Method for controlling a wall sawing system when making a cut-off cut

Description

Technisches Gebiet

[0001] The present invention relates to a method for controlling a wall sawing system when making a separation cut according to the preamble of claim 1. Stand der Technik

[0002] Examples of wall sawing systems are known from WO 2014 / 124912 A1, WO 2014 / 128095 A1 or WO 2014 / 124931 A1.

[0003] From EP 1 693 173 B1, a method for controlling a wall sawing system during the creation of a separation cut in a workpiece between a first endpoint and a second endpoint is known. The wall sawing system comprises a guide rail and a wall saw with a saw head, a motorized feed unit that moves the saw head parallel to a feed direction along the guide rail, and at least one saw blade that is attached to a saw arm of the saw head and driven about a rotary axis by a drive motor. The saw arm is designed to pivot about a pivot axis by means of a swivel motor. By pivoting the saw arm about the pivot axis, the penetration depth of the saw blade into the workpiece is changed. The motorized feed unit comprises a guide carriage and a feed motor, wherein the saw head is mounted on the guide carriage and moved along the guide rail by the feed motor.A sensor system with a swivel angle sensor and a displacement sensor is provided to monitor the wall saw system. The swivel angle sensor measures the current swivel angle of the saw arm, and the displacement sensor measures the current position of the saw head on the guide rail. The measured values ​​for the current swivel angle of the saw arm and the current position of the saw head are regularly transmitted to a control unit of the wall saw.

[0004] The known method for controlling a wall sawing system is divided into a preparation phase and a processing phase controlled by the control unit. In the preparation phase, the operator specifies at least the saw blade diameter, the positions of the first and second endpoints in the feed direction, and the final cutting depth; further parameters may include the material of the workpiece and the dimensions of any embedded reinforcing steel. Based on the entered parameters, the control unit determines a suitable sequence of main cuts, comprising at least a first main cut with a first main cutting angle of the saw arm and a first diameter of the saw blade used, and a subsequent second main cut with a second main cutting angle of the saw arm and a first diameter of the saw blade used.

[0005] The known method for controlling a wall saw system has the disadvantage that no specific control method is provided for processing hard materials. When processing hard materials, the cutting segments can be polished during the pivoting movement of the saw blade into the workpiece. This polishing reduces the service life of the cutting segments and the processing speed of the saw blade.

[0006] From WO 2014 / 124912 A1, a method for controlling a wall sawing system during the insertion of a saw blade into a workpiece is known. The wall sawing system is controlled by means of the arc length of the saw blade engaged with the workpiece and by means of a displacement of the saw head along a feed direction. A critical arc length of the saw blade, as well as a first displacement in a positive feed direction and a second displacement in a negative feed direction, are stored in a control unit of the wall sawing system. During the pivoting movement of the saw arm, the arc length is calculated by the control unit and compared with the critical arc length, whereby the pivoting movement of the saw arm is interrupted if the calculated arc length corresponds to the critical arc length of the saw blade.During the feed movement of the saw head, the displacement of the saw head is calculated by the control unit and compared with the first displacement or second displacement, whereby the feed movement of the saw head is interrupted if the displacement of the saw head corresponds to the first or second displacement. Darstellung der Erfindung

[0007] The object of the present invention is to develop a method for controlling a wall saw system which enables the processing of hard materials and in which the service life and processing speed of the saw blade are optimized.

[0008] This problem is solved according to the invention in the aforementioned method for controlling a wall saw system by the features of the independent claim. Advantageous embodiments are specified in the dependent claims. According to the invention, the pivoting movement of the saw arm from the first main cutting angle to a new pivoting angle is carried out in at least two steps with at least one intermediate angle, wherein between the pivoting movements of the saw arm to the intermediate angles, the saw blade is cleared, and the saw head is moved into a position such that, after the pivoting movement of the saw arm to the following intermediate angle or to the second main cutting angle, a first limit of the wall saw coincides with the first endpoint if the pivoting movement takes place in the region of the first endpoint, or a second limit of the wall saw coincides with the second endpoint.when the pivoting movement takes place in the area of ​​the second endpoint, the first boundary of the wall saw is formed by a first upper exit point of the saw blade used on the top of the workpiece, facing the first endpoint, if the first endpoint is a free endpoint without an obstacle; by a first edge of the saw blade used, facing the first endpoint, if the first endpoint is an obstacle and the work is carried out without a blade guard; and by a first edge of the blade guard used, facing the first endpoint, if the first endpoint is an obstacle and the work is carried out with a blade guard; and the second boundary of the wall saw is formed by a second upper exit point of the saw blade used, facing the second endpoint, on the top of the workpiece, if the second endpoint is a free endpoint without an obstacle; by aThe second edge of the saw blade used, facing the second endpoint, if the second endpoint presents an obstacle and the machining is carried out without a blade guard, and the second edge of the blade guard used, facing the second endpoint, if the second endpoint presents an obstacle and the machining is carried out with a blade guard.

[0009] Saw blades for wall saws are constructed in two parts: a main body and cutting segments around the circumference of the main body. The cutting segments consist of a matrix material in which diamond particles are embedded. A minimum surface pressure is required to expose the diamond particles during cutting. If this minimum surface pressure is not met, the diamond particles will not be exposed during cutting, and there is a risk of polishing the cutting segments. This reduces the lifespan of the cutting segments and the cutting speed of the saw blade. The minimum surface pressure of the cutting segments corresponds to a critical arc length of the saw blade, which must not be exceeded.The value for the critical arc length of a saw blade depends on several parameters, including the specification of the saw blade, the material of the workpiece to be machined, and the power and torque of the drive motor for the saw blade.

[0010] Dividing the pivoting movement into at least two steps reduces the risk of polishing the saw blade. A smaller pivot angle reduces the arc length of the saw blade engaged with the workpiece, or the number of cutting segments engaged with the workpiece. Clearing the saw blade between the pivoting movements of the saw arm further reduces the arc length of the saw blade engaged with the workpiece.

[0011] Preferably, the pivoting movement of the saw arm from the first main cutting angle to the new pivoting angle is performed in n steps with n-1 intermediate angles, with the saw blade being cleared between each pivoting movement of the saw arm to the intermediate angles. The number of steps depends, among other things, on the specifications of the saw blade, the hardness of the material, and the power and torque of the drive motor for the saw blade. The intermediate angles can be set by the operator, or the control unit of the wall saw system can determine the intermediate angles depending on various boundary conditions. For the method according to the invention, the intermediate angles represent an input variable that is used to control the wall saw.

