Joining device for joining a functional element on a hollow shaft

Abstract

Joining device (1) for joining at least one functional element (4), in particular a cam, having a hub (2) for a hollow shaft (3), on the hollow shaft (3), - with a joining table (5) with a joining table support (6) movable relative thereto, each with a through-opening (8, 7), wherein the functional element (4) to be joined can be placed on the joining table support (6) in such a way that the hub (2) is arranged in alignment with the through-openings (8, 7), - with a movable arm (10) which can be locked with respect to its mobility by means of a locking device (9) and with an openable joining gripper (11) for gripping the functional element (4) and for placing it on the joining table (5), - with a movable guide carriage (12) with a chuck (13) for the hollow shaft (3), - with a tailstock (15) with a centering point (16) for coaxial alignment of the hollow shaft (3) to the hub (2) and with expandable centering elements (17) for centering the functional element (4), wherein the centering elements (17) assume a defined position against the hub (2) in the functional element (4) in an extended position.

Description

[0001] The present invention relates to a joining device for joining at least one functional element having a hub for a hollow shaft.

[0002] After induction hardening and induction tempering of functional elements for hollow shafts, for example cams for camshafts, a cam bore is produced to a required bore dimension within a permissible bore tolerance for joining the functional elements to the ground or raw tube, i.e. the hollow shaft. According to the current state of the art, the inductively heated cam or generally the inductively heated functional element is picked up from the inductor by means of a transport gripper and placed on the joining table in the joining position. The functional element is aligned on the joining table via the outer contour of the functional element, which is defined by the four gripping points (joining gripper rollers) in the joining gripper. A centering point of the joining device then moves through the hub (cam bore) into the center of the hollow shaft and guides it into the axial and radial joining position of the joining program.

[0003] When the hollow shaft moves downwards, a locking device on the joining gripper opens, allowing the latter to move freely in a horizontal plane. However, when the hollow shaft, i.e. the camshaft, is inserted into the hub, i.e. the cam bore, for example, under the guidance of the centering tip, collisions repeatedly occur between the hub and a chamfer on the hollow shaft and thus the hollow shaft itself. If the joining gripper does not easily compensate for the difference between the hub axis and the joining axis when the index is open, i.e. when the locking device is open, a collision occurs between the hollow shaft and the functional element, which leads to material tearing out of a surface and to scoring in the area of ​​a ground shaft outer diameter.This results in machine downtime, rework and scrap costs, and at the same time, the axial and radial joining position of the functional element cannot be precisely achieved.

[0004] The present invention therefore addresses the problem of providing a joining device for joining at least one functional element having a hub for a hollow shaft, by means of which in particular machine downtimes as well as post-processing costs or general scrap costs can be reduced.

[0005] This problem is solved according to the invention by the subject matter of independent claim 1. Advantageous embodiments are the subject matter of the dependent claims.

[0006] The present invention is based on the general idea of ​​equipping a joining table of a joining device for joining at least one functional element having a hub for a hollow shaft with a joining table support that is movable relative thereto and is capable of easily, smoothly, and quickly compensating for coaxiality differences between the hub of the functional element to be joined and the hollow shaft, thereby reducing machine downtimes, rework effort, and scrap costs. The joining device according to the invention for joining at least one functional element having a hub for a hollow shaft, for example for joining a cam on a camshaft, has the aforementioned joining table with the joining table support that is movable relative thereto, wherein both the joining table and the joining table support that is movable relative thereto each have a through-opening.The functional element to be joined, for example a cam, can be placed on the joining table support in such a way that its hub is aligned with the through-opening in the joining table support and the through-opening in the joining table arranged underneath. Also provided is a movable arm, which can be locked with regard to its mobility by means of a locking device, with an openable joining gripper for gripping the functional element and for placing it on the joining table. The opening joining gripper can also be locked by means of an index, i.e. a type of locking device. Also provided is a movable guide carriage with a chuck in which the hollow shaft can be clamped. The joining device furthermore has a tailstock with a centering point, in particular a centering cone, for the coaxial alignment of the hollow shaft to the hub of the functional element, wherein the tailstock also has expandable, i.e.In particular, it has radially extendable centering elements for centering the functional element. In an extended position, the centering elements assume a defined position against the hub in the functional element, for example, the cam.

