gate valve

Abstract

A gate valve can determine whether a lock piston is in a latched state with respect to a latching hole. The gate valve (1) has a valve plate (4) that opens and closes a gate opening (2), a valve shaft (5) fixed to the valve plate (4), a cylinder (20) having a drive rod (21), and a valve moving mechanism (29) that reciprocates the valve plate (4) between a closed position that closes the gate opening (2) and a fully open position (P1) that fully opens the gate opening (2) in correspondence with the extension and retraction of the drive rod (21). The cylinder (20) has a cylinder housing (22) that has a lock mechanism that locks the valve plate (4) moved to the closed position and a lock detection portion that detects a lock state of the valve plate (4). The lock mechanism has a lock piston that is retractably provided on the cylinder housing (22). A cam frame (32) fixed to the drive rod (21) has a latching hole (32c) that latches the lock piston, and the lock detection portion detects whether the lock piston is in a latched state with respect to the latching hole (32c).

Description

TECHNICAL FIELD

[0001] The present application relates to a gate valve, for example, which is installed on a transfer passage connected to an opening of a vacuum processing cavity in a semiconductor manufacturing apparatus, and which communicates or hermetically seals the vacuum processing cavity through the opening with other cavities or the like. BACKGROUND

[0002] Generally, the gate valve is provided with a valve plate which opens and closes a gate opening leading to the vacuum processing cavity, a valve shaft which is installed on the valve plate, and a cylinder which drives the valve shaft. The valve shaft is driven by the supply and discharge of compressed air with respect to the cylinder, and the valve plate is configured to reciprocate between a closed position in which the gate opening is hermetically sealed and a fully open position in which the gate opening is fully opened, via an intermediate position which faces away from the gate opening with a gap.

[0003] In such a gate valve, as described in Patent Document 1, when the valve plate is moved from the intermediate position to the closed position, the valve shaft is inclined and rotated to the closed position side, and a sealing member of the valve plate is pushed against a valve seat of the gate opening to seal the gate opening.

[0004] The position of the valve plate at the closed position is maintained by maintaining the pressure of the compressed air in the cylinder. Therefore, in a state in which the valve plate is moved to the closed position, the pressure of the compressed air in the cylinder is lost, and in this case, there is a risk that the gate opening is opened and the closed state cannot be maintained.

[0005] Therefore, in the gate valve described in Patent Document 1, a locking mechanism which locks the movement of the valve plate in a state in which the valve plate is moved to the closed position is provided. This locking mechanism, when the cylinder is in a contracted state, engages a locking cylinder with a groove provided on a piston of the cylinder to restrict the movement of the piston, the locking cylinder being provided to be able to advance and retreat with respect to a cylinder tube of the cylinder.

[0006] The locking cylinder of this locking mechanism is provided to be able to slide within a housing installed in the cylinder tube of the cylinder. In the housing, a locking spring which loads the locking cylinder in a direction in which the locking cylinder advances with respect to the piston is provided, and on the other hand, the housing is configured to be able to supply compressed air for moving the locking piston in a retreat direction in which the locking piston retreats from the piston. Therefore, when the cylinder is contracted, if the compressed air is not supplied to the housing, since the locking cylinder is loaded in the direction in which the locking cylinder advances with respect to the piston by the locking spring, the locking cylinder can be inserted into the groove provided on the piston to restrict the movement of the piston.

[0007] [Patent Document]

[0008] [Patent Document]

[0009] [Patent Document 1] Japanese Patent No. 3349962 SUMMARY

[0010] Problem to be solved by the Invention

[0011] However, in the lock mechanism described in Patent Literature 1, in the case where the lock spring has failed in the state where the valve plate is moved to the closed position, there is a risk that the lock cylinder can no longer enter the groove side of the piston. Therefore, the valve plate becomes movable, and there is a risk that the cavity can no longer be hermetically closed through the gate opening. In this case, because the lock spring is provided in the housing, it is difficult to determine whether the lock cylinder of the lock mechanism is in the engaged state where it has entered the groove side of the piston. Therefore, it is desirable to provide a gate valve in which it is possible to determine whether the lock cylinder of the lock mechanism is in the engaged state where it has entered the groove side of the piston.

