JP4576369B2 - Injection valve and orifice machining method - Google Patents

Description

  The present invention relates to an injection valve for injecting a fluid, and more particularly to an orifice for measuring a flow rate, a method for processing the orifice, and an injection valve using the orifice.

  Conventionally, an orifice (injection hole) provided in a spherical portion has a press work as disclosed in Patent Document 1. The injection hole disclosed in Patent Document 1 is formed by drilling an injection hole in a flat plate by pressing or the like, and then drawing the periphery of the injection hole into a dome shape.

JP-A-7-63140

  However, the technique disclosed in Patent Document 1 is to perform a drawing process around a perforation by injection hole press or drilling. For this reason, an injection hole becomes a taper shape and cannot obtain a cylindrical orifice. Further, since the orifice is deformed into a taper during drawing, it is difficult to maintain the accuracy of the injection hole during drilling. For this reason, it is extremely difficult to obtain a highly accurate injection hole in units of μm.

  In order to solve the problems as described above, the present invention improves the spray homogeneity by providing a concave portion having a plurality of steps on the curved surface portion on the downstream side of the orifice, and forming the orifice in the concave portion. It is an object of the present invention to provide a method for processing an orifice for improving the homogeneity of an injection valve and spray.

Injector of the present invention, contact of the movably provided the valve body, and driving means for driving the valve body, a valve seat which the valve body is in contact away, and the valve body and the valve seat An injection valve constituted by a nozzle having an orifice provided downstream of the position,
A convex curved surface portion is provided at the tip of the nozzle,
The orifice is formed in a direction having an angle with respect to the axis of the nozzle,
On the downstream side of the orifice, a plurality of concave-shaped portions having different diameters are formed, and the concave-shaped portion positioned on the upstream side is smaller than the flat-surface portion formed by the bottom surface of the concave-shaped portion positioned on the downstream side. A recess formed by laminating in the direction of the central axis of the orifice is provided so as to form an opening surface,
The bottom surface of each concave-shaped part constituting the concave part is pressed so as to be substantially perpendicular to the central axis of the orifice,
The orifice is press-worked so as to form an opening surface smaller than the bottom surface of the concave portion located on the upstream side .

The orifice processing method of the present invention is an orifice processing method for ejecting fluid,
A first pressing step of forming a first concave shape portion by performing extrusion processing or half-punching processing on a convex curved surface portion formed in a blank;
A second concave shape portion having a smaller diameter than the first concave shape portion is formed by further extruding or half-punching the flat portion constituted by the bottom surface of the first concave shape portion. Pressing process,
A third press working step for forming an orifice having a diameter smaller than that of the second concave-shaped portion on the bottom surface of the second concave-shaped portion by extrusion processing, half punching processing, or punching processing;
The first press working step, the second press working step, and the third press working step are executed in this order, and the bottom surface of the first concave shape portion and the bottom surface of the second concave shape portion are It is characterized by being pressed so as to be substantially perpendicular to the central axis of the orifice .

According to the present invention, the length of the cutting blade portion of the punch that presses the first concave shape portion (the concave shape portion located on the downstream side) is larger than the diameter of the punch cutting blade portion that presses the orifice. Since it can be increased, the bending rigidity can be increased, and even if bending load is applied during processing, the punch is not broken, and a plane portion substantially perpendicular to the central axis of the orifice can be formed. Furthermore, when pressing the second concave shape part (the concave shape part located on the upstream side) in the next step and pressing the orifice, the bending edge is not applied to the cutting edge part of the punch used in each press process. Without breaking the punch, the bottom surface of the second concave shaped portion can be pressed with good coaxiality substantially perpendicular to the central axis of the orifice. Thereby, the homogeneity of spraying can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an overall configuration of an injection valve according to an embodiment of the present invention. In addition, the injection valve of a present Example is a fuel injection valve which injects fuels, such as gasoline, and is used in order to inject a fuel to the engine of a motor vehicle.

