JP2006183468A - Fuel injection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection device which injects two kinds of fuels and can part injection of the fuels. <P>SOLUTION: The fuel injection device is provided with a nozzle body 11 which injects and feeds fluid concerning combustion to an internal combustion engine and in which a first nozzle hole 30 and a second nozzle hole 40 are formed; an outside needle 50 which switches the presence of injection of the fluid through the first injection hole by lift operation by accommodation able to reciprocate to the inside of a nozzle body; an inside needle 60 which switches the presence of the fluid through the second injection hole by lift operation by accommodation able to effect reciprocating movement to the inside of the outside needle; and flow paths 16 and 17 through which two kinds of fluids concerning combustion are separately guided to each of the first and second injection holes. Further, it is desirable that the flow paths are provided with the first flow path 16 which is formed in the first gap between the outer periphery of the outside needle and the inside periphery of the nozzle body and through which first fluid flows; and the second flow path 17 formed in a second gap between the outer periphery of the inside needle and the inner periphery of the outside needle and through which second fluid flows. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel injection device, and is suitably applied to, for example, a fuel injection device that injects and supplies two types of fuel to an internal combustion engine.

As a fuel injection device, for example, a fuel injection valve that directly injects fuel into a combustion chamber of an internal combustion engine is known (see Patent Document 1). The fuel injected from the fuel injection valve is atomized, develops while mixing with the air in the combustion chamber, self-ignites near the ideal mixture ratio, and starts combustion. If the combustion ratio near the stoichiometric mixture ratio is high, the combustion gas becomes high temperature and a large amount of nitrogen oxide (NO _x ) is generated, so improving the combustion characteristics of the fuel that affects the mixture formation It is important.

  Patent Document 1 discloses a technique for injecting two types of fuel, fuel and fluid such as water other than fuel. In this technique, a fuel injection valve is accommodated coaxially in one fluid injection valve, and a needle as a valve member that performs injection and stop of fuel is incorporated in the fuel injection valve. The fuel injection valve itself functions as a valve member in the fluid injection valve, and is configured so that fluid can be injected and stopped by reciprocating movement of the fuel injection valve. It is possible to adjust the combustion characteristics of the fuel by injecting the fluid with delay during the fuel injection.

The fluid injection holes are provided on the outside extension of the fuel injection holes. The number of fluid injection holes and the number of fuel injection holes is the same, and the number of fluid injection holes is larger than that of the fuel injection holes. It has a large diameter. It may be considered that the size of the nozzle hole outlet contributing to atomization of the spray is determined by the fluid nozzle hole.
Japanese Patent Laid-Open No. 11-30164

  However, in the prior art disclosed in Patent Document 1, it is possible to inject a fluid with a delay during fuel injection, but since the nozzle hole outlets are substantially the same, it is difficult to inject two fluids separately.

  The applicant is considering what can be switched to an optimal spray state in, for example, a low load region and a high load region. When the technique of Patent Document 1 is applied to such a thing, spray spraying cannot be performed in a low load region and a high load region, and at a high load, the nozzle hole outlet has a relatively large diameter. There is a possibility that the high penetration power cannot be obtained.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a fuel injection device capable of separately injecting two types of fuel having different combustion characteristics. There is to do.

  Another object is to inject two types of fuels having different combustion characteristics. These fuels can be sprayed separately, and an optimal spray state is formed according to the operating state of the internal combustion engine. An object of the present invention is to provide a fuel injection device that can improve the performance of the fuel injection system.

  In order to achieve the above object, the present invention comprises the following technical means.

  That is, according to the first to fifth and seventh aspects of the present invention, the nozzle body in which the first injection hole and the second injection hole are formed to inject and supply the fluid related to the combustion into the cylinder of the internal combustion engine, and the first injection An outer needle that switches whether or not the fluid is ejected from the hole by a lift operation that can be reciprocated inside the nozzle body, and whether or not the fluid is ejected from the second nozzle hole can be reciprocated into the outer needle. And an inner needle that is switched by a lift operation by proper accommodation, and a flow path that individually guides the two types of fluids related to combustion to the respective injection holes of the first injection hole and the second injection hole.

  Thus, in the case of injecting two types of fuel related to combustion, it is possible to inject these fuels separately.

  In particular, in the invention according to claim 2, the two types of fluids are a first fluid and a second fluid, and the flow path is provided between the outer periphery of the outer needle and the inner periphery of the nozzle body. A first flow path formed by the first gap, through which the first fluid flows, and a second flow path formed by the second gap between the outer periphery of the inner needle and the inner periphery of the outer needle, through which the second fluid flows. It is characterized by providing these.

