DE202009014682U1 - End position damping device of a linear pressure electricity consumer - Google Patents

Abstract

End position damping device (8) for a linear pressure flow consumer, which, when approaching a piston (4) into an end position, a pressure medium from a damped in the direction of movement damping space only throttled over a gap (17) of a split piston ring (13) can flow, characterized that the end position damping device (8) consists of two spacer bushes (9; 11) with a collar (10; 12), between which a split piston ring (13) with a nearly T-shaped cross-section within a, between the collar (10; 12) of two spacer bushes (9; 11) formed annular gap, is received axially displaceable, and a between the two spacers (9; 11) arranged spacer ring (14).

Description

The The invention relates to a cushioning device of a linear Druckstromverbrauchers, in particular a pneumatic or hydraulic working cylinder.

to Achieving a damping of the movement of a piston of a linear pressure current consumer when approaching into one End position, it is known, a pressure medium from a direction of movement locked room to drain only throttled.

From the publication EP 0 949 422 B1 is a generic device for cushioning a fluid-operated device known.

The then used device for delaying the stroke of Piston within a damping region has a split Piston ring and in the stroke end positions of the cylinder interchangeable conical Damping sockets on.

Of the split piston ring widens by its residual stress behavior on and slides so well during the undamped Hubs on the inner surface of the cylinder tube. Of the largest gap of the piston ring is when retracting of the piston into the conical damping bushing.

at As movement progresses, the gap width decreases, causing the pressure medium enclosed by the piston in the conical damping bush the ever-decreasing gap, as discharge cross section, only throttled can flow away and so a progressive Damping of the piston movement takes place.

The Sliding the split piston ring on the inner surface the cylinder tube also during the piston movement outside of the damping area causes an additional Wear and the piston ring can when driving over be damaged by functional holes.

at Reversal of the direction of movement of the piston from an end position arise within the attenuation range considerable, the efficiency of the Working cylinder reducing back pressures, as the pressure medium initially only flow over the gap of the piston ring can.

The The object of the invention is a Endlagendämpfungsvorrichtung to develop for a linear pressure flow consumer, the efficiency does not affect negatively and no the lifetime reducing additional wear of Caused components thereof.

The Task is specified by the protection claim 1 Characteristics solved. Preferred developments emerge from the dependent claims.

A End-position damping device according to the invention a linear pressure electricity consumer consists essentially of two disc-shaped spacers with a collar between which a split piston ring with a nearly T-shaped Cross-section within one, between the collar of the two spacer bushings trained annular gap is axially displaceable, as well as a arranged between the two spacers spacer. Spacers and spacer ring can of course also be integrated with each other structurally in whole or in part.

The Height of the annular gap is determined by the thickness of the spacer ring certainly.

Of the Outer diameter of the spacers is smaller than the Outer diameter of the piston ring.

Of the between the spacers recorded split piston ring with nearly T-shaped cross section is in the manner of a piston ring designed with a double-sided bundartigem approach.

The collar-like projections of the split piston ring become guided radially on the collar of the spacer bushes, resulting in the diameter of the split piston ring due to its residual stress can not enlarge.

simultaneously becomes with the collar-like approaches the axial displacement the split piston ring in the annular gap on the inside of the collar of the Spacers guaranteed.

Of the Outer diameter of the recorded between the spacers split piston ring is slightly smaller than the Inner diameter of the cylinder tube, whereby this during the Lifting movement outside the damping section, where its gap width is greatest, not on the inner surface of the cylinder tube slides, but a gap between the inner surface of the cylinder tube and a sliding surface of the split piston ring is.

First in the damping section, with respect to the inner diameter of the cylinder tube of reduced diameter comes the sliding surface in contact with an inner wall of the linear pressure electricity consumer.

The split piston ring has on one side additional radial grooves and in the area of the radia len grooves on axial through holes.

The Installation position of the split piston ring between the spacer bushings is such that the radial grooves are on the side that oriented in the direction of the end stop.

Of the split piston ring shifts during movement of the piston rod axially in the annular gap between the spacers always opposite to their direction of movement.

The Axial through holes are when extending the piston rod in cooperation with the top of the collar one of the spacers locked.

With the entrance of the Endlagendämpfungsvorrichtung in the damping section of the linear Druckstromverbrauchers can that in the damping chamber caged pressure medium only over the gap of the piston ring flow out, whereby the damping is achieved.

With a conical damping section becomes a progressive Damping of the movement of the piston rod scored as the gap of the piston ring and thus the outflow cross section steadily reduced.

at Direction reversal of the movement of the piston rod from an end position within the damping range, when retracting, the split piston ring shifted in the opposite direction, the axial through holes are open.

