Bushing for an engine cylinder block and systems, assemblies, components, and methods thereof
By designing a bushing and insert combination without a bottom sealing groove, the balance problem between the bushing and the cylinder block sealing area is solved, achieving efficient sealing and structural strength, reducing repair costs, and adapting to different material exposure environments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CATERPILLAR INC
- Filing Date
- 2021-09-28
- Publication Date
- 2026-06-23
AI Technical Summary
In the lower coolant sealing area between the bushing and the cylinder block, existing technologies struggle to balance maintaining the integrity of the bushing structure with the effectiveness of the seal. The design of the sealing groove may damage the bushing structure, and repairability and reusability are challenged.
Design a bushing structure in which the cylindrical wall has no sealing groove at the bottom and is combined with the bushing by an insert. The insert has a sealing groove to accommodate the sealing ring and form an effective seal. The bushing is thicker at the top and thinner at the bottom, with an acute-angle transition. The insert is constrained by the inner diameter of the cylinder.
It achieves effective sealing within a confined space, reduces the mixing of engine coolant and oil, lowers repair costs, improves structural strength and sealing effect, and adapts to different material exposure environments.
Smart Images
Figure CN114320645B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a bushing for an engine cylinder block, and systems, components, parts, and methods thereof, as well as related systems, components, parts, and methods. Background Technology
[0002] Finding a balance between bushing structure and sealing effectiveness in the lower coolant sealing region between the bushing and the cylinder block presents a challenge for cylinder liners. Providing one or more sealing recesses for sealing elements (e.g., O-rings) in the bushing can compromise the bushing structure. On the other hand, accommodating one or more sealing recesses in the bushing can result in suboptimal bushing thickness, and / or challenges in cylinder block repair and reusability in this area during initial and subsequent engine overhauls.
[0003] U.S. Patent No. 7,726,273 ('273 Patent) describes a high-strength steel cylinder liner for a diesel engine. According to the '273 Patent, the diesel engine is fitted with a thin-walled wet bushing made of steel, wherein the ratio of the composite bushing thickness to the inner diameter is in the range of 1.5% to 4%. Summary of the Invention
[0004] In one aspect, the invention describes a bushing for a cylinder of an internal combustion engine. The bushing may include a cylindrical wall having a radially inner surface, a radially outer surface opposite the radially inner surface, and open top and bottom ends, wherein the radially outer surface may not have any sealing grooves, at least in its bottom portion. The cylindrical wall may include a thicker portion at least in its middle portion, and a thinner portion located below the thicker portion and extending to the bottom end of the cylindrical wall. A transition from the thicker to the thinner portion can be provided by varying the outer diameter of the radially outer surface of the cylindrical wall.
[0005] In another aspect, the present invention describes a method. The method may include: providing a bushing adapted to be disposed in a machined cylinder of an engine cylinder block such that the bushing is radially supported by a sidewall portion of the machined cylinder, the bushing being a hollow cylinder and having an inner surface, an outer surface opposite the inner surface, and open top and bottom ends; and providing an insert adapted to be retained in the engine cylinder block having the machined cylinder, the insert being in the form of a ring and radially disposed around the outer surface of the bushing. The bushing may have no sealing grooves on its outer surface, at least at its bottom portion. The insert may have an inner surface having a plurality of sealing grooves adapted to receive and retain corresponding sealing rings such that, when the insert is radially disposed around the outer surface of the bushing, the sealing rings form a seal between the insert and the outer surface of the bushing. The bushing may have a thicker portion in its middle portion and a thinner portion in its bottom portion, wherein the transition from the thicker portion to the thinner portion may form an acute angle on the outer surface of the bushing, and the thinner portion defines the thinnest portion of the bushing at its bottom end.
[0006] In another embodiment, an assembly for a cast iron engine cylinder block of an internal combustion engine is described. The assembly may include: a steel bushing adapted for insertion and retention in a machined cylinder of the cast iron engine cylinder block, such that the steel bushing is top-supported by a top surface of the cast iron engine cylinder block and radially supported by a sidewall portion of the machined cylinder block; the steel bushing having a hollow cylindrical body having an inner surface, an outer surface opposite the inner surface, and open top and bottom ends; and a stainless steel insert adapted for retention in the cast iron engine cylinder block having the machined cylinder, the stainless steel insert being symmetrically annular and radially disposed around the outer surface of the body of the steel bushing. The body of the steel bushing may not have any sealing grooves, at least in its bottom portion. The stainless steel insert may have an inner surface with a plurality of sealing grooves adapted to receive and retain corresponding O-rings, such that when the stainless steel insert is radially disposed around the outer surface of the body of the steel bushing, the O-rings form a seal between the stainless steel insert and the outer surface of the body of the steel bushing. The main body of the steel bushing may have a thicker portion in its middle part and a thinner portion in its bottom part. The transition from the thicker portion to the thinner portion forms an acute angle on the outer surface of the main body of the steel bushing, and the thinner portion gradually thins at its bottom end to become the thinnest part of the main body of the steel bushing.
