JP4405359B2 - Fuel injection valve and method of processing fuel injection hole - Google Patents

Description

The present invention relates to a fuel injection valve mainly used in a fuel supply system of an internal combustion engine, and in particular, a valve seat member in which a valve seat and a valve hole penetrating the center of the valve seat are formed in a front end wall, and the valve seat. A valve body that operates to open and close the valve hole, and an injector plate that has a plurality of fuel injection holes that are radially displaced from the valve hole and is joined to the front end surface of the valve seat member; the valve seat member and the fuel injection valve defining a flat fuel diffusion chamber Ru is communicating between the valve hole and the fuel injection orifice is between injector plate, and a processing method of the fuel injection hole in its fuel injection valve.

Such a fuel injection valve is already known as disclosed in Patent Document 1 below.
JP 2002-130074 A

  Such an electromagnetic fuel injection valve has an advantage that a desired spread angle can be given to the fuel spray foam from the fuel injection hole by selecting the axial distance between the fuel injection hole and the valve hole.

  In this fuel injection valve, while facilitating the punching of the fuel injection hole into the injector plate, air is mixed into the injection fuel from the fuel injection hole with a simple structure so that the fine particles of the injection fuel can be obtained. It aims to be able to promote conversion.

In order to achieve the above object, the present invention provides a valve seat, a valve seat member having a valve hole penetrating the center of the valve seat formed in the front end wall, and a valve body that opens and closes the valve hole in cooperation with the valve seat. And an injector plate having a plurality of fuel injection holes arranged radially offset from the valve hole and joined to the front end surface of the valve seat member, and between the valve seat member and the injector plate, in the fuel injection valve defining a flat fuel diffusion chamber Ru is communicating between holes and the fuel injection hole, the fuel injection hole, thereby forming perpendicular to the plate surface of the injector plate by punching, the fuel injection hole the portion of the valve hole side of the inner circumferential surface, a first feature in that a the depression widens towards the exit of the fuel injection hole.

In addition to the first feature, the present invention provides the second feature in that the flange portion is disposed at a portion opposite to the fuel injection direction from the fuel injection hole with the axis of the fuel injection hole interposed therebetween. And

Further, in the present invention, in forming the fuel injection hole with the turning portion in the injector plate according to the first or second feature, the injector plate is mounted on the work mounting surface of the die in which the punching hole opens vertically, the punch can be inserted into the punching holes, punching fuel injection hole in the injector plate by Rukoto is operated in a state of being offset to one side with respect to the central axis of the hole punching axis of the punch, at that time fuel injection orifice According to a third feature of the present invention, the beveled portion is formed by peeling off the meat of the injector plate that occurs at a portion of the inner peripheral surface opposite to the offset direction of the punch.

According to the first feature of the present invention, since the plurality of fuel injection holes are formed perpendicularly to the injector plate, the punching process can be facilitated and the life of the punching tool can be extended to improve the productivity. Can be achieved. In addition, at the swirl part provided on the valve hole side of the inner peripheral surface of each fuel injection hole, during fuel injection, negative pressure associated with the fuel injection is generated and surrounding air is entrained, and that air is mixed into the injected fuel. By doing so, atomization of the injected fuel can be promoted, and its structure is very simple.

According to the second feature of the present invention, the beveled portion is disposed at a portion on the opposite side of the fuel injection direction from the fuel injection hole with the axis of the fuel injection hole interposed therebetween. The generation space of the negative pressure is expanded and air entrainment is increased, so that atomization of the injected fuel can be promoted more effectively.

Further according to the third aspect of the present invention, by punching by a die and a punch, when punching the fuel injection hole in the injector plate, only Ru is offset to one side with respect to the central axis of the hole punching axis of the punch Therefore, it is possible to form a fuel nozzle hole with a swirl portion at once, and a special process for forming the swirl portion is unnecessary. Therefore, it is necessary to punch the fuel hole perpendicularly to the injector plate. The punching process can be facilitated and the life of the punching tool, especially the punch, can be extended, which can greatly contribute to the improvement of productivity.

  Embodiments of the present invention will be described below on the basis of preferred embodiments of the present invention shown in the accompanying drawings.

