Automatic screwdriving device and robot tool

Abstract

Automatic screwing device for the automated screwing of belt-guided screws (2) into workpieces, comprising: - a motor (3) with a motor shaft (4) to which a bit holder (5) is coupled, which carries a screw bit (6) that can be rotated by the motor (3) and is adjustable in its axial position, for automatically driving a screw (2) attached to the screw bit (6) into a workpiece, - a loading device (7) for feeding a belt (8) on which several screws (2) are pre-assembled at uniform screw intervals (A) from one another and in parallel orientations to one another, wherein the loading device (7) has a guide (9) on which the screws (2) are guided such that a loading screw (2a) foremost in the feed direction (V) can be fed into a position directly below the screw bit (6) by advancing the belt (8), and wherein the loading device (7) has a conveying device (10) which is designed to transport the belt (8) within the guide (9), and wherein - the conveying device (10) has at least one conveying pawl (11.1, 11.2) which is mounted to be driven to move back and forth in repeating cycles between a feed position and a retraction position along the feed direction (V), wherein the conveying pawl (11.1, 11.2) has a contact surface (12.1, 12.2) which is designed to bear against a transport screw (2b) of the belt (8) following the loading screw (2a) in order to convey the belt (8) by a screw distance (A) within one cycle in the feed direction (V), and the conveying device (10) has at least one stop pawl (13.1, 13.2) which is designed to hold the loading screw (2a) in its position directly below the screw bit (6) when the belt (8) transported by the conveying pawl (11.1, 11.2) moves the loading screw (2a) against the stop pawl (13.1, 13.2) presses, characterized in that the guide (9) is interchangeably attached to a base body (18) of the loading device (7).

Description

[0001] The invention relates to an automatic screwing device for the automated screwing of belt-guided screws into workpieces, comprising a motor with a motor shaft to which a bit holder is coupled. The bit holder carries a screw bit that is rotatably driven by the motor and adjustable in its axial position for automatically driving a screw attached to the screw bit into a workpiece. The invention also relates to a robot tool with several such automatic screwing devices.

[0002] DE 10 2011 002 010 A1 describes an automatic screw tightening device which transfers a screw from a screw feeding mechanism to a screw tightening mechanism by means of a screw transfer mechanism using air suction of the screw tightening mechanism, which engages the screw with a screw insert portion of a front end of the screw tightening mechanism and which tightens or loosens the screw against a predetermined screwing range.tightens, wherein an output unit is provided at a front end of a transmission hose of the screw feeding mechanism, a rotary arm is installed on the output unit, and a feed head unit is installed at a front end of the rotary arm to be brought into close contact with a screw bit portion of a front end of the screw tightening mechanism, the feed head unit is movable between a close contact position, wherein the feed head unit is in close contact with the screw bit portion of the front end of the screw tightening mechanism, and a discharge position, wherein the feed head unit is away from the screw bit unit, and in the close contact position, the screw bit portion of the front end of the screw tightening mechanism is brought into contact with the screw and sucks a head portion of the screw to be engaged with the screw.

[0003] EP 0 003 004 B1 describes a device for screwing in screws with washers. The screws are fed from a laterally arranged magazine via a carrier strip and brought into a feed chute by means of grippers. A magazine for the washers is also provided, with these washers being fed by a slide that can be moved or pivoted transversely to the screwing axis. The control of the slides feeding the washers and the grippers inserting the screws takes place as a function of the feed movement of the screwing device. Various control rods and pins are provided for this purpose, which come into contact with grooves in rotating bodies or on pivoting levers. The special course of the grooves and the design of the levers achieve a rotating or sliding movement of the required parts.

[0004] The object of the invention is to create an automatic screwdriving device that can drive screws into workpieces with high screwing performance and high process reliability. A further object is to create a robot tool that can automatically handle multiple automatic screwdriving devices together.

[0005] The task is solved by an automatic screwing device for the automated screwing of belt-guided screws into workpieces, comprising: - a motor with a motor shaft to which a bit holder is coupled, which carries a screw bit which is rotatably driven by the motor and which is adjustable in its axial position, for automatically driving a screw attached to the screw bit into a workpiece, - a loading device for feeding a belt on which a plurality of screws are pre-assembled at equal screw spacings from one another and in parallel alignments to one another, wherein the loading device has a guide on which the screws are guided in such a way that a respective foremost loading screw in the feed direction can be fed into a position immediately below the screw bit by advancing the belt, and wherein the loading device has a conveyor device which is designed to transport the belt within the guide, and wherein - the conveyor device has at least one conveyor pawl which is mounted in a driven manner so as to be movable back and forth in repeating cycles between an advance position and a retraction position along the advance direction, wherein the conveyor pawl has a contact surface which is designed to bear against a transport screw of the belt following the loading screw in order to convey the belt by a screw spacing within one cycle in the advance direction, and the conveyor device has at least one stop pawl which is designed to hold the loading screw in its position immediately below the screw bit when the belt transported by the conveyor pawl presses the loading screw against the stop pawl, wherein the guide is fastened replaceably to a base body of the loading device.

[0006] The motor can be an electric motor, for example. In addition to the motor shaft and the bit holder, the motor or a drive unit comprising the motor can have other components. The drive unit can thus be designed in the manner of a conventional drywall screwdriver. If necessary, commercially available drywall screwdrivers can be used with an automatic screwdriving device according to the invention. For example, it can also be provided that the commercially available drywall screwdriver is modified so that it can be operated in fully automatic mode, for example, automatically controlled by a separate drive control.