[0007] Other features and aspects of the invention will become apparent from the following description and accompanying drawings. Attached Figure Description
[0008] Figure 1 It is a cross-sectional view of the cylinder block of an internal combustion engine according to one or more embodiments of the disclosed subject matter.
[0009] Figure 2 and Figure 3 It is for one or more embodiments of the disclosed subject matter. Figure 1 A cross-sectional view of the cylinder components of the cylinder block.
[0010] Figure 4 It shows Figure 2 and Figure 3 A cross-sectional view of the bottom part of the component.
[0011] Figure 5 A cross-sectional view of a sealing interface according to an embodiment of the disclosed subject matter is shown.
[0012] Figure 6 This is a partial side cross-sectional view of a bushing according to one or more embodiments of the disclosed subject matter.
[0013] Figure 7 This is a partial side cross-sectional view of another bushing according to one or more embodiments of the disclosed subject matter.
[0014] Figure 8 yes Figure 6 An enlarged view of the transition section of the bushing.
[0015] Figure 9 yes Figure 6 An enlarged view of a portion of the bottom part of the bushing.
[0016] Figure 10 It is a perspective view of an insert according to one or more embodiments of the disclosed subject matter.
[0017] Figure 11 yes Figure 10 The end view of the insert.
[0018] Figure 12 yes Figure 11 The insert is shown in the cross-sectional view along line 12-12.
[0019] Figure 13 yes Figure 12 A magnified portion of the cross-sectional view. Detailed Implementation
[0020] This invention relates to a bushing for an engine cylinder block, and related systems, components, parts, and methods.
[0021] Figure 1 This is a cross-sectional view of the cylinder block 100 of an internal combustion engine according to one or more embodiments of the disclosed subject matter. The internal combustion engine can be any suitable internal combustion engine, including diesel engines or gasoline engines. For example, Figure 1The cylinder block 100 is used in a diesel engine (V12), but embodiments of the disclosed subject matter are not limited thereto. That is, embodiments of the disclosed subject matter can be implemented in or applied to compression ignition engines and spark ignition engines.
[0022] like Figure 1 As shown, the cylinder block 100 can be made of cast iron and may include a plurality of cylinder bores 200. The cylinder bores 200 can be essentially cylindrical; therefore, the cylinder bores 200 may be referred to herein as cylinders 200. Figure 1 A cross-section of half of the cylinder 200 (shown in the diagram) of the cylinder block 100 is shown. Typically, during operation, a corresponding piston (not explicitly shown) reciprocates within the cylinder 200 to generate mechanical power due to fuel combustion. As will be discussed in more detail below, the cylinder 200 can be machined or drilled. Drilling can mean that some of the base material of the cylinder block 100 defining the cylinder 200 has been drilled or machined, causing a change in the geometry of the cylinder 200 relative to the previous operating geometry of the internal combustion engine. The previous operating geometry can refer to the initial construction of the internal combustion engine or a previous reconstruction of the internal combustion engine.
[0023] The components according to embodiments of the disclosed subject matter may consist of a bushing 300 and an insert 400, and may be individually provided for some or all of them in the cylinder 200. Typically, the insert 400 may be disposed in the cylinder body 100, radially surrounding the bottom portion 330 of the bushing 300, such as... Figure 2 and Figure 3 As shown. According to one or more embodiments, the bushing 300 may be steel, and / or the insert 400 may be stainless steel. The assembly may also include one or more sealing rings 500 disposed between the insert 400 and the bushing 300, as shown. Figure 4 and Figure 5 As shown.
[0024] The bushing 300 may be wholly or substantially housed within the cylinder 200. Optionally, a portion of the bushing 300 may protrude from the cylinder 200. For example, as... Figure 1 , Figure 2 and Figure 3 As shown, the top portion 310 of the bushing 300 may extend from the top surface of the cylinder block 100 or the cover plate 110. According to one or more embodiments, the bushing 300 may be a top-supported bushing, which means that the top portion 310 (e.g., its flange 312) may rest or be positioned on the top surface 110 of the cylinder block 100.
[0025] In any case, the bushing 300 can be removably disposed in the cylinder 200 so as to be radially supported by the sidewall portion of the cylinder body 100 defining the cylinder 200. According to one or more embodiments, the bushing 300 can be inserted into and retained in the cylinder 200 by a relatively tight fit between the bushing 300 and the sidewall portion defining the cylinder 200. For example, the bushing 300 can be pressed and / or locked in the cylinder 200 by a relatively tight fit between the bushing 300 and the sidewall portion defining the cylinder 200. In this respect, the portion of the bushing 300 in the cylinder 200 having the largest outer diameter can be constrained, particularly by the inner diameter of one or more sidewall portions of the upper portion of the cylinder body 100. Some or all of these sidewall portions can be referred to as pilots (e.g., upper cylinder body pilots) and can be used to position the bushing 300 in the cylinder 200.
