DE102020200111A1 - Device for joining at least one connecting section of a workpiece arrangement - Google Patents

Abstract

The invention relates to a device for joining at least one connecting section (A) of a workpiece arrangement (W) from at least two workpieces (3), having a heating device (2) for generating heat input into the connecting section (A) and a clamping and / or holding device for Fixation of the workpieces (3), the heating device (2) being integrated into the clamping and / or holding device.

Description

The invention relates to a device for joining at least one connecting section of a workpiece arrangement from at least two workpieces, having a heating device for generating a heat input into the connecting section and a clamping and / or holding device for fixing the workpieces.

In the field of motor vehicle body construction, current developments consist of joining constantly thinner outer body parts to load-bearing body parts. The challenge here is in particular that the joining of these thin exterior body parts, especially by means of conventionally used welding processes such as resistance spot welding, cannot be carried out or can only be carried out at great expense and with a high level of reworking effort. This is due to the fact that the outer body part, due to the heat input during welding in combination with the small thickness, for example, a distortion, cannot have a sufficient connection with the composite body part or even have flaws.

In addition to welded connections, it is known that other joining processes carried out by melting materials, such as soldering, can also be used to join components. For example, US 2004/0 182 843 A1 describes a soldering method for producing a butt joint, in particular, of two thin workpieces made of titanium aluminum, with a solder melted by means of a laser being introduced between the workpieces.

The EP 3 266 550 A1 a joining device, in this case a joining gun, in particular for use in stud gluing or stud welding, can also be found, by means of which a stud held in a stud holder can be joined to a surface of a workpiece, in particular designed as sheet metal. An electrical energy supply to the joining device can make it possible to carry out a welding process or also a bolt bonding process by supplying an inductive heating device.

Another cohesive type of joining, which is preferably suitable for joining the outer body parts due to the lack of heat input, is gluing. In this case, however, production steps carried out during or after an adhesive application and as yet uncured adhesive, which exert a negative influence on the adhesive connection, are problematic. Especially in production steps that cause a mutually facing, alternating movement of the body components, which occurs in particular when the body components are tightened and loosened relative to one another, the connection width can be reduced due to the springback of the body components. In addition, cavities can arise in which media such as air and / or liquids - such as. B. Process fluids - penetrate. These media can lead to defects in the adhesive bond during a subsequent curing process in a drying oven.

With regard to the hardening of adhesive connections produced between body parts, which are used in a drying oven in particular without a hardening process, various solutions are already known from the prior art.

Through the EP 1 224 841 B1 For this purpose, a heating device with a flexible conductor loop is disclosed, the heating device being used for the inductive hardening of a continuous adhesive line in the field of body repairs. For this purpose, the conductor loop is laid essentially along the entire, in particular circumferential, adhesive line of two electrically conductive and preferably also flanged body panels and then inductively heated so that an adhesive introduced between the body panels is cured to at least a further processing hardness.

Also through the generic EP 1 056 312 A2 an inductive heating device and also a method for gelling, accordingly for the flanged seal, as well as for annealing, so for example to carry out recrystallization processes of body parts is described. For this purpose, the body component can optionally be fixed in the desired position on a frame by means of clamping elements. The heating device also has at least one conductor loop, which consists of a plurality of conductor sections coupled to one another via connecting elements, in this case in particular bent copper pipes. In different embodiments, these conductor sections follow the contour of the body component to be heated, for example a vehicle door, essentially circumferentially or the body component is locally heated at several points. The conductor sections are designed to be adjustable in relation to the body component, so that the inductively coupled-in heat influence can be changed. In addition to the direct, inductive coupling into the body component, heating is provided by means of radiators that come into direct contact with the body component and thus by conduction, with the radiators themselves being heated inductively by means of the conductor loop.

However, the proposed solutions are always inflexible, stationary designs which have to be adapted to the body components to be joined in an extremely complex manner.

Against this background, the invention is based on the object of designing the device of the type mentioned at the outset in such a way that joining workpieces of different geometries is simplified.

This object is achieved with a device according to the features of patent claim 1. The subclaims relate to particularly expedient developments of the invention.

