Brake apparatus for a vehicle

A brake apparatus comprising:

• a master cylinder which generates a master cylinder pressure;
• a wheel cylinder which produces wheel braking force upon receipt of the master cylinder pressure;
• and
• an ABS actuator for controlling brake fluid pressure applied to said wheel cylinder, said ABS actuator comprising:
• a reservoir which accumulates brake fluid discharged from said wheel cylinder;
• a pressure increasing valve for controlling brake fluid supplied to said wheel cylinder;
• a pressure reducing valve for controlling brake fluid discharged from said wheel cylinder;
• a housing for containing said reservoir and said pressure increase and pressure reducing valves, wherein
• a conduit for connecting said wheel cylinder to said master cylinder while bypassing said pressure increasing valve is formed in said housing,
• said conduit includes a first conduit and a second conduit,
• said first conduit has a small diameter portion whose one end is communicated with said reservoir, a large diameter portion formed in the housing and whose one end is opened to one surface of said housing, and a taper shaped valve seat formed so as to bridge another end of the small diameter portion and another end of the large diameter portion, at least the large diameter portion forming a portion of the taper shaped valve seat, and
• one end of said second conduit is connected to said large diameter portion and an another end of said second conduit is communicated with said master cylinder;
• a first ball movably disposed in said large diameter portion, said first ball seating on said valve seat to close said conduit when pressure in said large diameter portion is higher than that in said small diameter portion, and separating from said valve seat to open said conduit when pressure in said large diameter portion is equal to or lower than that in said small diameter portion;
• a lid with which fills said one end of said first conduit opened to said one surface of said housings, said lid being fixed to said one end of the first conduit for prohibiting brake fluid communication between the first conduit and the outside of the housing;
• and
• a second ball disposed between said first ball and said lid in said large diameter portion, for limiting moving range of said first ball so that a center of said first ball is located on a side of said valve seat rather than an axis of said second conduit.

A brake apparatus comprising:

• a master cylinder which generates a master cylinder pressure;
• a wheel cylinder which produces wheel braking force upon receipt of the master cylinder pressure;
• a reservoir which accumulates brake fluid discharged from said wheel cylinder when a wheel cylinder pressure is reduced;
• a main conduit for connecting said master cylinder to said wheel cylinder;
• a first conduit for connecting said wheel cylinder to said reservoir;
• a second conduit for connecting said reservoir to said master cylinder;
• a pressure increasing valve disposed in said main conduit, said pressure increasing valve being in a communicating state when non-energized;
• a pressure reducing valve disposed in said first conduit, said pressure reducing valve being in a cut-off state when non-energized;
• a first non-return valve connected in parallel to said pressure increasing valve, for allowing brake fluid to flow from said wheel cylinder to said master cylinder when the wheel cylinder pressure is higher than said master cylinder pressure, an valve opening pressure of said first non-return valve being substantially equal to an atmospheric pressure;
• a second non-return valve disposed in said second conduit, for allowing brake fluid to flow from said reservoir to said master cylinder when pressure of brake fluid accumulated in said reservoir is higher than said master cylinder pressure, a valve opening pressure of said second non-return valve being substantially equal to an atmospheric pressure;
• and
• a housing containing said pressure increasing and pressure reducing valves, said reservoir, said main, first and second conduits and said first and second non-return valves,
• said first non-return valve comprising:
• a first branch conduit bypassing the main conduit,
• a first non-return valve conduit whose one end is opened to an outside surface of the housing and whose another end is connected with said first branch conduit,
• a first valve seat formed at said another end of the first non-return valve conduit so as to bridge the first non-return valve conduit and the first branch conduit,
• a first lid fixed to said one end of the first non-return valve conduit for prohibiting brake fluid communication between said first branch conduit and said outside of the housing, and
• a first ball disposed in said first non-return valve conduit and to be seated on the valve seat by brake fluid flow from said master cylinder to said wheel cylinder for interrupting the brake fluid flow thereof, and
• said second non-return valve comprising:
• a second non-return valve conduit whose one end is opened to an outside surface of the housing and whose another end is connected with said second conduit,
• a second valve seat formed at said another end of the second non-return valve conduit so as to bridge the second non-return valve conduit and the second conduit,
• a second lid fixed to said one end of the second non-return valve conduit for prohibiting brake fluid communication between said second conduit and said outside of the housing, and
• a second ball disposed in said second non-return valve conduit and to be seated on the second valve seat by brake fluid flow from said master cylinder to said reservoir for interrupting the brake fluid flow thereof.

A brake apparatus comprising:

• a master cylinder which generates a master cylinder pressure;
• a wheel cylinder which produces wheel braking force upon receipt of the master cylinder pressure;
• a main conduit for connecting said master cylinder to said wheel cylinder;
• an actuator disposed in said main conduit for controlling brake fluid pressure applied to said wheel cylinder,
• said actuator comprising:
• an aluminum housing block;
• plural control valves installed in said aluminum housing block for controlling brake fluid supplied to and discharged from said wheel cylinder;
• a reservoir formed by a hole provided in said housing, which accumulates brake fluid discharged from said wheel cylinder;
• conduits formed in said housing by drilling, which interconnect among said master cylinder, said wheel cylinder, said plural solenoid valves, and said reservoir;
• and
• a non-return valve disposed in said conduits, said non-return valve having substantially no valve opening pressure with respect to brake fluid flowing toward said master cylinder,
• said non-return valve comprising:
• a non-return valve conduit whose one end is opened to an outside surface of the aluminum housing block and whose other end is connected with said conduit,
• a valve seat formed at said other end of the non-return valve conduit so as to bridge the non-return valve conduit and the conduit,
• a lid fixed to said one end of the non-return valve conduit for prohibiting brake fluid communication between said conduit and said outside of the housing, and
• a ball disposed in said non-return valve conduit and to be seated on the valve seat by brake fluid flow from said master cylinder for interrupting the brake fluid flow thereof.