[0026] One or more coolant passages for circulating coolant can be provided between the upper portion of the cylinder block 100 and the middle portion 320 of the bushing 300. An upper seal can be provided directly below the flange 312, providing an upper sealing interface between the upper portion of the cylinder block 100 and the middle portion 320 of the bushing 300 to seal one or more coolant passages. According to one or more embodiments, the upper sealing interface can be provided by a relatively shallow recess in the bushing 300, and the upper sealing interface can be referred to as a filler band.
[0027] Reference Figure 4 and Figure 5 The insert 400 can be disposed in a recess 130 defined in the cylinder body 100. The recess 130 can be defined by a countersunk feature formed in the cylinder body 100 by machining or drilling the structure of the cylinder body 100. In this respect, the insert 400 can be constrained by the inner diameter of the sidewall portion of the upper portion of the cylinder body 120 defining the cylinder 200. That is, according to one or more embodiments, the maximum outer diameter of the insert 400 can be no greater than the inner diameter of one or more sidewall portions (e.g., guide portions) of the upper portion 120 of the cylinder body 100 forming the innermost surface of the cylinder 200. The machining process can leave residual parent material of the cylinder body 100 to define at least a portion of the recess 130. For example, as Figure 4 and Figure 5 As shown, the protrusion 132 can be held on a surface where it can rest and remain when the insert 400 is inserted into the cylinder body 100.
[0028] The inner or inner surface 410 of the insert 400 may be adapted to seal against the outer surface 302 of the bushing 300, particularly at the bottom portion 330 of the bushing 300. Typically, one or more non-metallic seals (e.g., elastomeric seals) may be provided. For example, one or more sealing rings 500 may be provided in corresponding one or more sealing grooves 450 formed on the inner surface 410 of the insert 400. For example, as... Figure 4 and Figure 5 As shown, three sealing rings 500 can be provided, but embodiments of the disclosed subject matter are not limited thereto. One or more sealing rings 500 can be O-rings, D-rings (i.e., D-shaped cross-sectional geometry), having a square cross-sectional geometry, etc.
[0029] In the case of multiple sealing rings 500, the sealing rings 500 may have the same dimensions (e.g., cross-section, diameter, etc.) and therefore may have the same fill percentage as the sealing groove 450. Optionally, some or all of the sealing rings 500 may have the same compressibility (e.g., compression percentage). According to one or more embodiments, the dimensions (e.g., cross-sectional dimensions, such as diameter) of one or more sealing rings 500 may be greater than the depth of the corresponding sealing groove in one or more sealing grooves 450, such that at least when the insert 400 is provided with one or more sealing rings 500 and the bushing 300 is not provided radially inward of the insert 400, a portion of the sealing ring 500 extends from the sealing groove 450 through the inner surface 410 of the insert 400. Optionally, one or more sealing rings 500 may be retained in the corresponding sealing groove 450 even when the bushing 300 is not provided radially inward of the insert 400. As described above, according to one or more embodiments, some or all of the one or more sealing rings 500 may be O-rings, such as... Figure 4 and Figure 5 As shown. According to embodiments of the disclosed subject matter, sealing rings with other cross-sectional geometries (e.g., squares) can also be realized, particularly where a portion of the cross-sectional area can protrude from the sealing groove 450.
[0030] One or more sealing rings 500 may be adapted to a specific geometry of one or more sealing recesses 450 of the insert 400 and / or the outer surface 302 of the bushing 300. One or more sealing rings 500 may also be adapted based on one or more materials to which they will be exposed. In this regard, typically, a seal 600 may be formed of one or more sealing rings 500 and a bushing 300 to provide a barrier for engine coolant at the top portion of the insert 400 and a barrier for engine oil at the bottom portion of the insert 400. Therefore, one or more sealing rings 500 forming the seal 600 may be made of one or more materials capable of adapting to specific exposed parts. In this context, adaptation may refer to resistance or protection, for example, resistance to or protection against coolant (including water), or resistance to or protection against oil. As an example, for Figure 4 and Figure 5 The sealing ring 500, since the top sealing ring 500 can contact the engine coolant, can be made of ethylene propylene diene monomer (EPDM). Since the bottom sealing ring 500 can be exposed to oil in the crankcase, it can be made of fluorocarbon (FKM). And / or the intermediate sealing ring 500 can be formed of a material such as hydrogenated nitrile butadiene rubber (HNBR), which can withstand exposure to both engine coolant and engine oil. Therefore, the intermediate sealing ring 500 can serve as a support for the top and bottom sealing rings 500.
[0031] Reference Figures 6 to 9 The bushing 300 may have a hollow body 301, which is defined by a wall having an outer or outer surface 302, an inner or inner surface 304 opposite to the outer surface 302, a top end 306, and a bottom end 308 opposite to the top end 306. Both the top end 306 and the bottom end 308 may be open.
[0032] The body 301 of the bushing 300 may be cylindrical, although the thickness of the body 301 may vary along its length. Optionally, according to one or more embodiments, only the surface profile of the outer surface 302 may be changed, wherein the inner diameter of the bushing 300 defined by the inner surface 304 may remain constant along the entire length of the body 301. As described above, the body 301 of the bushing 300 may be characterized as having a top portion 310, a middle portion 320, and a bottom portion 330.
