JP2011185183A - Orifice processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an orifice processing method capable of elaborately forming orifices with sufficient yield by suppressing deformation as small as possible even if a space between adjoining ones is very narrow when forming the respective orifices in an orifice plate with press work. <P>SOLUTION: According to the method, when forming respective recesses of different inclination angles to a nozzle axis 15b in a spherical part 30 of the orifice plate 15, if there is a relationship 0.25D&le;Lmin&lt;0.5D between the minimum wall thickness Lmin on a downstream side of adjoining ones of the recesses and the aperture diameter D, the recesses 544, 555 are formed by repeating a pressing process multiple times to one and the other recess forming positions for respectively forming parts of the recesses so that a relationship between a punch driving-in depth Y and the aperture diameter D is Y&le;0.3D, and then the same conditions are applied when opening bottom portions 544s, 555s to form the orifices, and the respective orifices are formed by repeating the pressing process multiple times for respectively forming a part of the orifices. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an orifice processing method for precisely forming a plurality of orifices, which serve as fuel injection holes in a fuel injection valve used in an internal combustion engine of an automobile, with respect to an orifice plate by pressing.

  Conventionally, when a plurality of orifices are formed by press working on the orifice plate, the fuel injection valve is formed on the curved surface portion that protrudes from the bottom of the recessed opening formed on one surface side of the orifice plate. After a plurality of recesses having different inclination angles from the central axis are formed by pressing, the bottoms of the respective recesses are opened based on the pressing to form the basic shapes of the plurality of orifices substantially concentrically. The technique is universal. Each orifice itself has a seat surface (valve seat) by removing the other side of the curved surface of the orifice plate (substantially concentric with the one side before pressing) into a substantially conical shape. Is formed so that the upstream side is opened and penetrated.

  As a well-known technique for forming an orifice on the curved surface portion of such an orifice plate based on press working, for example, one of the orifice plates can be easily processed so that an orifice deflected in one direction or multiple directions can be easily processed. A flat part is formed in the spherical part of the surface, and an orifice is formed in the flat part, and has a punch bending reduction function for forming an initial concave part necessary for forming the orifice and an adjustment function of the orifice length with respect to the concave part. “Processing method of injection valve and orifice” (refer to Patent Document 1), and further, in order to process the same orifice as in Patent Document 1, for the recessed portion, a second recessed portion that opens the orifice, The first concave portion having a large diameter and opening to the curved surface portion has a two-stage configuration, and the punch concave reduction function is provided in the formation of the first concave portion, so that the second concave portion Etc. gave an orifice length adjustability to the forming "processing method of the injection valve and orifice" (see Patent Document 2).

JP 2007-77843 A JP 2008-101499 A

  The orifice forming technology based on the press working on the curved surface portion of the orifice plate according to Patent Document 1 or Patent Document 2 described above, when the strength of the orifice plate member decreases during the formation of the orifice or the recessed portion, the other orifice or recessed portion. Since it is not considered to deform adjacent orifices or recesses due to plastic flow during press forming, the more the number of orifices increases and the distance between adjacent ones becomes narrower, the more difficult the press work is. As a result, there is a problem that the degree of freedom in designing the orifice (the number of holes, the inclination angle, the interval, etc.) with respect to the curved surface portion of the orifice plate having a standardized dimension is limited.

  In particular, if the inclination angle of the orifice with respect to the central axis of the fuel injection valve is made different for each orifice so that the orifice has directivity in a desired direction, the distance between the specific recesses or between the recesses and the orifices is increased. It becomes small and it becomes easy to deform | transform a recessed part or a recessed part and an orifice at the time of press work. If the concave portion or the orifice is deformed in this manner, a structure in which the spraying direction, which is the target position of spraying, is shifted is caused, which is a problem.

  The present invention has been made to solve such problems, and its technical problem is to form a plurality of orifices on an orifice plate by pressing, even if the interval between adjacent ones is very narrow. Another object of the present invention is to provide an orifice processing method capable of suppressing the deformation as much as possible and forming an orifice precisely with a high yield.

  In order to achieve the above technical problem, one of the orifice machining methods of the present invention is to form a plurality of orifices based on press machining so that the inclination angle from the central axis of the fuel injection valve differs with respect to the orifice plate. When there is a relationship of 0.25D ≦ Lmin <0.5D between the minimum thickness Lmin on the downstream side of adjacent ones of the plurality of orifices and the dimension D of the diameter, one orifice forming position The first pressing step for forming a part of the orifice so that the relationship between the punch indentation depth Y and the diameter D is Y ≦ 0.3D, and the punch indentation depth with respect to the other orifice formation position A second pressing step for forming a part of the orifice so that the relationship between the height Y and the diameter D is Y ≦ 0.3D. And forming the basic shape of which fits Ri.

  In this orifice processing method, the first pressing step and the second pressing step are performed continuously after the orifice plate blank is chucked without releasing the chuck, and the orifice plate blank has a carbon content. It is preferably 0.25% or more martensitic stainless steel, and the hardness after quenching is HRC52 or more.

