JP4495677B2 - Processing method of nozzle - Google Patents

Description

  The present invention relates to a technique for processing a nozzle hole in a fuel injection nozzle of an engine.

The fuel injection valve of the engine is required to have high machining accuracy in the machining process of the nozzle, which is the fuel nozzle, because the fuel injection characteristics affect the performance and fuel consumption of the engine. Conventionally, as a processing method of a nozzle of a fuel injection nozzle, as shown in Patent Document 1 or Patent Document 2, a processing method by fluid polishing has been known and widely practiced. According to this processing method by fluid polishing, the inlet shape of the nozzle hole can be adjusted with high accuracy and a smooth continuous surface can be formed, so that a fuel injection nozzle with little variation in injection characteristics can be manufactured. It has become.
Japanese Patent No. 2695848 JP 2000-161174 A

  However, in the conventional processing method using fluid polishing, the flow of the slurry-like abrasive used for polishing is uneven depending on the position, so that the amount of polishing (R processing) at the nozzle inlet and the cross-sectional shape of the nozzle become non-uniform. I was doing. Moreover, the conventional processing method contributes to the improvement of the inlet shape of the nozzle hole, and the inner wall surface and outlet shape of the nozzle hole cannot be adjusted. For this reason, the conventional processing method cannot be adjusted to a nozzle shape that optimizes the fuel injection characteristics. Therefore, in the present invention, in view of the current situation as described above, a processing method by fluid polishing that enables control of the nozzle shape of the fuel injection nozzle is provided.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

In Claim 1, with respect to the injection hole (58) in the fuel injection nozzle (50) of the engine (1), the pin (61) is inserted from the outlet portion toward the inlet portion, and the pin (61) is inserted. In this state, slurry-like abrasive is injected at a high pressure from the gap (50a) side, which is the inside of the injection nozzle (50), and the abrasive is ejected to the outlet, which is outside the nozzle (58). In this method, the pin (61) has a cross-sectional shape in which a curved surface process is performed on the inlet portion inside the nozzle hole (58) and the inner wall surface of the nozzle hole (58) is polished. In a state where the pin (61) is arranged through the nozzle hole (58) and the gap on one side is small and the gap on the other side is large. In this state, the abrasive is allowed to flow from the upper part of the gap (50a). The curved surface processing of the inlet portion of the nozzle (58) is processed uniformly or non-uniformly, and a portion where the gap between the pin (61) and the inner wall surface of the nozzle (58) is wide is a polishing amount. On the contrary, in a portion where the gap between the pin (61) and the inner wall surface of the nozzle hole (58) is narrow, the amount of polishing is reduced, and the cross-sectional shape of the inner wall of the nozzle hole (58) is made uniform or non-uniform. It is processed into a uniform substantially elliptical shape .

According to claim 2, the slurry-like abrasive is applied to the nozzle (58) of the fuel injection nozzle (50) of the engine (1) from the gap (50a) side which is the inside of the injection nozzle (50). In the injection hole processing method for polishing the inner wall surface of the injection hole (58) by injecting the abrasive at an outlet portion outside the injection hole (58) by injecting at a high pressure, the injection hole (58 The stepped pin (62) is inserted from the outside into the outlet of the step), and the diameter of the tip of the stepped pin (62) is smaller than the diameter of the main body and smaller than the diameter of the nozzle (58). The diameter of the main body of the pin (62) is configured to be larger than the diameter of the nozzle (58), the stepped pin (62) is inserted from the outside of the nozzle (58), and the stepped pin (62) Tip outer periphery, inner periphery of the nozzle (58), and stepped pin (62) A portion where a gap is formed between the stepped pin (62) and the outlet portion in a state where a predetermined gap is formed between the surface and the outlet portion outer surface of the nozzle (58). Increases the amount of polishing, and conversely reduces the amount of polishing at locations where the gap between the stepped pin (62) and the outlet is narrow, and reduces the amount of polishing at the outlet of the nozzle (58). It adjusts with the amount of clearance gaps between an attached pin (62) and the exit part of the said nozzle hole (58) .

