DE102007057783A1 - traction means tightening device - Google Patents

Abstract

The invention relates to a Zugmittelspannvorrichtung (1), in particular a timing chain tensioning device comprising a clamping element (2) comprising a piston-cylinder system (3, 4), wherein in a piston-cylinder system (3, 4) leading 6) a check valve (7) is arranged and wherein the piston-cylinder system (3, 4) has an outflow path (8) for oil (6), in which a pressure relief valve (9) is arranged , In order to achieve optimum adaptation to desired operating conditions, the invention provides that at least one of the two valves (7, 9) is designed as a plate valve.

Description

Field of the invention

The The invention relates to a traction mechanism, in particular a timing chain tensioning device having a tensioning element, which comprises a hydraulic piston-cylinder system, wherein in one leading to the piston-cylinder system feed path for oil a check valve is arranged and wherein the piston-cylinder system having a drainage path for oil, in which a pressure relief valve arranged is.

Background of the invention

A chain tensioning device of this kind is from the DE 36 39 389 A1 known. Here, a chain is tensioned with a piston-cylinder system and lubricated by the oil that is conveyed by the piston-cylinder system. For this purpose, an oil feed path to the interior of the piston-cylinder unit is provided, in which a spring-biased check ball valve is arranged. Similarly, located in an oil drain path from the interior of the piston-cylinder unit, a spring-biased pressure ball valve. In relative movements - stimulated by the movements of the chain - between the piston and the cylinder therefore oil is conveyed into the interior of the piston-cylinder system from an oil reservoir and further applied to the chain, which not only kept the chain under tension, but is also lubricated.

It has proved to be disadvantageous that in the previously known Device the use of ball check and overpressure valves not always to optimum working conditions of the tensioning device leads. In particular, demands the large variety of variants the systems needed to ensure that optimal operating conditions not with the usual ball check valves can be achieved. In particular, an adjustment the tensioning device to the engine dynamics difficult.

Object of the invention

Of the The present invention is therefore based on the object, a Zugmittelspannvorrichtung, in particular a timing chain tensioning device of the type mentioned so to train that optimal adaptation to desired Operating conditions is possible, which is a big one Variety of options covering the used tensioning devices covers. This should cover different needs can and a good adaptation to the engine dynamics possible become.

Summary of the invention

The Solution of this problem by the invention is characterized in that that at least one of the two valves is designed as a plate valve is.

A first, preferred variant provides that both the check valve as well as the pressure relief valve designed as a plate valve is.

It But it is also possible that one of the valves as a ball valve and one of the valves is designed as a plate valve. there can be provided in particular that the check valve as a plate valve and the pressure relief valve as a ball valve is trained. But it can also be provided vice versa, that the check valve as a ball valve and the pressure relief valve is designed as a plate valve.

Of the Outflow path for oil from the piston-cylinder system can be considered a concentric bore in the piston of the piston-cylinder system be formed, which are arranged in the axial end region of the piston is.

each Valve is advantageous by means of a spring element in the closing direction biased the valve.

Further is preferably provided that the piston-cylinder system by means of a spring element is biased so that the piston and cylinder be pushed away from each other.

Under Plate valve is to be understood in the present case that for the production the tightness of the valve is a plate-shaped element pressed against the opening of a flow path is, preferably with an engaging spring. In the case of the ball valve This is known to be a bullet.

The inventive design allows it that the Zugmittelspannvorrichtung in an improved manner be adapted to the specific case of need. This is especially true when it comes to a timing chain tensioning system in an internal combustion engine is. The required vote of the generic Clamping on the engine dynamics can with the proposed design better, resulting in an overall improved performance, compared to the previously known equipment with ball valves.

Brief description of the figures

In the drawing embodiments of the invention are illustrated. Show it:

1 a timing chain tensioning device in the side view, partially shown only very schematically and cut,

2 a piston-cylinder system of the tensioning device after 1 according to a first embodiment of a check valve and a pressure relief valve,

3 one too 2 alternative embodiment and

4 another one too 2 alternative embodiment.

Detailed description the figures

In 1 is a timing chain tensioner 1 to see. With her is a timing chain 15 Tense, that of two sprockets 13 and 14 to be led. To the chain 15 to tension, is a tensioning rail 16 pressed against the load-free chain center, the tensioning rail 16 around a pivot axis 17 is pivotally mounted.