[0012] Therefore, the technical problem of the present application is to provide a gate valve in which it is possible to determine whether the lock piston of the lock mechanism is in the engaged state where it has entered the engaged portion.

[0013] Means for solving the problem

[0014] In order to solve the above problem, the gate valve of the present application, which opens and closes a gate opening formed in a valve tank by a valve plate provided in the valve tank, is characterized in that it comprises the valve plate, a valve shaft, a cylinder, and a valve moving mechanism, one end of the valve shaft is attached to the valve plate, the other end side extends from the valve tank and is supported so as to be movable with respect to the valve tank, the cylinder is disposed outside the valve tank and has a drive rod, the valve moving mechanism moves the valve plate via the valve shaft in correspondence with the extension and contraction movement of the drive rod of the cylinder, and the valve plate is reciprocally moved between a closed position where the gate opening is hermetically closed and an open position where the gate opening is fully opened, the valve moving mechanism has a first block, a second block, and a linking member, the first block is fixed to the drive rod, the second block is fixed to the valve shaft extending from the valve tank, and the linking member links the second block with respect to the first block so as to be relatively movable, the cylinder has a cylinder housing which supports the drive rod so as to be extendable and contractible, a lock mechanism for locking the valve plate moved to the closed position and a lock detection portion which detects whether the valve plate is in the state where it is locked by the lock mechanism are provided in the cylinder housing, the lock mechanism has a lock piston which is provided in a facing wall of the cylinder housing facing the first block so as to be movable with respect to the first block, an engaging hole portion for engaging the lock piston which has entered the first block side in the state where the valve plate is moved to the closed position is provided in the first block, and the lock detection portion detects whether the lock piston is in the engaged state with respect to the engaging hole portion.

[0015] Preferably, the lock detection portion has a detected body provided at a retreat-side end portion of the lock piston and extending toward the retreat side, and a detection main body portion that detects the detected body when the lock piston is in the engaged state with the engagement hole portion.

[0016] At this time, more preferably, the detection main body portion is a proximity sensor, and the detected body extends in the advance-and-retreat direction of the lock piston, has a small-diameter portion formed at an advance-side in the advance-and-retreat direction, and has a large-diameter portion formed at a retreat-side in the advance-and-retreat direction and larger in diameter than the small-diameter portion, and the proximity sensor detects the large-diameter portion of the detected body when the lock piston is in the engaged state with the engagement hole portion.

[0017] In addition, the lock piston, the detected body, and the proximity sensor can be provided inside a housing provided on the cylinder housing, and the housing can be detachably attached to a cutout portion formed in the cylinder housing.

[0018] In addition, the proximity sensor can be inductive, the housing can be formed of a non-magnetic material, and the detected body can be formed of a magnetic material having electrical conductivity.

[0019] In addition, in the cylinder housing of the air cylinder, a drive piston fixed to the drive rod can be provided, a first pressure chamber that drives the valve plate from the fully open position to the closed position can be provided on the drive rod side of the drive piston, a second pressure chamber that drives the valve plate from the closed position to the fully open position can be provided on the side opposite to the drive rod in the cylinder housing, the lock piston of the lock mechanism can be housed in a housing hole portion provided on the facing wall of the cylinder housing, a load spring that allows the lock piston to enter toward the first block side can be provided at a retreat-side in the advance-and-retreat direction of the lock piston, a lock release pressure chamber for allowing the lock piston to retreat can be formed at an advance-side in the advance-and-retreat direction of the lock piston, and the lock release pressure chamber can communicate with a lock gas passage that is connected to a port through which compressed air is supplied to the second pressure chamber.

[0020] In addition, the valve moving mechanism can reciprocally move the valve plate between the closed position and the fully open position through an intermediate position in which the valve plate is spaced apart from the gate opening.

[0021] [Effects of the Invention]

[0022] As described above, according to the present application, it is possible to provide a gate valve in which it is possible to determine whether the lock piston of the lock mechanism is in the engaged state with the engaged portion. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a perspective view showing a state in which the valve plate exposed by omitting a part of the valve chest in the gate valve of one embodiment of the present application is in a fully open position of the gate opening.

[0024] Figure 2 (a) is a rear view of the gate valve in a state in which the valve plate is in a fully open position of the gate opening, Figure 2 (b) is a bottom view of the gate valve.

