Fuel injector sleeve and engine system remanufacturing method using same

Abstract

A fuel injector sleeve for use in remanufacturing an engine includes an elongated sleeve body including a clamping shoulder facing in an axial direction and forming an undercut and a sealing ridge transitioning between the undercut and an outer sleeve surface. The sealing ridge defines a sealing line extending radially outward of the undercut and circumferentially and uniformly around the longitudinal axis. The sealing line provides line contact between the sleeve and the clamping surface of the cylinder head to form an erosion-resistant sealing outer plate on the clamping surface prior to use. Related apparatus and remanufacturing methods are also disclosed.

Description

Technical Field

[0001] The present invention relates generally to the field of remanufacturing, and more specifically, to a fuel injector sleeve for use in the remanufacturing of an engine, the sleeve having a sealing ridge configured for line contact with a clamping surface in the cylinder head. Background Technology

[0002] The repair, maintenance, reuse, and remanufacturing of various types of machinery and machine parts is a well-known industry worldwide. In the context of internal combustion engines, engineers are constantly seeking new strategies to restore used engines and engine parts to their original use, especially heavy-duty engines such as diesel engines.

[0003] Diesel engines may be used in the field for many years, requiring regular inspection, maintenance, and sometimes replacement of various systems and components. Nevertheless, during a comprehensive overhaul of the machinery, the ultimate goal is to attempt to salvage parts that can be reused or repaired. Due to the harsh and variable operating environment, engineers in the remanufacturing field often encounter complex new problems related to wear, surface erosion, part deformation, changes in material properties, and numerous other challenges. A known strategy for remanufacturing in the field of engines and fuel systems is known from U.S. Patent No. 8,291,927B2 to Johnson et al. Summary of the Invention

[0004] In one aspect, a fuel injector sleeve includes an elongated sleeve body defining a longitudinal axis and including an inner sleeve surface forming an injector orifice extending axially between a first sleeve end and a second sleeve end, the second sleeve end having a threaded assembly and forming an injector nozzle opening. The elongated sleeve body also includes an intermediate section having an outer sleeve surface extending between the first and second sleeve ends and a clamping shoulder facing axially and extending radially outward from the second sleeve end to the intermediate section. The clamping shoulder forms an undercut and a sealing ridge that transitions between the undercut and the outer sleeve surface and defines a sealing line extending radially outward and circumferentially and uniformly around the longitudinal axis.

[0005] In another aspect, an engine system includes a cylinder head having: an upper deck surface; a lower deck surface; a sleeve bore extending between the upper and lower deck surfaces and opening in the lower deck surface; and a clamping surface exposed in the sleeve bore. The engine system also includes a sleeve within the sleeve bore defining a longitudinal axis and having a threaded assembly that engages with the cylinder head threads and a clamping shoulder that clamps into contact with the clamping surface via the threaded engagement. The clamping surface extends from a radially inward initial position to a radially outward position, and the clamping shoulder includes a sealing ridge defining a sealing line that is radially spaced outward at the radially inward initial position and extends circumferentially and uniformly around the longitudinal axis.

[0006] In another aspect, a method of remanufacturing a cylinder head includes receiving a cylinder head that has been decommissioned from use in an engine and forming a sleeve bore extending between an upper deck surface and a lower deck surface, as well as a clamping surface exposed in the sleeve bore. The method further includes installing a sleeve in the sleeve bore and clamping the sleeve to the cylinder head to form a fluid seal between a sealing ridge of the sleeve and the clamping surface at a sealing line located radially outward from a radially inward starting position on the clamping surface. Attached Figure Description

[0007] Figure 1 This is a partial cross-sectional side view of an internal combustion engine according to one embodiment;

[0008] Figure 2 yes Figure 1 A cross-sectional side view of a portion of the engine;

[0009] Figure 3 This is an isometric view of the sleeve according to one embodiment;

[0010] Figure 4 Is it like this? Figure 3 A cross-sectional side view of a portion of the sleeve;

[0011] Figure 5 Is it like this? Figure 3 A schematic view of a portion of the sleeve;

[0012] Figure 6 Is it like this? Figure 3 Another illustrated view of a portion of the sleeve;

