JP3435358B2 - Electromagnetic fuel injection valve - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic fuel injection valve for an internal combustion engine, and more particularly to a swirl type electromagnetic fuel injection valve.

[0002]

2. Description of the Related Art A conventional device is a swirl plate having a guide hole for accommodating balls and a swirl passage for introducing fuel into the guide hole from a direction substantially tangential to the guide hole, as described in JP-A-56-75955. It was possible to improve atomization of the fuel by the structure in which the housing is provided.

[0003]

In the above-mentioned prior art, the fuel passage in the direction along the axis connecting to the swirl passage (axial direction) is constituted by a vertical hole formed in the swirl plate.
Sufficient consideration has not been given to increasing the productivity of electromagnetic fuel injection valves by facilitating work and processing around swirl plates. Further, the above-mentioned prior art has not taken into consideration that the swirl passage and the four fuel passage holes communicating with the swirl passage are converted into sufficient swirl velocity energy without loss when the pressurized fuel passes through. .

It is an object of the present invention to provide an electromagnetic fuel injection valve which is excellent in productivity and which is capable of injecting and supplying fuel with excellent atomization characteristics by efficiently giving swirling force to fuel.

[0005]

In order to achieve the above object, an electromagnetic fuel injection valve of the present invention comprises an assembly that constitutes an electromagnet, a fuel injection hole for injecting fuel, and a fuel injection hole. A valve seat provided on the upstream side and a valve body that is driven by an electromagnetic force generated by an assembly that constitutes the electromagnet to open and close a fuel passage between the valve seat and a driving direction of the valve body. Is arranged around a virtual central axis, and is formed in a straight line so as to direct in a direction eccentric to the central axis,
A plurality of swirling fuel passages for introducing fuel from the outer peripheral side toward the central axis side and imparting swirling force to the passing fuel,
A guide member provided in a through hole penetrating in the axial direction of the central axis to guide the valve body; and a guide member having the plurality of swirling fuel passages and the guide surface formed therein, the guide member comprising: In the hollow portion formed by the inner peripheral wall surface portion in the direction along the central axis and the bottom surface portion in the direction crossing the central axis,
The valve seat and the fuel injection hole are fixed so as to be in contact with the bottom surface portion in a direction along the central axis and to be in contact with the inner peripheral wall surface portion in a direction transverse to the central axis. Is formed in the bottom surface portion, and by utilizing the space remaining around the guide member in the hollow portion as a fuel passage, the outer peripheral surface of the guide member and the inner wall surface serve as passage walls, and the upstream end to the downstream end. To the edge
An axial fuel passage is formed which can be seen in the direction along the central axis, and the swirling fuel passage forms a reduction passage on the downstream side of the axial fuel passage with respect to the axial fuel passage. And a total cross-sectional area of the plurality of swirling fuel passages is formed between the valve seat and the valve body when the valve body is separated from the valve seat and the fuel passage is opened. Is formed so as to be larger than the cross-sectional area of the annular gap, and the valve seat and the fuel injection hole are assembled with the guide member , the valve body penetrates the through hole, It is fixed to an assembly that constitutes an electromagnet.