  1 is a longitudinal sectional view of an electromagnetic fuel injection valve according to a first embodiment of the present invention, FIG. 2 is an enlarged view of part 2 of FIG. 1, FIG. 3 is an enlarged view of part 3 of FIG. FIG. 5 is an enlarged view taken along arrow 5 in FIG. 3, FIG. 6 is a view corresponding to FIG. 5, showing a second embodiment of the present invention, and FIG. 7 is a diagram showing fuel injection to the injector plate in each embodiment. It is hole processing-method explanatory drawing.

First, the description starts with the first embodiment of the present invention. 1 and 2, the valve housing 2 of the electromagnetic fuel injection valve I is coaxially coupled to a cylindrical valve seat member 3 having a valve seat 8 on the front end wall and a rear end portion of the valve seat member 3. A magnetic cylinder 4 that is coupled to the rear end of the magnetic cylinder 4 and a fixed core 5 that is coupled to the rear end of the nonmagnetic cylinder 6 by press-fitting and welding. , And a fuel inlet tube 26 coaxially connected to the rear end of the fixed core 5.

  As shown in FIGS. 3 to 5, the valve seat member 3 passes through a cylindrical guide hole 9, a conical valve seat 8 connected to the front end of the guide hole 9, and the central portion of the valve seat 8. And a valve hole 7. The valve seat 8 of the valve seat member 3 is formed in a conical shape. Between the valve seat 8 and the valve hole 7, the fuel that has passed through the valve seat 8 is collected and guided to the valve hole 7. A collective recess 35 is formed.

  A circular recess 37 concentrically surrounding the valve hole 7 is formed on the front end surface of the valve seat member 3, and in this recess 37, the injector plate 10 is attached to the valve seat member 3 via an annular weld 38. Bonded liquid-tight. A circular and flat fuel diffusion chamber 36 centering on the valve hole 7 is defined on the opposing surface of the injector plate 10 and the valve seat member 3. In the illustrated example, the fuel diffusion chamber 36 is a valve seat member. Consists of three side recesses. A plurality of fuel injection holes 11, 11... Opened in the fuel diffusion chamber 36 are formed in the injector plate 10, and these fuel injection holes 11, 11. Communicate. These fuel injection holes 11, 11... Are formed such that their respective axis lines Y are perpendicular to the plate surface of the injector plate 10 and parallel to the axis line O of the valve hole 7, and surround the axis line O of the valve hole 7. Then, they are arranged annularly and at equal intervals (see FIGS. 3 and 5). Accordingly, the spread angle α of the fuel spray form F formed by the injected fuel from all the fuel injection holes 11, 11... Is set by selecting the axial distance R between each fuel injection hole 11 and the valve hole 7. .

As best shown in Figure 4, each fuel injection hole 11, the inner peripheral surface of the valve hole 7 side, it spreads that the depression 39 toward the outlet of each fuel injection hole 11 is formed.

  In FIGS. 1 and 2 again, a hollow cylindrical fixed core 5 is liquid-tightly pressed into the inner peripheral surface of the nonmagnetic cylindrical body 6 from the rear end side, whereby the nonmagnetic cylindrical body 6 and the fixed core 5 are Coaxially coupled to each other. At this time, a portion that does not fit with the fixed core 5 remains at the front end portion of the nonmagnetic cylindrical body 6, and the valve assembly V is accommodated in the valve housing 2 extending from the portion to the valve seat member 3.

The valve assembly V is connected to the valve rod portion 17 including a valve portion 16 that opens and closes with respect to the valve seat 8 and a valve rod portion 17 that supports the valve portion 16, and is connected to the valve rod portion 17. It consists of a movable core 12 straddling the cylindrical body 6 and inserted into them and confronted with the fixed core 5 coaxially. The valve rod portion 17 is formed to have a smaller diameter than the guide hole 9, and the journal portion 17 a that protrudes radially outward at the outer periphery thereof and is slidably supported on the inner peripheral surface of the guide hole 9. Are integrally formed. In addition, a journal portion 17 b is formed on the outer periphery of the movable core 12 so as to be slidably supported on the inner peripheral surface of the magnetic cylindrical body 4.

The valve assembly V, a longitudinal hole 19 ending in front of the valve portion 16 from the rear end face of the movable core 12, the longitudinal hole 19, a plurality of first transverse hole 20a of Ru is communicated with the movable core 12 outer circumference, a plurality of second transverse hole 20b of the valve rod section 17 outer peripheral surface Ru is communication between the Dotateana 19 and the journal portion 17a and the valve unit 16 is provided. At that time, an annular spring seat 24 facing the fixed core 5 is formed in the middle of the vertical hole 19.

