EP1646769B1 - Device for altering the control times of gas exchange valves in an internal combustion engine, in particular a rotating piston adjustment device for the rotation angle adjustment of a camshaft relative to a crankshaft - Google Patents

Description

Field of the invention

The invention relates to a device for changing the timing of gas exchange valves of an internal combustion engine according to the preamble of forming features of claim 1, and it is particularly advantageous in a rotary piston adjustment for rotational angle adjustment of a camshaft relative to a crankshaft realized.

Background of the invention

From the German patent application DE 101 50 856 A1 is a generic device for changing the timing of gas exchange valves of an internal combustion engine is known, which is fixed to the drive side end of a cylinder head mounted in the engine camshaft and is formed in principle as a function of various operating parameters of the engine controllable hydraulic actuator. This device essentially consists of a drive wheel which is in driving connection with a crankshaft of the internal combustion engine and an impeller rotatably connected to a camshaft of the internal combustion engine, wherein the drive wheel has a cavity formed by a hollow cylindrical peripheral wall and two side walls, in which five radial boundary walls five hydraulic work spaces are formed. Accordingly, the impeller has at the periphery of its hub five radially extending into the working space wings, which divide the work spaces in two oppositely acting hydraulic pressure chambers, the swivel movement or fixation of the impeller with respect to the drive wheel and at selectively or simultaneously pressurization with a hydraulic pressure medium thus cause the camshaft relative to the crankshaft. In addition, the impeller when falling below a required for adjustment pressure medium pressure, such as when switching off the engine by a separate locking element in a preferred base position within its adjustment with the drive wheel mechanically coupled to a particular when restarting the engine to build up the required pressure medium pressure From the alternating torques of the camshaft resulting stop clatter of the impeller to avoid the boundary walls of the drive wheel. This, designed as a cylindrical locking pin locking element is displaceable by a spring element designed as a compression coil spring into a locking position within a receptacle in the camshaft side wall of the drive wheel and arranged together with the spring element in a direction parallel to the longitudinal center axis of the device through hole in the wheel hub of the impeller. In this case, the locking pin on its back on an axial blind hole in which one end of the compression coil spring is fixed, while the other end of the compression coil spring is supported on a plastic counter-holder inserted into the through hole with a centering, in turn, by back contact with a Side wall of the drive wheel is axially fixed.

A disadvantage of this known device, however, is that the locking mechanism used by the fixation of the counter-holder for the compression coil spring on a side wall of the drive wheel is only suitable for a certain width of the impeller when the compression coil spring should always act with the same defined spring force on the locking pin , The use of such a lock on other devices, each with different width of the impeller thus makes for compliance the force acting on the locking pin defined spring force always requires an adjustment of the lock to the respective impeller, which is usually done by execution of the counter-holder of the compression coil spring with different lengths. As a result, a separate counter-holder for the compression coil springs is necessary for each width of an impeller, which increases the already existing variety of parts and error rates even with a corresponding number of different devices and thus contributes to a disadvantageous increase in the manufacturing cost of each device. In addition, the fixation of the counter-holder for the compression coil spring on a side wall of the drive wheel has also been found to be disadvantageous in that the counter-holder is subject to increased wear by the pivotal movements of the impeller and the associated frictional contact with the side wall of the drive wheel through which the on the Locking pin acting spring force of the compression coil spring steadily reduced, thus increasing the locking time of the locking pin. The publication DE 10044423 discloses a phaser with a similar locking mechanism.

Object of the invention

The invention is therefore based on the object, a device for changing the timing of gas exchange valves of an internal combustion engine, in particular rotary piston adjustment for rotational angle adjustment of a camshaft with respect to a crankshaft, to design their locking mechanism while avoiding a frictional contact of the counter-holder for the compression coil spring of the locking pin to a side wall the drive wheel without adjusting the length of this counter-holder ensures compliance with a defined, acting on the locking pin spring force even when used in devices with different widths of the impeller compliance.

Summary of the invention

According to the invention, this object is achieved in a device according to the preamble of claim 1 such that the counter-holder for the other End of the compression coil spring of the locking pin is designed as a hollow cylindrical cartridge which can be locked by force or positive locking in any axial position within the through hole in the wheel hub of the impeller. Such a design of the counter-holder as a freely positionable cartridge thus makes it possible to position the counter regardless of the width of the impeller or regardless of the axial length of the through hole in the impeller always in exactly that axial position within the through hole, in the desired with the compression coil spring defined spring force is achieved on the locking pin.