[0012] Preferably, before the start of the machining process controlled by the control unit, the saw arm length, defined as the distance between the pivot axis of the saw arm and the axis of rotation of the saw blade, and the distance between the pivot axis and the top of the workpiece are also specified. For controlled machining of a cut, the control unit must know various parameters. These include the saw arm length, which is a fixed, device-specific dimension of the wall saw, and the vertical distance between the pivot axis and the surface of the workpiece, which depends not only on the geometry of the wall saw but also on the geometry of the guide rail used.

[0013] It is particularly advantageous to define, prior to the start of controlled machining, a first width for a blade guard used in the first main cut and a second width for a blade guard used in the second main cut. The first and second widths are each composed of the first distance of the axis of rotation to the first edge of the blade guard and the second distance of the axis of rotation to the second edge of the blade guard. If an endpoint presents an obstacle, the saw head's position is controlled via the blade guard edge facing the obstacle. With an asymmetrical blade guard, the first and second distances of the axis of rotation to the blade guard edges are different, whereas with a symmetrical blade guard, the first and second distances of the blade guard edges correspond to half the width of the blade guard.

[0014] In a first preferred embodiment of the method according to the invention, the pivoting movement from the first main cutting angle to the new main cutting angle at the first endpoint takes place, and the saw head is positioned in the j-th step, j = 1 to n-1, such that after the pivoting movement of the saw arm to the j-th intermediate angle, a first boundary of the wall saw facing the first endpoint coincides with the first endpoint, wherein the first boundary of the wall saw is formed by a first upper exit point of the saw blade used on the top of the workpiece facing the first endpoint, if the first endpoint is a free endpoint without obstruction, by a first edge of the saw blade used facing the first endpoint, if the first endpoint is an obstruction and the machining is carried out without a blade guard, and by a first edge of the blade guard used facing the first endpoint.if the first endpoint presents an obstacle and the editing is done with sheet protection.

[0015] Each step comprises the process steps of positioning the saw head, pivoting the saw arm to the intermediate angle, and moving the saw head to clear the saw blade. After the saw arm pivots to the intermediate angle, the first limit coincides with the first endpoint. If the endpoint is unobstructed, position control is achieved via the first upper exit point of the saw blade on the top of the workpiece. If the first endpoint is obstructed, the first edge of the saw blade (machining without a blade guard) or the first edge of the blade guard (machining with a blade guard) is used for position control.

[0016] After the saw arm pivots to the j-th intermediate angle, where j = 1 to n-1, the first upper exit point coincides with the first endpoint if the pivot axis is a distance from the first endpoint of √[h(±β 1,j ) · (D - h(±β 1,j ))] - δ · sin(±β 1,j ), where h(±β 1,j ) = D / 2 - Δ - δ · cos(±β 1,j ) denotes the penetration depth of the saw blade into the workpiece at the j-th intermediate angle; the first edge of the saw blade coincides with the first endpoint if the pivot axis is a distance from the first endpoint of D / 2 - δ · sin(±β 1,j ); and the first edge of the blade guard coincides with the first endpoint if the pivot axis is a distance from the first endpoint of B 2a - δ · sin(±β 1,j ) exhibits.

[0017] After the pivoting movement, the saw head is moved in the j-th step, j = 1 to n-1, with the saw arm inclined at the j-th intermediate angle, by a distance of √[h 2 · (D - h 2 )] - δ · sin(±α 2 ), where h 2 = h(±α 2 , D) = D / 2 - Δ - δ · cos(±α2) denotes the penetration depth of the saw blade into the workpiece at the second principal cutting angle. The feed movement of the saw head frees the saw blade and reduces the portion of the saw blade in contact with the workpiece.

[0018] After the n-1th step, the saw head is positioned so that, after the pivoting movement of the saw arm into the new main cutting angle, the first boundary of the wall saw facing the first endpoint coincides with the first endpoint.After the saw arm pivots into the second principal cutting angle, the first upper exit point coincides with the first endpoint if the pivot axis is a distance from the first endpoint of √[h 2 · (D - h 2 )] - δ · sin(±α 2 ) where h(±α 2 ) = D / 2 - Δ - δ · cos(±α 2 ) denotes the penetration depth of the saw blade used into the workpiece at the second principal cutting angle with the second diameter, the first edge of the saw blade used coincides with the first endpoint if the pivot axis is a distance from the first endpoint of D / 2 - δ · sin(±α 2 ), and the first edge of the blade guard used coincides with the first endpoint if the pivot axis is a distance from the first endpoint of B a - δ · sin(±α 2 ).

[0019] In a second preferred embodiment of the method according to the invention, the pivoting movement from the first main cutting angle to the new main cutting angle at the second endpoint takes place, and the saw head is positioned in the j-th intermediate cut, j = 1 to n-1, such that after the pivoting movement of the saw arm to the j-th intermediate angle, a second boundary of the wall saw facing the second endpoint coincides with the second endpoint, wherein the second boundary of the wall saw is formed by a second upper exit point of the saw blade used on the top of the workpiece facing the second endpoint, if the second endpoint is a free endpoint without obstruction, by a second saw blade edge of the saw blade used facing the second endpoint, if the second endpoint is an obstruction and the machining is carried out without a blade guard, and by asecond edge of the sheet guard used, if the second endpoint presents an obstacle and processing is carried out with a sheet guard.

[0020] Each step includes the process steps of positioning the saw head, pivoting the saw arm to the intermediate angle, and moving the saw head to clear the saw blade.

[0021] After the saw arm pivots to the j-th intermediate angle, where j = 1 to n-1, the second upper exit point coincides with the second endpoint if the pivot axis is a distance from the second endpoint of √[h(±β 2,j ) · (D - h(±β 2,j ))] + δ · sin(±β 2,j ), where h(±β 2,j ) = D / 2 - Δ - δ · cos(±β 2,j ) denotes the penetration depth of the saw blade into the workpiece at the j-th intermediate angle; the second edge of the saw blade coincides with the second endpoint if the pivot axis is a distance from the second endpoint of D / 2 + δ · sin(±β 2,j ); and the second edge of the blade guard coincides with the second endpoint if the pivot axis is a distance from the second endpoint of B b + δ · sin(±β 2,j ) exhibits.

[0022] After the pivoting movement, the saw head is moved in the j-th step, j = 1 to n-1, with the saw arm inclined at the j-th intermediate angle, by a distance of √[h 2 · (D - h 2 )] - δ · sin(±α 2 ), where h 2 = h(±α 2 , D) = D / 2 - Δ - δ · cos(±α2) denotes the penetration depth of the saw blade into the workpiece at the second principal cutting angle. The feed movement of the saw head frees the saw blade and reduces the portion of the saw blade in contact with the workpiece.

