DE102012214765A1 - Traction unit tensioner for traction drive of internal combustion engine of motor vehicle such as motorcycle, has damping device which is provided between outer wall of piston and inner wall of housing - Google Patents

Abstract

The tensioner (1) has a housing (2) that is provided with a piston (3) whose one end is contacted with clamping rail for deflecting traction unit such as chain or belt. A clamping device (9) is provided between the outer wall (8) of piston and inner wall (7) of housing, so that retraction of the piston is stopped in the housing. A damping device (10) is provided between outer wall of piston and inner wall of housing.

Description

Field of the invention

The invention relates to a Zugmittelspanner for a traction mechanism drive of an internal combustion engine of a motor vehicle, such as a motorcycle, with a retractable from a housing piston, one end of which is prepared in contact with a clamping rail for deflecting a traction means, such as a chain or a belt, the Piston has an outer wall which adjoins an inner wall of the housing, wherein a clamping device between the outer wall of the piston and the inner wall of the housing is provided so that a retraction movement of the piston is prevented in the housing.

Such Zugmittelspanner can also be used in cars or trucks.

Zugmittelspanner, in particular mechanical Zugmittelspanner, such as chain tensioners, are used especially in motorcycles. In particular, mechanical traction mechanism tensioners are used in SOHC engines in Asia.

In applications in Asia, mainly mechanical chain tensioners are used. In this case, according to the current state of the art, raster clamps and threaded clamps are used. These tensioners act in one direction, so that in case of chain wear, the tensioning rail is pressed against the chain. If a belt, such as a toothed belt is used instead of a chain, the tensioning rail is pressed against this traction means. In the other direction, the tensioners lock, so the Zugmittelspanner so that the system can not swing up. The blocking effect is realized in a raster tensioner by the detent and the threaded clamp on the self-locking.

In the case of a grid clamp, only a stepped clamping is usually possible due to its detent. In addition, the raster voltage has little or no damping effect, which can lead to high load peaks during operation. Although the thread tensioner is continuously variable in contrast to the grid tensioner, it is also without or with only limited damping effect in this embodiment.

To compensate for the missing damping characteristic a little, in some solutions when using the o. G. Spanner a flexible clamping rail made of plastic with a steel support body, which acts as a leaf spring used.

From the state of the art, about the DE 10 2008 028 457 A1 , Clamping devices for traction drives are known. From this document is, for example, a mechanical, working according to a rotation principle known solution.

However, there are also hydraulic traction means, which are also referred to as tensioning devices, which involve a linear movement of a piston. For example, the DE 10 2007 057 782 A1 , A Zugmittelspannvorrichtung, in particular a belt tensioning device comprising a tensioning element comprising a tensioner housing and a tensioner, wherein the tensioner is displaced relative to the tensioner housing by means of a coil spring designed as a spring element in a translational displacement direction spring biased. In order to facilitate the assembly process, this document provides that a sleeve-shaped component is arranged in the tensioner housing into which the tensioner extends with one of its axial end regions, wherein the axial end portion of the tensioner is guided linearly displaceable in the sleeve-shaped component, wherein in the circumference the sleeve-shaped component is incorporated at least one link and wherein at least one sliding block is arranged in the axial end region of the tensioner, which is guided in the backdrop.

While out of the DE 10 2007 057 782 A1 the tensioning of a belt formed as Endloszugmittels is disclosed, for example, discloses the DE 10 2010 012 918 A1 a tensioning device for a chain, wherein a combination valve is used. In this DE 10 2010 012 918 A1 discloses a tensioning device for a chainless Endlostriebmittel, comprising a housing in which an extendable cylinder is present, wherein between the housing and the cylinder with a pressure fluid via a supply port of the housing fillable pressure chamber is present, the supply port of a combination valve a check valve to be opened in the direction of the pressure chamber having a movable first blocking body and a pressure relief valve having a movable second blocking body to be opened against this direction, wherein the first blocking body of the non-return valve is arranged substantially on the pressure chamber side of the second blocking body. Basically, it should be added that tensioning devices, in particular hydraulic tensioning devices, are frequently used in traction mechanism drives for internal combustion engines. As a rule, the tensioning devices are required for deflecting a slide rail over which the endless drive means is passed. The Endlostriebmittel is usually designed as a chain or belt. If a chain is used, it is usually made of steel links.

Such known from the prior art Zugmittelspanner be in traction mechanisms used. Such traction drives are in turn used in particular in internal combustion engines, which are used in motor vehicles, such as cars, trucks, tractors but also other land, water or airborne vehicles.

Very often Zugmitteltriebe between a crankshaft of an internal combustion engine and a camshaft of an internal combustion engine are used, often also ancillaries on the traction drive, which uses a traction means, such as a chain or a belt driven.

