Preheating device for welding device, corresponding welding device, preheating method and welding method

Abstract

The preheating device for the welding device comprises a preheating device defining a first plane by a first center line extending along a first axis X and a second center line extending along a second axis Y perpendicular to the first axis X. The first preheating structure is asymmetric with respect to the first and / or second center lines, and the corresponding axis is an asymmetric axis. The second preheating structure corresponds to the first preheating structure and has the same orientation as the first preheating structure, so that when viewed along a third axis Z perpendicular to the first plane, the first and second preheating structures are arranged one above the other. The preheating device comprises a first rotating tool for rotating the preheating device between a first position and a second position, so that the preheating structure in the first position has a first orientation and a second orientation in the second position, they are rotated 180° around the asymmetric axis compared to the first orientation, or they are rotated around the third axis Z compared to the first orientation by an angle in the range of 0°<α<360°, preferably 90°≤α≤270°, and particularly preferably α=180°.

Description

Technical Field

[0001] The invention relates to a preheating device for a welding device, a corresponding welding device, a preheating method using the preheating device, a welding method using the welding device and a modification method. Background Art

[0002] Preheating devices are generally known, in particular in combination with welding devices for welding two components, in particular plastic components, to one another.

[0003] Typically, the welding device comprises a frame or housing in which a lower tool and an upper tool are arranged. The lower tool is fixed on a lifting table, while the upper tool is rigidly mounted on the upper tool plate. With the aid of the lifting table, the lower tool can be moved in the direction of the upper tool to weld a first component in the lower tool to a second component in the upper tool by friction or vibration welding.

[0004] Such welding devices are used, for example, in the automotive industry or in medical technology. In the automotive industry, welding devices are used to produce lamps, but can also be used to produce other components or component groups that consist of plastic or contain plastic. In a similar manner, welding devices can be used to produce devices and / or component groups in medical technology or to produce consumer goods.

[0005] The basic operation of the welding device including the preheating device is as follows. First, the user places the first component on the lower tool. Subsequently, he places the second component on the first component of the lower tool. Then, the lifting table with the lower tool and the component arranged thereon moves along the vertical axis from the initial position in the direction of the upper tool until the second component is received in the upper tool.

[0006] The lifting table is now moved back to a position in which the preheating device can be arranged from the idle or parked position to the alignment or preheating position between the two components. After the preheating device has been arranged between the two components, the two components are preheated at the point to be welded. For this purpose, the preheating device has a corresponding preheating structure. After preheating, the preheating device is moved back to the idle or parked position.

[0007] The lifting table is then moved to the welding position and the welding of the first component to the second component takes place, in particular by friction or vibration welding. After welding is finished, the lifting table is moved along the vertical axis from the welding position back to the initial position together with the lower tool and the composite of the first component and the second component arranged thereon. Once the lifting table has reached the initial position, the user removes the composite of the first component and the second component.

[0008] An example of a welding apparatus comprising a preheating device is described in EP 3 009 254 A2.

[0009] The disadvantages of the above-described welding device and thus of the preheating device become apparent if several components that are to be welded to one another have complex congruent weld structures which are oriented differently on both sides of the components.

[0010] For example, assume that the parts to be welded have a rectangular shape and define a plane by a first centerline extending between and parallel to the longitudinal sides of the rectangle and a second centerline extending between and parallel to the transverse sides of the rectangle. Each part includes a first welding structure on a first side and a second welding structure on an opposite second side. Both welding structures are superimposed and asymmetric with respect to the first centerline. In addition, assume that the welding structure on the second side is rotated 180° around an axis perpendicular to the plane. Therefore, when viewed along this axis, that is, when viewed from above and through the part, the first welding structure and the second welding structure have different orientations so that they do not completely overlap.

[0011] In the first cycle, the worker places a part in the lower tool and another part in the upper tool. Here, he must pay attention to the orientation of the weld structure so that the weld structure of the part facing the lower tool in the upper tool corresponds to the weld structure of the part facing the upper tool in the lower tool.

[0012] After the components are correctly arranged in the welding device, the welding method is implemented, including preheating by a preheating device with a correspondingly oriented preheating structure. Here, it must be taken into account that for reliable preheating, the preheating structure of the preheating device is adapted to the welded structure to be preheated.

[0013] After the first cycle, the component that was in the upper tool at the beginning of the cycle now defines a new (i.e. differently oriented) weld structure, with its side facing the upper tool. The weld structure on this side (which was received in the upper component in the first cycle) is therefore oriented differently, i.e. rotated 180° around the third axis as described above. As a result, the preheating structure of the preheating device does not match the weld structure, so that reliable preheating of the component cannot be ensured. The same applies to the weld structure of the corresponding component arranged in the upper tool, so that the two components have matching weld structures.

[0014] Therefore, it is a problem of the present invention to provide a preheating device by means of which the above-mentioned disadvantages can be overcome so that a plurality of components to be welded to one another to form a welded component stack can be preheated with low effort and in a simple and reliable manner. In addition, it is a problem to provide a corresponding welding device, a preheating method and a welding method. Summary of the invention

[0015] The above problems are solved by the preheating device according to the present application, the welding device according to the present application, the preheating method according to the present application, the welding method according to the present application and the retrofitting method according to the present application. Further preferred embodiments and improvements are derived from the following description, the drawings and the appended claims.

[0016] The preheating device of the present invention is used for a welding device, which has an upper tool mounted on an upper support and a lower tool mounted on a lower support. The upper support and the lower support can be moved relative to each other between an initial position and a welding position. The preheating device includes a preheating device, which defines a first plane by a first center line extending along a first axis and a second center line extending along a second axis perpendicular to the first axis. The preheating device has a first side with a first preheating structure and an opposite second side with a second preheating structure, wherein the first preheating structure is asymmetric with respect to the first center line and / or the second center line, so that the corresponding axis is an asymmetric axis. The second preheating structure corresponds to the first preheating structure and has the same orientation as the first preheating structure, so that when viewed along a third axis perpendicular to the first plane, the first preheating structure and the second preheating structure are arranged one above the other. The preheating device further includes a first rotating tool for rotating the preheating device between a first position and a second position, so that the preheating structure in the first position has a first orientation, and the preheating structure in the second position has a second orientation, wherein in the second orientation they are rotated 180° around the asymmetric axis relative to the first orientation, or in the second orientation they are rotated around a third axis relative to the first orientation by an angle α in the range of 0°<α<360°, preferably 90°≤α≤270°, and particularly preferably α=180°.

[0017] In the following, the preheating device of the present invention will be described according to its use in a welding device. In this regard, the process of preheating is particularly considered. In addition to the preheating device of the present invention, the exemplary welding device also includes a lower tool mounted on a lower support and an upper tool mounted on an upper support. The lower support and the upper support are movable relative to each other between an initial position and a welding position. The preheating device is movable between a parking position and a preheating position, so that the preheating device is arranged in a preheating position between the upper support and the lower support. In addition, when the preheating device is in the preheating position, the upper support and the lower support are each arranged in a plane parallel to the first plane defined by the preheating device. Therefore, the term "third axis" refers to an axis perpendicular to the corresponding plane.

