JP4363363B2 - Fuel injection valve for internal combustion engine with oil repellent coating - Google Patents

Description

  The present invention relates to a fuel injection valve for an internal combustion engine provided with an oil repellent coating. The present invention is particularly useful for preventing the occurrence of deposits derived from oily substances such as gasoline, light oil, and lubricating oil in internal combustion engine fuel injection valves.

  In an internal combustion engine such as an automobile engine, sprayed fuel or lubricating oil droplets may adhere and stay in the vicinity of the injection hole of the fuel injection valve. If a part of the nozzle hole is blocked, the spray characteristics of the fuel injection valve are significantly impaired, and the normal operation of the engine is adversely affected.

  In order to prevent the formation of deposits, it is necessary to quickly drop the fuel and lubricating oil droplets from the deposit without retaining them.

  For this purpose, it is effective to impart high oil repellency to the surface in the vicinity of the nozzle hole where the droplet stays and stays. From the viewpoint that both of these are liquid-repellent, the water-repellent property is used to prevent water droplets from staying and staying. Common with water-based application.

  For imparting water repellency, for example, in Patent Document 1, a water-repellent part having a contact angle with water of 150 ° or more (corresponding to CF, CF2, and CF3) and a hydrophilic part having a contact angle with water of 70 ° or less (NHCO And a printing plate suitable for waterless offset printing, in which O and a crosslink via a cyclic chain) coexist.

  However, since the constituent medium of the droplets is oil instead of water, it is impossible to achieve oil repellency simply as an extension of water repellency.

  That is, in order for the substrate surface to exhibit liquid repellency, it is necessary that the surface tension of the substrate surface is sufficiently smaller than the surface tension of the medium constituting the droplet. When the medium is water, the surface tension is 70 dyne / cm. On the other hand, when the medium is an oily medium such as gasoline, light oil, or lubricating oil, the surface tension is 17-22 dyne / cm. Much smaller than that. Accordingly, it is relatively easy to select a water repellent film material having a surface tension sufficiently smaller than 70 dyne / cm for imparting water repellency, whereas the surface tension is more than 17 to 22 dyne / cm for imparting oil repellency. It is actually very difficult to select a sufficiently small oil repellent film material.

  For this reason, conventionally, it has not been possible to impart sufficient oil repellency to quickly drop fuel or lubricating oil droplets from the surface near the nozzle hole of the fuel injection valve.

  That is, as an example in which an oil repellent film is formed, Patent Document 2 discloses a hydrodynamic bearing device in which an oil repellent film (ETFE, PVF, PVDF, ECTFE, PCTFE, PFA, PTFE, FEP) is formed. A refrigerating cycle is disclosed in which an oil-repellent film is formed on the inner wall surface of the refrigerant pipe of the compressor and the evaporator and the refrigerant piping on the suction side of the compressor, and the lubricant oil of the compressor is prevented from adhering to the tube of the heat exchange part. Patent Document 4 discloses a turbocharger in which an oil repellent film is formed on the seal plate adjoining part and the housing adjoining part facing each other across the diffuser flow path of the supercharger to prevent oil mist adhesion and carbonization layer formation. However, none of them is effective in preventing the accumulation and retention of oil droplets in the fuel injection valve of the internal combustion engine.

  Further, Patent Document 5 discloses a hydrodynamic bearing device in which the surface roughness of the application region of the oil repellent agent is made rougher than the surface roughness of the shaft body or the rotating body that is not coated, and Patent Document 6 has an oil repellent film formed thereon. It is disclosed that the surface roughness is formed with a rougher surface roughness than the bearing surface constituting the fluid dynamic pressure bearing to prevent the oil repellent film from peeling off, but both improve the adhesion of the oil repellent film to the base material. The oil repellent film itself is not considered to prevent the adhesion and retention of oil droplets in the fuel injection valve of the internal combustion engine.

