JP2550127B2 - Electromagnetic fuel injection valve - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electromagnetic fuel injection valve for an internal combustion engine, which does not particularly require adjustment of a static flow rate and has extremely good productivity and atomization characteristics. Relates to an excellent electromagnetic fuel injection valve.

[Prior Art] A conventional device is a swirl plate having a guide hole for accommodating balls as described in JP-A-56-75955 and a swirl passage for introducing the fuel almost tangentially or into the guide hole. It is said that the atomization of the fuel can be improved by the structure in which the housing is provided.

[Problems to be Solved by the Invention]

The prior art described above does not consider the point of converting the swirl passage and the four fuel passage holes communicating with the swirl passage into sufficient swirl velocity energy without loss when the pressurized fuel passes, There was a problem that the atomization of fuel could not be performed efficiently.

An object of the present invention is to provide an electromagnetic fuel injection valve capable of converting pressurized fuel into swirling fuel without loss and performing injection supply with excellent atomization characteristics while securing a static flow rate of fuel. To do.

[Means for solving the problem]

The object is to provide a fuel swirl element, which is arranged upstream of the valve seat and in which a plurality of fuel passages for giving swirl force to the supplied fuel are formed, and the fuel swirl element provided downstream of the valve seat. An electromagnetic fuel injection valve comprising a single-hole fuel injection hole for injecting swirling fuel and a ball valve driven by an electromagnet to open and close a fuel passage between the valve seat and the ball valve, The area (A ₂ ) of the minimum portion of the annular gap formed between the ball valve and the valve seat when lifted is made larger than the cross-sectional area (A ₃ ) of the fuel injection hole, and This is achieved by making the fuel passage smaller than the sum (A ₁ ) of the sectional areas of the fuel passages.

[Action]

Securing a static flow rate is an essential condition for fuel injection holes. In order to ensure this static flow rate, a throttle may be provided in any of the fuel passages to regulate the amount here. However, in order to regulate the passages in the swivel element, it is necessary to increase the machining accuracy of the plurality of passages.
In order to regulate the flow rate in the annular gap formed between the ball valve and the valve seat, processing accuracy for obtaining a predetermined lift amount is required. Therefore, focusing on the fact that the fuel injection hole is a single hole, the processing accuracy is relatively easy to obtain, so it was decided to secure the static flow rate by narrowing it down.

However, when the shape is narrowed by the injection hole, atomization of the fuel at the time of injection may be hindered even if the static flow rate is secured.