  According to this, in the fuel injection device that includes the inner needle and the outer needle that are doubly arranged inside and outside, and the nozzle body that accommodates the inner needle and the outer needle so as to be reciprocally movable, As a flow path for individually guiding the fluid to each nozzle hole of the first nozzle hole and the second nozzle hole, a fluid is formed in a first gap between the outer periphery of the outer needle and the inner periphery of the nozzle body. The first flow path is configured to include a second flow path formed by a second gap between the outer periphery of the inner needle and the inner periphery of the outer needle, and the second fluid flows. As a result, the flow of the two types of fluid is divided into a first flow path and a second flow path formed by a gap between the inner needle, the outer needle, and the inside of the valve body, which are arranged in duplicate inside and outside, respectively. And the first nozzle hole and the second nozzle hole, for example, when the outer needle is opened, the first fluid flows into the first nozzle hole along the first flow path when the outer needle opens. When the valve is opened, the second fluid can flow into the second nozzle hole along the second flow path. Therefore, in the case of injecting two types of fuels having different combustion characteristics, these fuels can be injected separately.

  According to a third aspect of the present invention, the nozzle body includes each valve seat from which the inner needle and the outer needle are separated and seated, and when the outer needle is closed, the upstream position of the fluid flow in the first nozzle hole The downstream position is seated, and when the inner needle is closed, the upstream position of the fluid flow of the second nozzle hole is seated.

  According to this, the nozzle body includes the valve seats on which the inner needle and the outer needle are separated and seated, and when the outer needle is closed, the upstream position and the downstream position of the fluid flow of the first nozzle hole are seats. When the inner needle is closed, it is preferable that the upstream position of the fluid flow of the second nozzle hole is seated. Accordingly, the outer needle for switching the presence / absence of the fluid injection from the first nozzle hole by the lift operation by the reciprocating housing inside the nozzle body and the presence / absence of the fluid injection from the second nozzle hole are changed. An internal needle that is switched by a lift operation by reciprocating accommodation inside, and a flow path that individually guides the two types of fluids related to combustion to the respective injection holes of the first injection hole and the second injection hole Can be easily formed.

  The invention according to claim 4 is characterized in that a seat member capable of being urged to the valve seat is provided, and the seat member is disposed in the second gap.

  According to this, it is preferable to provide a seat member that can be biased to the valve seat, and to dispose the seat member in the second gap. Thereby, when the inner needle and the outer needle are independently opened, the first fluid can be sprayed separately from the first nozzle hole and the second fluid can be sprayed independently from the second nozzle hole.

  In the inventions according to claims 5 and 7, when two types of fuels having different combustion characteristics are injected, these fuels can be sprayed separately, and an optimum spray can be selected according to the operating state of the internal combustion engine. The state is formed and the performance of the internal combustion engine can be improved.

In the invention according to claim 7, since the two kinds of fluids related to combustion, that is, the first fluid and the second fluid are two kinds of fuels having different boiling point temperatures,
For example, in a low load region of an internal combustion engine, fuel having a relatively low boiling point temperature is injected from one of the first and second nozzle holes, and in the high load region, the boiling point temperature is injected from the other nozzle hole. It is possible to inject a relatively high fuel. Therefore, in a low load range, the fuel can be evaporated quickly with a fuel having a relatively low boiling point, and the mixture can be diluted. On the other hand, in a high load region, the evaporation can be delayed with a fuel having a relatively high boiling point, and the spray can be blown far away.

In the invention according to claim 5, the fuel injection device according to claims 1 to 4 is used for an internal combustion engine to which two types of fluid relating to combustion are supplied by injection,
A driving device that independently drives the inner needle and the outer needle, and a control unit that controls the spray pattern of at least one of the two types of fluids related to combustion by driving and controlling the driving device; Prepared,
The control means is characterized by opening the inner needle when the operating state of the internal combustion engine is in the low load region, and opening the outer needle and the inner needle when the operating state is in the high load region.

  Thus, the outer needle and the inner needle are opened in the high load region of the internal combustion engine, so that fuel can be injected from the first nozzle hole and the second nozzle hole at a large flow rate. Furthermore, since the inner needle is opened when in the low load region, for example, the air-fuel mixture can be diluted using the specific combustion characteristics of the second fluid of the two types of fluids.

