WO2016209145A1

WO2016209145A1 - Orbital machine, method, computer program and a computer program product for using said machine

Info

Publication number: WO2016209145A1
Application number: PCT/SE2016/050548
Authority: WO
Inventors: Hans-Petter ANDERSSON; Björn Pettersson
Original assignee: Novator Ab
Priority date: 2015-06-26
Filing date: 2016-06-08
Publication date: 2016-12-29

Abstract

The present invention relates to an orbital machine, comprising a longitudinal extending body (4), which is rotatable supported in a machine housing (8), a spindle (10) for detachably supporting a tool (2), which spindle (10) is rotatable supported in the longitudinal extending body (4), and at least one motor (18) for rotating the longitudinal extending body (4) about a first rotational axis(20) and the spindle (10) about a second rotational axis (22). The spindle (10) is so supported in the longitudinal extending body (4) that the tool (2) moves in a circle with a fixed radius (r) around the first rotational axis (20) of the longitudinal extending body (4) when the longitudinal extending body (4) rotates about the first rotational axis (20). The invention also relates to a method for controlling a tool (2) in an orbital machine (1).

Description

ORBITAL MACHINE, METHOD, COMPUTER PROGRAM AND A

COMPUTER PROGRAM PRODUCT FOR USING SAID MACHINE

TECHNICAL FIELD The present invention relates to an orbital machine with a tool, which tool is both rotation about its own axis and moving in an orbital path around another axis.

BACKGROUND A reliable and repeatable hole quality is essential, for instance in structurally important, load bearing, aerospace applications. The hole quality depends on type of hole making apparatus, type and quality of cutting tool, process parameters, tool wear and type of material in which the hole is produced. When the work piece is a stack of sheets of different materials the hole quality depends on how the hole is produced in the different materials and the material characteristics of each sheet in the stack.

Different types of hole making apparatuses are available. For special applications such as hole making in the aircraft structure of an aircraft the demands of accuracy are extremely high and therefore special hole making apparatuses should preferably be provided. Such a special hole making apparatus may use the orbital drilling technique. Orbital drilling is based on machining the material both axially and radially by rotating the cutting tool about its own axis as well as eccentrically about a principal axis while feeding the cutting tool through the material. Orbital drilling permits production of holes without strength reducing damage to the material being machined. Also, the method permits the production of holes free from damage without having to perform a hole and then machine the edges of said hole in a second process step. Further, the method permits the production of holes of small and precise tolerances.

US2010183395 discloses an orbital drilling tool unit configured to be detachably mounted to a rotatable spindle of a stationary machine tool. The tool unit comprises an outer eccentric body having an eccentric, longitudinally extending cylindrical hole, an inner eccentric body rotatable supported in the eccentric hole of the outer eccentric body and having likewise an eccentric, longitudinally extending cylindrical hole, a spindle motor for detachably supporting a cutting tool and rotatable supported in the eccentric hole of the inner eccentric body. The machine tool end of the outer eccentric body is configured to be concentrically mounted to a tool holder attached to the machine tool spindle for rotating the outer eccentric body. A radial offset adjusting means is configured for rotating the inner eccentric body relative to the outer eccentric body for adjusting the radial offset of the spindle motor center axis relative to the center axis of the machine tool spindle, and a means is provided for transferring power to the spindle motor for rotating the cutting tool. When working with large work pieces and holes of large diameters, the stability of the orbital drilling tool may in some case not be enough, due to the tolerances between the eccentric bodies and volume restrictions limiting the material thickness of the components comprising the orbital drilling tool. The lack of stability may influence on the accuracy of the produced holes.

The eccentric bodies are also complicated to produce due to small

tolerances. Therefore, the cost for producing the orbital drilling tool increases.

Also, the cost for producing such an orbital drilling tool increases due to the need of several motors and complicated transmissions for rotating the machine tool spindle and for rotating the outer eccentric body. A separate motor and transmission is also needed for displacing the tool axially. Together, the eccentric bodies contribute to that the overall dimensions of orbital drilling tool increase, which in some cases complicates the mounting of the orbital drilling tool on a template at the work piece.

The above-mentioned known orbital drilling tool unit is useful when drilling holes with medium sized diameters. However, such known orbital drilling tool units have shortcomings when drilling holes in large work pieces and holes of large diameters due to lack of stability, and when drilling holes with small diameters arranged close to each others in a workpiece.

