WO2019098025A1

WO2019098025A1 - Fuel injection valve

Info

Publication number: WO2019098025A1
Application number: PCT/JP2018/040453
Authority: WO
Inventors: 一樹吉村; 石井　英二; 威生三宅; 保夫生井沢
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2017-11-17
Filing date: 2018-10-31
Publication date: 2019-05-23
Also published as: JP6899756B2; JP2019090395A

Abstract

The purpose of the present invention is to provide a fuel injection valve with which it is possible to reduce break away of fuel flow within an injection hole by applying simple machining to the entrance of the injection hole. In the present invention, a plurality of injection holes 201a1, 201b1 are classified into a first injection hole 201a1 that has a greater inclination angle and a second injection hole 201b1 that has a smaller inclination angle, with respect to the central axis line 210 of a valve element. The first injection hole 201a1 is configured such that a radially-outer-side entrance opening edge 201a1A of a valve seating face 203 is disposed on the inner side of a first groove 202a1 formed in the valve seating face 203 so as to cause an outer-diameter-side entrance angle θa1 to be increased. The second injection hole 201b1 is configured such that the radially-inner-side entrance opening edge 201b1B of the valve seating face 203 is disposed on the inner side of a second groove 202b1 formed in the valve seating face 203 so as to cause the inner-diameter-side entrance angle θb1 to be increased.

Description

Fuel injection valve

The present invention is a fuel injection valve used in an internal combustion engine such as a gasoline engine, and the valve body abuts against the valve seat surface to prevent fuel leakage, and the valve body leaves the valve seat surface for injection. It relates to fuel injection valves.

In fuel injection valves used in automobile engines, if fuel droplets scattered during injection or coarse fuel droplets generated after injection adhere to the tip of the fuel injection valve, deposits are generated due to incomplete combustion, The problem is that it causes changes in the spray performance and generation of unburned particulate matter.

By suppressing the separation of the fuel flow from the side wall (inner wall surface) of the injection hole, the scattering of droplets can be suppressed, and the adhesion of fuel to the tip of the fuel injection valve can be suppressed. As a method of suppressing separation, there is a method of rounding the corners of the injection hole inlet to make the injection hole inlet curved. For example, Japanese Patent Application Laid-Open No. 2015-124648 (Patent Document 1) describes a method of forming the injection hole inlet in a curved surface shape using fluid polishing (see abstract).

Unexamined-Japanese-Patent No. 2015-124648

In fluid polishing, the curved surface shape to be processed changes depending on the inclination angle (perforation angle) of the injection hole and the flow path shape on the upstream side, so it is difficult to control the polishing agent and the polishing time, and the processing cost increases.

An object of the present invention is to provide a fuel injection valve capable of reducing the separation of the fuel flow in the injection hole by simple processing to the injection hole inlet.

In order to achieve the above object, the fuel injection valve of the present invention is
With a disc,
A valve seat surface on which a seat portion for sealing fuel is formed by the abutment of the valve body;
And a plurality of injection holes opened in the valve seat surface,
The plurality of injection holes have a plurality of injection holes having a large inclination angle and a small inclination angle according to the inclination angle of the central axis of the injection hole with respect to the central axis of the valve body. Divided into the second injection holes,
In the first injection hole, an outer diameter side inlet opening edge which is an outer inlet opening edge in the radial direction of the valve seat surface is disposed inside a first groove formed in the valve seat surface. An outer diameter side inlet angle formed by a surface of the first groove and a side wall surface of the first injection hole at a portion of the outer diameter side inlet opening edge is the valve seat surface when the first groove is absent Has a large angle as compared with a virtual outer diameter side inlet angle formed by the side wall surface of the first injection hole,
The second injection hole is disposed on the inner side of a second groove formed in the valve seat surface, which is an inner inlet opening edge which is an inner inlet aperture edge in the radial direction of the valve seat surface. The inner diameter side inlet angle formed by the surface of the second groove and the side wall surface of the second injection hole at the portion of the inner diameter side inlet opening edge is the valve seat surface and the second surface when the second groove is absent. The angle is larger than the imaginary inner diameter inlet angle formed by the side wall surface of the injection hole.

According to the present invention, it is possible to provide a fuel injection valve capable of reducing the separation of the fuel flow in the injection hole by simple processing to the injection hole inlet. Problems, configurations, and effects other than those described above will be apparent from the description of the embodiments below.

It is a sectional view showing an outline of a fuel injection valve concerning a 1st example of the present invention. It is a sectional view showing an outline of a tip structure of a fuel injection valve concerning a 1st example of the present invention. It is the schematic (top view) for demonstrating arrangement | positioning of the injection hole which concerns on 1st Example of this invention, and the structure of the groove provided in the injection hole vicinity. It is the schematic for demonstrating the structure and fuel flow of the injection hole vicinity which concern on 1st Example of this invention. It is a sectional view showing an outline of a tip structure of a fuel injection valve of a comparative example for comparing with a 1st example of the present invention. It is the schematic (top view) for demonstrating arrangement | positioning of the injection hole which concerns on 2nd Example of this invention, and the structure of the groove provided in the injection hole vicinity. It is a fragmentary sectional view which shows a part of VIB-VIB cross section of FIG. 6A. It is the schematic (top view) for demonstrating the arrangement | positioning of the injection hole which concerns on 3rd Example of this invention, and the structure of the groove provided in the injection hole vicinity.

Hereinafter, examples according to the present invention will be described.

Example 1
The fuel injection valve according to the first embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

<< Injection valve basic operation explanation >>
FIG. 1 is a cross-sectional view schematically showing a fuel injection valve according to a first embodiment of the present invention. FIG. 1 shows an electromagnetic fuel injection valve as an example of a fuel injection valve according to the present embodiment. In particular, although the electromagnetic fuel injection valve 100 in FIG. 1 is an electromagnetic fuel injection valve for a direct injection gasoline engine in a cylinder, it may be used for an electromagnetic fuel injection valve for a port injection gasoline engine. The effects of the invention can be achieved. Further, the present invention is not limited to the electromagnetic type, and is effective also in a fuel injection valve driven by a piezo element or a magnetostrictive element.

