GB2546313A

GB2546313A - Turbulators for an internal combustion engine

Info

Publication number: GB2546313A
Application number: GB1600792.4A
Authority: GB
Inventors: Snuis Hans-Bernhard; Schelle Jorg
Original assignee: Caterpillar Energy Solutions GmbH
Current assignee: Caterpillar Energy Solutions GmbH
Priority date: 2016-01-15
Filing date: 2016-01-15
Publication date: 2017-07-19
Also published as: GB201600792D0; EP3192994A2; EP3192994A3; EP3192994B1

Abstract

A coke scraper ring 18 for placement proximate to a top dead center 24 position of a piston 16 in a cylinder 13 of an internal combustion engine 10 is disclosed. The coke scraper ring 18 includes an inner surface 34 configured to face a fuel-air mixture. A plurality of turbulators 20 are formed on the inner surface 34 for inducing turbulence in the fuel-air mixture. The turbulators 20 may be in the form of protrusions or indentations (or a mix of both) and can be symmetrical or asymmetric in shape. Also disclosed are turbulators located on the inner surface (34, fig.2) of the cylinder and/or on the top surface (30, fig.4) of the piston. The turbulators may enhance the turbulence in the fuel-air mixture in the combustion chamber 22 to improve combustion within the engine cylinder and to improve emissions from the engine.

Description

Turbulators for an Internal Combustion Engine

Technical Field [0001] The present disclosure relates generally to an internal combustion engine. In particular, the present disclosure relates to a structure for inducing turbulence in an internal combustion engine.

Background [0002] In an internal combustion engine a piston moves between a top dead center and a bottom dead center to perform various strokes of the internal combustion engine. In a compression stroke, the piston moves from a bottom dead center to a top dead center in the cylinder to compress fuel-air mixture. At the end of the compression stroke the fuel-air mixture is confined in a limited volume in the combustion chamber of the internal combustion engine. It is desirable to induce turbulence in the fuel-air mixture in the combustion chamber for achieving better combustion.

[0003] German Patent Publication No. DE10121852 A1 discloses a flame ring with grooves to increase elasticity of the flame ring, and prevent the ring from failure due to thermal load. PCT Publication No. WO 97/03280 discloses a coke scraper ring with grooves to prevent damage to the piston rings.

Summary of the Invention [0004] A coke scraper ring for placement proximate to a top dead center in a cylinder of an internal combustion engine is disclosed. The coke scraper ring includes an inner surface that is configured to face a fuel-air mixture. A plurality of turbulators are formed on the inner surface for inducing turbulence in the fuel-air mixture.

[0005] In another aspect, a cylinder for an internal combustion engine is disclosed. The cylinder includes an inner surface that faces a fuel-air mixture and a plurality of turbulators are formed at an upper portion of the inner surface.

[0006] In another aspect, a piston for an internal combustion engine is disclosed. The piston includes a top surface having a plurality of turbulators for inducing turbulence in fuel-air mixture.

Brief Description of the Drawings [0007] FIG. 1 illustrates a cut-away perspective view of an engine with turbulators positioned on a coke scraper ring.

[0008] FIG. 2 illustrates a cut-away perspective view of an engine with turbulators positioned on cylinder.

[0009] FIG. 3 illustrates a cut-away perspective view of an engine with turbulators positioned on a cylinder liner.

[0010] FIG. 4 illustrates a cut-away perspective view of an engine with turbulators positioned on a piston and a coke scraper ring.

Detailed Description [0011] FIG. 1 illustrates an engine 10 with a cylinder block 12, a cylinder head 14, a piston 16, a coke scraper ring 18 and plurality of turbulators 20 formed on the coke scraper ring 18. The engine 10 may be any internal combustion engine, for example a diesel engine, a petrol engine or any gas engine. The engine 10 may provide power to any machine or system coupled to the engine 10. The cylinder block 12, cylinder head 14 and the piston 16 may together enclose a volume to define a combustion chamber 22. The volume of the combustion chamber 22 may vary with movement of the piston 16 in the cylinder block 12.

[0012] The cylinder block 12 defines a cylinder 13 that reciprocally receives the piston 16. In other embodiments, the cylinder block 12 may define a multiple cylinders. The piston 16 may reciprocate in the cylinder 13 between a top dead center 24 and a bottom dead center 26 within the cylinder block 12. The piston 16 may reciprocate between the top dead center 24 and the bottom dead center 26 for performing various strokes of the engine 10.

[0013] The cylinder head 14 may cover one end of the cylinder 13 near the top dead center 24. The cylinder head 14 may have openings for arrangement of various devices, for example valves 42, injectors or spark plugs 44, conduits, etc., as required for working of the engine 10.

