Device and method for receiving and placing bolts

Abstract

The invention relates to a device (16) for receiving a screw shaft (8B) of a screw (8) and for placing a screw head (8A) of the screw (8) in a screwing sleeve (7) of an external screwing unit (6), a screw outer sleeve (23) and a screw inner sleeve (26) supported in the screw outer sleeve (23) being adjustably supported in the screw outer sleeve (23) by respective thread pairs that engage with one another. According to the invention, when the bolt (8) is received by means of a device (16) which is moved only in the axial direction in the longitudinal extension, the bolt shaft (8B) is received by the gripping element (38) with the bolt head (8A) exposed, and when the bolt (8) is placed, the exposed bolt head (8A) of the received bolt (8) is placed in the screwing sleeve (7), and the gripping element (38) is placed in the screwing sleeve (7). And the spiral inner sleeve (26) performs superposed axial rotation relative to the spiral outer sleeve (23).

Description

[0001] The invention relates to a device for receiving a screw shank of a screw and for placing the screw head of the screw into a screw sleeve of an external screw unit.

[0002] When mounting, for example, a chassis on the body of a vehicle, a so-called modular mounting frame is used, here referred to as a chassis bracket. It is a mechanical support structure that circulates in the equipment technology system and accommodates and positions all necessary technical components that must be mounted under the vehicle until the so-called "wedding assembly phase", in which the chassis is screwed to the body together with the engine. For this purpose, for example, the engine, exhaust system, axles and axle dampers are included without requiring integrity. The significance of such a modular mounting frame or chassis bracket is to design the assembly process so that the components to be assembled and the corresponding bolts as fixing elements can be inserted from above conveniently and cost-effectively before the bolt receptacle in the form of a screw sleeve can no longer be reached or can be reached with difficulty. Therefore, the usual vehicle separation of the body and chassis contributes to the efficient design of the assembly process. In a typical vehicle assembly line with about 1,000 vehicles per day, about 50 of these modular mounting frames or chassis brackets are used, which rotate in a cycle and are repeatedly re-equipped.

[0003] As mentioned above, one of the first steps is to insert the corresponding bolts into the screw sleeves of the screwing unit, which are then used to fix the individual modules. Here, the bolt head of each matching bolt must be inserted with the bolt shank upward into the corresponding screw sleeve present on the modular mounting frame or chassis bracket. In order to prevent the bolts, which can be up to 120 cm long, from getting lost during the transportation of the mounting frame or chassis bracket, the screw sleeves contain magnets, which hold the bolts at the head with the bolt shank facing upward. In the subsequent workstations, the parts that have to be screwed and fixed can therefore be placed on these bolts. If all parts are positioned, the mounting frame or chassis bracket is moved under the appropriate vehicle body, and the automatic screwing unit then gradually and according to a fixed process plan tightens all bolts with the appropriate torque.

[0004] The number of bolts to be positioned on the chassis is approximately 50 per chassis bracket, depending on the vehicle size and on additional modules (eg four-wheel drive). The bolting process is preferably carried out at a plurality of workstations during chassis assembly.

[0005] There is a need to automate the loading of the screw sleeve with the bolts, or rather the placing of the bolts into the screw sleeve.

[0006] Measures for automating assembly processes themselves have been known for a long time in various designs.

[0007] Such bolting devices are known from patent documents DE102008018848A1DE and DE102009053130A1. Patent document EP3782773A1 describes a tool for a collaborative robot. The robot has a movable mechanical arm, at the free end of which the tool is fixed to the tool holder. Patent document DE102018117238A1 discloses a centering device for a screwdriver with a screw blade, for centering the screw blade of the screwdriver on the bolt to be screwed. Patent document DE102012108476A1 describes a bolt fixing device.

[0008] The object of the present invention is to provide an improved device for receiving and securely placing a screw having a screw head and a screw shank in a screw sleeve of an external screw unit.

[0009] This object is achieved by a device according to the features of claims 1 to 9 .

[0010] A method for receiving and securely placing a screw in a screw sleeve by means of a device according to at least one of claims 1 to 9 is described in claims 10 and 11 .

[0011] The present invention is further described below in the embodiments according to the accompanying drawings.

[0012] Figure 1 A perspective individual view shows an assembly frame according to the prior art circulating in an assembly facility for vehicle manufacturing, which is equipped with replaceable frame modules;

[0013] Figure 2 Shown integrated into the Figure 1 a screwing unit in a frame module of an assembly frame, which has a screwing sleeve for accommodating a bolt;

[0014] Figure 3 a schematic diagram showing a first design variant of an assembly facility;

[0015] Figure 4 a schematic diagram showing a detail of a second design variant of an assembly facility;

[0016] Figure 5 A perspective single view of an industrial robot of an assembly plant is shown with a plurality of devices according to the invention for receiving and placing bolts according to Figure 1 In each of the screw sleeves of the screw unit of the frame module of the assembly frame;

[0017] Figure 6 Shown with basis Figure 5 A schematic diagram of an industrial robot of the device;

[0018] Figure 7 A perspective view of a screw and a perspective view of a screw sleeve are shown together with the associated longitudinal axis or the associated rotation axis;

[0019] Figure 8 showing a perspective view of a bolt in a gripping element after the bolt has been received by the device;

[0020] Fig. 9 A perspective view showing a gripping element;

[0021] Fig.10 The gripping element is formed to accommodate the Figure 8 A three-dimensional view of the introduction funnel of the bolt;

[0022] Fig.11 A perspective view of the device with a bolt accommodated in a gripping element is shown, and also a spiral inner sleeve in which the gripping element is arranged;

[0023] Fig. 12A , 12B Shown through the bolt, screw sleeve and sleeve (only Fig. 12A ) section, used to explain the principle of preventing the screw sleeve from rotating when the bolt is placed in the screw sleeve;

[0024] Fig.13A In a first design variant, a screw sleeve is shown with a clamping element for preventing the screw sleeve from rotating when a screw is inserted into the screw sleeve;

[0025] Fig. 13B In a second design variant, a screw sleeve is shown having a first blocking sleeve for preventing the screw sleeve from rotating when a screw is inserted into the screw sleeve;

[0026] Fig. 13C In a third design variant, a screw sleeve is shown having a second blocking sleeve for preventing the screw sleeve from rotating when a screw is inserted into the screw sleeve.

