel supply passages 24 and 25 to the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular concave groove 33), the fuel introduction passage (clearance 34), the annular concave portion. Since the flow path (second path) through which high-pressure fuel flows quickly into the intermediate flow path (fuel flow paths 47, 48) through the groove 43 and the axial clearance (axial recess 46), the electromagnetic control valve is closed. It is possible to shorten the valve closing response time, which is a period required for the fuel pressure in the intermediate flow path (fuel flow paths 47 and 48) to recover after the valve is turned on. Thereby, the valve closing response of the nozzle needle 9 can be improved.

  Further, the block 20 is provided with a valve guide (inner peripheral portion of the first housing recess 44) for guiding the valve 14 of the intermediate valve so as to be slidable in the valve movement direction (valve hole opening direction). For this reason, since the valve 14 of the intermediate valve can move without inclining with respect to a prescribed valve moving direction (a direction parallel to the axial direction of the nozzle needle 9), the fuel communicating with the fuel supply passages 24, 25 The introduction channel (fuel channel 31, in-orifice 32, annular groove 33) can be quickly opened. As a result, the fuel supply passages 24 and 25 to the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular groove 33), the fuel introduction passage (the clearance 34), the fuel introduction passage (the gap 35, the fuel flow). Since the high pressure fuel can be introduced into the control chamber 12 and the intermediate flow passages (fuel flow passages 47, 48) through the passage 36) at once, the fuel pressure in the control chamber 12 can be rapidly increased. Thereby, the valve closing response of the needle can be improved.

Here, a valve guide that guides (supports) the valve 14 of the intermediate valve so as to be slidable back and forth is a separate part from the cylinder 22 in which the control chamber 12 is formed. The outer peripheral surface (outer surface) of the second cylindrical portion 72 of the valve 14 of the intermediate valve and the inner peripheral surface of the second accommodating recess 45 of the cylinder 22 (the outer periphery of the valve 14 of the intermediate valve) are provided. The gap (radial gap) 35 between the circumferential wall and the circumferential wall surface can be expanded in the radial direction. Therefore, from the fuel supply flow paths 24 and 25 to the fuel introduction flow path (the fuel flow path 31, the in-orifice 32, the annular concave groove 33), the fuel introduction flow path (clearance 34), and the fuel introduction flow path (gap 35, fuel flow path). Since the flow rate of the high-pressure fuel introduced into the control chamber 12 through 36) can be increased, the valve closing speed of the nozzle needle 9 can be improved. Thereby, the valve closing response of the nozzle needle 9 can be further improved.
Further, in the case of the injector 5 of the present embodiment, the gap 35 can be reduced. In this case, the outer diameter of the second cylindrical portion 72 of the valve 14 of the intermediate valve can be increased, and the pressure receiving area of the pressure received from the fuel in the control chamber 12 can be increased. Thereby, for example, even if the spring 15 is not provided, the valve 14 of the intermediate valve can be urged (closely contacted) against the second seat surface of the block 20, so that the fuel introduction flow path (the fuel flow path 31, the The orifice 32 and the annular groove 33) can be reliably cut off (closed).

Here, the valve 14 of the intermediate valve is simpler in shape in that it slides along the inner peripheral surface of the second accommodating recess 45 of the cylinder 22 that forms the control chamber 12 therein. 2 Forming the sliding clearance 17 between the inner circumferential surface of the housing recess 45 and the outer circumferential surface of the second cylindrical portion 72 of the valve 14 of the intermediate valve and the inner circumferential surface of the second housing recess 45 of the cylinder 22 Since the L / d ratio, which is the ratio of the sliding diameter (d) between the two and the intermediate valve sliding portion length (L), is small, the outer peripheral surface of the second cylindrical portion 72 of the valve 14 of the intermediate valve and the cylinder 22 This is inappropriate for forming a sliding portion between the inner peripheral surface of the second housing recess 45.
However, a slide provided in a valve guide (specifically, the inner peripheral portion of the first receiving recess 44 of the block 20) other than the inner peripheral surface of the second receiving recess 45 of the cylinder 22 that forms the control chamber 12 therein. If the sliding clearance 17 is formed between the moving surface and the sliding surface, the sliding diameter (D) can be reduced, so that the L / D ratio can be improved. For example, when the sliding portion length (L) is made equal to that of the prior art, the outer peripheral surface of the second cylindrical portion 72 of the valve 14 of the intermediate valve and the inner peripheral surface of the second accommodating recess 45 of the cylinder 22 slide. In contrast to the cylinder sliding, the L / D ratio is increased in the second embodiment, which is very advantageous for sliding performance. This can improve the condition of the sliding clearance 17 (so that the valve 14 of the intermediate valve can be smoothly moved in the valve hole opening direction and the valve hole closing direction).