  As effects of the present invention, the following effects can be obtained.

In Claim 1, with respect to the injection hole (58) in the fuel injection nozzle (50) of the engine (1), the pin (61) is inserted from the outlet portion toward the inlet portion, and the pin (61) is inserted. In this state, slurry-like abrasive is injected at a high pressure from the gap (50a) side, which is the inside of the injection nozzle (50), and the abrasive is ejected to the outlet, which is outside the nozzle (58). In this method, the pin (61) has a circular cross-sectional shape in which the inlet portion, which is the inside of the nozzle hole 58, is curved and the inner wall surface of the nozzle hole (58) is polished. In a state where the pin (61) is disposed through the nozzle hole (58), the pin (61) is arranged in an adjusted state so that the gap on one side is small and the gap on the other side is large, By flowing the abrasive from the top of the gap (50a) in the state The curved surface processing of the inlet portion of the nozzle hole (58) is processed uniformly or non-uniformly, and the portion where the gap between the pin (61) and the inner wall surface of the nozzle hole (58) is wide increases the amount of polishing processing. On the other hand, in a portion where the gap between the pin (61) and the inner wall surface of the nozzle hole (58) is narrow, the amount of polishing is reduced, and the sectional shape of the inner wall of the nozzle hole (58) is uniform or non-uniform. Since this is a nozzle processing method for processing into a substantially elliptical shape, the polishing amount of the nozzle of the injection nozzle can be controlled.

  In addition, the curved R processing amount around the injection nozzle inlet of the injection nozzle can be made uniform or non-uniform.

Moreover, the cross section of the injection nozzle of the injection nozzle can be made uniform or non-uniform.
Thereby, the shape of the spray can be adjusted so that the combustion is optimized.

According to claim 2, the slurry-like abrasive is applied to the nozzle (58) of the fuel injection nozzle (50) of the engine (1) from the gap (50a) side which is the inside of the injection nozzle (50). In the injection hole processing method for polishing the inner wall surface of the injection hole (58) by injecting the abrasive at an outlet portion outside the injection hole (58) by injecting at a high pressure, the injection hole (58 The stepped pin (62) is inserted from the outside into the outlet of the step), and the diameter of the tip of the stepped pin (62) is smaller than the diameter of the main body and smaller than the diameter of the nozzle (58). The diameter of the main body of the pin (62) is configured to be larger than the diameter of the nozzle (58), the stepped pin (62) is inserted from the outside of the nozzle (58), and the stepped pin (62) Tip outer periphery, inner periphery of the nozzle (58), and stepped pin (62) A portion where a gap is formed between the stepped pin (62) and the outlet portion in a state where a predetermined gap is formed between the surface and the outlet portion outer surface of the nozzle (58). Increases the amount of polishing, and conversely reduces the amount of polishing at locations where the gap between the stepped pin (62) and the outlet is narrow, and reduces the amount of polishing at the outlet of the nozzle (58). Since the processing method of the nozzle hole is adjusted by the gap amount between the attached pin (62) and the outlet portion of the nozzle hole (58), the polishing amount of the nozzle nozzle outlet portion of the injection nozzle can be controlled.

  In addition, the curved R processing amount around the outlet of the injection nozzle can be made uniform or non-uniform.

  Thereby, the shape of the spray can be adjusted so that the combustion is optimized.

  Next, embodiments of the invention will be described.

  First, the overall configuration of the engine 1 according to the present invention will be described with reference to FIG.

  In the following description, the vertical direction of the drawing in FIG.

  As shown in FIG. 1, an engine 1 according to the application of the present invention is provided with a cylinder head 4 on the upper side of a cylinder block 3 and an oil pan 5 for storing lubricating oil attached on the lower side of the cylinder block 3. .