There is thus a need for an improved orbital machine for machining processes to overcome these problems of prior art. SUMMARY OF THE INVENTION

Notwithstanding the existence of such prior art devices and methods described above, there is a need for an orbital machine with increased stability and an orbital machine with decreased dimensions. Also, there is a need for an orbital machine which may be produced at lower costs.

An objective problem to be solved by the invention is therefore to achieve an orbital machine with increased stability.

Another problem to be solved by the invention is to achieve an orbital machine with decreased dimensions.

Still another problem to be solved by the invention is to achieve an orbital machine, which may be produced at lower costs. Still another problem to be solved by the invention is to achieve an orbital machine, which could use only one motor for operating the machine. These objects above are achieved by an orbital machine according to claim 1 , a method for controlling a tool in an orbital machine according to claim 13, a computer program comprising a program code according to claim 16, a computer program product comprising program code stored on a media according to claim 17, and a computer program product directly storable in an internal memory into a computer according to claim 18.

According to an embodiment of the invention, the orbital machine, comprises a longitudinal extending body, which is rotatable supported in a machine housing, a spindle for detachably supporting a tool, which spindle is rotatable supported in the longitudinal extending body, and at least one motor for rotating the longitudinal extending body about a first rotational axis and the spindle about a second rotational axis. Furthermore, the spindle is so supported in the longitudinal extending body that the tool moves in a circle with a fixed radius around the first rotational axis of the longitudinal extending body when the longitudinal extending body rotates about the first rotational axis. Such an orbital machine will have an increased stability, will show decreased dimensions, could use only one motor for operating the machine and may be produced at lower costs. However, several motors could also be used, which may be useful in some applications. The tool of the orbital machine will move in a very precise orbit around the first rotational axis due to the radius of said orbital movement being fixed. This further has the advantage that an operation performed with the orbital machine may achieve very accurate results with small tolerances. Also, the tolerance chain will be shorter, which lead to a very accurate machine which can be made to lower cost and which is easy to assemble.

According to another embodiment of the invention, the longitudinal extending body is provided with a longitudinally extending cylindrical bore having a central axis substantially parallel to the first rotational axis and in that the central axis of the bore is arranged at a fixed distance to the first rotational axis of the longitudinal extending body.

This has the advantage that the fixed radius of the orbital movement of the spindle, caused by the rotation of the longitudinal extending body, is easily defined by the geometry of the longitudinal extending body when said spindle is arranged in said longitudinally extending cylindrical bore. Also, such a longitudinal extending body will have an increased stability, will decrease the dimensions of the orbital tool and the orbital tool may be produced at lower costs. The increased stability is useful when drilling holes in large work pieces and holes of large diameters.

Also, when the orbital machine according to the invention is provided with only one longitudinal extending body having an eccentric arranged bore, the dimensions of the orbital machine in a direction orthogonal to the central axis of the bore will be reduced. This will facilitate the mounting of the orbital drilling machine on a template at the work piece, which template may be provided with several openings arranged in a close relation to each others.

According to a further embodiment of the invention, the spindle is rotatable supported in the longitudinally extending cylindrical bore.

This has the advantage that the spindle is able to move in an orbital movement around the first rotational axis and also be able to rotate about the second rotational axis, within the longitudinal extending body. This further has the advantage that a tool arranged in said spindle may be moved to any position on the orbital path around the first rotational axis and be placed in said position with any possible rotational displacement about the second rotational axis.

According to a further embodiment of the invention, the longitudinal extending body is axially supported in the machine housing. This has the advantage that the axial movement of the longitudinal extending body may be directly controlled by the axial movement in the machine housing. The axial movement of the longitudinal extending body in relation to the housing may be controlled manually, electrically, pneumatically or hydraulically.

According to a further embodiment of the invention, the at least one motor is arranged for displacing the longitudinal extending body axially in relation to the machine housing. The motor may be an electrically, pneumatically or hydraulically controlled motor. This has the advantage that the axial displacement of the longitudinal extending body in relation to the machine housing may be controlled by means of said at least one motor. Thus, only one motor for operating the machine will be needed. However, in some applications several motors may be used. According to a further embodiment of the invention, at least one transmission is arranged between the motor and the longitudinal extending body and the spindle, respective.

This has the advantage that the power output of the motor is used in an effective way and that the rotation of the longitudinal extending body in relation to the machine housing and the rotation of the spindle in relation to the longitudinal extending body can be performed and controlled individually without the need to alter the power output of the motor directly.

