Abstract:
The invention relates to space-saving, easily-assembled guide systems for mechanical, variable value controllers, cam followers ( 1 ), driven by a cam ( 6 ) via a cam roller ( 5 ), the pivot joint ( 2 ) of which, for driving a tappet ( 4 ) which operates the value ( 3 ), is arranged in the tappet ( 4 ), or the pivot joint for the adjustment thereof runs in an arc around the axis of rotation of a roller, which is arranged on a tappet operating a value. The cam followers drive the tappets by means of the contact surface with the roller thereof. The guide systems are embodied with slide blocks ( 11 ), adjustable within slide housings ( 10 ), guide arms mounted in rollers and guide levers mounted in crank levers. According to application, the guide systems comprise contact surfaces, rollers or pivot joints.

Description:
This application is a continuation of International Application No. PCT/EP03/03262, filed Mar. 28, 2003, and claims the benefit of priority to German patent application 102 14 802.3, filed Apr. 4, 2002. 

   BACKGROUND OF THE INVENTION 
   The present invention concerns space-saving and easily assembled systems for guiding mechanical and variable valve controls. Each system includes a rocker and a walker. The rocker is driven by a cam by way of a follower. The rocker is articulated to and drives the walker by way of a swivel accommodated on the walker. The swivel can be shifted by a steering mechanism along the arc of a circle or along a similar curve around the axis of rotation of a follower mounted on the walker that actuates the valve. The rocker drives the walker by way of an engagement contour and by means of a follower. 
   The rocker can alternatively drive the walker by way of an engagement contour that arches outward in the form of an arc of a circle, in which case the rocker can be shifted along the arc of a circle or along a similar curve around the axis of the arching engagement contour. 
   The rocker can alternatively be driven by a cam by way of an engagement contour. 
   The rocker can alternatively drive one-armed and two-armed levers. 
   Valve controls wherein the rocker&#39;s swivel can be shifted in a circular path around the axis of rotation of a follower accommodated in the walker and engaged by the rocker are disclosed in German Application 10 136 612.4. 
   The valve controls disclosed in German Application 10 155 007.3 feature an engagement contour or a follower shifted along a circular path by a shift and engaged either by a rocker and a follower or by an engagement contour, whereby the rockers drive a valve-actuating walker by way of a swivel. 
   The valve controls disclosed in German Application 10 136 612.4 feature a shift that shifts a swivel along a circular path, whereby a rocker is articulated to the swivel and drives a valve-actuating walker by way of a follower. 
   The shifts in these embodiments can be complicated to install because of lack of space or of assembly problems, and can also be too delicate, in that the swivels lie along the axis of rotation of the swivel accommodated on the walker and in reach as long as the valve remains closed or along that of the follower accommodated on the walker. 
   SUMMARY OF THE INVENTION 
   The present invention accordingly concerns three different embodiments that take up little space and are easy to install.  FIGS. 1 and 2  depict a mechanism for setting valve controls. A flat or sliding block has similarly curved and mutually engaging tracks inside a case. The flat is provided with an engagement contour that acts as a cam. The engagement contour is engaged by a follower mounted on a rocker. Alternatively, the flat itself can be provided with a follower that operates in conjunction with an engagement contour on the rocker that acts as a cam. The flat itself can also alternatively be provided with a swivel. 
     FIG. 3  depicts another embodiment of a mechanism for setting valve controls. A contoured flat is secured between two banking rollers, one on each side, or more. The rollers are provided with flanges. The flat is provided with a follower that engages an engagement contour on a rocker. 
   Alternatively, the flat itself can be provided with either a follower for engaging the engagement contour on a rocker or with a swivel for guiding a rocker. 
