Working cylinder

Abstract

The invention relates to a working cylinder having a cylinder (11) and a piston unit (12), characterized in that the cylinder (11) has a bottom-side joint head (20) having a bottom-side joint head base body (21) and a bottom-side joint bearing (22), the bottom-side joint base body (21) is designed as an annular body and has a bottom-side concentric receiving bore (23), in which the bottom-side joint bearing (22) is received, and a bottom-side radial annular outer surface (24), and the bottom closure (15) has a bottom closure profiled section (15.1), the bottom closure profile section (15.1) is designed as an integral section of the bottom closure (15), protrudes axially from the outer top surface (15.2) of the bottom closure and has a web-like basic shape following a radius, and the bottom closure profile section (15.1) has a concave indentation, which forms a bottom-side receiving section (15.3), the bottom-side hinge head base body (21) has a bottom-side radially inner surface (15.4) corresponding to the bottom-side radially annular outer surface (24), and the bottom-side hinge head base body (21) is welded on the bottom-side radially annular outer partial surface (25) to the bottom closure (15) on the bottom-side radially inner surface (15.4) by means of a bottom-side laser ring segment weld (26).

Description

Technical Field

[0001] The invention relates to a working cylinder having a connecting section for articulated connection to a device to be actuated. Background Art

[0002] It is known from the prior art that a working cylinder and a device to be actuated are connected via a connection module for force transmission. Herein, a hinge head is particularly known as the connection module from the prior art.

[0003] The hinge head is particularly manufactured as a forging or casting and houses a hinge bearing in a hinge hole. The hinge head can have different degrees of freedom so that the working cylinder can be connected without bending stress.

[0004] For connection at the bottom closure, it is known from the prior art that the hinge head is connected in a material-locking manner by means of MAG welding. For this purpose, not only the dimensions but also the shape of the hinge head must be disadvantageously determined depending on the working cylinder to be connected, whereby its provision becomes expensive. Generally, the hinge head has a straight outer contour section which is welded flat onto the top surface of the bottom closure. To withstand higher forces, the MAG weld is dimensioned generously. The filler material present as a weld bead at the root of the weld can unfavorably require a corresponding margin with respect to the spacing of the outer contour section relative to the so-called hinge hole in order to ensure sufficient free movement space around the hinge hole. Due to the large heat input during welding, temperature-sensitive components, particularly for example the hinge bearing, may disadvantageously only be assembled after welding or must be provided with a material margin of generally at least 30% at the hinge head in order to be able to dissipate the heat sufficiently.

[0005] To connect the hinge head to the piston rod, a threaded connection is particularly known from the prior art. For this purpose, an external thread must be milled on the piston rod on the one hand, while on the other hand the hinge head with a blind hole is prepared with an internal thread. In addition to the high costs for manufacturing the thread pair, the necessary minimum structural length of the thread must also be disadvantageously considered, and if necessary, a further length margin for the wrench face which is also to be milled and which is determined for applying torque or for anti-fixing in the case of the threaded connection can be added to this minimum structural length. Summary of the Invention

[0006] The object of the invention is to provide a working cylinder which can be connected by means of a hinge head and which requires less structural space and can be manufactured with reduced material use and time costs.

[0007] This object is achieved by the features listed in claim 1 and in other aspects according to the invention by the features listed in protective claim 8. Preferred refinements result from the dependent claims.

[0008] The working cylinder according to the invention has a cylinder and a piston unit as basic elements and is characterized by a coupling section with hinge joints constructed in a special way.

[0009] The cylinder of the working cylinder according to the invention has a cylinder tube, a first closure and a second closure in a known manner.

[0010] Here, the cylinder tube has two opposite cylinder tube ends. The two opposite cylinder tube ends are hereinafter referred to as the first cylinder tube end and the second cylinder tube end and collectively as the cylinder tube ends.

[0011] The first closure is arranged at the first cylinder tube end, while the second closure is arranged at the second cylinder tube end. Hereinafter, the first closure and the second closure are also collectively referred to as closures. The first closure is constructed as a guide closure, while the second closure is constructed as a bottom closure.

[0012] The cylinder tube and the closures arranged thereon form a cylinder inner cavity. For this purpose, the two closures are constructed such that they are pressure-sealed to the corresponding cylinder tube ends. For the connection, the two closures are preferably laser-welded to the cylinder tube along an annular common contact surface respectively.