In an expedient development of the device according to the invention, the hollow cylindrical cartridge is designed as a punched drawing part of a steel sheet, which has a plate-shaped axial recess for fixing the other end of the compression coil spring in its bottom end face. The diameter of this axial recess corresponds approximately to the outer diameter of the spring coils of the compression coil spring and the depth of the axial recess is preferably formed such that some two spring coils of the compression coil spring are radially supported in the axial recess. In addition, the cartridge longitudinally in the axial recess on a venting bore opening into the cavity of the cartridge, through which the accumulating behind the locking pin in the through hole in the impeller hydraulic pressure fluid is discharged to another vent hole in the adjacent side wall of the drive wheel.

An alternative development of the device according to the invention is also to form the hollow cylindrical cartridge for fixing the other end of the compression coil spring on its bottom end face with a peg-shaped axial extension. The diameter of this Axialverlängerung corresponds approximately to the inner diameter of the spring coils of the compression coil spring and the length of Axialverlängerung is again formed so that about two spring coils of the compression coil spring are supported radially on the Axialverlängerung. Also, such a trained cartridge is produced as a punched drawing part of a steel sheet without cutting and has as well as the first-mentioned embodiment longitudinal axial in the axial extension opening into the cavity of the cartridge vent hole for discharging the accumulating behind the locking pin in the through hole hydraulic pressure fluid.

As a further embodiment of the device according to the invention, a plurality of embodiments for locking the counter-holder of the compression coil spring of the locking pin in the through-hole in the impeller beyond the example are proposed below, which have proven to be the most cost-effective among the variety conceivable Arretierungsmöglichkeiten.

Such a first embodiment for locking the hollow cylindrical cartridge in the through hole is, for example, to form the cartridge on its lateral surface with a slightly larger diameter than the through hole in the wheel hub of the impeller and frictionally secure by press fit in this through hole. In this case, the cartridge is pressed from the camshaft-side bore opening of the through hole as far as in this until it reaches the position defined by an auxiliary inserted into the through hole counter stop position in the through hole in which the compression coil spring exerts the desired defined spring force on the locking pin. A likewise possible implementation form to secure the cartridge by press fit in the through hole in the wheel hub of the impeller, it would also form the cartridge in the manner of a dowel pin with a longitudinal axial slot in its lateral surface and bottomless and the thus formed cartridge by compressing the Slots in the through hole to introduce. The other end of the compression coil spring is designed such that its first spring coil is supported on the then annular bottom face of this cartridge.

As an alternative to the first embodiment, it is proposed as a second embodiment of the locking of the hollow cylindrical cartridge in the through hole, the hollow cylindrical cartridge on its lateral surface with a slight smaller diameter than the through hole in the wheel hub of the impeller form and form fit to attach by conditioning their end edge to a snap ring inserted into a circumferential groove in the through hole in the through hole. In this embodiment, the position of the cartridge in the through-hole in which the compression coil spring exerts the desired defined spring force on the locking pin is determined taking into account the axial length of the cartridge by the circumferential groove in the through-hole.

A third embodiment of the locking of the hollow cylindrical cartridge in the through hole, it is finally, the hollow cylindrical cartridge also with a slightly smaller diameter than the through hole in the wheel hub of the impeller and with multiple open axial slots in its outer surface and an outwardly angled end edge form, with which the cartridge is positively secured by clipping its end edge in a circumferential groove in the through hole in selbiger. The thus formed cartridge is introduced as well as the according to the second embodiment of the camshaft distal bore opening of the through hole in this, the axial slots in the lateral surface of the cartridge allow compression of the angled end edge in the through hole. The position of the cartridge in the through-hole in which the compression coil spring exerts the desired defined spring force on the locking pin is also determined in this embodiment by the positioning of the circumferential groove in the through hole, taking into account the axial length of the cartridge.

It should be mentioned only that in addition to the attachment of the hollow cylindrical cartridge in the through hole by pure force or positive connection but so-called Mischbefestigungsarten are conceivable in which the cartridge, for example, by wedging in a defined position in the through hole, both by traction and is attached by positive engagement in the through hole. It is also possible, the hollow cylindrical cartridge by cohesive connections, as for example When welding, soldering and gluing arise, in the through hole in the wheel hub of the impeller to attach. In addition, it is also conceivable that the cartridge not hollow cylindrical but fully cylindrical form and equip with the said possibilities for fixing the other end of the compression coil spring. The assembly of such a fully cylindrical cartridge in the through hole in the wheel hub of the impeller is then by pressing or by material connections or in the manner of a grooved pin and the vent of the through hole can by one or more centric or eccentric axial bores or by one or more axial grooves on Scope of the cartridge can be realized.