[0027] Fig.13D A perspective view of a screw shortly before it is inserted into a screw sleeve and a perspective view of a second blocking sleeve, for example, for preventing the screw sleeve from rotating when the screw is inserted into the screw sleeve;

[0028] Fig.14 Show according to Figure 7 , but with the additional spiral outer sleeve shown transparently to show the spiral profile on the inner surface of the spiral outer sleeve;

[0029] Fig.15 A three-dimensional external view of the device is shown;

[0030] Fig.16 The invention shows a method of passing through a device extending along the longitudinal extension thereof. Fig.15 The cross section of the central axis of the device;

[0031] Fig.17 The upper part of the device is shown with a transparently shown spiral outer sleeve and a transparently shown screw-in flange into which the spiral outer sleeve is screwed;

[0032] Fig.18 The device is shown in a perspective view with a spiral outer sleeve shown transparently and a spiral inner sleeve shown transparently and a screw-in flange shown transparently, as well as a slide located in the spiral outer sleeve, in which the first sensor is arranged and on which a pin is arranged, which contacts the slide according to Fig. 22B The bolt shank of the inserted bolt is in contact to indicate the function of the sensor and the pin;

[0033] Fig.19 Shown by Fig.18 A perspective view of a cross-section of a device to illustrate the function of the second sensor;

[0034] Fig. 20 Shown by Fig.18 A perspective view of a cross-section of the device to illustrate the function of the third sensor;

[0035] Fig.21A , 21B A perspective view showing the receipt of a bolt through the device;

[0036] Fig.22A A cross section through the device is shown to illustrate that when a bolt fails to be accommodated or a bolt that is too short is accommodated and the expected length of the bolt is not detected, the first sensor is used according to Fig.18 and detecting the length of the bolt with the associated first detector element;

[0037] Fig. 22B A cross section through the device is shown to illustrate that when the bolt is detected to be at the correct length specified, the first sensor is used according to Fig.18 and detecting the length of the bolt with the associated first detector element;

[0038] Fig. 22C A cross section through the device is shown to illustrate that when an overlong bolt is detected that is not within the specified correct length, the first sensor is used according to Fig.18 The first detector element associated therewith detects the length of the bolt.

[0039] Figure 1 An assembly frame 1 is shown, which has, for example, three exchangeable frame modules 2 , 3 , 4 for the positionally accurate fastening of further components (not shown).

[0040] The assembly frame 1 is guided in operation in an assembly facility 5 for vehicle structures (see Figure 3 and Figure 4 ) and, for example, as already explained above, for the so-called “wedding assembly phase”, in which the chassis together with the engine is screwed to the body of a vehicle (not shown).

[0041] The assembly frame 1 and / or the frame modules 2, 3, 4 comprise a plurality of screw units 6 integrated therein, which have at their free upper ends respectively screw sleeves 7 known per se with an internal hexagon for receiving screws 8 or their screw heads 8A with an external hexagon in a form-fitting and force-fitting manner. The form fit is formed according to the known method by corresponding form-fitting contours of the screw sleeves 7 and the screw heads 8A, whereas the force fit is achieved magnetically by providing the screw sleeves 7 with permanent magnets or electromagnets. The screws 8 are placed with their screw shanks 8B upwards into the respective screw sleeves 7, and then within the scope of the "wedding assembly phase" the components to be screwed and fixed are placed on the assembly frame 1 and its frame modules 2, 3, 4 and are joined to one another by means of the screws 8.

[0042] Figure 2 The screw unit 6 is shown with a screw sleeve 7 , wherein the screw sleeve 7 is arranged so to speak exposed, ie accessible laterally and from above over the entire circumference.

[0043] Figure 3 A section of a first possible design of an assembly facility 5, for example a vehicle structure, with a rotating assembly frame 1 is schematically shown. The assembly frame 1 and / or its frame modules 2, 3, 4 have a plurality of screwing positions 10, each with a screw sleeve 7, and are successively transferred to an assembly area 11, in which the screw sleeves 7 are equipped with screws 8. The screws 8 are removed from a screw storage 12 by a screw conveyor known per se and also not shown, and are arranged in a preparation area 14 accessible to a handling unit 13, in this case in the form of an industrial robot 13A (also called a bolt placement robot), to be precise upright with the bolt shaft facing upwards. For example, four industrial robots 13A are shown here, each of which is equipped with a screw storage 12 and a preparation area 14.

[0044] The industrial robot 13A is preferably an articulated arm robot (see Figure 5 ), further preferably with multiple axes of motion. A device 16 for receiving and placing the bolt 8 is arranged on the end member 15 of the industrial robot 13A.

[0045] For example, according to Figure 3 and Figure 5 Each industrial robot 13A has an end component 15 with a holding device 17 with, for example, five such devices 16 .

[0046] As a result, five screws 8 can be accommodated simultaneously and, if necessary or under corresponding conditions, placed simultaneously or successively in each screw sleeve 7 .

[0047] according to Figure 3 The assembly facility 5 ′ of EMBODIMENT 2 differs from the above-described assembly facility 5 ″ in that a pre-sorting station 18 is associated with each of two industrial robots 13 a of the above-described type.

[0048] According to the exemplary embodiment, each pre-sorting station 18 has five screw storages 19. Such a pre-sorting station 18 is provided in particular when screws 8 of different sizes are to be placed on the screw sleeves 7.

[0049] Each bolt storage 19 is assigned a pre-sorting robot 20 which is known per se and is preferably also designed as an articulated-arm robot, which places the bolts 8 upright with the bolt heads 8A facing downwards in a defined position on a pallet 21. The pallet 21 is arranged on a conveyor device 22, whereby the pallet is moved, so to speak, past the pre-sorting robots 20 which are arranged one behind the other and opposite to each other.

[0050] In order to support the bolts 8 on the pallet 21 in such a way that they do not fall over during travel and subsequent reception by the industrial robot 13A (bolt placing robot), they are magnetically fixed to a magnetic plate 21 , in particular a support plate 21A.

[0051] Preferably, the magnetic force generated by the permanent magnet or electromagnet is only generated at the specific position, whereby the bolt 8 can be advantageously detached from the plate 21A by the industrial robot 13A (bolt placement robot) simply by moving the bolt 8 lateraly relative to the plate 21A and subsequently lifting the bolt 8 after overcoming the magnetic force by the lateral movement.