The axial through holes act together with the top of the Bunds one of the spacers as a valve.

at Use of the end position damping device in a simple acting linear pressure flow consumers can thus the pressure medium on the Gap in the piston ring, the axial holes and radial grooves with only slight back pressure in the previous damping chamber stream.

Also for end-of-range damping in double-acting linear pressure consumers if the described end position damping device can be used, this then arranged mirror-inverted on both sides of the piston becomes.

The particular advantages of the described Endlagendämpfungsvorrichtung exist in addition to their simple and inexpensive construction especially in the increase of the overall efficiency of the linear Druckstromverbrauchers, the reduced wear of the same as well as the simple adjustment of the damping characteristic by means of a gap width of the piston ring to be selected.

The End position damping device is preferably between arranged a piston rod carrying the piston and the piston.

The Invention will be described as an embodiment with reference to

1 as a section of a single-acting linear Druckstromverbrauchers with a Endlagendämpfungsvorrichtung

2 as a partial section in the end position damping device with the position of the split piston ring in the damping region

3 as a partial section in the end stop damping device with the position of the split piston ring at reversal of movement, retracting piston rod in the region of the cylinder tube and

4 as a cross section through the single-acting linear Druckstromverbraucher in the region of the split piston ring within the cylinder tube
closer explanatory.

To 1 has a single-acting linear pressure flow consumer in the usual way at least one cylinder tube 1 , a guide part 2 for a piston rod 3 with a piston 4 and a main line 5 for a print medium.

The guide part 2 has a conical damping zone 6 on.

The piston 4 is as usual through a guide ring 7 guided with a gap.

The piston 4 is on the piston rod 3 a cushioning device 8th upstream.

Like from the 2 and 3 closer, there is the Endlagendämpfungsvorrichtung 8th from a first distance bush 9 with a first fret 10 , a second distance bush 11 with a second fret 12 , a split piston ring 13 with a T-shaped cross section and a spacer bush 14 ,

The split piston ring 13 is in one between the two ties 10 . 12 the spacers 9 . 11 by means of the spacer bush 14 trained annular gap axially displaceable, wherein the split piston ring 13 whose T-shaped cross-section is the unspecified combination of a known piston ring with a gap 17 to 4 as well as an upper and lower bun dartigen approach results, with the collar-like approaches of the insides of the league 10 . 12 to be led.

The split piston ring 13 can thus not increase its diameter, which would otherwise be due to its residual stress.

Within an undamped stroke in the cylinder tube 1 is therefore a piston ring gap 18 available.

In the split piston ring 13 are axial through holes 15 and one-sided radial grooves 16 brought in. Out 4 , which traces a section AA of the single-acting linear pressure-current consumer 1 in the area of the split piston ring 13 the Endlagendämpfungsvorrichtung 8th shows, is an exemplary arrangement of the axial through holes 15 and radial grooves 16 in the split piston ring 13 out.

In the split piston ring 13 are in the region of the actual piston ring, the axial through holes 15 ( 15.1 to 15.7 ) as well as the radial grooves 16 ( 16.1 to 16.7 ) are preferably introduced at an angle of 45 degrees to each other.

The axial through holes 15 ( 15.1 to 15.7 ) lie on a perimeter such that their openings in the area egg ner top of the second covenant 12 the second spacer 11 lie and are closed in conjunction with it, resulting in a valve effect.

When operating the single-acting linear Druckstromverbrauchers for extending the piston rod 3 to 1 the pressure medium flows over the main connection 5 and acts on the piston 4 over the piston surface 19 with pressure.

At the same time, the pressure medium flows through a gap in the guide ring 7 in a piston rod space 20 , so that the extending movement of the piston rod 3 by the pressure transmission between a piston ring surface 21 and the piston surface 19 is achieved.

The split piston ring 13 lies during the extending movement of the piston rod 3 at the second fret 12 the second spacer 11 on, whereby the axial through holes 15 ( 15.1 to 15.7 ) are closed like a valve.

Within the undamped stroke, the split piston ring 13 by means of its T-shaped cross section and the bundles 10 . 12 the spacers 9 . 11 kept radially constant.

Between a sliding surface 22 of the split piston ring 13 and an inner surface 23 of the cylinder tube 1 can the pressure medium through the piston ring gap 18 and the gap 17 of the split piston ring 13 with low back pressure from the piston rod space 20 flow out.

In the course of the extending movement of the piston rod 3 reaches the end position damping device 8th the conical damping zone 6 , wherein the sliding surface 22 of the split piston ring 13 with the surface of the conical damping zone 6 comes into contact.

