EP1706604B1 - Device from changing the control times of gas exchange valves in an internal combustion engine in particular a rotating piston adjustment device for angular 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 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 attached to the drive end of a cylinder head mounted in an internal combustion engine camshaft and formed in principle as a function of various operating parameters of the internal combustion engine controllable hydraulic actuator. This device essentially consists of a drive wheel which is in driving connection with the crankshaft of the internal combustion engine and of an impeller rotatably connected to the camshaft of the internal combustion engine, which are in power transmission connection and transmit the torque of the crankshaft to the camshaft of the internal combustion engine. The drive wheel has one formed by a hollow cylindrical peripheral wall and two side walls Cavity, in which five hydraulic working spaces are formed by five to the longitudinal central axis of the device extending radial boundary walls. Accordingly, the impeller has at the periphery of its hub five radially extending into the working spaces wings, which divide the working spaces in each case an A-pressure chamber and a B-pressure chamber, which in case of selective or simultaneous pressurization with a hydraulic pressure means pivotal movement or fixation of the impeller relative to the drive wheel and 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 sleeve-like cylinder pin locking element is arranged in a continuous axial bore in the wheel hub of the impeller and by a trained as a compression coil spring element, which is supported on the one hand on the back of the locking element and on the other hand on a likewise inserted into the axial counterholder in a locking position within a recording in the camshaft facing away from the side wall of the drive wheel slidably. The recording of the locking element is connected via a side facing away from the inner surface of the camshaft pressure medium Zuführnut with one of the A-pressure chambers of the device, so that upon pressurization of the A-pressure chambers, the locking element hydraulically in an unlocked position within the axial bore in the hub of Impeller is movable.

A disadvantage of this known device, however, is that the locking element for mechanical coupling of the impeller with the drive wheel in its unlocked position and outside the base position of the impeller via the pressure medium supply groove to its inclusion in the side wall of the drive wheel is constantly in pressure fluid communication with the corresponding A-pressure chamber of the device, so that when pressurizing the A-pressure chambers permanently applied the pressure medium pressure and the pressure peaks of the pressure medium occurring also on the locking element or act on the entire locking mechanism. Since the pressurized locking element is supported at its arranged in the axial bore of the wheel hub counterhold and the plastic mostly existing counterpart in turn is supported on the axial bore occluding camshaft facing side wall of the drive wheel, permanently acting on the locking element pressure medium pressure by the constant relative rotation between the Impeller and the drive wheel thus to increased wear on the anvil and on the side wall of the drive wheel. However, this wear adversely affects the function of the locking mechanism and can lead to the failure of the function over the life of the device.

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 relative to a crankshaft to conceive, in which this from the permanent pressure medium connection of the locking element with one of the pressure chambers of the device or that the resulting from the permanent pressurization of the locking element adverse effects on the entire locking mechanism can be avoided in a simple manner.

Summary of the invention

According to the invention this object is achieved in a device according to the preamble of claim 1 such that within the incorporated into the inner surface of the respective side wall of the drive wheel pressure medium Zuführnut a local lock is arranged, through which the pressure medium supply for receiving the locking element pivoted from the base position Impeller is permanently interrupted. However, in order to further enable a hydraulic unlocking of the locking element, a bypass is additionally arranged in the pressure medium Zuführnut opposite side surface of the wheel hub of the impeller such that only when pivoted in the base position impeller bridging the local lock and a pressure medium supply for receiving the locking element is possible.

The locking element is formed in a conventional manner as a sleeve-like cylindrical pin which is arranged in a continuous axial bore in the wheel hub of the impeller and trained by a helical spring spring element which on the one hand on the back of the locking element and on the other hand also in the axial bore inserted counter support is displaced into its locking position in the receptacle in one of the side walls of the drive wheel.

The recording of the locking element is accordingly formed in a known manner as a local depression in the inner surface of the locking element opposite side wall having a preferably square-shaped and by a defined game greater than the cross-sectional area of the locking element contour and in which preferably having a curved course Druckmittel-Zufühmut opens.

In an expedient development of the device according to the invention, the receptacle formed in this way the locking element and the pressure medium Zuführnut are preferably arranged in the inner surface of the camshaft side wall and made without cutting by impressing in this side wall, wherein the local lock in the pressure medium Zuführnut preferred as in Impressing remaining material web is formed. In accordance with opposite arrangement of the locking element However, in the axial bore in the wheel hub of the impeller, it is also possible to arrange the receptacle of the locking element and the pressure medium supply groove in the camshaft side wall facing the drive wheel. As an alternative to embossing, it is also possible to produce the receptacle of the locking element and its pressure medium feed groove by milling into the corresponding side wall of the drive wheel and also to form the local barrier in the pressure medium feed groove as the remaining material web. In addition, it may also be particularly advantageous in the retrofitting not inventively designed devices to form the local lock by subsequent insertion of a corresponding dowel pin in a bore within the usually continuously formed pressure medium Zuführnut.

