TENSIONING DEVICE HAVING A TRANSPORT SECURING CONCEPT

Abstract

A tensioning device (1) for tensioning a traction mechanism of a traction mechanism drive, including a housing (2), a piston (3) that is mounted such that the piston can be displaced in an axial direction inside the housing (2), and a transport securing element (4), which in at least one transport position of the tensioning device (1) is arranged in the housing (2) transversely to the piston (3) and in abutment with the piston (3) such that a displacement of the piston (3) in at least one first axial direction is blocked. The transport securing element (4) is provided with a support portion (5), wherein in the transport position at least one first web area (6) of the support portion (5) is in abutment with one end face (7) of the piston (3), and an additional web area (8) of the support portion (5) extending in an axial direction away from the first web area (6) is supported in the housing (2), at least in a radial direction.

Claims

1-10. (canceled)

11. A tensioning device for tensioning a traction mechanism of a traction mechanism drive, the tensioning device comprising: a housing; a piston displaceably supported in the axial direction within this housing; and a transport securing element, the transport securing element, in at least one transport position of the tensioning device, being situated transversely to the piston and in abutment with the piston in the housing in such a way that a displacement of the piston in at least one first axial direction is blocked, the transport securing element including a supporting section, a first web area of the supporting section being in abutment with an end face of the piston in the transport position, and a second web area of the supporting section, the second web area extending away from the first web section in the axial direction, being supported on the housing at least in the radial direction.

12. The tensioning device as recited in claim 11 wherein the transport securing element has an L-shaped, double L-shaped, S-shaped or Z-shaped cross section, at least in the area of the supporting section, viewed in cross section, the first web area being designed as a first leg of the cross section and the second web area being designed as a second leg of the cross section, or another, third web area of the supporting section being designed as a third leg of the cross section.

13. The tensioning device as recited in claim 11 wherein the transport securing element is designed as a pin-shaped component, or an additional web area is longer than the first web area, viewed in the axial direction of the piston.

14. The tensioning device as recited in claim 11 wherein an inner side of the first web area abuts the end face of the piston in the transport position.

15. The tensioning device as recited in claim 14 wherein an outer side of the first web area facing away from the inner side of the first web area abuts a hook-shaped projection of the housing in the transport position.

16. The tensioning device as recited in claim 11 wherein an inner side of an additional web area faces an outer shell side of the piston in the transport position.

17. The tensioning device as recited in claim 16 wherein an outer side of the second web area faces away from the inner side of the additional web area is supported on the housing in the radial direction in the transport position.

18. The tensioning device as recited in claim 11 wherein an additional web area of the transport securing element is positioned in a recess of the housing in the transport position.

19. The tensioning device as recited in claim 11 wherein the transport securing element is manufactured from a metal material or from a plastic material.

20. The tensioning device as recited in claim 11 wherein the transport securing element is manufactured from a profiled wire.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention is now explained in greater detail below on the basis of figures, in which connection different specific embodiments are illustrated.

[0020] FIG. 1 shows a longitudinal sectional representation of a tensioning device according to the present invention according to a first specific embodiment, the tensioning device being shown in the transport position, and the transport element supporting the piston relative to the housing in a first axial direction being cut in an L-shaped supporting section, viewed in cross section; and

[0021] FIG. 2 shows a longitudinal sectional representation of a tensioning device according to the present invention according to a second specific embodiment, which is essentially designed according to the first specific embodiment, the supporting section of the transport securing element now having a double L-shape design, viewed in cross section.

DETAILED DESCRIPTION

[0022] The figures are only of a schematic nature and are used exclusively for the sake of understanding the present invention. Identical elements are provided with the same reference numerals.

[0023] Tensioning device 1 according to the present invention is clearly illustrated in FIG. 1 in the form of a chain tensioner. In another specific embodiment, tensioning device 1 is designed as a belt tensioner. Tensioning device 1 is used in an operating state of an internal combustion engine, for example a gasoline engine or a diesel engine of a motor vehicle, such as a passenger car, a truck, a bus or an agricultural utility vehicle, for tensioning a traction mechanism, a chain in this case (further preferably a belt) of the traction mechanism drive (chain drive, further preferably a belt drive).

