JP3130439B2 - Fluid injection nozzle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid injection nozzle, and more particularly to an injection nozzle portion of an electromagnetic fuel injection valve for injecting and supplying fuel to an internal combustion engine for an automobile.

[0002]

2. Description of the Related Art In general, a fuel injection valve used in an internal combustion engine has a valve member housed in a guide hole formed in an axial direction of a valve body so as to be reciprocally slidable. Is opened and closed by the vertical movement of the valve member. For this reason, the valve member
The lift amount at the time of opening the valve is precisely controlled so as to secure an appropriate fuel injection amount.

[0003]

In such a fuel injection valve, when the valve member reciprocates up and down inside the guide hole formed in the valve body, the gap between the inner wall of the guide hole and the sliding portion of the valve member is formed. If the clearance of the valve member becomes large, the axis of the valve member may be inclined with respect to the axis of the guide hole.
3 (A) and as shown in FIG. 14 (A), "deviation" of the injection angle disturbance or the fuel stream F ₁ fuel injected from the distal end side of the injection hole of the valve member may occur. When such a “deviation” occurs in the main flow of the fuel, the amount of fuel adhering to the inner wall of the intake port increases, and there is a problem that it is difficult to supply good spray into the combustion chamber. Then, a large amount of unburned HC etc. is generated in the exhaust gas, which causes a problem in exhaust emission,
The operability of the internal combustion engine also becomes unstable.

On the other hand, if the clearance between the inner wall forming the guide hole of the valve body and the sliding portion of the valve member is to be reduced, the dimensional accuracy of the valve body and the dimensional accuracy of the valve member are reduced during manufacturing. Precise dimensional control is required, and there is a problem that productivity is reduced. That is, as shown in FIG. 12, for example, the inner diameter of the inner diameter of the guide hole of the valve body and the outer diameter of the sliding portion of the valve member vary. Select and assemble a combination of the valve body and the valve member that match the outer diameter. For this reason, the operation of selecting and assembling a valve member having a sliding portion adapted to the guide hole of each valve body becomes complicated.

It is an object of the present invention to provide a fuel injection nozzle capable of obtaining an injection main flow with less deviation in the flow of fuel injected from an injection hole. Another object of the present invention is that a clearance between an inner wall of a guide hole of a valve body (hereinafter, referred to as “valve body”) and a sliding portion of a valve member (hereinafter, referred to as “needle”) is within a predetermined range. It is an object of the present invention to provide a fuel injection nozzle having a uniform fuel injection flow even if there is a difference in the size of the fuel injection nozzle.

It is still another object of the present invention to provide a fuel injection nozzle which improves the production efficiency of a valve body and a needle adapted thereto. Still another object of the present invention is to provide a fuel injection nozzle that achieves both prevention of fuel injection flow bias and improvement in productivity of a fluid injection nozzle.

[0007]

According to a first aspect of the present invention, there is provided a fluid injection nozzle having a cylindrical body and a valve body having a conical slope formed on an inlet side of the cylindrical hole. A needle having a contact portion capable of contacting a part of the conical slope, and a needle capable of contacting and separating from a part of the conical slope, being attached to a cylindrical hole exit surface of the valve body, and communicating with the cylindrical hole; An orifice plate having an orifice penetrating in the plate thickness direction, wherein the orifice is located closer to the cylindrical hole outlet center than the position where the main flow direction of the fluid downstream of the contact portion intersects the inlet surface of the orifice plate. At the radially outer position, the needle tip
The height h from the end to the orifice plate entrance surface is
A configuration characterized by setting 0.1 ≦ h ≦ 0.5 (mm) is adopted.

According to a second aspect of the present invention, in the fluid injection nozzle, the orifice is formed as follows: [(a boundary point between the conical inclined surface and the cylindrical surface forming the cylindrical hole) and (this boundary). A straight line m connecting a line between the line connecting the line that is the closest distance from the point to the needle tip surface and the intersection point of the needle tip surface) and the abutment portion is the entrance surface of the orifice plate. The center of the entrance surface of the orifice is located radially outward of the intersection that intersects with the orifice.

