JP2003336563A - Fuel injection valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection valve for an engine capable of promoting the atomization of injection fuel while improving the accuracy of fuel injection amount by reducing a space occupied by residual fuel from a valve seat to a fuel injection hole as much as possible when closing the valve. <P>SOLUTION: This fuel injection valve is provided with a valve seat member 3 having a valve seat 8 and an injector plate 36 joined with a front end face of the valve seat member 3. It forms a plurality of lateral passages 38 communicating with the downstream end of the valve seat 8 and a plurality of swirl chambers 39 in which downstream ends of these lateral passages 38 are opened in the tangential direction between the valve seat member 3 and the injector plate 36. It is formed with a plurality of fuel injection holes 40 for injecting fuel in these swirl chambers 39 to the outside in the injector plate 36. A plurality of side holes 37 whose one end each is opened in a peripheral fringe part at the downstream end of the valve seat 8 and other end each is connected with an upstream end of the lateral passage 38 are formed between the valve seat 8 and a plurality of lateral passages 38. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection valve mainly used in a fuel supply system of an internal combustion engine, and more particularly to a valve body and a downstream end of a valve seat cooperating with the valve body, which is opened at a front end face. Valve seat member and an injector plate joined to the front end surface of the valve seat member, and communicating with the downstream end of the valve seat between the valve seat member and the injector plate, A plurality of lateral passages extending in the lateral direction substantially orthogonal to the axis and a plurality of swirl chambers whose downstream ends are opened tangentially are formed. The present invention relates to an improvement of a fuel injection valve in which a plurality of fuel injection holes for respectively injecting to the outside are formed in the injector plate.

[0002]

2. Description of the Related Art Such a fuel injection valve is disclosed, for example, in Japanese Patent No. 26.
It is already known as disclosed in Japanese Patent No. 59789.

[0003]

[Problems to be Solved by the Invention] Such a fuel injection valve is
The swirl is given to the fuel injected from the fuel injection hole to promote atomization of the injected fuel. However, in the conventional fuel injection valve, a plurality of holes are formed from one central opening communicating with the valve seat. The lateral passages of the
When the valve is opened, the fuel that has passed through the valve seat is first gathered in the central opening and then distributed to multiple lateral passages. Therefore, the central opening can smoothly collect and distribute the fuel. Sufficient volume must be provided. However, such a volume of the central opening becomes a dead space volume when the valve is closed, and the fuel remaining therein may flow out from the fuel injection hole due to temperature rise, vibration, etc., and may distort the fuel injection amount. Further, due to the turbulent flow of the distributed fuel due to the collection and distribution of the fuel in the central opening, it is difficult to evenly distribute the fuel to the plurality of swirl chambers, and therefore the fuel foam generated from each fuel injection hole is made uniform. Is difficult.

The present invention has been made in view of the above circumstances, and when the valve is closed, the space occupied by the residual fuel from the valve seat to the fuel injection hole is minimized to improve the accuracy of the fuel injection amount. That is, it is an object of the present invention to provide the fuel injection valve capable of promoting atomization of the injected fuel.

[0005]

In order to achieve the above-mentioned object, the present invention provides a valve body, a valve seat member which cooperates with the valve body, and has a downstream end of the valve seat opened to a front end face, and the valve. An injector plate joined to the front end surface of the seat member, communicating with the valve seat member and the injector plate at the downstream end of the valve seat, and in a lateral direction substantially orthogonal to the axis of the valve seat. A plurality of lateral passages that extend and a plurality of swirl chambers whose downstream ends are tangentially open, and a plurality of fuels swirled in the swirl chambers are injected outside In a fuel injection valve having injection holes formed in the injector plate, one end is opened at the downstream end peripheral portion of the valve seat and the other end is provided between the valve seat and a plurality of lateral passages. Connect to the upstream end of the lateral passage A first feature in that a number of side holes.

According to the first feature, when the valve is opened, the fuel passing through the valve seat is immediately and evenly divided into the plurality of lateral passages through the plurality of side holes connected to the peripheral edge of the downstream end of the valve seat. , Swirl is applied to each corresponding swirl chamber at high speed in the tangential direction. The fuel injected from the corresponding fuel injection holes forms a uniform hollow cone-shaped fuel spray foam by the action of the injection pressure and the centrifugal force, and can promote atomization of the fuel. Moreover, by opening the side holes individually connected to each lateral passage in the peripheral portion of the valve seat, it is possible to reduce the dead space volume occupied by the residual fuel from the valve seat to each fuel injection hole when the valve is closed. In addition, since the fuel distribution to each swirl chamber is even, the accuracy of the fuel injection amount can be improved.

