GB2570294A - Cylinder liner inspection - Google Patents

Cylinder liner inspection Download PDF

Info

Publication number
GB2570294A
GB2570294A GB1800640.3A GB201800640A GB2570294A GB 2570294 A GB2570294 A GB 2570294A GB 201800640 A GB201800640 A GB 201800640A GB 2570294 A GB2570294 A GB 2570294A
Authority
GB
United Kingdom
Prior art keywords
cylinder liner
chamber
inspection device
plane
measurements
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB1800640.3A
Other versions
GB201800640D0 (en
Inventor
Michael Andrew Rodey Patrick
Dyhr Friis John
Kjaer Normann Rasmus
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AP Moller Maersk AS
Original Assignee
AP Moller Maersk AS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by AP Moller Maersk AS filed Critical AP Moller Maersk AS
Priority to GB1800640.3A priority Critical patent/GB2570294A/en
Publication of GB201800640D0 publication Critical patent/GB201800640D0/en
Publication of GB2570294A publication Critical patent/GB2570294A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
    • B64U20/00—Constructional aspects of UAVs
    • B64U20/80—Arrangement of on-board electronics, e.g. avionics systems or wiring
    • B64U20/87—Mounting of imaging devices, e.g. mounting of gimbals
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/08—Measuring arrangements characterised by the use of optical techniques for measuring diameters
    • G01B11/12—Measuring arrangements characterised by the use of optical techniques for measuring diameters internal diameters
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B5/00—Measuring arrangements characterised by the use of mechanical techniques
    • G01B5/08—Measuring arrangements characterised by the use of mechanical techniques for measuring diameters
    • G01B5/12—Measuring arrangements characterised by the use of mechanical techniques for measuring diameters internal diameters
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
    • G01N21/954—Inspecting the inner surface of hollow bodies, e.g. bores
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64U—UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
    • B64U2101/00—UAVs specially adapted for particular uses or applications
    • B64U2101/30—UAVs specially adapted for particular uses or applications for imaging, photography or videography
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M15/00—Testing of engines
    • G01M15/04—Testing internal-combustion engines
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
    • G01N21/9515—Objects of complex shape, e.g. examined with use of a surface follower device
    • G01N2021/9518—Objects of complex shape, e.g. examined with use of a surface follower device using a surface follower, e.g. robot
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
    • G01N21/954—Inspecting the inner surface of hollow bodies, e.g. bores
    • G01N2021/9542—Inspecting the inner surface of hollow bodies, e.g. bores using a probe
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
    • G01N21/954—Inspecting the inner surface of hollow bodies, e.g. bores
    • G01N2021/9548—Scanning the interior of a cylinder

Abstract

A self-propelled device 100, e.g. an unmanned aerial vehicle such as a drone, is used for inspecting a cylinder liner of an engine, e.g. of marine vessels or ships. The device 100 is insertable into a lower portion of a chamber 12 encircled by a circumferential wall 11 of a cylinder liner 10 via a hole 16, e.g. a scavenger port. The self-propulsion mechanism (102, Fig. 2) may comprise rotors for propelling the device up the chamber or may comprise suction cups or magnets. The device 100 comprises apparatus (104, Fig. 2) for determining information about one or more characteristics of the cylinder liner when located in the chamber. The device 100 may be remote controlled and may determine a radius or diameter of the liner or sleeve.