[0007] In general, the functional element is joined as follows: First, the joining gripper picks up the heated functional element, for example, the inductively heated cam, from a heating station and then places it in the specified joining position on the joining table support. The tailstock then moves upwards from below with its centering point through the through-holes in the joining table and the joining table support, as well as the hub. During this process, both the joining gripper and the locking device of the joining gripper arm are open, enabling smooth, central alignment of the functional element in the hub relative to the joining axis of the joining device. The functional element to be joined, for example, the camshaft component to be joined, is aligned via its hub to the joining axis by the centering elements arranged in the tailstock.The central alignment of the functional element in the hub can be achieved in different positions: in the middle, at the hub end (top), or at the hub beginning (bottom). After the functional element has been mechanically aligned via the hub, the joining gripper is closed and the centering elements are simultaneously retracted. The functional element remains in its aligned position. The centering tip, which is retracted into the hollow shaft, now guides the latter through the hub of the functional element to be joined. As the hollow shaft begins to penetrate into the hub (cam bore), the index of the joining gripper opens, allowing the functional element to be joined into its radial and axial position using the joining gripper.It is also conceivable that the position of the hub of the functional element to be joined is controlled in such a way that the joining gripper achieves the deposition of the functional element based on the smallest / minimal bore offset from the zero position of the joining axis of the joining device. Overall, the joining device according to the invention can achieve extremely precise, preferably exactly coaxial alignment of the functional element with respect to its hub relative to the hollow shaft, thereby preventing, in particular, material tearing on the surface of the hub and, associated with this, scoring in the area of ​​a ground hollow shaft outer diameter. This also reduces machine downtime and scrap costs.

[0008] In an advantageous development of the device according to the invention, gripper rollers for positioning and aligning the functional element are arranged on the openable gripper. Such gripper rollers are used, in particular, to angularly align the functional element, for example, a cam, so that the functional element can be joined with precise angles to the hollow shaft, for example, a camshaft tube. This allows for the simple and rapid production of a high-quality camshaft.

[0009] In an advantageous further development of the joining gripper, at least three, preferably even four, joining gripper rollers are arranged on it. For example, four such joining gripper rollers allow for particularly precise alignment and simultaneous fixation of the functional element in the joining gripper.

[0010] A fixing device is advantageously provided to secure the joining table support relative to the joining table. This fixing device can thus prevent any relative movement of the joining table support relative to the joining table, which leads to precise adherence to a previously determined joining position, especially after alignment.

[0011] The joining table expediently has a recess for the joining table support, whereby the joining table support can be arranged flush with the surface and, in particular, floating in the recess of the joining table. The joining table support is thus protected in the recess of the joining table and, thanks to its flush arrangement, does not pose any obstacle when moving the functional element to be joined on the joining table support or on the joining table parallel to its surface.

[0012] In a further advantageous embodiment of the joining device, the joining table support is mounted in the recess via a ball bearing. Such a ball bearing can be formed by a plurality of balls arranged between the recess of the joining table support, which allow smooth movement of the joining table support in the plane of the joining table. The joining table support is arranged in the recess with play, whereby the play is dimensioned such that the joining table support can be adjusted in the plane of the joining table to such an extent that any coaxiality errors between the hub of the functional element to be joined and the hollow shaft to be joined can be compensated.

[0013] In an advantageous development of the joining device according to the invention, a heating device, in particular an induction heating device, is provided for heating the functional elements to be joined. Such an induction heating device can achieve rapid and extremely precise heating of the functional elements to be joined, for example, with locally varying heating temperatures. Alternatively, it is also conceivable to provide a separate heating device, in particular in the form of a furnace. Alternatively, it is of course also conceivable for the functional element to be heated in the joining gripper or on the joining table support, for example, inductively.

[0014] In a particularly preferred embodiment of the joining device according to the invention, a transport gripper is provided for moving the hollow shaft to the guide carriage and its chuck. Such a transport gripper enables a separate arrangement of the heating device described in the previous paragraphs and, at the same time, a quick and extremely precise placement of the heated functional element on the joining table support, as well as, if necessary, a rapid movement of the finished joined camshaft.

[0015] Further important features and advantages of the invention emerge from the subclaims, from the drawings and from the associated description of the figures based on the drawings.

[0016] It is understood that the features mentioned above and those to be explained below can be used not only in the respective combination specified, but also in other combinations or on their own, without departing from the scope of the present invention. Components mentioned above and those to be mentioned below of a higher-level unit, such as a device, a device, or an arrangement, which are designated separately, may form separate parts or components of this unit or be integral areas or sections of this unit, even if this is shown differently in the drawing.

[0017] Preferred embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally identical components.

[0018] They show, schematically, Fig. 1 a sectional view through a joining device according to the invention, Fig. 2 a plan view of a joining table of the joining device according to the invention with a joining table support.

[0019] According to the Fig. 1 comprises a joining device 1 according to the invention for joining at least one, a hub 2 (see also Fig. 2) for a functional element 4 having a hollow shaft 3, for example a cam on a camshaft, a joining table 5 with a joining table support 6 that is movable relative thereto and each has a through-opening 7, 8. The functional element 4 to be joined, for example the cam, can be placed on the joining table support 6 in such a way that the hub 2 of the functional element 4 is aligned with the through-openings 7, 8 of the joining table support 6 or the joining table 5. Also provided is a movable arm 10, whose mobility can be locked by means of a locking device 9, for example an index or a pin, and which has an openable joining gripper 11 for gripping the functional element 4 and for placing it on the joining table support 6 or the joining table 5.