  Another method of machining an orifice according to the present invention is to provide a fuel injection valve with respect to a curved surface portion of an orifice plate having a curved surface portion protruding in a convex shape from the bottom of a recessed opening formed on one surface side. A plurality of concave portions having different inclination angles from the central axis are formed by pressing, and the basic shapes of the plurality of orifices are formed substantially concentrically by opening each of the bottom surfaces of the plurality of concave portions based on the pressing. In the case where there is a relationship of 0.25D ≦ Lmin <0.5D between the minimum thickness Lmin on the downstream side of adjacent ones of the plurality of recesses and the dimension D of the diameter, one recess A first pressing step for forming a part of the recess so that the relationship between the punch indentation depth Y and the aperture dimension D is Y ≦ 0.3D with respect to the formation position, and the punch with respect to the other recess formation position. Push A second pressing step for forming a part of the recess so that the relationship between the depth Y and the diameter D is Y ≦ 0.3D, and the adjacent one of the plurality of recesses is repeated a plurality of times. It has the procedure which forms.

  In the orifice processing method, after the first pressing step and the second pressing step are repeated to form all of the plurality of concave portions required for forming the plurality of orifices by press processing, the bottom portions of the plurality of concave portions are respectively formed. When there is a relationship of 0.25D ≦ Lmin <0.5D between the minimum thickness Lmin on the downstream side of adjacent ones of the plurality of orifices formed by opening and the dimension D of the diameter, A third pressing step for forming a part of the orifice so that the relationship between the punch indentation depth Y and the bore size D is Y ≦ 0.3D with respect to the orifice forming position, and the other orifice forming position. A fourth pressing step of forming a part of the orifice so that the relationship between the punch indentation depth Y and the diameter D of Y ≦ 0.3D is repeated a plurality of times, It is preferred to have a procedure for forming a basic shape of the adjacent ones of the orifice.

  In any of the above-described orifice processing methods, the curved surface portion of the orifice plate is preferably a spherical shape.

  Furthermore, in any one of the above orifice processing methods, the first pressing step, the second pressing step, the third pressing step, and the fourth pressing step are performed by releasing the chuck after chucking the blank of the orifice plate. It is preferable to carry out the process continuously.

  In addition, in the above-mentioned orifice processing method, the orifice plate blank is preferably martensitic stainless steel having a carbon content of 0.25% or more, and the hardness after quenching is preferably HRC52 or more.

  According to the present invention, when a plurality of orifices are formed on the orifice plate by press working, those having a very small interval between adjacent ones are distributed a plurality of times by distributing the pressing process. Deformation can be suppressed as much as possible at the time of formation, and the orifice design freedom (number of holes, angle of inclination, spacing, etc.) and ease of processing are improved and the orifice that determines the desired injection direction is more accurate than ever before. A highly formed orifice plate can be manufactured with high yield.

It is sectional drawing in the vertical direction which showed the whole structure of the fuel injection valve provided with the orifice plate which has each orifice formed by the orifice processing method of this invention. It is the perspective view which showed the detailed structure of the orifice plate with which the fuel injection valve shown in FIG. 1 was equipped. It is sectional drawing of the orifice plate in the AA sectional view direction of FIG. The orifice plate in the BB line direction of FIG. 2 is shown to explain the formation of the first recess by one execution of the first press step and the second press step that bear the first half of the orifice processing method of the present invention. It is a partial expanded sectional view. 2 is a partial enlarged view of the orifice plate in the direction of the line B-B shown in FIG. 2 for explaining the formation of the recesses by performing the first press step and the second press step, which are the first half of the orifice processing method of the present invention, twice. It is sectional drawing. FIG. 6 is a partial enlarged cross-sectional view of the orifice plate in the direction of the line BB in FIG. 2 for explaining a state when the concave portion in the state shown in FIG. 5 is formed by a single pressing step. For the recess machining shown in order to explain the formation of the recess in the spherical portion of the orifice plate by the first press process and the second press process that bear the first half of the orifice processing method of the present invention described in FIGS. It is a partial expanded sectional view of the principal part using a punch, die | dye, and a collect chuck. The punch, die, and collect chuck for orifice processing shown to explain the formation of the orifice with respect to the bottom surface portion of the concave portion of the orifice plate by the third and fourth press steps that bear the latter half of the orifice processing method of the present invention It is a partial expanded sectional view of the principal part using these.

  Below, the orifice processing method of this invention is demonstrated in detail with reference to drawings.

  FIG. 1 is a longitudinal sectional view showing the overall configuration of a fuel injection valve including an orifice plate 15 having orifices 54, 55, 56, 57 formed by the orifice processing method of the present invention.

  This fuel injection valve is used to inject fuel such as gasoline into an automobile engine. The fuel injection valve body 1 includes a magnetic circuit including a core 2, a yoke 3, a housing 4, and a mover 5, and a magnetic circuit. A coil 6 for exciting the circuit and a terminal bobbin 7 for energizing the coil 6 are provided. A seal ring 8 is coupled between the core 2 and the housing 4 to prevent a fluid such as fuel from flowing into the coil 6.

  Valve parts are housed inside the housing 4. Specifically, a movable element 5, a nozzle 9, and a ring 10 for adjusting the stroke amount of the movable element 5 are arranged. The movable element 5 is obtained by connecting the valve body 11 and the movable core 12 with a joint 13. The movable element 5 is bound between the movable core 12 and the joint 13 when the movable element 5 is closed in cooperation with the pipe 18. The plate 14 which suppresses is provided.