[0023] After the n-1th step, the saw head is positioned so that, after the pivoting movement of the saw arm into the new main cutting angle, the second boundary of the wall saw, facing the second endpoint, coincides with the second endpoint.

[0024] After the saw arm pivots into the second principal cutting angle, the second upper exit point coincides with the second endpoint if the pivot axis is a distance from the second endpoint of √[h 2 · (D - h 2 )] + δ · sin(±α 2 ), where h(±α 2 ) = D / 2 - Δ - δ · cos(±α2) denotes the penetration depth of the saw blade used into the workpiece at the second principal cutting angle, the second edge of the saw blade used coincides with the second endpoint if the pivot axis is a distance from the second endpoint of D / 2 + δ · sin(±α 2 ), and the second edge of the blade guard used coincides with the second endpoint if the pivot axis is a distance from the second endpoint of B b + δ · sin(±α 2 ).

[0025] The first and second main cuts are performed with one saw blade and one blade guard. Alternatively, the first main cut is performed by one saw blade with a first diameter and one blade guard with a first width, and the second main cut is performed by a second saw blade with a second diameter and one blade guard with a second width. Ausführungsbeispiele

[0026] Exemplary embodiments of the invention are described below with reference to the drawing. The drawing is not necessarily intended to represent the exemplary embodiments to scale; rather, where helpful for explanation, it is presented in schematic and / or slightly distorted form. With regard to additions to the teachings directly apparent from the drawing, reference is made to the relevant prior art. It should be noted that numerous modifications and changes concerning the form and detail of an embodiment can be made without deviating from the general idea of ​​the invention. The features of the invention disclosed in the description, the drawing, and the claims can be essential for the further development of the invention, both individually and in any combination.Furthermore, the invention encompasses all combinations of at least two of the features disclosed in the description, the drawing, and / or the claims. The general idea of ​​the invention is not limited to the exact shape or detail of the preferred embodiment shown and described below, nor is it limited to an object that would be restricted compared to the object claimed in the claims. For given design ranges, values ​​lying within the stated limits are also disclosed as limit values ​​and may be used and claimed as desired. For the sake of simplicity, identical or similar parts, or parts with identical or similar functions, are used below.

[0027] They show: FIG. 1 A wall sawing system with a guide rail and a wall saw; FIG. 2A, B The machining of a separation cut between a first and second free endpoint without obstruction; FIG. 3A, B The machining of a separation cut between a first and second obstruction with a saw blade not enclosed by a blade guard; FIG. 4A, B The machining of a separation cut between a first and second obstruction with a saw blade enclosed by a blade guard; FIG. 5A-K The wall sawing system of the FIG. 1 when creating a separation cut between a first endpoint that represents an obstacle and a second free endpoint without an obstacle

[0028] FIG. 1 shows a wall saw system 10 with a guide rail 11, a tool device arranged slidably on the guide rail 11 12 and a remote control 13.The tool is designed as a wall saw 12 and includes a machining unit. 14 and a motorized feed unit 15. The machining unit is designed as a saw head 14 and includes a machining tool designed as a saw blade. 16, that on a saw arm 17 is attached and driven by a drive motor 18 around an axis of rotation 19 is powered.

[0029] To protect the operator, the saw blade 16 is protected by a blade guard. 21 surrounded, which is attached to the saw arm 17 by means of a blade guard holder. The saw arm 17 is powered by a swivel motor. 22 around a pivot axis 23 Designed to swivel. The swivel angle a des The saw arm 17, with a saw blade diameter D of the saw blade 16, determines how deep the saw blade 16 cuts into a workpiece to be machined. 24 immerses. The drive motor 18 and the swivel motor 22 are housed in a single device casing. 25arranged. The motorized feed unit 15 includes a guide carriage. 26 and a feed motor 27, which in the exemplary embodiment is also arranged in the device housing 25. The saw head 14 is mounted on the guide carriage 26 and is moved along the guide rail 11 in a feed direction by the feed motor 27. 28 Designed to be movable. In the device housing 25, in addition to the motors 19, 22, 27, there is a control unit. 29 arranged for controlling the saw head 14 and the motorized feed unit 15.

[0030] A sensor device with several sensor elements is provided for monitoring the wall sawing system 10 and the machining process. A first sensor element 32 It functions as a swivel angle sensor and a second sensor element 33designed as a position sensor. The swivel angle sensor 32 measures the current swivel angle of the saw arm 17 and the position sensor 33 measures the current position of the saw head 14 on the guide rail 11. The measured values ​​are transmitted by the swivel angle sensor 32 and position sensor 33 to the control unit 29 and used to control the wall saw 12.

[0031] The remote control 13 includes a device housing 35, an input device 36, a display device 37 and a control unit 38, which is located inside the device housing 35. The control unit 38 converts the inputs from the input device 36 into control commands and data, which are transmitted to the wall saw 12 via a first communication link. The first communication link is a wired and wireless communication link. 41 or as a communication cable 42The wireless communication link is designed in the exemplary embodiment as a radio link 41, which connects a first radio unit. 43 on the remote control 13 and a second radio unit 44 at the tool device 12. Alternatively, the wireless communication connection 41 can be in the form of an infrared, Bluetooth, WLAN or Wi-Fi connection.

[0032] FIGN. 2A , B The guide rail 11 and the wall saw 12 of the wall saw system 10 are shown. FIG. 1 when creating a separation cut 51 in workpiece 24 of the workpiece thickness d.The parting line 51 has a final depth T and extends in the feed direction 28 between a first endpoint E 1 and a second endpoint E 2. The X-direction is defined as a direction parallel to the feed direction 28, with the positive X-direction pointing from the first endpoint E 1 to the second endpoint E 2, and the Y-direction is defined as a direction perpendicular to the X-direction extending into the depth of the workpiece 24.

[0033] The endpoint of a separation cut can be defined as a free endpoint without an obstacle or as an obstacle. Both endpoints can be defined as free endpoints without obstacles, both endpoints as obstacles, or one endpoint as a free endpoint and the other as an obstacle. At a free endpoint without an obstacle, an overlap is permitted. Due to the overlap, the cutting depth at the endpoint reaches the final depth T of the separation cut. In the exemplary embodiment of the FIGN. 2A , B form the endpoints E 1 , E 2 free endpoints without obstacles, where an overlap is not permitted at the free first endpoint E 1 and an overlap has occurred at the second endpoint E 2.