  In the inventions according to claims 6 and 7, in the case of injecting two types of fuels having different combustion characteristics, these fuels can be sprayed separately, and an optimal spray can be selected according to the operating state of the internal combustion engine. The state is formed and the performance of the internal combustion engine can be improved. For example, in a low load region of an internal combustion engine, fuel having a relatively low boiling point temperature is injected from the second injection hole by opening the inner needle, and in a high load region, the boiling point temperature of the first injection hole is increased by opening the outer needle. It is possible to inject a relatively high fuel. As a result, in a low load range, the fuel is evaporated quickly with a fuel having a relatively low boiling point, and the air-fuel mixture is diluted. On the other hand, in a high load region, the evaporation can be delayed with a fuel having a relatively high boiling point, and the spray can be blown far away. Furthermore, since the inner needle is opened in addition to the opening of the outer needle in the high load region, fuel can be injected at a large flow rate from the first injection hole and the second injection hole, and the output of the internal combustion engine can be improved. .

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments in which a fuel injection device of the present invention is embodied will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic cross-sectional view showing the configuration of the fuel injection device of the present embodiment. FIG. 2 is a partial cross-sectional view showing the main part of the valve portion related to the fuel injection device of the present embodiment. FIG. 3 is a view for explaining an open / close state of the valve portion of the fuel injection device, and is a partial cross-sectional view showing a state in which the inner needle and the outer needle of the valve portion in FIG. 1 are closed. FIG. 4 is a view for explaining the open / close state of the valve portion of the fuel injection device, and is a partial cross-sectional view showing a state in which the inner needle is opened. FIG. 5 is a partial cross-sectional view illustrating a state where the valve portion of the fuel injection device is opened and closed, and showing a state where the outer needle is opened. FIG. 6 is a partial cross-sectional view illustrating a state where the valve portion of the fuel injection device is opened and closed, in which the inner needle and the outer needle are opened. FIG. 7 is a map configuration diagram for setting the spray form so that two types of fluids can be sprayed corresponding to the combustion state executed in the internal combustion engine. FIG. 9 is a schematic cross-sectional view showing an embodiment of the drive device in FIG. In FIG. 7, the region I and region II are divided by a solid line in the drawing, and the region I having the rotation speed Ne1 and the load factor T1 or less in the drawing is mainly referred to as a low load region, and the region II which is another region Is mainly called the high load region. The broken line in FIG. 7 shows an example of the performance characteristic example of the internal combustion engine.

  A fuel injection device 1 shown in FIG. 2 is inserted and mounted in a cylinder head of an engine (not shown), and is configured to inject directly into each cylinder of the engine. The fuel injection device 1 includes a fuel injection valve 2 that injects two types of fuel, a common rail 5 that accumulates pressurized high-pressure fuel supplied to the fuel injection valve 2, and a pressure applied to the common rail 5. A high-pressure pump 6 for supplying fuel and an ECU 90 as control means are provided.

  The fuel injection valve 2 has a substantially cylindrical shape, receives fuel from a fuel introduction portion (not shown) (in the direction of the arrow indicating fuel inflow in the figure), and injects fuel from the tip via internal fuel passages 23 and 24. . The fuel injection valve 2 includes a valve portion that blocks and allows fuel injection, and a driving device 80 (see FIG. 9) that drives the valve portion. The fuel injection valve 2 controls the fuel that has flowed into the fuel passage from the fuel introduction portion. Is supplied to the engine cylinder.

  The high-pressure fuel supplied from the high-pressure pump 6 through the fuel pipe to the common rail 5 is accumulated at a constant high pressure in the common rail 5 and introduced into the fuel injection valve 2 disposed in each cylinder through the fuel pipe. Introduced into the department. Of the introduced fuel, surplus fuel is returned to the fuel tank 7 via a fuel outlet (not shown) (in the direction of the arrow indicating fuel return in FIG. 9). The high pressure pump 6 is provided so as to adjust the fuel discharge pressure according to the engine speed, load, intake fuel pressure, intake air amount, cooling water temperature, and the like. Here, two types of fuel are supplied to the fuel injection valve 2, and as shown in FIG. 1, among the two types of fuel, the fuel A is a fuel tank 7a, a high-pressure pump 6a, and a common rail. The fuel path 5a is supplied to the internal fuel passage 24. On the other hand, the fuel B is supplied to the internal fuel passage 23 through the fuel passage of the fuel tank 7b, the high-pressure pump 6b, and the common rail 5b.

  Here, the fuel A and the fuel B constitute two kinds of fluids related to combustion described in the claims, respectively. The fuel A is the second fluid and the fuel B is the first fluid. Further, the driving device 80 is not limited to the structure of the electromagnetic driving unit such as the known electromagnetic valve shown in FIG. 9 as long as it independently drives the outer needle 50 and the inner needle 60. It may be a drive member that expands and contracts. Note that the driving device 80 described in the following embodiment is a solenoid valve.