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. The structure and operation of the electromagnetic fuel injection valve (hereinafter referred to as “injection valve”) 1 will be described with reference to FIG. The injection valve 1 is for injecting fuel by opening and closing a seat portion by an ON-OFF signal of a duty calculated by a control unit (not shown). The magnetic circuit includes a core 2 composed of a bottomed cylindrical yoke 3, a plug portion 2a closing the open ends of the yoke 3 and a columnar portion 2b extending to the center of the yoke 3, and a plunger 4 facing the core 2 with a gap. Consists of. At the center of the columnar portion 2a of the core 2, a spring 10 as an elastic member for pressing a movable portion 4A including a plunger 4, a rod 5 and a ball valve 6 against a seat surface 9 of an orifice 8 formed in a valve guide 7 is inserted. There is a hole to hold it. The upper end of the spring 10 is in contact with the lower end of a spring adjuster 11 inserted through the center of the core 2 for adjusting the set load. An O-ring 12 is provided between the core 2 and the adjuster 11 in order to prevent the fuel from flowing out from the gap between the two.
Is provided. In addition, between the core 2 and the yoke 3,
An O-ring 13 is interposed to prevent the fuel from flowing out from the gap between the core 2 and the yoke 3. The coil 15 excited by the magnetic circuit is wound around the bobbin 14, and the outside thereof is molded with a plastic material. The terminal 18 of the coil assembly 16 composed of these is inserted into the hole 17 provided in the flange portion of the core 2, and the O-ring 1 is provided between the terminal 18 and the core 2.
9 is installed. A collar 20 for preventing a mold resin (hereinafter referred to as a yoke mold) 19a on the outside of the injection valve 1 from entering the inside of the injection valve 1 at the time of molding is provided with a hole 17.
Over the entrance. A gap 21, an upper passage 22, and a lower passage 23 from the core 2 are provided as passages for fuel and fuel vapor. An annular groove 25 is formed on the outer periphery of the yoke 3, and an O-ring 24 that prevents fuel from flowing out from a gap between the injection valve 1 and a socket (not shown) serving as a housing is held therein. Around the yoke 3, an inflow passage 26 through which fuel flows and an outflow passage 27 through which excess fuel including bubbles accumulated in the injection valve 1 flow out are opened. Further, a plunger receiving portion 28 for receiving the movable portion 4A is opened in the bottom portion of the yoke 3, and a valve guide receiving portion 30 for receiving the stopper 29 and the valve guide 7 there is larger in diameter than the plunger receiving portion 28. Is extended to the tip of the yoke. Further, an annular filter 31 is provided on the outer periphery of the yoke 3 to prevent dust and foreign matter in the fuel and in the pipe from entering the valve seat side from the fuel inflow passage 26. A terminal 32 for transmitting a signal from the control unit to the coil 15 is joined to the terminal 18. These terminals 32 are molded on the upper end of the solenoid valve assembly by molding resin to form a molded connector 33. Moving part 4
A is a guide ring made of a magnetic material plunger 4, a rod 5 having one end joined to the plunger 4, a ball joined to the other end of the rod 5, and a non-magnetic material fixed to an upper opening of the plunger 4. And 34. The guide ring 34 and the inner wall 35 of the hollow portion opened at the tip of the core 2, and the ball valve 6 is the inner peripheral surface 38 of the cylindrical fuel swirl element 37 inserted into the inner wall 36 of the hollow portion of the valve guide 7. , Each guided valve guide 7
Includes a cylindrical fuel swirl element 3 for guiding the ball valve 6.
7, the seat surface 9 on which the ball valve 6 is seated.
Is formed, and the fuel injection hole 8 is formed in the center of the seal surface 9.
Has been drilled. The valve guide 7 also has a seat surface 9
A tubular portion 39 extending in the opposite direction is formed. An O-ring 40 for sealing fuel is interposed between a socket (not shown) and the outer peripheral surface of the valve guide 7. In the embodiment, an O-ring receiving portion 41 is formed as an annular groove on the outer circumference of the valve guide 7.