[0033] According to one or more embodiments, the top portion 310 of the bushing 300 (which may include a top end 306) may define a flange 312. The flange 312 may define the maximum outer diameter of the outer surface 302 of the bushing 300 and / or the maximum thickness of the bushing 300.
[0034] In terms of relative thickness, the middle portion 320 is typically thicker than the bottom portion 330, and particularly thicker than the so-called thinner portion 332 of the bottom portion 330. In this respect, the middle portion 320 may have a so-called thicker portion 322, which may form the thickest part of the middle portion 320 (although other portions of the middle portion 320 may have the same thickness). Optionally, the thicker portion 322 may be characterized as a guide portion for placing the bushing 300 in the cylinder 200.
[0035] The thicker portion 322 may be located at least at the midpoint of the longitudinal length between the top end 306 and the bottom end 308 of the bushing 300. Figure 6 In the embodiments, relative to Figure 7 Implementation examples, Figure 6 The length of the thicker portion 322 in the embodiment is greater than Figure 7 The length of the thicker portion 322 in the embodiment. Therefore, the thicker portion 322 can be located at an intermediate position between the top end 306 and the bottom end 308 of the bushing 300, and according to one or more embodiments, the thicker portion 322 can continuously extend to the thickness transition portion 329. For example... Figure 6 As shown, the thicker portion 322 can also extend in the direction opposite to the transition portion 329. The thicker portion 322 can have a uniform thickness along its length, such as... Figure 6 and Figure 7 As shown. Incidentally, Figure 6 and Figure 7 The transition portion 329 and the thinner portion 332 of the bushing 300 can be the same in both embodiments. That is, the height of the transition portion 329 and the geometry of the transition portion 329 and the thinner portion 332 can be the same.
[0036] In any case, a thickness transition 329 from the thicker portion 322 to the thinner portion 332 can be formed at the bottom portion 330 of the bushing 300. As described above, according to one or more embodiments, the transition 329 can be implemented by changing the height of the outer surface 302 of the bushing 300. (Refer to...) Figure 8 The angle θ of the transition portion 329 can be an acute angle. In other words, according to one or more embodiments, the transition portion 329 may not be square (i.e., 90 degrees).
[0037] The thinner portion 332 of the bushing 330 can extend from the transition portion 329 to the bottom end 308 of the bushing 300. According to one or more embodiments, the thickness of any portion of the thinner portion 322 is no greater than the thickness of any portion of the thicker portion 322. Similarly, except at the interface with the thicker portion 322, no portion of the transition portion 329 is thicker than the thicker portion 322. Furthermore, according to one or more embodiments, no portion of the thinner portion 322 is thicker than any portion of the intermediate portion 320. Given that the top portion 310 is at least as thick as the thicker portion 322, the above thickness comparison naturally applies to the comparison between the top portion 310 and the bottom portion 330 of the bushing 300.
[0038] Optionally, the thinner portion 332 can gradually thin towards the bottom end 308. As described above, the thinning can be applied to the outer surface 302 of the bushing 300. For example, as... Figure 9 As shown, the thinner portion 332 can be thinnest at the bottom end 308 of the bushing 300. Therefore, the bushing 300 can have its thinnest portion at the bottom end 308 of the bushing 300.
[0039] The outer surface 302 of the bushing 300 may be wholly or partially devoid of any sealing grooves suitable for receiving a sealing ring (e.g., a D-ring or O-ring). According to one or more embodiments, the outer surface 302 may be completely devoid of any such sealing grooves at the bottom portion 330 of the bushing 300. Nevertheless, according to embodiments of the disclosed subject matter, the outer surface 302 at the bottom portion 330 of the bushing 300 may be adapted for sealing engagement with an insert assembly (e.g., an insert assembly consisting of the insert 400 discussed herein and one or more sealing rings 500).
[0040] Turn now Figures 10 to 13 The insert 400, which can be referred to as a sleeve, may have a cylindrical ring or an annular body, having a hollow interior and an open first end 402 and a second end 406. Therefore, in an end view, for example... Figure 11 As shown, the insert 400 can be circular.
[0041] The insert 400 may have an inner or inner surface 410 and an outer or outer surface 414 opposite to the inner surface 410. The outer surface 414 may be smooth and may define the maximum outer diameter of the insert 400. Optionally, the first end 402 and the second end 406 may be beveled on the outer surface 414 and / or the inner surface 410. Figure 12 As shown, the insert 400 can be beveled on both the inner surface 410 and the outer surface 414. Furthermore, this bevel on the outer surface 414 and / or the inner surface 410 can be made at one or both of the first end 402 and the second end 406. For example, Figure 12The first end 402 and the second end 406 are shown being beveled. Alternatively, the inner surface 410 and / or the outer surface 414 may have a radial (bent) geometry or a square geometry at the first end 402 and / or the second end 406 of the insert 400.
