DE102016213538A1 - Zugmittelspanneinheit with resettable latching system - Google Patents

Abstract

The invention relates to a tensioning unit (1) for a traction mechanism drive of an internal combustion engine, comprising a housing (2), a displaceably accommodated in this housing (2) and protruding out of an opening (3) of the housing (2), wherein the Tensioning piston (4) by means of a spring element (5) in a direction of extension relative to the housing (2) is biased and a latching contour (6), with a partially in an axial space (7) of the housing (2) received locking element (8) cooperates such that the tensioning piston (4) is supported in a plurality of displacement positions against the extension direction, wherein the axial space (7) in at least one axial direction of the tensioning piston (4) by a separately manufactured from the housing (2) and on the housing (2 ) fixed stop member (9) is limited; as well as a traction mechanism drive with an endless traction means as well as a traction means tensioner (1) given a tension of the endless traction means.

Description

The invention relates to a clamping unit / Zugmittelspanneinheit for a traction drive of an internal combustion engine, such as a gasoline or diesel engine, a motor vehicle, such as a car, truck, bus, agricultural vehicle or motorcycle, with a housing, a slidably received in this housing and from an opening the clamping body (partially) protruding clamping piston, wherein the clamping piston is biased by a spring element in a direction of extension relative to the housing and having a latching contour, with a partially received in an axial space of the housing / arranged locking element cooperates such that the clamping piston in several displacement positions can be supported / supported against the extension direction. The invention also relates to a traction mechanism drive, preferably a chain drive, alternatively also a belt drive, with an endless traction means (chain or belt) and a clamping unit which predetermines a tension of the endless traction means.

Generic clamping devices are already known from the prior art. In this context, the US 2003/0 139 235 A1 a chain tensioner having a tubular housing having a bottom, a hollow piston slidably disposed in the housing, a return spring disposed in a hollow portion of the piston and urging the piston with an outward pressure force. Also, a plurality of locking grooves is provided on an outer side of the piston. An engageable in this locking grooves ring is also included in the chain tensioner.

However, it has proved to be disadvantageous in these embodiments that the latching devices used (having the blocking element and the latching contour) are often relatively complicated to produce. In particular, the axial space, for example by undercuts, often formed relatively complex. Furthermore, the assembly of the locking device during assembly of Zugmittelspanners then relatively complicated.

It is therefore the object of the present invention to remedy the known from the prior art disadvantages and in particular to achieve a simple mountable construction of a possible wear-resistant Zugmittelspanners.

This is achieved according to the invention in that the axial space is defined / defined in at least one axial direction of the tensioning piston by a stop element produced separately from the housing and fastened to the housing. As a result, the blocking element is secured against loss on the housing.

In particular, the mounting of the blocking element is substantially simplified by this training, since first the locking element inserted into the axial space relatively easy and can be completed in the connection of the axial space by attaching the stop element to the housing. Furthermore, an axial dimension of the axial space, which indirectly also defines a return stroke movement of the tensioning piston, can be adjusted particularly accurately by the relative position of the stop element to the housing during mounting.

Further advantageous embodiments are claimed in the subclaims and explained in more detail below.

If the stop element continues to be annular, i. in the form of a stop ring, formed, the stop element is designed to be particularly robust and stably received on the housing.

If the stop element held in a receptacle of the housing non-positively and / or positively, the mounting of the stop element is further simplified.

In this context, it is particularly advantageous if the stop element is pressed into a receptacle of the housing / held by a press fit. This allows a particularly stable recording and axially easily adjustable attachment of the stop element in the housing.

When the blocking element is substantially annular, that is, the blocking element extends substantially 360 ° around a center point and has two ends, i. if it is not endless, a provision of the clamping piston in the housing can be particularly easily generated by an expansion of the locking element. In other embodiments, however, it is also possible to perform the blocking element without ends for expansion. The blocking element is then designed as a continuous ring. The reset would then be possible when resting against the stop element / the press-fit sleeve and by clamping the locking element / locking ring.

In this regard, it is also expedient if the blocking element is so elastically deformable and is received in the axial space, that in an unlocked position (the locking element / the clamping piston) allows a (free) displacement of the clamping piston against the extension direction / released. Thus, one can The return movement of the tensioning piston is particularly easy to implement.

In addition, it is advantageous if the blocking element is formed from an elastic wire / spring wire. Thus, the manufacturing cost of the blocking element is further reduced.

If the blocking element has two supporting sections, which are each received displaceably in the axial space, a support of the clamping piston during a return stroke movement, i. an axial movement of the locking element within the axial space due to a force acting on the tensioning piston, ensured.