[0013] The piston unit forms at least one working chamber in the cylinder inner cavity. The piston unit is preferably constructed as a structural group consisting of a piston and a piston rod, wherein the piston rod slides through the guide closure. The piston unit can however also exist as a plunger piston or as a piston unit of a synchronous cylinder, for example. The working cylinder according to the invention can however also be of other types, in particular also a differential working cylinder or a tension cylinder. It is preferably a hydraulic cylinder, but is not limited thereto.

[0014] The piston unit has an external end section. The external end section is understood as the head section of the piston unit, preferably the distal end of the piston rod, which is outside the cylinder inner cavity. In the case of a plunger cylinder, it is the distal head of the plunger piston.

[0015] Furthermore, the working cylinder according to the invention is characterized by a coupling section constructed in a special way.

[0016] The coupling section in the sense of the present invention is understood as the following part of the working cylinder, which is connected to the device to be actuated by the working cylinder, such as an excavator arm, and via which the force provided by the working cylinder is transmitted or the force starting from the device to be actuated is borne. The device to be actuated itself is not a component of the working cylinder according to the invention. It is only the functional context of the working cylinder according to the invention. In general, two opposite coupling sections are arranged on the working cylinder, wherein at least one coupling section is constructed according to the invention.

[0017] For this purpose, the working cylinder according to the first independent claim has, according to the invention, a bottom-side articulated head.

[0018] The bottom-side articulated head has a bottom-side articulated head base body and an articulated bearing arranged therein, which serves for the friction-optimized and torque-free coupling of the working cylinder to the device to be actuated by means of a coupling pin in at least one rotational degree of freedom.

[0019] According to the invention, the base body of the joint head on the bottom side is designed as an annular body. An annular body is understood to be a rotationally symmetrical component which, in contrast to the cast or forged parts known from the prior art, can be produced with high precision by simple turning. Preferably, the annular body has a roughly hollow cylindrical basic shape.

[0020] The bottom-side articulated head basic body has a concentric receiving bore in which the articulated bearing is received.

[0021] Furthermore, the bottom-side joint head base body has an annular body outer surface which extends circumferentially in the radial direction on the outer surface of the annular body.

[0022] According to the invention, the bottom closure of the working cylinder has a bottom closure profile section which is designed in a special manner.

[0023] The bottom closure profile section is designed as an integral section of the bottom closure and is provided in particular by milling. The bottom closure profile section protrudes from the outer bottom closure top surface in the axial distal direction beyond the plane spanned by it. The bottom closure profile section has a web-shaped profile that follows a radius. A web-shaped basic shape is understood to mean an approximately prismatic body, the bottom and top sides of which are arranged transversely to the bottom closure top side. A radius-following basic shape is understood to mean that the bottom closure profile section has a concave indentation in its approximately prismatic basic shape. At this concave indentation there is a concavely curved surface which is geometrically designed as a section of the cylindrical side surface and is referred to below as the radial inner side surface of the bottom side.

[0024] The concave indentation forms a receiving section. The receiving section is shaped in such a way that it has a radial inner surface corresponding to the outer surface of the radial annular body. The shape of the cylindrical side surface section of the receiving section advantageously enables the flat receiving of the articulated head base body. The section of the radial outer surface of the annular body that flatly abuts against the radial inner surface of the concave receiving section of the bottom closure part molding section is also referred to below as the outer surface part surface of the annular body.

[0025] This surface support advantageously enables high-force transmission of pressure, as is particularly the case in the extended operating state of the working cylinder. By means of the corresponding surface, a positionally defined positive fit is simultaneously provided between the hinge head base body and the bottom closure, which resists torsion and tilting of the hinge head base body.

[0026] The bottom-side hinge head base body is welded to the bottom closure at the radially inner surface at the radially outer part surface of the radially annular body outer surface by means of a bottom-side laser ring segment weld. The full-surface welding of the hinge head base body and the bottom closure at the corresponding surfaces establishes a reliable material-locking connection between the two parts and enables the transmission of high tensile forces, as is particularly the case in the situation of the working cylinder's retracted operating state.

[0027] The solution according to the invention for providing an articulable working cylinder in particular has the following advantages.