[Configuration of Example 3]
FIG. 9 shows the third embodiment of the present invention and is a view showing the periphery of the intermediate valve of the injector 5.

The intermediate valve of the present embodiment has a valve 14 having a convex section in which a main out orifice (hereinafter referred to as an out orifice 37) and an axial hole 38 are formed. A spring 15 that biases the valve 14 of the intermediate valve toward the side pressing the second seat surface of the block 20 (the valve hole closing direction) may be provided.
As in the second embodiment, the valve 14 of the intermediate valve reciprocates in the first cylindrical portion 71 accommodated in the first accommodating recess 44 of the block 20 so as to be slidable in a reciprocating manner and in the second accommodating recess 45 of the cylinder 22. It has the 2nd cylindrical part 72 accommodated movably.
A sliding surface that forms a sliding portion (sliding clearance 17) between the first cylindrical portion 71 and the inner peripheral surface of the first receiving recess 44 of the block 20, similar to the second embodiment, An axial groove 46 (axial gap: see FIG. 6) extending in the axial direction of the sliding surface is formed. An annular top surface facing the fuel flow path 47 is provided on the distal end surface (the upper end surface in the drawing) of the first cylindrical portion 71.
On the outer peripheral surface of the second cylindrical portion 72, an outer surface facing the inner peripheral surface (peripheral wall surface) of the second accommodating recess 45 of the cylinder 22 with a gap 35 therebetween is formed.

Similar to the first and second embodiments, the fuel supply path includes fuel supply passages 24 to 28 that connect the inlet port 23 and the nozzle chamber 11, and the nozzle chamber passes through the fuel supply passages 24 to 28 from the common rail 4. 11 is a path for supplying high-pressure fuel to 11.
As in the second embodiment, the fuel introduction path includes a fuel introduction path (fuel path 31, in-orifice 32, annular groove 33) communicating with the fuel supply paths 24 and 25, and a fuel introduction path (clearance 34). And a fuel introduction channel (gap 35, fuel channel 36).

The fuel discharge path includes a communication channel (out orifice 37, axial hole 38, communication port 39) communicating with the control chamber 12, and an intermediate channel (fuel channels 47, 48, out orifice 49) communicating with the communication channel. ), And fuel discharge passages (fuel passages 51 and 52) communicating the intermediate passages (fuel passages 47 and 48, out orifice 49) with the outlet port of the injector 5. Here, like the first and second embodiments, the communication channel and the intermediate channel constitute a fuel outflow channel that communicates with the control chamber 12 and communicates between the control chamber 12 and the fuel channel 51.
The communication channel is formed inside the valve 14 of the intermediate valve. This communication flow path has an axial hole 38 extending in the axial direction of the valve 14 and a communication port 39 that communicates the sliding surface of the first cylindrical portion 71 with the axial hole 38.

The axial hole 38 is used as a flow path that connects the out orifice 37 and the intermediate flow path (fuel flow paths 47 and 48). The axial hole 38 has a bottom surface provided on the control chamber 12 side and an opening portion that opens to face the fuel flow path 47 on the top surface of the first cylindrical portion 71.
The communication port 39 has a sliding side opening that opens at the sliding surface of the first cylindrical portion 71 of the valve 14 of the intermediate valve.
Further, inside the valve 14 of the intermediate valve, the control chamber 12 communicates with the intermediate flow path (fuel flow paths 47 and 48, the out orifice 49) and the communication flow path (the axial hole 38 and the communication port 39). An out-orifice (squeezing part) 37 for narrowing the cross-sectional area of the channel is formed. The out orifice 37 is formed closer to the control chamber 12 than the sliding side opening of the communication port 39.

  Here, the fuel introduction path is such that when the electromagnetic control valve is closed and the intermediate valve is opened, the fuel supply flow paths 24 and 25 to the fuel introduction flow path (the fuel flow path 31, the in-orifice 32, the annular concave groove). 33), a first passage through which high-pressure fuel flows into the control chamber 12 via the fuel introduction passage (clearance 34) and the fuel introduction passage (gap 35, fuel passage 36). Further, when the electromagnetic control valve is closed and the intermediate valve is opened, the fuel supply passages 24 and 25 bypass the sliding clearance 17 and the out orifice 37, and the fuel introduction passages (fuel passage 31). , The in-orifice 32, the annular groove 33), the fuel introduction passage (clearance 34), the annular groove 43, the axial clearance (axial recess 46), and the intermediate passage (fuel passages 47, 48) with high pressure. A second path through which the fuel flows is provided. Further, when the electromagnetic control valve is closed and the intermediate valve is opened, the fuel supply passages 24 and 25 to the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular concave groove 33), the fuel introduction flow There is a third path through which high-pressure fuel flows into the intermediate flow path (fuel flow paths 47 and 48) via the path (clearance 34), the annular concave groove 43, the communication port 39, and the axial hole 38.

