WORKING CYLINDER AND METHOD FOR THE PRODUCTION THEREOF

Abstract

A working cylinder has a cylinder tube has closure parts arranged at tube ends. The cylinder tube and the closure parts define a cylinder interior. The cylinder has a coupling section that has one of the closure parts, a cylinder tube end and a hollow adapter body. The closure part has an external thread and the adapter body has an internal thread that define a common threaded section constructed to releasably couple the closure part and the adapter body. The cylinder tube end is connected to the adapter body on a cylinder tube side thereof by a ring weld seam. The weld seam defines a sealing plane sealed with respect to a pressure media. The piston unit defines at least one working chamber inside the cylinder.

Claims

1-10. (canceled)

11. A working cylinder, comprising: a cylinder having a cylinder tube, a closure part and a further closure part, said cylinder tube having a cylinder tube end and a further cylinder tube end, said closure part is arranged at said cylinder tube end and said further closure part is arranged at said further cylinder tube end, said cylinder tube and said closure parts defining a cylinder interior, said cylinder having a coupling section including said closure part, said cylinder tube end and a hollow cylindrical adapter body, said closure part having an external thread and said adapter body having an internal thread corresponding to said external thread and defining a common threaded section constructed to releasably couple said closure part and said adapter body, said cylinder tube end being positively connected to said adapter body at an adapter body end on a cylinder tube side thereof by a circumferential ring weld seam and said ring weld seam defining a sealing plane being sealed tight with respect to a pressure media in the cylinder; a piston unit defining at least one working chamber in said cylinder interior.

12. The working cylinder according to claim 11, wherein said closure parts each have a respective laterally arranged pressure medium connection.

13. The working cylinder according to claim 11, wherein said ring weld seam is a laser weld seam.

14. The working cylinder according to claim 11, wherein said ring weld seam has a ring weld seam depth which has a ratio of 1.1 to 2.5 with respect to a cylinder tube wall thickness.

15. The working cylinder according to claim 11, wherein said ring weld seam has a ring weld seam center axis which has a ring weld seam inclination angle of 20 to 70 degrees with respect to a main longitudinal axis of said cylinder tube.

16. The working cylinder according to claim 11, wherein an adapter body wall thickness is greater than a cylinder tube wall thickness and said adapter body has an overlapping section which radially overlaps said cylinder tube at said cylinder tube end.

17. The working cylinder according to claim 11, wherein said adapter body end on a closure part side thereof has a tapered wall section, said tapered wall section has an axial ring surface and said closure part has an axial ring counter-surface, said axial ring surface and said axial ring counter-surface are in positive pressure contact with each other in a coupling state and define a circumferential pressure contact surface, and said pressure contact surface defines a sealing plane, a surface pressure in the area of said pressure contact surface results in a deformation within an elasticity limit of said adapter body and of said closure part both without and with pressurization of a pressure medium.

18. The working cylinder according to claim 11, wherein said further closure part at said further cylinder tube end defines a further coupling section which includes a further hollow cylindrical adapter body, said further closure part has a further external thread and said further adapter body has a further internal thread corresponding to said further external thread and defining a common threaded section constructed to releasably couple said further closure part and said further adapter body, said further cylinder tube end has an appositive substance connection to said further adapter body at a further adapter body end on a further cylinder tube side provided by a further circumferential ring weld seam and said further ring weld seam defines a further sealing plane sealed tight with respect to the pressure media.

19. A method of producing a working cylinder according to claim 11, comprising the following process steps: a) screwing the adapter body onto the closure part; b) applying a torque to the adapter body and providing a pre-assembly consisting of the closure part and the adapter body; c) positioning the cylinder tube with the cylinder tube end at the adapter body end on the cylinder tube side; and d) producing the circumferential ring weld seam.

20. The method of producing a working cylinder according to claim 19, comprising: after the process step c), a process step c1) of aligning the cylinder tube in an angular position around the main longitudinal axis relative to the pre-assembly.

Description

[0074] FIG. 1 Sectional view of a working cylinder with two coupling sections

[0075] FIG. 2 Enlarged detail of the working cylinder

[0076] FIG. 3 Enlarged detail of the coupling section with wall taper

[0077] FIG. 4 Enlarged detail of a coupling section with overlapping section and inclined ring weld seam.

[0078] It is noted that the same reference numerals in the various figures always refer to the same features or components. The reference numerals are also used in the description if they are not shown in the respective figure.