  The injection valve body 1 includes a magnetic circuit including a core 2, a yoke 3, a housing 4, and a mover 5, a coil 6 for exciting the magnetic circuit, and a terminal bobbin 7 for energizing the coil 6. 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, and a movable element 5, a nozzle 9, and a ring 10 that adjusts 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, and suppresses the bounce when the movable element 5 is closed in cooperation with the pipe 18 between the movable core 12 and the joint 13. A plate 14 is provided.

  The housing 4 and the nozzle 9 constituting the outer cover member cover the periphery of the movable element 5. The nozzle 9 is provided with an orifice plate 15 having a seat surface 15a (valve seat) and an orifice 32 at the tip, and a guide plate B17 for slidably guiding the movable element 5 together with the guide plate A16. The orifice plate 15 and the guide plate B17 may be configured separately from the nozzle 9, or may be configured by integrating them.

  A spring 19 that presses the valve element 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 contamination from the outside are disposed inside the core 2. Has been.

  Next, the operation of the injection valve body 1 will be described in detail.

  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 a gap is formed between the valve seat portion 11a at the tip of the mover 5 and the seat surface 15a (opening). Valve state). The pressurized fuel first enters the nozzle 9 from the core 2, the adjuster 20, and the pipe 18 through the fuel passage 13 a in the mover 5. Next, the fuel enters the passage 17a of the guide plate B from the fuel passage 16a of the guide plate A16 and the passage 9a of the nozzle, and is injected through the orifices 54 to 59 from the gap between the valve seat portion 11a and the seat surface 15a. The orifices 54 to 59 are formed at different angles in the direction deflected with respect to the axis of the injection valve.

  On the other hand, when the current of the coil 6 is interrupted, the valve seat portion 11a of the mover 5 is brought into contact with the seat surface 15a by the force of the spring 19, and the valve is closed.

  Next, the configuration of the orifice plate 15 and the orifices 54 to 59 of the injection valve body 1 will be described in detail.

  2 and 3 show an embodiment of the present invention. FIG. 2 is a perspective view of the orifice plate 15, and FIG. 3 is a longitudinal sectional view of the orifice plate 15.

The orifice plate 15 is made of a substantially disk-shaped metal plate, and a spherical surface portion 30 as a convex curved surface portion is integrally provided at a substantially central portion of one end surface, opposite to the spherical surface portion 30. The side end surface is provided with a substantially conical seat surface 15a having a step forming a valve seat. In this spherical surface portion 30, orifices 54, 55, 56, 57, 58, 59 for injecting fuel are formed at different angles in the direction with respect to the axis of the nozzle, that is, in the deflected direction. In the outer periphery of the spherical portion, positioning holes 31a used for positioning during assembly are provided.
31b and 31c are provided in a concave shape having a bottom at three places in the circumferential direction. Of these positioning holes 31a, 31b, and 31c, 31a and 31b are provided at opposing positions that are approximately 180 degrees apart in the circumferential direction, and 31c is provided at a substantially intermediate position between 31a and 31b in the circumferential direction. It has been. Further, the valve body 11 is provided so as to be detachable from the seat surface 15a on the upstream side of these orifices.

  As shown in FIG. 3, substantially circular recesses A54a, 55a, 56a, and 57a that form steps are formed on the side that opens to the spherical portion 30 on the downstream side of each of the orifices 54, 55, 56, 57, 58, and 59. , 58a, 59a are provided on the bottom side of the concave portion A on the side connected to the upstream orifice, the concave portions B54b, 55b, 56b, 57b, 58b, 59b having a smaller diameter than the concave portion A and substantially circular. Therefore, the concave portion has two steps as a whole. The bottom surfaces of the recesses A and B are formed so as to be substantially perpendicular to the center axis of the orifice, and the center axes of the recess A and the recess B and the center axis of the orifice are substantially aligned. It has become. The depth of the recess A is smaller than the length of the orifice, and the depth of the recess A is smaller than the depth of the recess B.

