Welded working cylinder assembly and method for production thereof

Abstract

The invention relates to a welded working cylinder assembly having a working cylinder component (1), an additional part (2) and a weld seam (3) and characterized in that the weld seam (3) is designed as a stepped hybrid weld seam having a lower weld seam region (4) and an upper weld seam region (5), in the lower weld zone (4), the working cylinder component (1) has a lower working cylinder component weld surface (4.1) and the additional part (2) has a lower additional part weld surface (4.2) and the lower weld surfaces (4.1, 4.2) have a butt joint (4.3) and the lower weld zone (4) is designed as a laser weld. In the upper weld zone (5), the working cylinder component (1) has an upper working cylinder component weld surface (5.1) and the additional part (2) has an upper additional part weld surface (5.2) and the upper weld surfaces (5.1, 5.2) have a surface spacing (5.3) and the upper weld zone (5) is designed as a laser hybrid weld and has a weld additive fill (5.6) in an upper weld space (5.5) formed by the surface spacing (5.3). The invention further relates to a method for producing a working cylinder assembly for such a welded connection.

Description

Technical Field

[0001] The invention relates to a welded working cylinder assembly and a method for producing such a working cylinder assembly, in particular for a hydraulic working cylinder with a high actuating force. Background Art

[0002] It is known from the prior art that hydraulic working cylinders are provided with additional parts for transmitting the actuating force generated by the working cylinder to the device to be actuated. Such additional parts can be, in particular, so-called articulation eyes.

[0003] For this reason, it is also known from the prior art to weld such additional parts. Since very high forces are required to be absorbed here via the welded connection in the case of larger hydraulic cylinders, the weld produced, for example, as a MAG weld, must have a large weld surface and thus a large weld depth.

[0004] The disadvantage here is that, on the one hand, a high heat input is necessary, which brings the risk of scale formation in the working cylinder, thermal deformation or damage to components that can be less thermally loaded (such as seals or guides). In addition, it is determined that the high consumption of welding wire and energy is disadvantageous.

[0005] It is also known from the prior art to produce laser-welded connections in which very high laser powers have to be used for the necessary weld seam depth, which in turn disadvantageously makes laser welding very expensive and uneconomical. Summary of the invention

[0006] The object of the present invention is to provide a welded working cylinder assembly which has a very high load capacity and can be produced in a resource-saving and economical manner. In addition, the object of the present invention is to specify a reliable and at the same time economical method for producing such a working cylinder assembly.

[0007] This object is achieved with respect to the working cylinder assembly by the features listed in patent claim 1 and with respect to the method for production by the features listed in patent claim 5. Preferred developments are derived from the respective dependent claims.

[0008] The welded working cylinder assembly according to the present invention comprises a working cylinder component as basic parts, an additional part and a weld seam.

[0009] The working cylinder component is designed in a known manner as a piston rod or as a closure part. A working cylinder in the sense of the invention is understood to be a linear pressure flow consumer in which a pressure medium acts on a piston surface and thus provides an actuating force, which can be present as a thrust or pressure. Preferably, the working cylinder is a hydraulic working cylinder. The working cylinder can be designed as a differential working cylinder, a tension cylinder, a synchronous cylinder or a plunger cylinder.

[0010] The working cylinder component is the component of the working cylinder from which the operating force is obtained. Here, it can be a closure component in particular, such as a bottom closure component. In addition, it can be a piston unit, in particular a piston rod, wherein the section of the plunger piston located outside is also understood as a piston rod.

[0011] The additional part is a coupling module which is designed to be coupled to the device to be actuated for force transmission. The coupling module is connected to the device to be actuated when the working cylinder is used as intended, wherein this is generally an articulated connection and the coupling module is designed for this purpose as an articulated bearing, also called an articulated eye or an articulated head. However, the coupling module can also be designed in another way.

[0012] The cylinder components and the additional parts are also collectively referred to below as coupling partners.

[0013] Furthermore, the welded working cylinder assembly according to the invention has a weld seam which connects the working cylinder component and the additional part in a materially bonded manner.

[0014] According to the invention, the weld seam is designed in a special manner and is characterized in that it is designed as a stepped hybrid weld seam.

[0015] For this purpose, the weld seam has a lower weld seam region and an upper weld seam region. Here, the positional specifications of the lower and upper weld seams are to be understood independently of the position in space. The specification of the lower weld seam region with respect to the weld seam depth refers to the section facing away from the component surface and the direction of action of the welding means, while the specification of the upper weld seam region with respect to the weld seam depth refers to the section adjoining the component surface, covering the lower weld seam region and facing the direction of action of the welding means.

