Actuating cylinder and manufacturing method thereof

Abstract

The invention relates to an actuating cylinder and a method for its manufacture, the actuating cylinder comprising a cylinder 1 and a piston unit 2, the cylinder 1 comprising a cylinder tube 3, a closure part 4a and a further closure part 4b, the cylinder tube 3 comprising a cylinder tube end 5a and a further cylinder tube end 5b, the closure part 4a being located at the cylinder tube end 5a and the further closure part 4b being located at the further cylinder tube end 5b, the cylinder comprising a connection section 7a with the closure part 4a, the cylinder tube end 5a and a hollow cylindrical adapter body 8a, the closure part 4a having an external thread 9a and the adapter body 8a having an internal thread 10a corresponding to the external thread 9a, the external thread 9a and the internal thread 10a forming a common thread section designed for releasably connecting the closure part 4a and the adapter body 8a, the cylinder tube end 5a being integrally connected to the adapter body 8a at the adapter body end 8a.1 of the cylinder tube by a circumferential annular weld seam 11a, the annular weld seam 11a forming a sealing surface which is tight against the pressure medium.

Description

[Technical Field]

[0001] The present invention relates to an actuation cylinder, in particular a hydraulic actuation cylinder, and to a method for manufacturing the same. [Background technology]

[0002] Actuating cylinders are known from the prior art. Generally, an actuating cylinder comprises a cylinder tube and a closure part.

[0003] According to the prior art, such actuating cylinders are usually manufactured by screwing a closure part into the cylinder tube, and therefore these actuating cylinders are also called screw-type or screw-in cylinders in the prior art.

[0004] For example, it is known from the prior art to connect the base closure part to the cylinder tube by MAG welding and then simply screw the guide closure part into place.

[0005] The threads on the cylinder tube and closure piece are usually produced by a shape-cutting operation.

[0006] Cylinders with both threads and cylinders with only one closure part threaded and the other MAG welded are available in the prior art and have proven to be high quality and reliable products.

[0007] However, a disadvantage from a manufacturing point of view is that the thread necessarily weakens the cylinder tube, so the material thickness, i.e., the wall thickness of the tube, must be increased to insert the thread subtractively. However, this results in a wall thickness that is too large to absorb the forces during operation, especially those generated by the working pressure of the fluid. This disadvantageously increases the material consumption and the final weight of the actuating cylinder. Furthermore, machining a relatively long cylinder tube is complicated from a manufacturing point of view. Furthermore, in the case of a desired special angular position between the closure part and the cylinder tube, it is difficult from a manufacturing point of view to match the thread of the closure part and the cylinder tube to each other so that a suitable tightening torque is applied when screwed together. Summary of the Invention [Problem to be solved by the invention]

[0008] It is an object of the present invention to provide an actuation cylinder that can be manufactured and removed in a reliable and cost-effective manner, and to disclose a method for manufacturing such an actuation cylinder. [Means for solving the problem]

[0009] The problem with respect to the actuating cylinder is solved by the features recited in claim 1, and with respect to the method for manufacturing such an actuating cylinder, by the features recited in claim 9. Preferred further developments result from the respective dependent claims.

[0010] The actuating cylinder according to the invention comprises as basic elements a cylinder and a piston unit and is characterized in particular by a special connecting section.

[0011] The cylinder of the working cylinder according to the invention comprises a cylinder tube, a closure part and a further closure part.

[0012] As is known per se, a cylinder tube has a cylinder tube end and a further cylinder tube end, thus having two opposing cylinder tube ends. A closure element is provided on the cylinder tube end, and a further closure element is provided on the further cylinder tube end. Hereinafter, the cylinder tube end and the further cylinder tube end will be collectively referred to as cylinder tube ends, and the closure element and the further closure element will be collectively referred to as closure elements. The cylinder tube and the closure element provided thereon form the cylinder interior.