  Here, for example, in order to optimally set the length of the orifice 54 in consideration of the spray shape and workability, the depth of the recess B54b may be changed as appropriate. The same applies to the other orifices. By changing the depth of the recess B, the length of the orifice can be changed, so that the spray shape can be optimized and the workability can be improved. For this reason, at least two of the recesses B have different depths for each orifice. At this time, since it is not necessary to change the thickness of the orifice plate tip 15c, the rigidity of the orifice plate 15 is not lowered. Therefore, it is suitable for a high fuel pressure type injection valve of 10 MPa or more where the pressure applied to the orifice plate tip 15c is large.

  By doing as described above, since the outlet of the recess B and the outlet of the orifice are perpendicular to the axis of the orifice, the injection timing of the fluid is the same all around, and even the orifice deflected with respect to the axis of the injection valve The penetration length can be made uniform, and the spray homogeneity can be improved. At this time, since the depth of the recess A is sufficiently smaller than the recess B, the recess A does not affect the spraying.

  Next, a method for processing the orifice plate 15 will be described with reference to FIGS.

  FIG. 4 is a perspective view of the blank 15 '. FIG. 5 is a perspective view of an orifice plate in which positioning holes 31a are formed. FIG. 6 is a perspective view of the orifice plate in which the recess A is formed. FIG. 7 is a perspective view of the orifice plate in which the recesses A and B are formed. FIG. 8 is a perspective view of the orifice plate in which the recess A, the recess B, and the orifice are formed. FIG. 9 is a longitudinal sectional view of the blank 15 '. FIG. 10 is a longitudinal sectional view of the orifice plate in which the positioning hole 31a is formed. FIG. 11 is a longitudinal sectional view of the orifice plate in which the recess A is formed. FIG. 12 is a longitudinal sectional view of the orifice plate in which the recesses A and B are formed. FIG. 13 is a longitudinal sectional view of the orifice plate in which the recess A, the recess B, and the orifice are formed. FIG. 14 is a diagram showing a state in which the positioning hole 31a is being processed. FIG. 15 is a diagram showing a state in which the recess A is processed. FIG. 16 is a diagram showing a state in which the recess B is processed. FIG. 17 is a diagram showing a state where the orifice is processed.

First, as shown in FIGS. 4 and 9, the orifice plate 15 is formed by cutting a substantially disc-shaped blank 15 ′ having a spherical portion 30 at a substantially central portion of the end face. Further, a saddle-like recess is formed on the opposite end surface of the spherical surface portion 30 in the blank 15 '.

  Next, as shown in FIG. 14, the blank 15 ′ having the spherical surface portion 30 is placed on the upper surface of the die 41, and the outer diameter is firmly held by the collet chuck 42. Further, the outer periphery of the spherical surface portion 30 is pressed by the cutting blade portion 40a of the punch 40 while holding the blank 15 ', and the positioning hole 31a is processed. Similarly, the positioning holes 31b and 31c are processed, but the processing order is determined as appropriate according to the deflection direction of the orifice. In this manner, the positioning holes 31a, 31b, 31c are formed in the blank 15 'by press working, so that the positioning holes 31a, 31b, 31c are formed at three locations on the outer peripheral side of the spherical portion 30 as shown in FIGS. Is obtained.

  Next, as shown in FIG. 15, with the orifice plate 15 held by the collet chuck 42, the spherical portion 30 is pressed by the cutting blade portion 43a of the punch 43, and the recess A54a is extruded into a bag hole shape. . Similarly, the recesses A55a, 56a, 57a, 58a, and 59a are processed, but the processing order is appropriately determined according to the deflection direction of the orifice. In addition, the process of the recessed part A may carry out the work hardening of the surface while pressing. In this way, by forming the recess A in the orifice plate 15 by press working, the spherical surface 30 has a surface roughness substantially perpendicular to the central axis of the recess A as shown in FIGS. A recess A is formed.