According to a third aspect of the present invention, the fluid injection nozzle has an orifice circumscribed circle diameter D ₁ and an inner diameter D ₂ of a cylindrical hole of a valve body at an inlet surface of the orifice plate.
It is characterized in that a relationship of D ₁ ≦ D ₂ is set. Fluid injection nozzle according to claim 4, the inside diameter D ₂ of the cylindrical bore of the valve body, in relation to the effective opening area S ₂ of the total effective opening area S ₁ and the cylindrical bore of the orifice, 3S ₁ ≦
And setting such that S _2.

According to a fifth aspect of the present invention, the tip of the needle has a spherical surface or a curved surface close to a spherical surface.

According to a sixth aspect of the present invention, in the fluid jet nozzle, the sheet diameter φ corresponding to the position of the contact portion of the needle is φ
≦ 4 (mm).

[0012]

According to the first aspect of the present invention, the orifice is set at a position radially outward from the center of the cylindrical hole outlet from the position where the mainstream spray of the fluid downstream of the seat intersects the inlet surface of the orifice plate. By doing so, even when the needle is eccentric, it is possible to enhance the direction control of the fuel by preventing the main flow from directly passing through the hole. In addition, increase the injection amount during fuel boiling to an appropriate value
be able to.

According to the second aspect of the invention, it is possible to improve the direction control accuracy of the fuel with a simple configuration. According to the third aspect, it is possible to create a turbulent flow without being affected by the cylindrical surface. According to the fourth aspect, the orifice restricting effect can be ensured, the pressure distribution in each hole can be made uniform, the fuel injection direction can be reliably controlled, and the influence of uneven fuel flow can be suppressed.

According to the fifth aspect, the main flow is directed to the vicinity of the central axis along the curved surface of the tip of the needle, and the bias of the jet can be more reliably prevented. According to the sixth aspect , it is possible to prevent foreign matter from being caught between the needle and the valve seat.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIGS. 1 to 4 show an embodiment in which the present invention is applied to a fuel injection valve of a fuel supply device of a gasoline engine.

First, a fuel injection valve as a fluid injection nozzle will be described with reference to FIG. As shown in FIG. 2, a fixed iron core 21, a spool 91, an electromagnetic coil 32, a coil mold 31, and a metal plate 93 as a magnetic path are provided inside a resin housing mold 11 of the fuel injection valve 10 as a fluid injection nozzle. 94 are integrally formed. The fixed core 21 is made of a ferromagnetic material, and is provided in the housing mold 11 so as to protrude from above the coil mold 31. An adjusting pipe 29 is fixed to the inner wall of the fixed iron core 21.

An electromagnetic coil 32 is wound around the outer periphery of a spool 91 made of resin.
A coil mold 31 is resin-molded on the outer periphery of the electromagnetic coil 32. The coil mold 31 surrounds the electromagnetic coil 32.
The coil mold 31 protects the electromagnetic coil 32, and protects a lead wire electrically derived from the electromagnetic coil 32, and also retains a terminal 34 described later. And a protruding portion 31b protruding upward from. And coil mold 3
The spool 91 and the electromagnetic coil 32 are mounted on the outer periphery of the fixed iron core 21 in a state integrated by 1.

The two metal plates 93 and 94 are provided such that one upper end is in contact with the outer periphery of the fixed iron core 21 and the other lower end is in contact with the outer periphery of the magnetic pipe 23.
A member that forms a magnetic path through which magnetic flux flows when current is supplied to the cylindrical portion 31a, and is coated on the outer periphery of the cylindrical portion 31a so as to sandwich the cylindrical portion 31a from both sides. These two metal plates 93 and 9
4, the electromagnetic coil 32 is protected.

