Cylinder-piston unit with load-dependent throttle

Patent metadata

Field	Value
Publication number	US-11268589-B2
Application number	US-201816766395-A
Country	US
Kind code	B2
Filing date	Nov 24, 2018
Priority date	Nov 24, 2017
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

A cylinder-piston unit with load-dependent damping includes a piston longitudinally displaceable in a cylinder. The piston has a first piston channel and a second piston channel, which each connect a compensation space on one side of the piston to a displacement space side on an opposite side of the piston. On the displacement space side a throttle channel connects one first piston channel to the piston lateral surface. On its displacement space side the piston has a piston journal, which carries a resiliently deformable piston disc. The piston disc is displaceable and covers the throttle channel at least partially. The displacement space side has at least one relief portion deviating from a piston end face plane. The relief portion is delimited on a number of sides by a plurality of boundary lines running concentrically with respect to the central axis. Each of these boundary lines can be differentiated continuously.

First claim

The invention claimed is:

1. A cylinder-piston unit ( 10 ), comprising:
a cylinder ( 11 ); and
a piston ( 51 ) which is displaceable in a longitudinal direction ( 5 ) of the cylinder ( 11 ) and which is guided by a piston rod ( 41 ),
wherein the piston ( 51 ) has at least one first piston channel ( 62 ) and at least one second piston channel ( 63 ), which each connect a compensation space side ( 56 ) of the piston ( 51 ) facing a compensation space ( 93 ) with a displacement space side ( 53 ) of the piston ( 51 ) facing a displacement space ( 91 ),
wherein, on the displacement space side ( 53 ), at least one throttle channel ( 68 ) connects at least one first piston channel ( 62 ) with a piston lateral surface ( 57 ), and
wherein the piston ( 51 ) on its displacement space side ( 53 ) has a piston journal ( 54 ) arranged concentrically with respect to its center axis ( 55 ) oriented in the longitudinal direction ( 5 ),
wherein the piston journal ( 54 ) carries a resiliently deformable piston disk ( 101 ) which is displaceable in the longitudinal direction ( 5 ) and covers the throttle channel ( 68 ) at least in some sections, and
wherein the displacement space side ( 53 ) surrounding the piston journal ( 54 ) has at least one relief portion ( 69 ) deviating from a piston end face plane ( 72 ) lying normal to the center axis ( 55 ), and
wherein the relief portion ( 69 ) is delimited on a number of sides by a plurality of boundary lines ( 71 ) running concentrically with respect to the center axis ( 55 ),
wherein each of these boundary lines ( 71 ) can be differentiated continuously, and
wherein the relief portion ( 69 ) is delimited by at least one continuously differentiable top line ( 77 ) running in a radial plane, and
wherein the top line ( 77 ) is either a straight line and/or has at least one point of maximum distance ( 78 ) oriented in the direction of the displacement space ( 91 ) in the normal direction to the piston end face plane ( 72 ), and
wherein each of the boundary lines ( 71 ) includes, as two same kind extreme values ( 73 ; 74 ), either two minima ( 74 ) or two maxima ( 73 ), a distance (d) of which along an arc line around the center axis ( 55 ) is greater than or equal to the positive root of 9.6 times the product of a maximum height (a) of the relief portion ( 69 ), a thickness (h) of the piston disk ( 101 ), a modulus of elasticity of the piston disk ( 101 ), a safety factor and the reciprocal of a yield stress of a material of the piston disk ( 101 ).

2. The cylinder-piston unit ( 10 ) according to claim 1 , wherein the relief portion ( 69 ) is either an end face elevation ( 75 ) or a passage depression ( 76 ) radially penetrating an exterior area ( 67 ) of the displacement space side ( 53 ) surrounding the at least one first piston channels ( 62 ) and the at least one second piston channel ( 63 ).

3. The cylinder-piston unit ( 10 ) according to claim 2 , wherein at least one end face elevation ( 75 ) is formed as a radial bar, which connects the piston journal ( 54 ) and the piston lateral surface ( 57 ).

4. The cylinder-piston unit ( 10 ) according to claim 1 , wherein a height of the relief portion ( 69 ) parallel to the center axis ( 55 ) is less than an arc length of its width.

5. The cylinder-piston unit ( 10 ) according to claim 1 , wherein a cylinder interior wall ( 18 ) of the cylinder ( 11 ) has at least two cylinder channels ( 26 - 31 ) of different length oriented in the longitudinal direction ( 5 ), a dimension of which, oriented in the longitudinal direction ( 5 ), is shorter than a length of a cylinder interior ( 16 ).

6. The cylinder-piston unit ( 10 ) according to claim 5 , wherein the length, measured in the longitudinal direction ( 5 ), of the longest cylinder channel ( 31 ) of the at least two cylinder channels ( 26 - 31 ) is shorter than a maximum stroke of the piston ( 51 ) relative to the cylinder ( 11 ).

