Patent ID: 8915338

Claim:
An input device of a vehicle brake system, the input device being disposed as a separate unit from an electric brake actuator, the input device having a portion disposed in an engine room of the vehicle and a brake operation element extending from the portion and through a vehicle firewall, which separates the engine room and a passenger compartment of the vehicle, for being operated by a driver, the electric brake actuator provided for generating a first fluid pressure on the basis of at least an electric signal produced according to operation of the brake operation element, the input device of the vehicle brake system comprising: a master cylinder for generating a second fluid pressure when the operation of the brake operation element is input into the master cylinder; a stroke simulator for applying a simulated reaction force, produced by the operation of the brake operation element, to the brake operation element, the stroke simulator and the master cylinder forming an attachment body, with the stroke simulator disposed in parallel to the master cylinder and in communication with the master cylinder; and a component storage box provided on a portion of the attachment body spaced away from the stroke simulator and having a hollow inside space formed therein, wherein the component storage box houses a sensor unit containing a sensor for detecting the second fluid pressure in a fluid pressure passage, the fluid pressure passage communicating with at least one of the master cylinder and the stroke simulator; wherein the attachment body has a vent passage formed therein with a first end in communication with the hollow inside space of the component storage box, and a second end in communication with another space formed in the attachment body and facing a surface of the firewall having the input device mounted thereon; and wherein a gap is formed between the master cylinder and the firewall, and said another space formed in the attachment body opens into the gap to allow air to flow between the vent passage and a passenger compartment of the vehicle through the gap.