SAWING MACHINE FOR MITER CUTS

Description

[0001] The invention relates to a sawing machine for miter cuts in metal workpieces according to the preamble of claim 1. Such a sawing machine has a saw head in which a saw blade rotates around at least two running wheels, at least one of which is motor-driven. The sawing machine is also provided with a lifting and lowering device for moving the saw head up and down in order to move the saw blade in a sawing feed movement in a sawing area, i.e. to effect a cutting movement through a workpiece to be sawn while the saw blade is running. The lifting and lowering device can be a device that moves the saw head up and down in a translational manner; however, within the scope of the present invention it can also be a device for pivoting the saw head about a substantially horizontal axis, resulting in a rotary up and down movement of the saw blade in the sawing area.A combined rotation and translation movement of the saw head is also possible.

[0002] A sawing machine of the present type further comprises a transport path for feeding a workpiece to be sawn to the sawing area, wherein the feed movement along this transport path defines a feed direction. The upper saw section is held by a frame, and this frame can be pivoted about a vertical axis to adjust a miter angle between the saw blade and the feed direction. Furthermore, a movable saw table arranged in the sawing area for supporting the workpiece to be sawn during the sawing process, as well as a vice for clamping the workpiece to be sawn during the sawing process, are provided. The saw table and vice are designed to be movable in and against the feed direction.The saw table and the vice can be locked in two positions, a first position for a miter angle equal to or greater than 0 degrees and a second position for a miter angle equal to or less than 0 degrees.

[0003] Band saws for miter cuts have long been known, for example from DE 40 05 143 C2, and are widely used. They allow, in particular, elongated metal workpieces, such as I-beams, pipes, and other profiles, to be cut to length at a miter angle of almost -90 degrees to almost +90 degrees. A "miter angle" of 0° corresponds to a straight cut in which the saw blade is oriented orthogonally to the feed direction.

[0004] Both positive and negative miter angles pose geometric challenges during sawing, as the workpiece must be clamped as close to the cutting plane as possible to ensure a precise cut. However, due to its elongated shape, the workpiece must be clamped between two clamping jaws whose clamping surfaces run parallel to the feed direction or the longitudinal axis of the workpiece. Miter saws, in particular, use a vice for this purpose. One jaw is stationary, while the other jaw can be moved relative to the stationary jaw to clamp or release the workpiece.

[0005] To adjust the miter angle, it is practical and common practice to pivot the upper part of the saw about a vertical axis, which runs directly next to the stationary clamping jaw or in a recess in the same, through which the saw blade can be guided. However, the position at which the saw blade exits the sawing area varies for different miter angles, so the movable clamping jaw of the vice gets in the way, especially when cutting negative miter angles.Known remedies include positioning the vice further away from the sawing plane in order to free up the pivoting range of the miter saw, which can lead to only moderately accurate cuts due to the elastic mobility of metallic workpieces, or removing only the movable clamping jaw from the pivoting range, which, however, results in an asymmetrical clamping force in the vice with correspondingly resulting torques and thrust forces, which in turn endangers an exact cut, or completely dispensing with the possibility of a negative miter angle.

[0006] In order to avoid asymmetrical clamping with a movable clamping jaw that is adjustable along the feed direction, the stationary clamping jaw can also be widened along the feed direction so that the travel path of the movable clamping jaw is covered and a symmetrical clamping force is guaranteed. However, it has been found that miter saws are also used to a considerable extent for straight cuts. However, if a vice with a particularly wide stationary clamping jaw is used to clamp the workpiece during a straight cut, leftover pieces of the material to be sawn that are less long than the width of the stationary clamping jaw can be sawn with more if the workpiece is fed automatically or automated, i.e. disadvantageously long leftover pieces inevitably remain.

[0007] To address this problem, EP 0 491 120 B1 proposes using a vice with a stationary clamping jaw and a movable clamping jaw adjustable along the feed direction, as well as a saw table adjustable along the feed direction. However, the problem of crooked, asymmetrical clamping in the vice when sawing, particularly shallow miter angles, remains unsolved.

