US 6,718,863 B2Granted

Vacuum booster

AssigneeNissin Kogyo Co., Ltd.

InventorTakayoshi Shinohara

Life of this patent

Estimating the term…

Abstract

In a control valve of the vacuum booster, a valve portion is fitted with a valve cylinder to be slidably contacted with an inner wall of the valve cylinder, to form within said valve cylinder, a front annular chamber closed by a front face of the valve portion when the valve portion is seated on a vacuum introduction valve seat, and a read annular chamber, to which the rear of the valve portion is faced. The front annular chamber communicates with a first port, and the rear annular chamber communicates with a second port. An input rod is moved forward to separate the valve portion from an atmosphere introduction valve seat and to seat it on the vacuum introduction valve seat. Then, the valve portion is urged in accordance with the set load of a valve spring and the pressure difference between the front and rear annular chambers.

Claims21

Dependent claims

A vacuum booster, comprising:

a booster shell;
a booster piston accommodated in said booster shell to divide the interior of said booster shell into a front vacuum chamber communicating with a vacuum source and a rear operating chamber;
a valve cylinder connected to said booster piston;
a valve piston fitted into said valve cylinder so as to be slidable forward and backward;
an input rod connected to said valve piston at a front end thereof;
an input return spring urging said input rod backward;
and
a control valve arranged within said valve cylinder, for changing over the communication of said operating chamber with one of said vacuum chamber and the atmosphere in accordance with the forward and backward movement of said input rod, said control valve including:
a ring-shaped vacuum introduction valve seat formed in said valve cylinder;
an atmosphere introduction valve seat formed in said valve piston and disposed inside said vacuum introduction valve seat;
a valve element having:
a ring-shaped attachment bead portion securely held with respect to an inner wall of said valve cylinder;
an elastic cylinder axially extending from said attachment bead portion;
and, an annular valve portion connected in a flange shape to a front end of said elastic cylinder and facing said vacuum introduction valve seat and said atmosphere introduction valve seat, on which said valve portion is to be seated;
and
a valve spring urging said valve portion in a direction that said valve portion is seated on said vacuum introduction valve seat and said atmosphere introduction valve seat,
wherein a first port that communicates with said vacuum chamber is opened to an outer periphery side of said vacuum introduction valve seat, a second port that communicates with said operating chamber is opened between said vacuum introduction valve seat and said atmosphere introduction valve seat, and an inner periphery side of said valve portion is communicated with the atmosphere,
further wherein said valve portion is fitted with said valve cylinder so as to be slidably contacted with the inner wall of said valve cylinder, to define a front annular chamber and a rear annular chamber within said valve cylinder, said front annular chamber being closed by a front face of said valve portion when said valve portion is seated on said vacuum introduction valve seat, said rear annular chamber being formed so that the rear of said valve portion is faced thereto, and
further wherein said front annular chamber communicates with said first port, and said rear annular chamber communicates with said second port to introduce atmosphere into said rear annular chamber to reduce operating forces during normal braking conditions.

16 more elements

A vacuum booster, comprising:

a booster shell;
a booster piston accommodated in said booster shell to divide the interior of said booster shell into a front vacuum chamber communicating with a vacuum source and a rear operating chamber;
a valve cylinder connected to said booster piston;
a valve piston fitted into said valve cylinder so as to be slidable forward and backward;
an input rod connected to said valve piston at a front end thereof;
an input return spring urging said input rod backward;
and
a control valve arranged within said valve cylinder, including:
a ring-shaped vacuum introduction valve seat formed in said valve cylinder;
an atmosphere introduction valve seat formed in said valve piston and disposed inside said vacuum introduction valve seat;
a common valve portion facing in a first direction towards said vacuum introduction valve seat and said atmosphere introduction valve seat, on which said common valve portion is to be seated;
a valve spring urging said common valve portion in a direction that said common valve portion is seated on said vacuum introduction valve seat and said atmosphere introduction valve seat;
and
a sealing lip integrally formed with an outer wall of the said common valve portion,
wherein a first port that communicates with said vacuum chamber is opened to an outer periphery side of said vacuum introduction valve seat, a second port that communicates with said operating chamber is opened between said vacuum introduction valve seat and said atmosphere introduction valve seat, and an inner periphery side of said common valve portion is communicated with the atmosphere,
wherein when the atmosphere introduction valve seat is separated from the valve portion, and when the valve portion is seated on the vacuum introduction valve seat, a force with which the sealing lip is held against the inner wall of the valve cylinder is increased due to a pressure difference generated between the front and rear annular chambers such that between the front and rear annular chambers an airtight condition is obtained,
wherein introduction of atmosphere into the rear annular chamber reduces operating forces during normal braking conditions.

