Working cylinder

Abstract

The invention relates to a working cylinder comprising a cylinder (11) and a piston unit (12), characterized in that the cylinder (11) has a bottom-side joint head (20) which has a bottom-side joint head main body (21) and a bottom-side joint bearing (22); in that the bottom-side joint head main body (21) is in the form of an annular body and has a bottom-side concentric receiving bore (23), in which the bottom-side joint bearing (22) is received, and also has a bottom-side radial annular body outer lateral surface (24); in that the bottom closure part (15) has a bottom closure part shaped portion (15.1) which is formed as a monolithic portion of the bottom closure part (15) and which rises axially above an outer bottom closure part covering surface (15.2) and which has a projection-like basic shape that follows a radius; in that the bottom closure part shaped portion (15.1) has a concave indentation which forms a bottom-side receiving portion (15.3) which has a bottom-side radial inner lateral surface (15.4) corresponding to the bottom-side radial annular body outer lateral surface (24); and in that the bottom-side joint head main body (21) is welded, at a bottom-side radial annular body outer lateral partial surface (25), to the bottom closure part (15), at the bottom-side radial inner lateral surface (15.4), by means of a bottom-side annular-segment-shaped laser weld seam (26).

Description

[0001] Working cylinder

[0002] The invention relates to a working cylinder with coupling sections for an articulated coupling with a device to be actuated.

[0003] It is known from the prior art to couple working cylinders to devices to be actuated via connecting modules for the purpose of power transmission. Rod ends are particularly known as connecting modules from the prior art.

[0004] Rod ends are manufactured primarily as flame-cut parts or forged parts and accommodate a spherical plain bearing in a joint eye, which can have different degrees of freedom in order to be able to couple the working cylinder free from bending stresses.

[0005] For coupling to a base closure part, it is known from the prior art to couple the rod end by means of MAG welding. The disadvantage of this is that not only the size but also the shape of the rod ends must be specified depending on the working cylinder to be coupled, which increases their cost. As a rule, the rod end is provided with a straight outer contour section that is welded flush onto the top surface of the base closure part. The MAG weld seam is generously dimensioned to absorb the high forces. The material deposit present as a weld bead in the fillet, which can be up to 15 mm thick, disadvantageously requires a corresponding allowance based on the distance between the outer contour section and the so-called rod eye in order to ensure sufficient free movement space around the rod eye.Due to the high heat input during welding, temperature-sensitive components, such as spherical plain bearings in particular, can be installed only after welding or a material allowance of at least 30% of the mass must be provided on the rod end in order to be able to dissipate the heat sufficiently.

[0006] Confirmation copy: A screw connection is known from the prior art for coupling a rod end to a piston rod. For this, an external thread must be milled into the piston rod, and the rod end must be prepared with a blind hole with an internal thread. In addition to the considerable effort required to manufacture the thread pair, a necessary minimum thread length must also be observed. This may also require an additional length allowance for the spanner flats that also need to be milled, which are intended for applying torque or for counter-holding during screwing.

[0007] The object of the invention is to provide a working cylinder that can be coupled by means of a joint head, which requires little installation space and can be manufactured with a reduced use of material and time.

[0008] The problem is solved by the features listed in claim 1 and, according to a further aspect of the invention, by the features listed in claim 8. Preferred developments are set out in the subclaims.

[0009] The working cylinder according to the invention has a cylinder and a piston unit as basic elements and is characterized by a specially designed coupling section with a joint head.

[0010] The cylinder of the working cylinder according to the invention comprises, in a manner known per se, a cylinder tube, a first closure part and a second closure part.

[0011] The cylinder tube has two opposing cylinder tube ends. The two opposing 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. The first closure part is arranged at the first cylinder tube end, and the second closure part is arranged at the second cylinder tube end. The first closure part and the second closure part are hereinafter collectively referred to as the closure parts. The first closure part is designed as a guide closure part, and the second closure part is designed as a base closure part.