[0018] According to the welding device of the embodiment now described, a plurality of components are welded to each other. Each of these components includes a first welding structure on a first side and a second welding structure on an opposite second side. The first welding structure and the second welding structure are formed to overlap with the first preheating structure and the second preheating structure of the preheating device. Overlapping means that in this respect they have the same shape and size. Therefore, the first preheating structure and the second preheating structure and the first welding structure and the second welding structure are identical in shape and size.

[0019] In addition, the first weld structure and the second weld structure are oriented so that the first weld structure and the second weld structure are rotated 180° around the asymmetric axis or around the third axis by an angle α relative to each other. In other words, and according to a particularly preferred embodiment, the weld structures are rotationally symmetric relative to each other. Specifically, rotating one of the weld structures by 180° around at least one of the first center line and the second center line produces another or opposite weld structure.

[0020] To make this feature easier to understand, assume that the component has a rectangular shape. A first centerline of the component is parallel to and extends between the lateral sides of the component. A second centerline is parallel to and extends between the longitudinal sides of the component. Thus, the first centerline and the second centerline define a plane and divide the component into four geometrically equal parts. The intersection of the centerlines represents the geometric center of the component. In the further process of this embodiment, it is assumed that the component is viewed in a horizontal or horizontal form, which means that the longitudinal sides extend from left to right.

[0021] A first welding structure is arranged on the first side of the component. The welding structure is formed, for example, as a rectangle with rounded corners, wherein the first welding structure has a protrusion at each of two adjacent corners. With reference to the four geometrically equal parts into which the component is divided by the center line, it is assumed that when the first side is observed from above (i.e. along a third axis extending perpendicular to the plane), the two protrusions of the welding structure appear in the upper left and upper right parts of the first side of the component. Therefore, the second center line extending between and parallel to the two longitudinal sides is an asymmetric axis, while the first center line extending between and parallel to the two lateral sides is a symmetric axis. Although this is an exemplary embodiment, it is preferred that the remaining part of the first center line or the second center line is a symmetric axis, especially when the component has a rectangular shape.

[0022] A second weld structure is arranged on the second side of the component. The weld structure is superimposed on the first weld structure. Therefore, as described above, it has the same size and shape. However, compared with the first weld structure on the first side, the second weld structure is arranged in a different orientation on the second side.

[0023] This different orientation is achieved by the second weld structure being arranged in a rotated manner on the second side compared to the first weld structure. Thus, the first weld structure and the second weld structure are arranged so that they are not arranged completely one above the other when viewed from above the first side or the second side and through the component.

[0024] The term "one above the other" means that the shadow of one structure produced by an imaginary light shining from one side through the parts completely covers the other structure. Therefore, since the welded structures are not arranged one above the other, i.e. one is completely on top of the other, the second welded structure must have a different orientation compared to the first welded structure.

[0025] This different orientation can be achieved by rotating the second weld structure 180° relative to the first weld structure around the asymmetric axis, or by rotating the second weld structure relative to the first weld structure around a third axis (which is perpendicular to the plane) by a certain angle α.

[0026] With respect to the above embodiment, the second weld structure of the second side is rotated 180° about the asymmetric axis relative to the first weld structure, resulting in two protrusions being arranged at the lower left and lower right parts. This is applicable when the component is viewed from the first side and through the component.

[0027] For this reason, if the component is turned from a position where the first side is visible about the axis of asymmetry (i.e., about the longitudinal centerline) to a position where the second side is visible, the second weld structure will appear to the observer in the same orientation as the first weld structure. On the other hand, if the component is turned from the first side to the second side about the axis of symmetry (i.e., about the transverse centerline), the second weld structure will appear in a different orientation relative to the first weld structure. In particular, two protrusions will appear on the second side of the lower part of the component, whereas they appeared on the first side of the upper part.

[0028] Alternatively, the second welded structure can be rotated relative to the first welded structure by a certain angle α around a third axis (which is perpendicular to the plane). With respect to the rotation of the first embodiment described above, if the second welded structure is rotated by 180° around the third axis, the result is the same as a rotation around an asymmetric axis. Therefore, regardless of other possible rotation angles, a rotation of 180° is particularly preferred. However, in particular in the case where the welded structure is asymmetric relative to the two center lines, rotations of other angles other than 0° and 360° may be useful and preferred.

[0029] With regard to the overall design of the components to be welded to one another, the welding method and the resulting preheating method, a few exemplary welding cycles will be described.

[0030] First, a first component is arranged in the upper tool and a second component is arranged in the lower tool, the second component being identical to the first component or having a matching or identical welding structure. As an alternative, a stack of already welded components is already present in the lower tool. In this case, the side of the stack of already welded components facing the first component has a third welding structure. In each case, the first component and the second component or the first component and the stack of already welded components are arranged so that their welding structures match each other.

[0031] For ease of understanding, and with respect to the exemplary components and their welded structures described above, it is assumed that the first component is arranged so that the first side with the first welded structure is facing down the tool and the second side with the second welded structure is arranged in the upper tool. Thus, for example, a second component identical to the first component is arranged in the lower tool so that the first side with the first welded structure is facing up the tool, i.e., the first side of the first component is located in the upper tool. For clarity, the welded structure revealed by the second component or the welded component stack is referred to as the third welded structure. This will become clear in the subsequent second cycle.

[0032] As initially discussed, the first component is fixed in the upper tool by means of negative pressure. In addition, for exemplary operation, the upper support of the welding device is an upper mounting plate, and the lower support is a lifting table, preferably a lifting table driven by a motor. In use, the lower support with the lower tool moves relative to the upper support along the third axis.

[0033] Thus, after the first component has been arranged in the upper tool, the lifting table is moved along the third axis into an intermediate position in which the preheating device can be moved from the parking position into the preheating position between the components.

[0034] For this purpose, the preheating device is arranged in a first position, wherein the preheating structure arranged on the first side and the second side matches the welding structure. In other words, in the case of observing the welding device along the third axis (i.e. the axis perpendicular to the first plane), the welding structure and the preheating structure are arranged one above the other (in particular completely). Therefore, when observing from this angle through the individual parts and components, only one structure can be seen. In the case of a vibration welding device, the first plane can also be called a vibration welding plane.

[0035] Since the preheating structures of the preheating device must match the welding structure, the preheating structures must also overlap the welding structure and each other, as described above. Furthermore, the preheating structures of the preheating device must be oriented in the same way as opposed to the welding structure of one component, i.e. they must be arranged one above the other, in particular completely, when viewed from above and along a third axis and through the preheating device, respectively. Thus, as described above, the term "one above the other" means that the shadow of one structure generated by an imaginary light irradiated from one side through the component completely covers the other structure. Since the preheating structures are arranged one completely above the other, the second preheating structure must have the same orientation compared to the first preheating structure.

[0036] In this regard, it is particularly preferred that the preheating device has a rectangular shape with the first axis extending parallel to the lateral sides of the rectangle and the second axis extending parallel to the longitudinal sides of the rectangle, as discussed above for the exemplary first component.

[0037] After the preheating device is arranged between the two components, the welded structure of the two components is preheated by the matching preheating structure. Therefore, the preheating structure covers the welded structure at the preheating position. In this regard, the first preheating structure and the second preheating structure are preferably infrared (IR) preheating structures.

[0038] After preheating, the preheating device moves from the preheating position back to the parking position. Thereafter, the lifting table moves along the second axis to the welding position, in which the first component is abutted against the second component or the welded component stack and welded to each other, for example by vibration welding or infrared welding. After welding, the lower support moves back to its initial position relative to the upper support.