[0052] Depend on Figure 6 An arrangement can be seen which shows the end piece 15 of the industrial robot 13A together with a holding device 17 with, for example, four devices 16 for receiving and placing four bolts 8 , wherein the device 16 for receiving the bolts 8 held on the pallet 21 is arranged above the pallet 21 .

[0053] The object of the invention is to provide a device, indicated by reference numeral 16 , for receiving and securely placing a screw 8 with a screw head 8A and a screw shank 8B in a screw sleeve 7 of an external screw unit and to improve it compared to the solutions known from the prior art.

[0054] According to the following Figures 7 to 22C The device 16 and its working method are explained in detail:

[0055] First (see Figure 7 ) has the task of centering the rotation axis Z8 of the screw 8 relative to the rotation axis Z7 of the screw sleeve 7 .

[0056] The screw 8 must be guided into the screw sleeve 7 in the axial direction Z. During this movement, a rotation of the screw 8 relative to the screw sleeve 7 of at least 30 degrees is necessary so that the screw head 8A of the screw 8 is accommodated in the screw sleeve 7 .

[0057] according to Figure 8 It is provided that the bolt 8 is clamped on the bolt shank 8B by means of a gripping element 38, a so-called clamp, in a friction fit. The gripping element 38 has a fixing hole 38A in each case. The clamp forms an introduction funnel 39 (see FIG. 1 ) in the form of a centering cone. Fig. 9 and Fig.10 ), wherein the clamp is inclined at its introduction end, namely at the receiving opening 31 of the introduction funnel 39 and thus has an introduction bevel, thereby making it easier for the bolt shank 8B of the bolt 8 to be introduced into the introduction funnel 39.

[0058] The gripping elements 38 are pressed together by means of a clamping element 40. The clamping element 40 exerts a constant pressure in the radial direction relative to an axis Z extending centrally in the longitudinal extension of the introduction funnel 39 of the device 16. In the embodiment, the clamping element 40 is a rubber ring (see Figure 8 and Fig.10 ), which always (elastically) presses the clamps of the introduction funnel 39 together in the radial direction of the center axis Z extending in the longitudinal extension of the introduction funnel 39.

[0059] The outer diameter of the clamp is designed to be slightly larger than the maximum outer diameter of the bolt shank 8B of the bolt 8 .

[0060] Here, it is arranged that the outer circumference of the screw sleeve 7 is guided in the first guide device 41A and the outer diameter of the clamp is guided in the second guide device 41B. Fig. 12A shown.

[0061] The basic idea of ​​the guide cannula 41 is that the guide devices 41A, 41B are centered relative to each other via the guide cannula 41. In a further development according to the invention, this basic idea leads to a so-called hold-down device 44 which is designed as the guide cannula 41, wherein the hold-down device 44 is explained in more detail below.

[0062] Fig. 12B It is shown that the screw sleeve 7 must be prevented from rotating about the rotation axis Z7 when the screw head 8A of the screw 8 is inserted into the screw sleeve 7 in a superimposed rotational and simultaneously translatory movement along the axis 7 in the direction of the screw sleeve 7 .

[0063] Because according to Fig. 12B The screw 8 is inserted, which completely covers the screw sleeve 7 from above (from the screw shank 8B), especially when the washer 8C is put on, so that the outer circumference of the screw sleeve 7 can be used to retain or lock the screw sleeve 7 according to the invention, as described below.

[0064] The screw sleeve 7 can be held in place using three basic principles that can be combined: The screw sleeve 7 is held in place by friction and / or by form fit and / or by force fit, whereby a number of design variants are possible according to the invention, wherein preferred design variants are suggested and explained below.

[0065] In accordance with Fig.13A In a preferred design variant of the device 16, a clamping element 42 is integrated into the device 16, which clamping element 42 grips and holds the screw sleeve 7 on its outer circumference. Fig.13A The loosened end shown in FIG. 1 is connected to the spiral inner sleeve 26. The clamping element 42 is preferably installed together with the gripping element 38 in the receiving element 26C of the spiral inner sleeve 26. The receiving element 26C is Fig.11 Shown.

[0066] In this design variant, the friction and force fit of the clamping element 42 form the holding force of the screw sleeve 7 .

[0067] In another preferred design variant, according to Fig. 13B , a first blocking sleeve 43 is provided, which surrounds the screw sleeve 7 at least partially or, according to the design variant shown, completely on the outer circumference. The blocking sleeve 43 has a toothing on the end side, which corresponds to the toothing on the same end side of the hold-down device 44, as shown in Figure 13. In this design variant, the form fit of the intermeshing teeth forms a holding force for the screw sleeve 7.

[0068] In another preferred design variant, according to Fig. 13C A second barrier sleeve 45 is provided which likewise completely surrounds the screw sleeve 7 on the circumference.

[0069] The blocking sleeve 45 has a toothing on the outer circumference, which corresponds to the toothing on the inner circumference with at least one tooth of the hold-down device 44, not shown further in the figure. In this design variant, the form fit of the intermeshing toothing also forms the holding force of the screw sleeve 7.

[0070] For the hold-down device 44 according to 13D used in the above-described preferred embodiment, it is disclosed that it is elastically supported by a spring element 53 .

[0071] The spring element 53 is supported at one end on the hold-down device 44 and at the other end on the collar 26D of the spiral inner sleeve 26 (see above). Fig.21A and 21B ), the spiral inner casing is Fig.21A and 21B and 12D are surrounded by a spiral outer sleeve 23, which will be described in detail.

[0072] In this case, the rotation of the spiral inner sleeve 26 is not transmitted to the spring element 53 via the collar 26D, but the spring element 53 is supported axially in the Z-axis direction in the hold-down device 44 .

[0073] This means that only the axial movement of the spiral inner sleeve 26 is transmitted to the spring element 53 and thus to the hold-down device 44 .

[0074] Independently of the design variant, the hold-down device 44 fulfills two functions.

[0075] The first function is to center the screw sleeve 7. Fig. 13B and 13C As shown, a centering bevel is provided on the screw sleeve 7 , which corresponds oppositely to the centering bevel of the hold-down device 44 .

[0076] By means of the clamping device 44, the device 16 and thus the bolt 8 (on the axis Z, see Figure 7 ) are centered relative to the screw sleeve 7, that is, Z7 and Z8 are centered along Z in the longitudinal extension of the device 16.

