MANIPULATOR AND MANIPULATOR UNIT

Description

[0001] The invention relates to a manipulator for machining weld roots, in particular weld roots on recuperative heat exchangers.

[0002] A recuperative heat exchanger has a 180° elbow with a half-shell welded construction, meaning the 180° elbow has two longitudinal welds, with an unground weld root on the inside. To achieve greater mechanical strength of the elbow, the weld roots must be ground. However, these weld roots are difficult to access with a grinding tool, as the available space of 50 x 25 mm is too small for conventional grinding tools. Therefore, a miniature grinding manipulator is required.

[0003] GB 893,658 A shows a polishing machine mounted next to a moving conveyor belt. Various articles to be polished can be transported on the conveyor belt. Polishing is carried out using a rotating polishing element attached to the end of a shaft. The shaft is located in a housing. The housing is connected via a bracket to a sleeve which is attached to a column for height adjustment. In addition, the bracket can be rotated horizontally to adjust the orientation of the polishing element. The column can be mounted on a carriage which is movably mounted on rails by means of wheels. In this way, the polishing element can follow the movement of an article on the conveyor belt for a predetermined distance.

[0004] EP 0 398 457 A1 discloses a device for machining the inner surface of circular welds in pipes. This device uses a tool carrier equipped with trolleys, allowing it to move axially within the pipeline. A suspension is rigidly attached to the tool carrier, on which a tool holder is rotatably mounted by means of a pendulum axis. Furthermore, the tool carrier can be rotated about a pivot axis perpendicular to the pendulum axis.

[0005] JP S61 257756 A discloses a grinding device that uses a grinding wheel to remove a weld seam inside a housing. The grinding wheel is located on an adjustment means that is connected to a support device via a holding arm. The support device is arranged on a base that is moved on rails by means of wheels.

[0006] JPH07227751A relates to a polishing device for the inner surface of pipelines for removing a weld bead extending along the pipe axis in a pipe curved with a small diameter. A plurality of guide rail sections are connected to each other so that they can bend and run along the guide rail. A polishing machine includes a pivoting grinder, a grinding stone pivotally mounted on the carriage and driven to rotate around a central axis intersecting the pipe axis, and the grinder is pressed against the section to be polished.

[0007] The manipulator considered here comprises a drive for moving the manipulator. The manipulator further comprises a grinding head with a frame, on which, preferably, four first wheels are provided, in particular attached, for moving the grinding head along guide rails, and a shaft provided, in particular attached, to the grinding head. A grinding wheel for grinding weld roots, in particular weld roots of a heat exchanger, is provided on the shaft.

[0008] However, known grinding manipulators have the disadvantage that the grinding wheel cannot always be brought into ideal contact with the weld root in order to achieve the best possible grinding result.

[0009] It is therefore an object of the invention to provide a novel manipulator, in particular a manipulator that allows for ideal contact between the grinding wheel and the weld root. Furthermore, it is an object of the invention to provide a novel manipulator unit.

[0010] This object is achieved with regard to the manipulator by the features of claim 1 and with regard to the manipulator unit by the features of claim 11. Advantageous embodiments and further developments are specified in the respective dependent claims.

[0011] The manipulator according to the invention includes that the shaft is pivotable horizontally and vertically in order to bring the grinding wheel into targeted contact with the weld root, and that the direction of rotation of the grinding wheel at the weld root to be machined is perpendicular to the longitudinal extent of the weld root to be machined.

[0012] A horizontal pivoting movement of the shaft is understood in particular to mean a movement that, when projected onto a plane spanned by the first wheels and / or a plane spanned by the frame, represents a movement in this plane. A vertical pivoting movement of the shaft is understood to mean a movement that preferably runs perpendicular to the aforementioned plane.

[0013] In particular, an angular range of + / - 10°, preferably + / - 5°, is provided for the horizontal pivoting movement and an angular range of 0° to 10°, preferably 0° to 5°, is provided for the vertical pivoting movement.