A connector portion 11a is provided above the housing mold 11 so as to protrude from an outer wall of the housing mold 11. Then, a terminal 34 that is electrically connected to the electromagnetic coil 32 is embedded in the connector part 11 a and the coil mold 31. The terminal 34 is connected to an electronic control unit (not shown) via a wire harness.

One end of the compression coil spring 28 contacts the upper end surface of the needle 25 fixed to the movable iron core 22 by welding, and the other end of the compression coil spring 28 contacts the bottom of the adjusting pipe 29. The compression coil spring 28 urges the movable iron core 22 and the needle 25 downward in FIG. 2, and seats the seat portion of the needle 25 on the valve seat 263 of the valve body 26. When an exciting current flows from the terminal 34 to the electromagnetic coil 32 via a lead wire by an electronic control unit (not shown), the needle 25 and the movable core 22 are attracted toward the fixed core 21 against the urging force of the compression coil spring 28. You.

The non-magnetic pipe 24 is connected to the lower part of the fixed iron core 21. Then, one end portion 2 is provided below the fixed core 21 so as to partially protrude from the lower end of the fixed core 21.
4a is connected. Further, a small diameter portion 23b of a magnetic pipe 23 made of a magnetic material and formed in a stepped pipe shape is connected to a lower end of the other end 24b of the nonmagnetic pipe 24. The other end 2 of the non-magnetic pipe 24
4b is a guide of the movable iron core 22.

Next, a cylindrical movable iron core 22 made of a magnetic material is provided in the internal space of the non-magnetic pipe 24 and the magnetic pipe 23. The outer diameter of the movable core 22 is set slightly smaller than the inner diameter of the other end 24b of the non-magnetic pipe 24, and the movable core 22 is
4 is slidably supported. The upper end face of the movable iron core 22 is provided so as to face the lower end face of the fixed iron core 21 via a predetermined gap.

At the upper part of the needle 25, a joint 43 is formed. Then, the joint 43 and the movable iron core 22 are laser-welded, and the needle 25 and the movable iron core 22 are integrally connected. A double chamfer as a fuel passage is provided on the outer periphery of the joining portion 43. Above the fixed iron core 21, there is provided a filter 33 for removing foreign substances such as dust in the fuel which is pressure-fed from a fuel tank by a fuel pump or the like and flows into the fuel injection valve 10.

The fuel that has flowed into the fixed iron core 21 through the filter 33 flows from the guide pipe 29 to the joint 4 of the needle 25.
3, the gap between the two chamfered portions, and the cylindrical surface 261 of the valve body 26 and the sliding portion 41 of the needle 25.
Through the gap between the four chamfers formed in the
5 reaches a valve portion composed of a seat portion (contact portion) 251 and a valve seat 263 at the tip end, and reaches a cylindrical surface 264 forming an injection hole from this valve portion.

Next, the configuration of the discharge section 50 of the fuel injection valve 10 will be described with reference to FIG. A valve body 26 is inserted into a large diameter portion 23a of the magnetic pipe 23 via a hollow disk-shaped spacer 27 and is laser-welded. The thickness of the spacer 27 is adjusted so that the air gap between the fixed core 21 and the movable core 22 shown in FIG. 2 is maintained at a predetermined value. A cylindrical surface 261 on which the sliding portion 41 of the needle 25 slides and a valve seat 26 on which the conical seat portion 251 of the needle 25 sits are provided on the inner wall of the valve body 26.
3 are formed. Further, an injection hole 264 is formed at the bottom center of the valve body 26.

A flange 36 is formed on the needle 25 so as to oppose a lower end surface of the spacer 27 accommodated in the inner wall of the large diameter portion 23a of the magnetic pipe 23 via a predetermined gap. The flange 36 is formed on the seat portion 42 side formed at the tip of the needle 25 in the entire length of the needle 25, and the valve body 26 is provided below the flange 36.
Sliding part 41 slidable on cylindrical surface 26a formed on
Are formed.

A flow control mechanism 51 is provided at the outlet of the injection hole 264 of the valve body 26. The flow control mechanism 51 includes a needle 25, a valve body 26, and an orifice plate 52, as shown in FIGS.
, And the combination thereof.