According to a further embodiment of the invention, a first bearing is arranged between the longitudinal extending body and the machine housing. This has the advantage that the rotation of the longitudinal extending body in relation to the machine housing will result in less frictional force. With lower friction between the longitudinal extending body and the machine housing, less heat will therefore be generated which is beneficial in regards to the mechanical and thermal stress applied on the machine.

According to a further embodiment of the invention, the first bearing could be a ball cage bearing. This has the advantage that longitudinal extending body and the machine housing can move in relation to each other both in an axial and a rotational movement. A ball cage bearing is further advantageous to use as it is a common technical solution which is easy to replace and alter depending on the needs of the machine and its applications. Ball cage bearings can be used with very small tolerances and deliver highly accurate results.

Preferably, several balls are distributed between the longitudinal extending body and the machine housing.

According to a further embodiment of the invention, at least one second bearing is arranged between the longitudinal extending body and the spindle. This has the advantage that the rotation of the spindle in relation to the longitudinal extending body will result in less frictional force. With lower friction between the spindle and the longitudinal extending body, less heat will therefore be generated which is beneficial in regards to the mechanical and thermal stress applied on the machine. According to a further embodiment of the invention, the second bearing is at least one ball bearing.

This has the advantage that the rotation of the spindle in regards to the longitudinal extending body can be achieved with low friction while still having small tolerances in regards to the movement of the tool. According to a further embodiment of the invention, the tool is a cutting tool or a measuring probe. A cutting tool has the advantage that machining processes such as drilling or machining can be performed with the machine. Said machining processes can be performed with small tolerances and precise results which is beneficial for industrial purposes. A measuring probe has the advantage that the machine can perform different types of measuring tasks such as measuring the depth of a machined hole, the surface structure of the sides of a hole or similar. A further advantage is that the tool can be alternated between said cutting tool or measuring probe, which is advantageous as only one machine is needed to perform different types of tasks. An even further advantage is that the alternating tools may be used to complement each other in a machining process.

According to a further embodiment of the invention, the spindle is provided with a holding element for detachably holding the tool.

This has the advantage that the tool can easily be attached and de-attached to the spindle and hence the machine. This makes it easy to alternate said tool if another type of tool or if a tool of another dimension is needed. An integrated tool holder may be used, wherein the cutting tool is detachably arranged on the distal end of the spindle by means of for example a threaded element. According to a further embodiment of the invention, a fixation device is arranged on the housing for fixating the machine at a template, which fixation device is provided with a nose piece having dimensions adapted to the fixed radius of the circle in which the tool moves.

Since the orbital machine according to the invention is provided with only one longitudinal extending body having an eccentric arranged bore, the dimensions of the orbital machine in a direction orthogonal to the central axis of the bore will be reduced. When several holes should be drilled in the workpiece and the holes should be arranged closed to each others, the dimensions of the orbital machine will make it possibility to arrange the holes close to each other in the workpiece.

According to a further embodiment of the invention, the invention relates to a method for controlling a tool in an orbital machine. The orbital machine comprises a longitudinal extending body, which is rotatable supported in a machine housing, a spindle for detachably supporting a tool, which spindle is rotatable supported in the longitudinal extending body, and

at least one motor for rotating the longitudinal extending body about a first rotational axis and the spindle about a second rotational axis. The method of the present invention is characterized in the steps of:

a) rotating the spindle about the second rotational axis, and

b) rotating the longitudinal extending body about the first rotational axis, so that the tool moves in a circle with a fixed radius around the first rotational axis.

This has the advantage that the tool can reach a larger portion of a work piece when the tool is moved in an orbital path around the first rotational axis. This means that the usage of the machine and the process step associated with the rotation of the spindle about its own axis may be performed on a larger portion than the size of the tool itself. A further advantage is that the tolerances of the work performed in a process using the orbital machine will be very small as the radius in which the tool moves is fixed. If for example said tool is a cutting tool, said cutting tool will be able to perform very precise cutting to a work piece, wherein the hole machined by the cutting tool will be larger than the cutting tool itself. The inner surfaces of said machined hole will further have very smooth surfaces due to the fixed radius of the orbital movement of the cutting tool.

According to a further embodiment, the invention relates to a method for controlling a tool in an orbital machine, wherein the longitudinal extending body is provided with a longitudinally extending cylindrical bore having a central axis substantially parallel to the first rotational axis and in that the central axis of the bore is arranged at a fixed distance to the first rotational axis of the longitudinal extending body.

