A method for operating a brake system for motor vehicles, comprising a master brake cylinder actuable by a brake pedal, an electrically controllable pressure provision device, a pressure medium reservoir tank, from which the master brake cylinder and the pressure provision device are supplied with pressure medium, and at least two hydraulically actuable wheel brakes and at least one electrically actuable inlet valve per wheel brake, wherein the wheel brakes are actuable either by the master brake cylinder or by the pressure provision device, the pressure medium reservoir tank is monitored by a device for determining a level of the pressure medium, wherein the wheel brakes are divided into at least one first wheel brake group and one second wheel brake group, and wherein the inlet valves of the first wheel brake group are closed when the determined level falls below a first limit value (s.sub.1).

To acquire a hydraulic pressure control unit and a straddle-type vehicle brake system capable of adding an auxiliary plunger pump while suppressing extreme enlargement of the hydraulic pressure control unit. In a base body, a combination of a first plunger pump and a first accumulator and a combination of a second plunger pump and a second accumulator for a different system of a hydraulic circuit therefrom are separately provided on both sides of a reference surface including a center axis of a motor hole. A first plunger pump hole and a second plunger pump hole are separately provided on a second surface and a third surface constituting both ends of the base body in a first direction. A first accumulator hole, a second accumulator hole, and an auxiliary plunger pump hole are provided on a fourth surface constituting an end of the base body in a second direction.

A method for checking functionality of a motor vehicle braking system. The braking system has a main module, including: hydraulically actuatable wheel brakes, pairs being assigned to respective brake circuits; at least one electrically actuatable wheel valve per wheel brake sets wheel-specific brake pressures; a pressure provision device actively builds up pressure in the wheel brakes; a pressure-medium reservoir at atmospheric pressure, and an auxiliary module, which has for each of two wheel brakes: a pressure sensor for measuring pressure in a wheel brake line; an open when deenergized isolating valve in the wheel brake line; a pump. At least one variable is measured to assess functionality of the braking system. Using least one acceptance criterion, and checked whether the variable satisfies the acceptance criterion. Determining at least one variable representing the viscosity of the brake fluid, and the at least one acceptance criterion depends on a variable representing viscosity.

This application is applicable to intelligent automobiles, new energy automobiles, conventional automobiles, or the like. In embodiments of this application, a fluid outlet pipe of a first hydraulic chamber 16 is configured in segments on a push rod support portion 14 and a push rod 13. In this way, when a piston 12 is located at an inner stop point of a piston stroke, a first hydraulic adjustment port 14a located on the push rod support portion 14 communicates with a second hydraulic adjustment port 13a located on the push rod 13, and when the piston 12 is located at a position other than the inner stop point in the piston stroke, the first hydraulic adjustment port 14a does not communicate with the second hydraulic adjustment port 13a.

A brake system includes a reservoir and a motor-driven master cylinder operable during a backup braking mode by actuation of an electric motor of the master cylinder to generate brake actuating pressure for hydraulically actuating the pair of front wheel brakes and the pair of rear wheel brakes. A power transmission unit is configured for selectively providing pressurized hydraulic fluid to a PTU output for actuating the pair of front wheel brakes and the pair of rear wheel brakes in a normal non-failure braking mode. First and second two-position three-way valves are each hydraulically connected with the master cylinder, the power transmission unit, and a selected pair of the front and rear wheel brakes. Each of the first and second three-way valves selectively controls hydraulic fluid flow from a chosen one of the master cylinder and the power transmission unit to the selected pair of front and rear wheel brakes.

A brake system may include an actuating device, in particular a brake pedal; a first piston-cylinder unit having two pistons subjecting the brake circuits to a pressure medium via a valve device, wherein one of the pistons can be actuated by the actuation device; a second piston-cylinder unit having an electric motor drive, a transmission at least one piston to supply at least one of the brake circuits with a pressure medium via a valve device; and a motor pump unit with a valve device to supply the brake circuits with a pressure medium. The brake system may also include a hydraulic travel simulator with a pressure or working chamber which is connected to the first piston-cylinder unit.

An electronic brake system is disclosed. An electronic brake system according to the present embodiment may comprise: a reservoir in which a pressurizing medium is stored; an integrated master cylinder comprising a master piston connected to a brake pedal, a master chamber having a volume varied by a displacement of the master piston, and a sealing member for sealing the master chamber; a liquid-pressure supply device for operating a hydraulic piston according to an electric signal that is output in response to a displacement of the brake pedal, thereby generating a liquid pressure; a hydraulic control unit provided between the liquid-pressure supply device and multiple wheel cylinders so as to control a flow of the pressurizing medium supplied to the multiple wheel cylinders; a circuit pressure sensor for sensing a liquid pressure provided by the liquid-pressure supply device; a cylinder pressure sensor for sensing a liquid pressure in the master chamber; an inspection channel for connecting the master chamber and the liquid-pressure supply device; and an inspection valve provided in the inspection channel so as to control the flow of the pressurizing medium.

An electro-hydraulic brake system includes a master cylinder (MC) configured to supply fluid into a first MC fluid passageway in response to pressing force on a brake pedal; a pressure supply unit (PSU) assembly having a PSU motor coupled to a ball screw actuator, a PSU housing defining a piston bore having a terminal end opposite the PSU motor, and a PSU piston dividing the piston bore into a first chamber and a second chamber and movable by the ball screw actuator, with each of the first chamber and the second chamber containing a hydraulic fluid; and a backup pump assembly including a pump for supplying the brake fluid to at least one of the wheel brakes. The ball screw actuator includes an actuator nut assembly having a plurality of ball bearings each disposed within the piston bore and submerged in the hydraulic fluid.

A vehicle braking system includes a first wheel cylinder, a second wheel cylinder, a master cylinder including a first master cylinder chamber in fluid communication with the first wheel cylinder via a first circuit and a second master cylinder chamber in fluid communication with the second wheel cylinder via a second circuit, and an electronically controlled pressure generating unit separate from the master cylinder. The vehicle braking system is operable to provide braking in a first configuration in which the electronically controlled pressure generating unit pressurizes fluid, through the master cylinder, in the first circuit, to the first wheel cylinder. In the first configuration, the electronically controlled pressure generating unit pressurizes fluid in the second circuit to the second wheel cylinder, bypassing the master cylinder.

Disclosed is a valve block of an electronic control brake system. The valve block of an electronic control brake system includes two hydraulic pressure circuits, and a plurality of accommodation bores at which a plurality of valves, a pump, a low-pressure accumulator, a pressure sensor, and a motor are installed so as to control braking hydraulic pressure delivered to a wheel cylinder installed at each of wheels, and a plurality of flow paths configured to connect the plurality of accommodation bores to one another, wherein a pressure sensor accommodation bore, at which the pressure sensor is installed, is provided with at least one wheel cylinder pressure sensor accommodation bore configured to accommodate the pressure sensor which is connected to each of wheel cylinder ports to detect oil pressure, and the at least one wheel cylinder pressure sensor accommodation bore is connected by a sensor connection flow path formed at the valve block, and connects a selected wheel cylinder port among the wheel cylinder ports, which are connected to wheels, to the at least one wheel cylinder pressure sensor accommodation bore by adjusting lengths of a port connection flow path, which is connected to each of the wheel cylinder ports and the sensor connection flow path.