Fuel injector nozzle cooling structure, fuel injector and engine

Abstract

The utility model discloses a fuel injector nozzle cooling structure, a fuel injector and an engine, the fuel injector nozzle cooling structure comprises a fuel injector bushing and a nozzle body, the nozzle body is installed in the fuel injector bushing, the nozzle body and the fuel injector bushing are in clearance fit, a plurality of annular grooves are arranged on the outer wall surface of the nozzle body, and the annular grooves are communicated with the fuel injector bushing. An elastic split ring is installed in the annular groove, the upper surface and the lower surface of the elastic split ring are attached to the upper inner wall face and the lower inner wall face of the annular groove respectively, and the outer surface of the elastic split ring is attached to the inner wall face of the oil sprayer bush. On the premise that the structural strength of an original cylinder cover is kept, cooling is achieved, the cracking risk caused by the thin wall is avoided, meanwhile, the overall structure is simple and convenient to assemble, the split elastic ring can be installed through an assembly tool, the split elastic ring can be independently replaced, and the maintenance cost is reduced.

Description

Technical Field

[0001] This utility model belongs to the technical field of injector nozzle structure improvement, specifically relating to an injector nozzle cooling structure, an injector, and an engine. Background Technology

[0002] The statements herein provide only background information related to this invention and do not necessarily constitute prior art.

[0003] The fuel injector is a crucial component for controlling the amount of fuel injected into an engine, playing a vital role in its normal operation. In compression-ignition internal combustion engines, the injector nozzle operates in a high-temperature, high-pressure environment, making it susceptible to overheating, which can lead to fuel coking and carbon buildup, affecting fuel injection performance and even clogging the injection holes.

[0004] To ensure proper mounting of the nozzle body onto the injector bushing, a clearance fit is typically used between the nozzle body and the injector bushing. This clearance creates a significant thermal resistance layer, obstructing the heat conduction path of the nozzle body and causing the nozzle to remain at a high temperature for extended periods, preventing the injector from functioning properly. Common methods to reduce nozzle temperature include thinning the cylinder head base plate to shorten the distance between the nozzle and the cooling water passages. However, this can weaken the cylinder head structure, reduce reliability, and prevent meeting the expected design life. Another method is to move the nozzle upwards to reduce its protrusion, but this is often limited by the injection angle and structural design, offering limited adjustment space and poor cooling performance. Other techniques include adding a heat-insulating coating to the outer surface of the nozzle, but these are costly to manufacture and difficult to mass-produce. Utility Model Content

[0005] The purpose of this invention is to provide a fuel injector nozzle cooling structure, fuel injector, and engine. By utilizing an elastic ring, the assembly gap between the nozzle body and the fuel injector bushing can be eliminated, the heat conduction path can be expanded, and the nozzle temperature can be effectively reduced.

[0006] To achieve the above objectives, this utility model is implemented through the following technical solution:

[0007] In a first aspect, embodiments of this utility model provide a fuel injector nozzle cooling structure, including a fuel injector bushing and a nozzle body. The nozzle body is installed inside the fuel injector bushing, and there is a clearance fit between the nozzle body and the fuel injector bushing. A plurality of annular grooves are provided on the outer wall surface of the nozzle body, and a spring-loaded open ring is installed in the annular groove. The upper and lower surfaces of the spring-loaded open ring are respectively in contact with the upper and lower inner wall surfaces of the annular groove, and the outer surface of the spring-loaded open ring is in contact with the inner wall surface of the fuel injector bushing.

[0008] As a further technical solution, the height of the elastic opening ring is equal to the height of the annular groove, and the thickness of the elastic opening ring is greater than the gap thickness between the nozzle body and the injector bushing.

[0009] As a further technical solution, the plurality of annular grooves are arranged at intervals from top to bottom in the vertical direction.

[0010] As a further technical solution, the height of the annular groove is greater than the distance between two adjacent annular grooves.

[0011] As a further technical solution, the opening positions of two adjacent elastic open rings are staggered.

[0012] As a further technical solution, the elastic opening ring is made of an elastic metal material.

[0013] As a further technical solution, in the free state, the inner diameter of the elastic open ring is larger than the inner diameter of the annular groove, and the outer diameter is equal to the inner diameter of the injector bushing.

[0014] As a further technical solution, in the assembled state, the inner diameter of the elastic open ring is equal to the inner diameter of the annular groove, and the outer diameter is equal to the outer diameter of the annular groove.

