JP6656169B2 - Valve actuation device for internal combustion engines - Google Patents

Description

  The invention has at least one gas exchange valve operable on a camshaft, said camshaft being at least two axially displaceable and rotationally fixed via a valve stroke switching device. An active part interacting with the cam piece connected passive part, comprising at least one cam piece having a different cam profile, wherein the valve stroke switching device is axially displaceable away from the at least one cam shaft axis. And a valve actuation device for a reciprocating internal combustion engine having at least one cylinder.

  A valve drive for an internal combustion engine with a camshaft is known from DE 102004055852, in which the camshaft comprises a cam device with different cam profiles, the cam device comprising a valve stroke switching device. Can be displaced in the axial direction via. The displacement takes place via a shift fork which acts on the cam device via the shift finger.

  A control device for a charge exchange valve is known from DE 42 30 877, in which a cam carrier is arranged on a base shaft in a torque-resistant and axially displaceable manner. The cam carrier comprises a tubular support on which at least one cam is arranged, wherein several different cam tracks are generated such that they are axially offset from a common reference circle. As a result of the axial displacement of the cam carrier on the base shaft, the gas exchange valve is actuated by differently shaped cam tracks, which can differ with respect to stroke profile and / or phase position.

  A further development of this device is described in published German patent application DE 10148243, in which the basic camshaft and the cam carrier are connected to one another via a plurality of axially extending meshes, The camshaft has external teeth meshing and the cam carrier has internal teeth meshing.

  DE 102 01 100 3024 describes a sliding cam system having a sliding cam which is axially displaceable on a camshaft of a reciprocating internal combustion engine. A fixed electromagnetic displacement device with an operating pin is provided for displacement of the sliding cam, the operating pin engaging in a displacement groove operatively connected to the sliding cam. A locking device formed as a friction lock is provided for locking the sliding cam.

  A valve drive for an internal combustion engine for actuating a gas exchange valve is known from DE 102 01 110 1871 A1 which comprises a lever shaft on which at least one lever is provided. And a displacement axis. The sleeve having the guideway is provided on a displacement shaft that is torque-resistant, but is rotatable in an axially displaceable manner, and its lever is directly or indirectly supported by the guideway. An engagement element fixed to the housing permanently engages the guideway and supports the sleeve with respect to the housing. A further engagement element engages the guideway radially along the guideway and is offset with respect to the engagement element fixed to the housing and fixedly connected to the lever. Switching between different cams of a group of cams is caused by twisting the displacement axis.

  DE 102 01 110 868 A1 discloses a device for varying the charge exchange valve stroke in an internal combustion engine, the device comprising a displacement shaft arranged parallel to the camshaft and having a displacement axis on the camshaft. For axial displacement of the cam carrier at The first transmission element is torque-resistant, but is arranged on the displacement shaft so as to be displaceable in the axial direction, and the transmission element includes a guideway. The first engagement element is guided along a guideway during the twisting of the displacement axis, and this engagement element is fixedly connected to the housing of the internal combustion engine. The second engagement element is further guided along the guideway during twisting of the displacement axis, the second engagement element being arranged for axial displacement of the cam carrier on the second transmission element. .

DE 10 2004 055 852 A1 German Patent Application No. 42 30 877 German Patent Application No. 10148243 German Patent Application Publication No. 102011003024 German Patent Application Publication No. 102011101871 German Patent Application No. 10 201 110 868

  It is an object of the present invention to provide a simple and compact switching of the valve stroke.

  This object is achieved according to the present invention in that the active part and the passive part are configured to be rotationally symmetric, and the active part is provided so as to be rotatable and displaceable around a shaft arranged parallel to the camshaft axis. Is done.

  Preferably, the displacement device comprises at least one curved element and at least one operating pin interacting with the curved element, wherein the active part is displaced in the axial direction by the displacement device, whereby the passive part together with the cam piece has the camshaft. Is displaced along.

  In particular, this simple switching of the valve stroke is such that the active part comprises a first curved element, preferably comprising one thread, on a first surface, provided on a fixed part, and between an idle position and an active position. The first operating pin displaceable between is achieved in the operating position by being pushed out into the area of the first curved surface. Similarly, the active part also comprises a second curved element, preferably composed of one thread, on a second surface facing away from the first surface, provided on the fixed part, with an idle position and an active position. In the operating position, the second operating pin displaceable between is protruded into the area of the second curved surface. Each curved element extends over an angle of up to 360 ° around the axis of rotation of the active part. A simple displacement can be achieved if the first and second curved elements have gradients in opposite directions. The at least one operating pin is radially displaceable on the shaft and is hydraulically deflectable against a restoring force formed by a restoring element, preferably a spring, and preferably the idle position is Desirably, it is defined by the restoring force.

