Ultrasonic solder, welding device having the same, and related welding method and positioning method

Abstract

The invention relates to a sonotrode for friction welding of at least two joining parts, which are at least partially made of a weldable material, in particular a plastic material. The sonotrode includes a base body having a first axial end and an opposing second axial end, the base body having a central longitudinal axis extending through the first and second axial ends, the sonotrode being movable along the central longitudinal axis in operation. Furthermore, near the second axial end, a working surface is provided on the base body transversely with respect to the central longitudinal axis, which working surface is attachable in operation to one of the at least two joining parts such that joining energy can be introduced transversely into a joining region between the at least two joining parts. The working surface surrounds the main body in the circumferential direction, preferably without any discontinuity, and comprises a first structure, the shape of which is adaptable or adapted to the shape of at least one of the two engagement parts.

Description

Technical Field

[0001] The invention relates to a sonotrode for friction welding at least two joining parts, which at least partially consist of a weldable material, in particular a plastic material, a corresponding welding device, a positioning method for positioning a first joining part, and a corresponding welding method and an associated container. Background Art

[0002] In the production of containers, such as yogurt cups, disposable drinking cups or other containers with a bottom and / or an intermediate bottom, firstly, a body of the container is provided, for example in the form of a hollow cylinder. In order to close the body on one side, the bottom is usually fixed to the body by means of an adhesive. In addition, the connection between the body and the bottom can be achieved by thermal heating of the joining partners, for example by hot air or hot stamping, and by mechanical connection, for example by pressure elements or rollers.

[0003] The disadvantages here are the short cycle times and the amount of work caused by the use of adhesives to connect the body to the base. In addition, when producing such containers for the food and pharmaceutical industries, specific requirements must be observed, especially for the adhesives used, which leads to high production costs. In addition, accessibility to the body is not always fully guaranteed.

[0004] The objective technical object of the present invention is therefore to provide an alternative production method for containers with bottoms, which are particularly used in the packaging, food and pharmaceutical industries. Here, the production method should primarily provide a reliable connection between the container body and the bottom and should be economically optimized. Summary of the invention

[0005] The above-mentioned objects are solved by a sonotrode according to the invention, a corresponding welding device according to the invention, a positioning method according to the invention, a welding method according to the invention and a container according to the invention. Advantageous embodiments and further developments emerge from the subsequent description, the drawings and the appended claims.

[0006] The ultrasonic welding electrode of the present invention is used for friction welding at least two joining parts, wherein the joining parts are at least partially made of a weldable material, in particular a plastic material, and the ultrasonic welding electrode comprises a base body having a first axial end and an opposite second axial end, wherein the base body has a central longitudinal axis extending through the first axial end and the second axial end, and the ultrasonic welding electrode can be moved along the central longitudinal axis during operation, or the ultrasonic welding electrode can be offset along the central longitudinal axis during operation, and, at a position adjacent to the second axial end, a working surface is arranged on the base body laterally relative to the central longitudinal axis, and the working surface can be attached to one of the at least two joining parts during operation, so that the joining energy can be introduced laterally into the joining area between the at least two joining parts, wherein the working surface preferably surrounds the base body without any interruption and comprises a first structure, whose shape can be suitable or adapted to the shape of at least one of the two joining parts.

[0007] The sonotrode of the invention described above will now be described in more detail with respect to its function in a corresponding friction welding method, with reference being made by way of example to the production of yogurt cups or disposable drinking cups as containers.

[0008] The cup as a container comprises a bottom as a first engaging part and a hollow body as a second engaging part. For example, the body has the shape of a cylinder or a cone. The body should be closed with a bottom on one side. This means that the bottom is fastened near the axial end of the body. Such a bottom is also called a closed bottom. Alternatively, it is preferred to fasten the bottom at another position in the body. In this case, the bottom is an intermediate bottom. Therefore, in this specification, the term "bottom" generally includes a closed bottom or an intermediate bottom.

[0009] Due to the welding method used, the material of the main body must be weldable with the material of the bottom. Therefore, the main body and / or the bottom must have a weldable material at least at the joint or must consist of a weldable material. Examples of such weldable materials are, for example, suitable coated or laminated paper or the like. For example, the paper comprises a plastic coating, in particular a plastic coating made of polyethylene (PE) or polypropylene (PP). The main body and the bottom, i.e. the second joining part and the first joining part, can be made of the same or different materials. The same materials are particularly preferred because a particularly reliable welding connection can be achieved.