[0034] FIG. 2A shows the saw head 14 in a mounting position X 0 and the saw arm 17 in a basic position of 0°. The saw head 14 is positioned by the operator in the mounting position X0 on the guide rail 11 using the guide carriage 26. The mounting position X0 of the saw head 14 lies between the first and second endpoints E1, E2 and is determined by the position of the swivel axis 23 in the feed direction 28. The position of the swivel axis 23 is particularly suitable as a reference position XRef for monitoring the position of the saw head 14 and controlling the wall saw 12, since the X-position of the swivel axis 23 remains unchanged even during the swiveling movement of the saw arm 17. Alternatively, a different X-position on the saw head 14 can be defined as a reference position, in which case the distance in the X-direction to the swivel axis 23 must also be known.

[0035] In this embodiment, the X-positions of the first and second endpoints E1 and E2 are defined by entering partial lengths. The distance between the mounting position X0 and the first endpoint E1 defines a first partial length L1, and the distance between the mounting position X0 and the second endpoint E2 defines a second partial length L2. Alternatively, the X-positions of the endpoints E1 and E2 can be defined by entering a partial length (L1 or L2) and a total length L as the distance between the endpoints E1 and E2.

[0036] The separation cut 51 is created in several partial cuts until the desired final depth T is reached. The partial cuts between the first and second endpoints E1 and E2 are defined as main cuts, and the sequence of these main cuts is called the main cut sequence. Additional corner machining can be performed at the endpoints of the separation cut; this is referred to as obstacle machining if there is an obstacle, and as overcut machining if there is a free endpoint with an overlap.

[0037] The main cutting sequence can be set by the operator, or the control unit of the wall saw system can determine the main cutting sequence based on several boundary conditions. Typically, the first main cut, also known as the pre-cut, is performed with a reduced cutting depth and reduced drive motor power to prevent blade polishing. Subsequent main cuts are usually performed with the same cutting depth, but can also have different cutting depths. Boundary conditions typically set by an operator include the cutting depth of the pre-cut, the power of the pre-cut, and the maximum cutting depth of the subsequent main cuts. From these boundary conditions, the control unit can determine the main cutting sequence.

[0038] The main cuts of a separation cut are made with one saw blade diameter or with two or more saw blade diameters. If multiple saw blades are used, processing usually begins with the smallest saw blade diameter. In order to mount the saw blade 16 on the saw arm 17, the saw blade 16 must be positioned above the workpiece 24 in the basic position of the saw arm 17. Whether this boundary condition is met depends on two device-specific parameters of the wall saw system 10: firstly, on a vertical distance Δ between the pivot axis 23 of the saw arm 17 and a top surface. 53The device-specific parameters are twofold: the workpiece 24 and the saw arm length δ of the saw arm 17, which is defined as the distance between the axis of rotation 19 of the saw blade 16 and the pivot axis 23 of the saw arm 17. If the sum of these two device-specific parameters is greater than half the saw blade diameter D / 2, the saw blade 16 is positioned above the workpiece 24 in its home position. The saw arm length δ is a fixed device-specific parameter of the wall saw 12, whereas the vertical distance Δ between the pivot axis 23 and the surface 53 depends not only on the geometry of the wall saw 12 but also on the geometry of the guide rail 11 used.

[0039] The saw blade 16 is mounted on a flange on the saw arm 17 and, during sawing operation, is driven by the drive motor 18 around the axis of rotation 19. In the basic position of the saw arm 17, which is in FIG. 2A As shown, the swivel angle is 0° and the axis of rotation 19 of the saw blade 16 lies above the swivel axis 23 in the depth direction 52. The saw blade 16 is moved into the workpiece 24 from its initial position at 0° by a swivel movement of the saw arm 17 about the swivel axis 23. During the swivel movement of the saw arm 17, the saw blade 16 is driven about the axis of rotation 19 by the drive motor 18.

[0040] To protect the operator, the saw blade 16 should be surrounded by the blade guard 21 during operation. The wall saw 12 is operated with or without the blade guard 21. For example, the blade guard 21 may need to be removed to perform the cut-off in the area of ​​the endpoints E1 and E2. If different saw blade diameters are used for the cut-off, different blade guards with corresponding widths are generally used.

[0041] FIG. 2B shows the saw arm 17, which rotates in a negative direction 54 The saw arm 17 is inclined at a negative swivel angle -α. It is adjustable in the negative direction of rotation 54 between swivel angles from 0° to -180° and in a positive direction of rotation opposite to the negative direction of rotation 54. 55 Adjustable between swivel angles from 0° to +180°. The in FIG. 2B The illustrated arrangement of the saw arm 17 is referred to as a pulling arrangement when the saw head 14 is in a positive feed direction. 56 is moved. If the saw head 14 is moved in a negative feed direction opposite to the positive feed direction 56, 57 When moved, the arrangement of the saw arm 17 is referred to as a thrusting arrangement.

[0042] At a swivel angle of ±180°, the maximum penetration depth of the saw blade 16 into the workpiece 24 is achieved. The swivel movement of the saw arm 17 about the swivel axis 23 shifts the position of the axis of rotation 19 in the X and Y directions. The displacement of the axis of rotation 19 depends on the saw arm length δ and the swivel angle α of the saw arm 17. The displacement path δ x In the X direction, δ . sin(±α) and the displacement path is δ y In the Y direction, δ · cos(±α) is given.

[0043] The saw blade 16 creates a cutting wedge in the workpiece 24 in the form of a circular segment with a height h and a width b.The height h of the circular segment corresponds to the penetration depth of the saw blade 16 into the workpiece 24. The following relationship applies to the penetration depth h: D / 2 = h + Δ + δ · cos(α), where D is the saw blade diameter, h is the penetration depth of the saw blade 16, Δ is the perpendicular distance between the pivot axis 23 and the top surface 53 of the workpiece 24, δ is the saw arm length, and α is the first pivot angle. The following relationship applies to the width b: b 2< = D / 2 · 8h - 4h 2< = 4Dh - 4h 2< = 4h · (D - h), where h is the penetration depth of the saw blade 16 into the workpiece 24 and D is the saw blade diameter.

[0044] The control of the wall saw 12 during the cutting process depends on whether the endpoints are defined as obstacles, and, if an obstacle exists, on whether the cutting is performed with or without the blade guard 21. With a free endpoint and no obstacle, the wall saw 12 is controlled according to the inventive method via the upper exit points of the saw blade 16 on the top surface 53 of the workpiece 24. The upper exit points of the saw blade 16 can be calculated from the reference position XRef of the pivot axis 23 in the X-direction, the displacement δx of the rotary axis 19 in the X-direction, and the width b. An upper exit point facing the first endpoint E1 is designated as the first upper exit point. 58 designated and an upper exit point facing the second endpoint E 2 as the second upper exit point 59.For the first upper exit point 58, X(58) = X Ref + δ x - b / 2 and for the second upper exit point 59, X(59) = X Ref + δ x + b / 2 with b = √[h · (D - h)] and h = h(α, D).