[0012] The cylinder tube and the closure parts arranged thereon form a cylinder interior. For this purpose, the two closure parts are designed to be pressure-tightly connected to the respective cylinder tube ends. To connect them, the two closure parts are preferably laser-welded to the cylinder tube along the circumferential common contact surface.

[0013] The piston unit forms at least one working chamber in the cylinder interior. The piston unit is preferably designed as an assembly comprising a piston and piston rod, with the piston rod sliding through the guide closure part. However, the piston unit can also be a plunger piston or a piston unit of a double-acting cylinder, for example. The working cylinder according to the invention can also be of other types, in particular a differential working cylinder or a pull cylinder. It is preferably a hydraulic cylinder, but is not limited thereto.

[0014] The piston unit has an outer end section. The outer end section is the distal head section of the piston unit, preferably the piston rod, located outside the cylinder interior. In the case of a plunger cylinder, this is the distal head of the plunger piston.

[0015] The working cylinder according to the invention is also characterized by a coupling section designed in a special way.

[0016] A coupling section within the meaning of the present invention is understood to be the part of the working cylinder that is connected to a device to be actuated, for example, an excavator arm, and via which the forces provided by the working cylinder are transmitted or the forces emanating from the device to be actuated are absorbed. The device to be actuated itself is not a component of the working cylinder according to the invention. It merely represents the functional context of the working cylinder according to the invention. Typically, two opposing coupling sections are arranged on the working cylinder, with at least one coupling section being designed 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 joint head.

[0018] The bottom-side rod end comprises a bottom-side rod end body and a spherical plain bearing arranged therein. The spherical plain bearing serves to provide a friction-optimized and torque-free coupling of the working cylinder to a device to be actuated by means of a coupling pin.

[0019] According to the invention, the base-side joint head body is designed as a ring body. A ring body is understood to be a rotationally symmetrical component that, unlike the flame-cut or forged parts known from the prior art, can advantageously be produced with high precision by simple turning. The ring body preferably has a substantially hollow-cylindrical basic shape.

[0020] The base of the joint head body has a concentric mounting hole in which the spherical plain bearing is accommodated.

[0021] In addition, the base-side rod end body has an annular body outer surface. This extends circumferentially in the radial direction on the outer surface of the annular body. According to the invention, the base closure part of the working cylinder has a specially designed base closure part molding section.

[0022] The bottom closure part shaped section is formed as a monolithic section of the bottom closure part and is produced in particular by milling. The bottom closure part shaped section rises from the outer bottom closure part cover surface above the plane spanned by it in the axially distal direction. The bottom closure part shaped section has a web-shaped basic shape that accompanies the radius. A web-shaped basic shape is understood to be an essentially prismatic body whose base and cover surfaces are arranged transversely to the bottom closure part cover surface. A radius-accompanying basic shape is understood to mean that the bottom closure part shaped section has a concave indentation in its essentially prismatic basic shape. At the concave indentation there is a concavely curved surface that geometrically forms a section of a cylinder jacket surface and is referred to below as the bottom-side radial inner jacket surface.

[0023] The concave recess forms a receiving section. The receiving section is shaped such that it has a radial inner surface corresponding to the radial outer surface of the ring body. The shape of a cylindrical surface section of the receiving section advantageously enables a flat reception of the rod end base body. The section of the radial outer surface of the ring body that lies flat against the radial inner surface of the concave receiving section of the base closure part mold section is also referred to below as the outer surface of the ring body.

[0024] This surface support advantageously enables high force transmission of compressive forces, which is particularly present when the working cylinder is extended. The corresponding surfaces also provide a partial positive locking for the positional fixation between the rod end body and the base closure part, which counteracts twisting and tilting of the rod end body. The base-side rod end body is welded to the base closure part on the radial inner surface of the radial ring body outer surface by means of a base-side laser ring segment weld.The full-surface welding of the rod end base body and the base closure part on the corresponding surfaces creates a reliable, material-locking connection between the two parts and enables the transmission of high tensile forces, which are particularly present when the working cylinder is in the retracted operating state.