[0013] Figure 7 Is it like this? Figure 3 A cross-sectional side view of a portion of the sleeve; and

[0014] Figure 8 This is a comparison view of the sleeve installed in the remanufactured engine compared to the original sleeve installed in the engine that is still to be remanufactured. Detailed Implementation

[0015] refer to Figure 1 An internal combustion engine 10 according to one embodiment is shown. The engine 10 includes a cylinder block 12 having a plurality of cylinders 14 formed therein. A plurality of pistons 16 are positioned in the cylinders 14 and move in a generally conventional manner between top dead center and bottom dead center positions to rotate a crankshaft 18. The cylinders 14 can include any number in any suitable arrangement, such as inline, V-type, or others. The engine 10 also includes a cylinder head 20 attached to the cylinder block 12. A plurality of engine valves 26 are supported in the cylinder head 20 and may include two intake valves and two exhaust valves for each cylinder 14. A plurality of fuel injectors 22 are also supported in the cylinder head 20, and each fuel injector includes an injector nozzle 24 extending into a corresponding cylinder in the cylinder 14. In one embodiment, the engine 10 includes a compression ignition diesel engine, although the invention is not limited thereto. Engine 10 may also include a remanufactured engine that has been decommissioned from a machine system and has undergone inspection, repair, overhaul, and is equipped with suitable replacement parts, as discussed further herein. Engine 10 can be used in any known application, such as operating a transmission system in a land vehicle or vessel, or operating a generator, compressor, or pump, to name just a few.

[0016] Now referencing Figure 2 The cylinder head 20 is shown in further detail. The cylinder head 20 may be formed from multiple independent cylinder head sections, each associated with a corresponding cylinder in the cylinder 14, or formed as a so-called plate cylinder head, which is associated with more than one and potentially all cylinders in the engine 10. The cylinder block 20 includes an upper deck surface 34 and a lower deck surface 36. At least one cooling chamber 28 is defined between the upper deck surface 34 and the lower deck surface 36. As illustrated, an intake duct or port 30 extends through the cylinder head 20 to an intake opening 38 in the lower deck surface 36. An exhaust duct or port 32 extends from an exhaust opening 40 also formed in the lower deck surface 36. The cylinder block 20 also includes a sleeve bore 42 for receiving a fuel injector sleeve and a fuel injector, which extends between the upper deck surface 34 and the lower deck surface 36 and opens in each of the upper deck surface 34 and the lower deck surface 36. Injector sleeve 44 is positioned within sleeve bore 42 and is configured to receive and support a corresponding fuel injector in fuel injector 22 used in engine 10.

[0017] It has been observed that the surfaces of engine 10 may exhibit some form of damage or degradation during use. In some cases, and as further discussed herein, the seal between the fuel injector sleeve and the cylinder head may be compromised by erosion of the material of at least one of the cylinder head and the fuel injector sleeve, typically in the form of surface erosion, whereby material is removed from the clamping and sealing surfaces of the cylinder head and the fuel injector sleeve. If left uncorrected, this erosion may potentially lead to coolant leakage between the fuel injector sleeve and the cylinder head into the associated combustion cylinder during use or during remanufacturing. The surfaces of the inner side of the cylinder head (including within the fuel injector bores) may be difficult and potentially impossible to machine, coat, or otherwise repair to achieve a reliable seal in a remanufactured engine intended for reuse. As will become further apparent from the following description, the present invention provides a unique strategy for establishing a new coolant seal between the fuel injector sleeve and the cylinder head in a remanufactured engine.

[0018] Now referencing Figures 3 to 6 The features of the fuel injector sleeve 44 are shown in further detail. The sleeve 44 includes an elongated sleeve body 46 defining a longitudinal axis 48 and having an inner sleeve surface 50 forming an injector orifice 52 extending axially between a first sleeve end 54 and a second sleeve end 56, the second sleeve end having a threaded assembly 58 and forming an injector nozzle opening 60. When used in an engine 10, an injector nozzle 24 extends through the injector nozzle opening 60.