[0045] If the endpoints E1 and E2 are defined as obstacles, it is not possible for the wall saw 12 to pass over them. In this case, the wall saw 12 is controlled according to the inventive method via the reference position XRef of the swivel axis 23 and the limit of the wall saw 12. A distinction is made between processing without a blade guard 21 and processing with a blade guard 21.

[0046] FIGN. 3A , B Figure 10 shows the wall saw system 10 creating a separation cut between the first endpoint E1 and the second endpoint E2, which are defined as obstacles, with the machining taking place without blade guard 21. During machining without blade guard 21, a first saw blade edge forms 61,which faces the first endpoint E 1, and a second saw blade edge 62, which faces the second endpoint E 2, the boundary of the wall saw 12.

[0047] The X positions of the first and second saw blade edge 61, 62 in the X direction can be calculated from the reference position X Ref of the swivel axis 23, the displacement path δ x of the rotary axis 19 and the saw blade diameter D. FIG. 3A Figure 12 shows the wall saw with the saw arm 17 inclined in the negative direction of rotation 54 at a negative swivel angle -α (0° to -180°). For the first saw blade edge 61, X(61) = X Ref + δ · sin(-α) - D / 2 applies, and for the second saw blade edge 62, X(62) = X Ref + δ · sin(-α) + D / 2 applies. FIG. 3B Figure 12 shows the wall saw with the saw arm 17 inclined in the positive direction of rotation 55 under a positive swivel angle α (0° to +180°). For the first saw blade edge 61, X(61) = X Ref + δ · sin(α) - D / 2 applies, and for the second saw blade edge 62, X(62) = X Ref + δ · sin(α) + D / 2 applies.

[0048] FIGN. 4A , B Figure 10 shows the wall saw system 10 creating a separation cut between the first endpoint E1 and the second endpoint E2, which are defined as obstacles, with the machining being carried out with blade guard 21. When machining without blade guard 21, a first blade guard edge forms 71, which faces the first endpoint E 1, and a second blade guard edge 72, which faces the second endpoint E 2, the boundary of the wall saw 12.

[0049] The X positions of the first and second blade guard edge 71, 72 in the X direction can be calculated from the reference position X Ref of the pivot axis 23, the displacement path δ x of the rotation axis 19 and the blade guard width B. FIG. 4A Figure 12 shows the wall saw 12 with the saw arm 17 inclined at a negative swivel angle -α (0° to -180°) and the mounted blade guard 21 of blade guard width B. In the case of an asymmetrical blade guard, the distances of the axis of rotation 19 to the blade guard edges 71, 72 are determined before the start of the controlled machining, whereby the distance to the first blade guard edge 71 is referred to as the first distance B a and the distance to the second blade guard edge 72 as the second distance B b.

[0050] For the first leaf protection edge 71, X(71) = X Ref + δ · sin(α) - B a and for the second leaf protection edge 72, X(72) = X Ref + δ · sin(α) + B b . FIG. 4B Figure 12 shows the wall saw with the saw arm 17 inclined at a positive swivel angle α (0° to +180°) and the mounted blade guard 21 of blade guard width B. For the first blade guard edge 71, X(71) = X Ref + δ · sin(α) - B a and for the second blade guard edge 72, X(72) = X Ref + δ · sin(α) + B b .

[0051] FIGN. 2A , B show a separation section between two endpoints E 1 , E 2 , which are defined as free endpoints without obstacles, and FIGN. 3A Figures B and 4A, B show a separation cut between two endpoints E1, E2, which are defined as obstacles. In practice, separation cuts are also possible where one endpoint is defined as an obstacle and the other endpoint is a free endpoint without an obstacle, whereby the wall saw is controlled at the free endpoint via the upper exit point of the saw blade and at the obstacle via the saw blade edge (machining without blade guard 21) or the blade guard edge (machining with blade guard 21).

[0052] The first upper exit point 58, the first saw blade edge 61 and the first blade guard edge 71 are collectively referred to as the "first limit" of the wall saw 12 and the second upper exit point 59, the second saw blade edge 62 and the second blade guard edge 72 are collectively referred to as the "second limit".

[0053] FIGN. 5A-K show the wall saw system 10 of the FIG. 1 with the guide rail 11 and the wall saw 12 when creating a separation cut of the final depth T in the workpiece 24 between a first endpoint E 1, which represents an obstacle, and a second endpoint E 2, which represents a free endpoint without an obstacle.

[0054] In the inventive method, the separation cut is made in a main cutting sequence of several main cuts until the desired final depth T is reached. The main cutting sequence comprises a first main cut with a first main cutting angle. α 1 of the saw arm 17, a first diameter D 1 and a first penetration depth h 1 of the saw blade used, a second main cut with a second main cutting angle α 2 of the saw arm 17, a second diameter D 2 and a second penetration depth h 2 of the saw blade used, as well as a third main cut with a third main cutting angle α 3 of the saw arm 17, a third diameter D 3 and a third penetration depth h 3 of the saw blade used.

[0055] The first, second, and third main cuts are performed by the saw blade 16 with saw blade diameter D and by the blade guard 21 with blade guard width B. The diameters D1, D2, D3 of the main cuts correspond to the saw blade diameter D, likewise the widths B1, B2, B3 of the main cuts correspond to the blade guard width B.

[0056] The main cuts of the separation cut are performed either with a saw arm 17 arranged in a pulling motion or the saw arm 17 is arranged alternately in a pulling and pushing motion. The pulling motion of the saw arm 17 enables stable guidance of the saw blade during processing and a narrow kerf. A separation cut in which the saw arm 17 is arranged alternately in a pulling and pushing motion has the advantage that the non-productive times required for positioning the saw head 14 and pivoting the saw arm 17 are reduced. In the exemplary embodiment, the saw head 14 is moved in the positive feed direction 56 with the saw arm 17 arranged in a pulling motion during the first and third main cuts; during the intermediate second main cut, the saw head 14 is moved in the negative feed direction 57 with the saw arm 17 arranged in a pushing motion. The saw arm 17 is arranged in the negative direction of rotation 54 in each of the three main cuts.

