Automotive inspection device

An automotive device for the inspection of internal spaces having ferromagnetic surfaces includes at least two magnetic wheels (3) or caterpillars, or at least two magnetic legs for the advancement of the device along the surfaces to be inspected. According to the invention, the device includes actively powered rotating arms (1) attached to a wheel (3), caterpillar, or leg of the device. Each rotating arm (1) has a length longer than the shortest distance between the point of attachment of the rotating arm to the device and the surface. When the device is in a position, where there is magnetic contact to the surface in two or more points and the device is no longer able to advance due to the strength of the magnetic forces, the rotating arms are brought into non-magnetic contact with the surface in order to create an air gap between the surface and the magnetic wheel and thus reduce the magnetic forces. The device is thereby enabled to overcome the magnetic forces and advance the device along the surface.

TECHNICAL FIELD

The invention pertains to an automotive device for inspection of surfaces, in particular of internal spaces having ferromagnetic surfaces.

BACKGROUND ART

Devices used for the inspection of internal spaces are configured to move automotively, without the aid of movement from another source or human being. They contain actuators or motors for the movement of wheels, legs, or caterpillars, which advance the device along a surface. In order to allow the inspection of the entire internal space the devices are equipped such that they can remain in contact with all surfaces, including sidewall and ceiling surfaces. In the case of ferromagnetic surfaces as for example in machines, turbines, or motors, such devices are equipped with permanent magnets or electromagnets incorporated into the legs, wheels, or caterpillars. The magnets allow movement of the inspection device along very steep or vertical walls as well as when it is upside down.

Automotive devices for inspection of internal spaces are dimensioned according to the size of an opening provided to enter the internal space to be inspected. In particular, the size of legs, caterpillar or diameter of wheels and the motor for advancing the device are limited according to the opening. The devices are accordingly suitable for the inspection of flat and convex surfaces as well as surfaces having concave contours that are large compared to the size of the legs, wheels, or caterpillars. If the contour of the surface however, is more complex and includes piping, steps, holes, or grooves, as for example in steam turbine parts such as steam chests, then advancing a device along the surfaces becomes more complex. In particular, when concave contours are smaller than the size of the wheels or caterpillars, the device is no longer able to advance as illustrated for example inFIG. 1.FIG. 1shows wheels of an inspection device equipped with wheels3with magnets providing contact with a ferromagnetic surface4at all times. The wheels3of the device have reached a concave step of the surface4, where the step height is smaller than the wheel diameter. The wheel is in contact at two points of the surface, the magnetic forces acting at both points. The motor is not strong enough to overcome the magnetic forces and cannot advance the device any further along the surface.

SUMMARY OF INVENTION

It is an object of the invention to provide an automotive device for inspection of internal spaces having ferromagnetic surfaces where the device is able to advance along the surfaces by means of wheels, caterpillars, or legs having magnets in contact with the surfaces. The device shall in particular be able to advance over contours of all sizes and shapes including concave surfaces with step sizes or radius of curvatures smaller than the size of the wheel, caterpillar, or leg of the automotive device.

An automotive device for the inspection of internal spaces having ferromagnetic surfaces includes at least two magnetic wheels or caterpillars, or at least two magnetic legs for the advancement of the device along the surfaces to be inspected. According to the invention, the device includes additionally actively powered rotating arms attached to at least one of the wheels, caterpillars, or legs of the device. Each rotating arm has a length that is longer than the shortest distance between the location of the rotation axis of the rotating arm at the device and the ferromagnetic surface.

When the device is in a position of the type as shown inFIG. 1 and 3aand its motor cannot overcome the magnetic forces keeping the device in contact with the surfaces, the rotating arms are brought into a position in the direction of the ferromagnetic surface as shown inFIG. 3b. Due to the length of the rotating arms, a non-magnetic contact between the device and the surface is achieved and pressure forces are created against the surface at one or more contact points on at least one of the wheels or caterpillars, or legs. No magnetic forces act on these contact points created by the rotating arms. The pressure forces lift up the wheel or caterpillar, or leg, whereby an air gap between the surface and the wheel, caterpillar, or leg is formed. By means of the rotating arms, the magnetic force on the wheels or caterpillar at a specific point are reduced. The motor of the device then overcomes the magnetic force and can again advance the device along the surface. Once the device is able to advance again, the rotating arms are brought into a position away from the surfaces such that they do not make any contact and the magnetic forces can act in full.

By means of the rotating arms on both sides of the wheels, caterpillars or legs, the device is more stabilized against tilting in a direction at an angle to the direction of advancement.

In an embodiment of the invention, the rotation axis of the actively powered rotating arms is coaxial with the axis of the device's wheels or caterpillars, or is placed at the level of the leg. This allows most universal and symmetric movement of the device in all directions.