The method of assembling the injection valve and the method of adjusting the flow rate will be described below. First, a method for assembling the electromagnet assembly will be described. The O-ring 1 is attached to the terminal 18 of the coil assembly 16.
After attaching 9, the terminal 18 is inserted into the hole 17 of the collar portion of the core 2, and then the collar 20 is inserted from above the terminal 18. After that, an O-ring 13 is attached to the lower part of the outer periphery of the plug part of the core and fitted into the yoke 3. In this state, the core abutting surface portion 42 at the upper end of the inner circumference of the yoke 3 is pressed in the axial direction, and the material of the yoke 3 is radially poured by plastic flow into the groove 43 provided on the outer circumference of the plug portion of the core 2. Fix with tense force. The so-called metal flow is performed. The movable part guides the ball valve 6 by the inner wall surface 38 of the fuel swirl element 37, and guides the non-magnetic ring 34 by the inner wall surface 35 of the tip of the core 2, so that 2
Since it guides at a place and moves back and forth in the axial direction, the inner diameter of the receiving portion 30 of the valve guide 7 of the yoke 3 and the inner wall surface 35 of the core 2
It is important that the coaxiality of is accurately obtained. Therefore, the metal flow is performed with the inner diameter of the receiving portion 30 of the valve guide 7 and the inner wall surface 35 of the core 2 accurately supported. After that, the terminal 32 is fixed to the terminal 18 by crimping, soldering, welding, or the like, and then molding is performed with resin. Next, the assembly of the valve guide assembly will be described. The valve guide is composed of the movable portion 4A, the fuel swirl element 37, and the valve guide 7. The movable portion 4A is formed by welding the ball valve 6 and the quench-hardened stainless steel rod 5 by resistance welding or laser welding. Next, the other end of the rod 5 and the plunger 4 are fixed to the groove 44 provided on the outer periphery of the rod 5 by fluid pressure bonding of the inner wall of the plunger 4 by metal flow. Further, the guide ring 34 and the plunger 4 are coupled with each other by receiving the ball valve side surface 45 of the plunger 4 and axially pressing the guide ring contact portion 46 at the inner peripheral edge of the tip of the plunger 4 to form a guide ring. It can be done in metal flow by applying radial tension.

The fuel swirl element 37 is formed in a cylindrical shape by using a sintered alloy, and is pressure-fixed to the inner wall surface 36 of the valve guide 7. That is, the outer peripheral surface 47 of the fuel swirl element 37
(Four places) are fluid pressure bonded to the groove 48 of the valve guide 7 by metal flow (FIG. 2 and FIG. 3 viewed from the direction A in FIG. 2). In this embodiment, the method of crimping and fixing by the metal flow as described above will be described. However, even if the fuel swirl element 37 is fixed by the elastic member in the direction A shown in FIG. 2, the function can be similarly satisfied. .

The fuel swirl element 37 is provided with an axial groove 49 and a radial groove 50. In this embodiment, the axial groove 49
Formed a D-cut surface. The grooves 49 and 50 are fuel passages introduced in the axial direction, but the fuel passing through the grooves 49 is introduced eccentrically from the axial center in the grooves 50. A so-called fuel is given a swirling force and has a function of promoting atomization when ejected from the fuel injection hole 8 of the outlet orifice provided in the valve guide 7.

Here, the fuel swirl element 37 is designed and manufactured in consideration of the following, and is fixed by pressure to the inner wall surface 36 of the valve guide 7.

Factors that affect the static flow rate of fuel are the pressure loss in the flow path of the fuel swirl element 37 and the swirl force applied. The pressure loss of the flow channel is mainly controlled by the cross-sectional area of the groove. The cross-sectional shape of the radial groove 50 in this embodiment is shown in FIG.
(Cross-sectional view taken along the line BB of FIG. 3). Using the rheological equivalent diameter represented by the groove width W and the groove depth H in FIG. 4, the cross-sectional area A ₁ is

[0012]

[Equation 1]

[0013] Here, n is the number of grooves.

The sectional area A ₁ is the sectional area A of the fuel injection hole 8.
_Three

[0015]

[Equation 2]

The ratio σ = A ₁ / A ₃ is 1.5 <σ <6.5
And is designed to prevent pressure loss as much as possible. The experimental results of the authors are shown in FIGS. 5 and 6, which will prove that the effect of the loss is negligible. FIG. 5 shows the influence of the groove width W on the static flow rate. The change rate of the flow rate is slightly less than 0.2% at the tolerance of ± a with respect to the reference groove width W ₀ . FIG. 6 shows the influence of the groove depth H on the static flow rate. The change rate of the flow rate is slightly less than 0.1% at the tolerance ± a with respect to the reference groove depth H ₀ . Therefore, the influence of the groove on the static flow rate is negligible in the above design conditions. 5 and 6, the static flow rate Q ₀ is the target flow rate, Qmax represents + 3% of Q ₀ , and Qmin is Q
_It represents -3% of ₀ . Further, the tolerance ± a is about 20 μm in this embodiment.