7. The cylinder-piston unit ( 10 ) according to claim 1 , wherein the displacement space side ( 53 ) faces a cylinder base ( 13 ).

8. The cylinder-piston unit ( 10 ) according to claim 1 , wherein the piston rod ( 41 ) has a support collar ( 43 ) resting flat on the piston ( 51 ).

9. A cylinder-piston unit ( 10 ), comprising:
a cylinder ( 11 ); and
a piston ( 51 ) which is displaceable in a longitudinal direction ( 5 ) of the cylinder ( 11 ) and which is guided by a piston rod ( 41 ),
wherein the piston ( 51 ) has at least one first piston channel ( 62 ) and at least one second piston channel ( 63 ), which each connect a compensation space side ( 56 ) of the piston ( 51 ) facing a compensation space ( 93 ) with a displacement space side ( 53 ) of the piston ( 51 ) facing a displacement space ( 91 ),
wherein, on the displacement space side ( 53 ), at least one throttle channel ( 68 ) connects at least one first piston channel ( 62 ) with a piston lateral surface ( 57 ), and
wherein the piston ( 51 ) on its displacement space side ( 53 ) has a piston journal ( 54 ) arranged concentrically with respect to its center axis ( 55 ) oriented in the longitudinal direction ( 5 ),
wherein the piston journal ( 54 ) carries a resiliently deformable piston disk ( 101 ) which is displaceable in the longitudinal direction ( 5 ) and covers the throttle channel ( 68 ) at least in some sections, and
wherein the displacement space side ( 53 ) surrounding the piston journal ( 54 ) has at least one relief portion ( 69 ) deviating from a piston end face plane ( 72 ) lying normal to the center axis ( 55 ), and
wherein the relief portion ( 69 ) is delimited on a number of sides by a plurality of boundary lines ( 71 ) running concentrically with respect to the center axis ( 55 ),
wherein each of these boundary lines ( 71 ) can be differentiated continuously, and
wherein the relief portion ( 69 ) is delimited by at least one continuously differentiable top line ( 77 ) running in a radial plane, and
wherein the top line ( 77 ) is either a straight line and/or has at least one point of maximum distance ( 78 ) oriented in the direction of the displacement space ( 91 ) in the normal direction to the piston end face plane ( 72 ), and
wherein a height of the relief portion ( 69 ) parallel to the center axis ( 55 ) is less than an arc length of its width.

10. A cylinder-piston unit ( 10 ), comprising:
a cylinder ( 11 ); and
a piston ( 51 ) which is displaceable in a longitudinal direction ( 5 ) of the cylinder ( 11 ) and which is guided by a piston rod ( 41 ),
wherein the piston ( 51 ) has at least one first piston channel ( 62 ) and at least one second piston channel ( 63 ), which each connect a compensation space side ( 56 ) of the piston ( 51 ) facing a compensation space ( 93 ) with a displacement space side ( 53 ) of the piston ( 51 ) facing a displacement space ( 91 ),
wherein, on the displacement space side ( 53 ), at least one throttle channel ( 68 ) connects at least one first piston channel ( 62 ) with a piston lateral surface ( 57 ), and
wherein the piston ( 51 ) on its displacement space side ( 53 ) has a piston journal ( 54 ) arranged concentrically with respect to its center axis ( 55 ) oriented in the longitudinal direction ( 5 ),
wherein the piston journal ( 54 ) carries a resiliently deformable piston disk ( 101 ) which is displaceable in the longitudinal direction ( 5 ) and covers the throttle channel ( 68 ) at least in some sections, and
wherein the displacement space side ( 53 ) surrounding the piston journal ( 54 ) has at least one relief portion ( 69 ) deviating from a piston end face plane ( 72 ) lying normal to the center axis ( 55 ), and
wherein the relief portion ( 69 ) is delimited on a number of sides by a plurality of boundary lines ( 71 ) runnin

Assignees

• Zimmer Martin
• Zimmer Guenther

Inventors

• Zimmer Martin
• Zimmer Günther

Classifications

• E05Y2800/268

  cylindrical; disc-shaped; circular · CPC title

• E05Y2800/678

  Elastomers · CPC title

• F16F9/512

  Means responsive to load action, {i.e. static load} on the damper or {dynamic} fluid pressure {changes} in the damper, {e.g. due to changes in velocity (F16F9/504, F16F9/516 take precedence; non-automatic damper adjustment from a distance using servo control, the servo pressure being created by the flow of damping fluid F16F9/465; self-pumping fluid springs in vehicle suspensions B60G17/044)} · CPC title

• F16F9/346

  Throttling passages in the form of slots arranged in cylinder walls · CPC title

• E05Y2800/12

  Sealing · CPC title