[0039] As a result, a welded stack of components consisting of a first component and a second component now appears in the lower tool. In contrast to known methods, this stack of components is held in the lower tool. Thus, the side of the welded stack facing the upper tool corresponds to the side of the previous first component that was arranged in the upper tool during the first cycle. This side with the second welded structure now represents the third welded structure of the welded stack of components.

[0040] In the following second cycle, the new first component is arranged in the upper tool. Since the welded component stack determines the weld structure, the new first component must be arranged in the upper tool so that the second side with the second weld structure is downwardly facing the tool or the welded component stack arranged therein.

[0041] Now, the above process is repeated. Since the orientation of the weld structure has been changed from the first weld structure to the second weld structure, the previous device of the preheating device is not suitable and cannot ensure reliable preheating of the weld structure within this cycle.

[0042] To overcome this, the preheating device is rotated from a first position to a second position, in particular in the parking position. In the second position, the preheating device has a second orientation, wherein the preheating structure is rotated 180° around the asymmetric axis relative to the first orientation, or is rotated around the third axis relative to the first orientation by an angle α in the range of 0°<α<360°, preferably 90°≤α≤270°, and particularly preferably α=180°. In the present embodiment, wherein the welding structure is a rectangle with rounded corners, and therefore the preheating structure is a rectangle with rounded corners, and there is a protrusion at each of the two adjacent corners, the desired effect can be achieved by rotating 180° around the asymmetric axis or by 180° around the third axis. However, the latter is only applicable to a specific design of the welding structure, and therefore only to a specific design of the preheating structure, which will be described later with respect to a specific embodiment.

[0043] After rotating like this, the preheating structure matches the exposed welding structure (i.e. the second welding structure and the corresponding third welding structure here) in the preheating position of the preheating device. Therefore, the corresponding welding structure can be reliably preheated by the preheating device to implement the second cycle.

[0044] After preheating and welding have been performed, as described above, the cycle can be repeated. This third cycle usually corresponds to the first cycle. Therefore, the preheating device must be rotated back to the first position.

[0045] Generally, the cycle is repeated, whereby the process of welding a new first component to the welded component stack is repeated until a welded component stack having the desired number of layers or thickness is present.

[0046] A generally positive effect of preheating is that, in the case of friction or vibration welding of components, solid-on-solid friction is skipped at the beginning of the welding process. As a result, the formation of particles is at least partially prevented and a clean joint can be obtained. In addition, also for vibration welding, the friction forces are reduced and lower amplitudes can be used to form the weld between the components to be welded. These reduced forces are advantageous if the components to be welded are structurally less stable and tend to bend easily, which usually leads to amplitude losses and poor weld connections. Thus, even in the case of components that tend to bend easily, a reliable weld connection can be established by means of the preheating device according to the invention.

[0047] Furthermore, the method is simple and the structure of the device is space-saving, in particular because the preheating device is designed so that it can be rotated so that the preheating structure is matched to the welded structure to be preheated in each cycle. No additional preheating device is required to provide a preheating structure adapted to the welded structure to be preheated, nor is it necessary to remove the welded component stack and rearrange it in a different orientation in the lower tool. This reduces the complexity of the device and the control method and the required installation space, while also maintaining a high welding quality.

[0048] For the sake of completeness, it is pointed out that the preheating device can also define a second plane perpendicular to the first plane. For example, in relation to the above-mentioned rectangle, the welding device can have the shape of a cuboid, wherein superimposed preheating structures are arranged on opposite faces. As a result, the field of application of the corresponding preheating device can be further expanded. Assuming that the preheating structure appears on a surface parallel to the rotation axis relative to it, a 180° rotation must be implemented to switch between the first position and the second position, i.e. to use the first preheating structure and the second preheating structure, while to use the other preheating structures, i.e. the third preheating structure and the fourth preheating structure, a 90° rotation must be implemented. After the preheating structure is switched, the above steps are implemented similarly.

[0049] In a preferred embodiment of the preheating device, the first rotating tool is used to rotate the preheating device around an axis in the first plane parallel to the asymmetric axis, around the asymmetric axis or around a third axis. As mentioned above, the rotation around the third axis is only effective for specific designs of the preheated structure and the component to be welded. Therefore, particularly advantageous is an embodiment in which the first rotating tool is used to rotate the preheating device around the asymmetric axis or around an axis arranged in the first plane and parallel to the asymmetric axis. This is because after a 180° rotation around this axis, whether it is the asymmetric axis itself or an axis parallel thereto and in the first plane, leads to the same result.

[0050] The welding device of the present invention for welding a first component to a second component or a stack of already welded components comprises an upper tool mounted on an upper support for receiving the first component and a lower tool mounted on a lower support for receiving the second component or a stack of already welded components, and a preheating device of the present invention, wherein the preheating device is movable between a parking position and a preheating position, so that the preheating device is arranged in the preheating position between the upper support and the lower support, wherein in the preheating position the upper support and the lower support are each arranged in a plane parallel to the first plane, and the upper support and the lower support are movable relative to each other between an initial position and a welding position. The above discussion of the welding device of the present invention has been made when explaining the function of the preheating device of the present invention. Therefore, in order to avoid unnecessary repetition, please refer to the above discussion. The same applies to the technical effects and advantages resulting therefrom.

[0051] In a preferred embodiment of the welding device, the welding device is a vibration welding device or an infrared welding device. With this embodiment, the preheating device of the present invention can be used together with the vibration welding device and can also be used in combination with the infrared welding device. Therefore, the application field of the preheating device of the present invention is expanded and is applicable to the parts to be welded.

[0052] The preheating method of the present invention is to preheat a first component and a second component or a stack of welded components by means of a preheating device of the present invention, wherein the first component comprises a first welding structure on a first side and a second welding structure on an opposite second side, the first welding structure and the second welding structure are formed to overlap with the first preheating structure and the second preheating structure of the preheating device, and are oriented so that the first welding structure and the second welding structure are rotated 180° around an asymmetric axis or around a third axis relative to each other by an angle α, and the second component or the stack of welded components comprises a third welding structure on a side facing the first component, which is oriented so that when viewed along the third axis, the third welding structure The structure is arranged on a welding structure facing a second component or a first component of a stack of already welded components, wherein the preheating method comprises the following steps: moving a preheating device from a parking position to a preheating position between an upper tool and a lower tool of a welding device, wherein a preheating device of the preheating device is arranged in a first position having a first orientation, wherein the preheating structure covers the welding structure in the preheating position when viewed along a third axis; and arranging an upper support and a lower support of the welding device in a preheating position in a plane parallel to the first plane, respectively; preheating the first component and the second component or the stack of already welded components; and moving the preheating device from the preheating position to the parking position. The preheating method has been described in conjunction with the preheating device of the present invention. Therefore, to avoid repetition, please refer to the relevant description of the procedure, technical effects and advantages.

[0053] In a preferred embodiment of the preheating method, it comprises a further step after the preheating step: the preheating device is preferably rotated from a first position to a second position in the parking position by at least one rotating tool. This makes it possible to integrate components similar to the first component but with welding structures that do not rotate relative to each other into the component stack in an intermediate step. In the case where not every component in the component stack to be provided is a first component, but only, for example, every other component is a first component, this further expands the application field of the preheating device and the preheating method. Of course, any other mode can also be used. With regard to the rotation of the preheating device, it can also occur during the movement from the parking position to the preheating position, during the movement from the preheating position to the parking position or at any time in the parking position, for example during the loading of a new first component to be welded to the welding device.