According to the preferred arrangement of receiving the locking element in the camshaft side facing away from the drive wheel, it is finally proposed as a further advantageous development of the inventively designed device to also arrange the bypass for the local lock in the pressure medium supply groove in the camshaft side facing away from the wheel hub of the impeller and form as slot-like depression. It has proven to be particularly advantageous to miteinzuformen this slot-like depression in the usual powder metallurgy production of the wheel hub of the impeller tool falling into the corresponding side surface of the wheel hub, that is, the mold for the wheel hub of the impeller form such that no reworking at the bypass forming Deepening more necessary. Again, it is of course particularly in the use of other suitable materials for the wheel hub of the impeller or in the retrofitting not inventively designed devices possible, the bypass forming slot-like depression later by machining manufacturing process, such as milling, in the corresponding side surface of the hub to incorporate the impeller. To avoid additional throttling points for the pressure medium, it is also advantageous in the dimensioning of the bypass, if this at least twice as long as the Width of the local barrier forming material web is formed in the pressure medium supply groove, while its width and depth have approximately the same width and depth as the pressure medium supply groove in the side wall of the drive wheel.

With such a trained bypass in the side surface of the wheel hub of the impeller, it is thus possible to bridge the local lock in the pressure medium Zuführnut for receiving the locking element in the side wall of the drive wheel when the impeller of the device, such as when switching off the internal combustion engine, pivoted to its base position and the locking element of the device has been moved in this position into its receptacle in the side wall of the drive wheel. When pressurizing those pressure chambers of the device, one of which is also connected to the pressure medium Zuführnut for receiving the locking element, such as when restarting the internal combustion engine, the hydraulic pressure medium thus passes first to the local lock in the pressure medium Zuführnut, then flows within the Bypasses in the wheel hub of the impeller over the local lock away in the receptacle of the locking element and then moves the locking element into its unlocked position within the axial bore in the wheel hub of the impeller. The now unlocked impeller pivots then by the further pressurization of the pressure chambers out of its base position, so that also moves the bypass in the wheel hub from its bridging position to the local lock in the pressure medium Zuführnut and another pressure medium supply for receiving the locking element by the now the local lock adjacent flat side surface of the wheel hub of the impeller is interrupted.

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 the locking element for mechanical coupling of the impeller with the drive wheel outside the base position of the impeller by the arrangement of a simple local lock in the pressure medium Zuführnut to its inclusion in the side wall of the drive wheel is no longer in fluid communication with the corresponding pressurized pressure chamber of the device. By such a local lock, it is thus excluded au-ßerhalb its base position in any position of the impeller that when pressure is applied to the pressure medium Zuführnut associated pressure chamber neither the normally applied pressure of the hydraulic pressure medium nor its pressure peaks on the locking mechanism exert a negative effect, in particular the counter-holder of the locking element and the counter-holder supporting side wall of the drive wheel are thus subject to increased wear more, so that their function over the life of the device is guaranteed safe. At the same time it is still possible by the arranged in the hub of the impeller bypass as possible that the locking element can be moved hydraulically in its unlocked position in the wheel hub of the impeller when pivoted in the base position impeller in a conventional manner.

Brief description of the drawings

Figur 1

einen Querschnitt durch eine erfindungsgemäß ausgebildete Vorrichtung zum Verändern der Steuerzeiten von Gaswechselventilen einer Brennkraftmaschine;

Figur 2

den Schnitt A-A nach Figur 1 durch die erfindungsgemäß ausgebildete Vorrichtung bei in Basisposition verschwenktem Flügelrad;

Figur 3

eine vergrößerte Darstellung des Schnittes D-D nach Figur 2;

Figur 4

den Schnitt A-A nach Figur 1 durch die erfindungsgemäß ausgebildete Vorrichtung bei um ca. 5° aus der Basisposition heraus verschwenktem Flügelrad;

Figur 5

eine vergrößerte Darstellung des Schnittes E-E nach Figur 4;

Figur 6

eine Draufsicht auf die Innenfläche der nockenwellenabgewandten Seitenwand des Antriebsrades der erfindungsgemäß ausgebildeten Vorrichtung;

Figur 7

eine Draufsicht auf die nockenwellenabgewandte Seitenfläche der Radnabe des Flügelrades der erfindungsgemäß ausgebildeten Vorrichtung.