  Further, Patent Document 7 discloses a fuel injection valve in which a nozzle portion and a needle tip portion are covered with an oil-repellent coating, and a cylindrical shroud member having oil-repellent and thermal conductivity surrounding the nozzle portion is provided. Patent Document 8 discloses a fuel injection valve in which a fluorine coating having oil repellency is applied to an inner surface and an outer surface of an injection hole. However, simply applying a coating with oil repellency, such as a fluorine coating, will not allow the deposited fuel (gasoline, light oil) to slide down and prevent oil droplets from staying, so it is possible to avoid deposit formation around the nozzle hole. Therefore, it is impossible to eliminate the risk that the spray characteristics are deteriorated.

  In order to solve the above-described problems of the prior art, the inventor comprises an oil-repellent coating on the surface of a metal substrate, and the oil-repellent coating comprises a lower layer of PES in close contact with the substrate surface, A fuel injection valve for an internal combustion engine has been developed, which is composed of an upper layer in which discrete phases of FEP are dispersed in a continuous phase of PES integrated with PES, and the upper layer is exposed as the surface of the oil repellent coating. This oil-repellent coating dramatically improves oil repellency, and even if the oily substance does not become slidable oil droplets and spreads by wetting the surface, Therefore, it can slide down easily and the formation of deposits can be prevented.

  However, it has been found that even if the newly developed PES / FEP composite type oil repellent coating is used, if the fuel injection valve has a specific outer shape, the oil droplets may be prevented from sliding off.

  That is, in the fuel injection valve shown in FIG. 1, the outer shape of the needle contact portion 12 of the body 10 is a two-stage structure including a base portion 14 having a truncated cone shape and a head portion 16 protruding from the base portion 14. An intersection X between the outer circumferential surface A and the outer circumferential surface B of the head 16 is an inward corner, and a plurality of nozzle holes arranged circumferentially on the outer circumferential surface B immediately adjacent to the intersection X of the head 16 18 is open.

  The reason for adopting such a two-stage structure is to obtain an appropriate nozzle hole length while ensuring mechanical strength. That is, as shown in FIG. 2, since the conical surface C of the needle 20 and the conical inner wall surface D of the needle contact portion 12 are contacted / disengaged impactively, the fuel injection valve is opened and closed. The contact portion 12 needs to have a large thickness in order to ensure mechanical strength.

  On the other hand, the injection hole 18 needs to have an appropriate length so that the fuel f is injected from the injection hole 18 at an appropriate spray angle α. This is because the spray angle α becomes smaller as the length of the nozzle hole 18 becomes longer, resulting in a thin and linear injection shape. Therefore, there is an upper limit on the length of the nozzle hole 18 in order to ensure the necessary spray angle α. Since the length of the nozzle hole 18 is determined by the thickness of the portion through which the nozzle hole 18 penetrates, the thickness of the portion must be within the upper limit of the nozzle hole length.

  Thus, in order to ensure the mechanical strength and the appropriate nozzle hole length at the same time, the base part 14 of the needle contact part 12 is thickened to ensure the mechanical strength and the nozzle hole 18 is provided. The head 16 has a thin wall thickness in accordance with an appropriate nozzle hole length.

  Thus, in the case of a fuel injection valve having an outer shape with an inward corner-shaped intersection, the following problems peculiar to this shape occur, and good sliding performance cannot be stably obtained.

  FIG. 3 shows an enlarged cross section near the intersection X between the base 14 and the head 16. The oil droplet M adhering to the outer peripheral surface A of the base portion 14 slides down as it is, or slides down while growing repeatedly. In this case, the sliding driving force RA is generated by the oil repellency FA and gravity.