14 more elements

A vacuum booster, comprising:

a booster shell;
a booster piston accommodated in said booster shell to divide the interior of said booster shell into a front vacuum chamber communicating with a vacuum source and a rear operating chamber;
a valve cylinder connected to said booster piston;
a valve piston fitted into said valve cylinder so as to be slidable forward and backward;
an input rod connected to said valve piston at a front end thereof;
an input return spring urging said input rod backward;
and
a control valve arranged within said valve cylinder for changing over the communication of said operating chamber with one of said vacuum chamber and the atmosphere in accordance with the forward and backward movement of said input rod, said control valve including:
a ring-shaped vacuum introduction valve seat formed in said valve cylinder;
an atmosphere introduction valve seat formed in said valve piston and disposed inside said vacuum introduction valve seat;
a valve element having a valve portion facing said vacuum introduction valve seat and said atmosphere introduction valve seat, on which said valve portion is to be seated;
and
a valve spring sbrinkingly disposed between the valve portion and the input rod urging said valve portion in a direction that said valve portion is seated on said vacuum introduction valve seat and said atmosphere introduction valve seat.

10 more elements

(currently added) A vacuum booster, comprising:

a booster shell;
a booster piston accommodated in said booster shell to divide the interior of said booster shell into a front vacuum chamber communicating with a vacuum source and a rear operating chamber;
a valve cylinder connected to said booster piston;
a valve piston fitted into said valve cylinder so as to be slidable forward and backward;
an input rod connected to said valve piston at a front end thereof;
an input return spring urging said input rod backward;
and
a control valve arranged within said valve cylinder, for changing over the communication of said operating chamber with one of said vacuum chamber and the atmosphere in accordance with the forward and backward movement of said input rod, said control valve including:
a ring-shaped vacuum introduction valve seat formed in said valve cylinder;
an atmosphere introduction valve seat formed in said valve piston and disposed inside said vacuum introduction valve seat;
a valve element having:
a ring-shaped attachment bead portion securely held with respect to an inner wall of said valve cylinder;
an elastic cylinder axially extending from said attachment bead portion;
and, an annular valve portion connected in a flange shape to a front end of said elastic cylinder and facing said vacuum introduction valve seat and said atmosphere introduction valve seat, on which said valve portion is to be seated;
and
a valve spring urging said valve portion in a direction that said valve portion is seated on said vacuum introduction valve seat and said atmosphere introduction valve seat,
wherein a first port that communicates with said vacuum chamber is opened to an outer periphery side of said vacuum introduction valve seat, a second port that communicates with said operating chamber is opened between said vacuum introduction valve seat and said atmosphere introduction valve seat, and an inner periphery side of said valve portion is communicated with the atmosphere,
further wherein said valve portion is fitted with said valve cylinder so as to be slidably contacted with the inner wall of said valve cylinder, to define a front annular chamber and a rear annular chamber within said valve cylinder, said front annular chamber being closed by a front face of said valve portion when said valve portion is seated on said vacuum introduction valve seat, said rear annular chamber being formed so that the rear of said valve portion is faced thereto, and
further wherein said front annular chamber communicates with said first port, and said rear annular chamber communicates with said second port to introduce atmosphere into said rear annular chamber to reduce initial operating force during braking conditions.

