EP2252806A1

EP2252806A1 - Piston sealing element and retardation device having piston sealing element

Info

Publication number: EP2252806A1
Application number: EP09715650A
Authority: EP
Inventors: Günther Zimmer; Martin Zimmer
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-02-25
Filing date: 2009-02-23
Publication date: 2010-11-24
Also published as: JP5574984B2; US20110024248A1; WO2009106049A1; DE102008010908A1; DE102008010908B4; JP2011513657A

Abstract

The invention relates to a piston sealing element (51) having at least one sleeve-shaped deformation region (53) that is delimited in the longitudinal direction of the piston sealing element by two surfaces (58, 59), wherein said deformation region (53) has a lateral surface (56) with at least one channel (65) that connects said two surfaces (58, 59), and to a retardation device having such a piston sealing element. For this purpose, the channel (65) at least in sections is disposed wound in a helical line shape. With the present invention a piston sealing element has been developed, which achieves an effect that is largely independent of the ambient temperature at an efficiency that is comparable to conventional piston sealing elements.

Description

Piston sealing element and delay device with

Piston seal element

Description:

The invention relates to a piston sealing element with at least one sleeve-shaped deformation region bounded by two surfaces in the longitudinal direction of the piston sealing element, this deformation region having a jacket surface with at least one channel connecting the two surfaces mentioned, and a retarding device having such a piston sealing element.

From DE 102 14 596 Al a piston sealing element is known. When used in a delay device results in a high deceleration rate. However, the effect of the piston sealing element is dependent on the ambient temperature.

The present invention is therefore based on the problem to develop a piston sealing element that achieves a largely independent of the ambient temperature effect at comparable efficiency.

This problem is solved with the features of the main claim. For this purpose, the channel is at least partially arranged helically wound. Further details of the invention will become apparent from the dependent claims and the description below) _L T asked embodiments.

Figure 1: acceleration and deceleration device in a parking position;

Figure 2: acceleration and deceleration device in a parking position facing away from the end position;

FFiiggurr 33 :: Detail of the Delay Device of FIG. 1;

FIG. 4: sealing element;

Figure longitudinal section of Figure 4;

FIG. 6: cross-section of FIG. 4;

Figure 7: Detail of a sealing element with integrated sealing lip.

Figures 1 and 2 show a combined deceleration and acceleration device (10) with a driving element (16) in a parking position (6), see. Figure 1 and in an end position (7), cf. FIG. 2.

The combined deceleration and acceleration device (10) shown here is part of a guide system, for example a drawer guide of a piece of furniture or a sliding door arrangement. In such a guidance system, the combined deceleration and acceleration device (10) is attached, for example, to the piece of furniture to which the drawer is relatively movable. An actuator (4) is then attached to the drawer. The latter contacts, for example, when closing the drawer in a partial stroke adjacent to the closed end position of the drawer, the entrainment element (16) of the deceleration and acceleration device (10). The actuating element (4) engages in the taker recess (19) and releases the entrainment element (16) from the force and / or positively secured parking position (6) and performs it in the Einfahrhubrichtung (5) along a guide device (14) in the end position (7). The lifting movement of the drawer is delayed relative to the piece of furniture by means of the delay device (21). For example, simultaneously with the release of the Mitnahmelernents (16) from the parking position (6), the accelerator device (91) is activated, which pulls the drawer against the action of the delay device (21) in the example closed end position. The delay and acceleration device (10) remains in this case, for example, until reaching the closed end position of the drawer in engagement with the actuating element (4) of the drawer. Of course, such a delay and acceleration device (10) can also be achieved when the drawer is opened for delaying and accelerating the drawer movement before reaching the open end position.

The deceleration and acceleration device (10) comprises a basic component (11) on which the deceleration device (21), the acceleration device (91), the guide device (14) and the carrier element (16) are arranged.

For example, the base member (11) has six through-holes (12) to connect the deceleration and acceleration device (10) by means of attachment means, e.g. to attach to the piece of furniture.