[0008] Based on this prior art, the invention is based on the object of improving a sawing machine for miter cuts in metallic workpieces of the type mentioned at the outset in such a way that, on the one hand, straight cuts with only short residual pieces are possible, without, on the other hand, having to accept shear forces in the workpiece when clamping it in the vice or insufficient clamping forces that could impair the exact dimensional accuracy of the saw cut.

[0009] This object is achieved by a sawing machine having the features of claim 1. Preferred embodiments and further developments of the sawing machine according to the invention are set out in claims 2 to 14.

[0010] The sawing machine according to the invention, which comprises a saw head with at least two running wheels, at least one of which is motor-driven, and with a saw blade that rotates around the running wheels, and which further comprises a lifting and lowering device for (translational and / or rotational) extending and lowering the saw head in order to move the saw blade in a sawing feed motion in a sawing area, a transport path for feeding a workpiece to be sawn in a feed direction to the sawing area, a frame on which the saw head is held and which is pivotable about a vertical axis orthogonal to the feed direction in order to adjust a miter angle between the saw blade and the feed direction, a movable saw table arranged in the sawing area for placing the workpiece to be sawn during the sawing process, and a vice for clamping the workpiece to be sawn during the sawing process,The saw table and the vice are designed to be movable in and against the feed direction, and the saw table and the vice are lockable in two positions, a first position for a miter angle equal to or greater than 0 degrees and a second position for a miter angle equal to or less than 0 degrees. The vice is arranged in the first position, as seen in the feed direction, in front of a cutting plane, while in the second position, as seen in the feed direction, it is arranged behind the cutting plane. The saw table is preferably integrated into a movable vice, i.e., the movable vice also forms a saw table, or the saw table has clamping jaws to assume the function of a vice.

[0011] The mobility of the vice as a whole along the feed direction allows the location where the workpiece is clamped symmetrically to be selected depending on the set miter angle. This generally results in symmetrical or parallel clamping, yet even with straight cuts, it is possible to saw down to a conveniently short residual piece, since the stationary clamping jaw of the vice can advantageously be designed to be narrow. "Stationary" in the sense of the invention, in connection with the corresponding clamping jaw, means that it does not move perpendicular to the feed direction, thus remaining stationary with respect to the clamping movement of the vice. However, this does not mean that it is fixed along the feed direction. According to the invention, the vice as a whole, including its stationary clamping jaw, is movable in and against the feed direction.

[0012] The saw table and the vice, or the integrated movable vice, can be locked in two positions. The first position is intended for a positive miter angle of 0 to almost +90 degrees, and the second position is intended for a negative miter angle of almost -90 to 0 degrees. This allows the simplest way to clamp a workpiece as close as possible to the cutting plane during miter sawing: For positive miter angles, the vice is positioned in front of the cutting plane, viewed in the feed direction. For negative miter angles, it is positioned behind the cutting plane in the feed direction and locked there. This then allows the entire pivoting range of the saw blade from 0° to +90° or from 0° to -90°.

[0013] The saw table is preferably integrated into a movable vice in such a way that the saw table is designed with a horizontal support surface and a plate firmly connected to it as a stationary clamping jaw. The vertical plate interacts with a clamping jaw that is movable relative to this vertical plate to form the vice and to secure a workpiece during the sawing process. Preferably, the movable clamping jaw is attached directly to the saw table and, together with it, forms a carriage as a movable vice that can be moved on slide rails in and against the feed direction.

[0014] Further advantages arise if, according to a preferred development of the present invention, the saw table has a vertical guide rail on each side of its vertical plate as a guide rod for guiding the workpiece to be sawn during the feed movement. This vertical guide rail can serve not only to guide the workpiece during the feed movement, but also as lateral support for the workpiece during sawing, especially since the saw blade is preferably guided between the vertical plate and the respective guide rail. Since the saw table, which is integrated in a movable vice, is preferably arranged in front of the cutting plane for positive miter angles and behind the cutting plane for negative miter angles, the vertical guide rail acts as a counterbearing or lateral support for the part of the workpiece to be cut off.

[0015] The first and second positions of the movable vice, in which it can be locked for positive or negative miter angles, are expediently selected in such a way that the saw blade moves in the sawing area directly next to the vertical plate, preferably between the vertical plate and a vertical guide rail arranged next to it, and the vertical axis around which the upper part of the saw can be pivoted also runs directly next to the vertical plate and is therefore expediently located in the cutting plane or the plane of the saw blade.