In addition to the first feature of the present invention, an intermediate plate is joined between the valve seat member and the injector plate, and the lateral passage and the swirl chamber are provided on a surface of the intermediate plate facing the injector plate. The second feature is that the side hole is formed in a groove shape, and the side hole is formed in the intermediate plate so as to penetrate the front surface and the back surface thereof.

According to the second feature, the plurality of side holes, the lateral passages and the swirl chamber can be easily machined into the intermediate plate of the small parts with high accuracy, and the groove-shaped lateral passages and swirls can be formed. By setting the groove width and depth of the chamber, it becomes possible to form lateral passages and swirl chambers of different specifications in the intermediate plate having the same plate thickness, and it is possible to obtain versatility.

Further, in addition to the first or second feature, the present invention has a third feature in that each of the swirl chambers is arranged radially outward of the valve seat with respect to the corresponding side hole. .

According to the third feature, it is possible to provide a relatively large number of swirl chambers and fuel injection holes around a plurality of side holes, which is suitable for large fuel flow rate specifications.

Furthermore, in addition to the first or second feature, the present invention has a fourth feature in that each of the swirl chambers is arranged radially inward of the valve seat from a corresponding side hole. To do.

According to the fourth feature, the pitch circles of the plurality of fuel injection holes can be made sufficiently small, which is suitable for a small fuel flow rate specification.

Further, according to the present invention, in addition to any one of the first to fourth characteristics, the ratio of the total opening area of the side holes to the total opening area of the fuel injection holes is 1.5 to 3.0. The fifth feature is that the setting is made to.

According to the fifth feature, with a minimum required dead space volume, the fuel injection amount from the fuel injection hole at full load can be stabilized without being affected by the throttling resistance of the side hole. Can be secured.

Further, in addition to any one of the first to fifth features, the present invention is characterized in that each of the side holes is displaced radially outward of the valve seat toward the corresponding lateral passage. The sixth feature is that the tape is inclined.

According to the sixth feature, when the fuel moves from each side hole to the lateral passage, the flow of the fuel is not sharply bent and the flow becomes smooth, so that the velocity loss of the fuel is small. Therefore, the swirl effect on the fuel in the swirl chamber can be enhanced.

In addition to any one of the first to sixth features, the present invention further provides that each of the lateral passages is inclined with respect to the radial line of the valve seat passing through the center of the corresponding side hole. The seventh feature is that the angular positions of the corresponding side holes and swirl chambers with respect to the valve seat center are displaced from each other.

According to the seventh feature, even if the diameter difference between the pitch circles of the plurality of side holes and the pitch circles of the plurality of swirl chambers is small, it is possible to set each lateral passage to be long. Accurately guide the laminar flow of fuel in the tangential direction of the swirl chamber to obtain a good swirl effect of the fuel in each swirl chamber, and also to make the fuel spray foam compact to the inner wall of the engine intake port. Can contribute to the prevention of fuel adhesion.

In addition to any one of the first to seventh features, the present invention is such that each of the lateral passages is inclined so as to be displaced outward in the axial direction toward the corresponding swirl chamber. This is the eighth feature.

According to the eighth feature, when the fuel flows from each side hole to the lateral passage and the swirl chamber, the flow of the fuel is not sharply bent, and the flow becomes smooth. The velocity loss is small and therefore the swirl effect on the fuel in the swirl chamber can be enhanced.

Furthermore, in addition to any one of the first to eighth features, the present invention further comprises a plurality of side holes which are concentric with the valve seat.
A ninth feature is that the plurality of swirl chambers are arranged in a staggered manner on one pitch circle, and the swirl chambers are arranged in a staggered manner on two pitch circles that are concentric with the two pitch circles and have a larger diameter than them. .

According to the ninth feature, more side holes, swirl chambers, and fuel injection holes can be provided, which is suitable for a larger fuel flow rate specification.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below based on the embodiments of the present invention shown in the accompanying drawings.

