Injector assembly and installation method therefor

Abstract

The present invention provides an injector assembly for facilitating the assembly and replacement of a fuel injector. The injector assembly of the present invention comprises a case mounted to a cylinder head of an engine, the case being provided with: an injector seating part which accommodates a fuel injector; and a duct mounting hole into which a duct tube is inserted. The duct tube is fixed to the duct mounting hole of the case and enables fuel injected from a fuel injection nozzle to be delivered to a combustion chamber through a duct.

Description

Injector assembly and installation method thereof

[0001] The present invention relates to an injector assembly, and more specifically, to an injector assembly comprising a duct pipe for increasing combustion efficiency and a case for easily assembling the same.

[0002] The combustion injector is located at the top of the engine's combustion chamber and serves to induce combustion by atomizing fuel at high pressure and mixing it with compressed air. This device consists of a nozzle, injection pump, fuel supply line, and injection control valve, and is designed to inject fuel in fine particles to ensure uniform mixing with air.

[0003] Meanwhile, diesel engine combustion technology utilizes a compression ignition method to burn fuel and air, following the principle that atomized diesel fuel is mixed with compressed air and ignited at high temperature and pressure within the combustion chamber.

[0004] Diesel engine combustion technology is widely used in various industrial sectors, including automobiles, generators, and ships, due to its advantages of providing high fuel efficiency and powerful power output. In particular, ships utilize large diesel engines designed for high output and long-duration operation, establishing themselves as a reliable and economical fuel system for long-distance voyages.

[0005] Accordingly, various technologies have been developed to increase the combustion efficiency of diesel engines and reduce exhaust emissions; Ducted Fuel Injection (DFI) is one such technology that adopts a structure in which ducts are arranged and installed at the nozzle outlet of the fuel injection device.

[0006] This technology is effective in reducing unburned products (e.g., soot, hydrocarbons) by mixing injected fuel and compressed air inside a duct and igniting the mixture at a low equivalence ratio. This technology is attracting attention, particularly in large marine engines, for reducing air pollution and improving fuel efficiency.

[0007] However, DFI technology has the disadvantage of complex duct installation and assembly. The duct must be secured to the nozzle outlet of the fuel injector and maintained at a precisely designed position and angle. This process requires separate parts and tools to fix the duct, and demands additional time and effort during the engine assembly process.

[0008] In particular, in large structures such as marine engines, assembly work is not only spatially constrained, but the entire engine often has to be disassembled for duct maintenance or replacement, leading to significant work inefficiency.

[0009] Furthermore, if the duct is not properly installed or assembled, byproducts generated during the combustion process are likely to accumulate at the duct or the nozzle outlet of the fuel injector, potentially leading to long-term performance degradation and clogging.

[0010] These issues can lead to more significant problems in systems that must operate for extended periods, such as marine engines. Therefore, structural improvements are required to enhance assemblability, facilitate maintenance, and minimize the deposition of combustion byproducts while maintaining the advantages of DFI technology.

[0011] To solve the above problems, one embodiment of the present invention aims to provide a fuel injection device assembly that facilitates the installation and replacement of ducts and significantly improves assembly ease.

[0012] In addition, one embodiment of the present invention aims to provide an assembly that improves the durability and maintenance efficiency of a fuel injection device by minimizing the deposition of combustion by-products.

[0013] The problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

[0014] An injector assembly mounted on a cylinder head of an engine may include: a cylinder-shaped case having an injector mounting portion open at one end and a duct mounting hole formed at the other end; a fuel injector having a fuel injection nozzle inserted into the injector mounting portion at one end of the case and supplying fuel to the combustion chamber of the engine; and a duct pipe inserted into the duct mounting hole and positioned adjacent to the fuel injection port of the fuel injection nozzle.

[0015] The outer diameter of one end of the duct pipe may be larger than the inner diameter of the duct mounting hole, and the outer diameter of the other end may be smaller than the inner diameter of the duct mounting hole.

[0016] The above duct pipe may have a tapered shape in which the outer diameter decreases from one end to the other end.

[0017] The above duct pipe may have an inner diameter larger than the diameter of the fuel injection nozzle.

[0018] The above duct pipe may have an hourglass shape in the cross-section of its inner diameter.

[0019] The other end of the duct pipe protrudes outward from the case and is located in the combustion chamber, and may include a plurality of air inlet holes formed on the other end of the duct pipe.