In the following description, the lower side of the fuel injection valve 100 is referred to as a tip, and the upper side is referred to as a base, with reference to the fuel injection valve 100 of FIG. 1. Further, since the fuel flows from the upper side to the lower side of FIG. 1 in the fuel injection valve 100, the tip may be called the downstream end and the base may be called the upstream end based on the fuel flow direction. .

In FIG. 1, fuel is supplied from a fuel supply port 112 and is supplied to the inside of a fuel injection valve. The electromagnetic fuel injection valve 100 is a normally closed electromagnetic drive type, and when the coil 108 is not energized, the valve body 101 is biased by the spring 110 and pressed against the seat member (injection hole forming member) 102 And the fuel is sealed. The valve body 101 is displaceable in a direction along the central axis 100 a of the fuel injection valve 100. At this time, in the in-cylinder injection type fuel injection valve which directly injects the fuel into the cylinder of the engine, the pressure of the supplied fuel is adjusted to a range of approximately 1 MPa to 50 MPa.

FIG. 2 is a cross-sectional view schematically showing the tip structure of the fuel injection valve according to the first embodiment of the present invention.
This cross sectional view shows a cross section parallel to the central axis 100 a of the fuel injection valve 100 and including the central axis 100 a.

The nozzle body 104 is a member which is disposed on the outer peripheral side of the valve body 101 and forms a fuel flow path. The outer peripheral portion 102 a of the sheet member 102 is welded to the nozzle body 104 by a welding beam from the downstream direction. The method of fixing the sheet member 102 to the nozzle body 104 is not limited to welding, and may be screwing or press fitting. A conical valve seat surface 203 is formed on the opposite surface 102 b of the seat member 102 to the valve body 101.

When the electromagnetic fuel injection valve 100 is in the closed state, the tip end portion 101a of the valve body 101 abuts on the valve seat surface 203 of the seat member 102, thereby maintaining the fuel seal. A plurality of injection holes 201a1 and 201b1 are provided at the tip portion 102c of the seat member 102. More specifically, in the injection holes 201a1 and 201b1, the inlet is in contact with the valve body 101 so that the inlet is open to the valve seat surface 203 of the seat member 102 (abutment position, seat, seal portion It is provided so as to be located on the downstream side (tip side) than the.

The injection holes 201a1 and 201b1 have grooves 202a1 and 202b1 formed in the injection hole inflow portion by cutting and electroforming, for example, and cylindrical injection holes 201a1 and 201b1 are formed by punching or laser processing. The grooves 202a1 and 202b1 may be referred to as groove-shaped portions or concave portions. The grooves 202a1 and 202b1 are formed in a recessed shape in a groove shape (concave shape) from a conical surface (conical surface) which constitutes the valve seat surface 203.

Although not shown in FIG. 2, in order to adjust the length (longitudinal direction) of the injection holes 201 a 1, 201 b 1 along the injection hole axes 211 a 1, 211 b 1 downstream of the injection holes 201 a 1, 201 b 1, the injection holes 201 a 1 In some cases, a counterbore (also referred to as a recessed portion or a hole forming portion) having a diameter larger than that of 201b1 may be formed by punching or laser processing. The injection hole axis lines 211a1 and 211b1 coincide with the center lines of the injection holes 201a1 and 201b1.

In the present embodiment, the injection holes 201a1 and 201b1 are described as having a cylindrical shape (cylindrical shape) having a circular cross section, but the present invention is not limited to this. For example, the injection hole cross-sectional area It may be a tapered injection hole or an elliptical injection hole that changes along 211 b 1. Also, each injection hole may have a different diameter.

When the coil 108 is energized via the connector 111 shown in FIG. 1, magnetic flux is generated in the core (fixed core) 107, the yoke 109, and the anchor 106 that constitute the magnetic circuit of the solenoid valve. A gap is formed between the core 107 and the anchor 106 at the time of non-energization, and a magnetic attraction force is generated on the core 107 such that the anchor 106 is attracted. The biasing force of the spring (first spring) 110 and the biasing force of the above-described fuel pressure are applied to the anchor 106 in the downstream direction, but when the magnetic attraction force by energization becomes larger than these biasing forces, the anchor 106 Move toward the core 107.

The valve body 101 is guided by the guide member 103 at the downstream portion, and is guided by the valve body guide 105 configured separately from the guide portion 103 at the upstream portion. The guide member 103 and the valve body guide 105 are fixed and supported on the inner peripheral portion of the nozzle body 104. The anchor 106 is configured independently of the valve body 101, and the rod portion of the valve body 101 is inserted into a valve body insertion hole formed on the radially inner side of the anchor 106.

A flange portion having an outer diameter larger than that of the rod portion is formed at the upstream portion of the valve body 101, and in the valve closed state at the time of non-energization, the flange portion contacts the valve body support portion of the anchor 106. As a result, the anchor 106 is biased in the valve-closing direction via the collar, and an air gap is formed between the anchor 106 and the core 107. The anchor 106 is biased in the valve opening direction by a spring (second spring) 113 whose biasing force is smaller than that of the spring 110.

On the other hand, when the coil 108 is energized, the anchor 106 is attracted toward the core 107 by the magnetic attraction force. At this time, the valve body support portion of the anchor 106 and the flange portion of the valve body 101 are engaged, and the valve body 101 is biased toward the core 107 (the valve opening direction), so the valve opening state is reached.

In the valve open state, a gap (stroke) is formed between the valve seat surface 203 and the contact portion of the valve body 101 shown in FIG. 2, and fuel injection is started. When fuel injection is started, the energy given as fuel pressure is converted into kinetic energy and reaches the injection holes 201a1 and 201b1, and the fuel is injected toward the cylinder of the engine (not shown).

«Configuration and features of the embodiment»
The configuration of the embodiment according to the present invention will be described with reference to FIG. 2 to FIG.