[0019] The elongated sleeve body 46 also includes an intermediate section 62 having an outer sleeve surface 64 extending between the first sleeve end 54 and the second sleeve end 56. The intermediate section 62 also includes a clamping shoulder 66 facing axially and extending radially outward from the second sleeve end 56 to the intermediate section 62. When used in the cylinder head 20, the threaded assembly 58 engages with the internal threads (unnumbered) of the cylinder head 20. The clamping shoulder 66 also forms an undercut 68 and a sealing ridge 70 transitioning between the undercut 68 and the outer sleeve surface 64. The sealing ridge 70 defines a sealing line 72 that extends radially outward from the undercut 68 and circumferentially and uniformly around the longitudinal axis 48.

[0020] The sealing ridge 70 may include a radius 74 at the transition between the sealing line 72 and the outer sleeve surface 64. The sealing line 72 may be defined by the radius 74 at the outermost axial position of the clamping shoulder 66. In this description, the term "axially outward" and similar terms are understood to mean a direction extending generally parallel to the longitudinal axis 48 and away from the geometric center point of the sleeve 44. The term "axially inward" is understood to have a generally opposite meaning. "Radially outward" means a direction extending generally along the radius of a circle centered on the longitudinal axis 48 away from the longitudinal axis 48. The term "radially inward" has a generally opposite meaning.

[0021] by Figure 4 Importantly, the undercut portion 68 may include an undercut surface 76 that is axially inwardly spaced from the sealing line 72 and extends planarly between the sealing ridge 70 and the second sleeve end 56. The second sleeve end 56 may also form an inward cut 78 that extends circumferentially and uniformly around the longitudinal axis 48 and extends axially between the undercut surface 76 and the threaded assembly 58.

[0022] It should be recalled that when the injector sleeve is removed from a cylinder head that has been used in an engine, erosion can sometimes be observed against the sealing and clamping surfaces where the injector sleeve is clamped. As also discussed herein, erosion can make it difficult or impossible to form a reliable fluid seal between the injector sleeve and the clamping surfaces. According to the invention, the sealing line 72 provides static line contact, i.e., annular line contact, between the curved outer surface of the sealing ridge 70 and the planar portion of the clamping surface of the cylinder head 20 at a sealing location that avoids existing erosion.

[0023] Now Figure 7 For emphasis, an enlarged view of a portion of sleeve 44 is shown, illustrating some surfaces in more detail. Radius 74 may define a convex radius size 80. An inward cut 78 may define a concave radius size 82. The convex radius size 80 may be larger than the concave radius size 82. In an improvement, the convex radius size 80 may be approximately twice the convex radius size 82. As used herein, the term "approximately" should be understood as meaning roughly or approximately as understood by one of ordinary skill in the art of engine remanufacturing, including, for example, conventional rounding to a consistent number of significant figures or another geometric standard and tolerance standard applied within conventional techniques. In a further improvement, the convex radius size 80 is 2 mm with a tolerance of ±0.2 mm.

[0024] Figure 7 Further features of the sleeve 44 are also illustrated, including features of the inner sleeve surface 50. The inner sleeve surface 50 may include a first tapered surface 84 extending from the second sleeve end 56 in a second axial direction. The second axial direction is generally along axis 48 and... Figure 7The diagram shows the direction upwards towards the top of the page. The inner sleeve surface 50 may also include a second conical surface 86 and a planar transition surface 88 between the first conical surface 84 and the second conical surface 86. (See diagram from...) Figure 7 As can be seen, the sealing line 72 can be located radially outward from the plane transition surface 88.

[0025] Brief review Figure 3 As can be seen, the first sleeve end 54 includes a plurality of tool engagement grooves 96 for engaging and disengaging the threaded assembly 56 in the injector bore 42 in the cylinder head 20. The tool engagement grooves 96 may include open slots formed in the terminal portion of the first sleeve end 54. Other embodiments may include tool engagement grooves or tool engagement surfaces of different configurations, including an internal surface formed by the inner sleeve surface 50. In one embodiment, a custom tool for rotating the sleeve 44 may be used, which can engage in the tool engagement grooves 96. A plurality of O-ring grooves 98 are also formed in the first sleeve end 54 and Figure 3 It is shown in the figure for use in fluid sealing with cylinder head 20.