[0014] In particular, a pivoting range of + / - 10 mm, preferably + / - 5 mm, can be provided for the horizontal pivoting movement, and a pivoting range of 0 to 10 mm, preferably 0 to 5 mm, can be provided for the vertical pivoting movement. In particular, such a pivoting range is provided for manipulators that are no wider or taller than 50 x 25 mm, or whose shafts have a length in the range of 80 to 100 mm.

[0015] The improved grinding process, which can be carried out with the manipulator according to the invention, improves the mechanical resilience of the recuperative heat exchanger. This also increases the service life of the heat exchanger.

[0016] The manipulator is preferably manufactured in a miniature design and preferably has a cross-section of less than 50 x 25 mm.

[0017] According to the invention, it is provided that the manipulator on the grinding head comprises a first pivoting unit for the horizontal movement of the shaft, wherein the first pivoting unit comprises a first gear, in particular a helical linear gear, and a first motor for driving the first gear.

[0018] Such a helical linear gear can, for example, comprise a plunger which can be linearly retracted and extended by the motor, wherein the plunger is supported against a component on the shaft with an inclined surface.

[0019] When extended, the plunger presses against the inclined surface, and the shaft pivots horizontally. For resetting or pivoting in the opposite direction, the plunger can be connected to the inclined surface and pull it toward it when the plunger retracts, or the resetting is achieved by a spring force acting in the opposite direction to the plunger's extension direction.

[0020] Furthermore, it is provided that the manipulator on the grinding head comprises a second pivoting unit for the vertical movement of the shaft, wherein the second pivoting unit comprises a second gear, in particular a cam gear, and a second motor for driving the second gear.

[0021] Such a cam mechanism may, for example, comprise an eccentric, for example a drop-shaped one, which is rotated by the motor and is connected at its tangential outer surface to a component on the shaft.

[0022] If the motor rotates the eccentric in such a way that the outer surface presses against the component opposite to or in the radially widest area of ​​the eccentric, the shaft is raised; if the motor rotates opposite to or in the radially narrowest area of ​​the eccentric, the shaft is lowered again.

[0023] According to one embodiment of the invention, the grinding head comprises a horizontal slide and / or a vertical slide for supporting the shaft and the grinding wheel, and in particular the pivoting devices with motors and gears.

[0024] The first pivoting unit and the second pivoting unit are preferably integrated in a, preferably combined, carriage to enable the targeted horizontal and vertical movement of the shaft.

[0025] Preferably, a mount for the shaft is provided, wherein the mount is provided on the grinding head, and in particular at or near the rear end of the grinding head in the forward direction of movement of the manipulator. The mount can, in particular, be a pivot bearing to enable horizontal and vertical movement of the shaft.

[0026] According to a variant of the invention, the drive could be provided directly on the grinding head and, for example, drive some or all of its first wheels.

[0027] According to a preferred embodiment of the invention, however, it is provided that the drive comprises at least one, preferably two, drive units for pushing the grinding head, wherein each drive unit has a frame on which, preferably four, first wheels for moving the drive unit on guide rails are provided, in particular attached, wherein each drive unit comprises at least one motor for driving the first wheels of the drive unit.

[0028] It can be provided that the at least one drive unit and the grinding head and / or the drive units are connected to each other by a flexible coupling, wherein the at least one drive unit is arranged behind the grinding head in the forward direction of movement of the manipulator. The flexible coupling can be, for example, a bellows or universal joints.

[0029] The rotational movement of the grinding wheel and / or the shaft can be driven by a third motor, in particular an external motor. In the case of an external motor, the shaft can be connected to the external motor via a flexible shaft extension.

[0030] According to an advantageous and expedient development of the invention, it is provided that second wheels are provided for traveling over the surface of the heat exchanger, wherein the second wheels are provided, in particular attached, to the frame, in particular to the outside of the frame, of the grinding head and / or to the frame, in particular to the outside of the frame, of the at least one drive unit, wherein the second wheels are preferably spring-mounted on the respective frame to generate a contact pressure on the surface of the heat exchanger.

[0031] According to a further development of the invention, it is provided that the grinding head comprises a camera for monitoring the grinding process, wherein the camera is provided in front of the grinding wheel in the forward movement direction of the manipulator, and wherein the camera is provided, in particular attached, to the frame of the grinding head, and wherein the camera is preferably designed to be pivotable on the frame.