Hereinafter, each of these features will be sequentially described. (1) Needle 25 As shown in FIG. 3, the needle 25 has a solid cylindrical surface 250, an inclined surface 252, an inclined surface 253, an inclined surface 254, and a spherical surface 255 formed at its distal end. Each of these surfaces 25
0, 252, 253, 254, 255 are sequentially formed so that the boundary line becomes circular, and an annular line at the boundary between the solid cylindrical surface 250 and the inclined surface 252 is formed as a contact portion (sheet portion) 25.
It becomes 1. FIG. 3 shows a valve-closed state. In this valve-closed state, the contact portion 251 and the valve seat 263 form a contact point, and a group of the contact points forms an annular line.

(2) Valve Body 26 The valve body 26 comprises a cylindrical surface 261, a conical inclined surface 262, and a cylindrical surface 264 forming a cylindrical hole shown in FIG. 1, and the boundary between these surfaces 261, 262, and 264 is It has a circular shape. (3) Orifice Plate 52 The orifice plate 52 that constitutes a part of the flow control mechanism 51 is made of, for example, stainless steel, and is joined to the tip of the valve body 26 by welding, for example, full circumference welding as shown in FIGS. You. The orifice plate 52 includes
As shown in FIGS. 1B and 4, four orifices 5
4, 55, 56 and 57 are formed penetrating in the thickness direction.

Next, the features of the flow control unit of the present invention will be described sequentially with reference to FIG. Orifice (hole) inclination angle As shown in FIG. 4, the orifices 54, 55, 56, 57
(Hereinafter referred to as “holes 54, 55, 56, 57”)
In this case, four holes are provided.
5, 56 and 57 are formed in a cylindrical straight shape, and the cylindrical central axis is inclined by an inclination angle α with respect to the thickness direction line as shown in FIG. FIG. 9 is a cross section IX-IX of FIG.
Is shown.

This example is an example of two-way spraying. For example, as shown in FIG. 10, from the hole 54 and the hole 55. the fuel flow F ₁ is injected toward the bevel portion of one intake valve 102, the hole 5
Fuel flow F ₂ is injected from 7 and hole 56 toward the head of the other intake valve 101. These holes 54, 55, 56, 5
The inclination angle α of 7 is desirably in the range of 10 ≦ α ≦ 40 (°), and the value of α is appropriately set according to the specifications of the engine.

Position of Orifice (Hole) As shown in FIG. 3, the center 542 of the inlet surface of the hole 54 is closer to the intersection 101 between the flow direction of the main fuel flow downstream from the valve seat 263 and the inlet surface of the hole 54. It is located outside a circle centered on the center point 102. Specifically, assuming that the intersection point 105 between the intersection point 104 of the inclined surface 262 and the cylindrical surface 264 and the spherical surface 255 that is the shortest distance from the needle 25 to the needle 25, the middle point 106 of the line connecting the points 104 and 105 and the corresponding valve Seat 2
The entrance surface center point 542 of the hole 54 is located at a position radially outside the point 101 where the straight line m connecting the contact point 63 (contact portion 251) intersects with the entrance surface of the orifice plate 52. When the valve is opened, the needle 25 and the valve body 26
The direction of the main flow flowing through the gap between the two is substantially in the direction of the straight line m. Hole 54 so that plane center point 542 comes
Is formed, it is possible to prevent the main flow from directly passing through the hole 54, and it is possible to improve the fuel direction control accuracy even when the needle 25 is eccentric. The positions of the other holes 55, 56 and 57 are the same as the positions of the holes 54. Therefore, the fuel passing from the inlets of the holes 54, 55, 56, 57 to the outlets of the holes 54, 55, 56, 57 is accurately formed along the inclination angle α of the holes 54, 55, 56, 57. It is injected.