[0025] The solution according to the invention for providing an articulated, connectable working cylinder has the following advantages in particular.

[0026] A surprising solution was created by combining a flat fit of corresponding cylinder surface sections and a precise laser ring segment weld seam. This solution easily overcomes the long-standing disadvantages of state-of-the-art solutions for the production of rod ends. Neither complex thread milling is required, nor are the disadvantages of inaccurate MAG welding associated with high material deposits and high heat input.

[0027] Advantageously, the bottom closure part can also be provided as a turned part in a particularly simple and cost-effective manner. Due to its simple geometry, the bottom closure part mold section can also be manufactured using conventional milling machines during the production of the bottom closure part, using the same technology as the bottom closure part, without the need for an additional processing station. This results in a significant advantage in terms of manufacturing effort and the associated manufacturing costs. The low energy per unit length of laser welding enables small heat-affected zones, so that thermal damage or deformation of the bottom closure part or the rod end base body can be avoided. In particular, laser welding according to the invention is also possible with previously inserted sensitive components such as polymer seals or the like.

[0028] Furthermore, overcoming the disadvantages of the state-of-the-art technology associated with MAG welding, laser welding of the rod end body to the base closure part can be performed even with an already assembled spherical plain bearing. This allows the rod end to be mass-produced and highly precise as a finished assembly consisting of the rod end body and spherical plain bearing before welding. This advantageously achieves higher accuracies and tighter tolerances.

[0029] In an advantageous further development, the working cylinder is characterized in that a bottom-side pressure medium connection bore is arranged at least in sections in the bottom closure part mold section.

[0030] Advantageously, this refinement allows the installation space provided by the bottom closure part mold section to be used for the arrangement of the pressure medium connection bore. By utilizing the axially distal elevation of the bottom closure part mold section, the overall length of the working cylinder can be reduced while maintaining the same stroke length.

[0031] Advantageously, a functional integration is created by means of the bottom closure part mold section in that the bottom closure part mold section firstly accommodates the joint head in a force-transmitting manner and secondly creates an installation space for accommodating the pressure medium connection bore axially distally beyond the bottom closure cover surface.

[0032] In a special variant based on this, the working cylinder is characterized in that the base-side pressure medium connection bore extends, at least in sections distally, beyond a transverse plane spanned by a vertex line of the receiving section to a longitudinal axis. The vertex line of the receiving section is the point at which the base closure part mold section has the lowest elevation above the base closure part cover surface and where, in an assembled state, the joint head base body extends the furthest in the proximal direction.

[0033] The pressure medium connection can thus be positioned in the bottom closure part in an area with the greatest material coverage and, at the same time, very distally. This achieves maximum flexural rigidity of the connection. This advantageously enables a particularly significant reduction in the overall length without compromising the stroke length.

[0034] According to a further advantageous development, the working cylinder is characterized in that it has a rod-side joint head. This forms the rod-side articulated coupling of the working cylinder to a device to be actuated.

[0035] The rod-side rod end also has a rod end base body – hereinafter referred to as the rod-side rod end base body – and a spherical plain bearing – hereinafter referred to as the rod-side spherical plain bearing. The descriptions of the base-side rod end and its arrangement on the working cylinder therefore also apply to the rod-side rod end, unless specific details arise from the following description sections.

[0036] The rod-side rod end body is also designed as a ring body. It has a concentric receiving bore on the rod side. The rod-side spherical plain bearing is accommodated in this bore. Like the base-side rod end body, the rod-side rod end body also has a substantially hollow-cylindrical basic shape. The rod end body also has a radial annular body outer surface on the rod side. The piston unit has a rod-side shaped section at the outer end section.

[0037] The rod-side mold section corresponds to the base closure part mold section, taking into account the rod-side special features. The rod-side mold section is machined from the cylindrical basic shape of the outer end section of the piston unit, preferably by milling. This is then formed as a monolithic section of the piston unit. Accordingly, the rod-side mold section rises axially distally above the cylindrical section of the piston unit and has a web-shaped basic shape that follows the radius. The rod-side mold section has a concave recess that forms a rod-side receiving section. Furthermore, the rod-side receiving section has a radial inner surface that corresponds to the radial annular body outer surface.