Further, the fuel discharge path is such that when the electromagnetic control valve is opened and the intermediate valve is closed, the sliding clearance 17 is bypassed, and the communication flow path (out orifice 37, axial hole 38) extends from the control chamber 12. The first flow path for discharging the fuel to the fuel flow paths 51 and 52 through the intermediate flow paths (the fuel flow paths 47 and 48 and the out orifice 49).
If the intermediate valve is opened when the electromagnetic control valve is opened, the sliding clearance 17 and the out orifice 37 are bypassed during the period from when the electromagnetic control valve is opened until the intermediate valve is closed. The fuel flow path from the control chamber 12 through the fuel flow path 36, the gap 35, the clearance 34, the annular concave groove 43, the communication port 39, the axial hole 38, the intermediate flow path (fuel flow paths 47 and 48, the out orifice 49). You may provide the 2nd path | route which discharges fuel to 51,52.

The sum of the cross-sectional areas of the sliding clearance 17 is set smaller than the cross-sectional area of the flow path of the out orifice 37.
Further, the cross-sectional area of the out-orifice 37 is set smaller than the cross-sectional area of the out-orifice 49.
Further, the cross-sectional area of the out-orifice 49 is set smaller than the cross-sectional area of the in-orifice 32.
The flow passage cross-sectional area of the in-orifice 32 is set smaller than the sum of the cross-sectional areas of the gap 35.
Further, the sum of the cross-sectional areas of the axial gaps (axial recess 46) is set smaller than the sum of the cross-sectional areas of the communication ports 39 of the communication flow path.
The flow passage cross-sectional area of the out orifice 37 is set smaller than the sum of the cross-sectional areas of the axial gaps (axial concave grooves 46).

[Operation of Example 3]
Next, the operation of the diesel engine injector 5 used in the common rail fuel injection system of this embodiment will be briefly described with reference to FIG.

First, when the electromagnetic control valve is opened and the intermediate valve is closed, the sliding clearance 17 is bypassed and the communication channel (out orifice 37, axial hole 38), intermediate channel is bypassed from the control chamber 12. A first path (a first path of the fuel discharge path) for discharging the fuel to the fuel discharge path (fuel flow paths 51 and 52) through (the fuel flow paths 47 and 48, the out orifice 49) is formed.
That is, when the electromagnetic control valve is opened, the fuel outflow channel (communication channel, intermediate channel) is opened. Thereby, the fuel in the intermediate flow path (fuel flow paths 47, 48, out orifice 49) flows out to the fuel discharge flow path (fuel flow paths 51, 52) side. For this reason, the intermediate valve maintains the closed state.

Subsequently, the fuel in the control chamber 12 flows out to the intermediate flow path side through the communication flow path including the throttle portion (out orifice 37) formed in the valve 14 of the intermediate valve, so that the inside of the control chamber 12 The fuel pressure will decrease. At this time, since the intermediate valve closes the fuel introduction passage (the fuel passage 31, the in-orifice 32, and the annular groove 33), the high-pressure fuel flows from the fuel introduction passage into the control chamber 12 or the intermediate passage. Is cut off. Thereby, the fuel pressure in the control chamber 12 decreases in a short time. That is, the fuel pressure in the control chamber 12 rapidly decreases.
If the intermediate valve is open when the electromagnetic control valve is opened, the period from the opening of the electromagnetic control valve to the closing of the intermediate valve is as shown in FIG. 17 and the out-orifice 37, bypassing the control chamber 12, the fuel flow path 36, the gap 35, the clearance 34, the annular groove 43, the communication port 39, the axial hole 38, the intermediate flow path (fuel flow paths 47, 48, You may form the 2nd path | route (2nd path | route of a fuel discharge path) which discharges a fuel to a fuel discharge flow path (fuel flow paths 51 and 52) through the out orifice 49).