In a further embodiment of the invention, the rotating arms include a non-magnetic wheel or ball attached, which make contact with the surface to be inspected when the rotating arm is rotated to point in the direction of the surface. This measure allows reduced friction at the contact points and thereby higher precision of the movement of the device. This in turn allows the use of a smaller actuator for the device.

In a further embodiment of the device, the device includes only two wheels, for example arranged in the manner of two bicycle wheels in line with the direction of advancing the device. The distance between the two non-magnetic contact points of the rotating arms with the surface are dimensioned such that the device is stabilized against tilting in a direction at an angle to the direction of advancement of the device. For this, the distance between the non-magnetic contact points shall in suitable manner be as large as possible.

In a further embodiment of the invention, the device includes at least two wheels for the advancement of the device and the actuator for the actively powered rotating arm and the actuator for the turning of the wheels are arranged parallel to the wheel axis and above the wheel, i.e. on the side of the wheel away from the surface. This configuration allows an overall size of the device having minimized width.

In a particular embodiment of the above embodiment the device includes spur gears and/or gear belts for the transmission of the power to the wheels and rotating arms.

The invention is suitable for devices having for advancement of the device either wheels or caterpillars or legs. It is also suitable for devices having wheels or caterpillars and, additionally, legs for advancement.

The device for inspection according to the invention can be equipped with inspection devices such as vision systems and sensing systems such as ultrasonic, eddy-current and x-ray devices.

BEST MODES FOR CARRYING OUT THE INVENTION

FIG. 2shows a wheel3for advancement of the device for inspection according to the invention, and in particular the actively powered rotating arms1and wheels2for achieving non-magnetic contact with the surface. The rotating arms1rotate about the shaft coaxial with the rotating axis of the wheel3. A dented wheel7connects the wheel3to its gear and actuator or motor (not shown). A dented wheel8drives the shaft that turns the rotating arms1.

FIG. 3aandbshow two different positions of the rotating arms1respectively.FIG. 3ashows the non-magnetic wheel2of the rotating arm1in a position away from a ferro-magnetic surface4. The wheel3is in contact at points5and6by magnetic forces Fmagwith a sidewall surface and a horizontal surface4, respectively.FIG. 3bshows the rotating arm in a position providing non-magnetic contact by means of the wheel2with the surface4. In the device shown, the rotation axis of the rotating arm coincides with the axis of rotation of the wheel3. The rotating arm1including the non-magnetic wheel2has a length considered from the axis of rotation of the rotating arm on the device along a straight line to its end at the circumference of the wheel2; this length is greater than the distance extending from the axis of rotation of the arm at the device along a straight line to the circumference of the magnetic wheel3. The rotating arm with the wheel2when positioned in the direction point6of the surface4, lifts the wheel3away from surface4by a distance “a”, creating an air gap such that the magnetic force Fmagat point6is reduced. The motor of the device is then able to overcome the remaining magnetic force and move the device in the direction indicated by the arrow12. The device remains in contact with the sidewall at point5by means of the magnetic force on the wheel3in direct contact with the sidewall surface.

FIG. 4shows the device for inspection of surfaces on a tilted surface, where the device could fall on its side in spite of the magnetic force Fmag. The rotating arms1are in a position such that the wheels2are in contact with the tilted surface, thus preventing a tilt of the device. In order to assure optimal stability the distance between the wheel3and the wheels2is chosen as large as suitably possible.

FIG. 5shows the device according to the invention and in particular the arrangement of actuators9for the wheel3for the rotating arms1with contact wheels2and for the wheel3for the advancement of the device. Gears7and8, for example spur gears, are arranged for the transmission of power from the actuators9to the wheels and rotating arms.

FIG. 6shows the device for inspection of surfaces having two wheels3for advancing the device, each equipped with rotating arms1with contact wheels2for reducing the magnetic force at selected contact points with the surfaces. Actuators9are arranged above each wheel3. A mechanism11for steering with one degree of freedom is connected to the axis of the wheel3for advancing the device. In an optional embodiment of the device, the steered wheel3includes a mechanism10for suspension of the wheel3.

FIG. 7a-7bshow the device for inspection of surfaces having caterpillar tracks20for advancing the device, each equipped with rotating arms1with contact wheels2for reducing the magnetic force at selected contact points with surfaces.

FIGS. 8a-8dshow the device for inspection of surfaces having two legs22for advancing the device, each equipped with rotating arms with contact wheels2for reducing the magnetic force at selected contact points with the surfaces.

Terms used in Figures

1actively powered rotating arms2wheel for non-magnetic contact3wheel for advancing the device for inspection4surface5,6contact points on surface7,8spur gears9actuator for wheel for advancing the device and for powering the rotating the arms10suspension system for wheel11steering system for wheel12direction of advancing the device