Fluid injection device injecting two kinds of fluids

Abstract

To inhibit a fuel from unintentionally flowing out from an injection hole in a fluid injection device which injects two kinds of fluids.SOLUTION: A fluid injection device 10 includes: a substantially cylindrical valve body 20 provided with an inverted cone surface 25 in which injection holes 29 are provided at its tip; and a valve element 30 which includes an introduction flow passage W12 of a first fluid therein and in which a conical surface 35 is formed at a tip. The valve element includes a second fluid supply passage W22 formed between itself and the valve body and housed in the valve body so that an inverted cone surface and the conical surface face each other. The conical surface includes: a downstream conical surface 35b; an upstream conical surface 35u; and an outlet 38 of the first fluid introduction passage provided between the downstream conical surface and the upstream conical surface. An apex angle of the conical surface of the valve element is smaller than an apex angle of the inverted cone surface of the valve body. The downstream conical surface separates from or is seated on the inverted cone surface to cause the first fluid and the second fluid to be injected or stop the injection. When the downstream conical surface is seated on the inverted cone surface, the upstream conical surface separates from the inverted cone surface.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a fluid ejection device that ejects two types of fluid. [Background technology]

[0002] Patent Document 1 describes a fluid injection device that injects two types of fluid. In this fluid injection device, CNG (compressed natural gas) is injected as the main fuel into a diesel engine, and diesel is injected as an ignition fuel. Since CNG has poor ignition characteristics compared to diesel, a small amount of diesel is injected into the cylinder of the diesel engine for ignition.

[0003] The fluid injection device described in Patent Document 1 includes a valve body and a valve element. The valve body has an inverted cone-shaped valve seat surface including a first valve seat and a second valve seat. The valve element has a cone-shaped valve portion surface including a first valve portion and a second valve portion. The first valve portion is disposed opposite the first valve seat and is seated and unseated from the first valve seat. The second valve portion is disposed opposite the second valve seat and is seated and unseated from the second valve seat. The first valve portion and the first valve seat are disposed downstream close to the fuel injection hole, and the second valve portion and the second valve seat are disposed upstream far from the fuel injection hole. An annular groove is provided between the first valve portion and the second valve portion. A flow path for diesel is formed inside the valve element and opens into the annular groove. A flow path for the main fuel is formed between the valve element and the valve body and communicates with a flow path formed between the first valve portion and the first valve seat. The first valve portion is separated from and seated on the first valve seat, thereby causing injection and stopping of injection of both the first fluid and the second fluid. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-139435 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the fluid injection device described in Patent Document 1, the conical valve portion surface and the inverted conical valve seat surface are designed to have the same apex angle. When designed in this way, depending on manufacturing variations, the distance between the second valve portion located on the upstream side and the second valve seat may be closer than the distance between the first valve portion located on the downstream side and the first valve seat. In this case, the second valve portion located on the upstream side may be seated on the second valve seat without the first valve portion being seated on the first valve seat, which may cause a situation in which diesel, which is the ignition fuel, unintentionally flows out of the injection hole.

[0006] In view of the above, the present invention provides a technique for preventing fuel from unintentionally leaking out of an injection hole in a fluid injection device that injects two types of fluid. [Means for solving the problem]

[0007] The fluid injection device according to the present invention is a fluid injection device for injecting two types of fluids, a first fluid and a second fluid, and includes a substantially cylindrical valve body having an injection hole at a tip and an inverted conical surface formed on the inner peripheral surface of the tip, and a valve body having an introduction flow path for the first fluid inside and a conical surface formed on the outer peripheral surface of the tip. The valve body is accommodated in the valve body such that an introduction flow path for the second fluid is formed between the valve body and the valve body, and the inverted conical surface and the conical surface face each other. The conical surface includes a downstream conical surface provided on the downstream side close to the injection hole, an upstream conical surface provided on the upstream side far from the injection hole with respect to the downstream conical surface, and an outlet of the introduction flow path for the first fluid provided between the downstream conical surface and the upstream conical surface. The apex angle of the conical surface of the valve disc is smaller than the apex angle of the inverted conical surface of the valve body, and the downstream conical surface lifts off and seats on the inverted conical surface to thereby inject and stop injection of both the first fluid and the second fluid, and when the downstream conical surface is seated on the inverted conical surface, the upstream conical surface and the inverted conical surface are separated from each other.

[0008] According to the above fluid injection device, an inverted conical surface is formed on the inner peripheral surface of the tip of the valve body. A conical surface is formed on the outer peripheral surface of the tip of the valve body. The conical surface includes a downstream conical surface provided downstream close to the injection hole, an upstream conical surface provided upstream far from the injection hole with respect to the downstream conical surface, and an outlet of an introduction flow path of a first fluid provided between the downstream conical surface and the upstream conical surface. The first fluid flowing through the introduction flow path of the first fluid is introduced from the outlet of the introduction flow path of the first fluid provided between the downstream conical surface and the upstream conical surface into a flow path (referred to as a downstream injection flow path) formed between the downstream conical surface and the inverted conical surface when the downstream conical surface is separated from the inverted conical surface. The second fluid flowing through the second introduction flow path is introduced into the downstream injection flow path through a flow path (referred to as an upstream injection flow path) formed between the upstream conical surface and the inverted conical surface. On the other hand, the downstream injection flow path is closed when the downstream conical surface is seated against the inverted conical surface. Therefore, the downstream conical surface lifts off and seats on the inverted conical surface, thereby injecting and stopping both the first fluid and the second fluid. Furthermore, according to the fluid injection device, the apex angle of the conical surface of the valve disc is smaller than the apex angle of the inverted conical surface of the valve body, so that when the downstream conical surface seats on the inverted conical surface, the upstream conical surface and the inverted conical surface are separated from each other. Regardless of the machining variations in the valve body and the valve disc, it is possible to prevent the upstream conical surface and the inverted conical surface from seating on each other when the downstream conical surface and the inverted conical surface are not seated on each other. As a result, in a fluid injection device that injects two types of fluids, it is possible to prevent fuel from unintentionally flowing out of the injection hole. [Brief description of the drawings]