[0032] Furthermore, it can be provided that the grinding head comprises a lighting device, in particular for illuminating the weld root to be ground, wherein the lighting device is provided in front of the grinding wheel in the forward movement direction of the manipulator, and wherein the lighting device preferably forms a structural unit with the camera.

[0033] Preferably, the manipulator comprises, in particular on the grinding head and / or on the drive unit(s), a cable harness for power supply and / or signal transmission, wherein the cable harness is provided for connecting the manipulator to a control station.

[0034] The manipulator unit according to the invention comprises a manipulator according to the invention and a control station for controlling, in particular remotely controlling, the manipulator.

[0035] According to a further development of the manipulator unit, it is provided that the manipulator is remotely controllable by the control station, wherein the horizontal and vertical pivoting of the shaft of the manipulator and / or movement of the first wheels of the at least one drive unit and / or the rotational speed of the grinding wheel is remotely controllable by the control station.

[0036] According to an advantageous and expedient development of the manipulator unit, it is provided that the control station comprises a joystick for controlling the manipulator, and / or an input device, and / or a monitor for displaying the images recorded by the camera and / or a power supply.

[0037] The invention will be explained in more detail below with regard to further features and advantages based on the description of exemplary embodiments and with reference to the accompanying drawings. FIG 1a first embodiment of the manipulator according to the invention in a view from above; FIG 2 a first embodiment of the grinding head of the manipulator according to the invention in a view from above; FIG 3 a second embodiment of the grinding head of the manipulator according to the invention in a front view; FIG 4 a third embodiment of the grinding head of the manipulator according to the invention in a view from above; FIG 5 a fourth embodiment of the grinding head of the manipulator according to the invention in a side view.

[0038] FIG 1 shows a first embodiment of the manipulator 10 according to the invention for machining weld roots 11 on recuperative heat exchangers 12. The manipulator 10 comprises a drive 26 for driving the movement of the manipulator 10.

[0039] The drive 26 comprises two drive units 27 for pushing the grinding head 18. Each drive unit 27 has a frame 15, to which four first wheels 16 are mounted for moving the drive unit 10 on guide rails 17. Each drive unit 27 also comprises a motor 32 for driving the first wheels 16 of the drive unit 27.

[0040] The drive units 27 and the grinding head 18 and the drive units 27 are connected to each other by a flexible coupling 33, wherein the drive units 27 are provided behind the grinding head 18 in the forward movement direction C of the manipulator 10.

[0041] FIG 1 to FIG 5 show that the manipulator comprises a grinding head 18 with a frame 15, to which four first wheels 16 are attached for moving the grinding head 18 on guide rails 17.

[0042] The manipulator further comprises a shaft 20 attached to the grinding head 18, wherein a grinding wheel 19 is provided on the shaft 20 for grinding weld roots 11 of a heat exchanger 12. The rotary movement of the shaft 20 can be generated by an external motor (not shown), to which the shaft 20 is connected via a flexible shaft extension (not shown).

[0043] The shaft 20 can be pivoted horizontally and vertically in order to bring the grinding wheel 19 into targeted contact with the weld root 11. Horizontal pivoting movement is understood in particular to mean a movement of the shaft which FIG 2 and FIG 4 in the projection onto the drawing plane leads to a movement in the drawing plane. FIG 4 shows the maximum horizontal deflection of shaft 20 by 5 mm to the right. Vertical pivoting movement is understood in particular as a movement of the shaft which FIG 2 and FIG 4perpendicular to the plane of the drawing and in FIG 5 runs in the drawing plane. FIG 5 shows the maximum vertical deflection of shaft 20 by 5mm upwards.

[0044] The manipulator 10 comprises on the grinding head 18 a first pivoting unit 28 for the horizontal movement of the shaft 20, wherein the first pivoting unit 28 comprises a helical linear gear 30 and a first motor 14 for driving the helical linear gear 30.