[0057] The processing of the separation cut begins at the first endpoint E1. After starting the method according to the invention, the saw head 14 is positioned in a starting position XStart, in which the pivot axis 23 has a distance of √[h1 · (D1 - h1)] - δ · sin(-α1) to the first endpoint E1, where h1 = h(-α1, D1) = D1 / 2 - Δ - δ · cos(-α1) denotes the penetration depth of the saw blade used into the workpiece 24 at the negative first main cutting angle -α1, with the first diameter D1. The first diameter D1 for the first main cut corresponds to the saw blade diameter D. In the starting position XStart, the saw arm 17 is pivoted from the basic position at 0° in the negative direction of rotation 54 to the negative first main cutting angle -α1. After the pivoting movement into the negative first principal cutting angle -α 1, the first blade guard edge 71 of the blade guard 21 borders the obstacle at the first endpoint E 1 .Subsequently, the saw head 14 is moved in the positive feed direction 56 with the saw arm 17 inclined under the negative first main cutting angle -α 1 , and the rotating saw blade 16 ( ). FIG. 5A During the feed movement, the position of the saw head 14 is regularly measured by the displacement sensor 33.

[0058] The feed movement of the saw head 14 is stopped when the pivot axis 23 has a distance to the second endpoint E 2 of √[h 1 · (D 1 - h 1 )] + δ · sin(-α 1 ) where h 1 = h(-α 1 , D 1 ) = D 1 / 2 - Δ - δ · cos(-α 1 ) denotes the penetration depth of the saw blade into the workpiece 24 at the negative first principal cutting angle -α 1 with the first diameter D 1, which corresponds to the saw blade diameter D. In this position, the second upper exit point 59 of the saw blade 16, facing the second endpoint E 2, coincides with the second endpoint E 2.

[0059] The pivoting movement from the negative first principal cutting angle -α1 to the negative second principal cutting angle -α2 occurs in two steps with an intermediate angle -β2,1. The first index of the intermediate angle indicates whether the pivoting movement occurs at the first or second endpoint E1, E2, where the index "1" represents the first endpoint E1 and the index "2" represents the second endpoint E2. The second index indicates the step and varies from 1 to n-1, n ≥ 2. After the pivoting movement of the saw arm 17 to the intermediate angle -β2,1, the saw blade 16 is freed from the cutting area.

[0060] The saw head 14 is positioned in the feed direction 28 such that the pivot axis 23 has a distance to the second endpoint E 2 of √[h(-β 2,1 ) · (D - h(-β 2,1 ))] + δ · sin(-β 11 ) where h(-β 2,1 ) = D / 2 - Δ - δ · cos(-β 2,1 ) denotes the penetration depth of the saw blade used into the workpiece 24 at the intermediate angle -β 2,1 ( FIG. 5B ). In this position, the saw arm 17 is pivoted from the negative first main cutting angle -α 1 to the intermediate angle -β 2.1 ( FIG. 5C ). When positioning in FIG. 5C The distance is adjusted so that the second upper exit point 59 of the saw blade 16, which faces the second endpoint E 2, coincides with the second endpoint E 2 at the intermediate angle -β 2.1 after the pivoting movement of the saw arm 17.

[0061] To free the saw blade 16, the saw head 14 is displaced in the negative feed direction 57 by a path length of √[h 2 · (D 2 - h 2 )], where h 2 = h(-α 2 , D 2 ) = D 2 / 2 - Δ - δ · cos(-α 2 ) denotes the penetration depth of the saw blade into the workpiece 24 at the negative second principal cutting angle -α 2 with the second diameter D 2 , which corresponds to the saw blade diameter D . FIG. 5D The saw head 14 is positioned in the feed direction 28 such that the pivot axis 23 has a distance of √[h 2 · (D 2 - h 2 )] + δ · sin(-α 2 ) to the second endpoint E 2. In this position, the saw arm 17 is pivoted from the intermediate angle -β 2.1 to the negative second principal cutting angle -α 2 ( FIG. 5E ). During positioning, the distance is adjusted so that the second upper exit point 59 of the saw blade 16, which faces the second endpoint E 2, coincides with the second endpoint E 2 after the pivoting movement of the saw arm 17 into the negative second principal cutting angle -α 2.

[0062] The saw head 14 is moved in the negative feed direction 57 towards the first endpoint E 1, with the position of the saw head 14 being measured regularly by the displacement sensor 33 during the feed movement. The feed movement of the saw head 14 is stopped when the pivot axis 23 is at a distance of B 2 / 2 - δ · sin(-α 2 ) from the first endpoint E 1 and the first blade guard edge 71 of the blade guard 21 is adjacent to the obstacle at the first endpoint E 1 ( FIG. 5F ).

[0063] The pivoting motion from the negative second principal section angle -α 2 to the negative third principal section angle -α 3 occurs in two steps with an intermediate angle -γ 2,1. The first index of the intermediate angle indicates whether the pivoting motion occurs at the first or second endpoint E 1, E 2, where the index "1" denotes the first endpoint E 1 and the index "2" the second endpoint E 2. The second index denotes the step and varies from 1 to n-1, n ≥ 2.

[0064] Before the saw arm 17 pivots to the intermediate angle -γ 2.1, the saw head 14 is positioned. Since the positioning at the obstacle is at E 1 and the intermediate angle -γ 2.1 is less than -90°, it is not possible to position the saw head 14 such that the second blade guard edge 72 is adjacent to the obstacle E 1 after the pivoting movement to the intermediate angle -γ 2.1. The saw head 14 is positioned using the critical angle α crit of -90°, and the saw arm 17 is then pivoted to the intermediate angle -β 21 ( FIG. 5G The critical angle of -90° must be taken into account, as the first endpoint E1 must not be exceeded during the pivoting movement. At the critical angle αcrit of -90°, the pivot axis 23 has a distance of B(2) / 2 - δ · sin(-90°) = B(2) / 2 + δ from the first endpoint E1.

[0065] After the pivoting movement of the saw arm 17 to the intermediate angle -γ 2,1, the saw blade 16 is freed from cutting. For this purpose, the saw head 14 with the saw arm 17 inclined at the intermediate angle -γ 2,1 and the rotating saw blade 16 is moved in the positive feed direction 56 by a distance of √[h 3 · (D 3 - h 3 )] ( FIG. 5H ), where h 3 = h(-α 3 , D 3 ) = D 3 / 2 - Δ - δ · cos(-α 3 ) = D 3 / 2 - Δ + δ denotes the penetration depth of the saw blade 16 into the workpiece 24 at the negative third principal cutting angle -α 3 with the third diameter D 3, which corresponds to the saw blade diameter D. After the cutting is complete, the saw head 14 is positioned using the critical angle α crit of -90° and the saw arm 17 is then pivoted from the intermediate angle -γ 2.1 to the negative third principal cutting angle -α 3 ( FIG. 5I ).