FIG. 1 is a longitudinal sectional view of an electromagnetic fuel injection valve for an internal combustion engine according to a first embodiment of the present invention, FIG. 2 is an enlarged view of a main part of FIG. 1, and FIG. 3 is a sectional view taken along line 3-3 of FIG. 4 and 4 in FIG. 2 and FIG.
A line sectional view, FIG. 5 is a view taken in the direction of arrow 5 in FIG. 2, and FIG.
FIG. 8 is an enlarged cross-sectional view, FIG. 7 is an operation explanatory view corresponding to FIG.
Shows a second embodiment of the present invention, a correspondence diagram with FIG. 5, FIG. 9 shows a third embodiment of the present invention, a correspondence diagram with FIG. 5, and FIG. 10 shows a fourth embodiment of the present invention FIG. 11, a diagram corresponding to FIG. 5, FIG. 11 is a diagram obtained by a test showing the relationship between the ratio of the total opening area A of the side holes to the total opening area B of the fuel injection holes and the maximum fuel injection amount, and FIG. (A) with one fuel injection hole
It is a comparison explanatory view of the fuel spray foam at the time of making (B) and the fuel injection hole into three pieces by making the adjoining space narrower than (B).

First, the first embodiment of the present invention shown in FIGS. 1 to 7 will be described.

In FIG. 1, a casing 1 of an electromagnetic fuel injection valve I for an internal combustion engine includes a cylindrical valve housing 2 (magnetic material) and a bottomed cylinder liquid-tightly coupled to a front end portion of the valve housing 2. And a cylindrical fixed core 5 which is liquid-tightly coupled to the rear end of the valve housing 2 with an annular spacer 4 interposed therebetween.

The annular spacer 4 is made of non-magnetic metal such as stainless steel, and the valve housing 2 and the fixed core 5 are abutted on both end faces thereof and liquid-tightly welded all around.

A first fitting tubular portion 3a and a second fitting tubular portion 2a are formed at the opposite ends of the valve seat member 3 and the valve housing 2, respectively. Then, the first fitting tubular portion 3a is press-fitted into the second fitting tubular portion 2a together with the stopper plate 6, and the stopper plate 6 is sandwiched between the valve housing 2 and the valve seat member 3. After that, laser welding or beam welding is performed over the entire circumference of the corner portion sandwiched between the outer peripheral surface of the first fitting tubular portion 3a and the end surface of the second fitting tubular portion 2a, whereby the valve housing 2 and the valve seat member 3 are Are liquid-tightly coupled to each other.

The valve seat member 3 is provided with a conical valve seat 8 having a downstream end opened at its front end surface, and a cylindrical guide hole 9 connected to the upstream end of the valve seat 8, that is, the large diameter portion. Has been
The guide hole 9 is formed coaxially with the second fitting tubular portion 2a.

A movable core 12 facing the front end surface of the fixed core 5 is slidably accommodated in the valve housing 2 and the annular spacer 4, and the guide hole 9 is provided in the movable core 12.
A valve body 16 is slidably housed in the valve body 16 and is integrally coupled to the valve body 16. This valve body 16 is in contact with the stopper plate 6 and a spherical valve portion 16a that can be seated on the valve seat 8, a pair of front and rear journal portions 16b and 16b slidably supported in the guide hole 9, and the valve plate 16a. A flange 16c that defines the valve opening limit of the body 16 is integrally provided, and each journal portion 16b
Includes a plurality of chamfered parts 17, 1 that enable the flow of fuel.
7 ... are provided.

The fixed core 5 has a hollow portion 21 which communicates with the inside of the valve housing 2. In the hollow portion 21, the movable core 12 is arranged in the closing direction of the valve body 16, that is, in the seating direction on the valve seat 8. A coil-shaped valve spring 22 that urges and a pipe-shaped retainer 23 that supports the rear end of the valve spring 22 are housed.

At the rear end of the fixed core 5, an inlet cylinder 25 having a fuel inlet 25a communicating with the hollow portion 21 of the fixed core 5 through a pipe-shaped retainer 23 is integrally connected, and the fuel inlet 25a is connected to the inlet cylinder 25a. A fuel filter 27 is attached.

A coil assembly 28 is fitted around the outer circumferences of the annular spacer 4 and the fixed core 5. This coil assembly 28
Is composed of a bobbin 29 fitted on the outer peripheral surface of the annular spacer 4 and the fixed core 5, and a coil 30 wound around the bobbin 29. One end of a coil housing 31 surrounding the coil assembly 28 is a valve. It is joined to the outer peripheral surface of the housing 2 by welding.

Coil housing 31, coil assembly 28
The fixed core 5 and the fixed core 5 are embedded in a cover 32 made of synthetic resin, and a coupler 34 for accommodating a connection terminal 33 connected to the coil 30 is integrally connected to an intermediate portion of the cover 32. .

As shown in FIGS. 2 to 5, a steel plate injector plate 36 is liquid-tightly welded all around the front end surface of the valve seat member 3 with a steel plate intermediate plate 35 interposed therebetween.