[0010] Taking a cup as an example of a container, one end of the material of the hollow body is bent radially inwards at a first portion, and then bent towards the other end of the body. In this way, a surrounding U-shape is formed at one end inside the body. The bottom has a radially outer portion, which preferably extends parallel or approximately parallel to the surface normal of the bottom and is then at least partially arranged in the U-shape formed by the body.

[0011] The welding device comprises a sonotrode according to the invention and a fixture having an anvil with a base and at least one pressure section. Taking a cup as an example, the base of the anvil has a shape that is preferably complementary to the cup body. However, this is not absolutely necessary for all containers, as will be described later based on alternative examples.

[0012] Firstly, the welding method comprises the steps of providing a first and a second joining part, which are at least partially made of a weldable plastic. Taking a cup as an example, the first joining part, i.e. the bottom, is preferably arranged on the base of the anvil. In this way, the part of the bottom parallel to the surface normal is facing away from the base. Now, the second joining part, i.e. the hollow body, is arranged on the base of the anvil so that the U-shape of the body receives the part of the bottom extending parallel to the surface normal. In this way, the first and second joining parts overlap in this part, so that this overlapping part is also called the joining area or joining part.

[0013] The sonotrode and the anvil are now moved relative to one another, preferably only along one axis, so that the transverse or radially outer working surface of the sonotrode is adjacent to the joining part. To achieve a secure positioning of the joining part, at least one pressure segment, preferably at least two pressure segments (in the case of a cylindrical body, for example formed as a semicircle) are moved in the direction in which the joining parts are to be connected to one another until the joining parts are pushed against the working surface of the sonotrode. Preferably, there are a plurality of pressure segments so that the two joining parts can be welded together in one step in the joining location.

[0014] Next, the sonotrode is directed to vibrate so that joining energy is introduced laterally or radially into the joining region and a welded connection is formed between the first and second joining components.

[0015] In particular, as parameters for setting the welding process, the amplitude of the sonotrode, the pressure applied to the joined parts to be welded and the joining time are varied. Therefore, in a preferred embodiment, the vibration frequency of the sonotrode is constant.

[0016] After the welding process is finished, the working surface of the ultrasonic welding electrode and at least one pressure section are removed so that the first and second joining parts welded together are taken out of the welding device. For this purpose, while or after removing the pressure section, the ultrasonic welding electrode is also moved relative to the anvil.

[0017] The advantage of the invention is that with this design, friction welded connections can be produced in containers with closed contours, thus eliminating the need for separate glue. This simplifies the production of the containers and allows for fast work cycles, since the welding process is fast, efficient and cost-effective. Similarly, the maintenance effort and space required for the welding device are low compared to other manufacturing methods, as is the effort for controlling the method.

[0018] In an advantageous configuration of the sonotrode, the working surface has a second structure, in particular in the form of a plurality of elevations. By means of the second structure, the joining component pressed against the sonotrode during operation is dragged by the sonotrode and vibrates. The second structure of the sonotrode can therefore also be referred to as a traction structure. Preferably, the traction structure digs into the adjacent joining component so that the adjacent joining component performs substantially the same movement as the sonotrode. In this way, a connection between two components can be effectively achieved by friction welding.

[0019] Furthermore, it is preferred that the first structure has one of the following shapes in longitudinal cross section: circular, elliptical, oval, polygonal (preferably with rounded corners) or a combination thereof. In this way, the first structure and the working surface of the sonotrode can be optimally adapted or matched to the joining parts to be connected to each other, for example, to hollow bodies configured as cylinders, cones, rectangles with rounded corners, etc.

[0020] In a particularly preferred embodiment of the sonotrode, the base body comprises at least one channel, one end of which is arranged at the second axial end of the base body of the sonotrode and the other end of which can be connected to a source of negative pressure, so that the first engaging part can be held and / or positioned by means of the sonotrode. This has the advantage that the first engaging part, i.e. the cup bottom in the above example, can be held by the sonotrode. The sonotrode can thus position the bottom at the desired position in the hollow body of the container and fix it there by friction welding in combination with the at least one pressure section. In this way, the body of the container can be provided with an intermediate bottom, for example after a partial volume of the container has been filled with product. In this case, the base body of the anvil consists, for example, of a plane on which the body is arranged or placed, since it does not have to assume any function of stabilizing the body.