[0028] Surprisingly, a solution has been created using the combination of the corresponding partial cylindrical side surfaces and the surface matching of the precise laser ring segment welds, by means of which the long-known disadvantages of the solutions for manufacturing hinge heads known from the prior art are overcome in a simple manner. Complex thread milling is not necessary, nor do the disadvantages of inaccurate MAG welding associated with a higher material input and a stronger heat input occur.

[0029] Advantageously, in addition, the bottom closure can be provided as a turned part in a particularly simple and cost-effective manner. Similarly, the bottom closure forming section can be manufactured in the process of manufacturing the bottom closure using the same technology as the bottom closure on a common milling machine without requiring additional processing stations due to its simple geometry. This results in significant advantages with regard to manufacturing effort and the associated manufacturing costs. The lower linear energy of the laser welding enables a smaller heat input area, thus avoiding thermal damage or deformation of the bottom closure or the hinge head base body.

[0030] In particular, laser welding according to the invention is also possible in the case of previously inserted sensitive components such as polymer seals or the like.

[0031] Furthermore, laser welding of the hinge head base body and the bottom closure can be achieved even in the case of an already assembled articulation bearing in overcoming the disadvantages of the prior art (as they occur in MAG welding). This makes it possible to manufacture the hinge head as a finished structural group consisting of the hinge head base body and the articulation bearing in series production with high precision before welding. Advantageously, higher precision and smaller tolerances are thus achieved.

[0032] In an advantageous development, the working cylinder is characterized in that bottom-side pressure medium connection openings are arranged at least partially in the bottom closure profile section.

[0033] Advantageously according to this improved solution, the structural space provided by the bottom closure molding section is simultaneously used for arranging the pressure medium connection hole.By utilizing the projection of the bottom closure molding section at the axial distal end, the structural length of the working cylinder can be reduced under the same stroke length.

[0034] Advantageously, the bottom closure profile section thus achieves functional integration in such a way that it firstly accommodates the joint head in a force-transmitting manner and secondly creates a structural space for accommodating a pressure medium connection opening axially distally beyond the bottom closure upper surface.

[0035] In a special variant based on this, the working cylinder is characterized in that the pressure medium connection opening on the bottom side at least partially spans a transverse plane spanned by the apex line of the receiving section distally with respect to the longitudinal axis.

[0036] The apex line of the receiving section is the point at which the bottom closure profile section has the smallest projection over the bottom closure top surface and at which the joint head base body reaches the farthest in the proximal direction in the assembled state.

[0037] The pressure medium connection can thus be arranged in the bottom closure in an area with a greater material coverage and at the same time very far distally. This achieves a maximum bending stiffness of the connection. This advantageously enables a particularly significant reduction in the structural length without affecting the stroke length.

[0038] According to another advantageous development, the working cylinder is characterized in that it has a rod-side articulated joint, which is designed as a rod-side articulated coupling of the working cylinder to the device to be actuated.

[0039] The rod-side joint also has a joint base (hereinafter referred to as the rod-side joint base) and a joint bearing (hereinafter referred to as the rod-side joint bearing). Therefore, the description of the base-side joint and its arrangement on the working cylinder also applies to the rod-side joint in a corresponding manner, unless special points are drawn from the following description.

[0040] The hinge base body on the rod side is also designed as an annular body. It has a concentric receiving hole on the rod side. The hinge bearing on the rod side is accommodated in this receiving hole accordingly. Like the hinge base body on the bottom side, the hinge base body on the rod side therefore also has a roughly hollow cylindrical basic shape. In addition, the hinge base body has a radial annular body outer surface on the rod side.

[0041] The piston unit has a rod-side formed section at the outer end section thereof.

[0042] In the case of attaching importance to special points on the rod side, the rod-side formed section corresponds to the bottom closure formed section. The rod-side formed section is machined from the cylindrical basic shape of the outer end section of the piston unit, preferably by milling. Subsequently, this formed section is configured as an integral section of the piston unit. Correspondingly, the rod-side formed section axially protrudes from the cylindrical section of the piston unit at the distal end and has a web-shaped and radius-following basic shape. The rod-side formed section has a concave indentation, which configures the rod-side receiving section. In addition, the rod-side receiving section has a radially inner surface corresponding to the outer surface of the radially annular body.

[0043] The rod-side formed section forms an exact receiving mating shape in terms of diameter and preferably also in terms of width with respect to the outer surface of the hinge head base. The rod-side receiving section is preferably limited in length by the outer diameter of the piston rod.