[0020] The fuel injector includes a guide projection protruding outwardly, and the case may include a guide groove on its inner surface into which the guide projection engages so as to align the direction of the fuel injection nozzle with the direction of the duct mounting hole.

[0021] The above case may have an air flow hole located adjacent to the duct mounting hole.

[0022] The above case may include an opening at the other end that communicates with the injector mounting portion.

[0023] A method for installing an injector assembly according to another embodiment of the present invention may include the steps of: mounting a case having a duct mounting hole in a port of a cylinder head connected to a combustion chamber of an engine; inserting a duct pipe into the duct mounting hole of the case; and inserting a fuel injector into the case such that the direction of the inserted duct pipe matches the direction of the fuel injection nozzle.

[0024] According to at least one embodiment of the present invention, by providing a case into which a duct pipe is inserted, the installation and replacement of the duct can be made easy.

[0025] In addition, according to at least one embodiment of the present invention, by providing air inlet holes in the duct and case, the mixing of fuel and air can be smoothly achieved, thereby increasing combustion efficiency.

[0026] In addition, according to at least one embodiment of the present invention, by increasing the mixing efficiency of fuel and air to improve combustion performance, the accumulation of combustion by-products can be prevented and the durability of the device can be improved, and unburned products can be reduced and exhaust gases can be reduced.

[0027] Further scopes of the applicability of the present invention will become apparent from the following detailed description. However, since various changes and modifications within the spirit and scope of the present invention are clearly understood by those skilled in the art, specific embodiments, such as the detailed description and preferred embodiments of the present invention, should be understood as being given merely as examples.

[0028] FIG. 1 shows a cross-sectional view of an injector assembly installed according to one embodiment of the present invention.

[0029] FIG. 2 is an injector assembly according to one embodiment of the present invention.

[0030] Figure 3 is an enlarged view of part A of Figure 1.

[0031] FIG. 4 is a drawing for illustrating various duct pipes according to embodiments of the present invention.

[0032] FIG. 5 is a drawing for explaining various cases according to embodiments of the present invention.

[0033] FIG. 6 is a flowchart of a method for installing an injector assembly according to one embodiment of the present invention.

[0034] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Identical or similar components regardless of drawing symbols are given the same reference number, and redundant descriptions thereof will be omitted.

[0035] The suffixes "module" and "part" for components used in the following description are assigned or used interchangeably solely for the sake of ease of drafting the specification, and do not inherently possess distinct meanings or roles. Furthermore, in describing the embodiments disclosed in this specification, detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions could obscure the essence of the embodiments disclosed in this specification.

[0036] In addition, the attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, and the technical concept disclosed in this specification is not limited by the attached drawings; it should be understood that all modifications, equivalents, and substitutions included within the concept and technical scope of the present invention are included.

[0037] Terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another.

[0038] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. On the other hand, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

[0039] A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0040] In this application, terms such as “comprising” or “having” are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0041] FIG. 1 shows a cross-sectional view of an injector assembly (100) installed according to one embodiment of the present invention. An enlarged view of part A is shown in FIG. 3. An injector assembly (100) according to one embodiment of the present invention can be mounted on a cylinder head (1) of an engine. The injector assembly (100) mounted on the cylinder head (1) can finely inject fuel into a combustion chamber (2) through a fuel injection nozzle (131).

[0042] Typically, in a diesel engine or the like, the fuel injector (130) induces the fuel to be finely injected and mixed with the air in the combustion chamber (2), thereby maximizing combustion efficiency and minimizing incomplete combustion.

[0043] The injector assembly (100) of the present invention includes a duct pipe (120) for increasing combustion efficiency. Ducted fuel injection technology provides the effect of improving combustion performance and reducing unburned products by allowing fuel to pass through the duct pipe (120) and be uniformly mixed with air.

[0044] However, existing technology had limitations in that the installation and assembly of the duct pipe (120) were complex and maintenance was difficult. In particular, combustion byproducts accumulated in the injection hole (131) of the fuel injector (130), causing clogging, which can lead to engine performance degradation and durability issues.

[0045] To solve these problems, the present invention proposes a fuel injection device assembly (100) that facilitates the installation and replacement of the duct pipe (120) and improves durability by minimizing the deposition of combustion by-products by additionally installing a case (110). Hereinafter, an injector assembly (100) according to an embodiment of the present invention will be described in detail with reference to FIGS. 2 and FIGS. 3.