[0021] A corresponding positioning method using such a configured sonotrode therefore comprises a first step of providing a first engaging element. Thereafter, the first engaging element is arranged in the vicinity of the second axial end of the sonotrode and is held there by negative pressure. The sonotrode with the first engaging element is now placed at the desired location, for example in a container already filled with a product.

[0022] The invention relates to a welding device for friction welding at least two joined parts, the joined parts at least partially consisting of a weldable material (e.g. a plastic material), the welding device comprising the invention's ultrasonic welding electrode and a fixing device having an anvil with a base body and at least one pressure section (preferably at least two pressure sections), wherein during operation of the welding device, the at least two joined parts can be pressed against the working surface of the ultrasonic welding electrode by the at least one pressure section. With regard to the operating method and the resulting advantages, reference is made to the above description of the invention's ultrasonic welding electrode.

[0023] In a preferred embodiment of the welding device, the shape of the matrix of the anvil can be adapted to or matched to the shape of at least one of the two engaging parts. Through this design, the matrix of the anvil has assumed stabilization and positioning functions, for example, for the main body of a container to be produced.

[0024] Preferably, the shape of at least one pressure segment is at least partially adapted or suitable to the shape of at least one of the two joining parts. The purpose of the pressure segment is to protect the welded connection in the joining part, as described above. In order to perform this operation in as few steps as possible, preferably only one step, it is necessary to use a plurality of pressure segments, which press the entire joining part against the working surface of the ultrasonic probe. For this purpose, the pressure segment is preferably able to adapt to the shape of the second joining part.

[0025] Furthermore, it is preferred that at least one pressure segment comprises a structure, preferably on the part of the pressure surface, in particular in the form of a plurality of projections. Due to the plurality of projections, the respective joining component can be particularly securely fixed or clamped between the pressure surface of the pressure segment and the working surface of the sonotrode. In particular, the pressure surface of the pressure segment reaches into the respective joining component adjacent to the pressure surface via the second structure. In this way, an effective tightening and holding of the respective joining component can be achieved. Therefore, the structure of the pressure surface of the pressure segment can also be referred to as a holding structure. This embodiment is particularly preferably combined with a sonotrode, which has a second structure for pulling the joining component adjacent to it.

[0026] A positioning method according to the invention is used for positioning a first joining component by means of a sonotrode, the first joining component at least partially consisting of a weldable material, in particular plastic, the sonotrode having a base body, the base body having a first axial end, an opposite second axial end, a side working surface present circumferentially around the base body, and at least one channel, wherein one end of the channel is arranged at the second axial end of the base body of the sonotrode, and the other end of the channel is connected to a negative pressure source, in particular in an embodiment having at least one channel, connected by the sonotrode according to the invention, the positioning method comprising the steps of providing a first joining component, arranging the first joining component near the second axial end of the sonotrode, holding the first joining component arranged near the second axial end of the sonotrode by negative pressure, and positioning the sonotrode holding the first joining component in a desired position. In a preferred embodiment, the positioning method comprises the further step of releasing the first joining component at the desired position. With regard to the advantages resulting therefrom, reference is made to the above description of the sonotrode with a channel to avoid repetition.

[0027] The welding method according to the invention, in particular the welding method using the welding device according to the invention, comprises the following steps: providing first and second joining parts at least partially made of weldable material, arranging the first and second joining parts between the working surface of the sonotrode (arranged transversely to the vibration direction of the ultrasonic probe) and at least one pressure section, in particular pressing the first and second joining parts against the working surface of the sonotrode by means of the at least one pressure section, directing the sonotrode to vibrate so as to introduce joining energy transversely into the joining region and to establish a welded connection between the first joining part and the second joining part, and moving the working surface of the sonotrode away from the at least one pressure section in order to remove the welded first and second joining parts from the welding device. During the welding method, it is advantageous if the sonotrode is directed to vibrate so that the working surface is parallel to the vibration direction of the sonotrode. With regard to the functioning of the welding method according to the invention, reference is made to the above description of the sonotrode according to the invention. The resulting advantages correspond to those discussed in connection with the sonotrode according to the invention.