As shown in FIG. 4, the circumscribed circle diameter D _{1 at} the entrance of each of the holes 54, 55, 56, and 57 is determined by the valve body diameter D ₂ of the cylindrical surface 264 forming the injection hole. (Diameter of injection hole), D ₁ ≦ D ₂ .

If the orifice hole is close to the cylindrical surface 264 of the cylindrical hole, the injection is disturbed or the injection amount becomes unstable due to the influence of the cylindrical surface. Therefore, this is suppressed by setting the above range, and fuel is injected with high accuracy. Opening area of injection hole of valve body Effective opening area of injection hole of valve body 26 (cylindrical surface 264)
Opening _{area) S 2 (S = πD 2} 2/4), holes 54 and 55,
When the sum S ₁ of the cross section effective opening area of 56, 57,
It is set so that 3S ₁ ≦ S ₂ .

The aperture effect of the holes 54, 55, 56, and 57 is set by setting the body opening area S ₂ to be sufficiently larger than the total sum S ₁ of the effective opening areas of the cross sections of the holes 54, 55, 56, and 57. Therefore, even if the needle is eccentric, the pressure distribution in each hole becomes uniform. Holes 54, 55, 56, 5
7, the fuel injection direction control is reliably performed, and the influence of the fuel flow "bias" can be suppressed.

The tip shape of the needle 25 is, as shown in FIG.
55. According to the present invention, it is also possible to adopt a curved surface shape approximating a spherical surface without strictly pursuing the shape of the spherical surface 255. By making such a curved surface close to a spherical surface, the needle 25 and the valve body 26
When fuel flows from the vicinity of the valve seat 263 in the lower left direction in FIG.
4 through the gap between the conical surface 262 and the spherical surface 25
5 and the conical slope 262, the direction of the main flow is changed by causing the flow of the fuel along the direction of the spherical surface 255, and the main flow collides near the central axis of the orifice plate 52. This prevents the main flow from opening to the orifice even when the needle 25 is eccentric. Therefore, it is possible to more reliably prevent the fuel jet injected through the holes 54, 55, 56, and 57 from being biased.
Therefore, there is an effect that the direction control of the fuel spray shape can be performed more precisely.

Distance h from the tip of the needle to the orifice inlet surface h The distance (height h) from the spherical surface 255 as the needle tip to the inlet surface of the orifice plate 52 is 0.1 ≦ h
Set to ≤0.5 (mm). If the height h is 0.1> h, manufacturing processing becomes difficult. Further, the flow of fuel through the gap between the needle 25 and the valve body 26 is
4, 55, 56, and 57, which makes it difficult to suppress the influence of the imbalance of the spray when the needle is eccentric. In order to reduce the influence of the fuel flow bias at the time of the needle eccentricity, 0.1 ≦ h is set.

On the other hand, if 0.5 <h, when the temperature becomes high when the valve is closed, the fuel in the space from the seat portion 251 to the orifices 54 to 57 boils, the volume expands, and most of the fuel flows out of the orifice. Would. Then, at the start of the next fuel injection, the adjustment is performed only in the seat portion, so that the injection amount increases. This phenomenon becomes more remarkable as the volume of this space, that is, h, increases. Therefore, by setting h in the above range, it is possible to prevent the injection imbalance at the time of eccentricity of the needle 25 and to suppress the increase in the injection amount at the time of high temperature.

Assuming that the diameter of the contact portion (seat portion) 251 where the needle 25 contacts the valve seat 263 is φ, φ ≦ 4 (mm). In order to make the passage flow rate of the seat portion the same, the lift amount of the needle 25 must be reduced. If the lift amount is too small, not only does foreign matter get stuck in this portion, but also the effect of the eccentricity of the fuel flow when the needle is eccentric becomes significant. Therefore, by setting the sheet diameter in the above range, the intrusion of foreign matter is suppressed, and the needle 2
Spray imbalance at the time of 5 eccentricity can be suppressed.