  Advantageously, the active part and the passive part are connected in rotation. Rotationally connected means within the scope of the present disclosure that the rotational movement of the active part is transmitted to the passive part and vice versa. The rotational connection can take place in a particularly simple manner, wherein the active part comprises a first gear and the passive part comprises a second gear, and the first and second gears are in meshing engagement.

  The axial connection between the active part and the passive part is such that the active part or the passive part comprises, in the area of their surface, two axially spaced-apart thrust washers, the two thrust washers being open. This is easily achieved if a space is defined and the passive or active part engages in the open space between the two thrust washers. Axial coupling, within the scope of the present disclosure, means that the passive part is displaced with the axial displacement of the active part, and vice versa. The thrust washer is arranged, for example, on the active part, so that the active part surrounds the passive part like a fork by the thrust washer. In addition, kinematic reversal may be possible by disposing the thrust washer in the passive unit.

  Preferably, the thrust washers are arranged on both surfaces of the first and second gears, and the diameter of the thrust washers is larger than the root circle diameter, preferably the tip circle diameter of the adjacent first or second gear. . As a result, the thrust washer acts on the side of the gear engaged during the displacement process and thus displaces the passive part which is preferably connected by an interference fit with the cam piece.

  The cam piece can be locked in at least one cam contour position, preferably each cam contour position, by a locking device, wherein at least one cam contour position, preferably each cam contour position, for example, comprises a camshaft. Defined by a stopper.

  The displacement is started by the protruding of the first or second operation pin. In the operating position, the first and second operating pins respectively contact the first and second curved surfaces. The rotation of the camshaft is transmitted to the active part via two gears. The curved surface formed as a thread is in contact with a fixed operating pin, and the active part is deflected in the axial direction by the rotational movement of the active part and the curved surface. The axial deflection of the active part is transmitted to the passive part via a thrust washer, whereby the cam pieces on the camshaft are axially displaced, thereby juxtaposed to activate each gas exchange valve. It can be switched between two cam profiles. In principle, switching between three or more cam profiles is also possible with the solution according to the invention by providing additional operating pins.

  The invention will be explained in more detail with reference to non-limiting embodiments shown in the drawings.

FIG. 1 is a perspective view showing a valve operating device according to the present invention. FIG. 2 shows the valve actuator in a longitudinal section. It is a figure showing an active part and a shaft in a first embodiment by a top view. FIG. 4 is a diagram showing the active portion and the shaft in a cross-sectional view along line IV-IV in FIG. 3. It is a figure which shows the active part and axis | shaft in 2nd embodiment by a top view. FIG. 6 shows the active part and the shaft in a sectional view along the line VI-VI in FIG. 5.

  1 and 2 show a valve actuator 1 for a reciprocating internal combustion engine, not shown in detail, which has a cam piece 3 and a camshaft 2 rotatable about a camshaft shaft 2a. The cam piece 3 is connected to the camshaft 2 in a torque-resistant manner, but is arranged so as to be displaceable in the axial direction of the camshaft 2. The cam piece 3 comprises at least two different cam profiles 4, 5 which are axially juxtaposed to one another, in order to operate a gas exchange valve, not shown, one of the two cam profiles 4, 5 always has one cam follower. 6, for example, meshing with a roller tappet.

  For switching between the two cam profiles 4, 5, a valve-stroke switching device 7 is provided, which comprises an active part 8 and a passive part 9 fixedly connected to the cam piece 3, The unit 8 and the passive unit 9 are configured to be rotationally symmetric.

The active part 8 comprises a first gear 10 and the passive part 9 comprises a second gear 11, wherein the active part 8 and the first gear 10 are rotatable on a fixed shaft 12 and axially displaced. Provided and arranged as possible. The first gear 10 and the second gear 11 are in meshing engagement with each other and are therefore rotationally connected. Thrust washers 13, 14 are arranged on each surface 8 a, 8 b of the active part 8, and the thrust washers 13, 14 are directly adjacent to the first gear 10. The diameter D of the thrust washers 13 and 14, in this embodiment, are of equal size (however, may be different), larger than the tooth bottom circle diameter d _f of the first gear 10, in particular the addendum circle It is larger than the diameter d _k . The passive part 9 is engaged in an open space 15 formed between the two thrust washers. The meshing portion of the passive part 9 is surrounded on both sides by two thrust washers 13, 14, which enables the active part 8 to displace the passive part 9 in the axial direction. Therefore, the active part 8 and the passive part 9 are connected in this way in the axial direction.