[0028] In a preferred embodiment of the welding method, the vibration of the sonotrode occurs in the ultrasonic range, preferably between 15 and 40 kHz, particularly preferably between 20 and 40 kHz. Due to the above-mentioned frequency range, the sonotrode operates in the ultrasonic range and ensures that the two joining parts are connected to each other quickly, efficiently and economically.

[0029] Furthermore, it is preferred that the welding method further comprises the steps of the positioning method of the present invention, wherein the steps of the positioning method of the present invention are implemented during the providing and arranging steps. According to a preferred embodiment of the positioning method, the releasing step is preferably performed during or after the welding step. With regard to the advantages arising therefrom, reference is made to the description of the channeled ultrasonic welding electrode and the positioning method of the present invention.

[0030] The container of the invention consists of a bottom as a first joining part and a hollow body as a second joining part, wherein the first and second joining parts consist at least partially of a weldable material and are welded together in the joining part, preferably completely welded together, in particular by the welding method of the invention. In a preferred embodiment of the container, the cross section of the joining part has one of the following shapes: circular, elliptical, oval, polygonal (preferably with rounded corners) or a combination of these shapes. Here again, reference is made to the above description for the description of the advantages to avoid repetition. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention is described in detail below in conjunction with the accompanying drawings. In the accompanying drawings, the same reference numerals represent the same components and / or elements. Shown as:

[0032] Figure 1 is a schematic diagram of a first embodiment of an ultrasonic welding electrode according to the present invention,

[0033] Figures 2 to 4 Schematic diagram of the first embodiment of the welding device of the present invention at different stages of the manufacturing process of the first container,

[0034] Figures 5 to 7 Schematic diagram of the second embodiment of the welding device of the present invention at different stages of manufacturing a second container,

[0035] Figure 8 is a schematic diagram of a third embodiment of a welding device according to the present invention,

[0036] Fig. 9 is a flow chart of an embodiment of a positioning method of the present invention, and

[0037] Fig.10 The figure is a flow chart of an embodiment of the welding method of the present invention. DETAILED DESCRIPTION

[0038] The exemplary embodiments of the welding device according to the invention and of the sonotrode according to the invention are described by means of the production of containers such as yogurt cups or disposable drinking cups and containers with an intermediate bottom.

[0039] The cup as a container comprises a bottom as a first engaging part 1 and a hollow body (e.g. in the shape of a cylinder or cone) as a second engaging part 3. One side of the body should be closed with the bottom. Therefore, the bottom is fastened near the axial end of the body. In this regard, reference is made to Figures 2 to 4 Alternatively, the bottom is preferably fixed at another position in the body, such as Figure 1 and 5 to 8. In this case, the bottom is the middle bottom.

[0040] Due to the welding method, the main body material must be welded together with the bottom material. Therefore, the main body and / or the bottom must include a weldable material at least in the joint area or must be made of a weldable material. Examples of such weldable materials are suitable coated or laminated papers or the like. For example, the paper has a plastic coating, in particular made of polyethylene (PE) or polypropylene (PP). The main body and the bottom, i.e. the second joining part 3 and the first joining part 1, can be made of the same or different materials. The same materials are particularly preferred because this allows a particularly reliable welded connection to be achieved.

[0041] Now special reference Figure 1 , a first embodiment of an ultrasonic welding electrode 10 for friction welding a first joining component 1 and a second joining component 3 is described. The ultrasonic welding electrode 10 includes a base body 12, which has a first axial end 14 and an opposite second axial end 16. In addition, the base body includes a central longitudinal axis 18. It extends through the first axial end 14 and the second axial end 16. In operation, the ultrasonic welding electrode 10 can be moved or offset along the central longitudinal axis 18, such as Figure 3 and 6 As shown by the arrow S in the direction of vibration.