[0038] The rod-side shaped section forms a precise counter-shape in diameter and preferably also in width to the outer surface of the rod end body. The rod-side receiving section is preferably limited in length by the outer diameter of the piston rod.

[0039] For the positive connection of the rod-side shaped section with the rod-side rod end base body, the latter is welded to a rod-side radial ring body outer surface part of the rod-side radial ring body outer surface with the piston unit on the rod-side radial inner surface by means of a rod-side laser ring segment weld seam.

[0040] According to a particularly advantageous development, the working cylinder with a base-side and rod-side rod end is characterized by the fact that the base-side rod end body and the rod-side rod end body are designed as identical components. Advantageously, the production of the rod ends can be streamlined. Furthermore, significant advantages arise for the production logistics of the working cylinder, as there is no need to consider different rod ends for the base side and the rod side. In conjunction with the low thermal stress caused by laser ring segment welding, it is possible to manufacture the rod ends as a finished assembly consisting of a base body and a spherical plain bearing in large quantities and with high quality.

[0041] Furthermore, the invention offers the advantage that the rod ends can be manufactured in graduated sizes without specific manufacturer specifications, and that for adaptation only the bottom closure part mold section or the rod-side mold section has to be milled according to the respective size of the rod ends available in large quantities.

[0042] According to a further advantageous development, the working cylinder is characterized in that the base-side laser ring segment weld seam or the rod-side laser ring segment weld seam is designed as a double-sided weld seam.

[0043] This has the advantage of increasing stability and simultaneously reducing thermal stress because the introduced energy is distributed over time.

[0044] A further aspect of the invention relates, according to the independent claim, to a working cylinder which has a joint head according to the invention only on the rod side.

[0045] The basic structure of the working cylinder, with respect to the cylinder, the cylinder barrel, the closure parts, and the piston unit, corresponds to the working cylinder according to the main claim, so that the description contents there also apply accordingly to the working cylinder according to the independent claim described here. Furthermore, with regard to the rod-side joint head and the design of the rod-side shaped section at the outer end section of the piston unit, the description contents of the dependent claim apply accordingly to the additional rod-side joint head.

[0046] The invention is illustrated by way of example with reference to

[0047] Fig. 1 schematic sectional view of the working cylinder

[0048] Fig. 2 schematic representation of the piston rod as a side view

[0049] Fig. 3 schematic representation of the piston rod side mold section with the ring body

[0050] Fig. 4 schematic representation of the working cylinder as a side view

[0051] Fig. 5 schematic sectional view of the bottom section of the working cylinder explained in more detail.

[0052] Identical reference symbols in the various figures refer to identical features or components. These reference symbols are used in the description even if they are not shown in the respective figure.

[0053] Fig. 1 shows a schematic sectional view of an embodiment of the working cylinder.

[0054] Its basic components consist of a cylinder 11 and a piston unit 12. The cylinder tube 13 is closed with a guide closure part 14 and a bottom closure part 15 and thus forms a cylinder interior 16.

[0055] In this exemplary embodiment, the working cylinder has a joint head 20, 30 designed according to the invention on both the base side and the rod side. The base-side joint head 20 and the rod-side joint head 30 are each designed as an annular body and, in this case, specifically as a turned part.

[0056] The bottom-side rod end 20 has the bottom-side rod end body 21 and the bottom-side spherical plain bearing 22 pressed into its bottom-side receiving bore 23. The bottom-side rod end body 21 has a bottom-side radial annular body outer surface 24.

