HYDRAULIC CONTROL DEVICE FOR VEHICLES

• US 20180339684A1
• Filed: 09/28/2016
• Published: 11/29/2018
• Est. Priority Date: 09/28/2015
• Status: Active Grant

• Current Assignee: Advics Company Limited (Aisin Corp.)
• Original Assignee: Advics Company Limited (Aisin Corp.)
• Inventors: TAKEYA, Yusuke, HASHIMOTO, Kosuke, NOHIRA, Shun
• Granted Patent: US 10,773,696 B2
• Time in Patent Office: Days
• CPC Class Codes: B60T 13/166 Part of the system directly actuated by booster pressure
• CPC Class Codes: B60T 13/662 characterised by specified functions of the control system components
• CPC Class Codes: B60T 13/686 in hydraulic systems or parts thereof
• CPC Class Codes: B60T 8/00 Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force by changing number of effective brake cylinders in power brake systems B60T17/10
• CPC Class Codes: B60T 8/17 Using electrical or electronic regulation means to control braking detecting or indicating faulty operation B60T8/885
• CPC Class Codes: B60T 8/173 Eliminating or reducing the effect of unwanted signals, e.g. due to vibrations or electrical noise
• CPC Class Codes: B60T 8/34 having a fluid pressure regulator responsive to a speed condition
• CPC Class Codes: B60T 8/36 including a pilot valve responding to an electromagnetic force
• CPC Class Codes: F16K 31/06 using a magnet , e.g. diaphragm valves, cutting off by means of a liquid
• CPC Class Codes: F16K 31/0655 Lift valves

Abstract

In the present invention, a brake device is equipped with: differential pressure control valves; pressure adjusting units which are connected to the differential pressure control valves through liquid passages; and a control device which controls the WC pressure Pwc in wheel cylinders by operating the differential pressure control valves and the pressure adjusting units. When predetermined suppression control permission conditions are satisfied while both the supply pumps of the pressure adjusting units and the differential pressure control valves are in operation, the control device performs self-excited vibration suppression control over the differential pressure control valves, the self-excited vibration suppression control being carried out in such a manner that a valve element separated from a valve seat is caused to abut on the valve seat, and, upon abutting on the valve seat, the valve element is separated from the valve seat.

Claims

1. A hydraulic control device for vehicles, comprising:

an electromagnetic valve connected to a control target disposed in a vehicle, through a fluid passage in which a fluid flows;

a pressure adjusting unit connected to the electromagnetic valve through the fluid passage in which the fluid flows; and

a control unit configured to actuate the electromagnetic valve and the pressure adjusting unit to control an inflow of the fluid into the control target,

the electromagnetic valve including a valve seat, a valve element configured to move in a direction approaching the valve seat and in a direction away from the valve element, and a solenoid in which a current flows,

the electromagnetic valve being configured to change an interval between the valve seat and the valve element depending on the current flowing in the solenoid, wherein

under a situation in which both the electromagnetic valve and the pressure adjusting unit are actuated, when predetermined suppression control permission conditions are satisfied, the control unit executes, on the electromagnetic valve, a self-excited vibration suppression control that brings the valve element separated from the valve seat into contact with the valve seat and separates the valve element from the valve seat when the valve element is brought into contact with the valve seat.

2. The hydraulic control device for vehicles according to claim 1, wherein

the control target is a wheel cylinder disposed on a wheel, brake force applied to the wheel increases as a hydraulic pressure in the wheel cylinder is increased,

the hydraulic control device for vehicles further comprises a hydraulic pressure generating device that is disposed opposite the wheel cylinder across the electromagnetic valve in the fluid passage in which the fluid flows and is configured to generate a hydraulic pressure depending on an operation of a brake operation member,

the pressure adjusting unit includes a retention valve that is a normally-opened type electromagnetic valve disposed in a fluid passage connecting the electromagnetic valve to the wheel cylinder, and a pump configured to pump a fluid to a fluid passage connecting the retention valve to the electromagnetic valve,

the electromagnetic valve is a differential pressure control valve configured to adjust a differential pressure between a pressure on the hydraulic pressure generating device side of the electromagnetic valve and a pressure on the retention valve side of the electromagnetic valve in a situation in which the fluid is pumped from the pump, and

the control unit is configured to actuate the differential pressure control valve and the pressure adjusting unit to adjust the hydraulic pressure in the wheel cylinder.

3. The hydraulic control device for vehicles according to claim 2, wherein when the control unit actuates both the differential pressure control valve and the pump to adjust the hydraulic pressure in the wheel cylinder, then the control unit executes the self-excited vibration suppression control on the differential pressure control valve on an assumption that the predetermined suppression control permission conditions are satisfied when the retention valve is not closed.