This has the advantage that the fixed radius of the orbital movement of the spindle, caused by the rotation of the longitudinal extending body, is easily defined by the geometry of the longitudinal extending body when said spindle is arranged in said longitudinally extending cylindrical bore.

According to a further embodiment, the invention relates to a method for controlling a tool in an orbital machine, wherein the method before step b), performs the further step: c) displacing the longitudinal extending body axially in relation to the machine housing.

This has the advantage that the tool can be moved towards a work piece before the orbital movement is initiated. This movement can be performed without moving the machine housing, which machine housing can be fixated by fastening means. The axial movement of the tool by means of the axial movement of the longitudinal extending body coupled with the rotation of the tool and the orbital movement of the tool has the advantage that the tool may perform machining work in three dimensions.

According to a further embodiment, the invention relates to a method for controlling a tool in an orbital machine, wherein the method before step a), performs the further step: d) fixating the machine at a template by means of a fixation device arranged on the housing, which fixation device is provided with a nose piece having dimensions adapted to the fixed radius of the circle in which the tool moves. This has the advantage that several holes can be drilled in the workpiece and that the holes can be arranged closed to each others. The reason for this is that the dimensions of the orbital machine will make it possibility to arrange the holes close to each other in the workpiece. According to a further embodiment of the invention, the method for controlling a tool in an orbital machine may be performed by means of a computer program comprising a program code for performing the method steps described above, when said computer program is run on a computer. According to a further embodiment of the invention, the program code of the computer program may be implemented in a computer program product, wherein said program code is stored on a media, readable by a computer for performing the method steps described above, when said computer program is run on the computer. According to a further embodiment of the invention, the computer program product may be directly storable in an internal memory into a computer, comprising a computer program for performing the method steps described above, when said computer program is run on the computer.

This has the advantage that the method steps of the method according to the present invention can be performed with high accuracy and be repeated with identical or close to identical results as the method is performed by a program code by means of a computer. This further has the advantage that the method is easy to implement in an industrial process.

By the term "hole" is meant forming of an opening or recess in the material by the working process that results in a hole configuration or geometry. Thus, the hole is not limited to a circular hole but can be of any shape, such as triangular, polygonal shaped or a counter sink hole. The hole can be a through hole or a blind hole. Hence, by the term hole "diameter" is meant any distance straight across the opening that forms the hole and not only the largest opened distance cross the hole. BRIEF DESCRIPTION OF THE DRAWINGS

The invention will hereinafter be described with reference to embodiments of the invention and the enclosed figures, where

Fig. 1 shows a schematically sectional view of a first embodiment of an orbital machine according to the invention,

Figures 2a - 2c show templates together with workpieces in a view from above,

Fig. 3 shows a schematically sectional view of a second embodiment of an orbital machine according to the invention, Fig. 4 shows a view in perspective of a longitudinal extending body in an orbital machine according to the invention,

Figures 5a and 5b show cutting tools with two different diameters for cutting holes in a work piece using an orbital machine according to the invention, and

Fig. 6 shows a block diagram of a method for controlling a tool in an orbital machine according to the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

The orbital machine 1 , the method for controlling a tool 2 in an orbital machine 1 , the computer program and the computer program product for using said machine 1 according to the invention will now be described by way of example only. The disclosure is not intended to limit the scope of the enclosed claims in any way.

Fig. 1 shows a schematically sectional view of a first embodiment of an orbital machine 1 according to the invention. The orbital machine 1 comprises a longitudinal extending body 4, which is rotatable supported by means of a first bearing 6 in a machine housing 8. A spindle 10 is rotatable supported by means of a second bearing 12 in the longitudinal extending body 4. Preferably, the first bearing 6 is a ball cage bearing, which allows the longitudinal extending body 4 to both rotate and move axially in relation to the machine housing 8. The spindle 10 is provided with a holding element 14 for detachably holding the tool 2, which may be a cutting tool or a measuring probe. According to the first embodiment, the machine housing 8 is provided with handles 16 for moving the orbital machine 1 manually.

A motor 18 is arranged for rotating the longitudinal extending body 4 about a first rotational axis 20 and the spindle 10 about a second rotational axis 22. Preferably, the torque from the motor 18 is transferred to the spindle 10 and the longitudinal extending body 4 by means of transmission 24. Also, the longitudinal extending body 4 is axially supported in the machine housing 8, so that that motor 18 can displace the longitudinal extending body 4 axially in relation to the machine housing 8. Thus, the motor 18 is via the transmission 24 arranged to rotate the spindle 10 and the longitudinal extending body 4 and to move the longitudinal extending body 4 axially. The motor 18 may be an electric, pneumatic or hydraulic driven engine. However, in some applications several motors 18 may be used.

