WOODWORKING MACHINE HAVING A DISENGAGEABLE PARALLEL STOP

Abstract

A woodworking machine, such as a sliding table saw includes a workpiecee table with a substantially horizontal workpiece support surface and a sawing slot. A saw unit with a circular saw blade is arranged so as to be able to protrude from the sawing slot and defines a substantially horizontal saw line. A workpiece stop is movably arranged above the workpiece support surface with a vertically standing workpiece stop surface, such that a plate-shaped workpiece resting on the workpiece support surface in a support region arranged horizontally in front of the workpiece stop can be placed with a side edge against the workpiece stop surface. A, sensor device is configured to generate a sensor signal, wherein the sensor signal characterizes an end of cut.

Claims

1-14. (canceled)

15. A woodworking machine comprising: a workpiece table with a horizontal workpiece support surface and a saw slot; a saw unit with a circular saw blade arranged to protrude from the saw slot and defining a horizontal saw line; a workpiece stop movably arranged above the workpiece support surface, the workpiece stop having a vertically standing workpiece stop surface disposed such that a plate-shaped workpiece resting on the workpiece support surface in a support area arranged horizontally between the saw blade and the workpiece stop can be placed with a side edge against the workpiece stop surface; and a sensor device; wherein the sensor device is configured to generate a sensor signal, wherein the sensor signal characterizes a start of cut or an end of cut; wherein an actuator is mechanically coupled to the workpiece stop or the saw unit; wherein a control unit is coupled to the actuator and the sensor device in terms of signaling, and wherein the control unit is configured to receive the sensor signal and to generate an actuator control signal in dependence on the sensor signal and transmit it to the actuator; and wherein the actuator is adapted to move the workpiece stop or the saw unit upon receipt of the actuator control signal such that a clamping distance leading to clamping of the workpiece between the circular saw blade and the workpiece stop surface is eliminated.

16. The woodworking machine according to claim 15, wherein: the workpiece stop is configured as a parallel stop, wherein the workpiece stop surface of the parallel stop is aligned parallel to the circular saw blade, and wherein the actuator is configured as a parallel stop actuator and is configured to move or to pivot the parallel stop back and forth to suspend the clamping distance; the workpiece stop is configured as a stop flap on an angular stop, and wherein the actuator is configured as a flap actuator and configured to move or to pivot the stop flap back and forth to suspend the clamping distance; or the saw unit is configured for pivoting the circular saw blade about a horizontal axis aligned transversely to the saw line to suspend the clamping distance, and wherein the actuator is configured as a saw blade actuator and is configured to displace or pivot the saw blade to suspend the clamping distance.

17. The woodworking machine according to claim 16, wherein the parallel stop is configured as a right-hand stop.

18. The woodworking machine according to claim 15, wherein the sensor device is disposed to detect a start edge or an end edge of a plate-shaped workpiece at at least one predetermined position on the workpiece support surface and generates the sensor signal when the start edge or the end edge is detected at the at least one predetermined position, wherein the predetermined position is determined by one or more of: a saw blade diameter of the circular saw blade; a saw blade height of the circular saw blade above the workpiece support surface; a workpiece thickness; or a saw blade pivot angle.

19. The woodworking machine according to claim 15, wherein the workpiece table comprises the sensor device and the sensor device comprises a first workpiece sensor and a second workpiece sensor, wherein the first workpiece sensor and the second workpiece sensor are spaced apart from one another in the direction of the saw line.

20. The woodworking machine according to claim 19, wherein the sensor device comprises a third workpiece sensor, wherein the third workpiece sensor is arranged offset in a horizontal direction and transversely to the saw line with respect to the first workpiece sensor and the second workpiece sensor, and wherein the third workpiece sensor is arranged between the first workpiece sensor and the second workpiece sensor in the direction of the saw line.

21. The woodworking machine according to claim 20, wherein at least two of the workpiece sensors of the sensor device are arranged on a sensor carrier, wherein the workpiece table comprises the sensor carrier.

22. The woodworking machine according to claim 21, wherein the sensor carrier is recessed into the workpiece table.

23. The woodworking machine according claim 19, wherein at least one workpiece sensor of the sensor device is arranged in the direction of the saw line in front of the saw slot.

24. The woodworking machine according to claim 15, wherein the control unit is adapted to receive a guide signal characterizing a guiding cutting at the parallel stop or at the angle stop; and wherein the control unit is further adapted to generate an actuator control signal upon receipt of a guide signal characterizing a leading cutting at the angle stop, wherein the actuator moves the parallel stop away from the saw line upon receipt of the actuator control signal.