Description

TECHNICAL FIELD [0001] The present invention relates to cylinder liner inspection devices, and to methods of inspecting cylinder liners, such as cylinder liners for engines of marine vessels.
BACKGROUND [0002] A cylinder liner (sometimes known as a cylinder sleeve) is a hollow cylindrical part to be fitted into a cylinder block (also known as a cylinder jacket) of an engine to form the cylindrical space or combustion chamber in which a piston of the engine is to reciprocate. The engine may, for example, be a marine engine, such as the engine of a container ship.
[0003] Manufacturing cylinder liners as separate parts from the cylinder blocks in which they are to be located provides a number of advantages. One advantage is that the cylinder liner may be manufactured using a material that is superior to that of the cylinder block. For example, while the cylinder block may be made from cast iron, the cylinder liner may be manufactured from a cast iron alloyed with chromium, vanadium and molybdenum. Such alloying elements can help resist corrosion and improve wear resistance at high temperatures. Another advantage is that reciprocation of the piston in the chamber will wear the component that defines the chamber. By making this component a separate cylinder liner, it may be replaced without the cylinder block also having to be replaced. A further advantage is that, at working temperatures, the cylinder liner may be a lot hotter than the cylinder block. As compared to the cylinder block, the cylinder liner may be permitted to expand more and to be free to expand diametrically and lengthwise. If the cylinder liner and cylinder block were instead cast as one piece, then unacceptable thermal stresses could be set up, causing fracture of the cylinder block. A still further advantage is that there is a lower risk of defects being present in a cylinder liner, since it tends to be more simply-shaped than a cylinder block. The more complex the casting, the more difficult to produce a homogenous casting with low residual stresses.
[0004] The inner surface of a cylinder liner may become worn or lose its smooth finish, for example due to the reciprocation of the piston rings along it, due to soot or other abrasives being deposited over time, and/or due to corrosive attacks. Such wear, deposits and attacks often are non-uniform or present only in portions of the surface, due to uneven distribution of lubricant, gas leakage between the piston rings and the cylinder liner, and/or variations of the temperature of the cylinder liner, for example. A cylinder liner can also deform in shape over time. For example, it may become oval in cross section over time, for example due to linear forces exerted by the piston. Increased wear and/or misshaping of the cylinder liner is undesirable because it means that there may be increased friction between the cylinder liner and the piston crown, which reduces fuel efficiency. The state of marine engines, and particularly their cylinder liners, are therefore checked regularly, to help identify and mitigate any imperfections early on in their development, maintain operational performance and avoid shutdowns.
[0005] Conventional inspections of cylinder liners are performed manually, and require the cylinder head and possibly other components of the engine to be dismantled for an inspector to gain access to the combustion chamber. This can result in lengthy downtime of the cylinder and the engine, and ship as a whole.
[0006] WO2011/152797, WO99/15893 and US2017/0097306 all disclose devices for inspecting cylinder liner interiors, which avoid the need for an inspector themselves to enter a combustion chamber. However, all these systems still require the cylinder head to be removed or other components of the engine to be dismantled for the devices to access the chamber to carry out the inspection. Reassembly of the dismantled cylinder and engine is time consuming and not guaranteed to bring the cylinder back into working order. Often additional maintenance is required to ensure there are no leaks.
[0007] W02009/152851, EP2261594 and DK201700501 all disclose devices for measuring cylinder liner interiors that do not require the cylinder head to be removed. Instead, these devices are compact enough to be placed in the chamber encircled by the cylinder liner via a scavenger port in the circumferential wall of the cylinder liner. The devices are positioned on the upper surface or crown of a piston in the combustion chamber, and then are carried by the piston as they take measurements inside the chamber. However, after the piston crown has moved past the scavenger port during this motion, communication with the device via the scavenger port is hindered or impossible. It is suggested to remove an air valve or a fuel injector or the like to facilitate communication with the device from a position above the piston crown, but this again requires components of the engine to be dismantled, which risks damaging the components, requires the components to be checked after reassembly, and altogether can make an inspection procedure a lengthy process. Similarly, leaks are often encountered when the cylinder is reassembled. Moreover, if the devices get stuck in the chamber above the scavenger port, removal of the cylinder head to retrieve the device may be required.
[0008] DEI 9631970 discloses the use of an optical glass fibre with an eyepiece and light source at its outer end, and which can be introduced into difficult to access locations of an internal combustion engine using a guide tube. However, use of such a system in a very large combustion chamber, as may be found in an engine of a marine vessel for example, without an inspector entering the chamber themselves is considerably limited. This is because the precision with which the eyepiece may be positioned, for example if it were threaded into the chamber via a scavenger port, is very low due to the flexibility of the glass fibre and guide tube. Moreover, this system is unable to take measurements within the chamber.
[0009] Embodiments of the present invention aim to address the aforementioned problems.
SUMMARY [0010] A first aspect of the present invention provides a cylinder liner inspection device that is insertable into a lower portion of a chamber encircled by a cylinder liner via a hole in a circumferential wall of the cylinder liner, comprises a self-propulsion mechanism for thereafter propelling the cylinder liner inspection device away from the lower portion of the chamber towards an upper portion of the chamber, and comprises apparatus for determining information about one or more characteristics of the cylinder liner when located in the chamber.
[0011] This means that neither a cylinder head nor any other component at the upper end of the chamber need be removed for the device to access the chamber, and moreover that a piston in the chamber need not be moved to carry the device. Accordingly, communication with the device remains possible via the hole through which the device was inserted into the chamber. Inspection of a cylinder liner may therefore be carried out with relatively little disruption and in relatively little time.
[0012] Optionally, the cylinder liner inspection device comprises an unmanned aerial vehicle.
[0013] Optionally, the self-propulsion mechanism comprises one or more rotors for creating lift for propelling the cylinder liner inspection device away from the lower portion of the chamber towards the upper portion of the chamber.
[0014] Optionally, the cylinder liner inspection device comprises one or more accelerometers for use in determining whether the cylinder liner inspection device is horizontally aligned.
[0015] Optionally, the apparatus comprises a measurer for taking at least one measurement of a distance between an axial end of the chamber and the cylinder liner inspection device. Optionally, the measurer is for taking the at least one measurement when, or only when, the cylinder liner inspection device is determined to be horizontally aligned in the chamber.
[0016] Optionally, the measurer comprises one or more of a laser range finder, an infrared range finder, a measurer for measuring distance using ultrasound, a measurer for measuring distance using radar, a measurer for measuring distance using sonar, and a measurer for measuring distance using lidar.
[0017] Optionally, the apparatus comprises a measurer for taking at least one measurement of an inner radius or diameter of the cylinder liner. Optionally, the measurer is for taking the at least one measurement when, or only when, the cylinder liner inspection device is determined to be horizontally aligned in the chamber.
[0018] Optionally, the measurer for taking at least one measurement of an inner radius or diameter of the cylinder liner comprises plural measurement devices for taking respective angularly-offset measurements of the inner radius or diameter of the cylinder liner, or a measurement device that is movable relative to a body of the cylinder liner inspection device for taking plural angularly-offset measurements of the inner radius or diameter of the cylinder liner between respective periods of movement of the measurement device relative to the body.
[0019] Optionally, the measurer comprises one or more of a laser range finder, an infrared range finder, a measurer for measuring distance using ultrasound, a measurer for measuring distance using radar, a measurer for measuring distance using sonar, and a measurer for measuring distance using lidar.
[0020] Optionally, the apparatus comprises at least one optical imaging device for imaging at least a portion of the cylinder liner.
[0021] Optionally, the cylinder liner inspection device comprises a communication interface for communicating with a user terminal remote from the cylinder liner inspection device. Optionally, the communication interface is a wireless communication interface for wirelessly communicating with the user terminal.
[0022] Optionally, the cylinder liner inspection device is operable in temperatures of up to 80 degrees Celsius.
[0023] Optionally, the cylinder liner inspection device is configurable to fit through the hole.
[0024] Optionally, the hole has a height of no more than 0.3 metres and a width of no more than 0.1 metres.
[0025] Optionally, the cylinder liner inspection device comprises a line by which the cylinder liner inspection device is tetherable to an object.
[0026] A second aspect of the present invention provides a cylinder liner inspection system comprising the cylinder liner inspection device of the first aspect of the present invention, and a user terminal remote from the cylinder liner inspection device and comprising a communication interface for communicating with the cylinder liner inspection device.
[0027] Optionally, the communication interface of the user terminal is a wireless communication interface for wirelessly communicating with the cylinder liner inspection device.
[0028] Optionally, the user terminal comprises one or more of a controller for controlling the cylinder liner inspection device; a display for displaying an image captured by an optical imaging device of the apparatus of the cylinder liner inspection device and communicated to the user terminal via the communication interface of the user terminal; and storage for storing data based on the information determined by the apparatus and communicated to the user terminal via the communication interface of the user terminal.
[0029] Optionally, the display is for showing a video image. Optionally, the video image is communicated in real time to the user terminal via the communication interface of the user terminal.
[0030] A third aspect of the present invention provides a method of inspecting a cylinder liner, the method comprising when the cylinder liner inspection device of the first aspect of the present invention is in a lower portion of a chamber encircled by the cylinder liner, causing the self-propulsion mechanism of the cylinder liner inspection device to propel the cylinder liner inspection device towards an upper portion of the chamber; and causing the apparatus of the cylinder liner inspection device to determine information about one or more characteristics of the cylinder liner when the cylinder liner inspection device is located in the chamber.
[0031] Optionally, the method comprises causing a measurer of the apparatus to take a first plurality of angularly-offset measurements of an inner radius or diameter of the cylinder liner in a first plane of the chamber.
[0032] Optionally, the method comprises causing the cylinder liner inspection device to be positioned at another location within the first plane, when at least some the measurements differ from each other by more than a predetermined amount. Optionally, the predetermined amount is zero.
[0033] Optionally, the method comprises causing the measurements to be compared with each other.
[0034] Optionally, the causing the cylinder liner inspection device to be positioned at another location within the first plane comprises causing the self-propulsion mechanism to propel the cylinder liner inspection device within the first plane.
[0035] Optionally, the method comprises determining that the cylinder liner inspection device is on a central axis of the chamber, when the measurements do not differ from each other by more than a predetermined amount. Optionally, the predetermined amount is zero.
[0036] Optionally, the method comprises causing the measurements to be compared with each other.
