Swing-door gate valve

Abstract: A gate 3 for opening and closing an opening 2 of a chamber 1 is fixed to a top end of an arm 7 and is swung between a position facing the opening and a retreated position on a side thereof. A base end of the arm 7 is supported by an output shaft 10 of a fluid pressure cylinder 8 driven in parallel with a direction in which the gate comes into contact with and is separated from the opening 2. A cam follower 12 is provided at the base end of the arm 7 and is movable in a guide groove 14 of a machine frame 6. The guide groove comprises an axial-direction groove 14a for moving the gate 3 from a position facing the opening 2 to a position in the vicinity of the opening of the chamber 1, and a slant-periphery direction groove 14b connected thereto for retreating the gate to the side of the opening.

Description: The present invention relates to a swing-door gate valve for opening and closing an opening of a chamber. A swing-door gate valve opens an opening of a chamber by moving a gate for closing the opening to a side position, so that a work or the like can be taken in and out of the chamber. When the gate is brought into contact with or separated from the opening of the chamber, unless the gate is brought into contact with or separated from a sealing surface of the chamber vertically and, for closing, is brought into a position in which the gate faces the opening of the chamber, there is sliding between sealing material provided at the gate and the sealing surface of the chamber, resulting in occurrence of abrasion or dust due to friction. However, it is difficult to realise a simple and cheap mechanism for performing contact/separation of the gate in a vertical direction relative to the chamber sealing surface and for moving it between a position facing the opening of the chamber and a position to a side. An object of the present invention is to provide a simple and cheap mechanism for a swing-door gate valve for achieving contact/separation of the gate in the vertical direction relative to the chamber sealing surface and the movement between the position facing the opening of the chamber and the retreated position on a side thereof. Another object of the present invention is to provide a swing-door gate valve in which no seal sliding occurs so that substantially no dust is produced on bringing the gate into contact with and separating it from the sealing surface of the chamber. A still further object of the present invention is to provide a swing-door gate valve in which a driving section of the gate has a simple and compact structure which is driven by a single actuator, and the driving of which is cheap and easy to control, and as a result, a signal system for which can also be simply and cheaply configured. U.S. 4219183 discloses an operating mechanism for valves and the like comprising a housing with a port situated therein which is to be opened and closed. Associated with the port is a seat and a valve plate for closing the port. A rotatable shaft drive mechanism for the valve plate includes a shaft which rotates in one direction to effect movement of the valve plate from its open position to its closed position followed by a pressing movement over the valve plate against the seat and rotates in the other direction to effect movement of the valve plate in the opposite direction. The rotatable shaft drive mechanism includes an intermittent drive for the transformation of the rotatory movement of the shaft to the desired movement of the valve plate. A swing-door gate valve according to the present invention comprises an output shaft supported by a frame such as to be rotatable around the axis thereof, an arm having a base end fixed to the output shaft and extending in a direction perpendicular to the output shaft, a gate attached to the other end of the arm for opening and closing an opening of a chamber and a direction-changing mechanism for changing one form of movement of the output shaft into a different form of movement of the gate, characterised in that the shaft is freely movable in the axial direction thereof; in that the valve comprises an actuator for moving the output shaft axially, and in that the direction-changing mechanism is for changing forward and backward movement of the output shaft to a swinging movement of the gate between a position facing the opening of the chamber and a position retreated to the side of the opening, and a vertical-direction movement of the gate relative to the opening of the chamber into or out of contact with the opening. The direction-changing mechanism may include a guide groove formed in the machine frame and a cam follower provided at a base end of the arm which is movable in the guide groove wherein the guide groove includes a first, axial-direction groove, portion that is parallel with the output shaft and a second, slant-periphery direction groove, portion extending slantly from an end of the shaft-direction groove. In addition, the gate is preferably attached to the top end of the arm with free movement and the actuator is preferably a fluid pressure cylinder. When the actuator of a gate valve with such a structure is driven, the arm is moved by the thrust on the output shaft and the direction is controlled by the direction-changing mechanism. More specifically, the cam follower is moved along the guide groove via the arm, and thereby the gate is moved between a closing position for closing the opening of the chamber and the retreated position retreated from the opening to the side thereof. When the gate is moved from the retreated position retreated to the side of the opening of the chamber to close the opening, the gate is first moved to the position facing the opening by the swing of the arm, and after the gate has reached the position facing the opening, the gate is moved vertically to engage the sealing surface of the chamber. On the other hand, when the gate is moved from the position closing the opening to a position at which the opening is