JP4039370B2 - Orifice machining method - Google Patents

Description

  The present invention relates to an orifice for injecting fluid, and relates to an orifice or orifice processing method processed into a nozzle or orifice plate for measuring the fluid and controlling the injection direction of spray, and more particularly to an orifice of a fuel injection valve.

  Conventionally, as a method for processing an orifice in manufacturing a nozzle, there is an example of press working as described in JP-A-2001-96196. In this orifice processing method, extrusion (or half punching) or punching is performed from the downstream side of the orifice, and then the upstream side is machined to obtain a full shear surface.

  In the processing method described in JP-A-7-97969, a preliminary hole forming step of forming a preliminary hole with a first press pin and a finishing step of slightly shaving an inner wall surface with a slightly larger second press pin, so-called The fracture surface was reduced by shaving.

JP 2001-96196 A JP-A-7-97969

  In the technique described in Japanese Patent Laid-Open No. 2001-96196, an orifice is pressed into a flat portion or a concave portion, so that the rigidity of the material is relatively high and the material is difficult to be deformed to the outer diameter side. For this reason, processing stress becomes high, and it is a severe condition for deep hole processing in terms of punch strength. Further, since the extruded portion is freely deformed, cracks are likely to occur, which is inconvenient for obtaining a longer shear surface.

  In the technique described in Japanese Patent Application Laid-Open No. 7-97969, since the punch for processing the preliminary hole has a small diameter, the processing limit is determined by the strength of the preliminary hole punch, which is disadvantageous for deep hole processing. Further, since the material flow is restricted by the die, the punching stress is higher than that of the extrusion process described in Japanese Patent Laid-Open No. 2001-96196. Further, although shaving is performed, the surface roughness of the punch, the shape, and the material flow are not taken into consideration, so it is difficult to reduce the surface roughness of the orifice inner surface to Rmax 1 μm or less.

SUMMARY OF THE INVENTION An object of the present invention is to provide an orifice processing method that can easily and inexpensively increase the productivity of an orifice having an aspect ratio of 1.5 or more by press working .

In order to achieve the above object, an orifice machining method of the present invention is an orifice machined into a nozzle or an orifice plate of a fuel injection valve, where the length L of the orifice and the diameter d of the orifice are L / d ≧ In the orifice processing method satisfying the relationship of 1.5, a convex portion having a small diameter with respect to the nozzle or orifice plate is provided on the first surface of the nozzle or orifice plate, and the clearance is set to 25% or more. Using a die having a portion, setting the nozzle or orifice plate to the die with the second surface opposite to the first surface on which the convex portion is formed facing the die side, The nozzle or orifice plate is formed by biting the punch into the convex portion from the first surface side so that the outlet of the orifice is formed in the convex portion. Press the material that forms the sheet to the inner diameter part of the die, and finish the press process before the orifice penetrates the second surface side, and the sheet surface on the second surface side. The orifice is penetrated by machining.

At this time, the orifice may be formed in a curved shape toward the outlet side so as to increase in diameter.

A die having a space between the nozzle and the second surface of the orifice plate is provided in the inner diameter portion of the die, and the die is provided in the inner diameter portion after the material to be extruded by the pressing process exceeds a maximum processing stress. I want to touch the die.

Further, the convex portion may be formed in a spherical shape.

Further, in the press working, a punch having a slope portion of 7 ° to 20 ° on the tip surface, a corner portion of the tip of R0.03 or more, and a surface polished to Rmax 0.2 μm or less is used. Good.

Further, the orifice may be processed while being deflected with respect to the axis of the fuel injection valve.

Further, when machining by deflecting the orifice with respect to the axis of the fuel injection valve, a positioning mark for determining the position in the rotation direction machined by a press may be machined by the orifice and one chuck.

At this time, the bottom surface of the positioning mark may be processed into a tapered surface of 60 ° to 150 °.

The positioning mark may be processed in the same direction as the axis of the nozzle or orifice plate, and processed in a direction different from the axis of the orifice.

According to the present invention, the material to be extruded can be freely deformed by using a die having an inner diameter portion whose clearance is set to 25% or more, so that the maximum pressing stress can be reduced, and the nozzle or by providing the convex portion on a first surface of the orifice plate, because the material during press working lowers the rigidity in the radial direction flows easily to the outer circumferential side, the aspect ratio is easy to 1.5 or more orifice or by pressing In addition, it can be processed with high productivity at low cost.

Further, since the orifice deflected with respect to the axis and the positioning mark in the rotation direction can be processed with a single chuck by pressing, the positioning accuracy is high and the processing with excellent productivity can be performed.