[0016] In the lower weld region, the cylinder component has a lower cylinder component weld surface and the attachment part has a lower attachment part weld surface. The lower cylinder component weld surface and the lower attachment part weld surface are also collectively referred to as lower weld surfaces below.

[0017] According to the invention, the lower weld seam surfaces have a butt joint which is connected to one another in a material-locking manner by means of a laser weld. The laser weld seam is performed flush and without gaps and the welding is performed without welding additives.

[0018] In the upper weld zone, the cylinder component and the attachment also have weld surfaces of the same design, which are located at a certain interval from each other and the space formed thereby is called the weld space. This arrangement makes it possible for the laser beam to pass through, so as to make laser welding in the lower weld zone possible.

[0019] Here, the working cylinder component has an upper working cylinder component weld surface and the add-on has an upper add-on component weld surface. The upper working cylinder component weld surface and the upper add-on component weld surface are also collectively referred to as upper weld surfaces below. The lower and upper weld surfaces are also collectively referred to as weld surfaces.

[0020] The upper weld seam surfaces are spaced apart from one another. This means that the upper weld seam surfaces are arranged approximately in parallel planes and spaced apart from one another. The space thus opened between the upper weld seam surfaces is referred to as the upper weld seam space. The upper weld seam space is arranged in such a way that a free cross section of the laser beam for producing the laser weld of the lower weld seam region is provided through the weld seam space.

[0021] Under these prerequisites of the design, the upper weld zone is designed as a laser hybrid weld and is an essential part of the solution according to the invention, since here the laser beam simultaneously takes over the melting of the welding electrode, which is preferably approximately 0.8 mm thick. The upper weld zone thus has a welding filler material filler, which fills the upper weld space and thus indirectly connects the upper weld surfaces to one another in a material-locking manner. The laser hybrid weld of the upper weld zone is present as a so-called I-shaped seam, which according to the invention has a greater width than the laser weld of the lower weld zone.

[0022] The upper weld seam space thus advantageously fulfills two functions simultaneously, which are essential for the solution according to the invention.

[0023] This allows unimpeded access for the laser beam to the lower weld seam region.

[0024] It provides the space necessary to accommodate the filler of welding additive material.

[0025] The welding additive is preferably the material of the welding wire. The welding means for the upper weld zone is also a laser beam. Here, the laser beam in the upper weld zone is applied after the laser beam in the lower weld zone. Preferably, it is the same laser beam, which is applied again after the lower weld zone and now hits the welding additive filling part in the upper weld space. This can be achieved particularly advantageously at rotationally symmetrical welding partners, because the lower and upper welds can be produced continuously. The lower weld is achieved in the first rotation cycle and the melting of the additive material is achieved in the second rotation cycle and at the same time the gap between the participating welding partners in the upper weld space is filled.

[0026] The connection provided according to the present invention can also be referred to as laser-laser hybrid connection or stepped hybrid welding. It has the following advantages in particular.

[0027] Particularly precise positioning is achieved by the butt joint of the lower weld zone, since these weld surfaces hold the welded counterpart in position without deformation during the subsequent cooling. Another advantage is the increased energy efficiency, since the solidification heat released by the lower weld zone serves as preheating of the upper weld zone. In addition, it is advantageous in terms of production technology that by dividing the total weld into two weld zones, it is possible to work with lower laser power, so that lower-power laser welding facilities can be used, which has a very favorable impact on investment costs. The use of laser hybrid welding connections can be realized with all known technologies for laser beam generation, such as YAG lasers, CO2 lasers, and is independent of a certain type of laser generation. In addition, in terms of production technology, the higher process speeds produced with welds are advantageous, thereby completely eliminating expensive and time-consuming processes, such as friction welding and prefabricated forgings. Finally, the quality of the connection is improved by reducing the heat in the welding process, i.e., the formation of oxide scale can be completely eliminated and the sensitive components of the working cylinder are protected due to this heat reduction.

[0028] Specifically, the following applies supplementarily.

[0029] It provides a connection with particularly high quality. The butt joint of the lower weld zone makes it possible to position the connection partners particularly accurately. It surprisingly found a solution according to which the accurate positional relationship is also reliably maintained during the welding process and until the end of the welding process and is provided for a working cylinder assembly for completing the welded connection in the following way, that is, advantageously, very little linear energy must be applied in the lower weld zone at first and thus minimize thermal deformation. This possible less linear energy is based on the laser welding technology on the one hand, but also on the other hand, it is also based on the total weld depth that is first reduced to the lower weld zone depth. In addition, the introduced linear energy advantageously acts only directly on the lower weld zone, so that the material body that is initially still cold in the area of ​​the upper weld zone supports the material body of the lower weld zone and additionally offsets its thermal deformation. In this regard, there is also the advantage that with the creation of the upper weld space, a direct channel to the lower weld zone is created for the laser beam without additional costs.