[0045] The manipulator 10 further comprises a second pivot unit 29 on the grinding head 18 for the vertical movement of the shaft 20. The second pivot unit 29 comprises a cam gear 31 and a second motor 25 for driving the cam gear 31. Furthermore, a mount 24 is provided for the shaft 20, the mount being provided on the grinding head 18 and near the rear end of the grinding head 18 in the forward movement direction C of the manipulator. The mount 24 is a pivot bearing to enable the horizontal and vertical movement of the shaft 20.

[0046] The direction of rotation of the grinding wheel 19 at the weld root to be machined is perpendicular to the longitudinal extension of the weld root 11 to be machined. The term "perpendicular" is understood broadly here and also includes an angular range of around 90°, which results from the horizontal deviation due to the pivoting movement of the shaft 20. In other words, grinding is carried out perpendicular to the longitudinal extension of the weld root 11.

[0047] Second wheels 13 are provided for driving on the surface of the heat exchanger 12 (see FIG 3 ), wherein the second wheels 13 are mounted on the outside of the frame 15 of the grinding head and on the outside of the frame 15 of the two drive units 27. The second wheels 13 are spring-mounted on the respective frame 15 to generate a contact pressure against the surface of the heat exchanger 12.

[0048] The grinding head 18 includes a camera 21 for monitoring the grinding process. The camera 21 is provided in front of the grinding wheel 19 in the forward movement direction C of the manipulator 10, and the camera 21 is mounted on the frame 15 of the grinding head 18. Furthermore, the camera 21 is pivotable on the frame 15.

[0049] Furthermore, the grinding head 18 comprises an illumination device 22 for illuminating the weld root 11 to be ground, wherein the illumination device 22 is provided in front of the grinding wheel 19 in the forward movement direction C of the manipulator 10. The illumination device 22 forms a structural unit with the camera 21.

[0050] The manipulator 10 includes a cable harness 23 for power supply and / or signal transmission on the grinding head 18 and the drive units 27. The cable harness 23 is intended for connecting the manipulator 10 to a control station (not shown in the figures).

[0051] The control station serves for the remote control of the manipulator 10, whereby the horizontal and vertical pivoting of the shaft 20 of the manipulator 10 and the movement of the first wheels 16 of the drive units 27 as well as the rotational speed of the grinding wheel 19 can be remotely controlled by the control station.

[0052] Grinding the weld root 11 with the manipulator 10 can, for example, be carried out by the manipulator 10 first moving to a specific position and then being moved forward and backward by the drive 26, with the horizontal and vertical pivot position of the shaft 20 being varied by an operator based on the image provided by the camera 21. After sufficient grinding of the weld root 11 at the approached position, the manipulator 10 is moved to another position and repeats the previously described process.

[0053] For this purpose, the control station comprises a joystick for controlling the manipulator 10, an input device, a monitor for displaying the images taken by the camera 21 and a power supply. List of reference symbols

[0054] 10Manipulator 11Weld root 12Heat exchanger 13Second wheels 14First motor 15Frame 16First wheels 17Guide rail 18Grinding head 19Grinding wheel 20Shaft 21Camera 22Lighting device 23Cable harness 24Bracket 25Second motor 26Drive 27Drive unit 28First swivel unit 29Second swivel unit 30First gear 31Second gear 32Motor 33Flexible coupling 34Base plate ALongitudinal axis BDirection of rotation CForward movement direction

Claims

1. Manipulator (10) for machining weld roots (11) on recuperative heat exchangers (12), comprising a drive (26) for moving the manipulator (10), a grinding head (18) with a frame (15) on which, preferably four, first wheels (16) for moving the grinding head (18) on guide rails (17) are provided, in particular attached, a shaft (20) provided and in particular attached to the grinding head (18), a grinding wheel (19) for grinding weld roots (11) of a heat exchanger (12) being provided on the shaft (20), characterized in that the shaft (20) can be pivoted horizontally and vertically in order to bring the grinding wheel (19) into targeted contact with the weld root (11), wherein the direction of rotation of the grinding wheel (19) at the weld root (11) to be worked is perpendicular to the longitudinal extent of the weld root (11), wherein second wheels (13) are provided for traveling on the surface of the heat exchanger (12), wherein the second wheels (13) are provided on the frame (15) of the grinding head, wherein the second wheels (13) are spring-mounted on the respective frame (15) to generate a contact pressure on the surface of the heat exchanger (12), and wherein the manipulator (10) on the grinding head (18) comprises a first pivot unit (28) for the horizontal movement of the shaft (20), the first pivot unit (28) comprising a first gear (30) and a first motor (14) for driving the first gear (30), and that the manipulator (10) comprises a second pivot unit (29) on the grinding head (18) for the vertical movement of the shaft (20), wherein the second pivot unit (29) comprises a second gear (31) and a second motor (25) for driving the second gear (31).