[0025] Figure 3 is a longitudinal sectional view of the gate valve corresponding to the III-III line of Figure 2 (b).

[0026] Figure 4 represents a cylinder, Figure 4 (a) is a right side view of the cylinder, Figure 4 (b) is a rear view of the cylinder.

[0027] Figure 5 represents a cam frame, Figure 5 (a) is a plan view of the cam frame, Figure 5 (b) is a side view of one side of the cam frame, Figure 5 (c) is a rear view of the cam frame, Figure 5 (d) is a left side view of the other side of the cam frame.

[0028] Figure 6 is a partially enlarged sectional view of the valve chest showing a state in which the valve plate is in a fully open position with respect to the gate opening.

[0029] Figure 7 is a partially enlarged sectional view of the valve chest showing a state in which the valve plate is in an intermediate position with respect to the gate opening.

[0030] Figure 8 is a partially enlarged sectional view of the valve chest showing a state in which the valve plate is in a closed position with respect to the gate opening.

[0031] Figure 9 is a longitudinal sectional view of the gate valve in a state in which the cylinder is in a contracted state.

[0032] Figure 10 is a partially enlarged sectional view of the portion corresponding to Figure 9 C of

[0033] Figure 11 (a) is a partially enlarged sectional view of the locking mechanism and the lock detection portion corresponding to Figure 4 XI-XI of (a), Figure 11 (b) is a partially enlarged sectional view of the locking mechanism and the lock detection portion in a state in which the lock piston is moved to a locked position.

[0034] Figure 12 is an enlarged sectional view for explaining adjustment of the lock detection section.

[0035] Figure 13 is an explanatory view that schematically shows a flow path of compressed air when the valve plate is moved from the closed position to the fully open position side.

[0036] Figure 14 is an explanatory view that schematically shows a flow path of compressed air when the valve plate is moved from the fully open position side to the closed position side. DETAILED DESCRIPTION

[0037] Manner of carrying out the invention

[0038] Hereinafter, a gate valve of an embodiment of the present application will be described. In the present embodiment, a gate valve in which a valve plate is movable in the up-down direction with respect to a gate opening formed in a valve case, and the valve plate is reciprocally movable through an intermediate position facing away from the gate opening at an interval, between a closed position in which the gate opening is hermetically closed, and a fully open position in which the gate opening is fully opened, will be described as an example. In addition, in the following description, there are cases in which the scale and the like in each configuration are made different from the actual configuration in order to explain each configuration.

[0039] In addition, in the present specification, the up-down direction of the gate valve shown in Figure 1 will be simply described as "up-down direction", the left-right direction will be simply described as "left-right direction" when viewed from the front of the gate valve, and a direction orthogonal to the left-right direction of the gate valve will be described as "front-rear direction".

[0040] <Overall Configuration>

[0041] As shown in Figure 1 , Figure 2 (a), Figure 2 (b), Figure 3 , a gate valve 1 of an embodiment of the present application has a valve case 3 (refer to Figure 6 ) having a gate opening 2 (refer to Figure 6 ) for communicating with a vacuum processing cavity not shown, a valve plate 4 housed in the valve case 3, a valve shaft 5 installed on the valve plate 4, a cylinder 20 having a drive rod 21, and a valve moving mechanism 29 that reciprocally moves the valve plate 4 through an intermediate position P2 (refer to Figure 7 ) facing away from the gate opening 2 at an interval, between a closed position P3 (refer to Figure 8 ) in which the gate opening 2 is closed, and a fully open position PI (refer to Figure 1 , Figure 6 ) in which the gate opening 2 is fully opened.

[0042] Further, the gate valve 1 has a locking mechanism 50 (refer to Figure 10 ) that locks the valve plate 4 in the closed position P3, and a lock detection section 60 (refer to Figure 11 (a)) that can detect whether the valve plate 4 is in a state locked by the locking mechanism 50. Hereinafter, each structural component will be described in detail.