[0030] Furthermore, the laser beam is advantageously used to create only a very narrow melting zone in the lower weld zone and to input correspondingly less thermal energy for this purpose. This thermal energy can be removed very quickly via the lower weld surface into the material of the connection partner, so that it solidifies rapidly in the lower weld zone. Thus, while the cooling and solidification phase lasts longer in the upper weld zone due to the wider weld and the higher heat input, the connection partner is already materially fixed in its position, so that thermal deformations due to the upper weld zone are compensated.

[0031] Another advantage is the increased energy efficiency. The solidification heat released by the solidification of the molten zone in the lower weld zone is conducted away into the material of the connecting partner and provides preheating of the weld in the upper weld zone, so that the input energy to be applied there can be reduced by this proportion. Particularly advantageously, the upper weld zone is heated from below, so that rapid melting and thermal homogenization are then achieved in the upper weld zone by the heat input of the laser beam when it is applied a second time from above.

[0032] Furthermore, it is advantageous in terms of production technology that both the lower laser weld and the upper laser hybrid weld require less laser power than is the case in the case of laser welding of the overall weld. Thus, in order to provide the welded working cylinder assembly according to the invention, a low-cost laser welding system with a lower power of approximately 5 to 10 kW for the production of medium-sized hydraulic working cylinder assemblies can also be used and the investment costs can be significantly reduced.

[0033] Furthermore, welding additive material, for example welding wire, is advantageously only required for the upper weld seam region, thus making material and cost savings possible here.

[0034] Advantageously, the weld seam can be designed both vertically and obliquely.

[0035] Finally, quality is improved by reducing the heating of the working cylinder components and avoiding the formation of oxide scale or damage to heat-sensitive components.

[0036] According to claim 2, according to another aspect of the invention, the working cylinder component is present as a cylinder tube and the additional part is present as a closure part or another closure part. This can be both a closure part that is welded to the connection module according to the invention (in particular, it is designed as a bottom closure part) and another closure part that is not welded to the connection module according to the invention. In particular, it can also be a guide closure part. The closure part or another closure part in the sense of this further aspect of the invention is referred to below as a closure part for short.

[0037] The weld according to this further aspect of the invention thus connects the cylinder tube to the closure part. Here, the upper weld zone is configured as an outer annular surface and the lower weld zone is configured as an inner annular surface. Furthermore, all descriptions of the weld in the case of a welded connection between the piston rod or the closure part and the coupling module also apply to the weld in the case of a welded connection between the cylinder tube and the closure part.

[0038] This embodiment of the invention is particularly advantageous in the case of a welded connection according to the invention on a heavy hydraulic cylinder. A heavy hydraulic cylinder is understood to be a hydraulic cylinder with a cylinder tube wall thickness of 10 mm and more, particularly preferably 15 mm and more. In this case, preferably there is a cylinder tube diameter of 100 mm and more, particularly preferably 150 mm and more.

[0039] In the case of heavy hydraulic cylinders, the manufacturing advantages, in particular the saving of cost-intensive welding materials, the reduction of laser costs and the improvement of precision are significant.

[0040] According to an advantageous improvement, the welded working cylinder assembly is characterized in that the lower weld area and the upper weld area form a total weld area and the area ratio of the lower weld area to the total weld area is 15% to 40%. Particularly preferably, this area ratio is 20% to 30%. Experiments have shown that the weld can be produced very precisely and without deformation in the case of this ratio.

[0041] Rapid solidification of the molten zone is achieved in the lower weld zone.

[0042] These weld seam surfaces are rotationally symmetrical geometries, especially in the case of welded connections at the piston rod. In the case of rotationally symmetrical parts, the lower weld seam area is an inner circular surface in the case of a complete weld, and the upper weld seam area is an annular surface, which radially surrounds the lower weld seam area. The inner circular surface of the lower weld seam area and the outer circular annular surface of the upper weld seam area together form a total circular surface, which forms the total weld seam area surface; therefore, both surfaces form the total weld. According to this improvement, the area ratio of the inner circular surface to the total circular surface is 15% to 40% and particularly preferably 20% to 30%. It is advantageous that the two areas to be welded can be realized by two consecutive rotations with only one clamping.

[0043] According to another advantageous development, the welded working cylinder assembly is characterized in that the surface spacing in the upper weld seam region is 0.5 mm to 2.0 mm. Particularly preferably, the surface spacing is 1.0 mm to 1.5 mm.