  As shown in FIGS. 1 and 2, the fuel injection valve 2 includes a nozzle body 11, a first needle 50 and a second needle 60 that are accommodated in the nozzle body 11 so as to be reciprocally movable, and an electromagnetic valve 80. Has been. The nozzle body 11, the first needle 50, and the second needle 60 constitute a valve portion that blocks and allows fuel injection. The electromagnetic valve 80 constitutes an electromagnetic drive unit that drives the valve unit by hydraulic pressure. More specifically, the nozzle body 11, the first needle 50, and the second needle 60 constitute a valve body (hereinafter referred to as a nozzle body) 10 that performs fuel flow and shut-off. The nozzle body 10 is coupled to the valve housing 20 having the fuel introduction portion by a fastening member such as a retaining nut 19.

  As shown in FIG. 1, the nozzle body 11 is a bottomed, generally hollow cylindrical body, and includes a guide hole 11 a that accommodates the first needle 50 and the second needle 60 in a reciprocating manner therein, and a valve seat 12. And the nozzle holes 30 and 40 are formed. The guide hole 11a extends in the axial direction inside the nozzle body 11, and accommodates the first needle 50 and the second needle 60 so as to be movable in the axial direction. The guide hole 11 a has one end connected to a back pressure chamber 70 as a pressure control chamber and the other end connected to the valve seat 12.

  As shown in FIGS. 1 and 2, the valve seat 12 is formed in a substantially conical surface, and a first injection hole 30 and a second injection hole 40 are formed on the downstream side of the fuel flow of the valve seat 12. Has been. The sack portion 18 is defined by the lower end surface 65 of the second needle 60 and the valve seat 12. The sack portion 18 is a sack hole formed in a bag shape with a small space volume on the tip side of the nozzle body 11. Here, the sac portion 18 constitutes a sac chamber having a bag-like predetermined space volume.

  In addition, the valve seat 12 comprises each valve seat from which the 2nd needle 60 as an inner needle described in a claim and the 1st needle 50 as an outer needle are separated and seated here. The valve seat 12 and the guide hole 11a constitute the inner periphery of the nozzle body 11 described in the claims.

  An abutting portion (hereinafter referred to as a first abutting portion) 51 of the first needle 50 is disposed on the valve seat 12 so as to be capable of abutting and separating. Further, the second contact portion 61 of the second needle 60 is disposed on the valve seat 12 so as to be capable of contacting and separating. The contact portion 61 is a so-called line seal portion, and theoretically has a circular shape. The contact part 51 is a so-called face seal part, and has a shape of a truncated cone.

  Here, the contact portions 51 and 61 and the valve seat 12 are configured such that the fuel flows as shown in FIGS. 2 and 3 when the contact portions 51 and 61 contact and separate from the valve seat 12. The first seal portion S1 and the second seal portion S2 are configured to block and allow the above. By the seating of the contact portion 51 on the valve seat 12, the first seal portion S1 sets the upstream position and the downstream position of the fluid flow in the first nozzle hole 30 when the first needle 50 is closed. A sheet portion for sheeting is configured. By the seating of the contact portion 61 on the valve seat 12, the second seal portion S2 seats the upstream position of the fluid flow in the second nozzle hole 40 when the second needle 60 is closed. Part.

  As shown in FIGS. 1 and 2, the nozzle holes 30 and 40 are formed as passages that communicate between the inside and the outside of the nozzle body 11. Here, the nozzle hole (hereinafter referred to as the first nozzle hole) 30 is disposed on the downstream side of the first seal portion S1, and the first fuel that is blocked and permitted by the first seal portion S1 is injected. A fuel injection means is comprised. The nozzle hole (hereinafter referred to as the second nozzle hole) 40 is disposed downstream of the second seal portion S2, and is a second fuel injection means for injecting fuel that is blocked and allowed by the second seal portion S2. Configure.

  As shown in FIG. 1, the oil sump chamber 14 is formed in an annular recess in the middle portion of the inner wall that forms the guide hole 11 a. A fuel supply passage 23 to which fuel B is supplied is connected to the oil reservoir 14.

  The first needle 50 as an outer needle is formed in a substantially cylindrical shape, and is loosely fitted into the guide hole 11a through a predetermined gap (first gap). A first upper end surface 53 that receives the hydraulic pressure in the back pressure chamber 70 is formed on the side opposite to the nozzle hole of the first needle 50, and on the nozzle hole side of the first needle 50, facing the first valve seat 12b, A substantially conical first lower end surface 55 is formed. The first lower end surface 55 is disposed to face the valve seat 12 in parallel. When the first contact portion 51 is seated on and separated from the valve seat 12, the first needle 50 is closed and opened, so that the fuel from the first injection hole 30 is shut off and allowed. A gap (first gap) that expands and contracts by seating and separation is formed between the first lower end surface 55 and the valve seat 12, and a fuel passage 16 is formed as a first gap.