[0007] For example, a handle, a manual on / off switch, and / or, if applicable, a manual rotation direction switch can be removed from a commercially available drywall screwdriver. The electric motor of the thus modified drywall screwdriver can then be attached to a height-adjustable carriage of the screwing device according to the invention. Such height adjustability of the carriage relates to the longitudinal extent of the screw bit, i.e., the axis of rotation about which the motor rotates the screw bit. The height adjustability of the carriage thus relates to a vertical alignment of the motor or motor shaft, with the screw bit pointing downwards in this case.

[0008] The carriage can be mounted on a base frame of the screwdriving device so that it can be automatically adjusted by a linear drive. The linear drive can, for example, comprise a pneumatic cylinder which is supplied with compressed air, and electrically controllable valves can be provided in order to be able to automatically control the pneumatic cylinder via a control device so that the screw bit driven by the motor can be automatically adjusted in the axial direction, i.e. advanced and retracted again. The screw bit can be interchangeably accommodated in the bit holder. Depending on the screw size and screw head profile, different types of screw bits can be optionally inserted into the bit holder and used in conjunction with a belt which carries screws that match the screw bit.

[0009] The motor drives the bit holder and consequently the screw bit, allowing a screw to be rotated automatically when the screw bit engages the screw head profile. The linear drive advances the motor, or rather the bit holder and the screw bit, so that a screw attached to the screw bit is driven into the workpiece, while the motor and the screw bit rotate the screw.

[0010] In the screwing device according to the invention, the screws, which can be connected by a belt, are to be fed automatically so that the screwing device can automatically drive screws into one or more workpieces in cycles. A loading device and a conveyor system are provided for automatic feeding.

[0011] The loading device holds and guides the screws directly, for example, by guiding the screws along the surfaces below the screw heads, or the loading device holds and guides the belt that carries the screws. The screws are driven directly from the belt into the workpiece by the motor-driven screw bit. Therefore, the screws are not fed to the screw bit one at a time. Rather, the belt is guided toward the screw bit by the loading device so that the foremost screw on the belt, the so-called loading screw, is positioned directly beneath the screw bit.

[0012] For this purpose, the loading device has a guide along which the belt is guided. The guide can, for example, have two opposing rails that guide or hold the belt from two opposite sides. At least one of the two rails can have a rail shoulder on which the belt can rest and is guided along a linear feed path so that the screws, which are pre-assembled on the belt at equal screw spacing from one another and aligned parallel to one another, can be fed in alignment with the axial extension of the screw bit.In a feed position, the foremost loading screw is then positioned directly below the screw bit, with the screw head directly next to the screw bit, so that the profile of the screw bit can fit positively into the matching screw head profile when the screw bit is moved axially downwards towards the screw.

[0013] The guides can be detachably attached to a base body of the screwing device. For example, the guides can be screwed to the base body. Due to a detachable attachment, particularly by means of screws, the guides can be easily replaced. This may be necessary, in particular, if the automatic screwing device is to be converted to a different type of screw. Depending on the type of screw head, the screw head profile, and / or the diameter and / or, if applicable, the length of the screws, it may be necessary to replace the guides.

[0014] According to the invention, the screws, along with the belt carrying the screws, are moved in the feed direction by the conveyor device in that the conveyor device has at least one conveyor pawl, the contact surface of which directly contacts a screw held on the belt and pushes it forward in the feed direction. As the screw is pushed, the entire belt and the other screws held on it are also moved. The conveyor device, i.e., the at least one conveyor pawl, does not engage the belt itself, but rather only a screw of the belt.

[0015] The conveyor device or the at least one conveyor pawl works in cycles, i.e. in each cycle the belt is conveyed forwards by one screw pitch in the feed direction. After a first loading screw has been automatically screwed into the workpiece using the screw bit, the previous support point of the loading screw on the belt is emptied and the next screw is conveyed forwards by the screw pitch in the feed direction so that a new loading screw is again positioned directly below the screw bit. So that the conveyor device or the at least one conveyor pawl can convey the belt forwards by a further screw pitch in the feed direction, the at least one conveyor pawl is moved back again by one screw pitch against the feed direction.The at least one conveyor pawl jumps over a transport screw following the loading screw on the belt in order to get behind this transport screw, so that the at least one conveyor pawl can engage behind this loading screw with its contact surface in order to feed this transport screw forward by one screw spacing in the feed direction in a new cycle step. A screw preceding the transport screw in the feed direction forms the loading screw. The at least one conveyor pawl therefore does not engage with its contact surface on the screw that is moved directly under the screw bit and thus forms the loading screw. Rather, the at least one conveyor pawl engages with its contact surface on a screw following on the belt, which then forms a transport screw different from the loading screw.

[0016] The at least one stop pawl specifies the position in which the loading screw is located centrally under the screw bit, so that only by a linear movement of the screw bit in the axial direction towards the loading screw, the profile of the screw bit can engage in a form-fitting manner with the screw head profile of the loading screw.

[0017] The at least one stop pawl can be adjustably mounted on the loading device. The adjustable mounting allows the stop pawl to be adapted to different types of screws and / or different sizes of screws. The at least one stop pawl can, in particular, be pivotably mounted.

[0018] In a special embodiment, the conveyor device can have a first conveyor pawl which is designed and mounted in such a way that a first contact surface of the first conveyor pawl directly engages a shaft section of the adjacent transport screw which is exposed above the belt during the feed movement, and the conveyor device can have a second conveyor pawl which is designed and mounted in such a way that a second contact surface of the second conveyor pawl directly engages a shaft section of the adjacent transport screw which is exposed below the belt during the feed movement.