The orbital machine 1 could be controlled by a control unit 26. The control unit 26 receives information from the memory M about a receipt containing for example collected tool and material parameters, whereby the control unit 26 uses the information for running a drilling or measuring operation. The control unit 26 is preferably run by a computer 28, having a software algorithm adapted for providing calculations.

The orbital machine 1 could be connected to the control unit 26 by means of electrical wires 30. Also, the computer 28 is connected to the control unit 26 by means of electrical wires 30. The control unit 26 and the computer 28 may be installed into the orbital machine 1 or as separate units outside the orbital machine 1 . The orbital machine 1 may also communicate wireless with the control unit 26 and the computer 28.

A template 32 is connected to a work piece 40, by means of connecting elements. Openings 34, 36 are located in a pattern in the template 32 corresponding to the positions of holes 38 to be formed or measured in the work piece 40 to which the template 32 is attached. Guide bushings 42, 44 may be inserted in the openings 34, 36 of the template 32 to form guide holes 37 for the orbital machine 1 .

The orbital machine 1 has a suitable fixation device 48 for fixating the machine 1 to the bushings 42, 44 of the template 32. The fixation device 48 is arranged at an end part of the machine housing 8 and allows the longitudinal extending body 4 and the tool 2 to be displaced axially in relation to the machine housing 8. The fixation device 48 is provided with a nose piece 49 which has an external diameter smaller than the diameter of the openings 34, 36 in the template 32. The fixation device 48 comprises a clamping mechanism 55 for detachably connecting the drilling machine 1 to the guide bushing 42, 44. The nose piece 49 defines an aperture 57 concentric with the respective template opening 34, 36 and through which the cutting tool 2 of the drilling machine 1 may be axially and radially advanced into the work piece 40 while rotating about the first and second rotational axis 20, 22. The clamping mechanism 55 may be provided with an expandable sleeve 59 arranged to be urged towards the inner circumferential wall of the guide bushing 42, 44 in order to fixate the drilling machine 1 to the template 32. The expandable sleeve 55 may be controlled by means of pneumatically controlled pressure cylinder 61 .

The nose piece 49 of the fixation device 48 is axially displaced into the opening 34, 36 of the template 32 and is clamped against the inner surface of the opening 34, 36. Thereafter the tool 2 arranged at the spindle 10 is rotated and axially displaced in the direction of the work piece 40 by means of the axially displacement of the longitudinal extending body 4. The nose piece 49 may be of different types and shapes, and provided with different types of clamping mechanism 55.

The nose piece 49 has dimensions adapted to the fixed radius r of the circle in which the tool 2 moves. This means that the inner diameter of the nose piece 49 must be provided with such a large diameter that the orbital movement of the tool 2 is allowed. Since the orbital machine 1 according to the invention is provided with only one longitudinal extending body 4 having an eccentric arranged bore 56, the dimensions of the orbital machine 1 in a direction orthogonal to the central axis of the bore 56 will be reduced. When several holes 38 should be drilled in the work piece 40 and the holes 38 should be provided with a diameter in the range of 4 - 8 mm the dimensions of the orbital machine 1 will limit the possibility to arrange the holes 30 close to each other in the work piece 40. Thus, the reduced dimensions of the orbital machine 1 in a direction orthogonal to the central axis of the bore 56 will make it possible to arrange the holes 30 close to each other in the work piece 40. The reason to this is that the diameter of the nose piece 49 can be reduced and therefore the openings 34, 36 in the template 32 may be arranged with small diameters. When the openings 34, 36 in the template 32 are allowed to be arranged with small diameters the openings 34, 36 may be located close to each others in the template 32. This will facilitate the mounting of the orbital drilling machine on the template, which template may be provided with several openings arranged in a close relation to each others. The work piece 40 may consist of a stack of sheets s1 , s2 of different materials, such as fibre-reinforced composite materials, laminates, metals and stacks of identical or various materials, etc. In fig. 1 the work piece 40 consists of a stack of two sheets s1 , s2, wherein each sheet s1 , s2 has a thickness and specific material characteristics.