The intermediate plate 35 has a large number of axially extending axially extending from the downstream edge of the valve seat 8 so as to penetrate the front and back surfaces of the intermediate plate 35 and arranged at equal intervals around the axis of the valve seat 8. Side holes 37, 37 ... Are bored, and a large number of radially extending outward from the side seats 37, 37 ... In the radial direction of the valve seat 8 are formed on the surface of the intermediate plate 35 facing the injector plate 36. The lateral passages 38, 38 ... And a large number of swirl chambers 39, 39 ... In which the downstream ends of the lateral passages 38, 38 ... Are opened tangentially are formed in a groove shape.

At this time, preferably, each side hole 37 is arranged so as to be inclined so as to be displaced outward in the radial direction of the valve seat 8 toward the corresponding lateral passage 38, and each lateral passage 38 is also arranged. Are inclined so as to be displaced outward in the axial direction toward the corresponding swirl chamber 39.

The plurality of swirl chambers 39, 39 ... Are also arranged at equal intervals around the axis of the valve seat 8, like the side holes 37, 37. The tangential direction of each lateral passage 38 opening to each swirl chamber 39 is constant, and the swirl direction imparted to the fuel in each swirl chamber 39 is constant.

The injector plate 36 is provided with a large number of fuel injection holes 40, 40 ... Opening into the large number of swirl chambers 39, 39. The thickness of the injector plate 36 is smaller than the inner diameter of each fuel injection hole 40, and the axis line of each fuel injection hole 40 has a valve seat 8
It is arranged so as to be parallel to the axis line of.

As clearly shown in FIG. 6, each fuel injection hole 40
Are offset from the center of the corresponding swirl chamber 39 to the upstream end of the corresponding lateral passage 38 by a predetermined distance e. Further, a large number of fuel injection holes 40, 40 ...
As shown in FIG. 5, they are arranged so that their adjacent interval p is 2.5 mm or less.

When the total opening area of the large number of side holes 37, 37 ... Is A and the total opening area of the large number of fuel injection holes 40, 40 ... is B, A / B = 1.5 to 3 The side holes 37, 37 ... And the fuel injection holes 40, 40 ... Are formed so as to be 0.0.

Again, in FIG. 1, an annular seal holder 48 is fitted around the valve housing 2 and the valve seat member 3 at their outer circumferences, and is fitted to the seal holder 48 and the front end portion of the valve seat member 3. An annular groove 46 is defined between the annular groove 46 and the synthetic resin cap 45, and an O-ring 47 that is in close contact with the outer peripheral surface of the valve seat member 3 is attached to the annular groove 46. When the electromagnetic fuel injection valve I is mounted in a fuel injection valve mounting hole of an intake manifold (not shown), the O-ring 47 comes into close contact with the inner peripheral surface of the mounting hole.

Next, the operation of the first embodiment will be described. When the coil 30 is demagnetized, the movable core 12 and the valve body 16 are pressed forward by the urging force of the valve spring 22, and the valve portion 16a is seated on the valve seat 8. Therefore, the high-pressure fuel supplied into the valve housing 2 through the fuel filter 27 and the inlet cylinder 25 is made to stand by in the valve housing 2.

When the coil 30 is excited by energization, the magnetic flux generated thereby is generated by the fixed core 5 and the coil housing 3.
1, the valve housing 2 and the movable core 12 are sequentially run, and the magnetic force causes the movable core 12 to be attracted to the fixed core 5 together with the valve body 16, and the valve seat 8 is opened. After passing through the valve seat 8 via the chamfered portions 17, 17, ... Of the body 16, immediately branch from the peripheral portion thereof to a large number of side holes 37, 37.
7, 37 ... From corresponding lateral passages 38, 38 respectively
Since the fuel flows into the corresponding swirl chamber 39 at a high speed in a tangential direction after passing through, the swirls are imparted to the fuel by swirling each swirl chamber 39 at a high speed.

In particular, each side hole 37 is inclined so as to be displaced outward in the radial direction of the valve seat 8 toward the corresponding lateral passage 38, and each lateral passage 38 is connected to the corresponding swirl chamber 39. When it is arranged so as to be displaced outward in the axial direction as it goes, there is no sharp bend in the fuel flow until it reaches the swirl chamber 39 through each side hole 37 and the lateral passage 38, Since the flow is smooth, there is little fuel velocity loss.

Further, since each fuel injection hole 40 is arranged offset from the center of each swirl chamber 39 on the upstream end side of the corresponding lateral passage 38 by a predetermined distance e, the swirl chamber 39 is formed.
Most of the fuel that has flowed into the fuel cell is injected from the fuel injection hole 40 while the swirl chamber 39 makes one revolution, and the velocity loss of the fuel in the swirl chamber 39 is small.