  The housing 4 and the nozzle 9 constituting the outer cover member cover the periphery of the movable element 5 in a state where the mounting portion 9b of the nozzle 9 is assembled inside the housing 4. The nozzle 9 includes a seat surface (valve seat) 15a having a conical surface at the tip and an orifice plate 15 having orifices 54 to 57, and another guide plate 17 that slidably guides the movable element 5 together with the guide plate 16. Is provided. Here, the orifice plate 15 and the guide plate 17 may be configured separately from the nozzle 9 or may be configured integrally.

  Inside the core 2 is a spring 19 that presses the valve body 11 against the seat surface 15a via the pipe 18 and the plate 14, an adjuster 20 that adjusts the pressing load of the spring 19, and a filter 21 that prevents entry of contaminants from the outside. Is arranged.

  In addition, in the state shown in FIG. 1, the end surface 2a of the core 2 and the end surface 12a of the movable core 12 are in contact with each other, and the fuel such as gasoline passes from the fuel path 13a of the joint 13 through the passage 9a around the valve body 11 in the nozzle 9. Flows to the seat surface 15a of the orifice plate 15 through the passages 17a and 17c formed so as to be connected to the inside of the side wall 17b of the guide plate 17.

  The operation of this fuel injection valve will be briefly described below. When the coil 6 is energized, the mover 5 is attracted in the direction of the core 2 against the urging force of the spring 19, and the valve seat portion 11 a at the tip of the valve body 11 coupled to the mover 5 and the seat of the orifice plate 15. A gap is formed between the surface 15a and the valve is opened.

  In this open state, the pressurized fuel enters the nozzle 9 from the core 2, the adjuster 20, and the pipe 18 through the fuel passage 13 a of the joint 13 in the mover 5, and passes through the passage 16 a of the guide plate 16 and the nozzle 9. The passage 9a enters the passages 17a and 17c of the guide plate 17 and is injected from the gap between the valve seat portion 11a and the seat surface 15a through the orifices 54 to 57 of the orifice plate 15. Incidentally, the orifices 54 to 57 here are formed at different angles in the direction deflected with respect to the central axis of the fuel injection valve.

  Further, when the energization of the coil 6 is interrupted (current is interrupted), the movable element 5 is bent by the urging force of the spring 19 and moves away from the core 2, and the valve element 11 coupled to the movable element 5 is moved. The valve seat portion 11a at the tip comes into contact with the seat surface 15a, and the gap between the valve seat portion 11a and the seat surface 15a is closed and the valve is closed.

  FIG. 2 is a perspective view showing a detailed configuration of the orifice plate 15 provided in the fuel injection valve. 3 is a cross-sectional view of the orifice plate 15 in the cross-sectional direction along the line AA in FIG.

  The detailed configuration of the orifice plate 15 and the orifices 54 to 57 will be described below with reference to FIGS.

  The orifice plate 15 here is made of a substantially disk-shaped metal plate, and a spherical surface portion 30 that is a curved surface portion protruding in a convex shape from the bottom of the recessed opening is formed at a substantially central portion on one surface side. A seat surface 15 a having a substantially conical shape constituting a valve seat is provided on the other surface side opposite to the spherical surface portion 30.

  A plurality of (here, four) recesses 544, 555, 566, and 577 having different inclination angles θ from the nozzle axis 15b indicating the central axis of the fuel injection valve are formed in the spherical portion 30 here by pressing. At the same time, a plurality of (four in this case) orifices for injecting fuel substantially concentrically by opening the bottom surfaces of the recesses 544, 555, 566, and 577 on the downstream side based on press working. 54-57 basic shapes are formed, and further, the other surface side, which is substantially concentric with one surface side, is processed into a substantially conical shape before pressing to form the sheet surface 15a. Openings are formed in the orifices 54 to 57 on the upstream side.

  In the example shown in FIG. 3, the inclination angle θ from the nozzle axis 15b to the recess 544 having a diameter φ of D and the axis 54i of the orifice 54 is closer to the recess 566 having the diameter φ of D from the nozzle axis 15b to the axis 56i of the orifice 56. It is formed in the direction in which the inclination angle θ increases, that is, the direction in which the axes 54i and 56i of the orifices 54 and 56 are deflected.

  Here, the inclination angle θ is different for each of the orifices 54 to 57, and the orifices 54 to 57 are formed so as to be directed in desired directions, respectively. Of course, the inclination angle θ is formed to be the same. May be included.

  Incidentally, the above-described valve body 11 has a substantially conical shape so that the tip portion thereof contacts the seat surface 15a on the upstream side of the orifices 54 to 57 and closes the orifices 54 to 57 or opens away. It has become.

  Referring to FIG. 2, regarding the downstream side wall thickness L of the adjacent ones of the recesses 544, 555, 566, and 577, the thicknesses of the recesses 555 and 566 are expressed as L 1, and the recesses 544 and 555. When the thickness is L2, the thickness between the concave portion 544 and the concave portion 577 is L3, and the thickness between the concave portion 566 and the concave portion 577 is L4, the relationship with the dimension D of the diameter φ of each of the concave portions 544, 555, 566, and 577 , D <L1, 0.25D ≦ L2 <0.5D, D <L3, and D <L4 are satisfied. Here, the thickness L2 between the recess 544 and the recess 555 is the minimum thickness Lmin.