The active part 8 is displaced in the axial direction by the displacement device 30, so that the passive part 9 and the cam piece 3 are also displaced along the camshaft 2. The active part 8 has a first curved surface element 16 having a thread formed outside the thrust washer 13 in the area of the first surface 8a.
The first operation pin 17 is provided on the shaft 12 so as to be displaceable in a radial direction between an idle position A and an operation position B. In the idle position A, the first operating pin 17 is completely within the shaft 12 and the first operating pin 17 is also completely disposed within the shaft 12 by a first restoring element in the form of a first restoring spring 18. It is held at the idle position A. Similarly, the active part 8 comprises a threaded second curved element 19 outside the thrust washer 14 in the region of the second surface 8b.

  Within the scope of the present invention, the curved elements 16, 19 are understood as elements having a guideway extending outside the shaft 12, the guideway being arranged from a starting point located close to the first gear 10, from an axis. Starting in the direction (the axis of rotation 8 ′ of the shaft 12), it rises away from the gear 10 and wraps around the shaft 12 to an end point located further away from the first gear 10. The guideway has a constant or variable slope. In the case of a thread, the guideway is wound around the shaft 12 with a constant gradient.

  The second operation pin 20 is also provided on the shaft 12 so as to be displaceable between an idle position A and an operation position B. In the idle position A, the second operating pin 20 is completely within the shaft, and the second operating pin 20 is also idled by a second restoring element in the form of a second restoring spring 21 that is also completely located within the shaft 12. It is held at position A.

  The first curved surface element 16 and the second curved surface element 19 are fixedly connected to the active part 8 or its thrust washers 13, 14. The threads of the first curved surface element 16 and the second curved surface element 19 have opposite gradients as shown in FIGS. Each of the two curved elements 16, 19 extends over an angle β of at most 360 ° around the axis of rotation 8 ′ of the active part 8. FIGS. 3 and 4 show an embodiment in which the raised curved elements 16, 19 extend over substantially a half circumference, i.e. the angle [beta] around the axis of rotation 8 'is about 180 [deg.]. In the embodiment shown in FIGS. 5 and 6, the curved elements 16, 19 are each formed by full threads and thus extend over an angle β of about 360 ° around the axis of rotation 8 '.

  Each operation pin 17, 20 is adjacent to a pressure chamber 22, 23 to which oil is supplied. The idle position A of the operation pins 17 and 20 is defined by a state where no pressure is applied to each of the pressure chambers 22 and 23. When the pressure in the pressure chambers 22 and 23 increases, each of the first operation pin 17 or the second operation pin 20 is pressed radially outward from the idle position A to the operation position B, and the first or second curved surface element It protrudes into regions 16 and 19. The area of the first curved element 16 or of the second curved element 19 is here understood as an axial part along the shaft 12, in which each curved element 16, 19 is defined by the rotation axis 8 ′ of the active part 8. Is the part that passes during (at least) one revolution around

  The first curved surface element 16 or the second curved surface element 19 is pressed by the corresponding operation pins 17 and 20 by the rotational movement of the active portion 8 and the curved surface elements 16 and 19 connected to the camshaft 2. Since the active part 8 is provided on the shaft 12 so as to be displaceable in the axial direction, the active part 8 is displaced in the axial direction by the interaction between the operation pins 17 and 20 and the curved surface elements 16 and 19. Due to the displacement of the active part 8, both the passive part 9 and therefore the cam piece 3 are displaced. The first operation pin 17 and the second operation pin 20 are operated in opposite directions, so that one of the two operation pins 17, 20 is located at the idle position A and the other is located at the operation position B.

  A locking device 24 is provided for holding the cam piece 3 in each position, the locking device comprising at least one spring clip 25 which resiliently engages in the grooves 26, 26 'of the cam piece 3. The cam profile layer of the cam piece 3 is further defined by stoppers 27, 28 of the camshaft 2, which are arranged on the passive part 9 or on opposing faces of the cam piece 3. The spring clip 25 is fixed to the camshaft 2 in at least one region of the stoppers 27 and 28.

  The displacement of the cam piece 3 is started by the protruding of the first operation pin 17 or the second operation pin 20. In the operating position B, the first and second operating pins 17 and 20 are in contact with the corresponding first and second curved elements 16 and 19. The rotation of the camshaft 2 is transmitted to the active part 8 via two gears 10 and 11. The curved surface 16 or 19 comes into contact with operation pins 17 and 20 that are fixedly provided, and the active portion 8 is deflected in the axial direction by the rotational movement of the active portion 8 and the curved surfaces 16 and 19. The axial deflection of the active part 8 is transmitted to the passive part 9 via thrust washers 13, 14, whereby the cam piece 3 is displaced axially on the camshaft 2, so that each gas exchange valve Can be switched between the cam contours 4,5 to actuate.

