DE202022104212U1 - Suction tube system and device therefor - Google Patents

Abstract

Suction pipe system (B) for a joining device (V), with a suction pipe (P) formed around a pipe axis (Z _R ) along a longitudinal direction (Z), the suction pipe (P) comprising a pipe part (R) and a sleeve (H). , and wherein the sleeve (H) can be connected via a sleeve section (A _H ) to a tube section (A _R ) of the tube part (R) (connected state) and detachable therefrom (released state), characterized in that the sleeve section (A _H ) and the pipe section (A _R ) have projections (V _H , V _R ) and undercuts (H _H , H _R ), whereby in the connected state a projection of the sleeve section (A _H ) has an undercut ( _HR ) of the pipe section and/or a projection (V _R ) of the pipe part section (A _R ) engages behind an undercut (H _H ) of the sleeve section (A _H ) in a form-fitting manner in such a way that a relative movement of the sleeve (H) and pipe part (R) in the longitudinal direction (Z) is blocked.

Description

The present invention relates to a suction tube system which is provided for a joining method in which a fastening element is introduced into a workpiece. The method can in particular be a screwing process in which a screw is screwed into a thread of a workpiece. Instead of a screwing process, one can generally speak of a joining process.

In particular, the fastening element can be a substantially rotationally symmetrical screw with a shank-possibly tapering to a point-with a threaded section and a head which is radially expanded relative to the shank and adjoins the shank at the rear. In general terms, the fastening element can therefore also be referred to as a screw.

The joining process, which is known per se, takes place with the aid of a joining device (also fastening device or screwing device), which is carried by a robot, for example, and can be moved in space on multiple axes in order to be able to position the screw appropriately on the workpiece. With the joining device, the screw is placed on the workpiece with its point first. The screw is then screwed into the workpiece. Finally, the screw is screwed into the workpiece up to the head rest and tightened (final tightening).

In preparation for this process, the screw is fed through a feed to the joining device and is initially held there in a ready position, from which the screw is introduced into the workpiece in a longitudinal direction Z.

In practice, the problem often arises that the joining position on a workpiece is not freely accessible, for example due to disturbing workpiece edges or unfavorable workpiece shapes. Then, due to its dimensions, a head of the joining device holding the screw cannot be brought sufficiently close to the joint in order to be able to place the screw on the workpiece without any problems.

Here you can help yourself with a suction pipe carried by the joining device and protruding from it. The screw is pre-positioned at its free front end in a suitable process step. The intake manifold can be subjected to a negative pressure and is temporarily closed at its free front end by the head of the screw. This holds the screw in place and, with the help of the suction tube protruding from the joining device, it can also be positioned in hard-to-reach areas of the workpiece for the subsequent joining process. Inside the suction tube, a receiving rod that can be displaced in the longitudinal direction relative thereto is guided. At its rod end facing the free front end of the suction pipe there is a tool which can be detached from the receiving rod and which can engage in an engagement feature in the screw head in order to set the screw in rotation and screw it into the workpiece.

Preferably, the suction tube is as narrow as possible and ideally the outside diameter is not larger than the outside diameter of the screw head in order to also reach joining positions that are difficult to access. On the other hand, the receiving rod guided inside the intake manifold should have the largest possible outer diameter in order to transmit sufficiently large torques into the fastening element. This suggests that the wall thickness of the intake manifold should be as small as possible, which places special demands on the stability of the intake manifold. In addition, the suction pipe is exposed to high wear at the front free end, in particular when the fastening element held there is set in rotation by the tool, while it is held on the non-rotating suction pipe by means of negative pressure.

The production of such intake manifolds with appropriate material properties is complicated and expensive. In addition, in previously known practice, the replacement of the suction tube or its removal from the joining device always takes place together with the receiving rod arranged therein, in a time-consuming and cost-intensive manner.

It was therefore the object of the invention to overcome the aforementioned disadvantages and to offer a structurally simple and cost-effective alternative to the intake manifolds known hitherto. The object is achieved by an intake manifold system according to claim 1 or an associated joining device according to claim 11.

The invention is based on the finding that only the front section of the suction tube facing the workpiece or the screw is exposed to particular loads or particular wear. In a first step of the invention, a two-part suction pipe was therefore developed, consisting of a rear part of the pipe facing away from the fastening element, which is carried by the joining device and can be subjected to the negative pressure and is generally exposed to less wear. The pipe part is at a front, the fastener or the workpiece facing pipe section with a sleeve portion of a particularly wear-resistant and stable sleeve detachably connected, which forms the free front end of the intake manifold. When the sleeve is connected to the tubular part (“connected state”), the negative pressure generated in the tubular part continues to act as far as the front free end of the sleeve, so that the fastening element can be temporarily held there in the manner described above.

