DE102011003114A1 - Device for changing angular position of cam shaft relative to crankshaft, in internal combustion engine, has spacing element provided with two attaching units that are attached with screws and/or nuts in form- and/or force-fit manner - Google Patents

Abstract

The device has a lid fixed to the device by attachment screws and/or nuts (3). A spring element i.e. torsion spring, is arranged in the lid. A rotatable part exerts restoring movement relative to a housing portion by using the spring element. A spacing element (5) i.e. flat ring, is arranged in a region of axial extension of the screws and/or nuts to define an axial support surface (6) for the spring element. The spacing element is provided with two attaching units that are attached with the screws and/or nuts in a form- and/or force-fit manner, in circumferential direction (U). The attaching units of the spacing element are formed as a serrate-shaped profile, and a radially resilient element in form of a spring-elastic arc-like element (10).

Description

Field of the invention

The invention relates to a device for changing the relative angular position of a camshaft relative to a crankshaft of an internal combustion engine, wherein the device comprises a toothed wheel, which is driven by a rotatably connected to the crankshaft drive element and the device rotates about an axis, wherein the device Area of the gear has a cover member with which a housing part of the device is completed, wherein the lid member is fixed with a number of fastening screws or nuts on the device, wherein in the cover member, a spring element is arranged, with a relative to the housing part rotatable part of the device can be exerted a restoring moment, and wherein a spacer element in the region of the axial extension of the fastening screws or nuts is arranged to define an axial bearing surface for the spring element.

Background of the invention

Camshaft adjusters, particularly those that operate hydraulically, are well known in the art. In the hydraulic camshaft adjuster an impeller is present in which wings are molded or arranged. The wings are located in hydraulic chambers, which are incorporated in an outer rotor (usually referred to as a stator). By appropriate loading of the respective side of the hydraulic chambers with hydraulic fluid, an adjustment of the inner rotor (connected to the camshaft) can take place relative to the stator between an "early stop" and a "late stop". The flow of hydraulic oil is controlled by an electrically controlled directional control valve.

Camshaft adjuster of this type are for example from the DE 10 2007 028 187 A1 known. A similar solution shows the DE 10 2008 001 078 A1 ,

In a special construction (see the following 1 and 2 ) has the camshaft adjuster in the region of a drive gear 1 for the adjuster a cover element 2 on, with a housing part of the camshaft adjuster is completed. The cover element 2 is with a number of mounting nuts 3 (in this case with four nuts) fixed on the camshaft adjuster. Furthermore, in the cover element 2 a spring element 4 arranged, with which on a relative to the housing part rotatable part of the device, a restoring moment can be exerted. So that the spring element 4 properly guided or stored and not under the fastening nuts 3 can guess is a spacer 5 in the form of a flat ring in the region of the axial extent of the fastening nuts 3 arranged to for the spring element 4 an axial bearing surface 6 define.

The mounting of the spacer (spacer disc or ring) in the cover element is usually done by axial pressing. In this case, the spacer element is clamped to the fastening nuts of the cover element. The very rigid, inelastic clamping leads to high insertion forces, which must be applied during assembly. As a result, it can happen that chips are generated by scraping off of material particles during Eipressens that get inside the camshaft adjuster and thus in the oil circuit of the adjuster.

In some embodiments of camshaft adjusters, a spacer is used for this reason, which can be used with play in the cover element. The disadvantage of this solution, however, that it sometimes comes to an axial protrusion of the spacer. Another problem may be that the phaser must be turned during assembly so that the shim may fall out.

Object of the invention

The present invention has the object, a device of the type mentioned in such a way that it is possible to avoid the disadvantages mentioned. Accordingly, the risk of generation of chips when mounting the spacer should be eliminated. Depending on the application, it should be possible, depending on the assembly concept, to mount the spacer disc firmly or only loosely. This should simplify the assembly and reduce the cycle time during assembly. It should be suitable for both a fixed and for a loose assembly of the spacer only a single shim. This should lead to economic advantages in parts production.