[0044] For the form-fitting connection of the rod-side formed section to the rod-side hinge head base, the rod-side formed section is welded to the piston unit at the rod-side outer partial surface of the rod-side outer surface of the radially annular body by means of a rod-side laser ring segment weld at the rod-side radially inner surface.

[0045] According to a particularly advantageous refinement, the working cylinder with a bottom-side hinge head and a rod-side hinge head is characterized in that the bottom-side hinge head base and the rod-side hinge head base are configured as structurally identical components.

[0046] Advantageously, the manufacture of the hinge head can be rationalized. In addition, quite significant advantages also result for the production logistics of the working cylinder, since there is no need to pay attention to different hinge heads for the bottom side and the rod side. This is made even more possible in combination with the lower heat load due to the laser ring segment welding, namely, the hinge heads can be produced in large quantities and with high quality as a structural group consisting of the base and the hinge bearing.

[0047] In addition, the present invention offers the advantage that the hinge head can be manufactured in stepped dimensions without special manufacturer specifications, and then only the bottom closure formed section or the rod-side formed section has to be milled according to the corresponding dimensions of a large number of available hinge heads for matching.

[0048] According to another advantageous refinement, the working cylinder is characterized in that the bottom-side laser ring segment weld or the rod-side laser ring segment weld is configured as a double-sided weld.

[0049] Advantageously, on the one hand, the stability is increased, and at the same time the heat load is reduced, because the introduced linear energy is distributed over time.

[0050] On the other hand, according to the parallel independent claims, the present invention relates to a working cylinder having a hinge joint according to the present invention only on the rod side.

[0051] The basic structure of the working cylinder with respect to the cylinder, the cylinder tube, the closure, and the piston unit corresponds to that of the working cylinder according to the main claim, so that the description content there also applies to the working cylinder according to the parallel independent claims described herein in a corresponding manner. In addition, the description content of the dependent claims regarding the hinge joint on the rod side and the structural configuration of the end section of the formed section on the rod side outside the piston unit applies to the relatively additional hinge joint on the rod side in a corresponding manner. Brief Description of the Drawings

[0052] The present invention is described in detail by way of the following drawings as embodiments:

[0053] Figure 1 : A schematic cross-sectional view of the working cylinder is shown,

[0054] Figure 2 : A schematic view of the piston rod is shown as a side view,

[0055] Figure 3 : A schematic view of the formed section on the piston rod side with an annular body is shown,

[0056] Figure 4 : A schematic view of the working cylinder is shown as a side view,

[0057] Figure 5 : A schematic cross-sectional view of the section on the bottom side of the working cylinder is shown. Detailed Description of the Embodiment

[0058] Here, the same reference numerals in different drawings refer to the corresponding identical features or components. If they are not shown in the relevant drawings, these reference numerals are also used in the description.

[0059] Figure 1 A schematic cross-sectional view of an embodiment of the working cylinder is shown.

[0060] The working cylinder is composed of a cylinder 11 and a piston unit 12 in its basic components. The cylinder tube 13 is closed by a guide closure 14 and a bottom closure 15 and thus forms a cylinder inner cavity 16.

[0061] In this embodiment, the working cylinder has hinge joints 20, 30 constructed according to the present invention not only on the bottom side but also on the rod side. The hinge joint 20 on the bottom side and the hinge joint 30 on the rod side are each constructed as an annular body and are specifically constructed as turned parts in this case.

[0062] The bottom-side joint head 20 has a bottom-side joint head base body 21 and a bottom-side joint bearing 22 pressed into its bottom-side receiving hole 23. The bottom-side joint head base body 21 has a bottom-side radial annular body outer side surface 24.

