Valve drive of an internal combustion engine

Technical Field

The invention relates to a valve mechanism of the internal combustion engine, the valve mechanism with a camshaft and the actuating element, wherein the cam shaft includes a load-bearing shaft and the bearing shaft to the relative resistance of the two rotate and can move between the axial position of the cam members are arranged in such a fashion, the cam piece has at least one cam unit and axial chute (Axialkulisse), the at least one cam unit by direct adjacent, with different cams of a cam of the jut part, the axial sliding thereof with two in the axial direction on the periphery of the track curve extending, the manoeuvring element is connected with the groove, the two curved track for moving in the direction of the cam member.

Background Art

This valve mechanism is used for mobile by means of a cam variable actuation of the gas exchange valve, and wherein the cam members each of which only it is sufficient for the operating element, so that the cam member in the axial direction of the two chute moving in the direction of the curved track, as this kind of valve mechanism the general forms of DE101   48   177A1 known by the public. The structure of the invention with optionally the axial direction of the two cam members of the sliding groove, wherein 1st axial chute guides the wall are used to form in the middle of the guide plate, used for presenting sink to the chute until the operating element in the form of a cylindrical pin, 2nd axial chute formed only by external cube corner.

The latter structure scheme has the following advantages, in other words, is used for axial sliding through the elimination of waste of manufacturing guide plate and obviously less. However, in view of the functional reliability of the valve mechanism of the, important in the design of the risk is that, only when the inertia is enough of the cam member, of the cam member will be the moving process is complete, that is to say, the end without failure, so that the cam member in the region of the curved track, even if there is no cylindrical pins will be forced also to a certain extent move in free flight to the other in one final position. The cam member is obviously sufficient inertia of the minimum rotational speed of the camshaft, the minimum speed depends directly on the cam member and the friction between the bearing shaft. Below this minimum rotational speed of the cam member of the cam member move, can lead to the stay on "halfway", and cannot control a loading of the plurality of cams to the cam follower of the gas exchange valve by the high mechanical load and at the same time of loading. Furthermore, in this case no longer possible by means of the cam member is then cylindrical pin in one of the shift to the final position, because no longer exists between the cylindrical pin and external cube corner of the axial coordinate.

However, the function with the risk of the axial direction of the center of the guide plate in the programme of the chute design 1st significantly more small, the rotational speed is low when the cam members, the guide plate for the inner guide wall further accelerate the forced guide portion of the cylindrical pin. However, in this case the following dangerous, in other words, cylindrical pin after cross-region is not the access to the preset curve track, but also in high mechanical load of the collision the front surface of the guide plate.

Content of the invention

Therefore, the task of this invention lies in, improved by the following way the valve mechanism of the aforementioned type, that is, at least partial exclusion of the mentioned limitations and function of the function of risk. The specific expressions of this task, when the the use of a unique operating element is used for two mobile direction, even when the camshaft is at the low rotating speed, for example during the starting process of the internal combustion engine, to ensure the success of the cam member that is to say also of the complete the conversion process.

This task by providing a solution to the valve mechanism of internal combustion engine, the valve mechanism with a camshaft and the actuating element, wherein the cam shaft includes a bearing shaft in the bearing shaft and to resist relative rotation of the two shafts and the moving way between the positions of the cam members, said cam member having at least one cam unit and the axial groove, the at least one cam unit by direct adjacent, with different cams of a cam of the jut part, the axial sliding of the shaft with the two to slide axially on the periphery of the track curve extending to the contrary, the operating element and the axial slide groove, for moving in the direction of the curved track of said cam member, wherein the curvilinear track in the axial direction in series in a circumferential direction of the sliding way to one arrangement.

With respect to the known prior art, the present invention relates to the important difference between the axial sliding of the mutual arrangement of the curved track, these curve track now to one (that is to say connected in series mode) and no longer arranged and (that is to say in parallel) distribution, and therefore no longer cross. Through the elimination of cross area, moving in the axial direction of the cam member with respect to the sliding of the operating element is forced guided continuously carried out under the condition of, thus even when the camshaft is also to ensure that the lowest rotating speed of the cam member when the conversion process of complete.

On the control element and the axial slide groove structural design proposal of the different possibilities exist in, should be effectively respectively of the curved track groove structure, and the control element should be configured to block connected to the groove of the cylindrical pin. In this preferably, is provided with a curved track limits the trough respectively different of the wall of the groove to the stroke of the shaft, the track sections which follow each other, i.e., into the section having no stroke, and the stroke section of the slope section, wherein compared with the stroke section of the slope section having a significantly more big axial acceleration.

Furthermore, the cam should have a common base circle area, the base circle region of the curved track in the slope of the 1st and 2nd the first section of the curved track terminating in the stroke section. Because common base circle area can be understood as a of cam member of the cam in which all of the angle region are not jut, so that movement of the cam member of the cam only in the design of the ventilation valve is closed, and to be brought into the cam during the entire process of moving is also located in its base circle position. Therefore, during the moving process, no the cam member and the friction between the bearing axis of the valve spring the force is applied to the cam member. In order to maintain the cam members the axial acceleration as small as possible, base circle area and the start and end of the beginning and end of the movement process is preferably the same.