[0013] The piston unit forms at least one working chamber inside the cylinder. The piston unit is preferably designed as an assembly of a piston and a piston rod, the piston rod slidingly passing through one of the closure elements, which in turn becomes the guide closure element. However, the piston unit can also be provided, for example, as a plunger piston or as a piston unit of a cylinder with a continuous piston rod and therefore two equally large effective surfaces for extension and retraction.

[0014] The actuation cylinder according to the invention is also characterized by a specially designed coupling section.

[0015] According to the invention, the coupling section comprises a closure part, a cylinder tube end, and a hollow cylindrical adapter body.

[0016] The closure part has external threads and the adapter body has internal threads that are designed to correspond to one another and engage one another in the intended final assembled state, where they form a common thread section designed to releasably couple the closure part and the adapter body.

[0017] Furthermore, the connection section is characterized in that the end of the cylinder tube is directly connected to the adapter body at one end of the adapter body on the cylinder tube side by a circumferential ring weld seam, which forms a flat surface that is tight against the pressure medium.

[0018] Thus, in the final assembled state, the adapter body actually forms a longitudinal continuation of the cylinder tube, and although the inner and outer diameters of the adapter body and the cylinder tube are the same, the inner and / or outer diameters may differ from one another.

[0019] The actuating cylinder according to the invention has, in particular, the advantages explained below.

[0020] Compared to cylindrical tubes, adapter bushings can be machined much more economically due to their smaller axial dimensions. This is especially true when cutting internal threads. The length of the adapter body can usually be significantly smaller than its diameter. The adapter body is preferably made of tubing material that is available as so-called prefabricated rod goods. In particular, the cutting to length process, clamping process, and handling can be performed much faster than with relatively long cylindrical tubes. Furthermore, machining machines with significantly smaller machining spaces can be used, which are correspondingly less costly, and the smaller design also requires less installation space.

[0021] A further advantage is that the angular position of the closure part can be freely and precisely adjusted. In contrast to screw-type actuating cylinders, the adjustment of the angular position is independent of the tightening torque when screwing in. This means that the angular position can be freely selected. Furthermore, contrary to the screw-type actuating cylinder, elastic torsional deformation of the cylinder tube is not possible and does not have to be taken into account, so the angular position can be adjusted particularly easily and precisely.

[0022] At the same time, a special advantage is that the adapter bushings can be installed with an optimized tightening torque. Since the angular position of the adapter bushing relative to the closure part does not have to be taken into account, the screw connection can be made exactly with the desired tightening torque. This fact allows cost-effective metal seals to be used.

[0023] Furthermore, the assembly has the advantage that any element protecting the adapter body from unscrewing can be installed even before the cylinder tube is attached, which offers both advantages in handling due to the relatively small dimensions of the pre-assembly made up of the closure part and the adapter body, and the advantage that any associated contamination of the inside of the cylinder is avoided.

[0024] Furthermore, there is the advantage that the wall thickness of the adapter body is independent of the wall thickness of the cylinder tube. In particular, the wall thickness of the cylinder tube can be selected to be smaller, since, contrary to prior art screw-type actuation cylinders, the cylinder tube is not weakened by the threads in its wall cross section. Conversely, the wall thickness of the adapter body can be selected to be greater than the wall thickness of the cylinder tube in order to ensure that the loads in the thread area can be absorbed.

[0025] Furthermore, compared to prior art welded actuation cylinders, it is advantageous that the material pairing for welding is not necessarily determined by the material of the closure part, but rather the material pairing for the cylinder tube material can be optimized by selecting a suitable material for the adapter body.

[0026] Similarly, it is advantageous to optimize the material of the adapter body since it is not fixed by the material of the cylinder tube. Rather, a more suitable material can be selected for machining.

[0027] As an advantage, the relatively expensive material of the cylinder tube is saved since its length is reduced by the length of the adapter body.