     FIG. 4  depicts still another embodiment of a mechanism for setting valve controls. A steering lever is supported at two points by swivels accommodated on two crankshafts or camshafts. The angled end of the lever is provided with a swivel for guiding the engagement contour of a rocker. A slide in the form of a flat must be provided in this case to position the engagement contour for engagement by a follower. The situation is more complicated in that the steering lever must be supported at two swiveling points by two contoured flats. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIGS. 1 and 2  show a mechanism for setting valve controls, in accordance with the present invention; 
       FIG. 3  shows another embodiment of a mechanism for setting valve controls; and 
       FIG. 4  shows still another embodiment of a mechanism for setting valve controls. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  illustrates an assembly for mechanically setting variable valve controls. The assembly includes a rocker  1 , a walker  4 , and a contoured flat  11 . Rocker  1  has two arms and pivots around a swivel  2  mounted on walker  4 . Walker  4  actuates a valve  3 . Rocker  1  is driven by a cam  6  by way of a follower  5  mounted on the end of one arm. Mounted on the rocker&#39;s other arm is another follower  7  that follows the engagement contour of flat  11 . Flat  11  slides clockwise and counterclockwise inside a case  10  around the axis of swivel  2  while the swivel remains in the position it is in as long as valve  3  is closed. The flat&#39;s engagement contour is divided into two segments  8  and  9 . Segment  8  participates in maintaining valve  3  closed, and segment  9  in allowing the valve to open. Segment  8  curves inward with a radius R. Radius R is the radius of a circle centered on the axis of swivel  2  as long as valve  3  is closed. Segment  9  terminates in a spur that extends inward and considerably beyond segment  8 . The length of radius R equals the length of a radius R 1  extending from the axis of swivel  2  to the axis of follower  7  plus the length of a radius R 2  extending from the axis of follower  7  to its circumference. 
     FIG. 2  is a cross-section through a case  10  to be employed with a cylindrical alignment of such assemblies. Each face of each flat  11  is, in this practical illustrated version, secured in case  10  by a longitudinal polyvinyl cogged section  12 . Flat  11  is forced against the stationary cogged section  12  by an expanding component  14 . Expanding component  14  is subject to the force of a ram  13 . Expanding component  14  is maintained in the direction associated with setting the controls inside case  10  and is provided with a matching cogged section. This approach prevents play. In a cylindrical alignment, each expanding component  14  can be subject to the force of a ram  13  exerted from each side. Rams  13  derive their force mechanically from springs, from the pressure of the oil in an automotive lubrication system, or from both. 
   Flat  11  can alternatively be guided by other appropriate circular longitudinal cogged sections, mounted radially. Flat  11  is positioned by a cogged section  15  that engages a cogwheel  16  mounted on a rotating shaft  17 . 
   Valve  3  will be maintained closed as long as the spur, the segment  9  of the engagement contour of flat  11 , that is, remains in position A. Once the spur is in position B, however, the valve will be able to open with its longest and slowest stroke. As long as valve  3  is maintained closed, follower  7  will engage the circular segment  8  of the engagement contour of flat  11  without activating the valve. To actuate the valve, flat  11  will be shifted out of its valve-closed position and along the arc of a circle inside case  10  by a rotation of shaft  17 , allowing the spur to be engaged by the follower  7  mounted on rocker  1 . The extent of the engagement will determine the length and accordingly the duration of the opening stroke. Flat  11  can alternatively be positioned by an articulated rod driven for example by an eccentric shaft. 
   Assembly can be facilitated if case  10  and shaft  17  are integrated into bearing blocks screwed to cylinder head  18 . The bearing blocks to be employed with a specific cylindrical alignment of such assemblies can be subassembled in advance along with cases  10 , shaft  17 , and flats  11 , already accommodated inside the cases, as well as, when practical with the shaft  19  of cam  6  if they share the same bearing blocks, on a mount screwed to cylinder head  18 . 
     FIG. 3  illustrates another embodiment of an assembly for mechanically guiding variable valve controls. The assembly includes a rocker  20  and a walker  23 . Rocker  20  has two arms and pivots around a swivel  21  mounted on walker  23 . Walker  23  actuates a valve  22 . Rocker  20  is driven by a cam  25  by way of a follower  24  on the end of one arm. At the other end of the arm, rocker  20  is provided with an engagement contour. The engagement contour is divided into two curved segments  26  and  27 . Segments  26  and  27  are engaged by a follower  28  mounted on a steering rod in the form of a similarly curved contoured flat  31 . Contoured flat  31  is secured by two radial banking rollers  29  and  30 , one on each engagement contour. Each banking roller has a flange on each face. Segment  26  participates in maintaining valve  22  closed, and segment  27  in allowing the valve to open. The longitudinal axis of contoured flat  31  extends concentric around the axis of the swivel  21  mounted on walker  23  that is in reach as long as valve  22  is closed. The segment  26  that participates in maintaining valve  22  closed curves outward in the form of an arc of a circle with a radius R. The center of the circle coincides with the axis of the swivel  21  mounted on walker  23 . The segment  27  that participates in allowing the valve to remain open is provided with an outward-projecting spur that extends considerably beyond segment  26 . 
   To allow adjustment of contoured flat  31 , banking roller  30  is composed of two halves and mounted on a rotating shaft  32 . Accommodated between the two halves is a cogwheel fixed tight to rotating shaft  32  and engaging a cogged section  34  of flat  31 . 
