Hydraulic valve lash adjuster for a valve train of an internal combustion engine

    公开(公告)号:US20080022955A1

    公开(公告)日:2008-01-31

    申请号:US11879904

    申请日:2007-07-19

    IPC分类号: F01L1/20

    CPC分类号: F01L1/24

    摘要: A hydraulic valve lash adjuster for a valve train of an internal combustion engine, for example for an automotive vehicle, said hydraulic valve lash adjuster comprising a piston (2) that is guided for displacement in a piston housing (4) and elastically supported against said housing, said piston (2) comprising a low pressure chamber (3) that communicates via an axial opening (26) in a piston bottom (19) with a high pressure chamber (5) defined by the piston housing (4) and the piston (2), and further comprising a control valve (6) acting between said pressure chambers (3, 5), said control valve (6) comprising a valve closing body (7) that can be brought to bear sealingly against a valve seat (24) that surrounds the axial opening (26) on a piston body undersurface (28) and is received in a closing body cap (9) whose cap bottom (21) acts as a stroke limitation of the valve closing body (7), and said control valve (6) further comprising a control valve spring (8) that loads the valve closing body (7) in opening direction, and, during a collapsing movement between the piston (2) and the piston housing (4), said valve closing body (7) being hydraulically loadable in closing direction against the biasing force of the control valve spring (8) by a pressure build-up in the high pressure chamber (5).To improve the valve lash adjuster so that undesired operational fluctuations are reduced, the valve closing body (7) is configured as a needle-shaped, elongate sealing piston whose valve seat-proximate end comprises a plate-shaped sealing surface (10) that cooperates with a correspondingly configured sealing surface (25) of the valve seat (24) and whose valve seat-distal end comprises a surface of application (12) for hydraulic loading, and the valve closing body (7) substantially fills a space volume of the closing body cap (9) surrounding the valve closing body (7).

    Hydraulic tensioner
    7.
    发明申请
    Hydraulic tensioner 有权
    液压张紧器

    公开(公告)号:US20050130777A1

    公开(公告)日:2005-06-16

    申请号:US10995959

    申请日:2004-11-23

    IPC分类号: F16H7/08 F16H7/22

    摘要: A tensioner for a traction drive includes a cylinder arranged in a housing at a distance to a housing wall to thereby define an interior space which contains hydraulic fluid. A piston is received in the cylinder for back-and-forth movement and bounds a pressure chamber containing hydraulic fluid. The piston has a cylinder-distal end which is operatively connected to a spring-biased tension roller supported on a traction member. Formed between the piston and the cylinder is a leakage gap, and a reservoir for hydraulic fluid is provided in an area of the leakage gap to prevent ingress of air into the pressure chamber, when the traction drive is at a rest.

    摘要翻译: 用于牵引驱动器的张紧器包括布置在与壳体壁一定距离的壳体中的气缸,从而限定包含液压流体的内部空间。 活塞被容纳在气缸中用于往复运动,并且限定了包含液压流体的压力室。 活塞具有气缸 - 远端,其可操作地连接到支撑在牵引构件上的弹簧偏压张力辊。 在活塞和气缸之间形成有泄漏间隙,并且在牵引驱动器处于静止状态时,在泄漏间隙的区域中设置用于液压流体的储存器,以防止空气进入压力室。

    Hydraulic valve lash adjuster with idle stroke function for a valve train of an internal combustion engine

    公开(公告)号:US20080087244A1

    公开(公告)日:2008-04-17

    申请号:US11904693

    申请日:2007-09-28

    IPC分类号: F01L1/245

    摘要: A hydraulic valve lash adjuster with idle stroke function for a valve train of an internal combustion engine, said hydraulic valve lash adjuster comprising a piston (2, 2′, 2″) that is guided for displacement in a piston housing (4) and elastically supported against said housing (4), said piston (2, 2′, 2″) comprising a low pressure chamber (3) that communicates via an axial opening (7) in a piston bottom (8) with a high pressure chamber (5) defined by the piston housing (4) and the piston (2, 2′, 2″), and further comprising a control valve (9, 9′, 9″, 9′″) acting between said pressure chambers (3, 5), said control valve (9, 9′, 9″, 9′″) comprising a valve closing body (10, 10′, 10″) that can be brought to bear sealingly against a valve seat (15, 15′) that surrounds the axial opening (7) on a piston body undersurface (18) and is received in an element (12, 12′) that limits a closing body stroke (17), and said control valve (9, 9′, 9″, 9′″) further comprising a control valve spring (11) that loads the valve closing body (10, 10′, 10″) with a spring force in opening direction, and an idle stroke being produced during a collapsing movement between the piston (2, 2′, 2″) and the piston housing (4) during which said valve closing body (10, 10′, 10″) is hydraulically loaded in closing direction against the action of the control valve spring (11) by a pressure build-up in the high pressure chamber (5), whereby a retarded pressure build-up can be obtained through a flow control device (23, 23′) arranged on a high pressure chamber-side and comprising a flow control element (24, 24′) and a medium pressure chamber (19) that extends between the flow control element (24, 24′) and the axial opening (7) of the piston (2).