  When the oil droplet M reaches the inward corner-shaped intersection X, the oil droplet M also has an oil repellency FB from the outer peripheral surface B of the head 16 in addition to an oil repellency FA from the outer peripheral surface A of the base 14. Works. However, since this new oil repellency FB acts in a direction crossing the direction of action of the oil repellency FA, the sliding drive force RX is reduced by the action of the oil repellency FB, so that the oil drop M is prevented from sliding down. Some oil drops are stopped. As a result, there is a problem that the accumulated oil droplets are thermally changed and deposits are generated.

Japanese Patent No. 3340377 JP 2004-211851 A JP 09-210513 A JP 2004-044452 A JP 2003-065336 A JP 2004-239346 A Japanese Utility Model Publication No. 63-151970 Japanese Patent Laid-Open No. 10-274134

  The present invention is a fuel injection valve for an internal combustion engine having an oil repellent coating of a PES / FEP composite type and having an inward corner-shaped intersection on the outer shape of a needle contact portion. It is an object of the present invention to provide a fuel injection valve for an internal combustion engine with improved oil repellency and surface morphology so that it can slide down quickly without staying in the vicinity of the injection hole.

In order to achieve the above object, according to the first invention,
An oil-repellent coating is provided on the surface of a metal substrate, and the oil-repellent coating is in a continuous phase of PES (polyethersulfone) adhering to the surface of the substrate and PES integrated with the PES of the lower layer. And an upper layer in which a discrete phase of FEP (tetrafluoroethylene / hexafluoropropylene copolymer) is dispersed, and the upper layer is exposed as the surface of the oil repellent coating. Because
The outer shape of the needle contact portion of the body is a two-stage structure with a truncated cone-shaped base and a head protruding from the base, and the intersection of the outer peripheral surface of the base and the outer peripheral surface of the head is inward In the fuel injection valve for an internal combustion engine in which a plurality of injection holes arranged circumferentially are opened on the outer peripheral surface in the immediate vicinity of the intersection of the heads,
On the outer peripheral surface of the base near the intersection, an oil droplet that slides from the base outer peripheral surface to the head outer peripheral surface can extend on an extension line that desires the fuel supply direction from the nozzle hole of the head. A fuel injection valve for an internal combustion engine is provided.

  In the first invention, it is desirable that the maximum height of the microprotrusions is a height that does not block the spray range from each nozzle hole.

According to the second invention,
An oil-repellent coating is provided on the surface of a metal substrate, and the oil-repellent coating has an FEP discrete phase in a lower layer of PES in close contact with the surface of the substrate and a continuous phase of PES integrated with the lower layer PES. A fuel injection valve for an internal combustion engine, the upper layer being exposed as a surface of the oil repellent coating,
The outer shape of the needle contact portion of the body is a two-stage structure with a truncated cone-shaped base and a head protruding from the base, and the intersection of the outer peripheral surface of the base and the outer peripheral surface of the head is inward In the fuel injection valve for an internal combustion engine in which a plurality of injection holes arranged circumferentially are opened on the outer peripheral surface in the immediate vicinity of the intersection of the heads,
The outer peripheral surface that continues from the base to the head through the intersection is a depression that is dug down by one step from the outer surface of the other region from the region closer to the base than the nozzle hole to the region between the nozzle holes. A fuel injection valve for an internal combustion engine is provided in which the contour of the recess is formed in a V-shape closed in the oil drop sliding direction.

Furthermore, according to the third invention,
An oil-repellent coating is provided on the surface of a metal substrate, and the oil-repellent coating has an FEP discrete phase in a lower layer of PES in close contact with the surface of the substrate and a continuous phase of PES integrated with the lower layer PES. A fuel injection valve for an internal combustion engine, the upper layer being exposed as a surface of the oil repellent coating,
The outer shape of the needle contact portion of the body is a two-stage structure with a truncated cone-shaped base and a head protruding from the base, and the intersection of the outer peripheral surface of the base and the outer peripheral surface of the head is inward In the fuel injection valve for an internal combustion engine in which a plurality of injection holes arranged circumferentially are opened on the outer peripheral surface in the immediate vicinity of the intersection of the heads,
A plurality of outer peripheral surfaces that continue from the base to the head through the intersecting portion have a width and depth larger than the size of the sliding oil droplets from a region closer to the base than the nozzle hole to a region between the nozzle holes. A fuel injection valve for an internal combustion engine, characterized in that the oil droplet guide grooves extend in the vertical direction, and the oil droplet sliding direction tips of the plurality of oil droplet guide grooves are combined in the region between the nozzle holes. .