According to the invention, therefore, a device is provided for joining - in particular for gluing - at least one connecting section of a workpiece arrangement from at least two - correspondingly arranged on one another - work pieces. The workpieces are preferably body components of a motor vehicle, wherein at least one of the body components can be designed as a thin-walled outer body component.

According to the invention, the device here has a heating device for generating a heat input into the connecting section and a clamping and / or holding device for fixing the workpieces - in particular with respect to one another and / or on a workpiece carrier. Furthermore, according to the invention, the heating device is integrated into the clamping and / or holding device. By integrating the heating device into the clamping and / or holding device, a locally limited heat input can be introduced into the workpiece arrangement in an advantageously simple manner, the workpieces being essentially only joined together in the connecting section, preferably glued. In addition, errors caused in particular by clamping the workpieces and a resulting, alternating movement of the workpieces, which are caused in particular in the case of thin-walled body components, can be profitably avoided. There is also the possibility that the heat input by means of the heating device takes place conductively, convectively or also by radiation. For this purpose, the heating device could, for. B. have a resistance heating element. However, the heat input into the connecting section would preferably be generated inductively.

The clamping and / or holding device according to the invention could also, for. B. be designed as a gripper. It would be possible here for this to be arranged on an industrial robot and for the industrial robot to join, in particular gluing, in the connecting section when the workpiece arrangement is displaced.

Furthermore, it is conceivable that the workpiece arrangement is also fixed via several devices according to the invention, the devices being arranged at a distance from one another along an in particular circumferential connection area and thus a heat input in the workpiece arrangement can be generated in several locally delimited connection sections of the connection area. This has the advantage that, for example, an adhesive introduced in the particular circumferential connection area between the workpieces cures to a locally limited extent and at the same time it can be made possible, in particular by varying the pressure applied to the workpiece arrangement, to set defined joint gaps. In addition, there is the possibility of adapting the design of the clamping and / or holding device to different component geometries of the workpieces with little effort.

Possible embodiments of the device continue to exist, for. B. in a clamping frame or a component store, for example a shelf, in which the workpiece arrangements are temporarily stored, whereby at the same time joining, preferably gluing, can take place in several connecting sections of the connecting area by means of the device. A complete end connection could be achieved, especially in the case of gluing, in a subsequent curing process, e.g. B. produce in a hardening furnace.

In general, it can be said that the device according to the invention can be used to carry out further manufacturing processes such as welding processes in an advantageous, time-optimizing manner in parallel with the joining.

In a particularly advantageous further development of the invention, the clamping and / or holding device is a component clamp, the component clamp having a pressure impact head which is arranged movably in relation to a base body of the component clamp and in which the heating device is integrated. Such a component clamp can be designed, for example, as a push clamp, a swing clamp or also as a clamp according to the toggle lever principle, wherein the component clamp could be operated electrically, pneumatically or electro-pneumatically. The design as a component clamp creates a high degree of flexibility in the fixation of the workpiece arrangement, since a component clamp or several component clamps can or can be largely freely arranged with regard to its position in the connection area of the workpiece arrangement. The integration in the pressure impact head also offers a largely simple possibility of changing the distance between the workpiece arrangement and the heating device via the arrangement of adjustment plates and thereby changing the heat input. In addition, when the heating device is designed in the pressure impact head, there is profitably the possibility of applying pressure to one side by means of the pressure impact head on the workpiece arrangement and, for example, to dispense with the formation of a counter bearing on the component clamp. A counter-surface which is formed in particular on the base body and functions as a counter-bearing is of course still possible.

An embodiment of the invention also proves to be profitable if the clamping and / or holding device is a component clamp, wherein the component clamp is a print head of the component clamp that interacts with a print head of the component clamp that is movably arranged in particular with respect to a base body and that is in particular also arranged on the base body Has counter-position in which the heating device is integrated. The counter support forms a counter support to the pressure impact head, so that the workpieces of the workpiece arrangement would be fixed between the pressure impact head and counter support during the joining. Here, the integration of the heating device in the counter-position offers the advantage that - in particular electrical - supply lines which, for. B. are required to supply power to the heater, due to the immovable arrangement of the counter-surface opposite the base body, in contrast to the movable pressure impact head, do not have to be carried with the counter-surface and thus there would be no or only little mechanical stress on the supply lines. If the counter-support was implemented, then the workpiece arrangement would be pressurized on both sides.

