US 11,970,145 B2Granted

Brake system for a two-axle vehicle and method for the operation thereof

AssigneeRobert Bosch GmbH

InventorYasutaka Nagakura

Life of this patent

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Abstract

A brake system for a two-axle vehicle having a master brake cylinder. The brake system includes at least one connected brake circuit, each having front and rear wheel brake cylinders, front wheel inlet and outlet valves, rear wheel inlet and outlet valves, an accumulator chamber, and a control device via which, by opening the at least one rear wheel outlet valve, a brake fluid pressed out of master brake cylinder is displaceable via the open rear wheel outlet valve into the respectively downstream disposed accumulator chamber. When the at least one front wheel outlet valve is kept closed or closed, the control device is configured to increase and limit a brake pressure prevailing in the respectively associated front wheel brake cylinder to an accumulator chamber pressure actively prevailing in the accumulator chamber of the same brake circuit by keeping open or opening the at least one front wheel inlet valve.

Claims10

Dependent claims

A brake system for a two-axle vehicle, comprising:

a master brake cylinder to which a brake actuating element is connected in such a way that a target vehicle deceleration desired by a driver of the vehicle is input by actuating the brake actuating element;
at least one brake circuit which is connected to the master brake cylinder, each of the at least one brake circuit having a respective front wheel brake cylinder, a respective rear wheel brake cylinder, a respective front wheel inlet valve associated with the respective front wheel brake cylinder, a respective front wheel outlet valve associated with the respective front wheel brake cylinder, a respective rear wheel inlet valve associated with the respective rear wheel brake cylinder, a respective rear wheel outlet valve associated with the respective rear wheel brake cylinder and a respective accumulator chamber downstream of the respective front wheel outlet valve and the respective rear wheel outlet valve;
and
a control device which, in response to an actively input target vehicle deceleration unequal to zero, is able to discern or effect that a generator operation of at least one electric motor of the vehicle is able to effect a recuperative vehicle deceleration that is equal to the input target vehicle deceleration, and which is configured to optionally displace a brake fluid pressed out of the master brake cylinder via the respective rear wheel outlet valve into the respective downstream disposed accumulator chamber by opening the respective rear wheel outlet valve;
wherein, when the respective front wheel outlet valve is kept closed or closed, the control device is configured to optionally increase and limit a brake pressure prevailing in the respective associated front wheel brake cylinder to an accumulator chamber pressure actively prevailing in the respective accumulator chamber of the same brake circuit by keeping open or opening the respective front wheel inlet valve.

2 more elements

A method for operating a brake system of a two-axle vehicle comprising a master brake cylinder, a brake actuating element being connected to the master brake cylinder, and at least one brake circuit connected to the master brake cylinder, each of the at least one brake circuit having a respective front wheel brake cylinder, a respective rear wheel brake cylinder, a respective front wheel inlet valve associated with the respective front wheel brake cylinder, a respective front wheel outlet valve associated with the respective front wheel brake cylinder, a respective rear wheel inlet valve associated with the respective rear wheel brake cylinder, a respective rear wheel outlet valve associated with the respective rear wheel brake cylinder, and a respective accumulator chamber disposed downstream of the respective front wheel outlet valve and the respective rear wheel outlet valve, the method comprising the following steps:

detecting a target vehicle deceleration unequal to zero input by a driver of the vehicle by actuating the brake actuating element;
based on the detecting, checking whether a generator operation of at least one electric motor of the vehicle is able to effect that a recuperative vehicle deceleration equals the input target vehicle deceleration;
optionally, opening the respective rear wheel outlet valve to displace a brake fluid pressed out of the master brake cylinder via the respective rear wheel outlet valve into the respectively downstream disposed accumulator chamber;
and
keeping open or opening the respective front wheel inlet valve when the respective front wheel outlet valve is kept closed or closed, so that a brake pressure prevailing in the respective front wheel brake cylinder is increased and limited to an accumulator chamber pressure actively prevailing in the respective accumulator chamber of the same brake circuit.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/981,886Filed 7 Mar 2019
Priority: DE 102018205520.312 Apr 2018
Published: US 2021/0001827 A17 Jan 2021
Granted: 30 Apr 2024
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

B60T 13/662
Electrical control in fluid-pressure brake systems: characterised by specified functions of the control system components
B60T 13/68
Electrical control in fluid-pressure brake systems: by electrically-controlled valves
B60T 17/221
Devices for monitoring or checking brake systems; Signal devices: procedure or apparatus for checking or keeping in a correct functioning…
B60T 13/745
With electrical assistance or drive: acting on a hydraulic system, e.g. a master cylinder