  As shown in FIG. 1, a crankshaft 7 is supported in the horizontal direction at the bottom of the cylinder block 3, and a piston 8 is connected to the crankshaft 7 via a connecting rod 9, and the piston 8 is substantially vertically up and down. The crankshaft 7 is rotationally driven by being reciprocally moved. That is, a cylinder 10 is formed on the upper side (cylinder head 4 side) in the cylinder block 3, and a piston 8 connected to the crankshaft 7 and the connecting rod 9 in the cylinder 10 slides in a substantially vertical direction. It is movably fitted inside.

  A bonnet (valve arm case) 11 is attached to the upper side of the cylinder head 4, and the inside of the bonnet 11 serves as a valve arm chamber 12 to constitute a valve operating mechanism. That is, in the valve arm chamber 12, a valve arm support 13 is mounted on the cylinder head 4, and a valve arm shaft that pivotally supports a valve arm 14 for operating the intake valve and the exhaust valve on the valve arm support 13, respectively. 29 is fitted. One end of the valve arm 14 is brought into contact with the upper end of a valve rod 15 of an intake valve or an exhaust valve, and one end of a push rod 16 is connected to the other end. The other end of the push rod 16 is brought into contact with a cam 32a on a cam shaft 32 rotated by the rotation of the crankshaft 7, and the push rod 16 is reciprocated substantially up and down by the rotation of the cam 32a. A spring 17 is disposed on the outer periphery of the valve rod between one end of the valve arm 14 and the cylinder head 4. Thus, each valve arm 14 is rotated by the push rod 16 to rotate with respect to the valve arm support 13 and pushes the valve rod 15 of the intake valve or exhaust valve downward against the elastic force of the spring 17. On the other hand, when the push rod 16 is released, the spring 17 rotates to return (close) to its original position by the elastic force of the spring 17.

  A combustion chamber formed by the lower surface of the cylinder head 4 and the piston heads of the cylinder 10 and the piston 8 is provided with the tip (lower end) of the fuel injection valve 18 penetrating the cylinder bed 4 in the vertical direction. Yes. That is, the fuel is injected when the intake valve or the exhaust valve is closed and the piston 8 is raised. In addition, an intake port (intake manifold) 19 and an exhaust port (exhaust manifold) 20 are formed on the side surface of the cylinder head 4 to supply air to the intake valve and exhaust gas discharged from the exhaust valve. The gas is discharged outside the machine.

  A fuel injection pump 21 is disposed on the side of the cylinder block 3, and fuel stored in a fuel tank (not shown) is pressurized by the fuel injection pump 21 and supplied to the fuel injection valve 18. . A lubricating oil pump 26 is disposed below the fuel injection pump 21, and the lubricating oil stored in the oil pan 5 is pumped up and supplied to each part through an oil passage (not shown) in the wall of the cylinder block 3. In addition, the inside of the engine 1 is lubricated by circulating lubricating oil. In addition, a cell motor 27 is disposed on the opposite side portion so that the engine 1 can be easily started only by pressing a switch or the like. The above is the description of the overall configuration of the engine 1 according to the present invention.

  Next, the fuel injection valve 18 which is a main part of the present invention will be described with reference to FIG. As shown in FIG. 2, the fuel injection valve 18 includes an injection nozzle 50, a connecting member 51, a nozzle holder 52, a nut 53, a needle valve 54, a rod 55, a rod holder 56, a nozzle spring 57, and the like.

  The injection nozzle 50 is a member obtained by turning a cylindrical metal member into a bamboo shoot shape. The injection nozzles 58 and 58 are bored at the tip, and the needle valve 54 is accommodated on the central axis of the member. A gap 50a communicating with 58 is drilled, and a fuel passage 50b for guiding fuel to the gap 50a is drilled.