As shown in FIG. 2, in each of the injection holes 201a1 and 201b1, the central axes (injection hole axes) 211a1 and 211b1 of the injection holes correspond to the central axis (valve body axis) 210 of the valve body 101 according to the target position of the fuel spray. And it has an injection hole inclination angle (here θa, θb) with respect to the central axis (center line) of the valve seat surface 203. The one with a large injection hole inclination angle is denoted by θa, and the one with a low injection hole inclination angle is denoted by θb. In an actual design, the injection hole inclination angle of each injection hole 201a1, 201b1 is determined depending on the target spray shape. In this embodiment, it is assumed that θa> θb. In the present embodiment, the central axis of the valve seat surface 203 coincides with the valve axis 210, and the valve axis 210 coincides with the central axis 100 a of the fuel injection valve 100.

FIG. 3 is a schematic view (plan view) for explaining the arrangement of the injection holes and the structure of the grooves provided in the vicinity of the injection holes according to the first embodiment of the present invention. FIG. 3 shows how the injection holes 201a1 to 201a3 and 201b1 to 201b3 are viewed from the inlet side, and the injection holes 201a1 to 201a3 and 201b to 201b3 and the grooves 202a1 to 202a3 and 202b to 202b3 are taken along the valve body axis 210 and It is a figure projected on a plane perpendicular to central axis 100a of fuel injection valve 100.

The plurality of injection holes 201a1 to 201a3 and 201b1 to 201b3 provided in the seat member 102 have different injection hole inclination angles. In the injection holes 201a1 to 201a3 and 201b1 to 201b3, the centers of the injection hole inlets are arranged on the same circumference (injection hole arrangement circle) 200 centered on O. In the present embodiment, the central axis 210 of the valve body 101 and the central axis 100 a of the fuel injection valve 100 pass through the center O of the arrangement circle 200. Note that O corresponds to the central axis of the cone or truncated cone formed by the valve seat surface 203. The inlet opening edge of the injection holes 201a1 to 201a3 is located on the radially outer side of the valve seat surface 203 (outer diameter side (Inlet opening edge) 201a1A to 201a3A, and inlet opening edge (inner diameter side inlet opening edge) 201a1B to 201a3B located radially inward of the valve seat surface 203. Further, the inlet opening edge of the injection holes 201b1 to 201b3 is located on the radially inner side of the valve seat surface 203 and the inlet opening edge (outer diameter side inlet opening edge) 201b1A to 201b3A located radially outward of the valve seat surface 203. The inlet opening edge (inner diameter side inlet opening edge) 201b1B to 201b3B located.

The injection holes 201a1 to 201a3 have a larger injection hole inclination angle than the injection holes 201b1 to 201b3. Grooves (groove-shaped portions or concave portions) 202a1 to 202a3 are provided on the sheet portion 214 side (upstream side) near the injection hole inlet with respect to the injection holes 201a1 to 201a3 having a large injection hole inclination angle. That is, in the plan view of FIG. 3, the grooves 202a1 to 202a3 are provided radially outside the valve seat surface 203 with respect to the injection hole inlets of the injection holes 201a1 to 201a3. On the other hand, for the injection holes 201b1 to 201b3 having a small injection hole inclination angle, the grooves (groove shape portion or concave shape portion) 202b1 to 202b3 are provided on the valve body axis 210 side (downstream side) near the injection hole inlet. There is. That is, in the plan view of FIG. 3, the grooves 202b1 to 202b3 are provided radially inward (the center O side of the circumference 200) with respect to the injection hole inlets of the injection holes 201b1 to 201b3.

Here, the radial direction is the radial direction of the valve seat surface 203. Hereinafter, in the description of the arrangement of the grooves 202a1 to 202a3 and 202b1 to 202b3, the radial direction means a radial direction centering on the central axis (coincident with O) of the valve seat surface 203.

In the present embodiment, the grooves 202a1 to 202a3 and 202b1 to 202b3 are formed as independent grooves for each of the injection holes 201a1 to 201a3 and 201b1 to 201b3. Thus, the configuration (for example, the shape) of the grooves 202a1 to 202a3 and 202b1 to 202b3 can be changed in accordance with the configuration (for example, the inclination angle) of each of the injection holes 201a1 to 201a3 and 201b1 to 201b3. Grooves can be formed.

The grooves 202a1 to 202a3 and 202b1 to 202b3 have a side wall surface 207 parallel to the valve body axis 210, the center axis 100a and the valve body axis, the depth direction of which coincides with the direction along the central axis 100a and the valve body axis 210. And a bottom surface 208 perpendicular to 210. That is, the grooves 202a1 to 202a3 and 202b1 to 202b3 have a side wall surface 207 parallel to the central axis of the valve seat surface 203 formed of a conical surface and a bottom surface 208 perpendicular to the central axis of the valve seat surface 203.

FIG. 4 is a schematic view for explaining the structure and fuel flow in the vicinity of the injection hole according to the first embodiment of the present invention. This cross sectional view shows a cross section parallel to the central axis 100 a of the fuel injection valve 100 and including the central axis 100 a.

Although the injection hole 201a1 will be described as the injection hole having a large injection hole inclination angle, the injection holes 201a2 and 201a3 are configured similarly to the injection hole 201a1. In addition, although the injection hole 201b1 will be described as the injection hole having a small injection hole inclination angle, the injection holes 201b2 and 201b3 are configured similarly to the injection hole 201b1.

The injection hole 201a1 is provided with the groove 202a1, so that the inlet angle of the injection hole 201a1 formed by the injection hole 201a1 and the side wall surface 207 of the groove 202a1 is θa1. The inlet angle θa1 is a component surface (side wall surface 207) of the groove 202a1 at a portion (outer diameter side inlet opening edge) 201a1A of the inlet opening edge of the injection hole 201a1 located radially outward of the valve seat surface 203 And the side wall surface 201a1C of the injection hole 201a1 (outer diameter side inlet angle).

By providing the groove 202b1, the injection hole 201b1 has an inlet angle of θb1 formed by the injection hole 201b1 and the bottom surface 208 of the groove 202b1. In the inlet opening edge of the injection hole 201b1, the inlet angle θb1 is a portion (bottom surface 208) of the groove 202b1 and the injection surface at a portion (inner diameter side inlet opening edge) 201b1B located radially inward of the valve seat surface 203. It is an angle (inner diameter side inlet angle) which the side wall surface 201b1C of the hole 201b1 forms.