[0054] The welding method of the present invention is to weld a first component to a second component or a stack of welded components by means of a welding device of the present invention, wherein the first component comprises a first welding structure on a first side and a second welding structure on an opposite second side, the first welding structure and the second welding structure are formed to overlap with the first preheating structure and the second preheating structure of the preheating device, and are oriented so that the first welding structure and the second welding structure are rotated 180° around the asymmetric axis or around a third axis by an angle α relative to each other, and the second component or the stack of welded components comprises a third welding structure on a side facing the first component, which is oriented so that the third welding structure is arranged on a side facing the second component when viewed along the third axis. The invention relates to a method for welding a first component or a first component facing a welded component stack, wherein the welding method comprises the following steps: arranging a first component with a first side in an upper tool; moving a lower support of a lower tool with a second component or a welded component stack arranged thereon to an intermediate position relative to an upper support; implementing the preheating method of the invention, wherein the preheating device is arranged in a first position; moving the lower support with the second component or with the welded component stack along a third axis relative to the upper support to a welding position; welding the first component to the second component or the welded component stack, thereby producing an increased welded component stack; and thereafter moving the lower support back to the initial position. The welding method, like the preheating method, has been described above in conjunction with the preheating device of the invention. Therefore, reference is made to these descriptions for the procedure, technical effects and advantages.

[0055] In a preferred embodiment of the welding method, the step of arranging the first component in the upper tool comprises the steps of arranging the first component in the lower tool, preferably on the second component or on the stack of already welded components; and moving the lower support with the first component along the third axis relative to the upper support from an initial position to a transfer position. With these method steps, the user places the first component on the lower tool and then moves the lower tool to transfer the first component to the upper tool. This saves the manual step of arranging the first component in the upper tool.

[0056] In another preferred embodiment of the welding method, it comprises, after the step of moving the lower support back to the initial position, the further steps of: arranging a further first component in the upper tool so that the welding structure facing the side of the lower tool matches the third welding structure revealed by the already welded component stack in the lower tool; and repeating the step of moving the lower support to the intermediate position; implementing the preheating method of the invention; moving the lower support to the welding position; welding the components to each other and moving the lower support to the initial position, wherein the preheating device has been rotated and arranged in the second position. By means of this method step, it is ensured that in the case where a new first component should be welded to the already welded component stack, the preheating device is arranged so that the preheating structure matches the orientation of the welding structure of the components to be welded to each other.

[0057] Preferably, the welding method comprises, after the step of moving the lower support back to the initial position, a further step of arranging a third component in the upper tool, wherein the third component comprises a fourth welding structure on a first side and a fifth welding structure on an opposite second side, wherein the fourth welding structure and the fifth welding structure correspond to the third welding structure and are oriented so that when viewed along a third axis perpendicular to the first plane, the fourth preheating structure and the fifth preheating structure are arranged one above the other, wherein the third component is arranged in the upper tool so that the welding structure on the side facing the lower tool matches the third welding structure revealed by the stack of welded components in the lower tool; and repeating the steps of moving the lower support to an intermediate position, performing the preheating method of the invention, moving the lower support to a welding position, welding the components to each other and moving the lower support to the initial position, wherein the preheating device is maintained in the first position or the second position. This single step allows the third component to be welded to the stack of welded components. The third component corresponds to the first component in that it has the same welding structure. However, it differs from the first component in that the corresponding welding structures are not rotated relative to each other. In other words, they are arranged one above the other, just like the design of the preheating structure of the preheating device. Thus, in conjunction with the previous preferred method steps, the preheating device is not rotated every time in the parking position, but only when required. This makes the welding method more flexible and allows the production of a stack comprising at least two different types of components. The first type is the above-mentioned first component, and the second type is the third component.

[0058] In this regard, with respect to each of the preferred further method steps described above, the arrangement of the additional first component or third component may include the following steps: arranging the first component or third component in the lower tool, preferably on the second component or the welded component stack; and moving the lower support with the first component or third component along the third axis relative to the upper support from an initial position to a transfer position.

[0059] The modification method for a welding device of the present invention comprises the following steps: providing a preheating device of the present invention, joining the preheating device to the welding device, and implementing the preheating device in a control method of the welding device. By this method, an existing welding device (such as a vibration welding device or an infrared welding device) can be equipped with the preheating device of the present invention, thereby achieving the technical effects and advantages discussed above. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Hereinafter, the present invention will be described in detail according to the accompanying drawings. In the accompanying drawings, the same reference symbols represent the same elements and / or components. It is shown as:

[0061] Figure 1 An embodiment of a welding device according to the invention is shown, which has an embodiment of a preheating device according to the invention arranged in a first position;

[0062] Figure 2 An embodiment of a welding device according to the invention is shown, which has an embodiment of a preheating device according to the invention arranged in a second position;

[0063] Figure 3 A first side of a first component is shown to illustrate a welded structure;

[0064] Figure 4 Shows Figure 3 a first side of a first component of the invention, wherein a first centerline and a second centerline are identified;

[0065] Figure 5 Shows Figure 4 an enlarged view of the right side of the first component;

[0066] Figure 6 Shows Figure 3 a first component, wherein a second weld structure is additionally shown on an opposite second side;

[0067] Figure 7 Shows Figure 6 a first component, wherein a first centerline and a second centerline are identified;

[0068] Figure 8 Shows Figure 7 an enlarged view of the right side of the first component;

[0069] Fig. 9 A flow chart showing an embodiment of the preheating method of the present invention;

[0070] Fig.10 A flow chart showing an embodiment of the welding method of the present invention; and

[0071] Fig.11 A flow chart showing an embodiment of the retrofitting method of the present invention. DETAILED DESCRIPTION

[0072] The function of an embodiment of the preheating device according to the invention in a welding device is described in detail below. Generally speaking, the welding device and the preheating device can be used in the automotive industry or medical technology. In particular, it can be used in any application in which a plurality of components should be welded to each other in a reliable manner, for example by vibration or infrared welding.

[0073] First, refer to Figure 1 and Figure 2A vibration welding device of the present invention is described, which includes an embodiment of the preheating device of the present invention. The welding device includes an upper tool for receiving a first component 20 mounted on an upper support 1 in a known manner. In addition, the welding device also includes a lower tool for receiving a second component or a stack of welded components mounted on a lower support 3. The upper support 1 and the lower support 3 can be moved relative to each other between an initial position and a welding position. In the initial position, the components to be welded can be loaded into the welding device. In the welding position, the components in the welding device are in an adjacent state so that they can be welded to each other. According to a first alternative, the welding device is a vibration welding device, so that the components are welded to each other at the welding position by vibration welding. In a second alternative, the welding device is an infrared welding device, so that the components are welded to each other at the welding position by infrared welding.

[0074] During operation, the first component 20 is fixed in the upper tool by means of negative pressure. In addition, for exemplary operation, the upper support 1 of the welding device is an upper mounting plate, and the lower support 3 is a lifting platform, preferably a lifting platform driven by a motor.