And according to the fourth invention,
An oil-repellent coating is provided on the surface of a metal substrate, and the oil-repellent coating has an FEP discrete phase in a lower layer of PES in close contact with the surface of the substrate and a continuous phase of PES integrated with the lower layer PES. A fuel injection valve for an internal combustion engine, the upper layer being exposed as a surface of the oil repellent coating,
The outer shape of the needle contact portion of the body is a two-stage structure with a truncated cone-shaped base and a head protruding from the base, and the intersection of the outer peripheral surface of the base and the outer peripheral surface of the head is inward In the fuel injection valve for an internal combustion engine in which a plurality of injection holes arranged circumferentially are opened on the outer peripheral surface in the immediate vicinity of the intersection of the heads,
The outer peripheral surface that continues from at least the base to the head through the intersection is an alignment roughened surface in which vertical fine streak grooves having a width and depth smaller than the size of the sliding oil drop are densely packed. A fuel injection valve for an internal combustion engine is provided.

  In any of the first to fourth inventions, the weight ratio PES wt%: FEP wt% of the PES and FEP constituting the oil repellent coating is preferably 40: 60-80: 20, and 60: 40-75. : 25 is more desirable.

  According to the first aspect of the present invention, when the oil droplet that has slid down the outer peripheral surface of the base portion climbs on the fine protrusion, the oil droplet is blown off and removed by the injection pressure during operation at the nozzle hole portion, and at the intersection other than the nozzle hole portion. Thus, the oil droplets do not straddle both outer peripheral surfaces, and the sliding driving force due to the oil repellency from the outer peripheral surface of the base acts effectively, and the oil droplets do not stay at the intersections.

  According to the second aspect of the invention, the oil droplets are selectively collected in the region between the nozzle holes while sliding down the inside of the hollow dug down by one step, so that they do not stay in the vicinity of the nozzle holes and become a deposit.

  According to the third invention, since the oil droplet is selectively guided to the region between the nozzle holes while sliding down in the oil droplet guide groove, it does not stay in the vicinity of the nozzle hole and become a deposit.

  According to the fourth aspect of the invention, the oil droplets are promoted to slide by the orientation roughened surface where the fine streak grooves are dense and are selectively collected in the region between the nozzle holes, so that the oil droplets stay in the vicinity of the nozzle holes and become a deposit. There is no.

Embodiment 1
An embodiment of a fuel injection valve for an internal combustion engine according to the first invention will be described with reference to FIG.

  FIG. 4 is an enlarged cross-sectional view showing a part of the fuel injection valve for an internal combustion engine of the second invention. The illustrated fuel injection valve 100 is provided with the aforementioned PES / FEP composite type oil repellent coating on the outer peripheral surface.

  The outer shape of the needle contact portion 12 of the body is a two-stage structure having a truncated cone-shaped base portion 14 and a head portion 16 protruding from the base portion 14, and the outer peripheral surface A of the base portion 14 and the outer peripheral surface B of the head portion 16 The intersection X is an inward corner, and a plurality of nozzle holes 18 arranged in a circle are opened on the outer peripheral surface B of the head 16 in the immediate vicinity of the intersection X.