[0015] Secondly, embodiments of this utility model provide an injector, including the injector injection cooling structure described in the first aspect.

[0016] Thirdly, embodiments of the present invention provide an engine including the injector described in the second aspect.

[0017] The beneficial effects of the above-described embodiments of this utility model are as follows:

[0018] The injector nozzle cooling structure of this utility model has multiple annular grooves machined on the outer wall of the injector nozzle body, and a matching elastic open ring is introduced. The elastic open ring is stretched open by its own elastic force, and its outer surface will form good pressure contact with the injector bushing under the action of elastic force, ultimately realizing the function of expanding the heat transfer path and reducing the nozzle temperature.

[0019] The injector nozzle cooling structure of this utility model utilizes the natural rebound of the open elastic ring, which allows its outer surface to make pressure contact with the surface of the injector bushing, forming a good contact state. This fundamentally avoids the possibility of gaps between the outer surface of the elastic ring and the surface of the bushing. At the same time, relying on the natural rebound of the elastic ring, there is no internal stress caused by interference fit and extrusion, nor is there any risk of structural deformation.

[0020] The injector nozzle cooling structure of this utility model achieves cooling while maintaining the original cylinder head structural strength, avoiding the risk of cracking caused by thin-walled construction. At the same time, the overall structure is simple and easy to assemble. The open elastic ring can be installed by means of assembly tooling, and the open elastic ring can be replaced separately, reducing maintenance costs. Attached Figure Description

[0021] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute an improper limitation of this utility model.

[0022] Figure 1 This is a schematic diagram of the fuel injector nozzle cooling structure of this utility model;

[0023] Figure 2 This is a schematic diagram of the nozzle body of this utility model;

[0024] Figure 3 This is a schematic diagram of the elastic open ring of this utility model;

[0025] Figure 4 yes Figure 1 A magnified view of a section at point A in the middle;

[0026] Figure 5 This is a schematic diagram of the assembly of the fuel injector nozzle cooling structure of this utility model.

[0027] Figure 6 yes Figure 5 A magnified view of a section at point B in the middle;

[0028] Figure 7 This is a schematic diagram of the assembly tooling used during the assembly of the fuel injector nozzle cooling structure of this utility model.

[0029] The diagram is for illustrative purposes only.

[0030] Among them, 1. Injector bushing; 2. Nozzle body; 201. Annular groove; 3. Needle valve body; 4. Elastic opening ring; 401. Upper surface; 402. Lower surface; 403. Outer surface; 404. Inner surface; 5. Assembly fixture. Detailed Implementation

[0031] It should be noted that the following detailed description is exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0032] Example 1

[0033] In a typical embodiment of this utility model, such as Figures 1-4 As shown, a fuel injector nozzle cooling structure is provided, including a fuel injector bushing 1 and a nozzle body 2. The nozzle body 2 is installed inside the fuel injector bushing 1, and a needle valve body 3 is provided inside the nozzle body 2. The nozzle body 2 and the fuel injector bushing 1 are clearance-fitted. A plurality of annular grooves 201 are provided on the outer wall surface of the nozzle body 2. A spring-loaded open ring 4 is installed in the annular grooves 201. The upper surface 401 and the lower surface 402 of the spring-loaded open ring 4 are respectively attached to the upper inner wall surface and the lower inner wall surface of the annular groove 201. The outer surface 403 of the spring-loaded open ring 4 is attached to the inner wall surface of the fuel injector bushing 1.

[0034] In this embodiment, the height of the elastic open ring 4 is equal to the height of the annular groove 201, and the thickness of the elastic open ring 4 is greater than the gap thickness between the nozzle body 2 and the injector bushing 1. In its free state, the inner diameter of the elastic open ring is greater than the inner diameter of the annular groove, and its outer diameter is equal to the inner diameter of the injector bushing. In its assembled state, the inner diameter of the elastic open ring is equal to the inner diameter of the annular groove, and its outer diameter is equal to the outer diameter of the annular groove. This ensures that the elastic pressure ring can be fully embedded in the annular groove in the assembled state, facilitating the assembly process. It also ensures that the elastic pressure ring can connect the nozzle body and the injector bushing in its natural state, establishing a stable contact interface and thus expanding the heat transfer path from the nozzle body to the injector bushing.