[0028] A further important advantage is the fact that the actuation cylinder according to the invention, in contrast to welded actuation cylinders, remains removable and can therefore be maintained and repaired. In this manner, it is also advantageous that after reassembly, substantially the same tightening torque can again provide the angular position of the closure parts relative to one another, since the angular position between the adapter body and the cylinder tube is maintained by the permanent welded connection.

[0029] The actuation cylinder according to the invention therefore combines the advantages of a threaded connection with the advantages of a laser welded connection, in other words it combines the advantages of a welded actuation cylinder with the advantages of a threaded actuation cylinder.

[0030] According to a first advantageous further development, the closing parts of the actuating cylinders each have a laterally arranged pressure medium connection.

[0031] This advantageous further development is based on the fact that many applications require an actuating cylinder that should have pressure fluid connections for both working chambers arranged laterally in the closure part, and that a specific angular position for the application around the main longitudinal axis is required for both pressure fluid connections. The angular position may be required, for example, at 0 degrees, i.e., in one line, or at 180 degrees, i.e., on both sides. However, all other possible angular positions may also be required.

[0032] In this aspect, the actuating cylinder according to the invention offers an advantageous solution, since after mounting the adapter body, the cylinder tube with the further closure part is aligned freely rotatably about its main longitudinal axis and can be welded to the adapter body in this angular position.

[0033] According to another further development, the ring weld seam is formed as a laser weld seam.

[0034] According to this further development, only a low energy input per unit length is provided to the weld joint: for example, in comparison with MAG welding, which is common in the prior art, this only slightly heats the pre-assembly consisting of the closure part and the adapter body, so that already installed seals or guides are not damaged.

[0035] According to ongoing further developments, the ring weld seam has a ring weld seam depth with a ratio of 1.1 to 2.5 to the wall thickness of the cylinder tube.

[0036] According to this further development, the ring weld seam is inclined relative to a cross section perpendicular to the main longitudinal axis. This allows the depth of the ring weld seam to exceed the wall thickness of the cylinder tube, and is 1.1 to 2.5 times the wall thickness of the cylinder tube, depending on the angle of inclination. This is particularly advantageous for providing a larger connection surface and therefore a stronger positive material connection between the adapter body and the cylinder tube.

[0037] According to another further development, the ring weld seam has a ring weld seam central axis with a ring weld seam inclination angle α of 20 to 70 degrees relative to the main longitudinal axis of the cylinder tube.

[0038] The central axis of the V-shaped ring weld seam is inclined relative to the transverse plane, with the ring weld seam inclination angle α being between 20 and 70 degrees. This range of inclination has been found to achieve a further increase in strength, since the components of the multiaxial loads on the weld seam due to tensile and buckling stresses are advantageously distributed by the inclination, and, on the other hand, to provide an adequately low energy input per unit length in order to avoid undesirable excessive heating during welding.

[0039] According to another further development, the wall thickness of the adapter body is greater than the wall thickness of the cylinder tube. Furthermore, the adapter body has an overlap section that radially overlaps the cylinder tube at the end of the cylinder tube.

[0040] An overlap section in the sense of this further development is understood to be a geometrical shape of the adapter body and the cylinder tube in which, viewed in the eccentric direction, a section of the adapter body is arranged radially above the cylinder tube. For example, the overlap can be designed so that a section of the adapter body lies above the cylinder tube like a circumferential ring. It is also possible for the adapter body and the cylinder tube to each have inclined flanks, with the flanks of the adapter body being radially above the flanks of the cylinder tube.

[0041] In either case, according to this further development, the elastic expansion of the cylinder tube caused by the pressure of the pressure medium, hereinafter referred to as bulging, is limited by the overlap. Therefore, the connection between the adapter body and the cylinder tube advantageously accommodates a positive force transmission component, and thus an undulation of the ring weld seam, in addition to a positive material connection.