[0046] FIG. 2 is an injector assembly (100) [Park H1.1] [Myung Kim 1.2] according to one embodiment of the present invention. FIG. 2(a) is a drawing showing the exterior of the injector assembly (100), and FIG. 2(b) is a drawing showing the BB' cross-section of FIG. 2(a).

[0047] Figure 3 is an enlarged view of part A of Figure 1.

[0048] First, referring to FIG. 3, an injector assembly (100) according to one embodiment of the present invention may include a case (110), a duct pipe (120), and a fuel injector (130). [Park H2.1]

[0049] The case (110) may refer to an outer housing that encloses the fuel injector (130). The case (110) may be mounted in a port of the cylinder head (1) that is connected to the combustion chamber (2) of the engine.

[0050] The case (110) may have a hollow cylindrical shape overall. In this case, it may be a cylinder shape with one end or the top open, and other components may be inserted and properly mounted through the open end. In this case, the body component on which the fuel injector (130) inserted through the open end is seated may be called the injector mounting part (111).

[0051] Additionally, the case (110) may include a duct mounting hole (112) at the other end or bottom. The duct mounting hole (112) may refer to a hole into which a duct pipe (120) is inserted and fixed when assembling the fuel injector (130). At least one duct mounting hole (112) may be provided, and multiple holes may be provided in a number corresponding to the number of required duct pipes (120).

[0052] Referring to FIG. 2(a), a cylinder-shaped case (110) visible from the outside and a plurality of duct pipes (120) mounted in the duct mounting holes (112) of the case (110) are shown. As shown in the drawing, the plurality of duct pipes (120) can be arranged in a radial shape. That is, they can be arranged at regular intervals in a circular direction.

[0053] The case (110) and the plurality of duct pipes (120) are separable, and with reference to FIG. 2(b), the interior of the case (110) can be seen in the [H3.1]BB' cross-sectional view in which the case (110) and the plurality of duct pipes (120) are separated. As described above, the case (110) may include an injector mounting portion (111) and a duct mounting hole (112).

[0054] Referring again to FIG. 3, a cross-sectional view of an injector assembly (100) according to one embodiment of the present invention can be seen, and as shown in the drawing, a duct pipe (120) can be inserted and fixed into the duct mounting hole (112) of the case (110).

[0055] In addition, a fuel injector (130) can be inserted and seated through one end in the injector seating portion (111) of the case (110).

[0056] The fuel injector [Park H4.1][Myeong Kim 4.2] (130) serves to inject fuel into the combustion chamber (2) of the engine. The fuel injector (130) may be equipped with a fuel injection nozzle (131) that includes a fuel injection port at the end. Fuel can be finely injected into the combustion chamber (2) using the fuel injection nozzle (131).

[0057] As for the individual configurations of the other fuel injectors (130), they are substantially the same as those known or can be easily derived by a person skilled in the art, so a detailed description thereof is omitted.

[0058] The duct pipe (120) may be configured for mixing and guiding fuel and air. The duct pipe (120) may be positioned in the form of a short pipe to serve to connect the fuel injector (130) and the combustion chamber (2). The duct pipe (120) may be positioned adjacent to the fuel injection port and may be arranged so that the direction of combustion injection of the fuel injection nozzle (131) and the direction of the passage of the duct pipe (120) are the same.

[0059] As described above, the duct pipe (120) can be inserted into and fixed in the duct mounting hole (112) of the case (110). At this time, one end of the duct pipe (120) is positioned adjacent to the fuel injection port, but may also be positioned at a certain distance apart.

[0060] Accordingly, in an injector assembly (100) according to one embodiment of the present invention, it is preferable that the direction of the fuel injection nozzle (131) of the fuel injector (130), the installation direction of the duct pipe (120) through which the fuel injected from the fuel injection nozzle (131) passes, and the direction of the duct mounting hole (112) where the duct pipe (120) is installed are all aligned in a straight line.

[0061] Additionally, the end of the fuel injection nozzle (131) from which fuel is injected must be spaced apart from the case (110) and the inlet of the duct pipe (120). This is because it is required to provide a certain gap between the fuel injection nozzle (131) and the duct pipe (120) so that the end of the fuel injection nozzle is exposed and air can pass through the duct pipe (120).