[0043] (valve plate)

[0044] The valve plate 4 is formed in a substantially rectangular flat plate shape that is long in the left-right direction, as shown in Figure 1 and Figure 6 . The front side of the valve plate 4 forms a substantially flat seal surface 4a, and an annular seal groove 4b is formed in the outer peripheral portion of the seal surface 4a. An annular seal member 9 composed of an elastic material such as an O-ring is installed in the seal groove 4b, and a portion of the annular seal member 9 protrudes from the seal surface 4a.

[0045] (valve case)

[0046] The valve case 3, the inside of which is formed in a hollow box shape, has a pair of side walls 3a, 3b that face each other at a distance in the front-rear direction. The gate opening 2 is provided in the upper portion of the side wall 3a on the front side, and the back side opening 2a, which is substantially the same shape and size as the gate opening 2, is provided in the upper portion of the side wall 3b on the rear side at the same height as the gate opening 2. The gate opening 2 is substantially rectangular like the valve plate 4 and is slightly smaller than the valve plate 4. An annular valve seat 8 composed of a flat surface is provided in the outer peripheral portion of the gate opening 2 in the inner surface of the side wall 3a in such a manner as to surround the gate opening 2. The seal member 9 that moves in conjunction with the valve plate 4 is brought into contact with and separated from this valve seat 8, and the gate opening 2 is opened and closed.

[0047] In the bottom portion of the valve case 3, a valve cap 10 that is fixed to the side walls 3a, 3b so as to extend between the respective lower end portions of the pair of side walls 3a, 3b is provided airtightly, as shown in Figure 1 and Figure 6 . A through hole 10a that penetrates in the up-down direction is provided in the central portion in the left-right direction of the valve cap 10, and the valve shaft 5 is inserted so as to be movable in the up-down direction (refer to the axis L1 direction Figure 2 (a)) and in the front-rear direction. In the present embodiment, the through hole 10a is circular as viewed in the up-down direction.

[0048] (valve shaft)

[0049] The valve shaft 5, as shown in Figure 1 , Figure 2 (a), Figure 2(b) shown is a rod-shaped member connected to the lower left and right central portions of the valve plate 4 and extending downward, and the upper portion of the portion extending downward compared to the lower surface 10b of the valve cap 10 is covered by a non-illustrated bellows that expands and contracts in conjunction with the upward and downward movement of the valve shaft 5. The upper end of the bellows is connected airtightly with respect to the lower surface 10b of the valve cap 10 in a manner surrounding the through hole 10a, and the lower end of the bellows is connected airtightly with respect to the second block 40 (a lever member 41 described later). In addition, in the present embodiment, the upper side of the valve shaft 5 has a rectangular cross-sectional shape, and the lower side of the valve shaft 5 has a circular cross-sectional shape.

[0050] (cylinder)

[0051] The cylinders 20, 20, as shown in Figure 2 (a) and Figure 3 are arranged facing each other with the valve shaft 5 sandwiched therebetween. The cylinder 20 has a hollow cylinder housing 22 arranged facing each other on the respective left and right outer sides of a pair of cam frames 32, 32 that constitute a part of the first block 30 described later, and fixed so as to extend in a direction orthogonal to the lower surface 10b of the valve cap 10 (an up and down direction), a drive rod 21 arranged inside the cylinder housing 22 so as to extend in a direction orthogonal to the valve cap 10 (a direction parallel to the face of the valve seat 8), and a drive piston 23 arranged inside the cylinder housing 22, fixed to the upper end portion of the drive rod 21, and reciprocally movable in conjunction with the up and down movement of the drive rod 21.

[0052] In the present embodiment, the cylinder housing 22, as shown in Figure 3 , Figure 4 (a), Figure 4 (b), the side wall of the cylinder housing 22 facing the cam frame 32 of the first block 30 connected to the cylinder 20 functions as a facing wall (roller frame) 26 for mounting the first guide roller 27a and the second guide roller 27b described later. Therefore, in the following description, the side wall of the cylinder housing 22 on which the first guide roller 27a and the second guide roller 27b are mounted will be described as "roller frame 26". In addition, this roller frame 26 can be formed separately from the cylinder housing 22 as long as it is in a fixed relationship with the cylinder housing 22 of the cylinder 20.

