JPH068628B2 - Method for manufacturing electromagnetic fuel injection valve - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an electromagnetic fuel injection valve, and more particularly to an electromagnetic fuel injection valve suitable for a fuel injection valve for an internal combustion engine.

[Background of the Invention]

BACKGROUND ART Conventionally, an electromagnetic fuel injection valve (hereinafter referred to as an injection valve) is disclosed in
As shown in Japanese Patent No. 51944, a seat element, a spiral guide plate,
The spraying tip is provided in the nozzle case part to give a swirling force to the fuel to atomize it, and the stroke of the movable part is changed by the movement of the spraying tip to adjust the continuous flow rate. However, in this structure, it is difficult to machine a hole (swirl hole) that is formed in the spiral guide plate in an eccentric manner with respect to the center, and it takes a long time to process, and the through passage at the spray tip (orifice) is large. Since the fuel discharged from the swirl hole hits the inner wall of the orifice, the spray spreads in a film form at a certain angle, but a large atomization effect cannot be obtained. Further, the continuous flow rate can be adjusted by the movement of the spraying tip, and is fixed by laser welding or the like after the movement, but it may be deviated from a predetermined position due to looseness of the screw at the time of welding. Further, a large space formed between the seat element and the spiral guide plate downstream of the seat is always filled with the fuel when the fuel is injected, but this may cause back drooling or suction when negative pressure acts on the nozzle. It has been clarified by experiments that more fuel is injected than the amount of fuel injected during a predetermined valve opening time.

[Object of the Invention]

An object of the present invention is to provide a method of manufacturing a fuel injection valve that is inexpensive, easy to process, excellent in atomization of fuel, and high in injection amount accuracy.

[Outline of Invention]

According to the present invention, a yoke of a magnetic material surrounding an exciting coil, a core located at the center of the exciting coil and having one end in contact with the yoke, and a plunger provided so as to reciprocate in the axial direction of the yoke and the core are provided. An electromagnetic fuel injection valve that constitutes a magnetic circuit, and fuel is supplied to a seat portion through a central portion of the core and through a gap between a nozzle and a rod, and a plurality of electromagnetic fuel injection valves are provided downstream of the seat portion. Fuel injection system including a fuel passage, a plurality of slits that are eccentric with respect to a geometric center for giving a swirling force to the fuel, and an orifice that uniformizes the spray shape of the fuel given the swirling force. In the method for manufacturing a valve, a fuel flow dividing element having the plurality of fuel passages and a swirl force generating element having the plurality of slits and the orifice are formed as separate members, and the fuel flow dividing element and the fuel flow dividing element are formed. The times force generating element and a metal ring is arranged to overlap with the nozzle tip, the metal ring is plastically deformed, characterized in that fixed to the nozzle tip.

Example of Invention

An embodiment of the present invention will be described below with reference to FIGS. 1, 2, 3, and 4.
This will be described with reference to FIGS. 5, 5, 6 and 7. A core 3 around which an exciting coil 7 is wound, a yoke 2 and a plunger 4 that forms a magnetic circuit with the core 3, a rod 6 that connects and fixes the ball valve 12 and the plunger 4 to form a movable portion, and a fuel is seated inside. A fuel distribution element 501 having a seat surface 11 and a guide surface 13 that guides the rod 6 at two points and having a plurality of fuel passages 504 downstream of the seat surface 11 and a geometric center for giving a swirling force to the fuel. A nozzle 5 having a plurality of eccentric slits 505 and an orifice 506 for uniformizing the spray shape of fuel given a swirling force and a swirl force generating element 502 fixed by metal flow through a ring 503, a movable part Stopper 18 for determining a predetermined stroke of the ball valve 12 on the seat surface 11.
It is composed of a spring 19 for pressing, a spring adjuster 20 for adjusting the force of the spring 19, a fuel connector 54 for separating inflow and outflow of fuel.

Next, the fuel flow dividing element 501 and the swirl force generating element 502 will be described in detail with reference to FIGS. 3 and 4.