[0016] Since the sawing machine according to the invention is a sawing machine for sawing metal workpieces, it is unavoidable that the saw blade cuts into the saw table at the end of the sawing process when the saw blade hits the saw table. In addition to the fact that during subsequent sawing processes, a fed workpiece can become stuck on saw marks in the saw table during feeding, and in addition to the risk of increased burr formation on the workpiece due to a saw table surface that has become uneven due to saw marks, the need to replace a saw table that has been sawn into several times from time to time is a not insignificant cost factor.

[0017] To mitigate these additional costs, it is advantageous within the scope of the present invention to mount a turntable on the saw table or integrated into the saw table surface in an area around the vertical axis around which the saw head can be pivoted. This turntable is preferably designed to pivot with the saw head. Such a turntable prevents a large-area depression in the saw table surface from forming relatively quickly in the area of ​​the vertical axis, where saw marks on the saw table surface are particularly close together, which could seriously disrupt the feeding of workpieces.

[0018] As an alternative to the turntables, it is preferred within the scope of the present invention if the horizontal support surface of the saw table is designed to be substantially the same width in the feed direction as the vertical plate of the saw table, with the saw blade running alongside the horizontal support surface in a vertical projection, i.e., a projection viewed from above onto the saw table. This means that when the workpiece has been completely sawn, the saw blade does not hit the surface of the saw table and therefore cannot cause any saw marks there.

[0019] The horizontal support surface of the saw table can also be narrower than the vertical plate of the saw table, again viewed in the feed direction, to allow the attachment of an additional strip as a wear part to the edge of the horizontal support surface. This strip lies in the cutting plane, i.e., the saw blade hits this strip at the end of the saw cut. While this will cause wear, it is easy and inexpensive to replace, while ensuring that the workpiece remains in the cutting plane during sawing. This can be advantageous with regard to the prevention of unwanted burr formation.

[0020] Within the scope of the present invention, it is particularly preferred if at least one pivotable cutting bar is mounted next to the saw table - preferably on both sides of the saw table - whereby this cutting bar can be pivoted together with the upper part of the saw about essentially the same vertical axis. The cutting bar has a horizontal surface which essentially forms a plane with the horizontal support surface of the saw table, so that as a result the workpiece is always supported on both sides of the cutting plane: on the one hand by the saw table and on the other hand by the pivotable cutting bar. This plane, which is formed by the horizontal support surface of the saw table and the horizontal surface of the cutting bar, is interrupted by a gap in which - again seen in vertical projection - the saw blade runs.At the end of the sawing process, the saw blade is positioned in this gap, so there's no risk of the surface of the cutting strip becoming sawn into. This gap naturally widens the further the upper part of the saw, and thus the cutting strip, are pivoted—that is, the greater the set miter angle.

[0021] It can also be advantageous to attach an easily and inexpensively replaceable wear bar to such a cutting bar. This wear bar is located in the cutting plane to support the workpiece at this point during the sawing process. For this purpose, the cutting bar can be conveniently provided with a recess on the side facing the horizontal support surface of the saw table, i.e., the side facing the gap, for attaching a wear bar.

[0022] Preferably, a mechanical coupling is provided between the cutting bar and the frame supporting the upper part of the saw, which can be selectively activated and deactivated. A locking driver on the frame, which automatically moves the cutting bar when the miter angle is adjusted, is preferred.

[0023] To ensure a defined position of the cutting bar even when it is not coupled to the frame, it is advantageous if the pivoting cutting bar and / or the saw table have a locking device to secure the cutting bar to the saw table as needed. This is particularly advantageous when the saw table is moved in or against the feed direction, as the locking mechanism prevents uncontrolled pivoting of the cutting bar.

[0024] If two pivoting cutting guides are provided, one of the two pivoting cutting guides covers the range of positive miter angles, while the other of the two cutting guides covers the range of negative miter angles, effectively supporting the workpiece directly next to the cutting plane, even if the cutting plane is relatively far away from the saw table at larger miter angles. This better ensures the dimensional accuracy of the saw cut.