  The orifices 54 to 57 have openings on the outlet side in the bottom surface portions 544s, 555s, 566s, and 577s of the concave portions 544, 555, 566, and 577 formed on the spherical surface of the convex spherical surface portion 30, and the seat surface 15a. An opening on the inlet side is provided on the substantially conical surface to be formed.

  The lengths of the orifices 54 to 57 are highly sensitive to the length of the penetration, and the lengths can be set optimally by changing the depths (steps) of the recesses 544, 555, 566, and 577 as appropriate. As a result, the spray shape can be optimized, and the workability can be facilitated. Therefore, the orifices 54 to 57 are formed so that the depth is different between at least two of the recesses 544, 555, 566, and 577. Yes. In such a case, it is not necessary to change the thickness of the tip 15c of the orifice plate 15, so that the rigidity of the orifice plate 15 does not decrease. Therefore, it is suitable for a high fuel pressure type injection valve of 10 MPa or more in which the pressure applied to the tip 15c of the orifice plate 15 is large.

  As described above, by forming the orifices 54 to 57 at different angles in the direction deflected with respect to the nozzle axis 15b, the fuel can be injected in any direction. Therefore, various manufacturers can be obtained by changing the injection direction. Various spray patterns corresponding to the combustion concept matched to the engine specifications can be formed. If injection is performed avoiding the intake valve and fuel is collected around the spark plug, the fuel can be uniformly injected into the combustion chamber, and an air-fuel mixture can be formed extremely ideally without impairing atomization.

  By the way, in the form in which the inlets of the orifices 54 to 57 are opened to the valve seat surface (seat surface 15a) of the orifice plate 15, the orifices are processed as compared with the case where the orifices are formed on a thin and uniform plate member. The thickness of the member increases. In particular, the opening serving as the inlet of the orifice is arranged on the circumference centered on the nozzle axis 15b (coincided with the central axis of the fuel injection valve), and the inclination angle θ of the orifices 54 to 57 with respect to the nozzle axis 15b is made different between each other. In this case, the openings serving as the outlets of the orifices 54 to 57 do not line up on the circumference around the nozzle axis 15b. In such a case, the distances penetrating the orifices 54 to 57 are different for each of the orifices 54 to 57, and as a result, the lengths of the orifices 54 to 57 are different.

  Therefore, in such a form, it becomes important to make the lengths of the orifices 54 to 57 constant by changing the depths of the recesses 544, 555, 566, and 577 in particular. That is, the lengths of the orifices 54 to 57 are determined according to the desired spray shape, and the depths of the recesses 544, 555, 566, and 577 are determined accordingly.

  In general, when a large number of orifices are formed on the orifice plate 15 by pressing, when the minimum wall thickness L on the downstream side of each recess is equal to or less than the dimension D of the diameter φ of each recess, it is adjacent to each recess. Matching materials are easily deformed by plastic flow. In particular, if the inclination angle θ with respect to the nozzle axis 15b is made different for each of the orifices 54 to 57 and the respective orifices 54 to 57 are directed in a desired direction, the deformation easily occurs between specific recesses. In such a case, it is difficult to freely change the aperture of the recesses 544, 555, 566, and 577, the depth of the recesses 544, 555, 566, and 577, and the inclination angle θ of the recesses 544, 555, 566, and 577.

  Therefore, in the orifice processing method of the present invention, 0.25D ≦ Lmin ≦ 0.5D is established between the minimum thickness Lmin on the downstream side of each recess formed in the orifice plate 15 and the dimension D of the diameter φ of each recess. When the relationship is established, the above-mentioned problem is solved by performing the press forming for forming the orifice in several times. As a result, it is possible to form recesses and orifices that have high machining accuracy, are easy to machine, and have a high degree of design freedom.

  The technical summary of the orifice processing method of the present invention will be described below.

  FIG. 4 is a cross-sectional view taken along the line B- of FIG. 2 for explaining the formation of the first recesses 544a and 555a by one execution of the first press process and the second press process that bear the first half of the orifice processing method of the present invention. It is a partial expanded sectional view of the orifice plate 15 in the B line direction. Further, FIG. 5 is also shown in FIG. 2 for explaining the formation of the recesses 544 and 555 by performing the first pressing process and the second pressing process twice, which are responsible for the first half of the orifice processing method of the present invention. It is a partial expanded sectional view of the orifice plate 15 in the BB line direction.

  Here, in the first recess 555a and the recess 555, the thickness L2 between the first recess 544a and the recess 544 is the minimum thickness Lmin, and 0.25D ≦ Lmin between the diameter D of the diameter φ. A relationship of ≦ 0.5D is established. In addition, the blank before press-working the orifice plate 15 has a bowl-shaped concave portion 30 a formed on the other surface side opposite to the spherical surface portion 30.

  Therefore, referring to FIG. 4, in the first pressing step, the cutting edge 43 a of the punch 43 for recess processing is formed with respect to the position where one shallow first recess 544 a is formed in the spherical portion 30 of the orifice plate 15. Is pressed along the axis 54i, and the first recess 544a that is a part of the recess 544 is formed such that the relationship between the punch pressing depth Y and the diameter D is Y ≦ 0.3D by the first press working. In the same manner, the other shallow first concave portion 555a in the spherical surface portion 30 of the orifice plate 15 is pressed against the formation position with the blade edge portion 43a of the punch 43 along the axis 55i, and the first time. A second press that forms a first recess 555a that is a part of the recess 555 so that the relationship between the punch indentation depth Y and the diameter D is Y ≦ 0.3D by pressing. To implement the degree. Here, the bottom surface portion 544as of the first recess 544a and the bottom surface portion 555as of the first recess 555a are formed with substantially the same depth.