[0044] It was found that, on the one hand, this surface spacing advantageously enables good penetration of the laser beam into the lower weld zone and, on the other hand, also enables lower consumption of welding additives, such as in particular welding wire, and relatively lower energy input in the upper weld zone, while also enabling reliable welding in the upper weld zone.

[0045] According to a further advantageous development, the welded working cylinder assembly is characterized in that the lower weld zone is designed as an inner circular surface or inner annular surface and the upper weld zone is designed as an outer annular surface, which radially surrounds the lower weld zone. The two partial surfaces together form the total weld zone, which can then be present as a total circular surface or a total annular surface.

[0046] This development is not only advantageous insofar as, after the production of the laser weld of the lower weld zone, the heat dissipation downwards due to the radial geometry is less than that upwards. This additionally improves the preheating of the upper weld zone. At the same time, this development is advantageous in terms of production technology, because the lower weld zone and the upper weld zone can be produced continuously and during clamping by two successive rotations of the pre-positioned coupling partner under the laser beam.

[0047] According to another aspect of the invention, a method for producing a welded working cylinder assembly is described, wherein the working cylinder component is designed as a piston rod or a closure part, and wherein the additional part is designed as a connecting module. The connecting module is designed to be connected to a device to be actuated for force transmission.

[0048] The method has the following working steps:

[0049] a) Provide working cylinder components and accessories,

[0050] b) producing the weld surfaces to be connected, i.e. producing the lower cylinder component weld surface and the lower add-on component weld surface and the upper cylinder component weld surface and the upper add-on component weld surface, wherein at least one of the upper weld surfaces has a setback relative to the corresponding lower weld surface,

[0051] c) positioning the cylinder components and the additional parts to form a pre-assembled assembly while producing the butt joint of the lower weld surface and the surface separation of the upper weld surface,

[0052] d) laser welding the lower weld surface by means of a laser beam when producing a laser weld in the lower weld zone,

[0053] e) Laser hybrid welding of the upper weld surfaces by means of a laser beam and supply of welding additives, melting of the welding additive by means of the same laser beam and filling of the upper weld space between the upper weld surfaces.

[0054] The description with respect to the welded working cylinder assembly and the definitions of terms therein apply in a corresponding manner also to the method for producing the same.

[0055] In method step a), the working cylinder component and the additional part are provided. The two coupling parts are produced in a known manner.

[0056] In method step b), a lower cylinder component weld surface and a lower add-on component weld surface as well as an upper cylinder component weld surface and an upper add-on component weld surface are produced, wherein at least one of the upper weld surfaces has a setback relative to the respective lower weld surface.

[0057] Since the weld seam surface is generally a rotationally symmetrical component cross section, its production is preferably carried out by turning or milling. Preferably, the weld seam surface, in particular the lower one, is designed to be precisely flat. In the case of a symmetrical design, the setback of the upper weld seam surface is correspondingly half of the surface spacing required later. However, an asymmetrical distribution of the setback is also possible. In addition, in special cases, it is also possible to create a connection partner with weld seam surfaces that are not set back from each other and only another connection partner with setback, so that the setback alone then provides the surface spacing.

[0058] In method step c), the positioning of the cylinder components and the additional parts to form a pre-assembled assembly is carried out while producing the butt joint of the lower weld surface and the surface spacing of the upper weld surface.

[0059] The coupling partners are preferably pressed axially against each other so that the lower weld seam surfaces are in pressure contact with each other. The orientation of the two coupling partners along the longitudinal axis is carried out according to the desired subsequent position of the attachment part relative to the longitudinal axis of the working cylinder assembly. The positional relationship thus established is then preferably maintained during the further method steps until their completion.

[0060] In method step d), laser welding of the lower weld seam surface is carried out by means of a laser beam while producing a laser weld seam in the lower weld seam region.

[0061] According to the invention, an upper weld space is present here due to the surface spacing of the upper weld surface, which provides the laser beam with an undisturbed path to the upper starting point of the lower weld zone. The laser beam preferably penetrates precisely into the plane of the butt joint developed by the lower weld surface and the weld surface melts at its surface, thereby providing a thin flat melt which, after solidification, connects the connection partners in a material-locking manner at the lower weld surface and forms a laser weld. The production of the laser weld in method step d) is carried out without adding welding additives.

[0062] According to the invention, the solidification heat is at least partially conducted upwards into the upper weld zone, so that advantageously not only the upper weld zone is heated, but also the heat input into the lower weld zone is reduced and thus undesirable intensive heating in the surrounding area of ​​the lower weld zone is avoided.