[0025] With band saws, it is common and usually necessary to guide the saw blade with blade guides on both sides of the sawing area. These typically consist of a clamp-like holder with sliding pieces for sliding contact with the saw blade. The blade guides prevent the saw blade from tilting around its longitudinal axis during sawing due to sawing resistance. Depending on the orientation of the wheels in the upper section of the saw, it may also be necessary for the blade guides to rotate the saw blade by up to 90° around its longitudinal axis, otherwise the saw teeth will not be oriented downwards or toward the workpiece.

[0026] Due to the functions performed by the blade guides, it is essential for a precise saw cut that the blade guides are positioned as close as possible to the workpiece to be sawn. It is therefore common practice to mount at least one of the blade guides on an adjustable arm, allowing this adjustable blade guide to be moved closer to or further away from the other blade guide depending on the width of the workpiece to be sawn.

[0027] With miter saws, such adjustability of the blade guide spacing is useful, if not necessary, even when the width of the workpieces to be sawn does not vary at all. When sawing at a miter angle, the geometric relationships lengthen the cutting channel in the workpiece, and thus also the required free length of the saw blade in the sawing area. The flatter the miter angle, the further the blade guides must be spaced apart.

[0028] With conventional miter saws, it's still common practice for the adjustable blade guide to be adjusted accordingly when adjusting the miter angle, either manually or with motor assistance. However, it has been shown that in daily use, the blade guide is often forgotten, and many users therefore set the adjustable blade guide as far away from the other blade guide as possible to avoid problems when sawing even if the blade guide adjustment is forgotten. However, this results in poorer cut precision.

[0029] Within the scope of the present invention, it is therefore preferred not only to provide two band guides for guiding the saw band on both sides of the sawing area, at least one of which is adjustable, but also to design the adjustable band guide with a motor in order to increase or decrease a cutting width between the two band guides, and also to provide a control for the motorized adjustment in order to adjust the cutting width depending on the respectively set miter angle.

[0030] For this purpose, a measuring device for measuring the width of the workpiece to be sawn is preferably installed in the area of ​​the transport path and / or the saw table. The control system adjusts the cutting width depending on the measured width of the workpiece to be sawn and the respectively set miter angle, taking into account the resulting geometric relationships, so that the smallest possible distance between the two band guides is set. In the simplest case, the measuring device can be a measuring scale for reading the width of the workpiece to be sawn, whereby an operator must read this width and enter it into the control system. Given the harsh environmental conditions within a sawing machine, this can be the most advantageous design for a measuring device.Alternatively, however, it may also be appropriate to use a measuring device that is connected to the control system and automatically inputs the measured values ​​into the control system.

[0031] Finally, within the scope of the invention, it is preferred if feed clamping jaws are provided on the transport path, which can be moved back and forth along the feed direction. Such feed clamping jaws have long been known in band saw machines; they ensure precise dimensional accuracy during the feed, even with particularly heavy workpieces, which ultimately determines the dimensional accuracy of the workpiece part to be cut off by sawing.

[0032] In connection with such feed clamping jaws, the inventive concept of a movable vice in a miter saw is particularly advantageous because, as already mentioned, this allows only a very small overhang of the vice or saw table above the sawing plane on the feed side, if any overhang exists at all, and thus the feed clamping jaws can be moved completely or almost completely to the sawing plane. This ensures the great advantage that only very short offcuts remain during sawing.

[0033] An embodiment of a sawing machine according to the invention is described and explained in more detail below with reference to the accompanying drawings. They show: Figure 1 is a schematic perspective view of a sawing machine designed according to the invention; Figure 2 is a schematic perspective view of the movable vice from the sawing machine according to Figure 1; Figure 3the sawing machine from Figure 1 from the back, with the upper part of the saw omitted for illustration purposes; Figure 4 a representation as Figure 3 , but with saw top.

[0034] The Figure 1 The exemplary embodiment of a sawing machine designed according to the invention for miter cuts in metallic workpieces, shown in a schematic perspective view, comprises, in addition to the housing and attachments, which have been omitted here for better clarity of the invention, a stationary base 1 with a support 2 for a saw table 3, which is movable along two rails 4 on the support 2. On a feed side of the sawing machine, which is at the rear in the present illustration, a feed roller conveyor 6 is attached to the support 2 of the base 1 as a transport path 5.

