1. Technical Field
The present disclosure relates to driving mechanisms, and more particularly, to a clamping cylinder.
2. Description of Related Art
A cylinder may be used to clamp materials. Many cylinders may include a cylinder block defining a receiving chamber, a piston and a push rod received in the receiving chamber. The cylinder block may define two openings at opposite ends communicating with the receiving chamber. The piston may be movably received in the receiving chamber, a first end of the push rod may be fixed to the piston, and a second end of the push rod may extend out of the cylinder body via one opening. Airborne contaminants, such as dust particles, in a production facility may abrade and jam the piston and the push rod, and shorten the life of the cylinder. Moreover, the volume of the cylinder may be relatively large, and a significant amount of space may be needed to enable the cylinder to work.
Therefore, there is room for improvement in the art.
The components in the drawings are not necessarily drawn to scale, the emphasis instead placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Referring to
The mounting plate 10 is a substantially rectangular and defines a plurality of mounting holes (not shown) for mounting the cylinder block 20.
The cylinder block 20 includes a first cover 23, a second cover 25, and two sealing assemblies 27. The first cover 23 and the second cover 25 are together and located at a side of the main body 21. The two sealing assembles 27 are mounted on opposite ends of the main body 21 to seal the receiving chamber 212.
Also referring to
The first cover 23 and the second cover 25 are rectangular and function as one unit. The first cover 23 is located on the mounting recess 217 and seals the fixing hole 2173. The second cover 25 includes a position portion 251 located on an underside of the second cover 25 facing the fixing hole 2173. The second cover 25 defines a containing chamber 2511 at a second side opposite to a first side. The second cover 25 further defines a hole 2513 in the position portion 251 communicating with the containing chamber 2511. The position portion 251 is capable of engaging in the fixing hole 2173.
The two sealing assemblies 27 are mounted in the two openings 213. Each of the two sealing assembly 27 includes a sealing member 271, a blocking ring 273, an internal circlip 2175, and a buffering member 277. The sealing member 271 is fixed to the first joint portion 2131 in each of the two openings 213. The sealing member 271 is substantially a round disk. The sealing member 271 defines a sealing groove 2711 on a periphery, and includes a post 2713 in the middle of an end. The post 2713 and the periphery of the sealing member 271 cooperatively define an annular receiving space 2715. The blocking ring 273 is a ring sleeved on the sealing member 271 and engaged in the sealing groove 2711. The buffering member 277 is a split rubber ring which is press fit in the receiving space 2715.
The piston 30 is received in the receiving chamber 212 and is capable of sliding between the two openings 213 of the cylinder block 20. The piston 30 includes a base body 31, and two sealing rings 33. The base body 31 is substantially cylindrical in shape and includes a side surface 311, a first end surface 313, and a second end surface 315. The base body 31 further defines two annular grooves 316 on the side surface 311, adjacent to the first and second surfaces 313, 315; and a through groove 317 located between the two annular grooves 316. The through groove 317 has a shape of a thin oval. The base body 31 further includes a resisting surface 318 in the side surface 311 corresponding to the through hole 219. In the embodiment, the resisting surface 318 has an inclined surface, and distances between the resisting surface 318 and an inner surface of the peripheral walls 211 increase from the first end surface 313 toward the second end surface 315 of the piston 30. The two sealing rings 33 are mounted in the two annular grooves 316 to provide a hermetic seal for the piston 30.
The pushrod assembly 40 is slidably mounted in the through groove 317 of the piston 30. The pushrod assembly 40 includes a push block 41, a sleeve 43, a sliding rod 45, and a resilient member 47. The push block 41 is substantially a solid cuboid block and slidably engages in the through hole 219. The push block 41 includes an inclined surface 411 at one end matching a profile of the resisting surface 318 of the piston 30. The sleeve 43 extends through the through groove 317 and is cylindrical around a receiving hole 431. When the piston 30 slides along the receiving chamber 212, the sleeve 43 is always retained in the through groove 317. The sleeve 43 further defines an opening 433 and a bottom hole 435. The sleeve 43 includes a first resisting portion 4331 and a second resisting portion 4351. The opening 433 and the bottom hole 435 are located at opposite ends of the sleeve 43 and communicate with the receiving hole 431. The first resisting portion 4331 surrounds the opening 433, and the second resisting portion 4351 surrounds the bottom hole 435. The first resisting portion 4331 is an external flange with a diameter greater than a diameter of the sleeve 43. The second resisting portion 4351 is an internal flange with a diameter smaller than an interior diameter of the sleeve 43. The sliding rod 45 slidably extends through the bottom hole 435. The sliding rod 45 includes a head portion 451 received in the receiving hole 431 of the sleeve 43, and a rod portion 453 opposite to the head portion 451. The rod portion 453 is partially received in the receiving hole 431. One end of the rod portion 453 extends out of the sleeve 43 and is fixed to the inclined surface 411 of the push block 41. The resilient member 47 is sleeved on the rod portion 453 of the sliding rod 45 and positioned between the head portion 451 and the second resisting portion 4351.