Therefore, it was confirmed through various experiments that a static flow rate can be obtained and that atomization is not hindered if the passage shape is configured as described above. That is, the fuel swirl element controls the fuel flow directed downward in the axial direction through the sudden expansion hole of the nozzle body, the radial fuel flow directed toward the valve seat and the fuel injection hole, and the loss thereof to be small. The fuel pressurized by the fuel swirl element and given the swirl force flows through the annular gap formed by the ball and the valve seat narrower than the flow path of the fuel swirl element, and the fuel injection hole with a smaller cross-sectional area. Is jetted through. Therefore, the pressurized fuel can be efficiently exchanged into the swirl velocity energy and guided to the fuel injection hole, and can be injected and supplied with a sufficient swirl force from the fuel injection hole.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 9. Referring to FIG. 1, an electromagnetic fuel injection valve (hereinafter,
It is called an "injection valve". ) Structure and operation of 1) will be described. The injection valve 1 is a control unit (not shown).
The fuel is injected by opening and closing the seat portion according to the duty ON-OFF signal calculated by. The magnetic circuit is composed of a bottomed cylindrical yoke 3, a plug 2a that closes the open end of the yoke 3, and a columnar portion 2b that extends to the center of the yoke 3, and a plunger 4 that faces the core 2 with a gap. Consists of. At the center of the columnar portion 2a of the core 2, a movable portion 4A including a plunger 4, a rod 5 and a ball valve 6 is formed in a valve guide 7 and a seat surface 9 of an orifice 8 is formed.
A hole for inserting and holding a spring 10 as an elastic member that is pressed against is formed. 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 fuel from flowing out from the gap between the two. Also, core 2
An O-ring 13 for preventing the fuel from flowing out from the gap between the core 2 and the yoke 3 is interposed between and the yoke 3. The coil 15 for exciting 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 is provided between the terminal 18 and the core 2.
The ring 19 is interposed. A collar 20 is provided over the inlet of the hole 17 to prevent the molding resin (hereinafter referred to as a yoke mold) 19a outside the injection valve 1 from entering the inside of the injection valve 1 during molding. A gap 21, an upper passage 22, and a lower passage 23 with 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) 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 trapped 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 for receiving the stopper 29 and the valve guide 7 therein is larger in diameter than the plunger receiving portion 28. 30 is pierced to the tip of the yoke. Also,
An annular filter 31 is provided on the outer periphery of the yoke 3 to prevent dust and foreign matter in the pipe from entering from the fuel inflow passage 26 to the valve seat side. 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. The movable portion 4A is composed 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 the upper end opening of the plunger 4. It is composed of a guide ring 34. The guide ring 34 is an inner wall 35 of a hollow portion opened at the tip of the core 2, and the ball valve 6 is an inner peripheral surface 38 of a cylindrical fuel swirl element 37 inserted into the inner wall 36 of the hollow portion of the valve guide 7. A seat surface 9 for seating the ball valve 6 is formed in the valve guides 7 that are respectively guided, following the cylindrical fuel swirl element 37 that guides the ball valve 6, and the center of the seat surface 9 is formed. A fuel injection hole 8 is formed in this. The valve guide 7 is further formed with a tubular portion 39 extending in the direction opposite to the seat surface 9. 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.
After attaching the O-ring 19 to the terminal 18 portion of the coil assembly 16, the terminal 18 is inserted into the hole 17 of the flange portion of the core 2, and then the collar 20 is inserted from above the terminal 18. Then, the 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 edge of the inner circumference of the yoke 3 is pressed in the axial direction, and the material of the yoke 3 is radially poured into the groove 43 provided on the outer circumference of the plug portion of the core 2 by plastic flow. Fix with that tension. The so-called metal flow is performed. Since 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 and eventually guides it in two places to advance and retreat in the axial direction. It is important that the coaxiality of the inner diameter of the valve guide 7 receiving portion 30 of the yoke 3 and the inner wall surface 35 of the core 2 be 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 being 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. Then rod 5
The other end and the plunger 4 are provided with a groove 44 provided on the outer periphery of the rod 5.
Then, the inner wall of the plunger 4 is fixed by fluid pressure bonding with a metal flow. Further, the guide ring 34 and the plunger 4 are coupled to 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-bonded and fixed to the inner wall surface 36 of the valve guide 7. That is, the outer peripheral surfaces 47 (four places) of the fuel swirl element 37 are fluid-pressure bonded to the grooves 48 of the valve guide 7 by metal flow.
(FIGS. 2 and 3 viewed from the direction A in FIG. 2) In this embodiment, a method of crimping and fixing by the metal flow as described above will be described. However, the fuel swirl element 37 is made of an elastic member. Even if it is fixed from the direction A shown in FIG. 2, its 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 has a D-cut surface. The grooves 49, 50 are fuel passages introduced in the axial direction, but the fuel passing through the grooves 49 is introduced eccentrically in the grooves 50 from the axial center. A so-called fuel is given a swirling force, and has a function of promoting atomization when the fuel is 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 the fuel include 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. 4 (B- in FIG. 3).
(B-direction sectional view). Using the rheological equivalent diameter represented by the groove width W and groove depth H in FIG. 4, the cross-sectional area A ₁ is Becomes Here, n is the number of grooves.

The cross-sectional area A ₁ is the cross-sectional area A ₃ of the fuel injection hole 8. 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,
This will prove that the effect of the losses 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 less than 0.2% at the tolerance ± 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 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. In FIGS. 5 and 6, the static flow rate Q ₀ is the target flow rate, and Q _max is +3 of Q ₀ .
% And Q _min represents -3% of Q ₀ . The tolerance ± a is about 20 μm in this embodiment.