[0035] On the base 1, a frame 7 is pivotably mounted in the form of a frame, whereby a lower beam 8 of the frame 7 is seated with a (not visible) pin in a radial bearing 9 and can be pivoted about a vertical axis 10.

[0036] The frame 7 carries a saw head 11 with two wheels 12 around which a saw blade 13 rotates endlessly. Figure 1 The impeller 12 shown on the left is driven by an electric motor 14 in order to cause a circular movement of the saw band 13.

[0037] The saw upper part 11 also has a lifting and lowering device 15 (hidden here, see Figure 4 ), with which it can be raised and lowered on two threaded spindles 16, which are firmly connected to the frame 7. This embodiment thus involves a purely translational raising and lowering movement for the saw feed.

[0038] Since the wheels 12 of the saw upper part 11 in the present embodiment have approximately horizontally oriented axes of rotation, the saw blade 13 accordingly rotates in a horizontal orientation around the wheels 12. Therefore, it is necessary to provide a blade guide 18 in front of and behind a sawing area 17, which is designed like a pair of tongs and rotates the saw blade 13 from a horizontal to a vertical orientation by means of hard metal sliding pieces, so that in the sawing area 17 the saw teeth are oriented downwards, towards the saw table 3. The blade guides 18 also ensure that the saw blade 13 cannot tilt about its longitudinal axis in the sawing area 17 during the sawing process. Figure 1 The band guide 18 shown on the right is adjustable along the saw band 13, which is shown below using Figure 4 is described in more detail.

[0039] Finally, a rotating chip removal brush 19 ensures the removal of sawdust that adheres to the saw band 13, particularly in the area of ​​the saw teeth.

[0040] The pivoting movement of the frame 7, and with it the saw head 11, around the vertical axis 10 is achieved by means of a motorized miter angle adjustment. For this purpose, the base 1 is provided with a gear section 20 fixed thereto, into which a gear 21 engages. The gear 21 is mounted on a shaft of a gear drive 22 attached to the beam 8 of the frame 7.

[0041] For the sake of clarity, the saw table 3 is shown in connection with Figure 2 described in more detail. Figure 1It only remains to be mentioned that the saw table 3 is provided with pivotable cutting strips 23, each of which has a driver 24 on its end face, which can engage with the beam 8 of the frame 7 and is carried along by it when the frame 7 is pivoted, its pivot axis essentially coinciding with the vertical axis 10.

[0042] Figure 2 shows in a schematic perspective representation how Figure 1, but with the omission of several elements, parts essential to the invention of the present exemplary embodiment. This is the saw table 3, which is adjustable on two rails 4 along a feed direction 25. This saw table 3 has a horizontal support surface 26 and a vertical plate 27 firmly connected to it. A clamping jaw 28, which is movable relative to the vertical plate 27, is fastened to the saw table 3 and, together with the latter, in particular with the vertical plate 27, forms a vice that is movable along the feed direction 25. A stop 29 limits its movement along the rails 4 and secures the illustrated position of the saw table 3 against any forces that may act on the saw table 3 from a workpiece transported in the feed direction 25 on the transport path 5.

[0043] The vertical axis 10, around which the frame 7 and with it the saw head 11 can be pivoted to set a miter angle, runs, as in Figure 2 shown, directly next to the vertical plate 27, and the saw band 13 also runs through the vertical axis 10, so that a cutting plane, within which the saw band 13 runs during the sawing process, is located directly next to the vertical plate 27, specifically in the feed direction 25, here in front of the vertical plate 27. The horizontal support surface 26 of the saw table 3 is of the same width in the feed direction 25 as the vertical plate 27, so that, as can be seen from Figure 2 As is illustrated, the saw blade 13, in the case of a straight cut in which the saw blade 13 runs perpendicular to the feed direction 25, ends the saw cut next to the horizontal support surface 26 of the saw table 3. There is therefore no risk of sawing into the horizontal support surface 26.