A flow separation portion 302a is formed inside the injection hole 201a1 by the fuel flow 301a, and the fuel 301a is injected as a fuel spray 303a downstream of the injection hole 201a1.
Inside the injection hole 201b1, a flow separation portion 302b is formed by the fuel flow 301b, and the fuel 301b is injected as fuel spray 303b downstream of the injection hole injection hole 201b1.

FIG. 5 is a cross-sectional view schematically showing the tip structure of a fuel injection valve of a comparative example for comparison with the first embodiment of the present invention. This cross sectional view shows a cross section parallel to the central axis 100 a of the fuel injection valve 100 and including the central axis 100 a.

This comparative example shows the configuration in the case where the grooves 202a1 to 202a3 and 202b1 to 202b3 do not exist. In this comparative example, since there is no groove 202a1, the inlet angle θa2 on the upstream side (the seat portion 214 side) of the injection hole 201a1 is the angle formed by the side wall surface (inner wall surface) 201a1C of the injection hole 201a1 and the valve seat surface 203 Become. Further, since the inlet angle θb2 on the upstream side (the seat portion 214 side) of the injection hole 201a1 does not have the groove 202b1, the inlet angle θb2 on the downstream side (the valve body axis 210 side) of the injection hole 201b1 is the side wall surface 201b1C of the injection hole 201b And the valve seat surface 203 form an angle.

The inlet angle θa2 is an inlet angle at the outer diameter side inlet opening edge portion of the injection hole 201a1 formed by the valve seat surface 203 and the side wall surface of the injection hole 201a1 when the groove 202a1 of the embodiment according to the present invention is absent. , It may be called a virtual outer diameter side inlet angle. Further, the inlet angle θb2 is an inlet angle at the inner diameter side inlet opening edge portion of the injection hole 201b1 formed by the valve seat surface 203 and the side wall surface of the injection hole 201b1 when the groove 202b1 of the embodiment according to the present invention is absent. , It may be called a virtual inner diameter side inlet angle.

A flow separation portion 302a is formed inside the injection hole 201a1 by the fuel flow 311a, and the fuel 311a is injected as a fuel spray 313a downstream of the injection hole 201a1.
At this time, the fuel 304a adheres in the vicinity of the outlet of the injection hole 201a1. Further, a flow separation portion 302b is formed inside the injection hole 201b1 by the fuel flow 311b, and the fuel 311b is injected as a fuel spray 313b downstream of the injection hole 201b1. At this time, the fuel 304 b adheres to the vicinity of the outlet of the injection hole 201 b 1.

The features of this embodiment will be described.

As shown in FIG. 2, when focusing on the two injection holes 201a1 and 201b1, each injection hole 201a1 and 201b1 is an injection hole (injection hole inclination angle θa: first injection hole) 201a1 having a large injection hole inclination angle, The injection holes are divided into injection holes having a small injection hole inclination angle (injection hole inclination angle θb: second injection holes) 201 b 1. In the case of the injection hole 201a1 having the injection hole inclination angle θa, a groove (first groove) 202a1 for reducing fuel separation in the injection hole is provided on the seat portion 214 side (upstream side). In the case of the injection hole 201b1 of the injection hole inclination angle θb, the groove (second groove) 202b1 is provided on the valve body shaft 210 side (downstream side). In this case, the groove 202a1 is provided radially outward with respect to the injection hole 201a1, and the groove 202b1 is provided radially inward with respect to the injection hole 201b1.

Similarly, when explaining using FIG. 3, each of the injection holes 201a1 to 201a3 and 201b1 to 201b3 has a group of injection hole inclination angles (a group of injection hole inclination angle .theta.a: first injection hole) and injection hole inclination angles. It is divided into small groups (groups of injection hole inclination angle θb: second injection holes). It is not necessary that all of the injection holes 201a1 to 201a3 be the injection hole inclination angle θa, and it is not necessary that all the injection holes 201b1 to 201b3 be the injection hole inclination angle θb. For example, the injection hole inclination angle θc serving as a threshold may be set, and grouping may be performed on the injection hole inclination angle θa and the injection hole inclination angle θb. That is, the injection holes 201a1 to 201a3 having the injection hole inclination angle of θc or more are regarded as the injection holes belonging to the group having a large injection hole inclination angle (group of injection hole inclination angle θa), and the injection hole inclination angle is smaller than θc. The holes 201b1 to 201b3 may be regarded as injection holes belonging to a group having a small injection hole inclination angle (a group of injection hole inclination angle θa). In this case, θa means an angle of θc or more, and θb means an angle smaller than θc.

The injection holes 201a1 to 201a3 belonging to a group having a large injection hole inclination angle are provided with grooves (first grooves) 202a1 to 202a3 on the seat portion 214 side, and the injection holes 201b1 to 201b3 belonging to a group having a small injection hole inclination angle Grooves (second grooves) 202b1 to 202b3 are provided on the valve body axis 210 side. That is, the grooves 202a1 to 202a3 are provided radially outward of the injection holes 201a1 to 201a3, and the grooves 202b1 to 202b3 are provided radially inside of the injection holes 201b1 to 201b3.

The grooves 202a1 to 202a3 and 202b1 to 202b3 do not cover the entire circumference of the injection holes 201a1 to 201a3 and the inlet opening of the injection hole (in this embodiment, the grooves 202a1 to 202a3 and 202b1 to 202b3 are injection holes 201a1 to 201a3 and 201b1 to The injection holes (first injection holes) 201a1 to 201a3 are provided on the outside of the grooves (first grooves) 202a1 to 202a3 in the inner diameter side inlet opening edge portions 201a1B to 201a3B. In the injection holes (second injection holes) 201b1 to 201b3, the outer diameter side inlet opening edge portions 201b1A to 201b3A are arranged outside the grooves (second grooves) 202b1 to 202b3.