  As a feature of the first invention, the fine protrusions P are provided on the entire circumference of the outer peripheral surface A immediately adjacent to the intersecting portion X of the base portion 14. When the oil droplet M that has slid down the outer peripheral surface A from above the microprotrusions P rides on the microprotrusions P, there is a space during the transition to the outer peripheral surface B of the head 16. The oil repellency FA and the oil repellency FB from the head outer peripheral surface B are not simultaneously received. And after shifting to the head outer peripheral surface B, only the oil repellency FB is received and the sliding is continued. As a result, oil droplets are prevented from staying at the intersection X, and the formation of deposits is prevented.

  Conventionally, oil droplets are not formed in the first place, and the entire surface is in a wet state. Therefore, there is no effect even if such fine protrusions are provided. The problem itself of the generation of deposits due to oil droplet retention at the intersection X is a new problem peculiar to the case where a PES / FEP composite type oil repellent coating is used.

<Influence of crossing angle θ
The influence of the opening angle θ of the intersection X is large on whether or not the sliding down can be continued beyond the intersection X. Since the effect of the microprotrusions P is also expected to affect, sliding experiments were performed using samples set to various opening angles θ for gasoline, light oil, and lubricating oil. The experimental conditions were as follows.

[Oil-repellent coating conditions]
PES / FEP ratio = 70/30
Primary firing: 180 ° C. × 30 minutes Secondary firing: 350 ° C. × 30 minutes Film thickness: 9-10 μm
[Test medium]
Gasoline: Commercial regular light oil: Commercial oil Lubricating oil: Mineral, 5W-30
[Sample conditions]
A sample obtained by bending a flat plate coated with an oil-repellent coating at a predetermined opening angle θ was used.

[Experimental procedure]
A rough survey was performed by a dropping method using 5 μL of a microsyringe.

      The test temperature was 24 ° C.

  The test results are summarized in Table 1.

  The smaller the opening angle θ of the intersecting portion X, the easier it is to stay.

  In the case of a single medium, the lower limit values of the opening angle θ for reliably continuing sliding without staying at the intersection were gasoline 160 °, light oil 170 °, and lubricating oil 175 °.

  The lower limit of the opening angle θ in the case of gasoline / lubricating oil mixed medium is 160 ° when the amount of lubricating oil (lubricating oil%) is 10%, as in the case of gasoline alone, and the lower limit as the amount of lubricating oil increases. Was larger and was 175 ° at 80% as in the case of the lubricating oil alone.

  As described above, the tendency of occurrence of stagnation for each medium is influenced by the opening angle θ of the intersecting portion. Therefore, the size of the minute protrusion P, the inclination angle θ2 (FIG. 4) and the like for the prevention need to be set accordingly. There is.

[Embodiment 2]
An embodiment of a fuel injection valve for an internal combustion engine according to the second invention will be described with reference to FIG.

  FIG. 5 is an enlarged side view showing a part of the fuel injection valve for the internal combustion engine of the second invention. The illustrated fuel injection valve 110 is provided with the aforementioned PES / FEP composite type oil repellent coating on the outer peripheral surface.

  The outer shape of the needle contact portion 12 of the body is a two-stage structure having a truncated cone-shaped base portion 14 and a head portion 16 protruding from the base portion 14, and the outer peripheral surface A of the base portion 14 and the outer peripheral surface B of the head portion 16 The intersection X is an inward corner, and a plurality of nozzle holes 18 arranged in a circle are opened on the outer peripheral surface B of the head 16 in the immediate vicinity of the intersection X.

  As a feature of the second invention, the outer peripheral surfaces A to B continuing from the base portion 14 to the head portion 16 through the intersection X extend from the region 22 closer to the base portion 14 to the region 24 between the nozzle holes 18 than the nozzle holes 18. Other than the outer peripheral surfaces A and B of the regions 26 and 28, the contour of the recess is closed in the oil drop sliding direction (arrow Y in the figure) in the region 24 between the nozzle holes 18. V-shaped.