It also proves to be promising if the pressure impact head or the counter-support has the heating device and at least one pressure piece that comes into contact with the workpiece arrangement, the heating device being offset from the pressure piece - or the pressure pieces -, the workpiece arrangement. This would make the heater z. B. in a fixed position of the pressure impact head, in which this rests against the workpiece arrangement, have a distance from the workpiece arrangement. As a result, temperature influences and mechanical influences on the heating device caused by the application of pressure can advantageously be avoided.

Another advantageous embodiment of the invention is based on the fact that the heat input into the connecting section can be generated by means of the heating device via an induction unit of the heating device. This offers the advantage that an extremely good coupling of the heat input into the workpiece arrangement can be generated, it being possible, for example, to avoid high heat transfer resistances that occur in conductive processes due to insufficient contact. The heating of the heating device itself and thus any delay that might occur would not occur or at most to a small extent.

In a practical embodiment of the invention, the induction unit also has an - in particular water-cooled - induction coil and / or a ferrite core. Here, the ferrite core can be used profitably for concentrating the magnetic flux generated by means of the induction coil, whereby a further increase in the heat input and an improvement in the local limitation of the heat input into the workpiece arrangement can be expected.

Another extremely advantageous development of the invention is shown in that the heating device has at least one temperature measuring sensor. Promisingly, this allows the temperature and thus the heat input into the workpiece arrangement to be measured during joining, whereby the joining process, for example gluing the workpiece arrangement, can be monitored and, for example, excessively high temperatures can be avoided.

An embodiment of the invention also shows itself to be very promising when the temperature measuring transducer is an optical waveguide or records temperature measurement data via an optical waveguide. In this way, the actual temperature measuring transducer could be arranged at a distance from the heating device, thereby avoiding the temperature measurement being influenced by the heat input into the workpiece arrangement and the resulting offset errors.

An embodiment of the invention is also advantageous when the temperature measuring sensor is positioned centrally within the induction unit. This leads extremely advantageously to a slight influence on the temperature measurement due to a uniform spacing from the induction unit.

In an advantageous embodiment of the invention, the heating device also has a cooling unit and / or at least one coolant supply - in particular at least one coolant channel, preferably a compressed air channel. Via the cooling unit and / or the coolant supply, the Cool the workpiece arrangement after the heat input and the associated joints, in particular an at least partial hardening of an adhesive located in the connecting section. This advantageously leads to the possibility of being able to carry out the manufacturing steps following the joining after a shorter cooling and thus waiting time.

• 1 eine Weiterbildung der als Bauteilspanner ausgebildeten Spann- und/oder Haltevorrichtung;
• 2 den Druckaufschlagskopf in Offenstellung.

The invention allows numerous embodiments. To further clarify its basic principle, one of them is shown in the drawing and is described below. This shows in

• 1 a further development of the clamping and / or holding device designed as a component clamp;
• 2 the pressure charge head in the open position.

1 shows a further development of the component clamp 1 trained clamping and / or holding device, the heating device in accordance with the invention 2 in the component clamp 1 is integrated. The one from component clamps 1 and the heater 2 The existing device is used to glue the two workpieces 3 existing workpiece arrangement W. . For this purpose, there is a circumferential connection area (not shown in more detail) between the workpieces arranged opposite one another 3 Adhesive, for example in the form of an adhesive bead, introduced. The adhesive is thereby by means of the heating device 2 in the connection section 1 generated heat input into the workpiece arrangement W. at least as far or even completely cured, so that one for handling the workpiece arrangement W. and / or the connection strength is sufficiently high for subsequent manufacturing processes. The heating device 2 is here in the opposite of the main body 11 of the component clamp 1 pivotably arranged pressure impact head 4th integrated, with the pressure impact head 4th for pivotable arrangement with the one on the base body 11 articulated swivel arm 12th connected is. The pressure charge head 4th is also at least between the illustrated fixing position, which is a substantially closed component clamp 1 and the in 2 shown open position, which is an essentially open component clamp 1 corresponds, executed pivotable. Next to the heating element 2 shows the pressure charge head 4th also the two with the workpiece arrangement W. pressure pieces coming into contact 6th on which are on both sides of the heating device 2 are arranged. About this and the one with the pressure impact head 4th cooperating counter-position 5 are the workpieces 3 the workpiece arrangement W. fixed against each other. The counter-face 5 is here immobile with the main body 11 connected so that they act as a counter bearing when pressure is applied to the workpiece arrangement W. by means of the pressure charge head 4th acts. Furthermore, the heating device 2 opposite the pressure piece 6th , here the workpiece arrangement W. as well as the counter surface 5 in the opposite direction, offset, so that it is in the fixing position of the pressure impact head 4th a distance from the workpiece arrangement W. having. The distance in the pressure charge head 4th integrated heating device 2 from the workpiece arrangement W. can also be achieved by inserting adjustment plates between the cross holder 13th and the heater 2 change, with the cross holder 13th on that of the pressure head 4th facing end of the swing arm 12th is arranged.