  Next, as shown in FIG. 16, with the orifice plate 15 held by the collet chuck 42, the bottom surface of the recess A54a is pressed by the cutting edge 44a of the punch 44 from the same direction as the punch 43 formed with the recess A. Then, the recess B54b is extruded into a bag hole shape. Similarly, the recesses B55b, 56b, 57b, 58b, 59b are processed, but the processing order is determined as appropriate according to the deflection direction of the orifice. In addition, the process of the recessed part B may carry out the work hardening of the surface while pressing. In this way, by forming the recess B in the orifice plate 15 by pressing, the orifice plate 15 having the recess B with good surface roughness on the bottom surface of the recess A as shown in FIGS.

  Further, the punch 43 formed with the recess A and the punch 44 formed with the recess B are pressed from the same direction, and in particular, the bottom surface of the recess A is already a surface substantially perpendicular to the central axis of the recess A. Flows evenly in the circumferential direction. For this reason, the central axes of the recesses A and B can be substantially straight, and the bottom surface of the recess B is a perpendicular surface that is not displaced from the bottom axes of the recesses A with respect to the center axes of the recesses A and B. It can be.

Next, as shown in FIG. 17, with the orifice plate 15 held by the collet chuck 42, the cutting blade 45a of the punch 45 is pressed at right angles to the bottom surface of the recess B54b, so that the orifice 54 is shaped like a bag hole. Extrude into Similarly, orifices 55, 56, 57, 58,
59 is processed, but the processing order is appropriately determined according to the deflection direction of the orifice. In this way, by forming the orifice in the orifice plate 15 by pressing, an orifice plate 15 having an orifice on the bottom surface of the recess B as shown in FIGS. 8 and 13 is obtained. Since the orifice plate 15 is held by the collet chuck 42, the orifice plate 15 is processed with high positional accuracy so that the central axes of the concave portion A, the concave portion B, and the orifice are substantially aligned with respect to the positioning hole. Further, the orifice can be processed into a fully sheared surface by pressing it into a bag hole shape, and the surface roughness can be remarkably improved.

  Here, when the orifice is deflected with respect to the normal direction of the spherical surface 30, the punch comes into contact with each other at the time of processing the concave portion A, and the bending load is applied to the cutting edge portion 43 a of the punch 43, resulting in damage to the punch 43. is there. However, according to the present invention, the length of the cutting edge 43a of the punch 43 is shorter than the length of the cutting edge 45a of the punch 45 and the diameter can be increased. Even if a bending load is sometimes applied, the punch 43 is not broken, and a plane portion substantially perpendicular to the axis of the orifice can be formed. In addition, since the bending force is not applied to the cutting blade portion 44a of the punch 44 and the cutting blade portion 45a of the punch 45 at the time of processing the concave portion B and the orifice processing in the next step, the concave portion B is not broken without breaking the punch 44 and the punch 45. And the orifice can be processed with a press with good coaxiality. In addition, the bottom surface of the recess A that is the exit of the recess B and the bottom surface of the recess B that is the exit of the orifice and the axis of the orifice intersect substantially at right angles, but the bottom surface of the recess B intersects at a more right angle. be able to.

  Finally, by forming the orifice into a bag hole shape, the extruded portion 15b formed in the recess on the opposite end surface of the spherical portion 30 has a substantially conical seat surface 15a (valve seat) as shown in FIG. It is deleted by processing, and the orifice penetrates to the sheet surface 15a side. The machining method at this time is performed by turning or electric discharge machining.

  In this way, by providing a two-stage recess having a surface substantially perpendicular to the central axis of the orifice in the spherical portion on the downstream side of the orifice, it is possible to easily process the orifices having different injection directions with high accuracy by pressing. . Therefore, a deep hole having an aspect ratio of 1.5 or more can be easily processed with a press even in a martensitic stainless steel (for example, SUS420J2) having a carbon content of 0.25% or more. When martensitic stainless steel having a carbon content of 0.25% or more is used, the hardness after quenching is more preferably HRC52 or more.