The first embodiment is an example in which the present invention is applied to a two-way injection type as shown in FIG. An example of this two-way injection system will be briefly described with reference to FIG. As shown in FIG. 10, the combustion chamber 6 of the engine 60
Intake ports 62, 63 opening to intake valves 101, 1
02 is attached so as to be openable and closable. Between the intake port 62 and the intake port 63, a wall 64 that partitions both ports is provided.
Are formed. The fuel injection valve 10 having the flow control mechanism 51 is mounted so as to inject fuel toward the heads of the intake valves 101 and 102.

Next, another embodiment of an orifice plate applied to a one-way injection type injection valve is shown in FIGS. 5, 6, 7 and 8. FIG. As shown in FIG. 11, when the injection valve in one direction injection type, fuel flow F ₂ injected from the injection valve,
The fuel is injected at an injection angle θ of the fuel flow toward the valve head of one intake valve 101 of the intake port 621. (Second Embodiment) In a second embodiment applied to the one-way injection system, as shown in FIG. 5, holes 154, 155, 156, and 157 formed in the orifice plate 52 have a flow of fuel passing through these holes. Arrows 1541, 1551, 1561,
The orifice plate is formed to be inclined in the thickness direction so as to have a vector in the 1571 direction. By doing so, the flow of the fuel injected from the holes 154, 155, 156, and 157 and colliding with each other is precisely controlled in the valve head direction of the intake valve.

(Third Embodiment) A third embodiment applied to the one-way injection system has holes 254, 255,
The inclination direction of 256, 257 is the arrow 254 from the plate thickness direction.
1, 2551, 2561 and 2571. Thereby, four holes 254, 255, 256, 2
The fuel jetted from 57 collides at one point, and after the collision, the direction is precisely controlled toward the valve head of one intake valve. Therefore, fuel injection maintaining good injection direction control can be obtained.

(Fourth Embodiment) A fourth embodiment shown in FIG.
This is an example in which two holes are formed in the orifice plate. Holes 354, 3 formed in orifice plate 52
55 are arrows 3541 and 3551 respectively from the plate thickness direction.
It is penetrated by being inclined in the direction. The center lines of the holes 354 and 355 have an inclination angle α with respect to the thickness direction. This allows
Direction control of the fuel injection direction can be performed more precisely. Hole 3
The directions of 54 and 355 are inward arrows 3541 and 3, respectively.
Although the holes 354 and 355 are inclined so as to be 551, the holes 354 and 355 may be formed so as to be inclined outward and outward in the direction toward the outlet side.

(Fifth Embodiment) The fifth embodiment shown in FIG.
This is an example in which the number of holes formed in the orifice plate 52 is six. Six holes 454, 455, 456, 457,
458, 459 are concentric. The present invention can be applied to such six holes. In the present invention, the number of holes formed in the orifice plate is not limited, and the one-way injection method or the two-way injection method can be used by determining the inclination direction of the holes. FIGS. 13A and 13B show the deviation (A) of the fuel flow F _{1 in} the case of the two-way injection system and the fuel flow F ₂ in which the deviation has been corrected.
(B) of FIG. FIGS. 14A and 14B show a schematic diagram (B) of a deviation (A) of the fuel flow F ₁ and a fuel flow F ₂ in which the deviation is corrected in the case of the one-way injection system.

[Brief description of the drawings]

1A and 1B show an injection nozzle portion of a fuel injection valve according to a first embodiment of the present invention, wherein FIG. 1A is an enlarged sectional view thereof, and FIG.
Is a view in the direction of the arrow IV.

FIG. 2 is a longitudinal sectional view of a fuel injection valve to which the present invention is applied.

FIG. 3 is an enlarged view of a portion III shown in FIG. 1;

FIG. 4 is an entrance view showing a hole portion of the orifice plate of the first embodiment.

FIG. 5 is an entrance view showing a hole portion of an orifice plate according to a second embodiment.

FIG. 6 is an entrance view showing a hole portion of an orifice plate according to a third embodiment.

FIG. 7 is an entrance view showing a hole portion of an orifice plate according to a fourth embodiment.