[0009] [Figure 1] 1 is a block diagram showing an outline of a fluid ejection system including a fluid ejection device according to an embodiment. [Diagram 2] 2 is a cross-sectional view of the fluid ejection device shown in FIG. 1. [Diagram 3] 3 is a cross-sectional view showing an example of the operation of the fluid ejection device shown in FIG. 2. [Figure 4] 3 is a cross-sectional view showing an example of the operation of the fluid ejection device shown in FIG. 2. [Diagram 5] 3 is a diagram showing the apex angles of a conical surface and an inverted conical surface in the fluid ejection device shown in FIG. 2. [Figure 6] 2 is a diagram showing the relationship between the lift amount and the flow path area in the fluid ejection system shown in FIG. 1. [Figure 7] 2 is a diagram showing the relationship between the lift amount and the injection amount in the fluid injection device shown in FIG. 1. [Figure 8] 2 is a diagram illustrating a flow path cross-sectional area of ​​the fluid ejection device shown in FIG. [Figure 9] FIG. 11 is a cross-sectional view of a fluid ejection device according to a modified example. [Figure 10] 10 is a cross-sectional view showing an example of the operation of the fluid ejection device shown in FIG. [Figure 11] FIG. 13 is a diagram illustrating seating of a downstream conical surface on a downstream inverted conical surface. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] As shown in Fig. 1, a fluid injection system 110 according to the embodiment is a system that injects two types of fluids, a main fuel and an ignition fuel, into a cylinder 1 of a diesel engine of a vehicle. More specifically, the main fuel is ethanol, and the ignition fuel is diesel. In this embodiment, the diesel corresponds to the first fluid, and the ethanol corresponds to the second fluid.

[0011] The fluid injection system 110 includes the fluid injection device 10, a main fuel tank 111, a main fuel pump 112, a main fuel rail 113, an ignition fuel tank 114, an ignition fuel pump 115, an ignition fuel rail 116, a drive unit 117, a differential pressure sensor 120, a pressure sensor 121, and a controller 130. In this embodiment, the controller 130 corresponds to the control device.

[0012] Ethanol is stored in the main fuel tank 111. The main fuel pump 112 pressure-feeds the ethanol stored in the main fuel tank 111 to the fluid injection device 10. Alternatively, the main fuel pump 112 pressure-feeds the ethanol stored in the main fuel tank 111 to the fluid injection device 10 as ethanol pressurized to a pressure required for injection. Light oil is stored in the ignition fuel tank 114. The ignition fuel pump 115 pressure-feeds the light oil stored in the ignition fuel tank 114 to the fluid injection device 10.

[0013] The fluid injection device 10 includes a valve body 20 formed in a substantially cylindrical shape centered on an axis m1, and a valve element 30 housed inside the valve body 20. The valve element 30 is displaced in a direction along the axis m1 based on a driving force applied from a driving unit 117. As the driving unit 117, for example, an actuator that displaces the valve element 30 by applying an electromagnetic force to the valve element 30 using a solenoid or the like can be used. The valve element 30 is displaced by the driving unit 117, thereby opening and closing the valve element 30. In the fluid injection device 10, the valve element 30 is opened and closed, so that ethanol and diesel are injected into a cylinder 1 of a diesel engine.

[0014] The controller 130 is mainly composed of a microcomputer having a CPU, a memory, and the like. The controller 130 executes pressure control for adjusting the pressure of the main fuel and the ignition fuel, and drive control for controlling the drive of the valve body 30. More specifically, the controller 130 adjusts the pressure of the ethanol supplied to the fluid injection device 10 by controlling the main fuel pump 112 based on the detection value of the pressure of the ethanol detected by the pressure sensor 121. The pressure sensor 121 detects the pressure of the ethanol in the main fuel rail 113. The controller 130 also adjusts the pressure of the diesel fuel supplied to the fluid injection device 10 by controlling the ignition fuel pump 115 based on the differential pressure (the pressure difference between the pressure of the ethanol and the pressure of the diesel fuel) detected by the differential pressure sensor 120. The differential pressure sensor 120 detects the pressure difference between the pressure of the ethanol in the main fuel rail 113 and the pressure of the diesel fuel in the ignition fuel rail 116. The controller 130 obtains the detection values ​​of the differential pressure sensor 120 and the pressure sensor 121, and controls the main fuel pump 112 and the ignition fuel pump 115 based on these detection values. Since ethanol, which is the main fuel, affects the operation of the diesel engine, it is preferable to perform pressure control with high accuracy based on the detection value of the ethanol pressure. Therefore, the controller 130 controls the ethanol pressure based on the detection value of the pressure sensor 121. On the other hand, in the fluid injection device 10, it is preferable to accurately control the differential pressure between the ethanol pressure and the diesel pressure in controlling the lift amount of the valve body. Therefore, the controller 130 controls the diesel pressure based on the detection value of the differential pressure sensor 120.

[0015] Furthermore, the controller 130 controls the opening and closing operation of the valve body 30 by controlling the drive unit 117. The controller 130 executes fuel injection control to control the injection amount and injection timing of ethanol and diesel injected into the cylinder 1 through control of the main fuel pump 112, the ignition fuel pump 115, and the drive unit 117.

[0016] Next, the structure of the fluid ejection device 10 will be specifically described.

[0017] As shown in Fig. 2, the valve body 20 is formed in a cylindrical shape centered on the axis m1. For convenience, hereinafter, the positive direction of the Z axis parallel to the axis m1 shown in Fig. 2 may be referred to as the upward direction, and the negative direction of the Z axis may be referred to as the downward direction.