[0077] By means of the clamping element according to a preferred design variant ( Fig.13A ) or the teeth of the blocking sleeves 43, 45 ( Fig. 13B and 13C ) and the arranged centering bevel, in the second function of the clamping element 44, once the clamping element 44 is placed on the toothed portion of the first or second blocking sleeve 43, 45 of the screw sleeve 7 (in the case of the blocking sleeve 43) or bites (in the case of the blocking sleeve 45) or the clamping element 42 surrounds the screw sleeve 7, the rotation of the screw sleeve 7 is blocked.

[0078] The outer diameter of the hold-down device 44 can be adapted to the surroundings in order to avoid collisions with adjacent components.

[0079] Furthermore, a first or second barrier sleeve 43, 45, also referred to as a sleeve sleeve, is disclosed, which can be pushed onto each screw sleeve 7 after appropriate prefabrication and can be locked. Figure 7 As shown in FIG. 1 , the screw sleeve 7 has recesses 49 on its circumference, which are coordinated with correspondingly shaped elevations arranged on the inside (not shown) of the barrier sleeves 43 , 45 .

[0080] In other words, the blocking sleeves 43, 45 are arranged on the screw sleeve 7 in a form-fitting and friction-fitting manner. In addition, an opening is arranged in the screw sleeve 7, and an opening is arranged in the corresponding blocking sleeve 43, 45. When the blocking sleeves 43, 45 are positioned accordingly relative to the screw sleeve 7, a position fixing element in the form of a split pin or the like is introduced through the opening to ensure the position-matching arrangement of the screw sleeve 7 relative to the screw sleeve 7.

[0081] Fig.14 It is shown that in order to introduce the screw 8 or the screw head 8A into the screw sleeve 7 , the screw 8 must be rotated about the longitudinal axis by approximately 30°.

[0082] When the screw 8 is inserted into the screw sleeve 7 , a rotational movement takes place and at the same time a translational movement of the device 16 downwards takes place.

[0083] Rotational motion by Fig.14 The spiral outer sleeve 23 shown has a spiral profile 23A on its inner surface, which acts on the outer surface on the spiral profile 26A of the spiral inner sleeve 26 (see Fig.11 See you in advance Fig.17 ).

[0084] In a special design according to the invention, the helical profiles 26A, 23A are designed as internal and external threads, internal thread = corresponding to the helical profile 23A, external thread = corresponding to the helical profile 26A, as helical threads.

[0085] Fig.14 The upper end of the spiral outer sleeve 23 is shown to have an external thread 23B, which is used to screw the spiral outer sleeve 23 of the device 16 into the internal thread of the screw-in flange 50 (see above). Fig.15 ), wherein a mounting flange 51 is constructed on a screw-in flange 50, the mounting flange being connected to an end member 15 of a receiving device of a robot arm of an industrial robot 13A.

[0086] The device 16 thus comprises a spiral outer sleeve 23 having a first sleeve end 24 and a second sleeve end 25, and a spiral inner sleeve 26 supported therein.

[0087] The spiral inner sleeve 26 is adjustably supported in the spiral outer sleeve 23 by means of a thread pair which is preferably formed as a spiral thread, so that the spiral inner sleeve 26 and therefore the screw 8 executes a superimposed movement consisting of an axial and a rotational movement, whereby the screw 8 accommodated in the device 16 rotates about the rotation axis Z8, as shown in FIG. Fig.14 As indicated by the arrow in .

[0088] The spiral inner sleeve 26 is supported at one end on the screw-in flange 50 in the region of the upper end 24 of the spiral outer sleeve 23 by at least one spring element 29, preferably in the form of a helical spring, wherein the spring element 29 is supported at the other end in the spiral inner sleeve 26, preferably as Fig.19 shown.

[0089] Here, the thread pair preferably has such a pitch that the spiral inner sleeve 26 is easily compressed axially relative to the spiral outer sleeve 23 against the spring force of the preloaded spring element 29, wherein the spiral inner sleeve 26 and therefore the screw 8 rotate simultaneously about the rotation axis Z, while the spiral outer sleeve 23 only performs a translational movement along Z.

[0090] exist Fig.15 The device 16 is shown in a perspective view from the outside.

[0091] A screw-in flange 50 and a mounting flange 51 are shown, wherein the screw-in flange 50 has a viewing window 50A, which is also described. The mounting flange 51 comprises a plug 51A.

[0092] Furthermore, the spiral sleeve 23 is shown from the outside. Below the spiral sleeve 23 a flexible connecting element 52 is arranged, preferably in the form of a bellows, which is connected on the one hand to the second sleeve end 25 of the spiral sleeve 23 and on the other hand to the hold-down device 44 .

[0093] Once the clamping device 44 is in place, the clamping device 44 connected to the elastic bellows holds the screw sleeve 7 via the toothing and thus transmits the torque for screwing in the screw 8 only to the screw 8, wherein the screw sleeve 7 is simultaneously secured against rotation by the clamping device 44. The torque is generated by the helical thread between the spiral outer sleeve 23 and the spiral inner sleeve 26.

[0094] For example, Fig.15 According to Fig. 13B The first barrier sleeve 43 is provided.

[0095] Fig.15 The components of the device 16 shown are also Fig.16 It is shown in, where Fig.16 This allows an inside view of the device 16. The already explained spring element 29 becomes visible here, and a further spring element 53 is shown, which is arranged between the spiral inner sleeve 26 and the hold-down device 44 and is supported on both components. By means of this likewise preloaded spring element 53, when the spiral inner sleeve 26 is rotated about the rotation axis Z8 when the screw 8 is inserted, as described above, a superimposed axial and rotational relative movement of the spiral inner sleeve 26 relative to the hold-down device 44 is possible, wherein when the device with the screw 5 is set on the screw sleeve 7, the hold-down device 44 only performs an axial movement along the Z axis, which in turn is not affected by the screw 5. Fig.16 Not shown.

[0096] Fig.16 Also shown are the components of the length determination component set 54 , and the individual components thereof are described.

[0097] Other Fig.17 Additional features of the device 16 are shown.

[0098] Apart from Fig.15 and 16 In addition to the components, Fig.17The sensor 55 of the length determination component assembly 54 is shown. The sensor system of the length determination component assembly 54 is described in more detail.