25. The woodworking machine according to claim 15, wherein the workpiece table further comprises a stop actuation sensor, wherein: the stop actuation sensor is arranged in the direction of the saw line behind the saw slot and adapted to generate a first stop actuation signal, wherein the first stop actuation signal characterizes a non-presence of a workpiece in the area adjacent to the stop actuation sensor, and wherein the control unit, upon receipt of the first stop actuation signal, generates a second actuator control signal that controls the actuator such that the workpiece stop is moved to move the workpiece stop surface toward the saw line; and the stop actuation sensor is adapted to generate a second stop actuation signal, wherein the second stop actuation signal characterizes a presence of a workpiece in the area adjacent to the stop actuation sensor, and wherein the control unit, upon receipt of said second stop actuation signal, generates a third actuator control signal that prevents a movement of the workpiece stop surface toward the saw line.

26. The woodworking machine according to claim 15, wherein the control unit is adapted to generate a lowering signal when the sensor signal is received, wherein the lowering signal controls an actuator configured as a lowering actuator such that the circular saw blade is moved below the workpiece support surface.

27. The woodworking machine according to claim 15, wherein the control unit is adapted to generate a saw blade switch-off signal when the sensor signal is received, and wherein the saw blade switch-off signal controls a drive motor of the saw blade such that the drive of the circular saw blade is switched off.

28. The woodworking machine according to claim 25, wherein: at least one workpiece sensor or the stop actuation sensor is selected from the group consisting of: optical sensors; capacitive sensors; inductive sensors; pneumatic sensors; linear longitudinal sensors; and ultrasonic sensors.

29. The woodworking machine according to claim 15, wherein the woodworking machine has a first workpiece stop and a second workpiece stop, wherein the first workpiece stop is configured as a parallel stop, and the second workpiece stop is configured as a stop flap on an angle stop.

30. The woodworking machine according to claim 29, wherein the parallel stop comprises a right-hand stop.

31. A method for controlling a woodworking machine comprising the steps of: cutting a plate-shaped workpiece with a circular saw blade that defines a saw line, wherein one side of the workpiece is arranged at a workpiece stop surface of a movable workpiece stop, by means of a cut having a start of cut and an end of cut; detecting of the end of cut or the start of cut; and moving the workpiece stop such that, depending on the detection of the end of cut, a clamping distance leading to clamping of the workpiece between the circular saw blade and the workpiece stop surface is suspended, by: moving the workpiece stop surface horizontally; pivoting the saw blade about a horizontal axis; moving the saw blade vertically; or stopping the saw blade.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Preferred embodiments are explained by way of example with reference to the accompanying figures. It is shown by:

[0063] FIG. 1 is a perspective view of a woodworking machine;

[0064] FIGS. 2a and 2b are schematic, perspective views of the woodworking machine of FIG. 1;

[0065] FIG. 3 is a detailed perspective view of an embodiment of the woodworking machine shown in FIG. 1;

[0066] FIG. 4 is a detailed perspective view of a further embodiment of the woodworking machine shown in FIG. 1; and

[0067] FIG. 5 is a schematic method of controlling a woodworking machine.

DETAILED DESCRIPTION FO THE EMBODIMENTS

[0068] In the figures, identical or essentially functionally identical or similar elements are designated with the same reference signs.

[0069] FIG. 1 shows a perspective view of a woodworking machine. The woodworking machine 1 extends from a front end 2 to a rear end 4. The woodworking machine 1 has a frame 6. A workpiece table 10 is arranged at the frame 6, wherein the workpiece table 10 is adapted to support a workpiece, in particular a plate-shaped workpiece.

[0070] A trimming carriage 12 is also arranged at the frame 6 in a linearly movable manner. The trimming carriage 12 is arranged to be movable in particular in a saw line direction S. A cross table 14 is also arranged at the edging carriage 12, projecting in the clamping direction K. The cross table 14 comprises a stop flap 16, wherein the stop flap 16 is formed as a workpiece stop surface on the side facing the circular saw blade 28, which will be explained in more detail below.

[0071] The cross table 14 can also be arranged to pivot about the vertical direction V and is preferably configured as a parallelogram cross table.

