Patent Publication Number: US-10774695-B2

Title: Pressure medium supply to valve train elements

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This patent application claims the benefit, under 35 U.S.C. § 119(a), of German patent application 10 2017 108 060.0 filed Apr. 13, 2017, which patent application is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a pressure medium supply to valve train elements. The valve train elements are arranged in receptacle boreholes of a component of an internal combustion engine and are operationally connected to switchable valve actuating levers or to switchable support elements, with a longitudinal channel in the component of the internal combustion engine, which has at least two supply galleries by means of at least one partition wall or a pipe having at least one partition. Each receptacle borehole is connected using one overflow opening each to a supply gallery. 
     BACKGROUND 
     A pressure medium supply to valve train elements is known from commonly owned German patent application P 10 2016 208 470 (no prior publication). The partition wall or the partition in a pipe extend horizontally along a component of an internal combustion engine, so that an upper and a lower supply gallery are available. Valve train elements are designed as support elements, which are connected to switchable valve actuating levers. The support elements are connected to the upper gallery or the lower gallery, so that the valve actuating levers can be switched by variation of the pressures in the galleries. However, since the partition wall or the partition in the pipe are adjacent to the valve train elements and/or the receptacle boreholes in the component of the internal combustion engine into which the valve train elements are inserted, it is difficult to find the right dimensions for the cutting or the clearance for the receptacle boreholes. Flow connection to the galleries therefore has to be produced via boreholes below and above the partition wall or partition. The boreholes are incorporated into the cuts or the clearances in the wall of the pipe, which is expediently performed before installation of the pipe. The practical design of the flow connection between the galleries and the valve train elements is also very difficult and complex, in particular because of the tolerances. 
     SUMMARY 
     A partition wall or a partition in the pipe is embodied as twisted in a spiral along a longitudinal channel. By way of a suitable twist, which can be produced evenly or unevenly, a respective supply gallery is adjacent without obstruction by the partition or partition wall to the respective valve train element and can be connected directly to the receptacle borehole or the respective valve train element. 
     In an example embodiment, a flow connection between a receptacle borehole and a respective supply gallery is produced by cutting the supply gallery during the machining of the receptacle borehole or by a subsequent machining procedure. It is sufficient to form a suitable partition wall or a pipe having a partition in a spiral such that the flow connection is produced by machining the receptacle borehole. In an example embodiment, a borehole is produced in the respective supply gallery matching with the receptacle borehole before installation of the pipe. The spiral twist of the partition wall or the partition is embodied in this case such that two or three valve train elements, arranged adjacent to one another, are connected in pairs or in groups of three to the same supply gallery. By way of corresponding pressure control, switchable valve actuating levers are then switched to full stroke, partial stroke, or zero stroke. Depending on the desired design, the spiral twist also is embodied such that each two pairs or groups of three of the valve train elements are connected to the same supply gallery. The switchable valve actuating levers at cylinders  1  and  2  and also cylinders  3  and  4  are thus switched in pairs, but separately from one another. In an example embodiment, to switch the valve actuating levers of cylinders  1  and  4  and also cylinders  2  and  3  in groups. In the case of an internal combustion engine having six or more cylinders, the remaining cylinders are considered accordingly. Groups of three cylinders can also be combined. 
     In an example embodiment, the spiral twist is embodied such that the valve train elements are each alternately connected to another supply gallery along the longitudinal channel. As a result, for example, the switchable valve actuating levers switch the inlet or outlet valve(s) individually or in groups or switch all inlet or outlet valves of an internal combustion engine simultaneously. 
     For simple production of the pressure medium supply to valve train elements, method steps are proposed in which the partition wall or the partition with the pipe are installed in the longitudinal channel such that the supply galleries assume desired locations for the supply galleries. Subsequently or also previously, receptacle boreholes for the valve train elements are produced or drilled with cutting of the respective supply galleries. A cost-effective pressure medium supply device is thus producible using simple means. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments are disclosed, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, in which: 
         FIG. 1  shows a schematic illustration of a pipe with a spiral partition in a longitudinal channel for pressure medium supply; 
         FIG. 2  shows a side view of the pipe in  FIG. 1  at an end of the pipe and the beginning of the longitudinal channel; 
         FIG. 3  shows a cross-section generally along line A-A in  FIG. 1 ; 
         FIG. 4  shows a cross-section generally along line B-B in  FIG. 1 ; 
         FIG. 5  shows a cross-section generally along line C-C in  FIG. 1 ; 
         FIG. 6  shows a perspective view of a pipe having a spiral partition; 
         FIG. 7  shows a perspective view of a pipe corresponding to  FIG. 6  with sketched valve train elements; 
         FIG. 8  shows a longitudinal section through a pipe having a partition corresponding to  FIGS. 6 and 7 ; 
         FIG. 9  shows a spiral twisted partition wall; and 
         FIG. 10  shows a partition wall section according to the oval in  FIG. 9  in an enlarged scale and a cross section through the partition wall. 
     