  At this time, since the rigidity of the inter-hole thick portion 70a between the first recess 544a and the first recess 555a has a sufficient margin against the pressure due to the plastic flow of the press working, the first recess 555a is formed. The first recess 544a is hardly deformed. In addition, low-profile raised portions 544ae and 555ae are formed along the axis lines 54i and 55i in the bowl-shaped recess 30a on the other surface side opposite to the spherical surface portion 30. Note that the volume 555av is displaced by one press working of the first recess 555a.

  Further, referring to FIG. 5, in the first pressing step, the blade edge portion 43a of the punch 43 is again pressed along the axis 54i against the bottom surface portion 544as of the one shallow first recess 544a. After forming the concave portion 544 so that the relationship between the punch indentation depth Y and the diameter D is Y ≦ 0.3D by the second pressing, the other shallower portion of the spherical portion 30 of the orifice plate 15 is similarly formed. The relationship between the punch indentation depth Y and the caliber dimension D is determined by the second press working by pressing the blade edge 43a of the punch 43 again along the axis 55i against the bottom surface portion 555as of the first recess 555a. A second pressing step for forming the recess 555 so as to satisfy Y ≦ 0.3D is performed. Here, the bottom surface portion 544s of the concave portion 544 and the bottom surface portion 555s of the concave portion 555 are also formed with substantially the same depth.

  At this time, since the rigidity of the thick portion 70 between the recesses 544 and the recess 555 has a sufficient margin against the pressure due to the plastic flow of the press working, the recess 544 hardly deforms when the recess 555 is formed. In addition, raised portions 544e and 555e that are slightly raised along the axis lines 54i and 55i are formed in the bowl-shaped recess 30a on the other surface side opposite to the spherical surface portion 30. In the second press working of the recess 555a, the volume 555bv is pushed away.

  The above describes the case where the concave portions 544 and 555 are formed by repeating the first press processing and the second press processing twice. However, when the desired depth is not reached by two repetitions, the concave portions 544 and 555 are formed. The above procedure should be repeated until the desired depth is reached.

  6 is a partially enlarged cross-sectional view of the orifice plate 15 in the direction of the line BB in FIG. 2 for explaining the state when the recesses 544 and 555 in the state shown in FIG. 5 are formed by a single pressing process. It is.

  Referring to FIG. 6, in the first pressing step, the cutting edge portion 43 a of the punch 43 is pressed along the axis 54 i against the position where the one concave portion 544 is formed in the spherical portion 30 of the orifice plate 15. After the concave portion 544 is formed by pressing, the blade tip portion 43a of the punch 43 is similarly pressed along the axis 55i against the position where the other concave portion 555 is formed in the spherical portion 30 of the orifice plate 15. A second pressing step for forming the recess 555 by pressing is performed.

  Here, when the concave portion 544 and the bulging portion 544e are formed and pressed along the axis 55i with the blade edge portion 43a of the punch 43 against the position where the concave portion 555 of the spherical surface portion 30 is formed, most of the punch 43 is displaced. Although it flows into the bowl-shaped recess 30a to form the swelled portion 555e, a part of it flows in the radial direction or on the rear side opposite to the bowl-shaped recess 30a. At this time, if the rigidity of the inter-hole thick portion 70 is low and the amount of plastic flow during press working is large, the pressure of the plastic flow during press working deforms the adjacent recess 544 as shown in FIG. End up.

  Since the depth of the concave portion 544 is deeper than that of the first concave portion 544a described with reference to FIG. 4, the inter-hole thick portion 70 when the concave portions 544 and 555 are formed by a single press working has two concave portions 544 and 555. The rigidity is lower than that of the thick portion 70a between the holes when formed by press working dividedly. In addition, when the concave portions 544 and 555 are formed by pressing at one time, the volume 555v to be pushed away by the punch 43 is the first pressing step when the concave portions 544 and 555 are formed by pressing into two times. And the volume 555av displaced by the first execution of the second press process and the volume 555bv displaced by the second execution of the first press process and the second press process are large, and therefore the amount of plastic flow is large. .

  For this reason, when the recess 555 is formed, the inter-hole thick portion 70 between the recess 544 and the recess 555 cannot withstand the pressure due to the plastic flow of the press working, and the deformed portion 60 is generated in a part on the downstream side of the recess 544, In such a state, it becomes a factor which inhibits the homogenization of spray.

  By the way, even if the orifice processing method of the present invention described with reference to FIGS. 4 and 5 is applied, depending on the direction of the hole (the direction of the recesses 544, 555, 566, 577), The pressure due to plastic flow may increase remarkably, and it may happen that the generation of the deformed portion 60 cannot be prevented. However, since the amount of deformation is as small as 0.01 or less in cylindricity, the spray is almost homogeneous. It will not inhibit the conversion.

  By the way, with respect to the other recesses 566 and 577 shown in FIG. 2, the thickness of the inter-hole thick portion 70 is larger than the dimension D of the diameter φ, and the rigidity of the inter-hole thick portion 70 is high. You can set timely.