Furthermore, travel sections may respectively with limits the trough by the groove bottom of the radial stroke of the different, follow each other sections a partial stroke, i.e., not part of the 1st with radial travel of the stroke section and is provided with a radially outward part of the bottom of the 2nd stroke section. Known in the prior art in the geometry of the groove, the control bolt only under the state of the axial force, the radial rise to "exit" the grooves of the control bolt in the non-embedded rest position, relative to this advantageously, to trough's axis superposed radial stroke of the stroke and, in order to maximize the stroke section of the cam angle, respectively, in the stroke section and therefore a relatively high axial acceleration limited to mechanical controllable level.

Finally, according to the same background technique is arranged as follows, in other words, part of the 2nd stroke section and entering the section are respectively directly adjacent to each other, wherein the part of the bottom of the stroke section from the 2nd to the transition region of the sector on the whereabouts of the steep in a radial direction. Therefore, in particular axial sliding on the vertical drop of the periphery of the bottom of the case, that is to say in the 360° of the total angle of the curved track, when located in the stroke section between the length of the given section, can maximize the stroke section of the cam angle.

Description of drawings

Other features of this invention by the subsequent description and drawings to obtain, on the drawings show the one embodiment of the present invention. Wherein:

Figure 1 shows a longitudinal section to the valve mechanism according to the present invention;

Figure 2 according to Figure 5 the 1st X of the perspective view shown to the axial groove;

Figure 3 according to Figure 5 the Y to the 2nd perspective view is shown of the axial groove;

Figure 4 according to Figure 5 to Z of 3rd perspective view is shown of the axial groove;

Figure 5 is a side view of according to Figure 1 the, with radial matches the gas phase Bitmap in the axial direction of the sliding groove;

Figure 6 is-stroke diagram of the integrity of the groove.

Mode of execution

In Figure 1 is disclosed in the variable valve mechanism of internal combustion engine used for understanding the basic profiles of the present invention. Valve mechanism is provided with the camshaft 1, the camshaft 1 includes a bearing shaft 2 and the number of the cylinders of the internal-combustion engine, in the bearing shaft 2 relative to the resistance of the two rotate and can move between the axial position of the cam member of the 3. In order to move axially, bearing shaft 2 is provided with an external longitudinal engaging portion, and the cam member 3 is provided with a corresponding inner longitudinal meshing part. The joggle is well known in itself, and is not further introduced here.

The cam member 3 has arranged in a bearing part 4 of the two sides of the cam, these cams are respectively provided with two directly adjacent cam 5 and 6, these cam in the same having a different radius of the base circle of the cam protrusion portion. The movement of the cam members the outer protrusion of the cam, the cam 5, 6 of the common base circle region. Other cam protrusion portion in a known manner, here through only by the cam roller 7 symbolic cam follower shown (such as the rocker arm) depending on the cam members 3 to the current axial position of the selectively transmitted to the not illustrated ventilation valve. Different cam protrusion of the cam stroke can be understood as the different value and/or the cam 5, 6 of the different valve timing.

In order to in the cam 5 and 6 the conversion between the, cam member 3 is provided with as a single piece produced by means of interference assembly to engage and the axial groove 8. The axial groove 8 there are two structure on the periphery of its own opposite in the axial direction and extending in the axial direction of the groove 8 a is connected to a circumferential direction of the one arrangement of the curve orbit assumes the trough shape 9, 10, the actuating element 11 can be connected to these groove. This by fig. 2 to fig. 4 that further, in these Figure, the axial groove 8 by different angle perspective shown. The actuating element 11 is a cylindrical pin, the cylindrical pin is equally well known and there are no further clarification of the, valve mechanism used for this kind of part of the actuator. Cylindrical pin 11 relative to the camshaft 1 in the retention in the axial direction, but can be shifted in a radial direction is arranged in the internal-combustion engine in the manner, and for the two curve track 9, 10 move the cam member in the direction of 3.

Curve track 9, 10 smoon by fig. 2 to fig. 6 that the common display of. In fig. 2 to fig. 4 show in the axial groove 8 view, and Figure 5 a view in an arrow x, corresponding to or y z, in Figure 5 in, a side view is shown with the axial groove 8 according to the dashed-line additional curve track 9, 10 the radial distribution phase diagram. In Figure 1, Figure 2 and Figure 5 shown in the arrow-marked camshaft 1 in the direction of rotation of. The track is provided with a curve 9, 10 the radial direction and the axial stroke of the stroke of the complete map as a function of the camshaft angle by fig. 6 that.

