Steering damper
AssigneeUnisia Jkc Steering Systems Co., Ltd.
InventorsHirotetsu Sonoda, Tatsuya Harada
Life of this patent
Estimating the term…
Abstract
A steering damper has a pair of damper portions each including a variable throttle valve for restricting inflow from a power cylinder into a flow passage change-over valve, the variable throttle valve provided on the way to each cylinder passage and a first check valve for permitting inflow from the flow passage change-over valve into the power cylinder, the check valve connected in parallel with the variable throttle valve. The steering damper has a second check valve in communication to a tank between the first check valve and left and right chambers of the power cylinder.
Claims21
A steering damper attached to a power steering apparatus having a flow passage change-over valve for selectively changing a flow passage among a pump and a tank and left and right chambers of the power cylinder in accordance with steering operation of a steering wheel, and a pair of left and right cylinder passages for connecting the flow passage change-over valve to the left and right chambers, the steering damper comprising:
- a pair of damper portions each having:
- a variable throttle valve for restricting inflow from the power cylinder into the flow passage change-over valve, the variable throttle valve provided between the flow passage change-over valve and each of the left and right chambers of the power cylinder;
- and
- a first check valve for permitting inflow from the flow passage change-over valve into the power cylinder, the check valve connected in parallel with the variable throttle valve;
- and
- second check valves in communication to the tank, provided between the first check valves and the left and right chambers.
A steering damper attached to a power steering apparatus having a flow passage change-over valve for selectively changing a flow passage among a pump and a tank and left and right chambers of the power cylinder in accordance with steering operation of a steering wheel, and a pair of left and right cylinder passages for connecting the flow passage change-over valve to the left and right chambers, the steering damper comprising:
- a pair of damper portions each having:
- a variable throttle valve for restricting inflow from the power cylinder into the flow passage change-over valve in accordance with steering operation of a steering wheel, the variable throttle valve provided between the flow passage change-over valve and the left and right chambers of the power cylinder;
- and
- a first check valve for permitting inflow from the flow passage change-over valve into the power cylinder, the check valve connected in parallel with the variable throttle valve;
- wherein the variable throttle valve has:
- a step portion, which is a valve seat of the variable throttle valve formed on an inner surface of a housing;
- and
- a barrel-like valve plug for abutting with the step portion to close the variable throttle valve;
- wherein a first biasing member biases the barrel-like valve plug in a valve seat direction;
- wherein the first check valve has:
- a cylindrical valve plug with bottom for abutting an opening portion of the barrel-like portion to close the first check valve;
- and
- a second biasing member for biasing the cylindrical valve plug with bottom from a direction opposite to the first biasing member;
- and
- wherein a communication bore is formed through a bottom face of the cylindrical valve plug with bottom.
A power steering apparatus comprising:
- a pump for supplying oil;
- a tank for receiving returned oil;
- a power cylinder having left and right chambers;
- a flow passage change-over valve for selectively changing a flow passage among the pump and the tank and the left and right chambers in accordance with steering operation of a steering wheel;
- a steering damper having:
- a pair of damper portions each including:
- a variable throttle valve for restricting inflow from the power cylinder into the flow passage change-over valve, the variable throttle valve provided between the flow passage change-over valve and each of the left and right chambers of the power cylinder;
- and
- a first check valve for permitting inflow from the flow passage change-over valve into the power cylinder, the check valve connected in parallel with the variable throttle valve;
- and second check valves in communication to the tank, provided between the first check valves and the left and right chambers.
A power steering apparatus comprising:
- a pump for supplying oil;
- a tank for receiving returned oil;
- a power cylinder having left and right chambers;
- a flow passage change-over valve for selectively changing a flow passage among the pump and the tank and the left and right chambers in accordance with steering operation of a steering wheel;
- a steering damper having:
- a pair of damper portions each including:
- a variable throttle valve for restricting inflow from the power cylinder into the flow passage change-over valve, the variable throttle valve provided between the flow passage change-over valve and each of the left and right chambers of the power cylinder;
- and
- a first check valve for permitting inflow from the flow passage change-over valve into the power cylinder, the check valve connected in parallel with the variable throttle valve;
- and
- wherein the variable throttle valve has:
- a step portion, which is a valve seat of the variable throttle valve formed on an inner surface of a housing;
- and
- a barrel-like valve plug for abutting with the step portion to close the variable throttle valve;
- wherein a first biasing member biases the barrel-like valve plug in a valve seat direction;
- wherein the first check valve has:
- a cylindrical valve plug with bottom for abutting an opening portion of the barrel-like portion to close the first check valve;
- and
- a second biasing member for biasing the cylindrical valve plug with bottom from a direction opposite to the first biasing member;
- and
- wherein a communication bore is formed through a bottom face of the cylindrical valve plug with bottom.
Dependencies are inferred from the claim text.