[0063] The bottom closure 15 has a specially designed bottom closure profile section 15.1 for accommodating the bottom-side articulated head 20, wherein Figure 1 The section plane of the cross-sectional view of the bottom closure runs longitudinally through the bottom closure profile section 15.1. Figure 4 As can be seen better in the figure, the web-shaped bottom closure profile section 15.1 has a bottom-side receiving section 15.3 which is circular, concave and follows the radius of the joint head base body 21 at its radial annular body outer side surface 24. The receiving section 15.3 forms a bottom-side radial inner side surface 15.4, the radius of which corresponds to the bottom-side annular body outer side surface 24. The part of the bottom-side annular body outer side surface 24 that coincides with the bottom-side radial inner side surface 15.4 is the bottom-side radial annular body outer side part surface 25. The two surfaces 15.4, 25 are connected in a fully materially sealed manner by means of a bottom-side laser ring segment weld 26 introduced on both sides. The welded connection by materially sealed means, due to the local form-fit of the two surfaces 15.4, 25 of corresponding shapes, not only allows reliable pre-positioning before welding, but also allows a particularly stable connection after welding, which is advantageous in terms of production technology.

[0064] In addition, in the bottom closure molded section 15.1, in this embodiment, a bottom-side pressure medium connection hole 15.5 is partially arranged. This connection hole is advantageously arranged in the bottom closure molded section 15.1 in such a way that it is immersed in the transverse plane 15.7 that is supported by the proximal vertex 15.6. Due to the bottom closure molded section 15.1, which tapers on both sides from the cylindrical diameter of the bottom closure 15 at the distal end, there is enough space in the remaining web for the bottom-side pressure medium connection hole 15.5. Therefore, the axial extension between the piston in its bottom-side end position at the bottom closure 15 and the hinge point of the bottom-side hinged head 20 can be significantly reduced, which means a decisive advantage due to the reduced necessary structural space length of the working cylinder.

[0065] The hinge joint 30 on the rod side is used to hinge the piston unit 12 at the device to be actuated. Similar to the hinge joint 20 on the bottom side, the hinge bearing 32 on the rod side is also integrated into the hinge joint 30 on the rod side. The hinge bearing on the rod side is received in the receiving hole 33 on the rod side of the hinge joint base body 31 on the rod side. In order to receive the hinge joint 30 on the rod side at the outer end section 12.5 of the piston unit 12, the piston rod has a receiving section 12.3 on the rod side. This receiving section forms, with its concave shape, a mating section relative to the outer surface 35 of the outer part of the annular body on the rod side, and the outer surface 35 of the outer part of the annular body on the rod side is a section of the outer surface 34 of the annular body on the rod side. The formed section 12.1 on the rod side is offset distally in the width of the hinge bearing 32 on the rod side. There is a full-section end 12.2 there.

[0066] Figure 2 The piston rod of the piston unit 12 is shown in a schematic diagrammatic form. The piston rod has a formed section 12.1 on the rod side at its outer end section 12.5, and this formed section is configured to receive the hinge joint 30 on the rod side. For this purpose, the formed section 12.1 on the rod side is formed from the cylindrical diameter of the piston rod by a material-removing machining process, in particular by milling. For this purpose, two concave areas are created distally on both sides and in parallel. Thus, the full-section end 12.2 of the piston rod is formed. Further, the receiving section 12.3 on the rod side is introduced perpendicular to the main longitudinal axis 17 at the rod-side end of the piston rod. It depicts a sector segment having the same diameter as that of the hinge joint base body 21 on the bottom side.

[0067] Figure 3 The piston rod and the hinge joint 30 on the rod side are shown in a schematic exploded view. The hinge joint 30 on the rod side is additionally shown slightly tilted for better illustration. In the hinge joint 30 on the rod side, the hinge bearing 32 on the rod side (not shown in Figure 3 for simplicity) is received in the hinge joint base body 31 on the rod side.

[0068] The piston rod has a formed section 12.1 on the rod side at one end. It is provided by milling in this area. It forms a shoulder, which is produced by machining based on material removal by the full-section end 12.2. For the formed section 12.1 on the rod side, a prismatic section that is the prototype of the formed section 12.1 on the rod side is first obtained by symmetric milling on both sides of the cylindrical rod end. In order to accommodate the rod-side hinge joint 30, a concave rod-side receiving section 12.3 corresponding to the cylindrical outer shape of the rod-side hinge joint 30 is then machined. This receiving section axially constructs the radially inner surface 12.4 on the rod side. This surface is used to accommodate the rod-side hinge joint 30, whose cylindrical outer shape has a radially outer annular surface 34 on the rod side. The contact surface between the radially outer annular surface 34 on the rod side and the radially inner surface 12.4 on the rod side constitutes the radially outer partial surface 35 of the annular body on the rod side. Through this surface, all the pressure of the cylinder is transmitted to the cylinder receiving part. For material-locking assembly, a laser-ring segment weld 36 is axially introduced relative to the rod-side receiving hole 33 between the radially outer partial surface 35 of the annular body on the rod side and the radially inner surface 12.4, so that it connects these surfaces 12.4, 35. Thus, the piston unit 12 and the rod-side hinge joint 30 are reliably coupled.