[0042] According to another advantageous further development, the adapter body end facing the closure element has a tapered wall section. The tapered wall section has an axial ring surface, and the closure element has an axial ring counter surface, which, in the coupled state, are in positive pressure contact with each other and form a circumferential pressure contact surface. The pressure contact surface forms a sealing surface. The sealing surface prevents the escape of pressure medium from the working chamber at the joint between the adapter body and the closure element. The positive pressure contact is achieved by the generation of an axial force when the adapter body and the closure element are screwed together.

[0043] According to this further development, the surface pressure in the region of the pressure contact surface leads to deformation of the adapter body and the closure part within their elastic limits, whether or not pressure medium is applied.

[0044] The pressure contact between the ring surface and the ring counter surface results in a surface pressure at the contact surface. This surface pressure then causes a deformation of the adapter body, in particular its tapered wall section, as well as the closure element. According to this further development, the achieved deformation is within the elastic limit, regardless of whether a pressure medium is applied or not. The elastic limit depends on the materials of the adapter body and the closure element. If the adapter body and the closure element are made of different materials, the correspondingly different elastic limits must be taken into account.

[0045] In the case of high applied pressure, a significant axial force acts inside the closure part. This causes a small axial change in the position of the closure part relative to the adapter body. When no pressure is applied, a small axial change in position occurs in the opposite direction. The axial change in position affects the degree of deformation of the joint in the area adjacent to the pressure contact surfaces. Therefore, deformation is less at high pressure than at low pressure. At the same time, when high pressure is applied, the surface pressure is smaller than in the low pressure situation.

[0046] The deformations that occur are limited only to the elastic range in all pressure states according to the invention, so that they are fully reversible when the operating conditions are changed by applying and halting pressure. According to the invention, the effective surface pressure of the pressure contact and the pressure contact surfaces forms a sealing surface, and therefore a satisfactory seal between the adapter body and the closure part, is ensured under all operating conditions.

[0047] In this context, the term pressurization covers the entire range of values ​​from the minimum pressure of the pressure medium to the maximum permissible pressure, even at the maximum pressure, sufficient axial force remains on the sealing contact surfaces to maintain the function of the actuating cylinder.

[0048] The axial ring surface and the axial ring opposing surface preferably lie in a plane substantially perpendicular to the longitudinal axis.

[0049] It is particularly advantageous here that thanks to the actuation cylinder designed according to the invention, firstly, it is possible to choose a particularly suitable material pair for the adapter body and the closure part with a suitable elastic modulus, deviating from the material of the cylinder tube, and secondly, the deformation of the tapered wall section and the corresponding closure part section can be set exactly to the desired extent by means of a tightening torque that is independent of the angular position within the elastic limits.

[0050] According to another advantageous further development, the actuation cylinder has a further coupling section, which comprises a further closure part, a further cylinder tube end, and a further hollow cylindrical adapter body and is designed similarly to the described coupling section. In particular, the further closure part has a further external thread and the further adapter body has a further internal thread corresponding to the further external thread, so that the further external thread and the further internal thread form a further common thread section designed to releasably couple the further closure part and the further adapter body end. Furthermore, the further end of the cylinder tube is connected to the further adapter body at the further end of the adapter body on the cylinder tube side by a further circumferential ring weld seam, which forms a further sealing surface that is tight against the pressure medium.

[0051] The contents of the description of the coupling section also apply to the further coupling section in a complementary manner.

[0052] According to this further development, the actuating cylinder has a special coupling according to the invention for both closure parts, which is advantageous in particular cases when a releasability of the coupling is provided for both closure parts or when special components such as position sensors are arranged on the cylinder tube, in which defined angular positions are set both on the first closure part, referred to herein as the closure part, and on the second closure part, referred to herein as the further closure part.

[0053] According to a further aspect, the present invention relates to a method for manufacturing an actuation cylinder according to the invention.

[0054] The method according to the invention comprises the following process steps: a) screwing the adapter body onto the closure; b) applying a torque to the adapter body to provide a pre-assembly comprising a closure element and the adapter body; c) positioning the cylinder tube so that the end of the cylinder tube is positioned at the end of the adapter body on the cylinder tube side; d) creating a circumferential ring weld seam.