[0020] The hollow shaft 3 is adjusted in the vertical direction, i.e. generally in the joining direction 14, by means of a movable guide carriage 12 with a chuck 13. Also provided is a tailstock 15 with a centering point 16, for example a centering cone, for coaxial alignment of the hollow shaft 3 to the hub 2 of the functional element 4. Expandable, i.e. in particular radially adjustable, centering elements 17 for centering the functional element 4 are arranged on the tailstock 15, wherein the centering elements 17 assume a defined position relative to the hub 2 of the functional element 4 in an extended position.

[0021] The joining gripper 11 to be opened has joining gripper rollers 18, via which an exact fixation of the functional element 4 to be joined is enabled. The joining gripper 11 has at least three, preferably even four such joining gripper rollers 18, as is shown in the Fig. 2 is shown.

[0022] Also provided is a fixing device 19, by means of which the joining table support 6 can be fixed relative to the joining table 5. The joining table support 6 is adjustable in the plane of the joining table 5 and is thus able to compensate for coaxiality differences between the hub 2 of the functional element 4 and the hollow shaft 3.

[0023] The joining table 5 itself has a recess 20 in which the joining table support 6 is arranged, preferably in such a way that the joining table support 6 is arranged flush with the surface in the recess 20 of the joining table 5.

[0024] In order to compensate for coaxiality deviations between the hub 2 of the functional element 4 and the hollow shaft 3, the joining table support 6 is mounted in a floating manner, in particular via a ball bearing 21, in the recess 20. This allows for smooth and rapid correction of any coaxiality deviations that may exist.

[0025] Furthermore, a non-compliant Fig. 1, for example, a separate induction heating device, which enables rapid and extremely precise, possibly even locally limited, heating of the functional elements 4 to be joined. A transport gripper (also not shown) can also be provided for moving the hollow shaft 3 to the guide carriage 12 and its chuck 13, as well as for removing the, for example, fully joined camshaft from the joining device 1.

[0026] All in all, the joining device 1 according to the invention and the floating joining table support 6 allow for simple and rapid compensation of any coaxiality differences that may occur between the hub 2 and the hollow shaft 3, whereby in particular machine downtimes, post-processing costs and also rejects can be significantly reduced. List of reference symbols 1 joining device 2 Hub 3 hollow shaft 4 Functional element 5 Joining table 6 Joining table support 7 passage opening 8 passage opening 9 Locking device 10 arms 11 joining grippers 12 guide carriages 13 chucks 14 Joining direction 15 Tailstock 16 Centering point 17 Centering element 18 joining gripper rollers 19 Fixing device 20 recess 21 ball bearings

Claims

[1] Joining device (1) for joining at least one functional element (4), in particular a cam, having a hub (2) for a hollow shaft (3), on the hollow shaft (3), - with a joining table (5) with a joining table support (6) movable relative thereto, each with a through-opening (8, 7), wherein the functional element (4) to be joined can be placed on the joining table support (6) in such a way that the hub (2) is arranged in alignment with the through-openings (8, 7), - with a movable arm (10) which can be locked with respect to its mobility by means of a locking device (9) and with an openable joining gripper (11) for gripping the functional element (4) and for placing it on the joining table (5), - with a movable guide carriage (12) with a chuck (13) for the hollow shaft (3), - with a tailstock (15) with a centering point (16) for coaxial alignment of the hollow shaft (3) to the hub (2) and with expandable centering elements (17) for centering the functional element (4), wherein the centering elements (17) assume a defined position against the hub (2) in the functional element (4) in an extended position. [2] Joining device (1) according to claim 1, characterized by that joining gripper rollers (18) for positioning and aligning the functional element (4) are arranged on the openable joining gripper (11). [3] Joining device (1) according to claim 2, characterized by that at least three, preferably four, joining gripper rollers (18) are arranged on the joining gripper (11). [4] Joining device (1) according to one of the preceding claims, characterized by that a fixing device (19) is provided for fixing the joining table support (6) relative to the joining table (5). [5] Joining device (1) according to claim 4, characterized bythat the joining table (5) has a recess (20) for the joining table support (6), wherein the joining table support (6) is arranged flush with the surface in the recess (20) of the joining table (5). [6] Joining device (1) according to one of the preceding claims, characterized by that the joining table support (6) is mounted floatingly in the recess (20) via a ball bearing (21). [7] Joining device (1) according to one of the preceding claims, characterized by that a heating device, in particular an induction heating device, is provided for heating the functional elements (4) to be joined. [8] Joining device (1) according to one of the preceding claims, characterized by that a transport gripper is provided for moving the hollow shaft (3) to the guide carriage (12) and its chuck (13).

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