Mechanically prestressed traction means tensioners have the advantage that they are universally applicable, and have proven themselves in internal combustion engines. Such Zugmittelspanner serve in combination with appropriately designed clamping rails for synchronizing a camshaft and a crankshaft. Several of these cam or crankshafts can be used. An adjustment of the camshaft to the crankshaft is prevented by the use of a Zugmittelspanners, since the tension is always kept high within the traction means. If a chain is used, the tensioning device ensures that there is always the correct and required chain tension.

In order to absorb and compensate for impacts in the traction mechanism drive, for example due to different operating states of the internal combustion engine, in the case of known mechanical traction mechanism tensioners, as a rule, an attenuator is included which, however, has not yet been decoupled from the pretensioning force. Damping is therefore usually in both directions of movement, ie both when retracting the piston in the housing, as well as the extension of the piston from the housing. Steaming thus takes place in the clamping direction as well as in the direction of relaxation.

The object of the present invention is now to provide an improved traction mechanism tensioner or an improved traction mechanism drive. The object is, in particular, to develop a mechanical chain tensioner which, in addition to the tensioning of the chain, also provides a damping element. As a result, the execution of the clamping rail can be simplified, since this no longer has to have damping properties.

Disclosure of the invention

In a generic Zugmittelspanner, such as a mechanical Zugmittelspanner this type, this object is achieved in that in addition a damping device between the outer wall of the piston and the inner wall of the housing is present.

Advantageous embodiments are also claimed in the subclaims and are explained in more detail below.

Thus, it is advantageous if the damping device is provided on the side of the clamping device remote from the clamping side, in order to bring about an efficient interaction of the individual components.

In order to require as little space as possible, it is advantageous if the damping device and the clamping device are located in a common holding device.

It is also expedient if the clamping device has at least one roller as a clamping body.

It is advantageous in this case if the roller is supported on a flattened region of the outer wall and an inner wall of the housing running obliquely to the housing base. The housing base is the area of the housing, which faces away from the clamping rail.

An advantageous embodiment is also characterized in that there are at least four rolls equally distributed over the circumference of the piston. The distribution of force is then particularly even, which comes to the longevity.

It is also advantageous if the damping device has a prestressed O-ring, since then an adequate damping can be realized, but at the same time the production costs remain low.

Furthermore, it is advantageous if the clamping device acts as a blocking device, wherein the piston is infinitely lockable over the housing.

It is also advantageous if the clamping device has clamping bodies which are in operative connection with surfaces which taper in the opposite direction, wherein the clamping bodies are spring-loaded in the direction of tapering.

If the surfaces for the clamping body, the axially parallel to the piston executed wall of the piston and designed as a clamping ramp, tapered counter surface of the housing or a part of the housing, so a particularly well-acting embodiment can be achieved. As an alternative to rolls, balls can also be used.

It is advantageous if the surfaces in the piston piston grooves and the surfaces in the housing have housing grooves with arcuate cross-section.

Furthermore, it is expedient if the arcuate shapes for the piston grooves and housing grooves are selected such that the clamping bodies contact the piston grooves and the housing grooves in one point each.

If the arcuate shapes for the piston grooves and housing grooves are selected so that the clamping bodies contact the piston grooves and / or the housing grooves in one or two points, a further advantageous embodiment is provided.

• – mechanischer Kettenspanner mit linear freilaufendem Dämpfungselement
• – spanlose Fertigung von Gehäuse und Buchse mittels Tiefziehtechnik
• – spanlose Fertigung des Kunststoffkäfigs durch Spritzgusstechnik
• – Linearfreilauf mit Rollen als Klemmkörper und Rampen im Gehäuse
• – O-Ring als Dämpfungselement zwischen Buchse und Gehäuse
• – Schnappnasen, um ein Zerfallen der Einheit zu verhindern

A construction according to the invention is further characterized by the following points:

• - mechanical chain tensioner with linear free-running damping element
• - Non-cutting production of housing and socket by means of deep drawing technology
• - non-cutting production of the plastic cage by injection molding
• - Linear Freewheel with rollers as clamping body and ramps in the housing
• - O-ring as a damping element between the socket and housing
• - Snap-noses to prevent unit disintegration

In this way, a low-cost chain tensioner is provided for use in motorcycles, which brings with respect to the tensioners on the market considerable cost advantages.

It is advantageous if the unit can not be disassembled, for example with appropriate design of retaining lugs and a corresponding design of the piston.

The invention will be explained in more detail below with the aid of a drawing. Show it:

1 a longitudinal sectional view through a first embodiment of a Zugmittelspanners invention,

2 a representation of the top of the Zugmittelspanner off 1 in a partially broken representation, whereby the cut in the height of the line II from 1 is

3 a representation in a snap nose component is shown with appropriate cut selection.