The example shown here pneumatic retarding device (21) comprises a cylinder-piston unit (22) with a cylinder (23) and a guided in this piston (43) with a piston rod (41). The piston and the piston rod can be made in one piece and a piston-piston rod form a unit. On the piston rod head (42) the entrainment element (16) is pivotally mounted. The pivot axis is in the representation of Figures 1 and 2 normal to the plane of the drawing.

FIG. 3 shows a detail of the delay device (21). The cylinder (23) has, for example, a cylinder interior (29) tapering from the cylinder head (24) to the closed cylinder bottom (25), whose maximum diameter is e.g. nine millimeters. The cylinder inner wall (27) bounding the cylinder interior (29) in the radial direction has e.g. a longitudinal groove (28) adjoining the cylinder bottom (25), the length of which is 55% of the length of the cylinder interior (29). The longitudinal groove (28), for example, has a constant width and its groove bottom is e.g. parallel to the central axis of the cylinder (23). The inner cross section of the cylinder (23) thus decreases, for example, in the direction of the cylinder bottom (25). The inner cross section can also be constant over the length of the cylinder interior (29) or increase in the direction of the cylinder bottom (25). The cylinder (23) can also have a rectangular, square, elliptical, polygonal, etc. inner cross section. The cylinder head (24) is sealed by a piston rod seal (26) on the piston rod (41).

The piston (43) comprises, for example, a piston head (44), in which the piston rod (41) is inserted and glued, and a piston head part (45), which is mounted on a cylindrical central pin of the piston head (44) and glued thereto , In the exemplary embodiment, a free space (46) is formed in the piston head part (45), into which, for example, when the two piston parts (44, 45) are glued, the air is displaced. On the piston (43) sit two piston sealing elements (51, 81). A first sleeve-shaped sealing element (51) is seated with a clamping region (54) in a form-fitting manner and, for example, firmly clamped between the two piston parts (44, 45). The second piston sealing element (81) is, for example, a shaft sealing ring (81) which sits on the side of the first piston sealing element (51) facing away from the clamping region (54) in an annular groove (47) of the piston head part (45). The shaft sealing ring (81) has an outer sealing lip (82) which points in the direction away from the piston rod (41) and bears against the cylinder inner wall (27) at least in the position shown in FIGS. 1 and 3.

FIGS. 4 to 6 show the first piston sealing element (51). Here, FIG. 4 shows a dimetric view, FIG. 5 shows a longitudinal section, and FIG. 6 shows a cross section of this sealing element (51).

The piston sealing element (51) shown here has a length of 8.5 millimeters and a maximum diameter of

8.65 millimeters. It has a cylindrical portion (56) adjacent to the clamping area (54) and an inner collar (55). The inner diameter in the clamping area (54) is four millimeters. The wall thickness of the cylindrical section (56) increases from the inner collar (55) to the clamping area (54). It is a minimum of half a millimeter.

The piston sealing element (51) is produced, for example, from nitrile butadiene rubber with a hardness of, for example, 70 Shore. It can have a halogenated surface. The material is largely incompressible. This means that the volume of the piston sealing element (51) remains largely unchanged during deformations of the material. The outer surface (61) of the piston sealing element (51) comprises a cylindrical surface (63) and a lateral surface (62). These two surfaces (63, 62) are connected by means of an end-side transition surface (58). The edge (64) between the shell surface (62) and the transition surface (58) is bevelled, for example. In one embodiment of the piston sealing element (51) without a cylindrical surface (63) - for example, with continuous lateral surface (62) - the end-side transition surface (58) is part of the end face (57) on the clamping region (54) of the piston sealing element (51). The lateral surface (62) is bounded on the inner collar (55) by the inner collar-side end face (59) of the piston sealing element (51). Also, this surface (59) may have a plurality of mutually offset portions.

