DE102016220943A1 - Camshaft adjuster with locking mechanism - Google Patents

Abstract

The invention relates to a camshaft adjuster (1) of the vane type for an internal combustion engine, comprising a stator (2), a rotor rotatable relative to this stator (2) about an axis of rotation (3) and a locking mechanism (4) for blocking the rotor relative to the rotor Stator (2) in a blocking position, wherein in the locking position, a bolt (5) slidably received in the rotor projects into a push-in hole (7) of the locking mechanism (4) introduced in a stator-fixed cover (6), wherein the bolt (5) is positioned relative to a side wall (8) of the push - in hole (7) and the side wall (8) is shaped such that the bolt (5) bears against the side wall (8) in the blocking position in a contact region (9) which is in Seen in the radial direction of the axis of rotation (3) seen outside a center (10) of the bolt (5).

Description

The invention relates to a (preferably hydraulic) camshaft adjuster of a vane type for an internal combustion engine of a motor vehicle, i. for adjusting a relative phase position between a crankshaft and a camshaft of the internal combustion engine, comprising a stator, a rotor rotatable about a rotation axis relative to the stator and a locking mechanism for locking the rotor relative to the stator in a locked position, wherein in the locked position in the rotor displaceably received bolt projects positively into an inserted into a stator-fixed cover slide-in hole of the locking mechanism.

Generic prior art is already well known. For example, the US 2014/0144283 a camshaft adjuster, which has a plurality of locking mechanisms, which are arranged on different pitch circles concentric with the axis of rotation of the camshaft adjuster.

The WO 2005/049976 A1 discloses a camshaft adjuster with a locking pin, which is cylindrical and oil-tightly guided in a first blind hole in the hub and parallel to the axis and in a locking link of one of the two side walls on or ausriegelbar. The locking pin is also locked by a corresponding oil pressure guide in the working chambers (A and B) and on its front surface safely and without jamming in the locking link and from the same sealed.

The DE 10 2008 021 315 A1 also discloses that the locking hole can also be arranged at an acute angle to the adjustment of the rotor relative to the stator.

Also, the state of the art from the WO 2005/108752 A1 , of the WO 2008/107275 A1 as well as the DE 10 2007 019 920 A1 known.

A disadvantage, however, has been found in the prior art that the reaction force between the locking pin (bolt) and the locking link (Einschiebeloch) often causes a radial tensile force on the rotor, such as the rotor blade / wing of the rotor, with the locking hole (push-in hole) in that a cross section between the locking bore and the outer surface of the rotor blade is loaded to train. Often an additional oil inlet groove for the bolt is placed on the same cross-section, which acts as an additional notch. As a result, the cross-section is often overstressed to train, so that a safety factor against breakage is well below 1.

It is therefore the object of the present invention to remedy these disadvantages known from the prior art and in particular to provide a camshaft adjuster whose components are significantly better secured against breakage, wherein a tensile load should be converted as possible into a compressive load to higher To be able to absorb tensions and thus increase the safety factor again.

This is inventively achieved in that the bolt is positioned relative to a side wall of the slide-in hole and the side wall is formed such that the bolt rests on the side wall in the locking position in a contact region, which contact area seen in the radial direction of the axis of rotation outside a center (Preferably, a surface and / or volume and / or center of gravity) of the bolt is located.

This is intended that the rotor is loaded in the locked state / in the blocking position instead of train on pressure. Thus, the safety factor against breakage can be seen clearly, i. especially above 1. In particular, the change in the position of the contact area / contact point between the bolt and the insertion hole so that the bolt at the contact region through the insertion hole / upon rotation of the rotor in the locked state against the locking stop in the form of the side wall and with respect to the central axis of rotation / central axis of the Rotor is no longer radially outward, but slightly pressed radially inward, allows this positive effect. As a result, a reaction force or a resulting reaction force acts radially inwards, so that the tensile load is converted into a compressive load in the rotor blade. By converting the tensile load into the compressive load in the critical section of the rotor, in particular the rotor blade, the safety against breakage can be increased by about 20%, since the compressive strength of the rotor material is up to 21% higher than the tensile strength. Alternatively, the security against breakage can be increased by increasing the cross-sectional area or by increasing the wall thickness of the rotor, in particular the rotor blade, however, the space is limited due to the customer required adjustment angle of 36 ° (on the camshaft).