Next, the effect 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.

Where, L is the eccentricity of the groove (see FIG. 4) ds 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 . 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 equation (4).

Where Q: flow rate C ₀ : flow coefficient d: orifice diameter γ: specific weight P: fuel pressure. The flow coefficient C _{0 in the} equation (4) is expressed with a characteristic value K represented by the reciprocal of the swirl number S obtained by the equation (3). As shown in FIG. Become. As is clear from the figure, in this embodiment, the flow coefficient C
It is designed to allow the passage of fuel in a region where the rate of change of ₀ is small. In other words, the magnitude of the swirl number S in the equation (3) can be selected according to the eccentricity L of the groove. The amount of eccentricity L is naturally determined to a size that reduces the rate of change of the flow coefficient C ₀ , but this can be proved by FIG. 8 showing the experimental results by the authors.

In FIG. 8, the change rate of the static flow rate is a little less than ± 1% in the tolerance ± a with respect to the reference eccentric amount L ₀ . This corresponds to the flow rate change of the hatched portion in the figure, but this flow rate change is from the change C _0min to C of the flow rate coefficient C ₀ shown in FIG.
It can be said that it corresponds to _0max .

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

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

FIG. 9 shows the experimental result on the effect of the stroke l on the static flow rate. As is clear from the figure, as the stroke 1 increases, the flow rate starts to rise rapidly, and the slope gradually becomes gentle, resulting in a substantially constant flow rate Q ₀ . With this stroke, the area A _{2 of the} annular clearance formed between the ball 6 and the valve seat 9 is given by the equation (5), referring to FIG.

Here, D ₁ : lower piece of trapezoid in the figure D ₁ : upper piece of the number of figures in the figure, that is, sheet diameter h: height of trapezoid in the figure.

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

As described above, the stroke amount of the movable portion 4A is determined as an absolute amount that does not affect the static flow rate and has a sufficiently large dimensional tolerance. Therefore, as in the conventional case, the lift amount is once measured with the movable portion 4A and the valve guide 7 combined, and the end surface of the valve guide or the receiving surface 5a of the neck of the rod 5 is ground to a target range. There is no need to adjust to the stroke of, and only the management of the part dimensions is required. 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 fuel through the single fuel injection hole 8 is shown in FIG. The rate of change of the static flow rate with a tolerance of ± b with respect to the reference orifice diameter d ₀ is less than ± 1.5%. Here, the b dimension is about 5 μm.

As described above, the cross-sectional area A ₃ of the fuel injection hole 8 can be expressed by using the annular clearance area A ₂ at the time of the stroke of the movable portion 4A and the groove area A ₁ of the fuel swirl element 37, where A ₁ >. A ₂ > A ₃ (6) In the so-called injection valve 1 of this embodiment, fuel is measured by the fuel injection hole 8 of the orifice.

The ratio δ of A ₂ / A ₃ takes a value of 2 or more as described above, but at this time, the fluid loss in the fuel injection hole 8 is 95% of the total loss.
The above is confirmed and it is confirmed that the above-mentioned measurement is performed by this fuel injection hole 8.

Further, as described with reference to FIGS. 5 to 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 FIGS. 9 and 10. Is about ± 1%, which 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 changes by about ± 1% by the fuel swirl element 37 and by about ± 1.5% by the orifice, but it does not reach the target in the injection valve assembly. Can satisfy ± 3%.

That is, an inexpensive injection valve that does not need to be remanufactured by disassembling and assembling or adjusting the static flow rate and expensively. It is needless to say that even if the static flow rate of the orifice provided in the valve guide 7 is measured before crimping and fixing the fuel swirl element 37 to the valve guide 7, the static flow rate is managed within the target accuracy. Nor.