The lateral surface (62) of the piston sealing element (51) comprises at least one, in the exemplary embodiment, for example, four helically wound channels (65). Between the channels (65) webs (69) are arranged. Each of the channels (65) connects the two, the lateral surface (62) delimiting surfaces (58, 59). The helical turns have a constant pitch in the embodiment and close with both boundary surfaces (58, 59) an angle of 45 degrees. This angle can be between 15 and 75 degrees, for example. A non-constant gradient of the helically curved lines is also conceivable. Likewise, the individual channel (65) may be helically wound at least in sections. In such an embodiment, for example, it can have sections which are formed parallel or transversely to the longitudinal direction of the piston sealing element (51). The two boundary surfaces (58, 59) may be areas of intersecting planes. The said angle is then trapped by the helically wound line of the channel with at least one of these surfaces (58; 59). The channels (65) have, for example, a constant circular segment-shaped cross-section whose radius is, for example, one millimeter. The single channel (65) is for example 0.25 millimeters deep and 1.25 millimeters wide at its upper edge. The width of the channel (65) is for example at least four times its depth. The minimum wall thickness of the piston sealing element (51) is at least one-and-a-half times the channel depth and at most three times the channel depth. In this embodiment, the cross-sectional area of a channel (65) corresponds at least approximately to twice a cross-sectional segment of the envelope surface of the piston sealing element (51), wherein the segment-limiting chord intersects the mutually opposite channel edges (66, 67). In this case, the envelope surface is the surface which connects the webs (69) of the lateral surface (62) and is ideally cylindrical in the exemplary embodiment.

The length of the channel bottom (68) in the transverse direction thus corresponds at least approximately to the length of the imaginary enveloping circular arc of the piston sealing element (51). The surface area of the lateral surface (62) encompassing the channels (65) and the surface area of the imaginary enveloping surface are at least approximately the same in the exemplary embodiment. In this context, "at least approximately" means that the values compared with each other can differ by +/- three percent. Thus, e.g. the surface area of the cross-sectional area of the channel (65) is between 197 percent and 203 percent of the area of a cross-sectional segment of the imaginary envelope surface of the piston sealing element (51).

In each cross-section, the piston sealing element (51) has a constant wall thickness. In the region of the channels (65), protrusions (72) are formed on the inside (71) of the piston sealing element (51). The two surfaces (58, 59) delimiting the lateral surface (62) in the longitudinal direction of the piston sealing element (51) delimit a deformation region (53) of the piston sealing element (51). In a clamping in the clamping area (54), the piston sealing element (51) is deformed substantially radially in this deformation region (53), axially and / or by torsion.

The piston sealing element (51) may comprise a sealing lip (82). FIG. 7 shows a detail of such a sealing element (51). On the inner collar-side end face (59), an obliquely outwardly projecting flexible sealing lip (82) is integrally formed on the base body (52) of the piston sealing element (51) by means of a film hinge (83). The diameter of the film hinge (83) is smaller than a circle defined by the channel bottoms (68). In such an embodiment of the first piston sealing element (51), the second piston sealing element (81) can be dispensed with.

In the representation of FIGS. 1 and 2, the acceleration device (91) is arranged below the delay device (21). This includes an energy store (92), e.g. a tension spring (92). The latter is held, for example, on the driving element (16) and on the basic component (11) in spring receptacles (17, 18).

After assembly of the deceleration and acceleration device (10) limit in this embodiment, the piston (43) and the cylinder bottom (25) a Verdrängungs- space (31). The piston (43) and the piston rod seal (26) define a compensation chamber (32). The stroke (8) of the piston (43) and the piston rod (41) is for example 45 millimeters. If the drawer is open, the deceleration and acceleration device (10), for example, out of engagement with the actuating element (4). The driving element (16) is locked and pivoted by 20 degrees in the parking position (6). The piston rod (41) is extended. The tension spring (92) is tensioned.

For example, when closing the drawer contacted before reaching the closed end position, the actuating element (4) the driving element (16). The actuating element (4) in this case bears against the contact shoulder of the driving element (16) oriented in the direction of the cylinder (23). The driving element (16) is pulled out of the parking position (6) and thereby pivoted parallel to the piston rod (41). The actuation element (4) latches with the entrainment element (16) and pushes it along the guide device (14) in the direction of the end position (7).