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

It is particularly advantageous if an imaginary (first) circle, on which a contact point lies in the contact region between the locking pin and the locking link, is preferably larger by 0.1 mm to 1 mm than a radius imaginary (second) circle on which the center of the bolt lies. As a result, a particularly clever and robust design of the rotor and the inclusion of the bolt is implemented.

If the side wall is a section of the cross-sectionally circular slide-in hole, the slide-in hole is particularly simple in its geometry.

It is also advantageous if the side wall is alternatively formed by a just extending abutment surface of the push-in hole.

If the bolt of the locking mechanism is arranged / received in a wing of the rotor, the arrangement of the contact area is particularly effective.

It is furthermore advantageous if the abutment surface, viewed in a cross section of the camshaft adjuster, is arranged / oriented at an acute angle relative to an imaginary (first) radial line extending from the axis of rotation to a contact point of the contact region.

It is particularly advantageous if preferably an acute angle between 1 ° and 5 ° is provided.

Furthermore, it is expedient for the rotor to be produced from a sintered material, particularly preferably from a sintered D11, more preferably with a compressive strength of at least 450 N / mm ² . As a result, the compressive strength is further increased and is in particular higher than the standard value for the compressive strength of 400 N / mm ² according to DIN ISO 5755 and 21.6 ° higher than the standard value for the tensile strength of 370 N / mm ² according to DIN 30910-4 , However, the use of another sintered material, for example a Sint-D10, is also possible in principle.

In other words, a camshaft adjuster lock mechanism is thus implemented which solves the problem of reducing excessive stresses on the lock holes (push-in hole). In particular, the contact force vector is adjusted accordingly. In particular, the arrangement of the locking mechanism by the bolt in a wing of the rotor, as well as a circular contact surface, are further advantageous.

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

• 1 eine Querschnittsdarstellung eines Bereiches eines erfindungsgemäßen Nockenwellenverstellers nach einem ersten Ausführungsbeispiel, wobei ein Sperrmechanismus zu erkennen ist, in dem ein Bolzen in einer Sperrstellung in einem Einschiebeloch eines statorfesten Deckels eingeschoben ist, und
• 2 eine Querschnittsdarstellung eines Bereiches eines erfindungsgemäßen Nockenwellenverstellers nach einem zweiten Ausführungsbeispiel, wobei wiederum der Sperrmechanismus dargestellt ist, nun das Einschiebeloch nicht mehr, wie in dem ersten Ausführungsbeispiel, im Querschnitt betrachtet kreisrund ausgeführt ist, sondern mit einer Anschlagsfläche ausgestaltet ist.

Show it:

• 1 a cross-sectional view of a portion of a camshaft adjuster according to the invention according to a first embodiment, wherein a locking mechanism can be seen, in which a bolt is inserted in a locking position in a sliding hole of a statorfesten cover, and
• 2 a cross-sectional view of a portion of a camshaft adjuster according to the invention according to a second embodiment, in turn, the locking mechanism is shown, now the Einschiebeloch no longer, as in the first embodiment, viewed in cross-section circular, but is designed with a stop surface.

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.

Combined with 1 is an inventive camshaft adjuster 1 recognizable, with this camshaft adjuster 1 the sake of clarity is shown only in sections. The camshaft adjuster 1 is basically a camshaft phaser 1 built according to a wing cell type and functioning. The camshaft adjuster 1 is as a hydraulic camshaft adjuster 1 educated. In particular, in this context, the WO 2008/107275 A1 referenced, their structure for the camshaft adjuster 1 as incorporated herein.