As described above, the assembled valve guide assembly is inserted together with the stopper 29 into the valve guide receiving portion 30 of the yoke 3 of the electromagnet assembly to assemble the both. 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 gear so that the tip of the plunger 4 and the tip of the core 2 do not come into direct contact with each other when the movable portion is sucked. next,
The valve guide 7 is provided in the hole provided at the center of the core 2 of the electromagnet assembly.
From the opposite direction, insert the adjuster 11 holding the spring 10 at the tip and attaching the O-ring 12 on the outer periphery,
A filter 31 and an O-ring 24 are attached to the outer periphery of the yoke 3 and once housed in a hire (not shown), the injection amount test is started. In the injection amount test, first, the measurement is performed with the movable part having a full stroke, and it is confirmed that the injection amount at that time becomes the specified injection amount.

After that, the responsiveness 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 specified injection amount, and then the upper protrusion of the core 2 is determined.
The outer circumference of 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 by fixing.

The operation of the injection valve configured as described above will be described.
The injection valve 1 operates a movable part to open and close a valve seat by an electrical ON-OFF signal provided to the electromagnetic coil 15, and thereby injects fuel. Electrical signal coil
Given as a pulse to 15. When current flows through the coil 15, the magnetic circuit is composed of the core 2, the yoke 3, and the plunger 4.
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, separating from the seat surface of the valve seat 9 of the valve guide 7 and opening the fuel injection hole 8. The fuel is pressurized and adjusted by a fuel pump (not shown) or a fuel pressure regulator, flows into the solenoid valve assembly from the inflow passage 26 through the filter 34, and is passed through the lower passage 23 of the coil assembly 16, the outer periphery of the plunger 4 and the stopper. 2
The fuel is swirled and supplied to the seat through the grooves 49 and 50 of the fuel swirl element 37 in the gap between the rod 9 and the rod 5, and is injected into the intake pipe through the fuel injection hole 8 when the valve is opened.

When the electromagnetic coil 15 is de-energized, the movable part 4A moves to the spring 10
The ball valve 6 closes the seat surface of the valve seat 9 by being pushed to the valve seat side.

Although it has been clarified in the above description that the means for adjusting the flow rate is not required, 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 from 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 exit of the radial groove that is constructed. This swirling flow proceeds downstream through a lossless annular gap formed in 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.

When the grooves 49 and 50 and the ball 6 are lifted, the valve seat 9
The pressure drop of the fuel when flowing through the annular gap generated between the seat surfaces of the sheet is extremely 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 sufficient injection pressure is achieved at the fuel injection hole 8.
Since it is injected with a turning force, excellent atomized fuel can be obtained.

Here, 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. By design, 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 space for allowing the passage of fuel and a diameter of a pre-throttled shape in which fuel flow loss does not occur. Due to the direction groove 50, the pressure loss at the time of passage thereof is extremely small, and the fuel is the first fuel swirl chamber 54.
Flow into.

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 in the first embodiment can be obtained, and the structure is relatively simple and can be constructed at low cost.

Incidentally, the axial groove 49 and the radial groove 50 in this embodiment.
Can take any shape as is apparent from the examples. 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. further,
Needless to say, the same effect can be obtained even if the axial groove 49 has a chamfered structure.

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 a BB line in FIG.
FIG.

In FIG. 15, 37 is a fuel swirl element having a flange 51, and the outer peripheral surface of the 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 in the lower portion of the flange 51. From this, fuel flows from the radial groove 50 provided on the surface corresponding to the surface of the valve seat 9 to the first fuel swirl chamber 54.
To As shown in FIG. 16, 55 is communicated with the fuel reservoir 52 by a plurality of notches 55 provided in the flange 51.

Reference numeral 57 is a second fuel swirl chamber formed by a conical valve seat 9 below the ball 6, and promotes a swirl flow of the fuel flowing from the first fuel swirl chamber 54.

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 this spacer member 56 regulates the gap between the protrusion surface 8a of the valve device. That is, the upward movement of the valve device, that is, the lift amount is secured.

In this embodiment, the same effect as in the first embodiment can be obtained, but in particular, the pressurized fuel can be uniformly distributed immediately before the radial groove 50, and swirling fuel can be efficiently replaced. is there.