Next, the influence of the turning force on the static flow rate will be described. The swirl number S given as a parameter indicating the turning strength is given by the following equation.

[0018]

[Equation 3]

Where L is the eccentricity of the groove (see FIG. 4) d _S is the rheological equivalent diameter and is expressed using the groove diameter W and the groove depth H (see equation 1) n: The number of grooves is there. The influence of the magnitude of the swirl number S on the static flow rate will be described by the following equation and will be described together with the experimental results by the authors. First, the flow rate Q is given by the equation 4.

[0020]

[Equation 4]

Here, Q: flow rate C ₀ : flow rate coefficient d: orifice diameter γ: specific weight P: fuel pressure. The flow coefficient C ₀ in the equation 4 is represented by the characteristic value K shown by the reciprocal of the swirl number S obtained by the equation 3, which is shown in FIG. As is apparent from the figure, the present embodiment is designed so that the passage of fuel is allowed in the region where the rate of change of the flow coefficient C ₀ is small. In other words, the magnitude of the swirl number S in Formula 3 can be selected by the eccentricity L of the groove. The amount of eccentricity L is naturally determined to be a dimension that reduces the rate of change of the flow coefficient C ₀ , which will be proved by FIG. 8 showing the experimental results of the authors.

In FIG. 8, the change rate of the static flow rate is a little less than ± 1% at the tolerance ± a with respect to the reference eccentricity amount L ₀ . This corresponds to the flow rate change in the hatched portion in the figure, and this flow rate change is the change C ₀ mi in the flow rate coefficient C ₀ shown in FIG. 7.
It can be said that n corresponds to C ₀ max.

As described above, the fuel swirl element 37 has a comparatively small influence on the change in the static flow rate, and the inexpensive fuel swirl element 37 is provided by the simple structure in which the manufacturing accuracy is loose. . The fuel swirl element 37 is
After being manufactured to a desired size with a loose manufacturing accuracy, the valve guide 7 is fixed by fluid pressure bonding to the groove 48 of the inner wall surface 36 by a metal flow.

Next, the adjustment of the stroke of the movable portion 4A will be described. The stroke is the receiving surface 5 of the neck of the rod 5.
It is determined by the size of the gap between a and the stopper 29.

FIG. 9 shows the experimental result on the influence of the stroke l on the static flow rate. As is apparent from the figure, as the stroke 1 increases, the flow rate starts to rise rapidly, and the slope gradually becomes gentle to become a substantially constant flow rate Q ₀ . The area A _{2 of the} annular gap formed between the ball 6 and the valve seat 9 by this stroke is shown in FIG.
It is given by the number 5.

[0026]

[Equation 5]

Here, D _{1 is} the lower side of the trapezoid in the figure, D is the upper side of the number of sheets in the figure, that is, the sheet diameter h is the height of the trapezoid in the figure.

The area A ₂ for achieving a constant flow rate Q ₀ is
When expressed by the ratio δ = A ₂ / A ₃ to the area A ₃ of the fuel injection hole 8, 1 <δ. In this embodiment, as shown in FIG. 9, it can be seen that the tolerance ± a with respect to the reference stroke l0 is determined to have a sufficiently large dimension. The ratio .delta. In the tolerance -a of the stroke l0 is 2 or more. Note that the dimension a
Is about 20 μm as described above.