[0042] The insert 400 may have one or more sealing grooves 450 formed or disposed in the inner surface 410. For example, the insert 400 has three sealing grooves 450. The sealing grooves 450 may extend around the entire circumference of the inner surface 410 of the insert 400 and may be adapted to receive and retain corresponding sealing rings, such as... Figure 4 The sealing ring shown is 500.
[0043] In the case of multiple sealing grooves 450, the sealing grooves 450 may be evenly spaced from each other in the longitudinal or height direction of the insert 400. Optionally, the sealing grooves 450 may also be evenly spaced from each other and spaced from the first end 402 and the second end 406, for example... Figure 13 As shown. Alternatively, the sealing groove 450 may be asymmetrical relative to the first end 402 and the second end 406 of the insert 400, and / or asymmetrical relative to each other in the case of multiple sealing grooves 450. Furthermore, according to one or more embodiments, the geometry of the sealing grooves 450 may be identical. Therefore, the dimensions of the sealing grooves 450 may be identical. Alternatively, the geometry (e.g., dimensions) of one or more sealing grooves in the sealing grooves 450 may differ from one or more other sealing grooves in the sealing grooves 450. According to embodiments of the disclosed subject matter, the insert 400 may be symmetrical in all respects.
[0044] The depth of the sealing groove 450 can be driven by the amount of compression of the corresponding sealing ring 500 disposed therein. Optionally, for example, before and / or during the insertion of the bushing 300, the depth of the sealing groove 450 can be determined based on the sealing ring 500 being held in the sealing groove.
[0045] As described above, the insert 400 can be adapted to be held in the recess 130 of the cylinder body 100 to receive the bushing 300, such that the insert 400 only radially surrounds the thinner portion 332 of the bushing 300. The sealing ring 500 can be disposed in a corresponding sealing groove 450 and can contact the outer surface 302 of the bushing 300 to form a seal 600.
[0046] Industrial applicability
[0047] As described above, the present invention relates to a bushing for an engine cylinder block, and systems, components, parts and methods thereof, as well as related systems, components, parts and methods.
[0048] Embodiments of the disclosed subject matter can balance bushing adequacy and sealing effectiveness in the lower coolant sealing region between the bushing and the cylinder block. In this respect, embodiments of the disclosed subject matter can provide a sealing system between the bushing and the cylinder block in an internal combustion engine cylinder within a confined geometry to prevent or minimize the mixing of engine coolant and engine oil in the engine cylinder block.
[0049] The bushing, such as bushing 300, may have a variable wall thickness along its length, with a relatively thicker portion transitioning to a relatively thinner portion at the bottom of bushing 300. The relatively thicker portion of bushing 300 can be used to improve structural adequacy considering combustion, ignition pressure, cavitation, piston side load, etc., thereby protecting the surrounding cylinder block, while the relatively thinner portion of bushing 300 at the bottom can be used to provide a suitable seal between bushing 300 and cylinder block (and because the bottom portion of bushing 300 may bear relatively less stress due to combustion, ignition pressure, cavitation, piston side load, etc.).
[0050] At least in the thinner portion of the bushing 300, there may be no sealing groove suitable for receiving the corresponding sealing ring. More specifically, the sleeve or insert (e.g., insert 400) may have one or more sealing rings (e.g., sealing ring 500) provided in corresponding sealing grooves formed in the inner surface of the insert 400. The relatively thinner portion of the bushing 300 can provide space for the insert 400 and the sealing ring 500 with sufficient construction (e.g., cross-sectional dimensions) to provide a suitable seal with the bushing 300. That is, the outer diameter of the insert 400 may be constrained by the maximum counterbore diameter that can be machined in the cylinder block. Therefore, making the bottom portion of the bushing 300 relatively thin can provide space in the radially outward direction to receive the properly constructed insert 400 and sealing ring 500 without conflicting with the outer diameter constraint of the insert 400. In this respect, according to one or more embodiments, the one or more sealing rings 500 may be, for example, O-rings instead of D-rings, thereby making it possible to provide sealing rings with a relatively larger cross-sectional area.
[0051] For example, compared to placing the sealing ring in the cylinder block 100 itself, using the insert 400 (with the sealing ring 500) can reduce the repair cost of the cylinder block 100 during maintenance (e.g., initial maintenance or subsequent maintenance) because the insert 400 can be replaced if necessary, instead of having to machine the sealing groove in situ.
[0052] As described above, cylinder block 100 may include multiple cylinders, such as cylinder 200, wherein cylinder 200 may be machined or drilled. Drilling may mean that some of the base material of cylinder block 100 defining cylinder 200 has been drilled or machined, such that the geometry of cylinder 200 is changed relative to the previous working geometry of the internal combustion engine. The previous working geometry may refer to the initial construction of the internal combustion engine or a previous reconstruction of the internal combustion engine.
[0053] The components according to embodiments of the disclosed subject matter may consist of a bushing 300, an insert 400, and one or more sealing rings 500, and may be individually provided for some or all of them in the cylinder 200. Typically, the insert 400 may be provided together with one or more sealing rings 500 in the cylinder body 100, radially surrounding the bottom portion 330 of the bushing 300, such as... Figures 2 to 5 As shown. According to one or more embodiments, bushing 300 may be steel, and / or insert 400 may be stainless steel. When bushing 300 is made of steel, stainless steel as the material of bushing 400 can provide suitable wear characteristics for bushing 300.