[0019] Because the conveyor device has the first conveyor pawl and the second conveyor pawl at a distance therefrom, a transport screw can be conveyed perpendicular to its longitudinal extent. Due to the two spaced-apart points of engagement of the first conveyor pawl and the second conveyor pawl on the transport screw, it is ensured that the screw maintains its orientation with its longitudinal extent perpendicular to the feed direction and, in particular, does not tip over or become canted. The distance between the first conveyor pawl and the second conveyor pawl can be adapted to the total length of the screws to be used on the belt. The first conveyor pawl can contact the screw, for example, below the screw head, and the second conveyor pawl can contact the screw, for example from the free end of the screw tip. The belt can connect the multiple screws in a central section of the respective screw shanks.The belt runs in the intermediate area between the first conveyor pawl and the second conveyor pawl, guided directly on the at least one guide of the loading device or indirectly via the screws, which can be guided by means of their screw heads on the at least one guide of the loading device.

[0020] The at least one conveyor pawl can be pre-tensioned into its conveyor positions by means of a spring, such that when the conveyor pawl moves back from the feed position to the retracted position opposite to the feed direction, the conveyor pawl slides over a shaft section of a follower screw following the transport screw, in that the conveyor pawl can deflect transversely to the feed direction in order to be able to bypass the follower screw, so that the at least one contact surface can come into contact with the follower screw from behind in order to form the loading screw from the transport screw in the next cycle.

[0021] In an analogous manner, in the case of two conveyor pawls, it can be provided that the first conveyor pawl and the second conveyor pawl can be mounted in a pre-tensioned manner into their conveyor positions by means of at least one spring in each case, such that when the first conveyor pawl and the second conveyor pawl move back from their advance positions into their retracted positions counter to the advance direction, the first conveyor pawl and the second conveyor pawl slide over a shaft section of a follower screw following the conveyor screw, in that the first conveyor pawl and the second conveyor pawl can deflect transversely to the advance direction in order to be able to bypass the conveyor screw, so that the first contact surface and the second contact surface can come into contact with the follower screw in order to form the loading screw in the next cycle.

[0022] The at least one conveyor pawl, in particular the first conveyor pawl and the second conveyor pawl, can be pivotably mounted about a pivot axis on a base body of the loading device. The respective spring can have a spring coil section that can be positioned coaxially to the pivot axis, wherein a first spring leg adjoining the spring coil section can bear against the respective conveyor pawl, and a second spring leg adjoining the spring coil section opposite can bear against the base body.

[0023] The loading device can have a spring-biased locking pawl which projects into a guide channel of the loading device and is designed and mounted in such a way that the locking pawl is pressed out of the guide channel by a forwardly fed screw when the belt moves forward in the feed direction against its spring preload, and when the feed pawl, in particular the first feed pawl and the second feed pawl, moves back from the feed position into the retracted position against the feed direction, the locking pawl projects into the guide channel to prevent the belt from moving back.

[0024] For example, if the guide has two opposing strips that guide or hold the screw heads or the belt from two opposite sides, the space above and / or below the two opposing strips forms the respective guide channel for the screws. The locking pawl thus acts directly on the respective screw shaft. The locking pawl therefore does not act directly on the belt.

[0025] The locking pawl can, for example, comprise a pivoting lever that is pivotally mounted on the base body of the loading device. The pivoting lever can have a locking lug that has a front surface pointing in the feed direction. The front surface can be oriented at least substantially perpendicular to the feed direction. The locking lug can have a rear surface opposite the front surface, which can be oriented at an angle to the feed direction. The rear surface of the locking lug can be inclined in such a way that when a screw is fed forward by means of the feeding device, a screw shank of a subsequent screw can slide along the rear surface of the locking lug. The advancing movement of the screw, which presses against the rear surface of the locking lug, pushes the locking lug outwards against its spring preload, so that the screw in question can pass the locking lug.

[0026] If a screw which has already passed the locking lug is pulled back by the belt, possibly against the conveyor system in the feed direction, the screw shaft of the screw which has already passed runs against the front surface of the locking lug. As the front surface is arranged perpendicular to the feed direction, the screw shaft cannot force the locking lug out of the guide channel, but rather runs up against the front surface of the locking lug without the locking lug or the pivot lever moving. This prevents the belt from running back against the feed direction. If the locking pawl is designed as a pivot lever, the front surface can be at least approximately aligned with the pivot axis, so that when pressure is applied to the front surface no torque at all or at most a very slight torque is induced, which is less than the minimum torque that would be required to press the locking pawl out of the guide channel.

[0027] The at least one stop pawl can be adjustable between a holding position in which the loading screw is held in its position immediately below the screw bit and a release position in which the stop pawl is moved out of the guide channel in such a way that the loading screw can be moved further forward in the feed direction from its position immediately below the screw bit.

[0028] In a first embodiment, the at least one stop pawl can be driven or controlled for adjustment. In a second embodiment, the at least one stop pawl can be spring-loaded into the holding position. Such a spring-loaded mounting of the stop pawl thus requires no drive or additional drive energy to move the stop pawl.

[0029] In a special embodiment, two stop pawls can be provided. One stop pawl can be located to the right or left of the loading screw. The stop pawls can in particular be designed and arranged in such a way that during a conveying movement in the feed direction generated by the conveying device, the stop pawls cause the loading screw to strike in its head area. The belt is guided past the stop pawls without contact, so that a belt section that no longer has any screws is not stopped by the stop pawls, but is conveyed further in the feed direction by the conveying device or by the at least one conveying pawl indirectly via a screw that is resting on the contact surface and is still on the belt, beyond the position of the screw bit.