[0055] The process steps are described in more detail below.

[0056] a) Screwing the adapter body onto the closure In process step a), the external thread of the closure element and the internal thread of the adapter body are engaged with each other. Then, they are screwed together to form a common thread section. Screwing continues until the end of the adapter body facing the closure element abuts on the closure element.

[0057] b) applying a torque to the adapter body to provide a pre-assembly consisting of the closure and the adapter body end; In process step b), the screwing action continues by applying a torque that can be defined by the user, where in particular the desired elastic deformation of the pressure contact area of ​​the closure part and the adapter body can be set.

[0058] This results in process step b) of a pre-assembly comprising the closure part and the adapter body.

[0059] Optionally, immediately after process step b) or also after a subsequent process step, a protection element against unscrewing can be provided, which prevents loosening of the threaded connection between the adapter body and the closure part.

[0060] c) Position the cylinder tube so that the end of the cylinder tube is positioned at the end of the adapter body on the cylinder tube side. In step c), the cylinder tube is placed in the desired relative position with respect to the adapter body, which preferably has a length such that the closure part projects axially, so that the cylinder tube can be pressed and centred over this axial projection.

[0061] d) To create a circumferential ring weld seam In process step d), a circumferential ring weld seam is created. Preferably, this is a laser weld seam. During welding, the cylinder tube and the pre-assembly are held in a fixed relative position. As a result of process step d), a connection section is completed. In a special further development, the working cylinder is closed after process step d), unless a connection section according to the invention is also created as a further connection section at the end of the cylinder opposite the further closure part. Further process steps, such as painting, can then be carried out.

[0062] According to an advantageous further development of the method, the method comprises a process step c1) after process step c).

[0063] c1) Angular positioning of the cylinder tube about its main longitudinal axis relative to the pre-assembly In process step c1), the cylinder tube is adjusted to a rotational degree of freedom about the central main longitudinal axis of the actuating cylinder in addition to other degrees of freedom, thereby adjusting the angular position of the cylinder tube relative to the closure part. This is based on the fact that a further closure part is usually already connected to the cylinder tube by welding, so that the angular positions of the closure parts relative to each other can be determined simultaneously.

[0064] The invention will now be explained in more detail by way of example with reference to the following figures. [Brief explanation of the drawings]

[0065] [Figure 1] FIG. 1 is a cross-sectional view of an actuation cylinder having two coupling sections. [Figure 2] FIG. [Figure 3] FIG. 10 is an enlarged detail of the coupling section with tapered walls. [Figure 4] FIG. 10 is an enlarged detail view of a joining section with overlap section and angled ring weld seam. DETAILED DESCRIPTION OF THE INVENTION

[0066] It should be noted that the same reference numbers in the various figures always refer to the same features or components, and that these reference numbers are also used in the description even if they are not shown in the respective figures.

[0067] 1 shows an exemplary embodiment of an actuation cylinder according to the invention in a cross-sectional view. The exemplary embodiment is a differential actuation cylinder. In this exemplary embodiment, the actuation cylinder further comprises a further coupling section 7b.

[0068] The working cylinder includes a cylinder 1 and a piston unit 2. A cylinder tube 3 has opposing cylinder tube ends 5a and 5b. Together with the closure elements 4a and 4b, an interior 6 is formed. At least one working chamber 6.1, here the main working chamber, is formed between the piston of the piston unit 2 and the closure element 4a, here in the form of a base closure element. When the piston unit 2 is in the retracted position, the working chamber 6.1 is closed. A fully open piston rod chamber (not numbered) is separated by a further closure element 4b as a guide closure element and is located on the opposite side as a further working chamber. Hydraulic fluid is supplied to the working chamber 6.1 via a pressure medium connection 12a and to the piston rod chamber via a further pressure medium connection 12b.

