Vacuum pressure proportional control valve
AssigneeCkd Corporation
InventorsYoshiyuki Yamada, Shunsuke Umezawa
Life of this patent
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Abstract
A vacuum pressure proportional control valve placed on a pipe connecting between a reaction vessel and a vacuum pump to control the vacuum pressure in the reaction vessel includes a cylinder provided with a piston chamber, a piston housed in the piston chamber so as to make reciprocal linear movement, a valve seat surface, and a valve element which contacts with or separates from the valve seat surface according to the movement of the piston. A stopper member is provided in the cylinder so that a leading end portion of the stopper member is placed in the piston chamber. The stopper member is configured to move the piston back and forth in a moving direction of the piston by use of an adjusting unit to thereby adjust the position of the leading end portion.
Claims12
A vacuum pressure proportional control valve to be placed on a pipe connecting a reaction vessel and a vacuum pump to control vacuum pressure in the reaction vessel, the vacuum pressure proportional control valve comprising:
- a cylinder including a piston chamber;
- a piston housed in the piston chamber so that the piston makes reciprocal linear movement;
- a valve seat;
- a valve element configured to contact with or separate from the valve seat according to movement of the piston;
- a stopper member placed in the cylinder and including a leading end portion placed inside the piston chamber, the stopper member being configured to place the vacuum pressure proportional control valve in a fully-open state when the leading end portion contacts with the piston;
- and
- an adjusting unit configured to move the stopper member back and forth in a moving direction of the piston to adjust a position of the leading end portion, wherein
- the adjusting unit comprises:
- a contact member placed in a part of the cylinder, the part being located on an opposite side to the valve seat, so that the contact member can contact with a rear end of the stopper member;
- an urging member urging the stopper member toward the contact member;
- and
- a screw part configured to move the contact member in the moving direction of the piston.
Dependencies are inferred from the claim text.