[0035] Furthermore, the upper and lower surfaces of the elastic open ring and the upper and lower surfaces of the ring groove are in a small interference fit to ensure that the elastic ring always has an interference of 0.02-0.05mm, thus establishing a stable pressure contact interface.

[0036] In this embodiment, the plurality of annular grooves 201 are arranged sequentially from top to bottom in the vertical direction. Furthermore, the height of the annular grooves 201 is greater than the distance between two adjacent annular grooves, thereby maximizing the contact area between the elastic opening ring and the nozzle body and the injector bushing, extending the heat transfer distance while increasing the heat dissipation area, so as to ensure a better cooling effect on the nozzle body.

[0037] In this embodiment, the opening positions of two adjacent elastic opening rings 4 are staggered to disperse local overheating caused by the opening position of the elastic opening rings, and to avoid large-area local overheating of the nozzle body due to the opening positions being on the same vertical line. At the same time, it can also increase the complexity of the air passage between the nozzle body and the bushing, preventing the entry of high-temperature back gas in the cylinder.

[0038] In this embodiment, the elastic open ring 4 is made of an elastic metal material, such as beryllium copper alloy, which has a thermal conductivity of 105 W / m·K and maintains a stable elastic modulus at 200°C.

[0039] During assembly, such as Figure 5-7As shown, the elastic opening ring 4 is first assembled onto the nozzle body 2 using the cylindrical assembly fixture 5. At this time, the elastic opening ring 4 is closed, and the gap between the inner surface of the elastic opening ring 4 and the annular groove is reduced, or even in contact. Then, the injector is assembled onto the injector bushing 1. After assembly, the assembly fixture 5 is pulled away downwards along the injector axis. The elastic opening ring 4 opens due to its own elasticity, and its outer surface forms good pressure contact with the injector bushing under the action of elasticity, ultimately achieving the effect of expanding the heat transfer path and reducing the nozzle temperature.

[0040] This invention relates to a fuel injector nozzle cooling structure that utilizes the natural rebound of an open elastic ring to create pressure contact between its outer surface and the injector bushing surface, resulting in a good contact condition. This fundamentally avoids the possibility of gaps between the outer surface of the elastic ring and the bushing surface. Furthermore, relying on the natural rebound of the elastic ring, there is no internal stress caused by interference fit compression, nor is there any risk of structural deformation.

[0041] Example 2

[0042] In a typical embodiment of this utility model, an injector is provided, including the injector spray cooling structure as described in Example 1.

[0043] Example 3

[0044] In a typical embodiment of this utility model, an engine is provided, including the injector as described in Example 2.

[0045] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A fuel injector nozzle cooling structure, characterized in that, The device includes an injector bushing and a nozzle body. The nozzle body is installed inside the injector bushing with a clearance fit between it and the injector bushing. Multiple annular grooves are provided on the outer wall of the nozzle body. A spring-loaded open ring is installed in the annular groove. The upper and lower surfaces of the spring-loaded open ring are respectively in contact with the upper and lower inner wall surfaces of the annular grooves. The outer surface of the spring-loaded open ring is in contact with the inner wall surface of the injector bushing.

2. The fuel injector tip cooling structure of claim 1, wherein The height of the elastic opening ring is equal to the height of the annular groove, and the thickness of the elastic opening ring is greater than the gap thickness between the nozzle body and the injector bushing.

3. The fuel injector tip cooling structure of claim 1, wherein The plurality of annular grooves are arranged at intervals from top to bottom in the vertical direction.

4. The fuel injector tip cooling structure of claim 3, wherein The height of the annular groove is greater than the distance between two adjacent annular grooves.

5. The fuel injector tip cooling structure of claim 1, wherein The opening positions of two adjacent elastic open rings are staggered.

6. The fuel injector tip cooling structure of claim 1, wherein The elastic open ring is made of elastic metal material.

7. The fuel injector tip cooling structure of claim 1, wherein In its free state, the inner diameter of the elastic open ring is larger than the inner diameter of the annular groove, and the outer diameter is equal to the inner diameter of the injector bushing.

8. The fuel injector tip cooling structure of claim 1, wherein In the assembled state, the inner diameter of the elastic open ring is equal to the inner diameter of the annular groove, and the outer diameter is equal to the outer diameter of the annular groove.

9. A fuel injector, characterized in that, Includes the injector injection cooling structure as described in any one of claims 1-8.

10. An engine characterized by, Including the injector as described in claim 9.

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