That is, when the electromagnetic control valve is opened, the fuel outflow channel (communication channel, intermediate channel) is opened. As a result, the fuel in the control chamber 12 is set such that the sum of the cross-sectional areas of the axial clearance (axial recess 46) is smaller than the sum of the cross-sectional areas of the communication ports 39 of the communication flow path. , Bypassing the throttle part (out orifice 37), passing through gap 35, clearance 34, annular groove 43, communication port 39, axial hole 38 and intermediate passage (fuel passages 47, 48, out orifice 49) To the side. Further, the fuel that has flowed from the fuel introduction flow path (the fuel flow path 31, the in-orifice 32, and the annular groove 33) also bypasses the throttle portion (the out-orifice 37), and the clearance 34, the annular groove 43, and the communication flow path. It flows out through the (communication port 39, axial hole 38) to the intermediate flow path (fuel flow paths 47, 48, out orifice 49) side. Thereby, the fuel pressure in the control chamber 12 decreases in a short time. That is, the fuel pressure in the control chamber 12 rapidly decreases.
And since the pressure difference between the fuel pressure in the nozzle chamber 11 and the fuel pressure in the control chamber 12 increases, the valve opening force (force in the nozzle hole opening direction) acting on the nozzle needle 9 increases, and the spring When it becomes larger than the urging force (valve closing force) in the nozzle hole closing direction, the nozzle needle 9 opens. As a result, the high-pressure fuel supplied from the common rail 4 to the nozzle chamber 11 through the fuel supply path (fuel supply flow paths 24 to 28) is injected from the injection hole 8 into the combustion chamber for each cylinder of the engine E. That is, fuel injection into the combustion chamber for each cylinder of the engine E is started.

On the other hand, when the electromagnetic control valve is closed and the intermediate valve is opened, the fuel supply passages 24 and 25 to the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular groove 33), the fuel introduction A first path (first path of the fuel introduction path) through which high-pressure fuel flows into the control chamber 12 through the flow path (clearance 34) and the fuel introduction path (gap 35, fuel flow path 36) is formed. When the electromagnetic control valve is closed and the intermediate valve is opened, the fuel supply passages 24 and 25 bypass the sliding clearance 17 and the out orifice 37, and the fuel introduction passages (fuel passage 31). , The in-orifice 32, the annular groove 33), the fuel introduction passage (clearance 34), the annular groove 43, the axial clearance (axial recess 46), and the intermediate passage (fuel passages 47, 48) with high pressure. A second path (second path of the fuel introduction path) through which the fuel flows is formed. Further, when the electromagnetic control valve is closed and the intermediate valve is opened, the fuel supply passages 24 and 25 to the fuel introduction passage (the fuel passage 31, the in-orifice 32, the annular concave groove 33), the fuel introduction flow A third path (a third path of the fuel introduction path) through which high-pressure fuel flows into the intermediate flow path (fuel flow paths 47 and 48) via the passage (clearance 34), the annular concave groove 43, the communication port 39, and the axial hole 38 Is formed.
Since the sum of the cross-sectional areas of the axial gaps (axial recess 46) is set smaller than the sum of the cross-sectional areas of the communication ports 39 of the communication flow paths, the fuel supply flow paths 24, 25 The high-pressure fuel toward the intermediate flow path (fuel flow paths 47 and 48) mainly flows toward the third path rather than the second path.

  That is, when the electromagnetic control valve is closed, the fuel outflow channel (communication channel, intermediate channel) is closed. As a result, the outflow of fuel from the control chamber 12 and the intermediate flow path (the fuel flow paths 47 and 48, the out orifice 49) stops, so that the fuel pressure in the intermediate flow path (the fuel flow paths 47 and 48) and the control chamber The pressure difference with the fuel pressure in 12 becomes small. For this reason, the valve 14 of the intermediate valve is lifted downward in the figure by the fuel pressure in the fuel introduction passage (the fuel passage 31, the in-orifice 32, and the annular concave groove 33). That is, the valve 14 of the intermediate valve moves in the valve hole opening direction while being guided by the inner peripheral portion (valve guide) of the first receiving recess 44 of the block 20. Then, since the seal portion of the valve 14 of the intermediate valve is detached from the second seat surface of the block 20, the intermediate valve is opened.