[0030] In the case of a spring-loaded bearing, the stop pawls can be pre-loaded with such a spring force that a loading screw is positioned accurately, i.e. axially aligned with the screw bit, on the stop pawls by means of the stop pawls when at least one feed pawl has moved the transport screw into the feed position.

[0031] By means of a sensor, in particular an optical sensor such as a camera, the loading screw can be automatically checked in the feed position resting against the stop pawls to determine whether the screw presented as the loading screw is OK, i.e. for example whether the screw shaft has the correct length, the screw shaft is straight, the thread on the screw shaft is complete and flawless and / or the screw head is flawless. The automatic check can be carried out, for example, by means of image analysis on a control device which can automatically actuate the screwing device. By means of a sensor, in particular an optical sensor such as a camera, it can also be automatically checked whether the loading device or the belt is still loaded with screws.

[0032] If a screw presented as a loading screw is classified as not OK, i.e., as faulty, the screw bit is not actuated and the screw presented as a loading screw is not used, i.e., it is not automatically screwed into the workpiece. Instead, the screw bit remains in its pre-positioned position, and the feed pawl is moved an additional cycle so that a subsequent screw is presented as a new loading screw, and the screw classified as faulty is automatically transported forward past the stop pawls. In doing so, the screw overcomes the spring force of the stop pawls, causing the stop pawls to move, specifically pivot, out of the guide channel.After the screw classified as defective has left the loading position, the stop latches automatically close again due to spring preload, and the previous transport screw is presented as the new loading screw, striking the stop latches. If this new screw is identified as fault-free during a further optical evaluation and can therefore be used as a loading screw, the screw bit starts and drives the loading screw into the workpiece.

[0033] The guide is replaceably attached to a base body of the loading device. The guides are thus detachably attached to the base body of the screwing device. For example, the guides can be screwed to the base body. Due to a detachable attachment, in particular by means of screws, the guides can be easily replaced. This may be necessary, in particular, if the automatic screwing device is to be converted to a different type of screw. Depending on the type of screw head, the screw head profile, and / or the diameter and / or, if applicable, the length of the screws, it may be necessary to replace the guides.

[0034] The loading device can have a seat on its base body in which a centering bush is fastened, in particular replaceably, wherein the centering bush forms a centering guide for the screw bit in order to align the screw bit in a coaxial alignment with respect to the loading screw.

[0035] The shaft of the screw bit is guided in the centering bushing, allowing the screw bit to move axially through the centering bushing, but supporting and guiding it radially. The centering bushing prevents the shaft of the screw bit from swinging or oscillating. The centering bushing thus ensures that the profile of the screw bit is always coaxial with the matching screw head profile of the screw. Furthermore, as the profile of the screw bit engages the screw head profile, the screw being driven is stabilized and held in its axial alignment.

[0036] The centering bushing is adapted to the type and size of the screw bit. In particular, the centering bushing is adapted to the diameter of the screw bit's shank. Therefore, if the screwing device is to be able to automatically screw in other types of screws, a screw bit adapted to the type of screw must always be used, and consequently, the centering bushing must also be adapted to the modified screw bit. The centering bushing can be screwed into the seat. Alternatively, the centering bushing can also be releasably attached to the seat in another way, for example, by a locking device.

[0037] The automatic screwdriving device can be equipped with a drum magazine. The drum magazine can contain: - a drum axis designed to wind a belt on which a plurality of screws are pre-assembled at equal distances from one another and in parallel alignments to one another, - a first limiting disc arranged at one end of the drum axis and a second limiting disc arranged at the other end of the drum axis, wherein at least the first limiting disc and / or the second limiting disc is mounted axially displaceably on the drum axis for adaptation to different screw lengths and / or screw sizes.

[0038] The drum magazine can be mounted on the automatic screwing device in an interchangeable manner. Such a drum magazine can hold a coiled belt. The belt can hold, for example, several hundred or thousand screws.

[0039] By mounting at least the first limiting disc and / or the second limiting disc axially displaceably on the drum axis to accommodate different screw lengths and / or sizes, the drum magazine can be selectively loaded with different types and / or sizes of screws. By displacing at least one of the two limiting discs, the distance between the two opposing limiting discs can be specifically adjusted to the respective screw length used.

[0040] The loading device may comprise a knife guide configured to guide a cutting blade of a cutting device configured to automatically separate a webbing section that has passed through the loading device and / or is empty from the belt.

[0041] After a certain number of screws have been automatically removed from the belt by the screwing device and screwed into the desired workpiece, a certain empty partial length of the belt is also fed out of the loading device of the screwing device. To ensure that this empty partial length of the belt does not disrupt the further processing, a separating device, in particular a cutting device, can be provided which, after a predetermined number of screws have been removed from the belt, separates a corresponding, in particular empty, partial length of the belt from the remainder of the belt and thus removes it from the screwing device. The predetermined number of screws can be flexibly adjustable, i.e. can be specified. The processed screws are automatically counted accordingly.

[0042] The separating device or cutting device can be arranged as a component of the screwing device directly on the screwing device, in particular on the loading device. Alternatively, the separating device or cutting device can also be set up separately from the screwing device, for example as a stationary separating device or cutting device. If the screwing device is automatically guided and moved by a robot arm, for example, the screwing device can be moved up to the stationary separating device, the separating device can cut off an empty partial length of the belt there, and the screwing device can then be moved back by the robot arm to its actual workstation, where the screws are to be screwed into the workpieces.The empty lengths of the belt cut off at the stationary cutting device can fall into a collecting container so that they can be disposed of or recycled.

[0043] The separating device, in its cutting configuration, can have a cutting blade that can be moved automatically by a drive. The cutting blade can be guided along the knife guide of the loading device, allowing the knife to cross the path of travel of the empty belt sections. The cutting blade can be moved against a fixed support plate, allowing the empty belt sections to rest between the support plate and the cutting blade, where they can be cut off.