  The nozzle holder 52 is a member obtained by turning a cylindrical member, and a gap 52a that accommodates a nozzle spring 57 and the like is formed on the central axis of the member, and a fuel passage 52b that guides fuel to the injection nozzle 50. Is drilled. A fuel supply port 52 f through which fuel is supplied from the fuel injection pump 21 is formed on the upper side surface of the nozzle holder 52.

  The connecting member 51 is a columnar metal member. A fuel passage 51b for communicating the fuel passages 50b and 52b is formed, and a hole through which the rod 55 is inserted is formed on the central axis. Yes. A screw part 51a is formed on the circumferential side surface. The connecting member 51 is screwed into the cap nut 53 by the threaded portion 51 a to hold down the injection nozzle 50, thereby integrating the injection nozzle 50 and the nut 53, and a fuel path 50 b of the injection nozzle 50 and the nozzle holder 52. -52b is made to communicate. Further, positioning holes 51d and 51e for preventing displacement of the fuel passages 50b and 52b are formed in the lower surface and the upper surface of the connecting member 51, and positioning pins 60 and 63 are provided in the positioning holes 51d and 51e. The fuel passages 50b and 52b are connected to each other without being displaced by fitting and positioning with the positioning holes 50d and 52d formed corresponding to the injection nozzle 50 and the nozzle holder 52, respectively. .

  The needle valve 54 is always urged downward by the spring force of the nozzle spring 57 through the rod 55 and the rod holder 56, and the pointed end of the needle valve 54 is formed at the lower end of the gap 50a. 50e is pressed and closed. As a result, the fuel flow to the nozzle hole 58 is blocked. Further, when the fuel supply pressure rises, the inclined portion 54a formed at the substantially central portion of the needle valve 54 is pressed by the fuel, and an upward drag against the urging force by the nozzle spring 57 acts, The needle valve 54 is going to be lifted. At this time, when the drag exceeds the urging force of the nozzle spring 57, the fuel passage 51b can be circulated to the nozzle 58 and fuel is supplied. Thus, the fuel injection valve 18 includes a mechanism that automatically adjusts the fuel injection amount in accordance with the fuel supply pressure.

  Further, a return port 52e is formed in the side surface of the gap portion 52a of the nozzle holder 52, and when the nozzle ports 54 and 58 are closed by the needle valve 54, the nozzle is inserted from the gap between the needle valve 54 and the nozzle 50. An opening is formed for returning the fuel entering the spring 57 side to a fuel tank or the like (not shown). The above is description of the fuel injection valve 18 which is the principal part of this invention.

  Next, a fluid polishing method for the nozzle hole 58 which is the gist of the present invention will be described with reference to FIGS. 3 and 4A and 4B. As shown in FIG. 3, a nozzle hole 58 is formed at the tip of the injection nozzle 50. In the present embodiment, the example in which the injection hole 58 is formed inclining with respect to the axial direction (vertical direction) is shown, but the direction in which the injection hole 58 is formed is not limited. In such a case, the conventional fluid polishing processing method is such that a slurry-like abrasive is injected at a high pressure from the inside of the injection nozzle 50 (on the side of the gap 50a), and the abrasive is ejected from the injection nozzle 58. 58 inlets were rounded. As the abrasive, a mixture of lubricating oil and abrasive grains is used, and by adjusting the count of the abrasive grains, the mixing ratio, temperature, circulation time, circulation pressure, etc., the polishing amount and surface roughness of the part to be processed are adjusted. Can be adjusted.