The fuel flow dividing element 501 has a shape in which a notch is provided in a cylinder, and a clearance with the ball valve 12 is minimized within a possible range.
The fuel volume from the seat portion 11 to the orifice 506 provided in the turning force generating element 502 is made equal to or less than the fuel amount injected at the time of engine idling.
The turning force generating element 50 provided in the fuel flow dividing element 501.
The fuel passage 504 for feeding the fuel to the center 2 is located at a plurality of points having an angle from the center of the fuel distribution element 501 on the pitch circle in the range communicating with the slit 505 provided in the swirl force generating element 502. Is processed as. The turning force generating element 502 is provided with a plurality of slits 505 that are eccentric with respect to the geometric center, and contact with a circular hole 508 that is a concentric circle with the center of the turning force generating element 502.
A swirl groove that gives a swirl force to the fuel is formed by being sandwiched between the fuel flow dividing element 501 and the orifice 506 provided in the swirl force generating element 502. The orifice 506 is
The fuel given the turning force is squeezed and measured. Therefore, the total cross-sectional area of the fuel passage 504, the slit 505
The total cross-sectional area of each is larger than the cross-sectional area of the orifice 506.

The operation will be described based on this configuration. When the exciting current is not supplied to the exciting coil 7, the ball valve 12 is pressed against the seat surface 11 by the restoring force of the spring 19 and is closed. When an exciting current is supplied to the exciting coil 7, the sliding portion 8 of the rod 6 of the movable portion is guided by the guide surface 13 of the nozzle 5 and is attracted to the core 3 side against the force of the spring 19. Here, the stroke of the movable part is determined by the length of the nozzle 5 and the movable part, and has a structure in which it stops at the stopper 18, so that the plunger 4 and the core 3 do not come into direct contact with each other. On the other hand, the fuel passes through the filter 21 provided inside the fuel connector 54, the inside 55 of the spring adjuster 20, the inside of the core 3, the hole 22 formed in the plunger 4, the plunger 4 and the rod 6. It is supplied to the seat portion through the gap of the cut portion 23 of the surface and through the gap of the cut portion 24 of the four surfaces of the rod 6 and the guide surface 13 of the nozzle 5. Further, a part of the fuel is supplied from the stock 56 provided on the core 3 to the outer circumference of the plunger 4, the outer circumferences 58 and 59 of the bobbin 57 around which the coil 7 is wound,
It passes through 60, enters a recess 62 outside the spring adjuster 20 from a hole 61 provided in the middle of the core 3, and constantly flows through the fuel connector 54 and the gap 63 of the core 3.

When the ball valve 12 is opened, the fuel is separated from the fuel shunt element 50.
1 through the plurality of fuel passages 504 and the plurality of slits 505 provided in the swirl force generating element 502, where the fuel flow dividing element 501 and the swirl force generating element 5 are connected.
Since an eccentric fuel passage is formed between No. 02, a swirling force is applied to the fuel, and the fuel is squeezed and metered by an orifice 506 provided in the swirling force generating element 502, atomized, and injected into the outside air. The fuel passage 504 and the slit 5
Reference numeral 05 denotes the fuel flow dividing element 501 and the turning force generating element 5
The structure is positioned by the notch provided in No. 02. The angle and particle size of the injected spray are determined by the eccentricity amount / width / depth of the slit 505 and the diameter of the orifice 506, and are selected according to the required spray angle / particle size.