It is effective to provide the grooves 202a1 to 202a3 and 202b1 to 202b3 in the plan view of FIG. 3 so that the circumferential center portion coincides with the injection hole inclination direction (injection hole axis lines 211a1 to 211a3 and 211b1 to 211b3). is there. That is, it is preferable that the injection hole axis lines 211a1 to 211a3 and 211b1 to 211b3 or their extension lines are provided to cross the grooves 202a1 to 202a3 and 202b1 to 202b3 in the circumferential direction central part. However, the circumferential center portions of the grooves 202a1 to 202a3 and 202b1 to 202b3 may be provided to coincide with the radial direction (radial direction) of the injection hole arrangement circle 200. In this case, the grooves 202a1 to 202a3 are arranged such that the injection hole axis lines 211a1 to 211a3 or extension lines thereof cross the circumferential central portion of the grooves 202a1 to 202a3 on the radially outer side with respect to the injection holes 201a1 to 201a3. Ru. Further, the grooves 202b1 to 202b3 are arranged such that the injection hole axis lines 211b1 to 211b3 or extension lines thereof cross the circumferential central portion of the grooves 202b1 to 202b3 at the radially outer side with respect to the injection holes 201b1 to 201b3. .

The grooves corresponding to the grooves 202a1 to 202a3 and 202b1 to 202b3 do not necessarily have to be provided in the vicinity of all the injection hole inlets, and the grooves may be provided only in the injection holes whose separation is to be reduced.

Further, the features of this embodiment will be described using FIGS. 4 and 5 in comparison with a comparative example.

FIG. 5 shows the structure of the comparative example, and the inlet angle in the vicinity of the injection hole inlet is determined as θa2 and θb2 by the side wall surface of the injection hole and the valve seat surface according to the injection hole inclination angle. The inlet angle θa1 of the injection hole 201a1 is the inlet angle on the upstream side (the seat portion 214 side) of the injection hole 201a1. The inlet angle θb1 of the injection hole 201b1 is the inlet angle on the downstream side (the valve body axis 210 side) of the injection hole 201b1.

When the groove 202a1 is provided (FIG. 4), the entrance angle θa1 is larger than the entrance angle θa2 when the groove 202a1 is not provided (FIG. 5) (θa1> θa2). That is, by providing the groove 202a1, the inlet angle θa1 on the upstream side of the injection hole 201a1 can be made a larger angle. Since the inlet angle on the upstream side of the injection hole 201a1 having a large injection hole inclination angle is small, the improvement effect of the inlet angle θa1 by providing the groove 202a1 on the upstream side of the injection hole 201a1 is large.

When the groove 202b1 is provided (FIG. 4), the inlet angle θb1 is larger than the inlet angle θb2 when the groove 202b1 is not provided (FIG. 5) (θb1> θb2). That is, by providing the groove 202b1, the inlet angle θb1 on the downstream side of the injection hole 201b1 can be made a larger angle. Since the inlet angle on the downstream side of the injection hole 201b1 having a small injection hole inclination angle decreases, the improvement effect of the inlet angle θb1 by providing the groove 202b1 on the upstream side of the injection hole 201b1 is large.

By increasing the inlet angle θa1 in the injection hole 201a1, the flow separation portion 302a can be reduced, and fuel injection near the outlet of the injection hole 201a1 can be suppressed. Further, by increasing the inlet angle θb1 in the injection hole 201b1, the flow separation portion 302b can be reduced, and fuel injection near the outlet of the injection hole 201b1 can be suppressed.

In addition, the effect of peeling reduction by providing groove | channel 202a1, 202b becomes large, so that (theta) a2 and (theta) b2 of a comparative example are smaller value (at least 90 degrees or less).

«Description of flow and effect»
The operation and effect of the present embodiment will be described using FIGS. 4 and 5 in comparison with a comparative example.

Arrows

301a and 301b in FIG. 4 and

arrows

311a and 311b in FIG. 5 indicate fuel flows. As shown in FIG. 5, as the angles θa2 and θb2 become smaller, separation portions 302a ′ and 302b ′ occur in the injection holes 201a and 201b, and when the separations 302a ′ and 302b ′ increase until they reach the injection hole outlet, Since the air enters, the air-liquid interface is easily disturbed, and the sprays 313a 'and 303b' are easily spread. As a result,

fuel deposits

304a and 304b occur on the wall near the outlet of the injection hole.

On the other hand, as shown in FIG. 4, by providing the grooves 202a1 and 202b1, the fuel inlet angles θa1 and θb1 become large, so the ease of separation of the fuel flows 301a and 301b in the injection holes 201a1 and 201b1 is Reduced. Therefore, the peeling

portions

302a and 302b are smaller than those of the comparative example, and the fluctuations and spread of the

sprays

303a and 303b at the outlet of the injection hole are reduced, and the adhesion of fuel near the outlet of the injection hole is reduced.

In this embodiment, as shown in FIG. 4, in the first injection hole 201 a 1, an outer diameter side inlet opening edge portion 201 a 1 A which is an outer inlet opening edge in the radial direction of the valve seating surface 203 is formed in the valve seating surface 203. It is disposed inside the first groove 202a1. Thus, the outer diameter side inlet angle θa1 formed by the constituent surface 207 of the first groove 201a1 and the side wall surface 201a1C of the first injection hole 201a1 at the outer diameter side inlet opening edge portion 201a1A is the case where the first groove 202a1 does not exist (See FIG. 5) has a large angle as compared with an imaginary outside diameter side inlet angle θa2 formed by the valve seat surface 203 and the side wall surface 201a1C of the first injection hole 201a1. The other first injection holes 201a2 and 201a3 are configured in the same manner as the first injection hole 201a1.

Further, the second injection hole 201 b 1 is disposed inside the second groove 202 b 1 in which the inner diameter side inlet opening edge 201 b 1 B which is the outer inlet opening edge in the radial direction of the valve seat 203 is formed in the valve seat 203. As a result, when the second groove 202b1 does not exist, the inner side inlet angle θb1 formed by the constituent surface 208 of the second groove 202b1 and the side wall surface 201a1C of the second injection hole 201b1 at the inner side inlet opening edge 201b1B (see FIG. 5) has a large angle as compared with an imaginary inner diameter side inlet angle θb2 formed by the valve seat surface 203 and the side wall surface 201b1C of the second injection hole 201b1. The other second injection holes 201b2 and 201b3 are also configured in the same manner as the second injection hole 201b1.