  In any case, after the concave portions 544, 555, 566, and 577 are formed, the basic shapes of the orifices 54 to 57 are formed by pressing the bottom surface portions 544s, 555s, 566s, and 577s. At this time, when there is a relationship of 0.25D ≦ Lmin <0.5D between the minimum thickness Lmin on the downstream side of adjacent ones of the orifices 54 to 57 and the dimension D of the diameter, in the case of forming a recess Similarly, the third pressing step for forming a part of the orifice so that the relationship between the punch indentation depth Y and the bore size D is Y ≦ 0.3D with respect to one orifice forming position, and the other A fourth pressing step of forming a part of the orifice so that the relationship between the punch indentation depth Y and the bore size D is Y ≦ 0.3D with respect to the orifice forming position, and The basic shape of the adjacent ones of the orifices 54 to 57 (orifices 54 and 55) is formed by repeating the third pressing step and the fourth pressing step a plurality of times.

  Hereinafter, a manufacturing procedure of the orifice plate 15 shown in FIGS. 2 and 3 will be described with reference to FIGS. 7 and 8. FIG. 7 shows recesses 544, 555, 566, and 577 with respect to the spherical surface portion 30 of the orifice plate 15 in the first press step and the second press step described in FIGS. 4 and 5 that bear the first half of the orifice processing method of the present invention. FIG. 4 is a partial enlarged cross-sectional view of a main part using a recess processing punch 43, a die 41, and a collect chuck 42 shown to explain the formation of the concave portion; Further, FIG. 8 shows the bottom surface portions 544s, 555s, 566s, and 577s of the recesses 544, 555, 566, and 577 of the orifice plate 15 in the third and fourth pressing steps that bear the latter half of the orifice processing method of the present invention. 5 is a partial enlarged cross-sectional view of a main part using the orifice machining punch 45, the die 41, and the collect chuck 42 shown to explain the formation of the orifices 54 to 57.

  Referring to FIG. 7, when producing the orifice plate 15, first, a blank before pressing the orifice plate 15 is set on the upper surface of the die 41, and the punch 43 is formed while the outer diameter is firmly held by the collet chuck 42. The positions of the concave portions 544, 555, 566, and 577 in the spherical portion 30 are pressed by the cutting edge portion 43a and pressed, and the first pressing step and the second pressing step described above are repeated a plurality of times to form a bag hole shape. The recesses 544, 555, 566, and 577 are formed by extrusion. FIG. 7 shows a state in which the recess 566 is formed by pressing.

  At this time, swelled portions 544e, 555e, 566e, and 577e are formed on the flange-shaped recess 30a side toward the inside. The recesses 544, 555, 566, and 577 are preferably those that work harden the surface as they are pressed. In this manner, the concave portions 544, 555, 566, and 577 having good surface roughness can be obtained by forming the concave portions 544, 555, 566, and 577 by pressing.

  Referring to FIG. 8, after all the recesses 544, 555, 566, and 577 are formed, the bottom surface portion 544 s of the recesses 544, 555, 566, and 577 is held with the blank of the orifice plate 15 held by the collet chuck 42. With respect to 555s, 566s, and 577s, the cutting edge portion 45a of the other punch 45 having a smaller diameter than the cutting edge portion 43a of the punch 43 is pressed in a direction perpendicular to them, and the third pressing step described above is performed. The fourth pressing step is repeated a plurality of times, and the orifices 54 to 57 are extruded into a bag hole shape and formed into a bag hole shape. FIG. 8 shows a state where the orifice 56 is formed by press working.

  At this time, raised portions 54f, 55f, 56f, and 57f are formed on the side of the bowl-shaped concave portion 30a so as to be larger than the raised portions 544e, 555e, 566e, and 577e. In this manner, the orifice plate 15 is divided into a plurality of press processes to form the orifices 54 to 57, thereby forming the bottom surface portions 544s, 555s, and 566s of the recesses 544, 555, 566, and 577 as shown in FIG. An orifice plate 15 having a structure in which orifices 54 to 57 are provided in 577 s is manufactured.

  Since the blank of the orifice plate 15 here is held by the collet chuck 42, the concave portions 544, 555, 566, and 577 and the orifices 54 to 57 and their centers are based on the positioning holes that are schematically shown. Processing can be performed with good positional accuracy and coaxiality so that the axes 54i, 55i, 56i, and 57i are substantially straight. Further, the orifices 54 to 57 can be processed into a fully sheared surface by being pressed into a bag hole shape, and the surface roughness can be remarkably improved. Here, since the raised portions 544e, 555e, 566e, and 577e are formed when the concave portion is formed, the tensile force of the material exerted by the cutting edge portion 45a of the punch 45 even when the punch 45 is inserted to the inside of the bowl-shaped concave portion 30a. The swelled portions 544e, 555e, 566e, and 577e are not broken, and the orifices 54 to 57 can be formed on the entire shear surface, thereby suppressing spray variation.

  Finally, the raised portions 54f, 55f, 56f, and 57f formed on the other surface side opposite to the spherical portion 30 by forming the orifices 54 to 57 in the shape of the bag holes are substantially conical as shown in FIG. The sheet surface 15a (valve seat) is deleted so that the orifices 54 to 57 penetrate to the seat surface 15a side. The machining method here is preferably performed by turning or electric discharge machining, whereby the orifices 54 to 57 can be formed on the entire shear surface.