The fixed core 5 has a vertical hole 21 that communicates with the vertical hole 19 of the movable core 12, and a fuel inlet cylinder 26 that communicates internally with the vertical hole 21 is integrally connected to the rear end of the fixed core 5. The fuel inlet cylinder 26 is composed of a reduced diameter portion 26a connected to the rear end of the fixed core 5 and a subsequent enlarged diameter portion 26b, and a slotted pipe shape press-fitted into the vertical hole 21 from the reduced diameter portion 26a. A valve spring 22 for biasing the movable core 12 toward the valve closing side of the valve body 18 is provided between the retainer 23 and the spring seat 24. At that time, the set load of the valve spring 22 is adjusted by the depth of fitting of the retainer 23 into the vertical hole 21. The enlarged diameter portion 26b the fuel filter 27 is mounted, the sealing member is mounted on the outer periphery of the enlarged diameter portion 26b.

  The fixed core 5 is made of a ferrite-based high hardness magnetic material. On the other hand, in the movable core 12, a collar-like high-hardness stopper element 14 surrounding the valve spring 22 is embedded in a suction surface opposite to the suction surface of the fixed core 5. The stopper element 14 has its outer end slightly protruded from the suction surface of the movable core 12 and is normally opposed to the suction surface of the fixed core 5 with a gap corresponding to the valve opening stroke of the valve body 18. The

A coil assembly 28 is fitted to the outer periphery of the valve housing 2 so as to correspond to the fixed core 5 and the movable core 12. The coil assembly 28 includes a bobbin 29 fitted to the outer peripheral surface from the rear end portion of the magnetic cylindrical body 4 to the fixed core 5 and a coil 30 wound around the bobbin 29. The front end of the coil housing 31 that surrounds 28 is welded to the outer peripheral surface of the magnetic cylindrical body 4, and the rear end is welded to the outer peripheral surface of the yoke 5 a that protrudes in a flange shape from the outer periphery of the rear end of the fixed core 5. The coil housing 31 has a cylindrical shape, and a slit 31a extending in the axial direction is formed on one side.

  A part of the magnetic cylinder 4, the coil housing 31, the coil assembly 28, the fixed core 5, and the front half of the fuel inlet cylinder 26 are embedded in a synthetic resin cylindrical mold part 32 by injection molding. At that time, the mold portion 32 is filled into the coil housing 31 through the slit 31a. A coupler 34 protruding in one side is integrally formed in the middle portion of the mold portion 32, and the coupler 34 holds a current-carrying terminal 33 connected to the coil 30.

  Next, the operation of the first embodiment will be described.

  When the coil 30 is demagnetized, the valve assembly V is pressed forward by the biasing force of the valve spring 22, and the valve body 18 is seated on the valve seat 8. In this state, the fuel pumped from the fuel pump (not shown) to the fuel inlet cylinder 26 passes through the pipe-like retainer 23, the vertical hole 19 of the valve assembly V, and the first and second horizontal holes 20a and 20b. 3 is put on standby and used for lubrication around the journal portions 17a and 17b of the valve assembly V.

  When the coil 30 is energized by energization, the magnetic flux generated by the coil 30 sequentially travels through the fixed core 5, the coil housing 31, the magnetic cylindrical body 4, and the movable core 12, and the movable core 12 of the valve assembly V is set to the valve spring 22 by the magnetic force. Since the valve portion 16 of the valve body 18 is separated from the valve seat 8 of the valve seat member 3 against the load, the high pressure fuel in the valve seat member 3 passes through the valve seat 8. Thereafter, the fuel collecting recess 35 collects and guides the valve hole 7, reverses the flow through the valve hole 7, moves to the fuel diffusion chamber 36, and diffuses radially to form a plurality of fuel injection holes arranged at equal intervals in the injector plate 10. Are evenly distributed to the fuel injection holes 11, 11.

At this time, the fuel injection direction from each fuel injection hole 11 is given by the velocity component in the radial direction given by the flat fuel diffusion chamber 36 and the fuel injection hole 11 perpendicular to the plate surface of the injector plate 10. By combining with the velocity component in the axial direction, a direction inclined outward with respect to the axis Y of each fuel injection hole 11 is taken as shown in FIG. Accordingly, the swirl portion 39 formed on the inner peripheral surface of each fuel injection hole 11 on the valve hole 7 side is located on the opposite side of the inclination direction of the fuel injection direction across the axis Y. In the swirling portion 39, a negative pressure associated with fuel injection is generated and surrounding air is entrained, and the air is mixed into the injected fuel, thereby promoting atomization of the injected fuel.