[0063] In method step e), the laser hybrid welding of the upper weld seam surfaces is completed. The upper weld seam surfaces are laser hybrid welded by means of a laser beam and a supply of welding additives and filling of the upper weld seam space between the upper weld seam surfaces.

[0064] In the upper weld zone that has been preheated by method step d), the upper weld surface is further heated until it melts by re-application of the laser beam. Here, according to the invention, a welding additive is preferably added via a welding wire, which melts, forms part of the melt of the upper weld zone and fills the upper weld space formed between the upper weld surfaces and thus directly connects to the upper weld surface.

[0065] After the upper weld space has been filled with melt, the application of the laser beam is terminated and the upper weld region is subsequently cooled while the melt in the upper weld space solidifies and an indirect material-locking connection between the upper weld surfaces is formed, thus forming a hybrid weld. The indirect material-locking connection is based on the fact that the material connection between the upper weld surfaces is brought about by the solidifying melt with the participation of the welding additive.

[0066] As a result of carrying out all method steps, a welded working cylinder assembly is obtained which has a laser-laser hybrid weld seam according to the invention.

[0067] Furthermore, the invention includes the possibility that method step e) is carried out repeatedly and thus a layer-by-layer filling of the upper weld gap with welding additive material is achieved.

[0068] The advantages described with respect to the welded working cylinder assembly according to the invention apply in a corresponding manner to this method. It is particularly advantageous that solidification occurs at the lower weld surface in method step d) due to the lower input energy and the very narrow melt zone, while the upper weld zone with its wider melt zone due to the surface spacing between the upper weld surfaces has not yet solidified in the upper weld space. As a result, a connection between the connected parts is already present, which determines their positional relationship and protects against deformation due to the subsequent solidification of the upper weld zone. At the same time, the same advantages also apply in this method, which are of significance due to the use of a lower-power laser welding device.

[0069] For each location, the production of the laser hybrid weld of the upper weld seam region is carried out with a time offset of preferably 2 to a maximum of 10 seconds for the production of the laser weld of the lower weld seam region.

[0070] Furthermore, for the rotating component, i.e. if the upper weld surface is present as an outer annular surface, an increased bending stiffness can be produced at the weld without additional measures. The basis for this is that the lower laser weld has already solidified and thermally shrunk while the upper laser hybrid weld is being produced. By the subsequent thermal shrinkage of the upper laser hybrid weld, an elastic preload is created in the upper weld zone surface present here as an outer annular surface. This is supported by the fact that the upper weld zone is wider by means of the surface spacing of the upper weld surface than the lower weld zone present as a butt joint and that the thermal shrinkage of the upper weld zone is therefore stronger than that of the lower weld zone. The degree of preload can advantageously be adjusted as required not only by means of the surface ratio of the lower weld zone surface to the upper weld zone surface but also by means of the surface spacing of the upper weld surface and thus an assembly consisting of a cylinder component and an additional part with improved mechanical properties is obtained.

[0071] According to a next advantageous improvement, the method for manufacturing a welded working cylinder assembly is characterized in that the linear energy applied in the lower weld zone in method step d) relative to the lower weld zone surface is less than the linear energy applied in the upper weld zone in method step e) relative to the upper weld zone surface.

[0072] Advantageously, the smaller heat input in the lower weld zone in method step d) relative to the weld zone surface, as compared to the heat input in the upper weld zone in this method step, ensures that earlier solidification occurs in the lower weld zone than in the upper weld zone and that the positional relationship of the connecting partners is stabilized when deformation forces due to solidification of the upper weld zone act on the connecting partners.

[0073] According to a further advantageous development, the method for producing a welded working cylinder assembly is characterized in that the input energy in the lower weld zone in method step d) simultaneously corresponds to the requirement for melting the welding additive in the upper weld zone. Thus, the welds in each of the two weld zones can be produced with the same laser power and the same speed.

[0074] According to another improved scheme, the method for manufacturing a working cylinder component connected by welding is characterized in that the lower weld surface is constructed as an inner circular surface or an inner annular surface, and the upper weld surface is constructed as an outer annular surface, which radially surrounds the inner circular surface or the inner annular surface and in method step d) the relative movement of the preassembled component relative to the laser is performed by means of further rotation of the preassembled component.