[0014] The piston 16 may be fitted with piston rings 19 to seal a clearance between the cylinder 13 and the piston 16. The piston 16 may have a top surface 30 that is configured to face the fuel-air mixture. The piston 16 may be coupled to a crankshaft (not shown) via a piston rod 17 for converting the linear motion imparted to the piston 16 by the combustion of fuel-air mixture into a rotary motion, as known in the art.

[0015] The coke scraper ring 18 may be disposed in an annular recess 21 at an upper portion of the cylinder 13 near the top dead center 24. The coke scraper ring 18 may scrap away the coke deposits from the piston 16 to prevent damage to the cylinder 13 by abrasion. The coke scraper ring 18 is positioned such that movement of the piston 16 towards the top dead center 24 results in scraping away of coke deposits on the piston 16, for example coke deposits on the top surface 30. The coke scraper ring 18 has an inner surface 34. The internal diameter of the coke scraper ring 18 may be slightly lesser than the diameter of the cylinder 13. The inner surface 34 may have a bottom edge 36 and a top edge 38. The bottom edge 36 may scrap away coke deposits from the piston 16 when the piston 16 approaches and passes across the bottom edge 36 of the coke scraper ring 18.

[0016] The turbulators 20 are positioned on the coke scraper ring 18 to enhance the turbulence in the combustion chamber 22. The turbulators 20 may be a protrusion or an indentation such that the movement or flow of the fuel-air mixture across the turbulators 20 may convert a linear flow of the fuel-air mixture into a turbulent flow. The turbulators 20 may be positioned on the coke scraper ring 18 proximate to the top dead center 24.

[0017] In the embodiment as illustrated in FIG. 1 the coke scraper ring 18 positioned near the top dead center 24 is provided with a plurality of turbulators 20 in form of recesses or indentations on its inner surface 34. The turbulators 20 are placed between the top edge 38 and the bottom edge 36 of the inner surface 34 of the coke scraper ring 18. As illustrated, each turbulator 20 has a planar section 46 and a curved section 48. The planar section 46 has a stumbling edge 50 formed at the transition of the planar section 46 and the cylinder 13. The planar section 46 further has a circular edge 52 formed at the transition of the planar section 46 into the curved section 48. The curved section 48 further has a curved edge 54 formed at the transition of curved section 48 and the cylinder 13. Thus, the planar section 46 and the curved section 48 together define a part-cylindrical recess or indentations as turbulator 20. The turbulators 20 are substantially oriented horizontally to interact with a swirl flow in the combustion chamber 22.

[0018] FIG. 2 illustrates another embodiment of the engine 10 in accordance with the present disclosure. As illustrated, the cylinder 13 defines an inner surface 34 at an upper portion of the cylinder 13. The inner surface 34 is configured to face fuel-air mixture proximate to the top dead center 24. The turbulators 20 are provided on the inner surface 34 of the cylinder 13. As illustrated, the turbulators 20 are shown as part-cylindrical protrusions on the inner surface 34.

[0019] FIG. 3 illustrates an embodiment of the engine 10 in accordance with the present disclosure, where the cylinder block 12 receives a cylinder liner 40 for defining the cylinder 13. The turbulators 20 may be provided on the inner surface 34 defined by the cylinder liner 40 proximate to the top dead center 24.

As illustrated, the turbulators 20 are shown as part-cylindrical protrusions on the inner surface 34.

[0020] Further, FIG. 4 illustrates an embodiment of the engine 10 in accordance with the present disclosure. As illustrated, the top surface 30 of the piston 16 may be provided with the turbulators 20 in form of protrusions on the top surface 30. The turbulators 20 on the top surface 30 may enhance turbulence in the combustion chamber 22. For example, the turbulators 20 on the top surface 30 of the piston 16 may interact with a tumble flow or a squish flow in the combustion chamber 22 to enhance turbulence.

[0021] As illustrated in FIG. 4, additionally, the turbulators 20 may also be positioned on the inner surface 34 of the coke scraper ring 18. The turbulators 20 as shown in FIG. 4, may be a combination of protrusion and indentations on the inner surface 34. It may be understood by the person skilled in the art that the turbulators 20 may only be provided on either on the top surface 30 of the piston 16 or on the coke scraper ring 18. It may further be understood by a person skilled in the art that for purpose of illustration, the turbulators 20 in FIG. 4 are provided on the coke scraper ring 18. In an alternate embodiment, as discussed above, the turbulators 20 may be provided on an inner surface 34 defined by a cylinder liner 40.

[0022] A suitable number of turbulators 20 may be provided on the inner surface 34 or the piston 16. In an embodiment, a plurality of turbulators 20 may be positioned symmetrically or asymmetrically as suitable according to the size or configuration of the engine 10. In an embodiment, turbulators 20 in form of a protrusion or recess in any suitable shape and size may be provided. Moreover, An embodiment may be contemplated wherein the turbulators 20 may be provided in a combination of protrusions and indentations. Further, in an embodiment, the turbulators 20 may be asymmetric in shape. In an embodiment, the turbulators 20 may be oriented according to a flow of fuel-air mixture in the combustion chamber22. For example, the turbulators 20 may be oriented according to direction of swirl in the combustion chamber 22 in order to interact effectively with a swirl flow to enhance overall turbulence in the combustion chamber 22. The shape and dimensions of the turbulators 20 may be designed such as to not hamper the movement of piston 16 inside the cylinder block 12.

