DE102014214255A1 - Hydraulic chain tensioning unit made of formed parts - Google Patents

Abstract

The invention relates to a hydraulic Zugmittelspanner (1) for zugloszugmittelauslenkenden moving a clamping rail, with a piston (2), the hydraulic medium pressure due to a first end of a housing (3) is mounted extendable therefrom and one, a hydraulic fluid backflow interrupting switchable check valve unit (4), which is held stationary relative to the housing (3), wherein the housing (3) and the piston (2) are made of forming sheet without cutting. The invention also relates to a continuous traction drive with an endless traction means, such as a chain or a belt, which is deflected with the interposition of a tensioning rail by a hydraulic Zugmittelspanner (1) according to the invention.

Description

The invention relates to a hydraulic Zugmittelspanner for zugloszugmittelauslenkenden moving a tensioning rail, for a camshaft or secondary drive, eg. An internal combustion engine-powered vehicle, such as a car, a motorcycle, a truck or other commercial vehicle, with a piston, the hydraulic medium pressure due to a first end of a Housing is mounted extendable from this and a hydraulic fluid reflux interrupting switchable check valve unit which is held stationary relative to the housing.

Hydraulic tensioning devices in traction mechanism drives which serve to drive one or more camshafts or balancing shafts and / or ancillary units are already known from the prior art. A, the hydraulic principle using Zugmittelspanner is, for example, from the DE 10 2010 032 630 A1 known. There, a traction mechanism drive with a clamping device is presented, which has a housing in which a tensioning piston is mounted so extendable by means of a first compression spring that it deflects a system guided by a tensioning rail on the tensioning rail traction means, wherein between the housing and the surface of the Tensioning piston a locking device is formed, which prevents re-insertion of the clamping piston in the housing, wherein at that the clamping rail facing the end of the clamping piston a fluid-containing buffer capsule is arranged, which is at least indirectly brought into contact with the clamping rail.

Hydraulic chain tensioners are also from the DE 10 2007 037 720 A1 known. There, a control drive of an internal combustion engine is presented, which also uses a hydraulic Zugmittelspanner.

Conventional hydraulic chain tensioners are usually composed of machined individual parts. This entails numerous processing steps in the production, which makes such a Zugenspanner expensive. Also due to the variety of components, possibly to be used variants, the costs are driven upwards.

It is the object of the present invention to effect an increase in efficiency and box saving and to avoid the disadvantages known from the prior art.

This object is achieved in a generic device according to the invention in that the housing and the piston are made of forming sheet without cutting. The embodiments of the clamping element and its subassemblies and individual parts can be achieved, for example, by using a cold forming. This can significantly reduce costs. On turning, milling, grinding or drilling operations can be dispensed with. As a whole, machining steps can be dispensed with.

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

Thus, it is advantageous if in the housing a preferably concentrically arranged to this sleeve is present, which secures the check valve unit. In this way, a sufficiently large space on the far side of the piston housing, between the housing and the check valve unit can be kept in order to ensure efficient functioning of Zugmittelspanners. Of course, it is also possible that the sleeve is dispensed with and the check valve unit is fixed directly on the inner circumference of the housing. However, there should then be an oil supply port located coloufulously away from the check valve unit.

The cost-minimizing potential can be exploited if (also) the sleeve is made of forming sheet without cutting, for example, from the same material, such as the piston and / or the housing.

It is advantageous if the forming of a metal alloy, such as an iron alloy, (only) brought by non-cutting forming, such as by deep drawing, pressing and / or punching in the respective final shape. The tensioner / tensioner then produced is therefore very durable and at the same time inexpensive.

It is advantageous if between the housing and the piston a, preferably with the inside of the housing and the outer peripheral side of the piston, engageable / befindlicher retaining ring is arranged. About the locking ring a falling apart of Zugmittelspanners can be effectively prevented during assembly or during operation.

It is advantageous if the locking ring is arranged in a formed between an inner peripheral surface of the housing and the outer peripheral surface of the piston, over the circumference completely encircling, first or second ring pocket. The retaining ring can then have a radially outwardly acting bias, which causes a positive connection from a certain operating position of the piston in the housing between the three components, whereby a captive is ensured.

It is expedient if the first ring pocket axially and / or radially further inside than the second ring pocket is arranged in the retracted into the housing state of the piston. An intrusion or immersion of the retaining ring from the first ring pocket in the second ring pocket, with a corresponding operating position of the housing relative to the piston and vice versa, is then reached skillfully.

An advantageous embodiment is also characterized in that the two ring pockets and the locking ring are coordinated so that upon extension of the piston from the housing into a maximum position of the piston, the locking ring engages the second ring pocket so that further extension of the piston prevents is, in particular by using a bias of the retaining ring and a positive connection of the retaining ring with the housing and / or the piston.

