Electronic brake system
View Patent ↗An electronic brake system may be capable of providing a required hydraulic pressure continuously and constantly as well as a precise pressure control through a gear pump provided in a hydraulic pressure supply device. Also, the electronic brake system may be capable of minimizing a number of valves controlling hydraulic pressure flows to implement a simplified configuration and providing the braking by a pedal effort of a driver even when the brake system is abnormally operated.
1. An electronic brake system, which includes a reservoir storing oil, a master cylinder having first and second hydraulic ports and coupled to the reservoir so as to receive the oil, a pedal displacement sensor measuring a displacement of a brake pedal, and a simulation device connected to the master cylinder to provide a reaction force corresponding to a pedal effort of the brake pedal, comprising:
a hydraulic pressure supply device having a motor configured to be rotated by receiving an electrical signal from the pedal displacement sensor when the brake pedal is operated, a gear pump configured to discharge and suction a hydraulic pressure depending on a rotational force of the motor, and a power transmission unit configured to deliver the rotational force of the motor to the gear pump;
a hydraulic control unit having first and second hydraulic circuits configured to receive the hydraulic pressure by a force generated by the hydraulic pressure supply device to control hydraulic pressure flows delivered to wheel cylinders provided on wheels; and
an electronic control unit configured to control the motor and valves based on hydraulic pressure information and pedal displacement information,
wherein the gear pump is connected to the first hydraulic circuit through a first hydraulic passage and to the second hydraulic circuit through a second hydraulic passage connected to a branch passage that is branched off from the first hydraulic passage, and
the electronic brake system further comprising:
a release valve provided on a passage connecting the branch passage with the reservoir and opened to discharge the hydraulic pressure to the reservoir through the first hydraulic passage and the second hydraulic passage, and
wherein one end of the gear pump is connected to the reservoir and the other end of the pump is connected to the first hydraulic circuit to provide a common pressure to the first and second hydraulic circuits.
2. The electronic brake system according to claim 1 , further comprising:
a first reserving valve provided at a rear (in a direction of the first hydraulic circuit) of a position at which the branch passage of the first hydraulic passage is branched off to control a hydraulic pressure flow between the first hydraulic circuit and the gear pump; and
a second reserving valve provided on the second hydraulic passage to control a hydraulic pressure flow between the second hydraulic circuit and the gear pump.
3. The electronic brake system according to claim 2 , wherein the first and second reserving valves are made of a normally closed type solenoid valve that is closed in a normal operating state and is opened when an opening signal is received.
4. The electronic brake system according to claim 2 , wherein the second reserving valve is provided at a rear (in a direction of the second hydraulic circuit) of a position at which the second hydraulic passage is branched off from the branch passage.
5. The electronic brake system according to claim 2 , wherein the release valve is provided between the first and second reserving valves and the gear pump.
6. The electronic brake system according to claim 2 , wherein the release valve is provided with a normally closed type solenoid valve that is closed in a normal operating state and is opened when an opening signal is received.
7. The electronic brake system according to claim 1 , further comprising:
a first backup passage configured to connect the first hydraulic port with the first hydraulic circuit so as to directly provide the oil to the wheel cylinder when the electronic brake system is abnormally operated;
a second backup passage configured to connect the second hydraulic port with the second hydraulic circuit;
a first cut valve provided on the first backup passage to control an oil flow; and
a second cut valve provided on the second backup passage to control an oil flow.
8. The electronic brake system according to claim 7 , wherein the first and second cut valves are provided with a normally opened type solenoid valve that is open in a normal operating state and is closed when a closing signal from the electronic control unit is received.
9. The electronic brake system according to claim 1 , wherein the hydraulic control unit includes inlet valves each of which is provided on an upstream side of each of the wheel cylinders so as to control the hydraulic pressure flowing into the wheel cylinder installed on each of the wheels.
10. The electronic brake system according to claim 9 , wherein the hydraulic control unit further includes a plurality of outlet valves configured to independently control hydraulic pressure flows discharged from the wheel cylinders,
wherein each of the outlet valves are connected to the reservoir.
11. The electronic brake system according to claim 9 , wherein the inlet valves are provided with a normally opened type solenoid valve that is open in a normal operating state and is closed when a closing signal from the electronic control unit is received.
12. The electronic brake system according to claim 10 , wherein the outlet valves are provided with a normally closed type solenoid valve that is closed in a normal operating state and is opened when an opening signal is received.