[0062] To this end, the fuel injector (130) may include a guide projection (not shown) protruding outward, and the case (110) may include a guide groove (not shown) on its inner surface to engage with the guide projection (not shown). When engaging using the guide projection and the guide groove, the direction of the fuel injection nozzle (131) and the direction of the duct mounting hole (112) can be designed to coincide. By using such a configuration, the assembly process can be made easier.

[0063] The inner diameter of the duct pipe (120) is sufficiently large so that the fuel injected from the fuel injection nozzle (131) does not come into contact with the inner surface, which plays an important role in ensuring a smooth mixing process after fuel injection. That is, the duct pipe (120) has an inner diameter larger than the diameter of the fuel injection nozzle (131), so as to prevent the spray of the injected fuel from excessively wetting the duct pipe (120).

[0064] The outer diameter of the duct pipe (120) is designed to be stably fixed to the duct mounting hole (112) of the case (110), and a tapered shape may be applied to prevent detachment. That is, the outer diameter of one end may be larger than the inner diameter of the duct mounting hole (112), and the outer diameter of the other end may be smaller than the inner diameter of the duct mounting hole (112). Therefore, it may be a tapered shape in which the outer diameter decreases uniformly as it goes from one end to the other.

[0065] The other end of the duct pipe (120) has a small tapered shape and the other end has a diameter smaller than the inner diameter of the duct mounting hole (112), so the other end of the duct pipe (120) can be inserted into the duct mounting hole (112) from the inside of the case (110) toward the outside so that the other end of the duct pipe (120) faces the inside of the combustion chamber (2), that is, the outside of the case (110).

[0066] It can be fixed by applying pressure at the point where the inner diameter of the duct mounting hole (112) and the outer diameter of the duct pipe (120) match, or it can be fixed using a separate device.

[0067] Since the outer diameter of the duct pipe (120) has a tapered shape, the inner diameter of the duct mounting hole (112) may also have a corresponding tapered shape to make the installation process in the case (110) more efficient. That is, the duct pipe (120) and the duct mounting hole (112) may have a tapered shape in which the diameter decreases from the inside to the outside.

[0068] As described above, an injector assembly (100) according to one embodiment of the present invention may be installed using a case (110) instead of directly installing a duct pipe (120) in the engine, and through such a configuration, the engine performance can be improved and the assembly and replacement of the duct pipe (120) can be facilitated.

[0069] Meanwhile, the present invention includes an engine equipped with a fuel injection device and provides a configuration for increasing the mixing efficiency of fuel and air and improving combustion performance.

[0070] The engine according to the present invention may include a cylinder head housing a fuel injection device and a fuel injector that injects fuel into a combustion chamber. The fuel injector is connected to a duct pipe to ensure that the fuel is uniformly mixed with air, thereby maximizing combustion efficiency and reducing exhaust gases caused by incomplete combustion.

[0071] In addition, a case according to the present invention is installed in the cylinder head of the engine, designed to facilitate the assembly and replacement of fuel injectors and duct pipes. This configuration can contribute to improving engine performance while simultaneously simplifying maintenance and increasing durability. The engine of the present invention can be utilized in various applications, including large diesel engines.

[0072] FIG. 4 is a drawing for explaining various duct pipes (120) according to embodiments of the present invention. Each drawing shows a cross-sectional view of a duct pipe (120) according to a different embodiment.

[0073] FIG. 4(a) is a drawing showing a duct pipe (120) according to one embodiment of the present invention. As described above, the outer diameter may have a tapered shape. At this time, the inner diameter of the duct pipe (120) may be a straight passage with no change in diameter.

[0074] FIG. 4(b) shows the structure of a duct pipe (120) suitable for an engine in which a gas jet is injected, as another embodiment of the present invention. When using a fuel injector (130), such as a hydrogen engine, the shape of the internal passage of the duct pipe (120) can be designed in a specific way to effectively accelerate the injected gas jet and improve mixing efficiency.

[0075] In particular, the duct pipe (120) illustrated in FIG. 4(b) may be configured as an internal passage having a laval shape with a wide inner diameter at both ends and a narrow inner diameter in the middle. That is, the cross-section of the inner diameter may be hourglass-shaped.