[0075] Furthermore, the welding device comprises a preheating device. The preheating device can be moved between a parking position and a preheating position. In the preheating position, the preheating device is arranged between the upper support 1 and the lower support 3. Therefore, with reference to Figure 1 and Figure 2 , the preheating device is arranged in the preheating position.

[0076] The specific design of the preheating device will now be further described. In the embodiment shown, the preheating device comprises a preheating device 10 having a rectangular shape. The rectangular shape defines a first plane by a first centerline extending along a first axis X and a second centerline extending along a second axis Y perpendicular to the first axis X.

[0077] In the embodiment shown, the first axis X and the first centerline are parallel to and extend between the lateral sides of the rectangle, while the second axis Y and the second centerline are parallel to and extend between the longitudinal sides of the rectangle. Thus, the first centerline and the second centerline define a first plane and divide the preheating device 10 into four geometrically equal parts. The intersection of the centerlines represents the geometric center of the preheating device, wherein the coordinate system shown has an origin.

[0078] It can be seen directly that in the preheating position the support element 1 and the lower support element 3 are each arranged in a plane parallel to the first plane.

[0079] The preheating device 10 has a first side 12 with a first preheating structure 14. Figure 1. The first preheating structure 14 is asymmetric with respect to the first center line (i.e., the first axis X) and with respect to the second center line (i.e., the second axis Y), and therefore, the first axis X and the second axis Y are each an asymmetric axis. In other words, the image of one side of one of the center lines or axes is not mirror-symmetrical with respect to the other side of the corresponding center line or axis. Although this is an exemplary embodiment, it is particularly preferred that the remaining portion of the first center line or the second center line is a symmetric axis, especially when the component has a rectangular shape.

[0080] exist Figure 2 1 shows the opposite second side 16 of the preheating device 10. The second side 16 has a second preheating structure 18. The second preheating structure 18 corresponds to the first preheating structure 14. In particular, it is formed to be superimposed with the first preheating structure 14. Superimposed in this respect means that it has the same shape and size. Therefore, the first preheating structure 14 and the second preheating structure 18 are identical in shape and size.

[0081] Furthermore, the second preheating structure 18 is oriented in the same manner as the first preheating structure 14, so that when viewed along a third axis Z perpendicular to the first plane, the first preheating structure 14 and the second preheating structure 18 are arranged one above the other. The term "one above the other" means that the shadow of one structure generated by an imaginary light irradiated from one side through the preheating device 10 completely covers the other structure. Therefore, and since the preheating structures 14, 18 are arranged one above the other, i.e. one is completely above the other, the second preheating structure 18 must have the same orientation as the first preheating structure 14. This is also based on the fact that two parts that are to be welded to each other later when using the welding device have matching welding structures, which will be explained below.

[0082] In addition, also with regard to the preheating equipment, in comparison Figure 1 and Figure 2 It must be noted that the position of the preheating device 10 has changed from Figure 1 The first position is transformed into Figure 2 For example, this can be seen by two grooves on the longitudinal side of the preheating device 5. To implement this change of position, the preheating device comprises a first rotating tool for rotating the preheating device 10 between the first position and the second position.

[0083] Based on the required subsequent operation, the first position and the second position differ from each other in that the preheating structures 14, 18 have a first orientation in the first position and a second orientation in the second position, wherein in the first alternative they are rotated 180° around the asymmetry axis compared to the first orientation. Figure 1 and Figure 2 , because the welding device 10 has been rotated around the second center line (ie, the Y axis as the asymmetric axis).

[0084] According to an alternative solution, in particular when the preheating structure is mirror-symmetrical with respect to one of the first center line and the second center line, it is also preferred to rotate the preheating structure 14, 18 about the third axis Z relative to the first orientation by an angle α in the range of 0°<α<360°, preferably 90°≤α≤270°, and particularly preferably α=180°. In this case, if the preheating device 10 is rotated by 180° about the third axis Z, the result will be the same as the rotation about the asymmetric axis.

[0085] Based on the above description, the first rotating tool is used to rotate the preheating device 10 around an axis in the first plane parallel to the asymmetric axis (i.e., the second axis Y here) or around the asymmetric axis to achieve the illustrated embodiment. To achieve other alternatives, the first rotating tool can be used to rotate the preheating device 10 around the third axis Z. However, the rotation around the third axis Z is only useful for specific designs of the preheating structures 14, 18 and the parts 20 to be welded.

[0086] In addition to the first rotating tool, the preheating device can also be equipped with another rotating tool, such as a second rotating tool for rotating around the third axis Z. Alternatively, the preheating device can be equipped with a rotating tool on each axis, which will produce three rotating tools. Therefore, the preheating device is suitable for various preheating devices and preheating structures.

[0087] For the sake of completeness, it is pointed out that when the preheating device is in the preheating position, the upper support 1 and the lower support 3 are respectively arranged in planes parallel to the first plane defined by the preheating device 5. Therefore, the term "third axis" Z refers to an axis perpendicular to the corresponding plane.

[0088] A plurality of components are welded to each other by means of a welding device. Figures 3 to 8 An exemplary first component 20 is depicted.

[0089] The first component 20 has a rectangular shape like the preheating device 5. Therefore, the first center line of the component, i.e. the XC axis (see Figure 3 ), parallel to and extending between the lateral sides of the component, the second centerline, i.e., the YC axis (see Figure 3 ), parallel to the longitudinal sides of the first component 20 and extending therebetween. Thus, the first centerline and the second centerline define a plane and divide the component into four geometrically equal parts. The intersection of the centerlines represents the geometric center of the component, where the origin of the coordinate system is shown. The third axis ZC extends perpendicular to the plane.

[0090] A first welded structure 24 is arranged on the first side 22 of the first component 20. The first welded structure 24 is formed to overlap with the first preheating structure 14 and the second preheating structure 18 of the preheating device 10. As mentioned above, overlap in this regard means that it has the same shape and size. Therefore, the first preheating structure 14 and the second preheating structure 18 and the first welded structure 24 are identical in shape and size. Therefore, the first center line (i.e., the first axis XC) and the second center line (i.e., the second axis YC) are asymmetric axes. In other words, the image of one side of one center line or axis is not mirror-symmetrical with respect to the other side of the corresponding center line or axis.

[0091] A second welding structure 28 is arranged on the second side of the first component 20. The second welding structure 28 can be Figures 6 to 8 These figures show a view through the component so that both the first welded structure 24 and the second welded structure 28 can be seen simultaneously, although they are arranged on opposite sides.

[0092] The second welded structure 28 is superimposed on the first welded structure 24 and therefore also on the first preheating structure 14 and the second preheating structure 18. These structures 14, 18, 24, 28 therefore have the same size and shape.

[0093] However, from Figures 6 to 8 It can be seen that the second welded structure 28 is arranged in a different orientation on the second side compared to the first welded structure 24 on the first side 22. This different orientation is achieved in that the first welded structure 24 is arranged on the second side in a rotated manner relative to the second welded structure 28. In the embodiment shown, the second welded structure 28 on the second side is rotated 180° around the second axis YC to produce the first welded structure 24. Therefore, the first welded structure 24 and the second welded structure 28 are rotationally symmetric relative to each other.