During operation, the sleeve is exposed to higher loads and higher wear than the tubular part. Since the sleeve is detachably connected to the tube part, it can advantageously be replaced easily and quickly for maintenance or repair purposes, without having to remove the entire suction tube from the joining device and replace it. In addition, the requirements for special wear resistance or surface hardness or strength can be limited to the sleeve, which is particularly stressed in the joining process, while lower requirements can apply to the pipe part. As a result, manufacturing and maintenance costs can be saved.

In a further development of the invention, it was recognized as advantageous to improve and speed up the replacement of the sleeve by creating a particularly simple connection between the sleeve section and the tubular section that can preferably be actuated without tools. It is in principle conceivable to screw the sleeve to an external thread provided on the tubular part, for example via an internal thread. However, its production is expensive and due to the wall thickness of the sleeve and tubular part that has been selected to be as small as possible anyway, it can only be achieved at the expense of compactness or strength.

According to the invention, a connection with undercuts and thus mutually positively interacting projections on the sleeve section or on the tubular section was created. In the connected state, a projection of the sleeve section engages behind an undercut of the tubular section and/or a projection of the tubular section engages an undercut of the sleeve section, so that a relative movement of the sleeve and tubular section in the longitudinal direction is blocked. The sleeve is fixed relative to the tubular part at least in the longitudinal direction Z by the undercuts formed in this way. In order to separate the sleeve and the tube part from each other (released state), it is only necessary to disengage the projections and undercuts.

The interlocking projections or undercuts are preferably designed in such a way that the sleeve and tubular part are also positively connected to one another in the circumferential direction, that is to say non-rotatably. A torque introduced into the suction pipe on the sleeve is then passed on into the pipe part, for example in order to release the suction pipe from a bayonet lock on the head of the joining device.

According to a preferred embodiment, the projections and undercuts interacting with one another are designed in such a way that the sleeve can be detached from the pipe part by laterally displacing the sleeve section relative to the partial pipe section orthogonally to the longitudinal direction. The transfer from the connected to the released state is very easily possible by a simple, preferably purely translatory relative movement between the sleeve and the tubular part, which--unlike a screw connection, for example--can be carried out very quickly. The sleeve and tube part can then preferably be connected to one another or separated from one another along a straight direction of movement, preferably without tools.

According to an advantageous embodiment, the sleeve section and the tubular section touch each other in the connected state along a contact surface formed by the projections and undercuts, which is designed in such a way that a cut through the contact surface orthogonal to the longitudinal axis (Z) produces exclusively parallel cutting lines of the contact surface . In other words: the contact surface always runs parallel to the transverse direction Y (imagined orthogonal to the longitudinal axis (Z)) in which the sleeve and tubular part can be displaced relative to one another and detached from one another. This ensures that the sleeve can be detached from the pipe part by means of a movement orthogonal to the longitudinal axis Z relative to the pipe part. In this case, the undercuts or projections forming the contact surface can be produced particularly easily—in contrast to, for example, a screw connection—for example, by means of a preferably cutting or eroding tool guided purely translationally along the sleeve or the tubular part.

Preferably, the sleeve and/or the tubular part is designed as a hollow body in order to be able to accommodate a receiving rod with a tool. The sleeve and/or tube part are particularly preferably designed as a hollow cylinder with a cylinder wall running between the inner diameter and the outer diameter. Appropriately, the following condition applies to the ratio of the wall thickness s to the outer diameter D for the sleeve and/or the pipe part: $$\text{s}/\text{D<0}\text{,333}\text{, preferably s}/\text{d<0}\text{,1}$$

A fastening element designed as a screw could, for example, have a head diameter of 6 mm or more, which temporarily closes a sleeve with an outer diameter of approximately the same size at its front free end. Typical applications are screws with a metric thread, e.g. M3 to M6 or larger. The wall thickness of the sleeve and/or the tube part is preferably not less than 1.5 mm.

The sleeve and/or tube part can expediently have the same inside and/or outside diameter and thus, when connected, form a continuous suction tube with an outside contour and/or inside contour that is largely constant in the longitudinal direction.

According to an advantageous embodiment, the undercuts and/or projections are formed by material-free areas in the cylinder wall. The material-free areas preferably penetrate the cylinder wall completely from the inside to the outside. According to such an embodiment, it is provided that the sleeve section and/or the partial pipe section has at least one material section that protrudes from a base body section in the longitudinal direction Z and is tapered or reduced when viewed in the circumferential direction as an undercut, on which in the longitudinal direction Z there is a material area that is expanded when viewed in the circumferential direction as a projection connects. In this embodiment, the protruding material section of the sleeve or the tubular part extends forwards as a tongue, as it were, in the longitudinal direction and engages there with its expanded material area behind a complementary undercut of the tubular part or the sleeve. The protruding material area preferably has the same wall thickness as the respective (preferably cylindrical) base body section of the sleeve or the tubular part. Such material sections can be produced particularly easily from cylindrical blanks of the sleeve or tube part by removing part of the cylinder wall at the mutually facing ends of the sleeve section and the tube part section, while the remaining part forms the respective material section. This will become clear from the figures.