[0075] The advantages of the method according to the invention are particularly effective in the case of rotationally symmetrical connecting sections of the working cylinder assembly and the additional part. After the connecting partners have been combined into a preassembled assembly and fixed in their relative position, they can be guided and welded under the laser by rotation, so that reliable and uniform application with the laser can be achieved. With the help of the first rotation, a laser weld is thus produced according to method step d). After a 360-degree rotation, another complete rotation is performed, and the welding additive is supplied to the upper weld space. The laser beam now hits the welding additive and thus produces a melt, which fills the upper weld space and thus indirectly connects the upper weld surface with a material lock. After the second complete rotation is completed, a laser hybrid weld is also produced according to method step e).

[0076] According to another refinement, the method for producing a welded working cylinder assembly is characterized in that method step d) and method step e) are carried out in parallel in time, i.e., the relative movement of the preassembled assembly is carried out along the weld seam and the laser beam according to method step e) is arranged so as to be offset relative to the laser beam according to method step d) in the direction of the relative movement. This refinement presupposes the use of two laser beams and makes it possible to further improve their efficiency.

[0077] According to this development, the method is carried out with two laser beams, which are applied in parallel in time, but linearly offset along the feed movement. Due to the spatial offset, together with the linear speed of the laser welding, the temporal offset of the laser application can be precisely adjusted in the lower weld zone and in the upper weld zone at the same linear position of the weld and the weld formation can be optimized. In particular, in this way, it is possible to keep the temporal offset sufficiently small in the case of particularly large components. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] The present invention is described in detail as an embodiment with the help of the following figure:

[0079] Figure 1 : General view of the working cylinder assembly as a cross-sectional illustration,

[0080] Figure 2 : Schematic cross-sectional illustration of the weld area before assembly into a pre-assembled component,

[0081] Figure 3 : Schematic cross-sectional illustration of the weld seam region in the state as a preassembled component,

[0082] Figure 4 : Schematic cross-sectional illustration of a weld,

[0083] Figure 5 : A schematic representation of the method in method step d),

[0084] Figure 6 : A schematic representation of the method in method step e),

[0085] Figure 7 : a schematic illustration of a method in the case of parallel execution of method steps,

[0086] Figure 8 : Schematic illustration of the method in the case of rotation of the preassembled component.

[0087] Here, the same reference numerals in different figures denote correspondingly identical features or components. If they are not shown in the relevant figure, these reference numerals are also used in the description. DETAILED DESCRIPTION

[0088] Figure 1 The overall view of the working cylinder assembly is shown, which in this embodiment is present as a differential working cylinder. In this embodiment, the working cylinder component 1 forms both the piston rod 1.1 and the closing part 1.2. Both the piston rod 1.1 and the closing part 1.2 are connected to the additional part 2 (present here as a spherical bearing) via a weld seam 3.

[0089] according to Figure 1 Here it is shown that the cylinder tube 1.4 also forms the working cylinder component 1 and is also connected on both sides to the closure part 1.2 (here the bottom closure part) and the further closure part 1.3 (here the guide closure part) via a weld seam 3. Here, the weld seam 3 is configured vertically between the cylinder tube 1.4 and the closure part 1.2 (the bottom closure part) and the weld seam 3 is configured obliquely at a weld seam angle between the cylinder tube 1.4 and the further closure part 1.3 (here the guide closure part).

[0090] Figure 2 The connecting partners 1 , 2 are shown after method step b) and before being combined to form a preassembled assembly in method step c).

[0091] Figure 3 The connecting partners 1 , 2 are shown after they have been combined in method step c) to form a preassembled assembly.

[0092] Figure 2 and Figure 3They are described together below. In the subsequent lower weld zone 4, the lower cylinder component weld surface 4.1 and the lower additional component weld surface 4.2 are arranged opposite to each other as lower weld surfaces 4.1, 4.2, and in the subsequent upper weld zone 5, the upper cylinder component weld surface 5.1 and the upper additional component weld surface 5.2 are arranged opposite to each other as upper weld surfaces 5.1, 5.2. The lower weld surfaces 4.1, 4.2 constitute the subsequent lower weld zone surface 4.4, and the upper weld surfaces 5.1, 5.2 form the subsequent upper weld zone surface 5.4. After the combination in step (d), the lower weld surfaces 4.1, 4.2 constitute a butt joint, and the upper weld surfaces 5.1 and 5.2 constitute a surface gap 5.3. The upper weld space 5.4 is formed between the upper weld surfaces 5.1, 5.2 by the surface gap 5.3.

[0093] Figure 4 The weld seam is shown after the welding has been completed after carrying out method steps d) and e). In the lower weld seam region 4, a narrow laser weld seam is now present. In the upper weld seam region 5, the upper weld seam space 5.5 is now provided with a welding filler material filling 5.6, which is filled by the welding wire melted by means of the laser beam 6. The two connecting partners are now connected in a material-locking manner by means of the laser weld seam in the lower weld seam region 4 and the mixed weld seam of the upper weld seam region 5.