[0024] Tensioning device 1 furthermore includes a housing 2, which is open in the direction of an axial side. Within this housing 2, in a cylindrically extending housing area (hereinafter referred to as base section 17), a piston 3 is displaceably supported in the axial direction relative to housing 2. Tensioning device 1 is designed as a hydraulic tensioning device 1. Consequently, piston 3 is displaceably supported in both a spring-elastically and damped manner in housing 2 with the aid of a hydraulic pressure chamber 9 and a spring device 10. Tensioning device 1 functions, in principle, like the one disclosed in DE 10 2004 041975 A1, this disclosure being therefore regarded as integrated herein.

[0025] Tensioning device 1 is furthermore provided with a transport securing element 4, namely in a transport position of tensioning device 1 (transport position is that position in which tensioning device 1 is placed after assembly for the end customer for final mounting on the internal combustion engine). In this transport position, transport securing element 4 is used in tensioning device 1 in such a way that it is inserted into housing 2/situated/supported/held in housing 2 transversely to piston 3, i.e., transversely with respect to the longitudinal axis of piston 3, as well as in abutment with piston 3. Tensioning device 1 is inserted into housing 2 from the outside in such a way that a displacement of piston 3 in at least one first axial direction, namely out of housing 2, is blocked. To remove transport securing element 4 in a state mounted on the internal combustion engine side, an end of transport securing element 4 (which is not further illustrated for the sake of clarity) is provided, which extends outwardly into the surroundings of housing 2. As a result, transport securing element 4 may be easily removed after mounting has taken place.

[0026] Transport securing element 4 includes a supporting section 5 having an L-shaped cross section, at least one first web area 6 (also referred to as first leg area/leg) of supporting section 5 being pressed against/abutting end face 7 (also referred to as end surface) of piston 3 in this transport position illustrated in FIG. 1. Another, namely second, web area 8 (also referred to as second leg area/leg) of supporting section 5, is supported in housing 2 in the radial direction, this second web area 8 extending away from first web area 6 in the axial direction of piston 3 (viewed in the transport position).

[0027] Piston 3 is held on its end face 7 in the transport position by transport securing element 4, this end face 7 facing out of opening housing 2. Piston 3, which is designed as a hollow piston, has an essentially smooth, cylindrical outer side/outer shell side 11, which extends continuously along the axial extension of piston 3 with a uniform diameter. This outer side 11 may, however, have taperings/uneven areas/shoulders or recesses (for example, milled areas). Transport securing element 4 extends with second web area 8 into an angular/rectangular recess 12, which is formed on/in housing 2, on the one hand, and extends with first web area 6 inwardly in the radial direction (toward the piston center) out of this recess 12, on the other hand, so that a radial inner area of first web area 6 directly abuts end face 7 of piston 3 in the transport position.

[0028] Viewed in the axial direction, each of web areas 6, 8 has an inner side and an outer side. According to the location in the transport position of tensioning device 1, first web area 6 has an (axial) inner side, hereinafter referred to as first inner side 13, and an (axial) outer side facing away from this first inner side, hereinafter referred to as first outer side 14. First outer side 14 faces away from first inner side 13. First outer side 14 thus forms that axial side of first web area 6 which faces piston 3 in the transport position, namely in contact therewith. First outer side 14, in turn, is that axial side of first web area 6 which faces away from piston 3 or its end face 7 and is supported on/pressed against housing 2 in the axial direction (due to the piston pretensioning out of housing 2). Second web area 8 also has an inner side and an outer side, the inner side, hereinafter referred to as second inner side 15, represents a radial inner side. A (radial) outer side of second web area 8, hereinafter referred to as second outer side 16, is situated radially outside second inner side 15, namely facing away therefrom. Second inner side 15 is consequently the side of second web area 8 which faces outer shell side 11 of piston 3 in the transport position. Second outer side 16 is that side of second web area 8 which faces away from outer shell side 11 and is supported on housing 2 in the radial direction in the area of recess 12.