[0053] Inside the cylinder housing 22, as shown in Figure 3 and Figure 9As shown, a first pressure chamber 24a (lower than the drive piston 23) and a second pressure chamber 24b (upper than the drive piston 23) are respectively provided on the upper and lower sides of the cylinder housing 22. Furthermore, the drive rod 21 is airtightly and slidably supported within the end of the cylinder housing 22 on the lever side, and an annular member 24d is airtightly fitted to abut the lower end of the drive piston 23. On the other hand, an abutment portion 24c is provided at the end of the cylinder housing 22 on the head side, allowing the drive piston 23 to abut against the retracted end of the drive rod 21.

[0054] Furthermore, a first port 25a for supplying and discharging compressed air relative to the first pressure chamber 24a and a second port 25b for supplying and discharging compressed air relative to the second pressure chamber 24b are provided on the outer periphery of the cylinder housing 22. In this embodiment, the first port 25a is positioned lower than the second port 25b. These first ports 25a and second ports 25b are connected to the first pressure chamber 24a and the second pressure chamber 24b, respectively, via supply and discharge airflow paths provided on the cylinder housing 22 and the annular member 24d. Details of the supply and discharge airflow paths will be described later.

[0055] (Valve moving mechanism)

[0056] Next, the valve moving mechanism 29 will be described in detail. The valve moving mechanism 29, as... Figure 2 (a) Figure 2 (b) Figure 3 As shown, it has a first block 30 fixed to the drive rod 21, a second block 40 fixed to the valve shaft 5 extending from the valve box 3, and a connecting member 6 that connects the second block 40 relative to the first block 30 so that they can move relative to each other.

[0057] (First part, connecting component)

[0058] In this embodiment, the first block 30 has a lever arm 31 and a pair of plate-shaped left and right cam frames 32, 32. The lever arm 31 extends in the left and right direction and is plate-shaped, fixing the lower ends of the drive rods 21, 21 to the left and right sides. The pair of plate-shaped left and right cam frames 32, 32 are disposed between the second block 40 and the roller frame 26, fixed on the top of the lever arm 31, and extend upward parallel to the axis L2 of the drive rod 21. The lever arm 31 is disposed below the second block 40 and extends parallel to the valve cap 10. In addition, a concave spring seat 31a is formed in the center of the left and right direction of the surface of the lever arm 31 facing the second block 40. A compression spring 6' serving as a connecting member 6 is sandwiched between the spring seat 31a and the second block 40. The cam frame 32 will be described later.

[0059] (Second piece)

[0060] In the present embodiment, the second block 40, as shown in Figure 2 (a) and Figure 3 (b) is constituted by a lever member 41 fixed to the lower portion 5b of the valve shaft 5. The lever member 41, which is formed in a block shape in a substantially H shape as seen from the back, has a first recessed portion 41a recessed downward at the left and right direction central portion of the upper side end face facing the bonnet 10, a pair of first shoulder portions 41c formed at the left and right sides of the first recessed portion 41a, a second recessed portion 41b recessed upward at the left and right direction central portion of the lower side end face, and a pair of second shoulder portions 41d formed at the left and right sides sandwiching the second recessed portion 41b, which are side walls forming the first recessed portion 41a and the second recessed portion 41b.

[0061] The lever member 41 is fixed to the valve shaft 5, which penetrates between the first recessed portion 41a and the second recessed portion 41b in the up and down direction, and further, in the first recessed portion 41a, a lower end of a bellows (not shown) having an upper end connected to the bonnet 10 is connected. On the other hand, in the second recessed portion 41b, an upper end of a compression spring 6' having a lower end fixed to the spring seat 31a of the lever arm 31 is fixed.

[0062] Thus, by linking between the lever arm 31 of the first block 30 and the lever member 41 of the second block 40 by the compression spring 6', the second block 40 is allowed to move relatively to the first block 30 in the extension and contraction direction of the compression spring 6', that is, in the up and down direction parallel to the face of the valve seat 8 as the axis L1 direction of the valve shaft 5, and in the direction orthogonal thereto, that is, in the front and back direction orthogonal to the face of the valve seat 8.