  As shown in FIG. 4A, in the fluid polishing method for the inlet portion and the inner wall surface of the nozzle hole 58 according to the present invention, the fluid polishing process is performed with the pin 61 inserted through the nozzle hole 58 from the outside. I have to. In the processing of the inlet portion of the nozzle hole 58, when fluid polishing is performed with the pin 61 inserted, the flow rate of the abrasive is increased at a portion where the gap between the pin 61 and the inlet portion is wide, and the amount of polishing processing is increased. On the contrary, in a portion where the gap between the pin 61 and the inlet portion is narrow, the flow rate of the abrasive is reduced and the amount of polishing can be reduced. Similarly, when the fluid polishing process is performed with the pin 61 inserted in the inner wall surface of the nozzle hole 58, a portion where the gap between the pin 61 and the inner wall surface is wide can increase the polishing amount. On the other hand, the amount of polishing can be reduced at a portion where the gap between the pin 61 and the inner wall surface is narrow. In the present embodiment, the pin 61 having a circular cross-sectional shape is disposed so as to penetrate the nozzle hole 58 so that the upper gap is small and the lower gap is large. By flowing the abrasive from above the gap 50a in this state, the inlet portion of the nozzle hole 58 is processed into a curved surface (R shape), and the cross-sectional shape of the inner wall of the nozzle hole 58 is processed into a substantially elliptical shape in which the lower side swells. It will be. Further, by adjusting the diameter, cross-sectional shape, material, and the like of the pin 61 to be inserted, it is possible to adjust the polishing amount of the portion to be processed, the shape after polishing, and the like. For example, the processed shape can be changed by making the cross-sectional shape of the pin 61 an ellipse or adjusting the gap in the vertical and horizontal directions.

  As shown in FIG. 4B, in the fluid polishing method for the outlet portion of the nozzle 58 according to the present invention, fluid polishing is performed with the stepped pin 62 inserted into the nozzle 58 from the outside. In the processing of the outlet portion of the nozzle hole 58, the stepped pin 62 is configured such that the tip diameter is smaller than the diameter of the main body and smaller than the diameter of the nozzle hole 58, and the diameter of the main body is larger than the diameter of the nozzle hole 58. The protruding length of the tip is approximately the same as the diameter to form the stepped portion. Then, the stepped pin 62 is inserted from the outside (lower side) of the nozzle hole 58, and the outer periphery of the tip of the stepped pin 62 and the inner periphery of the nozzle hole 58, and the step surface of the stepped pin 62 and the outer surface of the nozzle outlet 58. If the fluid polishing process is performed in a state where a predetermined gap is formed therebetween, the amount of polishing process can be increased at a portion where the gap between the stepped pin 62 and the outlet portion is wide. A portion where the gap between 62 and the outlet is narrow can reduce the amount of polishing. Thus, the outlet portion of the nozzle hole 58 can be processed into a curved surface (R shape). Even in this case, by adjusting the diameter, cross-sectional shape, material, and the like of the stepped pin 62 to be inserted, it is possible to adjust the polishing amount of the processing target portion, the shape after polishing, and the like. For example, the tip of the pin 62 can be formed in a conical shape instead of a cylinder, or the stepped portion can be formed into a slope.

  In the above description, the processing method of the injection hole 58 in the injection nozzle 50 of the engine 1 is shown, which is characterized in that fluid polishing is performed in a state where the pin 61 is inserted into the injection hole 58. Thereby, the polishing amount of the nozzle hole 58 can be controlled.

  In addition, in the processing method of the nozzle hole 58, a processing method characterized by adjusting the polishing amount of the inlet portion of the nozzle hole 58 according to the gap amount between the pin 61 and the inlet portion of the nozzle hole 58 is also shown. Thereby, the amount of R processing around the inlet of the nozzle hole 58 can be made uniform or non-uniform.

  In addition, the processing method of the nozzle hole 58 also shows a processing method characterized in that the amount of polishing of the inner wall surface of the nozzle hole 58 is adjusted by the amount of clearance between the pin 61 and the inner wall surface of the nozzle hole 58. Thereby, the cross-section of the nozzle 58 can be made uniform or non-uniform, and the shape of the spray can be adjusted so that the combustion is optimal.

  Also shown is a processing method for the nozzle hole 58 in the injection nozzle 50 of the engine 1, in which fluid polishing is performed with the stepped pin 62 inserted in the outlet portion of the nozzle hole 58. ing. Thereby, the polishing amount of the outlet portion of the nozzle hole 58 can be controlled.