[0037] Optionally, the method comprises determining a control value of an inner radius or diameter of the cylinder liner based on the measurements, when the measurements do not differ from each other by more than a predetermined amount. Optionally, the predetermined amount is zero.
[0038] Optionally, the method comprises causing the measurements to be compared with each other.
[0039] Optionally, the method comprises causing the self-propulsion mechanism to propel the cylinder liner inspection device to a second plane of the chamber, the second plane being different from the first plane; and causing the measurer of the apparatus to take a second plurality of angularly-offset measurements of an inner radius or diameter of the cylinder liner in the second plane of the chamber.
[0040] Optionally, the method comprises causing the cylinder liner inspection device to be positioned at another location within the second plane, when the second plurality of angularly-offset measurements differ from each other by more than a predetermined amount. Optionally, this comprises causing the self-propulsion mechanism to propel the cylinder liner inspection device within the second plane.
[0041] Optionally, the method comprises causing respective comparisons to be made between the second plurality of angularly-offset measurements and the control value; and determining a condition of the cylinder liner in the second plane based on a result of the comparisons.
[0042] Optionally, the determining a condition of the cylinder liner comprises determining that the cylinder liner is oval in the second plane, when one of the second plurality of angularly-offset measurements of the inner diameter differs from the control value by more than a predetermined amount, and another of the second plurality of angularly-offset measurements of the inner diameter, perpendicular to the one of the second plurality of angularly-offset measurements, does not differ from the control value by more than the predetermined amount.
[0043] Optionally, the determining a condition of the cylinder liner comprises determining that the cylinder liner is oval in the second plane, when each of a first pair of 180-degree-offset measurements of the second plurality of angularly-offset measurements of the inner radius differs from the control value by more than a predetermined amount, and each of a second pair of 180-degree-offset measurements of the second plurality of angularly-offset measurements of the inner radius, perpendicular to the first pair, does not differ from the control value by more than the predetermined amount.
[0044] Optionally, the determining a condition of the cylinder liner comprises determining that the cylinder liner has a defect in the second plane, when one of the second plurality of angularly-offset measurements of the inner radius differs from the control value by more than a predetermined amount, and most or all of the others of the second plurality of angularly-offset measurements of the inner radius do not differ from the control value by more than the predetermined amount.
[0045] Optionally, the method comprises causing storage of the first plurality of angularly-offset measurements in association with information representative of the first plane of the chamber, and storage of the second plurality of angularly-offset measurements in association with information representative of the second plane of the chamber.
[0046] Optionally, the method comprises determining the information representative of the second plane of the chamber by causing a measurer of the apparatus to take at least one measurement of a distance between an axial end of the chamber and the cylinder liner inspection device. Optionally, the axial end of the chamber is defined by a piston. Optionally, the axial end of the chamber is defined by a cylinder head.
[0047] Optionally, the method comprises causing creation of a visual map of at least a portion of the inner surface of the cylinder liner based on the first plurality of angularlyoffset measurements, the information representative of the first plane of the chamber, the second plurality of angularly-offset measurements, and the information representative of the second plane of the chamber.
[0048] Optionally, the method comprises causing a comparison to be made between the visual map and an earlier visual map of the at least a portion of the cylinder liner; and determining a rate of change of the at least a portion of the cylinder liner based on a result of the comparison.
[0049] Optionally, the method comprises generating an image of at least a portion of the cylinder liner using at least one optical imaging device of the apparatus.
[0050] Optionally, the method is performed by a controller onboard the cylinder liner inspection device.
[0051] Optionally, the method is performed by a controller of a user terminal remote from the cylinder liner inspection device and comprising a communication interface for communicating with the cylinder liner inspection device.
[0052] Optionally, the method comprises inserting the cylinder liner inspection device into the lower portion of the chamber encircled by a circumferential wall of the cylinder liner via a hole in the circumferential wall.
[0053] Optionally, the hole in the circumferential wall of the cylinder liner is a scavenger port.
[0054] A fourth aspect of the present invention provides a non-transitory computerreadable storage medium storing instructions that, if executed by a processor of a cylinder liner inspection system, cause the processor to carry out the method of the third aspect of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS [0055] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:
[0056] Figure 1 shows a schematic cross-sectional side view of a cylinder of a marine engine, the cylinder including a cylinder liner to be inspected;
[0057] Figure 2 shows a schematic cross-sectional side view of an example of a cylinder liner inspection device according to an embodiment of the present invention;
[0058] Figure 3 shows a schematic view of an example of a cylinder liner inspection system according to an embodiment of the present invention, the system comprising the cylinder liner inspection device of Figure 2 and a user terminal;
[0059] Figure 4 shows a schematic cross-sectional side view of the cylinder of Figure 1 with the cylinder liner inspection device of Figure 2 in a lower portion of a chamber encircled by the cylinder liner;
[0060] Figure 5 shows a schematic cross-sectional top view of the cylinder liner inspection device of Figure 2 off-centre in the chamber;
[0061] Figure 6 shows a schematic cross-sectional top view of the cylinder liner inspection device of Figure 2 on a central axis of the chamber;
[0062] Figure 7 shows a schematic cross-sectional side view of the cylinder of Figure 1 with the cylinder liner inspection device of Figure 2 in an intermediate portion of the chamber;
[0063] Figure 8 shows a schematic diagram of three different example conditions of the shape of the cylinder liner in a given plane perpendicular to the central axis;
[0064] Figure 9 shows a schematic cross-sectional side view of the cylinder of Figure 1 with the cylinder liner inspection device of Figure 2 in an upper portion of the chamber;
[0065] Figure 10 shows a schematic diagram of an example of how a visual map of a cylinder liner may be created;
[0066] Figure 11 shows a flow chart illustrating an example of a method of inspecting a cylinder liner according to an embodiment of the present invention; and [0067] Figure 12 shows a flow chart illustrating an example of another method of inspecting a cylinder liner according to an embodiment of the present invention.
DETAILED DESCRIPTION [0068] Figure 1 shows a schematic cross-sectional side view of a cylinder of an engine, such as the engine of a marine vessel, e.g. a container ship. Although only one cylinder 1 is shown, it will of course be appreciated that the engine may comprise a plurality of cylinders 1.
[0069] The cylinder 1 includes a cylinder liner 10. The cylinder liner 10 comprises a circumferential wall 11 that encircles a combustion chamber 12 in which combustion takes place during engine operation. The engine includes a piston 13 that is connected to a piston rod 14 for reciprocation in the combustion chamber 12 in the direction of the arrows. In Figure 1, the piston 13 is shown at bottom dead centre (BDC) in the combustion chamber 12. The end of the cylinder 1 opposite from the piston 13 is closed by a cylinder cover 15. The piston 13 moves towards the cylinder cover 15 as it approaches top dead centre (TDC). Although not shown in Figure 1 for clarity, one or more fuel injectors, air valves, exhaust ports and/or other components may be present in, or mounted to, the cylinder cover 15. Together, the circumferential wall 11, the piston 13 and the cylinder cover 15 delimit the combustion chamber 12.
[0070] One or more scavenger ports or holes 16 is/are provided in the circumferential wall 11 of the cylinder liner 10. In this embodiment, there are plural scavenger ports or holes 16, which are spaced apart circumferentially around the combustion chamber 12. The or each scavenger port 16 may have a height (in the axial direction of the combustion chamber 12) of no more than 0.5 metres, such as no more than 0.3 metres. The or each scavenger port 16 may have a width (in the circumferential direction of the combustion chamber 12) of no more than 0.25 metres, such as no more than 0.1 metres. The or each scavenger port 16 may have other dimensions in other embodiments. The cylinder 1 comprises a cylinder frame 17 within which the cylinder liner 10 is located. The cylinder frame 17 has one or more scavenger port inspection hatches 18, which are openable by an inspector or other operative to gain access to the scavenger ports or holes 16.
[0071] The skilled person will be familiar with the components and operation of an engine cylinder including a cylinder liner, and so further detailed discussion thereof is omitted for brevity.
[0072] As noted above, during operation of the engine, an inner surface of the circumferential wall 11 of the cylinder liner 10 may be prone to becoming worn, deformed or losing its smooth finish. It is therefore preferable to regularly inspect the state of the cylinder liner 10, to help identify and mitigate any imperfections early on in their development, maintain operational performance and avoid shutdowns of the engine or cylinder 1. Embodiments of the present invention provide a cylinder liner inspection device for use in carrying out such inspections.
[0073] Figure 2 shows a schematic cross-sectional side view of an example of a cylinder liner inspection device according to an embodiment of the present invention. Broadly speaking, the cylinder liner inspection device 100 is insertable into a lower portion of the chamber 12 encircled by the circumferential wall 11 of the cylinder liner 10 via on of the scavenger holes 16 in the circumferential wall 11, comprises a self-propulsion mechanism 102 for thereafter propelling the device 100 away from the lower portion of the chamber 12 towards an upper portion of the chamber 12, and comprises apparatus 104 for determining information about one or more characteristics of the cylinder liner 10 when located in the chamber 12.
[0074] In this embodiment, the cylinder liner inspection device 100 is or comprises an unmanned aerial vehicle (UAV) (also known as a “drone”). As such, the device 100 is able to fly. In this embodiment, the device comprises a body 101 and the self-propulsion mechanism 102 comprises four rotors 103a-103d (only two of which are visible in Figure
2) that are rotatable relative to the body 101 for creating lift for propelling the device 100 away from the lower portion of the chamber 12 towards the upper portion of the chamber 12. In other embodiments, the self-propulsion mechanism 102 may have more than four rotors or fewer than four rotors, such as only one, two or three rotors. In some embodiments, the self-propulsion mechanism 102 comprises a guard structure for protecting the rotor(s) 103 from damage in the event that the device 100 knocks into a surface in use. In some embodiments, additionally or alternatively to rotor(s) 103, the self-propulsion mechanism 102 may comprise another mechanism, such as at least one miniature jet engine, for creating lift for propelling the device 100 away from the lower portion of the chamber 12 towards the upper portion of the chamber 12.
[0075] In addition to propelling the device 100 away from the lower portion of the chamber 12 towards the upper portion of the chamber 12, the self-propulsion mechanism 102 may be for propelling the device 100 in a radial and/or a circumferential direction in the chamber 12. For example, the self-propulsion mechanism 102 may be for steering the device 100 during flight within the chamber 12, such as by adjusting the relative rates of rotation of the rotors 103 and/or by adjusting the angle of the axis of rotation of one or more of the rotors 103 relative to the body 101 of the device 100.
[0076] In other embodiments, the cylinder liner inspection device 100 may be other than a UAV. For example, in some embodiments, the self-propulsion mechanism 101 may comprise a mechanism for mechanically engaging with the circumferential wall 11 of the cylinder liner 10. Such a mechanism may, for example, comprise one or more suction cups, magnets, or the like. For example, the self-propulsion mechanism 101 may comprise a plurality of legs to which are mounted respective suction cups or magnets, and the self-propulsion mechanism 101 may be configured to propel the device 100 away from the lower portion of the chamber 12 towards an upper portion of the chamber 12 by selectively disengaging, moving, and then engaging the suction cups or magnets with the circumferential wall 11 of the cylinder liner 10, so that the device 100 is able to “walk” up the circumferential wall 11. Other suitable self-propulsion mechanisms for propelling the device 100 upwards in the chamber 12 will be apparent to the skilled person.