[0069] The coupling section 7a comprises a closure part 4a, an adapter body 8a and a cylinder tube end 5a.

[0070] The closure part 4a has an external thread 9a, and the adapter body 8a has an internal thread 10b. The threads 9a and 10a correspond to and are designed to engage with each other. The adapter body 8a is releasably coupled to the closure part 4a by screwing it in via the threads 9a and 10a. The cylinder tube 3 is connected at its cylinder tube end 5a to the adapter body 8a by a ring weld seam 11b.

[0071] The structure and function of the further connecting section 7b with the further closure part 4b at the further cylinder tube end 5b, the further adapter body 8b, the further threads 9b and 10b and the further ring weld seam 11b correspond to the connecting section 7a. The statements made for the connecting section 7a therefore also apply correspondingly to the further connecting section 7b. In the exemplary embodiment, the actuating cylinder can be removed at both ends by means of the two connecting sections 7a and 7b.

[0072] Figure 2 shows in enlarged cross section the area of ​​the coupling section 7a in detail. The coupling area between the adapter body 8a and the closure part is shown in more detail in Figure 3, and therefore Figures 2 and 3 will be discussed together.

[0073] 2 and 3, the adapter body 8a has a tapered wall section 8a.4. This section has an axial ring surface 8a.5 in the direction of the closure part 4a, and on the opposite side in the direction of the adapter body 8a, the closure part 4a has an axial ring counter-surface 4a.1. Both ring surfaces 8a.5 and 4a.1 together form a pressure contact surface 13. This surface is subjected to axial forces generated by the threaded connection of the male and female threads 9a and 10a, which cause elastic deformation of the adapter body 8a and the closure part 4a in the area around the pressure contact surface 13.

[0074] 4 shows in detail in an enlarged cross section the region of the joining section 7a in the region of the ring weld seam 11a. In this exemplary embodiment, the adapter body 8a overlaps the cylinder tube 3 at its cylinder tube end 5a by means of an overlap section 8a.2.

[0075] Furthermore, the ring weld seam 11a is inclined, with its ring weld seam central axis 15 enclosing a ring weld seam inclination angle α relative to the main longitudinal axis 14 of the actuating cylinder, which angle is 30 degrees in the exemplary embodiment. Due to the overlap, the adapter body 8a again has a greater material thickness than the cylinder tube 3, but the ring weld seam 11a provides additional support to the connection and in particular reliably absorbs buckling forces when pressure medium is pressurized during operation of the actuating cylinder. [Explanation of symbols]

[0076] 1 cylinder 2 piston units 3 Piston Rod 4a Closure parts 4a.1 Axial ring facing surface 4b Further Closures 5a Cylinder tube end 5b Further cylinder tube end 6 Inside the cylinder 6.1 Workroom 7a Joint Section 7b Further Joint Section 8a Adapter body 8a.1 Adapter body end on the cylinder tube side 8a.2 Overlapping Sections 8a.3 Closure-side adapter body end 8a.4 Tapered wall section 8a.5 Axial Ring Surface 8b Additional adapter bodies 8b.1 Further adapter body end on the cylinder tube side 9a male thread 9b Further male threads 10a female thread 10b Additional female thread 11a ring welded seam 11b Further ring weld seams 12a Pressure medium connection 12b Further pressure medium connections 13 Pressure contact surface 14 Main longitudinal axis 15 Central axis of ring weld seam α Ring welding seam inclination angle α