Two curve track 9, 10 respectively with limits the trough the wall of the 12 different axial stroke (Figure 6 in the solid-line), the track sections which follow each other. These track sections is not provided with the axial travel of the sector or F C, used for compensating the cylindrical pin 11 relative to the wall 12 of the axial position of or A the tolerance of the slope section and the stroke section or B D E, wherein B stroke section, the axial acceleration compared with E obviously greater slope section. In the illustrated embodiment, the cam 5, 6 of a common base circle area and orbit section consistent to A E, that is to say, beginning with a common base circle region of the curved track 1st 9 A of the slope section of the curved track and terminates in 2nd 10 E the stroke section. To the contrary, the cam 5, 6 to the cam protrusion F in the area of the sector.

Stroke sector B and E are respectively formed by a partial stroke follow each other sector B1 and B2 or E1 and E2 composition, these partial stroke different of the sector lies in the bottom of the groove 13 (Figure 5 and 6 the dashed-line) travel in the radial direction. In this, part of the 1st stroke sector B1 and E1 having a constant, and with sector F consistent D A or C and of the depth of the bottom of the groove 13, and the bottom of the groove 13 in the stroke section 2nd section B2 and E2 is lifted outwardly in the radial direction, so that the cam member 3 already during the course of the movement of the cylindrical pin 11 out from the corresponding groove of the cylindrical pin in the rest position.

The cam member 3 along the curved track 1st the conversion of 9 to, that is to say, by the current-functioning of the cam 5 through the mode conversion to the cam 6 (see Figure 1) on, in other words, the cylindrical pin 11 in F sinking into the section (the cam protrusion of the size and duration of the scavenging valve is opened for the period), and subsequently B A and stroke section of the slope section, and supports the rotation of the cylindrical pin 11 of the cam member 3 is moved to the axial direction of the cam member in the 2nd position. Cylindrical pin 11 2nd partial stroke in the sector B2 have been adopted in the course of the rise in the radial direction of the bottom of the groove 13 to increase, and the end of the course of moving completely by the curve track 9 in-the cylindrical pin in the rest position.

And similarly, cam member 3 along the curved track 2nd printers 10 to, that is to say, from the functioning cam 6 pushed back by the following way of the cam 5 on, in other words, the cylindrical pin 11 in C sinking into the section, and subsequently E D and stroke section of the slope section, and supports the rotation of the cylindrical pin 11 of the cam member 3 to the time of the cam member in axial position 1st. Also in this case, the cylindrical pin 11 after 2nd stroke section of the part E2 through in the course of radial raised the bottom of the groove 13 to increase, and the end of the course of moving completely by the curve track 10 from in the cylindrical pin 11 is in the rest position.

As in fig. 2 to fig. 5 of the clear, 2nd stroke section of the part B2 or E2 respectively C or E and entering the section directly adjacent to each other, wherein the end of the groove 13 in the transition on these segments radially vertical drop, in order to preset C enter the section of the first length of the length of the stroke section B maximized.

In Figure 1 is shown in the retaining device for the cam member 3 fixed on the cam members relative to the bearing shaft 2 on the radial position. The stopper device includes two bearing shaft 2 to the structure of the radial hole of the through hole 14 in, the diameter of the upper opposed, movable stop body support 15 and the cam member 3 distributed on the inner periphery of the, side settling tank of the detent structure is 16 and 17, respectively in the in the axial position, by the spring device 18 in a radially outward force in the direction of the stop rod 15 locking in these stop groove.

Stop body 15 is a side open, thin-walled plate modified member. The opening of the stop side of the radial hole respectively to support structure 14 and surrounded by the compression spring is of a spiral structure of the spring device 18 of the hollow cylinder, the hollow cylinder and is closed on the side which is towards the stop groove 16, 17 is attenuated in the direction of the hollow body, the hollow body to a first structure on the front side is conical and spherical. In order to the cam member 3 to ensure that the movement of the stop body in the course of 15 low resistance to enter the radial bore 14 in, stop body 15 in the area of the taper shape of the hollow body is provided with a relief opening 19.

The function of the stopping device is not limited to only the cam member 3 fixed on the two axial position, also includes in the axial direction of the cam member relative to the direction of movement of the stroke section of the part B2 and E2 the end of the brake cam member 3. The brake through the spring-loaded stop body 15 in end 16, 17 of the apices 20 to the two side shafts of the wall of adjacent distribution to produce the contact and friction of the. Different from in fig. 1 shown, advantageously, end 16, 17 of the implemented for the geometry, and the apices 20, on the cam members 3 slaved to the detent of the 16, 17 the distance between the axial position of the, to be distributed in the middle.

The Figure mark

1   camshaft

2   bearing shaft

3   the cam member

4   bearing part

5   cam

6   cam

7   cam roller

8   axial chute

9 of the curved track   1st

10 of the curved track   2nd

11   operating element/cylindrical pin

12   wall

13   groove base

14   radial hole

15   stop

16   detent

17   detent

18 compression spring/spiral   spring apparatus

19   pressure-relief opening

20   stop groove vertex

A   slope section

B1, 2   stroke section

C   enter the section

D   slope section

E1, 2   stroke section

F   enter the section