When a piston proximal end portion of the housing is designed reduced thickness to a cylinder portion of the housing in a non-return valve unit adjacent region / end portion, at a small predefined location a thread, such as an external thread on the housing can be applied to a screwed / screwed the housing into a Engine block or a traction drive housing to ensure / enable. As a result, the external thread does not have to run over a great length, but only in the region of an axially relatively short annular section.

So that a stop can be held in the assembly on the housing, it is advantageous if in the non-return valve unit adjacent area of the housing (completely / partially) on the outer circumference of the housing encircling collar, such as a crimp, is formed and / or on the piston far away End of a nut-like outer contour is embossed, such as the manner of an external hexagon. The assembly is facilitated.

An advantageous embodiment is also characterized in that a compression spring biasing on the piston and a closure element, such as a ball, the check valve unit is arranged.

Finally, the invention also relates to a endless traction drive with an endless traction means, such as a chain or a belt, which is deflected with the interposition of a tensioning rail by a hydraulic Zugmittelspanner of the type according to the invention / is prepared for deflecting.

The hydraulic Zugmittelspanner thus consists of parts that are created over surface strengthening measures as a preform.

In other words, a clamping unit is proposed, which is designed as a screw plug version and comprises the following components: a housing, a piston, a sleeve, a check valve unit, a compression spring and a retaining ring. The housing is made of sheet metal and is produced without any turning, milling, grinding or drilling operations using a forming technology. The housing has a hexagonal shape at the rear end, wherein this form specifies a wrench size and used for mounting the clamping unit in the engine. With a collar begins, seen in the direction of the piston near end, the rotationally symmetric region of the housing. The collar also serves to seal the clamping unit to the environment and can be designed with or without additional sealing washer or sealing washers. At the housing circumference a thread is attached, which serves for fixing in the engine-side tensioner bore. In the case of the need for a captive additionally a screw lock, for example. Using materials such as are known as "Loctite", be applied to the threads.

In the area of the thread an oil supply opening is punched. At the front end of the housing, the wall thickness is reduced / stretched and forms after mounting and flanging a pocket in which the locking ring engages and protects the clamping unit from disintegration.

The piston is rotationally symmetric and has a diameter to length ratio of 1: 1 to 1: 4.

The front side has a mandrel embossed, which fixes the compression spring in position.

Centric, but also eccentric, an oil lubrication opening can be attached, with a maximum diameter of 1.2 mm.

In the rear third of the piston there is a groove which is stamped by a deformation, for example by means of rolling, and accommodates the retaining ring.

The width of the groove can be between 1 mm and 10 mm. Values of 2, 3, 4, 5, 6, 7 and 8 mm are particularly advantageous.

The sleeve in the interior of the clamping unit serves to fix the check valve unit on which the compression spring is supported. The sleeve separates a supply chamber from a high-pressure chamber of the clamping unit. About openings, the oil pass through the opening in the housing to the check valve unit and supply the high-pressure chamber with oil. The check valve unit may be formed as a standard component.

The invention will be explained in more detail below with the aid of a drawing. In this case, a first embodiment is shown. Show it:

1 a partially cutaway perspective view of a hydraulic Zugmittelspanners invention,

2 a perspective view of Zugmittelspanners 1 .

3 another, to the presentation 2 rotated perspective view of the hydraulic Zugmittelspanners the 1 and 2 .

4 a side view of Zugmittelspanners the 1 to 3 , and

5 a front view of a hexagonal head of the housing of Zugmittelspanners the 1 to 4 ,

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 an inventive hydraulic Zugmittelspanner 1 shown, which is useful as a chain tensioner. It is used in a traction drive, which serves to drive one or more camshafts or balancing shafts and ancillaries.

He has a piston 2 on, which acts on a tensioning rail, not shown, which in turn acts on an unillustrated endless traction means, such as a chain.

The piston 2 is in a housing 3 arranged concentrically. Here is the piston 2 slidable in the housing 3 stored, but with the outer circumference of the piston 2 so on the inner circumference of the case 3 is adapted that a good sealing effect between the two components is achieved.

A check valve unit 4 is at a piston distal end portion of the housing 3 , inside the case 3 and concentric, arranged. The check valve unit 4 relies on a concentric in the housing 3 arranged sleeve 5 from.

The check valve unit 4 also has a valve 6 on, in the manner of a ball 7 is trained. A compression spring 8th , like a coil spring 9 , rests on the piston 2 and a contact component 10 from. The contact component 10 contacts the valve 6 with the interposition of a biasing element 11 like another spring.

The piston 2 , the case 3 and the sleeve 5 are made of forming sheet without cutting, such as deep-drawn. The sleeve 5 has an opening 12 on, by the hydraulic means, such as pressure oil / (engine) oil from a supply room 13 into the interior of the sleeve 5 can then pass, then exerting pressure on the valve 6 act.

