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US 8,944,104 B2Granted
Hydraulic pilot control unit
AssigneeRobert Bosch GmbH
InventorsWolfgang Kauss, Gerard Laroze
Life of this patent
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Abstract
A hydraulic pilot control unit includes at least one pressure control valve that can be controlled by means of an actuating device. The pressure control valve includes a control piston connected to a stem by means of a neck. The stem has a resilient operative connection to the actuating device. The neck is fastened to the stem. Thus, the mass of the control piston, which tends to oscillate, is reduced compared to the prior art.
Claims11
A hydraulic pilot control unit comprising:
- at least one pressure-regulating valve, which can be controlled by way of an actuating device and which includes a control piston connected to a tappet by way of a neck,
- wherein the tappet is operatively connected to the actuating device, and
- wherein the neck is fixed to the tappet,
- wherein the tappet of each pressure-regulating valve and the associated control piston can be displaced by the actuating device in an opening direction of the control piston, and
- wherein a shear-elastic connection is provided between the neck of each pressure-regulating valve and the associated control piston, said shear-elastic connection including;
- a regulating spring, which is supported against the tappet and which biases the control piston in an opening direction, and
- a head, which is fixed to an end portion of the neck and is inserted into a recess formed on a first end portion of the control piston, and is displaceable therein in an opening direction.
4 more elements
A hydraulic pilot control unit comprising:
- at least one pressure-regulating valve, which can be controlled by way of an actuating device and which comprises a control piston connected to a tappet by way of a neck,
- wherein the tappet is operatively connected to the actuating device, and
- wherein the neck is fixed to the tappet,
- wherein each pressure-regulating valve has a return spring, which is supported against a housing of the associated pressure-regulating valve or a housing of the pilot control unit, and which biases the tappet in a closing direction,
- wherein the control piston is a stepped piston, which has a first ring surface acting in an opening direction and a second ring surface acting in a closing direction, both of which surfaces are subjected to the pressure of a working connection of the associated pressure-regulating valve, and
- wherein the first ring surface is smaller than the second ring surface.
3 more elements
A hydraulic pilot control unit comprising:
- at least one pressure-regulating valve, which can be controlled by way of an actuating device and which comprises a control piston connected to a tappet by way of a neck,
- wherein the tappet is operatively connected to the actuating device, and
- wherein the neck is fixed to the tappet,
- wherein each pressure-regulating valve has a return spring, which is supported against a housing of the associated pressure-regulating valve or a housing of the pilot control unit, and which biases the tappet in a closing direction,
- wherein each control piston comprises a longitudinal bore, and
- wherein a chamber arranged between the housing and a second end portion of the control piston remote from the respective tappet is connected to the tank pressure chamber by way of the longitudinal bore and by way of the passage.
3 more elements
Dependencies are inferred from the claim text.