Pneumatic cylinder with a self-adjusting end position damping arrangement, and method for self-adjusting end position damping

• US 20080289920A1
• Filed: 05/21/2008
• Published: 11/27/2008
• Est. Priority Date: 05/24/2007
• Status: Active Grant

• Current Assignee: Parker Origa Holding AG (Parker-Hannifin Corporation)
• Original Assignee: Hoerbiger-Origa Holding AG (Parker-Hannifin Corporation)
• Inventors: Bruder, Christian
• Granted Patent: US 8,596,431 B2
• Time in Patent Office: Days
• US Class Current: 188/297
• CPC Class Codes: F15B 15/223 having a piston with a piston extension or piston recess which completely seals the main fluid outlet as the piston approaches its end position

Abstract

A self-adjusting end position damping arrangement includes a stroke space 9 which is delimited by a movable stroke element 7, 24 and a part of the pneumatic cylinder 1, with the stroke space 9 being connected via a connecting duct 14 to the working pressure P₁ which acts on the cylinder piston 22 or to the ventilation pressure (P₃) in the outlet duct 3 and the stroke element 7, 24 being acted on via a damping duct 16 by the damping pressure P₂ in the damping volume 19, a non-return valve 12 is arranged in the connecting duct 14 upstream of the stroke space 9, which non-return valve 12 blocks in the direction of the working pressure P₁ or the ventilation pressure (P₃), respectively, and a ventilation duct 5 is provided, which ventilation duct 5 can be opened by means of the movable stroke element 7, 24 and which is connected to an outlet duct 3.

Claims

1. Pneumatic cylinder with a self-adjusting end position damping arrangement, having a cylinder housing (15) in which is arranged a movable cylinder piston (22), which is acted on at one side by a working pressure (P₁), and in which a damping volume (19) which is delimited from the non-pressurized side of the cylinder piston (22) is formed in the region of the end position of the cylinder piston (22) as a result of the movement of the cylinder piston (22), wherein the end position damping arrangement comprises a stroke space (9) which is delimited by a movable stroke element (7, 24) and a part of the pneumatic cylinder (1), with the stroke space (9) being connected via a connecting duct (14) to the working pressure (P₁) which acts on the cylinder piston (22) or to the ventilation pressure (P₃) in an outlet duct (3) and the stroke element (7, 24) being acted on via a damping duct (16) by the damping pressure (P₂) in the damping volume (19), including a non-return valve (12) in the connecting duct (14) upstream of the stroke space (9), which non-return valve (12) blocks in the direction of the working pressure (P1) or ventilation pressure (P₃), respectively, and including a ventilation duct (5) which can be opened by means of the movable stroke element (7, 24) and which is connected to the outlet duct (3).

2. The pneumatic cylinder according to claim 1, including a damping pin (18) which extends in an axial direction into the cylinder housing (15) in the region of the end stop of the cylinder piston (22), and the cylinder piston (22) is formed with a recess (23) which can receive the damping pin (18).

3. The pneumatic cylinder according to claim 1, wherein the outlet duct (3) is positioned laterally on the cylinder housing (15) and axially spaced apart from a cylinder cover (4).

4. The pneumatic cylinder according to claim 3, wherein the stroke element is formed as a damping piston (7) which is mounted in a guided fashion in the stroke space (9).

5. The pneumatic cylinder according to claim 4, wherein the stroke space (9) is in a cylinder cover (4) which closes off the pneumatic cylinder (1).

6. The pneumatic cylinder according to claim 4, wherein the stroke space (9) is in the piston (22).

7. The pneumatic cylinder according to claim 2, including an elastic sealing element (24) as a stroke element between the damping pin (18) and cylinder piston (22), with the sealing element (24) being hollow and being arranged in the cylinder piston (22).

8. The pneumatic cylinder according to claim 1, including a ventilation opening (17) on the pneumatic cylinder (1), which ventilation cross section (17) is connected to the damping volume (19).

9. The pneumatic cylinder according to claim 1, including a self-adjusting end position damping arrangement at both end positions of the cylinder piston (22).

10. Method for self-adjusting end position damping of a cylinder position (22), which moves in a cylinder housing (15), of a pneumatic cylinder (1), which cylinder piston (22) is acted on at one side by a working pressure (P₁), and with a damping volume (19), which is delimited from the non-pressurized side of the cylinder piston (22), being formed in the region of the end position of the cylinder piston (22) as a result of the movement of the cylinder piston (22), comprising the steps of generating a damping pressure (P₂) in the damping volume (19) as a result of the movement of the cylinder piston (22), which damping pressure (P₂) acts on a stroke element (7, 24), moving the stroke element (7, 24) by the damping pressure (P₂) counter to a pressure medium volume which is closed off in a stroke space (9) and which is acted on with the working pressure (p₁) or the ventilation pressure (P₃), and opening a ventilation duct (5) as a result of the movement of the stroke element (7, 24).