[0099] It is also shown that a receiving element 26C with different and / or differently positioned receiving openings is arranged in the spiral inner sleeve 26. Gripping elements 38 with different inner diameters can be arranged in the receiving openings, so that different bolt diameters of M8, M10, M12 and M14 can be clamped by the device 16 or the gripping element 38, so that different gripping elements 38 with different inner diameters are provided for different bolt diameters of M8, M10, M12 and M14.

[0100] It is provided that the gripping element 38, which is designed in the form of an elongated clamp, is arranged displaceably, so that positional deviations relative to a predetermined position of the screw or the rotation axis Z8 of the screw 8 relative to the rotation axis Z7 of the screw sleeve 7 can be compensated when receiving the screw 8 and placing the screw 8. Advantageously, positional deviations of up to 7 mm can be compensated.

[0101] In terms of the movable arrangement of the gripping element 38, the components 52, 44, 43 are provided in detail, wherein the gripping element 38 is arranged in the holding-down device 44 (see Fig.16 ) and relative to Fig.15 The components located above it in the embodiment of the present invention form a movable partial region of the device 16 via a movably arranged bellows 52.

[0102] In other words, in the use position, the lower components 52, 44, 43 can be advantageously pivoted apart transversely relative to the longitudinal axis Z by the introduction funnel 39. This means that a screw 8 which is positioned inaccurately to a certain extent can be accommodated in an improved manner. Similarly, the screw 8 can also be advantageously arranged in an improved manner even in a screw sleeve 7 which is offset in position, i.e. inaccurately positioned to a certain extent. The components used here, in particular the gripping element 38 in the hold-down device 44, are thereby also advantageously better protected from damage. Fig.18 A detail of the length determining component set 54 is shown. The sensor 55 is designed as an inductive sensor.

[0103] In addition, as Fig.19 , 20 , 21 and 22A to 22C, a pin 56 is arranged in the spiral outer sleeve 23 and the spiral inner sleeve 26, which is arranged according to Fig.18 The slider 58 is held in the direction of the arrow P1, wherein the slider 58 is Fig.18 The direction of the arrow P1 is axially along the longitudinal extension Z of the device 16 , which is elastically arranged and displaceably guided in the spiral inner sleeve 26 .

[0104] The length of the pin 56 corresponds to a determined length of one of the bolts 8 having different sizes M8, M10, M12, M14.

[0105] In other words, a set of gripping elements 38 and pins 56 are assigned to each bolt 8, wherein the respective pin 56 has a certain length, according to which the predetermined length of the respective bolt 8 can be detected, which is also according to the Figures 22A to 22C explain.

[0106] That is, when the slider 58 moves axially in the spiral inner sleeve 26, the pin 56 also moves together. It is important here that the slider 58 is axially displaced in the spiral inner sleeve 26 when the pin 56 moves.

[0107] In the initial position, the slide 58 is supported with its underside on the edge of the spiral inner sleeve 26, in particular as Fig.22A as shown in .

[0108] Best as Fig. 20 As shown, the slide 58 is arranged elastically via a further spring element 57. The spring element 57 is supported on the one hand on the upper side of the slide 58 and on the other hand on a support element 61 which carries a second detector element 62 which is designed in the form of a metal sleeve and projects into the screw-in flange 50. The second detector element 62 is described below.

[0109] A first fixed detector element 59 is arranged in the spiral inner sleeve 26 , which first detector element changes its position only together with the spiral inner sleeve 26 .

[0110] The first inductive sensor 55 is arranged in the slide 58 , and its position in the spiral inner sleeve 26 changes as described above.

[0111] Length detection:

[0112] from Fig.18 and related instructions and Figures 22A to 22C Initially, the length determination component set 54 thus essentially comprises a slide 58, a pin 56, an inductive sensor 55 and a first detector element 59, wherein the function of which is described in detail below. To summarize in advance: the bolt length of the bolt 8 is indirectly measured in the sense of "correct length", "too short length" or "too long length" via the pin 56, which is elastically supported in the center of the spiral inner sleeve 26. The pin 56 guides the sensor 55 through the fixed first detector element 59, which is preferably designed as a metal plate.

[0113] If the predetermined length of the screw 8 is correct, the sensor 55 is located in the region of the metal plate and the first detector element 59 supplies the signal pattern S+.

[0114] If the predetermined length of the bolt 8 is not present, i.e. the first detector element 59 does not provide an active signal pattern S+, but rather an active signal pattern S-, the bolt 8 is too short or no bolt 8 is accommodated. Advantageously, the length detection is also used to determine whether one or more bolts 8 may have been lost in transport or may have slipped so that they collide with installation components when placed.

[0115] If the length of screw 8 exceeds a predetermined length, first detector element 59 initially briefly supplies an active signal pattern S+, which transitions to an inactive signal pattern S−.

[0116] Then bolt 8 is simply too long.

[0117] The bolt 8 indirectly measured by the length determination component set 54 has the correct length only when an active signal pattern S+ is detected by the sensor 55 at a preprogrammable time when the bolt 8 is placed in the screw sleeve 7. It can thus be checked whether the bolt 8 has been accommodated, whether the desired / predetermined bolt length is correct, or whether a bolt 8 that is too short or too long has been accommodated by the device 16.

[0118] To make it clear, Figures 22A to 22B , a dashed signal plane is shown at the height of the fixed first detector element 59 , on which the explained signal diagram is formed.

[0119] Fig.22A For example, the first detector element 59, the sensor 55 and the pin 56 are shown in the device 16, but without the bolt 8. The sensor 55 does not reach the first detector element 59; therefore, the signal diagram S- is detected.

[0120] Fig. 22B By way of example, the first detector element 59, the sensor 55 and the pin 56 are shown in the device 16, with the screw 8 also being provided. The sensor reaches the first detector element 59; the signal diagram S+ is thus detected.

[0121] Fig. 22C For example, the first detector element 59, the sensor 55 and the pin 56 in the device 16 are shown, as well as the overlong bolt 8. The sensor 55 first reaches the first detector element 59, which then becomes inactive because the sensor 55 passes by the first detector element 59 due to the overlong bolt 8; thus, the signal diagram S+ / - is detected.

[0122] Monitoring detection:

[0123] Reference Fig.19 The device also comprises a second fixed sensor 60 , which is preferably arranged in the screw-in flange 50 .