[0044] The object is also achieved by a robot tool, comprising a base support, a tool flange arranged on the base support, which is designed to fasten the robot tool to a connecting flange of a robot arm, and comprising a plurality of mounting supports arranged on the base support, which are each designed to individually fasten an automatic screwing device according to one of the described embodiments.

[0045] The robot tool can accordingly have at least one automatic screwing device according to one of the described embodiments. It is expedient if the robot tool has several automatic screwing devices according to one of the described embodiments. The several automatic screwing devices can be attached to or mounted on the robot tool in a desired arrangement. For example, several automatic screwing devices can be arranged next to one another in a row. The screwing devices can be arranged at equal distances from one another. For example, several screws can be screwed into the workpiece simultaneously in a line at desired distances from one another. The workpiece can, for example, be a drywall panel or several drywall panels.The workpiece can also be, for example, one or more sheets of metal, or lightweight steel frames that are to be screwed together with self-tapping sheet metal screws.

[0046] By having the base support of the robot tool with multiple mounting supports, various numbers of screw fixtures can be optionally attached to the base support. The mounting supports can also be adjustably mounted on the base support, so that the relative distances between any two directly adjacent mounting supports or screw fixtures can be adjusted, i.e., changed.

[0047] The robot tool can be designed such that the attached screwing devices can be operated in any orientation, i.e., any spatial orientation. It can even be provided that the multiple screwing devices of the robot tool can be operated "overhead," i.e., for example, screws can be screwed into the workpiece in a screwing direction from bottom to top, with the screws being screwed into the underside of the workpiece.

[0048] The tool flange of the robot tool can have all electrical, pneumatic or hydraulic connectors or plug-in couplings so that all mounted screwing devices can be supplied with the required type of energy in order to be able to control the screwing devices automatically.

[0049] The connection flange of a robot arm can accordingly have corresponding electrical, pneumatic or hydraulic mating connectors or mating couplings so that the robot tool can be coupled to the robot arm and the mounted screwing devices can be supplied with the required type of energy via the robot arm.

[0050] The screwing devices can be automatically controlled via the robot arm by a separate controller. The separate controller for automatically controlling the screwing devices can be synchronized with a robot controller that automatically controls the movements of the robot arm. The separate controller and the robot controller can be designed as separate, independent control devices. Alternatively, the separate controller and the robot controller can be combined into a common process control system and, if necessary, even combined into a single control computer.

[0051] A specific embodiment of the invention is explained in more detail in the following description with reference to the accompanying figures. Regardless of the specific context in which they are mentioned, specific features of this exemplary embodiment may represent general features of the invention, even when considered individually or in further combinations.

[0052] They show: Fig. 1 a perspective view of an automatic screwing device according to the invention with the screw bit raised, Fig. 2 a perspective view of the automatic screwing device according to the invention according to Fig. 1 with lowered screw bit, Fig. 3 a perspective view of the loading device in a stand-alone position with a screw-carrying belt, Fig. 4 a perspective view of the loading device according to Fig. 3 from its back, Fig. 5 a perspective view of the loading device according to Fig. 3 from its front, Fig. 6 a top view of the conveyor device of the screwing device according to Fig. 3 with the conveyor pawl in the retracted position, Fig. 7 a top view of the conveyor device of the screwing device according to Fig. 3 with the conveyor pawl in the feed position, Fig. 8 a top view of the conveyor device of the screwing device according to Fig. 3 with the conveyor pawl during a return movement of the conveyor pawl from the advance position to the retraction position, Fig. 9 a top view of the conveyor device of the screwing device according to Fig. 3 with open stop latches, Fig. 10 is a partial perspective view of the automatic screwing device with a knife guide and a cutting device in a storage position, Fig. 11 a perspective partial view of the automatic screwing device with a knife guide and a cutting device in a cutting position, Fig. 12 a perspective view of a robot tool with several automatic screwing devices, Fig. 13 a perspective view of an automatic screwing device with a drum magazine for a screw-carrying belt, Fig. 14 a perspective view of the loading device in isolation with an inserted belt carrying the screws, Fig. 15 a perspective view of the drum magazine in a unique position from behind, and Fig. 16 an exploded view of the drum magazine according to Fig. 15 in a unique position from the front.

[0053] In the Fig. 1 shows an automatic screwing device 1. The automatic screwing device 1 is used for the automated screwing of belt-guided screws 2 ( Fig. 3, Fig. 14) into workpieces.

[0054] The automatic screwing device 1 has a motor 3 with a motor shaft 4 to which a bit holder 5 is coupled, which carries a screw bit 6 which can be driven in rotation by the motor 3 and which is adjustable in its axial position in the direction of arrow P1, for automatically driving a screw 2 attached to the screw bit 6 into a workpiece.

[0055] The automatic screwing device 1 has a loading device 7 for feeding a belt 8 ( Fig. 3, Fig. 14), on which several screws 2 are pre-assembled at equal screw spacings A from one another and in parallel alignments to one another, wherein the loading device 7 has a guide 9 ( Fig. 5), on which the belt 8 carrying the screws 2 is guided in such a way that a loading screw 2a which is the foremost one in the feed direction V can be fed into a position immediately below the screw bit 6 by advancing the belt 8, wherein the loading device 7 comprises a conveyor device 10 ( Fig. 4 to Fig. 9) which is designed to transport the belt 8 within the guide 9.

[0056] The guide 9 is replaceably fastened on opposite sides to a base body 18 of the loading device 7, as shown in Fig. 5 on one side of the loading device 7. The guide 9 is removably screwed to the base body 18 via fastening screws 19.

