Braking system equipped with cooling means

Patent metadata

Field	Value
Publication number	US-9726244-B2
Application number	US-201514716824-A
Country	US
Kind code	B2
Filing date	May 19, 2015
Priority date	May 19, 2014
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

The invention relates to a braking system ( 1 ) including:
a dynamic brake ( 10 ), including a hydraulic ram ( 11 ), including a cylinder ( 12 ), a piston ( 13 ) movable in the cylinder ( 12 ), and a chamber ( 14 ) capable of being filled to displace the piston within the cylinder and actuate the brake, a circuit ( 20 ) for feeding the brake, including a reservoir ( 21 ) a pump ( 22 ) and a brake feed line ( 26 ),

a brake control device ( 30 ), including a fluid pressure regulating valve ( 32 ) in the brake chamber, and progressive control ( 31 ), the valve including a path connected to the feed line, a path connected to the reservoir, and a path connected to the brake chamber, and being designed to selectively connect the path connected to the chamber to one or the other of the other paths, to deliver a predetermined pressure into the chamber according to a degree of actuation of the control,

the braking system being characterized in that it further includes a chamber cooling line ( 40 ), designed to renew the fluid contained in the chamber to ensure cooling of said chamber.

First claim

The invention claimed is:

1. A braking system including:
a dynamic brake, including a hydraulic ram, containing a cylinder, a piston movable within the cylinder, and a chamber capable of being filled to displace the piston within the cylinder and actuate the brake,
a brake feed circuit, including a reservoir, a pump and a line for feeding the brake,
a brake control device, including a fluid pressure regulating valve of the pressure within the brake chamber, and a progressive control, said device being designed to deliver a predetermined pressure into the chamber depending on the degree of actuation of the control,

wherein the fluid pressure regulating valve includes an inlet/outlet port connected to the feed line, an inlet/outlet port connected to the reservoir and an inlet/outlet port connected to the brake chamber, the fluid pressure regulating valve being designed to selectively connect the inlet/outlet port connected to the chamber to one or the other of the other ports depending on the pressure in the chamber and on the degree of actuation of the control, and wherein the braking system further includes a cooling line of the chamber, designed to renew the fluid contained in the chamber to provide cooling for said chamber.

2. The braking system according to claim 1 , wherein the pressure regulating valve is designed to deliver to the brake chamber a fluid pressure proportional to a degree of actuation of the control.

3. The braking system according to claim 1 , wherein the regulating valve includes:
a plunger movable in translation within a cylinder,
a pressure transfer member designed to exert a pressure on the plunger tending to put the inlet/outlet port connected to the feed line into communication with the inlet/outlet port connected to the brake chamber in response to the actuation of the control, and
a feedback chamber connected to the brake chamber by an inlet/outlet port of the valve, the chamber being positioned on a side opposite to the transfer member with respect to the plunger so that a fluid pressure in the chamber exerts a pressure on the plunger tending to put the inlet/outlet port connected to the brake chamber into communication with the inlet/outlet port connected to the reservoir.

4. The braking system according to claim 3 , wherein the fluid pressure regulating valve is designed to connect the inlet/outlet port connected to the chamber to the inlet/outlet port connected to the reservoir when the pressure in the chamber exceeds a pressure corresponding to a level of actuation of the control.

5. The braking system according to claim 1 , wherein the brake cooling line includes a restriction designed to allow circulation of a cooling flow greater than or equal to twice the volume of the chamber per minute.

6. The braking system according to claim 5 , including at least two dynamic brakes, and wherein the brake cooling line has as many restrictions as brakes.

7. The braking system according to claim 6 , wherein the restrictions are positioned in parallel, between each chamber of a brake and a withdrawal end of the cooling line.

8. The braking system according to claim 6 , wherein the cooling line includes a restriction positioned between one withdrawal end of the line and the brakes, and each other restriction connects the chambers of two brakes.