When the electromagnetic control valve is closed and the intermediate valve is opened, the fuel introduction flow path (clearance 34) from the fuel introduction flow path (fuel flow path 31, in-orifice 32, annular groove 33), fuel High-pressure fuel flows into the control chamber 12 through the introduction flow path (gap 35, fuel flow path 36). Thereby, the fuel pressure in the control chamber 12 rises in a short time. That is, the fuel pressure in the control chamber 12 rises rapidly.
Further, bypassing the sliding clearance 17 and the out-orifice 37, the fuel introduction channel (the fuel channel 31, the in-orifice 32, the annular groove 33) to the fuel introduction channel (clearance 34), the annular groove 43, and the communication The high-pressure fuel flowing into the intermediate flow path (fuel flow paths 47, 48) via the port 39 and the axial hole 38 quickly recovers the fuel pressure in the intermediate flow path (fuel flow paths 47, 48).
It should be noted that at the stage where the fuel pressure in the control chamber 12 and the fuel pressure in the fuel flow paths 47 and 48 are balanced, the valve 14 of the intermediate valve is placed in the first receiving recess 44 of the block 20 regardless of the presence or absence of the spring 15. It moves in the valve hole closing direction while being guided by the inner peripheral portion (valve guide) and is seated on the second seat surface of the block 20. As a result, the valve 14 of the intermediate valve closes the in-orifice 32. That is, the intermediate valve is closed.

[Effect of Example 3]
As described above, in the injector 5 for a diesel engine used in the common rail fuel injection system of this embodiment, the out orifice 37 is installed on the control chamber 12 side from the sliding side opening of the communication port 39. Yes. As a result, when the electromagnetic control valve is opened and the intermediate valve is closed, the sliding clearance 17 is bypassed, and the communication flow path (out orifice 37, axial hole 38) is passed from the control chamber 12 to the intermediate flow path. A first path (a first path of the fuel discharge path) for discharging the fuel to the fuel discharge path (fuel flow paths 51 and 52) through (the fuel flow paths 47 and 48, the out orifice 49) is formed. For this reason, the valve opening response time, which is a period from when the electromagnetic control valve is opened to when the nozzle needle 9 is opened, can be shortened. Thereby, the valve opening responsiveness of the nozzle needle 9 can be improved.

  If the intermediate valve is open when the electromagnetic control valve is opened, the sliding clearance 17 and the out orifice 37 are bypassed during the period from when the electromagnetic control valve is opened until the intermediate valve is closed. Then, the fuel is discharged from the control chamber 12 through the fuel flow path 36 → the gap 35 → the clearance 34 → the annular groove 43 → the communication port 39 → the axial hole 38 → the intermediate flow path (the fuel flow paths 47 and 48, the out orifice 49). You may provide the 2nd path | route (2nd path | route of a fuel discharge path) which discharges fuel to a flow path (fuel flow paths 51 and 52). In this case, the fuel flow path 36 → the gap 35 → the clearance 34 → the annular groove 43 → the communication port 39 → the axial hole 38 → the intermediate flow path (the fuel flow paths 47 and 48, the out orifice 49) from the control chamber 12. As a result, a flow path (second path) through which fuel quickly flows out to the fuel discharge flow path (fuel flow paths 51, 52) is formed, so that the fuel pressure in the control chamber 12 can be rapidly lowered. Thereby, the valve opening responsiveness of the nozzle needle 9 can be improved.

  Here, in the case of the injector 5 of the present embodiment (third embodiment), the out-orifice 37 is installed closer to the control chamber 12 than the sliding side opening of the communication port 39, so that the electromagnetic control valve is opened. When the valve 14 of the intermediate valve rises upward in the drawing, the fuel pressure in the control chamber 12 is opened at the communication port (sliding surface of the first cylindrical portion 71) rather than the injector 5 of the second embodiment. It is possible to quickly flow out from the (flow path) 39. Therefore, the fuel pressure in the control chamber 12 can be lowered more rapidly than the injector 5 of the second embodiment. Thereby, valve-opening responsiveness can further be improved.

  Further, in the case of the injector 5 of the present embodiment (third embodiment), the out-orifice 37 is installed closer to the control chamber 12 than the sliding side opening of the communication port 39, so that the electromagnetic control valve is closed. When the intermediate valve is opened, the fuel supply passages 24, 25 to the fuel introduction passage (fuel passage 31, in-orifice 32, annular groove 33), fuel introduction passage (clearance 34), annular recess A third path (a third path of the fuel introduction path) through which the high-pressure fuel flows into the intermediate flow path (fuel flow paths 47 and 48) through the groove 43, the communication port 39, and the axial hole 38 is formed. Therefore, the high-pressure fuel is supplied to the intermediate flow path (fuel flow paths 47 and 48) more quickly than the injector 5 of the second embodiment, and the valve closing speed of the nozzle needle 9 can be increased. Thereby, the valve closing response of the nozzle needle 9 can be further improved.