  A sleeve 18 that forms the back pressure chamber 70 is disposed between the first upper end surface 53 and the back pressure chamber 70, and is attached between the sleeve 18 and a seat 58 that is fixed to the needle 50 side. A first spring 59 is disposed as a biasing means. The first spring 59 is configured to urge the spring seat 58 in the seating direction for seating on the valve seat 12. By adjusting the pressure in the back pressure chamber 70, the first needle 50 is reciprocated in the axial direction. A predetermined gap (hereinafter referred to as a first gap) is formed between the outer periphery of the first needle 50 and the inner periphery of the guide hole 11a of the nozzle body 11 facing the outer periphery. A fuel passage 15 is formed by the gap (see FIG. 1). The fuel passage 15 constitutes a fuel path that guides the high-pressure fuel B supplied through the oil sump chamber 14 to the first injection hole 30 side.

  The second needle 60 as the inner needle is formed in a substantially cylindrical shape and is accommodated in the first needle 50 so as to be reciprocally movable. Specifically, it is accommodated in the inner periphery 52 of the first needle 50 so as to be able to reciprocate. An upper end surface for receiving the hydraulic pressure in the back pressure chamber 70 is formed on the side opposite to the injection hole of the second needle 60 (see FIG. 2), and the valve hole 12 of the second needle 60 is opposed to the valve seat 12; A second lower end surface 65 is formed. The second lower end surface 65 is disposed on the inner peripheral side with respect to the second contact portion 61.

  As shown in FIG. 1, a second spring 69 as an urging means is disposed between the flange 63 and the back pressure chamber 70, and the second spring 69 is seated in the seating direction in which the valve seat 12 is seated. It is comprised so that the collar part 63 may be urged | biased. By adjusting the pressure in the back pressure chamber 70, the second needle 60 is reciprocated in the axial direction. A predetermined gap (hereinafter referred to as a second gap) is formed between the inner periphery of the first needle 50 and the outer periphery of the second needle 60, and the fuel passage 17 is formed by the second gap. ing.

  A fuel supply passage 24 and a return passage 29 are connected to the back pressure chamber 70. An inlet throttle (not shown) is provided at the inlet, and an outlet throttle (not shown) is provided at the outlet. The fuel supply passage 24 is branched halfway in order to supply high-pressure fuel to the back pressure chamber 70 and the oil reservoir chamber 24. The return passage 29 is connected to a return fuel path for returning surplus fuel in the back pressure chamber 70 to the fuel tank. An electromagnetic valve 80 is provided on the downstream side of the return fuel path to switch communication between the return path 29 and the low pressure path on the fuel tank side. By adjusting the area ratio of the flow passage cross-sectional area of the inlet throttle and the outlet throttle by the electromagnetic valve 80, the balance between the inflow amount and the outflow amount of high-pressure fuel into the back pressure chamber 70 can be adjusted. Accordingly, the fuel pressure increase / decrease speed in the back pressure chamber 70 is adjusted.

  Here, the back pressure chamber 70 constitutes a common pressure control chamber for applying a pressure in the seating direction to the first needle 50 and the second needle 60.

  The electromagnetic valve 80 includes a control valve 81, and a solenoid 82 and a third spring 83 are provided on the upper portion thereof. When the drive current is not supplied to the solenoid 82, the control valve 81 is seated on a valve seat (not shown) by the urging force of the third spring 83 and blocks the return passage 29. When the drive current is supplied, the control valve 81 is separated from the valve seat by the exciting suction force generated in the solenoid 82 and opens the return passage 29. The drive current is supplied to the solenoid 82 at a timing obtained by the ECU 90 according to the operating state of the engine.

  The ECU 90 as a control means is a microcomputer having a known configuration in which a read only memory (ROM), a random access memory (RAM), a microprocessor (CPU), an input port, and an output port are connected to each other via a bidirectional bus. It is configured. The ECU 90 controls the energization period for the fuel injection valve 10. Various engine programs (not shown) are read by reading signals from various sensors (not shown) that detect engine operating conditions such as engine speed, intake pipe pressure (or intake air amount), and cooling water temperature. Accordingly, the operation of the electromagnetic drive unit S of the fuel injection valve 2 is controlled. Specifically, a reference position sensor that outputs a pulse signal every 720 ° CA according to the rotation state of the crankshaft, and a rotation angle that outputs a pulse signal every finer crank angle (for example, every 30 ° CA). And a sensor. A water temperature sensor for detecting the cooling water temperature is disposed in a cylinder (water jacket) (not shown) of the engine. The intake pipe is provided with an air flow meter for detecting the intake air flow rate. The exhaust pipe is provided with an air-fuel ratio sensor that outputs an air-fuel ratio signal in proportion to the oxygen concentration in the exhaust gas. In addition, an accelerator pedal sensor, a throttle opening sensor, and the like for detecting a driver's request and the like are provided.