As described above, the stroke amount of the movable portion 4A is an absolute amount that does not affect the static flow rate, and is determined by a dimensional tolerance with a sufficient margin. Therefore, as in the conventional case, the lift amount is once measured in a state where the movable portion 4A and the valve guide 7 are combined, and the end surface of the valve guide or the receiving surface 5a of the neck portion of the rod 5 is ground to stroke within the target range. There is no need to adjust it to just the management of the part dimensions. Therefore, the assembly work is easy and simple.

Next, the influence on the static flow rate of the fuel injection hole 8 which is the fuel injection port provided in the valve guide 7 will be described. The static flow rate of the fuel passing through the single fuel injection hole 8 is shown in FIG.
1 is shown. Tolerance ± b to standard orifice diameter d0
The rate of change of static flow rate at is less than ± 1.5%. Here, the b dimension is about 5 μm.

As described above, the cross-sectional area A of the fuel injection hole 8
3 indicates the relationship using the annular gap area A2 at the time of the stroke of the movable portion 4A and the groove area A1 of the fuel swirl element 37.

[0032]

[Equation 6] A ₁ > A ₂ > A ₃ (Equation 6). In the so-called injection valve 1 of this embodiment, fuel is measured by the fuel injection hole 8 of the orifice.

As described above, the ratio δ of A ₂ / A ₃ takes a value of 2 or more, but at this time, the fluid loss of the fuel injection hole 8 accounts for 95% or more of the total loss, and the above measurement is performed. What is done by this fuel injection hole 8 is supported.

Further, as described with reference to FIG. 5 to FIG. 8, the flow rate change rate considering the influence on the flow rate of the fuel swirl element 37 and the influence on the flow rate of the stroke described with reference to FIG. 9 and FIG. The value of about ± 1% also means that the flow rate is adjusted by the fuel injection hole 8 of the outlet orifice.

As described above, the static flow rate is hardly affected by the stroke, and the
Although it varies by about 1% and about ± 1.5% depending on the orifice, the target ± 3% in the injection valve assembly can be sufficiently satisfied.

In other words, it is an inexpensive injection valve that does not require the static flow rate adjustment to be disassembled, assembled, or remanufactured at high cost. Needless to say, the static flow rate of the orifice provided in the valve guide 7 is controlled within the target accuracy even by measuring the static flow rate before the fuel swirl element 37 is pressure-fixed to the valve guide 7. .

As described above, the assembled valve guide assembly is inserted into the valve guide receiving portion 30 of the yoke 3 of the electromagnet assembly together with the stopper 29 to assemble the two. The both are fixed by fixing the inner peripheral wall of the tip of the yoke 3 into the groove 51 provided on the outer periphery of the valve guide 7 by plastic flow by metal flow. At this time, the stopper 29 is set to have a thickness having a predetermined air gap so that the tip of the plunger 4 and the tip of the core 2 do not come into direct contact when the movable portion is sucked. Next, the adjuster 11 with the spring 10 held at the tip and the O-ring 12 attached to the outer periphery is inserted into the hole provided in the center of the core 2 of the electromagnet assembly from the direction opposite to the valve guide 7, while the yoke 3 of the yoke 3 is inserted. The filter 31 and the O-ring 24 are attached to the outer circumference, and the filter 31 and the O-ring 24 are temporarily stored in a hire (not shown), and the injection amount test is started there. The injection amount test is
First, measure the movable part with a full stroke, and confirm that the injection amount at that time is the specified injection amount.

After that, the response of the movable part is determined by changing the load of the spring 10 so that the injection amount for a constant period and a constant valve opening time becomes a prescribed injection amount, and then the core 2 is determined.
The outer periphery of the upper projecting portion 52 is pressed in the radial direction from the hole of the mold resin, and the inner wall of the core is fixed in the groove 53 of the adjuster.