When attaching the orbital machine 1 to one of the openings 34, 36 on the template 32, a sensor 52 on the machine 1 could detect the identity of the hole 38 by means of an adjacent information carrier 54 on the template 32 and transmit the information to the memory M containing all relevant information of the respective hole 38 to be formed or to be measured, such as type of hole 38 various processing and dimensional parameters thereof, e.g. diameter, depth and configuration of the hole 38, cutting advancement speed, shape of countersinks, etc. Also, information about number of sheets s1 , s2 in the stack, material characteristics of the material in each of the sheets s1 , s2 and the thickness of each sheet s1 , s2 are transmitted. Then, the control unit 26 is adapted to control the machine 1 to carry out the relevant hole cutting process or measuring process in the work piece 40 and switch on and off the vibrating means depending on information transmitted to and from the control unit 26. Thus, an operator may only have to fixate the orbital machine 1 on the bushing 42, 44 and to activate it to initiate the relevant hole cutting process or measuring process. According to fig. 1 the spindle 10 is so supported in the longitudinal extending body 4 that the tool 2 moves in a circle with a fixed radius r around the first rotational axis 20 of the longitudinal extending body 4 when the longitudinal extending body 4 rotates about the first rotational axis 20. This is achieved by arranging the spindle 10 in an eccentric position in relation to the first rotational axis 20 of the longitudinal extending body 4. Figures 2a - 2c show templates 32 together with work pieces 40 in a view from above. In fig. 2a, a template 32 is provided with openings 34, 36 for each hole 34, 36 that should be drilled into a work piece 40. Each hole 34, 36 that should be drilled into a work piece 40 has a diameter D1 and their centre axis are at the distance C1 to each others. The openings 34, 36 in fig. 2a have a diameter D2 and their centre axes are also at the distance C1 to each others. However, if the holes 38 in the work piece 40 should be arranged closer to each other, at a distance C2 between their centre axes, which is shown in fig. 2b, the openings 34, 36 in the template 32 will cut into each other. Thus, each opening 34, 36 is not provided with a continuous circumference, which leads to that the nose piece 49 of the fixation device 48 will not be embraced by the respective opening 34, 36 when arranged in the opening 34, 36. The result may be that the nose piece 49 cannot be clamped into the opening 34, 36.

Since the orbital machine 1 according to the invention is provided with only one longitudinal extending body 4 having an eccentric arranged bore 56, the dimensions of the orbital machine 1 in a direction orthogonal to the central axis of the bore 56 will be reduced. Thus, the reduced dimensions of the orbital machine 1 leads to that the diameter of the nose piece 49 can be reduced and therefore the openings 34, 36 in the template 32 may be arranged with smaller diameters D3, which is shown in fig. 2c. When the openings 34, 36 in the template 32 are allowed to be arranged with smaller diameters the openings 34, 36 may be located close to each others, at the distance C2 between their centre axes, in the template 32 as shown in fig. 2c.

Fig. 3 shows a schematically sectional view of a second embodiment of an orbital machine 1 according to the invention. According to the second embodiment, the orbital machine 1 is arranged on a robot arm 51 of a robot 53, so that the orbital machine 1 can be moved automatically to a position on the work piece 40. When a robot 53 is used to positioning the orbital machine 1 there is no need of a template 32. However, in some cases also a template 32 may be used in combination with a robot 53 connected to the orbital machine 1 . The robot 53 could be connected to the control unit 26 by means of electrical wires 30 or communicate wireless with the control unit 26. The longitudinal extending body may be axially supported in the machine housing, so that axial movement of the longitudinal extending body may be directly controlled by the axial movement in the machine housing. The axial movement of the longitudinal extending body in relation to the housing may be controlled manually, electrically, pneumatically or hydraulically. Fig. 4 shows a view in perspective of the longitudinal extending body 4, which is provided with a longitudinally extending cylindrical bore 56 having a central axis 58 coinciding with the second rotational axis 22 and substantially parallel to the first rotational axis 20. The central axis 58 of the bore 56 is arranged at a fixed distance d to the first rotational axis 20 of the longitudinal extending body 4. Therefore, the distance d between the central axis 58 of the bore 56 and the first rotational axis 20 is equal to the fixed radius r of the circle the tool 2 moves when the longitudinal extending body 4 rotates about the first rotational axis 20. Thus, the fixed radius r of the orbital movement of the spindle 10, caused by the rotation of the longitudinal extending body 4, is easily defined by the geometry of the longitudinal extending body 4 when said spindle 10 is arranged in said longitudinally extending cylindrical bore 56. Preferably, the longitudinal extension of the longitudinal extending body 4 is equal to or larger than twice the diameter of the longitudinal extending body 4.