[0044] In the feed direction 25, vertical guide rails 30 are provided in front of and behind the vertical plate 27, which serve to guide a workpiece. In order to be able to set even flat miter angles, the vertical plate 27 must be provided with acute-angled edges, and it must be prevented that a workpiece runs into such an edge. This is a primary function of the guide rails 30, in addition to providing lateral support for the workpiece and a part cut off from it.

[0045] As already shown by Figure 1 As mentioned above, the saw table 3 is finally provided on both sides with a pivotable cutting bar 23, which can be pivoted via drivers 24 together with the frame 7 and thus together with the saw head 11 and the saw band 13. In the present Figure 2a negative miter angle of approximately -45° is set, which is why the cutting bar 23 arranged in front of the vice 27, 28 (seen in the feed direction 25) has been pivoted by precisely this 45°. The saw blade 13 therefore runs, starting from the vertical axis 10, along the pivoted cutting bar 23, but in vertical projection continues between the cutting bar 23 and the horizontal support surface 26, so that at the end of the sawing process the saw blade 13 neither saws into the support surface 26 nor into a horizontal surface 31 of the cutting bar 23. At the same time, the horizontal surface 31 of the cutting bar 23 and the horizontal support surface 26 of the saw table 3 or the movable vice 27, 28 form a common support surface for a workpiece to be sawn, which is therefore supported on both sides of the cutting plane.

[0046] The procedure is similar for positive mitre angles, whereby the cutting bar 23 arranged in front of the movable vice 27, 28 in the feed direction 25 is pivoted back and rests on the saw table 3, while the cutting bar 23 arranged after the movable vice 27, 28 is pivoted in accordance with the positive mitre angle to be set.

[0047] For this purpose, the position of the saw table 3 or the movable vice 27, 28 is then adjusted by moving along the rails 4 against the feed direction 25 into a second position, in which the vertical axis 10 then runs on the other side of the vertical plate 27, viewed in the feed direction 25 behind the vertical plate 27 and between this and the guide rail 30 following thereafter.

[0048] Since the saw table 3 has then been adjusted so that the sawing plane runs on its other side, there is no longer any fear that the saw blade will cut into any surface of the saw table 3; rather, the saw blade runs, in vertical projection, within the gap between the horizontal support surface 26 and the cutting bar 23, which is arranged behind the movable vice 27, 28 in the feed direction 25.

[0049] The Figure 2 The first position shown is therefore intended for negative miter angles, while a second position (not shown) is selected for positive miter angles. In both cases, the workpiece is held as close as possible to the cutting plane by the movable vice 27, 28 and clamped symmetrically, without generating unwanted transverse or shear forces through the clamping.

[0050] Figure 3 shows the saw table 3 in the Figure 2illustrated installation position in the sawing machine according to the invention, wherein Figure 1 Again, some parts have been omitted, especially the upper part of the saw 11, to ensure better clarity. In all drawings, identical parts are provided with the same reference numerals, so that in addition to the descriptions of the Figures 1 and 2 reference is made.

[0051] In Figure 3 Shown again is the base 1 with the support 2, on which the saw table 3 is held, movable on rails 4 along the feed direction 25. The transport path 5 is realized with a feed roller conveyor 6 to feed workpieces to the saw table 3. The support for such a workpiece is formed by the horizontal support surface 26 and the two horizontal surfaces 31 of the cutting strips 23. In Figure 3 is the saw table 3, as in Figure 2, locked in a position intended for negative miter angles, with the cutting bar 23, located at the front in the feed direction 25, pivoted by an angle of approximately -45°. This illustration shows a pivot bearing 32 around which the cutting bar 23 has been pivoted and which is also arranged in the vertical axis 10. The cutting bar 23 is thus pivoted around the same vertical axis 10 and at the same miter angle as the frame 7.

[0052] In the Figure 3However, in the selected illustration of the sawing machine, no miter angle or a miter angle of 0° is set; i.e., the frame 7 is arranged for a straight cut. The pivoted cutting bar 23 is pivoted only for illustrative purposes. This illustration illustrates that any feed clamping jaws (not shown here) can be moved almost to the sawing plane marked by the vertical axis 10 if a straight cut is to be made. This is ensured by the particularly narrow design of the guide bar 30 arranged in front of the vertical axis 10 or the cutting plane in the feed direction 25.