  The operation of the fuel injection device 1 having the above-described configuration will be described below.

(When injection stops)
The relatively high-pressure fuels A and B accumulated in the common rails 5a and 5b are supplied to the back pressure chamber 70 and the fuel passage 15 through the fuel supply passages 23 and 24 as shown in FIG. At this time, since the drive current is not supplied to the solenoid 82, the control valve 81 is seated on the valve seat by the urging force of the third spring 83 to block the return passage 29. Since the supplied fuel A stays in the back pressure chamber 70, the fuel pressures in the pressure control chamber 70 and the fuel passage 15 are substantially equal. Since the urging force for pressing the first needle 50 against the valve seat 12 is larger than the urging force for lifting, the contact portion 51 is seated on the valve seat 12 and the fuel B in the fuel passage 15 is There is no injection from one injection hole 30. Further, since the urging force for pressing the second needle 60 against the valve seat 12 is larger than the urging force for lifting, the contact portion 61 is seated on the valve seat 12 and the fuel in the back pressure chamber 70 is A is not injected from the second injection hole 40 (see FIG. 3).

(Operation to the opening of the second nozzle hole 40)
When a drive current is supplied to the control valve 81, the control valve 81 is lifted by the magnetic attractive force generated by the solenoid 82, and the return passage 29 is opened. When the return passage 29 is opened, the fuel pressure in the back pressure chamber 70 decreases. When the fuel pressure in the back pressure chamber 70 decreases to the valve opening pressure of the second needle 60, the second needle 60 is lifted, the second contact portion 61 is separated from the valve seat 12, and the second needle 60 is opened. To be spoken. When the second needle 60 is opened, the fuel A in the back pressure chamber 70 and the fuel passage 17 flows into the second injection hole 40, and the fuel A is injected from the second injection hole 40 (see FIG. 4).

(Operation to the opening of the first nozzle hole 30)
When a drive current is supplied to the control valve 81, the control valve 81 is lifted by the magnetic attractive force generated by the solenoid 82, and the return passage 29 is opened. When the return passage 29 is opened, the fuel pressure in the back pressure chamber 70 decreases. The pressure decreases at a predetermined lowering speed according to the area ratio of the first inlet throttle 71 and the first outlet throttle 72. When the fuel pressure in the back pressure chamber 70 decreases to the valve opening pressure of the first needle 50, the first needle 50 is lifted, the first contact portion 51 is separated from the valve seat 12, and the first needle 50 is opened. To be spoken. When the first needle 50 is opened, the fuel B in the fuel passages 15 and 16 flows into the first injection hole 30 and the fuel B is injected from the first injection hole 30 as shown in FIG.

(Operation to the opening of the first nozzle hole 30 and the second nozzle hole 40)
In the opening process of the first nozzle hole 30 described above, when the first contact portion 51 is separated from the valve seat 12, the seal state of the first seal portion S1 is released, and the high pressure (common rail pressure) from the fuel passages 15 and 16 is released. ) Pd fuel B flows in. The fuel B is injected from the first injection hole 30. Further, when the second contact portion 61 is separated from the valve seat 12 in the opening process of the second nozzle hole 40, the sealing state of the second seal portion S2 is released, and the back pressure chamber 70 and the fuel passage 17 are removed. Fuel A of high pressure (common rail pressure) Pd flows. The fuel A is injected from the second injection hole 40 (see FIG. 6).

(Operation to stop injection)
When a predetermined valve opening time corresponding to the operating state of the engine has elapsed, the supply of drive current to the solenoid 82 is stopped. When the supply of the drive current is stopped, the magnetic attractive force of the solenoid 82 is lost, and the control valve 81 blocks the return passage 29. Then, since the fuel outflow from the outlet throttle downstream is stopped, the pressure in the back pressure chamber 70 starts to rise again. When the pressure in the back pressure chamber 70 rises to the valve closing pressure of the first needle 50, the first needle 50 closes. When the pressure in the back pressure chamber 70 rises to the valve closing pressure of the second needle 60, the second needle 60 closes. As a result, fuel injection from the first nozzle hole 30 and the second nozzle hole 40 is stopped (see FIG. 3).