[0124] When the spiral inner sleeve 26 contracts relative to the spiral outer spring 26 when accommodating the bolt 8 and directly placing the bolt 8, the second detector element 62 configured in the form of a metal sleeve moves upward together. Once the spiral inner sleeve 26 contracts, the second detector element 62 is guided in front of the second inductive sensor 60. It is thereby recognized whether the spiral inner sleeve 26 is contracted. If the sensor 60 provides an active signal, the spiral inner sleeve 26 is retracted within a predetermined range, that is, with a predetermined stroke.

[0125] Damage Detection:

[0126] 22 , the device also comprises a third fixed sensor 65 , which is also preferably arranged in the screw-in flange 50 .

[0127] When the spiral inner sleeve 26 contracts relative to the spiral outer spring 26 when the bolt 8 is received and placed directly, the second detector element 62, which is constructed in the form of a metal sleeve, moves upwards together. Once the spiral inner sleeve 26 contracts, the second detector element 62 is guided in front of the third inductive sensor 65 if necessary. It is thus detected whether the spiral inner sleeve 26 is retracted too deep, that is, exceeds the predetermined stroke. If the third sensor 65 provides an active signal, the spiral inner sleeve 26 is retracted too far and the device 16 or the industrial robot 13A connected thereto may be damaged. If there is an active signal at the sensor 65, an emergency stop of the industrial robot 13A is set as an operating condition in the robot program.

[0128] Reference Fig.15 , a viewing window 50A is advantageously arranged in the screw-in flange 50. Through this viewing window 50A, programmers and workers can recognize the retraction stroke of the spiral inner sleeve 26. Therefore, the optimal retraction of the spiral inner sleeve 26 can be easily programmed, especially in the programming of the device 16. The optimization of the retraction stroke of the spiral inner sleeve 26 is used to accurately accommodate the bolt 8 and reduce the cycle time; and also to identify critical positions during the operation of the device.

[0129] Before summarizing the process once again in the end, some important, non-final advantages of the device 16 are presented. By indicating the receiving element 26C of the spiral inner sleeve 26, a modular device 16 or a modular tool for all bolt diameters is involved. Very fast placement of the bolt can be achieved automatically. The device 16 does not include actively driven components. The sensors 55, 60, 65 allow sensory monitoring of the parameters. The variable pressing device 44 allows the accessibility of the device 16 to be adjusted relative to the bolt 8. When the bolt 8 is inserted into the screw sleeve 7, larger tolerances between the bolt 8 and the screw sleeve 7 are compensated. In other words, larger position tolerances between 7 and 8 are feasible or tolerable.

[0130] Wear parts, such as the gripping element 38 , can also advantageously be easily replaced.

[0131] The bolt 8 is received by the device 16:

[0132] Reference Fig.21A , 21B The summarized basic method sequence of receiving the bolt 8 is explained again:

[0133] In the first accommodation phase ( Fig.21A ), the three gripping elements 38 in the exemplary embodiment are moved onto the bolt shank 8B of the bolt 8, wherein the bolt 8 is axially centered in the introduction funnel 39. The holding-down device 44 is initially not yet retracted.

[0134] Then in the second accommodation phase ( Fig.21B ), the bolt rod 8B of the bolt 8 moves into the introduction funnel 39, wherein the clamping device 44 is retracted axially along the Z axis in the Z direction relative to the spiral inner sleeve 26 and the spiral outer sleeve 23, wherein the spiral inner sleeve 26 does not perform a superimposed movement consisting of an axial movement along Z and a rotational movement around Z.

[0135] The pressing device 44 is therefore retracted only axially in the direction of the longitudinal axis Z of the device 16. In the third accommodation phase, the gripping element 38 of the device 16 is moved "blockingly" onto the underside of the bolt head, wherein the gripping element 38 generates a friction force with a coefficient of friction relative to the bolt shank 8B of the bolt 8, which friction force is generated by the clamping element 40 acting radially relative to the Z axis.

[0136] The friction is balanced by the forces which displace the spiral outer sleeve 23 relative to the spiral inner sleeve 26. Therefore, if the screw shank 8B slides slightly into the introduction funnel 39 formed by the gripping element 38 and is compacted, no superimposed movement consisting of an axial movement in Z and a rotational movement about Z is performed during the accommodation (spiral outer sleeve 23 and spiral inner sleeve 26).

[0137] As explained, in the third accommodation phase ( Figure 8 ), the clamping element 40 presses the three introduced gripping elements 38 (also called clamping claws) onto the threaded tip of the bolt shank 8B on the circumferential side in the radial direction relative to the Z axis.

[0138] In the fourth accommodation stage, in order to release the bolt 8 from the "magnetic" support plate 21A, the fully accommodated bolt 8 is moved laterally away from the support plate 21A by the programmed industrial robot 13A until the suction force of the "magnetic plate" generated by the single magnet arranged under the support plate 21A is so small that the bolt 8 can be removed and then placed in the screw sleeve 7 at another position controlled by the industrial robot 13A.

[0139] Place bolt 8 through device 16:

[0140] The screw 8 received in this way is positioned above the screw sleeve 7 in a first placement phase of the screw 8 and is placed in the screw sleeve 7, while the screw shank 8B is arranged in the receiving opening 31 of the introduction funnel 39 formed by the three gripping elements 38, preferably as in Fig.13D as shown in .

[0141] The screw sleeve 7 is advantageously mounted in a freely rotatable manner, wherein provision is made for the screw sleeve 7 to be mounted in a floating manner transversely to the Z axis Z and / or the rotation axis Z7 in the X and Y direction to the extent of + / - 3 mm, thereby advantageously resulting in an easier insertion of the screw 8 into the screw sleeve 7 despite the resulting tolerances in the position of the screw sleeve 7. This floating mounting of the screw sleeve 7 is achieved by virtue of the spindle (not shown) of the screw unit 6 being slightly mounted within the tolerances, on which the screw sleeve 7 is arranged, so that the receiving opening 31 is axially opposite the spindle. During the further assembly process, the spindle ensures that the screw 8 arranged in the screw sleeve 7 can be subsequently mounted, i.e. screwed into the chassis, by the screw sleeve 7 being driven by the spindle. In the process, it has been shown that the tolerances resulting from the floatingly mounted spindle are advantageous during assembly, in particular when the screw 8 is introduced into a specified opening in the chassis.