[0094] Back to Figures 6 to 8 In the view shown therein, when viewed from above the first side 22 and through the first component 20, the first welded structure 24 and the second welded structure 28 do not completely overlap each other, i.e., they are not arranged completely on top of each other. The same applies to the case where the first component 20 is viewed from the second side.

[0095] The rotation for achieving this different orientation is performed by rotating the second welded structure 28 by 180° relative to the first welded structure 24 about the second axis YC as an axis of asymmetry.

[0096] Thus, when the first component 10 is turned from a position where the first side 22 can be observed to a position where the second side can be observed around the second axis YC as the asymmetric axis, the second weld structure 28 will appear to the observer to have the same orientation as the first weld structure 24. On the other hand, if the first component 20 is turned from the first side 22 to the second side around the first axis XC as the asymmetric axis, the second weld structure 28 will appear to have a different orientation than the first weld structure 24.

[0097] According to another alternative, in particular in the case where the welded structure is mirror-symmetrical with respect to one of the first axis XC and the second axis YC, the second welded structure 28 can be rotated by an angle α about a third axis ZC (perpendicular to the plane) compared to the first welded structure 24. For example, the rotation about the third axis ZC can be 180°. Therefore, a rotation of 180° is particularly preferred regardless of other possible rotation angles. However, in particular in the case where the welded structures 24, 28 are asymmetrical with respect to the two center lines, a rotation with other angle values ​​not equal to 0° and 360° may be useful.

[0098] With regard to the overall design of the first component 20 , and therefore of the components to be welded to one another, the welding method and the preheating method will be explained with respect to several exemplary welding cycles.

[0099] First, a first component 20 is arranged in the upper tool and a second component is arranged in the lower tool, the second component either being identical to the first component 20 or having a third welded structure on at least one side that is superimposed and matched with one of the first welded structures 24 or the second welded structures 28 of the first component 20. As an alternative, a stack of welded components is already present in the lower tool. In each case, the first component 20 and the second component or the first component 20 and the stack of welded components are arranged so that their welded structures match each other.

[0100] For ease of understanding, it is assumed that the first component 20 is arranged in the upper tool so that the first side 22 with the first weld structure 24 faces the lower tool, and the second side with the second weld structure 28 is arranged in the upper tool. Therefore, in this embodiment, the second component identical to the first component 20 is arranged in the lower tool so that the first side 22 with the first weld structure 24 faces the upper tool, that is, the first side 22 of the first component 20 is located in the upper tool. Subsequently, the weld structure revealed by the second component or the welded component stack present in the lower tool is referred to as the third weld structure.

[0101] After the first component 20 has been arranged in the upper tool, the lifting table is moved along the third axis Z into an intermediate position in which the preheating device can be moved from the parking position into a preheating position between the components 20 .

[0102] For this purpose, the preheating equipment is arranged as follows Figure 1 The first position is shown, in which the preheating structures arranged on the first side 12 and the second side 16 match the welding structures 24 of the first component 20 in the upper tool and the lower tool. In other words, the welding structure 24 and the preheating structures 14, 18 are arranged one above the other (in particular completely) in the case of the welding device viewed along the third axis Z. Therefore, when viewing through the individual parts and components, only one structure can be seen from this perspective. In the case of a vibration welding device, the first plane can also be called a vibration welding plane.

[0103] Since the preheating structures 14, 18 of the preheating device must be matched to the welding structure 24, the preheating structures 14, 18 of the preheating device 10 must be oriented in the same way as described above. Therefore, when viewed from above and along the third axis Z and through the preheating device 10, they must be arranged one above the other, in particular completely.

[0104] After the preheating device has been arranged between the two components 20, the welded structure 24 of the two components 20 is preheated by the matching preheating structures 14, 18. Therefore, the preheating structures 14, 18 cover the welded structure 24 in the preheating position. In this regard, the first preheating structure 14 and the second preheating structure 18 are preferably infrared preheating structures.

[0105] After preheating, the preheating device moves from the preheating position back to the parking position. Thereafter, the lifting table (i.e. the lower support 5) moves along the third axis Z to the welding position, in which the first component and the second component 20 or the welded component stack are adjacent and welded to each other, for example by vibration welding or infrared welding. After welding, the lower support 3 moves to its initial position relative to the upper support 1.

[0106] Thus, a welded component stack or an increased welded component stack 20 consisting of the first component and the second component 20 is now present in the lower tool.

[0107] In contrast to known methods, the component stack remains in the lower tool. Thus, the side of the welded component stack facing the upper tool or upper support 1 corresponds to the side of the previous first component 20 arranged in the upper tool in the first cycle. This side with the second welded structure 28 now represents the third welded structure of the welded component stack.

[0108] In the following second cycle, another first component 20 is arranged in the upper tool. Since the already welded component stack determines the weld structure and in particular its orientation, the new first component 20 must be arranged in the upper tool so that the second side of the tool with the second weld structure 28, i.e. the already welded component stack arranged therein, is downward.

[0109] Now, the above process is repeated. However, since the orientation of the weld structure has changed from the first weld structure 24 to the second weld structure 28, the previous position of the preheating device 10 is not suitable and cannot ensure reliable preheating of the weld structure 28 in this cycle.

[0110] To overcome this, Figure 2 As shown and described above, the preheating device is rotated from the first position to the second position, in particular in the parking position. After such a rotation, the preheating structures 14, 18 are matched again with the exposed welded structures (i.e., the second welded structure 28 and the corresponding third welded structure here) in the preheating position of the preheating device. Therefore, the corresponding welded structure 28 can be reliably preheated by the preheating device to implement the second cycle.

[0111] As mentioned above, the cycle can be repeated after preheating and welding have been performed. This third cycle usually corresponds to the first cycle. Therefore, the preheating device must be turned back to the first position.

[0112] Generally speaking, this cycle and welding of additional first components 20 to the welded component stack is repeated until a welded component stack having a desired number of layers or thickness is present.

[0113] The overall positive effect of preheating is that, in the case of friction or vibration welding of components, solid-on-solid friction is skipped at the beginning of the welding process. As a result, the formation of particles is at least partially prevented and a clean joint is obtained. In addition, also in the case of vibration welding, the friction forces are reduced and lower amplitudes can be used to form the weld between the components to be welded. These reduced forces are advantageous if the components to be welded are structurally unstable and tend to bend easily, which usually leads to amplitude losses and poor weld connections. Thus, even in the case of components that tend to bend easily, a reliable weld connection can be established by the preheating device according to the invention.

[0114] Furthermore, in particular, since the preheating device (in particular the preheating device 10) is designed to be rotatable so that the preheating structure 14, 18 is matched to the welded structure 24, 28 to be preheated in each cycle, the method is simple and the structure of the device is space-saving. Neither is it necessary to provide an additional preheating device to provide a preheating structure adapted to the welded structure to be preheated, nor is it necessary to remove the welded component stack and rearrange it in a different orientation in the lower tool. This reduces the complexity of the device and the control method and the required installation space, while maintaining a high welding quality.

[0115] For further elaboration, see Fig. 9 An embodiment of the preheating method of the present invention is described in which the first component 20 and the second component or the welded component stack are preheated by the preheating device of the present invention.