[Modification]
In the present embodiment, the intermediate valve is configured in the block 20, but the intermediate valve may be configured in the injector body 18 or the nozzle body 21.
In this embodiment, an electromagnetic control valve that is driven by an electromagnetic actuator is adopted as the first control valve. However, a valve that opens and closes the fuel discharge path to increase or decrease the fuel pressure in the control chamber 12 can be driven. As long as it is a drive device, a control valve including another actuator such as an electric actuator, a piezoelectric actuator, or a negative pressure actuator may be employed.
In this embodiment, the needle is composed of only the nozzle needle 9, but the needle may be composed of a nozzle needle and a piston that reciprocally moves in the axial direction in conjunction with the nozzle needle.

In this embodiment, an in-orifice 32 is provided as an inlet orifice downstream of the fuel introduction flow path 31 in the fuel flow direction. However, an upstream or intermediate position of the fuel introduction flow path 31 in the fuel flow direction is provided as the inlet orifice. You may provide the orifice (fixed throttle part) installed in a part.
In this embodiment, an out-orifice 49 is provided as a sub-outlet orifice on the downstream side in the fuel flow direction of the fuel outflow channel (intermediate channel). ) Or an intermediate portion (fixed throttle portion) installed upstream or in the fuel flow direction. Further, the sub outlet orifice need not be provided.

1 Fuel tank (fuel supply source)
5 Injector (fuel injection device)
8 Injection hole 9 Nozzle needle 10 Spring (needle urging means)
11 nozzle chamber 12 control chamber 13 electromagnetic control valve valve (first control valve) (first valves)
14 valve intermediate valve (second control valve) (second valves)
15 Intermediate valve (second control valve) spring (valve biasing means)
16 Axial convex part of the nozzle needle (valve guide)
17 Sliding clearance (sliding part)
18 Injector body (Injector housing)
19 Valve body (Injector housing)
20 blocks (first valve body, injector housing)
21 Nozzle body (Injector housing)
22 Cylinder (second valve body, injector housing)
24 Fuel supply flow path (fuel supply flow path)
25 Fuel supply flow path (fuel supply flow path)
26 Fuel supply flow path (fuel supply flow path)
27 Fuel supply flow path (fuel supply flow path)
28 Fuel supply flow path (fuel supply flow path)
31 Fuel flow path (fuel introduction flow path)
32 in orifice (fuel introduction flow path)
33 Annular groove (fuel introduction flow path)
34 Clearance (fuel introduction flow path)
35 gap (fuel introduction flow path)
36 Fuel flow path (fuel introduction flow path)
37 Out orifice ( communication flow path)
38 Axial hole ( communication flow path)
39 Communication port ( communication flow path)
40 Axial hole ( communication flow path)
41 Fuel flow path ( communication flow path)
42 Out orifice ( communication flow path)
43 annular groove (medium between passage)
44 First receiving recess 45 Second receiving recess 46 Axial groove (axial groove)
47 fuel channel (medium between passage)
48 fuel channel (medium between passage)
49 out orifice (medium between passage)
51 Fuel flow path (fuel discharge flow path)
52 Fuel flow path (fuel discharge flow path)
64 End face of the valve of the intermediate valve 65 Axial recess of the valve of the intermediate valve 71 First cylindrical part (first body part) of the valve of the intermediate valve
72 Second cylindrical part (second body part) of valve of intermediate valve

Claims (20)

