AN IMAGE OF AN INNER WALL OF A LINER

Technical field

The invention relates to a liner imaging device and a method for establishing an image of an inner wall of a liner.

Background art

In order to optimise the operational conditions of marine engines and to prevent shutdowns to the largest extent possible, the operational state of the engines is checked at regular intervals. One common cause for impaired engine state or for shutdowns is that the piston rings have become worn-out or burnt and consequently need to be replaced. Experience has shown, however, that the cause may equally well be the cylinder liners which, when examined, have been found to be in a worn state or to no longer exhibit a smooth surface because of depositions of soot or of abrasive or corrosive attacks on the cylinder liner walls.

Attacks of this kind might be due to sulphurous fuel used to operate the engine, which in combination with steam produces sulphuric acid that condenses at predetermined temperature and pressure levels in the engine. The effects on the cylinder from the abrasive or corrosion attacks are localised because of the uneven distribution of cylinder oil, of gas leakage via openings, such as passages between piston rings and cylinder liner, and/or variations of the cylinder wall temperature.

One way of checking the status of the cylinder liner walls is to provide a camera within the cylinder liner in order to take pictures which can be used to analyse the current status of the liner.

There are however problems associated with the method described above. In order to obtain a complete image of the cylinder liner, the camera must be continuously adjusted in relation to the liner in order to cover the entire circumference of the liner. This is a time consuming and inefficient procedure. Further problems are the lack of light and the high temperatures inside the cylinder liner due to the engine cooling water system is kept running at high temperature during the monitoring of the cylinder liner and the

temperature cannot be decreased due to the risk of cooling water leakages

Summary of the invention

It is an objective of the present invention to mitigate, alleviate or eliminate one or more of the above-identified deficiencies in the art and disadvantages singly or in any combination and solve at least the above mentioned problems.

According to a first aspect of the invention, these and other objects, and/or advantages that will be apparent from the following description of embodiments, are achieved, in full or at least in part, by a liner imaging device. The liner imaging device comprises a body, and at least two cameras provided on an outer surface of the body. The at least two cameras are arranged substantially in the same plane at a predetermined angular distance from each other, such that combined pictures from the at least two cameras cover the complete liner circumference.

This way, an image covering the complete liner circumference can be established from one single photographing without having to adjust the device within the liner.

The at least two cameras may be inclined in relation to the outer surface of the body. Specifically, the at least two cameras may be inclined in relation to an axial direction of the liner when placed in a radial plane of the liner.

The outer surface of the body is inclined. Specifically, the inclined outer surface of the body may be arranged to be inclined in relation to an axial direction of the liner when placed in a radial plane of the liner.

By inclining the cameras of the liner imaging device in relation to the liner it is possible to cover a larger section of the inner wall of the liner compared to when cameras are arranged in the conventional manner.

The components of the liner imaging device may be made from heat- resistant material in order to survive temperatures of up to at least 85 degrees. This is advantageous in that the liner imaging device will be able to sustain the temperatures that occur inside of a combustion engine and the risk of damage due to high temperatures is highly reduced.

The at least two cameras may be equally distributed over the outer surface of the body.

The body may have a bottom surface which is configured to align the liner imaging device with an uneven ground surface. This way, the liner imaging device will be able to stand straight and be properly aligned in relation the inner wall when placed within liner.

The body may further comprise a top surface which is rotational in relation to the bottom surface

The body of the liner imaging device may be annular. In one specific embodiment, the liner imaging device comprises three cameras arranged substantially in the same plane and spaced apart at an angular distance of 120 degrees.

The liner imaging device may be formed so that it is able to enter the liner through a hole in the liner wall, which is advantageous in that engine parts, such as the cylinder head and exhaust valve body, do not have to be dismantled to place the device within the liner.

The liner imaging device may further comprise at least one light source provided on the inclined outer surface in a space between two cameras.

The liner imaging device may further comprise an integrated memory card connected to the at least two cameras and adapted to store pictures.

The liner imaging device may further comprise a sensor (height sensor) which is adapted to detect a height position of the at least two cameras of the liner imaging device or of the liner imaging device itself in relation to the liner. The information from the sensor may be used in order to present to a user or customer exactly where in the liner the images or pictures have been taken by the at least two cameras. The sensor may be placed at any suitable position on the liner imaging device, such as on the top surface, the outer surface or the bottom surface thereof.

According to a second aspect of the invention, these and other objects are achieved, in full or at least in part, by a method for establishing an image an inner wall of a liner by means of a liner imaging device comprising a body and at least two cameras provided on an outer surface of the body, wherein the at least two cameras being arranged substantially in the same plane at a predetermined angular distance from each other. The method comprises the steps of arranging the liner imaging device in the liner in a plane substantially perpendicular to an axial axis of the liner, taking a picture in the liner with each one of the at least two cameras, and creating an image covering the entire circumference an inner wall of the liner by combining the pictures from the at least two cameras.

Effects and features of the second to the fifth aspect of the present invention are largely analogous to those described above in connection with the first aspect of the inventive concept. Embodiments mentioned in relation to the first aspect of the present invention are largely compatible with the further aspects of the invention.