[0063] A stop mechanism 70 is provided at the upper portion of the lever member 41. The stop mechanism 70 has stop rollers 71 respectively provided on the faces of the pair of first shoulder portions 41c of the lever member 41 facing the bonnet 10, and stop portions 72 respectively provided at positions of the lower face 10b of the bonnet 10 facing the stop rollers 71. The stop rollers 71 are supported so as to be rotatable about a central axis extending in the direction (left and right direction) orthogonal to the face of the valve seat 8 at the first shoulder portions 41c. Further, the stop portions 72 abut the stop rollers 71, and while preventing the lever member 41 from further moving in the axis L1 direction toward the front end direction (upper direction) of the valve shaft 5, allow the stop rollers 71 to roll in the front and back direction orthogonal to the face of the valve seat 8, and allow the lever member 41 to move in the front and back direction.

[0064] (Cam frame)

[0065] The cam frame 32, as shown in Figure 1 , Figure 3 , Figure 5 (a), Figure 5 (b), Figure 5 (c),Figure 5 (d) As shown, the cam frame 32 is formed in a rectangular parallelepiped shape extending in the up-down direction, and a plurality of grooves recessed concavely are formed on the outer side surface 32a on the side facing the roller frame 26 and the inner side surface 32b on the side opposite to the outer side surface 32a. In the present embodiment, a guide groove 33 is formed on the rear side of the outer side surface 32a of the cam frame 32, and the guide groove 33 extends continuously in the up-down direction between the both end portions of the outer side surface 32a, having a prescribed width in the front-rear direction. Further, a first cam groove 34a and a second cam groove 34b are formed on the upper and lower portions of the front side of the inner side surface 32b of the cam frame 32, penetrating in the left-right direction. Furthermore, the first cam groove 34a and the second cam groove 34b need not necessarily penetrate the cam frame 32 as in the present embodiment, but can be bottomed grooves blocked on the second block 40 side.

[0066] The bottom surface of the guide groove 33 has a flat bottom wall 33c, and on the upper side of the guide groove 33, a wide portion 33a is formed, which is formed wide in the front-rear direction and extends linearly in the up-down direction, and on the lower side of the guide groove 33, a narrow portion 33b is formed compared to the wide portion 33a, which is connected to the lower end of the wide portion 33a and extends linearly downward. The wide portion 33a and the narrow portion 33b are coaxially connected. Further, the guide groove 33 extends in parallel with respect to the axis L2 (refer to FIG. 2) of the drive rod 21, and the upper end portion of the wide portion 33a is open toward the valve bonnet 10. Figure 2 (a)) The wide portion 33a and the narrow portion 33b are coaxially connected. Further, the guide groove 33 extends in parallel with respect to the axis L2 (refer to FIG. 2) of the drive rod 21, and the upper end portion of the wide portion 33a is open toward the valve bonnet 10.

[0067] In the roller frame 26, at the positions corresponding to the guide groove 33, as shown in Figure 4 (a) and Figure 5 (b), the first guide roller 27a and the second guide roller 27b for freely fitting with respect to the guide groove 33 are provided. The first guide roller 27a is provided on the upper rear side of the roller frame 26, and the second guide roller 27b is provided on the lower rear side of the roller frame 26. Further, the first guide roller 27a is fitted with the wide portion 33a, and the second guide roller 27b, which is smaller in diameter than the first guide roller 27a, is fitted with the narrow portion 33b, thereby guiding the cam frame 32 in parallel with respect to the face of the valve seat 8. Furthermore, in order to suppress the shake at the time of guiding, it is desirable that the diameter of the first guide roller 27a and the groove width of the wide portion 33a are formed substantially equal, and the diameter of the second guide roller 27b and the groove width of the narrow portion 33b are formed substantially equal.

[0068] These guide groove 33, first guide roller 27a, and second guide roller 27b constitute the valve moving mechanism 29 for moving the valve plate 4 in Figure 1 and Figure 6 the full open position PI and Figure 7The parallel movement mechanism shown in the intermediate position P2 moves in the up-and-down direction. The first block 30 and the second block 40 do not move relative to each other by this parallel movement mechanism, but move integrally in the direction of the axis Ll of the valve shaft 5, whereby the valve plate 4 is moved in parallel with respect to the face of the valve seat 8, and the seal member 9 mounted on the sealing face 4a thereof does not come into contact with the inner face of the valve case 3.