[0042] Adjacent to the second axial end 16, a working surface 20 is provided on the base body 12 transversely relative to the central longitudinal axis 18. The working surface 20 can abut against one of the two joining parts 1, 3 during operation, so that joining energy is introduced transversely into the joining area or joining position between the first joining part 1 and the second joining part 3. In the process, the working surface 20 preferably surrounds the base body 12 in the circumferential direction without any interruption and comprises a first structure, the shape of which can be adapted or matched to the shape of at least the second joining part 3. Example shapes of the first structure are rhombus, wavy lines, lines, etc.

[0043] For example, the first structure has one of the following shapes in cross section relative to the longitudinal axis 18: circular, elliptical, oval, polygonal (preferably with rounded corners) or a combination of these shapes. In this way, the first structure of the sonotrode 10 and therefore the working surface 20 can be optimally adapted or adapted to the joining parts 1, 3 to be joined, for example, to a hollow body configured as a cylinder, a cone, a rectangle with rounded corners, etc.

[0044] In addition, the working surface 20 of the ultrasonic welding electrode 10 has a second structure, in particular, in the shape of a plurality of protrusions. During operation, the joining parts 1, 3 pressed against the ultrasonic welding electrode by the second structure are pulled by the ultrasonic welding electrode 10 and vibrate. Therefore, the second structure of the ultrasonic welding electrode 10 can also be called a pulling structure. Preferably, the pulling structure penetrates into the adjacent joining parts 1, 3, so that the adjacent joining parts 1, 3 basically perform the same movement as the ultrasonic welding electrode 10. In this way, an effective connection can be achieved between the two parts or joining parts 1, 3 by friction welding.

[0045] Reference now Figures 2 to 4 According to the function of the welding device in the corresponding friction welding method, the ultrasonic welding electrode of the above invention is described in more detail, wherein the production of yogurt cups or disposable drinking cups is taken as an example of containers.

[0046] Taking a cup as an example of a container, in the first part, one end of the hollow body is bent radially inwards, and in the subsequent second part, it is bent in the direction of the other end of the body. In this way, the inner end of the body as the second engaging part 3 forms a surrounding U-shape. The bottom as the first engaging part 1 has a radially outward part, which preferably extends parallel to or almost parallel to the surface normal of the bottom and is at least partially arranged in the U-shape formed by the body.

[0047] The welding device comprises a sonotrode 10 and a fixing device having an anvil 40 with a base body 42 and at least one pressure section 50. Figures 2 to 4 As shown, the base 42 of the anvil 40 has a shape that is complementary to the cup body as the second engaging part 3. With this configuration, the base 42 of the anvil 40 assumes the function of stabilizing and positioning the container body to be produced. However, this is not an absolute requirement for all containers, and will be discussed later. Figures 5 to 7 The illustrated embodiment is described.

[0048] In the embodiment shown, a pressure segment 50, preferably at least two pressure segments 50, are schematically indicated by arrows. The shape of the pressure segment 50 is at least partially adapted or matched to the shape of the second joining part 3. The task of the pressure segment 50 is to ensure the welded connection in the joining area. There are a plurality of pressure segments 50 so that this can be carried out in as few steps as possible, preferably only one step, wherein the pressure segments are able to press the entire joining area against the working surface 20 of the sonotrode 10. For this purpose, it is preferred that the pressure segment 50 is adapted or matched to the shape of the second joining part 3.

[0049] Advantageously, the pressure section 50 has a structure, preferably in the region of the pressure surface, which is present in particular in the form of a plurality of projections. Due to the plurality of projections, the respective joining parts 1, 3 can be fixed or clamped particularly securely between the pressure surface of the pressure section 50 and the working surface 20 of the ultrasonic welding electrode 10. In particular, the pressure surface of the pressure section 50 penetrates into the respective adjacent joining parts 1, 3 by means of this structure. In this way, an effective fixation of the respective joining parts 1, 3 can be achieved. Therefore, the structure of the pressure surface of the pressure section 50 can also be referred to as a holding or fixing structure. This embodiment is particularly preferably combined with an ultrasonic welding electrode 10, which comprises a second structure for pulling the joining parts 1, 3 adjacent thereto.