[0077] The apparatus 104 of the device 100 of this embodiment comprises a measurer
105 for taking at least one measurement of a distance between an axial end of the chamber 12 and the cylinder liner inspection device 100. The measurer 105 may, for example, comprise one or more of: a laser range finder, an infrared range finder, a measurer for measuring distance using ultrasound, a measurer for measuring distance using radar, a measurer for measuring distance using sonar, a measurer for measuring distance using lidar, and a device for taking a measurement by mechanical engagement with the axial end of the chamber 12. Other suitable forms of measurer 105 will be apparent to the skilled person.
[0078] The measurer 105 may be for measuring a distance between the crown of the piston 13 and the device 100, and/or for measuring a distance between the cylinder head 15 and the device 100. Such distance measurements are usable to determine the vertical or axial position of the device 100 within the chamber 12 relative to the axial end of the chamber 12. Data representing such an axial position can, for example, be usable to help control the device 100 within the chamber 12 and/or to associate with information determined by the device 100 about one or more characteristics of the cylinder liner 10 for the creation of a map of at least a portion of the cylinder liner 10, as will be described below. However, in some embodiments, the device 100 may be free from such a measurer 105.
[0079] The apparatus 104 of the device 100 of this embodiment comprises a measurer
106 for taking at least one measurement of an inner radius or diameter of the cylinder liner 10. The measurer 106 may, for example, comprise one or more of: a laser range finder, an infrared range finder, a measurer for measuring distance using ultrasound, a measurer for measuring distance using radar, a measurer for measuring distance using sonar, a measurer for measuring distance using lidar, and a device for taking a measurement by mechanical engagement with the cylinder liner 10. Moreover, the measurer 106 may comprise either (a) plural measurement devices for taking respective angularly-offset measurements of the inner radius or diameter of the cylinder liner 10, or (b) a measurement device that is movable relative to the body 101 of the device 100 for taking plural angularly-offset measurements of the inner radius or diameter of the cylinder liner 10 between respective periods of movement of the measurement device relative to the body 101. Other suitable forms of measurer 106 will be apparent to the skilled person.
[0080] It will be understood that laser range finders work by measuring the time for a light pulse to return to a sensor. In a curved reflective environment, such as the inside of the cylinder liner 11, reflections can be an issue. This is overcome in some embodiments by ensuring that the laser is normal to the surface of the cylinder liner, for example by ensuring that the device 100 is in the centre of the chamber 12. The variation of the measured radius is small. During calibration (described below), a control value or nominal radius is determined. This is then usable to exclude false readings from received reflections that have bounced around the inside of the cylinder liner 11.
[0081] Such distance measurements as obtained by the measurer 106 are usable to determine the radial position of the device 100 within the chamber 12 relative to the central axis A-A of the chamber 12. Data representing such a radial or diametrical position can, for example, be usable to help control the device 100 within the chamber 12. Such radial and/or diametrical measurements are also usable in the determination as to a condition of the cylinder liner 10 in a particular plane perpendicular to the central axis A-A, as will be described below, and/or in the creation of a map of at least a portion of the cylinder liner 10, as will be described below. However, in some embodiments, the device 100 may be free from such a measurer 106.
[0082] The cylinder liner inspection device 100 of this embodiment comprises one or more accelerometers 107 for use in determining whether the device 100 is horizontally aligned or level. In other embodiments, the one or more accelerometers 107 are used in determining whether the device 100 is perpendicular to a longitudinal axis of the chamber 12 or the cylinder liner 10, in the case when the cylinder liner 10 is in a ship that is moving and not itself level. The output of such accelerometer(s) 107 may be usable to help control the device 100 within the chamber 12. The output may additionally or alternatively be used to determine when the measurements taken by one or other of the measurers 105, 106 are true axial or radial/diametrical measurements, respectively, and/or when the device 101 is suitably aligned for the measurers 105, 106 to be able to take true axial or radial/diametrical measurements, respectively. That is, treatment of a measurement taken by one of the measurers 105, 106, and/or operation of one or each of the measurers 105, 106, may be dependent on the output of the accelerometer(s) 107. So, the measurer 105 may be for taking the at least one axial measurement when, or only when, the device 101 is determined to be horizontally aligned in the chamber 12 or perpendicular to a longitudinal axis of the chamber 12 based on the output of the accelerometer(s) 107. Similarly, the measurer 106 may be for taking the at least one radial and/or diametrical measurement when, or only when, the device 101 is determined to be horizontally aligned in the chamber 12 or perpendicular to a longitudinal axis of the chamber 12 based on the output of the accelerometer(s) 107. In some embodiments, however, the device 100 may be free from any such accelerometer(s) 107.
[0083] The apparatus 104 of the device 100 of this embodiment comprises an optical imaging device 108 for imaging at least a portion of the cylinder liner 10. The optical imaging device 108 may, for example, comprise one or more of: a visible spectrum camera, a still camera, a video camera, a digital camera, a film camera, and a panoramic camera. Additionally or alternatively, thermal or infrared cameras may be used. The cameras are preferably high definition and have suitable optics for obtaining close-up imagery of the inner surface of the cylinder liner 10. Furthermore, a 360-degree camera can be used for simultaneously taking an image of the entire surface of the cylinder liner 10 at a particular axial height. In other embodiments, any suitable optical imaging means or device can be used to obtain an image of the cylinder liner 10. Other suitable forms of optical imaging device 108 will be apparent to the skilled person. In some embodiments, the apparatus 104 of the device 100 may comprise plural optical imaging devices 108, which may all be of the same type or of different types of optical imaging device. When plural optical imaging devices 108 are present, the optical imaging devices 108 may be configured for taking respective angularly-offset optical images of the cylinder liner 10. When only one optical imaging device 108 is present, the optical imaging device 108 may be fixed relative to the body 101 of the device 100, or may be movable relative to the body 101 of the device 100 for taking plural angularly-offset optical images of the cylinder liner 10 between periods of movement of the optical imaging device 108 relative to the body 101. In other embodiments, the optical imaging device 108 may fixed with respect to the device 100, but a rotatable mirror arrangement (not shown) is used to direct an image of different parts of the cylinder liner 10 to the optical imaging device 108.
[0084] Optionally, the device 100 of this embodiment comprises a communication interface 109 for communicating with a user terminal 200, which is remote from the device 100 and will be described below. In this embodiment, the communication interface 109 is a wireless communication interface 109 for wirelessly communicating with the user terminal 200, but in other embodiments the communication interface 109 may be a non-wireless, or wired, communication interface 109. Wireless communication may be carried out using a wireless protocol such as the Bluetooth, Wifi, Zigbee or any other suitable wireless communication protocol. A wired communication interface 109 additionally means that the device 100 can be physically pulled out of the chamber 12 if the device 100 becomes stuck.
[0085] The device 100 of this embodiment comprises a controller 110. The controller 110 may comprise one or more microprocessors). The controller 110 is communicatively connected to, and for controlling, each of: the self-propulsion mechanism 102, the measurers 105, 106, the accelerometer(s) 107 and the optical imaging device 108. The controller 110 also is communicatively connected to the communication interface 109. The controller 110 may be configured to receive commands or other data from the user terminal 200 via the communication interface 109. The controller 110 may be configured to send data to the user terminal 200 via the communication interface 109.
[0086] The device 100 of this embodiment comprises an onboard power source (not shown). In this embodiment, the power source is an electrical power source, such as a rechargeable battery. In some embodiments, the electrical power source may be other than a rechargeable battery, such as a non-rechargeable battery or a capacitor. In other embodiments, the device 100 may have an interface (such as a plug or a socket) for connecting to a remote power source, such as a mains electricity supply, a ship-based electricity supply, or a battery that is not onboard the device 100. One or more or all of the self-propulsion mechanism 102, the measurers 105, 106, the accelerometer(s) 107, the optical imaging device 108, the communication interface 109, and the controller 110 may be connected, directly or indirectly, to the power source so as to be able to function.
[0087] The device 100 may be dimensioned to fit through one of the scavenger ports or holes 16 in the circumferential wall 11 of the cylinder liner 10 as is, i.e. without needing to be dismantled or otherwise reconfigured. Alternatively, the device 100 may be configurable to fit through the scavenger port 16. For example, one or more portions of the device 100 may suitably fold relative to one or more other portions of the device 100 so as to provide the device 100 with a profile that is suitably dimensioned to fit through the scavenger port 16. For example, the rotors 103 and the arms on which they are mounted can be pivotably mounted to move from a streamlined or relatively-compact stowed position to an expanded deployed position. In the stowed position, the cross section of the device 100 is smaller than the size of the scavenger port 16. Additionally or alternatively, the device 100 may be dismantlable into two or more pieces, each of which is suitably dimensioned to fit through the scavenger port 16, and then reassemblable in the chamber 12 by an operator reaching through the scavenger port 16.
[0088] The device 100 also comprises a line 120 by which the device 100 is tetherable to an object outside of the chamber 12 via the scavenger port 16. The line 120 may be fixed to the body 101 of the device 100. Accordingly, if for any reason the device 100 were to fail while in the chamber 12, an operative would be able to pull on the line 120 to draw the device 100 towards them and the scavenger port 16, and thereafter recover the device 100. In some embodiments, the line 120 is omitted. In some such embodiments, the device 100 may be communicatively (and physically) connected to the user terminal 200 by a wire, and the wire may be usable to recover the device 100 if it were to fail while in the chamber 12.
[0089] Preferably, the device 100 is operable in temperatures of up to 80 degrees Celsius, so as to be able to withstand residual heat that may be present in the chamber 12 following operation of the cylinder 1 or to withstand heat that permeates into the chamber 12 from parts of the engine outside the cylinder 1. In other embodiments, the temperature in which the device 100 is operable may be higher or lower than 80 degrees Celsius. The device
100 may comprise thermal insulation to protect temperature-sensitive components, such as electronics and a battery. In some embodiments, airflow can be directed over internal components of the device 100 to aid with cooling.
[0090] Figure 3 shows a schematic view of an example of a cylinder liner inspection system according to an embodiment of the present invention. The system 1000 comprises the cylinder liner inspection device 100 of Figure 2 and the user terminal 200 mentioned above. The user terminal 200 is remote from the device 100 and comprises a communication interface 209 for communicating with the device 100 (and more specifically with the communication interface 109 of the device 100). In this embodiment, the communication interface 209 is a wireless communication interface 209 for wirelessly communicating with the device 100, but in other embodiments the communication interface 209 may be a non-wireless, or wired, communication interface 209. Together, the device 100, the user terminal 200, and the communication system between the two may be considered an unmanned aircraft system (UAS).
