SLIDING CAM SYSTEM HAVING TWO-STAGE ACTUATOR STROKE

Abstract

A sliding cam system is provided including: at least one sliding cam arranged in a fixed, but axially slideable manner on at least one axially fixed base shaft for forming a cam shaft of a reciprocating internal combustion engine; at least one actuator device for adjusting the sliding cam into different axial positions using at least one actuator pin that can engage in at least one sliding groove on a circumference of the sliding cam, wherein the actuator device has a housing attached to the engine and the sliding grooves are arranged in a groove section of the sliding cam; and a bracket encompassing the groove section using side shoulders, directed parallel to a longitudinal axis of the base shaft and provided with an opening in a region of the actuator pins, wherein the sliding cam has at least two sliding grooves having at least partially different depths, wherein the bracket is directed in the actuator device and wherein a positive-fit depth stop device is provided between the bracket and the actuator pin(s).

Claims

1. A sliding cam system comprising at least one sliding cam that is arranged rotationally locked but movable in an axial direction on at least one axially fixed base shaft for forming a camshaft of a reciprocating piston internal combustion engine, at least one actuator device for adjusting the sliding cam into different axial positions by at least one actuator pin that engages in at least one sliding groove on a periphery of the sliding cam, the actuator device has a machine-fixed housing, the sliding grooves are arranged in a groove section of the sliding cam, a bracket surrounds the groove section by side shoulders thereof and is guided parallel to a longitudinal axis of the base shaft and is provided with an opening in an area of the actuator pins, the sliding cam has at least two of the sliding grooves that have at least partially different depths, the bracket is guided in the actuator device, and a positive-fit depth stop device is provided between the bracket and the at least one actuator pin.

2. The sliding cam system according to claim 1, wherein adjustment of the depth stop device is realized by shifting the bracket.

3. The sliding cam system according to claim 1, wherein at least one bar projecting in a direction toward the actuator pins is built on the bracket adjacent to the opening and each of the at least one actuator pin has a projecting ring that is formed as a stop that contacts the bar.

4. The sliding cam system according to claim 3, wherein the ring has a position on the at least one actuator pin such that an end of the actuator pin contacts a groove base of a less deep one of the sliding grooves when a bottom edge of the ring contacts an upper edge of the bar.

5. The sliding cam system according to claim 4, wherein the bar has at least one cut-out having a size that allows movement of the ring through the bar.

6. The sliding cam system according to claim 5, wherein a distance between the bottom edge of the ring/an upper edge of the bar and an upper edge of the ring/a lower edge of the bar essentially corresponds to a difference in depth of the sliding grooves.

7. The sliding cam system according to claim 1, wherein at least one recess is provided in a wall of the at least one actuator pin.

8. The sliding cam system according to claim 7, wherein two of the recesses are provided that are machined.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The invention is described in the drawings:

[0008] FIG. 1 shows a perspective view of a bracket of the locking device,

[0009] FIG. 2 shows a perspective view of the bracket similar to FIG. 1 with drawn actuator pins,

[0010] FIG. 3 shows a section radially through the base shaft, the sliding cams, and the actuator device,

[0011] FIGS. 4 to 6 show sections corresponding to lines I-I, H-H, and J-J in FIG. 3 through the sliding cam system,

[0012] FIG. 7 shows a section corresponding to FIG. 3 with a different depth position of the actuator pins, and

[0013] FIGS. 8 to 10 show sections corresponding to line I-I, H-H, and J-J in FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] In FIGS. 1 to 10, as far as shown in detail, a base shaft is designated with 1 on which a sliding cam 2 is arranged locked in rotation but movable in the axial direction. The sliding cam 2 has a projecting groove section 5 in which two sliding cams 3 and 4 are machined. Instead of the projecting groove section, this can also be separated by grooves or recesses from the other areas of the sliding cam 2, in order to enable engagement of the shoulders 10, 11 described below. The sliding groove 3 is machined into the groove section 5 with a smaller depth, while the sliding groove 4 engages deeper into the groove section 5. An actuator device is designated with 6, which is mounted on a component, not shown, of the reciprocating piston internal combustion engine. In the actuator device 6, two actuator pins 7 and 8 are built, which can be moved, e.g., by a not-shown electromagnetic switching device in the direction toward the groove section 5 or in the counter direction and can be preferably retracted again or extended by a spring element. On the end of the actuator device 6 facing the groove section 5 there is a bracket 9 that is guided parallel to the axis of the base shaft 1. The bracket 9 has shoulders 10 and 11 that surround the groove section 5 or engage in the grooves or recesses, so that the bracket 9 is likewise moved corresponding to the movement of the sliding cam 2. The bracket 9 has, on its guide rails, depressions 12 in which spring-loaded locking bodies engage and therefore lock the bracket 9 in different positions adapted to the positions of the sliding cam 2. The bracket 9 has a central opening 13, so that the actuator pins 7 and 8 can pass through this opening. In addition to the opening 13 there are side bars 14 and 15 whose distance, apart from play necessarily present, corresponds to the diameter of the actuator pins 7 and 8. Rings 16 and 17 that are prevented from moving by the bars 14 and 15 are mounted or attached to the actuator pins 7 and 8, so that they can extend only so far that the end of the actuator pins 7 and 8 can reach the groove base of the less deep sliding groove 3. On the bars 14 and 15, cut-outs 18 are also machined, whose inner diameter corresponds to the outer diameter of the rings 16 and 17, so that for the allocated position of the bracket 9 to the actuator pins 7, 8, the rings 16, 17 and thus the actuator pins 7, 8 can pass through the cut-outs 18, so that the actuator pins 7, 8 can also reach the deeper sliding groove 4 (see, in particular, FIGS. 7 and 9).

[0015] Instead of the rings 16, 17 that can prevent the actuator pins 7 and 8 with one side from moving into and with the other side from moving out from the deeper groove 4, two recesses can also be machined on the actuator pins 7 and 8, which can take over the tasks of the rings 16, 17 for modified dimensions of the bars 14 and 15 and also of the cut-outs 18 and optionally their positions.

[0016] The bracket 9 therefore forms a positive-fit depth stop for the actuator pins 7, 8 so that these are held in the sliding grooves 3 and 4 with different depths. The bracket 9 also has sufficient strength in its position because it is guided exactly in the actuator device.

LIST OF REFERENCE NUMBERS

[0017] 1) Base shaft [0018] 2) Sliding cam [0019] 3), 4) Sliding grooves [0020] 5) Groove section [0021] 6) Actuator device [0022] 7), 8) Actuator pins [0023] 9) Bracket [0024] 10), 11) Shoulders [0025] 12) Depressions [0026] 13) Openings [0027] 14), 15) Bars [0028] 16), 17) Rings [0029] 18) Cut-outs