[0050] The welding method first includes the steps of providing a first joining component 1 and a second joining component 3, which are at least partially composed of a weldable plastic material. First, the first joining component 1, i.e., the bottom, is arranged on the base 42 of the anvil 40. Here, the portion of the bottom extending parallel to the surface normal faces away from the base 42. The second joining component 3, i.e., the hollow body, is arranged on the base 42 of the anvil 40 so that the U-shaped receiving portion of the body extending parallel to the surface normal of the bottom. Therefore, the first joining component 1 and the second joining component 3 overlap in this area or position, so that the overlapping area is also called a joining area or a joining position or area. This is in Figure 2 Shown in.

[0051] The ultrasonic welding electrode 10 and the anvil 40 are now moved relative to each other, preferably only along one axis, so that the transverse or radially outer working surface 20 of the ultrasonic welding electrode 10 is close to the joint. In order to achieve a secure positioning of the joint parts, at least two pressure sections (schematically indicated by arrows 50 and in the case of cylindrical bodies, the two pressure sections form, for example, a semicircle) are moved in the direction in which the joint parts 1, 3 are to be connected to each other until they push the joint parts 1, 3 against the working surface 20 of the ultrasonic welding electrode 10. Preferably, as many pressure sections 50 as necessary are provided so that the two joint parts 1, 3 can be welded together in one step at the joint. The final arrangement can be as follows: Figure 3 shown.

[0052] At this time, the ultrasonic welding electrode 10 is vibrated, resulting in the joining energy being introduced laterally or radially into the joining area or the joining position, and forming a welding connection between the first joining component 1 and the second joining component 3 .

[0053] In particular, as parameters for setting the welding method, the amplitude of the sonotrode 10, the pressure applied to the joined parts 1, 3 to be welded and the joining time are variable. In a preferred embodiment, the vibration frequency of the sonotrode 10 is not varied.

[0054] Once the welding process is completed, the working surface 20 of the ultrasonic welding electrode 10 and the at least one pressure section 50 are removed so that the welded first and second joining parts 1 and 3 are removed from the welding device. To this end, the sonar probe 10 is also moved relative to the anvil 40 at the same time or after the pressure section 50 is removed. In this regard, please refer to Figure 4 .

[0055] The container manufactured in this way consists of a bottom as the first joining part 1 and a hollow body as the second joining part 3. The first joining part 1 and the second joining part 3 are at least partially made of weldable materials and are welded together at the joining part, preferably completely welded together. In cross section, the joining parts preferably have one of the following shapes: circular, elliptical, oval, polygonal (preferably with rounded corners) or a combination of the above shapes.

[0056] The advantage of the welding device is that a friction welded connection can be established in the case of containers with a closed contour, thereby eliminating the need for a separate glue. This simplifies the production of the containers and allows for fast work cycles, since the welding process is fast, efficient and cost-effective. Similarly, the maintenance effort for the welding device and the space required are low compared to other manufacturing methods, as is the effort to control the process. In addition, the risk of possible damage to the product to be filled, which could occur, for example, when the joining partners are thermally melted by hot air or hot stamping, is reduced.

[0057] Reference Figures 5 to 7 A second embodiment of a welding device is described. It is used to produce a container having a hollow body as the second joining part 3 and an intermediate bottom as the first joining part 1. This welding device differs from the first embodiment, in particular due to the anvil 140 used, since it consists only of a plane as a base on which the body is arranged or placed. The shape of the base 142 does not need to be complementary to the body, since it does not have to assume any stabilizing function for the body. However, it is advantageous if the base 142 can position the body to ensure a secure positioning.

[0058] Figure 8Another embodiment of an ultrasonic welding electrode 110 is shown, which comprises a base body 112 having a first axial end 114 and an opposite second axial end 116. Here, the base body 112 has at least one channel 122. One end of the channel 122 is arranged at the second axial end 116 of the base body 112 of the ultrasonic welding electrode 110. The other end of the channel 122 can be connected to a negative pressure source 130. This means that the first joining part 1 can be firmly fixed and / or positioned with the ultrasonic welding electrode 110. The advantage of this configuration is that the first joining part 1, i.e. the bottom of the cup with reference to the above example, can be firmly fixed by the ultrasonic welding electrode 110. Thus, the ultrasonic welding electrode 110 can place the bottom at the desired position in the hollow body of the container and fix it to the at least one pressure segment 50 by friction welding. In this way, the container body can be provided with an intermediate bottom, for example after part of the volume of the container has been filled with a product. In this regard, as Figures 5 to 7 Shown is a production example of a container.