[0091] The user terminal 200 is shown only schematically in Figure 3, but it could for example take the form of any one or more of: a personal computer, a desktop computer, a laptop computer, a headset, a virtual reality (VR) headset, a tablet, a phablet, a smartphone, or a touchscreen, or the like. The user terminal 200 may, for example, be handheld or wearable.
[0092] The user terminal 200 of this embodiment comprises a controller 210 for controlling the cylinder liner inspection device 100. The controller 210 may comprise one or more input devices for a user to input commands to the controller 210, such as button(s), dial(s), joystick(s) or a touchscreen. The controller 210 of this embodiment is communicatively connected to the communication interface 209. On the basis of an input command, the controller 210 may cause one or more instructions to be sent via the communication interfaces 109, 209 to the controller 110 of the device 100. Thereafter, the controller 110 of the device 100 may cause one or more of the self-propulsion mechanism 102, the measurer 105, the measurer 106, the accelerometer(s) 107, and the optical imaging device 108 to operate in a manner that was represented by the input command. In other embodiments, the user terminal 200 may be free from such a controller 210. For example, in some embodiments, the controller 110 of the device may be pre-programmed to cause the device 100 to undertake one or more predetermined operations, without instructions needing to be sent to the device 100 during its operation. In this way, the device 100 can autonomously navigate and move in the cylinder liner 10, such as in the chamber 12. Indeed, in some embodiments, there may not be a user terminal 200 remote from the device 100.
[0093] The user terminal 200 of this embodiment comprises a display 205 for displaying an image captured by the optical imaging device 108 of the apparatus 104 of the device 100 and communicated to the user terminal 200 via the communication interface 209 of the user terminal 200. The image may be a still image or a video image. The video image may be communicated in real time to the user terminal 200 via the communication interface 209 of the user terminal 200. The display 205 of this embodiment is communicatively connected to the controller 210. In other embodiments, the user terminal 200 may be free from a display 205. In some embodiments, the device 100 can be controlled with the terminal 200 by a first user, and a second user can inspect the cylinder liner 10 with the display 205. In some embodiments, there is a plurality of displays 205 including a first display for navigating the device 100 in the cylinder liner 10 and a second display for inspecting the cylinder liner 10.
[0094] The user terminal 200 of this embodiment comprises storage 202 for storing data based on the information determined by the apparatus 104 of the device 100 and communicated to the user terminal 200 via the communication interface 209 of the user terminal 200. The storage 202 of this embodiment is communicatively connected to the controller 210. In other embodiments, the user terminal 200 may be free from such storage 202. For example, in some embodiments, such data may be stored in storage onboard the device 100. Data stored on the device 100 may be downloaded on to a terminal after the device 100 has been removed from the scavenger port 16.
[0095] Example methods of inspecting a cylinder liner 10 according to respective embodiments of the present invention will now be described.
[0096] Figure 11 shows a flow chart illustrating an example of a method of inspecting a cylinder liner according to an embodiment of the present invention. The method comprises causing 1101 the self-propulsion mechanism 102 of a cylinder liner inspection device (such as the device 100 of Figure 2 or any of the variations thereto described herein) to propel the device 100 towards an upper portion of a chamber 12 encircled by a cylinder liner 10, when the device 100 is in a lower portion of the chamber 12. The method also comprises causing 1102 an apparatus 104 of the device 100 (such as the apparatus 104 or any of the variations thereto described herein) to determine information about one or more characteristics of the cylinder liner 10 when the device 100 is located in the chamber 12.
[0097] Further methods of inspecting a cylinder liner according to respectively embodiments of the present invention will now be described with reference to Figures 1 to 10 and Figure 12. These methods will be described with reference to the cylinder liner inspection device 100 of Figure 2, but it will be appreciated that in still further embodiments the cylinder liner inspection device 100 used in any of the methods may be any of the variations to the device 100 of Figure 2 described herein. Similarly, these methods will be described with reference to the cylinder liner 10 of Figure 1, but it will be appreciated that in still further embodiments the cylinder liner 10 used in any of the methods may be any of the variations to the cylinder liner 10 of Figure 1 described herein.
[0098] In some embodiments, the method comprises inserting 1201 the device 100 into the lower portion of a chamber 12 encircled by a circumferential wall 11 of a cylinder liner 10 via a hole 16 in the circumferential wall 11. The inserting 1201 may comprise placing the device 100 on the crown of a piston 13. The inserting 1201 may comprise attaching (such as by one or more magnets or suction cups of the device 100, as discussed above) the device 100 to an inner surface of the circumferential wall 11 of the cylinder liner 10. The inserting 1201 may comprise holding the device 100 in mid-air in the chamber 12 and then letting go of the device 100 while a self-propulsion mechanism of the device 100 retains the device 100 out of contact with the piston 13 and the circumferential wall 11.
[0099] In some embodiments, the hole 16 in the circumferential wall 11 of the cylinder liner 10 is a scavenger port 16. In some embodiments, the device 100 is dimensioned to fit through the hole 16 without needing to be dismantled or otherwise reconfigured. In other embodiments, the device 100 is reconfigured so as to be able to fit through the hole 16, such as by folding or by dismantling, and then reconfigured again once in the chamber 12, as described above.
[0100] In some embodiments, the method comprises causing 1202 the measurer 106 of the apparatus 104 of the device 100 to take a first plurality of angularly-offset measurements of an inner radius or diameter of the cylinder liner 10 in a first plane Pl of the chamber 12 (see Figure 4). The first plane Pl is thus perpendicular to the central axis A-A of the chamber 12. This may be for the purpose of positioning the device 100 on the central axis A-A of the chamber 12 or calibrating the device 100, in which case the first plane Pl should be at position of expected minimum wear of the cylinder liner 10. An example such position is at the lower end of cylinder liner 10 with the piston at BDC. The first plane Pl in Figure 4 is shown as being just below the scavenger ports 16, but alternatively the first plane Pl can be just above the scavenger ports 16. The device 100 may be retained in the first plane Pl through suitable operation of the self-propulsion mechanism 102 of the device 100, or by way of the device 100 sitting on the crown of the piston 13 or being attached to the inner surface of the circumferential wall 11. It will be appreciated that calibration should not be performed in the plane of the scavenger ports 16, since of course the ports would not be visible to the measurer 106.
[0101] As discussed above, the measurer 106 may take the first plurality of angularlyoffset measurements by the measurer 106 comprising plural measurement devices that take respective angularly-offset measurements of the inner radius or diameter of the cylinder liner 10, or by the measurer 106 comprising a measurement device that is movable (e.g. rotatable) relative to the body 101 of the device 100 to take plural angularlyoffset measurements of the inner radius or diameter of the cylinder liner 10 between periods of movement of the measurement device relative to the body 101. Still further, the first plurality of angularly-offset measurements may be taken by way of the device
100 rotating relative to the cylinder liner 10 and the measurer 106 taking respective angularly-offset measurements of the inner radius or diameter of the cylinder liner 10 between periods of movement of the device 100 relative to the cylinder liner 10.
[0102] Angular calibration can also be carried out in order to determine the relative angular orientation of the device 100 with respect to the cylinder liner 10. The angular calibration is achieved by optically identifying a distinctive feature of the internal surface of the cylinder liner 10. In some embodiments, there may be one or more unique identifying features on the inside of the cylinder liner 10. Some cylinder liners 10 have a starting air valve inlet at the top of the cylinder liner 10, and the distinctive feature may be such a starting air valve inlet. The distinctive or unique reference can be used to determine relative angular movement of the device 100 with respect to the cylinder liner 10. In some embodiments, the controller 210 of the terminal 200 identifies the circular hole of the starting air valve inlet at the top of the cylinder liner 10. Optical analysis of images from the optical imaging device 108 can determine the presence of the starting air valve inlet. Alternatively, since the starting air valve inlet is a hole, the measurer will show a very high measurement in a specific location at the top of the cylinder liner 10. This abnormal measurement will indicate the location of the starting air valve inlet. Angular calibration does not need to be carried out during the measurement of the cylinder liner 10. Indeed, angular calibration can be carried out post-measurement by the controller of the terminal 200. Post-measurement angular calibration means that previously-made measurements of the same cylinder liner 10 can be aligned and compared.
[0103] In some embodiments, the cylinder liner 10 may not have any uniquely identifying references on the interior surface of the cylinder liner 10. In this case, the terminal 200 may not be able to perform angular calibration during the measurements by the device 100. Instead, the terminal 200 may identify wear and deformation patterns after measurement has been carried out, which may provide a unique “fingerprint”. Accordingly, information from a sequence of measurements over time can be compared because each set of measurements will share the same unique wear and deformation pattern. This means that the change in wear over time can be identified.
[0104] In some embodiments, the method comprises determining 1203 whether at least some of the measurements taken in the first plane Pl by the measurer 106 differ from each other by more than a predetermined amount. The predetermined amount is an acceptable tolerance, which may be zero or may be a non-zero amount. Example nonzero amounts that may be used are 0.01 millimetres, 0.05 millimetres, 0.1 millimetres, 0.2 millimetres, 0.5 millimetres, 1 millimetre or 2 millimetres. The determining 1203 may comprise causing the measurements to be compared with each other. Alternatively, the determining 1203 may comprise causing each of the measurements to be compared with a predetermined value, and then comparing the respective differences between the measurements and the predetermined value with each other.
[0105] An example scenario is shown in Figure 5. Here it can be seen that four 90degree-offset measurements Ri, R2, R3, R4 of an inner radius of the cylindrical wall 11 of the cylinder liner 10 differ from each other (by more than the predetermined amount). In other scenarios, an adjacent pair of the 90-degree-offset measurements (such as Ri and R4) of the inner radius of the cylinder liner 10 may be equal to each other, but be different from another 90-degree-offset pair of the measurements (such as R2 and R3) (by more than the predetermined amount). In both cases it will be appreciated that at least some of the measurements differ from each other by more than the predetermined amount, and that this is indicative of the device 100 being offset from the central axis A-A of the chamber 12.
[0106] In some embodiments, the method comprises causing 1204 the device 100 to be positioned at another location within the first plane Pl, when at least some of the measurements do differ from each other by more than the predetermined amount. In some embodiments, such as those in which the self-propulsion mechanism of the device 100 is retaining the device 100 in mid-air, this causing 1204 comprises causing the selfpropulsion mechanism 102 to propel the device 100 within the first plane Pl. In other embodiments, the causing 1204 may comprise the operator manually placing the device 100 at another location in the first plane Pl, such as at another location on the crown of the piston 13.
[0107] When the device 100 has been positioned at another location within the first plane Pl, the method returns to 1202.