  Since the orifice is processed by press working, the inner surface of the orifice is work-hardened and has excellent durability such as wear even when used with raw materials.

Examples described later have the following characteristics.

Weighing flow body, and in processed orifice jetting direction nozzle or orifice plate which performs control of the spray orifice is at least L / d ≧ 1.5 (L = orifice length, d = orifice diameter) be the outlet side of the orifice is located in a convex in shape whose diameter of the nozzle or orifice plate, the orifice portion positioned protrusions that have a larger diameter in a curved shape toward the outlet side.

Good Mashiku is orifice you press working from the convex side of the nozzle blank or orifice plate.

Good Mashiku, by changing the outer diameter of the convex portion, adjust the ratio of the diameter in a curved shape toward the outlet side of the orifice increases.

Good Mashiku, the outer diameter of the projections you below 6 times the orifice diameter.

Good Mashiku is you projections spherically.

Good Mashiku is orifice you are the same direction, or deflection to the axis of the nozzle or orifice plate.

Weighing flow body, and in processed orifice jetting direction nozzle or orifice plate which performs control of the spray, the surface roughness of the orifice inner surface after processing is less Rmax0.2Myuemu, surface roughness when was further quenching the Ru der following Rmax0.5μm.

Good Mashiku is, the orifice is pressing, the punch used in the press working has a slope of 20 ° from 7 ° to the tip end face, there is a corner portion of the tip R0.03 above, surface Rmax0. It is polishing process to 2μm or less and that is a ceramic coating.

Weighing flow body, and in processed orifice jetting direction nozzle or orifice plate which performs control of the spray, the orifice outlet of the orifice in L / d ≧ 1.5 is sharp edges, processed pilot hole first means for, Ru fabricated with second means for pressing the outlet side of the orifice.

Weighing flow body, and in orifices machined into the nozzle or orifice plate which performs control of the injection direction of the spray, the orifice in the step of pressing, to the middle of the press working is freely deformed material to be extruded, up to material that is extruded from the past machining stress Ru is restrained by contact with the die.

Good Mashiku, the length of the orifice Ru thickness over der before orifice machining of the nozzle or orifice plate.

Good Mashiku, the diameter d of the orifice and the plate thickness t of the orifice processing section Ru t / d ≧ 2 der.

Good Mashiku the material of the nozzle or orifice plate is a carbon content 0.26% or more martensitic stainless steel, and processed into a predetermined shape inlet portion of the orifice machining after orifice cutting or grinding, then to facilities quenching.

Good Mashiku is, the orifice has a positioning mark for positioning in the rotational direction which is processed by the press, the orifice and the positioning mark Ru are processed in one chuck.

Good Mashiku the bottom surface of the positioning mark is Ru tapered surface der of 150 ° from 60 °.

Good Mashiku, the positioning marks are processed in the same direction as the axis of the nozzle or orifice plate, the axis of the orifice has name always in the same orientation.

  Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a longitudinal sectional view showing the overall configuration of an electromagnetic fuel injection valve according to an embodiment of the present invention.

  The electromagnetic fuel 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 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 jacket member cover the periphery of the movable element 5. The nozzle 9 includes the orifice plate 15 having a sheet surface 15 a and an orifice 15 b at the tip, and the guide plate 16 and the movable element 5. A swirler 17 is provided that slidably guides and applies a turning force to the fuel.

  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.

  The operation of the electromagnetic fuel injection valve body 1 configured as described above will be described. 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 passage 16 a of the guide plate 16 and the passage 9 a of the nozzle enter the passages 17 a and 17 b of the swirler 17, and a turning force is given by the turning groove 17 c of the swirler 17. The fuel given the turning force is injected through the orifice 15b from the gap between the valve seat portion 11a and the seat surface 15a.

  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.

  The orifice plate 15 and the orifice 15b of the electromagnetic fuel injection valve main body 1 having the above-described configuration are objects of the present invention, and the details and manufacturing method will be described below.

  2, 3 and 4 show a first embodiment of the present invention, and FIG. 2 is a longitudinal sectional view in which an orifice 15b is machined in the same direction with respect to the axis of the electromagnetic fuel injection valve main body 1. FIG. On the other hand, FIG. 3 is a longitudinal sectional view in which the orifice 30 b is processed in a direction deflected with respect to the axis of the electromagnetic fuel injection valve body 1.