[0026] Now referencing Figure 8 The figure shows a comparative view of the sleeve 44 according to the invention on the left side of the figure and a known sleeve 144 on the right side of the figure. Figure 8 In the diagram, numeral 89 indicates the clamping surface of cylinder head 20, against which sleeve 44 is clamped. Numeral 189 indicates the surface against which sleeve 144 is clamped to cylinder head 120. It should be recalled that erosion can be observed on the surface of cylinder heads in disused cylinder heads. From... Figure 8 As can be seen, the inclined surface 91 is adjacent to the clamping surface 89. Number 94 indicates an eroded surface or erosion feature on the inclined surface 91, extending upwards and into the clamping surface 89. Similar erosion features can be seen on the cylinder head 120. From... Figure 8 It can also be seen that the smooth surface 92 of the clamping surface 89 is located radially outward from the eroded surface 94. The sealing line 72 is defined at a position on the smooth surface 92. In an embodiment, the clamping surface 89 extends from a radially inward starting position 90 to a radially outward position at its intersection with the inclined surface 91, and the position and shape of the sealing ridge 68 defining the sealing line 72 are designed to space the sealing line 72 radially outward from the radially inward starting position 90. In the manner described, the sealing line 72 provides a fluid seal unaffected by the presence of the eroded features. In the illustration of the known sleeve 144, it can be seen that instead of a sealing line, there is a more diffuse sealing band 172 that extends across the interface contact between the sleeve 144 and the cylinder head 120 and includes the eroded features.

[0027] Industrial applicability

[0028] Refer to the attached diagram for general details, but continue with... Figure 8 Importantly, when the engine is decommissioned and ready for remanufacturing, the cylinder head 20 can be processed by removing the existing sleeve to expose the clamping surface 89. The cylinder head 20 can also be processed according to any other suitable and desired high-end overhaul practices. When reassembly begins, the sleeve 44 can be installed as a new sleeve in the sleeve bore 42. The sleeve 44 can be clamped to the cylinder head 20 to form a fluid seal between the sealing ridge 70 of the sleeve 44 and the clamping surface 89 at the sealing line 72, which is located radially outward from the radially inward starting position 90 of the clamping surface 89.

[0029] It should be recalled that sleeve 44 includes an undercut 68 and an inward cut 78. During the clamping of sleeve 44 into bore 42, the threaded engagement of threaded assembly 56 with the cylinder head 20 increases the contact pressure of sealing ridge 70 against clamping surface 89, where sleeve 44 is slightly stretched at the undercut 68 and / or inward cut 78. In some cases, the stretched sleeve 44 causes radius 74 to roll against planar clamping surface 89, particularly smooth planar surface 92. Therefore, a more concentrated clamping load and a robust metal-to-metal seal can be formed compared to conventional strategies.

[0030] This description is for illustrative purposes only and should not be construed as limiting the breadth of the invention in any way. Therefore, those skilled in the art will understand that various modifications can be made to the currently disclosed embodiments without departing from the full and reasonable scope and spirit of the invention. Other aspects, features, and advantages will become apparent from a study of the accompanying drawings and appended claims. As used herein, the articles “a” and “an” are intended to include one or more items and are interchangeable with “one or more”. The term “a” or similar language is used where only one item is desired. Furthermore, as used herein, the terms “has,” “have,” “having,” etc., are intended to be open-ended terms. Additionally, the phrase “based on” is intended to mean “at least partially based on”, unless otherwise explicitly stated.

Claims

1. A fuel injector sleeve, comprising: An elongated sleeve body, the elongated sleeve body defining a longitudinal axis and including an inner sleeve surface, the inner sleeve surface forming an injector hole, the injector hole extending in an axial direction between a first sleeve end and a second sleeve end, the second sleeve end having a threaded assembly and forming an injector nozzle opening; The elongated sleeve body further includes a middle section having an outer sleeve surface extending between the first sleeve end and the second sleeve end, and a clamping shoulder facing the axial direction and extending radially outward from the second sleeve end to the middle section. as well as The clamping shoulder forms a lower cut and a sealing ridge, the sealing ridge transitioning between the lower cut and the outer sleeve surface and defining a sealing line, the sealing line extending radially outward and circumferentially and uniformly around the longitudinal axis of the lower cut.