[0029] Transport securing element 4 is manufactured as a profiled band/wire element, which is manufactured from a steel band. Alternatively, however, it is also possible to manufacture transport securing element 4 from a plastic material, for example from a plastic molded part.

[0030] Transport securing element 4 is essentially designed as a straight, profiled pin, whereby recess 12 is consequently also designed as a recess essentially extending in a straight manner (in the form of a through-hole or blind hole). Transport pin/transport securing element 4 is positioned/situated along a circumferential plane of piston 3 in the transport position.

[0031] In closer examination, recess 12 is furthermore formed by a hook-shaped projection 18 extending in the axial direction away from an essentially circular base section 17 of housing 2. Projection 18 has recess 12 designed as a longitudinal groove on an inner side facing piston 3. On a side facing away from base section 17, projection 18 extends inwardly again in the radial direction to the extent that first outer side 14 of first web area 6 is directly supported by projection 18. The two web areas 6 and 8 extend along supporting section 5, pitched at an essentially 90° angle with respect to each other.

[0032] Another, second specific embodiment of tensioning device 1 according to the present invention is illustrated in FIG. 2, this second specific embodiment being designed and functioning according to the first specific embodiment, and only the differences are discussed below for the sake of brevity. In the second specific embodiment, transport securing element 4 is formed with a double-L shape in the area of supporting section 5. First web area 6 is again that area of supporting section 5 which extends in the radial direction (viewed in cross section). First inner side 13 is again in contact with end face 7 of piston 3. Since first web area 6 is furthermore situated outside recess 12, i.e. outside housing 2, first outer side 14 is also situated outside recess 12 and is not in contact with housing 2/projection 18.

[0033] Second web area 8 is again the area of supporting section 5 which extends essentially in the axial direction of piston 3 (i.e. perpendicularly to first web area 6) in the transport direction (viewed in cross section). Second web area 8 extends in the axial direction from first web area 6 into housing 2 to such an extent that second web area 8, in turn, extends into recess 12 and is supported directly on housing 2 with second outer side 16 in the radial direction in the area of recess 12.

[0034] Second web area 8 is also (indirectly) held in housing 2 in the axial direction. For this purpose, second web area 8 of transport securing element 4 has a third web area 19 extending outwardly in the radial direction on an axial end facing away from first web area 6 (viewed in cross section). Third web area 19, in turn, forms a first axial end surface (referred to as third outer side 21), which points in the same direction as end face 7 and has a second end surface (referred to as third inner side 20) facing away from first axial end surface. Transport securing element 4 is then, in turn, supported with third outer side 21 on housing 2 in the extension direction of piston 3. Third web area 19 extends perpendicularly away from second web area 8, radially to the outside, and runs in parallel to first web area 6. Transport securing element 4 is thus supported with third outer side 21 on housing 2 in the radial direction, optionally or simultaneously with respect to the second outer side. Third web area 19 is also used as a radial or axial contact surface on housing 2/projection 18 in addition to second web area 8 or instead of second web area 8.

[0035] Another advantage of the specific embodiment according to FIG. 2 is that the transport securing system is implemented even when piston 3 projects out of housing 2 (extending out of housing 2 by a certain distance in the transport position). Housing 2 may thus be provided with a compact design relatively independently with respect to piston 3. Due to projecting piston 3, functional components are also protected against colliding with housing 2.

[0036] In other specific embodiments, it is also possible to provide supporting section 5 of transport securing element 4 with S-shaped, Z-shaped or other advantageous cross-sectional designs instead of the cross-sectional L-shaped or double L-shaped design.

List of Reference Numerals

[0037] 1 tensioning device [0038] 2 housing [0039] 3 piston [0040] 4 transport securing element [0041] 5 supporting section [0042] 6 first web area [0043] 7 end face [0044] 8 second web area [0045] 9 pressure chamber [0046] 10 spring device [0047] 11 outer shell side [0048] 12 recess [0049] 13 first inner side [0050] 14 first outer side [0051] 15 second inner side [0052] 16 second outer side [0053] 17 base section [0054] 18 projection [0055] 19 third web area [0056] 20 third inner side [0057] 21 third outer side