[0076] This structure can maximize injection efficiency by accelerating gas flow and concentrating energy. Flow velocity increases in the contraction section, while pressure decreases in the expansion section, which can improve the mixing and injection characteristics of fuel and air.

[0077] At this time, the smallest inner diameter of the duct pipe (120) may be larger than the diameter of the fuel injection nozzle (131). [Park H 5.1][Myeong Kim 5.2] The outer diameter may still have a tapered shape, as in other embodiments.

[0078] FIG. 4(c) illustrates a duct pipe (120) including air inlet holes (121) as another embodiment of the present invention. Referring to FIG. 4(c), a plurality of air inlet holes (121) may be included on the other side of the duct pipe (120) exposed to the combustion chamber (2). That is, when such a duct pipe (120) is installed in the case (110), the other side having a narrow outer diameter protrudes outward from the case (110) and is located in the combustion chamber (2), and a plurality of air inlet holes (121) may be formed on the other side of the duct pipe (120) according to the present embodiment that is located in the combustion chamber (2). This configuration is intended to increase the amount of air flowing into the duct pipe (120), thereby allowing the injected fuel and air to be mixed more effectively.

[0079] FIG. 4(d) illustrates a duct pipe (120) according to another embodiment of the present invention. The length of the duct pipe (120) according to this embodiment may be longer than the length of the duct mounting hole (112). That is, the length exposed to the combustion chamber (2) may be longer than that of the duct pipe (120) according to another embodiment. This is to ensure that more time is required for mixing air and fuel, as, for example, in the case of fuels that require a large amount of air for combustion, such as diesel oil.

[0080] However, in such a case, for ease of installation, the length of the duct pipe (120) may be smaller than the inner diameter of the case (100). This is because the duct pipe (120) must be inserted into the case (100) for installation.

[0081] As described above, the present invention can be implemented in various embodiments. The present invention can be implemented in various different forms and is not limited to the embodiments described herein.

[0082] FIG. 5 is a drawing for explaining various cases (110) according to embodiments of the present invention. Each drawing shows the outer surface of a case (110) according to each embodiment.

[0083] FIG. 5(a) illustrates a case (110) according to one embodiment of the present invention. As described above in FIG. 2 and FIG. 3, the case (110) is in the form of a cylinder with one end open and may include at least one duct mounting hole (112a) at the other end.

[0084] FIG. 5(b) illustrates a case (110) including air flow holes (113b) according to another embodiment of the present invention. Referring to FIG. 5(b), the air flow holes (113b) may be located adjacent to the duct mounting holes (112b). As shown in the drawing, they may be arranged in a shape surrounding each duct mounting hole (112b) in a circumferential direction. This is merely one example, and the number, size, and location of the air flow holes (113b) are not limited thereto.

[0085] The air flow hole (113b) can serve to smoothly introduce air so that fuel and external air are effectively mixed inside the duct pipe (120).

[0086] FIG. 5(c) illustrates a case (110) having an opening (114c) according to another embodiment of the present invention. The case (110) may include an opening (114c) at the other end that communicates with an injector mounting portion (111). The opening (114c) may also serve to smoothly introduce air so that fuel and external air are effectively mixed inside the duct pipe (120).

[0087] A form in which part of the other end is open may be applied, and the number and size of the openings (114c) are not limited to the examples.

[0088] FIG. 5(d) illustrates a case (110) including an air flow hole (113d) and an opening (114d) according to another embodiment of the present invention.

[0089] Referring to FIG. 5(d), the case (110) may simultaneously have an opening (114d) and an air flow hole (113d) for smoothly introducing air so that fuel and external air are effectively mixed inside the duct pipe (120).

[0090] At this time, it is preferable that the air flow hole (113d) be located at the top between the plurality of duct mounting holes (112d) as illustrated. This arrangement increases the durability of the device and enables a smooth supply of air.

[0091] FIG. 6 is a flowchart of a method for installing an injector assembly according to one embodiment of the present invention.

[0092] First, a cylinder-shaped case is installed in a port of a cylinder head connected to the combustion chamber of the engine, having an injector mounting portion open at one end and a duct mounting hole formed at the other end (S6100).

[0093] At this time, the case is combined with the port, and the open end is installed at the top so that the injector mounting part can be open upward, and the other end containing the duct mounting hole is installed at the bottom.