As a result, the fuel injected from the respective swirl chambers 39 into the corresponding fuel injection holes 40 forms a hollow conical fuel spray foam F1 by the action of a large injection pressure and centrifugal force, and a high swirl velocity. Therefore, the atomization of fuel can be promoted more effectively, and the responsiveness of fuel injection can be improved.

Moreover, by opening a large number of side holes 37, 37 ... Which are individually connected to a large number of lateral passages 38, 38 ... In the peripheral portion of the valve seat 8, each fuel injection from the valve seat 8 is performed when the valve is closed. The dead space volume occupied by the residual fuel up to the hole 40 can be reduced, which can contribute to the improvement of the accuracy of the fuel injection amount. In particular, each side hole 37 and each fuel injection hole 40
Is formed so that A / B = 1.5 to 3.0 as described above, as is clear from the test data of FIG. 11, with the minimum required dead space volume,
The amount of fuel injected from each fuel injection hole 40 at full load is
It is possible to ensure the stability without being affected by the throttling resistance of each side hole 37.

FIG. 12 (A) shows the state of formation of the fuel spray foam F1 when tested with the single fuel injection hole 40, and FIG. 12 (B) shows the distance between the two fuel injection holes 40, 40. FIG. 12 (C) shows the formation state of the fuel spray foams F1 and F2 when set to 2.4 mm and tested.
Shows the formation state of the fuel spray foams F1 and F2 when the test was performed by setting the adjacent intervals of the three fuel injection holes 40, 40, 40 to 1.3 mm.

As shown in FIG. 12A, a hollow cone-shaped fuel spray foam F1 generated from a single fuel injection hole 40.
Shows a layered liquid film state immediately after exiting the fuel injection hole 40,
After that, it goes through the liquid thread state and becomes the atomized state.
In the embodiment, a large number of fuel injection holes 40 are provided around the axis of the valve seat 8.
40 are arranged such that the adjacent intervals are as narrow as 2.5 mm or less, and swirls in the same direction are imparted to the fuel in each swirl chamber 39, so a large number of hollow cone-shaped fuel spray forms F1, F1 ... As shown in FIG. 7 and FIGS. 12 (B) and 12 (C), in the liquid film state, the liquid film portions are brought into frontal collision with each other. As a result, the liquid thread state of all the fuel spray foams F1, F1 ... Is accelerated, and the atomization of the fuel can be effectively promoted accordingly. Moreover, a large number of fuel spray forms F1, F1 ...
By causing the liquid film portions to collide with each other in the front direction, finally, a single fuel spray foam F1 in which the fuel density is high in the central portion and low in the outer peripheral portion is formed, and the fuel spray foam F1 is formed on the inner wall of the intake passage of the engine. While preventing the fuel from adhering to the engine as much as possible, it is sucked into the engine together with the intake air, which can greatly contribute to the improvement of engine startability and output performance and the reduction of fuel consumption.

According to the test, the end of the liquid film state of many fuel spray foams F1, F1 ... Is in the area 0.5 to 3.0 mm away from the injector plate 36, and many fuel spray foams are in this area. It was confirmed that collision of F1, F1 ... Can effectively promote atomization of fuel. Further, in order to obtain such a collision between the fuel spray foams F1, F1 ..., It was extremely effective to set the adjoining intervals of the plurality of fuel injection holes 40, 40 ... to 2.5 mm or less as described above. .

By setting the thickness of the injector plate 36 to be smaller than the inner diameter of each fuel injection hole 40, the central angle of each hollow cone-shaped fuel spray foam F1 can be sufficiently expanded, and a large number of fuel spray foams F1 can be obtained. , F1 ... Can be reliably made to collide with each other in a liquid film state, and atomization of fuel can be further promoted.

By arranging the axes of a larger number of fuel injection holes 40, 40 ... In parallel, these fuel injection holes 40, 40 ...
It is possible to perform coaxial processing with high accuracy. As a result, the fuel spray foam F generated from all the fuel injection holes 40, 40 ...
1, F1 ... are always uniformized, and the frontal collisions of the liquid film portions with each other can always form a stable aggregated fuel spray foam F2, which improves engine startability and output performance and reduces fuel consumption. Can contribute.

