DE10312004A1 - Pneumatic cylinder with damping means on the end cover - Google Patents

Abstract

Pneumatic cylinder comprising a cylinder housing (1) with end covers (2a; 2b), a piston (3) slidably accommodated within the cylinder housing (1), at least one piston sealing ring (13a; 13b), arranged radially on the piston (3) to form at least one Pressure chamber (6a; 6b), at least one connection (5a; 5b) for ventilation of the pressure chamber (6a; 6b) divided by the piston (3), respective air outlets (7a; 7b) for establishing a connection to the pressure chamber (6a; 6b), each of which an outer connection (5a; 5b) is assigned, and which are arranged at an axial damping distance (X) with respect to the end of the cylinder housing (1), damping means for damping stopping the piston (3) by retaining the Air flowing out of the pressure chamber (6a; 6b) is provided, the damping means comprising at least one damping nozzle (8a; 8b) integrated in an end cover channel (9a; 9b), which is arranged in the end cover (2a; 2b), around which the pressure air flowing out of the chamber (6a; 6b) only through the damping nozzle (8a; 8b) when the piston sealing ring (13a; 13b) has passed the air outlet (7a; 7b) shortly before reaching the end position on the ventilation side of the piston (3), the end cover channel (9a; 9b) passing the pressure chamber (6a; 6b ) with the assigned outer connection (5a; 5b).

Description

The The present invention relates to pneumatic cylinders comprising a cylinder housing with end caps, one slidably housed inside the cylinder housing Piston, at least one piston sealing ring, arranged outside the radial on the piston to form at least one pressure chamber, at least one connection for ventilation the pressure chamber divided by the piston, respective air outlets for Establishing a connection to the pressure chamber, each of which has an external connection is assigned, and in an axial damping distance with respect to End of the cylinder housing are arranged, with damping means to the subdued Stop the piston by restraining it the flowing out of the pressure chamber Air are provided.

The US 5,307,729 discloses a pneumatic cylinder with such damping means. An adjusting screw is arranged in the area of the end cover of the pneumatic cylinder in order to enable a corresponding setting of throttling means for regulating the damping and the piston speed from outside the pneumatic cylinder. Each end cover is equipped with a damping sleeve, which serves as the main inlet or outlet and extends into the pressure chamber. The piston of the pneumatic cylinder is provided with a corresponding corresponding recess which has a sealing ring for interacting with the damping sleeve. When the piston reaches the area of its end position, the outflowing air only escapes through a remaining damping bypass channel and continues to pass the throttling means, which can be adjusted using the adjusting screw, and then leaves the pneumatic cylinder via the outer connection in the end cover. The bypass duct is arranged at a radial distance from the central inlet and outlet duct. The outer port also serves as an inlet port when the piston is to move to the opposite side. Since the adjusting screw of the damping means is completely integrated within the end cover together with the outer connection, the well-known pneumatic cylinder is quite long.

The GB 2 347 176 shows a short pneumatic cylinder, the damping means are completely integrated within the wall area of the cylinder housing. The damping means comprise outflow openings and a check valve. In order to move the internal piston, compressed air enters the pressure chamber through the bypass channel, the check valve and a first hole. When the piston continues to move, the piston ring exposes a second bore to allow unimpeded flow of compressed air from said port to the pressure chamber.

As soon as the piston has a damping distance of that reaches the stop position, covers and blocks the piston ring one of two outlet bores to the compressed air flowing out via a check valve with throttling means and to force a bypass duct to the external connection. Thus, this obstructed outflow causes a delay in the Piston movement. In fact, this structure allows a short construction Cylinder design; nevertheless, the damping means require a right here thick-walled cylinder housing for accommodation.

The DE 101 45 811 A1 discloses another pneumatic cylinder of the type of interest here. Here too, the damping means are completely integrated into the wall area of the cylinder housing. A total of three openings to each pressure chamber are required to supply compressed air and dampen the piston movement. The middle opening is equipped with an adjusting screw, which is screwed into the wall area of the cylinder housing in order to adjust the damping speed. Thus, a rather thick-walled cylinder housing is also required here to accommodate the damping means. Furthermore, the adjusting screw, viewed in the axial direction of the cylinder housing, requires a considerable amount of space, since this is inevitably to be arranged between the end cover and the outer connection. With this solution, the realization of a short damping length is only possible to a limited extent. The damping length would be too great, in particular for a so-called compact cylinder.

It is therefore the object of the present invention a pneumatic cylinder to create its damping agent a short and thin-walled Cylinder design enables.

The The task is based on a pneumatic cylinder according to the generic term of claim 1 in conjunction with its characterizing features solved. The following dependent Expectations give advantageous developments of the invention.