Claims (21)

Having at least one gas exchange valve operable on a camshaft (2) for each cylinder;
Said camshaft (2) is at least one cam piece (3) having at least two different cam profiles (4, 5) axially displaceable and rotationally fixed via a valve stroke switching device (7). )
The valve stroke switching device (7) is an active part interacting with a passive part (9) connected to the cam piece (3), which is separated from at least one camshaft shaft (2a) and is displaceable in the axial direction. A valve operating device (1) for a reciprocating internal combustion engine comprising (8),
The active part (8) and the passive part (9) are configured to be rotationally symmetric,
The active part (8) is provided rotatably and displaceably about a shaft (12) arranged parallel to the camshaft axis (2a) ,
The active part (8) is axially displaceable by a displacement device (30), whereby the passive part (9) together with the cam piece (3) is displaceable along the camshaft (2). And
The active part (8) includes a first curved surface element (16) on a first surface (8a),
The first operation pin (17) provided on the fixed portion and capable of being displaced between the idle position (A) and the operation position (B) is provided in the operation position (B) in the area of the first curved surface (16). A valve actuating device (1), characterized in that at least one operating pin (17, 20) is provided on the shaft (12) so as to be displaceable in the radial direction . The displacement device (30) comprises at least one curved element (16, 19) and at least one operating pin (17, 20) interacting with the curved element (16, 19). Valve actuating device (1) according to claim 1 . The valve actuating device (1) according to claim 1 or 2 , wherein the first curved surface element (16) comprises a thread. Said active part (8) comprises a second curved element (19) on a second surface (8b) facing away from said first surface (8a);
The second operation pin (20) provided on the fixed portion and capable of being displaced between the idle position (A) and the operation position (B) is provided in the operation position (B) in the area of the second curved surface (19). Valve actuating device (1) according to any one of the preceding claims, characterized in that the valve actuating device (1) is pushed out. The valve actuating device (1) according to claim 4 , wherein the second curved surface element (19) comprises a thread. Valve actuating device (1) according to claim 4 or 5 , characterized in that the first curved element (16) and the second curved element (19) have opposite gradients. 2. The at least one curved element (16, 19) extends around a rotation axis (8 ′) of the active part (8) over an angle (β) of at most 360 °. Valve actuating device (1) according to any one of claims 1 to 6 . The active portion (8) and said passive unit (9), the valve actuating apparatus according to any one of claims 1 to 7, characterized in that it is rotationally coupled (1). Said active part (8) comprises a first gear (10), and said passive part (9) comprises a second gear (11);
9. The valve actuating device (1) according to claim 8 , wherein the first and second gears (10, 11) are in meshing engagement. The active part (8) or the passive part (9) comprises in its area of the surface (8a, 8b) two axially spaced thrust washers (13, 14),
Said two thrust washers define an open space (15);
The driven part (9) to said active portion (8), any of claims 1 to 9, characterized in that engages the open space (15) between the two thrust washers (13, 14) A valve actuating device (1) according to claim 1. The thrust washers (13, 14) are arranged on both surfaces of the first and second gears (10, 11),
Diameter (D) of the thrust washer, the valve actuation according to claim 1 0, wherein the adjacent first or second gear (10, 11), and greater than the tooth bottom circle diameter (df) Apparatus (1). Diameter (D) of the thrust washer, the valve actuation according to claim 1 1, wherein the adjacent first or second gear (10, 11), and greater than the addendum circle diameter (dk) Apparatus (1). The driven part (9), said cam piece (3) the valve actuation system according to any one of claims 1 1 2, characterized in that it is pressed against (1). Said cam piece (3) is by means of a locking device (24), at least one valve actuating device according to claim 1, characterized in that it can be locked in 1 3 any one of the cam contour position (1 ). Said cam piece (3) is by means of a locking device (24), the valve actuation system according to claim 1 4, characterized in that it can be locked in the respective cam contour position (1). At least one cam contour position of the cam piece (3) is a stopper valve actuation system according to any one of claims 1 to 1 5, characterized in that defined by (27, 28) (1). Valve operating device (1) according to claim 16 , characterized in that each cam profile position of the cam piece (3) is defined by the stopper (27, 28). The valve actuating device (1) according to claim 16 or 17 , wherein the at least one stopper (27, 28) comprises the camshaft (2). At least one of the operating pin (17, 20) is against the restoring force which is formed by a restoring element, according to any one of claims 1 to 1 8, characterized in that the deflectable hydraulically Valve operating device (1). 20. Valve actuating device (1) according to claim 19 , wherein the restoring element is a spring (18, 21). Idle position of the operating pin (17,20) (A), the valve actuation system according to claim 19 or 2 0, characterized in that it is defined by the restoring force (1).

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