[0057] The base closure part 15 has a specially designed base closure part shaped section 15.1 for receiving the base-side joint head 20. In Fig. 1, the sectional plane of the sectional view of the base closure part runs longitudinally through the base closure part shaped section 15.1. The web-shaped base closure part shaped section 15.1—as better seen in Fig. 4—has a circular, concave base-side receiving section 15.3 that accompanies the radius of the joint head base body 21 on its radial annular body outer surface 24. The receiving section 15.3 forms a base-side radial inner surface 15.4, the radius of which corresponds to the base-side annular body outer surface 24. The part of the bottom-side annular body outer surface 24 which is congruent with the bottom-side radial inner surface 15.4 is the bottom-side radial annular body outer surface partial surface 25. These two surfaces 15.4, 25 are bonded together over their entire surface by means of the bottom-side laser ring segment weld seam 26 applied on both sides. The bonded welding, in conjunction with the partial positive connection due to the corresponding shape of the two surfaces 15.4, 25, enables both reliable pre-positioning before welding, which is advantageous from a manufacturing technology perspective, and a particularly stable coupling after welding. In addition, in the present exemplary embodiment, the bottom-side pressure medium connection bore 15.5 is arranged in sections in the bottom closure part mold section 15.1. This bore is advantageously accommodated in the bottom closure part mold section 15.1 in such a way that it extends into a transverse plane 15.7 spanned by the proximal apex 15.6. Due to the bottom closure part mold section 15, which is distally tapered on both sides from the cylindrical diameter of the bottom closure part 15.1, there is sufficient space in the remaining web for the bottom-side pressure medium connection bore 15.5. Therefore, the axial extension between the piston in its bottom-side end position on the bottom closure part 15 and the articulation point of the bottom-side rod end 20 can be significantly reduced, which represents a decisive advantage due to the reduced required installation length of the working cylinder.

[0058] The rod-side joint head 30 serves to link the piston unit 12 to a device to be actuated. Similar to the base-side joint head 20, a rod-side spherical plain bearing 32 is also integrated into the rod-side joint head 30. This is received in the rod-side receiving bore 33 of the rod-side joint head base body 31. To accommodate the rod-side joint head 30 at the outer end section 12.5 of the piston unit 12, the piston rod has a rod-side receiving section 12.3. With its concave shape, this section forms the counterpart section to the rod-side annular body outer surface 35, which is a section of the rod-side annular body outer surface 34. The rod-side shaped section 12.1 is offset distally in the width of the rod-side spherical plain bearing 32. This is where the full cross-section end 12.2 is located.

[0059] Fig. 2 shows a schematic representation of the piston rod of the piston unit 12. At its outer end section 12.5, this has the rod-side shaped section 12.1, which is designed to receive the rod-side joint head 30. For this purpose, the rod-side shaped section 12.1 is formed from the cylindrical diameter of the piston rod using a material-removing manufacturing process, in particular by milling. For this purpose, two recessed areas are created distally and parallel on both sides. This creates a solid cross-sectional end 12.2 of the piston rod. Furthermore, the rod-side receiving section 12.3 is introduced at the rod-side end of the piston rod perpendicular to the main longitudinal axis 17. This describes a circular section with the same diameter as the base-side joint head base body 21.

[0060] Figure 3 shows a schematic exploded view of the piston rod and the rod-side rod end 30. The rod-side rod end 30 is also shown slightly tilted for clarity. The rod-side spherical plain bearing 32—not shown in Figure 3 for simplicity—is housed in the rod-side rod end base body 31 of the rod-side rod end 30.

[0061] The piston rod has a rod-side shaped section 12.1 at one end. This is created by milling the area. A shoulder is created, which results from the solid cross-section end 12.2 due to the material removal during machining. For the rod-side shaped section 12.1, a prismatic section is first obtained from the cylindrical rod end by symmetrical milling on both sides, as a preliminary stage of the rod-side shaped section 12.1. To accommodate the rod-side rod end 30, a concave rod-side receiving section 12.3 corresponding to the cylindrical outer shape of the rod-side rod end 30 is subsequently machined. This forms a rod-side radial inner surface 12.4 in the axial direction. This serves to accommodate the rod-side joint head 30, the cylindrical outer shape of which has a rod-side radial annular body outer surface 34.The contact surface between the rod-side radial annular body outer surface 34 and the rod-side radial inner surface 12.4 forms a rod-side radial annular body outer surface partial surface 35. All compressive forces of the cylinder are transmitted to a cylinder mount via this surface. For material-to-material assembly, a laser-welded ring segment 36 is introduced axially to the rod-side mounting bore 33 between the rod-side radial annular body outer surface partial surface 35 and the radial inner surface 12.4, connecting these surfaces 12.4, 35. This reliably couples the piston unit 12 and the rod-side rod end 30.