At this time, the progressive damping sets by increasing reduction in the diameter of the split piston ring 13 and the associated reduction of the gap 17 , The thereby reducing Abströmquerschnitts for that in the conical damping zone 6 enclosed printing medium, a.

With reaching the end stop, with fully extended piston rod 3 , is the gap 17 of the split piston ring 13 severely narrowed or closed.

At reversal of movement, the retraction of the piston rod 3 , the split piston ring shifts 13 until the stop on the first fret 10 the first distance bush 9 ,

That in a piston chamber 24 located pressure medium flows initially over the now free axial through holes 15 ( 15.1 to 15.7 ) and the radial grooves 16 ( 16.1 to 16.7 ) into the conical damping zone 6 as part of the piston rod space 20 in this area. The above-described release of a highly narrowed or closed in this position gap 17 of the split piston ring 13 additional flow cross section over the axial through holes 15 ( 15.1 to 15.7 ) allows a faster inflow of the pressure medium in the damping zone 6 as the outflow of the pressure medium from the damping zone 6 , The otherwise occurring during the approach from the end position efficiency-reducing back pressures are avoided.

As the retraction of the piston rod progresses 3 then takes place the further outflow of the pressure medium from the piston chamber 24 additionally over the gap 17 and the piston ring gap 18 in the piston rod space 20 ,

1

cylinder tube

2

guide part

3

piston rod

4

piston

5

main Line

6

conical damping zone

7

guide ring

8th

Endlagendämpfungsvorrichtung

9

first Distanzbuchse

10

first Federation

11

second Distanzbuchse

12

second Federation

13

split piston ring

14

spacer

15

axial through holes ( 15.1 to 15.7 )

16

radial grooves ( 16.1 to 16.7 )

17

gap

18

Piston ring gap

19

piston area

20

Piston rod space

21

Piston Ring

22

sliding surface

23

palm

24

piston chamber

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• EP 0949422 B1 [0003]

Claims (9)

End position damping device ( 8th ) for a linear pressure flow consumer, the approach of a piston ( 4 ) in an end position, a pressure medium from a damped in the direction of movement damping chamber only throttled over a gap ( 17 ) of a split piston ring ( 13 ), characterized in that the end-position damping device ( 8th ) from two spacer bushings ( 9 ; 11 ) with a bunch ( 10 ; 12 ), between which a split piston ring ( 13 ) with a nearly T-shaped cross section within one, between the collar ( 10 ; 12 ) of the two spacer bushings ( 9 ; 11 ) formed annular gap, is received axially displaceable, and one between the two spacers ( 9 ; 11 ) arranged spacer ring ( 14 ), having. End position damping device ( 8th ) for a linear pressure flow consumer according to claim 1, characterized in that the split piston ring ( 13 ) axial through holes ( 15.1 to 15.7 ) and one-sided radial grooves ( 16.1 to 16.7 ) having. End position damping device ( 8th ) for a linear pressure flow consumer according to claim 2, characterized in that the radial grooves ( 16.1 to 16.7 ) of the split piston ring ( 13 ) in its installed position in the direction of the conical damping zone ( 6 ) are oriented. End position damping device ( 8th ) for a linear pressure flow consumer according to claim 2, characterized in that the axial through-holes ( 15.1 to 15.7 ) are arranged on a circumference such that their openings in the region of a top side of a second collar ( 12 ) of the second spacer ( 11 ) and in cooperation with each other there is a valve action. End position damping device ( 8th ) for a linear pressure flow consumer according to one of the preceding claims, characterized in that during retraction of the piston rod ( 3 ) the axial through holes 15.1 to 15.7 ) of the split piston ring ( 13 ) are open. End position damping device ( 8th ) for a linear pressure electricity consumer according to one of the preceding claims, characterized in that the outer diameter of the between the collar ( 10 ; 12 ) of the two spacer bushings ( 9 ; 11 ) received split piston ring ( 13 ) smaller than the inner diameter of a cylinder tube ( 1 ). End position damping device ( 8th ) for a linear pressure flow consumer according to one of the preceding claims, characterized in that the outer diameter of the spacer bushes ( 9 ; 11 ) smaller than the outer diameter of the split piston ring ( 13 ). End position damping device ( 8th ) for a linear pressure flow consumer according to one of the preceding claims, characterized in that the split piston ring ( 13 ) upon movement of the piston rod ( 3 ) in the annular gap between the spacers ( 9 ; 11 ) counter to the direction of movement of the piston rod ( 3 ) is axially displaced. End position damping device ( 8th ) for a linear pressure flow consumer according to one of the preceding claims, characterized in that the Endlagendämpfungsvorrichtung ( 8th ) on the piston rod ( 3 ) the piston ( 4 ) is arranged upstream.