   As long as the follower  28  mounted on contoured flat  31  remains in position A, valve  22  will be maintained closed. Once the follower is in position B, however, the valve will be able to open with its longest and slowest stroke. To maintain valve  22  closed, the outwardly curved segment  26  of the engagement contour will engage the follower  28  mounted on contoured flat  31  without activating valve  22 . To actuate valve  22 , shaft  32  is rotated, rotating in turn contoured flat  31 , and the follower  28  mounted on it, out of the position wherein it participates in maintaining the valve closed until the spur extending out of segment  27  engages follower  28 . The extent of engagement will determine the length and accordingly the duration of the opening stroke. 
   To eliminate play on the part of contoured flat  31 , banking roller  29  is accommodated on an articulated lever and provides the flat with a stabilizing moment of rotation derived from a ram. 
   To simplify assembly, the axes of banking rollers  29  and  30  can be accommodated in bearing blocks screwed to a cylinder head  35 . The bearing blocks associated with a particular cylindrical alignment of assemblies can be preliminarily mounted along with the shafts of the banking rollers, with the contoured flats  31  that they secure, and optionally with a camshaft  36  accommodated in the same bearing block, on a mount fastened to cylinder head  35 . 
     FIG. 4  illustrates a third embodiment of an assembly for mechanically guiding variable valve controls. 
   The upper end of a one-armed rocker  37  pivots around a swivel  39  accommodated at the end of a cantilever extending out of a steering lever  38 . Rocker  37  is driven by a cam  41  by way of a follower  40  more or less half-way along it. At its lower end, rocker  37  is provided with an engagement contour comprising segments  42  and  43 . Segments  42  and  43  engage a follower  44  mounted on a walker  46  that actuates a valve  45 . Segment  42  participates in maintaining valve  45  closed and segment  43  in allowing it to open. Steering lever  38  is controlled by two cranks  47  and  48 , the former mounted on a crankshaft  49  and the latter on a crankshaft  50 . The orientation of crankshafts  49  and  50 , the structure of steering lever  38  with its three points of articulation impossible to align, the establishment of an appropriate angle, and optionally a differentiation in the lengths of cranks  47  and  48  in the setting vicinity allow the generation of a circular motion that can accurately enough guide the axis of the swivel  39  mounted on rocker  37  around the axis of the follower  44  mounted on walker  46  and in reach as long as valve  45  remains closed. 
   To allow adjustment of steering lever  38 , one of the crankshafts, crankshaft  49 , also comprises a controlling shaft. As crankshaft  49  rotates, accordingly, the other crankshaft, crankshaft  50 , will be driven by way of steering lever  38  and will also execute a rotation, in that cranks  47  and  48 , both, in the adjustment area, are at an appropriate angle to the longitudinal axis of steering lever  38 . 
   The segment  42  of the engagement contour of rocker  37  that participates in maintaining valve  45  closed curves outward in the arc of a circle of radius R with its center coinciding with the axis of the swivel  39  mounted on steering lever  38 . The segment  43  associated with the valve&#39;s opening stroke is provided with an outward-bent spur that extends considerably beyond segment  42 . 
   As long as the swivel  39  mounted on steering lever  38  is in position A, the mechanism will be set to maintain valve  45  closed. With the swivel in position B, the valve will be able to open with its longest and slowest stroke. As long as valve  45  is maintained closed, outward curving segment  42  will engage the follower  44  mounted on walker  46  without activating the valve. To actuate the valve, the swivel  39  mounted on steering lever  38  will be rotated by a rotation of the controlling-shaft crankshaft  49  along with steering lever  38  out of the position associated with maintaining the valve closed until the spur associated with segment  43  engages the follower  44  mounted on walker  46 . The extent of engagement will determine the length and accordingly the duration of the stroke. 
   Since these mechanisms require only an acute setting angle, the crankshafts  49  and  50  employed therein can be produced from straight round structural section, without bends. Cranks  47  and  48  can be welded to the section for example. Otherwise, bushings can be fastened tight to a length of section to create crankshafts  49  and  50 . If the crankshafts are mounted on round section, the articulations for steering lever  38  can be undivided, with steering lever  38  comprising two flat bars. 
   To facilitate assembly, crankshafts  49  and  50  can be accommodated in bearing blocks to be screwed to a cylinder head  51 . The mechanisms intended for a single cylindrical alignment can be preliminarily assembled along with the two crankshafts, with the steering levers  38  mounted thereon, with the rockers  37  articulated to the steering levers by swivels  39 , and optionally with a camshaft  52  accommodated in the same bearing blocks, on a mount secured to cylinder head  51 .