Consequently, the camshaft adjuster according to the invention 1 in principle a stator 2 on, from here a lid 6 is shown. The stator 2 in turn rotates about a rotation axis 3 a rotor of the camshaft adjuster 1 rotatable on. The rotor is not shown for clarity. Rotor and stator 2 form a plurality of hydraulic working chambers between each other by radially extending inwardly extending projections on the stator and at radially outwardly projecting wings on the rotor. Depending on the pressurization of the working chambers, the rotor becomes relative to the stator 2 during operation of the camshaft adjuster 1 twisted. In 1 is a blocking position of the camshaft adjuster 1 implemented. Here, the rotor is relative to the stator 2 in its direction of rotation about the axis of rotation 3 by means of a locking mechanism 4 blocked.

The locking mechanism 4 has a bolt 5 on, which is also referred to as a locking pin. The bolt 5 is in an axial direction of the rotation axis 3 / of the rotor slidably received in a receiving hole of the rotor, namely in a wing of the rotor. In one direction in the slide hole 7 in / to the lid 6 there is a bolt 5 by means of a conventional spring, here a helical compression spring biased. Also includes a slide hole 7 to the locking mechanism 4 that in the lid 6 is provided. Like here in 1 is clearly visible, the bolt protrudes 5 in a blocking position of the camshaft adjuster 1 already in the slide hole 7 in and thus limited, depending on the dimensions of the slide hole 7 , ie in particular the length of the push-in hole 7 in the circumferential direction, the angle of rotation between the rotor relative to the stator 2 , In the normal state, in which the camshaft adjuster is not in the blocking position, in particular as a function of the pressure in the working chambers, a rotation of the rotor relative to the stator 2 can be converted by approx. 36 ° in one direction of rotation. The stator fixed cover 6 is here as a seen in the axial direction side cover of the stator 2 formed, which seals the working chambers to one axial side of the rotor.

In these embodiments, the bolt 5 in cross section 1 considered essentially circular. Also the slide hole 7 is made substantially circular, but has a larger diameter / radius than the bolt 5 , According to the invention, the bolt 5 now so relative to a side wall 8th (in the circumferential direction) of the insertion hole 7 positioned and the side wall 8th formed such that the bolt 5 on the side wall 8th in the illustrated blocking position in a contact area 9 is present, in the radial direction of the axis of rotation 3 seen outside of a midpoint 10 of the bolt 5 lies. This results in a particularly skillful alignment of the resulting force, as by pressing the contact area 9 on the bolt 5 acts. The contact area 9 is seen as a contact point in cross-section 12 formed, which by the formation of the respective outer and inner surfaces of the bolt 5 as well as the push-in hole 7 is conditional. Seen in the axial direction thus results in a plant line, which is the contact area 9 formed.

Also, it can be seen in cross-section that the side wall 9 the same radius / diameter as the further extension of the slide hole 7 in the circumferential direction. A radial force component F2 is thus in blocking the rotor relative to the stator 2 directed in the locked position inwardly and aligned an axial force component in the circumferential direction.

In particular, it is also clear that another (second) center 14 of the sliding hole 7 seen in cross section again radially within the (first) center point 10 and thus also within the contact area 9 / Contact point lies. Thus, the (third) radius R _{3 of} an imaginary (third) circle around the axis of rotation 3 through the (second) center 14 smaller than the (second) radius R _{2 of} an imaginary (second) circle about the axis of rotation 3 through the (first) center point 10 to the rotation axis 3 and smaller than the (first) radius R _{1 of} an imaginary (first) circle about the axis of rotation 3 through the contact area 9 / Contact point. One direction of rotation 15 of the bolt 5 and thus the rotor relative to the stator 2 is by means of the reference symbol 15 illustrated in principle.

Furthermore, it can be seen that an angle α ₁ between a vertical line 18 relative to a (first) radial line 13 from the axis of rotation 3 through the contact area 9 / Contact point is greater than an angle α ₂ , which is between the vertical line 18 and a (second) radial line 16 from the axis of rotation 3 through the center 10 runs, is. These two angles α ₁ and α ₂ are in turn greater than an angle α ₃ , that of the vertical line 18 and a (third) radial line 17 from the axis of rotation 3 to the (second) center 14 runs, is enclosed.

Furthermore, in particular, the rotor is formed of a sintered material.

Combined with 2 is then a second embodiment of the camshaft adjuster according to the invention 1 shown. This embodiment is largely constructed and functioning according to the first embodiment, which is why only the differences between the two embodiments are described below.

