Cavitation-erosion-resistant oil nozzle and oil sprayer

Abstract

The cavitation-resistant oil nozzle comprises an oil needle and an oil needle valve body, a pressure cavity is formed in the lower end of the oil needle valve body and comprises a first inner cavity and a second inner cavity, the lower end of the oil needle is a cone-shaped body, the first inner cavity is in a cone shape matched with the oil needle, and the second inner cavity is in a cone shape matched with the oil needle. When the oil needle descends, the lower end of the oil needle is tightly connected with the first inner cavity to seal the second inner cavity, the upper end of the second inner cavity is a cylinder connected with the first inner cavity in an arc transition mode, a plurality of spraying holes penetrating through the oil needle valve body are further formed in the second inner cavity, the bottom face of the oil needle is a plane, and the diameter of the plane is larger than that of the cylinder. Cavitation can be effectively reduced and avoided, the cavitation resistance of the oil nozzle of the oil injector is improved, the reliability of the oil injector is improved, and the service life of the oil injector is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to oil injector technical field especially relates to a kind of hole-erosion-resistant oil nozzle and oil injector. BACKGROUND

[0002] Fuel injection system is composed of high-pressure fuel pump, oil injector, common rail pipe and controller ECU.When fuel passes through the small hole of oil nozzle under high pressure, the flow rate increases sharply, and the pressure drops suddenly.If the pressure drops below the saturated vapor pressure of the liquid, gas bubbles (cavitation bubbles) will form in the liquid;When these bubbles flow with liquid to high pressure area, they will break rapidly, producing strong shock wave, which repeatedly acts on the surface of oil nozzle, leading to material fatigue and spalling, forming hole-erosion.Hole-erosion will cause the gradual corrosion of the internal metal surface of oil nozzle and oil injector, and further affect the performance and service life of oil injector. SUMMARY

[0003] The utility model aims at providing a kind of hole-erosion-resistant oil nozzle to overcome the deficiencies in the prior art.

[0004] To solve the above technical problems, the technical scheme of the utility model is as follows: a hole-erosion-resistant oil nozzle, comprising an oil needle and an oil needle valve body, the oil needle valve body has a pressure chamber at its lower end, the pressure chamber includes an inner cavity one and an inner cavity two, the lower end of the oil needle is a conical body, the inner cavity one is a cone that matches the oil needle, and when the oil needle descends, the lower end of the oil needle is tightly connected with the inner cavity one to seal the inner cavity two, the upper end of the inner cavity two is a cylindrical body that is connected with the inner cavity one in a circular arc transition, and a plurality of injection holes that penetrate through the oil needle valve body are further arranged in the inner cavity two, the bottom surface of the oil needle is a flat surface, and the diameter of the flat surface is greater than the diameter of the cylindrical body.

[0005] Further, the hole-erosion-resistant oil nozzle described above further includes a hemispherical body that is connected with the cylindrical body in a circular arc transition, and the injection holes are arranged at the transition between the cylindrical body and the hemispherical body.

[0006] Further, the hole-erosion-resistant oil nozzle described above has at least four injection holes that are evenly arranged along the circumference of the inner cavity two.

[0007] Further, the hole-erosion-resistant oil nozzle described above has injection holes with a diameter of 0.15-0.18 mm.

[0008] Further, the hole-erosion-resistant oil nozzle described above has a cylindrical body with a diameter that is 4.5-5.5 times the diameter of the injection holes.

[0009] Further, the hole-erosion-resistant oil nozzle described above has a cylindrical body with a height of 0.55-0.7 mm.

[0010] Further, the hole-erosion-resistant oil nozzle described above has a distance between the flat surface and the injection holes when the oil needle is lowered to the lowest end, which is 0.65-0.8 mm.

[0011] Furthermore, in the aforementioned cavitation-resistant nozzle, the inner wall and plane of the inner cavity two are both provided with a diamond plating layer.

[0012] This utility model also provides an injector, including the above-mentioned cavitation-resistant nozzle.