[0079] FIG. 1 shows an exemplary embodiment of a working cylinder according to the invention in a sectional view. The exemplary embodiment is a differential working cylinder. In this exemplary embodiment, the working cylinder additionally has a further coupling section 7b.

[0080] The working cylinder is composed of the cylinder 1 and the piston unit 2. The cylinder tube 3 has the opposed cylinder tube ends 5a and 5b. Together with the closing parts 4a and 4b, the interior 6 is formed. In addition, the 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 part 4a, which is provided in the form of a base closure part here. The piston unit 2 is in the retracted position so that the working chamber 6.1 is closed. The maximally opened piston rod chamber (without reference numeral), which is delimited by the further closure part 4b as a guide closure part, is located opposite as a further working chamber. Hydraulic fluid is supplied to the working chamber 6.1 via the pressure medium connection 12a and to the piston rod chamber via the further pressure medium connection 12b.

[0081] The coupling section 7a comprises the closure part 4a, the adapter body 8a and the cylinder tube end 5a.

[0082] The closure part 4a has an external thread 9a and the adapter body 8a has an internal thread 10b. The threads 9a and 10a are designed to correspond to each other and to engage with each other. The adapter body 8a is releasably coupled to the closure part 4a by screwing by means of the threads 9a, 10a. The cylinder tube 3 is connected with its cylinder tube end 5a to the adapter body 8a by the ring weld seam 11b.

[0083] The structure and function of the further coupling section 7b with the further closure part 4b, the further adapter body 8b, the further threads 9b and 10b as well as the further ring weld seam 11b at the further cylinder tube end 5b correspond to the coupling section 7a. Therefore, the description sections for the coupling section 7a also apply to the further coupling section 7b in a corresponding manner. In the exemplary embodiment, the working cylinder can be demounted at both ends due to the two coupling sections 7a and 7b.

[0084] FIG. 2 shows the area of the coupling section 7a as a detail in an enlarged section. The coupling area between the adapter body 8a and the closure part is shown in further detail in FIG. 3 so that FIG. 2 and FIG. 3 are explained together.

[0085] In the embodiment according to FIGS. 2 and 3, the adapter body 8a has a tapered wall section 8a.4. This section has the axial ring surface 8a.5 in the direction of the closure part 4a and, opposite in the direction of the adapter body 8a, the closure part 4a has the axial ring counter-surface 4a.1. Both ring surfaces 8a.5 and 4a.1 together form the pressure contact surface 13. This surface is subject to an axial force effectuated by the screw connection of the external thread 9a and the internal thread 10a, which causes an elastic deformation of the adapter body 8a and the closure part 4a in the area around the pressure contact surface 13.

[0086] FIG. 4. shows the area of the coupling section 7a in the area of the ring weld seam 11a as a detail in an enlarged section. 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.

[0087] In addition, the ring weld seam 11a is inclined and its ring weld seam centre axis 15 encloses a ring weld seam inclination angle ? with respect to the main longitudinal axis 14 of the working cylinder, which is 30 degrees in the exemplary embodiment. Due to the overlap, the adapter body 8a, which also has a greater material thickness than the cylinder tube 3 in this case, additionally supports the coupling by means of the ring weld seam 11a and, in particular, reliably absorbs buckling forces when the pressure medium is pressurized during the operation of the working cylinder.

LIST OF REFERENCE NUMERALS

[0088] 1 cylinder [0089] 2 piston unit [0090] 3 piston rod [0091] 4a closure part [0092] 4.a.1 axial ring counter-surface [0093] 4b further closure part [0094] 5a cylinder tube end [0095] 5b further cylinder tube end [0096] 6 cylinder interior [0097] 6.1 working chamber [0098] 7a coupling section [0099] 7b further coupling section [0100] 8a adapter body [0101] 8a.1 adapter body end on the cylinder tube side [0102] 8a.2 overlapping section [0103] 8a.3 adapter body end on the closure part side [0104] 8a.4 tapered wall section [0105] 8a.5 axial ring surface [0106] 8b further adapter body [0107] 8b.1 further adapter body end on the cylinder tube side [0108] 9a external thread [0109] 9b further external thread [0110] 10a internal thread [0111] 10b further internal thread [0112] 11a ring weld seam [0113] 11b further ring weld seam [0114] 12a pressure medium connection [0115] 12b further pressure medium connection [0116] 13 pressure contact surface [0117] 14 main longitudinal axis [0118] 15 centre axis of ring weld seam [0119] ? ring weld seam inclination angle alpha