[0054] Reference Figure 4 and Figure 5 The insert 400 can be disposed in a recess 130 defined in the cylinder body 100. Because the recess 130 can be defined by a countersunk hole feature formed in the cylinder body 100 by machining or drilling, the insert 400 can be constrained by the inner diameter of one or more sidewall portions of the upper portion of the cylinder body 100 defining the cylinder 200. That is, according to one or more embodiments, the maximum outer diameter of the insert 400 can be no greater than the inner diameter of one or more sidewall portions (e.g., guide portions) of the upper portion of the cylinder body 100 forming the innermost surface of the cylinder 200. Thus, during installation, the insert 400 can move through the internal volume defining the upper portion of the cylinder 200 to be placed in the recess 130.
[0055] The outer surface 414 of the insert 400 may be beveled at the first end 402 and / or the second end 406 of the insert 400. This beveled outer surface 414 facilitates easy installation of the insert 400 into the recess 130. Such a beveled outer surface 414 also facilitates easy installation of the insert 400 through the upper portion of the cylinder 200 when the first end 402 or the second end 406 of the insert 400 is the front end of the insert 400 entering the cylinder 200. In this respect, the insert 400 may be completely or at least symmetrical with respect to the outer surface 414 at the first end 402 and the second end 406 of the insert 400. Therefore, according to embodiments of the disclosed subject matter, the installation orientation of the insert 400 (i.e., regardless of whether the first end 402 or the second end 406 of the insert 400 forms the front end of the insert 400 entering the cylinder 200) does not need to be considered during installation. In any case, the front end of insert 400, whether it is the second end 406 or the first end 402, for example Figure 4 and Figure 5 As shown, all can be disposed in the recess 130 to place and hold the protrusion 132 (which may be the remaining parent material of the cylinder body 100). Although, for example Figure 4 and Figure 5 An insert 400 is shown disposed in the cylinder block 200 according to an interference fit, but embodiments of the disclosed subject matter are not limited thereto. Thus, the insert 400 may be disposed in the cylinder block 200 by other means of connection (e.g., threaded connection, its own hole, riveting, welding, and pinning).
[0056] One or more sealing rings 500 may be disposed in corresponding one or more sealing grooves 450 formed on the inner surface 410 of the insert 400. For example, as Figure 4 and Figure 5 As shown, three sealing rings 500 can be provided, but embodiments of the disclosed subject matter are not limited thereto. When the bushing 300 is not disposed radially inside the insert 400, one or more sealing rings 500 can be retained in corresponding sealing grooves 450. Thus, one or more sealing rings 500 can be disposed in corresponding one or more sealing grooves 450 for engagement with the insert 400. Alternatively, the insert 400 can be disposed in the cylinder 200, and one or more sealing rings 500 are disposed in corresponding one or more sealing grooves 450 once the insert 400 is positioned in the recess 130. In this respect, the sealing rings 500 can be removed from the insert 400 when the insert is located in the recess 130 (and the bushing 300 is not present) and / or when the insert 400 itself is removed from the cylinder 200.
[0057] Providing the sealing ring 500 in the insert 400 instead of the bushing 300 allows for the use of a relatively thicker (e.g., larger cross-sectional diameter) sealing ring 500, particularly an O-ring, since the sealing ring 500 is already in place when the bushing 300 is inserted into the cylinder 200. According to one or more embodiments, the dimensions (e.g., cross-sectional dimensions, such as diameter) of one or more sealing rings 500 may be greater than the depth of the corresponding sealing groove in one or more sealing grooves 450, such that at least when the insert 400 is provided with one or more sealing rings 500 and the bushing 300 is not provided radially inward of the insert 400, a portion of the sealing ring 500 extends from the sealing groove 450 through the inner surface 410 of the insert 400.
[0058] The bushing 300 may be disposed in the cylinder 200 after the insert 400 and the sealing ring 500. As described above, the bushing 300 may be disposed in the cylinder 200 in a removable manner (e.g., inserted, pressed, etc.) and may fit relatively tightly against a sidewall portion defining the cylinder 200. According to one or more embodiments, the bushing 300 may be locked in the cylinder 200. In this respect, the portion of the bushing 300 in the cylinder 200 having the largest outer diameter may be constrained, particularly by the inner diameter of one or more sidewall portions of the upper portion of the cylinder body 100. Some or all of these sidewall portions may be referred to as pilots (e.g., upper cylinder body pilots) and may be used to position the bushing 300 in the cylinder 200.
[0059] When the bushing 300 is disposed in the cylinder 200, the insert 400 and the sealing ring 500 may radially surround the outer wall or outer wall or surface 302 at a portion of the bottom portion 330 of the bushing 300, for example... Figure 4 As shown. According to one or more embodiments, the insert 400 may be disposed entirely within the body 301 of the bushing 300 below the transition 329 from the thicker portion 322 of the bushing 300 to the thinner portion 332 of the bushing 300. Furthermore, the insert 400 may be disposed only around the thinner portion 332, for example, the portion spaced apart from the bottom end 308 of the bushing 300.