[0013] Compared with the prior art, the beneficial effects of this utility model are as follows: By optimizing the shape and size of the inner cavity of the pressure chamber, the position of the nozzle and the shape of the oil needle, this utility model can effectively reduce and avoid cavitation, improve the cavitation resistance of the injector nozzle, improve the reliability of the injector, extend the service life of the injector, make the fuel injection volume more stable, improve the fuel atomization effect, and achieve more complete combustion, thereby improving the engine's power, reliability and economy. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the cavitation-resistant nozzle of this utility model;

[0016] In the diagram: 1. Oil needle; 11. Plane; 2. Oil needle valve body; 3. Inner cavity one; 4. Inner cavity two; 41. Cylinder; 5. Spray hole. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Example 1

[0019] like Figure 1As shown, a cavitation-resistant fuel injector includes a fuel needle 1 and a fuel needle valve body 2. The lower end of the fuel needle valve body 2 is provided with a pressure chamber, which includes an inner cavity 3 and an inner cavity 4. The lower end of the fuel needle 1 is conical, and the inner cavity 3 is conical to cooperate with the fuel needle 1. When the fuel needle 1 descends, the lower end of the fuel needle 1 is tightly connected to the inner cavity 3 to seal the inner cavity 4. The upper end of the inner cavity 4 is a cylinder 41 that is connected to the inner cavity 3 by an arc, and the lower end is a hemisphere that is connected to the cylinder 41 by an arc. The inner cavity 4 is also provided with a plurality of nozzles 5 penetrating the fuel needle valve body 2. The number of nozzles 5 is not less than 4. The plurality of nozzles 5 are evenly arranged around the inner cavity 4, and the nozzles 5 are located at the transition connection between the cylinder 41 and the hemisphere. Through this setting, the fuel injection volume of the fuel injector is more stable and the fuel atomization effect is better.

[0020] like Figure 1 As shown, the bottom surface of the oil needle 1 is a flat surface 11. Conventional oil needles have a sharp bottom. Setting the bottom of the oil needle 1 to a flat surface reduces turbulence and the formation of low-pressure areas, thereby reducing bubble formation. Furthermore, the diameter of the flat surface 11 is larger than the diameter of the cylinder 41, preventing the lower end of the oil needle 1 from entering the inner cavity 4, thus keeping the oil needle 1 away from the bubble formation area and reducing the impact of shock waves generated by bubbles on the oil needle 1. Specifically, when the oil needle 1 descends to its lowest point, the distance from the flat surface 11 to the nozzle 5 is 0.65 mm, away from the nozzle 5.

[0021] The diameter of the nozzle 5 is 0.15 mm.

[0022] The diameter of the cylinder 41 is 5 times the diameter of the nozzle, which can be 0.75 mm.

[0023] The height of the cylinder is 0.55mm, and the distance from the plane 11 to the nozzle 5 is extended as much as possible, so that the oil needle 1 is kept away from the bubble formation area.

[0024] In addition, the inner wall and plane 11 of the inner cavity 4 are provided with a diamond coating, specifically a DLC diamond coating. The diamond coating has high hardness, low coefficient of friction, excellent wear resistance and chemical stability, which can improve the oil needle and oil needle valve body's resistance to cavitation corrosion.

[0025] Example 2

[0026] like Figure 1As shown, a cavitation-resistant fuel injector includes a fuel needle 1 and a fuel needle valve body 2. The lower end of the fuel needle valve body 2 is provided with a pressure chamber, which includes an inner cavity 3 and an inner cavity 4. The lower end of the fuel needle 1 is conical, and the inner cavity 3 is conical to cooperate with the fuel needle 1. When the fuel needle 1 descends, the lower end of the fuel needle 1 is tightly connected to the inner cavity 3 to seal the inner cavity 4. The upper end of the inner cavity 4 is a cylinder 41 that is connected to the inner cavity 3 by an arc, and the lower end is a hemisphere that is connected to the cylinder 41 by an arc. The inner cavity 4 is also provided with a plurality of nozzles 5 penetrating the fuel needle valve body 2. The number of nozzles 5 is not less than 4. The plurality of nozzles 5 are evenly arranged around the inner cavity 4, and the nozzles 5 are located at the transition connection between the cylinder 41 and the hemisphere. Through this setting, the fuel injection volume of the fuel injector is more stable and the fuel atomization effect is better.