The figures are merely schematic in nature and are only for the understanding of the invention. The same elements are provided with the same reference numerals.

In 1 is a first embodiment of a Zugmittelspanners invention 1 shown. The tensioning device 1 has a housing 2 with a retractable piston 3 on. A tension near end 4 is on the other side of a housing ground 5 on the piston 3 present and can be brought into contact with a tensioning rail, not shown, which can deflect a traction means, such as a chain or a belt. Inside the piston 3 , in contact with the housing 5 is located, is a compression spring 6 available. The compression spring 6 is designed as a helical spring.

The housing 2 has an inner wall 7 on. The piston 3 has an outer wall 8th on. Between the inner wall 7 and the outer wall 8th is a clamping device 9 and a damper 10 available. The clamping device 9 includes a clamp body 11 like a role 12 and a biasing element 13 like a spring 14 , In the area of the clamp body 11 is the inner wall 7 as a clamping ramp 15 educated. The damping device 10 includes a preloaded O-ring 16 , The clamp body 11 are in a holding device 17 held, as well as the springs 14 ,

While the case 2 and the piston 3 consist of a steel alloy, is the holding device 17 made of plastic.

As already explained, the mentioned object is achieved in that a piston design also referred to as a sleeve by means of the compression spring 6 against the clamping rail, which is not shown, is pressed. The blocking in the other direction is realized via a linear freewheel. This will be the clamp body 11 by means of one or more springs 14 against the clamping ramps 15 in the case 2 pressed. The clamp body 11 and the springs 14 are held in a plastic cage holding the holding device 17 formed. The damping effect is via a damping element on the type of damping device 10 realized, which between socket and housing 2 used with radial preload.

To prevent the unit from disintegrating, the holding device is 17 with in 3 to recognize snapping noses 18 Mistake. These snap noses 18 grab behind the case 2 , which prevents the piston 3 completely out of the case 2 can slip out.

In order to meet low production costs, the invention is carried out such that the essential parts can be produced by chipless manufacturing process. The housing 2 and the piston 3 are designed as deep-drawn parts. The plastic cage, so the holding device 17 , is manufactured by injection molding. Alternatively, the Bushing or the piston 3 also be produced by extrusion.

The clamp body 11 are designed to transmit large return forces as rollers. However, it would also be conceivable to use balls or other sprags. The damping element, in the context of the damping device 10 is used, is the O-ring 16 ,

In 3 is a section along the line III 2 which should improve the spatial understanding.

LIST OF REFERENCE NUMBERS

1

Zugmittelspanner

2

casing

3

piston

4

close to the rail

5

housing base

6

compression spring

7

Inner wall of the housing

8th

Outer wall of the piston

9

clamper

10

attenuator

11

clamping bodies

12

role

13

biasing member

14

feather

15

clamping ramp

16

O-ring

17

holder

18

snap lug

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102008028457 A1 [0007]
• DE 102007057782 A1 [0008, 0009]
• DE 102010012918 A1 [0009, 0009]

Claims (4)

Traction device tensioner ( 1 ) for a traction drive of an internal combustion engine of a motor vehicle, such as a motorcycle, with one of a housing ( 2 ) retractable piston ( 3 ), whose one end ( 4 ) is prepared in abutment with a tensioning rail for deflecting a traction means, such as a chain or a belt, wherein the piston ( 3 ) an outer wall ( 8th ), which against an inner wall ( 7 ) of the housing ( 2 ), wherein a clamping device ( 9 ) between the outer wall ( 8th ) of the piston ( 3 ) and the inner wall ( 7 ) of the housing ( 2 ) is present, so that a retraction movement of the piston ( 3 ) in the housing ( 2 ) is prevented, characterized in that in addition a damping device ( 10 ) between the outer wall ( 8th ) of the piston ( 3 ) and the inner wall ( 7 ) of the housing ( 2 ) is available. Traction device tensioner ( 1 ) according to claim 1, characterized in that the damping device ( 10 ) on the side of the clamp direction away from the rail ( 9 ) is available. Traction device tensioner ( 1 ) According to claim 1 or 2, characterized in that the damping device ( 10 ) and the clamping device ( 9 ) in a common holding device ( 17 ) are located, wherein the damping device ( 10 ) designed as an O-ring. Traction device tensioner ( 1 ) according to one of claims 1 to 3, characterized in that the clamping of Zugmittelspanners ( 1 ) is achieved by means of an axially acting freewheel, such as by using clamping bodies ( 11 ), Ramps and springs, wherein preferably the clamping device ( 9 ) at least one role ( 12 ) or a ball as a clamping body ( 11 ) having.

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