[0018] Inside the valve body 20, a first valve body accommodating hole 21 and a second valve body accommodating hole 22 are formed so as to extend along the axis m1. The first valve body accommodating hole 21 is formed so as to extend upward from the tip of the valve body 20. The second valve body accommodating hole 22 is formed so as to communicate with the upper end of the first valve body accommodating hole 21. The cross-sectional shape of each of the first valve body accommodating hole 21 and the second valve body accommodating hole 22 perpendicular to the axis m1 is formed to be circular. The inner diameter of the second valve body accommodating hole 22 is larger than the inner diameter of the first valve body accommodating hole 21. The first valve body accommodating hole 21 and the second valve body accommodating hole 22 accommodate a valve body 30. A gap formed between the inner peripheral surface of the second valve body accommodating hole 22 and the outer peripheral surface of the valve body 30 constitutes a first supply flow path W11. Light oil is supplied to the first supply flow path W11. A gap formed between the inner peripheral surface of the first valve body accommodating hole 21 and the outer peripheral surface of the valve body 30 constitutes a second introduction flow path W22. Ethanol is supplied to the second introduction flow path W22 through a second supply flow path W21 formed in the valve body 20.

[0019] A sliding seal portion 40 is provided between the inner peripheral surface of the upper end of the first valve body accommodating hole 21 and the outer peripheral surface of the valve body 30. The sliding seal portion 40 is formed in an annular shape centered on the axis m1. The sliding seal portion 40 seals the gap formed between the inner peripheral surface of the first valve body accommodating hole 21 and the outer peripheral surface of the valve body 30. As a result, the first supply flow path W11 and the second introduction flow path W22 are configured as flow paths independent of each other. The sliding seal portion 40 supports the valve body 30 so that it can slide in the direction along the axis m1.

[0020] A sack portion 27 consisting of a cylindrical space is formed at the tip of the valve body 20. A plurality of injection holes 29 are formed in the valve body 20 so as to penetrate from the inner peripheral surface of the sack portion 27 to the tip surface of the valve body 20. In this fluid injection device 10, when the valve body 30 opens, the ethanol and diesel that have passed through the downstream injection flow passage W33 are temporarily stored in the sack portion 27 and then injected from the plurality of injection holes 29. The injection hole 29 is formed so as to penetrate from the first valve body accommodating hole 21 to the outside of the valve body 20. The injection hole 29 is a portion that injects ethanol and diesel into the cylinder 1. An inverted conical surface 25 is formed on the inner peripheral surface of the first valve body accommodating hole 21 at a portion located at the tip of the valve body 20. The inverted conical surface 25 is formed around the axis m1 and is formed so that the cross-sectional area of ​​the internal space perpendicular to the axis m1 becomes smaller as it approaches the injection hole 29.

[0021] The valve body 30 has a cylindrical portion formed in a substantially cylindrical shape around the axis m1, and a tip portion formed in a substantially conical shape around the axis m1. A conical surface 35 and a tip conical surface 39 are formed on the outer circumferential surface of the tip portion of the valve body 30. The tip conical surface 39 is formed at the tip of the valve body 30, and the conical surface 35 is formed between the tip conical surface 39 and the cylindrical portion of the valve body 30. The apex angle of the conical surface 35 is smaller than the apex angle of the tip conical surface 39, and an annular edge 37 is formed between the conical surface 35 and the tip conical surface 39 around the axis m1. The conical surface 35 is disposed so as to face the inverted conical surface 25 of the valve body 20. The conical surface 35 is provided with an annular groove 34 formed in a circular shape around the axis m1. The conical surface 35 of the valve body 30 is divided into two surfaces 35b, 35u with the annular groove 34 as a boundary. Hereinafter, the downstream surface 35b close to the injection hole 29 is referred to as the "downstream conical surface 35b", and the upstream surface 35u remote from the injection hole 29 is referred to as the "upstream conical surface 35u".

[0022] Inside the valve body 30, a valve body bore 31 extending along the axis m1 is formed. In the valve body 30, a valve body upper through hole 32 is formed so as to penetrate from the outer peripheral surface facing the first supply flow passage W11 to the inner peripheral surface of the valve body bore 31. In the tip of the valve body 30, a plurality of valve body tip through holes 33 are formed so as to penetrate so as to extend from the inner peripheral surface of the valve body bore 31 to the annular groove 34. A first fluid outlet 38 is formed in the annular groove 34. Since the annular groove 34 is provided between the downstream conical surface 35b and the upstream conical surface 35u, the first fluid outlet 38 is also provided between the downstream conical surface 35b and the upstream conical surface 35u. The valve body bore 31 constitutes the first introduction flow passage W12, and the valve body tip through hole 33 constitutes the first through introduction flow passage W13. Light oil is supplied to the first introduction flow passage W12 through the first supply flow passage W11. The light oil supplied to the first introduction passage W12 passes through the first through introduction passage W13 and is introduced into the downstream injection passage W33 from the first fluid outlet 38. The first through introduction passage W13 functions as a throttle section that adjusts the flow rate of the light oil introduced from the first introduction passage W12 to the downstream injection passage W33. With this configuration, it is possible to easily adjust the injection amount of light oil.

[0023] Figures 3 and 4 show the vicinity of the injection hole 29 of the fluid injection device 10 shown in Figure 2. Figure 3 shows the valve body 30 in an open state, and Figure 4 shows the valve body 30 in a closed state. The inner diameter of the downstream conical surface 35b is φ10, and the outer diameter is φ11. The inner diameter of the upstream conical surface 35u is φ12, and the outer diameter is φ13. The inner diameter and the outer diameter indicated by φ and a subscripted reference number indicate diameters.

[0024] Of the inverted conical surface 25 of the valve body 20, the surface facing the downstream conical surface 35b of the valve element 30 in the z direction is referred to as the downstream inverted conical surface 25b, and the surface facing the upstream conical surface 35u in the z direction is referred to as the upstream inverted conical surface 25u. The downstream inverted conical surface 25b is the downstream surface close to the injection hole 29, and the upstream inverted conical surface 25u is the upstream surface far from the injection hole 29. The inner diameter of the inverted conical surface 25 is smaller than φ10, and the outer diameter of the inverted conical surface 25 is larger than φ13.