[0057] The motor 3 together with the bit holder 5, the screw bit 6 and the screwdriver carriage 40 forms a screw unit.

[0058] The screwing unit also includes a stop 41, which defines the screwing depth of a screw 2. The stop 41 is attached to the feed unit 42, which carries the loading device 7. The counterpart 43 to the stop 42 is attached to the screwing unit. If the counterpart 43 and the stop 41 meet, as shown in Fig. 2, the screw unit can no longer move towards the workpiece and the screw bit 6 is disengaged from the screw 2 via a drywall coupling when the screw-in depth is reached.

[0059] Because in the case of the present embodiment, for example, a pressure sensor is used as the fixed stop 41, it can be automatically determined whether the screw 2 has reached the desired screw-in depth and, consequently, in view of the expected height position or height difference, the screw 2 has been screwed correctly.

[0060] If, for example, screw 2 has not been tightened in the event of a malfunction, this can be automatically evaluated by the control system, since in this case the signal that stop 41 has been reached comes too early and therefore screw 1 has not been turned. This faulty screw position can therefore automatically be evaluated as incorrect.

[0061] Since the stop 41 is mounted on the feed unit 42, it does not need to be mechanically adjusted, as the feed unit 42 always rests on the workpiece. Only the desired screw-in depth of screw 2 needs to be set on the counterpart 43.

[0062] In Fig. 2 shows how the stop 41 and the counterpart 43 lie against each other.

[0063] The conveyor device 10 has at least one conveyor pawl 11.1, 11.2, which can be moved between a feed position ( Fig. 7) and a retreat position ( Fig. 6) is mounted in a driven manner so as to be movable back and forth in repeating cycles along the feed direction V, wherein the conveyor pawl 11.1, 11.2 has a contact surface 12.1, 12.2 which is designed to bear against a transport screw 2b of the belt 8 following the loading screw 2a in order to convey the belt 8 within one cycle in the feed direction V by a screw spacing A, and the conveyor device 10 has at least one stop pawl 13.1, 13.2 which is designed to hold the loading screw 2a in its position immediately below the screw bit 6 when the belt 8 transported by the conveyor pawl 11.1, 11.2 presses the loading screw 2a against the stop pawl 13.1, 13.2.

[0064] In the case of the present embodiment, the conveyor device 10 has a first conveyor pawl 11.1 which is designed and mounted in such a way that a first contact surface 12.1 of the first conveyor pawl 11.1 directly engages a shaft section 2.1 of the adjacent transport screw 2b, which is exposed above the belt 8, during the feed movement, and the conveyor device 10 has a second conveyor pawl 11.2 which is designed and mounted in such a way that a second contact surface 12.2 of the second conveyor pawl 11.2 directly engages a shaft section 2.2 of the adjacent transport screw 2b, which is exposed below the belt 8, during the feed movement.

[0065] In the case of the present embodiment, both the first conveyor pawl 11.1 and the second conveyor pawl 11.2 are each moved into their conveyor positions ( Fig. 6, Fig. 7) is mounted in a pre-tensioned manner, such that when the first conveyor pawl 11.1 and the second conveyor pawl 11.2 are moved back from the feed position ( Fig. 7) into the retreat position ( Fig. 6) in a return movement direction R opposite to the feed direction V, the first conveyor pawl 11.1 and the second conveyor pawl 11.2 slide over a shaft section 2.1, 2.2 of a follower screw 2c following the conveyor screw 2b, as is particularly shown in Fig. 8, in that the first conveyor pawl 11.1 and the second conveyor pawl 11.2 can deflect in a transverse direction Q transverse to the feed direction V in order to be able to bypass the following screw 2c, so that the first contact surface 12.1 and the second contact surface 12.2 can come into contact with the following screw 2c from behind in order to form the loading screw 2b in the next cycle.

[0066] In the case of the present embodiment, the loading device 7 has a spring-biased locking pawl 16 projecting into a guide channel 15 of the loading device 7, which is designed and mounted in such a way that the locking pawl 16 is pressed out of the guide channel 15 by a screw 2 conveyed forwards when the belt 8 moves forward in the feed direction V against its spring preload of the spring means 17, and when the first feed pawl 11.1 and the second feed pawl 11.2 move back from the feed position ( Fig. 7) into the retreat position ( Fig. 6) the pawl 16 projects into the guide channel 15 opposite to the feed direction V in order to prevent the belt 8 from moving back, in that the upstream screw 2, 2c rests on the pawl 16.

[0067] The stop pawls 13.1, 13.2 are between a holding position ( Fig. 6 to 8), in which the loading screw 2a is held in its position directly below the screw bit 6 and a release position ( Fig. 9), in which the stop pawls 13.1, 13.2 are moved out of the guide channel 15 in such a way that the loading screw 2a can be moved further forward in the feed direction V from its position immediately below the screw bit 6.

[0068] In the case of a spring-loaded bearing, the stop pawls 13.1, 13.2 can be preloaded by means of the compression spring pins 20 with such a spring force that a loading screw 2a is positioned precisely, ie axially aligned with the screw bit 6, on the stop pawls 13.1, 13.2 by means of the stop pawls 13.1, 13.2 when the at least one conveyor pawl 11.1, 11.2 has moved the transport screw 2b into the feed position.