  Thus, atomization of the injected fuel is promoted by an extremely simple structure in which the beveled portion 39 that extends toward the outlet of each fuel injection hole 11 is formed on one side of the inner peripheral surface of each fuel injection hole 11. Can greatly contribute to the improvement of combustion efficiency in the engine. In particular, by disposing the bulging portion 39 on the inner peripheral surface of the fuel injection hole 11 on the side opposite to the inclination direction of the fuel injection direction, a negative pressure generation space on the flaring portion 39 side is widened, and air is trapped. Therefore, atomization of the injected fuel can be promoted more effectively.

  By the way, the radial velocity component imparted to the fuel in the fuel diffusion chamber 36 increases as the inter-axis distance R between the valve hole 7 and the fuel injection hole 11 increases. By selecting the size of the inter-axis distance R, the inclination of the fuel injection direction from each fuel nozzle hole 11 with respect to the axis Y of each fuel nozzle hole 11 can be set to be larger or smaller.

  In this first embodiment, since the plurality of fuel injection holes 11, 11... Are arranged at equal intervals around the axis O of the valve hole 7, the inclination of the fuel injection direction from each fuel injection hole 11 is constant. As a result, it is possible to form a conical fuel spray foam F extending downward about the axis O of the valve hole 7 by the injected fuel from all the fuel injection holes 11, 11. The spread angle α of the spray form F can be increased or decreased by selecting the size R of the axis. The electromagnetic fuel injection valve I for generating such fuel spray foam F is suitable for an engine having one intake port per cylinder.

  Moreover, since the plurality of fuel injection holes 11, 11... Are formed perpendicularly to the injector plate 10, the punching process can be facilitated and the life of the punching tool can be extended to improve productivity. Can be achieved.

  Next, a second embodiment of the present invention shown in FIG. 6 will be described.

  In this second embodiment, two sets of fuel injection holes 11, 11... Are formed in the injector plate 10 at a large distance from each other in the diameter direction of the injector plate 10. The plurality of fuel injection holes 11, 11... Constituting each set are arranged on an arc centered on the axis O of the valve hole 7. The minimum distance C between the two sets of fuel injection holes 11, 11... Is set sufficiently larger than the distance D between the fuel injection holes 11, 11.

And Thus, in this embodiment, high pressure fuel moves in the fuel diffusion chamber 36 from the valve hole 7 is first totally diffuse the radiation shape, between the two sets of fuel injection holes 11 group The directed fuel collides with the inner peripheral wall of the fuel diffusion chamber 36 and divides into two hands, respectively, and travels along the inner peripheral wall toward two sets of fuel injection holes 11, 11. Thus, due to the influence of the fuel flow along the inner peripheral wall of the fuel diffusion chamber 36, the injection directions of the fuel from the two sets of fuel injection holes 11, 11,... In view of this, the inner peripheral surface of each fuel injection hole 11 is formed with a turn portion 39 at a portion opposite to the inclination direction of the fuel injection direction. Even in this case, the bent portion 39 is provided at a portion of the inner peripheral surface of each fuel injection hole 11 on the valve hole 7 side as is apparent from FIG.

  Thus, as in the previous embodiment, the air injected by the negative pressure generated in the swirl portion 39 is mixed into the injected fuel from each fuel injection hole 11 to effectively promote atomization of the injected fuel. Two fuel spray foams F1, F2 facing in opposite directions can be formed by the injected fuel from the group of fuel injection holes 11, 11,. Thus, the electromagnetic fuel injection valve that generates the two fuel spray forms F1 and F2 is suitable for an engine having two intake ports per cylinder.

  The other configuration is the same as that of the previous embodiment, and the description thereof is omitted.

  Next, with reference to FIG. 7, a method for processing the fuel injection hole 11 having the turning portion 39 into the injector plate 10 will be described.

First, a die 40 in which a punching hole 41 opens perpendicularly to the workpiece mounting surface 40a and a punch 42 that can be inserted into the punching hole 41 are prepared. The cylindrical blade portion 42a of the punch 42 has the same diameter as the fuel injection hole 11 to be processed, while the punching hole 41 of the die 40 has a larger diameter than usual than the blade portion 42a of the punch 42. The punch 42 is arranged so as to move up and down along an axis A offset by a predetermined distance e to one side with respect to the central axis B of the punching hole 41. By doing so, the gap between the inner peripheral surface of the punching hole 41 and the outer peripheral surface of the punch 42 when the blade 42a of the punch 42 is inserted into the punching hole 41 is as small as S1 on the side where the punch 42 is offset as usual. , S2 is set larger than normal on the opposite side.