By the way, in the first embodiment, a large number of lateral passages 38, 38 ... And swirl chambers 39, 39 ... Are formed in a groove shape on the surface of the intermediate plate 35 facing the injector plate 36, and a large number of them are formed. .. are formed in the intermediate plate 35 so as to penetrate the front and back surfaces thereof, the plurality of side holes 37, 37.
... and the swirl chambers 39, 39 ... Can be easily machined to the intermediate plate 35 of small parts with high accuracy, and the groove-shaped lateral passages 38, 38 ... And the swirl chamber 3
9, 39 ... are lateral passages 38 of different specifications in the intermediate plate (*) having the same plate thickness, depending on the setting of the groove width and depth.
38 and swirl chambers 39, 39 ... Can be formed, and versatility can be obtained.

The swirl chambers 39, 39 ... Are arranged annularly on a pitch circle concentric with and larger than the pitch circles of the group of side holes 37, 37. , 37 ... Swirl chambers 39, 39 around the group
, And the fuel injection holes 40, 40 can be provided in a relatively large number, which is suitable for large fuel flow rate specifications.

Next, a second embodiment of the present invention shown in FIG. 8 will be described.

In this second embodiment, a large number of side holes 37, 37 are provided.
... are arranged in a staggered manner on two concentric pitch circles C1 and C2, and accordingly, a large number of swirl chambers 39, 39 ... Are two pitch circles having a diameter larger than and concentric with the pitch circles C1 and C2. The configuration is the same as that of the previous example except that the points are arranged in a staggered pattern on C3 and C4. In FIG. 8, parts corresponding to those of the previous example are designated by the same reference numerals, and description thereof will be given. Omit it.

According to this second embodiment, the side holes 37, 37
..., swirl chambers 39, 39 ... and fuel injection holes 40, 40 ...
It is possible to provide a larger number of fuel cells, which is suitable for higher fuel flow rate specifications.

Next, a third embodiment of the present invention shown in FIG. 9 will be described.

In this third embodiment, a plurality of swirl chambers 3
.. are arranged annularly on a pitch circle concentric with and smaller than the pitch circles of the group of side holes 37, 37. Further, each lateral passage 38 is inclined at an angle α with respect to the radial line L1 of the valve seat 8 passing through the center of the corresponding side hole 37, and the corresponding lateral hole 37 and the valve seat 8 of the swirl chamber 39 are inclined. The angular positions with respect to the center are offset from each other. Since the other structure is the same as that of the first embodiment, in FIG. 9, the portions corresponding to those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

According to this third embodiment, the swirl chamber 3
9 and 39 and the fuel injection holes 40, 40 ... Can not be provided so much, but the pitch circle of the fuel injection holes 40, 40 ... Group can be made sufficiently small, which is suitable for a small flow rate specification of fuel. . Further, even if the diameter difference between the pitch circle of the side holes 37, 37 ... Group and the pitch circle of the swirl chambers 39, 39 ... Group is small, it is possible to set each lateral passage 38 to be long.
Laminar flow of fuel in the tangential direction of each swirl chamber 39 can be accurately performed, and a good swirl effect of fuel can be obtained in each swirl chamber 39. In addition, each fuel spray form F
It is possible to make 1 and F2 compact and to contribute to the prevention of fuel adhesion to the inner wall of the engine intake port.

Next, a fourth embodiment of the present invention shown in FIG. 10 will be described.

In this fourth embodiment, each lateral passage 38 is
The radial line L of the valve seat 8 passing through the center of the corresponding side hole 37
The configuration is the same as that of the first embodiment, except that the angle positions of the corresponding side holes 37 and swirl chambers 39 with respect to the center of the valve seat 8 are shifted from each other by an angle β with respect to 2. In FIG. 10, parts corresponding to those of the first embodiment are designated by the same reference numerals, and description thereof will be omitted.

According to the fourth embodiment, the side holes 37, 37
Even when the diameter difference between the group pitch circle and the swirl chambers 39, 39 ... Group pitch circle is small, each lateral passage 38 can be set to be long, and the tangential direction of the fuel in each swirl chamber 39 can be set. The induction can be performed accurately and a good swirl effect of fuel can be obtained in each swirl chamber 39.

The present invention is not limited to the above embodiments, and various design changes can be made without departing from the scope of the invention.