[0053] The cutting bar 23, arranged behind the movable vice 27, 28 in the feed direction 25, can be pivoted accordingly using a pivot bearing (not visible here). When the saw table 3 or the adjustable vice 27, 28 is moved counter to the feed direction 25 into its position for positive miter angles, the space between the guide bar 30, located at the rear in the feed direction, and the vertical plate 27 of the saw table 3, lies on the vertical axis 10, so that the pivot bearing of the rear cutting bar 23 is then arranged correspondingly in the vertical axis 10, and the rear cutting bar 23 can be pivoted with and parallel to the frame 7.

[0054] The Figure 3 The half of the gear section 20 shown is accordingly intended for setting a negative miter angle.

[0055] Figure 4shows the embodiment shown in the preceding figures for a sawing machine designed according to the invention in comparison to Figure 1 in a rear view. In this view, the wheels 12 are not visible, but their drive by means of an electric motor 14 and a gear 33 is. Also clearly visible in this view are the lifting and lowering device 15 and the threaded spindles 16, by means of which the saw head 11 and, with it, the saw blade 13 can be raised and lowered for a saw feed movement. The two spindles 16 ensure that the saw blade 13 is moved in a translational motion, parallel to the horizontal support surface 26 of the saw table 3, for the saw feed and retraction movement.

[0056] Also clearly visible in this illustration is that the band guide 18, located here on the left, is motor-adjustable along the saw blade 13 in order to adjust the sawing width or the width of the sawing area 17. For this purpose, this movable band guide 18 is mounted on a guide arm 34, which in turn is held by an adjusting spindle 35 and can be moved along it by means of an adjusting motor 36.A control (not shown) of the adjustment motor 36 ensures that the guide arm 34 and with it the adjustable belt guide 18 are adjusted as a function of the workpiece width (for example as a function of the distance between the vertical plate 27 and the movable clamping jaw 28 in the clamped state, for which purpose an incremental encoder can be provided on the movable clamping jaw 28 in order to automatically measure the distance and report it to the control) and the set miter angle by selecting the optimum distance between the two belt guides 18, taking into account the required cutting width.

[0057] With the Figures 1 to 4The sawing machine shown, which is designed according to the invention and represents an exemplary embodiment of the present invention, achieves the advantages of the invention, i.e. the sawing machine is suitable for both miter cuts and straight cuts, with the latter in particular being able to saw down to an advantageously very short residual piece length. Automatic operation of the sawing machine, i.e. automatic feeding via feed clamping jaws that can be moved back and forth, is possible. At the same time, the workpiece is clamped as close to the cutting plane as possible, with this clamping always taking place parallel or symmetrically and as a result no asymmetrical stresses in the material or corresponding shear forces arise. This also makes it possible to saw workpiece packages in one sawing process.

[0058] There's no cutting into the saw table, although the workpieces are advantageously supported by a support surface both in front of and behind the cutting plane. Finally, the blade guides are optimally adjusted depending on the set miter angle to ensure high cutting precision. List of reference symbols

[0059] 1Base 2Carrier 3Saw table 4Rails 5Transport rail 6Feed roller conveyor 7Frame 8Beam 9Radial bearing 10Vertical axis 11Saw top 12Wheel 13Saw blade 14Electric motor 15Lifting and lowering device 16Threaded spindle 17Sawing area 18Blade guide 19Chip removal brush 20Gear section 21Gear 22Gear drive 23Cutting bar 24Driver 25Feed direction 26Horizontal support surface 27Vertical plate 28Movable clamping jaw 29Stop 30Guide bar 31Horizontal surface (of 23) 32Pivot bearing 33Gearbox 34Guide arm 35Adjusting spindle 36Adjusting motor

