Vehicle brake device

Patent metadata

Field	Value
Publication number	US-10029662-B2
Application number	US-201515128206-A
Country	US
Kind code	B2
Filing date	Jan 8, 2015
Priority date	Mar 25, 2014
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

A vehicle brake device includes a pressure adjusting device wherein as the volume of a pilot chamber is changed by the movement of a piston and the flow rate of liquid flowing in and out of the pilot chamber increases, the amount of movement of the piston increases with reference to the piston position in an equilibrium state where the force corresponding to the pilot pressure and the force corresponding to the output pressure are balanced, whereby the flow rate of the liquid flowing in and out of an output chamber increases. A control device, when judged by a limitation necessity judging portion that the gradient of output pressure should be limited, implements at least one of pressure increasing gradient limit control for opening a pressure decreasing electromagnetic valve under pressure increasing control, or pressure decreasing gradient limit control for opening a pressure increasing electromagnetic valve under pressure decreasing control.

First claim

The invention claimed is:

1. A vehicle brake device comprising:
a pressure adjusting device configured to output an output pressure corresponding to a pilot pressure inputted into a pilot chamber into an output chamber;

a high pressure source configured to accumulate a hydraulic pressure in a predetermined range;
a low pressure source configured to accumulate a hydraulic pressure lower than the hydraulic pressure accumulated in the high pressure source;
a pressure increasing electromagnetic valve configured to adjust a flow rate of a liquid flowing into the pilot chamber from the high pressure source;
a pressure decreasing electromagnetic valve configured to adjust a flow rate of a liquid flowing into the low pressure source from the pilot chamber; and
a control means configured to control the pressure increasing electromagnetic valve and the pressure decreasing electromagnetic valve, wherein
the vehicle brake device further includes a limiting necessity judging means configured to judge whether a gradient of the output pressure should be limited or not, based on a target output pressure which is a control target of the control means and an actual output pressure correlation value which correlates with an actual output pressure;

the pressure adjusting device configured to include a piston driven by a force generated by a difference between a force corresponding to the pilot pressure and a force corresponding to the output pressure, wherein a volume of the pilot chamber varies in response to a movement of the piston, a reference position of the piston being a position under a state that the force corresponding to the pilot pressure and the force corresponding to the output pressure are balanced and when the flow rate of the liquid flowing into or out of the pilot chamber increases, the movement of the piston from the reference position increases to thereby increase the flow rate of the liquid flowing into or out of the output chamber; and wherein
the control means executes at least one of a pressure increasing gradient limiting control in which the pressure decreasing electromagnetic valve is opened under a pressure increasing control and a pressure decreasing gradient limiting control in which the pressure increasing electromagnetic valve is opened under a pressure decreasing control, when the limiting necessity judging means judges that the gradient of the output pressure should be limited.

2. The vehicle brake device according to claim 1 , wherein the control means opens the pressure decreasing electromagnetic valve when executing the pressure increasing gradient limiting control and opens the pressure increasing electromagnetic valve when executing the pressure decreasing gradient limiting control, respectively by an opening degree corresponding to a deviation between the target output pressure and the actual output pressure correlation value.

3. The vehicle brake device according to claim 2 , wherein the control means opens the pressure decreasing electromagnetic valve when executing the pressure increasing gradient limiting control and opens the pressure increasing electromagnetic valve when executing the pressure decreasing gradient limiting control, respectively by the opening degree further corresponding to a gradient of the output pressure.

4. The vehicle brake device according to claim 1 , further comprising:
an output pressure obtaining means configured to obtain an actual output pressure which is the pressure actually outputted, wherein
the control means monitors the change of the actual output pressure obtained by the output pressure obtaining means while gradually increasing the opening degree of the pressure decreasing electromagnetic valve when executing the pressure increasing gradient limiting control or while gradually increasing the opening degree of the pressure increasing electromagnetic valve when executing the pressure decreasing gradient limiting control and closes the pressure increasing electromagnetic valve or the pressure decreasing electromagnetic valve in response to the change of the actual output pressure.

5. The brake device according to claim 1 , further comprising:
a valve opening time setting means configured to set a valve opening time of the pressure decreasing electromagnetic valve based on the deviation between the target output pressure and the actual output pressure correlation value, wherein the control means opens the pressure decreasing electromagnetic valve by the valve opening time when executing the pressure increasing gradient limiting control.

6. The brake device according to claim 1 , further comprising:
a valve opening time setting means configured to set a valve opening time of the pressure increasing electromagnetic valve based on the deviation between the target output pressure and the actual output pressure correlation value, wherein the control means opens the pressure increasing electromagnetic valve by the valve opening time when executing the pressure decreasing gradient limiting control.

7. The brake device according to claim 5 , wherein the valve opening time setting means is configured to set the valve opening time further based on the gradient of the output pressure.

Assignees

• Advics Co Ltd
• Toyota Motor Co Ltd
• Advics Co Ltd

Inventors

• Ninoyu Masaki
• Okano Takahiro
• Masuda Yoshio
• Nakata Daisuke

Classifications

• B60T13/146 Primary

  Part of the system directly actuated by booster pressure · CPC title

• B60T8/40

  comprising an additional fluid circuit including fluid pressurising means for modifying the pressure of the braking fluid, e.g. including wheel driven pumps for detecting a speed condition, or pumps which are controlled by means independent of the braking system · CPC title

• B60T8/4077

  Systems in which the booster is used as an auxiliary pressure source · CPC title

• B60T13/662

  characterised by specified functions of the control system components · CPC title

• B60T13/686

  in hydraulic systems or parts thereof · CPC title