[0060] The inner surface 410 of the insert 400 may be beveled at the first end 402 and / or the second end 406 of the insert 400 (in this respect, the insert 400 may be symmetrical). When the rear ends of the first end 402 and the second end 406 of the insert 400 have beveled inner surfaces 410, this bevel facilitates the placement of the bushing 300 through the internal volume of the insert 400. Additionally, when the bushing 300 is placed in the cylinder 200, the outer surface 302 of the bushing 300 may contact the sealing ring 500, causing the sealing ring 500 to compress. One or more sealing rings 500 may be held in corresponding one or more sealing grooves 450, and the bushing 300 may have a thinner portion 332 that gradually thins from the outer surface 302 toward the thinnest part of the body 301 of the bushing 300. Each sealing ring 500 may engage with the outer surface 302 of the bushing 300 such that when the bushing 300 moves downward in the cylinder 200 beyond the insertion length, the sealing ring 500 does not roll or is unlikely to roll.
[0061] In any case, a seal can be formed between each of one or more sealing rings 500 and the outer surface 302 of the bushing 300. These seals may be collectively referred to herein as seal 600. As described above, seal 600 may be located below transition 329 relative to the thinner portion 332 of bushing 300.
[0062] A thickness transition portion 329, from the thicker portion 322 to the thinner portion 332, can be formed at the bottom portion 330 of the bushing 300. As described above, according to one or more embodiments, the transition portion 329 can be implemented by changing the height of the outer surface 302 of the bushing 300. (Refer to...) Figure 8 The angle θ of the transition portion 329 can be an acute angle. In other words, according to one or more embodiments, the transition portion 329 may not be square (i.e., 90 degrees). Having a non-square angle in the transition portion 329 enables a configuration where no dead space or volume of engine coolant is created between the transition portion 329 and the cylinder block 100, or is minimized. Such a configuration prevents or minimizes cavitation of trapped engine coolant, as this condition is prevented or minimized.
[0063] In terms of relative thickness, the middle portion 320 is typically thicker than the bottom portion 330, and particularly thicker than the so-called thinner portion 332 of the bottom portion 330. In this respect, the middle portion 320 may have a so-called thicker portion 322, which may form the thickest part of the middle portion 320 (although other portions of the middle portion 320 may have the same thickness). Optionally, the thicker portion 322 may be characterized as a guide portion for placing the bushing 300 in the cylinder 200.
[0064] The thicker portion 322 may be located at least at the midpoint of the longitudinal length between the top end 306 and the bottom end 308 of the bushing 300. Figure 6 In the embodiments, relative to Figure 7 Implementation examples, Figure 6 The length of the thicker portion 322 in the embodiment is greater than Figure 7 The length of the thicker portion 322 in the embodiment. Therefore, the thicker portion 322 can be located at an intermediate position between the top end 306 and the bottom end 308 of the bushing 300, and according to one or more embodiments, the thicker portion 322 can continuously extend to the thickness transition portion 329. For example... Figure 6 As shown, the thicker portion 322 can also extend in the direction opposite to the transition portion 329. The thicker portion 322 can have a uniform thickness along its length, such as... Figure 6 and Figure 7 As shown. As mentioned above, Figure 6 and Figure 7 The transition portion 329 and the thinner portion 332 of the bushing 300 can be the same in both embodiments. That is, the height of the transition portion 329 and the geometry of the transition portion 329 and the thinner portion 332 can be the same.
[0065] The thinner portion 332 of the bushing 330 can extend from the transition portion 329 to the bottom end 308 of the bushing 300. According to one or more embodiments, the thickness of any portion of the thinner portion 322 is no greater than the thickness of any portion of the thicker portion 322. Similarly, except at the interface with the thicker portion 322, no portion of the transition portion 329 is thicker than the thicker portion 322. Furthermore, according to one or more embodiments, no portion of the thinner portion 322 is thicker than any portion of the intermediate portion 320. Given that the top portion 310 is at least as thick as the thicker portion 322, the above thickness comparison naturally applies to the comparison between the top portion 310 and the bottom portion 330 of the bushing 300.
[0066] The following provides non-limiting examples of thickness characteristics of one or more embodiments of the disclosed subject matter.
[0067] The thickness of the body 301 of the bushing 300 above the transition portion 329 can have an average wall thickness-to-inner diameter ratio between 3.5% and 4.5%. A ratio below 3.5% may cause structural strength problems, while a ratio greater than 4.5% may be impractical without sacrificing engine displacement.
[0068] The thickness of the body 301 of the bushing 300 below the transition portion 329 can have a thickness-to-diameter ratio between 1.5% and 2.5%. A ratio less than 1.5% may cause structural strength problems (even in the lower stress areas of the bushing 300), while a ratio greater than 2.5% may not provide sufficient space for the use of a suitable sealing ring 500 (e.g., an O-ring).