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

FIG. 1

a cross section through an inventively designed device for changing the timing of gas exchange valves of an internal combustion engine;

FIG. 2

the section AA of Figure 1 by the inventively constructed device with pivoted in base position impeller;

FIG. 3

an enlarged view of the section DD of Figure 2;

FIG. 4

the section AA of Figure 1 by the inventively constructed device pivoted by about 5 ° from the base position out impeller;

FIG. 5

an enlarged view of the section EE of Figure 4;

FIG. 6

a plan view of the inner surface of the camshaft side facing away from the drive wheel of the inventive device;

FIG. 7

a plan view of the camshaft side facing away from the wheel hub of the impeller of the inventively constructed device.

Detailed description of the drawings

From Figure 1 is clearly a device 1 for changing the timing of gas exchange valves of an internal combustion engine, which is designed as a rotary piston adjusting device for adjusting the rotational angle of a camshaft, not shown, with respect to a likewise not shown crankshaft of an internal combustion engine. This device 1 is attached to the drive end of the camshaft also mounted in the cylinder head, also not shown, and formed in principle as a hydraulic actuator which is controlled in dependence on various operating parameters of the internal combustion engine by the designated in Figure 1 with 22 hydraulic valve.

Furthermore, it can be seen in FIGS. 1, 2 and 4 that the device 1 consists essentially of a drive wheel 2, which is drivingly connected to the crankshaft, and of an impeller 3 connected rotationally fixed to the camshaft, the impeller 3 being pivotable in the drive wheel 2 is stored and is in power transmission connection with this. The drive wheel 2 in this case has a cavity formed by a hollow cylindrical peripheral wall 4 and two side walls 5, 6, in which five equally circumferentially distributed hydraulic working chambers 9 are formed by five directed to the longitudinal center axis of the device 1 radial boundary walls 7 and 8. The impeller 3 has accordingly on the circumference of its hub 10 five uniformly circumferentially distributed and each extending into a working space 9 of the drive wheel 2 wings 11, which divide the working spaces 9 in each case an A-pressure chamber 12 and a B-pressure chamber 13, which at wahlweiser or simultaneous pressurization with a hydraulic pressure means cause a pivoting movement or fixation of the impeller 3 relative to the drive wheel 2 and thus a rotational angle adjustment or a hydraulic clamping of the camshaft relative to the crankshaft.

It can also be seen from FIG. 1 that the device 1 has a separate locking element 14 at the start of the internal combustion engine in order to avoid a stop flap of the impeller 3 resulting from the alternating torques of the camshaft, with which the impeller 3 falls below a pressure medium pressure required for adjustment in a preferred base position within its adjustment range with the drive wheel 2 is mechanically coupled. This formed as a sleeve-like cylinder pin locking element 14 is a continuous axial bore 15 in the hub 10 of the impeller 3 and arranged by a trained as a compression coil spring element 16, which on the one hand on the back of the locking element 14 and on the other hand on a likewise inserted into the axial bore 15 counter-holder 17 supported, in a direction indicated in Figure 1 locking position within a receptacle 19 in the camshaft side facing away from the drive wheel 5 2 slidably. The receptacle 19 is, as can be seen in FIGS. 2, 4 and 6, connected to one of the A-pressure chambers 12 of the device 1 via a circular-arc-shaped pressure medium supply groove 18 incorporated into the inner surface of the camshaft side wall 5 of the drive wheel 2, so that upon pressurization of the A-pressure chambers 12, the locking element 14 in an unlocked position within the axial bore 15 in the wheel hub 10 of the impeller 3 is movable.

So that the locking element 14 is not permanently exposed to the applied pressure medium pressure when the A-pressure chambers 12, in the device 1 according to the invention within the incorporated into the inner surface of the side wall 5 of the drive wheel 2 pressure medium Zuführnut 18 in addition a clearly shown in Figure 6 local lock 20 arranged, wherein the receptacle 19 of the locking element 14 and the pressure medium Zuführnut 18 are made by impressing into the inner surface of the side wall and the local barrier 20 is formed as a material web remaining during embossing. In FIG. 5, it is clearly illustrated that the pressure medium supply for receiving 19 of the locking element 14 is permanently interrupted by the local barrier 20 within the pressure medium supply groove 18 when the impeller 3 is pivoted out of the base position and the pressure medium pressure thus exerts no negative effects on the locking element 14 can. However, in order to still allow in the base position of the impeller 3 shown in Figure 3, a hydraulic unlocking of the locking element 14 locked in this position, in the pressure medium Zuführnut 18 opposite side surface of the wheel hub 10 of the impeller 3 is a bypass shown in Figure 7 21 arranged, with the only when pivoted in base position impeller 3 bridging the local lock 20 and thus a pressure medium supply for receiving 19 of the locking element 14 is possible. This bypass 21 for the local lock 20 is clearly visible in FIG. 7 as a slot-like recess in the wheel hub 10 of the impeller 3, which is miteingeformt in the powder metallurgy production of the wheel hub 10 of the impeller 3 tool falling and which with the pivoting of the impeller 3 from whose base position moves away from its bridging position to the local lock 20 in the pressure medium supply groove 18.