According to one embodiment, it is sufficient if exactly one protruding material section is provided on the sleeve section and the partial pipe section, which engages in an undercut formed in a complementary manner thereto on the respective other element. As a result, the contact surface between the two elements is kept as small as possible in the connected state in order to prevent the undesired inflow of air into the intake manifold, which is subjected to negative pressure, in this area.

According to another advantageous embodiment, exactly two protruding material sections are provided on the sleeve section and the partial pipe section, which are each arranged symmetrically to a plane of symmetry lying in the pipe axis. Such material sections can be produced particularly easily by guiding the tool straight and allow the sleeve to be detached from the tubular part in one of two removal directions which run opposite to one another and are orthogonal to the longitudinal axis. In this case, too, the entire contact surface extends parallel to a transverse direction Y, which is orthogonal to the longitudinal axis Z. An exception to this would be another advantageous variant, in which a stop or projection acting transversely to the longitudinal axis Z would be formed on the sleeve section or the tubular section , which is intended to prevent the relative movement between the sleeve and the tubular part in the transverse direction in a certain relative position assumed. This can be helpful in aligning the sleeve precisely with the pipe part when connecting it.

The sleeve or the tubular part can each be made in one piece, for example by being manufactured starting from a cylindrical blank. The sleeve and tube part can differ with regard to the respective manufacturing process, the material or materials used, possible surface treatments, coatings, etc., in order to meet the different requirements in use, for example.

• - Aufnahme eines Werkzeugs für das Befestigungselement
• - Blockade bzw. Freigabe einer Relativbewegung von Hülse und Rohrteil quer zur Längsrichtung.

According to an advantageous development of the invention, the suction pipe system comprises, in addition to the sleeve and the pipe part, a receiving rod designed in the longitudinal direction Z, which can be designed in particular to receive a tool, which interacts with an engagement profile on the fastening element in order to be able to join the latter into the workpiece. In an inventive interaction with the detachable connection between the sleeve and the tubular part, the receiving rod in the connected state can be inserted and positioned in the longitudinal direction Z in the arrangement of the tubular part and the sleeve connected to it such that the receiving rod can cause the sleeve to move relative to the tubular part orthogonally to the longitudinal direction Z by positive locking blocked between the receiving rod S on the one hand and the sleeve or tubular part on the other hand (blocked condition). This means that the recording staff has a double function in an inventive way:

• - Recording of a tool for the fastener
• - Blocking or releasing a relative movement of sleeve and pipe part transversely to the longitudinal direction.

In the connected state--as already described above--the sleeve and the tube part are fixed relative to one another in the longitudinal direction Z by the interlocking projections or undercuts. According to the invention, the two elements can basically be detached from one another by a relative movement between the sleeve and the tubular part orthogonally to the longitudinal direction (ie in the transverse direction). The arrangement of the receiving rod within the suction tube ensures in a simple manner that this relative movement in the transverse direction is also suppressed, so that the sleeve and tube part remain securely connected to one another in a form-fitting manner. For this purpose, a guide section is preferably formed on the receiving rod, which on the inside abuts as narrowly and without play as possible on the contour of the sleeve section and the tubular section section connected thereto, where the two parts engage. As a result, the two parts are aligned precisely and preferably concentrically to one another and are forced to remain in this arrangement as long as the receiving rod or its guide section acts on the connection point on the inside.

The sleeve on the intake manifold according to the invention can be replaced particularly easily, preferably even without tools. All that is required is for the receiving rod to be pushed forwards or backwards relative to the suction pipe so far that it releases the connection area between the sleeve and the pipe part on the inside, in order to allow the lateral relative movement of the two parts in the transverse direction. This allows the projections and undercuts to be disengaged and the sleeve free for removal. Conversely, the sleeve can be connected to the tubular part by laterally pushing the sleeve with its projections and undercuts into the complementary shape on the tubular part. After inserting the pick-up rod, this transverse movement is positively blocked and the suction tube with a new sleeve can be used.

A fit that is as precise as possible between the sleeve section and the partial pipe section also produces a largely play-free and therefore tight connection in the longitudinal direction Z. This is important if the suction pipe is to be subjected to a negative pressure without unwanted air being able to penetrate in the connection area between the sleeve and the pipe part. In order to be able to transmit the negative pressure in the longitudinal direction through the connection area to the front free end of the sleeve (where the head of the fastening element is held by the negative pressure at the sleeve end), according to one embodiment of the invention in the sleeve and/or the tubular part and /or the receiving rod formed suction channels, which pass through the connection area without impeding the form-fitting connection between the sleeve and the tubular part. For example, the receiving rod can have longitudinal grooves along its lateral surface in the region of its guide section. In addition or as an alternative, longitudinal grooves can also be provided on the inside of the sleeve section and the tubular section.