[0069] The ratio of the thickness of the main body 301 of the bushing 300 above the transition portion 329 to the thickness of the main body 301 below the transition portion 329 can be between 1.5 and 3.
[0070] The thickness of the thinner portion 332 can account for 20%-40% of the total bushing length. Less than 20% may not provide sufficient length to accommodate the sealing ring 500, while more than 40% may not provide sufficient strength when higher stresses occur in the cylinder 200.
[0071] The ratio between the thickness of the thinner portion 332 and the diameter of the sealing ring 500 (e.g., an O-ring) can be less than 1. This allows the relatively larger O-ring 500 to abut against the relatively thinner bushing 300.
[0072] Although various aspects of the invention have been specifically shown and described with reference to the foregoing embodiments, those skilled in the art will understand that various additional embodiments can be conceived by modifying the disclosed machines, systems, and methods without departing from the spirit and scope of the invention. These embodiments should be understood to fall within the scope of the invention as defined by the claims and any equivalents thereof.
Claims
1. An assembly for a cast iron engine cylinder block of an internal combustion engine, the assembly comprising: A steel bushing adapted to be inserted into and held in a machined cylinder of the cast iron engine cylinder body, such that the steel bushing is supported by a top surface of the top surface of the cast iron engine cylinder body and radially supported by a side wall portion of the machined cylinder, the steel bushing having a hollow cylindrical body having an inner surface, an outer surface opposite to the inner surface, and an open top and bottom end; as well as A stainless steel insert, adapted to be held in the cast iron engine cylinder block having the machined cylinder, the stainless steel insert being symmetrically annular and radially disposed around the outer surface of the body of the steel bushing. The main body of the steel bushing has no sealing grooves, at least in its bottom portion. The stainless steel insert has an inner surface with multiple sealing grooves adapted to receive and retain corresponding O-rings, such that when the stainless steel insert is radially positioned around the outer surface of the main body of the steel bushing, the O-rings form a seal between the stainless steel insert and the outer surface of the main body of the steel bushing. The main body of the steel bushing has a thicker portion in its middle part and a thinner portion in its bottom part. The transition from the thicker portion to the thinner portion forms an acute angle on the outer surface of the main body of the steel bushing, and the thinner portion gradually thins at its bottom end to become the thinnest part of the main body of the steel bushing. When the stainless steel insert is radially arranged around the outer surface of the main body of the steel bushing, the stainless steel insert is located entirely below the transition portion from the thicker portion to the thinner portion of the main body of the steel bushing.
2. The component according to claim 1, wherein, The maximum outer diameter of the stainless steel insert is not greater than the inner diameter of the machined cylinder defined by one or more guide portions of the cast iron engine cylinder block.
3. The component according to claim 1, wherein, Each of the first end and the second end opposite to the first end of the stainless steel insert is obliquely cut from the inner surface of the stainless steel insert and the outer surface of the stainless steel insert opposite to the inner surface.
4. The component according to claim 1, wherein, The first end of the stainless steel insert rests on the protruding part of the machined cylinder in the cast iron engine cylinder block.
5. The component according to claim 1, wherein, The thickness-to-inner diameter ratio of the thinner portion is between 1.5% and 2.5%.
6. The component according to claim 1, further comprising: The O-ring is made of different materials depending on the fluid to be sealed inside the cast iron engine cylinder.
7. The component according to claim 1, wherein, in, The O-ring is held in the corresponding sealing groove in the sealing groove, and The O-ring forms a seal between the stainless steel insert and the outer surface of the main body of the steel bushing.
8. A method for assembling an engine cylinder block, comprising: A bushing is provided, the bushing being adapted to be disposed in a machined cylinder of an engine cylinder block such that the bushing is radially supported by a sidewall portion of the machined cylinder, the bushing being a hollow cylinder and having an inner surface, an outer surface opposite to the inner surface, and open top and bottom ends. as well as An insert is provided, the insert being adapted to be held in the engine cylinder block having the machined cylinder, the insert being in the form of a ring and radially disposed around the outer surface of the bushing. The bushing, at least in its bottom portion, has no sealing grooves on its outer surface. The insert has an inner surface with multiple sealing grooves adapted to receive and retain corresponding sealing rings, such that when the insert is radially positioned around the outer surface of the bushing, the sealing rings form a seal between the insert and the outer surface of the bushing. The bushing has a thicker portion in its middle portion and a thinner portion in its bottom portion, the transition from the thicker portion to the thinner portion forms an acute angle on the outer surface of the bushing, and the thinner portion defines the thinnest part of the bushing at its bottom end; The provision of the insert includes providing the insert only around the thinner portion of the bushing.
9. The method according to claim 8, wherein, The bushing is provided such that the insert radially surrounds the outer surface of the bushing and the seal is formed by the sealing ring.
10. The method according to claim 8, wherein, Providing the insert includes placing a first end of the insert on a protrusion of the remaining matrix material of the engine cylinder block.
11. The method according to claim 8, wherein, The bushing is made of steel, and the insert is made of stainless steel.