Further, the maximum injection amount of the injection valve 1 is the fuel shunt element 5
01, the swirl force generating element 502 is fixed by the metal flow through the ring 503, and the continuous flow rate is determined by combining the nozzle 5 and the ball valve 12. Therefore, the diameter of the orifice 506, the width of the slit 505, The eccentricity and depth and the accuracy of the clearance between the ball valve 12 and the nozzle 5 seat portion 11 at the time of valve opening are required, but the cross-sectional area of the fuel passage 504 of the fuel flow dividing element 501 and the swirling force generating element 502 are provided. Since the cross-sectional area of the orifice 506 provided in the swirling force generating element 502 is smaller than the fuel passage area of the slit 505, the orifice 506 is reprocessed after metal flow to be enlarged (FIG. 6), or Turning force generating element 50
On the outer surface of No. 2, a pressing member having an inner and outer diameter intermediate between the diameters of the orifice 506 and the metal flow portion is pressed 507 in a ring shape to change the diameter of the orifice 506 (see FIG. 7). The flow rate can be adjusted within a certain range after assembly, and the fuel flow dividing element 501 and the swirling force generating element 502 can be pressed or manufactured by powder metallurgy. On the contrary, since the fuel flow dividing element 501 and the swirling force generating element 502 are separate bodies, it is easy to improve the processing accuracy of a single piece. Further, since the fuel metering member has the minimum number of divisions, positioning of each fuel passage is easier than in the case where the number of divisions is three or more.

From the seat 11 to the orifice 5 in the turning force generating element 502
Since the fuel volume up to 06 is made as small as possible as described above, it has been confirmed by an experiment that the injection amount does not significantly change under a constant injection condition in the state where the negative pressure acts on the tip of the nozzle 5. . It has also been confirmed that the ring 503 used during metal flow does not affect the spray characteristics.

FIGS. 8, 9, and 10 show another embodiment in which the swirling force of fuel is larger than that of the injection valve of the present invention, and FIG. 11 shows the flow of fuel as seen from the fuel shunt element side. Indicates the status.

〔The invention's effect〕

According to the present invention, it is possible to provide an injection valve that is easy to process, has excellent atomization of fuel, and has high injection amount measurement accuracy.

[Brief description of drawings]

1 is a cross-sectional view of an injection valve of the present invention, FIG. 2 is a cross-sectional view of a nozzle in which a movable part including a ball valve is inserted, FIG. 3 is a fuel flow dividing element, FIG. 4 is a swirl force generating element, FIG. 5 is a view showing a state in which the fuel distribution element is incorporated in the swirl force generating element, and FIGS. 6 and 7 are enlarged views of the tip of the nozzle, FIG. 8, FIG. 9, and FIG.
FIG. 0 and FIG. 11 are sectional views showing another embodiment of the present invention. 2 ... Yoke, 3 ... Core, 4 ... Plunger, 5 ... Nozzle,
12 ... Ball valve, 501 ... Fuel flow dividing element, 502 ... Swirling force generating element.

Claims (3)

[Claims] 1. A yoke of a magnetic material surrounding an exciting coil,
A magnetic circuit is configured by a core located at the center of the exciting coil and having one end in contact with the yoke, and a plunger provided so as to be reciprocally movable in the axial direction of the yoke and the core. An electromagnetic fuel injection valve that is supplied to a seat through a gap between a through nozzle and a rod, and has a plurality of fuel passages provided downstream of the seat, and a geometric structure for giving a swirling force to the fuel. A method for manufacturing an electromagnetic fuel injection valve, comprising: a plurality of slits eccentric with respect to a geometrical center; and an orifice for equalizing a spray shape of a fuel given a swirling force. The flow dividing element and the swirl force generating element having the plurality of slits and the orifice are formed as separate members, and the fuel flow dividing element, the swirl force generating element, and the metal ring are stacked on the tip of the nozzle. Te place, a manufacturing method of an electromagnetic fuel injection valve, characterized in that the metal ring is plastically deformed to fix on the nozzle tip. 2. A valve body according to claim 1, wherein after the swirl force generating element is fixed to the nozzle, the orifice of the swirl force generating element is processed from the outside of the nozzle to seat the fuel. A method for manufacturing an electromagnetic fuel injection valve, characterized in that a continuous flow rate is adjusted in a state where nozzles are combined. 3. The method according to claim 1, wherein after the swirl force generating element is fixed to the nozzle, the orifice of the swirl force generating element is pressed from the outside of the nozzle to deform the orifice. A method for manufacturing an electromagnetic fuel injection valve, characterized in that a continuous flow rate is adjusted in a state where a valve body for seating fuel and the nozzle are combined.