[0025] As shown in Figures 5(a) and 5(b), the conical surface 35 is configured as a conical surface with an apex angle θ1, and the inverted conical surface 25 is configured as an inverted conical surface with an apex angle θ2. The apex angle θ1 of the conical surface 35 is smaller than the apex angle θ2 of the inverted conical surface 25. For this reason, as shown in Figure 4, when the valve body 30 is in a closed state, the downstream conical surface 35b is seated on the downstream inverted conical surface 25b, but the upstream conical surface 35u is not seated on the upstream inverted conical surface 25u, and the upstream conical surface 35u and the upstream inverted conical surface 25u are separated from each other. When the valve body 30 is in a closed state, the gap formed between the downstream conical surface 35b of the valve body 30 and the downstream inverted conical surface 25b of the valve body 20 is blocked, so that diesel and ethanol are not injected from the injection hole 29.

[0026] When the driving unit 117 lifts the valve body 30 from the state shown in Fig. 4, the downstream conical surface 35b is lifted from the downstream inverted conical surface 25b as shown in Fig. 2. That is, the downstream conical surface 35b and the upstream conical surface 35u are displaced together with the displacement of the valve body 30, and the valve body 30 opens. As a result, a downstream injection flow passage W33 is formed between the downstream conical surface 35b of the valve body 30 and the downstream inverted conical surface 25b of the valve body 20, and a sac portion flow passage W34 is formed between the sac portion 27 and the tip conical surface 39. In addition, the flow passage area of ​​the upstream injection flow passage W31 formed between the upstream conical surface 35u of the valve body 30 and the upstream inverted conical surface 25u of the valve body 20 is expanded. Therefore, the diesel fuel supplied to the first introduction passage W12 is introduced from the annular groove 34 through the first through introduction passage W13 to the downstream injection passage W33, and then flows into the sac section 27 through the downstream injection passage W33 and the sac section passage W34, and is injected from the injection hole 29. The ethanol supplied to the second introduction passage W22 is introduced into the downstream injection passage W33 through the upstream injection passage W31, and then flows into the sac section 27 through the downstream injection passage W33 and the sac section passage W34, and is injected from the injection hole 29. Thus, the diesel fuel and the ethanol are injected into the cylinder 1. The diesel fuel that has flowed through the first through introduction passage W13, which is composed of the multiple valve body tip through holes 33, flows into the annular groove 34, and the variation in the flow rate distribution of the diesel fuel in the circumferential direction of the conical surface 35 of the valve body 30 can be reduced. Therefore, the occurrence of unevenness in the injection state of the diesel fuel injected from the fluid injection device 10 can be suppressed.

[0027] In this manner, in the fluid injection device 10 of this embodiment, the downstream conical surface 35b of the valve element 30 lifts off and seats on the downstream inverted conical surface 25b of the valve body 20, thereby causing injection and stopping of both diesel and ethanol.

[0028] Due to variations in the processing of the valve element 30 and the valve body 20, the apex angle θ1 of the conical surface 35 of the valve element 30 and the apex angle θ2 of the inverted conical surface 25 of the valve body 20 may actually vary to some extent. According to the fluid injection device 10, as shown in Figs. 4 and 5, the apex angle θ1 of the conical surface 35 is designed to be smaller than the apex angle θ2 of the inverted conical surface 25, and when the valve element 30 is in a closed state, the upstream conical surface 35u and the upstream inverted conical surface 25u are separated from each other, so that the downstream inverted conical surface 25b is not prevented from seating on the downstream conical surface 35b. Therefore, regardless of variations in the processing, when the valve element 30 is in a closed state, the downstream inverted conical surface 25b can be reliably seated on the downstream conical surface 35b, and the gap formed between the downstream conical surface 35b and the downstream inverted conical surface 25b can be reliably closed. As a result, when the valve body 30 is in a closed state, it is possible to reliably prevent diesel and ethanol from being unintentionally injected from the injection hole 29.

[0029] 4, when the valve disc 30 is in a closed state, the downstream inverted conical surface 25b is seated on the downstream conical surface 35b at the edge 37. According to the fluid injection device 10 shown in FIG. 4, when the conical surface 35 of the valve disc 30 is brought into contact with the inverted conical surface 25 of the valve body 20 by the axial driving force applied to the valve disc 30 from the driving unit 117 or the like, it is possible to apply a force greater than the axial force applied to the valve disc 30 to the edge 37, which is the contact portion between the downstream inverted conical surface 25b and the downstream conical surface 35b, due to the wedge effect.

[0030] In the fluid ejection device shown in Fig. 11, as shown in Fig. 11(a) and (b), the apex angle of the inverted conical surface 325 in the valve body 320 and the apex angle of the conical surface 335 in the valve element 330 are designed to be the same apex angle θ3. The upstream conical surface 335u of the valve element 330 is lower than the downstream conical surface 335b in the thickness direction of the valve element 330, and is spaced apart parallel to the extension plane of the downstream conical surface 335b shown by the dashed line in Fig. 11(a). Therefore, as shown in Fig. 11(c), when the valve element 330 is in the closed state, with the upstream conical surface 335u and the upstream inverted conical surface 325u spaced apart, the downstream conical surface 335b is seated so that its entirety is in contact with the downstream inverted conical surface 325b.

[0031] As shown in Fig. 11, even if the downstream conical surface 335b is designed to be seated in its entirety in contact with the downstream inverted conical surface 325b, it is possible to seat the downstream conical surface 335b in contact with the downstream inverted conical surface 325b in a state in which the upstream conical surface 335u and the upstream inverted conical surface 325u are spaced apart. Even with the fluid injection device shown in Fig. 11, when the downstream conical surface 335b is seated in contact with the downstream inverted conical surface 325b, it is possible to apply a force greater than the axial force applied to the valve body 330 to the contact portion between the downstream inverted conical surface 325b and the downstream conical surface 335b due to the wedge effect.