The operation of the present injection valve constructed as above will be described. The injection valve 1 operates a movable part to open and close a valve seat by an electric ON-OFF signal provided to the electromagnetic coil 15, thereby injecting fuel.
The electric signal is applied to the coil 15 as a pulse. When a current is applied to the coil 15, a magnetic circuit is formed by the core 2, the yoke 3 and the plunger 4, and the plunger 4 is attracted to the core 2 side. When the plunger 4 moves, the ball valve 6 integrated with the plunger 4 also moves and separates from the seat surface of the valve seat 9 of the valve guide 7 to open the fuel injection hole 8. The fuel is pressurized and adjusted by a fuel pump or a fuel pressure regulator (not shown), flows into the inside of the solenoid valve assembly from the inflow passage 26 through the filter 34, and is connected to the lower passage 23 of the coil assembly 16, the outer periphery of the plunger 4, and the stopper. The fuel is swirled and supplied to the seat through the gap between the rod 29 and the rod 5, the grooves 49 and 50 of the fuel swirl element 37, and is injected into the intake pipe through the fuel injection hole 8 when the valve is opened.

When the electromagnetic coil 15 is deenergized, the movable portion 4A
Is pushed by the spring 10 and moves to the valve seat side,
The ball valve 6 closes the seat surface of the valve seat 9.

Although it has been clarified in the above description that the means for adjusting the flow rate is not necessary, the points that contribute to atomization of the fuel will be described here.

When the fuel reaches the fuel swirl element 37, the fuel flows toward the seat surface of the valve seat 9 through the axial groove 49 provided in the swirl element and the radial groove 50 communicating with the axial groove 49. A swirl flow occurs at the outlet of the radial groove that is more eccentrically constructed. This swirling flow proceeds downstream through a lossless annular gap formed on the seat surface 1 of the valve seat 9, but the flow is promoted to reach the fuel injection hole 8 while maintaining sufficient swirling energy.

The pressure drop of the fuel when flowing through the annular gap generated between the seat surfaces of the valve seat 9 when the grooves 49, 50 and the ball 6 are lifted is very small as is clear from the above description. . Therefore, the swirl supply of the fuel is performed while maintaining the supplied fuel pressure, and the fuel is injected with sufficient swirling pressure and swirling force in the fuel injection hole 8 portion, so that excellent atomized fuel can be obtained.

FIG. 12 shows the relationship between the fuel flow path and the flow velocity when the injection valve of the present invention is used. As is clear from FIG. 12, the flow velocity is highest in the fuel injection hole portion from the fuel introduction portion to the fuel outlet. Therefore, the flow rate can be measured only by the fuel injection hole, that is, the outlet orifice. The design means that the flow rate can be measured accurately if the outlet orifice is made accurately.

FIG. 13 shows another embodiment of the present invention, in which the fuel swirl element 37 has an axial groove 49 having a sufficient gap for allowing the passage of fuel and a pre-throttled shape in which no fuel flow loss occurs. With the radial groove 50, the pressure loss when passing through the radial groove 50 is extremely small, and the fuel flows into the first fuel swirl chamber 54.

FIG. 14 is a sectional view of a nozzle device according to another embodiment of the present invention. In FIG. 14, 37 is another fuel swirl element, 49 is an axial groove, and 50 is a radial groove.

Also in this embodiment, the same effect as that of the first embodiment can be obtained, and the structure is relatively simple and can be constructed at low cost.

The axial groove 49 and the radial groove 50 in this embodiment can have any shape as is apparent from this embodiment. That is, the injection pressure and the fuel swirling force can be adjusted, and the pattern of the spray injected from the fuel injection hole 8 can be selected. Needless to say, the same effect can be obtained by chamfering the axial groove 49.

Next, FIG. 15 is an enlarged view of a main part of an electromagnetic fuel injection valve according to still another embodiment of the present invention, and FIG. 16 is FIG.
5 is a sectional view taken along the line BB of FIG.