[0094] Figure 5 and Figure 6 The method is shown in the case of consecutive execution of method steps d) and e).

[0095] Figure 5 Method step d) is shown, in which the preassembled component is guided under the laser beam 6 in the direction of movement indicated by the arrow. The laser beam 6 strikes directly onto the lower weld zone 4, penetrates into the butt joint 4.3 and welds the lower weld surfaces 4.1, 4.2. Figure 6 As shown, in order to carry out method step e), the laser beam 6 is then applied again and for this purpose is guided again in the direction of movement indicated by the arrow via the already fixed and preheated preassembled component in the lower weld zone 4. At the same time, in parallel, the welding additive is supplied in the form of welding wire and brought into the active area of ​​the laser beam 6 in the upper weld space 5.5 and melted there to form a melt, which now fills the upper weld space 5.5. After solidification, the finished weld 3 is present, which consists of a laser weld in the lower weld zone 4 and a laser hybrid weld in the upper weld zone 5.

[0096] Figure 7The schematic diagram shows the parallel execution of method steps d) and e) in a modified embodiment of the method. The lower arrow shows the direction of movement of the pre-assembled component along the weld seam 3 shown here in longitudinal section. The laser beam 6 strikes the lower weld seam region 3 directly, penetrates into the butt joint 4.3 and welds the lower weld seam surfaces 4.1, 4.2.

[0097] By further moving the connecting partners 1, 2, they also reach the effective area of ​​the other laser beam 6. The spatial spacing, which is also dependent on the movement speed, results in a time interval that is determined in such a way that heat is also removed from the lower weld zone 4 to the upper weld zone 5 and thus solidification of the melt in the laser weld in the lower weld zone 4 and preheating in the upper weld zone 5 occur. The other laser beam 6 captures the supplied welding wire in the upper weld space 5.5, melts it and indirectly captures the upper weld surfaces 5.1, 5.2 at the same time and welds them at the same time. The melt thus formed fills the weld space 5.5, where a welding filler material filler 5.6 is formed in the upper weld zone 5. Thus, after solidification, a laser hybrid weld is formed.

[0098] Figure 8 The method is schematically shown in an exemplary embodiment in which the lower weld seam region 4 is designed as an inner annular surface and the upper weld seam region 5 is designed as a concentric outer annular surface.

[0099] As shown on the left, first in method step d) the lower weld zone 4 is produced as a laser weld seam with a first rotation using the laser beam 6 until it is present as a completely closed inner annular surface in a section longitudinal to the weld seam after an angular position of 360 degrees.

[0100] As shown on the right, in method step e), the upper weld zone 5 is subsequently produced as a laser hybrid weld with further rotations and addition of welding wire using the laser beam 6 until it also forms a completely closed outer annular surface after a complete rotation.

[0101] Figure 8 Two method steps are shown respectively after a rotation through approximately 240 degrees, wherein the arrows indicate the direction of rotation.

[0102] Reference numerals

[0103] 1 Working cylinder components

[0104] 1.1 Piston rod

[0105] 1.2 Closure components

[0106] 1.3 Another closing part

[0107] 1.4 Cylinder pipe

[0108] 2 Additional parts

[0109] 3 Welding seams

[0110] 3.4 Total weld surface

[0111] 4 Lower weld area

[0112] 4.1 Weld surface of the lower working cylinder component

[0113] 4.2 Weld surface of lower attachment

[0114] 4.3 Butt joint

[0115] 4.4 Lower weld zone

[0116] 5 Upper weld area

[0117] 5.1 Weld surface of the upper working cylinder component

[0118] 5.2 Upper attachment weld surface

[0119] 5.3 Surface spacing

[0120] 5.4 Upper weld area

[0121] 5.5 Upper weld space

[0122] 5.6 Welding material filling part

[0123] 6 Laser

Claims

1. A welded working cylinder assembly comprising a working cylinder component (1), an additional component (2) and a weld seam (3), wherein: The working cylinder component (1) is configured as a piston rod (1.1) or a closing component (1.2), wherein the additional component (2) is configured as a connecting module, which is configured to be connected to a device to be actuated for force transmission. It is characterized in that The weld seam (3) is designed as a stepped hybrid weld seam having a lower weld seam region (4) and an upper weld seam region (5). In the lower weld zone (4), the working cylinder component (1) has a lower working cylinder component weld surface (4.1) and the attachment (2) has a lower attachment weld surface (4.2), and the lower weld surfaces (4.1, 4.2) have a butt joint (4.3), and the lower weld zone (4) is configured as a laser weld, In the upper weld zone (5), the working cylinder component (1) has an upper working cylinder component weld surface (5.1), the attachment (2) has an upper attachment weld surface (5.2), and the upper weld surfaces (5.1, 5.2) have a surface spacing (5.3), and the upper weld zone (5) is constructed as a laser hybrid weld and has a welding additive filling portion (5.6) in the upper weld space (5.5) formed by the surface spacing (5.3).

