Sealing insert for preventing coolant leakage in internal combustion engines

Abstract

The described arrangements address coolant leakage in internal combustion engines through cracks forming in stress riser portions between the cylinder and surrounding coolant ports from thermal expansion or mechanical stress. A sealing insert, comprising a metallic ring with a surrounding O-ring, is installed in a recess formed between a cylinder sleeve and a coolant port. This configuration provides a positive seal to prevent coolant from leaking between the engine block and the cylinder head.

Description

Sealing Insert for Preventing Coolant Leakage in InternalCombustion EnginesField of the Invention

[0001] This invention relates generally to systems and methods for preventing leakage of engine coolant between an engine block and a cylinder head of an internal combustion engine.Background of the Invention

[0002] The fundamental operation of an internal combustion engine involves a piston moving inside a hollow cylinder.

[0003] When the piston reaches the cylinder's end, a mixture of air and fuel is compressed and ignited, causing the piston to retract, thus generating rotational force that affects other engine components.

[0004] These engines commonly use fuels like petrol / gasoline, diesels, and gasses.

[0005] The cylinder is typically formed between an engine block and a cylinder head which caps the cylinder's end to form the compression face.

[0006] During the engine's cycles, heat is generated by factors like ignition and friction. To prevent overheating and failure, this heat needs to be dissipated from the block and head. This is commonly achieved by circulating a liquid coolant throughout the engine, which then carries the excess heat to a radiator where it is removed.

[0007] The coolant flows through voids within the engine block and heads, ensuring these parts maintain the proper temperature.

[0008] Occasionally, small cracks or fissures may develop in the engine block. While these cracks usually don't lead to a block failure, they can be large enough to allow coolant seepage from the engine.

[0009] This seepage of coolant can significantly impair the engine's performance and reduce its potential lifespan.

[0010] The present invention seeks to provide a way that will overcome or substantially ameliorate at least some of the deficiencies of the prior art, or to at least provide an alternative.

[0011] It is to be understood that, if any prior art information is referred to herein, such reference does not constitute an admission that the information forms part of the common general knowledge in the art, in Australia or any other country.Summary of the Disclosure

[0012] The described arrangements address the problem of coolant leakage in internal combustion engines between the cylinder and surrounding coolant ports at the interface between the engine block and the cylinder head caused by cracks that develop over time due to thermal expansion or mechanical stress.

[0013] The present arrangement specifically addresses issues of coolant escaping through cracks forming in the stress riser portions of the engine block between the cylinder and surrounding coolant ports. These cracks may allow coolant to bypass filler band seals installed between a cylinder sleeve and the engine block and leak from between the engine block and the cylinder head.

[0014] As such, according to the present arrangement, a sealing insert comprising a metallic ring with a surrounding O-ring is installed between a cylinder sleeve and a coolant port in a recess formed in the engine block surrounding the cylinder. The O- ring is strategically located by the metallic ring (typically less than 0.200” below a top surface of the ring) to be positioned above the typical location where these stress riser cracks form, thereby providing a positive seal preventing the coolant from flowing up between the outer surface of the metallic ring and the engine block.

[0015] Preferably, the sealing insert is inserted under an upper annular flange of the cylinder sleeve and a filler band seal may be installed under the flange between the cylinder sleeve and the sealing insert. Additionally, a head spacer plate may lie against a face of the engine block surrounding the flange, with a head gasket installed between the head spacer plate and the cylinder head. Optionally, a tubular coolant seal can be installed in the coolant port between the engine block and the cylinder head. The metal ring and the recess are preferably configured to define an interference fit therebetween, which preferably has a tolerance of less than 0.010”.

[0016] The O-ring can be made of various materials, such as nitrile or EPDM, depending on the specific application requirements. The ring itself may feature asharp upper edge and a rounded lower edge to facilitate installation and improve sealing efficiency. This combination of features ensures a robust sealing mechanism that effectively prevents coolant leakage, thereby maintaining the integrity and performance of the engine.

[0017] Other aspects of the invention are also disclosed.Brief Description of the Drawings

[0018] Notwithstanding any other forms which may fall within the scope of the present invention, preferred embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which:

[0019] Figure 1 shows an exploded perspective view of an internal combustion engine;

[0020] Figure 2 shows a cross-sectional view of a sealing insert;

[0021] Figure 3 shows a cross-sectional view of the engine of Figure 1 ; and

[0022] Figure 4 shows a cross-sectional coolant port detail showing installation of the sealing insert of Figure 2 around a cylinder of the engine of Figure 1 .Description of Embodiments

[0023] Figure 1 shows an internal combustion engine 100 comprising an engine block 101 and a cylinder head 102 forming a cylinder 105 therebetween. In the embodiment shown, the internal combustion engine 100 comprises distinct cylinder heads 102 and may be configured in a V8, V12, V16, or V20 engine configuration, as examples.

[0024] The cylinder 105 may be encased by a cylindrical metallic cylinder sleeve 103, which may define an upper annular flange 104. A filler band seal 1 14 installed under the flange 104 may interface the cylinder sleeve 103 and the engine block 101 .