〔The invention's effect〕

According to the present invention, whilst ensuring a static flow rate and supplying fuel without pressure drop, swirling fuel with high efficiency can be obtained, and excellent atomized fuel can be obtained.

[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, and FIG. FIG. 4 is a sectional view taken along the line BB of FIG. 3, FIG. 5 is an experimental example showing the relationship between groove width and flow rate, and FIG. 6 is an experiment showing the relationship between groove depth and flow rate. Example, FIG. 7 is a diagram showing the relationship between the fuel swirl strength and the flow rate coefficient according to the embodiment of the present invention, FIG. 8 is a diagram showing the relationship between the groove eccentricity and the flow rate, and FIG. 9 is the valve stroke and the flow rate. FIG. 10 is a diagram showing the relationship, FIG. 10 is a diagram for explaining the annular clearance generated between the ball and the valve seat, FIG. 11 is a diagram showing the relationship between the orifice diameter and the flow rate, and FIG. 12 is the flow channel of the fuel and the flow velocity. FIG. 13 is a sectional view showing a ball valve body portion of another embodiment of the present invention, FIG. 15 is an enlarged sectional view of an essential portion of another embodiment of the present invention, and FIG. Is a B-B sectional view of Figure 15. 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 swirl element, 49 …… Axial groove, 50 …… Radial groove.

Front page continuation (72) Inventor Kyoichi Uchiyama 502 Jinrachicho, Tsuchiura-shi, Ibaraki Hitachi Machinery Research Institute Co., Ltd. (72) Inventor Haruo Watanabe 502 Jinre-cho, Tsuchiura-shi, Ibaraki Hitachi Machinery Research Co. ) Inventor Tokio Kosuge 2520 Takaba, Katsuta City, Ibaraki Prefecture Sawa Factory, Hitachi Ltd. (72) Inventor Akira Onishi 2520 Takaba, Katsuta City, Ibaraki Ltd. Sawa Factory, Hitachi (72) Invention Person Takumi Terasaki 2520, Takaba, Katsuta, Ibaraki Pref., Sawa Plant, Hitachi, Ltd. (72) Inventor, Hiroyuki Ando, 2520, Takaba, Katsuta, Ibaraki, Ltd., Sawa, Hitachi (72) Inventor, Hamajima Eiji 3085-5 Higashiishikawa Nishikonai, Katsuta City, Ibaraki Prefecture (56) References Japanese Automobile Engineering Co., Ltd. (56) References Japanese Patent Laid-Open No. 56-121860 (JP, A) Shoukai 56-8855 (JP, U)

Claims (4)

(57) [Claims] 1. A fuel swirl element disposed upstream of a valve seat and having a plurality of fuel passages for imparting swirl force to the supplied fuel; and a fuel swirl element provided downstream of the valve seat. A single hole fuel injection hole for injecting fuel swirled by
In an electromagnetic fuel injection valve that is driven by an electromagnet and has a ball valve that opens and closes a fuel passage with the valve seat, between the ball valve and the valve seat when the ball valve lifts. The area of the smallest part of the annular gap formed (A
₍₂ ) is larger than the cross-sectional area (A ₃ ) of the fuel injection hole and smaller than the sum (A ₁ ) of the cross-sectional areas of the plurality of fuel passages. 2. The ratio (A ₁ / A ₂ ) of the area (A ₂ ) of the minimum portion of the annular gap to the sum (A ₁ ) of the cross-sectional areas of the plurality of fuel passages is 2 or more. Electromagnetic fuel injection valve. 3. The ratio (A ₁ / A ₃ ) between the cross-sectional area (A ₃ ) of the fuel injection hole and the sum (A ₁ ) of the cross-sectional areas of the plurality of fuel passages is 1.5 or more. Electromagnetic fuel injection valve. 4. The fuel swirl element according to claim 1, wherein the fuel swirl element is provided with a plurality of notches, a fuel reservoir communicating with the notches, and a fuel reservoir communicating with the fuel reservoir. An electromagnetic fuel injection valve having a radial groove for introducing fuel eccentrically from the center.