    
    
     DETAILED DESCRIPTION 
     In  FIGS. 1 to 10 , insofar as shown in detail, receptacle boreholes are incorporated into a component of a reciprocating piston internal combustion engine, into which boreholes valve train elements  2  are inserted. Elements  2  are designed as support elements, optionally switchable and/or having hydraulic play compensation function. Valve train elements  2  are operationally connected to simple or switchable valve actuating levers, which are in turn supported on valve train elements  2  and are operationally connected to gas exchange valves, optionally with an actuating bridge interconnected. 
     Along valve train elements  2 , a longitudinal channel is provided, which can be cast or drilled in. According to  FIGS. 1 to 8 , pipe  5  including outer wall  11  and partition  6  inward of wall  11  and connected to wall  11 , is installed in the longitudinal channel, so that supply galleries A and B are formed in part by partition  6 . Partition  6  seals gallery A from gallery B. As seen in  FIGS. 1 to 5  in particular, pipe  5  and/or partition  6  in pipe  5  are embodied as twisted in a spiral, so that valve train elements  2  are connected to supply gallery A in section A and section C ( FIG. 1 ), while valve train elements  2  are connected to supply gallery B in sections B and D. For example, two respective overflow openings  10  are included in each of sections A, B, C, and D of pipe  5 . To illustrate the twist of partition  6 , in the end view of  FIG. 2  and in the respective sections of  FIGS. 3, 4, and 5 , partition  6  is in different respective circumferential positions with respect to wall  11 . 
     Pipe  5  having partition  6  can be produced from metal, plastic, or another suitable material and can consist of one piece or of individual parts that are assembled. Since corresponding supply galleries A and B are associated in a sufficient circumferential portion with respective associated valve train elements  2  (see  FIGS. 7 and 8 ), the flow connections between respective supply galleries A and B and valve train elements  2  can be produced in a simple manner by cutting the respective supply gallery A or B in conjunction with the production or machining of the receptacle borehole for valve train elements  2 , resulting in overflow openings  10 . In example embodiment, overflow openings  10  are incorporated before the installation of pipe  5 . Further, pipe  5  is sealed off in the longitudinal channel at least in the region of overflow openings  10 , for which purpose at least partial machining of the longitudinal channel is advantageous. 
     Overflow openings  10  are aligned along pipe  5 . For example, straight line L 1  passes through wall  11  and every opening  10  in pipe  5 . 
     In  FIGS. 9 and 10 , partition wall  7 , which is also embodied as twisted in a spiral shape, is installed in a longitudinal channel to form a seal. Partition wall  7  has, as can be seen from the right image of  FIG. 10 , lateral end strips, which increase the sealing in the longitudinal channel. Partition wall  7  can also be produced from plastic, metal, or another suitable material. In the designs, according to  FIGS. 9  to  10 , partition wall  7  is twisted so strongly that each following valve train element  2  is connected to another supply gallery A or B, so that the supply gallery A is followed by the supply gallery B, then in turn the gallery A and again the gallery B, and this corresponds to the number of the cylinders or the number of valve train elements  2 . 
     LIST OF REFERENCE CHARACTERS 
     A supply gallery 
     B supply gallery 
     L 1  line 
       2  valve train elements 
       5  pipe 
       6  partition 
       7  partition wall 
       10  overflow openings 
       11  outer wall