(A) a needle that opens and closes a nozzle hole for injecting fuel into the combustion chamber of the internal combustion engine;
(B) a nozzle chamber in which the internal fuel applies a force in the nozzle opening direction to the needle;
(C) a control chamber in which the internal fuel applies a force in the direction of closing the nozzle hole to the needle;
(D) needle urging means for urging the needle in the nozzle hole closing direction;
(E) a fuel supply path for supplying high-pressure fuel from a high-pressure generator that generates high-pressure fuel to the nozzle chamber;
(F) a fuel introduction path that communicates with the fuel supply path, and allows high-pressure fuel to flow from the fuel supply path to the control chamber via the fuel introduction path;
(G) a fuel discharge path that communicates with the control chamber, and discharges fuel from the control chamber through the fuel outflow path;
(H) a first control valve installed in the fuel discharge path to open and close the fuel outflow passage;
(I) a second control valve that is installed in the fuel introduction path and opens and closes the fuel introduction path;
(J) a housing that slidably supports the needle and that surrounds the periphery of the control chamber in a circumferential direction;
By closing or opening the first control valve to increase or decrease the fuel pressure in the control chamber, the needle is closed or opened to perform fuel injection control, and the first control valve is opened. In the fuel injection device for closing the fuel introduction flow path by closing the second control valve at the time of valve,
The fuel outflow channel has a communication channel communicating with the control chamber, and an intermediate channel communicating with the communication channel,
The communication flow path has a throttle portion that communicates the control chamber and the intermediate flow path, and narrows the cross-sectional area of the communication flow path,
The second control valve has a valve in which the throttle portion is formed,
The needle has a valve guide for guiding the valve in its reciprocating direction,
The housing has a peripheral wall surface surrounding the valve in the circumferential direction;
The valve has a sliding surface that forms a sliding portion with the valve guide, and an outer surface facing the gap with the peripheral wall surface,
In the fuel introduction path, when the first control valve is closed and the second control valve is opened, high-pressure fuel is supplied from the fuel supply path to the control chamber through the fuel introduction path and the gap. When the first path to be introduced and the first control valve are closed and the second control valve is opened, the fuel is introduced from the fuel supply path by bypassing the throttle portion and the sliding portion. A second path through which high-pressure fuel flows into the intermediate flow path via the flow path;
When the first control valve is opened and the second control valve is closed, the fuel discharge path bypasses the sliding portion and passes from the control chamber to the communication flow path and the intermediate flow path. A fuel injection device having a path for discharging fuel through The fuel injection device according to claim 1,
The needle has a fuel pressure receiving portion that receives fuel pressure in the control chamber, and an axial convex portion that protrudes in the axial direction from the fuel pressure receiving portion to one end side in the axial direction.
The valve has an opposing end face that faces the fuel pressure receiving portion with the control chamber therebetween, and the valve is opened at the opposing end face in an axial direction from the opening side to the back side. A fuel injection device comprising an extending axial recess. The fuel injection device according to claim 2, wherein
The valve guide is provided on the outer periphery of the axial convex portion,
The sliding surface of the valve is provided on the inner periphery of the axial recess,
The fuel injection device, wherein the sliding portion is formed between an outer peripheral surface of the axial convex portion and a sliding surface of the valve. The fuel injection device according to claim 2 or 3,
The fuel injection device according to claim 1, wherein the communication flow path is used as a flow path that connects the control chamber and the intermediate flow path via the throttle portion. The fuel injection device according to any one of claims 2 to 4,
The communication channel includes an axial hole extending in the axial direction of the needle from the tip surface of the axial convex portion toward the fuel pressure receiving portion, and the axial convex portion positioned on an extension line of the sliding portion. A communication port that communicates the outer peripheral surface of the shaft and the axial hole,
The communication port has an opening that opens to face the control chamber on the outer peripheral surface of the axial convex portion,
The fuel injection apparatus according to claim 1, wherein the axial hole is used as a flow path that connects the communication port and the throttle portion. (A) a needle that opens and closes a nozzle hole for injecting fuel into the combustion chamber of the internal combustion engine;
(B) a nozzle chamber in which the internal fuel applies a force in the nozzle opening direction to the needle;
(C) a control chamber in which the internal fuel applies a force in the direction of closing the nozzle hole to the needle;
(D) needle urging means for urging the needle in the nozzle hole closing direction;
(E) a fuel supply path for supplying high-pressure fuel from a high-pressure generator that generates high-pressure fuel to the nozzle chamber;
(F) a fuel introduction path that communicates with the fuel supply path, and allows high-pressure fuel to flow from the fuel supply path to the control chamber via the fuel introduction path;
(G) a fuel discharge path that communicates with the control chamber, and discharges fuel from the control chamber through the fuel outflow path;
(H) a first control valve installed in the fuel discharge path to open and close the fuel outflow passage;
(I) a second control valve that is installed in the fuel introduction path and opens and closes the fuel introduction path;
(J) a housing that slidably supports the needle and that surrounds the periphery of the control chamber in a circumferential direction;
By closing or opening the first control valve to increase or decrease the fuel pressure in the control chamber, the needle is closed or opened to perform fuel injection control, and the first control valve is opened. In the fuel injection device for closing the fuel introduction flow path by closing the second control valve at the time of valve,
The fuel outflow channel has a communication channel communicating with the control chamber, and an intermediate channel communicating with the communication channel,
