Provided herein is an actuation unit for a braking system. The actuation unit for a braking system includes a piston directly or indirectly connected to a brake pedal, an electronic control unit, a hydraulic pressure unit, an electronic memory unit mechanically connected to the hydraulic pressure unit, and a position sensor configured to detect movement of the piston connected to the brake pedal, wherein a signal of the position sensor is corrected, and data for correcting the signal is stored in the electronic memory unit.

A valve system includes an isolation check valve delivering pneumatic fluid as a supply pressure, a double-check valve adapted to deliver a braking demand control signal of the pneumatic fluid based on a higher of a first braking demand in a first pneumatic braking circuit and a second braking demand in a second pneumatic braking circuit, and a control module. The control module is adapted to receive the supply pressure as a control module supply pressure of the pneumatic fluid, receive a control module control pressure of the pneumatic fluid based on the braking demand control signal, and deliver a control module delivery pressure of the pneumatic fluid based on the control module supply pressure and the control module control pressure. A park control module selectively transmits the pneumatic fluid at the supply pressure based on a park brake control signal.

A valve system includes a control module on a tractor portion of a vehicle adapted to receive a supply pressure as a control module supply pressure of the pneumatic fluid, receive a control module control pressure of the pneumatic fluid, and deliver a control module delivery pressure of the pneumatic fluid based on the control module supply pressure and the control module control pressure. A park control module selectively transmits the pneumatic fluid at the supply pressure based on a park brake control signal. A supply glad-hand fluidly communicates the selectively transmitted supply pressure of the pneumatic fluid to supply a brake on an associated trailer portion of the vehicle. A control glad-hand fluidly communicates the control module delivery pressure of the pneumatic fluid to control the brake on the associated trailer portion of the vehicle. An exhaust valve, which fluidly communicates with both the selectively transmitted supply pressure and the control module delivery pressure, exhausts the control module delivery pressure of the pneumatic fluid from the control glad-hand.

A braking system in a hybrid vehicle is provided. The braking system includes a master cylinder having a first outlet, a second outlet, and a piston disposed therein and translatable from a proximal end to a distal end in response to brake pedal displacement. A brake fluid reservoir supplies hydraulic fluid to the master cylinder. A first fluid circuit connects the first outlet of the master cylinder to the brake fluid reservoir. A second fluid circuit connects the second outlet of the master cylinder to wheel brakes and supplies hydraulic fluid from the master cylinder to the wheel brakes in response to brake pedal displacement. The first outlet of the master cylinder is disposed between the second outlet and the proximal end of the master cylinder such that initial brake pedal displacement transfers brake fluid from the master cylinder to the fluid reservoir to inhibit hydraulic braking during regenerative braking.

A braking system in a hybrid vehicle is provided. The braking system includes a master cylinder having a first outlet, a second outlet, and a piston disposed therein and translatable from a proximal end to a distal end in response to brake pedal displacement. A brake fluid reservoir supplies hydraulic fluid to the master cylinder. A first fluid circuit connects the first outlet of the master cylinder to the brake fluid reservoir. A second fluid circuit connects the second outlet of the master cylinder to wheel brakes and supplies hydraulic fluid from the master cylinder to the wheel brakes in response to brake pedal displacement. The first outlet of the master cylinder is disposed between the second outlet and the proximal end of the master cylinder such that initial brake pedal displacement transfers brake fluid from the master cylinder to the fluid reservoir to inhibit hydraulic braking during regenerative braking.

An input rod is operated by a brake pedal to introduce the air into a variable-pressure chamber through a control valve to propel a power piston, thereby advancing a primary piston to generate a brake fluid pressure in a master cylinder. A part of the reaction force from the fluid pressure is transmitted to the input rod through a reaction member. The primary piston is provided with an idle stroke in which no fluid pressure is generated, and the reaction force to be transmitted to a plunger is limited by a reaction force adjusting spring. In the region of the idle stroke, a fluid pressure is supplied to a wheel cylinder through a fluid pressure control unit to perform regenerative cooperative control, and a reaction force from a reaction spring is applied to the input rod.

An input rod is operated by a brake pedal to introduce the air into a variable-pressure chamber through a control valve to propel a power piston, thereby advancing a primary piston to generate a brake fluid pressure in a master cylinder. A part of the reaction force from the fluid pressure is transmitted to the input rod through a reaction member. The primary piston is provided with an idle stroke in which no fluid pressure is generated, and the reaction force to be transmitted to a plunger is limited by a reaction force adjusting spring. In the region of the idle stroke, a fluid pressure is supplied to a wheel cylinder through a fluid pressure control unit to perform regenerative cooperative control, and a reaction force from a reaction spring is applied to the input rod.

The main innovation in the braking system presented for patent protection is that it avoids the use of a main brake valve, as well as the other cocks and valves used presently in the air brakes. The pressure in the brake chambers is regulated hydraulically or electrically at the input of each brake chamber individually. This minimizes, to the extent possible, the delay in the execution of the brake commands given by the driver. ABS control will also be individual for each wheel and will work several times faster and more accurately. Overall, the system will use much fewer air ducts, will be simpler and more secure. The diagnostics will be much faster and easier. For reequipping the vehicles with the presented braking system, no changes in their design are required.

The main innovation in the braking system presented for patent protection is that it avoids the use of a main brake valve, as well as the other cocks and valves used presently in the air brakes. The pressure in the brake chambers is regulated hydraulically or electrically at the input of each brake chamber individually. This minimizes, to the extent possible, the delay in the execution of the brake commands given by the driver. ABS control will also be individual for each wheel and will work several times faster and more accurately. Overall, the system will use much fewer air ducts, will be simpler and more secure. The diagnostics will be much faster and easier. For reequipping the vehicles with the presented braking system, no changes in their design are required.

A sub master cylinder includes a body formed with a chamber in which oil is stored; a first sub piston having one end which is secured to one end of the body and the other end which extends toward the other end of the body and is disposed to cross the chamber; and a second sub piston disposed between an inner surface of the body and an outer surface of the first sub piston to be moved in the chamber.