[0066] The third main cut represents the last main cut of the main cutting sequence, and prior to processing the last main cut, corner machining of the first endpoint E1 is performed, which is not part of the method according to the invention. For corner machining, the saw head 14 with the saw arm 17 inclined at -α3 is moved in the negative feed direction 57 until the first blade guard edge 71 of the blade guard 21 abuts the obstacle at the first endpoint E1 ( FIG. 5J The corner machining of the first endpoint E1 can be improved if the blade guard 21 is removed and the corner machining is carried out without the blade guard. Without the blade guard, the saw head 14 with the saw arm 17 inclined at -α3 is moved in the negative feed direction 57 until the first saw blade edge 61 of the saw blade 16 coincides with the first endpoint E1.

[0067] After the corner machining of the first endpoint E 1, the third main cut is carried out with the saw arm 17, inclined at the negative third main cutting angle -α 3, in the positive feed direction 56 ( FIG. 5K The feed movement of the saw head 14 is stopped when the pivot axis 23 has a distance of √[h 3 · (D 3 - h 3 )] + δ · sin(180°) = √[h 3 · (D 3 - h 3 )] to the second endpoint E 2, where h 3 = h(-α 3 , D 3 ) = D 3 / 2 - Δ - δ · cos(-180°) = D 3 / 2 - Δ + δ denotes the penetration depth of the saw blade into the workpiece 24 at the negative third main cutting angle -α 3 with the third diameter D 3, which corresponds to the saw blade diameter D. After the third main cut, corner machining of the second endpoint E 2 can be carried out, which is not part of the method according to the invention.

Claims

1. Method for controlling a wall saw system (10) comprising a guide rail (11) and a wall saw (12) having a saw head (14), a motorized feed unit (15) which displaces the saw head (14) parallel to a feed direction (28) along the guide rail (11), at least one saw blade (16) which is fastened to a saw arm (17) of the saw head (14) that is pivotable about a pivot axis (23) and is driven about a rotation axis (19), and at least one releasable blade guard (21) which surrounds the saw blade (16) when creating a separation cut (51) of the final depth (T) in a workpiece (24) of the workpiece thickness (d) between a first end point (E1) and a second end point (E2), the method comprising: ▪prior to starting a machining operation controlled by a control unit (29) of the wall saw system (10), at least the saw blade diameter (D) of the at least one saw blade (16), the positions of the first and second end points (E1, E2) in the feed direction (28), the final depth (T) of the separation cut (51) and a main cut sequence of m main cuts, where m ≥ 2, are determined, wherein the main cut sequence comprises at least one first main cut with a first main cutting angle (α1) of the saw arm (17) and a first diameter (D1) of the saw blade used, and a subsequent second main cut with a second main cutting angle (α2) of the saw arm (17) and a second diameter (D2) of the saw blade used, ▪ during the machining operation controlled by the control unit (29) - the first main cut is carried out with the saw arm (17) tilted at the positive or negative first main cutting angle (±α1), and - the second main cut is carried out with the saw arm (17) tilted at the positive or negative second main cutting angle (±α2), characterized in that the pivoting movement of the saw arm (17) from the first main cutting angle (±α1) to the second main cutting angle (±α2) is carried out in at least two steps at at least one intermediate angle (±β1, ±β2), wherein free cutting of the saw blade (16) takes place in each case between the pivoting movements of the saw arm (17) to the at least one intermediate angle (±β1, ±β2), wherein the saw head (14) during free cutting of the saw blade (16) is displaced to a position where, after the pivoting movement of the saw arm (17) to the following intermediate angle (±β1, ±β2) or to the second main cutting angle (±α2), a first delimitation (58, 61, 71) of the wall saw (12) coincides with the first end point (E1) if the pivoting movement takes place in the region of the first end point (E1), or a second delimitation (59, 62, 72) of the wall saw (12) coincides with the second end point (E2) if the pivoting movement takes place in the region of the second end point (E2), wherein the first delimitation (58, 61, 71) of the wall saw (12) is formed by a first upper exit point (58) of the saw blade used, facing the first end point (E1), on the upper side (53) of the workpiece (24), if the first end point (E1) represents a free end point without an obstacle, is formed by a first saw blade edge (61) of the saw blade used, facing the first end point (E1), if the first end point (E1) represents an obstacle and the machining operation takes place without a blade guard, and is formed by a first blade guard edge (71) of the blade guard used, facing the first end point (E1), if the first end point (E1) represents an obstacle and the machining operation takes place with the blade guard, and the second delimitation (59, 62, 72) of the wall saw (12) is formed by a second upper exit point (59) of the saw blade used, facing the second end point (E2), on the upper side (53) of the workpiece (24), if the second end point (E2) represents a free end point without an obstacle, is formed by a second saw blade edge (62) of the saw blade used, facing the second end point (E2), if the second end point (E2) represents an obstacle and the machining operation takes place without a blade guard, and is formed by a second blade guard edge (72) of the blade guard used, facing the second end point (E2), if the second end point (E2) represents an obstacle and the machining operation takes place with the blade guard.

2. Method according to Claim 1, characterized in that the pivoting movement of the saw arm (17) from the first main cutting angle (±α1) to the new main cutting angle (±α1, ±α2) is carried out in n steps, with n-1 intermediate angles (±β1,j, ±β2,j), j = 1 to n-1, wherein free cutting of the sawblade (16) takes places in each case between the pivoting movements of the saw arm (17) to the intermediate angles (±β1,j, ±β2,j).

3. Method according to one of Claims 1 to 2, characterized in that, prior to starting the machining operation controlled by the control unit (29), a saw arm length (δ) of the saw arm (17), which is defined as the spacing between the pivot axis (23) of the saw arm (17) and the rotation axis (19) of the saw blade (16), and a spacing (Δ) between the pivot axis (23) and an upper side (53) of the workpiece (24), are additionally established.

4. Method according to Claim 3, characterized in that, prior to starting the controlled machining operation, a first width (B1) for a blade guard used in the first main cut, and a second width (B2) for a blade guard used in the second main cut, are additionally established, wherein the first and second widths (B1, B2) consist in each case of a first spacing (B1a, B2a) of the rotation axis (19) from the first blade guard edge (71) of the blade guard, and a second spacing (B1b, B2b) of the rotation axis (19) from the second blade guard edge (72) of the blade guard.