Industrial Applicability L0023J The present disclosure provides for turbulators 20 for an engine 10. The turbulators 20 in accordance with the present disclosure may enhance turbulence in the fuel-air mixture in the combustion chamber 22 of the engine 10. In an internal combustion engine, at the end of the compression stroke, the fuel-air mixture may not have adequate turbulence for effective combustion of the fuel-air mixture. The turbulators 20 in accordance with the present disclosure may enhance the turbulence in the fuel-air mixture in the combustion chamber 22 for better combustion of the fuel-air mixture. The turbulators 20 in accordance with the present disclosure may enhance efficiency of the engine 10 by improving combustion in the combustion chamber 22 of the engine 10. Also, the turbulators 20 in accordance with the present disclosure may improve emissions from the engine 10 by facilitating fuller combustion of the fuel-air mixture.

[0024] The turbulators 20 in accordance with the present disclosure may be provided on any of the coke scraper ring 18, cylinder block 12, cylinder liner 40 or piston 16 for enhancing turbulence in the combustion chamber 22. The turbulators 20 in accordance with the present disclosure may be any recess or protrusion or a combination thereof on a cylinder 13 proximate to the top dead center 24 of the engine 10.

[0025] Further, the turbulators 20 in accordance with the present disclosure may be retrofitted in any internal combustion engine. The turbulators 20 may be formed on the cylinder 13 during overhaul or repairing of the engine 10 to improve the efficiency of the engine 10. For example, a coke scraper ring 18 with turbulators 20 may be put in the engine 10 during an overhaul, repair or service of the engine 10. Alternatively, for an engine 10 without a coke scraper ring, the turbulators 20 may be formed on the cylinder liner 40 or cylinder 13 during servicing.

Claims

Claims What is claimed is:

1. A coke scraper ring (18) for placement proximate to a top dead center (24) in a cylinder (13) of an internal combustion engine (10), the coke scraper ring (18) comprising: an inner surface (34) configured to face a fuel-air mixture; and a plurality of turbulators (20) formed on the inner surface (34) for inducing turbulence in the fuel-air mixture.

2. The coke scraper ring (18) of claim 1, wherein the turbulators (20) are a protrusion on the inner surface (34).

3. The coke scraper ring (18) of claim 1, wherein the turbulators (20) are an indentation on the inner surface (34).

4. The coke scraper ring (18) of claim 1, wherein the turbulators (20) are positioned between a top edge (38) and a bottom edge (36) of the inner surface (34).

5. The coke scraper ring (18) of claim 1, wherein the turbulators (20) are asymmetric in shape.

6. The coke scraper ring (18) of claim 1, wherein the turbulators (20) are part-cylindrical in shape.

7. The coke scraper ring (18) of claim 1, wherein the plurality of turbulators (20) comprise a combination of protrusions and indentations.

8. The coke scraper ring (18) of claim 1, wherein the turbulators (20) are oriented in direction of flow of fuel-air mixture.

9. A cylinder (13) for an internal combustion engine (10), the cylinder (13) comprising: an inner surface (34) for facing fuel-air mixture; and a plurality of turbulators (20) formed at an upper portion of the inner surface (34).

10. The cylinder (13) of claim 9, further comprising a cylinder liner (40) placed inside the cylinder (13), the cylinder liner (40) defining the inner surface (34).

11. The cylinder (13) of claim 9, wherein the turbulators (20) are a protrusion on the inner surface (34).

12. The cylinder (13) of claim 9, wherein the turbulators (20) are indentation on the inner surface (34).

13. The cylinder (13) of claim 9, wherein the turbulators (20) are asymmetric in shape.

14. The cylinder (13) of claim 9, wherein the plurality of turbulators (20) comprise a combination of protrusions and indentations.

15. The cylinder (13) of claim 9, wherein the turbulators (20) are oriented in direction of flow of fuel-air mixture.

16. A piston (16) for an internal combustion engine (10), the piston (16) comprising a top surface (30) having a plurality of turbulators (20) for inducing turbulence in fuel-air mixture.

17. The piston (16) of claim 16, wherein the turbulators (20) are a protrusion on the top surface (30).

18. The piston (16) of claim 16, wherein the turbulators (20) are an indentation on the top surface (30).

19. The piston (16) of claim 16, wherein the turbulators (20) are asymmetric in shape.

20. The piston (16) of claim 16, wherein the plurality of turbulators (20) comprise a combination of protrusions and indentations.