Further, in the first groove 202a1, the inner diameter side inlet angle formed by the valve seat surface 203 and the side wall surface 201a1C of the first nozzle hole 201a1 at the inner diameter side inlet opening edge portion 201a1B with the outer diameter side inlet angle θa1 of the first nozzle hole 201a1. It may be provided to be larger than θa1 ′. The second groove 202b1 has an outer diameter side inlet formed by the valve seat 203 and the side wall surface 201b1C of the second injection hole 201b1 at the outer diameter side inlet opening edge portion 201b1A of the second injection hole 201b1 at the inner diameter side inlet angle θb1. It may be provided to be larger than the angle θb1 ′.

The inlet opening edge where the outer diameter side inlet angle θa1 is configured in the first injection hole 201a1 is the inlet opening edge where the fuel that has passed through the seat portion 214 directly flows in, and fuel having a high flow velocity is the first injection hole 201a1 Flow into Therefore, by making the outer diameter side inlet angle θa1 of the first injection hole 201a1 larger than the inner diameter side inlet angle θa1 ′, the effect of suppressing the separation of the fuel flow can be enhanced. Further, by providing the second groove 202b1 in the second injection hole 201b1, the inside diameter side inlet angle θb1 which is originally a small angle can be enlarged. For example, when the flow velocity of the fuel flowing into the second injection hole 201b1 from the inner side in the radial direction of the valve seat 203 is high at high fuel pressure, the inner inlet angle θb1 can be enlarged to enhance the fuel flow separation suppression effect. be able to. By applying such a configuration to Examples 2 and 3 described later, the same effects can be obtained in Examples 2 and 3.

Example 2
A fuel injection valve according to a second embodiment of the present invention will be described with reference to FIGS. 6A and 6B. FIG. 6A is a schematic view (plan view) for explaining the arrangement of the injection holes and the structure of the grooves provided in the vicinity of the injection holes according to the second embodiment of the present invention. FIG. 6B is a partial cross-sectional view showing a part of the VIB-VIB cross section of FIG. 6A. 6A shows a view from the inlet side of the injection holes 401a1 to 401a3 and 401b1 to 401b3, and the injection holes 401a1 to 401a3 and 401b to 401b3 and the groove 402 are shown at the valve body axis 210 and the center of the fuel injection valve 100. It is a figure projected on the plane perpendicular to axis 100a. The cross sectional view of FIG. 6B shows a cross section parallel to the central axis 100 a of the fuel injection valve 100 and including the central axis 100 a. The same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

When the injection holes are divided into groups according to the injection hole inclination angle, the injection holes 401a1 to 401a3 and 401b1 to 401b3 are injection holes 401a1 of a group (injection hole inclination angle θa: first injection hole) having a large injection hole inclination angle. The injection holes 401b1 to 401b3 of the small injection hole inclination angle group (injection hole inclination angle θb: second injection holes) are arranged at the injection hole inlet The center of the circle is arranged on the circumference 200b of the large diameter. That is, the diameters of the injection

hole arrangement circles

200a and 200b differ depending on the injection hole inclination angle, and the diameter of the injection hole arrangement circle 200a of the first injection holes 401a1 to 401a3 is the diameter of the injection hole arrangement circle 200b of the second injection holes 401b1 to 401b3. It is configured to be smaller than that. The groove 402 is provided in a donut shape (annular shape) with the valve body axis 210 as a center O 402.

The groove 402 has the first grooves 202a1 to 202a3 provided in the first injection holes 201a1 to 201a3 and the second grooves 202b1 to 202b3 provided in the second injection holes 201b1 to 201b3 in Embodiment 1 as one groove. It is what was constructed. That is, in the present embodiment, the first grooves 202a1 to 202a3 of the first embodiment are constituted by respective portions formed around the first injection holes 401a1 to 401a3 in the groove 402, and the second grooves 202b1 to Reference numeral 202 b 3 is composed of portions formed in the groove 402 around the second injection holes 401 b 1 to 401 b 3.

In the present embodiment, the valve body axis 210 coincides with the center axis 100a and the center O of the injection

hole arrangement circles

200a and 200b.

In the present embodiment, the injection holes 401a1 to 401a3 of the group having a large injection hole inclination angle are disposed so that the injection hole inlets are in contact with the groove 402 on the seat portion 214 side, and the injection holes 401b1 to 401b3 of the group having a small injection hole inclination angle. Are arranged such that the injection hole inlet is in the groove 402 on the valve body axis 210 side. In this case, the groove 402 is provided radially outward with respect to the injection holes 401a1 to 401a3, and provided radially inward with respect to the injection holes 401b1 to 401b3.

That is, the groove 402 is composed of an outer peripheral surface (side wall surface) 402 a parallel to the valve body axis 210 and a parallel bottom surface 402 b perpendicular to the valve body axis 210. In this case, the groove 402 is formed of a side wall surface 402 a parallel to the central axis of the valve seat surface 203 formed of a conical surface and a bottom surface 402 b perpendicular to the central axis of the valve seat surface 203.

In the injection holes 401a1 to 401a3, the outer diameter side inlet opening edge (radial outside inlet opening edge) of the injection hole inlet is disposed inside the groove 402, and the inner diameter side inlet opening edge of the injection hole inlet (valve body axis The inlet opening edge on the 210 side, the radially inner inlet opening edge) is arranged outside the groove 502. In the injection holes 401b1 to 401b3, the inner diameter side inlet opening edge of the injection hole inlet (the inlet opening edge on the valve body axis 210 side, the radially inner inlet opening edge) is disposed inside the groove 402 The outer diameter inlet opening edge of the inlet (radially outer inlet opening edge) is located outside the groove 502. Accordingly, in the injection holes 401a1 to 401a3 of this configuration, a part (opening on the radially outer side) of the inlet opening opens inside the groove 402, and the opening on the radially inner side opens outside the groove 402. Further, in the injection holes 401 b 1 to 401 b 3, a part (opening on the inner side in the radial direction) of the inlet opening opens to the inside of the groove 402, and an opening on the outer side in the radial direction opens to the outside of the groove 402.

