Hydraulic control apparatus and hydraulic control method

Patent metadata

Field	Value
Publication number	US-10801494-B2
Application number	US-201815951646-A
Country	US
Kind code	B2
Filing date	Apr 12, 2018
Priority date	Jul 12, 2017
Publication date	Oct 13, 2020
Grant date	Oct 13, 2020

Abstract

A hydraulic control apparatus is provided including: an electromagnetic valve that has an input port communicating with a supply destination unit of oil and a control port that is switched between communication and disconnection by resultant force of a hydraulic pressure of the supply destination unit and electromagnetic force; a variable displacement pump which has a suction port communicating with a supply source of the oil, an ejection port communicating with the supply destination unit, and a control chamber communicating with the control port and rotates in accordance with drive of the supply destination unit, in which an amount of the oil ejected to the supply destination unit through the ejection port changes in accordance with a pressure in the control chamber; and a control unit that controls a value of a necessary current that is caused to flow through the electromagnetic valve.

First claim

What is claimed is:

1. A hydraulic control apparatus comprising:
an electromagnetic valve that has
a solenoid including a coil,
a cylindrical valve body connected to the solenoid,
an input port which is provided in an open manner on the valve body and communicates with a supply destination unit of oil,
a spool which is installed in a cylindrical portion of the valve body with a valve spring setting a threshold value for communication and is operated by a resultant force of a hydraulic pressure of the input port and an electromagnetic force of the coil exceeding the threshold value for communication, and
a control port which is installed side by side with the input port in the valve body and in which a communication and a disconnection to the input port are switched by the spool;

a variable displacement pump which includes
a housing that has a suction port communicating with a supply source of the oil and an ejection port communicating with the supply destination unit,
a control chamber that is formed in the housing and communicates with the suction port, the ejection port, and the control port,
a cam ring that is accommodated in the housing, sections the control chamber and the suction port, sections the control chamber and the ejection port, and is able to move in a direction in which the control chamber expands or contracts,
a rotor configured to rotate about an axial line perpendicularly intersecting a direction, in which the cam ring is able to move, inside of the cam ring, and
a plurality of vanes that are supported by the rotor to advance or retreat in a radial direction perpendicularly intersecting the axial line with a movement of the cam ring and that have outer end surfaces in the radial direction sliding an inner circumferential surface of the cam ring,

wherein an outer circumferential surface of the cam ring has
a pressure receiving surface on which an ejection pressure of oil ejected from the ejection port acts, and
a pressing surface that faces the pressure receiving surface and is pressed against an opening surface of the suction port in an inner surface of the housing in response to the ejection pressure,

the rotor rotates in accordance with a rotation drive of the supply destination unit, and
the variable displacement pump changes an amount of the oil ejected to the supply destination unit through the ejection port in accordance with a pressure in the control chamber by the control chamber expanding or contracting; and
a control unit that is electrically connected to the coil and controls a value of a necessary current applying to the electromagnetic valve required for generating the electromagnetic force,
wherein the control unit has
a state decision unit configured to determine a parameter indicating a load state of the supply destination unit;
a target hydraulic pressure calculation unit configured to calculate a target hydraulic pressure value of the supply destination unit based on a target hydraulic pressure map indicating a correlation between the determined parameter indicating the load state and the target hydraulic pressure value, and
a necessary current calculation unit configured to calculate the value of the necessary current based on a necessary current map indicating a correlation between the target hydraulic pressure value and the value of the necessary current.

2. The hydraulic control apparatus according to claim 1 ,
wherein the necessary current map is set such that the value of the necessary current decreases as the target hydraulic pressure value increases.

3. A hydraulic control method for a hydraulic control apparatus including:
an electromagnetic valve that has
a solenoid including a coil,
a cylindrical valve body connected to the solenoid,
an input port which is provided in an open manner on the valve body and communicates with a supply destination unit of oil,
a spool which is installed in a cylindrical portion of the valve body with a valve spring setting a threshold value for communication and is operated by a resultant force of a hydraulic pressure of the input port and an electromagnetic force of the coil exceeding the threshold value for communication, and
a control port which is installed side by side with the input port in the valve body and in which a communication and a disconnection to the input port are switched in a non-stepwise manner by the spool;

a variable displacement pump which has a suction port communicating with a supply source of the oil, an ejection port communicating with the supply destination unit, and a control chamber communicating with the control port, in which a rotor rotates in accordance with a rotation drive of the supply destination unit, and which changes an amount of the oil ejected to the supply destination unit through the ejection port in accordance with a pressure change in the control chamber; and
a control unit that is electrically connected to the coil and controls a value of a necessary current applying to the electromagnetic valve required for generating the electromagnetic force,
the method comprising causing the control unit to perform:
a step of determining a parameter indicating a load state of the supply destination unit;
a target hydraulic pressure value calculation step of calculating a target hydraulic pressure value of the supply destination unit based on a target hydraulic pressure map indicating a correlation between the determined parameter indicating the load state and the target hydraulic pressure value; and
a necessary current value calculation step of calculating the value of the necessary current based on a necessary current map indicating a correlation between the target hydraulic pressure value and the value of the necessary current.

4. The hydraulic control method according to claim 3 ,
wherein the method further comprises causing the control unit to perform:
a step of reading a signal of a lower limit switch which turns on in a case in which the hydraulic pressure of the supply destination unit falls below a lower limit threshold value, and
a step of forcibly reducing a current applying to the electromagnetic valve regardless of the value of the necessary current when the read signal of the lower limit switch indicates that the lower limit switch turns on.

5. The hydraulic control method according to claim 3 ,
wherein the method further comprises causing the control unit to perform:
a step of reading a signal of an upper limit switch which turns on in a case in which the hydraulic pressure of the supply destination unit exceeds an upper limit threshold value, and
a step of forcibly increasing a current applying to the electromagnetic valve regardless of the value of the necessary current when the read signal of the upper limit switch indicates that the lower limit switch turns on.

Assignees

• Yamada Mfg Co Ltd
• Keihin Corp

Inventors

• Senbongi Yuji
• Fujiki Kenichi
• Kobayashi Toru
• Kaneko Ken
• Satou Takahiro
• Kobayashi Haruyo
• Segawa Yoshiharu
• Oikawa Naoki
• Murayama Syu
• Yamanaka Kentaro
• Jyo Yuhki

Classifications

• F04C14/223 Primary

  using a movable cam · CPC title

• F16H61/431

  Pump capacity control by electro-hydraulic control means, e.g. using solenoid valves · CPC title

• F04C14/24

  characterised by using valves controlling pressure or flow rate, e.g. discharge valves {or unloading valves}(F04C14/10 takes precedence) · CPC title

• F04C14/226 Primary

  by pivoting the cam around an eccentric axis · CPC title

• F04C14/22

  by changing the eccentricity between cooperating members · CPC title