  Also, since the outlet of the recess B and the outlet of the orifice are perpendicular to the axis of the orifice, the fluid injection timing is the same all around, and the penetration length is uniform even with the orifice deflected with respect to the axis of the injection valve. And the homogeneity of spraying can be improved.

  Further, by changing the depth of the recess B, the length of the orifice can be changed, and the shape of the spray can be optimized. At this time, since it is not necessary to change the thickness of the orifice plate tip 15c, the rigidity of the orifice plate 15 is not lowered. For this reason, it is suitable for a high fuel pressure type injection valve of 10 MPa or more where the pressure applied to the orifice plate tip 15c is large.

  Moreover, since the depth of the recessed part A is sufficiently smaller than the recessed part B, the recessed part A does not affect the spraying.

  Further, since the concave portion A is provided in the spherical surface portion, the bending load is not applied to the concave portion B and the orifice during the orifice processing, and the concave portion B and the orifice can be pressed with good coaxiality. Can be processed with better surface roughness than the orifice processed. For this reason, it is possible to reduce the adhesion of burning debris, such as carbon, produced by the combustion of fuel during in-cylinder injection to the recess A and the recess B, and atomization of the spray and improvement of the shape and position accuracy are possible.

  Also, by positioning, processing the recess A, the recess B, and the orifice while the blank is chucked, a plurality of orifices deflected with respect to the axis of the injection valve need not be aligned in each step. It can be positioned and processed with high accuracy.

  Further, since the concave portion A, the concave portion B, and the orifice can be processed with a press with good coaxiality, the surface roughness can be processed with higher surface roughness than, for example, those obtained by processing the orifice by electric discharge machining or cutting. For this reason, it is possible to reduce the adhesion of burning debris, such as carbon, produced by the combustion of fuel during in-cylinder injection to the recess A and the recess B, and atomization of the spray and improvement of the shape and position accuracy are possible.

  Although the embodiments of the present invention have been specifically described above, the present invention is not limited to these embodiments, and various modifications can be made within the scope of the inventive idea. For example, in the above-described embodiment, the region where the flat surface portion 33 is formed is described as the spherical surface portion 30, but it may be a curved surface other than the spherical surface (curved surface portion).

  Moreover, in the said Example, although the spherical surface part 30 of blank 15 'was shape | molded by the cutting process, it is also possible to manufacture by press processes, such as forging.

  Moreover, in the said Example, although the orifice was shape | molded by press work, you may be based on a punching process.

It is a longitudinal cross-sectional view which shows the whole structure of an injection valve. It is a perspective view of an orifice plate. It is a longitudinal cross-sectional view of an orifice plate. It is a perspective view of a blank. It is a perspective view of the orifice plate in which the positioning hole was formed. It is a perspective view of the orifice plate in which the recessed part A was formed. It is a perspective view of the orifice plate in which the recessed part A and the recessed part B were formed. It is a perspective view of the orifice plate in which the recessed part A, the recessed part B, and the orifice were formed. It is a longitudinal cross-sectional view of a blank. It is a longitudinal cross-sectional view of the orifice plate in which the positioning hole was formed. It is a longitudinal cross-sectional view of the orifice plate in which the recessed part A was formed. It is a longitudinal cross-sectional view of the orifice plate in which the recessed part A and the recessed part B were formed. It is a longitudinal cross-sectional view of the orifice plate in which the recessed part A, the recessed part B, and the orifice were formed. It is a figure of the state which has processed the positioning hole 31a. It is a figure of the state which is processing the recessed part A. FIG. It is a figure of the state which is processing the recessed part B. FIG. It is a figure of the state which is processing the orifice.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Injection valve main body 10c Orifice plate front-end | tip part 15 Orifice plate 15a Sheet surface 30 Spherical surface part 31a-33a Positioning hole 40, 43, 44, 45 Punch 40a, 43a, 44a, 45a Punch cutting blade part 41 Die 42 Collet chucks 54-59 Orifices 54a-59a Recess A
54b-59b Recess B