In assembly, the piston 30 is received in the receiving chamber 212 to divide the receiving chamber 212 into two parts (not labeled), the resisting surface 318 facing the through hole 219. One blocking ring 273 is received into the sealing groove 2711 of one of the two sealing members 271. One buffering member 277 is sleeved on the post 2713 and pressed into the receiving space 2715. One sealing member 271 engages in one of the two openings 213 with the post 2713 facing the receiving chamber 212. The periphery of the blocking ring 273 resists the first joint portion 2131, the internal circlip 275 is compressed to be installed against the sealing member 271 and the second joint portion 2133, such that one of the two sealing assemblies 27 is assembled and held captive in the main body 21. Similarly, another one of the two sealing assemblies 27 is assembled to the main body 21 with another one of the two openings 213.
The second cover 25 is fixed to the mounting surface 2171 of the mounting recess 217 with the position potion 251 extending into the fixing hole 2173. The resilient member 47 is sleeved on the rod portion 453, and the sliding rod 45 extends into the receiving hole 431 of the sleeve 43. The sleeve 43 extends into the hole 2513 of the second cover 25, and into the through groove 317 of the piston 30. The first resisting portion 4331 is received in the containing chamber 2511 to prevent detachment of the sleeve 43 from the second cover 25. The head portion 451 of the sliding rod 45 is pressed towards the bottom hole 435. One end of the sliding rod 45 extends into the through groove 317. The push block 41 is slidably mounted in the through hole 219 with the inclined surface 411 facing the resisting surface 318 of the piston 30. The end of the sliding rod 45 furthest from the head portion 451 is fixed to the inclined surface 411. The head portion 451 is released, so that the resilient member 47 resists the head portion 451 and the second resisting portion 4351 to enable the sliding rod 45 to pull the push block 41 towards the piston 30. The first cover 23 is fixed to the second cover 25 to entirely seal the cylinder block 20. The assembly of the cylinder 100 is completed.
When in use, the two vents 215 communicate with two gas supplies (not shown) for supplying pressurized gas to the receiving chamber 212. When there is more air pressure upon the first end surface 313, the piston 30 is pushed toward one of the two openings 213. The resisting surface 318 moves along the receiving chamber 212. As the distance between the resisting surface 318 and the inner surface of the peripheral walls 211 decreases, the push block 41 is moved outwardly from the cylinder block 20 via the through hole 219. The push block 41 then has a clearance for clamping a workpiece. In reverse, when there is less air pressure upon the first surface 313, the piston 30 moves towards the first end surface 313 and the resilient member 47 pulls the push block 41 back. At the same time, the resilient member 47 is released and pulls the sliding rod 45 toward the second cover 25. The sliding rod 45 and the air pressure together pull the push block 41 inwards, such that the push block 41 moves inwards via the through hole 219 and thereby releases the workpiece.
Since the cylinder block 20 is entirely sealed and the push block 41 communicates with the outside only via the through hole 219, dust particles have very little opportunity of entering into the receiving chamber 212 of the cylinder block 20. Therefore, incidents of jamming problems caused by ingress of foreign matters and particles may decrease sharply. As the piston 30 moves between the two openings 213, and the push block 41 moves perpendicularly to the piston 30, the fitting and working space required for the cylinder 100 may be decreased. Moreover, since the piston 30 pushes on the push block 41 by means of the resisting surface 318 to resist the inclined surface 41, it may be almost impossible for the pushrod assembly 40 to be broken.
The distance between the resisting surface 318 and the inner surface of the peripheral walls 211 may be decreased from the first end surface 313 towards the second end surface 315. In other words, an angle of inclination from the surface 318 to the peripheral walls 211 may be decreased. In other embodiments, the resisting surface 318 may have other shapes, such as a curved surface with the distance between the curved surface and the inner surface of the peripheral walls 211 increasing from the first end surface 313 towards the second end surface 315. The two sealing assemblies 27 may be omitted if the cylinder block 20 is formed integrally, with both ends blind.
Finally, while various embodiments have been described and illustrated, the disclosure is not to be construed as being restricted thereto. Various modifications can be made to the embodiments by those skilled in the art without departing from the true spirit and scope of the disclosure as defined by the appended claims.
Number | Date | Country | Kind |
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201110185336.6 | Jul 2011 | CN | national |