[0032] However, when the contact portion between the downstream inverted conical surface 325b and the downstream conical surface 335b is a surface as shown in FIG. 11, it is difficult to obtain high sealing performance depending on the surface roughness of the downstream inverted conical surface 325b and the downstream conical surface 335b. On the other hand, when the contact portion between the downstream inverted conical surface 25b and the downstream conical surface 35b is an edge 37 as shown in FIG. 4, the contact area is smaller than when the contact portion is a surface, and the contact surface pressure is higher. Therefore, even if the downstream inverted conical surface 25b and the downstream conical surface 35b are rough, high sealing performance can be obtained relatively easily. According to the fluid injection device 10 shown in FIG. 4, when the downstream inverted conical surface and the downstream conical surface are rough, it is possible to close the gap formed between the downstream inverted conical surface 35b and the downstream inverted conical surface 25b more reliably and to close the valve body 30, compared to the fluid injection device shown in FIG. 11.

[0033] However, if the difference between the apex angle θ1 of the conical surface 35 and the apex angle θ2 of the inverted conical surface 25 is large, the distance between the upstream conical surface 35u and the upstream inverted conical surface 25u becomes large when the valve body 30 is seated, increasing the possibility that the main fuel, ethanol, and the ignition fuel, diesel, will mix while the valve body 30 is seated. Methods for avoiding this include the following (Method 1) to (Method 3).

[0034] (Method 1) The pressure of the main fuel and the pressure of the ignition fuel are controlled to be approximately equal. More specifically, the controller 130 controls the main fuel pump 112 and the ignition fuel pump 115 so that the pressures of the ethanol and the diesel fuel supplied to the fluid injection device 10 are approximately equal. By controlling in this way, it is possible to suppress the flow caused by the pressure difference between the ethanol and the diesel fuel, and to suppress the mixing of the two fuels.

[0035] When the controller 130 executes control to increase the pressure of diesel and ethanol with the valve body 30 closed, such as when starting injection by the fluid injection device 10, the controller 130 increases the pressure of diesel and ethanol while controlling the pressure of ethanol so that it does not exceed the pressure of diesel. If the pressure of ethanol exceeds the pressure of diesel, there is a concern that the valve body 30 may unintentionally leave its seat and fuel may be injected, so the controller 130 controls each pressure so that the pressure of ethanol does not exceed the pressure of diesel, for example, by increasing the pressure of diesel first.

[0036] (Method 2) Taking into account the variation in processing, the difference between the apex angles θ1 and θ2 is made as small as possible. For example, a predetermined angle θp (0<θp<180°) is set, the apex angle θ1 of the conical surface 35 is processed in the range of θp-1≦θ1≦θp-0.5°, and the apex angle θ2 of the inverted conical surface 25 is processed in the range of θp≦θ2<θp+1°. By designing in this way, it is possible to reduce the difference between the apex angles θ1 and θ2 while ensuring that the apex angle θ1<apex angle θ2 in consideration of the variation in processing. By reducing the difference between the apex angles θ1 and θ2, the distance between the upstream conical surface 35u and the upstream inverted conical surface 25u becomes narrow when the valve body 30 is seated, so that even if there is a pressure difference between the ethanol and the diesel, the flow rate of the flows that mix with each other can be suppressed.

[0037] (Method 3) The length Lu of the upstream conical surface 35u in the ridge direction is made longer than the length Lb of the downstream conical surface 35b in the ridge direction. Hereinafter, these lengths Lu and Lb in the ridge direction may be referred to as the upstream sheet length Lu and the downstream sheet length Lb. The upstream sheet length Lu is preferably at least longer than the downstream sheet length Lb, and more preferably as long as possible. Usually, it is desirable that the upstream sheet length Lu and the downstream sheet length Lb have a certain length in order to ensure durability against wear and damage due to foreign object attack. For this reason, the downstream sheet length Lb is made as short as possible and the upstream sheet length Lu is made as long as possible within a range in which the durability of the downstream conical surface 35b can be ensured. By designing the upstream sheet length Lu and the downstream sheet length Lb in this way, the flow path length of the upstream injection flow path W31 formed between the upstream conical surface 35u and the upstream inverted conical surface 25u can be made longer, so that even if there is a pressure difference between ethanol and diesel, the flow rate of the flows in which they mix with each other can be suppressed.

[0038] As shown in FIG. 3, in the fluid ejection device 10, the difference between the outer diameter and the inner diameter of the downstream conical surface 35b (referred to as the inner / outer diameter difference) is calculated by (φ11-φ10), and the length Lb in the ridgeline direction is calculated by Lb=(φ11-φ10) / 2sin(θ1 / 2). The inner / outer diameter difference of the upstream conical surface 35u is calculated by (φ13-φ12), and the length Lu in the ridgeline direction is calculated by Lu=(φ13-φ12) / 2sin(θ1 / 2). The inner / outer diameter difference (φ13-φ12) of the upstream conical surface 35u is larger than the inner / outer diameter difference (φ11-φ10) of the downstream conical surface 35b. Therefore, the length Lu in the ridgeline direction of the upstream conical surface 35u is longer than the length Lb in the ridgeline direction of the downstream conical surface 35b. That is, in the fluid ejection device 10, the upstream sheet length Lu is longer than the downstream sheet length Lb. Since the upstream conical surface 35u and the downstream conical surface 35b have the same apex angle, the upstream sheet length Lu and the downstream sheet length Lb can be easily designed by adjusting the inner and outer diameters φ12, φ13 of the upstream conical surface 35u and the inner and outer diameters φ10, φ11 of the downstream conical surface 35b. That is, by designing the inner and outer diameter difference (φ13-φ12) of the upstream conical surface 35u to be larger than the inner and outer diameter difference (φ11-φ10) of the downstream conical surface 35b, the upstream sheet length Lu can be easily made longer than the downstream sheet length Lb.