  Next, functions and effects of the present embodiment will be described. (1) In the present embodiment, the first needle 50, which is an inner needle that is double-arranged inside and outside the flow of two types of fluids A and B, respectively. The first flow path 16, the second flow path 17, the first injection hole 30, and the second injection hole 40 formed by a gap between the second needle 60, which is an outer needle, and the inside of the valve body 11. Therefore, when the first needle 50 opens the valve seat 12, the fuel B as the first fluid flows into the first nozzle hole 30 along the first flow path 16, and the second needle When the valve 60 is opened, the fuel A as the second fluid can flow into the second nozzle hole 40 along the second flow path 17. Therefore, in the case of injecting two types of fuels A and B having different combustion characteristics, these fuels can be injected separately.

  The fuels A and B may be gas and liquid or liquid and liquid regardless of liquid and liquid as fluids involved in combustion.

  (2) Not limited to the above configuration, the nozzle body 11 in which the first injection hole 30 and the second injection hole 40 are formed, and the first injection hole, which injects and supplies a fluid related to combustion into the cylinder of the engine. The outer needle 50 that switches the presence / absence of the fluid injection from 30 by the lift operation by the reciprocating accommodation inside the nozzle body 11 and the presence / absence of the fluid injection from the second injection hole 40 to the inside of the outer needle 50 The inner needle 60 which is switched by the lift operation by the reciprocating accommodation of the first and second flow paths 16 and 17 for individually guiding the two kinds of fluids related to the combustion to the respective injection holes of the first injection hole 30 and the second injection hole 40. As long as it is comprised so that it may be provided, any may be sufficient.

  (3) In this embodiment, the nozzle body 11 includes the valve seats 12 on which the inner needle 60 and the outer needle 50 are separated and seated. When the outer needle 50 is closed, the nozzle body 11 The upstream position and the downstream position of the fluid flow are seated by the first seat portion S1, and when the inner needle 60 is closed, the upstream position of the fluid flow of the second nozzle hole 40 is the second seat portion S2. It is preferable that it is sheeted. Thereby, the presence / absence of ejection of the fluid from the first nozzle hole 30 is switched by the lift operation by the reciprocating housing inside the nozzle body 11 and the presence / absence of the fluid ejection from the second nozzle hole 40. The inner needle 60 and the two kinds of fluids related to combustion are individually switched in the respective injection holes of the first injection hole 30 and the second injection hole 40. It is possible to easily form a configuration including the flow paths 16 and 17 leading to the above.

  (4) In the present embodiment, the fuel B as the first fluid and the fuel A as the second fluid are two types of fuels having different boiling point temperatures. In this embodiment, the fuel A is a low boiling point fuel and the fuel B is a high boiling point fuel. According to this, the fuel A having a relatively low boiling point temperature is injected from the second injection hole 40 in the low load region of the engine (see FIG. 4), and the fuel having a relatively high boiling point temperature from the first injection hole 30 in the high load region. It is possible to inject B (see FIG. 6). Thereby, according to the map division of the area | region I and the area | region II in the map of FIG. 7, in the low load area corresponding to the area | region I, it evaporates early with the fuel A which has a comparatively low boiling point, and an air-fuel | gaseous mixture is diluted. . On the other hand, in the high load region corresponding to the region II, the evaporation can be delayed by the fuel B having a relatively high boiling point, and the spray can be blown far away.

(5) The present embodiment includes an ECU 90 that controls the spray pattern of at least one of the first fluid B and the second fluid A by driving and controlling the electromagnetic valve 80, and
The ECU 90 opens the second needle 60 when the engine operating state is in the low load region, and opens the first needle 50 and the second needle 60 when the engine is in the high load region.

  As a result, the first needle 50 and the second needle 60 are opened in the high load region of the engine, so that fuel can be injected from the first injection hole 30 and the second injection hole 40 at a large flow rate. Furthermore, since the second needle 60 is opened when in the low load region, the mixture can be diluted, for example, using the specific combustion characteristics of the second fluid A of the two types of fluids.

(Second Embodiment)
A second embodiment will be described with reference to FIG. In the following description, the same or equivalent components as those in the first embodiment are denoted by the same reference numerals, and description thereof will not be repeated. FIG. 4 is a partial cross-sectional view showing the main part of the valve part according to this embodiment.

  In the second embodiment, as shown in FIG. 8, a seat member 156 that can bias the valve seat 12 is provided in the fuel passage 17 as the second flow path.

  Thus, when the first needle 50 and the second needle 60 are independently opened, the fuel B, which is the first fluid, is injected from the first injection hole 30 to the fuel A, which is the second fluid. It can be sprayed separately from the hole 40.