A joining device according to the invention with a suction tube system as described above is designed to carry out a joining method in which a fastening element is introduced into a workpiece (joining) and the fastening element previously temporarily closes the sleeve end facing away from the tube part and thus by a negative pressure generated in the suction tube at the sleeve end can be held in order to bring the fastening element to the intended joint location by moving the suction pipe.

To carry out the method, a receiving rod guided within the suction tube can preferably be driven to rotate about its longitudinal axis with a torque, preferably a predetermined one, with the receiving rod being displaceable in the longitudinal direction Z relative to the suction tube and being designed to receive a tool at its front end facing away from the tube part is. As a result, the tool can engage in a fastening element held on the sleeve end by advancing the locating rod, with the locating rod being movable after engaging in the fastening element together with the suction tube and/or relative thereto in the longitudinal direction Z in order to join the fastening element positioned at the joining location into the workpiece .

• Dazu ist folgender Verfahrensablauf vorgesehen:
  1. a) In einem ersten Verfahrensschritt wird das vom Werkzeug gegriffene Befestigungselement in Richtung auf das bzw. in das Werkstück bewegt, während das Befestigungselement das Hülsenende noch verschließt und durch Unterdruck im Saugrohr gehalten wird.
  2. b) In einem daran anschließenden zweiten Verfahrensschritt wird der Aufnahmestab mit dem Werkzeug soweit relativ zum Saugrohr vorgeschoben, dass das währenddessen mit dem Werkzeug ins Werkstück gefügte Befestigungselement vom Hülsenende abgehoben wird, um den Kontakt bzw. die Reibung zwischen Befestigungselement und Hülsenende aufzuheben.

The suction tube according to the invention facilitates the pre-positioning of the fastening element, even in places that are difficult to access. However, friction is generated between the front free end of the sleeve and the fastening element held there by the vacuum when the fastening element is rotated by the tool, while the suction tube does not carry out this rotational movement. There is often a requirement to insert or screw the fastening element into the workpiece with a specified torque or a torque that is to be measured precisely. The process section of the final tightening (see above) is particularly important. The applied torque should be able to be recorded here with as little disruption as possible. However, this is possible through a special process sequence, for which the suction pipe described above can also be used:

• The following procedure is provided for this:
  1. a) In a first method step, the fastening element gripped by the tool is moved in the direction of or into the workpiece, while the fastening element still closes the end of the sleeve and is held in the suction tube by negative pressure.
  2. b) In a subsequent second process step, the receiving rod with the tool is advanced so far relative to the suction tube that the fastening element that has been inserted into the workpiece with the tool is lifted from the end of the sleeve in order to eliminate the contact or friction between the fastening element and the end of the sleeve.

This ensures in a particularly elegant manner that the torque introduced into the fastening element is not impaired by friction losses between the fastening element and the intake manifold. The second method step is initiated before the fastening element has experienced the final tightening, and can also include further joining steps that take place earlier. In principle, the method allows the fastening element to be lifted off the intake manifold at any moment during the joining process. Preferably, however, the contact between the fastening element and the suction tube is only eliminated when the fastening element is inserted sufficiently deep or stable into the workpiece in order to have sufficient support for further joining even without contact with the suction tube.

According to a further advantageous embodiment of the invention, it is provided that the rear end of the suction tube facing away from the sleeve is received and mounted in the joining device with the aid of a spring-loaded seat. The suction tube is pressed into the seat by spring force and assumes a position that is preferred in the process, which can also be referred to as the starting position. If the intake manifold is subjected to forces in the longitudinal direction or transversely thereto, for example in the region of the sleeve, the spring preload allows the intake manifold to be temporarily moved out of its seat and slightly shifted or tilted laterally and/or longitudinally. The holding rod guided inside the suction tube is also coupled to the head of the joining device in such a way that it can carry out the slight tilting movement of the suction tube.

Said lateral loading can, for example, come from a screw which “finds” its thread during assembly and is screwed in along the thread axis if this axis does not perfectly match or align with the longitudinal axis of the suction pipe or the receiving rod. The screw then “forces” the tool to slightly correct the position of the receiving rod and the suction pipe, which is in contact via the guide section, which is made possible by the spring-loaded suspension according to the invention.

After the end of the loading, the intake manifold and the receiving rod automatically return to the initial position predetermined by the seat due to the spring preload. This recording makes it possible to slightly displace the suction tube relative to the joining device before or during the joining process in order to compensate for positioning tolerances. As a result, deformations or even breakage of the suction tube or the receiving rod are advantageously avoided.