  By the way, the flow rate when the fuel is at a constant pressure has a high sensitivity of the orifice diameter, and accurate management of the hole diameter is necessary for flow rate management. According to the present embodiment, management of the hole diameter is easy because it is only necessary to manage the punch diameter. On the other hand, the orifice formed by punching process has a large hole diameter in the fracture surface and the length of the fracture surface varies, so that it is difficult to manage the hole diameter as compared with the orifice plate 15 produced in this embodiment. It is. In addition, when the orifice is formed by electric discharge machining, it is necessary to manage the machining conditions such as machining speed and voltage in addition to the management of the electrode diameter. Compared with the orifice plate 15 produced in the present embodiment, the hole is formed. It is difficult to manage the aperture.

  In this way, the concave portions 544, 555, 566, and 577 having a surface that is concentric with and substantially perpendicular to the central axes 54i, 55i, 56i, and 57i of the orifices 54 to 57 in the spherical portion 30 on the downstream side of the orifices 54 to 57. The orifices 54 to 57 having different injection directions can be easily and accurately formed by pressing. Therefore, even if the blank of the orifice plate 15 is made of martensitic stainless steel (for example, SUS420J2) having a carbon content of 0.25% or more, the orifices 54 to 57 having an aspect ratio of 1.5 or more can be easily formed by pressing. Can be formed. In addition, it is more preferable that the martensitic stainless steel having a carbon content of 0.25% or more has a hardness after quenching of HRC52 or more.

  In addition, by optimizing the processing order of the orifices 54 to 57, the downstream side of the recesses 544, 555, 566, and 577 is not deformed. In addition to avoiding a situation in which a streak enters, it is also possible to avoid a situation in which the fuel hitting the deformed portion 60 of the recesses 544, 555, 566, and 577 drops into the cylinder of the engine and foreign matter such as carbon is generated.

  Furthermore, since the outlets of the orifices 54 to 57 are perpendicular to the axes 54i, 55i, 56i, and 57i of the orifices 54 to 57, the fluid injection timing is the same all around, and the axis of the injection valve (nozzle axis 15b) Even if the orifices 54 to 57 are deflected, the penetration length can be made uniform, and the spray homogeneity can be improved.

  In addition, since the concave portions 544, 555, 566, and 577 and the orifices 54 to 57 can be formed by press working, the surface roughness can be improved as compared with, for example, those in which the orifice is formed by electric discharge machining or cutting. . As a result, it is possible to reduce the adhering of combustion debris such as carbon produced by combustion of fuel during in-cylinder injection to the recesses 544, 555, 566, and 577 and the orifices 54 to 57, and atomization and shape of the spray.・ Position accuracy can be improved.

  For example, in an actual vehicle running test of a gasoline vehicle, the fuel injection valve using the orifice plate 15 in which the orifices 54 to 57 are formed by electric discharge machining has a burnt residue of the recesses 544, 555, 566, 577 and the orifice when traveling at 30,000 km. It has been experimentally found that it adheres to 54-57, which reduces the flow rate by 15%. On the other hand, when the orifice plate 15 manufactured in this embodiment is used, the concavities 544, 555, 566, and 577 and the orifices 54 to 57 have good concentricity and surface roughness. It was found that adhesion to 544, 555, 566 and 577 and the orifices 54 to 57 can be reduced, and the change in flow rate is suppressed to 1.7% or less.

  In addition, the recesses 544, 555, 566, and 577 and the orifices 54 to 57 are formed by pressing while the blank of the orifice plate 15 is chucked, so that the orifice 54 deflected with respect to the axis of the injection valve (nozzle axis 15b). ~ 57 can be easily and elaborately formed without the need for alignment.

  Further, the method of forming the orifices 54 to 57 by press working according to the present embodiment can reduce the machining time per hole to about 1/30 compared with the method of forming the orifices 54 to 57 by electric discharge machining. The capital investment can be suppressed, and the orifice plate 15 can be produced at a lower cost than in the case of electric discharge machining.

  The embodiment of the orifice processing method of the present invention has been specifically described above with reference to FIGS. 2 to 8, but the present invention relates to the recesses 544, 555, 566, 577 and the orifice 54 provided in the orifice plate 15. It is not limited to what was disclosed including the number and shape of -57.

  For example, in the above-described embodiment, the structure in which the recesses 544, 555, 566, and 577 are provided in a single stage has been described. However, the recess has a first recess that opens in the curved surface portion (spherical surface portion 30) and a second that opens the orifice. The first concave portion has a larger diameter than the second concave portion, and the first concave portion has a shallower depth than the second concave portion. May be formed.

  In the above-described embodiment, the formation region in which the recesses 544, 555, 566, and 577 are formed is described as the spherical portion 30, but the formation region may have a curved shape other than the spherical surface.

  Further, in the above-described embodiment, the case where the orifices 54 to 57 are formed by extrusion processing has been described. However, after the orifices 54 to 57 are formed by punching, the sheet surface 15a is deleted or formed by electric discharge machining from the upstream side. At this time, the fracture surfaces of the orifices 54 to 57 may be deleted, and the orifices 54 to 57 may be formed on the entire shear plane.