If an additional piston is used to guide the clamping piston between the clamping piston and the housing, a particularly wear-resistant / robust construction of Zugmittelspanners is guaranteed. In this context, it is also advantageous if the additional piston directly defines a leakage gap width. The clamping unit is designed so that it can be used in an installed position down.

Furthermore, it is advantageous if the clamping unit is designed as a hydraulic clamping unit / as a hydraulic Zugmittelspanner, whereby the operation of the Zugmittelspanners / the clamping unit is further improved.

In addition, the invention also relates to a traction mechanism drive with an endless traction means and a tensioning of the endless traction means predetermining clamping unit according to at least one of the embodiments described above. As a result, the traction mechanism drive is particularly efficient working.

In other words, according to the invention, a resettable (lockable) tensioner (clamping unit) is thus formed with a pressing piece (stop element). The pressing piece is pressed into the housing and serves as an end stop for the retaining ring (the blocking element). The thus formed additional sleeve (stop element) is used for easier assembly and for direct retention of the locking ring (blocking element).

The invention will now be explained in more detail with reference to figures, in which context also different embodiments are described.

Show it:

1 a longitudinal sectional view of a clamping unit according to the invention according to a preferred first embodiment,

2 a longitudinal sectional view of the clamping unit after 1 , where the cut is fixed in a cutting plane, which is rotated by about 90 ° to the in 1 is selected cutting plane, and wherein the clamping unit is now mirrored to the in 1 selected orientation is shown,

3 a perspective view of the entire clamping unit of 1 and 2 from its outside, wherein a transport locking element is used for fixing a tensioning piston relative to a housing of the tensioning unit in a transport state,

4 a front view of the clamping unit along with transport locking element after 3 wherein the extent of a locking element interacting with the tensioning piston is recognizable,

5 a view of the clamping unit together with transport locking element according to the 3 and 4 from a top,

6 a longitudinal sectional view of a clamping unit according to the invention according to a preferred second embodiment, wherein the internal structure of the clamping unit compared to the first embodiment is performed somewhat differently, for example, the tensioning piston is guided via an additional piston in addition in its displacement direction,

7 a longitudinal sectional view of the clamping unit after 6 , where the cut is fixed in a cutting plane, which is rotated by about 90 ° to the in 6 selected cutting plane, and wherein the clamping unit mirrored to the in 6 selected orientation is shown,

8th a perspective view of the entire clamping unit of 6 and 7 from its outside, again with a transport locking element for fixing the tensioning piston relative to the housing,

9 a view of the clamping unit with transport locking element after 8th from a top, and

10 a detailed view of the clamping unit of 6 to 9 on an end region of the tensioning piston projecting out of the housing.

The figures are merely schematic in nature and are for the sole purpose of understanding the invention. The same elements are provided with the same reference numerals. Also, the different features of the various embodiments can be combined freely with each other.

In 1 is a basic structure of a clamping unit according to the invention 1 according to a first embodiment in longitudinal section clearly visible. The clamping unit 1 is as a hydraulic clamping unit 1 executed. The clamping unit 1 used in their operation for tensioning a traction device / endless traction agent, which is why the clamping unit 1 Also referred to alternatively as Zugmittelspanner. The clamping unit 1 is designed in this embodiment as a chain tensioner / a chain tensioner. In other embodiments, however, is also a belt tensioner / a belt tensioner by the clamping unit 1 implemented. The clamping unit 1 is in operation part of a traction drive of an internal combustion engine.

The clamping unit 1 has, as usual, a housing 2 inside, within which a tensioning piston 4 in its longitudinal direction, ie in its axial direction (along the longitudinal axis 33 ), slidably guided. In particular, the tensioning piston 4 in a cylindrical wall area 17 of the housing 2 slidably received. The tensioning piston 4 protrudes in an operating state of the clamping unit 1 always with an end / end area 20 from an opening 3 of the housing 2 out. This from the opening 3 protruding end area 20 of the tensioning piston 4 is in the operating state in the usual way via a clamping element, such as a tensioner or a tensioning rail, applied to the endless traction means and acts on the endless traction means to compensate for the change in length and to control the traction mechanism drive.

The tensioning piston 4 is hollow. In one to a floor area 18 of the housing 2 opening cavity 19 of the tensioning piston 4 is a spring element 5 used in the form of a coil spring / helical compression spring. The spring element 5 is on the one hand at the bottom area 18 / fixed to the housing, on the other hand on the clamping piston 4 supported. Thus, the tensioning piston 4 against its retraction direction / in its extension direction relative to the housing 2 biased. The cavity 19 also forms part of a fluidic / hydraulic (high) pressure chamber 21 , which is filled in the operating state with a fluid / hydraulic medium, from. The pressure room 21 is typically further with a supply line 22 in the case 2 , with the interposition of a check valve 23 , coupled.