Thereby, in the injection holes 401a1 to 401a3, the inlet angle θa1 on the upstream side of the injection holes 401a1 to 401a3 can be made larger by the side wall surface 401a of the groove 202a1. In the injection holes 401b1 to 401b3, the bottom surface of the groove 202a1 The upstream inlet angle θb1 of the injection holes 401b1 to 401b3 can be made larger by 401b.
As described above, in the present embodiment, the groove 402 is provided on the seat portion 214 side or the valve body axis 210 side of the injection holes 401a1 to 401a3 and 401b1 to 401b3 according to the size of the injection hole inclination angle. The same effect can be obtained.

The center of the groove 402 does not have to coincide with the valve body axis 210, and the groove 402 is set so that the relation between the inlet opening of the injection holes 401a1 to 401a3 and 4011 to 401b3 and the groove 402 becomes the above-mentioned relation. It should just be arrange | positioned.

The configuration of this embodiment is the same as that of the first embodiment except for the configuration of the groove 402 and the injection holes 401a1 to 401a3 and 401b1 to 401b3 described above, and the same effects as those of the first embodiment can be obtained.

Unlike the first embodiment, it is not necessary to provide a groove for each injection hole in this embodiment, and the combination of the arrangement of the injection holes 401a1 to 401a3 and 4011 b1 to 401b3 and the groove 402 can obtain a peeling reduction effect in the injection holes. it can. For example, in the case where the groove is provided by cutting or electroforming, since the groove can be processed in a shorter time than in the first embodiment, the cost can be further reduced.

[Example 3]
A fuel injection valve according to a third embodiment of the present invention will be described with reference to FIG.

FIG. 7 is a schematic view (plan view) for explaining the arrangement of injection holes and the structure of grooves provided in the vicinity of the injection holes according to a third embodiment of the present invention. The same components as those of the first embodiment or the second embodiment are denoted by the same reference numerals, and the description thereof is omitted. FIG. 7 shows a view from the inlet side of the injection holes 201a1 to 201a3 and 201b1 to 201b3, and the injection holes 201a1 to 201a3 and 201b to 201b3 and the groove 502 are located at the valve body axis 210 and the center of the fuel injection valve 100. It is a figure projected on the plane perpendicular to axis 100a.

In the present embodiment, the injection holes 201a1 to 201a3 and 201b1 to 201b3 are arranged such that the center of the injection hole inlet is located on the circumference of the injection hole arrangement circle 200. Also in this embodiment, the injection hole (first injection hole) 201a to 201a3 has a larger injection hole inclination angle than the injection hole (second injection hole) 201b to 201b3. In the present embodiment, the groove 502 is provided in a donut shape (ring shape) centered at O 502, and the center axis 501 thereof is the side where the injection hole inclination angle is large from the center axis 500 of the injection hole arrangement circle 200 (here In this case, it is offset to the injection hole 201a1 side). The groove 502 has the same shape as the groove 402 of the second embodiment, but differs from the groove 402 of the second embodiment in that the position of the new O 502 is offset as described above.

The injection holes 201a1 to 201a3 provided on the side where the groove 501 is offset engage with the groove 502 on the seat portion 214 side, and conversely, the injection holes 201b1 to 201b3 engage with the groove 502 on the valve body axis 210 side. Thereby, the same effect as that of the first embodiment can be obtained. In this case, the groove 502 is provided radially outward with respect to the injection holes 201a1 to 201a3, and provided radially inward with respect to the injection holes 201b1 to 201b3.

That is, the groove 502 is formed of an outer peripheral surface (side wall surface) 502 a parallel to the valve body axis 210 and a bottom surface 502 b perpendicular to the valve body axis 210. In this case, the groove 502 is formed of a side wall surface 502 a parallel to the central axis of the valve seating surface 203 formed of a conical surface, and a bottom surface 502 b perpendicular to the central axis of the valve seating surface 203.

The groove 502 has the first grooves 202a1 to 202a3 provided in the first injection holes 201a1 to 201a3 and the second grooves 202b1 to 202b3 provided in the second injection holes 201b1 to 201b3 in Embodiment 1 as one groove. It is what was constructed. That is, in the present embodiment, the first grooves 202a1 to 202a3 of the first embodiment are constituted by respective portions formed around the first injection holes 201a1 to 201a3 in the groove 502, and the second grooves 202b1 to 202b3 are grooves 502. Of the second injection holes 201b1 to 201b3.

In the injection holes 201a1 to 201a3, the outer diameter side inlet opening edge (radial outer opening edge) of the injection hole inlet is disposed inside the groove 502, and the inner diameter side inlet opening edge of the injection hole inlet (valve body axis 210 side inlet The opening edge, the radially inner opening edge) is disposed outside the groove 502. In the injection holes 201b1 to 201b3, the inner diameter side inlet opening edge of the injection hole inlet (inlet opening edge on the valve body axis 210 side, radial inner opening edge) is arranged inside the groove 502, and the outer diameter of the injection hole inlet The side inlet opening edge (the radially outer opening edge) is disposed outside the groove 502. Therefore, in the injection holes 201a1 to 201a3 of this configuration, a part (opening on the radially outer side) of the inlet opening opens inside the groove 502, and the opening on the radially inner side opens outside the groove 502. Further, in the injection holes 201 b 1 to 201 b 3, a part (opening on the inner side in the radial direction) of the inlet opening opens to the inside of the groove 502, and an opening on the outer side in the radial direction opens to the outside of the groove 502.

In the present embodiment, the valve body axis 210 coincides with the center axis 100 a and the center O of the injection hole arrangement circle 200.

The configuration of the present embodiment other than the groove 502 described above is the same as that of the first embodiment, and the same effects as those of the first embodiment can be obtained. In the present embodiment, the position of the groove 502 is different from the position of the groove 402 in the second embodiment, and the positions of the injection holes 201a1 to 201a3 and 201b1 to 201b3 are the positions of the injection holes 401a1 to 401a3 and 401b1 to 401b3 in the second embodiment. It is different. The other configuration is the same as that of the second embodiment, and the effects exhibited by the first and second embodiments can be similarly exhibited.