[0066]

As described above, according to the first feature of the present invention, the valve body, the valve seat member that cooperates with the valve body, and the downstream end of the valve seat opens to the front end face, and the valve seat. An injector plate joined to a front end surface of the member, and communicating with the valve seat member and the injector plate at a downstream end of the valve seat, and extending in a lateral direction substantially orthogonal to an axis of the valve seat. A plurality of lateral passages and a plurality of swirl chambers whose downstream ends are open tangentially, and a plurality of fuel jets for injecting swirled fuel to the outside respectively. In the fuel injection valve having holes formed in the injector plate, one end is opened at the downstream end peripheral portion of the valve seat and the other end is formed between the valve seat and the plurality of lateral passages. Multiple side holes connected to the upstream end of the directional passage Since it is provided, when the valve is opened, the fuel that has passed through the valve seat is immediately and evenly diverted to the lateral passages through the side holes and swiftly flows tangentially into the corresponding swirl chambers at high speed. The fuel injected from the corresponding fuel injection holes can form a uniform hollow cone-shaped fuel spray foam by the action of the injection pressure and the centrifugal force, and can promote the atomization of the fuel. Moreover, by opening the side holes individually connected to each lateral passage in the peripheral portion of the valve seat,
When the valve is closed, the dead space volume occupied by the residual fuel from the valve seat to each fuel injection hole can be reduced, and the fuel distribution to each swirl chamber is even. The accuracy of can be improved.

Further, according to the second feature of the present invention, an intermediate plate is joined between the valve seat member and the injector plate, and the lateral passage and the swirl chamber are provided on a surface of the intermediate plate facing the injector plate. Since it is formed in the shape of a groove and the side holes are formed in the intermediate plate so as to penetrate the front and back sides, a plurality of side holes, lateral passages and swirl chambers can be easily and easily machined in the intermediate plate of small parts. Moreover, the groove-shaped lateral passage and swirl chamber can be formed in the intermediate plate of the same plate thickness with different specifications by setting the groove width and depth. ， The versatility can be obtained.

Further, according to the third aspect of the present invention, since the swirl chambers are arranged radially outward of the valve seat with respect to the corresponding side holes, the swirl chambers and the fuel injection holes are provided on a plurality of sides. A relatively large number of holes can be provided around the hole, which is suitable for large fuel flow specifications.

Furthermore, according to the fourth aspect of the present invention,
Since each of the swirl chambers is arranged radially inward of the valve seat with respect to the corresponding side hole, the pitch circle of the plurality of fuel injection holes can be made sufficiently small, which is suitable for the small fuel flow rate specification. is there.

Furthermore, according to the fifth feature of the present invention,
Since the ratio of the total opening area of the side holes to the total opening area of the fuel injection holes is set to 1.5 to 3.0, the dead space volume from the fuel injection holes at full load is maintained with the minimum dead space required. The fuel injection amount can be stably secured without being affected by the throttling resistance of the side holes.

Furthermore, according to the sixth feature of the present invention,
Since each side hole is inclined so as to be displaced radially outward of the valve seat toward the corresponding lateral passage, when the fuel moves from each side hole to the lateral passage, the Since the flow becomes smooth without giving a sharp bend, the velocity loss of the fuel is small, and therefore the swirl effect on the fuel in the swirl chamber can be enhanced.

Furthermore, according to the seventh feature of the present invention,
Since each of the lateral passages is inclined with respect to the radial line of the valve seat passing through the center of the corresponding side hole, the angular positions of the corresponding side holes and swirl chambers with respect to the center of the valve seat are offset from each other. , Even if the diameter difference between the pitch circles of the side holes and the pitch circles of the swirl chambers is small, it is possible to set each lateral passage long, and the laminar flow of fuel in the tangential direction of each swirl chamber The induction can be performed accurately, a good swirl effect of fuel can be obtained in each swirl chamber, and the fuel spray foam can be made compact, which can contribute to the prevention of fuel adhesion to the inner wall of the engine intake port.

Furthermore, according to the eighth feature of the present invention,
Since each of the lateral passages is inclined so as to be displaced outward in the axial direction toward the corresponding swirl chamber, when the fuel flows from each side hole to the lateral passage or swirl chamber, the flow of the fuel Since there is no sharp bend and the flow becomes smooth, the fuel velocity loss is small and therefore the swirl effect on the fuel in the swirl chamber can be enhanced.

Furthermore, according to the ninth feature of the present invention,
The plurality of side holes are arranged in a staggered manner on two pitch circles concentric with the valve seat, and the plurality of swirl chambers are also concentric with the two pitch circles on two pitch circles having a larger diameter than them. The staggered arrangement makes it possible to provide more side holes, swirl chambers, and fuel injection holes, which is suitable for higher fuel flow specifications.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an electromagnetic fuel injection valve for an internal combustion engine according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

3 is a sectional view taken along line 3-3 of FIG.

FIG. 4 is a sectional view taken along line 4-4 of FIG.

5 is a view taken in the direction of arrow 5 in FIG.