The pressing of the tensioning rail 16 to the chain 15 done with a clamping element 2 , which consists essentially of a piston-cylinder unit 3 . 4 consists. Here is a box-shaped cylinder 3 provided in which a piston 4 is arranged translationally displaceable. In the box-shaped cylinder 3 is a recording room 19 for oil 6 educated. This oil 6 also acts as a lubricant for the chain 15 and as fluid, the piston-cylinder unit 3 . 4 actuated. For this purpose, the following embodiment is provided:
From the recording room 19 for the oil 6 leads an inflow path 5 in the interior of the piston-cylinder unit 3 . 4 , At the flow path end of the inflow path 5 there is a check valve 7 that prevents oil from inside the piston-cylinder unit back into the receiving space 19 can flow. In the axial (right) end of the piston 4 There is also a flow path for oil, namely a drainage path 8th for oil. The oil can through the drainage path 8th and a hole 18 in the tensioning rail 16 on the chain 15 arrive, whereby this is lubricated. The exit in the drainage route 8th is equally through a valve, namely by a pressure relief valve 9 , locked.

It is essential that at least one of the two valves 7 and 9 is designed as a plate valve. Accordingly, at least one valve has a plate-shaped sealing element which is in the region of the flow path end of the inflow path 5 or the discharge path 8th is arranged. As in 1 can be seen, here are both valves 7 and 9 designed as plate valves. spring elements 10 respectively. 11 are provided to press the plate-shaped sealing element against the fluid opening. Accordingly, the plate valve closes 7 the end of the tributary path 5 against backflow of oil into the receiving space 19 , With appropriate overpressure inside the piston-cylinder system 3 . 4 Can continue to oil against the pressure of the spring 11 from the interior of the piston-cylinder system and over the bore 18 to the chain 15 reach.

The piston-cylinder system 3 . 4 is replaced by another spring element 12 biased to the effect that the spring element 12 piston 4 and cylinders 3 pushing each other away; ie the spring element 12 pushes the piston 4 out of the cylinder 3 out.

In the 2 to 4 Various concepts of the embodiment of the invention are provided. In 2 Once again the solution is reproduced, as in 1 is provided. Accordingly, here are the two valves 7 and 9 each formed as a plate valves.

In 3 is the check valve 7 designed as a plate valve, while the pressure relief valve 9 realized as a ball valve.

In 4 the exact opposite solution is provided for this purpose. Here is the check valve 7 a ball valve while the pressure relief valve 9 designed as a plate valve.

Depending on the choice of valve types, the timing chain tensioning device 1 optimally adapted to the engine dynamics.

The operation of the present tensioner is the same as that discussed in the above DE 36 39 389 A1 is described, to which reference is made.

1

traction means tightening device (The timing chain tensioning device)

2

clamping element

3, 4

Piston-cylinder system

3

cylinder

4

piston

5

inflow for oil

6

oil

7

check valve

8th

outflow path for oil

9

Pressure relief valve

10

spring element

11

spring element

12

spring element

13

Sprocket

14

Sprocket

15

Chain

16

tensioning rail

17

swivel axis

18

drilling

19

accommodation space

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

• - DE 3639389 A1 [0002, 0026]

Claims (8)

Traction device ( 1 ), in particular timing chain tensioning device comprising a tensioning element ( 2 ) having a piston-cylinder system ( 3 . 4 ), wherein in a piston-cylinder system ( 3 . 4 ) leading inflow ( 5 ) for oil ( 6 ) a check valve ( 7 ) and wherein the piston-cylinder system ( 3 . 4 ) a drainage path ( 8th ) for oil ( 6 ), in which a pressure relief valve ( 9 ), characterized in that at least one of the two valves ( 7 . 9 ) is designed as a plate valve. Traction device according to claim 1, characterized in that both the check valve ( 7 ) as well as the pressure relief valve ( 9 ) is designed as a plate valve. Traction device according to claim 1, characterized in that one of the valves ( 7 . 9 ) as a ball valve and one of the valves ( 7 . 9 ) is designed as a plate valve. Traction device according to claim 3, characterized in that the check valve ( 7 ) as a plate valve and the pressure relief valve ( 9 ) is designed as a ball valve. Traction device according to claim 3, characterized in that the check valve ( 7 ) as a ball valve and the pressure relief valve ( 9 ) is designed as a plate valve. Traction device according to claim 1, characterized in that the outflow path ( 8th ) for oil ( 6 ) as a concentric bore in the piston ( 4 ) of the piston-cylinder system ( 3 . 4 ) formed in the axial end region of the piston ( 4 ) is arranged. Traction device according to claim 1, characterized in that each valve ( 7 . 9 ) by means of a spring element ( 10 . 11 ) in the closing direction of the valve ( 7 . 9 ) is biased. Traction device according to claim 1, characterized in that the piston-cylinder system ( 3 . 4 ) by means of a spring element ( 12 ) is biased so that the piston ( 4 ) out of the cylinder ( 3 ) is pushed out.