The tensioning piston 4 is also designed as a locking piston / Rastierkolben. Thus, a locking device is partially on the clamping piston 4 executed. The tensioning piston 4 has a catch contour for this purpose 6 on its radial outer surface / outside 24 on. The locking contour 6 is by several axially juxtaposed and annular locking grooves / recesses 25 educated. The recesses 25 act with a blocking element 8th together, which is also part of the Rastiereinrichtung.

The blocking element 8th is also particularly good in its extent 4 recognizable. The blocking element 8th is configured substantially annular. In particular, the blocking element 8th preferably made of a spring wire, ie an elastically deformable wire / bent. The blocking element 8th has two engagement sections 26 and 27 on. The engaging sections 26 and 27 are along a circumference of the blocking element 8th considered staggered to each other. Each engaging section 26 and 27 extends along an imaginary arc segment. Each engaging section 26 and 27 , as in 1 recognizable engages in the respective displacement position of the tensioning piston 4 relative to the housing 2 in an axial recess 25 of the tensioning piston 4 one. In particular, the blocking element 8th with regard to the engaging sections 26 and 27 so on the outside diameter of the recess 25 matched that the engaging sections 26 and 27 in a normal state of the blocking element 8th with a bias to the outside 24 pressed / in the recess 25 are pressed.

In 4 is also apparent that in addition to the engagement sections 26 and 27 two support sections 13 and 14 on the blocking element 8th are formed. Along the circumference of the blocking element 8th considered in each case a support section 13 . 14 between the engaging portions 26 and 27 designed. The support sections 13 and 14 are in the circumferential direction of the blocking element 8th arranged substantially offset by 180 ° to each other.

The blocking element 8th is designed as an open ring. Consequently, the blocking element 8th not endless, but open with two ends 11 and 12 executed. The two designed as wire ends ends 11 and 12 of the blocking element 8th overlap in the circumferential direction by a certain length, so from a front view according to 4 a completely circumferential extent is configured.

According to the invention, the blocking element 8th , like in the 2 and 3 clearly visible in an axial space 7 , on / in the case 2 implemented, added. The axial space 7 on the one hand / in a first axial direction with respect to the longitudinal axis 33 by a separate from the housing 2 manufactured stop element 9 limited. The stop element 9 is designed as a stop ring. The stop element 9 is in a recording 10 of the housing 2 firmly attached. For attachment of the stop element 9 in the recording 10 serves a press fit. Here, the stop element is secured in position with its radial outer peripheral surface in the receptacle on the interference fit. Alternatively or additionally, however, it is also possible this stop element 9 positively in the housing 2 to install. In a, the first axial direction opposite, the second axial direction with respect to the longitudinal axis 33 is the axial space 7 again directly through a directly through the housing 2 trained / gehäuseeinteiligen stop area 28 limited.

The axial space 7 is chosen to be greater in the axial direction than an axial extension / width of the blocking element 8th , Consequently, the blocking element 8th with axial play in the axial space 7 held secured against loss. The tensioning piston 4 is thereby a certain return stroke, despite being latched the locking element 8th in the respective recess 25 , Retractable against the extension direction.

In the rearward direction, ie in the retraction direction, the tensioning piston 4 blocked via the locking mechanism / the locking device (via Rastnutengeometrie (locking contour) and a corresponding geometry on the housing 2 / Housing). A certain return stroke is set and over the stop element 9 in the form of a press-fit variable and precisely adjustable.

Furthermore, according to the 3 to 5 , is a transport locking element 16 at least in a transport state of the clamping unit 1 inserted into this. The transport locking element 16 that too in 2 is shown in sections, is in a hole 29 in the case 2 and at the same time in a recess 25 , axially offset to the locking element 8th , pushed in. Thus, the tensioning piston 4 in its displacement position relative to the housing 2 set in the transport state.

In the 6 to 10 a second, preferred embodiment is illustrated. This second exemplary embodiment is essentially constructed and functioning in accordance with the first exemplary embodiment, for which reason only the essential differences between these two exemplary embodiments will be discussed below.

In the 6 and 7 it can be seen that an additional piston 15 additionally in the tensioning piston 4 is inserted. This additional piston 15 is at the bottom area 18 supported. The additional piston 15 also serves to accommodate the check valve 23 , which is why an additional reservoir / fluid receiving space 30 between the floor area 18 and the end area 20 of the piston 4 is held.

The clamping unit 1 is preferably designed for the clamping direction down. A leak gap / leakage gap 23 the clamping unit 1 located between the additional piston / hydraulic piston 15 and the tensioning piston 4 , In the receiving housing / housing 2 is the unit of clamping piston 4 and additional piston 15 then only guided.