[0027] like Figure 1 As shown, the bottom surface of the oil needle 1 is a flat surface 11. Conventional oil needles have a sharp bottom. Setting the bottom of the oil needle 1 to a flat surface reduces turbulence and the formation of low-pressure areas, thereby reducing bubble formation. Furthermore, the diameter of the flat surface 11 is larger than the diameter of the cylinder 41, preventing the lower end of the oil needle 1 from entering the inner cavity 4, thus keeping the oil needle 1 away from the bubble formation area and reducing the impact of shock waves generated by bubbles on the oil needle 1. Specifically, when the oil needle 1 descends to its lowest point, the distance from the flat surface 11 to the nozzle 5 is 0.8 mm, away from the nozzle 5.

[0028] The diameter of the nozzle 5 is 0.18 mm.

[0029] The diameter of the cylinder 41 is 4.7 times the diameter of the nozzle, which can be 0.85 mm.

[0030] The height of the cylinder is 0.7mm, and the distance from the plane 11 to the nozzle 5 is extended as much as possible, so that the oil needle 1 is kept away from the bubble formation area.

[0031] In addition, the inner wall and plane 11 of the inner cavity 4 are provided with a diamond coating, specifically a DLC diamond coating. The diamond coating has high hardness, low coefficient of friction, excellent wear resistance and chemical stability, which can improve the oil needle and oil needle valve body's resistance to cavitation corrosion.

[0032] This utility model also provides an injector, including the above-mentioned cavitation-resistant nozzle.

[0033] This invention optimizes the shape and size of the inner cavity of the pressure chamber, the position of the nozzle, and the shape of the oil needle. This effectively reduces and avoids cavitation, improves the cavitation resistance of the injector nozzle, enhances the reliability of the injector, extends the service life of the injector, makes the fuel injection volume more stable, improves the fuel atomization effect, and achieves more complete combustion. As a result, the engine's power, reliability, and economy are also improved.

[0034] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0035] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A cavitation-resistant nozzle, characterized in that: The device includes an oil needle and an oil needle valve body. The lower end of the oil needle valve body is provided with a pressure chamber, which includes an inner cavity one and an inner cavity two. The lower end of the oil needle is conical. The inner cavity one is conical and matches the oil needle. When the oil needle descends, the lower end of the oil needle is tightly connected to the inner cavity one and seals the inner cavity two. The upper end of the inner cavity two is a cylinder that is connected to the inner cavity one by an arc transition. The inner cavity two is also provided with multiple spray holes that penetrate the oil needle valve body. The bottom surface of the oil needle is flat, and the diameter of the flat surface is larger than the diameter of the cylinder.

2. The cavitation-resistant nozzle according to claim 1, characterized in that: The inner cavity 2 also includes a hemisphere that is connected to the cylinder by an arc transition, and the nozzle is located at the transition connection between the cylinder and the hemisphere.

3. The cavitation-resistant nozzle according to claim 1, characterized in that: The nozzle has at least four holes, which are evenly arranged along the two circumferences of the inner cavity.

4. The cavitation-resistant nozzle according to claim 1 or 2, characterized in that: The diameter of the nozzle is 0.15-0.18 mm.

5. The cavitation-resistant nozzle according to claim 4, characterized in that: The diameter of the cylinder is 4.5-5.5 times the diameter of the nozzle.

6. The cavitation-resistant nozzle according to claim 5, characterized in that: The height of the cylinder is 0.55-0.7mm.

7. The cavitation-resistant nozzle according to claim 6, characterized in that: When the oil needle descends to its lowest point, the distance from the plane to the nozzle is 0.65-0.8 mm.

8. The cavitation-resistant nozzle according to claim 1, characterized in that: The inner wall and plane of the second cavity are both coated with diamond.

9. A fuel injector, characterized in that: Including the cavitation-resistant nozzle as described in any one of claims 1-8.

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