[0108] In some embodiments, the method comprises determining 1205 that the device 100 is on the central axis A-A of the chamber 12, when the measurements do not differ from each other by more than the predetermined amount. An example scenario is shown in Figure 6. Here it can be seen that four 90-degree-offset measurements Ri, R2, R3, R4 of an inner radius of the cylinder liner 10 do not differ from each other by more than the predetermined amount (in this embodiment they are equal to each other). It will be appreciated that this is indicative of the device 100 being on the central axis A-A of the chamber 12.
[0109] Further, it will be appreciated that each of the measurements Ri, R2, R3, R4 is indicative of the true inner radius of the cylinder liner 10 (within the acceptable tolerance dictated by the predetermined amount). Accordingly, in some embodiments the method comprises determining 1206 a control value of an inner radius or diameter of the cylinder liner 10 based on the measurements, when the measurements do not differ from each other by more than the predetermined amount. This control value may be an average of the measurements, such as a mean, mode or median of the measurements. This control value may be stored at the device 100 or sent to the user terminal 200 (when present) for storage.
[0110] As will be understood, this control value can be used to estimate or determine information about one or more dimensional characteristics of the cylinder liner in other planes perpendicular to the central axis A-A of the chamber 12.
[0111] The method comprises causing 1207 the self-propulsion mechanism 102 to propel the device 100 away from the lower portion of the chamber 12 towards an upper portion of the chamber 12. More specifically, in this embodiment, this comprises causing 1207 the self-propulsion mechanism 102 to propel the device 100 to a second plane P2 of the chamber 12 (see Figure 7), the second plane P2 being different from the first plane Pl.
[0112] The method of this embodiment then comprises causing 1208 the measurer 106 of the apparatus 104 of the device 100 to take a second plurality of angularly-offset measurements of an inner radius or diameter of the cylinder liner 10 in the second plane P2 of the chamber 12.
[0113] In order for the second plurality of angularly-offset measurements to be truly representative of the inner radius or diameter of the cylinder liner 10 in the second plane P2, they should be taken when the device 100 is on the central axis A-A of the chamber 12. Accordingly, in some embodiments, the method comprises determining 1209 whether at least some of the measurements taken in the first plane P2 by the measurer 106 differ from each other by more than the predetermined amount. Again, the determining 1209 may comprise causing the measurements to be compared with each other, or causing each of the measurements to be compared with a predetermined value and then comparing the respective differences between the measurements and the predetermined value with each other.
[0114] In some embodiments, the method comprises causing 1210 the device 100 to be positioned at another location within the second plane P2, when at least some of the second plurality of angularly-offset measurements do differ from each other by more than the predetermined amount. In some embodiments, this causing 1210 comprises causing the self-propulsion mechanism 102 to propel the device 100 within the second plane P2. In other embodiments, the causing 1210 may comprise the operator manually moving the device 100 to another location in the second plane P2.
[0115] When the device 100 has been positioned at another location within the second plane P2, the method returns to 1208.
[0116] In some embodiments, the method comprises determining 1211 that the device 100 is on the central axis A-A of the chamber 12, when the second plurality of angularlyoffset measurements do not differ from each other by more than the predetermined amount.
[0117] When it is determined that the device 100 is on the central axis A-A of the chamber 12, the method of this embodiment then comprises causing 1212 respective comparisons to be made between the second plurality of angularly-offset measurements and the control value that was determined at 1206, and determining 1213 a condition of the cylinder liner 10 in the second plane P2 based on a result of the comparisons. Reference now is made to Figure 8, which shows a schematic diagram of three different example conditions of the shape of the cylinder liner 10 in a given plane perpendicular to the central axis A-A, in this case the second plane P2.
[0118] With reference to the top graph in Figure 8 and the associated circular diagram to the left of the graph, the determining 1213 may comprise determining that the cylinder liner 10 is circular in the second plane P2, when each of the second plurality of angularlyoffset measurements (Ri, R2, R3, R4) does not differ from the control value by more than the predetermined amount (e.g. is equal to the control value).
[0119] With reference to the middle graph in Figure 8 and the associated elliptical diagram to the left of the graph, the determining 1213 may comprise determining that the cylinder liner 10 is oval in the second plane P2, when each of a first pair (R5, Re) of 180degree-offset measurements of the second plurality of angularly-offset measurements of the inner radius differs from the control value by more than the predetermined amount, and each of a second pair (Ri, R3) of 180-degree-offset measurements of the second plurality of angularly-offset measurements of the inner radius, perpendicular to the first pair (Rs, R6), does not differ from the control value by more than the predetermined amount (e.g. is equal to the control value).
[0120] Alternatively, when the measurer 106 is for taking measurements of an inner diameter of the cylinder liner 10, the determining 1213 may comprise determining that the cylinder liner 10 is oval in the second plane P2, when one of the second plurality of angularly-offset measurements of the inner diameter differs from the control value by more than the predetermined amount, and another of the second plurality of angularlyoffset measurements of the inner diameter, perpendicular to the one of the second plurality of angularly-offset measurements, does not differ from the control value by more than the predetermined amount (e.g. is equal to the control value).
[0121] With reference to the bottom graph in Figure 8 and the associated irregular diagram to the left of the graph, the determining 1213 may comprise determining that the cylinder liner 10 has a defect in the second plane P2, when one (R7) of the second plurality of angularly-offset measurements of the inner radius differs from the control value by more than a predetermined amount, and most or all of the others (Ri, R2, R4) of the second plurality of angularly-offset measurements of the inner radius do not differ from the control value by more than the predetermined amount (e.g. are equal to the control value).
[0122] In some embodiments, the method comprises generating 1214 an image of at least a portion of the cylinder liner 10 using the optical imaging device 108 of the apparatus 104 of the device 100. The portion of the cylinder liner 10 in question may be that in the second plane P2 which it is thought to have the defect, on the basis of the result of the determining 1213. The image generated may be relayed in real time to a display, such as the display 205 of the user terminal 200 (when present). In some embodiments, the optical imaging device 108 may be used to generate one or more images of all of the inner surface of the cylinder liner 10 in the second plane P2. That is, the image taken of the inner surface in a given, or each, plane may comprise a 360-degree image or a series of images that together depict the full 360-degree extent of the inner surface in that plane. The image(s) may be stored at the device 100 or sent to the user terminal 200 (when present) for storage.
[0123] In some embodiments, the method comprises determining 1215 information representative of the second plane P2 of the chamber 12 by causing the measurer 105 of the apparatus 104 of the device 100 to take at least one measurement of a distance between an axial end of the chamber 12 and the device 100, when the device 100 is at the second plane P2. The axial end may be that defined by the piston 13 or that defined by the cylinder head 15. The information representative of the second plane P2 may be stored at the device 100 or sent to the user terminal 200 (when present) for storage.
[0124] The method may comprise causing 1216 storage of the first plurality of angularlyoffset measurements in association with information representative of the first plane Pl of the chamber 12, and storage of the second plurality of angularly-offset measurements in association with information representative of the second plane P2 of the chamber 12.
[0125] The information representative of the second plane P2 of the chamber 12 may be that determined at 1215. The information representative of the first plane Pl of the chamber 12 may, for example, be a zero reference value. Alternatively, it may have been determined by causing the measurer 105 to take at least one measurement of a distance between an axial end of the chamber 12 and the device 100, when the device 100 was at the first plane Pl, for example.
[0126] It will be appreciated that storing the measurements and information in this way creates a mapping between information representative of given planes and the sets of measurements taken in those respective planes.
[0127] The actions from 1207 to 1216 can be iterated multiple times, for example as many times as there are planes of the chamber 12 to be inspected. That is, the device 100 can be propelled still further away from the lower portion of the chamber 12 towards the upper portion of the chamber 12 to third and still further planes P3.. .Pn, as shown in Figure 9. In each of the planes P3.. .Pn, it can be determined when the device 100 is on the central axis A-A of the chamber 12 as described above, and then information representative of the respective planes P3...Pn can be determined and stored in association with the plurality of angularly-offset measurements taken in the respective planes P3.. .Pn. Since such associations are made, the device 100 is able to visit each plane in succession, or to visit the planes out of the order in which they are arranged in the chamber 12. Moreover, in some embodiments, the device 100 may visit one or more or all planes more than once during performance of the method.
[0128] It will therefore be appreciated that information about characteristics of the cylinder liner 10 throughout at least a portion, and in some cases all, of the axial length of the chamber 12 can be determined and optionally stored.
[0129] To help an operative, or another person to whom the information is provided, better understand the characteristics of the cylinder liner 10 so determined, in some embodiments the method may comprise causing 1217 creation of a visual map of at least a portion of the inner surface of the cylinder liner 10 based on the first plurality of angularly-offset measurements, the information representative of the first plane Pl of the chamber 12, the second plurality of angularly-offset measurements, and the information representative of the second plane P2 of the chamber 12. Indeed, in some embodiments, the visual map can be based on the information representative of all the planes Pl.. Pn visited by the device 100 during performance of the method and the sets of measurements taken in those respective planes Pl.. .Pn. The visual map may be created on the display 205 of the user terminal (when present) or elsewhere. A depiction of how a visual map may be created is shown in Figure 10.
[0130] The visual map may include images based on the images generated by the optical imaging device 108 of the device 100, or may be a 3D lidar map based on measurements taken by the measurer 106. Identified defects in the cylinder liner 10 may be highlighted on the visual map based on the measurements taken by the device 100.
[0131] To better understand how the cylinder liner 10 is wearing over time, the above process can be repeated at time-spaced intervals. The method may then comprise causing 1218 a comparison to be made between the visual map and an earlier visual map of the at least a portion of the cylinder liner 10, and determining a rate of change of the at least a portion of the cylinder liner 10 based on a result of the comparison.
[0132] In some embodiments, the method may be performed by the controller 110 onboard the cylinder liner inspection device 100. In other embodiments, the method may be performed by the controller 210 of the user terminal (when present), or by a combination of those controllers 110, 210. There is thus also provided a non-transitory computer-readable storage medium storing instructions that, if executed by a processor of a cylinder liner inspection system, cause the processor to carry out the method. The processor may be the controller 110 of the device 100, the controller 210 of the user terminal (when present), or a combination of those controllers 110, 210.
[0133] In other embodiments, two or more of the above described embodiments may be 5 combined. In other embodiments, features of one embodiment may be combined with features of one or more other embodiments.
[0134] Embodiments of the present invention have been discussed with particular reference to the examples illustrated. However, it will be appreciated that variations and 10 modifications may be made to the examples described within the scope of the invention.