[0039] When the valve element 30 is seated on the valve body 20 and the gap (corresponding to the flow path width) between the upstream conical surface 35u and the upstream inverted conical surface 25u is small, the flow rate of the fluid flowing through the upstream injection flow path W31 is proportional to the pressure difference between the upstream end and downstream end of the upstream injection flow path W31, inversely proportional to the flow path length of the upstream injection flow path W31 (i.e., the upstream seat length Lu), and proportional to the cube of the flow path width of the upstream injection flow path W31 (the distance between the upstream conical surface 35u and the upstream inverted conical surface 25u). For this reason, the above (Method 2) is the most effective way to prevent ethanol and diesel from mixing.

[0040] When injecting ethanol and diesel into cylinder 1 of a diesel engine of a vehicle, it is preferable to inject so that the ratio of diesel is high at the beginning of the injection. On the other hand, since it is not necessary to inject diesel from the middle of the injection onwards, it is preferable to make the ratio of diesel as small as possible.

[0041] Fig. 6 is a diagram showing the relationship between the minimum flow area S1 of the light oil flow path from the first introduction flow path W12 to the annular groove 34 and the minimum flow area S2 of the ethanol flow path from the second supply flow path W21 to the annular groove 34, and the lift amount of the valve body 30. Note that the flow area means the area of ​​the flow path cross section perpendicular to the flow direction, and the minimum flow area means the minimum value of the flow path area. Fig. 7 is a diagram showing the relationship between the flow rates of light oil and ethanol flowing through the injection hole 29 and the lift amount of the valve body 30. In Fig. 7, reference number F1 indicates the flow rate of light oil, and reference number F2 indicates the flow rate of ethanol.

[0042] 6, the flow path area of ​​the first introduction flow path W12 and the first through-introduction flow path W13 does not depend on the lift amount of the valve element 30, and therefore the flow path area of ​​the light oil is constant and does not depend on the lift amount of the valve element 30. In contrast, the flow path area of ​​the ethanol increases as the lift amount of the valve element 30 increases.

[0043] As shown in FIG. 8, in the fluid injection device 10, the sum of the flow path areas S11 perpendicular to the flow direction of the first through-introduction flow path W13 is defined as the first flow path area S1, and the flow path area perpendicular to the flow direction on the most downstream injection flow path W33 side of the upstream injection flow path W31 is defined as the second flow path area S2. The arrows shown in FIG. 8 indicate the flow directions of the first through-introduction flow path W13 and the upstream injection flow path W31. Also, since the flow path area perpendicular to the flow direction of the upstream injection flow path W31 becomes smaller as it approaches the downstream injection flow path W33, the second flow path area S2 is the minimum value of the flow path areas perpendicular to the flow direction of the upstream injection flow path W31. The fluid injection device 10 is designed and manufactured such that S1 > S2 when the valve body 30 is seated and immediately after it leaves the seat, and S1 < S2 when the lift amount of the valve body 30 becomes a predetermined value or more. The fluid injection device 10 is designed and manufactured such that S1 < S2 at least when the valve body 30 is in the full lift state.

[0044] By designing the fluid injection device 10 based on the first and second flow path areas S1 and S2 as described above, for example, as shown in FIG. 7, a large amount of light oil can be injected while the lift amount of the valve body 30 is up to A1, and the flow rate of ethanol can be gradually increased. Also, after the lift amount of the valve body 30 exceeds A1, the flow rate of light oil can be reduced, and the flow rate of ethanol can be controlled to a substantially constant value exceeding a predetermined flow rate R.

[0045] Also, if the flow path area of the injection hole 29 is smaller than either the flow path area of the downstream injection flow path W33 or the sack portion flow path W34, when ethanol and light oil flow into the sack portion 27 through the downstream injection flow path W33 and the sack portion flow path W34, ethanol and light oil can be temporarily stored in the sack portion 27. As a result, the pressure inside the sack portion 27 can be increased, so that ethanol and light oil can be injected more accurately.

[0046] (First Modified Example) As shown in FIGS. 9 and 10, the fluid injection device 10 may further include throttles 220, 230 that reduce the flow path area of ​​ethanol according to the lift amount of the valve body 30. The valve body throttle 220 provided on the valve body 20 side is configured as a protruding portion that protrudes from the inner peripheral surface of the first valve body accommodating hole 21. The valve body throttle 220 is provided on the entire circumferential direction of the inner peripheral surface of the first valve body accommodating hole 21 in an annular shape centered on the axis m1. The valve body throttle 230 is configured as a groove portion recessed into the outer peripheral surface of the valve body 30. The valve body throttle 230 is provided on the entire circumferential direction of the outer peripheral surface of the valve body 30 in an annular shape centered on the axis m1. The length from the upper end 231 to the lower end 232 of the valve body side orifice 230 is longer than the length from the upper end 221 to the lower end 222 of the valve body side orifice 220, and the lengths are such that when the valve body 30 is in a full lift state, the lower end 232 of the valve body side orifice 230 and the lower end 222 of the valve body side orifice 220 are separated by a distance that does not hinder the injection of ethanol.

[0047] 9 shows a case where the valve element 30 is in an open state and the lift amount of the valve element 30 is a predetermined lift amount A2. In this case, the upper end 221 of the valve body-side throttle 220 is spaced downward from the upper end 231 of the valve element-side throttle 230, and the flow path area of ​​the second introduction flow path W22 is secured. In other words, the flow path area of ​​the ethanol is not throttled.

[0048] 10 shows a case where the valve element 30 is in a closed state. In this case, the upper end 221 of the valve body-side throttle 220 is located above the upper end 231 of the valve element-side throttle 230. This results in a state where a part of the inner circumferential surface 223 of the valve body-side throttle 220 overlaps with a part of the outer circumferential surface 233 of the valve element 30-side throttle. In this overlapping portion, the flow path area of ​​the second introduction flow path W22 becomes significantly smaller, and the flow path area for ethanol is restricted.