FIG. 8 is an entrance view showing a hole portion of an orifice plate according to a fifth embodiment.

FIG. 9 is an explanatory view showing a portion of a hole and an injection hole of the orifice plate of the first embodiment.

FIG. 10 is an explanatory diagram showing a fuel spray state of a two-way injection system.

FIG. 11 is an explanatory diagram showing a fuel spray state of a one-way injection system.

FIG. 12A is an explanatory diagram showing a guide hole inner diameter distribution of a valve body, and is an explanatory diagram showing a needle sliding portion outer diameter distribution.

FIG. 13A is a schematic diagram showing a bias of an injection flow of a two-way injection system, and FIG. 13B is a schematic diagram showing a correction state thereof.

FIG. 14A is a schematic diagram illustrating a bias of a one-way injection type jet flow, and FIG. 14B is a schematic diagram illustrating a correction state thereof.

[Explanation of symbols]

 Reference Signs List 10 fuel injection valve 25 needle 26 valve body 41 sliding portion 51 flow control mechanism 52 orifice plate 54, 55, 56, 57 hole 110 circumscribed circle 250 cylindrical portion 251 contact portion 252 inclined surface 253 inclined surface 254 inclined surface 255 spherical surface 261 cylindrical surface Guide hole) 262 Conical surface 263 Valve seat 264 Cylindrical surface (injection hole) θ Injection angle α Inclination angle of orifice (hole)

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Nobuo Ota 1-1-1, Showa-cho, Kariya-shi, Aichi, Japan Inside Denso Co., Ltd. (72) Inventor Hideo Kiuchi 1-1-1, Showa-cho, Kariya-shi, Aichi Japan Nihon Denso Co., Ltd. (72) Inventor Kenji Okubo 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Chishiro Sugimoto 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (56) References International Publication 93/20349 (WO, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02M 39/00-71/04

Claims (6)

(57) [Claims] 1. A valve body having a cylindrical hole and a conical slope formed on the inlet side of the cylindrical hole, and a contact portion capable of contacting a part of the conical slope, and a part of the conical slope. An orifice plate attached to an outlet surface of a cylindrical hole of the valve body and having an orifice communicating with the cylindrical hole and penetrating in the thickness direction of the valve body. the position where the main flow direction of the downstream side of the fluid intersects the inlet surface of the orifice plate parts, there from the cylindrical hole exit center radially outward position, the orifice plate inlet surface or from said needle tip
Height h is set to 0.1 ≦ h ≦ 0.5 (mm)
Fluid injection nozzle, characterized in that it has. 2. The orifice includes: [(a boundary point between the conical slope and the cylindrical surface forming the cylindrical hole) and ((a boundary point from the boundary point to a needle tip surface) on a plane including a central axis of the cylindrical hole. A straight line m connecting the midpoint of the line connecting the line that is the closest distance to the needle tip surface) and the abutment portion is larger in diameter than the intersection that intersects the entrance surface of the orifice plate. 2. The fluid ejection nozzle according to claim 1, wherein the center of the entrance surface of the orifice is located outward in the direction. 3. The relationship of D ₁ ≦ D ₂ , wherein an orifice circumscribed circle diameter D ₁ and an inner diameter D ₂ of a cylindrical hole of a valve body are set at an inlet surface of the orifice plate. Or the fluid ejection nozzle according to 2. Wherein the inner diameter D ₂ of the cylindrical bore of the valve body,
In relation to the effective opening area S ₂ of the total effective opening area S ₁ and the cylindrical bore of the orifice, the fluid injection nozzle according to claim 1, 2 or 3 wherein the set to satisfy 3S ₁ ≦ S ₂ . 5. The fluid ejection nozzle according to claim 1, wherein a tip shape of the needle is a spherical surface or a curved surface close to a spherical surface. Wherein said sheet diameter phi corresponding to the position of the contact portion of the needle, phi ≦ 4 fluid injection nozzle of any one of claims 1-5, characterized in that set in (mm) .