[0059] refer to Fig. 9 , a corresponding positioning method for the ultrasonic welding electrode 100 configured in this way is described. First, a first joining component 1 is provided in a first step a. Thereafter, the first joining component 1 is arranged near the second axial end 116 of the ultrasonic welding electrode 110 (step b) and is fixed there by negative pressure (step c). Now, in step d, the ultrasonic welding electrode 110 and the first joining component 1 ultrasonic welding electrode held there are positioned at a desired position, such as the middle bottom in a container filled with a product. Thereafter, the first joining component 1 is released at the desired position in step e. With regard to the welding method described subsequently, this can be carried out during or after welding the middle bottom as the first joining component 1 to the body as the second joining component 3.

[0060] Finally, reference Fig.10 , an embodiment of a welding method is described. In a first step A, a first joining component 1 and a second joining component 3 are provided, which are at least partially made of a weldable material. This step can include the positioning method described above, in particular when a sonotrode 110 equipped with a channel 122 is used.

[0061] Thereafter, the first joining component 1 and the second joining component 3 are arranged between the working surface 20, 120 of the sonotrode 10, 110 and the at least one pressure section 50, which is arranged transversely to the vibration direction of the sonotrode 10, 110. This is done in particular in such a way that the first joining component 1 and the second joining component 3 are pushed against the working surface 20, 120 of the sonotrode 10, 110 by the at least one pressure section 50. In this position, the sonotrode 10, 110 is guided to vibrate in step C so that the joining energy can be introduced transversely into the joining region and a welded connection is formed between the first joining component 1 and the second joining component 3. Finally, the working surface 20, 120 of the sonotrode 10, 110 and the at least one pressure section 50 are moved away from each other so that the welded first joining component 1 and the second joining component 3 can be removed from the welding device. During the welding method, it is advantageous if the vibration of the ultrasonic welding electrode 10, 110 is guided with the working surface 20, 120 parallel to the vibration direction of the sonic probe. It is also advantageous if the vibration of the ultrasonic welding electrode 10, 110 occurs in the ultrasonic range, preferably between 15 and 40 kHz, particularly preferably between 20 and 40 kHz. In particular, due to the above-mentioned frequency range, the ultrasonic welding electrode 10, 110 operates in the ultrasonic range, which ensures a fast, efficient and economical connection between the two joining parts 1, 3.

[0062] Reference numerals list

[0063] 1 First joining member

[0064] 3 Second joining member

[0065] 10 Ultrasonic welding electrode

[0066] 12 Matrix

[0067] 14 First axial end

[0068] 16 Second axial end

[0069] 18Center vertical axis

[0070] 20 working surface

[0071] 40 Anvil

[0072] 42 Matrix

[0073] 50 pressure range

[0074] 110 Ultrasonic welding electrode

[0075] 112 matrix

[0076] 114 first axial end

[0077] 116 Second axial end

[0078] 120 working surface

[0079] 122 channels

[0080] 130 Negative pressure source

[0081] 140 anvil

[0082] 142 matrix

[0083] S Vibration direction of ultrasonic welding electrodes 10, 110

Claims

1. An ultrasonic welding electrode (10, 110) for friction welding at least two joining parts (1, 3), wherein the at least two joining parts are at least partially made of weldable materials, the ultrasonic welding electrode comprising: a) a base body (12, 112) having a first axial end (14, 114) and an opposite second axial end (16, 116), wherein the base body (12, 112) has a central longitudinal axis (18) extending through the first axial end (12, 112) and the second axial end (14, 114), and the sonotrode (10, 110) is movable along the central longitudinal axis during operation, and b) adjacent to the second axial end (16, 116), a working surface (20, 120) is arranged on the base body (12, 112) transversely with respect to the central longitudinal axis (18), the working surface being attachable to one of the at least two joining parts (1, 3) during operation so that joining energy can be introduced transversely into the joining region between the at least two joining parts (1, 3), wherein c) The working surface (20, 120) surrounds the base body (12, 112) in the circumferential direction and comprises a first structure, the shape of which can be adapted to the shape of at least one of the two engaging components (1, 3).