Claims (14)

A movable valve body,
And drive means for driving the valve body,
A valve seat which the valve body contacts away, a injection valve constituted by a nozzle having an orifice provided downstream of the contact position between the valve body and the valve seat,
A convex curved surface portion is provided at the tip of the nozzle,
Said orifice is formed in a direction having an angle relative to the axis of the front Symbol nozzle,
On the downstream side of the orifice, a plurality of concave-shaped portions having different diameters are formed, and the concave-shaped portion positioned on the upstream side is smaller than the flat-surface portion formed by the bottom surface of the concave-shaped portion positioned on the downstream side. A recess formed by laminating in the direction of the central axis of the orifice is provided so as to form an opening surface,
The bottom surface of each concave-shaped part constituting the concave part is pressed so as to be substantially perpendicular to the central axis of the orifice,
The orifice is press-worked so that an opening surface smaller than the bottom surface is formed on the bottom surface of the concave portion located on the upstream side . The injection valve according to claim 1,
The nozzle has an orifice plate in which the said valve seat orifice is provided, the orifice plate, the injection valve, characterized in that it is fixed to the tip of the nozzle. The injection valve according to claim 1 or 2,
The said recessed part is comprised by two recessed shape parts, The injection valve characterized by the above-mentioned. The injection valve according to any one of claims 1 to 3 ,
A plurality of orifices are provided, at least two of which are formed at different angles. The injection valve according to any one of claims 1 to 4 ,
The injection valve according to claim 1, wherein a central axis of the orifice and the recess is substantially in a straight line. The injection valve according to any one of claims 1 to 5 ,
The said curved surface part is a spherical shape, The injection valve characterized by the above-mentioned. The injection valve according to claim 3,
The injection valve characterized in that the depth of the concave portion located on the downstream side of the two concave portions constituting the concave portion is smaller than the length of the orifice. The injection valve according to claim 3,
A plurality of the orifices are provided,
Of the two concave portions constituting the recesses, the injection valve the depth of the concave portion located downstream, characterized in that at least two different for each the orifice. The injection valve according to claim 2,
An injection valve characterized in that a positioning hole is formed in the orifice plate. A method of machining an orifice for injecting a fluid,
A first press working step of forming a first concave shape part by extruding or half-punching the convex curved part formed in the blank ;
The first further extruded to a plane portion formed by the bottom surface of the concave portion, or half die cutting the second forming a second concave portion of diameter smaller than the first concave portion by performing Pressing process,
A third press working step for forming an orifice having a diameter smaller than that of the second concave-shaped portion on the bottom surface of the second concave-shaped portion by extrusion processing , half punching processing, or punching processing ;
The first press working step, the second press working step, and the third press working step are executed in this order, and the bottom surface of the first concave shape portion and the bottom surface of the second concave shape portion are A method of processing an orifice, wherein the pressing is performed so as to be substantially perpendicular to the central axis of the orifice. The method for machining an orifice according to claim 10 ,
Before the first press working step, there is a step of forming the convex curved surface portion in the blank,
After the step of molding the blank processing method orifice and a step of pressing a positioning hole on the outer peripheral side of the curved portion. The orifice processing method according to claim 10 or 11 ,
After the step of processing the orifice, processing method of orifices and having a step of processing the valve seat upstream turning, or electrical discharge machining to the blank. The method of processing an orifice according to claim 11 , wherein
The orifice processing method, wherein the step of pressing the positioning hole, the second press processing step, and the third press processing step are performed while the blank is chucked. The method for processing the orifice according to claim 1 0,
The blank is made of martensitic stainless steel having a carbon content of 0.25% or more, and the hardness after quenching is HRC52 or more.

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