Smc Corporation

Masao Kajitani

Toyonobu Sakurai

Kazuo Hiramatsu

Seiichi Furutate

An evacuating valve includes a chamber port structure to be connected to a vacuum vessel in which a plasma is produce to create a plasma atmosphere, a pump port structure to be connected to a vacuum pump; a valve casing defining a passage connecting the chamber port structure and the pump port structure, and a valve mechanism for opening and closing the chamber port structure. At least two expended parts are formed by expanding an end part of the inside surface of the chamber port structure, and the valve element has a large part capable of being pressed against the valve seat with the sealing member held between the large part and the valve seat, and at least two small parts capable of being fitted in the expanded parts of the chamber port structure.

Evacuating valve

Disclosed is a two-port valve in which a fluid passage between two ports is gradually openable without a rapid flow rate, by stepwise lifting a valve member off a valve sent using two pistons, to open the valve in a phased manner. A cylinder portionfor driving a valve memberhas a first pistonthrough which a valve shaftslidably extends, a sleevemovably disposed in a second pressure chamberto limit an operating stroke of the first piston, and a second pistonslidably disposed in the sleeveand connected to the shaft. In an initial phase of opening of the valve, the pistonsacting like a unit are together moved to a position at which the first pistoncontacts the sleeve, to slightly open the valve member. Thereafter, the valve memberis moved by the second pistonto its fully open position.

Two-port valve for vacuum operation

A vacuum regulating valve which is simplified in structure and where the flow rate characteristic in evacuating a vacuum vessel is improved, comprises (i) a main valveA of a large size which has: a principal bodyhaving two main portsconnected to a vacuum vesseland a vacuum pump, respectively, a valve seatdisposed in a fluid passage connecting the ports, a valve elementseated on and separated from the valve seat, and a shaftextending from the valve element; and a valve element operating unitfor operating the valve elementvia the shaft, and (ii) a sub valveA of a small size similar in structure to the main valveA. The sub valveA is attached to an outer side surface of a casingof the main valveA.

Vacuum regulating valve

A vacuum regulating valve has high controllability, wherein the opening of a valving member can be quickly and accurately controlled by using a small and inexpensive electric motor. In accordance with a signal indicative of a pressure set value and a pressure signal from the pressure sensor, the main controller in the valve control section outputs a signal for setting the opening of the valving member to a motor controller that controls the electric motor, and performs control to cause a pilot fluid to be supplied to a pressure receiving chamber of the piston, thereby causing the piston to move to the position of abutment with the stopper.

A vacuum regulating valve includes a valve casing provided with two main ports, a passage connecting the two main ports, a valve seat formed in the passage, a valve element capable of being seated on the valve seat, a valve stem extending from the valve element, and a piston attached to the free end of the valve stem. A valve opening setting unit includes a valve opening setting shaft having a free end held in contact with the back surface of the piston, and a driving mechanism capable of continuously axially moving the valve opening setting shaft to a desired position to set the piston at an operating position corresponding to a desired valve opening.

An annular valve seat is formed in a connecting path connecting a first main port and a second main port, a circular flow path wall having a diameter greater than a seat diameter is formed around the valve seat so as to surround the valve seat, a circular outer peripheral wall having a diameter greater than the seat diameter and smaller than a diameter of the flow path wall is formed at a disc-shaped valve member, and a restricted flow path is formed between the flow path wall and the outer peripheral wall when the valve member is fitted in the flow path wall.

Vacuum pressure regulating valve

A vacuum regulating valve is capable of precisely controlling the flow of a fluid so that the flow rate may increase gradually in an initial stage of a valve opening operation. The vacuum regulating valve includes a valve casing having a valve chamber and provided with a first opening connected to a vacuum vessel and a second opening connected to a vacuum pump, a valve seat, a valve element seated on the valve seat, a valve stem connected to the valve element, a bellows sealing the valve stem therein, and a baffle member attached to the back surface of the valve element and surrounding the bellows. The baffle member is formed in an axial length such that the baffle member is able to cover the second opening entirely when the valve element is seated on the valve seat. The outside diameter of the baffle member is determined such that an outside space of the smallest possible thickness is defined between the outer circumference of the baffle member and the inner circumference of the side wall of the valve casing, and the thickness of the outside space is great enough to keep the baffle member spaced from the inner circumference of the side wall of the valve casing and is small enough to prevent a fluid from flowing through the outside space into an inside space formed between the baffle member and an imaginary cylinder circumscribed about the bellows.

A first piston and a second piston are accommodated in a piston chamber of a cylinder. The first piston is connected to a main valve member which opens and closes a main flow passage. The second piston is connected to a second rod having a stopper whose position can be adjusted. Pressure fluid is supplied to the second pressure chamber to move the second piston forward to a position where the stopper abuts against the abutting portion. In this state, pressure fluid is supplied to the first pressure chamber to move the first piston to a position where the first piston abuts against the second piston, thereby opening the main valve member by a stroke of the first piston.

Two-port vacuum valve capable of adjusting valve-opening

A main valve mechanism for opening and closing a main flow path between a first port and a second port has a main valve body, a large-diameter first piston for opening the main valve body, a main pressure operating chamber for driving the first piston, and first spring means for closing the first piston. An auxiliary valve mechanism for opening and closing an auxiliary flow path has an auxiliary valve body, a small-diameter second piston for opening the auxiliary valve body, an auxiliary pressure operating chamber for driving the second piston, and second spring means for closing the second piston. The main pressure operating chamber and the auxiliary pressure operating chamber are connected to each other through a connecting hole. There are such relationships between piston diameters of both the pistons and repulsing forces of both the spring means that the second piston is actuated by lower fluid pressure than the first piston.

Pilot-type two-port vacuum valve

In a vacuum valve including a main flow path and an auxiliary flow path for connecting a chamber port and a pump port in parallel, a main valve body for opening and closing a main valve seat in the main flow path, and an auxiliary valve body for opening and closing an auxiliary valve seat in the auxiliary flow path, the main valve body includes, in addition to a valve sealing member for opening and closing the main valve seat in a poppet manner, a flow rate adjusting portion in a gradually-tapered shape to be fitted in an inner hole of the main valve seat and the flow rate adjusting portion functions to gradually increase an exhaust flow rate when the main valve body opens after opening of the auxiliary valve body.

A smooth exhaust valve includes a main flow path having a large cross-sectional area and an auxiliary flow path having a small cross-sectional area for connecting a first port and a second port in parallel, a main valve body for opening and closing the main flow path, an auxiliary valve body for opening and closing the auxiliary flow path, a first piston for opening and closing the main valve body, a second piston for opening and closing the auxiliary valve body, a first spring device for repulsing the main valve body in a valve-closing direction, a second spring device for repulsing the auxiliary valve body in a valve-closing direction, and an adjusting rod mounted to a valve casing so as to be operated from outside to move forward and rearward and for changing a compressed amount of the second spring device by operation of forward and rearward movements of the adjusting rod to adjust a repulsing force of the second spring device.

Growing community of inventors

Ibaraki, Japan

Masao Kajitani