Other objectives, features and advantages of the present invention will appear from the following detailed disclosure, from the attached claims, as well as from the drawings. It is noted that the invention relates to all possible combinations of features.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the [element, device, component, means, step, etc.]" are to be interpreted openly as referring to at least one instance of the element, device, component, means, step, etc., unless explicitly stated otherwise.

As used herein, the term "comprising" and variations of that term are not intended to exclude other additives, components, integers or steps.

The term "circumference" is intended to mean along entire inner periphery of the liner at a specific section in height thereof.

The term "incline" and variations of that term is intended to mean any type of angled surface and thus also includes spherical surfaces and all types of "not-straight surfaces".

The term "picture" and variations of that term is intended to include all type of pictures, both still pictures and moving pictures (such as material provided by an infrared camera).

Brief description of the drawings

The above, as well as additional objects, features and advantages of the present invention, will be better understood through the following illustrative and non-limiting detailed description of embodiments of the present invention, with reference to the appended drawings, where the same reference numerals may be used for similar elements, and wherein:

Fig. 1 is a perspective view of one exemplary embodiment of a liner imaging device according to a first aspect of the invention.

Fig. 2 is a perspective view of the liner imaging device in Fig. 1 when placed inside a liner.

Fig. 3a to 3f are perspective views of further exemplary embodiments of the liner imaging device.

Detailed description of preferred embodiments of the invention

Fig. 1 illustrates a liner imaging device 1 according to one exemplary embodiment of the invention. The liner imaging device 1 comprises a body 2 and three cameras 3 arranged on an inclined outer surface 4 of the body 2.

The cameras 3 are arranged in the same plane and spaced apart at an angular distance of 120 degrees so that combined pictures from the three cameras 3 will cover the complete liner circumference.

The body 2 is annular and has a top surface 5 and a bottom surface 6. The bottom surface 6 is configured so that liner imaging device 1 will rest steady on a ground surface on which it is placed.

The inclined outer surface 4 of the body 2 is arranged to be inclined at an angle of approximately 45 degrees in relation to an axial direction of the annular body 2. This way, the inclined outer surface 4 will be inclined at the same angle in relation to an axial direction of a liner 7 when placed in a radial plane thereof. The liner imaging device 1 further comprises two light emitting diodes 8 provided on the inclined outer surface 4 in the space between the cameras 3, i.e. a total number of six light emitting diodes 8.

The liner imaging device 1 also has a battery (not shown) and an integrated memory card (not shown) connected to the cameras 3 and adapted to store pictures captured by the cameras 3. This way, the liner imaging device 1 is completely self-sufficient and requires no external cables or network connection in its simplest form.

The liner imaging device 1 is formed so that it is able to enter the liner 7 through a hole in the liner wall and the components of the liner imaging device 1 are made from heat-resistant material in order to survive

temperatures of up to at least 85 degrees.

In Fig. 2, the liner imaging device 1 has been placed within the liner 7 on top of a piston head 9 thereof. Since the top portion of the piston head 9 is curved, the bottom surface of the liner imaging device 1 is preferably curved inwardly from the bottom surface 6 towards the top surface 5 of the liner imaging device 1 . Alternately, the bottom surface of the liner imaging device 1 is provided with protrusions and/or some sort of feet in order to compensate for the curved top portion of the piston head 9. This way, the liner imaging device 1 will be properly aligned in relation to the inner liner wall when placed inside the liner 7.

Fig. 3a to 3f illustrate further exemplary embodiments of the liner imaging device 1 . The body 2 of the liner imaging device 1 may for example be square, triangular, annular or spherical. It may include a straight outer surface, an inclined outer surface or a combination of both.

When the status of the liner 7 is to be monitored, the piston is for example lowered to a bottom position. Thereafter, the image liner device 1 can be introduced within the liner 7 via the hole 10 in the liner wall and placed on top of the piston head 9.

In one preferred embodiment, the image liner device 1 is further equipped with a motion sensor (not shown) in order the monitor the position of the image liner device 1 when the cameras 3 are taking pictures of the inner circumference of the liner 7. This will simplify the synchronization of the pictures taken. It will also be possible to save energy by using the motion sensor if pictures for example are to be taken during the downward

movement only or during the upward movement only.

Naturally, the number and location of the cameras 3 are dependent on the shape of the body 2. In order to be able to cover the complete

circumference of the liner 7, the cameras 3 need to be equally distributed over the outer surface of the body 2. The same applies to the inclination of the cameras 3. With a straight outer surface of the body 2, the actual cameras 3 need to be inclined. However, with an inclined outer surface of the body 2, there is no need to incline the cameras 3 themselves.

It is understood that other variations in the present invention are contemplated and in some instances, some features of the invention can be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly in a manner consistent with the scope of the invention.

For instance, the number, size and shape of the components of the imaging liner device 1 may be varied in any suitable way.

The imaging liner device 1 may be equipped with a printed circuit board and a transmitter for wireless transmission of pictures to a further device.

The imaging liner device 1 may be further provided with a light source, such as a light emitting diode, on the top surface 5.