[0142] As mentioned above, in the first placement phase (see Figure 7 and Figure 8 ), when the bolt shank 8B is located in the receiving opening 31 of the introduction funnel 39 formed by the three gripping elements 38, the bolt 8 is positioned above the screw sleeve 7 and is subsequently centered in a further placement phase by further pressing down in the direction of the screw sleeve 7 by the device 16.

[0143] The centering by means of the hold-down device 44 and the clamping element 42 or one of the blocking sleeves 43, 45 has already been explained in detail. Figure 7 ) are centered relative to the screw sleeve 7, that is, Z7 and Z8 are centered along Z in the longitudinal extension of the device 16.

[0144] Then, in the next placement phase, the device 16 continues to press down in the direction of the screw sleeve 7, and the screw sleeve 7 is blocked when the pressing device 44 contacts the screw sleeve 7 via the clamping element 42 or one of the blocking sleeves 43, 45 and blocks it on the rotation side.

[0145] By means of the device 16, the screw sleeve 7 is pressed further downwards against the spring force of the spring element 29 and the spring force of the spring element 49, so that the screw head 8A of the screw 8 enters the screw sleeve 7 directly in the further setting phase and is held in the screw sleeve 7 by the magnetic force of the permanent magnet 9 in the final setting phase (see Fig. 12A and 12B ).

[0146] If this ideal situation is not seen, the bolt head 8A of the bolt 8 directly enters the screw sleeve 7 in the further placement phase, because the outer hexagon of the bolt head 8A is not positioned ideally relative to the inner hexagon of the screw sleeve 7, and the bolt head 8A is supported with its end face on the receiving projection in the end face or inner surface of the screw sleeve 7 (see Fig.13A , 13B ), the threads between the spiral outer sleeve 23 and the spiral inner sleeve 26 act in such a way that when the device 16 is pressed down, in the further placement phase, the spiral inner sleeve 26 rotates until the bolt head 8A is ideally positioned relative to the screw sleeve 7 and enters its internal hexagon (see Fig.14 ). In this case, the bellows as a flexible connecting element 52 is compressed in the longitudinal extension Z of the device 16 .

[0147] This process, in which the spiral inner sleeve 26 undergoes a rotation while the device 16 is pressed axially downward in the longitudinal extension in the further placement phase, is generally the case since the screw head 8A of the screw 8 usually does not enter the screw sleeve 7 directly, as is ideal.

[0148] After the bolt 8 has been successfully placed, the device 16 is lifted off the bolt 8 and the screw sleeve 7. The device 16 assumes its initial position again here, since the spring elements 29, 49 arranged for pretensioning are relieved of stress. The magnetic force of the permanent magnet 9 for holding the bolt 8 in the screw sleeve 7 is set so high that when the device 16 is lifted, the holding force of the clamping device 32 of the device 16 is overcome.

[0149] During the placement of the bolt 8 , the already explained length detection of the bolt 16 in the device 16 , monitoring detection of the device 16 , and damage detection of the device 16 are performed.