  In addition, in the processing method of the nozzle hole 58, a processing method characterized by adjusting the polishing amount of the outlet portion of the nozzle hole 58 according to the gap amount between the stepped pin 62 and the outlet portion of the nozzle hole 58 is also shown. Yes. Thereby, the amount of R processing around the outlet of the nozzle hole 58 can be made uniform or non-uniform, and the shape of the spray can be adjusted so that the combustion is optimized.

1 is a side sectional view showing an overall configuration of an engine according to an embodiment to which the present invention is applied. The side sectional view showing the composition of the fuel injection valve concerning one example to which the present invention is applied. BRIEF DESCRIPTION OF THE DRAWINGS Side surface sectional drawing which showed the structure of the injection nozzle which concerns on one Example to which this invention is applied, and the elements on larger scale of a nozzle part. Explanatory drawing which showed the fluid polishing processing method of the nozzle part which concerns on this invention. (A) A processing method of an injection hole inlet part and an inner wall surface, (b) A processing method of an injection hole outlet part.

1 Engine 50 Injection nozzle 58 Injection hole 61 Pin

Claims (2)

With respect to the injection port (58) in the fuel injection nozzle (50) of the engine (1), a pin (61) is inserted from the outlet portion toward the inlet portion, and the injection nozzle is inserted with the pin (61) being inserted. (50) The slurry-like abrasive is injected at a high pressure from the gap (50a) side which is the inner side of (50), and the abrasive is ejected to the outlet part which is the outer side of the nozzle (58). In the processing method for the nozzle hole, in which the inlet portion which is the inner side of (58) is curved and the inner wall surface of the nozzle (58) is polished, the pin (61) has a circular cross-sectional shape. (61) is arranged in an adjusted state so that the gap amount on one side is small and the gap amount on the other side is large in a state where it is arranged through the nozzle hole (58). By flowing from the upper part of the gap (50a), the nozzle (58) The curved surface processing of the inlet portion is processed uniformly or non-uniformly, and the portion where the clearance between the pin (61) and the inner wall surface of the injection hole (58) is wide is increased, and conversely the pin ( 61) where the gap between the inner wall surface of the nozzle hole (58) is narrow, the amount of polishing is reduced, and the sectional shape of the inner wall of the nozzle hole (58) is processed into a uniform or non-uniform substantially elliptical shape. A processing method for a nozzle hole characterized by the above. A slurry-like abrasive is injected into the nozzle (58) of the fuel injection nozzle (50) of the engine (1) from the gap (50a) side inside the injection nozzle (50) at a high pressure. In the processing method of the nozzle hole that polishes the inner wall surface of the nozzle hole (58) by ejecting the abrasive to the outlet part that is outside the nozzle hole (58), the outlet part of the nozzle hole (58) A stepped pin (62) is inserted from the outside, and the diameter of the tip of the stepped pin (62) is smaller than the diameter of the main body and smaller than the diameter of the nozzle (58), and the stepped pin (62) The diameter of the main body is configured to be larger than the diameter of the nozzle hole (58), the stepped pin (62) is inserted from the outside of the nozzle hole (58), and the outer periphery of the tip of the stepped pin (62) and the nozzle hole (58), the step surface of the stepped pin (62), and the nozzle (58) A polishing process is performed in a state where a predetermined gap is formed between the outer surface of the outlet part of each of the two parts, and a portion where the gap between the stepped pin (62) and the outlet part is wide increases a polishing process amount, Conversely, a portion where the gap between the stepped pin (62) and the outlet portion is narrow reduces the amount of polishing, and the amount of polishing at the outlet portion of the nozzle (58) is reduced by the amount of polishing at the outlet (58). (58) A method for processing a nozzle, which is adjusted according to a gap amount with an outlet portion .

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