Claims (27)

CLAIMS:
1. A cylinder liner inspection device that is insertable into a lower portion of a chamber encircled by a circumferential wall of a cylinder liner via a hole in the circumferential wall, comprises a self-propulsion mechanism for thereafter propelling the cylinder liner inspection device away from the lower portion of the chamber towards an upper portion of the chamber, and comprises apparatus for determining information about one or more characteristics of the cylinder liner when located in the chamber.
2. The cylinder liner inspection device of claim 1, wherein the cylinder liner inspection device comprises an unmanned aerial vehicle.
3. The cylinder liner inspection device of claim 2, wherein the self-propulsion mechanism comprises one or more rotors for creating lift for propelling the cylinder liner inspection device away from the lower portion of the chamber towards the upper portion of the chamber.
4. The cylinder liner inspection device of any one of claims 1 to 3, comprising one or more accelerometers for use in determining whether the cylinder liner inspection device is horizontally aligned.
5. The cylinder liner inspection device of any one of claims 1 to 4, wherein the apparatus comprises a measurer for taking at least one measurement of a distance between an axial end of the chamber and the cylinder liner inspection device.
6. The cylinder liner inspection device of any one of claims 1 to 5, wherein the apparatus comprises a measurer for taking at least one measurement of an inner radius or diameter of the cylinder liner.
7. The cylinder liner inspection device of claim 6, wherein the measurer for taking at least one measurement of an inner radius or diameter of the cylinder liner comprises:
plural measurement devices for taking respective angularly-offset measurements of the inner radius or diameter of the cylinder liner, or a measurement device that is movable relative to a body of the cylinder liner inspection device for taking plural angularly-offset measurements of the inner radius or diameter of the cylinder liner between respective periods of movement of the measurement device relative to the body.
8. The cylinder liner inspection device of any one of claims 1 to 7, wherein the apparatus comprises at least one optical imaging device for imaging at least a portion of the cylinder liner.
9. The cylinder liner inspection device of any one of claims 1 to 8, comprising a communication interface for communicating with a user terminal remote from the cylinder liner inspection device.
10. A cylinder liner inspection system comprising the cylinder liner inspection device of claim 9, and a user terminal remote from the cylinder liner inspection device and comprising a communication interface for communicating with the cylinder liner inspection device.
11. The cylinder liner inspection system of claim 10, wherein the user terminal comprises one or more of:
a controller for controlling the cylinder liner inspection device;
a display for displaying an image captured by an optical imaging device of the apparatus of the cylinder liner inspection device and communicated to the user terminal via the communication interface of the user terminal; and storage for storing data based on the information determined by the apparatus and communicated to the user terminal via the communication interface of the user terminal.
12. A method of inspecting a cylinder liner, the method comprising:
when the cylinder liner inspection device of any one of claims 1 to 9 is in a lower portion of a chamber encircled by the cylinder liner, causing the self-propulsion mechanism of the cylinder liner inspection device to propel the cylinder liner inspection device towards an upper portion of the chamber; and causing the apparatus of the cylinder liner inspection device to determine information about one or more characteristics of the cylinder liner when the cylinder liner inspection device is located in the chamber.
13. The method of claim 12, comprising:
causing a measurer of the apparatus to take a first plurality of angularly-offset measurements of an inner radius or diameter of the cylinder liner in a first plane of the chamber.
14. The method of claim 13, comprising:
causing the cylinder liner inspection device to be positioned at another location within the first plane, when at least some the measurements differ from each other by more than a predetermined amount.
15. The method of claim 14, wherein the causing the cylinder liner inspection device to be positioned at another location within the first plane comprises causing the selfpropulsion mechanism to propel the cylinder liner inspection device within the first plane.
16. The method of any one of claims 13 to 15, comprising:
determining that the cylinder liner inspection device is on a central axis of the chamber, when the measurements do not differ from each other by more than a predetermined amount.
17. The method of any one of claims 13 to 16, comprising:
determining a control value of an inner radius or diameter of the cylinder liner based on the measurements, when the measurements do not differ from each other by more than a predetermined amount.
18. The method of any one of claims 13 to 17, comprising:
causing the self-propulsion mechanism to propel the cylinder liner inspection device to a second plane of the chamber, the second plane being different from the first plane; and causing the measurer of the apparatus to take a second plurality of angularly-offset measurements of an inner radius or diameter of the cylinder liner in the second plane of the chamber.
19. The method of claim 18, when dependent on claim 17, comprising:
causing respective comparisons to be made between the second plurality of angularly-offset measurements and the control value; and determining a condition of the cylinder liner in the second plane based on a result of the comparisons.
20. The method of claim 18 or claim 19, comprising:
causing storage of the first plurality of angularly-offset measurements in association with information representative of the first plane of the chamber, and storage of the second plurality of angularly-offset measurements in association with information representative of the second plane of the chamber.
21. The method of claim 20, comprising determining the information representative of the second plane of the chamber by causing a measurer of the apparatus to take at least one measurement of a distance between an axial end of the chamber and the cylinder liner inspection device.
22. The method of claim 20 or claim 21, comprising:
causing creation of a visual map of at least a portion of the inner surface of the cylinder liner based on the first plurality of angularly-offset measurements, the information representative of the first plane of the chamber, the second plurality of angularly-offset measurements, and the information representative of the second plane of the chamber.
23. The method of claim 22, comprising:
causing a comparison to be made between the visual map and an earlier visual map of the at least a portion of the cylinder liner; and determining a rate of change of the at least a portion of the cylinder liner based on a result of the comparison.
24. The method of any one of claims 12 to 23, comprising:
generating an image of at least a portion of the cylinder liner using at least one optical imaging device of the apparatus.
25. The method of any one of claims 12 to 24, comprising:
inserting the cylinder liner inspection device into the lower portion of the chamber encircled by a circumferential wall of the cylinder liner via a hole in the circumferential wall.
26. The method of claim 25, wherein the hole in the circumferential wall of the cylinder liner is a scavenger port.
27. A non-transitory computer-readable storage medium storing instructions that, if executed by a processor of a cylinder liner inspection system, cause the processor to carry out the method of any one of claims 12 to 24.
GB1800640.3A 2018-01-15 2018-01-15 Cylinder liner inspection Withdrawn GB2570294A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB1800640.3A GB2570294A (en) 2018-01-15 2018-01-15 Cylinder liner inspection