Claims

1. Sawing machine for bevel cuts in metal workpieces, comprising an upper saw portion (11) with at least two running wheels (12), at least one of which is motor driven, and with a saw band (13) which rotates about the running wheels (12), further comprising a lifting and lowering device (15) for the upward and downward movement of the upper saw portion (11) in order to move the saw band (13) with a sawing advance movement in a sawing region (17), a transport path (5) for supplying a workpiece to be sawn in a supply direction (25) to the sawing region (17), a frame (7) on which the upper saw portion (11) is retained and which can be pivoted about a vertical axis (10) in order to adjust a bevel angle between the saw band (13) and the supply direction (25), a movable sawing table (3) which is arranged in the sawing region (17) for positioning the workpiece to be sawn, and a clamping vice (27, 28) for clamping the workpiece to be sawn during the sawing operation, wherein the sawing table (3) and the clamping vice (27, 28) are designed to be movable in and counter to the supply direction (25), and wherein the sawing table (3) and the clamping vice (27, 28) are securable in two positions, of which the first position is provided for a bevel angle greater than or equal to 0 degrees and the second position is provided for a bevel angle less than or equal to 0 degrees, characterized in that the clamping vice (27, 28) is arranged in the first position, as seen in the supply direction, in front of a cutting plane, whereas it is arranged in the second position, as seen in the supply direction, behind the cutting plane.

2. Sawing machine according to claim 1, wherein the sawing table (3) is integrated into a movable clamping vice (27, 28).

3. Sawing machine according to any one of claims 1 or 2, wherein the sawing table (3) has a horizontal support face (26) and a vertical plate (27) which is securely connected thereto and which cooperates with a clamping jaw (28) that is movable relative thereto in order to form the clamping vice (27, 28) and to fix a workpiece during the sawing operation.

4. Sawing machine according to claim 3, wherein the movable clamping jaw (28) is fastened to the sawing table (3) and forms therewith a movable clamping vice that is movable in and against the supply direction (25), preferably on rails (4).

5. Sawing machine according to any one of claims 3 or 4, wherein the sawing table (3) has, on both sides of the vertical plate, a vertical guiding bar (30) for guiding the workpiece to be sawn during the supply movement.

6. Sawing machine according to any one of claims 3 to 5, wherein the first and second positions are selected such that the saw band (3) moves in the sawing region directly beside the vertical plate (27) and the vertical axis (10) about which the upper saw portion (11) is pivotable also runs directly beside the vertical plate (27).

7. Sawing machine according to claim 6, wherein the sawing table (3) is provided in a region around the vertical axis (10) with rotary plates which are preferably designed to pivot together with the upper saw portion (11).

8. Sawing machine according to claim 6, wherein the horizontal support face (26) of the sawing table (3) is designed substantially as wide as or narrower than the vertical plate (27) in the supply direction (25), and wherein the saw band (3) runs in a vertical projection beside the horizontal support face (26).

9. Sawing machine according to claim 8, wherein, beside the sawing table (3), at least one pivotable cutting bar (23) is fitted which is pivotable together with the upper saw portion (11) about substantially the same vertical axis (10), and which has a horizontal surface (31) that substantially forms a plane with the horizontal support face (26) of the sawing table (3), which plane is interrupted by a gap in which the saw band (13) runs in vertical projection.

10. Sawing machine according to claim 9, wherein the cutting bar (23) is provided on its side oriented toward the horizontal support face (26) of the sawing table (3) with a shoulder for fitting a wear bar.

11. Sawing machine according to any one of claims 9 or 10, wherein the cutting bar (23) is connectable via a mechanical coupling, in particular a latching catch (24), to the frame (7) which carries the upper saw portion (11).

12. Sawing machine according to any one of claims 9 to 11, wherein the pivotable cutting bar (23) and / or the sawing table (3) have a securing device to secure the cutting bar (23) to the sawing table (3) as needed.

13. Sawing machine according to any one of claims 1 to 12, wherein the upper saw portion (11) further has two band guides (18) for guiding the saw band (13) on both sides of the sawing region (17), of which at least one is motor adjustable to increase or decrease a cutting width between the two band guides (18), and wherein a controller is provided for the motor adjustment of the adjustable band guide (18) to adjust the cutting width depending on the respectively set bevel angle.

14. Sawing machine according to claim 13, wherein in the region of the transport path (5) and / or the sawing table (3) a measuring device is fitted for measuring the width of the workpiece to be sawn, wherein the controller adjusts the cutting width depending on the measured width of the workpiece to be sawn and the respectively set bevel angle, and wherein the measuring device is in particular a measuring scale for reading the width of the workpiece to be sawn or preferably a measuring instrument that is connected to the controller and automatically inputs the measured values into the controller.