| 摘要 |
PCT No. PCT/EP96/01227 Sec. 371 Date Oct. 20, 1997 Sec. 102(e) Date Oct. 20, 1997 PCT Filed Mar. 21, 1996 PCT Pub. No. WO96/34185 PCT Pub. Date Oct. 31, 1996In a switchable cam follower (1) comprising an inner element (2) and an outer element (3), with said inner element (2) comprising a hydraulic clearance compensation device (10), a coupling of the two elements (2, 3) is effected by radially extending coupling means (4). These coupling means (4) and the clearance compensation device (10) which is integrated in the inner element (2) are loaded by hydraulic pressure from a cylinder head of an internal combustion engine through separate channels (9, 8). According to the invention, the spring means (5) for the coupling means (4) are configured so that from a hydraulic medium pressure from about 0.6 bars on (idling engine speed), the elements (2, 3) are uncoupled. When a switching engine speed, for example, 3,000 rpm, has been reached, the hydraulic pressure in the channel (9) is reduced to about 0.1 bars by a control valve (11). The coupling means (4) are displaced by the spring means (5) into a coupling position. The two elements (2, 3) are connected physically to each other. At the same time, unchoked hydraulic pressure continues to prevail in the channel (8) so that even with increasing speed of the internal combustion engine, the clearance compensation device (10) is optimally supplied with hydraulic pressure.
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