2. Manipulator (10) according to claim 1, characterised in that the first gear (30) is a helical linear gear and that the second gear (31) is a cam gear.

3. Manipulator (10) according to claim 1 or 2, characterised in that a mounting (24), in particular a pivot bearing, is provided for the shaft (20), wherein the mounting is provided on the grinding head (18), and in particular at or near the rear end of the grinding head (18) in the direction of forward movement (C) of the manipulator (10).

4. Manipulator (10) according to one of the preceding claims, characterised in that the drive (26) comprises at least one, preferably two, drive units (27) for pushing the grinding head (18), each drive unit (27) having a frame (15) on which, preferably four, first frames (16) for moving the drive unit (10) on guide rails (17) are provided, in particular mounted, wherein each drive unit (27) comprises at least one motor (32) for driving the first wheels (16) of the drive unit (27).

5. Manipulator (10) according to claim 4, characterised in that the at least one drive unit (27) and the grinding head (18) and / or the drive units (27) are connected to one another by a flexible coupling (33), wherein the at least one drive unit (27) is provided behind the grinding head (18) in the forward movement direction (C) of the manipulator (10).

6. Manipulator (10) according to one of the preceding claims, characterised in that the rotary movement of the grinding wheel (19) is driven by a third motor, in particular an external motor, and / or in that the direction of rotation of the grinding wheel (19) at the machining weld root (11) to be machined runs perpendicular to the longitudinal extension of the machining weld root (11) to be machined.

7. Manipulator (10) according to one of the preceding claims, characterised in that the second wheels (13) are provided, in particular mounted, on the outside of the frame (15) of the grinding head and / or in that second wheels (13) are provided, in particular mounted, on the frame, in particular on the outside of the frame (15), of the at least one drive unit (27).

8. Manipulator (10) according to one of the preceding claims, characterised in that the grinding head (18) comprises a camera (21) for monitoring the grinding process, wherein the camera (21) is provided in front of the grinding wheel (19) in forward movement direction (C) of the manipulator (10), and wherein the camera (21) is provided in particular mounted, on the frame (15) of the grinding head (18), and wherein the camera (21) is preferably designed to be pivotable on the frame (15).

9. Manipulator (10) according to claim 8, characterised in that the grinding head (18) comprises an illumination device (22), in particular for illuminating the machining weld root (11) to be ground off, wherein the illumination device (22) is provided in front of the grinding wheel (19) in the forward movement direction (C) of the manipulator (10), and wherein the illumination device (22) preferably forms a structural unit with the camera (21).

10. Manipulator (10) according to one of the preceding claims, characterised in that the manipulator (10), in particular on the grinding head (18) and / or on the drive unit(s) (27), comprises a cable harness (23) for power supply and / or for signal transmission, the cable harness (23) being provided for connecting the manipulator (10) to a control station.

11. Manipulator unit, comprising a manipulator (10) according to one of the preceding claims, and a control station for controlling, in particular remotely controlling, the manipulator (10).

12. Manipulator unit according to claim 11, characterised in that the manipulator (10) can be remotely controlled by the control station (23), wherein the horizontal and vertical pivoting of the shaft (20) of the grinding head (18) and / or movement of the first wheels (16) of the at least one drive unit (27) and / or the rotational speed of the grinding wheel (19) can be remotely controlled by the control station.

13. Manipulator unit according to claim 11 or 12, characterised in that the control station comprises a joystick for controlling the manipulator (10), and / or an input device, and / or a monitor for displaying the images recorded by the camera (21), and / or a power supply.