  FIG. 4 is a longitudinal sectional view showing a processing step of the orifice 15b of FIG. As shown in FIG. 4- (I), the orifice plate 15 set on the die 51 having a sufficiently large clearance (preferably 25% or more) so that the raised portion 15e can be freely deformed with respect to the punch 50a 52 is centered in the radial direction. Next, as shown in FIG. 4- (II), the punch 50 bites into the convex portion 15c of the orifice plate 15 as the punch 50 descends, and the extruded material becomes a raised portion 15e on the opposite surface. Further, the punch 50 is lowered to a predetermined position as shown in FIG.

  Although not shown, the raised portion 15e is machined into a sheet surface 15a by machining such as turning to penetrate the orifice 15b, and if necessary, quenching is performed to finish the sheet surface 15a, whereby the orifice plate 15 of FIG. Complete.

  Here, when machining the orifice 15b, the outer diameter of the convex portion 15c is set to 6 times or less of the diameter of the orifice 15b. By setting in this way, the radial rigidity is lowered, the material is easy to flow to the outer diameter side during pressing, and the portion of the orifice 15b located at the convex portion 15c is a curved surface that expands toward the outlet side. The shape can be 15d. Further, the size of the curved surface 15d can be controlled to some extent by the outer diameter, height and shape of the convex portion 15c.

  FIG. 3 shows an embodiment in which the orifice 30b is machined in a direction deflected with respect to the axis of the electromagnetic fuel injection valve body 1, and the machining process is the same as that in FIG. The convex portion 30c has a spherical shape so that the obliquely moving punch 50 can easily hit the convex portion 30c at a right angle.

  FIG. 5 shows the detailed shape of the punch 50. The cutting edge part 50a of the punch 50 can be made to flow easily by providing a taper part 50b having a taper angle of 10 ° at the tip part and an angle R part 50c of R0.03. The surface roughness is transferred to the inner surface of the orifice 15b to improve the surface roughness of the orifice 15b. Further, the tip of the cutting blade portion 50a of the punch 50 is lapped and finished to Rmax 0.2 μm or less, and is further coated with titanium such as TiC to prevent seizure.

  6, 7, and 8, the prepared hole is processed in advance by press working or machining such as turning before the orifice 15 b is pressed.

  As shown in FIG. 6, for example, a pilot hole 31 smaller by about 0.1 than the cutting edge 50 a of the punch 50 is machined, and the orifice 15 b is machined as shown in FIG. As shown in FIG. 9, a sharp edge 15j can be obtained. This is because when the punch 50 bites into the orifice plate 15, the material flows into the pilot hole 31 with a relatively small stress. The same effect can be obtained with the pilot hole 32 in FIG. 7 and the pilot hole 33 in FIG. 8, and deep hole machining such as L / d ≧ 1.5 (L = orifice length, d = orifice diameter) can also be achieved in FIG. As shown in the drawing, an orifice having a good cylindricity and a sharp edge can be obtained.

  In particular, if the pilot hole is penetrated as shown in FIG. 8, the stress in the orifice processing itself can be reduced, and deeper hole processing becomes possible.

  FIGS. 10 and 12 show an embodiment in which the length of the orifice is processed to be equal to or larger than the blank thickness of the orifice plates 30 and 35.

  FIG. 11 is a process diagram showing the processing of the orifice plate 34, and the orifice plate 34 set on the die 51 and the die 53 is centered in the radial direction by the chuck 52 as shown in FIG. Here, the die 53 is shorter than the die 51, and there is a space between the die 53 and the orifice plate. Next, as shown in FIG. 11- (II), the punch 50 bites into the convex portion 34c of the orifice plate 34 as the punch 50 descends, and the extruded material becomes a bulge 34a on the opposite surface. It is not in contact with the die 53. Further, as shown in FIG. 11- (III), the punch 50 is lowered to a predetermined position, and the machining of the orifice is completed. At this time, the swell 34a hits the die 53, and the material extruded into the inner diameter portion of the die 53 becomes 34d.

  Although not shown, the raised portion 34a is processed by machining such as turning to penetrate the orifice 34b, and the orifice plate 34 of FIG. 10 is completed.

  As described above, by providing a space between the die 53 and the orifice plate 34, the punch 50 a can be made to bite more than the plate thickness of the orifice plate 34, and the length of the orifice 34 b is machined beyond the plate thickness of the orifice plate 34. can do. Further, if the inner diameter of the die 53 is made smaller than the outer diameter of the punch 50a, the fracture 34 is not generated, and the orifice 34b having the entire shear surface can be obtained.