[0150] Reference numerals list

[0151] 1 Assemble the frame

[0152] 2 Framework Modules

[0153] 3 Framework Modules

[0154] 4 Framework Modules

[0155] 5' Assembly Facility

[0156] 5'' assembly facility

[0157] 6 screwing units

[0158] 7. Screw sleeve

[0159] 8 Bolts

[0160] 8A bolt head

[0161] 8B bolt rod

[0162] 8C Washer

[0163] 9 permanent magnets

[0164] 10 screw positions

[0165] 11Assembly Area

[0166] 12 bolt storage

[0167] 13 control unit

[0168] 13A Industrial Robot

[0169] 14 Preparation Area

[0170] 15 End member

[0171] 16 devices

[0172] 17 Bracket

[0173] 18 Pre-sorting station

[0174] 19 bolt storage

[0175] 20 Pre-sorting robots

[0176] 21 Pallets

[0177] 21A support plate

[0178] 22Conveying device

[0179] 23 spiral outer sleeve

[0180] 23A spiral profile

[0181] 23B external thread

[0182] 2423 first casing end

[0183] Second casing end of 2523

[0184] 26 spiral inner casing

[0185] 26A spiral profile

[0186] 26B external thread

[0187] 26C housing element

[0188] 26D shaft collar

[0189] 29 Spring element

[0190] 38 Grabbing elements

[0191] 38A fixing hole

[0192] 39 Import Funnel

[0193] 40 Clamping elements

[0194] 41 Guide cannula

[0195] 41A First guide device

[0196] 41B Second guide device

[0197] 42 Clamping element

[0198] 43 first barrier sleeve

[0199] 44 Clamping device

[0200] 45 second blocking sleeve

[0201] 49 notches

[0202] 50 Screw into flange

[0203] 50A observation window

[0204] 51 Mounting flange

[0205] 51A plug

[0206] 52 Flexible components

[0207] 53 Spring element

[0208] 54 Length detection component set

[0209] 55 First Sensor

[0210] 56 pins

[0211] 57 Spring element

[0212] 58 Sliders

[0213] 59 First detector element

[0214] 60 Second sensor

[0215] 61 Support element

[0216] 62 Second detector element

[0217] 65 Third Sensor

[0218] 66 spindle accommodation part

[0219] Z is the axis in the longitudinal extension of the device 16

[0220] Z77's rotation axis

[0221] Z88's rotation axis

[0222] P1 Arrow

Claims

1. A device (16) for receiving a bolt shank (8B) of a bolt (8) and for placing a bolt head (8A) of a bolt (8) into a screw sleeve (7) of an external screw unit (6), wherein: The spiral outer sleeve (23) and the spiral inner sleeve (26) supported in the spiral outer sleeve (23) are adjustably supported in the spiral outer sleeve (23) by corresponding interlocking thread pairs, wherein, as soon as an axial force is exerted on the spiral outer sleeve (23) in the longitudinal extension of the device (16) and the spiral inner sleeve (26) is indirectly supported against the axial force, the device (16) as a whole performs an axial movement in the longitudinal extension (Z) and the spiral inner sleeve (26) performs an axial movement in the longitudinal extension of the device (18). A superimposed movement consisting of an axial movement and a rotational movement about an axis (Z), wherein a spring element (29) is arranged, which supports the spiral inner sleeve (26) axially movably relative to the spiral outer sleeve (23), characterized in that the spiral inner sleeve (26) has a receiving element (26C) at its end facing the bolt (8), and a gripping element (38) protrudes from the receiving element (26C), and the gripping element (38) is supported on the support plate (21A) against axial forces when the device (16) is in use, wherein the gripping element (38) is supported on the support plate (21A) against axial forces, wherein the gripping element (38) is supported on the support plate (21A) against axial forces. The gripping element (38) forms an introduction funnel (39) with a receiving opening (31) for a bolt shank (8B), wherein when the bolt (8) is received by means of a device (16) which is movable only in the axial direction in the longitudinal extension, the bolt shank (8B) is received by the gripping element (38) with the bolt head exposed, wherein when the bolt (8) is placed, the exposed bolt head (8A) of the received bolt (8) is placed in the screw sleeve (7), and the gripping element (38) is supported against axial forces in the screw sleeve (7). 7), the spiral inner sleeve (26) performs a superimposed axial rotation relative to the spiral outer sleeve (23), wherein a clamping device (44) is arranged on the spiral outer sleeve (23) and can be axially displaced in the longitudinal extension of the device (16), and when the bolt head (8A) is arranged in the screw sleeve (7), the clamping device blocks the rotation of the screw sleeve (7), which is caused by the bolt shank (8B) acting from the spiral inner sleeve (26) on the bolt (8) and on the screw sleeve (7) when the contact is placed.

2. The device (16) according to claim 1, characterized in that The device (16) has a length determination component set (54) which allows the length of the bolt (8) to be detected when the bolt (8) is placed, wherein the length determination component set (54) includes components (55, 56, 57, 58, 59, 61).

3. The device (16) according to claim 1, characterized in that The device (16) has units (57, 58, 60, 62) which allow monitoring detection during the placement of the bolt (8), wherein the retraction of the spiral inner sleeve (26) relative to the spiral outer sleeve (23) via the spring element (29) within a predetermined retraction range is detected.

4. The device (16) according to claim 1, characterized in that The device (16) has units (57, 58, 62, 65) which allow damage detection when placing a screw (8), wherein it is detected that the spiral inner sleeve (26) is retracted further relative to the spiral outer sleeve (23) via the spring element (29) than within a predetermined retraction range.

5. The device according to claim 1, characterized in that The hold-down device (44) has a clamping element (42) which clamps the screw sleeve (7) on its outer circumference during the placement so that a rotation acting on the screw sleeve (7) is blocked during the placement contact.

6. The device (16) according to claim 1, characterized in that The clamping device (44) is provided with a toothed portion on the end side, and when the bolt (8) is placed in contact with the screw sleeve (7), the toothed portion engages into the opposite toothed portion of the first blocking sleeve (43), wherein the first blocking sleeve (43) is fixedly arranged on the outer circumference of the screw sleeve (7) in a form-fitting and / or friction-fitting and / or force-fitting manner, so that rotation acting on the screw sleeve (7) is blocked when the screw sleeve (7) is placed in contact.

7. The device (16) according to claim 1, characterized in that The clamping device (44) is provided with a toothed portion on its inner circumference, and when the bolt (8) is placed in contact with the screw sleeve (7), the toothed portion engages with an opposite toothed portion on the outer circumference of the second blocking sleeve (45), wherein the second blocking sleeve (45) is arranged on the outer circumference of the screw sleeve (7) in a form-fitting and / or friction-fitting and / or force-fitting manner, so that rotation acting on the screw sleeve (7) is blocked when the screw sleeve (7) is placed in contact.

8. The device (16) according to claim 1, characterized in that When the screw (8) is received and placed, the gripping element (38) is pressed onto the screw shaft (8B) by means of a clamping element (40) in a radial direction relative to an axis Z extending centrally in the longitudinal extension of an inlet funnel (39) of the device (16), wherein the clamping element (40) is in particular a rubber ring which elastically surrounds the gripping element (38).

9. The device (16) according to claim 1, characterized in that The intermeshing pair of threads is a helical thread.

10. A method for receiving a bolt shank (8B) of a bolt (8) by means of a device (16) according to at least one of claims 1 to 9, characterized in that When the device (16) moves downwardly relative to the bolt (8), wherein the bolt is on an axis (Z) located in the longitudinal extension of the device (16), In a first receiving phase, the gripping element (38) of the device (16) is moved past the bolt shank (8B) of the bolt (8), wherein the bolt (8) is axially centered in the introduction funnel (39) formed by the gripping element (38), wherein then, as the device (16) is moved further downwards, In the second accommodation phase, the bolt shank (8B) of the bolt (8) is moved into the introduction funnel (39), wherein the pressing device (44) is retracted axially only in the longitudinal extension of the device (16) relative to the spiral inner sleeve (26) and the spiral outer spring (23), wherein then, when the device (16) is moved further downwards, In a third accommodation phase, the gripping element (38) is "closely" moved onto the underside of the bolt head (8A), wherein the gripping element (38) generates a friction force with a friction coefficient relative to the bolt shank (8B) of the bolt (8), which friction force is generated by the clamping element (40) acting radially relative to the axis (Z) located in the longitudinal extension of the device (16).

11. A method for placing a bolt head (8A) of a bolt (8) in a screw sleeve (7) of an external screw unit (6) by means of a device (16) according to at least one of claims 1 to 9, characterized in that When the device (16) moves downwardly relative to the bolt (8), wherein the bolt is on an axis (Z) located in the longitudinal extension of the device (16), In a first placement phase, the bolt (8) received in the device (16) is positioned on the screw sleeve (7), wherein then, as the device (16) is moved further downwards, In a second placement phase, the screw (8) and the screw sleeve (7) are centered by the pressing device (44) on an axis (Z) located in the longitudinal extension of the device (16), wherein then, when the device (16) is moved further downwards, In the third placement phase, the screw sleeve (7) is blocked on the rotation side by the hold-down device (44), wherein then, as the device (16) is moved further downwards, In a fourth placement phase, the bolt head (8A) of the bolt (8) enters the screw sleeve (7) against the spring force of the spring element (29), wherein the spiral inner sleeve (26) undergoes a rotation relative to the spiral outer sleeve (23) about an axis (Z) located in the longitudinal extension of the device (16) until the bolt head (8A) is ideally positioned relative to the screw sleeve (7) and enters the inner hexagon of the screw sleeve (7), wherein then, when the device (16) is moved further downwards, In the fifth placement phase, the magnetic force of the permanent magnet (9) at the hexagonal base of the screw sleeve (7) magnetically holds the screw sleeve (7).

Images