The inventively designed device for changing the timing of gas exchange valves of an internal combustion engine, in particular rotary piston adjusting the rotational angle adjustment of a camshaft relative to a crankshaft, thus has the advantage over the known from the prior art devices has the advantage that their locking mechanism by forming the counter-holder of the compression coil spring Locking pin as a hollow cylindrical cartridge, which is fixed by force or positive engagement in the through hole in the wheel hub of the impeller, without any adjustment work now also in device with different width of the impeller is used and always maintaining a defined, acting on the locking pin spring force guaranteed. Since the fixation of the counter-holder for the compression coil spring also no longer takes place on a side wall of the drive wheel but within the through hole in the wheel hub of the impeller, the pivoting movements of the impeller have no influence on the locking mechanism, so that the counter-holder of the compression coil spring of the locking pin practically wear-free is.

Short description of the drawing

Figur 1

einen Längsschnitt durch eine erfindungsgemäße ausgebildete Vorrichtung;

Figur 2

eine vergrößere Darstellung der Einzelheit Z nach Figur 1 mit einer ersten Ausführungsform der Fixierung der Druckschrau- benfeder des Verriegelungsstiftes an deren Gegenhaltung und einer ersten Ausführungsform der Fixierung des Gegenhalters in der Durchgangsbohrung in der Radnabe des Flügelrades;

Figur 3

eine vergrößerte Darstellung der Einzelheit Z nach Figur 1 mit einer zweiten Ausführungsform der Fixierung der Druckschrau- benfeder des Verriegelungsstiftes an deren Gegenhalter und der ersten Ausführungsform der Fixierung des Gegenhalters in der Durchgangsbohrung in der Radnabe des Flügelrades;

Figur 4

eine vergrößerte Darstellung der Einzelheit Z nach Figur 1 mit der zweiten Ausführungsform der Fixierung der Druckschrau- benfeder des Verriegelungsstiftes an deren Gegenhalter und einer zweiten Ausführungsform der Fixierung des Gegenhalters in der Durchgangsbohrung in der Radnabe des Flügelrades;

Figur 5

eine vergrößerte Darstellung der Einzelheit Z nach Figur 1 mit der zweiten Ausführungsform der Fixierung der Druckschrau- benfeder des Verriegelungsstiftes an deren Gegenhalter und einer dritten Ausführungsform der Fixierung des Gegenhalters in der Durchgangsbohrung in der Radnabe des Flügelrades.

The invention will be explained in more detail with reference to several embodiments and is shown schematically in the accompanying drawings. Showing:

FIG. 1

a longitudinal section through a device according to the invention formed;

FIG. 2

an enlarged view of the detail Z after FIG. 1 with a first embodiment of the fixation of the Druckschrau- benfeder of the locking pin at their counter-holding and a first embodiment of the fixation of the counter-holder in the through hole in the wheel hub of the impeller;

FIG. 3

an enlarged view of the detail Z after FIG. 1 with a second embodiment of the fixation of the pressure screw spring of the locking pin to its counter-holder and the first embodiment of the fixation of the counter-holder in the through-hole in the wheel hub of the impeller;

FIG. 4

an enlarged view of the detail Z after FIG. 1 with the second embodiment of the fixation of the pressure screw spring of the locking pin to its counter-holder and a second embodiment of the fixation of the counter-holder in the through-hole in the wheel hub of the impeller;

FIG. 5

an enlarged view of the detail Z after FIG. 1 with the second embodiment of the fixation of the pressure screw spring of the locking pin to its counter-holder and a third embodiment of the fixation of the counter-holder in the through-bore in the wheel hub of the impeller.