In FIG. 15, 37 is a fuel swirl element having a flange 51, and the outer peripheral surface of this flange 51 is fixed to the inner surface of the sudden expansion hole 5 of the nozzle device 2. Reference numeral 52 denotes a fuel reservoir formed at the bottom of the flange 51, whereby the fuel is supplied to the radial groove 5 provided on the surface corresponding to the valve seat 9 surface.
From 0 to the first fuel swirl chamber 54. As shown in FIG. 16, a plurality of notches 55 provided in the flange 51 communicate with the fuel reservoir 52.

57 is a conical valve seat 9 below the ball 6.
The second fuel swirl chamber formed by the first fuel swirl chamber 5
4 promotes the swirling flow of the fuel flowing in.

Reference numeral 56 denotes a spacer member inserted between the bearing surface 1a of the yoke 3 and the bearing surface 2a of the nozzle device 7, and the spacer member 56 forms a gap with the protruding surface 8a of the valve device. It regulates and secures the upward movement of the valve device, that is, the lift amount.

In this embodiment, the same effect as in the first embodiment can be obtained, but in particular, just before the radial groove 50, a uniform distribution of the pressurized fuel can be obtained and the swirling fuel can be efficiently replaced. It can be done.

[0054]

According to the present invention, the axial fuel passage has a valve.
Since it is configured on the outer peripheral surface of the member that guides the body in the axial direction,
The processability of this axial fuel passage is improved. Also, axial direction
Even if the cross-sectional area of the fuel passage in the
Secure the passage length of the swirling fuel passage connected to the fuel passage
It becomes easier to move the swirling fuel passage in the axial direction.
Easy to configure as a reduced passage for the fuel passage
become. Furthermore, the swirling fuel passage is changed to the axial fuel passage.
On the other hand, by configuring it as a reduced passage,
Pressure loss in the fuel passage can be reduced and continues
It is easy to obtain the required turning force in the turning fuel passage.
It In addition, the cross-sectional area of the swirling fuel passage is calculated from the valve seat and valve body.
Larger than the cross-sectional area of the annular gap formed between
To reduce the pressure loss in this swirling fuel passage.
Therefore, the pressure energy can be efficiently
It can be converted into Rugi and can obtain excellent atomized fuel.
You can Further, the valve seat, the fuel injection hole and the guide element
Fix the assembly assembled with and to the assembly that constitutes the electromagnet
Due to this configuration, the valve seat, fuel injection hole and
It is easy to maintain and maintain the coaxiality with the guide surface provided on the drive element.
It

[Brief description of drawings]

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

FIG. 2 is a vertical sectional view for explaining a fuel swirl element and a valve guide assembly structure.

FIG. 3 is a view from the direction A in FIG.

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

FIG. 5 is an experimental example showing the relationship between groove width and flow rate.

FIG. 6 is an experimental example showing the relationship between groove depth and flow rate.

FIG. 7 is a diagram showing the relationship between the fuel swirl strength and the flow coefficient according to the embodiment of the present invention.

FIG. 8 is a diagram showing a relationship between an eccentric amount of a groove and a flow rate.

FIG. 9 is a diagram showing a relationship between a valve stroke and a flow rate.

FIG. 10 is a view for explaining an annular gap generated between a ball and a valve seat.

FIG. 11 is a diagram showing a relationship between an orifice diameter and a flow rate.

FIG. 12 is a diagram showing a relationship between a fuel flow path and a flow velocity.

FIG. 13 is a sectional view of a ball valve element portion of another embodiment of the present invention.

FIG. 14 is a sectional view of a ball valve body portion of another embodiment of the present invention.

FIG. 15 is an enlarged cross-sectional view of the essential parts of another embodiment of the present invention.

16 is a sectional view taken along line BB of FIG.

[Explanation of symbols]

1 ... Injection valve, 2 ... Core, 3 ... Yoke, 4a ... Movable valve, 4
... Plunger, 5 ... Rod, 6 ... Ball valve, 8 ... Fuel injection hole, 9 ... Valve seat, 15 ... Coil, 37 ... Fuel swirling element,
49 ... Axial groove, 50 ... Radial groove.