In the processing of fuel injection holes 11, on the die 40 work placement surface 40a, when placing the injector plate 10 to be machined, the depression 39 to be formed, on the opposite side of the offset direction of the punch 42 Adjust the orientation of the injector plate 10 to come. If the punch 42 is driven down along the axis A, the fuel injection hole 11 corresponding to the blade portion of the punch 42 can be punched out into the injector plate 10. However, the punch 42 is centered in the punching hole 41 as described above. Since the gap between the punching hole 41 and the punch 42 is set larger than usual on the opposite side to the offset direction with respect to the line B, in the latter half of the punching of the fuel injection hole 11, Separation of the meat of the injector plate 10 occurs on the side where the gap is large, and a turn 39 is formed at the trace. In FIG. 6, reference numeral 43 indicates scrap generated by punching the fuel injection hole 11.

  Thus, by the punching process using the die 40 and the punch 42, the fuel injection hole 11 with the swirl portion 39 can be formed in the injector plate 10 at once, and a special process for forming the swirl portion 39 is unnecessary. It is. Therefore, when the fuel injection hole 11 is punched perpendicularly to the injector plate 10, the punching process can be facilitated and the life of the punching tool, particularly the punch 42, can be extended, greatly contributing to the improvement of productivity. Can do.

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

1 is a longitudinal sectional view of an electromagnetic fuel injection valve according to a first embodiment of the present invention. FIG. 2 is an enlarged view of part 2 of FIG. 1. FIG. 3 is an enlarged view of part 3 of FIG. 2. 4 enlarged view of FIG. FIG. FIG. 6 is a view corresponding to FIG. 5 showing a second embodiment of the present invention. Explanatory drawing of the processing method of the fuel injection hole to the injector plate in each Example.

3 ... Valve seat member 7 ... Valve hole 8 ... Valve seat 10 ... Injector plate 11 ... Fuel injection hole
18 .... Valve 36 ...... Fuel diffusion chamber 39 ...... Bearing part 40 ... Die 40a ... Work placement surface 41 ...... Punching hole A ... Punch Axis B ... Punching hole center axis e ... Punch offset amount I ... Fuel injection valve O ... Valve hole axis Y ... Fuel Axis of nozzle hole

Claims (3)

The valve seat (8) and a valve hole (7) penetrating through the center of the valve seat (8) are formed on the front end wall, and the valve seat (3) cooperates with the valve seat (8). ) And a plurality of fuel injection holes (11) arranged to be shifted in the radial direction from the valve hole (7) and joined to the front end face of the valve seat member (3). it comprises an injector plate (10), the valve seat member (3) and the injector plate (10) between the valve hole (7) and the fuel injection holes (11) between Ru is communicating a flat fuel diffusion chamber (36 ) In the fuel injection valve
The fuel injection hole (11) is formed perpendicularly to the plate surface of the injector plate (10) by punching , and at the part on the valve hole (7) side of the inner peripheral surface of the fuel injection hole (11), A fuel injection valve provided with a ridge portion (39) extending toward the outlet of the fuel injection hole (11). The fuel injection valve according to claim 1, wherein
The fuel injection is characterized in that the ridge portion (39) is disposed at a portion opposite to the fuel injection direction from the fuel injection hole (11) across the axis (Y) of the fuel injection hole (11). valve. In processing the fuel injection hole (11) with the ridge portion (39) in the injector plate (10) according to claim 1 or 2,
A punch (42) in which the punching hole (41) is opened vertically, the injector plate (10) is placed on the work placement surface (40a) of the die (40), and the punch (42) can be inserted into the punching hole (41), axis of the punch (42) the central axis of (a) punching holes (41) fuel injection orifice to the injector plate (10) by Rukoto is operated in a state of being offset to one side relative to (B) (11) punching, formed in the inner peripheral surface at that time fuel injection orifice (11), wherein the depression by a release of meat punch injector plate caused by the offset direction opposite to the portion of (42) (10) and (39) A method for processing a fuel injection hole in a fuel injection valve.

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