The damping means according to the invention comprise at least one end cover channel formed in the end cover of the pneumatic cylinder with an integrated damping nozzle in order to force the compressed air flowing out of the pressure chamber only through the damping nozzle when the piston sealing ring shortly before reaching the end position of the piston has passed the air outlet, the end cover channel connecting the pressure chamber to the associated outer connection.

in the Within the scope of the present invention, it is also conceivable that the end cover channel itself includes the function of the damping nozzle. In this Case can be a separate damping nozzle as a component omitted. The pneumatic cylinder according to the present invention comes within without a long damping nozzle the pressure chamber, what the space required for this saves the pressure chamber, so that the overall length of the cylinder housing is small is what, in turn, favorable conditions to miniaturize the pneumatic cylinder. Furthermore is because of the integration of most of the damping agent components a thin-walled one in the end cover Cylinder design possible.

According to one advantageous development of the invention is provided additional Elastomer damping ring to be attached to the inside of the end cover of the cylinder housing. The elastomer damping ring serves to absorb hard end-of-stroke impacts and is particularly suitable for pneumatic cylinders with a high piston speed is an advantage.

According to one preferred embodiment any external connection of the pneumatic cylinder with an external throttle check valve Adjustment of the speed of the piston movement connected. Around the throttle check valve outside of the cylinder housing can provide this speed control means within a common separate housing be arranged, the housing either is attached directly to the pneumatic cylinder, or to an outside of the pneumatic cylinder installation location, with a corresponding Connection must be provided by means of a pressure medium line.

Around to avoid contamination of the damping nozzle, is according to one advantageous development of the invention proposed a filter element between the damping nozzle and the To place the pressure chamber. The filter element can consist of one porous Ceramic material or metal material exist, the filter element preferably interchangeably mounted within the end cover channel is.

According to one Another development of the invention is a check valve on the inside of the End cover attached, which connects the outer connector of the pneumatic cylinder to the pressure chamber produces a high initial acceleration of the piston when the pressure chamber is pressurized with compressed air to achieve through the use of parallel feed channels. Preferably is this check valve After formed on a lip seal, the corresponding on the end cover is appropriate.

According to one Another development of the invention, the damping nozzle can also be directly in said Lip sealing ring can be integrated to make a passage through the Lip seal to form. In this case, a separate end cover channel can pass through the end cover is omitted.

Further measures improving the invention are described below together with the description of preferred embodiments the invention with reference to the figures.

It shows:

1 a side view with a detail A, a first embodiment of a pneumatic cylinder with damping means in a position before the start of damping (during the stroke), and

2 a side view with detail A of a second embodiment of a pneumatic cylinder with damping means in a position before the start of damping (during the stroke).

A pneumatic cylinder according to 1 has a cylinder housing 1 whose two open ends are through end covers 2a and 2 B are closed, a piston 3 , which can be acted upon alternately and sealed against the cylinder housing 1 is slidably housed therein, and a piston rod 4 that on the piston 3 is attached.

In both end areas of the cylinder housing 1 are two external connections 5a and 5b provided for the application and ventilation of compressed air, which is in an axial damping distance X on the cylinder housing 1 are arranged. These outer connections 5a and 5b communicate with a pair of pressure chambers 6a and 6b that are on both sides of the piston 3 are trained via air outlets 7a and 7b , The piston 3 is mutually inside the cylinder housing 1 through ventilation and ventilation from or to the pressure chamber 6a respectively. 6b via the outer connections 5a . 5b and the associated air outlets 7a . 7a acted upon. The outer connections 5a . 5b stand with an external throttle check valve 14a respectively. 14b to regulate the speed of the piston movement in connection when the pressure chamber 6a or 6b is pressurized with compressed air.

There are also damping means for damped stopping of the piston 3 by going back keep the air to be vented from the corresponding pressure chamber 6a respectively. 6b intended. The damping means comprise - in the following only one side of the pneumatic cylinder - a damping nozzle 8b (see detail A) which is at right angles from an end cover duct 9b outgoing section is used herein. An additional filter element 12b is between the damping nozzle 8b and the pressure chamber 6b placed to contaminate the damping nozzle 8b to avoid.

The retained air inside the pressure chamber 6a of the pneumatic cylinder described above only passes through the damping nozzle 8a if the piston seal 13a the air outlet 7a on the ventilation side shortly before the piston reaches the end position 3 has passed, the end cover channel 9a the pressure chamber 6a with the outer connector 5a combines. The end of the piston stroke is through an elastomer sealing ring 11a defined that on the inside 10 of the end cover 2a is attached. The elastomer sealing ring 11a absorbs hard shocks from the piston 3 ,

There is also a lip seal 16a and 16b on the other side of the end cover 2a respectively. 2 B provided to the piston 3 during the initial application of compressed air to the pressure chamber 6a or 6b via a parallel channel 15a or 15b to act in addition. The said lip seal 16a respectively. 16b thus has the function of a check valve.