The spindle 10 is rotatable supported in the longitudinally extending cylindrical bore 56 by means of the second bearing 12, which in the embodiments in fig. 1 and fig. 3 are two ball bearings.

The tool 2 of the orbital machine 1 will move in a very precise orbit around the first rotational axis 20 due to the radius r of said orbital movement being fixed. Thus, the orbital machine 1 may achieve very accurate results with small tolerances. The fixed radius r of the orbital movement of the spindle 10, caused by the rotation of the longitudinal extending body 4, is defined by the geometry of the longitudinal extending body 4 when said spindle 10 is arranged in said longitudinally extending cylindrical bore 56.

Figures 5a and 5b show cutting tools 2 with two different diameters for cutting holes 38 in a work piece 40 using an orbital machine 1 according to the invention. When the tool 2 is moved in the orbital path around the first rotational axis 20, the tool 2 reaches a larger portion of the work piece 40 than the diameter of the tool 2 itself. This means that the usage of the machine 1 and the process step associated with the rotation of the spindle 10 about its own axis may be performed on a larger portion than the size of the tool 2 itself. The diameter of the finished hole 38 using the tool 2 in fig. 5a will be smaller than the finished hole 38 using the tool 2 in fig. 5b. The reason for this is that the diameter of the tool 2 itself in fig. 5a is smaller than the diameter of the tool 2 in fig. 5b. Thus, by using cutting tools 2 with different diameters it may be possible to determine the diameter of the hole 38 to be drilled by the orbital machine 1 according to the invention. The diameter of the hole 38 to be drilled may also be determined by using different orbital machines 1 according to the invention, wherein each different machine 1 has a specific distance d between the first and second rotational axis 20, 22.

The tolerances of the work performed in a process using the orbital machine 1 will be very small as the radius r in which the tool 2 moves is fixed. If for example said tool 2 is a cutting tool 2, said cutting tool 2 will be able to perform very precise cutting to a work piece 40, wherein the hole 38 machined by the cutting tool 2 will be larger than the cutting tool 2 itself. The inner surfaces of said machined hole 38 will further have very smooth surfaces due to the fixed radius r of the orbital movement of the cutting tool 2.

In operation, the method according to the invention is illustrated in a block diagram in Fig. 6. The method according to the first embodiment comprising the steps of:

a) rotating the spindle 10 about the second rotational axis 22, and

b) rotating the longitudinal extending body 4 about the first rotational axis 20, so that the tool 2 moves in a circle with a fixed radius r around the first rotational axis 20.

Preferably, the longitudinal extending body 4 is provided with a longitudinally extending cylindrical bore 56 having a central axis 58 substantially parallel to the first rotational axis 20 and in that the central axis 58 of the bore 56 is arranged at a fixed distance d to the first rotational axis 20 of the longitudinal extending body 4.

Preferably, the method, before step b), performs the further step:

c) displacing the longitudinal extending body 4 axially in relation to the machine housing 8.

Thus, the tool 2 can be moved towards a work piece 40 before the orbital movement is initiated. This movement can be performed without moving the machine housing 8, which machine housing 8 can be fixated by a fixation device 48 to the template 32. The axial movement of the tool 2 by means of the axial movement of the longitudinal extending body 4 coupled with the rotation of the tool 2 and the orbital movement of the tool 2 has the advantage that the tool 2 may perform machining work in three dimensions.

The invention also relates to a computer program P and a computer program product for performing the method steps. The computer program P

comprises a program code for performing the method steps according to the present invention as mentioned herein, when said computer program P is run on a computer 28. The computer program product comprises a program code stored on a, by a computer 28 readable, media for performing the method steps according to the invention as mentioned herein, when said computer program P is run on the computer 28. Alternatively, the computer program product is directly storable in an internal memory M into the computer 28, comprising a computer program P for performing the method steps according to the present invention, when said computer program P is run on the computer 28.

The control unit 26 and/or the computer 28 comprise a computer program P, which can include routines to control the orbital machine 1 according to the invention. The program P may be stored in an executable form or

compressed form in the memory M and/or in a read/write memory M.

Preferably there is provided a computer program product comprising a program code stored on a, by a computer 28 readable medium for performing the steps above, when said program is run on the control unit 26 or the computer 28 connected to the control unit 26. Said code may be non-volatile, stored in said computer 28 readable medium.