[0072] In the direction of the saw line S to the right of the trimming carriage 12, the circular saw blade 28 is arranged, as can be seen in particular from FIGS. 2a, 2b, 3, and 4. The circular saw blade 28 is a rotationally symmetrical disc with saw teeth arranged at the circumference generally at regular intervals. The circular saw blade 28 projects from a saw slot 30 with a circumferential portion.

[0073] The circular saw blade 28 may be arranged on a saw unit not shown here. The saw unit is generally arranged below the workpiece support surface of the workpiece table 10. The saw unit comprises, for example, drive elements that rotationally drive the circular saw blade 28. Furthermore, the saw unit can pivot the circular saw blade 28 about an axis aligned parallel to the direction of the saw line S. Furthermore, the saw unit can also move the circular saw blade 28 back and forth in the vertical direction V, for example, in order to set the circular saw blade 28 to a defined height above the workpiece table 10 and also in order to move the circular saw blade 28 below the workpiece support surface of the workpiece table 10. A splitting wedge 32 is arranged behind the circular saw blade 28 in saw line direction S. A scoring saw blade 38 is arranged in front of the circular saw blade 28 in saw line direction S.

[0074] The woodworking machine 1 further comprises a control unit 22 arranged on a cantilevered arm of a table column. Furthermore, the woodworking machine 1 comprises a protective hood 20 that is also arranged on a cantilevered arm of the table column. The protective hood position can be monitored during a sawing process.

[0075] A plate-shaped workpiece can be cut with the woodworking machine 1. For this purpose, the trimming carriage 12 is moved in the direction of the saw line S towards the front end 2. In this position, a workpiece is arranged on the trimming carriage 12, the workpiece table 10, and, if the workpiece is of a corresponding size, also on the cross table 14 in such a way that a first section of the workpiece is located to the right of the saw line 36 formed by the circular saw blade 28 in the saw line direction S and a second section of the workpiece is located to the left of the saw line 36. Cutting of the workpiece is effected by movement of the trimming carriage 12 and the workpiece disposed thereon in the direction of the saw line S from the front end 2 toward the rear end 4. Through this, a relative movement between the workpiece and the circular saw blade 28 is effected.

[0076] In order to be able to saw dimensionally accurate workpieces, workpieces are usually placed against workpiece stops. For this purpose, the woodworking machine 1 shown has a stop rail 15, the workpiece stop surface 18 of the stop flap 16, and a parallel stop 24. The parallel stop 24 is guided by a guide element 25. The parallel stop 24 has a second workpiece stop surface 26. When the workpiece is cut through, two workpiece parts are produced that are no longer connected to each other. One workpiece part is arranged to the left of the saw line 36 and one workpiece part is arranged to the right of the saw line 36. To detect against which workpiece stop a workpiece is placed, the workpiece stops may include sensors. For example, a sensor can be arranged on the parallel stop 24 and/or on the stop flap 16.

[0077] In particular, it is clear from FIG. 2b that a workpiece portion may be disposed between the circular saw blade 28 and the second workpiece stop surface 26 of the parallel stop 24. It frequently happens that the workpiece part is clamped between the circular saw blade 28 and the second workpiece stop surface 26. In the clamping direction K, a woodworking machine 1, therefore, has a clamping distance 40 between the circular saw blade 28 and the parallel stop 26 when the parallel stop 26 is set. In particular, the clamping distance is aligned parallel to an orthogonal direction of the circular saw blade 28 and/or the second workpiece stop surface 26.

[0078] A workpiece clamped between the parallel stop 24 and the circular saw blade 28 may perform uncontrolled movements due to the rotation of the circular saw blade 28, since usually this separated part of the workpiece is not guided by an operator. For example, the part of the workpiece clamped between the circular saw blade 28 and the parallel stop 24 may be hurled in the direction of the front end 2. In addition, the latter may also perform movements in the vertical direction V and thus damage parts of the woodworking machine 1. In particular, however, there is a safety risk for operators of the woodworking machine 1 and for other persons in the vicinity of the woodworking machine 1.

[0079] Accordingly, the invention proposes to cancel the clamping situation at the moment of workpiece separation. This is achieved by suspending the clamping distance 40. In a first variant, this can be done by disengaging the parallel stop 24 in the disengaging direction 42. For this purpose, the parallel stop 24 has a guide element 25 that is guided in a guide of the stop 11 of the woodworking machine 1.