The suction pipe can preferably be removed from the joining device without tools using a bayonet lock. It is particularly helpful that the receiving rod guided inside the suction tube can remain connected to the joining device during this time. In this case, after unlocking it from the bayonet lock, the suction pipe can simply be pulled off the joining device in the longitudinal direction, which at the same time eliminates the blocking effect of the receiving rod in the connection area between the sleeve and the pipe part. The tool held by the receiving rod is then freely accessible for replacement, and the suction tube can also be replaced as a whole or in parts (sleeve or tube part).

The inventive idea for simplified detachment of a sleeve from the tubular part was described above in a variant in which an essentially undivided receiving rod stabilizes the detachable connection between the sleeve and tubular part in a form-fitting manner. However, it is also conceivable, alternatively or additionally, to design the receiving rod in two parts, with the two parts arranged one behind the other in the longitudinal direction being connectable to one another by means of projections and undercuts in a manner analogous to the manner described above for the suction tube. This can be useful if, for example, the replacement of the complete (one-piece) receiving rod is unnecessary or expensive and instead only a certain section of it is to be designed to be detachable. A suction tube pushed over this connection then serves to block a lateral relative movement of the receiving rod parts in a form-fitting manner, vice versa, analogously to the function of the receiving rod in the variant described in detail above. In this case, the intake manifold could be designed in one piece or in several parts. In particular, both the suction tube and the pickup rod could have components that can be positively connected to one another according to the type described for the sleeve and the tube part, with the suction tube and receiving rod then blocking each other positively against a lateral loosening movement (preferably the connecting areas of the suction tube parts are then shaped differently than the connecting areas of the receiving rod parts and/or in the circumferential direction or offset in the longitudinal direction).

The invention is also not limited to exactly two parts to be connected to one another in a form-fitting manner, as is described with reference to the sleeve and the tubular part. The suction tube or pick-up wand may also comprise three or more elements connected in tandem in this way.

Although the present invention is geared in particular in connection with the joining of screws into existing threads, the suction pipe according to the invention can theoretically also be used for joining flow-drilling screws, which form their own thread in the workpiece during the joining process.

Any other type of fastening element can also be positioned with the suction pipe according to the invention if the fastening element is suitable for temporarily closing the suction pipe at its front free end in order to be held in place by the negative pressure in the suction pipe. In addition, for example, the suction pipe itself could also be driven in a rotational and/or translational movement for loading and joining a fastening element held by it. For this purpose, the suction tube could have a suitable engagement profile at the front free end in order to interact with the fastening element. A safety bar guided inside the intake manifold could then ensure the form fit based on the example of the guide section of the receiving bar, but without having to hold a tool at the same time.

• 1 einen Ausschnitt einer Fügevorrichtung in vereinfachter perspektivischer Ansicht, teilweise geschnitten,
• 2 eine erfindungsgemäße Verbindung zwischen Hülse und Rohrteil,
• 3 einen vergrößerten Ausschnitt aus 2, und
• 4 ein erfindungsgemäßes Saugrohrsystem mit Hülse, Rohrteil und Aufnahmestab.

The invention is explained in more detail below using a figure example. while showing

• 1 a section of a joining device in a simplified perspective view, partially sectioned,
• 2 a connection according to the invention between sleeve and tubular part,
• 3 an enlarged section 2 , and
• 4 an inventive suction pipe system with sleeve, pipe part and pick-up rod.

1 shows a perspective view of the front part of a joining device V, which can be carried and positioned by a robot, for example. The joining device V comprises a suction pipe system B with a suction pipe P, which extends along its pipe axis Z _R , which runs in a longitudinal direction Z. The suction pipe P comprises a longer pipe part R at a rear end facing the device V and a shorter sleeve H at a front end facing away from the joining device Shaft and has a head that is enlarged relative to the shank.

The intake manifold P can be subjected to a negative pressure by means that are not specified in more detail. The expanded head of the fastening element L closes the suction tube P at the free end M, whereby the fastening element L can be held there temporarily and arranged together with the suction tube P at a joining position in order to be joined there in a workpiece Q shown in simplified form. In particular, the fastening element L can be a screw which is screwed into the workpiece by rotation. A tool W positioned within the suction tube P and held by a locating rod T engages the head of the fastener for assembly, as shown in FIG 4 will still be seen.

