Valves and valve actuation – Fluid actuated or retarded – Piston type expansible chamber reciprocating valve actuator
Reexamination Certificate
2002-09-17
2004-08-10
Look, Edward K. (Department: 3754)
Valves and valve actuation
Fluid actuated or retarded
Piston type expansible chamber reciprocating valve actuator
C092S128000
Reexamination Certificate
active
06772989
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a two-port valve which can be easily maintained and is used as a high vacuum L valve or the like.
PRIOR ART
As shown in
FIG. 18
, a two-port valve used as the high vacuum L valve or the like is conventionally well known.
The well-known two-port valve has a valve body
111
which includes ports
112
and
113
formed in an orthogonal direction, a valve seat
114
provided in a flow path connecting these ports
112
and
113
to each other, and an open end
115
facing the valve seat
114
. A cylinder
120
of a pneumatic cylinder system
119
which drives a valve element
123
is formed in a bonnet
117
which is airtight attached to the open end
115
through a bellows plate
116
.
A valve rod
124
of the valve element
123
which opens and closes the valve seat
114
airtight penetrates the bonnet
117
and is connected to a piston
121
of the pneumatic cylinder
119
, and a return spring
125
is compressed between the valve element
123
and the bonnet
117
. Further, the bonnet
117
is provided with a port
127
which supplies and discharges compressed air to and from a bellows plate
116
-side pressure chamber
126
which is defined by the piston
121
.
The both ends of a bellows
128
which surrounds the valve rod
124
are airtight, fixedly attached to the inner peripheral surface of the bellows plate
116
and to the valve element
123
, and annular attachment grooves
130
for respectively attaching seal rings
131
are formed on the surface of the valve element
123
on which the valve element
123
faces the valve seat
114
.
However, the well-known two-port valve has the following problem. It is necessary to detach the bonnet
117
from the valve body
111
so as to exchange the seal ring
131
of the valve element
123
or to wash the bellows
128
or the inner surface of the valve body
111
. Since the bonnet
117
is fixedly attached to the valve body
111
by bolts (not shown), it is necessary to loosen the bolts to detach the bonnet from the valve body
111
. However, since the bonnet
117
cannot be easily attached and detached to and from the valve body
111
, it takes time to do maintenance.
DISCLOSURE OF THE INVENTION
The present invention has been made to solve such a problem and its technical object is to provide a two-port valve capable of easily dissembling and assembling a valve body and a bonnet and making maintenance easy.
It is another technical object of the present invention to provide a safe two-port valve capable of preventing a bonnet from being detached from a valve body by an erroneous operation while having a structure of enabling simple dissemble.
To solve the problem, a maintenance-easy two-port valve according to the present invention comprises: a valve body including two ports, a valve seat in a flow path connecting the two ports to each other, and an open end; a valve member opening and closing the valve; a bonnet airtight connected to the open end of the valve body, and containing a cylinder system driving the valve member; and a connection mechanism for detachably connecting the bonnet to the valve body, and is characterized in that the connection mechanism comprises: a plurality of shafts attached to the valve body, penetrating the bonnet in an axial direction, and each having a tip end protruding outward from an outer end face of the bonnet; a handle attached onto the outer end face of the bonnet to be rotatable around an axis and displaceable in the axial direction, and having one or a plurality of engagement pins on a surface facing the outer end face of the bonnet; a plate provided between the bonnet and the handle to be rotatable around the axis, and including a plurality of engagement grooves engaged with or disengaged from upper ends of the shafts, respectively, and one or a plurality of engagement holes into which or from which the one or plurality of engagement pins are fitted or disengaged, respectively; and a spring disposed between the handle and the plate, and urging the handle and the plate in a direction in which the handle and the plate are away from each other and a direction in which the handle and the plate are rotated relative to each other.
According to the present invention, the two-port valve is constituted so that the bonnet includes a lock pin engaged with and disengaged from the plate, and the lock pin is stopped at the plate to lock the plate to the bonnet if the plate is at a position at which the plate is engaged with the shafts and a position at which the plate is disengaged from the shafts, and the lock pin is detached from the plate to release locking of the plate to the bonnet while the plate is rotated from the position at which the plate is engaged with the shafts to the position at which the plate is disengaged from the shafts.
According to the present invention, the two-port valve is further constituted so that the handle includes a plurality of elliptic grooves, the upper ends of the shafts being displaceably fitted into the elliptic grooves, respectively, a push-down position of the handle is specified when an end wall on one longitudinal side of each of the elliptic grooves is abutted on each of the shafts, and a position at which the shafts are disengaged from the engagement grooves of the plate, respectively, is specified when an end wall on the other side of each of the elliptic grooves is abutted on each of the shafts, and constituted so that the plate includes one or a plurality of elliptic holes, a bolt fixed to the bonnet being displaceably fitted into each of the elliptic holes, a position at which the shafts are engaged with the engagement grooves of the plate, respectively is specified when an end wall on one longitudinal side of each of the elliptic holes is abutted on the bolt, and a position at which the shafts are disengaged from the engagement grooves of the plate, respectively is specified when an end wall on the other side of each of the elliptic holes is abutted on the bolt.
According to another aspect of the present invention, the cylinder system includes a piston actuated by a function of fluid pressure; and a valve rod penetrating the bonnet to extend into the valve body, and connecting the piston to the valve member, and a return spring urging the valve member in a valve opening direction and a bellows surrounding the valve rod and the return spring are provided between the bonnet and the valve member.
Furthermore, according to the present invention, the two-port valve is constituted so that a counter rotation prevention pin is provided at the handle, a hole, into which the counter rotation prevention pin is displaceable fitted, is provided in the plate, and so that the counter rotation prevention pin is constituted to be stopped in the hole and to prevent the handle from being rotated in a counter direction when the bonnet is connected to the valve body.
According to the maintenance-easy two-port valve, even if the handle is to be pushed down at the rotation position other than the push-down rotation position, the push-down prevention pin is abutted on the plate and the handle cannot be, therefore, pushed down. However, if the handle is rotated to the push-down rotation position, the position of the push-down prevention pin coincides with the position of the engagement hole provided in the plate. It is, therefore, possible to push down the handle and to engage the push-down prevention pin with the engagement hole.
If the handle is rotated in this state, the plate can be rotated to the position at which the engagement groove thereof is detached from the retaining groove of each shaft since the plate is engaged with the handle by the push-down prevention pin. If the handle is lifted at this position, the bonnet connected to the handle can be detached from the valve body.
Furthermore, if the bonnet is inserted into the valve body and the handle is rotated to the push-down rotation position and pushed down, then the push-down prevention pin can be engaged with the engagement hole. If the handle is rotated in this state, t
Enzaki Akira
Sakurai Toyonobu
Fristoe Jr. John K.
Look Edward K.
SMC Corporation
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