[0080] Furthermore, the clamping distance 40 can be suspended by pivoting the circular saw blade 28 about an axis aligned parallel to the saw line direction S, in a counterclockwise direction as seen from the front end 2. In addition, clamping of a workpiece on the left side can be effected by moving the stop flap 16 to the left. The parallel stop 24 is preferably coupled to a parallel stop actuator. The parallel stop actuator is arranged to move the parallel stop 24 in the clamping direction K. In particular, the parallel stop actuator is configured to move the parallel stop 24 in the disengaging direction 42. In addition, the stop flap 16 can also be connected to an actuator.

[0081] In order to determine the time at which a workpiece is cut through and thus also to determine the time for suspending the clamping distance 40, the woodworking machine 1 comprises a sensor device 100. The sensor device 100 is adapted to detect the start of cut and/or the end of cut. As soon as the sensor device 100 detects the start of cut and/or the end of cut, the sensor device 100 generates a sensor signal. The actuators mentioned in the foregoing, in particular, the parallel stop actuator, are coupled to the sensor device 100 in terms of signaling and are configured in such a way that, when the sensor signal is generated, a disengagement of the parallel stop 24 in the disengaging direction 42, a movement of the stop flap 16 and/or a pivoting of the circular saw blade 28 takes place.

[0082] The actuators known in the foregoing are preferably configured, after the parallel stop 24 has been disengaged in the disengaging direction 42 or after the stop flap 16 has been moved or after the circular saw blade has been pivoted or moved, to move or pivot these back to the starting position.

[0083] For example, the sensor device 100 detects the end of cut by detecting a rear edge of a workpiece. A rear edge of a workpiece is possible by means of the first row of workpiece sensors 102 and the second row of workpiece sensors 104 shown in FIG. 3. The workpiece sensors of the first row 102 and the second row 104 are arranged offset from each other in the direction of the saw line S. Furthermore, the first row 102 and the second row 104 are slightly spaced apart from each other in the clamping direction K. The sensor device 100 is spaced from the circular saw blade 28 by a sensor distance 108. In particular, it can be seen from FIG. 3 that an end of cut at a rear edge of a workpiece depends, in particular, on how far the circular saw blade 28 protrudes from the saw slot 30 in the vertical direction V. Furthermore, the position of the rear edge depends on the diameter of the circular saw blade 28. Other parameters to be taken into account for determining the end of cut can be a pivot angle of the circular saw blade 28 and a workpiece thickness.

[0084] The workpiece sensors of the sensor device 100 are designed, in particular, in such a way that they can detect the presence and/or absence of a workpiece. Optical, capacitive, and inductive sensors are particularly suitable for this purpose. In addition, pneumatic sensors as well as ultrasonic sensors and linear link sensors are also conceivable. In addition, an end of cut can also be detected by means of a camera. The sensor device can also be designed as a sensor array 100a, as shown in FIG. 4. A sensor array 100a comprises a plurality of sensors as one component. The sensor array 100a may be recessed into the workpiece table 10, and preferably the upper surface of the sensor array 100a may be aligned with the upper support surface of the workpiece table 10. Advantageously, it is configured as an interchangeable component.

[0085] The workpiece table 10 further comprises a stop actuation sensor 106. The stop actuation sensor 106 is arranged behind the circular saw blade 28 in the saw line direction S. The stop actuation sensor 106 is preferably arranged in the saw line direction S in alignment with the sensor device 100 and/or the first row 102 of workpiece sensors and/or the second row 104 of workpiece sensors. The stop actuation sensor 106 is adapted to detect a workpiece located in the region adjacent to the stop actuation sensor 106. As a result, the stop actuation sensor 106 can detect a presence and a non-presence of a workpiece adjacent to the stop actuation sensor 106. It is preferred that movement of the parallel stop 24 in a direction opposite to the disengaging direction 42 is inhibited when a workpiece is present on the workpiece table 10, and, in particular, in an area adjacent to the stop actuation sensor 106, as this presents a risk of collision of the workpiece with the circular saw blade 28.

[0086] The method shown in FIG. 5 comprises the step of cutting 200 a plate-shaped workpiece with a circular saw blade 28 defining a saw line 36, wherein one side of the workpiece is arranged at a workpiece stop surface 18, 26 of a movable workpiece stop, for example, a parallel stop 26 or a stop flap 18. Further, the method comprises the step of determining 202 an end of cut.

[0087] Further, the method comprises the step of moving 204 the workpiece stop 16, 24 such that in response to detecting an end of cut, the workpiece stop surface is moved away from the saw line 36.