[0069] If a screw 2 presented as loading screw 2a is classified as not OK, i.e. as faulty, the screw bit 6 is not operated and the screw 2 presented as loading screw 2a is not used, i.e. it is not automatically screwed into the workpiece. Rather, the screw bit 6 remains in its pre-position and the feed pawls 11.1, 11.2 are instead moved by an additional cycle, so that a subsequent screw 2, the transport screw 2b, is presented as a new loading screw 2a and the screw 2 classified as faulty is automatically transported out past the stop pawls 13.1, 13.2, as shown in Fig. 9. In doing so, the screw 2 overcomes the spring force of the compression spring pins 20 of the stop pawls 13.1, 13.2, so that the stop pawls 13.1, 13.2 are moved, in particular pivoted, out of the guide channel 15. After the screw 2 classified as defective has left the loading position, the stop pawls 13.1, 13.2 close automatically again due to the spring preload, and the previous transport screw 2b is presented as the new loading screw 2a, striking the stop pawls 13.1, 13.2.

[0070] Returning to Fig. 3, the loading device 7 can have on its base body 18 a seat 21 in which a centering bushing 22 is replaceably fastened, wherein the centering bushing 22 forms a centering guide for the screw bit 6 in order to align the screw bit 6 with respect to the loading screw 2a in a coaxial alignment.

[0071] As in Fig. 10 and Fig. 11, the loading device 7 can have a knife guide 23 which is designed to guide a cutting blade 24 of a cutting device 25 which is designed to automatically separate a section of belt webbing which has passed through the loading device 7 and / or is empty from the belt 8. The cutting device 25 can, as in Fig. 10 and Fig. 11, as a component of the screwing device 1, can be arranged directly on the screwing device 1, in particular on the loading device 7.

[0072] The cutting device 25 can have a cutting blade 24 that can be moved automatically by a drive 26. The cutting blade 24 can be guided along the knife guide 23 of the loading device 7, so that the cutting blade 24 can cross the path of movement of the empty partial lengths of the belt 8. The cutting blade 24 can be moved against a fixed counter-holding plate 27, so that the empty partial lengths of the belt 8 come to rest between the counter-holding plate 27 and the cutting blade 24 and can be cut off there. Fig. 10 shows the cutting blade 24 in its non-cutting position and the Fig. 11 shows the cutting blade 24 in its cutting position.

[0073] The Fig. 12 shows a robot tool 28, comprising a base support 29, a tool flange 30 arranged on the base support 29, which is designed to fasten the robot tool 28 to a connecting flange of a robot arm (not shown), and comprising a plurality of, in the case of the present embodiment eight, mounting supports 31 arranged on the base support 29, which are each designed to individually fasten an automatic screwing device 1 according to one of the described embodiments.

[0074] The Fig. 13 additionally shows a drum magazine 32 mounted on the automatic screwing device 1. The drum magazine 32 is in Fig. 15 and Fig. 16 is shown in more detail.

[0075] The drum magazine 32 has a drum axis 33 which is designed to wind up a belt 8 ( Fig. 14), on which a plurality of screws 2 are pre-assembled at equal screw spacings A from one another and in parallel alignments to one another.

[0076] The drum magazine 32 has a first limiting disc 34.1 arranged at one end of the drum axis 33 and a second limiting disc 34.2 arranged at the other end of the drum axis 33, wherein at least the first limiting disc 34.1 and / or the second limiting disc 34.2 is mounted axially displaceably on the drum axis 33 for adaptation to different screw lengths and / or screw sizes. For this purpose, a plurality of locking seats 35 can be provided on the drum axis 33. The second limiting disc 34.2 can be detachably attached to the drum axis 33, as shown. The drum magazine 32 can have a carrying handle 36.

[0077] Returning to Fig. 1, the loading device 7 can be mounted by means of a carriage 37 relative to the motor 3 and thus relative to the screw bit 6 in the direction of arrow P2 on the same rails as the motor 3 or on separate rails 38. For this purpose, the carriage 37 can be pre-tensioned downwards by means of an air spring 39. Thus, by a joint movement of the screw device 1 towards the workpiece, for example in Fig.1 in a downward direction, first the loading device 7 rests on the workpiece, whereby the motor 3 and the screw bit 6 can be moved even further downwards against the spring force of the air spring 39 without the screw bit 6 first engaging a screw 2 in a form-fitting manner. In the case of the present embodiment, the air spring 39 is attached to a base plate and is therefore independent of the movement of the screw bit 6. The air spring 39 ensures that the loading device 7 always rests flush against the workpiece. The air spring 39 is automatically moved downwards so that the screwdriver and feed unit are apart. The robot presses the air spring 39 in slightly after it has been placed on the workpiece. The air spring 39 ensures that the loading device 7 is not lifted by the screwing forces during screwing.The end position of the air spring 39 should not be reached, since otherwise the screw bit 6 would penetrate too deeply and an emergency stop would be triggered to protect the devices (crash protection).

[0078] If, for example, multiple screwing devices 1 are provided on the robot tool 28, each individual screwing device 1 can be applied to a surface of the workpiece independently of the other screwing devices 1. Accordingly, with uneven workpieces, the multiple screwing devices 1 can assume different heights. Only then is the motor unit, comprising the motor 3, the bit holder 5, and the screw bit 6, moved downward, so that the screw bit 6 can be positioned on the associated screw head of a supplied screw 2, and by an advancing movement of the motor 3, the bit holder 5, and the screw bit 6, the loading screw 2a can be driven into the workpiece while simultaneously rotating the loading screw 2a.