6 is an enlarged sectional view taken along line 6-6 of FIG.

FIG. 7 is an operation explanatory diagram corresponding to FIG.

FIG. 8 is a diagram showing a second embodiment of the present invention, corresponding to FIG.

FIG. 9 is a diagram corresponding to FIG. 5, showing a third embodiment of the present invention.

FIG. 10 is a diagram showing a fourth embodiment of the present invention, corresponding to FIG.

FIG. 11 is a diagram obtained by a test showing a relationship between a ratio of a total opening area A of side holes to a total opening area B of fuel injection holes and a maximum fuel injection amount.

FIG. 12: When the number of fuel injection holes is one (A), when there are two fuel injection holes (B), and the distance between adjacent fuel injection holes is smaller than that of (B), there are three. (C) Fuel spray foam comparison explanatory diagram

[Explanation of symbols]

C1, C2 ... Two pitch circles of side hole group of staggered arrangement C3, C4 ... Two pitch circles of swirl chamber group of staggered arrangement I ... Fuel injection valves L1, L2 ...・ Radius line of valve seat 3 ... Valve seat member 8 ... Valve seat 35 ... Intermediate plate 36 ... Injector plate 37 ... Side hole 38 ... Direction passage 39 ... Swirl chamber 40 ... Fuel injection hole

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3G066 AD07 BA03 BA51 CC06U                       CC15 CC25 CC26 CC37 CC43                       CC70 CD30 CE22

Claims (9)

[Claims] 1. A valve body (16), a valve seat member (3) in which a downstream end of a valve seat (8) cooperating with the valve body (16) opens to a front end face, and the valve seat member (3). ) And an injector plate (36) joined to the front end surface of the valve seat member (3) and the injector plate (36), and communicating with the downstream end of the valve seat (8), A plurality of lateral passages (3) extending in a lateral direction substantially orthogonal to the axis of the valve seat (8).
8) and a plurality of swirl chambers (39) each having a downstream end of each of the lateral passages (38) opening in a tangential direction, and the swirl-filled fuel is respectively discharged to the outside. A plurality of fuel injection holes (4
0) in the injector plate (36), in the fuel injection valve, between the valve seat (8) and the plurality of lateral passages (38), at the peripheral edge of the downstream end of the valve seat (8). A fuel injection valve characterized in that a plurality of side holes (37) are provided which open one end and connect the other end to the upstream end of the lateral passage (38). 2. The fuel injection valve according to claim 1, wherein an intermediate plate (35) is joined between the valve seat member (3) and the injector plate (36), and the lateral passage (3) is connected.
8) and the swirl chamber (39) to the intermediate plate (35)
Is formed in a groove shape on the surface facing the injector plate (36), and the side hole (37) is formed on the intermediate plate (3).
5) A fuel injection valve characterized by being formed so as to penetrate the front and back thereof. 3. The fuel injection valve according to claim 1, wherein each of the swirl chambers (39) is arranged radially outward of the valve seat (8) from a corresponding side hole (37). Fuel injection valve characterized by. 4. The fuel injection valve according to claim 1, wherein each swirl chamber (39) is arranged radially inward of the valve seat (8) from a corresponding side hole (37). Fuel injection valve characterized by. 5. The fuel injection valve according to claim 1, wherein the ratio of the total opening area of the side holes (37) to the total opening area of the fuel injection holes (40) is 1.5. A fuel injection valve having the above settings. 6. The fuel injection valve according to claim 1, wherein each side hole (37) has a radius of the valve seat (8) as it goes to a corresponding lateral passage (38). A fuel injection valve characterized by being inclined so as to be displaced outward in the direction. 7. The fuel injection valve according to any one of claims 1 to 6, wherein the valve seat (8) passes through each lateral passage (38) through the center of a corresponding side hole (37). Inclining with respect to the radial lines (L1, L2), the angular positions of the corresponding side holes (37) and swirl chambers (39) with respect to the center of the valve seat (8) are offset from each other.
Fuel injection valve. 8. The fuel injection valve according to claim 1, wherein each lateral passage (38) is displaced axially outwardly toward a swirl chamber (39) corresponding thereto. A fuel injection valve characterized by being tilted to. 9. The fuel injection valve according to claim 1, wherein the plurality of side holes (37) are staggered on two pitch circles (C1, C2) concentric with the valve seat (8). And the plurality of swirl chambers (39) are arranged in a staggered manner on two pitch circles (C3, C4) which are concentric with the two pitch circles (C1, C2) and have a larger diameter than them. Fuel injection valve characterized by.