9. The braking system according to claim 1 , wherein the cooling line connects the chamber of the brake to a line at a pressure greater than or equal to the reservoir pressure.

10. The braking system according to claim 9 , wherein the brake cooling line is connected to the feed line, to withdraw from it or to inject into it the cooling flow of said line.

11. The braking system according to claim 9 , the system being mounted in a vehicle further including a secondary hydraulic circuit, wherein the cooling line is connected to said circuit to withdraw from it or to inject it into the cooling flow.

12. The braking system according to claim 11 , wherein the secondary circuit is a booster circuit of a transmission circuit.

13. A vehicle including a braking system according to claim 1 .

14. A method for cooling a brake of a vehicle including a braking system including:
a dynamic brake, including a hydraulic ram, containing a cylinder, a piston movable within the cylinder, and a chamber capable of being filled to displace the piston within the cylinder and actuate the brake,
a brake feed circuit, including a reservoir, a pump and a line for feeding the brake,
a brake control device, including a fluid pressure regulating valve of the pressure within the brake chamber, and a progressive control, said device being designed to deliver a predetermined pressure into the chamber depending on the degree of actuation of the control,

wherein the fluid pressure regulating valve includes an inlet/outlet port connected to the feed line, an inlet/outlet port connected to the reservoir and an inlet/outlet port connected to the brake chamber, the fluid pressure regulating valve being designed to selectively connect the inlet/outlet port connected to the chamber to one or the other of the other ports depending on the pressure in the chamber and on the degree of actuation of the control, and wherein the braking system further includes a cooling line of the chamber, designed to renew the fluid contained in the chamber to provide cooling for said chamber,
the method including, when the brake is not actuated, feeding the chamber of the brake through the cooling line at a pressure less than the brake actuating pressure, and the discharge of the chamber toward the reservoir by the pressure regulating valve of the control device.

15. The cooling method according to claim 14 , in a vehicle equipped with a braking system wherein the brake cooling line is connected to the feed line, to withdraw from it or to inject into it the cooling flow of said line, the system further including at least one hydraulic accumulator and a module designed for charging the accumulator or to selectively achieve a vacuum of the pump when the accumulators are full, and the brake feed line comprising a portion upstream of the module and a portion downstream of the module, the method further including, when the brake is actuated:
simultaneous feeding of the chamber by the feed line and the cooling line, and discharge of the chamber toward the reservoir by the pressure regulating valve, for regulating the pressure in the chamber when the module charges the accumulator or achieves a vacuum of the pump and the pressure in the chamber is less than the pressure in the upstream portion of the feed line, or
feeding the chamber through the downstream portion of the feed line and discharging the chamber toward the upstream portion of the feed line through the restriction when the module achieves a vacuum of the pump and the pressure in the chamber is greater than the pressure in the upstream portion of the feed line.

16. The cooling method according to claim 14 , in a vehicle including a secondary hydraulic circuit and equipped with a braking system wherein the cooling line is connected to said circuit to withdraw from it or to inject into it the cooling flow, further including, when the brake is actuated, feeding the chamber through the feed line and discharging of the chamber toward the secondary circuit through the cooling line if the braking pressure in the chamber is greater than the pressure of the secondary circuit, or feeding of the chamber by the secondary circuit and its discharge toward the reservoir through the pressure regulating valve if the pressure in the chamber is

Assignees

• Poclain Hydraulics Ind

Inventors

• Heren Jean Andre

Classifications

• B60T15/36

  Other control devices or valves characterised by definite functions {(electrically controlled valves in fluid-pressure brake systems B60T15/027, B60T15/028)} · CPC title

• F16D65/853 Primary

  with closed cooling system · CPC title

• B60T5/00 Primary

  Vehicle modifications to facilitate cooling of brakes · CPC title

• F16D2065/782

  the brake-actuating fluid being used as a coolant · CPC title

• F16D65/78

  Features relating to cooling · CPC title