2. The fuel injector sleeve according to claim 1, wherein: The sealing ridge includes a radius that transitions between the sealing line and the outer sleeve surface, and the sealing line is defined by the radius at the outermost axial position of the clamping shoulder; and The lower cut portion includes a lower cut surface that is axially inwardly spaced from the sealing line and extends planarly between the sealing ridge and the second sleeve end.

3. The fuel injector sleeve according to claim 2, wherein, The second sleeve end forms an inward cut, which extends circumferentially and uniformly around the longitudinal axis and extends axially between the undercut surface and the thread assembly.

4. The fuel injector sleeve according to claim 3, wherein, The radius defines the size of the convex radius, and the inward cut defines the size of the concave radius, wherein the size of the convex radius is greater than the size of the concave radius.

5. The fuel injector sleeve according to claim 4, wherein, The radius of the convex shape is approximately twice the radius of the concave shape.

6. The fuel injector sleeve according to claim 5, wherein, The radius of the convex shape is two millimeters, with a positive and negative tolerance of 0.2 millimeters.

7. The fuel injector sleeve according to any one of claims 1 to 6, wherein, The inner sleeve surface includes: a first tapered surface extending from the second sleeve end in a second axial direction; a second tapered surface; and a planar transition surface between the first tapered surface and the second tapered surface, wherein the sealing line is located radially outward from the planar transition surface.

8. The fuel injector sleeve according to any one of claims 1 to 7, wherein, The first sleeve end includes a plurality of tool engagement grooves for thread engagement of the thread assembly in the sleeve bore in the cylinder head.

9. An engine system comprising: A cylinder head, the cylinder head comprising: an upper deck surface; a lower deck surface; a sleeve bore extending between the upper deck surface and the lower deck surface and opening in the lower deck surface; and a clamping surface exposed to the sleeve bore; A sleeve within the sleeve bore, the sleeve defining a longitudinal axis and including a threaded assembly that engages with the cylinder head thread and a clamping shoulder that clamps into contact with the clamping surface via threaded engagement; and The clamping surface extends from a radially inward starting position to a radially outward position, and the clamping shoulder includes a sealing ridge that defines a sealing line that is radially spaced outward from the radially inward starting position and extends circumferentially and uniformly around the longitudinal axis.

10. The engine system according to claim 9, wherein: The sealing ridge includes a radius defining the sealing line, and wherein the clamping shoulder forms an undercut, and the sealing line is radially outward from the undercut; The sleeve includes an outer sleeve surface, and the radius transitions between the sealing line and the outer sleeve surface; and The sleeve forms a cut, and the lower cut extends between the cut and the sealing ridge.

11. The engine system according to claim 9 or 10, wherein, The clamping surface includes a smooth surface that is contacted by the sealing ridge at the sealing line and an eroded surface that extends between the sealing line and the radially inward starting position.

12. A method for remanufacturing a cylinder head, comprising: Receive a cylinder head that is no longer used in an engine and form an extended sleeve bore between the upper deck surface and the lower deck surface, as well as a clamping surface exposed to the sleeve bore; Install the sleeve in the sleeve hole; as well as The sleeve is clamped to the cylinder head to form a fluid seal between the sealing ridge of the sleeve and the clamping surface at the sealing line, the sealing line being located radially outward from a radially inward starting position on the clamping surface.

13. The method according to claim 12, wherein, The sealing line is located radially outward from the eroded surface of the clamping surface.

14. The method according to claim 12, wherein, Clamping the sleeve includes clamping the sleeve via threaded engagement of the sleeve end with the cylinder head, and the method further includes stretching the sleeve between the sleeve end and the sealing line by clamping the sleeve.

15. The method according to claim 14, wherein, The sleeve forms an undercut between the sleeve end and the sealing ridge, and the method further includes rolling the radius defining the sealing line against the clamping surface during the stretching of the sleeve.

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