opened, the gate performs a reverse operation to that described above by the driving of the actuator in a reverse direction and is moved to a position retreated from the opening at the side thereof. With the above described swing-door gate valve, the contact/separation of the gate in the vertical direction relative to the chamber sealing surface and the movement between the position facing the chamber opening and the retreated position on the side thereof can be realised with a simple, compact, and cheap configuration using a single actuator. In addition, the gate can be brought into contact with and separated from the sealing surface of the chamber vertically, so that no sealing material sliding occurs whereby substantially no dust is produced. Furthermore, since a single actuator is used, driving control is easy, and consequently, the signal system can also be configured simply and cheaply. The invention will now be described by way of example with reference to the accompanying drawings in which: Fig. 1 is a sectional side elevation view showing an embodiment of a gate valve according to the present invention. Fig. 2 is a bottom plan view of the embodiment. Fig. 3 is a left side elevation view of a machine frame in the embodiment in Fig. 1. Fig. 4 is a development view showing the details of a guide groove in Fig. 3. Fig. 1 and Fig. 2 illustrate a constructional example of a swing-type gate valve according to the present invention. The gate valve includes a gate 3 for opening and closing an opening 2 at a lower part of a chamber 1. The gate 3 has a sealing material 4 for closing the opening 2 at a periphery thereof by coming into contact with a sealing surface formed at the periphery of the opening 2 of the chamber 1, and which is connected to a top end of an arm 7 supported by a machine frame 6 with a free movement of vertical non-uniformity. The arm 7 carries the gate 3 to be movable between a closing position (a position indicated by a solid line in Fig. 2) at which the gate 3 closes the opening 2 of the chamber 1 and a retreating position (a position indicated by a dot-dash line in Fig. 2) at which the gate 3 retreats from the opening 2 to the side thereof, and facilitates a work or the like to be taken in and out of the chamber 1 at the retreating position of the gate not facing the opening 2. The machine frame 6 is provided with an actuator and an output shaft 10 in order to support the arm 7 to be freely swung, and to enable the arm to perform the opening/closing operation. The actuator is constructed by a fluid pressure cylinder 8 disposed at a lower part of the machine frame 6, wherein the output shaft 10 is connected to a piston 9. The output shaft 10 is disposed so as to be driven in parallel with a direction in which the gate 3 comes into contact with and is separated from the opening 2 of the chamber 1 while fronting thereto, which is supported by bearings 11 and 11 to be movable at an upper and lower parts of the machine frame 6, and which is also supported in the axial direction to be slidable. The supporting of the output shaft 10 by the bearing 11 is not necessarily conducted at the upper and lower parts of the machine frame 6, but only at one of the upper part or the lower part of the machine frame 6, alternatively, only at an intermediate part between the upper part and the lower part. Furthermore, the sliding of the output shaft 10 to the bearing 11 can be performed by a key groove mechanism, a ball spline shaft, or the like. In addition, reference numerals 16a and 16b in the drawings indicate ports for supplying and exhausting pressure fluids (compressed air) to/from the opposite sides of the piston 9 of the fluid pressure cylinder 8. The arm 7 is fixedly attached to the output shaft 10 of the fluid pressure cylinder 8, and is moved in an axial direction of the output shaft 10, following a forward and backward movement of the output shaft 10 by the fluid pressure cylinder 8. The machine frame 6 is provided with a direction-changing mechanism for changing the movement of the arm 7 in the axial direction to a swing-direction movement with the output shaft 10 as the center, in which the gate 3 at the top end of the arm is moved between the position facing the opening 2 of the chamber 1 and the position retreated to the side of the opening 2, and a vertical-direction movement in which the gate 3 is moved vertically relative to the opening 2 of the chamber 1 to come into contact with and is separated from the opening 2. The direction-changing mechanism swings the arm 7 by the driving of the fluid pressure cylinder 8 in a manner so as to carry the gate 3 at the position facing the opening 2 when the gate 3 is located at a position in the vicinity of the opening 2 of the chamber 1, and to retreat the gate 3 to the side of the opening 2 when the gate 3 is located at a position away from the opening 2. Specifically, as shown in Fig. 3 and Fig. 4, the direction-changing mechanism comprises a cam follower (rolling body) 12 fixed to a base end of the arm 7 to be ratatable via the bearing, and a guide groove 14 provided on a wall surface 13 around the output shaft 10 of the fluid pressure cylinder 8 in the machine frame 6, in which the cam follower 12 is fit. The guide groove 14 includes, as clearly shown in Fig. 4, an axial-direction groove 14a that is parallel with the output shaft 10, and a slant-periphery direction groove 14b extending slantly from an end of the axial-direction groove 14a along the circumference surrounding the output shaft 10. When the gate 3 is located at the position in the vicinity of the opening 2 of the chamber 1, the axial-direction groove 14a carries the gate 3 at the position facing the opening 2, and guides the sealing material 4 in the direction coming into contact with and separated from the sealing surface at the periphery of the opening 2 vertically by the driving of the fluid pressure cylinder 8. When the gate 3 is located at the position slightly away from the opening 2, the slant-periphery