Front page continuation (72) Inventor Kyoichi Uchiyama 502 Jinrachicho, Tsuchiura City, Ibaraki Prefecture, Hitachi, Ltd., Mechanical Research Laboratory (72) Inventor Haruo Watanabe 502, Jinmachicho, Tsuchiura City, Ibaraki, Ltd., Hitachi Ltd., Mechanical Research Laboratory (72) ) Inventor Tokuo Kosuge 2520, Takaba, Hitachinaka City, Ibaraki Prefecture, Sawa Plant, Hitachi Ltd. (72) Inventor, Akira Onishi 2520, Takaba, Hitachinaka City, Ibaraki Prefecture, Ltd., Sawa Plant, Hitachi Ltd. (72) Inventor, Terasaki ▲ Akane ▼ 2520 Takaba, Hitachinaka City, Ibaraki Prefecture, Sawa Factory, Hitachi, Ltd. (72) Inventor Hiroyuki Ando 2520, Takaba, Hitachinaka City, Ibaraki Prefecture, Ltd. (72), Sawa Factory, Hitachi, Ltd. Eiji Hamajima, Ibaraki 3085-5 Higashiishikawa Nishikonai, Hitachinaka City, Japan Hitachi Automotive Engineering Co., Ltd. (56) References JP-A-56-75955 (JP, A) JP-A-61-118556 (JP, A) JP 59-162360 (JP, A) JP flat 1-159460 (JP, A) patent 156492 (JP, C1) (58 ) investigated the field (Int.Cl. ^7, DB name) F02M 51/08 F02M 61/08 F02M 61/18

Claims (2)

(57) [Claims] 1. An assembly forming an electromagnet, a fuel injection hole for injecting fuel, a valve seat provided upstream of the fuel injection hole, and an electromagnetic wave generated by the assembly forming the electromagnet. A valve element that is driven by force to open and close a fuel passage between the valve seat and a valve element that is arranged around a central axis that is virtual in the driving direction of the valve element and that is oriented in a direction eccentric to the central axis. A plurality of swirling fuel passages that are linearly formed so as to introduce a fuel from the outer peripheral side toward the central axis side and give a swirling force to the passing fuel, and penetrate in the axial direction of the central axis. A guide member provided in the through hole for guiding the valve body; and a guide member having the plurality of swirling fuel passages and the guide surface formed therein, wherein the guide member is in a direction along the central axis. Formed by the peripheral wall surface and the bottom surface in the direction crossing the central axis The hollow portion is fixed in such a manner that it contacts the bottom surface portion and is positioned in a direction along the central axis, and contacts the inner peripheral wall surface portion so as to be positioned in a direction that traverses the central axis. The seat and the fuel injection hole are formed in the bottom surface portion, and by utilizing a space remaining around the guide member in the hollow portion as a fuel passage, the outer peripheral surface of the guide member and the inner wall surface are connected to the passage wall. As an axial fuel passage is formed from the upstream end to the downstream end in the direction along the central axis, and the swirling fuel passage is located downstream of the axial fuel passage in the axial fuel passage. And a total cross-sectional area of the plurality of swirling fuel passages when the valve body is separated from the valve seat and the fuel passage is opened. Between the valve body Is formed so as to be larger than the cross-sectional area of the annular gap to be made, assembly assembled with the guide member and the valve seat and the fuel injection hole, the valve body so as to penetrate the through hole An electromagnetic fuel injection valve fixed to an assembly forming the electromagnet. 2. The electromagnetic fuel injection valve according to claim 1, wherein an outer circumferential surface of the guide member is circumferentially spaced from an upstream end to a downstream end in a direction along the central axis. A plurality of contact surfaces that come into contact with the inner peripheral wall surface portion, and the fuel passage in the axial direction is formed between the contact surfaces.