The 2 is also an embodiment of the device according to the invention in the open position of the pressure impact head 4th can be seen, whereby the design of the in the component clamp 1 integrated heating device 2 is clarified in more detail. In particular, it is shown that to generate the heat input into the in 1 indicated connection section A. by means of the heating device 2 , the heater 2 the induction unit 7th has, which in turn at least from the induction coil 8th as well as a ferrite core not shown in detail. The heating device also has 2 also via the temperature sensor 9 , which in this case is designed as an optical waveguide and is centered within the induction unit 7th , especially the induction coil 8th is positioned. In addition, are in the heating device 2 two on either side of the induction coil 8th arranged coolant supply lines 10 executed in the form of compressed air channels through which the in the 1 workpiece arrangement shown W. after the heat input and thus the at least partial hardening of the in the connecting section A. located adhesive can be cooled.

List of reference symbols

1

Component clamp

2

Heating device

3

workpiece

4th

Pressure charge head

5

Counter-face

6th

Pressure piece

7th

Induction unit

8th

Induction coil

9

Temperature sensor

10

Coolant supply

11

Base body

12th

Swivel arm

13th

Cross holder

A.

Connection section

W.

Workpiece arrangement

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 3266550 A1 [0004]
• EP 1224841 B1 [0007]
• EP 1056312 A2 [0008]

Claims (10)

Device for joining at least one connecting section (A) of a workpiece arrangement (W) made of at least two workpieces (3), having a heating device (2) for generating heat input into the connecting section (A) and a clamping and / or holding device for fixing the workpieces (3), characterized in that the heating device (2) is integrated into the clamping and / or holding device. Device according to Claim 1 , characterized in that the clamping and / or holding device is a component clamp (1), the component clamp (1) having a movably arranged pressure impact head (4) in which the heating device (2) is integrated. Device according to the Claims 1 or 2 , characterized in that the clamping and / or holding device is a component clamp (1), the component clamp (1) having a counter-surface (5) which interacts with a movably arranged pressure impact head (4) of the component clamp (1) and in which the heating device (2) is integrated. Device according to at least one of the preceding claims, characterized in that the pressure impact head (4) or the counter support (5) has the heating device (2) and at least one pressure piece (6) coming into contact with the workpiece arrangement (W), the heating device ( 2) opposite the pressure piece (6), the workpiece arrangement (W) is offset. Device according to at least one of the preceding claims, characterized in that the heat input into the connecting section (A) can be generated by means of the heating device (2) via an induction unit (7) of the heating device (2). Device according to at least one of the preceding claims, characterized in that the induction unit (7) has an induction coil (8) and / or a ferrite core. Device according to at least one of the preceding claims, characterized in that the heating device (2) has at least one temperature measuring sensor (9). Device according to at least one of the preceding claims, characterized in that the temperature measuring sensor (9) is an optical waveguide or records temperature measurement data via an optical waveguide. Device according to at least one of the preceding claims, characterized in that the temperature measuring sensor (9) is positioned centrally within the induction unit (7). Device according to at least one of the preceding claims, characterized in that the heating device (2) has a cooling unit and / or at least one coolant supply (10).

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