[0025] A head spacer plate 107 may lie flat against a face 109 of the engine block 101 surrounding the cylinder 105 and may have the same thickness as the flange 104 of the cylinder sleeve 103 to form a flat face therewith for flush mounting of the cylinder head 102. A spacer plate shim 108 may be installed between the head spacer plate 107 and the engine block 101 , and a head gasket 1 10 may be installed between the head spacer plate 107 and the cylinder head 102.

[0026] A plurality of coolant ports 1 1 1 are formed around the cylinder 105. In the embodiment shown, each cylinder 105 is surrounded by eight coolant ports 1 1 1 . With reference to Figure 4, engine coolant may flow up through a plenum 1 12 formed between the sleeve 103 and the engine block 101 into a reservoir 1 13 and up through a coolant port 1 1 1 into the cylinder head 102. A tubular coolant seal 106 may interface the coolant port 1 1 1 between the engine block 101 and the cylinder head 102.

[0027] An annular recess 1 15 is machined into the face 109 of the engine block 101 surrounding the cylinder 105. The recess 1 15 may define an inner surface and a bottom surface orthogonal to each other and be open at the top and inner side thereof. A sealing insert 125 is then installed in the recess 1 15. The sealing insert 125 comprises a metallic ring 1 16 which has an outer surface 124 defining an outer channel 1 18 with a surrounding O-ring 1 17 installed therein. The O-ring 1 17 may be an EPDM seal.

[0028] Figure 2 shows a crack 1 19 formed in a stress riser portion 120 of the engine block 101 between the machined insert recess 1 15 and the coolant port 1 1 1. The O- ring 1 17 locates above the crack 1 19, thereby preventing the coolant from flowing up between the outer surface 124 of the metallic ring 1 16 and the engine block 101 .

[0029] Preferably, the ring 1 16 and the recess 1 15 are configured so that the O-ring 117 locates less than 0.200” below a top surface 121 of the ring 116. The metal ring 1 16 and the recess 1 15 are preferably configured to define an interference fit therebetween. Preferably, the interference fit has a tolerance of less than 0.010”, such as 0.005” - 0.006”. As such, the metal ring 116 is typically pressed into the recess 1 15 using a mechanical press (not shown).

[0030] As is evident from Figure 4, an inner edge of the recess 1 15 is a sharp edge which may shave the O-ring 1 17 during installation of the ring 1 16. Therefore, during installation, the O-ring is preferably compressed into the channel 1 18 to pass the inner edge of the recess 1 15 without damage. In embodiments, a metal compression band (not shown) may be installed around the ring 1 16 to compress the O-ring 1 17 into the channel 1 18 while the ring 1 16 passes through the compression band into the recess 1 15.

[0031] With reference to Figure 2, the ring 116 may have a sharp upper edge 122 conforming with the sharp inner edge of the recess 115. However, the ring 1 16 may comprise a rounded lower edge 123 to aid the installation of the ring 1 16.

[0032] The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that specific details are not required in order to practise the invention. Thus, the foregoing descriptions of specific embodiments of the invention are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed as obviously many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the following claims and their equivalents define the scope of the invention.

Claims

Claims1 . An internal combustion engine comprising an engine block and a cylinder head forming a cylinder therebetween, wherein a sealing insert comprising a metallic ring with a surrounding O-ring is installed between a cylinder sleeve and a coolant port in a recess formed in the engine block surrounding the cylinder.

2. The engine as claimed in claim 1 , wherein the sealing insert is inserted under an upper annular flange of the cylinder sleeve.

3. The engine as claimed in claim 2, wherein a filler band seal is installed under the flange between the cylinder sleeve and the sealing insert.

4. The engine as claimed in claim 2, wherein a head spacer plate lies against a face of the engine block surrounding the flange.

5. The engine as claimed in claim 4, wherein a head gasket is installed between the head spacer plate and the cylinder head.

6. The engine as claimed in claim 1 , wherein a tubular coolant seal is installed in the coolant port between the engine block and the cylinder head.

7. The engine as claimed in claim 1 , wherein the O-ring is located less than 0.200” below a top surface of the ring.

8. The engine as claimed in claim 1 , wherein the metal ring and the recess are configured to define an interference fit therebetween.

9. The engine as claimed in claim 8, wherein the interference fit has a tolerance of less than 0.010”.

10. The engine as claimed in claim 1 , wherein the O-ring is a nitrile seal.1 1 . The engine as claimed in claim 1 , wherein the ring has a sharp upper edge.

12. The engine as claimed in claim 1 , wherein the ring has a rounded lower edge.

13. A method for preventing coolant leakage from an engine block and cylinder head interface, the method comprising installing a sealing insert comprising a metallic ring with a surrounding O-ring between a cylinder sleeve and a coolant port in a recess formed in the engine block surrounding the cylinder.

14. The method as claimed in claim 13, wherein the O-ring is located less than 0.200” below a top surface of the ring.

15. The method as claimed in claim 13, wherein the metal ring and the recess are configured to define an interference fit therebetween.

16. The method as claimed in claim 15, wherein the interference fit has a tolerance of less than 0.010”.

17. The method as claimed in claim 15, further comprising compressing the O-ring into the channel when installing the ring into the recess.

18. The method as claimed in claim 17, further comprising installing a compression band around the ring during installation to compress the O-ring into the channel while the ring passes through the compression band into the recess.

19. The method as claimed in claim 13, wherein the O-ring comprises EPDM.

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