The housing 3 has a hexagonal shape at its end remote from the piston 14 put on a covenant 15 borders. The Bund 15 is made by a crimp or bend / Umfalzung. On the side of the covenant facing away from the hexagon 15 is an oil supply opening 16 available. About this can be oil / pressure oil / engine oil in the interior of the supply room 13 reach. Next, on the bundabgewandten side of the oil supply opening 16 , is a thread 17 , Applied approximately in the manner of an external thread, and ends at a dilution / reduced-thickness section 18 of the housing. The wall thickness of the dilution zone 18 is smaller than in the other area of the housing.

The piston 2 has an inwardly directed circumferential groove 19 on. The groove allows the formation of a first ring pocket / bag 20 between the inner peripheral surface of the housing 3 and the outer peripheral surface of the piston 2 , Towards a distal end 21 of the piston 2 is another bag, namely a second ring bag 22 educated. In the first ring bag 20 is a circlip 23 available.

So that the compression spring 8th is held correctly and centered, is a dome 24 axially inwardly placed at the bottom of the piston 2 available. There is (central or eccentric) an oil lubrication opening 25 contain. About the oil lubrication hole 25 The tensioning rail, not shown, and also the endless traction means can be lubricated in a targeted manner.

The maximum thickness of the bottom of the piston 2 So the area of the piston 2 , which also acts on the clamping rail displacing, is between 1.1 mm and 1.3 mm, preferably 1.2 mm dimensioned. An axially measured width of the first ring pocket 20 and / or the second ring bag 22 is between 1 and 10 mm. In 2 is a rotationally symmetric area 26 of the housing 3 referenced.

In 3 to 5 is the Zugmittelspanner 1 sketches further.

LIST OF REFERENCE NUMBERS

1

Zugmittelspanner

2

piston

3

casing

4

Check valve assembly

5

shell

6

Valve

7

Bullet

8th

compression spring

9

coil spring

10

contact component

11

biasing member

12

opening

13

supply room

14

Hexagonal shape

15

Federation

16

Oil supply opening

17

thread

18

dilution range

19

groove

20

first ring bag

21

distal end

22

second ring bag

23

circlip

24

cathedral

25

Oiling port

26

rotationally symmetric region of the housing

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 102010032630 A1 [0002]
• DE 102007037720 A1 [0003]

Claims (10)

Hydraulic traction mechanism tensioner ( 1 ) for infinitely Zugmittelauslenkenden moving a tensioning rail, with a piston ( 2 ), the hydraulic medium pressure due to a first end of a housing ( 3 ) is mounted therefrom extendable and one, a hydraulic fluid (back) flow interruptively switchable check valve unit ( 4 ), which are relative to the housing ( 3 ) is held stationary, characterized in that the housing ( 3 ) and the piston ( 2 ) are made of forming sheet without cutting. Traction device tensioner ( 1 ) according to claim 1, characterized in that in the housing ( 3 ) a sleeve ( 5 ), which is the check valve unit ( 4 ) attached. Traction device tensioner ( 1 ) according to claim 2, characterized in that the sleeve ( 5 ) is made of forming sheet without cutting. Traction device tensioner ( 1 ) according to one of claims 1 to 3, characterized in that the forming plate is constructed of a metal alloy and is brought by non-cutting forming in the respective final shape. Traction device tensioner ( 1 ) according to one of claims 1 to 4, characterized in that between the housing ( 3 ) and the piston ( 2 ) a retaining ring ( 23 ) is arranged. Traction device tensioner ( 1 ) according to claim 5, characterized in that the retaining ring ( 23 ) in between an inner peripheral surface of the housing ( 3 ) and the outer peripheral surface of the piston ( 2 ) formed first or second ring bag ( 20 . 22 ) is arranged. Traction device tensioner ( 1 ) according to claim 6, characterized in that the first ring pocket ( 20 ) axially and / or radially further inside than the second ring pocket ( 22 ) in the housing ( 3 ) retracted state of the piston ( 2 ) is arranged. Traction device tensioner ( 1 ) according to claim 6 or 7, characterized in that the two ring pockets ( 20 . 21 ) and the retaining ring ( 23 ) are coordinated so that an extension of the piston ( 2 ) out of the housing ( 3 ) in a maximum position, the retaining ring ( 23 ) in the second ring bag ( 22 ) engages in order to further extend the piston ( 2 ) to prevent. Traction device tensioner ( 1 ) according to one of claims 1 to 8, characterized in that a piston-near end portion of the housing ( 3 ) reduced in thickness to a cylinder portion of the housing ( 3 ) is configured in a region adjacent to a check valve unit. Continuous traction drive with an endless traction means, the interposition of a clamping rail by a hydraulic Zugmittelspanner ( 1 ) is deflected according to one of claims 1 to 9.

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