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1.
公开(公告)号:US20240035400A1
公开(公告)日:2024-02-01
申请号:US18268876
申请日:2019-12-20
摘要: In order to provide a more reliable configuration for a hydraulic drive for accelerating and braking in particular a gas exchange valve (20) of internal combustion engines or other reciprocating engines, in particular if the occurring maximum travel of the moving mass can deviate considerably from an expected setpoint position, it is proposed that the drive piston (23) has at least one control edge (31) corresponding to an inflow opening (33), which, when a defined travel hab has been attained, prevents the inflow of drive pressure p1 into the drive chamber (27) and/or prevents the low-loss outflow of pressure medium from the brake chamber (29) to the basic pressure level (40), wherein the remaining hydraulic drive force vanishes, becomes small or changes its sign when said travel hab is attained.
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公开(公告)号:US11156134B2
公开(公告)日:2021-10-26
申请号:US16615175
申请日:2018-05-18
申请人: EMPA Eidgenossische Material-prufungs- Und Forschungsanstalt , Wolfgang Schneider Ingenieurburo
摘要: In order to ensure a simple, reliable and recuperative operation in a hydraulic drive (10) for accelerating and braking a gas exchange valve (20) of internal combustion engines or other reciprocating engines, it is proposed that a first pressure reservoir (41) for providing a first pressure p1 comprises a restoring energy accumulator, preferably configured as a spring (25), and at least one hydraulic base pressure reservoir (40), which has a lower pressure p0 than the first pressure reservoir (41). In a connecting line (48) between the first hydraulic pressure reservoir (41) and the working cylinder (22), a controllable opening (49) of a first valve (46) comprising at least one check valve (47) is arranged upstream or downstream in the flow path, which allows the pressure medium (30) to flow in the direction of working cylinder (22), but prevents a backflow towards the pressure reservoir (41).
In order to also initiate the closing movement or to enable the breaking of the gas exchange valve in a hydraulically simple and reliable manner, in a second connecting line (58) between the first pressure reservoir (41) and the working cylinder (22) there is arranged a controllable opening (59) of a second valve (56) comprising a check valve (57), which prevents a flow in the direction of the working cylinder (22), but allows a return flow in the direction of the pressure reservoir (41).-
公开(公告)号:US20210003045A1
公开(公告)日:2021-01-07
申请号:US16615175
申请日:2018-05-18
申请人: EMPA Eidgenossische Material-prufungs- Und Forschungsanstalt , Wolfgang Schneider Ingenieurburo
摘要: In order to ensure a simple, reliable and recuperative operation in a hydraulic drive (10) for accelerating and braking a gas exchange valve (20) of internal combustion engines or other reciprocating engines, it is proposed that a first pressure reservoir (41) for providing a first pressure p1 comprises a restoring energy accumulator, preferably configured as a spring (25), and at least one hydraulic base pressure reservoir (40), which has a lower pressure p0 than the first pressure reservoir (41). In a connecting line (48) between the first hydraulic pressure reservoir (41) and the working cylinder (22), a controllable opening (49) of a first valve (46) comprising at least one check valve (47) is arranged upstream or downstream in the flow path, which allows the pressure medium (30) to flow in the direction of working cylinder (22), but prevents a backflow towards the pressure reservoir (41).
In order to also initiate the closing movement or to enable the breaking of the gas exchange valve in a hydraulically simple and reliable manner, in a second connecting line (58) between the first pressure reservoir (41) and the working cylinder (22) there is arranged a controllable opening (59) of a second valve (56) comprising a check valve (57), which prevents a flow in the direction of the working cylinder (22), but allows a return flow in the direction of the pressure reservoir (41).
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