IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
US-0505404
(2009-11-09)
|
등록번호 |
US-8655567
(2014-02-18)
|
국제출원번호 |
PCT/JP2009/005963
(2009-11-09)
|
§371/§102 date |
20120501
(20120501)
|
국제공개번호 |
WO2011/055419
(2011-05-12)
|
발명자
/ 주소 |
|
출원인 / 주소 |
- Toyota Jidosha Kabushiki Kaisha
|
대리인 / 주소 |
|
인용정보 |
피인용 횟수 :
3 인용 특허 :
10 |
초록
▼
Included are pressure increasing valves and pressure reducing valves as flow control valves, placed between a brake fluid pressure generation unit on an upstream side that generates brake fluid pressure and a braking force generation unit on a downstream side that generates braking force in accordan
Included are pressure increasing valves and pressure reducing valves as flow control valves, placed between a brake fluid pressure generation unit on an upstream side that generates brake fluid pressure and a braking force generation unit on a downstream side that generates braking force in accordance with the brake fluid pressure to a wheel, that regulates the brake fluid pressure to the braking force generation unit by controlling the flow rate of brake fluid, and an electronic control unit is provided with: a differential pressure obtaining unit that obtains information on the difference of brake fluid pressure from the brake fluid pressure on upstream and downstream sides of the flow control valve; a hydrodynamic force obtaining unit that obtains information on hydrodynamic force induced in a valve element by the flow of brake fluid passing through the flow control valve; and a brake fluid pressure control unit that controls the flow control valve by use of the information on the differential pressure and the information on the hydrodynamic force.
대표청구항
▼
1. A brake control device comprising: a flow control valve, placed between a brake fluid pressure generation unit on an upstream side that generates brake fluid pressure and a braking force generation unit on a downstream side that generates braking force in accordance with the brake fluid pressure
1. A brake control device comprising: a flow control valve, placed between a brake fluid pressure generation unit on an upstream side that generates brake fluid pressure and a braking force generation unit on a downstream side that generates braking force in accordance with the brake fluid pressure to a wheel, that regulates the brake fluid pressure to the braking force generation unit by controlling a flow rate of brake fluid;a differential pressure obtaining unit that obtains, from brake fluid pressure on upstream and downstream sides of the flow control valve, information on a difference of the brake fluid pressure;a hydrodynamic force obtaining unit that obtains information on hydrodynamic force that is a sum of forces in valve closing and opening directions working on a valve element by a flow of brake fluid passing through the flow control valve; anda brake fluid pressure control unit that controls the flow control valve by use of the information on the differential pressure and the information on the hydrodynamic force. 2. The brake control device according to claim 1, wherein applied current for operating the valve element is set by use of the information on the differential pressure and the information on the hydrodynamic force, andthe brake fluid pressure control unit applies the applied current to the flow control valve configured as an on-off valve that controls a flow rate of brake fluid by opening and closing a flow passage of the brake fluid with the valve element, thereby driving the flow control valve to be opened and closed. 3. The brake control device according to claim 1, wherein applied rectangular wave current for operating the valve element is obtained by use of the information on the differential pressure and the information on the hydrodynamic force and a current value of the applied current at the time when the valve is open is corrected in accordance with a pulse width of the rectangular wave at the time when the valve is open, andthe brake fluid pressure control unit applies the corrected applied current to the flow control valve configured as an on-off valve that controls a flow rate of brake fluid by opening and closing a flow passage of the brake fluid with the valve element, thereby driving the flow control valve to be opened and closed. 4. The brake control device according to claim 3, wherein the current value of the applied current at the time when the valve is open is corrected to decrease a valve opening degree of the flow control valve as the pulse width at the time when the valve is open becomes longer while being corrected to increase the valve opening degree of the flow control valve as the pulse width at the time when the valve is open becomes shorter. 5. The brake control device according to claim 1, further comprising: a brake flow rate obtaining unit that computes a necessary brake fluid passage flow rate, in the flow control valve, necessary to increase the brake fluid pressure to the braking force generation unit with a desired target pressure increase gradient, and computes a brake fluid passage flow rate in each opening degree stage of the flow control valve;a opening degree stage setting unit that sets the opening degree stage of the flow control valve to an opening degree stage corresponding to a minimum satisfying the necessary brake fluid passage flow rate or a maximum not exceeding the necessary brake fluid passage flow rate, among the brake fluid passage flow rates; andan applied current setting unit that determines a pulse width of applied rectangular wave current at the time when the valve is open for operating the valve element based on the differential pressure, a valve opening degree in the set opening degree stage and the necessary brake fluid passage flow rate, and obtains a current value of the applied current at the time when the valve is open by use of the information on the differential pressure and the information on the hydrodynamic force as well as corrects the current value at the time when the valve is open in accordance with the pulse width of the rectangular wave at the time when the valve is open, whereinthe brake fluid pressure control unit applies the corrected applied current to the flow control valve configured as an on-off valve that controls a flow rate of brake fluid by opening and closing a flow passage of the brake fluid with the valve element, thereby driving the flow control valve to be opened and closed. 6. The brake control device according to claim 1, further comprising: a settable valve open pulse width computing unit that obtains a pulse width of applied rectangular wave current settable within a range not exceeding a predetermined pressure increase control time at the time when the valve is open;a brake flow rate obtaining unit that computes a total brake fluid passage volume of the flow control valve necessary to increase the brake fluid pressure to the braking force generation unit with a desired target pressure increase gradient as well as computes a brake fluid passage volume settable by all combinations of opening degree stages of the flow control valve and the settable pulse widths at the time when the valve is open, and selects a maximum not exceeding the total brake fluid passage volume or a minimum exceeding the total brake fluid passage volume from the settable brake fluid passage volumes;an opening degree stage setting unit that sets the opening degree stage of the flow control valve to an opening degree stage corresponding to the selected brake fluid passage volume; andan applied current setting unit that sets the pulse width of the applied current at the time when the valve is open to a pulse width corresponding to the selected brake fluid passage volume, and obtains a current value of the applied current at the time when the valve is open by use of the information on the differential pressure and the information on the hydrodynamic force as well as corrects the current value at the time when the valve is open in accordance with the set pulse width at the time when the valve is open, whereinthe brake fluid pressure control unit applies the corrected applied current to the flow control valve configured as an on-off valve that controls a flow rate of brake fluid by opening and closing a flow passage of the brake fluid with the valve element, thereby driving the flow control valve to be opened and closed. 7. The brake control device according to claim 1, wherein the force in the valve closing direction is Bernoulli force proportional to a square of the differential pressure, and the force in the valve opening direction is cavitation force proportional to the differential pressure and inversely proportional to the brake fluid pressure on the downstream side of the flow control valve. 8. The brake control device according to claim 1, wherein the flow control valve includes an elastic body causing elastic force in a direction opposite to acting force on the valve element by applied current, to act on the valve element, andthe brake fluid pressure control unit controls the flow control valve by use of information on the elastic force in addition to the information on the differential pressure and the information on the hydrodynamic force. 9. The brake control device according to claim 2, wherein the flow control valve includes an elastic body causing elastic force in a direction opposite to acting force on the valve element by the applied current, to act on the valve element, andthe applied current setting unit sets the applied current by use of information on the elastic force in addition to the information on the differential pressure and the information on the hydrodynamic force. 10. The brake control device according to claim 1, wherein master cylinder pressure is obtained as the brake fluid pressure on the upstream side of the flow control valve, andthe brake fluid pressure to the braking force generation unit is estimated as the brake fluid pressure on the downstream side of the flow control valve.
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