  The depth of the recesses 22 to 24 is desirably equal to or greater than the size of the sliding oil drop (typically about 50 μm). The oil droplets sliding down from the base region 22 are collected in the depressions in the region 24 between the nozzle holes 18 and fall in the depressions, so that they do not stay in the vicinity of the nozzle holes 18 and therefore deposits are generated. Absent.

  One method for producing the fuel injection valve 110 for an internal combustion engine is to form a recess in the regions 22 to 24 by machining, electrolytic polishing, etching, etc., and then surface roughening by shot blasting, and finally PES / FEP. A composite oil repellent film is formed.

[Embodiment 3]
An embodiment of a fuel injection valve for an internal combustion engine according to the third invention will be described with reference to FIG.

  FIG. 6 is an enlarged side view showing a part of the fuel injection valve for the internal combustion engine of the third invention. The illustrated fuel injection valve 120 is provided with the aforementioned PES / FEP composite type oil repellent coating on the outer peripheral surface.

  The outer shape of the needle contact portion 12 of the body is a two-stage structure having a truncated cone-shaped base portion 14 and a head portion 16 protruding from the base portion 14, and the outer peripheral surface A of the base portion 14 and the outer peripheral surface B of the head portion 16 The intersection X is an inward corner, and a plurality of nozzle holes 18 arranged in a circle are opened on the outer peripheral surface B of the head 16 in the immediate vicinity of the intersection X.

  As a feature of the third invention, the outer peripheral surfaces A to B continuing from the base portion 14 to the head portion 16 through the intersection portion X slide down from the region 30 closer to the base portion 14 to the region 32 between the nozzle holes 18 than the nozzle holes 18. A plurality of oil droplet guide grooves 34 having a width and depth larger than the size of the oil droplets extend in the vertical direction (double-headed arrow Z in the figure), and a plurality of oil droplet guides are formed in the region 32 between the nozzle holes 18. The tips of the grooves 34 in the oil drop sliding direction (arrow Y in the figure) are united.

  The typical size of the sliding oil droplet is about 50 μm, and the width and depth of the oil droplet guide groove 34 are desirably larger than this. The oil droplets that slide down from the base-side region 30 travel in the guide groove 34 and are collected and dropped in the region 32 between the nozzle holes 18, so that they do not stay near the nozzle holes 18, and therefore deposits may occur. Absent.

  As an additional effect, the PES / FEP composite-type oil repellent coating around the nozzle hole 18 has improved adhesion for improved peeling resistance due to lateral grooves.

[Embodiment 4]
An embodiment of a fuel injection valve for an internal combustion engine according to the fourth invention will be described with reference to FIG.

  FIG. 7 is an enlarged side view showing a part of the fuel injection valve for the internal combustion engine of the fourth invention. The illustrated fuel injection valve 130 is provided with the aforementioned PES / FEP composite type oil repellent coating on the outer peripheral surface.

  The outer shape of the needle contact portion 12 of the body is a two-stage structure having a truncated cone-shaped base portion 14 and a head portion 16 protruding from the base portion 14, and the outer peripheral surface A of the base portion 14 and the outer peripheral surface B of the head portion 16 The intersection X is an inward corner, and a plurality of nozzle holes 18 arranged in a circle are opened on the outer peripheral surface B of the head 16 in the immediate vicinity of the intersection X.

  As a feature of the fourth invention, the outer peripheral surfaces E to A to B continuing from the end portion 36 of the body main body portion to the head portion 16 through the base portion 14 and the intersection portion X are smaller in width and depth than the size of the sliding oil droplets. This is an orientation roughened surface in which fine streak grooves in the vertical direction (double-headed arrow Z in the figure) are dense.

  Since the oil droplets are promoted to slide down by the orientation roughened surface where the fine streak grooves are densely gathered and are selectively collected in the region between the nozzle holes, they do not stay in the vicinity of the nozzle holes and become a deposit.

  The fine streak of the present invention can be formed by wire brush processing, resin brush processing with abrasive grains attached, etching processing, or the like.