The rear end of the suction pipe P can be detachably connected to the head of the joining device V via a spring-loaded bayonet catch J. A spring pushes the suction tube forwards in the longitudinal direction Z towards the free end M and at the same time into a seat which determines the position of the suction tube relative to the joining device (initial position). On the intake manifold - for example in the region of its sleeve H - acting loading in the longitudinal direction Z or transversely thereto allows a (preferably small) movement of the intake manifold against the spring force from its initial position. When the pressure ends, the intake manifold automatically moves back to its original position due to the spring force. Also regarding 4 The receiving rod T described in more detail is arranged at the head of the joining device V in such a way that it can follow the movement of the suction pipe from the starting position.

By briefly pushing the suction tube in the direction of the head of the joining device and then turning it around the tube axis Rz - e.g. clockwise - the suction tube P can be released from the bayonet catch and pulled out of the device V towards the front. In the reverse procedure, the intake manifold can be inserted into the front reinsert direction. A related to 4 The receiving rod T, which is described in more detail and is arranged inside the suction tube, can remain in the device V and can be exposed by removing the suction tube P.

2 shows the pipe part R with the sleeve H in an enlarged view. The sleeve H, which is designed as a hollow cylinder around the tube axis (not shown), comprises a base body G _H and a sleeve section A _H adjoining it and facing the tube part R. The hollow-cylindrical tubular part R also comprises a base body G _R , which is adjoined by a partial tubular section A _R facing the sleeve. In the illustrated embodiment, the outer diameter D of the sleeve H also corresponds to the outer diameter of the tubular part R. The wall thickness s of the sleeve H also corresponds to the wall thickness of the tubular part R (apart from special profile areas within the sleeve H or the tubular part R).

According to 3 showing an enlarged detail 2 shows, the sleeve section A _H comprises two projections V _H protruding from the base body G _H in the longitudinal direction Z, which each comprise a section that is reduced in the circumferential direction and an adjoining section that is widened again in the circumferential direction. The two protrusions are symmetrically opposed to each other with respect to the tube axis (and are only partially visible in the figure representation). In this embodiment, each reduced section also forms two undercuts H _H in the sleeve section A _H (for each of the two projections V _H there is an undercut in 3 designated).

In a comparable manner, two projections V _R of the tubular section A _R extend in the longitudinal direction Z towards the sleeve H, starting from the tubular part base body G _R . These projections V _R also each include a region that is reduced in the circumferential direction, which then widens again when viewed in the longitudinal direction Z, thereby forming undercuts H _R on the tubular part R. The projections or undercuts of the tube part R are also formed opposite one another symmetrically to the tube axis, only one of the two projections V _R of the tube part being clearly visible in the figures. The projections on the sleeve section A _H and/or on the partial pipe section A _R are preferably produced purely by removing material from the cylinder wall.

The sleeve H can be connected to the tubular part R in a lateral or orthogonal relative movement to the longitudinal direction Z by pushing the projections V _R of the tubular part R into the undercut of the sleeve H and at the same time the projections V _H of the sleeve H into the undercuts H _R am Pipe part are introduced and thereby interlock positively. The big arrows in 2 indicate this relative movement. After the mutual engagement, the sleeve H and the tubular part R are positively connected to one another and are thereby secured against movement relative to one another in the longitudinal direction Z. For example, this state is in 1 or 4 shown. In the connected state, the sleeve and the tube part are exactly aligned one behind the other when viewed along the longitudinal direction or tube axis Z _R . In the connected state, the sleeve is also non-rotatably positively connected to the tube part, so that a torque introduced into the sleeve H can be transmitted into the tube part R—as free of play as possible.

In this state, the sleeve and tube part touch along a contact surface F. The interlocking projections or undercuts are made to fit so precisely that the sleeve H is ideally connected to the tube part R without play when it is connected, and the connection point is therefore designed as tightly as possible. This ensures that a negative pressure built up in the intake manifold P is maintained as best as possible without undesired air getting into the interior of the intake manifold along the contact surface from the outside.

From the 2 and 3 it becomes clear that the sleeve H can be detached particularly easily from the tubular part R in a relative lateral movement, preferably even without the aid of a tool. The front part of the suction tube that is particularly exposed to wear, namely the sleeve that is designed separately according to the invention, can thus be replaced easily and inexpensively without having to replace the entire suction tube.

In order to also secure the connection between the sleeve H and the pipe part R transversely to the pipe axis Z _R , the invention makes use of a receiving rod T, which according to 4 is guided inside the intake manifold P. This representation shows a selected area of the intake manifold system B, namely the foremost section of the intake manifold R and the sleeve H connected thereto, in a simplified sectional representation. A receiving rod T formed about the pipe axis Z _R extends inside the suction pipe P and carries a tool W in the form of a bit at its tip. The tool W is intended to engage in a gripping feature formed in the head of the fastener L in order to loosen the fastener L to be able to apply a torque (and a feed force).