  FIG. 12 has a sheet surface 35a with respect to FIG. This makes it necessary to minimize the plate thickness of the orifice plate 35 in order to make the finer orifice 35b workable, and has a counterbore 35b as shown in FIG. 13- (I). FIG. 13 is a process diagram showing the processing of the orifice plate 35 of FIG. 12. As shown in FIG. 13- (I), the orifice plate 35 set on the die 51 and the die 54 is centered in the radial direction by the chuck 52. Is done. Here, the die 54 is longer than the die 51, but there is a space between the die 54 and the counterbore 35b. Next, as shown in FIG. 13- (II), the punch 50 bites into the convex portion 35c of the orifice plate 35 as the punch 50 descends, and the extruded material becomes like a raised portion 35d on the opposite surface. 35 d is not in contact with the die 54. Further, as shown in FIG. 13- (III), the punch 50 is lowered to a predetermined position, and the machining of the orifice is completed. At this time, the swelled portion 35d hits the die 54, and the material extruded into the inner diameter portion of the die 54 becomes 35e. Further, the counterbore part 35b is completely crushed and becomes a machining allowance for the sheet surface 35a by turning or the like.

  Although not shown, the raised portion 35d is machined into a sheet surface 15a shape by machining such as turning to penetrate the orifice 35b, and the orifice plate 35 of FIG. 12 is completed.

  FIG. 14 illustrates a normal punching method for comparison of press working stress.

  FIG. 14 is a process diagram showing processing of the orifice plate 36 by general punching. As shown in FIG. 14- (I), the orifice plate 34 set on the die 51 is centered in the radial direction by the chuck 52. Then, as the punch 50 is lowered, the punch 50 bites into the convex portion 36c of the orifice plate 36, and the extruded material becomes a swell 36a on the opposite surface. Further, as shown in FIG. 14- (II), the punch 50 is lowered to a predetermined position, and the machining of the orifice is completed. At this time, the clearance between the punch 50a and the die 51 is 5%, and the punched material is like 36b.

  FIG. 15 shows the relationship between the punch stroke and the press working stress for each processing method. The punch diameter is 0.7, the thickness of the orifice plate is 2 mm, and the material is SUS420J2.

  Data A is based on the normal punching method shown in FIG. 14, and the maximum press working stress is about 4400 MPa, which cannot be processed with a general carbide punch.

  Data B is the pressing method shown in FIG. 4, wherein the clearance between the punch 50 a and the die 51 is 25% or more so that the extruded material can be freely deformed without being constrained by the die 51. The maximum pressing stress at this time is 3800 MPa, and the pressing stress can be reduced by 14% with respect to data A. For this reason, the orifice can be machined with a lower press working stress than a normal punching method. However, in FIG. 4- (III), if the punch 50 is further stroked deeply, a fracture occurs, so that a shear surface greater than the plate thickness of the orifice plate 15 cannot be obtained.

  Data C is the pressing method shown in FIG. 11 and shows a curve almost the same as data B up to a punch stroke of 1.2 mm. The maximum pressing stress is 3800 MPa. From the punch stroke of 1.2 mm, the extruded material (swell 34a) hits the die 53, and the flow of the material is restricted, so that the press working stress increases. However, the maximum pressing stress does not exceed 3800 MPa. Further, since the inner diameter of the die 53 is smaller than the punch 50a (so-called negative clearance), the extruded material (swell 34a) does not generate a fracture surface, and the same maximum pressing as in FIG. A shear surface having a thickness greater than that of the orifice plate 15 can be processed by stress. For this reason, it is possible to machine a thinner or longer (L / d ≧ 2) orifice than the normal punching method of FIG. 14 or the pressing method of FIG.

  FIG. 16 shows an embodiment in which the orifice 30b is deflected with respect to the axis of the electromagnetic fuel injection valve body 1 and the positioning hole 40 in the deflection direction is machined. 17 and 18 are process diagrams showing the machining process. As shown in FIG. 17, the orifice plate 30 set on the die 51 is centered and fixed in the radial direction by the chuck 52. In this state, the punch 60 is lowered to process the positioning hole 40. In the next step, as shown in FIG. 18, the orifice 30 b is processed by the punch 50 while the orifice plate 30 is chucked.

  As described above, since the positioning hole 40 and the orifice 30b are sequentially processed while the orifice plate 30 is chucked, the positioning holes can be easily processed by press working without causing a phase shift between the two. Further, if the angle of the bottom surface of the positioning hole 40 is in the range of 60 ° to 150 °, it is good for image processing, and preferably 120 ° is suitable. Furthermore, since it is processed by a press, the shape is stable, the surface roughness is good, and there is no generation of chips or the like.