[0116] As described above, the first component 20 includes a first weld structure 24 on a first side 22 and a second weld structure 28 on an opposite second side. The first weld structure 24 and the second weld structure 28 are formed to overlap with the first preheating structure 14 and the second preheating structure 18 of the preheating device 10 and are oriented so that the first weld structure 24 and the second weld structure 28 are rotated 180° about the asymmetric axis or about the third axis relative to each other by an angle α. The second component or the welded component stack includes a third weld structure on a side facing the first component 20, which is oriented so that when viewed along the third axis Z, the third weld structure is arranged above the weld structures 24, 28 of the first component 20 facing the second component or the welded component stack.

[0117] In a first step A, the preheating device is moved from a parking position to a preheating position between an upper tool and a lower tool of the welding device. The preheating device of the preheating device is arranged in a first position with a first orientation in which the preheating structure 14, 18 covers the welding structure 24 or 28 in the preheating position when viewed along the third axis Z. The upper support 1 as well as the lower support 3 of the welding device are each arranged in a plane parallel to the first plane in the preheating position.

[0118] Next, in step B, the first component 20 and the second component or the welded component stack are preheated.

[0119] In step C, the preheating device is moved from the preheating position to the parking position.

[0120] In particular in the parking position, a further step D of rotating the preheating device from the first position to the second position by means of at least one first rotating tool is carried out. According to an alternative, this rotation takes place during or after the preheating device has been moved from the preheating position to the parking position. In this respect, the rotation can be carried out at any time in the parking position, for example when a new first component to be welded is loaded into the welding device. According to another alternative, this step is carried out during or before the preheating device is moved from the parking position to the preheating position.

[0121] In general, this additional step makes it possible to integrate a third component (which is similar to the first component, but has welded structures that do not rotate relative to each other) into the component stack in an intermediate step. In this regard, reference is made to the following description of an embodiment of the welding method according to the invention including welding a third component. This further expands the field of application of the preheating device and the preheating method in the case that not every component in the component stack to be provided is a first component 20, but only, for example, every other component is a first component. Of course, any other mode can also be used.

[0122] Reference Fig.10An embodiment of the welding method of the present invention is described in which a first component 20 is welded to a second component or a stack of welded components by using the welding device of the present invention.

[0123] Likewise, the first component 20 comprises a first weld structure 24 on a first side 22 and a second weld structure 28 on an opposite second side. The first weld structure 24 and the second weld structure 28 are formed to overlap with the first preheating structure 14 and the second preheating structure 18 of the preheating device 10. Furthermore, the first weld structure 24 and the second weld structure 28 are oriented such that the first weld structure 24 and the second weld structure 28 are rotated 180° about the asymmetric axis or about the third axis Z relative to each other by an angle α. The second component or the welded component stack comprises a third weld structure on a side facing the first component 20, which is oriented such that when viewed along the Z axis, the third weld structure is arranged above the weld structures 24, 28 facing the second component or the welded component stack.

[0124] In a first step i, the first component 20 is arranged in the upper tool with its first side in the upper tool. In the described embodiment, this step i comprises a further step i1 of arranging the first component 20 in the lower tool, preferably on a second component or a stack of already welded components, and a step i2 of moving the lower support 3 with the first component 20 along the third axis Z relative to the upper support 1 from an initial position to a transfer position. With these method steps, the user places the first component 20 on the lower tool and then moves the lower tool to transfer the first component 20 to the upper tool. This saves the manual step of arranging the first component in the upper tool.

[0125] After the first step i, in a step ii the lower support 3 with the lower tool with the second component or the welded component stack arranged thereon is moved relative to the upper support 1 into an intermediate position.

[0126] In this intermediate position, the above-described embodiment of the preheating method of the invention is implemented in step iii. To this end, the preheating device 10 is arranged in the first position.

[0127] Thereafter, in step iv, the lower support 3 with the second component or with the welded stack of components is moved relative to the upper support 1 along the third axis Z into the welding position. In step v, the first component 20 is welded to the second component or to the welded stack of components, thereby generating an increased stack of welded components. In each subsequent cycle, this increase in the stack is taken into account when approaching the welding position. Thereafter, the lower support 3 is moved back to the initial position in step vi.

[0128] In a first alternative, the welding method now comprises a step vii of arranging a further first component 20 in the upper tool. This is implemented so that the welding structure on the side facing the lower tool matches the third welding structure revealed by the stack of components already welded in the lower tool. Subsequently, the above steps ii to vi are repeated: moving the lower support 3 to the intermediate position, implementing the preheating method of the invention, moving the lower support 3 to the welding position, welding the components to each other and moving the lower support 3 to the initial position. However, it must be taken into account that the preheating device 10 has been rotated before the preheating of this cycle, so that it is arranged in the second position. Through this alternative, it can be ensured that in the case where a further or new first component 20 is welded to the stack of components already welded, the preheating device is arranged so that the orientation of the preheating structures 14, 18 is consistent with the orientation of the welding structures 24, 28 of the components to be welded to each other.

[0129] In a second alternative, the welding method comprises a step viii of arranging a third component (not shown) in the upper tool after a step vi of moving the lower support 3 back to the initial position. The third component comprises a fourth welding structure on a first side and a fifth welding structure on an opposite second side. The fourth welding structure and the fifth welding structure correspond to the third welding structure and are oriented so that when viewed along a third axis perpendicular to the first plane, the fourth preheating structure and the fifth preheating structure are arranged one above the other.

[0130] Likewise, similar to the other first component, the third component is arranged in the upper tool so that the weld structure facing the side of the lower tool matches the third weld structure revealed by the welded component stack in the lower tool. Thereafter, steps ii to vi are repeated: moving the lower support 3 to the intermediate position, implementing the preheating method of the present invention, moving the lower support 3 to the welding position, welding the components to each other, and moving the lower support 3 to the initial position. Here, it must be taken into account that the preheating device is kept in the first position or the second position.

[0131] Thus, this single step enables the third component to be welded to the stack of already welded components. The third component corresponds to the first component in that it has the same welded structure. However, it differs from the first component in that the corresponding welded structures are not rotated relative to each other. In other words, they are arranged one above the other, similar to the orientation of the preheating structures 14, 18 of the preheating device 10.

[0132] Thus, in conjunction with the first alternative, the preheating device 10 is not rotated every time in the parking position, but only when needed. This makes the welding method more flexible and allows the production of a stack comprising at least two different types of components. The first type is the first component mentioned above, and the second type is the third component.

[0133] Finally, Fig.11An embodiment of the retrofit method of the present invention for a welding device is discussed. The method first comprises a step I of providing a preheating device of the present invention. Subsequently, the preheating device is incorporated into the welding device in step II. Finally, the preheating device is implemented into a control method of the welding device in step III. Thus, an already existing welding device (e.g., a vibration welding device or an infrared welding device) is equipped with the preheating device of the present invention through the method, thereby achieving the technical effects and advantages discussed above.

