Patent ID: 6036283
Filing Date: 2000-03-14
Classification: B60T

Abstract:
A brake liquid pressure device comprising a piston valve, said piston valve having a front stage inlet connected with a first main route of a brake liquid pressure main pump and a rear stage inlet connected with a second main route of said brake liquid pressure main pump, a front stage outlet connected to a front brake liquid pressure dividing pump of said first main route, a rear stage outlet connected to a rear brake liquid pressure dividing pump of said second main route, said brake liquid pressure main pump producing liquid pressure when the brake of an automobile is operated, pressure liquid flowing to said piston valve and adding pressure and flow out of said front and said rear stage outlet and through said first main route and said second main route to reach said front and said rear liquid pressure dividing pumps said piston valve consisting of:a base having a center circular hollow for containing a coil spring and a piston, a threaded cap threadably closing a left opening of said center circular hollow with an anti-leak gasket fitting around said opening, a liquid space formed between said hollow and said piston together with said threaded cap, said rear stage inlet formed in an upper wall defining said hollow, said rear stage outlet formed in a lower wall defining said hollow, a first leak hole formed in said upper wall, said front stage outlet formed in a rear wall communicating with said hollow, and a second leak hole formed in the upper wall and communicating with said front stage outlet;said piston contained in said base, having a front small diameter portion and a rear large diameter portion, a spring hole formed to have an opening in a rear end of said rear large diameter portion and to extend forward in a half part of said small diameter portion, said front small diameter portion fitting movably in a rear hole of said threaded cap, said rear large diameter portion movably fitting in said center circular hollow of said base, a coil spring contained in said spring hole, a through hole formed in said front small diameter portion and communicating with said spring hole and said front stage inlet in said threaded cap;said coil spring contained in said spring hole of said piston and having its front end contacting a wall defining a front end of said spring hole and a rear end contacting a wall defining a rear end of said hollow of said base;said threaded cap having a rear small diameter portion and a front large hexagonal portion, said front stage inlet formed in said front large portion, male threads formed in said rear small diameter portion and engaging with female threads in said hollow of said base with a gasket fitted around said opening of said hollow;said first and said second leak holes exhausting air in said center circular hollow of said base out when brake liquid flows in said piston base and sealed by said piston pressed to move rearward by brake liquid to push all the air in said piston valve, said brake liquid pressure main pump producing liquid pressure to force brake liquid flow in said piston valve and through said front stage inlet to press and move said front small diameter portion and said rear large diameter portion of said piston so that brake liquid filling the space between said piston and said threaded cap may press said piston to force the brake liquid in the space between said rear large portion and said coil spring flow through said front stage outlet and through said front stage tube route to reach said front stage liquid dividing pump, said front stage route thus performing braking action by means of said piston swiftly increasing pressure, said brake liquid main pump continuing to produce pressure to let brake liquid flow through said front stage inlet through said through hole of said piston and into said spring hole in case that said front stage liquid pressure dividing pump gets the necessary volume of brake liquid for braking but said rear liquid dividing pump did not have enough volume for braking, said coil spring recovering resilience to press back said piston forward to its original position when said front stage pressure dividing pump gets the necessary volume of brake liquid so that the brake liquid in said liquid space may quickly flow back in the rear stage tube route through said rear stage outlet to perform braking said front stage of wheels at first and then both said front stage and said rear stage of wheels synchronously next and thus shortening the distance of braking.