5. Method according to one of Claims 3 to 4, characterized in that the pivoting movement from the first main cutting angle (±α1) to the new main cutting angle (±α1, ±α2) takes place at the first end point (E1), and the saw head (14) is positioned in the jth step, where j = 1 to n-1, in such a way that, after the pivoting movement of the saw arm (17) to the jth intermediate angle (±β1,j), a first delimitation (58, 61, 71) of the wall saw (12), facing the first end point (E1), coincides with the first end point (E1), wherein the first delimitation (58, 61, 71) of the wall saw (12) is formed by a first upper exit point (58) of the saw blade used, facing the first end point (E1), on the upper side (53) of the workpiece (24), if the first end point (E1) represents a free end point without an obstacle, is formed by a first saw blade edge (61) of the saw blade used, facing the first end point (E1), if the first end point (E1) represents an obstacle and the machining operation takes place without a blade guard, and is formed by a first blade guard edge (71) of the blade guard used, facing the first end point (E1), if the first end point (E1) represents an obstacle and the machining operation takes place with the blade guard.

6. Method according to Claim 5, characterized in that, after the pivoting movement of the saw arm (17) to the jth intermediate angle (±β1,j), where j = 1 to n-1, the first upper exit point (58) coincides with the first end point (E1) if the pivot axis (23) has a spacing from the first end point (E1) of √[h(±β1,j) · (D - h(±β1,j))] - δ · sin(±β1,j), where h(±β1,j) = D / 2 - Δ - δ · cos(±β1,j) denotes the penetration depth of the saw blade used into the workpiece (24) at the jth intermediate angle (±β1,j), the first saw blade edge (61) of the saw blade used coincides with the first end point (E1) if the pivot axis (23) has a spacing from the first end point (E1) of D / 2 - δ · sin(±β1,j), and the first blade guard edge (71) of the blade guard used coincides with the first end point (E1) if the pivot axis (23) has a spacing from the first end point (E1) of Ba - δ · sin(±β1,j).

7. Method according to Claim 6, characterized in that the saw head (14) in the jth step, where j = 1 to n-1, is displaced with the saw arm (17) tilted at the jth intermediate angle (±β1,j) by a distance of √[h2 · (D - h2)] - δ · sin(±α2), where h2 = h(±α2, D) = D / 2 - Δ - δ · cos(±α2) denotes the penetration depth of the saw blade used into the work piece (24) at the second main cutting angle (±α2).

8. Method according to Claim 7, characterized in that the saw head (14) is positioned after the n-1th step in such a way that, after the pivoting movement of the saw arm (17) to the new main cutting angle (±α1, ±α2), the first delimitation (58, 61, 71) of the wall saw (12), facing the first end point (E1), coincides with the first end point (E1).

9. Method according to Claim 8, characterized in that, after the pivoting movement of the saw arm (17) to the second main cutting angle (±α2), the first upper exit point (58) coincides with the first end point (E1) if the pivot axis (23) has a spacing from the first end point (E1) of √[h2 · (D - h2)] - δ · sin(±α2), where h(±α2) = D / 2 - Δ - δ · cos(±α2) denotes the penetration depth of the saw blade used into the workpiece (24) at the second main cutting angle (±α2) with the second diameter (D2), the first saw blade edge (61) of the saw blade used coincides with the first end point (E1) if the pivot axis (23) has a spacing from the first end point (E1) of D2 / 2 - δ · sin(±α2), and the first blade guard edge (71) of the blade guard used coincides with the first end point (E1) if the pivot axis (23) has a spacing from the first end point (E1) of B2a - δ · sin(±α2).

10. Method according to one of Claims 3 to 4, characterized in that the pivoting movement from the first main cutting angle (±α1) to the new main cutting angle (±α1, ±α2) takes place at the second end point (E2), and the saw head (14) is positioned in the jth intermediate cut, where j = 1 to n-1, in such a way that, after the pivoting movement of the saw arm (17) to the jth intermediate angle (±β2,j), a second delimitation (59, 62, 72) of the wall saw (12), facing the second end point (E2), coincides with the second end point (E2), wherein the second delimitation (59, 62, 72) of the wall saw (12) is formed by a second upper exit point (59) of the saw blade used, facing the second end point (E2), on the upper side (53) of the workpiece (24), if the second end point (E2) represents a free end point without an obstacle, is formed by a second saw blade edge (62) of the saw blade used, facing the second end point (E2), if the second end point (E2) represents an obstacle and the machining operation takes place without a blade guard, and is formed by a second blade guard edge (72) of the blade guard used, facing the second end point (E2), if the second end point (E2) represents an obstacle and the machining operation takes place with the blade guard.

11. Method according to Claim 10, characterized in that, after the pivoting movement of the saw arm (17) to the jth intermediate angle (±β2,j), where j = 1 to n-1, the second upper exit point (59) coincides with the second end point (E2) if the pivot axis (23) has a spacing from the second end point (E2) of √[h(±β2,j) · (D - h(±β2,j))] + δ · sin(±β2,j), where h(±β2,j) = D / 2 - Δ - δ · cos(±β2,j) denotes the penetration depth of the saw blade used into the workpiece (24) at the jth intermediate angle (±β2,j), the second saw blade edge (62) of the saw blade used coincides with the second end point (E2) if the pivot axis (23) has a spacing from the second end point (E2) of D / 2 + δ · sin(±β2,j), and the second blade guard edge (72) of the blade guard used coincides with the second end point (E2) if the pivot axis (23) has a spacing from the second end point (E2) of Bb + δ · sin(±β2,j).

12. Method according to Claim 11, characterized in that the saw head (14) in the jth step, where j = 1 to n-1, is displaced with the saw arm (17) tilted at the jth intermediate angle (±β2,j) by a distance of √[h2 · (D - h2)] - δ · sin(±α2), where h2 = h(±α2, D) = D / 2 - Δ - δ · cos(±α2) denotes the penetration depth of the saw blade used into the workpiece (24) at the second main cutting angle (±α2).

13. Method according to Claim 12, characterized in that the saw head (14) is positioned after the n-1th step in such a way that, after the pivoting movement of the saw arm (17) to the new main cutting angle (±α1, ±α2), the second delimitation (59, 62, 72) of the wall saw (12), facing the second end point (E2), coincides with the second end point (E2).

14. Method according to Claim 13, characterized in that, after the pivoting movement of the saw arm (17) to the second main cutting angle (±α2), the second upper exit point (59) coincides with the second end point (E2) if the pivot axis (23) has a spacing from the second end point (E2) of √[h2 · (D - h2)] + δ · sin(±α2), where h(±α2) = D / 2 - Δ - δ · cos(±α2) denotes the penetration depth of the saw blade used into the workpiece (24) at the second main cutting angle (±α2), the second saw blade edge (62) of the saw blade used coincides with the second end point (E2) if the pivot axis (23) has a spacing from the second end point (E2) of D / 2 + δ · sin(±α2), and the second blade guard edge (72) of the blade guard used coincides with the second end point (E2) if the pivot axis (23) has a spacing from the second end point (E2) of B2b + δ · sin(±α2).