The receiving rod T can be moved relative to the suction tube P in the longitudinal direction Z and can rotate about its longitudinal axis via a drive that is not shown in detail. For example, he can go so far pushed forward inside the suction tube until the tool W engages the head of the fastener L. At this point in time, the fastening element L is still held at the front end M of the sleeve H by the negative pressure built up in the intake manifold. The fastening rod T can then be advanced together with the suction tube or relative thereto in the longitudinal direction Z in order to insert the fastening element L into the (in 1 indicated) to screw workpiece Q. 4 shows a state in which the receiving rod T has already been pushed forward so far relative to the suction pipe P that the tool W has separated or lifted the fastening element L from the free end M of the sleeve. This method step preferably takes place only after the fastening element has been inserted sufficiently deep into the workpiece, without requiring a further stabilizing holder at the front end of the sleeve H. By separating the (rotating) fastening element L from the sleeve H, frictional forces between these components are advantageously avoided.

The receiving rod T comprises a guide section E, which rests closely against the sleeve or the tube part on the inside where their projections and undercuts engage in one another in the connected state. The guide section E of the receiving rod T thus prevents the in 2 indicated lateral relative movement between sleeve H and tube part R, so that the two components in the connected state and with the receiving rod T inserted into the suction tube P are securely and precisely fixed to each other both in the longitudinal direction Z and orthogonally to it. According to the invention, the receiving rod assumes a dual function in that on the one hand it carries the tool W and can be moved relative to the suction pipe P, and on the other hand it interacts with the projections or undercuts of the sleeve and the pipe part in a form-fitting manner inside the suction pipe P orthogonally to the longitudinal direction Z. The axial length of the guide section E is preferably chosen so that in every relative position between the receiving rod T and the suction pipe P that is required for proper operation, the connection between the sleeve H and the pipe part R remains securely blocked in a form-fitting manner.

In order to separate the sleeve from the tube part, it is first necessary to loosen the suction tube P from the bayonet fitting J on the head of the joining device V and pull it forwards. The receiving rod T, which is held unchanged by the joining device V, with its guide section E, then slides out of the suction pipe relative to the latter, so that the lateral form fit between the sleeve and the pipe part is eliminated. The sleeve can then be disengaged from the tubular part by lateral displacement relative to the latter. The assembly - for example with an exchanged new sleeve - is done in reverse order.

In order to be able to pass on a negative pressure introduced at the rear end in the suction pipe P to the front free end M or to be able to build it up there, several suction channels K are provided in the inner cylinder wall of the sleeve and the pipe part, which flow with the front free end M of the sleeve H connect to the rear end of the intake manifold. The suction channels K are designed as longitudinal grooves and run along or past the guide section E when the receiving rod T is inserted, without impairing the form-fitting interaction between the sleeve H and the tubular part R or between these and the guide section E.

Reference List

AH

sleeve section

AR

pipe section

B

intake manifold system

D

Outside diameter of a tubular section

E

guide section

f

contact surface

GH

Body portion of the sleeve

GR

Body portion of the tube part

H

sleeve

HH

Undercut on sleeve section

MR

Undercut on the tube part

J

bayonet lock

K

suction channel

L

fastener

M

front sleeve end facing away from the tube part

P

intake manifold

Q

workpiece

R

tube part

s

Wall thickness of a tubular section

T

recording staff

V

joining device

VH

Protrusion on sleeve section

VR

Projection on the pipe part

W

Tool

Z

Longitudinal, longitudinal axis

ZR

pipe axis

Claims (13)