In particular, the slide-in hole 7 constructed slightly differently in the second embodiment. The slide-hole 7 has a flat and oblique to a radial line, such as the first radial line 13 , extending stop surface 11 on top of the side wall 8th forms to one side in the circumferential direction. The usual circumstances of the arrangements of the center 10 relative to the contact area 9 however, they are the same. Furthermore, this is an angle α ₄ between the contact area 9 with the rotation axis 3 connecting first radial line 13 relative to the extension line of the stop surface 11 educated. This angle α ₄ is an acute angle, ie an angle between 0 and 90 °. In this embodiment, the angle α _{4 is} in particular about 5 °, but may also be particularly preferably between 1 ° and 5 °. Because the stop surface 11 in this figure, parallel to the vertical line 18 is aligned, corresponds in this figure, the angle α ₄ the angle α ₁ . Again, in turn, the reaction force in the radial direction is directed inward, so that a pressure load instead of a tensile load in the rotor blade occurs.

In other words, according to the invention is thus a camshaft adjuster 1 allows to realize a voltage optimized rotor with a smaller wall thickness. Also, the camshaft adjuster 1 a larger adjustment at the same weight, or a lighter camshaft adjuster 1 reach at the same adjustment angle as in the embodiments of the prior art. The safety against breakage on the locking wing (wing) is increased by about 20% compared to the prior art and the failures in the field in the locked state (blocking position) of the camshaft adjuster 1 clearly avoided. In particular, a change in the reaction force F _{R is} implemented, which is changed in their direction. The change can be either in the case of a round locking gate 7 , eg with a pressed-in cup in the locking lid 6 such that the radius of the contact between the locking pin 5 and the locking link 7 should be greater than the position radius of the locking pin 5 (preferably around 0.1 to 1 mm). In another case may also be a locking link 7 with line contact surface 11 , eg in the case of a deformed locking link 7 be implemented. It is further possible to the embodiments of the first embodiment that an angle α ₄ for the contact point 9 between locking pin 5 and locking linkage 7 is formed as an acute angle greater than 0 ° and less than 90 °, preferably between 1 ° and 5 °.

LIST OF REFERENCE NUMBERS

1

Phaser

2

stator

3

axis of rotation

4

locking mechanism

5

bolt

6

cover

7

Einschiebeloch

8th

Side wall

9

contact area

10

Focus

11

stop surface

12

contact point

13

first radial line

14

second center

15

direction of rotation

16

second radial line

17

third radial line

18

vertical line

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 2014/0144283 [0002]
• WO 2005/049976 A1 [0003]
• DE 102008021315 A1 [0004]
• WO 2005/108752 A1 [0005]
• WO 2008/107275 A1 [0005, 0022]
• DE 102007019920 A1 [0005]

Claims (4)

Camshaft adjuster (1) according to a vane type for an internal combustion engine, comprising a stator (2), a rotor rotatable about a rotation axis (3) relative to said stator (2), and a locking mechanism (4) for blocking the rotor relative to the stator (2 ) in a blocking position, wherein in the blocking position, a bolt (5) slidably received in the rotor projects into a push-in hole (7) of the locking mechanism (4) introduced in a stator-fixed cover (6), characterized in that the bolt (5) is positioned relative to a side wall (8) of the push - in hole (7) and the side wall (8) is shaped such that the bolt (5) bears against the side wall (8) in the blocking position in a contact region (9) which is in Seen in the radial direction of the axis of rotation (3) seen outside a center (10) of the bolt (5). Camshaft adjuster (1) to Claim 1 , characterized in that the side wall (8) is a portion of the circular cross-section Einschiebelochs (7). Camshaft adjuster (1) to Claim 1 or 2 , characterized in that the side wall (8) by a just extending stop surface (11) of the push-in hole (7) is formed. Camshaft adjuster (1) to Claim 3 , characterized in that the abutment surface (11), viewed in a cross section of the camshaft adjuster (1), at an acute angle relative to one of the rotational axis (3) to a contact point (12) of the contact region (9) extending radial line (13) is arranged.

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