As in the second embodiment, this embodiment can reduce the cost by reducing the processing time. On the other hand, it is limited to the case where the injection hole inclination angle can be divided into right and left. For example, in the case of the arrangement of the injection holes in which the magnitudes of the injection hole inclination angles alternate in the circumferential direction, this embodiment can not be applied. However, since the inlet openings of the injection holes 401a1 to 401a3 and 401b1 to 401b3 can be arranged on the same circumference, it is superior to the second embodiment in that the flow rate of the fuel flowing into each injection hole is made uniform.

According to the present invention, it is possible to reduce the amount of fuel adhering to the tip of the fuel injection valve by enhancing the stability of the spray by reducing the peeling in the injection hole, and to realize the internal combustion engine with enhanced exhaust performance. An injection valve can be provided.

The present invention is not limited to the above-described embodiments, but includes various modifications. For example, the embodiments described above are described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations. Also, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. In addition, with respect to a part of the configuration of each embodiment, it is possible to add, delete, and replace other configurations.

100: electromagnetic fuel injection valve, 100a: central axis of fuel injection valve, 101: valve body, 102: seat member, 200: injection hole arrangement circle, 201a1 to 201a3, 201b1 to 201b3: injection hole (fuel injection hole), 202a1 to 202a3, 202b1 to 202b3 ... groove, 203 ... valve seat surface, 207 ... groove side wall surface, 208 ... groove bottom surface, 210 ... valve body axis, 211a1 to 211a3, 211b1 to 211b3 ... central axis of injection hole (injection Hole axis line 214, contact portion (contact position, seat portion, seal portion) between the valve body 101 and the seat member 102, 401a1 to 401a3, 401b1 to 401b3 injection hole (fuel injection hole) 402, groove 411a1 to 411a3, 411b1 to 411b3 ... central axis of injection hole (injection hole axis), 500 ... central axis of injection hole arrangement circle, 501 ... offset groove Central axis, 502 ... groove.

Claims

With a disc,
A valve seat surface on which a seat portion for sealing fuel is formed by the abutment of the valve body;
And a plurality of injection holes opened in the valve seat surface,
The plurality of injection holes may be formed by the plurality of injection holes having a large inclination angle and the plurality of injection holes in accordance with the inclination angle of the central axis of the injection hole with respect to the central axis of the valve seat surface. Divided into small second injection holes,
In the first injection hole, an outer diameter side inlet opening edge which is an outer inlet opening edge in the radial direction of the valve seat surface is disposed inside a first groove formed in the valve seat surface. An outer diameter side inlet angle formed by a surface of the first groove and a side wall surface of the first injection hole at a portion of the outer diameter side inlet opening edge is the valve seat surface when the first groove is absent Has a large angle as compared with a virtual outer diameter side inlet angle formed by the side wall surface of the first injection hole,
The second injection hole is disposed on the inner side of a second groove formed in the valve seat surface, which is an inner inlet opening edge which is an inner inlet aperture edge in the radial direction of the valve seat surface. The inner diameter side inlet angle formed by the surface of the second groove and the side wall surface of the second injection hole at the portion of the inner diameter side inlet opening edge is the valve seat surface and the second surface when the second groove is absent. A fuel injection valve having a large angle as compared with a virtual inner diameter side inlet angle formed by the side wall surface of the injection hole.
In the fuel injection valve according to claim 1,
In the first injection hole, an inner diameter inlet opening edge which is an inner inlet opening edge in a radial direction of the valve seat surface is disposed outside the first groove,
The fuel injection valve, wherein an outer diameter side inlet opening edge, which is an outer inlet opening edge in a radial direction of the valve seat surface, of the second injection hole is disposed outside the second groove.
In the fuel injection valve according to claim 2,
The valve seat surface is composed of a conical surface or a frusto-conical surface,
The first groove of the first injection hole and the second groove of the second injection hole are side wall surfaces parallel to the central axis of the conical surface or the conical surface, and perpendicular to the central axis of the conical surface or the conical surface And a bottom surface,
The outer diameter side inlet opening edge of the first injection hole is formed on the bottom surface of the first groove,
The outer diameter side inlet angle of the first injection hole is configured between the side wall surface of the first groove and the side wall surface of the first injection hole,
The inner diameter side inlet opening edge of the second injection hole is formed on the bottom surface of the second groove,
The fuel injection valve, wherein the inside diameter side inlet angle of the second injection hole is formed between the side wall surface of the second groove and the side wall surface of the second injection hole.
In the fuel injection valve according to claim 3,
The fuel injection valve, wherein the first groove and the second groove are formed as grooves independent of each injection hole.
In the fuel injection valve according to claim 1,
The fuel injection valve, wherein the first groove and the second groove are constituted by one annular groove.
In the fuel injection valve according to claim 5,
The first injection hole is composed of a plurality of injection holes whose centers of the inlet opening face are arranged on the first injection hole arrangement circle,
The second injection hole is composed of a plurality of injection holes, the center of the inlet opening surface being disposed on the second injection hole arrangement circle,
The fuel injection valve, wherein the diameter of the first injection hole arrangement circle is smaller than the diameter of the second injection hole arrangement circle.
In the fuel injection valve according to claim 5,
The first injection hole and the second injection hole are disposed such that the centers of the respective inlet opening surfaces are on one injection hole arrangement circle,
The fuel injection valve, wherein the center of the annular shape formed by the annular groove is offset to the side of the first injection hole with respect to the center of the injection hole arrangement circle.
In the fuel injection valve according to claim 3,
In the first groove, the outer diameter side inlet angle of the first injection hole is compared with the inner diameter side inlet angle formed by the valve seat surface and the side wall surface of the first injection hole at the inner diameter side inlet opening edge Provided to be
The second groove is formed such that the inner diameter side inlet angle of the second injection hole is an outer diameter side inlet angle formed between the valve seat surface and the side wall surface of the second injection hole at the outer diameter side inlet opening edge. Fuel injection valve provided to be larger than the other.