LIST OF REFERENCE NUMBERS

1

contraption

2

drive wheel

3

impeller

4

peripheral wall

5

Side wall

6

Side wall

7

boundary wall

8th

boundary wall

9

working space

10

wheel hub

11

wing

12

A pressure chamber

13

B-pressure chamber

14

locking element

15

axial bore

16

spring element

17

backstop

18

Pressure medium supply

19

admission

20

barrier

21

bypass

22

hydraulic valve

Claims (3)

1. Device for changing the timing of gas exchange valves of an internal combustion engine, in particular rotary-piston adjustment device for adjusting the angle of rotation of a camshaft with respect to a crankshaft, with the following features:

   ■ the device (1) is attached to the drive end of a camshaft mounted in the cylinder head of the internal combustion engine and is configured in principle as a hydraulic actuator controllable in dependence on various operating parameters of the internal combustion engine;

   ■ the device (1) consists essentially of a drive wheel (2) in driving connection to a crankshaft of the internal combustion engine and of a vane wheel (3) connected non-rotatably to a camshaft of the internal combustion engine;

   ■ the drive wheel (2) includes a cavity formed by a hollow-cylindrical circumferential wall (4) and two side walls (5, 6), in which cavity at least one hydraulic working chamber (9) is formed by at least two radial boundary walls (7, 8);

   ■ the vane wheel (3) has on the circumference of its hub (10) at least one vane (11) extending radially into a working chamber (9) of the drive wheel (2), which vane (11) subdivides said working chamber (9) respectively into an A pressure chamber (12) and a B pressure chamber (13);

   ■ the pressure chambers (12, 13), upon being pressurized selectively or simultaneously with a hydraulic pressure medium, effect a swivelling movement or a fixing of the vane wheel (3) with respect to the drive wheel (2), and therefore of the camshaft with respect to the crankshaft;

   ■ if the pressure of the pressure medium falls below a pressure required for adjustment, the vane wheel (3) is mechanically couplable to the drive wheel (2) by a separate locking element (14) in a preferred base position within its range of adjustment;

   ■ the locking element (14) is arranged in an axial bore (15) in the hub (10) of the vane wheel (3) and is displaceable by a spring element (16) to a locking position inside a receptacle (19) in one of the side walls (5, 6) of the drive wheel (2);

   ■ the receptacle (19) of the locking element (14) is hydraulically connected to at least one pressure chamber (12 or 13) inside the device (1) via a pressure medium supply groove (18) worked into the inner face of the respective side wall (5, 6) of the drive wheel (2);

   ■ upon pressurization of the pressure chamber (12 or 13) connected to the pressure medium supply groove (18), the locking element (14) is movable hydraulically to an unlocked position inside the axial bore (15) in the hub (10) of the vane wheel (3),

   characterized in that

   ■ a local obstruction (20), by which the supply of pressure medium to the receptacle (19) of the locking element (14) is permanently interrupted when the vane wheel (3) is swivelled out of the base position, is arranged inside the pressure medium supply groove (18) worked into the inner face of the respective side wall (5, 6) of the drive wheel (2);

   ■ a bypass (21) is arranged in the lateral face of the hub (10) of the vane wheel (3) located opposite the pressure medium supply groove (18) such that a bypassing of the local obstruction (20) and a supply of pressure medium to the receptacle (19) of the locking element (14) is possible only when the vane wheel (3) is swivelled to the base position.
2. Device according to Claim 1, characterized in that the receptacle (19) of the locking element (14) and the pressure medium supply groove (18) of said receptacle (19) are preferably arranged in the inner face of the side wall (5) of the drive wheel (2) facing away from the camshaft and are produced by stamping, the local obstruction (20) in the pressure medium supply groove (18) being preferably formed as a material land which remains in the stamping process.
3. Device according to Claim 2, characterized in that the bypass (21) for the local obstruction (20) in the pressure medium supply groove (18) is preferably arranged in the side face of the hub (10) of the vane wheel (3) facing away from the camshaft and is configured as a slot-like depression which may be formed using the press mould in the preferably powder-metallurgical production of the hub (10) of the vane wheel (3).

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