16 more elements

A vacuum booster, comprising:

a booster shell;
a booster piston accommodated in said booster shell to divide the interior of said booster shell into a front vacuum chamber communicating with a vacuum source and a rear operating chamber;
a valve cylinder connected to said booster piston;
a valve piston fitted into said valve cylinder so as to be slidable forward and backward;
an input rod connected to said valve piston at a front end thereof,
an input return spring urging said input rod backward;
and
a control valve arranged within said valve cylinder, including:
a ring-shaped vacuum introduction valve seat formed in said valve cylinder;
an atmosphere introduction valve seat formed in said valve piston and disposed inside said vacuum introduction valve seat;
a common valve portion facing in a first direction towards said vacuum introduction valve seat and said atmosphere introduction valve seat, on which said common valve portion is to be seated;
a valve spring urging said common valve portion in a direction that said common valve portion is seated on said vacuum introduction valve seat and said atmosphere introduction valve seat;
and
a sealing lip integrally formed with an outer wall of the said common valve portion,
wherein a first port that communicates with said vacuum chamber is opened to an outer periphery side of said vacuum introduction valve seat, a second port that communicates with said operating chamber is opened between said vacuum introduction valve seat and said atmosphere introduction valve seat, and an inner periphery side of said common valve portion is communicated with the atmosphere,
wherein when the atmosphere introduction valve seat is separated from the valve portion, and when the valve portion is seated on the vacuum introduction valve seat, a force with which the sealing lip is held against the inner wall of the valve cylinder is increased due to a pressure difference generated between the front and rear annular chambers such that between the front and rear annular chambers an airtight condition is obtained,
wherein introduction of atmosphere into the rear annular chamber reduces initial operating force during braking conditions.

14 more elements

Dependencies are inferred from the claim text.

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Abstract

A vacuum booster, comprising:

a booster shell;
a booster piston accommodated in said booster shell to divide the interior of said booster shell into a front vacuum chamber communicating with a vacuum source and a rear operating chamber;
a valve cylinder connected to said booster piston;
a valve piston fitted into said valve cylinder so as to be slidable forward and backward;
an input rod connected to said valve piston at a front end thereof;
an input return spring urging said input rod backward;
and
a control valve arranged within said valve cylinder, for changing over the communication of said operating chamber with one of said vacuum chamber and the atmosphere in accordance with the forward and backward movement of said input rod, said control valve including:
a ring-shaped vacuum introduction valve seat formed in said valve cylinder;
an atmosphere introduction valve seat formed in said valve piston and disposed inside said vacuum introduction valve seat;
a valve element having:
a ring-shaped attachment bead portion securely held with respect to an inner wall of said valve cylinder;
an elastic cylinder axially extending from said attachment bead portion;
and, an annular valve portion connected in a flange shape to a front end of said elastic cylinder and facing said vacuum introduction valve seat and said atmosphere introduction valve seat, on which said valve portion is to be seated;
and
a valve spring urging said valve portion in a direction that said valve portion is seated on said vacuum introduction valve seat and said atmosphere introduction valve seat,
wherein a first port that communicates with said vacuum chamber is opened to an outer periphery side of said vacuum introduction valve seat, a second port that communicates with said operating chamber is opened between said vacuum introduction valve seat and said atmosphere introduction valve seat, and an inner periphery side of said valve portion is communicated with the atmosphere,
further wherein said valve portion is fitted with said valve cylinder so as to be slidably contacted with the inner wall of said valve cylinder, to define a front annular chamber and a rear annular chamber within said valve cylinder, said front annular chamber being closed by a front face of said valve portion when said valve portion is seated on said vacuum introduction valve seat, said rear annular chamber being formed so that the rear of said valve portion is faced thereto, and
further wherein said front annular chamber communicates with said first port, and said rear annular chamber communicates with said second port to introduce atmosphere into said rear annular chamber to reduce operating forces during normal braking conditions.

16 more elements