[0062] Fig. 4 shows, as a schematic representation of the working cylinder, in particular the positional relationships of the base-side joint head 30 and the base closure part 15. The base closure part 15 also has an originally cylindrical shape. The base closure part shaped section 15.1 is milled out through two recesses that extend distally to the main longitudinal axis 17 of the cylinder. Its web width corresponds to the axial extent of the base-side joint head base body 21. Advantageously, it is therefore sufficiently wide so that the base-side pressure medium connection bore 15.5 can also be arranged here. This creates a decisive space advantage, as the working cylinder can be built shorter overall. As a transition to the cylinder, the cylinder tube 13 and the base closure part 15 are also laser-welded in the exemplary embodiment.

[0063] Fig. 5 additionally shows, in a sectional view of the base section of the working cylinder, the base closure part mold section 15.1 without the base joint head 20. The dashed line indicates the boundary to the rest of the base closure part 15, which is not visible due to the sectional plane, as well as the plane of the base closure part cover surface 15.2. The base closure part mold section 15.1 has the base-side receiving section 15.3. The receiving section 15.3 forms the base-side radial inner surface 15.4.

[0064] Reference symbols used

[0065] 11 cylinders

[0066] 12 piston unit

[0067] 12.1 rod-side mold section

[0068] 12.2 Full cross-section end

[0069] 12.3 Rod-side receiving section

[0070] 12.4 rod-side radial inner surface

[0071] 12.5 outer end section

[0072] 13 Cylinder barrel

[0073] 14 Guide closure part

[0074] 15 Bottom closure part

[0075] 15.1 Bottom closure part mold section

[0076] 15.2 Bottom closure part cover surface

[0077] 15.3 bottom-side receiving section

[0078] 15.4 bottom-side radial inner surface

[0079] 15.5 bottom pressure medium connection hole

[0080] 15.6 proximal vertex

[0081] 15.7 Transverse plane

[0082] 16 cylinder interior

[0083] 17 Main longitudinal axis

[0084] 20 bottom-side joint head

[0085] 21 bottom-side rod end body

[0086] 22 bottom-side spherical bearing

[0087] 23 bottom mounting hole

[0088] 24 bottom-side radial ring body outer surface

[0089] 25 bottom-side radial ring body outer shell surface

[0090] 26 bottom-side laser ring segment weld seam rod-side rod end rod-side rod end base body rod-side spherical plain bearing rod-side mounting bore rod-side radial ring body outer surface rod-side radial ring body outer surface rod-side laser ring segment weld seam