2. A welded working cylinder assembly comprising a working cylinder component (1), an additional component (2) and a weld seam (3), wherein: The working cylinder component (1) is configured as a cylinder tube (1.4), wherein the additional part (2) is configured as the closing part (1.2) or as another closing part (1.3), It is characterized in that The weld seam (3) is designed as a stepped hybrid weld seam having a lower weld seam region (4) and an upper weld seam region (5). In the lower weld zone (4), the working cylinder component (1) has a lower working cylinder component weld surface (4.1), the attachment (2) has a lower attachment weld surface (4.2), the lower weld surfaces (4.1, 4.2) have a butt joint (4.3), and the lower weld zone (4) is configured as a laser weld, In the upper weld zone (5), the working cylinder component (1) has an upper working cylinder component weld surface (5.1), the attachment (2) has an upper attachment weld surface (5.2), and the upper weld surfaces (5.1, 5.2) have a surface spacing (5.3), and the upper weld zone (5) is constructed as a laser hybrid weld and has a welding additive filling portion (5.6) in the upper weld space (5.5) formed by the surface spacing (5.3).

3. The welding-connected working cylinder assembly according to claim 1, characterized in that: The lower weld area (4.4) and the upper weld area (5.4) form a total weld area (3.4), and the area ratio of the lower weld area (4.4) to the total weld area (3.4) is 15% to 40%.

4. A welded working cylinder assembly according to any one of the preceding claims, characterized in that: The surface spacing (5.3) in the upper weld zone is 0.5 mm to 2.0 mm.

5. A welded working cylinder assembly according to any one of the preceding claims, characterized in that: The lower weld zone surface (4.4) is configured as an inner circular surface or an inner annular surface, and the upper weld zone surface (5.4) is configured as an outer annular surface which radially surrounds the lower weld zone surface (4.4).

6. A method for manufacturing a welded working cylinder assembly, wherein: The working cylinder assembly comprises the working cylinder component (1) and the additional component (2), and has the following working steps: a) providing the working cylinder component (1) and the additional component (2), b) producing a lower cylinder component weld surface (4.1) and a lower add-on component weld surface (4.2) as well as an upper cylinder component weld surface (5.1) and an upper add-on component weld surface (5.2), wherein at least one of the upper weld surfaces (5.1, 5.2) has a setback relative to the corresponding lower weld surface (4.1, 4.2), c) positioning the cylinder component (1) and the additional part (2) to form a pre-assembled assembly while producing a butt joint (4.3) of the lower weld surface (4.1, 4.2) and a surface spacing (5.3) of the upper weld surface (5.1, 5.2), d) laser welding the lower weld seam surfaces (4.1, 4.2) by means of a laser beam while producing a laser weld in the lower weld seam region (4), e) Mixing and welding the upper weld surfaces (5.1, 5.2) by means of the laser beam and the supply of welding additives and filling the upper weld space (5.5) between the upper weld surfaces in the upper weld zone (5).

7. The method for manufacturing a welded working cylinder assembly according to claim 6, characterized in that: The heat input applied in the lower weld zone (4) in method step d) relative to the lower weld zone surface (4.4) is less than the heat input applied in the upper weld zone (5) in method step e) relative to the upper weld zone surface (5.4).

8. The method for manufacturing a welded working cylinder assembly according to any one of the preceding claims 5 or 6, characterized in that: The lower weld zone surface (4.4) is configured as an inner circular surface or an inner annular surface and the upper weld zone surface (5.4) is configured as an outer annular surface which radially surrounds the lower weld zone surface (4.4). In method step d), the relative movement of the preassembly to the laser beam 6 is carried out by means of a rotation of the preassembly and in method step e) the relative movement of the preassembly to the laser beam is carried out by means of a further rotation of the preassembly.

9. The method for manufacturing a welded working cylinder assembly according to any one of claims 5 to 7, characterized in that: Method step d) and method step e) are carried out in parallel in time, the relative movement of the preassembled components is carried out along the weld seam 3) and the laser beam 6 according to method step e) is arranged offset relative to the laser beam (6) according to method step d) in the direction of the relative movement.

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