[0069] Figure 4 The schematic illustration of the working cylinder particularly shows the positional relationship between the bottom-side hinge joint 30 and the bottom closure 15. Here, the bottom closure 15 also has its original cylindrical shape. Through two recesses that also extend towards the main longitudinal axis 17 of the cylinder at the distal end, a bottom-closure formed section 15.1 is milled out. This formed section corresponds in its web width to the axial extension of the bottom-side hinge-joint base 21. Advantageously, it is thus simultaneously wide enough so that the bottom-side pressure-medium connection hole 15.5 can also be arranged here. This creates a crucial structural-space advantage, because the working cylinder can thus be constructed shorter overall. As a transition to the cylinder, the cylinder tube 13 and the bottom closure 15 are also laser-welded in this embodiment.

[0070] Figure 5 Supplementary, in the cross-sectional view of the bottom-side section of the working cylinder, the bottom-closure formed section 15.1 without the bottom-side hinge joint 20 is shown, where the dashed line shows the boundary relative to the rest of the bottom closure 15 that is not visible due to the cutting plane and simultaneously shows the plane of the top surface 15.2 of the bottom closure. The bottom-closure formed section 15.1 has a bottom-side receiving section 15.3. This receiving section 15.3 is constructed as the radially inner surface 15.4 on the bottom side.

[0071] List of reference numerals

[0072] 11 Cylinder

[0073] 12 Piston unit

[0074] 12.1 Forming section on the rod side

[0075] 12.2 Full-section end

[0076] 12.3 Receiving section on the rod side

[0077] 12.4 Radially inner surface on the rod side

[0078] 12.5 Outer end section

[0079] 13 Cylinder tube

[0080] 14 Guide seal

[0081] 15 Bottom seal

[0082] 15.1 Forming section of the bottom seal

[0083] 15.2 Top surface of the bottom seal

[0084] 15.3 Receiving section on the bottom side

[0085] 15.4 Radially inner surface on the bottom side

[0086] 15.5 Pressure medium connection hole on the bottom side

[0087] 15.6 Proximal vertex

[0088] 15.7 Transverse plane

[0089] 16 Cylinder inner cavity

[0090] 17 Main longitudinal axis

[0091] 20 Hinge joint on the bottom side

[0092] 21 Hinge joint base on the bottom side

[0093] 22 Hinge bearing on the bottom side

[0094] 23 Receiving hole on the bottom side

[0095] 24 Outer surface of the radially annular body on the bottom side

[0096] 25 Outer partial surface of the radially annular body on the bottom side

[0097] 26 Laser ring segment weld on the bottom side

[0098] 30 Hinge joint on the rod side

[0099] 31 Hinge joint base on the rod side

[0100] Hinge bearing on the side of the 32-bar

[0101] Receiving hole on the side of the 33-bar

[0102] Outer surface of the radial annular body on the side of the 34-bar

[0103] Outer partial surface of the radial annular body on the side of the 35-bar

[0104] Laser ring segmental weld on the side of the 36-bar

Claims

1. A working cylinder comprising a cylinder (11) and a piston unit (12), Among them, The cylinder (11) comprises a cylinder tube (13), a guide closure (14) and a bottom closure (15). The cylinder tube (13) has a first cylinder tube end (13.1) and a second cylinder tube end (13.2), wherein the guide closure (14) is arranged at the first cylinder tube end (13.1) and the bottom closure (15) is arranged at the second cylinder tube end (13.2), wherein the cylinder tube (13) and the closure members (14, 15) form a cylinder cavity (16), The piston unit (12) forms at least one working chamber (16.1) in the cylinder interior (16), slides through the guide closure (14) and has an outer end section (12.5). It is characterized in that The cylinder (11) has a bottom-side articulated joint (20), which has a bottom-side articulated joint base (21) and a bottom-side articulated bearing (22). The bottom-side articulated head base body (21) is configured as an annular body and has a concentric receiving hole (23) on the bottom side and a radial annular body outer surface (24) on the bottom side, wherein the bottom-side articulated bearing (22) is received in the receiving hole. The bottom closure (15) has a bottom closure profile section (15.1) which is designed as an integral section of the bottom closure (15) and projects axially beyond the outer bottom closure top surface (15.2) and has a web-like basic shape following a radius. The bottom closure molding section (15.1) has a concave indentation, which constructs a bottom-side accommodating section (15.3), which has a bottom-side radial inner surface (15.4) corresponding to the bottom-side radial annular body outer surface (24), and the bottom-side hinge head base (21) is welded to the bottom closure (15) at the bottom-side radial inner surface (15.4) at the bottom-side radial annular body outer part surface (25) by means of a bottom-side laser ring segment weld (26).