The piston rod (41) of the pneumatic retardation device (21) is retracted under the influence of the external force in the retracting stroke direction (5). The piston (43) is displaced from the cylinder head (24) in the direction of the cylinder bottom (25). In this case, the volume of the displacement chamber (31) is reduced. The gas pressure, e.g. the air pressure in the displacement (31) increases and acts as an internal force on the

Piston sealing element (51). According to the principle of self-help, the sealing ring (81) with the sealing lip (82) is pressed against the cylinder inner wall (27) immediately after the beginning of the retraction movement of the piston rod (41). The displacement chamber (31) and the compensation chamber (32) are virtually hermetically isolated from each other. At the same time a negative pressure builds up in the compensation chamber (32), which is insulated in the exemplary embodiment from the environment (1), which supports the sealing effect of the sealing ring (81). The pressure which builds up in the displacement space (31) also acts on the deformation area (53) of the piston sealing element (51). The latter is mounted twice on the inner collar (55) and on the clamping area (54). When pressurizing its large inner surface (71) by the overpressure in the displacement chamber (31) it bulges in the radial direction to the outside. The maximum deflection is, for example, in the middle region of the deformation range (53). The deformation area (53) bears in the radial direction on the inner wall (27) of the cylinder (23) when the piston (43) moves from the cylinder head end position of the displacement chamber (31). Upon further retraction of the piston rod (41) causes the on the cylinder inner wall (27) pressed KoI- bendichtelement (51), the brake sleeve (51), a high delay of the piston stroke. The movement of the drawer is greatly slowed down by means of this delay device (21).

In the deformation of the deformation region (53), the piston sealing element (51) is shortened in the axial direction and thus additionally reinforced the braking effect. In each case, the channels (65) wound along a helix lead to a deformation which is greater than that of a piston sealing element (51) with the same number of channels arranged parallel to the longitudinal direction. Due to the reduced spring stiffness, the described piston sealing element (51) responds faster and is therefore more efficient than a sealing element with channels arranged parallel to the longitudinal axis. The braking effect occurs suddenly. Optionally, the piston sealing element (51) can also be twisted thereby, whereby it undergoes an additional shear deformation. With a loose clamping of the clamping area (54), the entire piston sealing element (51) can rotate about its longitudinal axis (75). The geometric structure of the piston sealing element (51) enables reliable operation of the deceleration device (21) even at low temperatures. Thus, even in the temperature range of the glass transition point of the material of the piston sealing element (51) - in the case of nitrile butadiene rubber, for example, this can be ensured at 8 degrees Celsius - safe braking.

As soon as the piston sealing element (51) has passed the edge of the longitudinal groove (28), air is displaced from the displacement chamber (31) via this throttle channel (28) and along the channels (65) into the compensation chamber (32). The pressure in the displacement space (31) falls e.g. abruptly. The piston sealing element (51) may in this case still rest on the cylinder inner wall (27) or assume its initial position before the start of the lifting movement.

As the stroke of the piston rod (41) increases and, e.g. steadily increasing cylinder cross-section reduces the contact surface of the sealing lip (82) and the deformation region (53) on the cylinder inner wall (27). The normal force on the cylinder inner wall (27) caused by the gas pressure in the displacement chamber (31) decreases and thus the delay of the stroke movement caused by the friction.

As soon as the sealing lip (82) has completely detached from the inner wall (27), additional air flows from the displacement chamber (31) into the compensation chamber (32). The sealing ring (81) resumes its initial position before the start of the lifting movement. The brake sleeve (51) can in this case still rest against the cylinder inner wall (27), wherein the air flows through the channels (65) during the lifting movement. Upon further stroke of the piston rod (41), the brake collar (51) completely dissolves from the cylinder inner wall (27) and assumes its starting position. In this case, the helically wound channels (65), which are pulled in the piston stroke in the longitudinal direction of the cylinder inner wall (27), prevent sticking of the webs (69) to the cylinder inner wall (27). This ensures a safe release of the piston sealing element (51) from the cylinder inner wall (27), regardless of the temperature and / or the moisture content of the gas in the cylinder interior (29).

In the case of a piston sealing element (51) with integrated sealing lip (82), the piston sealing element (51) is released from the cylinder inner wall (27) analogously as described above.