  In addition, in the above-described embodiment, the orifices 54 to 57 are formed by pressing the bottom surface portions 544s, 555s, 566s, and 577s of the concave portions 544, 555, 566, and 577 formed in the spherical surface portion 30 of the orifice plate 15. However, if the blank of the orifice plate 15 is hard and thin, and the curved surface is slightly flat, the inclination from the central axis (nozzle axis 15b) of the fuel injection valve with respect to the orifice plate 15 is explained. It is also possible to form each orifice directly based on pressing so that the angle θ is different. However, also here, when there is a relationship of 0.25D ≦ Lmin <0.5D between the downstream minimum wall thickness Lmin and the diameter D of adjacent ones of the orifices, one orifice forming position The first pressing step for forming a part such that the relationship between the punch pressing depth Y and the diameter D is Y ≦ 0.3D, and the punch pressing depth Y with respect to the other orifice forming position The basic shape of the adjacent ones of the orifices may be formed by repeating the second pressing step for forming a part so that the relationship between the diameter D and the diameter D satisfies Y ≦ 0.3D.

  Even in such a case, if the first pressing step and the second pressing step are continuously performed without releasing the chuck after the blank of the orifice plate 15 is chucked, the deformation in the adjacent ones when forming each orifice. Can be prevented, and the degree of freedom in design (number of holes, inclination angle, interval, etc.) of each orifice can be increased. Incidentally, the blank of the orifice plate 15 is also made of a martensitic stainless steel having a carbon content of 0.25% or more, and it is desirable that the hardness after quenching is HRC52 or more.

DESCRIPTION OF SYMBOLS 1 Injection valve main body 15 Orifice plate 15a Sheet surface 30 Spherical surface part 41 Die 42 Collet chuck 43, 45 Punch 43a, 45a Cutting edge part 54, 55, 56, 57 Orifice 60 Deformation part 544, 555, 566, 557 Recessed part 544a, 555a, 566a, 577a First recess

Claims (8)

In an orifice processing method for forming a plurality of orifices based on press processing so that the inclination angle from the central axis of the fuel injection valve differs with respect to the orifice plate,
When there is a relationship of 0.25D ≦ Lmin <0.5D between the minimum wall thickness Lmin on the downstream side of adjacent ones of the plurality of orifices and the dimension D of the diameter, with respect to one orifice forming position The first pressing step of forming a part of the orifice so that the relationship between the punch pressing depth Y and the diameter D is Y ≦ 0.3D, and the punch pressing depth with respect to the other orifice forming position. The second pressing step of forming a part of the orifice so that the relationship between the length Y and the diameter D of the aperture satisfies Y ≦ 0.3D, and a plurality of the basic orifices that are adjacent to each other. An orifice machining method characterized by forming a shape.   2. The orifice processing method according to claim 1, wherein the first press step and the second press step are continuously performed without releasing the chuck after chucking the blank of the orifice plate. Orifice processing method.   The orifice processing method according to claim 2, wherein the blank of the orifice plate is martensitic stainless steel having a carbon content of 0.25% or more, and hardness after quenching is HRC52 or more. Processing method. Pressing a plurality of recesses with different inclination angles from the central axis of the fuel injection valve with respect to the curved surface portion of the orifice plate having a curved surface portion protruding in a convex shape from the bottom of the recessed opening formed on one surface side In the orifice processing method of forming the basic shape of the plurality of orifices substantially concentrically by opening each of the bottom surfaces of the plurality of recesses based on the press processing,
When there is a relationship of 0.25D ≦ Lmin <0.5D between the minimum thickness Lmin on the downstream side of adjacent ones of the plurality of recesses and the dimension D of the diameter, with respect to one recess forming position The first pressing step for forming a part of the recess so that the relationship between the punch pressing depth Y and the diameter D is Y ≦ 0.3D, and the punch pressing depth with respect to the other recess forming position. The second pressing step of forming a part of the recess so that the relationship between Y and the dimension D of the aperture is Y ≦ 0.3D is repeated a plurality of times to form adjacent ones of the plurality of recesses. An orifice processing method comprising the steps of:   5. The orifice processing method according to claim 4, wherein the plurality of concave portions required for forming the plurality of orifices are all formed by the press processing by repeating the first pressing step and the second pressing step, and then the plurality of the plurality of concave portions are formed. 0.25D ≦ Lmin <0 between the downstream minimum wall thickness Lmin and the diameter D of adjacent ones of the plurality of orifices formed so as to open to the bottom surface of the concave portion. When there is a relationship of .5D, a third press that forms part of the orifice so that the relationship between the punch indentation depth Y and the diameter D is Y ≦ 0.3D with respect to one orifice forming position. And forming a part of the orifice so that the relationship between the punch indentation depth Y and the diameter D is Y ≦ 0.3D with respect to the other orifice forming position. Orifice processing method characterized by comprising the step of the pressing step, the forming a plurality of times repeatedly basic shape of adjacent ones of the plurality of orifices.   6. The orifice processing method according to claim 4 or 5, wherein the curved surface portion of the orifice plate has a spherical shape.   The orifice processing method according to claim 5 or 6, wherein the first press step, the second press step, the third press step, and the fourth press step chuck a blank of the orifice plate. An orifice processing method, which is performed continuously without releasing the chuck later.   8. The orifice processing method according to claim 7, wherein the orifice plate blank is martensitic stainless steel having a carbon content of 0.25% or more, and hardness after quenching is HRC52 or more. Processing method.

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