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

1 is a longitudinal sectional view showing the overall configuration of an electromagnetic fuel injection valve showing a first embodiment of the present invention. The longitudinal cross-sectional view which processed the orifice in the same direction with respect to the axis line of the electromagnetic fuel injection valve main body which shows 1st Example of this invention. The longitudinal cross-sectional view which processed the orifice in the direction deflected with respect to the axis line of the electromagnetic fuel injection valve main body which shows 1st Example of this invention. The longitudinal cross-sectional view which shows the manufacturing process of the orifice which shows 1st Example of this invention. The detail drawing of the punch which shows 2nd Example of this invention. The longitudinal cross-sectional view of the orifice plate blank which shows 3rd Example of this invention. The longitudinal cross-sectional view of the orifice plate blank which shows 3rd Example of this invention. The longitudinal cross-sectional view of the orifice plate blank which shows 3rd Example of this invention. The longitudinal cross-sectional view of the orifice plate which shows 3rd Example of this invention. The longitudinal cross-sectional view of the orifice plate which shows 4th Example of this invention. The longitudinal cross-sectional view which shows the manufacturing process of the orifice which shows 4th Example of this invention. The longitudinal cross-sectional view of the orifice plate which shows 4th Example of this invention. The longitudinal cross-sectional view which shows the manufacturing process of the orifice which shows 4th Example of this invention. The longitudinal cross-sectional view which shows the manufacturing process of the orifice which supplements 4th Example of this invention. The relationship diagram of punch stroke and press work stress which shows 4th Example of this invention. The longitudinal cross-sectional view of the orifice plate which shows 5th Example of this invention. The longitudinal cross-sectional view which shows the manufacturing process of the positioning hole which shows 5th Example of this invention. The longitudinal cross-sectional view which shows the manufacturing process of the orifice which shows 5th Example of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electromagnetic fuel injection valve main body, 15, 30 ... Orifice plate, 15a ... Sheet surface, 15b, 30b ... Orifice, 15c, 30c ... Convex part, 15d, 30d ... Curved surface, 15e ... Swelling part, 50 ... Punch, 51, 53, 54 ... Die, 52 ... Chuck.

Claims (9)

An orifice machined into a nozzle or orifice plate of a fuel injection valve, wherein the orifice length L and the orifice diameter d satisfy the relationship L / d ≧ 1.5,
A convex portion having a small diameter with respect to the nozzle or orifice plate is provided on the first surface of the nozzle or orifice plate,
Use a die having an inner diameter part with a clearance set to 25% or more, and direct the second surface opposite to the first surface on which the convex part is formed toward the die side or the nozzle or Set the orifice plate on the die,
A punch is bitten into the convex portion from the first surface side so that the outlet of the orifice is formed in the convex portion, and the material forming the nozzle or orifice plate is pushed out to the inner diameter portion of the die. Applying the press work, and terminating the press work before the orifice penetrates the second surface side,
A method of processing an orifice, wherein the orifice is penetrated by machining a sheet surface on the second surface side. 2. The method of processing an orifice according to claim 1, wherein the orifice is formed so that the diameter increases in a curved shape toward the outlet side. The orifice processing method according to claim 1, wherein a die having a space between the nozzle and the second surface of the orifice plate is provided in an inner diameter portion of the die, and the material extruded by the press processing is a maximum processing. A method of processing an orifice, characterized in that after passing the stress, the die abuts on the inner diameter portion. 2. The orifice processing method according to claim 1, wherein the convex portion is formed in a spherical shape. 2. The method for machining an orifice according to claim 1, wherein the press working has a slope portion of 7 ° to 20 ° on the tip surface, the corner portion of the tip is R0.03 or more, and the surface is Rmax 0.2 μm. A method for machining an orifice, characterized by using a polished punch below. 2. The method for machining an orifice according to claim 1, wherein the orifice is machined while being deflected with respect to an axis of the fuel injection valve. 7. The method for processing an orifice according to claim 6, wherein a positioning mark for determining a position in a rotational direction processed by a press is processed by the orifice and one chuck. 8. The method of processing an orifice according to claim 7, wherein a bottom surface of the positioning mark is processed into a tapered surface of 60 ° to 150 °. The orifice processing method according to claim 7 or 8, wherein the positioning mark is processed in the same direction as an axis of the nozzle or orifice plate, and is processed in a direction different from the axis of the orifice. Processing method.

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