During the lifting movement of the piston rod (41), the tension spring (92) relaxes. The acceleration device (91) causes an acceleration force applied to the carrier element (16) by discharging the energy store (92), the tension spring (92). At the beginning of the lifting movement, ie when leaving the parking position (6), the amount is in the

Einfahrhubrichtung (5) directed, caused by the spring (92) acceleration force less than the amount of the stroke movement opposite retarding force of the retarding device (91). The acceleration force of the tension spring (92) decreases, for example. linear along the stroke.

The drawer now moves slowly and with only a small speed and a slight delay to its end position. There she stays without rebound. The tension spring (92) now has a low residual stress.

If the drawer is pulled out again, air flows largely unhindered out of the compensation chamber (32) via the throttle channel (28) and the channels (65) into the displacement chamber (31). The Piston sealing elements (51, 81) remain at least approximately undeformed. The extension movement thus runs at least approximately free of resistance. At the same time, the energy store (92) is reloaded when the drawer is extended by pulling the spring ends apart.

Once the piston rod (41) is fully extended, the driving element (16) is back in the park position (6). The piston rod seal (26) hereby equals e.g. a misalignment of the piston rod (41), so that the cylinder (23) is closed at each piston position. In this position, the actuating element (4) detaches from the driving element (16). The deceleration and acceleration device (10) is disengaged.

The above-described embodiments can also be combined with each other. Also, the use of the piston sealing element (51) in a pure delay device (21) is conceivable.

List of reference numbers:

1 environment

4 actuator

5 retraction stroke direction

6 parking position

7 end position

8 stroke

10 deceleration and acceleration device

11 basic component

12 through holes

14 guide device

15 slot

16 Carrier element 17, 18 Spring retainers

19 Mitnehmerausnehmung

21 delay device

22 cylinder piston unit

23 cylinders

24 cylinder head 25 cylinder bottom

26 piston rod seal

27 cylinder inner wall

28 longitudinal groove, throttle channel

29 cylinder interior

31 displacement space

32 compensation room

41 piston rod 42 piston rod end

43 pistons

44 piston bottom

45 piston head part 46 free space

47 annular groove

51 sealing element, piston sealing element, brake collar

52 main body 53 deformation area, cuff

54 clamping area

55 inner waistband

56 cylindrical section

57 end face 58 surface, boundary surface, transition surface

59 surface, boundary surface, inner side end face

61 outer surface

62 lateral surface

63 cylindrical surface

64 edge

65 channels

66, 67 Kana Irander

68 channel grounds

69 footbridges

71 inside

72 surveys

75 longitudinal axis

81 piston seal

82 sealing lip

83 Filmescence O

91 acceleration device

92 energy storage, tension spring

Claims

claims:

1. Piston sealing element (51) with at least one sleeve-shaped, in the longitudinal direction of the piston sealing element (51) by two surfaces (58, 59) limited deformation region (53), said deformation region (53) has a lateral surface (62) with at least one, the Having two said surfaces (58, 59) connecting channel (65), characterized in that the channel (65) is at least partially arranged spirally wound helical.

Second piston sealing element (51) according to claim 1, characterized in that the channel (65) is formed helically wound along its entire length.

3. piston sealing element (51) according to claim 1, characterized in that the minimum wall thickness of the piston sealing element (51) corresponds to at least one and a half times and a maximum of three times the channel depth.

4. piston sealing element (51) according to claim 1, characterized in that the surface area of the lateral surface (62) of the piston sealing element (51) at least approximately corresponds to the area of its envelope surface.

5. piston sealing element (51) according to claim 1, characterized in that the lateral surface (62) at least four Ka O

has channels (65) whose helical lines have the same pitch.

6. piston sealing element (51) according to claim 1, characterized in that the width of the channels (65) corresponds to at least four times their depth.

7. piston sealing element (51) according to claim 1, characterized in that at least one of the channel (65) defining surfaces (58; 59) is arranged normal to the longitudinal axis (75) of the piston sealing element (51).

8. piston sealing element (51) according to claim 7, characterized in that the helices with this surface (58; 59) enclose an angle of 45 degrees.

9. piston sealing element (51) according to claim 1, characterized in that it comprises a sealing lip (82).

10. retarding device (21) with a cylinder-piston unit (22), wherein the piston (43) carries at least one piston sealing element (51) according to claim 1.