Claims

1. An actuating cylinder comprising a cylinder (1) and a piston unit (2), The cylinder (1) comprises a cylinder tube (3), a closure part (4a) and a further closure part (4b), the cylinder tube (3) has a cylinder tube end (5a) and a further cylinder tube end (5b), the closure part (4a) is arranged at the cylinder tube end (5a) and the further closure part (4b) is arranged at the further cylinder tube end (5b), The cylinder tube (3) and the closure parts (4a, 4b) form a cylinder interior (6), The piston unit (2) defines at least one working chamber (6.1) inside the cylinder (6), the cylinder has a connection section (7a) comprising the closure part (4a), the cylinder tube end (5a) and a hollow cylindrical adapter body (8a); the closure part (4a) has an external thread (9a) and the adapter body (8a) has an internal thread (10a) corresponding to the external thread (9a), the external thread (9a) and the internal thread (10a) forming a common thread section designed to releasably couple the closure part (4a) and the adapter body (8a); 1. An actuating cylinder, wherein the cylinder tube end (5a) is directly connected to the adapter body (8a) at the cylinder tube-side adapter body end (8a.1) by a circumferential ring weld seam (11a), the ring weld seam (11a) forming a tight sealing surface against pressure medium.

2. 2. An actuating cylinder according to claim 1, characterized in that the closure parts (4a, 4b) each have a laterally arranged pressure medium connection (12a, 12b).

3. 3. The actuating cylinder according to claim 1 or 2, characterized in that the ring weld seam (11a) is made as a laser weld seam.

4. 4. The actuating cylinder according to claim 1, wherein the ring weld seam (11a) has a ring weld seam depth with a ratio of 1.1 to 2.5 to the wall thickness of the cylinder tube.

5. 5. The actuating cylinder according to claim 1, wherein the ring weld seam (11a) has a ring weld seam central axis with a ring weld seam inclination angle α of 20 to 70 degrees relative to the main longitudinal axis of the cylinder tube.

6. 6. The actuation cylinder according to claim 1, wherein the wall thickness of the adapter body is greater than the wall thickness of the cylinder tube, and the adapter body (8a) has an overlap section (8a.2) which radially overlaps the cylinder tube (3) at the cylinder tube end (5a).

7. the adapter body end (8a.3) facing the closure part has a tapered wall section (8a.4), the tapered wall section (8a.4) has an axial ring surface (8a.5), the closure part has an axial ring counter surface (4a.1); the axial ring surface (8a.5) and the axial ring counter surface (4a.1) are in positive pressure contact with each other in a mated state to form a circumferential pressure contact surface (13), the pressure contact surface (13) forming a sealing surface; 7. An actuating cylinder according to claim 1, characterized in that as a result of the surface pressure in the region of the pressure contact surface (13), there is a deformation of the adapter body and the closing part, with or without pressure medium pressurization within the elastic limits.

8. a further connecting section (7b) comprising said further closure part (4b), said further cylinder tube end (5b) and a further hollow cylindrical adapter body (8b), the further closure part (4b) has a further external thread (9b) and the further adapter body (8b) has a further internal thread (10b) corresponding to the further external thread (9b), the further external thread (9b) and the further internal thread (10b) forming a further common thread section designed to releasably couple the further closure part (4b) and the further adapter body (8b), 8. The actuation cylinder according to claim 1, wherein the further cylinder tube end (5b) has a positive material connection to the further adapter body (8b) at the cylinder tube-side further adapter body end (8b.1) by means of a further circumferential ring weld seam (11b), which forms a further sealing surface that is tight against the pressure medium.

9. A method for manufacturing an actuation cylinder, comprising: The actuating cylinder according to any one of claims 1 to 8 is formed by the following process steps: a) screwing said adapter body (8a) onto said closure part (4a); b) applying a torque to said adapter body (8a) to provide a pre-assembly consisting of said closure part (4a) and said adapter body (8a); c) positioning the cylinder tube (3) with the cylinder tube end (5a) positioned at the cylinder tube side of the adapter body end (8a.1); d) creating said circumferential ring weld seam (11a); A method for manufacturing an actuating cylinder, comprising:

10. After the process step c), the following process step c1):

10. A method for manufacturing an actuation cylinder according to claim 9, comprising: c1) angularly positioning said cylinder tube (3) relative to said pre-assembly about its main longitudinal axis.

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