[0049] As shown in Fig. 10, when the inner peripheral surface 223 of the valve body throttle 220 and the outer peripheral surface 233 of the valve disc 30 throttle overlap, the flow path area of ​​ethanol can be adjusted by adjusting the length of this overlapping portion and the distance between them (the distance between the inner peripheral surface 223 and the outer peripheral surface 233), and the amount of ethanol sprayed can be suppressed. Even when the inner peripheral surface 223 of the valve body throttle 220 and the outer peripheral surface 233 of the valve disc 30 throttle do not overlap, the flow path area of ​​ethanol is restricted if the distance between the upper end 221 of the valve body throttle 220 and the upper end 231 of the valve disc throttle 230 is narrow. In this case, the flow path area of ​​ethanol can be adjusted by adjusting the distance between the upper end 221 of the valve body throttle 220 and the upper end 231 of the valve disc throttle 230, and the amount of ethanol sprayed can be suppressed.

[0050] 9 and 10, when the lift amount of the valve body 30 is less than a predetermined lift amount threshold (e.g., lift amount A2), the flow path area for ethanol can be made smaller than when the lift amount of the valve body 30 is equal to or greater than the lift amount threshold, and the amount of ethanol injected can be reduced. Therefore, the amount of ethanol injected can be reduced at the beginning of injection, and the fuel ratio of diesel can be increased. By increasing the fuel ratio of diesel at the beginning of injection, ethanol becomes easier to ignite, and ignition performance can be improved.

[0051] (Second Modification) In order to improve the wear resistance of the sliding seal portion 40 shown in FIG. 2, it is desirable to actively introduce diesel, which has a higher viscosity than ethanol and a higher wear suppression effect, into the sliding seal portion 40 and the like. The controller 130 of this modification controls the main fuel pump 112 and the ignition fuel pump 115 so that the pressure of diesel is higher than the pressure of ethanol supplied to the fluid injection device 10. That is, in this modification, the pressure for injection applied to diesel is higher than the pressure for injection applied to ethanol. With this configuration, it is possible to make the diesel flowing through the first supply flow passage W11 flow into the sliding portion between the sliding seal portion 40 and the valve body 30. In addition, it is possible to make the diesel flowing through the first supply flow passage W11 flow into the minute gap between the upstream inverted cone surface 25u and the upstream cone surface 35u through the first introduction flow passage W12 and the first through introduction flow passage W13. By introducing diesel into those sliding portions or gaps, those sliding portions or gaps can be lubricated, and therefore wear of the sliding portions or gaps can be suppressed. In addition, the light oil has the effect of suppressing wear of the downstream inverted conical surface 25b and the downstream conical surface 35b by penetrating into the minute gap between the downstream inverted conical surface 25b and the downstream conical surface 35b. If wear of the downstream inverted conical surface 25b and the downstream conical surface 35b progresses, or if the downstream inverted conical surface 25b and the downstream conical surface 35b elastically deform when the valve body 30 is seated, there is a concern that the upstream inverted conical surface 25u and the upstream conical surface 35u may come into contact. By suppressing wear of the downstream inverted conical surface 25b and the downstream conical surface 35b with the light oil, it is possible to suppress contact between the upstream inverted conical surface 25u and the upstream conical surface 35u.

[0052] For example, when the valve body 30 is seated, the controller 130 controls the ethanol pressure to 50 MPa ± 1 MPa based on the detection value of the pressure sensor 121, and controls the differential pressure between the diesel and the ethanol to 2 MPa ± 1 MPa based on the detection value of the differential pressure sensor 120. When detecting the diesel pressure and controlling the diesel pressure based on the detection value, it is preferable that the controller controls the diesel pressure to 53 MPa ± 1 MPa.

[0053] The control unit and the method described in the present disclosure may be realized by a special-purpose computer provided by configuring a processor and a memory programmed to execute one or more functions embodied in a computer program. Alternatively, the control unit and the method described in the present disclosure may be realized by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and the method described in the present disclosure may be realized by one or more special-purpose computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. In addition, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by a computer.