<Experiment to confirm the effect of orientation roughening>
The surface of the SUS304 test piece was previously polished with emery paper from one direction to create a polished surface with a surface roughness Rz = 5 μm. The polished surface was ultrasonically cleaned in acetone and then spray coated with a PES / FEP ratio of 70/30. Thereafter, primary firing at 180 ° C. for 30 minutes and secondary firing at 350 ° C. for 30 minutes were performed in the air to form a PES / FEP composite type oil-repellent coating.

  The obtained sample surface was inclined by 32 ° in the emery polishing direction (A direction) and in the direction perpendicular to the emery polishing direction (B direction), and commercial light oil (20 μL) was dropped to measure the sliding time between distances of 10 mm. did.

  For comparison, the same measurement was performed on a sample that was subjected to isotropic roughening by shot blasting without being roughened by emery polishing. The obtained results are shown in FIG.

  From the result shown in the figure, the polishing direction (direction A) of the sample roughened by emery polishing has a sliding time of 10 mm for 18 seconds, which is 64% compared with 28 seconds for the sample roughened by shot blasting. It was shortened. The 10 mm sliding time in the direction perpendicular to the polishing direction (B direction) of the orientation roughened sample by emery polishing was 47 seconds, which was considerably longer than that of the isotropic roughened sample by shot blasting. The A direction sliding time of the orientation roughened sample is ½ or less of the B direction sliding time.

  According to the present invention, there is provided a fuel injection valve for an internal combustion engine having an oil repellent coating of a PES / FEP composite type and having an inward corner-shaped intersection on the outer shape of the needle contact portion. Provided is a fuel injection valve for an internal combustion engine that has improved oil repellency and surface morphology so that droplets can be quickly slid down without staying in the vicinity of the injection hole.

It is a side view which shows the needle contact part vicinity of the fuel injection valve for internal combustion engines made into the object of this invention. It is sectional drawing which shows the needle contact part vicinity of the fuel injection valve for internal combustion engines made into the object of this invention. FIG. 3 is an enlarged cross-sectional view showing the behavior of sliding oil droplets in the vicinity of the intersection of the outer peripheral surface of the needle contact portion of the fuel injection valve for the internal combustion engine shown in FIGS. 1 and 2. It is sectional drawing for demonstrating one Embodiment by 1st invention. It is sectional drawing for demonstrating one Embodiment by 2nd invention. It is sectional drawing for demonstrating one Embodiment by 3rd invention. It is sectional drawing for demonstrating one Embodiment by 4th invention. It is a graph which shows the experimental result about the sliding-down acceleration effect by 4th invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Body 12 Needle contact part 14 Base 16 Head 18 Injection hole 20 Needle 22 Base part area | region 24 Inter-hole area | region 26, 28 Other area | region 30 Base part vicinity area | region 32 Inter-hole area 34 Oil droplet guide groove 36 Body main body End portion 100, 110, 120 Fuel injection valve A, B, C, D, E Outer peripheral surface M Oil droplet FA, FB Oil repellency G space P Micro protrusion RA, RX Sliding drive force X Intersection

Claims (7)