(Other embodiments)
In the present embodiment described above, the two types of fluids related to combustion have been described as fuels having different boiling point temperatures, that is, combinations of liquids and liquids, but any combination of liquids and gases or combinations of gases and gases may be used. Good

It is typical sectional drawing which shows the structure of the fuel-injection apparatus of the 1st Embodiment of this invention. It is a fragmentary sectional view which shows the principal part of the valve part concerning the fuel-injection apparatus of 1st Embodiment. It is a figure explaining the opening-and-closing state of the valve part of a fuel injection device, and is a fragmentary sectional view showing the state where the inner needle and the outer needle of the valve part in Drawing 1 are closed. It is a figure explaining the opening-and-closing state of the valve part of a fuel injection device, and is a fragmentary sectional view showing the state where an inner needle has opened. It is a figure explaining the opening-and-closing state of the valve part of a fuel injection device, and is a fragmentary sectional view showing the state where an outside needle is opened. It is a figure explaining the opening-and-closing state of the valve part of a fuel injection device, and is a fragmentary sectional view showing the state where an inner needle and an outer needle open. It is a map block diagram for setting a spray form so that two types of fluid can be sprayed according to the combustion state performed with an internal combustion engine. It is a figure which shows the principal part of the valve part concerning the fuel-injection apparatus of 2nd Embodiment, Comprising: It is a fragmentary sectional view which shows the state in which the outer needle is opening. It is typical sectional drawing which shows one Example of the drive device in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel injection apparatus 2 Fuel injection valve 10 Nozzle main body 11 Nozzle body 11a Guide hole 12 Valve seat 16 Fuel path (1st flow path)
17 Fuel passage (second passage)
19 Retaining nut 20 Valve housing 30 First nozzle hole 40 Second nozzle hole 50 First needle (outer needle)
51 First contact portion 59 First spring 60 Second needle (inner needle)
61 Second contact portion 69 Second spring 70 Back pressure chamber (pressure control chamber)
80 Solenoid valve (drive device)
90 ECU (control means)
S1 1st seal part S2 2nd seal part

Claims (7)

A nozzle body in which a first injection hole and a second injection hole are formed to inject and supply a fluid related to combustion into a cylinder of an internal combustion engine;
An outer needle that switches the presence or absence of ejection of the fluid from the first nozzle hole by a lift operation by reciprocating accommodation inside the nozzle body;
An inner needle that switches whether or not the fluid is ejected from the second nozzle hole by a lift operation by reciprocating accommodation inside the outer needle;
A fuel injection apparatus comprising a flow path for individually guiding two kinds of fluids related to combustion to each of the first nozzle holes and the second nozzle holes. The two types of fluids are a first fluid and a second fluid,
The flow path is
A first flow path formed by a first gap between the outer periphery of the outer needle and the inner periphery of the nozzle body;
A second flow path formed by a second gap between the outer periphery of the inner needle and the inner periphery of the outer needle;
The fuel injection device according to claim 1, comprising: The nozzle body includes valve seats on which the inner needle and the outer needle are separated and seated,
When the outer needle is closed, the upstream position and the downstream position of the fluid flow of the first nozzle hole are seated,
The fuel injection device according to claim 2, wherein when the inner needle is closed, the upstream position of the fluid flow of the second injection hole is seated. A seat member capable of being biased to the valve seat;
The fuel injection device according to claim 2 or 3, wherein the sheet member is disposed in the second gap. The fuel injection device according to any one of claims 1 to 4 is used for an internal combustion engine to which two types of fluids related to the combustion are injected and supplied.
A driving device for independently driving the inner needle and the outer needle;
Control means for controlling the spray pattern of at least one of the two types of fluids involved in the combustion by controlling the driving of the driving device;
The control means includes
When the operating state of the internal combustion engine is in a low load region, the inner needle is opened,
The fuel injection device characterized by opening the outer needle and the inner needle when in a high load region. In a fuel injection device for injecting and supplying a fluid related to combustion into a cylinder of an internal combustion engine,
A nozzle body in which a first nozzle hole and a second nozzle hole are formed;
An outer needle that switches the presence or absence of ejection of the fluid from the first nozzle hole by a lift operation by reciprocating accommodation inside the nozzle body;
An inner needle that switches whether or not the fluid is ejected from the second nozzle hole by a lift operation by reciprocating accommodation inside the outer needle;
A flow path for individually guiding the two kinds of fluids related to combustion to each of the first nozzle holes and the second nozzle holes;
A driving device for independently driving the inner needle and the outer needle;
Control means for controlling the spray pattern of at least one of the two types of fluids involved in the combustion by controlling the driving of the driving device;
The control means includes
When the operating state of the internal combustion engine is in a low load region, the inner needle is opened,
The fuel injection device characterized by opening the outer needle and the inner needle when in a high load region. The fuel injection device according to any one of claims 1 to 6, wherein the two kinds of fluids related to the combustion are two kinds of fuels having different boiling point temperatures.

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