Linear solenoid valve
First Claim
1. A linear solenoid valve, comprising:
- a spool that strokes to one side in an axis direction by conduction of current to a coil;
an urging member that urges the spool to the other side in the axis direction; and
a control part for controlling the conduction of the current to the coil,wherein an oil pressure in a hydraulic circuit is controlled by adjusting a discharge amount of an oil from a pressure adjusting port communicating with the hydraulic circuit by the spool that strokes in the axis direction,wherein the control part includes;
a determination unit for determining start of an operation to remove foreign substances by the spool;
a command value setting unit for setting a command value for the current conducted to the coil; and
a dither current setting unit for setting a dither current superimposed on the command value of the current, andwherein when the determination unit determines the start of the foreign substance removing operation,the dither current setting unit changes an oscillation frequency of the dither current superimposed on the command value of the current to an oscillation frequency lower than an oscillation frequency at a current point in time, andthe command value setting unit periodically increases and reduces the command value on which the changed oscillation frequency is superimposed.
1 Assignment
0 Petitions
Accused Products
Abstract
A pressure control valve includes a spool that strokes to one side in the direction of an axis due to the conduction of current to a coil, a spring that urges the spool to the other side in the axis direction, a control device for controlling the conduction of the current to the coil, a determination unit for determining the start of a foreign substance removing operation by the spool, a command value setting unit for setting a command value for the current conducted to the coil, and a dither current setting unit for setting a dither current superimposed on the command value. When the determination unit determines the start of the foreign substance removing operation, the dither current setting unit changes an oscillation frequency of the dither current to an oscillation frequency lower than the frequency at the current point in time, and the command value setting unit periodically increases and reduces the command value on which the changed oscillation frequency is superimposed.
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Citations
5 Claims
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1. A linear solenoid valve, comprising:
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a spool that strokes to one side in an axis direction by conduction of current to a coil; an urging member that urges the spool to the other side in the axis direction; and a control part for controlling the conduction of the current to the coil, wherein an oil pressure in a hydraulic circuit is controlled by adjusting a discharge amount of an oil from a pressure adjusting port communicating with the hydraulic circuit by the spool that strokes in the axis direction, wherein the control part includes; a determination unit for determining start of an operation to remove foreign substances by the spool; a command value setting unit for setting a command value for the current conducted to the coil; and a dither current setting unit for setting a dither current superimposed on the command value of the current, and wherein when the determination unit determines the start of the foreign substance removing operation, the dither current setting unit changes an oscillation frequency of the dither current superimposed on the command value of the current to an oscillation frequency lower than an oscillation frequency at a current point in time, and the command value setting unit periodically increases and reduces the command value on which the changed oscillation frequency is superimposed. - View Dependent Claims (2, 3, 4, 5)
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Specification