Summary of the invention

The solution of this object by the invention is characterized in that the spacer element is provided with fastening means to form and / or non-positively fix it in the circumferential direction of at least one of the fastening screws or nuts.

The spacer element is preferably formed as a flat ring.

According to a first embodiment of the invention it is provided that the spacer element for the fastening screws or nuts has recesses which are formed lying in the radially outer region of the spacer over a greater circumferential extent than would correspond to the shape of the fastening screw or nut, wherein the fastening means is designed as a serrated profile formed in the radially inner region of at least one recess.

An alternative embodiment provides that the annular spacer has an interruption at a peripheral location, wherein at least one end of the spacer element, seen in the circumferential direction, a recess for a fastening screw or nut is arranged, wherein the recess defining part of the spacer as radially resilient part is formed, which can be snapped around a portion of the circumference of a fastening screw or nut. In this case, radially resilient parts are preferably arranged at both ends of the spacer element, as seen in the circumferential direction. The radially elastic part is preferably designed as a circumferentially extending arcuate structure.

Due to the here provided interruption of the annular spacer advantageously results in an embodiment, according to which the spacer extends at n mounting screws or nuts over a circumferential angle of (n - 1) / n × 2π.

The spacer element is preferably an injection molded part made of plastic.

The spacer element may further comprise at least one recess for an assembly tool in its area outside the recesses for the fastening screws or nuts.

To safely avoid chip formation during assembly, it can be provided that the annular spacer element is tolerated relative to the cover element and the fastening screws or nuts arranged therein so that it can be pushed axially into the cover element into its end position with a clearance fit can.

The proposed concept makes it possible to use the spacer element in designs that provides only loose insertion of the spacer element, but also in those constructions in which the spacer element must be fixedly arranged in the cover element.

If only a loose assembly is required, the spacer is inserted; the cycle time of the assembly and the installation costs are correspondingly low. However, if a fixed arrangement of the spacer is necessary (in particular due to the assembly concept, namely, when the camshaft adjuster must be turned during assembly, whereby the spacer element would fall out), can be used with the same spacer. By a rotation in the circumferential direction, the spacer can be spent in a tight fit.

Brief description of the figures

In the drawings, embodiments of the invention are shown. Show it:

1 a perspective view of a part of a device for changing the relative angular position of a camshaft relative to a crankshaft of an internal combustion engine, ie a camshaft adjuster, wherein a cover element, a drive gear for the camshaft adjuster and a spring element and a spacer can be seen,

2 the arrangement without spring element and seen in the axial direction, wherein a configuration according to the prior art is shown,

3 a spacer element in a first embodiment of the invention, viewed in the axial direction,

4 a section of the spacer after 3 , wherein two relative positions of a fastening nut is shown,

5 a spacer element in a second embodiment of the invention, viewed in the axial direction, and

6 the spacer according to 5 in the assembled state, with four fastening nuts are marked.

Detailed description of the figures

In 1 is again the above-described construction of a part of a camshaft adjuster shown in perspective. For rotary drive, the illustrated end part of the adjuster comprises a cover element 2 on, that with four nuts 3 on an only indicated housing 12 is attached; on the right side of the housing, which is only partially illustrated, the further camshaft adjuster joins the actual adjusting mechanism.

To act on a - not shown - inner rotor in the housing with a restoring moment in a zero position, in the axial end region of the camshaft adjuster a spring element 4 arranged in the form of a torsion spring. In order for their function is properly ensured, is in the cover element 2 before mounting the spring element 4 a spacer element 5 used in the form of a flat ring. The spacer element 5 forms an axial bearing surface 6 for the spring element 4 so this particular not under the nuts 3 can guess what the function of the spring element 4 would affect.

A first embodiment of the spacer element 5 is in the 3 and 4 to see the same solution. The spacer element 5 does not extend around the entire circumference (circumferential direction U) around the central axis of the cover element, but only over approximately 270 °. Before mounting the spring element 4 First, the spacer element 5 in the lid element 2 used. This can be done without high axial insertion forces, the spacer element 5 in terms of the radial dimensions of the cover element 2 and to the nuts 3 tolerated so that game is present.