[0134] Reference numerals

[0135] 1 Upper support

[0136] 3 Lower support

[0137] 10 Preheating device

[0138] 12 The first side of the preheating device 10

[0139] 14 The first preheating structure of the first side 12

[0140] 16 The second side of the preheating device 10

[0141] 18 The second preheating structure of the second side 16

[0142] 20 First Part

[0143] 22 first side of the first component 20

[0144] 24 The first welding structure of the first side 22

[0145] 28 The second welding structure on the second side

[0146] X-first axis

[0147] Y Second Axis

[0148] Z third axis

Claims

1. A preheating device for a welding device, the welding device having an upper tool mounted on an upper support (1) and a lower tool mounted on a lower support (3), wherein the upper support (1) and the lower support (3) are movable relative to each other between an initial position and a welding position, and the preheating device include: a. a preheating device (10) defining a first plane by a first centerline extending along a first axis X and a second centerline extending along a second axis Y perpendicular to the first axis X, and b. The preheating device has a first side (12) with a first preheating structure (14) and an opposite second side (16) with a second preheating structure (18), wherein c. The first preheating structure (14) is asymmetric relative to the first center line and / or the second center line, so the corresponding axis is an asymmetric axis, and d. The second preheating structure (18) corresponds to the first preheating structure (14) and is oriented in the same direction as the first preheating structure (14), so that when viewed along a third axis Z perpendicular to the first plane, the first preheating structure (14) and the second preheating structure (18) are arranged one above the other, wherein e. The preheating device further comprises a first rotating tool for rotating the preheating device (10) between a first position and a second position, so that the first and second preheating structures (14, 18) have a first orientation in the first position and a second orientation in the second position, e1. wherein, in the second orientation, the first and second preheating structures (14, 18) are rotated 180° about the asymmetric axis relative to the first orientation, or e2. wherein, in the second orientation, the first and second preheating structures (14, 18) are rotated about the third axis Z relative to the first orientation by an angle α in the range of 0°<α<360°. 2 . The preheating device according to claim 1 , wherein the remaining center line of the first center line or the second center line is a symmetry axis.

3. The preheating device according to claim 1 or 2, wherein the first rotating tool is used to a. rotating the preheating device around an axis in the first plane parallel to the asymmetric axis, b. rotating the asymmetric axis or c. rotating the preheating device around the third axis Z.

4. The preheating device according to claim 1 or 2, wherein the preheating device (10) has a rectangular shape, and the first axis X extends parallel to the lateral sides of the rectangle, and the second axis Y extends parallel to the longitudinal sides of the rectangle.

5. The preheating device according to claim 1 or 2, wherein the first preheating structure (14) and the second preheating structure (18) are infrared preheating structures.

6. A welding device for welding a first component (20) to a second component or a stack of already welded components, comprising: a. an upper tool mounted on the upper support member (1) for receiving the first member (20), and b. a lower tool mounted on a lower support (3) for receiving said second component or said welded component stack, and c. The preheating device according to any one of claims 1 to 5, wherein d. the preheating device is movable between a parking position and a preheating position, so that the preheating device is arranged at the preheating position between the upper support (1) and the lower support (3), wherein in the preheating position, the upper support (1) and the lower support (3) are each arranged in a plane parallel to the first plane, and e. The upper support (1) and the lower support (3) are movable relative to each other between an initial position and a welding position.

7. The welding device according to claim 6, wherein at the welding position, the first component (20) can be welded to the second component or the welded component stack by vibration welding or infrared welding.

8. A preheating method, comprising preheating a first component (20) and a second component or a welded component stack by means of a preheating device according to any one of claims 1 to 5, wherein The first component (20) includes a first weld structure (24) on a first side (22) and a second weld structure (28) on an opposite second side, the first weld structure (24) and the second weld structure (28) being formed to overlap with the first preheat structure (14) and the second preheat structure (18) of the preheating device (10) and being oriented so that the first weld structure (24) and the second weld structure (28) are rotated 180° relative to each other around the asymmetric axis or around the third axis by the angle α, and The second component or the welded component stack comprises a third welding structure on the side facing the first component (20), which is oriented so that when viewed along the third axis Z, the third welding structure is arranged above the welding structure facing the second component or the first component (20) of the welded component stack, wherein the preheating method The following steps are involved: Step A: moving the preheating device from a parking position to a preheating position between the upper tool and the lower tool of the welding device, wherein the preheating device of the preheating device is arranged in the first position with the first orientation, wherein when viewed along the third axis Z, the first and second preheating structures (14, 18) cover the first and second welding structures (24, 28) in the preheating position, and the upper support (1) and the lower support (3) of the welding device are respectively arranged in the preheating position in a plane parallel to the first plane, and Step B: preheating the first component (20) and the second component or the welded component stack, and Step C: moving the preheating device from the preheating position to the parking position.

9. The preheating method according to claim 8, comprising a further step after the preheating in step B: Step D: Rotating the preheating device from the first position to the second position by at least one of the rotating tools.

10. A welding method, comprising welding a first component (20) to a second component or a stack of already welded components by means of a welding device according to claim 6 or 7, wherein The first component (20) includes a first weld structure (24) on a first side (22) and a second weld structure (28) on an opposite second side, the first weld structure (24) and the second weld structure (28) being formed to overlap with the first preheating structure (14) and the second preheating structure (18) of the preheating device and being oriented so that the first weld structure (24) and the second weld structure (28) are rotated 180° relative to each other around the asymmetric axis or around the third axis Z by the angle α, and the second component or the stack of welded components comprises a third welding structure on the side facing the first component (20), which is oriented such that when viewed along the third axis Z, the third welding structure is arranged above the welding structure facing the second component or the first component (20) of the stack of welded components, in, The welding method comprises the following steps: Step i: arranging the first component (20) in the upper tool so that the first side (22) thereof is located in the upper tool, Step ii: moving the lower support (3) with the lower tool with the second component or the welded component stack arranged thereon into an intermediate position relative to the upper support (1), Step iii: implementing the preheating method according to claim 8 or 9, wherein the preheating device (5) is arranged at the first position, Step iv: moving the lower support (3) with the second component or the welded component stack relative to the upper support (1) along the third axis (Z) to the welding position, Step v: welding the first component (20) to the second component or to the welded component stack, thereby producing an increased welded component stack, thereafter Step vi: Move the lower support member (3) back to the initial position.

11. The welding method according to claim 10, wherein the step of arranging the first component (20) in the upper tool The following steps are involved: Step i1: placing the first component (20) in the lower tool, and Step i2: Moving the lower support (3) with the first component (20) along the third axis Z relative to the upper support (1) from the initial position to a transfer position.

12. The welding method according to claim 10 or 11, comprising, after step vi of moving the lower support (3) back to the initial position, a further step of: Step vii: arranging a further first component (20) in the upper tool so that the weld structure on the side facing the lower tool matches the third weld structure revealed by the stack of welded components in the lower tool, and Steps ii to vi are repeated, wherein the preheating device (5) is rotated.

13. The welding method according to claim 10 or 11, comprising, after step vi of moving the lower support (3) back to the initial position, a further step of: Step viii: arranging a third component on the upper tool, wherein the third component comprises a fourth weld structure on the first side and a fifth weld structure on the opposite second side, wherein the fourth weld structure and the fifth weld structure correspond to the third weld structure and are oriented so that when viewed along the third axis perpendicular to the first plane, the fourth weld structure and the fifth weld structure are arranged one above the other, and wherein the third component is arranged in the upper tool so that the weld structure on the side facing the lower tool matches the third weld structure revealed by the welded component stack in the lower tool, and Steps ii to vi are repeated, wherein the preheating device remains in the first position or the second position.

14. A method for modifying a welding device, The following steps are involved: Step I: providing a preheating device according to any one of claims 1 to 5, Step II: combining the preheating device with the welding device, and Step III: Implementing the preheating device in the control method of the welding device.

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