The 2 shows a direct integration of the damping nozzle according to the second embodiment 8a . 8b in the respective lip sealing ring 16a ' . 16b ' , which causes passages through the lip seal 16a and 16b (here detail A). Both lip seals 16a . 16b serve to form a check valve function for the initial acceleration of the piston 3 , as explained above.

There the structure and function of the pneumatic cylinder according to the second embodiment otherwise essentially identical to the first embodiment is with regard to the further detailed description of the above Detailed description of the first embodiment.

The damping means according to the present Enable invention a short cylinder housing, with a damping sleeve inside the Pressure chamber attached either to the piston or to the end cover is ultimately eliminated. Still a thin walled one Cylinder design possible.

The The present invention is not limited to having pneumatic cylinders a piston rod - as above described - but is also suitable for rodless cylinders.

1

cylinder housing

2

End covers

3

piston

4

piston rod

5

outer connection

6

pressure chamber

7

air outlet

8th

damping

9

Enddeckelkanal

10

Inner surface

11

Elastomer damping ring

12

filter element

13

Piston sealing ring

14

Speed Controller

15

parallel channel

16

Lip seal ring

Claims (8)

Pneumatic cylinder, comprising a cylinder housing ( 1 ) with end caps ( 2a ; 2 B ) sliding inside the cylinder housing ( 1 ) housed pistons ( 3 ), at least one piston seal ( 13a ; 13b ), arranged radially on the piston ( 3 ) to form at least one pressure chamber ( 6a ; 6b ), at least one connection ( 5a ; 5b ) for ventilation of the piston ( 3 ) divided pressure chamber ( 6a ; 6b ), respective air outlets ( 7a ; 7b ) to establish a connection to the pressure chamber ( 6a ; 6b ), each with an external connection ( 5a ; 5b ) and which is at an axial damping distance (X) with respect to the end of the cylinder housing ( 1 ) are arranged, damping means for damping stopping the piston ( 3 ) by retaining the pressure chamber ( 6a ; 6b ) outflowing air are provided, characterized in that the damping means at least one in an end cover channel ( 9a ; 9b ) integrated damping nozzle ( 8a ; 8b ) which are in the end cover ( 2a ; 2 B ) is arranged around the pressure chamber ( 6a ; 6b ) Air flowing out only through the damping nozzle ( 8a ; 8b ) if the piston sealing ring ( 13a ; 13b ) the air outlet ( 7a ; 7b ) shortly before reaching the end position on the vent side of the piston ( 3 ) has passed, the end cover channel ( 9a ; 9b ) the pressure chamber ( 6a ; 6b ) with the assigned external connection ( 5a ; 5b ) connects. Pneumatic cylinder according to claim 1, characterized in that an additional elastomer damping ring ( 11a ; 11b ) on the inner surface ( 10 ) of the end cover ( 2a ; 2 B ) of the cylinder housing ( 1 ) is arranged to absorb hard end stops ren. Pneumatic cylinder according to claim 1, characterized in that each connection ( 5a ; 5b ) with an external throttle check valve ( 14a ; 14b ) is connected to the setting of the piston speed. Pneumatic cylinder according to claim 1, characterized in that a filter element ( 12a ; 12b ) between the damping nozzle ( 8a ; 8b ) and the pressure chamber ( 6a ; 6b ) is placed to prevent contamination of the damping nozzle ( 8a ; 8b ) to prevent. Pneumatic cylinder according to claim 1 or 4, characterized in that the damping nozzle ( 8a ; 8b ) and / or the filter element ( 12a ; 12b ) interchangeable within the end cover channel ( 9a ; 9b ) is or are positioned. Pneumatic cylinder according to one of the preceding claims, characterized in that a check valve on the inside of the end cover ( 2a ; 2 B ) is arranged to accelerate the piston ( 3 ) with ventilation of the pressure chamber ( 6a ; 6b ) via a parallel channel ( 15a ; 15b ) to achieve. Pneumatic cylinder according to claim 6, characterized in that the check valve in the manner of a lip sealing ring ( 16a ; 16b ) is formed, which on the associated end cover ( 2a ; 2 B ) is attached. Pneumatic cylinder according to one of the preceding claims, characterized in that at least one damping nozzle ( 8a ; 8b ) directly in the lip seal ring ( 16a '; 16b ' ) is integrated around a through hole through the lip sealing ring ( 16a '; 16b ' ) to build ( 2 ).