2. The ultrasonic welding electrode (10, 110) according to claim 1, wherein: The working surface (20, 120) has a second structure.

3. The ultrasonic welding electrode (10, 110) according to claim 1 or 2, wherein: In a cross section relative to the longitudinal axis (18), the first structure has one of the following shapes: circular, elliptical, oval, polygonal, or a combination thereof.

4. The ultrasonic welding electrode (110) according to claim 1 or 2, wherein: The base body (112) comprises at least one channel (122), wherein one end of the channel (122) is arranged at the second axial end (116) of the base body (112) of the ultrasonic welding electrode (110), and the other end of the channel (122) can be connected to a negative pressure source (130), so that one of the at least two joining components (1, 3) can be held and / or positioned by the ultrasonic welding electrode (110).

5. A welding device for friction welding at least two joining parts (1, 3), the at least two joining parts at least partially consisting of weldable material, the welding device comprising: a) A sonotrode (10, 110) according to any one of claims 1 to 4, and b) A holding device having an anvil (40, 140) and at least one pressure section (50), wherein the anvil has a base body (42, 142), c) When the welding device is in operation, the at least two joining components (1, 3) can be pressed against the working surface (20, 120) of the ultrasonic welding electrode (10, 110) by the at least one pressure section (50).

6. The welding device according to claim 5, wherein: The shape of the base body (42) of the anvil (40) can be adapted to the shape of at least one of the two engagement parts (1, 3).

7. The welding device according to claim 5 or 6, wherein: The shape of the at least one pressure section (50) is at least partially adapted to the shape of one of the at least two joining components (1, 3).

8. The welding device according to claim 5 or 6, wherein: The at least one pressure section (50) comprises a structure.

9. A positioning method for positioning a first joining component (1) using the ultrasonic welding electrode (110) according to claim 4, wherein the first joining component is at least partially composed of a weldable material, the ultrasonic welding electrode has a base (112), the base has a first axial end (14, 114), an opposite second axial end (116) and a transverse working surface (120) circumferentially around the base (112) and at least one channel, wherein one end of the channel (122) is arranged at the second axial end (116) of the base (112) of the ultrasonic welding electrode (110), and the other end of the channel (122) is connected to a negative pressure source (130), the positioning method comprising the following steps: a) providing (step a) the first joining component (1), b) arranging (step b) the first joining component (1) near the second axial end (116) of the sonotrode (110), c) maintaining the first joining component (1) arranged near the second axial end (116) of the sonotrode (110) by means of negative pressure (step c), and d) Positioning the sonotrode (110) and the first joining component (1) held therein (step d) in the desired position.

10. The positioning method according to claim 9, comprising the further step of: e) releasing the first engagement member (1) at the desired position (step e).

11. A welding method using the welding device according to any one of claims 5 to 8, comprising the following steps: a) providing (step A) a first joining component (1) and a second joining component (3), which are at least partially made of a weldable material, b) arranging (step B) the first joining component (1) and the second joining component (3) between a working surface (20, 120) of a sonotrode (10, 110) and at least one pressure section (50), wherein the working surface (20, 120) is arranged transversely to the vibration direction of the sonotrode (10, 110), c) directing (step C) the ultrasonic welding electrode (10, 110) to vibrate so that joining energy is introduced laterally into the joining area and a welded connection is established between the first joining component (1) and the second joining component (3), and d) moving the working surface (20, 120) of the ultrasonic welding electrode (10, 110) away from the at least one pressure section (50) (step D) so that the first and second joined parts (1, 3) welded together can be removed from the welding device.

12. The welding method according to claim 11, wherein: The vibration of the sonotrode (10, 110) occurs in the ultrasonic range.

13. The welding method according to claim 11 or 12, further comprising the step of the positioning method according to claim 9 or 10, wherein the step of the positioning method according to claim 9 is implemented during the providing step.

14. A container, comprising a bottom as a first joining component (1) and a body as a second joining component (3), wherein the first joining component (1) and the second joining component (3) are at least partially made of weldable materials and are welded together at a joining portion by a welding method according to any one of claims 11 to 13.

15. The container according to claim 14, wherein In cross section, the engagement member has one of the following shapes: circular, elliptical, oval, polygonal, or a combination of these shapes.

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