Features and components of the different embodiments above may be combined within the scope of the invention.

Claims

1 . An orbital machine, comprising

a longitudinal extending body (4), which is rotatable supported in a machine housing (8),

a spindle (10) for detachably supporting a tool (2), which spindle (10) is rotatable supported in the longitudinal extending body (4), and

at least one motor (18) for rotating the longitudinal extending body (4) about a first rotational axis (20) and the spindle (10) about a second rotational axis (22), characterized in that the spindle (10) is so supported in the longitudinal extending body (4) that the tool (2) moves in a circle with a fixed radius (r) around the first rotational axis (20) of the longitudinal extending body (4) when the longitudinal extending body (4) rotates about the first rotational axis (20).

2. A machine according to claim 1 , characterized in that the longitudinal extending body (4) is provided with a longitudinally extending cylindrical bore (56) having a central axis (58) substantially parallel to the first rotational axis (20) and in that the central axis (58) of the bore (56) is arranged at a fixed distance (d) to the first rotational axis (20) of the longitudinal extending body (4).

3. A machine according to claim 2, characterized in that the spindle (10) is rotatable supported in the longitudinally extending cylindrical bore (56).

4. A machine according to any of the preceding claims, characterized in that the longitudinal extending body (4) is axially supported in the machine housing (8).

5. A machine according to any of the preceding claims, characterized in that the at least one motor (18) is arranged for displacing the longitudinal extending body (4) axially in relation to the machine housing (8).

6. A machine according to any of claims 1 and 5, characterized in that at least one transmission (24) is arranged between the motor (18) and the longitudinal extending body (4) and the spindle (10), respective.

7. A machine according to any of the preceding claims, characterized in that a first bearing (6) is arranged between the longitudinal extending body (4) and the machine housing (8).

8. A machine according to claim 7, characterized in that the first bearing (6) is a ball cage bearing.

9. A machine according to any of the preceding claims, characterized in that a second bearing (12) is arranged between the longitudinal extending body (4) and the spindle (10).

10. A machine according to claim 9, characterized in that the second bearing (12) is at least one ball bearing.

1 1 . A machine according to any of the preceding claims, characterized in that the tool (2) is a cutting tool or a measuring probe.

12. A machine according to any of the preceding claims, characterized in that the spindle (10) is provided with a holding element (14) for detachably holding the tool (2).

13. A machine according to any of the preceding claims, characterized in that a fixation device (48) is arranged on the housing (8) for fixating the machine at a template (32), which fixation device (48) is provided with a nose piece (49) having dimensions adapted to the fixed radius (r) of the circle in which the tool (2) moves.

14. A method for controlling a tool (2) in an orbital machine (1 ), comprising a longitudinal extending body (4), which is rotatable supported in a machine housing (8),

at least one motor (18) for rotating the longitudinal extending body (4) about a first rotational axis (20) and the spindle (10) about a second rotational axis (22), characterized in the steps of:

a) rotating the spindle (10) about the second rotational axis (22), and b) rotating the longitudinal extending body (4) about the first rotational axis (20), so that the tool (2) moves in a circle with a fixed radius (r) around the first rotational axis (20).

15. A method according to claim 14, characterized in that the longitudinal extending body (4) is provided with a longitudinally extending cylindrical bore

(56) having a central axis (58) substantially parallel to the first rotational axis (20) and in that the central axis of the bore (56) is arranged at a fixed distance (d) to the first rotational axis (20) of the longitudinal extending body (4).

16. A method according to any of claims 14 and 15, characterized in that before step b), performing the further step: c) displacing the longitudinal extending body (4) axially in relation to the machine housing (8).

17. A method according to any of claims 14 - 16, characterized in that before step a), performing the further step: d) fixating the machine at a template (32) by means of a fixation device (48) arranged on the housing (8), which fixation device (48) is provided with a nose piece (49) having dimensions adapted to the fixed radius (r) of the circle in which the tool (2) moves.

18. Computer program (P) comprising a program code for performing the method steps of claims 14 - 17, when said computer program (P) is run on a computer (28).

19. Computer program product comprising a program code stored on a media, readable by a computer (28) for performing the method steps of claims 14 - 17, when said computer program (P) is run on the computer (28).

20. Computer program product directly storable in an internal memory (M) into a computer (28), comprising a computer program (P) for performing the method steps according to claims 14 - 17, when said computer program (P) is run on the computer (28).