Detailed description of the drawing

Out FIG. 1 clearly shows a device 1 for changing the timing of gas exchange valves of an internal combustion engine, which is concretely designed as a rotary piston adjusting device for adjusting the rotational angle of a camshaft relative to a crankshaft and attached to the drive end end of the cylinder head of the engine, not shown camshaft. This device 1 is designed in principle as a function of various operating parameters of the engine controllable hydraulic actuator and consists essentially of a standing with the crankshaft of the engine drivingly connected drive wheel 2 and a non-rotatably connected to the camshaft of the engine impeller 3. The drive wheel indicates, as well as from FIG. 1 it can be seen, a cavity formed by a hollow cylindrical peripheral wall 4 and two side walls 5, 6, in which a plurality of hydraulic working spaces are formed by a plurality of radial boundary walls 7. The impeller 3 has accordingly on the circumference of its hub 8, the same number radially extending into a working space of the drive wheel wings 9, which divide the work spaces in two oppositely acting hydraulic pressure chambers 10, 11, the case of selective or simultaneous pressurization with a hydraulic pressure medium cause a pivoting movement or fixation of the impeller 3 relative to the drive wheel 2 and thus the camshaft relative to the crankshaft. In addition, in FIG. 1 to see that the device 1 has a separate locking element with which the impeller 3 is mechanically coupled when falling below a pressure medium pressure required for adjustment in a preferred base position within its adjustment range with the drive wheel 2. This locking element is clearly visible as a cylindrical locking pin 12 which is displaceable by a spring element into a locking position within a receptacle 13 in the side wall 5 of the drive wheel 2. The spring element is designed as a compression coil spring 14 which, together with the locking pin 12 in a direction parallel to the longitudinal central axis of the device 1 through hole 15 is arranged in the wheel hub 8 of the impeller and whose one end 17 is fixable in an axial base bore 16 on the back of the locking pin 12. The other end 18 of the compression coil spring 14 for the locking pin 12, however, is supported on a disposed in the through hole 15, also in FIG. 1 clearly visible counter-holder, which is designed according to the invention as by force or positive locking in any axial position within the through hole 15 in the hub 8 of the impeller 3 lockable hollow cylindrical cartridge 19.

By the in FIG. 2 shown enlarged view of the detail Z after FIG. 1 It is clear that the hollow cylindrical cartridge 19 is formed as a stamped drawing part of a steel sheet which has a plate-shaped axial recess 21 for fixing the other end 18 of the compression coil spring 14 in its bottom end face 20, whose diameter corresponds to the outer diameter of the spring coils 22 of the compression coil spring 14. Alternatively, in FIG. 3 illustrated that the hollow cylindrical cartridge 19 may also be formed as a stamped drawing part of a steel sheet which has a pin-shaped axial extension 23 for fixing the other end 18 of the compression coil spring 14 at its bottom end face 20, whose diameter corresponds to the inner diameter of the spring coils 22 of the compression coil spring 14.

Both off FIG. 2 as well as out FIG. 3 In addition, a first embodiment of the fixation of the counter-holder in the through hole 15 in the wheel hub 8 of the impeller 3 can be seen, which consists in that the hollow cylindrical cartridge 19 on its lateral surface 24 has a slightly larger diameter than the through hole 15 in the wheel hub eighth having the impeller 3 and frictionally secured by press fit in this through hole 15.

In the FIG. 4 second embodiment of the fixation of the counter-holder in the through hole 15, however, differs in that the hollow cylindrical cartridge 19 on its lateral surface 24 'a slightly smaller Diameter than the through hole 15 in the wheel hub 8 of the impeller 3 and is positively secured by conditioning their end edge 25 on an inserted into a circumferential groove 26 in the through hole 15 snap ring 27 in the through hole 15.

A likewise positive fixing of the counter-holder in the through hole 15 is finally alternatively as a third embodiment in FIG. 5 shown. In this embodiment, the hollow cylindrical cartridge 19 formed on its lateral surface 24 "likewise with a slightly smaller diameter than the through-bore 15 in the wheel hub 8 of the impeller 3 has a plurality of open axial slots 28 in its lateral surface 24" and an outwardly angled terminal edge 25 ', with which the cartridge 19 is fixed by clipping its end edge 25 'in a circumferential groove 29 in the through hole 15 in selbiger.