[0054] Characteristic configurations extracted from each of the above-described embodiments will be described below. [Configuration 1] A fluid ejection device (10) that ejects two types of fluid, a first fluid and a second fluid, a substantially cylindrical valve body (20) having an injection hole at a tip and an inverted conical surface (25) formed on the inner peripheral surface of the tip; a valve body (30) having an introduction flow path (W12) for the first fluid therein and a conical surface (35) formed on the outer circumferential surface of a tip end thereof, the valve disc is accommodated in the valve body such that an introduction flow path (W22) for the second fluid is formed between the valve disc and the valve body, and the inverted conical surface and the conical surface (35) face each other; The conical surface is a downstream conical surface (35b) provided downstream close to the injection hole; An upstream conical surface (35u) provided upstream of the downstream conical surface away from the injection hole; an outlet (38) of the first fluid introduction passage provided between the downstream conical surface and the upstream conical surface; The apex angle of the conical surface of the valve element is smaller than the apex angle of the inverted conical surface of the valve body; the downstream conical surface lifts off and seats on the inverted conical surface to cause injection and cessation of injection of both the first fluid and the second fluid; A fluid injection device, wherein the upstream conical surface and the inverted conical surface are spaced apart when the downstream conical surface is seated against the inverted conical surface. [Configuration 2] 2. The fluid ejection device according to configuration 1, wherein the length of the downstream conical surface in the ridge line direction is shorter than the length of the upstream conical surface in the ridge line direction. [Configuration 3] An upstream injection flow passage (W31) is formed between the upstream conical surface and the inverted conical surface, A downstream injection passage (W33) is formed between the downstream conical surface and the inverted conical surface, The tip of the valve body is provided with one or more through-introduction passages (W13) that penetrate from the inside of the valve body to an outlet of the introduction passage for the first fluid, When the downstream conical surface is seated against the inverted conical surface, a first flow path area, which is a sum of flow path areas perpendicular to the flow direction of the through-introduction flow paths, is larger than a second flow path area, which is a flow path area perpendicular to the flow direction at a portion of the upstream injection flow path closest to the downstream injection flow path, 3. The fluid ejection device according to configuration 1 or 2, wherein the first flow passage area is smaller than the second flow passage area when the valve body is in a full lift state. [Configuration 4] a throttle (220, 230) that reduces a flow path area of ​​the introduction flow path of the second fluid in accordance with a lift amount of the valve body, A fluid injection device described in any one of configurations 1 to 3, wherein the throttle reduces the flow path area of ​​the second fluid when the lift amount of the valve body is less than a predetermined lift amount threshold compared to when the lift amount of the valve body is equal to or greater than the lift amount threshold. [Configuration 5] A control device (160) for adjusting the pressure of the first fluid and the second fluid, The viscosity of the first fluid is higher than the viscosity of the second fluid; 5. The fluid ejection device according to any one of configurations 1 to 4, wherein the control device makes the pressure of the first fluid higher than the pressure of the second fluid. [Configuration 6] A control device (130) for adjusting the pressure of the first fluid and the second fluid, the first fluid is an ignition fuel; the second fluid is a primary fuel; The fluid ejection device described in any one of 1 to 5, wherein the control device controls the pressure of the second fluid based on a detection value of the pressure of the second fluid, and controls the pressure of the first fluid based on a detection value of the differential pressure between the pressure of the first fluid and the pressure of the second fluid. [Configuration 7] A control device (130) for adjusting the pressure of the first fluid and the second fluid, The fluid injection device described in any one of configurations 1 to 6, wherein the control device adjusts the pressures of the first fluid and the second fluid so that the pressure of the second fluid does not become higher than the pressure of the first fluid when the pressure of the first fluid and the second fluid is increased with the downstream conical surface seated against the inverted conical surface. [Explanation of symbols]

[0055] 10... fluid injection device, 20... valve body, 25... inverted cone surface, 30... valve element, 35... cone surface, 35b... downstream cone surface, 35u... upstream cone surface, 38... outlet, W12... inlet flow path for first fluid, W22... inlet flow path for second fluid

Claims

1. A fluid ejection device (10) that ejects two types of fluid, a first fluid and a second fluid, a substantially cylindrical valve body (20) having an injection hole at a tip and an inverted conical surface (25) formed on an inner peripheral surface of the tip; a valve body (30) having an introduction flow path (W12) for the first fluid therein and a conical surface (35) formed on the outer circumferential surface of a tip portion thereof; The valve element is accommodated in the valve body such that an introduction flow path (W22) for the second fluid is formed between the valve element and the valve body, and the inverted cone surface and the cone surface face each other. The conical surface is A downstream conical surface (35b) provided downstream close to the injection hole; An upstream conical surface (35u) provided upstream from the injection hole with respect to the downstream conical surface; an outlet (38) of the first fluid introduction passage provided between the downstream conical surface and the upstream conical surface; The apex angle of the conical surface of the valve element is smaller than the apex angle of the inverted conical surface of the valve body; the downstream conical surface lifts off and seats on the inverted conical surface to effect injection and cessation of injection of both the first fluid and the second fluid; A fluid injection device, wherein the upstream conical surface and the inverted conical surface are spaced apart when the downstream conical surface is seated against the inverted conical surface.

2. The fluid ejection device according to claim 1 , wherein a length of the downstream conical surface in a ridge line direction is shorter than a length of the upstream conical surface in a ridge line direction.

3. An upstream injection flow passage (W31) is formed between the upstream conical surface and the inverted conical surface, A downstream injection flow passage (W33) is formed between the downstream conical surface and the inverted conical surface, The tip of the valve body is provided with one or more through-introduction passages (W13) that penetrate from the inside of the valve body to an outlet of the introduction passage for the first fluid, When the downstream conical surface is seated on the inverted conical surface, a first flow path area, which is a sum of flow path areas perpendicular to the flow direction of the through-introduction flow paths, is larger than a second flow path area, which is a flow path area perpendicular to the flow direction at a portion of the upstream injection flow path closest to the downstream injection flow path, The fluid ejection device according to claim 1 , wherein the first flow passage area is smaller than the second flow passage area when the valve body is in a full lift state.

4. a throttle (220, 230) for reducing a flow path area of ​​an introduction flow path of the second fluid in accordance with a lift amount of the valve body, The fluid injection device according to claim 1 or 2, wherein the throttle reduces a flow path area of ​​the second fluid when the lift amount of the valve body is less than a predetermined lift amount threshold compared to when the lift amount of the valve body is equal to or greater than the lift amount threshold.

5. A control device (160) for adjusting the pressure of the first fluid and the second fluid, The viscosity of the first fluid is higher than the viscosity of the second fluid; The fluid ejection device according to claim 1 , wherein the control device makes the pressure of the first fluid higher than the pressure of the second fluid.

6. A control device (130) for adjusting the pressure of the first fluid and the second fluid, the first fluid is an ignition fuel; the second fluid is a primary fuel; The fluid ejection device according to claim 1 or 2, wherein the control device controls the pressure of the second fluid based on a detection value of the pressure of the second fluid, and controls the pressure of the first fluid based on a detection value of a differential pressure between the pressure of the first fluid and the pressure of the second fluid.

7. A control device (130) for adjusting the pressure of the first fluid and the second fluid, 3. The fluid injection device according to claim 1, wherein the control device adjusts the pressure of the first fluid and the second fluid so that the pressure of the second fluid does not become higher than the pressure of the first fluid when the pressure of the first fluid and the second fluid is increased with the downstream conical surface seated against the inverted conical surface.

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