Claims

[1] Automatic screwing device for the automated screwing of belt-guided screws (2) into workpieces, comprising: - a motor (3) with a motor shaft (4) to which a bit holder (5) is coupled, which carries a screw bit (6) which can be driven in rotation by the motor (3) and which is adjustable in its axial position, for automatically driving a screw (2) attached to the screw bit (6) into a workpiece, - a loading device (7) for feeding a belt (8) on which a plurality of screws (2) are pre-assembled at equal screw spacings (A) from one another and in parallel alignments to one another, wherein the loading device (7) has a guide (9) on which the screws (2) are guided in such a way that a respective foremost loading screw (2a) in the feed direction (V) can be fed into a position immediately below the screw bit (6) by advancing the belt (8), and wherein the loading device (7) has a conveyor device (10) which is designed to transport the belt (8) within the guide (9), and wherein - the conveyor device (10) has at least one conveyor pawl (11.1, 11.2) which is mounted in a driven manner so as to be movable back and forth in repeated cycles between an advancing position and a retracting position along the advancing direction (V), wherein the conveyor pawl (11.1, 11.2) has a contact surface (12.1, 12.2) which is designed to bear against a transport screw (2b) of the belt (8) following the loading screw (2a) in order to convey the belt (8) within one cycle in the advancing direction (V) by a screw spacing (A), and the conveyor device (10) has at least one stop pawl (13.1, 13.2) which is designed to hold the loading screw (2a) in its position immediately below the screw bit (6) when the belt (8) transported by the conveyor pawl (11.1, 11.2) presses the loading screw (2a) against the Stop pawl (13.1, 13.2) presses, characterized bythat the guide (9) is replaceably fastened to a base body (18) of the loading device (7). [2] Automatic screwing device according to claim 1, characterized by that the conveyor device (10) has a first conveyor pawl (11.1) which is designed and mounted in such a way that a first contact surface (12.1) of the first conveyor pawl (11.1) directly engages a shaft section (2.1) of the adjacent conveyor screw (2b) which is exposed above the belt (8) during the feed movement, and the conveyor device (10) has a second conveyor pawl (11.2) which is designed and mounted in such a way that a second contact surface (12.2) of the second conveyor pawl (11.2) directly engages a shaft section (2.2) of the adjacent conveyor screw (2b) which is exposed below the belt (8) during the feed movement. [3] Automatic screwing device according to claim 1 or 2, characterized bythat the conveyor pawl (11.1, 11.2), in particular the first conveyor pawl (11.1) and the second conveyor pawl (11.2), are mounted in a pre-tensioned manner in their conveyor positions by means of at least one spring (14), such that when the conveyor pawl (11.1, 11.2), in particular the first conveyor pawl (11.1) and the second conveyor pawl (11.2), are moved back from the advance position into the retracted position opposite to the advance direction (V), the conveyor pawl (11.1, 11.2), in particular the first conveyor pawl (11.1) and the second conveyor pawl (11.2), slides over a shaft section of a follower screw (2c) following the transport screw (2b), in that the conveyor pawl (11.1, 11.2), in particular the first conveyor pawl (11.1) and the second conveyor pawl (11.2), can deflect transversely to the feed direction (V) in order to be able to bypass the follower screw (2c), so that the at least one contact surface (12.1, 12.2), in particular the first contact surface (12.1) and the second contact surface (12.2), can come into contact with the following screw (2c) from behind in order to form the loading screw (2b) in the next cycle. [4] Automatic screwing device according to one of claims 1 to 3, characterized by in that the loading device (7) has a spring-biased locking pawl (16) which projects into a guide channel (15) of the loading device (7), which is designed and mounted in such a way that the locking pawl (16) is pressed out of the guide channel (15) by a forwardly advanced screw (2) when the belt (8) moves forward in the feed direction (V) against its spring preload, and when the feed pawl (11.1, 11.2), in particular the first feed pawl (11.1) and the second feed pawl (11.2), moves back from the feed position into the retracted position against the feed direction (V), the locking pawl (16) projects into the guide channel (15) in order to prevent the belt (8) from moving back. [5] Automatic screwing device according to one of claims 1 to 4, characterized by that at least one stop pawl (13.1, 13.2) is adjustable between a holding position in which the loading screw (2a) is held in its position immediately below the screw bit (6) and a release position in which the stop pawl (13.1, 13.2) is moved out of the guide channel (15) in such a way that the loading screw (2a) can be moved further forward in the feed direction (V) from its position immediately below the screw bit (6). [6] Automatic screwing device according to one of claims 1 to 5, characterized by that the loading device has on its base body (18) a seat (21) in which a centering bush (22) is replaceably fastened, wherein the centering bush (22) forms a centering guide for the screw bit (6) in order to align the screw bit (6) in a coaxial alignment with respect to the loading screw (2a). [7] Automatic screwing device according to one of claims 1 to 6, characterized by a drum magazine (32) comprising: - a drum axis (33) which is designed to wind up a belt (8) on which a plurality of screws (2) are pre-assembled at equal screw spacings (A) from one another and in parallel alignments to one another, - a first limiting disc (34.1) arranged at one end of the drum axis (33) and a second limiting disc (34.2) arranged at the other end of the drum axis (33), wherein at least the first limiting disc (34.1) and / or the second limiting disc (34.2) is mounted axially displaceably on the drum axis (33) for adaptation to different screw lengths and / or screw sizes. [8] Automatic screwing device according to one of claims 1 to 7, characterized byin that the loading device (7) has a knife guide (23) which is designed to guide a cutting blade (24) of a cutting device (25) which is designed to automatically separate a belt section which has passed through the loading device (7) and / or is empty from the belt (8). [9] Robot tool, comprising a base support (29), a tool flange (30) arranged on the base support (29) and designed to fasten the robot tool (28) to a connecting flange of a robot arm, and comprising a plurality of mounting supports (31) arranged on the base support (29), each of which is designed to individually fasten an automatic screwing device (1) according to one of claims 1 to 8.

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