LIST OF REFERENCE NUMBERS

1

contraption

2

drive wheel

3

impeller

4

peripheral wall

5

Side wall

6

Side wall

7

boundary wall

8th

wheel hub

9

wing

10

pressure chamber

11

pressure chamber

12

locking pin

13

admission

14

Compression coil spring

15

Through Hole

16

blind hole

17

an end

18

other end

19

cartridge

20

Bottom face

21

axial groove

22

spring coils

23

axial elongation

24

lateral surface

24 '

lateral surface

24 "

lateral surface

25

end edge

25 '

end edge

26

groove

27

snap ring

28

axial slots

29

groove

Claims (6)

1. Device for varying the control times of gas exchange valves of an internal combustion engine, in particular a rotary-piston adjustment device for the rotational angle adjustment of a camshaft relative to a crankshaft, having the following features:

   ■ the device (1) is fastened to the drive-side end of a camshaft mounted in the cylinder head of the internal combustion engine, and is designed in principle as a hydraulic actuating drive which can be controlled as a function of different operating parameters of the internal combustion engine,

   ■ the device (1) is composed substantially of a drive wheel (2) which is drive-connected to a crankshaft of the internal combustion engine and of a vane wheel (3) which is rotationally fixedly connected to a camshaft of the internal combustion engine,

   ■ the drive wheel (2) has a cavity formed by a hollow cylindrical peripheral wall (4) and two side walls (5, 6), in which cavity at least one hydraulic working chamber is formed by at least one radial boundary wall (7),

   ■ the vane wheel (3) has, on the periphery of its wheel hub (8), at least one vane (9) which extends radially into a working chamber of the drive wheel (2) and which divides said working chamber into two hydraulic pressure chambers (10, 11) which act counter to one another,

   ■ the pressure chambers (10, 11), upon being selectively or simultaneously pressurized with a hydraulic pressure medium, effect a pivoting movement or a fixing of the vane wheel (3) relative to the drive wheel (2) and therefore of the camshaft relative to the crankshaft,

   ■ if a pressure of the pressure medium falls below a pressure required for adjustment, the vane wheel (3) can be mechanically coupled, in a preferred base position within its adjustment range, to the drive wheel (2) by a separate locking element,

   ■ the locking element is designed as a cylindrical locking pin (12) which can be moved by a spring element into a locking position within a receptacle (13) in one of the side walls (5, 6) of the drive wheel (2),

   ■ the spring element is designed as a helical compression spring (14) and is arranged together with the locking pin (12) in a through bore (15), which is parallel to the longitudinal central axis of the device (1), in the wheel hub (8) of the vane wheel (3),

   ■ one end (17) of the helical compression spring (14) can be fixed in an axial base bore (16) on the rear side of the locking pin (12), while the other end (18) of the helical compression spring (14) is supported on a counter bracket arranged in the through bore (15), characterized in that

   ■ the counter bracket for the other end (18) of the helical compression spring (14) of the locking pin (12) is designed as a hollow cylindrical cartridge (19) which can be locked in any desired axial position within the through bore (15) in the wheel hub (8) of the vane wheel (3) by means of non-positive or positive locking.
2. Device according to Claim 1, characterized in that the hollow cylindrical cartridge (19) is formed as a punched, drawn part from a steel sheet and, for fixing the other end (18) of the helical compression spring (14), has in its base end surface (20) a plate-shaped axial depression (21) whose diameter corresponds to the outer diameter of the spring windings (22) of the helical compression spring (14).
3. Device according to Claim 1, characterized in that the hollow cylindrical cartridge (19) is formed as a punched, drawn part from a steel sheet and, for fixing the other end (18) of the helical compression spring (14), has on its base end surface (20) a peg-shaped axial elongation (23) whose diameter corresponds to the inner diameter of the spring windings (22) of the helical compression spring (14).
4. Device according to Claim 2 or 3, characterized in that the hollow cylindrical cartridge (19) has, on its lateral surface (24), a slightly larger diameter than the through bore (15) in the wheel hub (8) of the vane wheel (3), and is fastened in said through bore (15) in a non-positively locking fashion with an interference fit.
5. Device according to Claim 2 or 3, characterized in that the hollow cylindrical cartridge (19) has, on its lateral surface (24'), a slightly smaller diameter than the through bore (15) in the wheel hub (8) of the vane wheel (3), and is fastened in the through bore (15) in a positively locking fashion by means of the abutment of its terminating edge (25) against a circlip (27) inserted into an encircling groove (26) in the through bore (15).
6. Device according to Claim 2 or 3, characterized in that the hollow cylindrical cartridge (19) has, on its lateral surface (24"), a slightly smaller diameter than the through bore (15) in the wheel hub (8) of the vane wheel (3), and is formed with a plurality of open axial slots (28) in its lateral surface (24") and with an outwardly angled terminating edge (25'), by means of which the cartridge (19) is fastened in the through bore (15) in a positively locking fashion by virtue of its terminating edge (25') being clipped into an encircling groove (29) in said through bore (15).

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