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1800640.3A GB2570294A (en) 2018-01-15 2018-01-15 Cylinder liner inspection

Publications (2)

Publication Number Publication Date
GB201800640D0 GB201800640D0 (en) 2018-02-28
GB2570294A true GB2570294A (en) 2019-07-24

Family

ID=61256103

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1800640.3A Withdrawn GB2570294A (en) 2018-01-15 2018-01-15 Cylinder liner inspection

Country Status (1)

Country Link
GB (1) GB2570294A (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100108801A1 (en) * 2008-08-22 2010-05-06 Orville Olm Dual rotor helicopter with tilted rotational axes
US20150321755A1 (en) * 2014-04-28 2015-11-12 Arch Aerial, Llc Collapsible multi-rotor uav
US20160340021A1 (en) * 2015-01-04 2016-11-24 Beijing Zero Zero Infinity Technology Co., Ltd Foldable drone
US20170247098A1 (en) * 2016-02-25 2017-08-31 Parrot Drones Drone with folding linking arms
US20170313400A1 (en) * 2016-04-27 2017-11-02 Atlas Dynamic Limited Collapsible unmanned aerial vehicle (uav)

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100108801A1 (en) * 2008-08-22 2010-05-06 Orville Olm Dual rotor helicopter with tilted rotational axes
US20150321755A1 (en) * 2014-04-28 2015-11-12 Arch Aerial, Llc Collapsible multi-rotor uav
US20160340021A1 (en) * 2015-01-04 2016-11-24 Beijing Zero Zero Infinity Technology Co., Ltd Foldable drone
US20170247098A1 (en) * 2016-02-25 2017-08-31 Parrot Drones Drone with folding linking arms
US20170313400A1 (en) * 2016-04-27 2017-11-02 Atlas Dynamic Limited Collapsible unmanned aerial vehicle (uav)

Also Published As

Publication number Publication date
GB201800640D0 (en) 2018-02-28

Similar Documents

Publication Publication Date Title
US11536670B2 (en) System and method for engine inspection
US10775315B2 (en) Probe insertion system
EP2705304B1 (en) Inspection system for a combustor of a turbine engine
JP6153410B2 (en) Blade inspection apparatus and blade inspection method
US9015002B2 (en) System for monitoring a high-temperature region of interest in a turbine engine
US9681107B2 (en) Flexible tether position tracking camera inspection system for visual inspection of off line industrial gas turbines and other power generation machinery
US9513117B2 (en) Situ blade mounted tip gap measurement for turbines
KR20110036910A (en) Cylinder diameter measurement
WO2015059241A1 (en) Collaborative robot for visually inspecting an aircraft
CN101750025B (en) A method of measuring cylinder liner diameter in a two-stroke crosshead internal combustion engine, a diameter gauge device, and a flexible ring for use in the method
US9599537B2 (en) Internal inspection of machinery by stitched surface imaging
JP2010285984A (en) Cylinder liner inspection device and method of inspecting cylinder liner
KR20080108424A (en) Wavefront aberration and distance measurement phase camera
US20220084178A1 (en) Method and device for inspecting hard-to-reach components
JP6242105B2 (en) Blade inspection apparatus and blade inspection method
GB2570294A (en) Cylinder liner inspection
US20200049564A1 (en) Systems and methods for thermal imaging systems
US10126175B2 (en) Long wave infrared sensing for turbomachine
CN107532880B (en) System and method for inspecting cylinder liner, holder for imaging device, and cylinder liner
KR102281135B1 (en) Industrial endoscope robot
ES2940809T3 (en) Procedure and device for borescope inspection
US20190262995A1 (en) Controlling a robot in an environment
US11913345B2 (en) System and method of using a tool assembly
CN106546594A (en) A kind of two-stroke internal combustion engine cylinder interior visual inspection and cylinder diameter measuring apparatus
JP6909751B2 (en) Unmanned aerial vehicle and relative reflectance calculation method

Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)