For the nuts 3 has the spacer element 5 correspondingly shaped recesses 9 on. At the in the circumferential direction 9 lying ends of the spacer 5 are the recesses 9 ' approximately quarter-circular shaped; accordingly, here is room for two of the nuts 3 , Next to it, the spacer element 5 two more recesses 9 '' for the other two nuts 3 on. Here you can see that the recesses 9 '' are formed over a larger circumferential extent than the shape of the nuts 3 would correspond. Accordingly, the spacer element 5 after putting it in the lid element 2 is used, are rotated in the circumferential direction U by a certain angle of rotation. For this purpose, a (not shown) tool is used, which in window-like recesses 11 in the spacer element 5 intervene and with which this can be turned.

As can be seen, the spacer element points 5 in the area of the recesses 9 '' fastener 7 in order to form it in the circumferential direction U and / or non-positively on at least one of the fastening nuts 3 set.

Specifically, the fasteners 7 here as a serrated profile in the radially inner region of the recesses 9 '' educated. This is in 4 shown in detail. The individual spikes 13 project radially into the region of the recess 9 '' into it and form a knurl, which is for the here located mother 3 . 3 ' (in the micro range) represent a positive connection or a frictional connection in the circumferential direction U.

Accordingly, the spacer provides 5 two possible uses:
Should or can the spacer 5 Loosely mounted, it is so in the cover element 2 inserted that nuts 3 in the relative position to the spacer element 5 to come to rest, as by the mother 3 in 4 is indicated. It can be seen that radial play 14 between the mother 3 and the spacer 5 in the region of the recess 9 is present. In this position, the further assembly of the camshaft adjuster, ie the installation of the spring element takes place 4 ,

Should or must meanwhile the spacer element 5 is fixed, it is first inserted as described above, ie in the relative position between mother 3 and spacer 5 as it is through the mother 3 in 4 is specified. Then, however, the spacer element 5 in the circumferential direction U by means of a tool rotated by a small angle, so that there is a relative position between the spacer and the mother, as is the mother 3 ' in 4 is drawn. Accordingly, now is the mother 3 ' with the serrated fastener 7 engaged so that the spacer element 5 is held with frictional engagement (or in the micro range with positive locking). Now the camshaft adjuster can - for the purpose of further assembly - also be reversed, without having to worry about the spacer element 5 fall out.

Another embodiment of the invention is in the 5 and 6 to see. Again, there are fasteners 8th at the spacer element 5 , The spacer element is in turn formed here as a ring extending over approximately 270 ° (in radians: 3 / 2π), so that here end portions of the spacer element 5 result. The fasteners 8th are as radially resilient parts in the form of resilient elbows 10 formed, the the circumferential shape of the nuts 3 are modeled. The bows 10 have accordingly recesses 9 ''' for the nuts 3 on, however, after assembly, elastic on the circumference of the nuts 3 issue. However, there are two more recesses 9 '''' provided, which are formed after the mounting of the spacer element 5 see with, which are formed, after mounting the spacer 5 with play relative to the nuts 3 to come to rest.

In 6 is the assembled state of the spacer 5 indicated. As can be seen, lie the bows 10 now elastic on a peripheral portion of the nuts 3 and thus fix the spacer element 5 so that it stays in the mounted position even if the Camshaft adjuster is turned with the open side down. When mounting the spacer 5 so are the elastic bows 10 around two of the nuts 3 cocked or snapped so that the spacer element 5 is fixed. A sufficient mobility of the bows 10 during assembly is through corresponding recesses 15 guaranteed.

The circumferential extent of the spacer element 5 is four nuts 3 about 270 ° (in radians: 3 / 2π). Generally speaking, n would be mother 3 the circumferential angle (n-1) / nπ.

Accordingly, the proposed spacer allows 5 a variable application, either for the loose or the fixed seat. If loose installation is envisaged or possible, cost savings can be made by reducing assembly cycle time.