There is also a pressure relief valve 31 in the tensioning piston 4 intended. This pressure relief valve 31 is also in 10 shown again in detail. The pressure relief valve 31 is preferably designed as a plate valve and arranged such that it is at an overpressure within the pressure chamber 21 that between the auxiliary piston 15 and the tensioning piston 4 is formed, opens. In addition, the by this additional piston 15 formed leakage gap 23 radially between the additional piston 15 and the tensioning piston 4 arranged.

In the 8th and 9 is again the arrangement with the transport locking element 16 illustrated.

In other words, according to the invention is a locking ring (blocking element 8th ), which on the chain tensioner (clamping unit 1 ) is held by an additional press-fit ring (stop element 9 ). In this case, the return stroke by a defined distance between a preferably designed with a slope geometry in the receiving housing 2 , usually made of aluminum, and a press-fit ring 9 set differently. (In addition, the press-fit ring 9 to reduce wear between the locking piston (clamping piston 4 ) and the chain tensioner housing 2 (including for a more accurate leakage gap 32 ) serve.) The locking ring 8th can by pressing two ends 11 and 12 be pressed or unlocked to suspend the locking function. With a locking ring 8th , which is installed horizontally or vertically or is installed arbitrarily, the release can be actuated. Also, the chain tensioner 1 Regarding venting and idling in the clamping direction upwards or horizontally inclined. The chain tension unit 1 can also be inclined downwards in terms of ventilation and idling in the clamping direction. In the same design, it can with a chain tensioning unit or a piston unit, in which a pressure relief valve 31 is used, combined.

LIST OF REFERENCE NUMBERS

1

 clamping unit

2

 casing

3

 opening

4

 clamping piston

5

 spring element

6

 catch contour

7

 axial space

8th

 blocking element

9

 stop element

10

 admission

11

 first end

12

 second end

13

 first support section

14

 second support section

15

 additional piston

16

 Transport locking element

17

 wall area

18

 floor area

19

 cavity

20

 end

21

 Pressure chamber (high pressure chamber)

22

 feed

23

 check valve

24

 outside

25

 recess

26

 first engagement section

27

 second engagement section

28

 stop area

29

 drilling

30

 Fluid receiving space (reservoir)

31

 Pressure relief valve

32

 leakage gap

33

 longitudinal axis

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

• US 2003/0139235 A1 [0002]

Claims (10)

Clamping unit ( 1 ) for a traction drive of an internal combustion engine, with a housing ( 2 ), one in this housing ( 2 ) slidably received as well as from an opening ( 3 ) of the housing ( 2 ) extending clamping piston ( 4 ), wherein the tensioning piston ( 4 ) by means of a spring element ( 5 ) in a direction of extension relative to the housing ( 2 ) is biased and a locking contour ( 6 ), with which a section in an axial space ( 7 ) of the housing ( 2 ) received blocking element ( 8th ) cooperates such that the tensioning piston ( 4 ) is supported in several displacement positions against the extension direction, characterized in that the axial space ( 7 ) in at least one axial direction of the tensioning piston ( 4 ) by a separate from the housing ( 2 ) and on the housing ( 2 ) fixed stop element ( 9 ) is limited. Clamping unit ( 1 ) according to claim 1, characterized in that the stop element ( 9 ) is annular. Clamping unit ( 1 ) according to claim 1 or 2, characterized in that the stop element ( 9 ) in a recording ( 10 ) of the housing ( 2 ) is held positively and / or positively. Clamping unit ( 1 ) according to one of claims 1 to 3, characterized in that the stop element ( 9 ) in a recording ( 10 ) of the housing ( 2 ) is held pressed. Clamping unit ( 1 ) according to one of claims 1 to 4, characterized in that the blocking element ( 8th ) is substantially annular and two ends ( 11 . 12 ) having. Clamping unit ( 1 ) according to one of claims 1 to 5, characterized in that the blocking element ( 8th ) is designed so elastically deformable and in the axial space ( 7 ) is received, that in an unlocked position, a displacement of the tensioning piston ( 4 ) is allowed against the extension direction. Clamping unit ( 1 ) according to one of claims 1 to 6, characterized in that the blocking element ( 8th ) is formed of an elastic wire. Clamping unit ( 1 ) according to one of claims 1 to 7, characterized in that the blocking element ( 8th ) two support sections ( 13 . 14 ), which in the axial space ( 7 ) are slidably received. Clamping unit ( 1 ) according to one of claims 1 to 8, characterized in that the clamping unit ( 1 ) Is designed so that it can be used in an installed position down. Traction drive with an endless traction means and a voltage of the endless traction means predetermining clamping unit ( 1 ) according to one of claims 1 to 9.

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