direction groove 14b swings the arm 7 in a manner so as to retreat the gate 3 to the side of the opening 2. In the gate valve having the aforesaid structure, when the piston 9 is moved upward by supplying the pressure fluid to the port 16a of the fluid pressure cylinder 8 from a state in which the piston 9 is located at a lower end of the fluid pressure cylinder 8, and the gate 3 is located at the position indicated by the dot-dash line in Fig. 2, which is retreated from the opening 2 of the chamber 1 to the side thereof, that is, from a state in which the cam follower 12 is located at a terminal (lower end) of the slant-periphery direction groove 14b, the cam follower 12 at the base end of the arm 7 is moved by the thrust applied to the output shaft 10, along the slant-periphery direction groove 14b at the guide groove 14, so that the gate 3 is moved (swung) in the direction fronting onto the opening 2 of the chamber 1 from the retreating position retreated to the side relative to the opening 2 while coming close to the opening 2 of the chamber 1. When the gate 3 moves toward the opening 2 by the swing of the arm 7, and correspondingly, the cam follower 12 reaches a connecting part of the slant-periphery direction groove 14b relative to the axial-direction groove 14a, the gate 3 reaches the position fronting onto the opening 2 by the arm 7, and next, the cam follower 12 is moved in the axial direction of the output shaft 10 along the axial-direction groove 14a, consequently, the gate 3 is moved vertically toward the sealing surface of the chamber 1. As a result, since the gate 3 can be brought into contact with the sealing surface of the chamber 1 vertically, no slide occurs at the sealing material 4, thereby producing no dust substantially. On the other hand, in the case where the gate 3 is moved from a state closing the opening 2 to the position to release the opening 2, the gate performs a complete reverse operation to the above by the driving of the actuator in a reverse direction, and which is moved from the opening to the position retreated aside. That is, when the pressure fluid in the port 16a of the fluid pressure cylinder 8 is exhausted, and also the pressure fluid is supplied to the port 16b, the piston 9 is moved downward in order to move the cam follower 12 downward along the axial-direction groove 14a via the arm 7, consequently, the closing state of the opening 2 of the chamber 1 by the gate 3 is released. When the piston 9 is further moved downward, the cam follower 12 reaches the connecting part of the axial-direction groove 14a relative to the slant-periphery direction groove 14b, where the cam follower 12 is moved horizontally while moving in the axial direction along the slant-periphery direction groove 14b by the thrust applied to the output shaft 10, thereby swinging the arm 7 in order to move the gate 3 from the position indicated by the solid line, which fronts to the opening of the chamber, to the position indicated by the dotted line, which is retreated to the side of the opening 2 in Fig. 2. In this state, the work or the like can be easily taken in and out of the chamber 1. With the swing-door gate valve described above, the contact/separation of the gate in the vertical direction relative to the chamber sealing surface and the movement between the position facing the chamber opening and the retreating position on the side thereof is realised with a simple, compact, and cheap configuration using the single actuator. In addition, since the gate is brought into contact with and separated from the sealing surface of the chamber vertically, no sealing material sliding occurs thereby producing substantially no dust. Furthermore, since the gate can be driven by the single actuator, the driving control is easy and, consequently, the signal system can also be configured simply and cheaply.

Claims: A swing-door gate valve comprising an output shaft (10) supported by a frame (6) such as to be rotatable around the axis thereof, an arm (7) having a base end fixed to the output shaft (10) and extending in a direction perpendicular to the output shaft, a gate (3) attached to the other end of the arm (7) for opening and closing an opening (2) of a chamber (1) and a direction-changing mechanism (12, 14) for changing one form of movement of the output shaft (10) into a different form of movement of the gate (3), characterised in that the shaft (10) is freely movable in the axial direction thereof; in that the valve comprises an actuator (8) for moving the output shaft (10) axially, and in that the direction-changing mechanism (12, 14) is for changing forward and backward movement of the output shaft (10) to a swinging movement of the gate (3) between a position facing the opening (2) of the chamber (1) and a position retreated to the side of the opening (2), and a vertical-direction movement of the gate (3) relative to the opening (2) of the chamber (1) into or out of contact with the opening (2). A swing-door gate valve as claimed in Claim 1, wherein the direction-changing mechanism includes a guide groove (14) formed in the machine frame (6) and a cam follower (12) provided at the base end of the arm (7) and movable in the guide groove (14), wherein the guide groove has a first portion (14a) parallel with the output shaft (10) and a second portion (14b) extending at an angle from an end of the first portion (14a). A swing-door gate valve as claimed in Claim 1 or Claim 2 wherein the gate (3) is attached to the top end of the arm (7) with free movement. A swing-door gate valve as claimed in any preceding claim wherein the actuator is a fluid pressure cylinder (18).

Inventors: ISHIGAKI TSUNEO, KANZAKA IKUO, WARAGAI KENJI, ISHIGAKI, TSUNEO, KANZAKA, IKUO, WARAGAI, KENJI, Ishigaki, Tsuneo, SMC Corp. Tsukuba Tech. Ctr., Kanzaka, Ikuo, SMC Corp. Tsukuba Tech. Ctr., Waragai, Kenji, SMC Corp. Tsukuba Tech. Ctr.
Applicants: SMC CORP, SMC CORPORATION
Application year: 2000
Main classification: F16K3
IPC codes: F16K3, F16K31