2. The working cylinder according to claim 1, It is characterized in that Bottom-side pressure medium connection openings (15.5) are at least partially arranged in the bottom closure profile section (15.1).

3. The working cylinder according to claim 2, It is characterized in that The bottom-side pressure medium connection opening (15.5) at the distal end relative to the main longitudinal axis (17) at least partially spans a transverse plane (15.7) spanned by a proximal apex (15.6) of the bottom-side receiving section (15.3).

4. A working cylinder according to any one of the preceding claims, It is characterized in that The piston unit (12) has a rod-side joint (30), which has a rod-side joint base body (31) and a rod-side joint bearing (32). The hinge joint base body (31) on the rod side is configured as an annular body and has a concentric receiving hole (33) on the rod side in which the hinge bearing (32) on the rod side is received, and a radially annular outer surface (34) on the rod side. The piston unit (12) has a formed section (12.1) on the rod side at its outer end section (12.5), which is configured as an integral section of the piston unit (12), axially protrudes from the full-section end (12.2) at the distal end, and has a web-like basic shape following a radius. The formed section (12.1) on the rod side has a concave indentation, which forms a receiving section (12.3) on the rod side. The receiving section has a radially inner surface (12.4) on the rod side corresponding to the radially annular outer surface (34) on the rod side, and the hinge joint base body (31) on the rod side is welded to the piston unit (12) at the radially inner surface (12.4) on the rod side by means of a bottom-side laser ring segment weld (36) at the radially annular outer partial surface (35) on the rod side.

5. The working cylinder according to any one of the preceding claims, characterized in that the bottom-side hinge joint base body (21) and the rod-side hinge joint base body (31) are configured as turned parts with the same structure.

6. The working cylinder according to any one of the preceding claims, characterized in that the bottom-side laser segment weld (26) or the rod-side laser segment weld (36) is configured as a double-sided weld.

7. A working cylinder having a cylinder (11) and a piston unit (12), Among them, wherein the cylinder (11) has a cylinder tube (13), a first closure and a second closure, wherein the cylinder tube (13) has a first cylinder tube end (13.1) and a second cylinder tube end (13.2), and wherein the first closure is arranged at the first cylinder tube end (13.1) and the second closure is arranged at the second cylinder tube end (13.2), and wherein the cylinder tube (13) and the closures (14, 15) form a cylinder inner cavity (16), wherein the piston unit (12) forms at least one working cavity (16.1) in the cylinder inner cavity (16), slides through the first closure and has an outer end section (12.5), characterized in that the piston unit (12) has a hinge joint (30) on the rod side, and the hinge joint (30) on the rod side has a hinge joint base body (31) and a hinge bearing (32) on the rod side, the hinge joint base body (31) on the rod side is configured as an annular body and has a concentric receiving hole (33) on the rod side in which the hinge bearing (32) on the rod side is received, and a radially annular outer surface (34) on the rod side, the piston unit (12) has a formed section (12.1) on the rod side at its outer end section (12.5), which is configured as an integral section of the piston unit (12), axially protrudes from the full-section end (12.2) at the distal end, and has a web-like basic shape following a radius. The formed section (12.1) on the rod side has a concave indentation that forms the receiving section (12.3) on the rod side. The receiving section has a radially inner surface (12.4) on the rod side corresponding to the outer surface (34) of the radially annular body on the rod side, and the head base (31) on the rod side is welded to the piston unit (12) at the radially inner surface (12.4) on the rod side at the outer surface (35) of the radially annular body on the rod side by means of a bottom-side laser ring segment weld (36).

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