The communication flow path has a throttle portion that communicates the control chamber and the intermediate flow path, and narrows the cross-sectional area of the communication flow path,
The second control valve has a valve in which the throttle portion is formed,
The housing has a valve guide for guiding the valve in a reciprocating direction thereof, and a peripheral wall surface surrounding the periphery of the valve in a circumferential direction,
The valve is a sliding surface that forms a sliding portion with the valve guide, and a shaft that is used as a flow path that connects the fuel introduction flow path and the intermediate flow path between the valve guide and the valve guide. An axial groove extending in the axial direction of the valve, and an outer surface facing the gap with a gap between the circumferential wall and the axial groove
In the fuel introduction path, when the first control valve is closed and the second control valve is opened, high-pressure fuel is supplied from the fuel supply path to the control chamber through the fuel introduction path and the gap. When the first path to be introduced and the first control valve are closed and the second control valve is opened, the fuel is introduced from the fuel supply path by bypassing the throttle portion and the sliding portion. A second path through which high-pressure fuel flows into the intermediate flow path through the flow path and the axial gap;
When the first control valve is opened and the second control valve is closed, the fuel discharge path bypasses the sliding portion and passes from the control chamber to the communication flow path and the intermediate flow path. A fuel injection device having a path for discharging fuel through The fuel injection device according to claim 6, wherein
The housing has a first valve body having a first receiving recess formed therein, and a second valve body having a second receiving recess formed therein,
The valve includes a first body portion that is slidably reciprocally accommodated in the first housing recess, and a second body portion that is reciprocally movable in the second housing recess. A fuel injection device. The fuel injection device according to claim 7, wherein
The valve guide is provided on the inner periphery of the first receiving recess,
The sliding surface of the valve is provided on the outer periphery of the first body part,
The fuel injection device, wherein the sliding portion is formed between an inner peripheral surface of the first housing recess and a sliding surface of the first body portion. The fuel injection device according to claim 7 or 8,
The communication flow path has an axial hole extending in the axial direction of the valve, and a communication port that connects the sliding surface of the first body portion and the axial hole,
The communication port has an opening that opens at the sliding surface of the first body portion, and the fuel introduction passage is only when the first control valve is closed and the second control valve is opened. Or it is used as a flow path which connects the said gap and the said axial direction hole, The fuel-injection apparatus characterized by the above-mentioned. The fuel injection device according to claim 9, wherein
The narrowed portion is formed closer to the intermediate flow path than the opening of the communication port,
The fuel injection apparatus according to claim 1, wherein the axial hole is used as a flow path that connects the control chamber and the throttle portion. The fuel injection device according to claim 10, wherein
When the first control valve is closed and the second control valve is opened, the fuel introduction path passes through the fuel introduction path, the communication port, and the axial hole from the fuel supply path. A fuel injection device having a third path through which high-pressure fuel flows into the control chamber. The fuel injection device according to claim 9 or 10,
The fuel discharge path bypasses the sliding portion when the first control valve is opened and the second control valve is closed, and from the control chamber, the axial hole, the throttle portion, A fuel injection device having a path for discharging fuel through the intermediate flow path. The fuel injection device according to any one of claims 10 to 12,
The fuel injection device according to claim 1, wherein a flow path cross-sectional area of the throttle portion is set smaller than a sum of cross-sectional areas of the axial gaps. The fuel injection device according to claim 9, wherein
The throttle portion is formed on the control chamber side with respect to the opening portion of the communication port,
The fuel injection apparatus according to claim 1, wherein the axial hole is used as a flow path that connects the throttle portion and the intermediate flow path. The fuel injection device according to claim 14, wherein
When the first control valve is closed and the second control valve is opened, the fuel introduction path bypasses the throttle portion and the sliding portion, and connects the communication port to the communication port. A fuel injection device comprising a third path through which high-pressure fuel flows into the intermediate flow path through the axial hole. The fuel injection device according to claim 14 or 15,
The fuel discharge path bypasses the sliding portion when the first control valve is opened and the second control valve is closed, and the throttle portion, the axial hole, A fuel injection device having a path for discharging fuel through the intermediate flow path. The fuel injection device according to any one of claims 7 to 16,
The first valve body is a valve body that surrounds the periphery of the first body portion in the circumferential direction,
The second valve body is a cylinder that circumferentially surrounds the control chamber and the second body part,
The fuel injection device according to claim 1, wherein the valve guide is provided in the valve body made of a separate part from the cylinder. The fuel injection device according to any one of claims 1 to 17,
The fuel injection device according to claim 1, wherein the sum of the cross-sectional areas of the sliding portions is set to be smaller than a flow passage cross-sectional area of the throttle portion. The fuel injection device according to any one of claims 1 to 5, and 14 to 16.
The fuel injection device according to claim 1, wherein a flow path cross-sectional area of the throttle portion is set to be smaller than a sum of cross-sectional areas of the gaps. The fuel injection device according to any one of claims 1 to 19,
The valve is a valve body that closes and opens a valve hole communicating with the fuel introduction channel,
The fuel injection device according to claim 1, wherein the second control valve includes valve urging means for urging the valve in a valve hole closing direction.

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