4. The hydraulic control device for vehicles according to claim 2, wherein in a case where a hydraulic pressure set to protect the fluid passage connecting the differential pressure control valve to the retention valve is defined as a system upper-limit pressure, when the control unit actuates both the differential pressure control valve and the pump to adjust the hydraulic pressure in the wheel cylinder, then the control unit executes the self-excited vibration suppression control on the differential pressure control valve on an assumption that the suppression control permission conditions are satisfied when the hydraulic pressure in the fluid passage connecting the differential pressure control valve to the retention valve is predicted to be equal to or lower than the system upper-limit pressure when the differential pressure control valve is closed.

5. The hydraulic control device for vehicles according to claim 2, wherein

the retention valve is configured such that as the current flowing in the retention valve increases, a degree of opening of the retention valve decreases, or a valve closing rate increases, and

when the control unit actuates both the differential pressure control valve and the pump to adjust the hydraulic pressure in the wheel cylinder, then the control unit executes the self-excited vibration suppression control on the differential pressure control valve on an assumption that the suppression control permission conditions are satisfied when a change rate of the current flowing in the retention valve is equal to or higher than a determination change rate.

6. The hydraulic control device for vehicles according to claim 5, wherein in the self-excited vibration suppression control, the control unit increases force pressing the valve element against the valve seat when the valve element sits on the valve seat as the change rate of the current flowing in the retention valve is higher.

7. The hydraulic control device for vehicles according to claim 5, further comprising a plurality of hydraulic pressure circuits each having the differential pressure control valve and the pressure adjusting unit, wherein

each of the hydraulic pressure circuits is connected through the hydraulic pressure generating device, and

when control unit executes the self-excited vibration suppression control on the differential pressure control valve of one of the plurality of hydraulic pressure circuits, then the control unit also executes the self-excited vibration suppression control on the differential pressure control valves of the other hydraulic pressure circuits.

8. The hydraulic control device for vehicles according to claim 3, wherein in a case where a hydraulic pressure set to protect the fluid passage connecting the differential pressure control valve to the retention valve is defined as a system upper-limit pressure, when the control unit actuates both the differential pressure control valve and the pump to adjust the hydraulic pressure in the wheel cylinder, then the control unit executes the self-excited vibration suppression control on the differential pressure control valve on an assumption that the suppression control permission conditions are satisfied when the hydraulic pressure in the fluid passage connecting the differential pressure control valve to the retention valve is predicted to be equal to or lower than the system upper-limit pressure when the differential pressure control valve is closed.

9. The hydraulic control device for vehicles according to claim 3, wherein

the retention valve is configured such that as the current flowing in the retention valve increases, a degree of opening of the retention valve decreases, or a valve closing rate increases, and

when the control unit actuates both the differential pressure control valve and the pump to adjust the hydraulic pressure in the wheel cylinder, then the control unit executes the self-excited vibration suppression control on the differential pressure control valve on an assumption that the suppression control permission conditions are satisfied when a change rate of the current flowing in the retention valve is equal to or higher than a determination change rate.

10. The hydraulic control device for vehicles according to claim 4, wherein

the retention valve is configured such that as the current flowing in the retention valve increases, a degree of opening of the retention valve decreases, or a valve closing rate increases, and

when the control unit actuates both the differential pressure control valve and the pump to adjust the hydraulic pressure in the wheel cylinder, then the control unit executes the self-excited vibration suppression control on the differential pressure control valve on an assumption that the suppression control permission conditions are satisfied when a change rate of the current flowing in the retention valve is equal to or higher than a determination change rate.

11. The hydraulic control device for vehicles according to claim 8, wherein

the retention valve is configured such that as the current flowing in the retention valve increases, a degree of opening of the retention valve decreases, or a valve closing rate increases, and

when the control unit actuates both the differential pressure control valve and the pump to adjust the hydraulic pressure in the wheel cylinder, then the control unit executes the self-excited vibration suppression control on the differential pressure control valve on an assumption that the suppression control permission conditions are satisfied when a change rate of the current flowing in the retention valve is equal to or higher than a determination change rate.

12. The hydraulic control device for vehicles according to claim 9, wherein in the self-excited vibration suppression control, the control unit increases force pressing the valve element against the valve seat when the valve element sits on the valve seat as the change rate of the current flowing in the retention valve is higher.

13. The hydraulic control device for vehicles according to claim 10, wherein in the self-excited vibration suppression control, the control unit increases force pressing the valve element against the valve seat when the valve element sits on the valve seat as the change rate of the current flowing in the retention valve is higher.

14. The hydraulic control device for vehicles according to claim 11, wherein in the self-excited vibration suppression control, the control unit increases force pressing the valve element against the valve seat when the valve element sits on the valve seat as the change rate of the current flowing in the retention valve is higher.

15. The hydraulic control device for vehicles according to claim 6, further comprising a plurality of hydraulic pressure circuits each having the differential pressure control valve and the pressure adjusting unit, wherein

each of the hydraulic pressure circuits is connected through the hydraulic pressure generating device, and

when control unit executes the self-excited vibration suppression control on the differential pressure control valve of one of the plurality of hydraulic pressure circuits, then the control unit also executes the self-excited vibration suppression control on the differential pressure control valves of the other hydraulic pressure circuits.