[0094] In addition, guide grooves are formed on the inner surface of the case to align the direction of the fuel injector and the direction of the duct pipe, thereby guiding the components to be accurately joined.

[0095] Next, a duct pipe is inserted into the duct mounting hole of the mounted case (S6200). The outer diameter of the duct pipe has a tapered shape that decreases from one end to the other, so that it can be gradually joined with the case and stably fixed during the insertion process.

[0096] The other end of the duct pipe protrudes outward from the case and is located in the combustion chamber, and an air inlet is formed on the other side of the duct pipe to regulate airflow and increase combustion efficiency.

[0097] In addition, the inner diameter of the duct pipe can be larger than the nozzle diameter of the fuel injector. Furthermore, the longitudinal section of the duct pipe is designed in an hourglass shape to improve fuel injection and mixing efficiency.

[0098] Finally, the fuel injector is inserted into the case so that the direction of the inserted duct pipe matches the direction of the fuel injection nozzle (S6300). The fuel injector includes a guide projection protruding outward, and can be inserted so that this projection engages with the guide groove of the case.

[0099] Through this, the direction of the fuel injector is aligned and can be fixed to the injector mounting part. That is, since the fuel injection nozzle of the fuel injector and the duct pipe are aligned in a straight line facing the same direction, the fuel injection nozzle is positioned adjacent to the fuel injection port of the duct pipe, so that fuel can be smoothly supplied to the combustion chamber.

[0100] Through the assembly method described above, assembly can be performed much more easily than with conventional methods. Additionally, it offers the advantage of allowing work to be done without completely disassembling the cylinder head in the event of a duct failure or replacement.

[0101] As such, the injector assembly according to one embodiment of the present invention is designed such that the duct pipe and the fuel injector are separable from the case, allowing each component to be easily assembled or replaced. Accordingly, the time and complexity required during the maintenance process can be reduced, and work efficiency can be increased.

[0102] It is obvious to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit and essential features of the invention.

[0103] The foregoing detailed description should not be interpreted restrictively in all respects and should be considered exemplary. The scope of the invention shall be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the invention are included within the scope of the invention.

Claims

1. An injector assembly mounted on a cylinder head of an engine, A cylinder-shaped case including an injector mounting portion open at one end and a duct mounting hole formed at the other end; A fuel injector having a fuel injection nozzle that is inserted into the injector mounting portion at one end of the above case and supplies fuel to the combustion chamber of the engine; and An injector assembly comprising a duct pipe inserted into the duct mounting hole and positioned adjacent to the fuel injection nozzle.

2. In Paragraph 1, The above duct pipe An injector assembly characterized in that the outer diameter of one end is larger than the inner diameter of the duct mounting hole, and the outer diameter of the other end is smaller than the inner diameter of the duct mounting hole.

3. In Paragraph 2, The above duct pipe An injector assembly characterized by having a tapered shape in which the outer diameter decreases from one end to the other.

4. In Paragraph 1, The above duct pipe An injector assembly characterized by having an inner diameter larger than the diameter of a fuel injection nozzle.

5. In Paragraph 1, The above duct pipe An injector assembly characterized by the longitudinal section of the inner diameter being hourglass-shaped.

6. In Paragraph 1, The above duct pipe The other side protrudes to the outside of the above case and is located in the combustion chamber, and An injector assembly characterized by including a plurality of air inlet holes formed on the other side of the above-mentioned duct pipe.

7. In Paragraph 1, The above fuel injector It includes a guide projection protruding outward, The above case is An injector assembly characterized by including a guide groove on the inner surface to which the guide projection engages so as to align the direction of the fuel injection nozzle with the direction of the duct mounting hole.

8. In Paragraph 1, The above case is An injector assembly characterized by having an air flow hole located adjacent to the above-mentioned duct mounting hole.

9. In Paragraph 1, The above case is An injector assembly characterized by including an opening at the other end that communicates with the injector mounting portion.

10. An engine comprising an injector assembly according to any one of claims 1 to 9.

11. A step of mounting a case having a duct mounting hole in a port of a cylinder head connected to the combustion chamber of an engine; A step of inserting a duct pipe into the duct mounting hole of the above case; and A method for installing an injector assembly comprising the step of inserting a fuel injector into the case such that the direction of the inserted duct pipe matches the direction of the fuel injection nozzle.

12. An engine in which an injector assembly is installed using the method according to paragraph 11.

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