A chip formation during assembly of the spacer element 5 is also excluded because there is no axial pressing of the spacer 5 There is more, but only a twisting of the spacer 5 in the circumferential direction U or the snapping of the sheets 10 when a fixed arrangement of the spacer is sought.

The spacer element is realized as a cost-effective injection molded plastic part.

The proper operation of the spring element 4 is still through the spacer element 5 ensured, ie the spring element 4 can not in collision with the nuts 3 reach.

LIST OF REFERENCE NUMBERS

1

gear

2

cover element

3

Fixing screw / fixing nut

3 '

Fixing screw / fixing nut

4

spring element

5

Spacer element (disc)

6

axial bearing surface

7

fastener

8th

fastener

9

recess

9 '

recess

9 ''

recess

9 '' '

recess

9 '' ''

recess

10

radially elastic part (elastic bend)

11

recess

12

casing

13

jag

14

game

15

recess

U

circumferentially

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 102007028187 A1 [0003]
• DE 102008001078 A1 [0003]

Claims (10)

Device for changing the relative angular position of a camshaft relative to a crankshaft of an internal combustion engine, the device comprising a gearwheel ( 1 ) which is driven by a drive element rotatably connected to the crankshaft and rotatably drives the device about an axis, wherein the device in the region of the gear ( 1 ) a cover element ( 2 ), with which a housing part of the device is completed, wherein the cover element ( 2 ) with a number of fastening screws or nuts ( 3 ) is fixed to the device, wherein in the cover element ( 2 ) a spring element ( 4 ) is arranged, with which on a relative to the housing part rotatable part of the device, a restoring moment can be exerted, and wherein a spacer element ( 5 ) in the region of the axial extent of the fastening screws or nuts ( 4 ) is arranged to for the spring element ( 4 ) an axial bearing surface ( 6 ), characterized in that the spacer element ( 5 ) with fastening means ( 7 . 8th ) is provided to it in the circumferential direction (U) positive and / or non-positively on at least one of the fastening screws or nuts ( 3 ). Apparatus according to claim 1, characterized in that the spacer element ( 5 ) is formed as a flat ring. Apparatus according to claim 1, characterized in that the spacer element ( 5 ) for the fastening screws or nuts ( 3 ) Recesses ( 9 ), which in the radially outer region of the spacer element ( 5 ) lying over a greater circumferential extent than the shape of the fastening screw or nut ( 3 ), the fastening means ( 7 ) as a serrated profile in the radially inner region of at least one recess ( 9 ) is trained. Apparatus according to claim 2, characterized in that the annular spacer element ( 5 ) has an interruption at a peripheral location, wherein at least one end of the spacer element, seen in the circumferential direction (U), a recess ( 9 ) for a fastening screw or nut ( 3 ) is arranged, wherein the recess ( 9 ) limiting part of the spacer element ( 5 ) as a radially elastic part ( 10 ) is formed around a part of the circumference of a fastening screw or nut ( 3 ) can be caught. Apparatus according to claim 4, characterized in that at both ends of the spacer element ( 5 ), seen in the circumferential direction (U), radially elastic parts ( 10 ) are arranged. Apparatus according to claim 4, characterized in that the radially resilient part ( 10 ) is formed as in the circumferential direction (U) extending arcuate structure. Apparatus according to claim 4, characterized in that the spacer element ( 5 ), with n fastening screws or nuts ( 3 ) extends over a circumferential angle of (n-1) / n × 2π. Apparatus according to claim 1, characterized in that the spacer element ( 5 ) Is an injection molded plastic part. Apparatus according to claim 1, characterized in that the spacer element ( 5 ) in its area outside the recesses ( 9 ) for the fastening screws or nuts ( 3 ) at least one recess ( 11 ) for an assembly tool. Apparatus according to claim 2, characterized in that the annular spacer element ( 5 ) relative to the cover element ( 2 ) and arranged in this fastening screws or nuts ( 3 ) is tolerated so that it with clearance fit axially on or in the cover element ( 2 ) can be inserted into its final position.

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