An oil-repellent coating is provided on the surface of a metal substrate, and the oil-repellent coating has an FEP discrete phase in a lower layer of PES in close contact with the surface of the substrate and a continuous phase of PES integrated with the lower layer PES. A fuel injection valve for an internal combustion engine, the upper layer being exposed as a surface of the oil repellent coating,
The outer shape of the needle contact portion of the body is a two-stage structure with a truncated cone-shaped base and a head protruding from the base, and the intersection of the outer peripheral surface of the base and the outer peripheral surface of the head is inward In the fuel injection valve for an internal combustion engine in which a plurality of injection holes arranged circumferentially are opened on the outer peripheral surface in the immediate vicinity of the intersection of the heads,
On the outer peripheral surface of the base near the intersection, an oil droplet that slides from the base outer peripheral surface to the head outer peripheral surface can extend on an extension line that desires the fuel supply direction from the nozzle hole of the head. A fuel injection valve for an internal combustion engine, characterized in that a small protrusion is provided.   2. The fuel injection valve for an internal combustion engine according to claim 1, wherein the maximum height of the minute projection is set to a height that does not block a spray range from each nozzle hole. An oil-repellent coating is provided on the surface of a metal substrate, and the oil-repellent coating has an FEP discrete phase in a lower layer of PES in close contact with the surface of the substrate and a continuous phase of PES integrated with the lower layer PES. A fuel injection valve for an internal combustion engine, the upper layer being exposed as a surface of the oil repellent coating,
The outer shape of the needle contact portion of the body is a two-stage structure with a truncated cone-shaped base and a head protruding from the base, and the intersection of the outer peripheral surface of the base and the outer peripheral surface of the head is inward In the fuel injection valve for an internal combustion engine in which a plurality of injection holes arranged circumferentially are opened on the outer peripheral surface in the immediate vicinity of the intersection of the heads,
The outer peripheral surface that continues from the base to the head through the intersection is a depression that is dug down by one step from the outer surface of the other region from the region closer to the base than the nozzle hole to the region between the nozzle holes. A fuel injection valve for an internal combustion engine, which is formed and has a V-shaped contour that is closed in the oil drop sliding direction in the region between the nozzle holes. An oil-repellent coating is provided on the surface of a metal substrate, and the oil-repellent coating has an FEP discrete phase in a lower layer of PES in close contact with the surface of the substrate and a continuous phase of PES integrated with the lower layer PES. A fuel injection valve for an internal combustion engine, the upper layer being exposed as a surface of the oil repellent coating,
The outer shape of the needle contact portion of the body is a two-stage structure with a truncated cone-shaped base and a head protruding from the base, and the intersection of the outer peripheral surface of the base and the outer peripheral surface of the head is inward In the fuel injection valve for an internal combustion engine in which a plurality of injection holes arranged circumferentially are opened on the outer peripheral surface in the immediate vicinity of the intersection of the heads,
A plurality of outer peripheral surfaces that continue from the base to the head through the intersecting portion have a width and depth larger than the size of the sliding oil droplets from a region closer to the base than the nozzle hole to a region between the nozzle holes. A fuel injection valve for an internal combustion engine, characterized in that the oil droplet guide grooves extend in the vertical direction, and the oil droplet sliding direction tips of the plurality of oil droplet guide grooves are combined in the region between the nozzle holes. . An oil-repellent coating is provided on the surface of a metal substrate, and the oil-repellent coating has an FEP discrete phase in a lower layer of PES in close contact with the surface of the substrate and a continuous phase of PES integrated with the lower layer PES. A fuel injection valve for an internal combustion engine, the upper layer being exposed as a surface of the oil repellent coating,
The outer shape of the needle contact portion of the body is a two-stage structure with a truncated cone-shaped base and a head protruding from the base, and the intersection of the outer peripheral surface of the base and the outer peripheral surface of the head is inward In the fuel injection valve for an internal combustion engine in which a plurality of injection holes arranged circumferentially are opened on the outer peripheral surface in the immediate vicinity of the intersection of the heads,
The outer peripheral surface that continues from at least the base to the head through the intersection is an alignment roughened surface in which vertical fine streak grooves having a width and depth smaller than the size of the sliding oil drop are densely packed. A fuel injection valve for an internal combustion engine.   6. The oil-repellent coating according to claim 1, wherein the weight ratio of PES and FEP constituting the oil-repellent coating is PES wt%: FEP wt% of 40:60 to 80:20. A fuel injection valve for an internal combustion engine.   In Claim 6, PESwt%: FEPwt% is 60: 40-75: 25, The component provided with the oil-repellent film characterized by the above-mentioned.

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