Claims

Patent claims 1. Working cylinder, comprising a cylinder (11) and a piston unit (12), wherein the cylinder (11) has a cylinder tube (13), a guide closure part (14) and a bottom closure part (15), wherein the cylinder tube (13) has a first cylinder tube end (13.1) and a second cylinder tube end (13.2), wherein the guide closure part (14) at the first cylinder tube end (13.1) and the bottom closure part (15) is arranged on the second cylinder tube end (13.2), and wherein the cylinder tube (13) and the closure parts (14, 15) form a cylinder interior (16), wherein the piston unit (12) forms at least one working chamber (16.1) in the cylinder interior (16), slidingly passes through the guide closure part (14) and has an outer end section (12.5), characterized in that the cylinder (11) has a bottom-side joint head (20) which has a bottom-side joint head base body (21) and a bottom-side joint bearing (22), that the bottom-side joint head 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 body outer surface (24), that the bottom closure part (15) has a Bottom closure part mold section (15.1) which is designed as a monolithic section of the bottom closure part (15) and rises axially above an outer bottom closure part cover surface (15.2) and has a radius-accompanying web-shaped basic shape, that the bottom closure part shaped section (15.1) has a concave indentation which forms a bottom-side receiving section (15.3) which. a bottom-side radial inner surface (15.4) corresponding to the bottom-side radial annular body outer surface (24), and in that the bottom-side joint head base body (21) is welded to the bottom closure part (15) at a bottom-side radial annular body outer surface (25) by means of a bottom-side laser ring segment weld seam (26). Working cylinder according to claim 1, characterized in that a bottom-side pressure medium connection bore (15.5) is arranged at least in sections in the bottom closure part mold section (15.1). Working cylinder according to claim 2, characterized in that the bottom-side pressure medium connection bore (15.5) at least partially distally exceeds a transverse plane (15.7) spanned by a proximal apex (15.6) of the bottom-side receiving section (15.3) to a main longitudinal axis (17).Working cylinder according to one of the preceding claims, characterized in that the piston unit (12) has a rod-side joint head (30) which has a rod-side joint head base body (31) and a rod-side joint bearing (32), that the rod-side joint head base body (31) is designed as an annular body and has a rod-side concentric receiving bore (33) in which the rod-side joint bearing (32) is received, and a rod-side radial annular body outer surface (34), that the piston unit (12) has a rod-side shaped section (12.1) on the outer end section (12.5), which is designed as a monolithic section of the piston unit (12) and extends axially distally. a solid cross-sectional end (12.2) and has a radius-accompanying web-shaped basic shape, in that the rod-side shaped section (12.1) has a concave indentation which forms a rod-side receiving section (12.3) which has a rod-side radial inner surface (12.4) corresponding to the rod-side radial annular body outer surface (34), and in that the rod-side joint head base body (31) is welded at a rod-side radial annular body outer surface partial surface (35) to the piston unit (12) at the rod-side radial inner surface (12.4) by means of a base-side laser ring segment weld seam (36). Working cylinder according to one of the preceding claims, characterized in that the base-side joint head base body (21) and the rod-side joint head base body (31) are designed as structurally identical turned parts.Working cylinder according to one of the preceding claims, characterized in that the base-side laser segment weld seam (26) or the rod-side laser segment weld seam (36) is formed as a double-sided weld seam. Working cylinder comprising a cylinder (11) and a piston unit (12), wherein the cylinder (11) has a cylinder tube (13), a first closure part, and a second closure part, wherein the cylinder tube (13) has a first cylinder tube end (13.1) and a second cylinder tube end (13.2), wherein the first closure part is arranged at the first cylinder tube end (13.1) and the second closure part is arranged at the second cylinder tube end (13.2), and wherein the cylinder tube (13) and the closure parts (14, 15) form a cylinder interior (16). wherein the piston unit (12) forms at least one working chamber (16.1) in the cylinder interior (16), slidably passes through the first closure part and has an outer end section (12.5), characterized in that the piston unit (12) has a rod-side joint head (30) which has a rod-side joint head base body (31) and a rod-side spherical plain bearing (32), that the rod-side spherical plain bearing base body (31) is designed as an annular body and has a rod-side concentric receiving bore (33) in which the rod-side spherical plain bearing (32) is received, as well as a rod-side radial annular body outer surface (34), that the piston unit (12) has at the outer end section (12.5) a rod-side shaped section (12.1), which is designed as a monolithic section of the piston unit (12) and extends axially distally over a solid cross-sectional end (12.2) and has a radius-accompanying web-shaped basic shape, that the rod-side shaped section (12.1) has a concave indentation which forms a rod-side receiving section (12.3) which has a rod-side radial inner surface (12.4) corresponding to the rod-side radial annular body outer surface (34), and that the rod-side joint head base body (31) is welded on a rod-side radial annular body outer surface part (35) to the piston unit (12) on the rod-side radial inner surface (12.4) by means of a bottom-side laser ring segment weld seam (36).

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