Suction pipe system (B) for a joining device (V), with a suction pipe (P) formed around a pipe axis (Z _R ) along a longitudinal direction (Z), the suction pipe (P) comprising a pipe part (R) and a sleeve (H). , and wherein the sleeve (H) can be connected via a sleeve section (A _H ) to a tube section (A _R ) of the tube part (R) (connected state) and detachable therefrom (released state), characterized in that the sleeve section (A _H ) and the pipe section (A _R ) have projections (V _H , V _R ) and undercuts (H _H , H _R ), whereby in the connected state a projection of the sleeve section (A _H ) has an undercut ( _HR ) of the pipe section and/or a projection (V _R ) of the pipe part section (A _R ) engages behind an undercut (H _H ) of the sleeve section (A _H ) in a form-fitting manner in such a way that a relative movement of the sleeve (H) and pipe part (R) in the longitudinal direction (Z) is blocked. intake manifold system (B). claim 1 , characterized in that the sleeve (H) from the pipe part (R) - preferably without tools - is solvable by the sleeve section (A _H ) relative to the pipe section (A _R ) orthogonally to the longitudinal direction (Z) is displaced. intake manifold system (B). claim 1 or 2 , characterized in that a) that the sleeve section (A _H ) and the partial pipe section (A _R ) touch in the connected state along a contact surface (F), b) a cut orthogonal to the longitudinal axis (Z) through the contact surface (F). generated exclusively mutually parallel cutting lines in the contact surface (F). Intake pipe system (B) according to one of the preceding claims, characterized in that the sleeve (H) and/or the pipe part (R) is designed as a hollow cylinder with a cylinder wall, the undercuts (H _H , H _R ) and/or projections ( V _H , V _R ) are formed by material-free areas in the cylinder wall. Intake pipe system (B) according to one of the preceding claims, characterized in that the sleeve (H) and the pipe part (R) lie one behind the other in the connected state, viewed in the longitudinal direction (Z), that the outer contours and/or inner contours formed by cuts orthogonal to the pipe axis of the sleeve (H) and the tube part (R) are flush with each other. Intake pipe system (B) according to one of the preceding claims, characterized in that a) that the sleeve section (A _H ) and/or the partial pipe section (A _R ) protrudes at least one from a respective base body section (G _H , G _R ) in the longitudinal direction (Z). , has a material section that tapers when viewed in the circumferential direction as an undercut, which is adjoined in the longitudinal direction (Z) by a material area that is expanded as a projection in the circumferential direction, and/or b) that the projections (V _H , V _R ) and/or undercuts (H _H , H _R ) of the sleeve section and/or of the partial pipe section are arranged symmetrically to a plane of symmetry lying in the pipe axis (Z _R ). Intake pipe system (B) according to one of the preceding claims, characterized in that a) the partial pipe section (A _R ) and/or the sleeve section (A _H ) and/or the sleeve (H) is designed in one piece, and/or b) that the sleeve section (A _H ) and/or the sleeve (H) is made of a different material and/or has a different surface finish than the tubular part (R), and/or c) that the sleeve (H) and/or the Tubular part (R) have at least one tubular section in which the ratio of wall thickness (s) to outside diameter (D) applies: $$\text{s}/\text{D<0}\text{,333}\text{, preferably s}/\text{D<0}\text{,1}\text{.}$$

Suction pipe system (B) according to one of the preceding claims, further comprising a receiving rod (T) formed in the longitudinal direction (Z) which, in the connected state, can be inserted and positioned in the longitudinal direction (Z) in the arrangement of the pipe part and the sleeve connected thereto such that the The receiving rod (T) blocks a movement of the sleeve relative to the tubular part orthogonally to the longitudinal direction (Z) by a positive fit between the receiving rod (T) on the one hand and the sleeve or tubular part on the other (blocked state). Suction tube system (B) according to the preceding claim, characterized in that the receiving rod (T) has a guide section (E), the outer contour of which, in the blocked state, fits complementarily and closely to the inner contour of the sleeve (H) and/or the tube part (R) applies and thereby aligns the sleeve (H) concentrically to the pipe part (R). Suction pipe system (B) according to the preceding claim, characterized in that a) the sleeve section (A _H ) and/or the partial pipe section (A _R ), and/or b) the guide section (E) is equipped with suction channels (K) through in the blocked state in the pipe part (R) generated negative pressure at Füh tion section (E) can be forwarded over or through it into the sleeve (H). Joining device (V) with a suction pipe system (B) according to one of the preceding claims, wherein the joining device (V) is designed to introduce a fastening element (L) into a workpiece (joining), and wherein the fastening element (L) is previously attached to the pipe part (R) temporarily closes the sleeve end (M) facing away and can thus be held in place at the sleeve end (M) by a negative pressure generated in the suction tube (P) in order to bring the fastening element (L) to the intended joining location by moving the suction tube (P). Joining device according to the preceding claim and claim 8 , characterized in that a) that a receiving rod (T) guided within the intake manifold (P) can be driven to rotate about its longitudinal axis with a - preferably predefinable - torque, and b) that the receiving rod (T) in the longitudinal direction (Z) relative to the Suction tube (P) is displaceable and is designed to receive a tool (W) at its front end facing away from the tube part (R), c) so that the tool (W) can be moved by advancing the receiving rod (T) into one held at the sleeve end (M). Fastening element (L) can engage, d) wherein the receiving rod (T) can be moved together with the suction tube (P) and/or relative thereto in the longitudinal direction (Z) after engaging in the fastening element (L) in order to position the fastening element ( L) into the workpiece. Joining device (V) according to the preceding claim, wherein the joining device (V) is designed to a) in a first joining step, to move the fastening element (L) gripped by the tool (W) in the direction of or into the workpiece, while the fastening element (L) still closes the sleeve end (M) and through negative pressure in the suction pipe (P) is held, and b) in a subsequent second joining step, to advance the receiving rod (T) with the tool (W) so far relative to the suction tube (P) that the fastening element (L) meanwhile joined into the workpiece is lifted from the sleeve end (M) in order to reduce friction between retain fastener (L) and sleeve end (M).

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