[0069] On the other hand, the first cam groove 34a and the second cam groove 34b, as shown in Figure 3 and Figure 5 (d), are structures for fitting the first cam roller 42a and the second cam roller 42b provided on the second block 40 (the lever member 41) respectively. On the pair of cam frames 32 provided on the left and right sides, the first cam groove 34a is provided on the front upper side of the cam frame 32, and the second cam groove 34b is provided on the front lower side of the cam frame 32, but on the left and right side faces of the second block 40, the first cam roller 42a and the second cam roller 42b are respectively mounted on positions corresponding to these first cam groove 34a and second cam groove 34b. These first cam groove 34a and second cam groove 34b, together with the first cam roller 42a and the second cam roller 42b, constitute the valve movement mechanism 29 in which the valve plate 4 is moved in the direction orthogonal to the face of the valve seat 8. Figure 7 The vertical movement mechanism shown in the intermediate position P2 and Figure 8 the closed position P3.

[0070] By moving the valve plate 4 in the direction orthogonal to the face of the valve seat 8 by this vertical movement mechanism, the seal member 9 is pushed against the valve seat 8, the gate opening 2 is hermetically closed, and the valve plate 4 is returned to the intermediate position P2 with the seal member 9 spaced from the valve seat 8. In addition, according to the vertical movement mechanism, not only can the seal member 9 and the valve seat 8 be brought into contact with a uniform contact pressure, but also generation of dust due to sliding of the seal member 9 on the face of the valve seat 8, generation of seal failure due to deterioration or twisting of the seal member 9, and the like can be prevented.

[0071] On the cam frame 32, a fitting hole portion 32c for engaging the lock piston 51 of the lock mechanism 50 (see Figure 10 ) described later, which enters the cam frame 32 side in a state in which the valve plate 4 is moved to the closed position P3, is provided. In the present embodiment, as shown in Figure 1 , Figure 5 (b), Figure 10 the fitting hole portion 32c is provided on the front lower side of the outer side face 32a of the cam frame 32.

[0072] Hereinafter, the valve movement mechanism 29 will be described more specifically.

[0073] The first cam groove 34a, as shown in Figure 1 andFigure 5 (d) shown, is formed to be inclined in a direction that gradually approaches the face side (front side) of the valve seat 8 as it goes from the upper side toward the lower side, and the end portion of the upper side is open toward the bonnet 10.

[0074] Also, when the valve plate 4 is in the fully open position P1 (refer to Figure 1 and Figure 6 ) and the intermediate position P2 (refer to Figure 7 ), the first cam roller 42a is disposed at a first position C1 of the area on the upper side of the first cam groove 34a. In addition, when the valve plate 4 is in the closed position P3 (refer to Figure 8 ), the first cam roller 42a is disposed at a second position C2 of the area on the lower side of the first cam groove 34a.

[0075] On the other hand, the second cam groove 34b has an area on the lever arm 31 side that is inclined in a direction that gradually approaches the face side (front side) of the valve seat 8 as it goes from the bonnet 10 side (upper side) toward the lever arm 31 side (lower side), and an area that extends in parallel with the face of the valve seat 8 or in a direction away from the valve seat 8 as it goes from the bonnet 10 side (upper side) toward the lever arm 31 side (lower side). The second cam groove 34b links these two areas to each other.

[0076] This second cam groove 34b, like the first cam groove 34a, has a first position C1 and a second position C2, and the second cam roller 42b is disposed at these first position C1 and second position C2 at the same timing that the first cam roller 42a is engaged with the first cam groove 34a.

[0077] Incidentally, in such a gate valve 1, as shown in Figure 8 and Figure 9 , the position of the valve plate 4 in the closed position P3 is maintained, and generally, this is done by maintaining the pressure of the first pressure chamber 24a inside the cylinder 20 constant. Therefore, in the case where the pressure of the first pressure chamber 24a inside the cylinder 20 is lost for some reason when the valve plate 4 is in the closed position P3, there is a danger that the proper closed state of the gate opening 2 can no longer be maintained. Therefore, in the gate valve 1 of the present application, a locking mechanism 50 for locking the valve plate 4 in the closed position P3 is provided.

[0078] (Locking mechanism)

[0079] The locking mechanism 50, as shown in Figure 4 (a), Figure 9 , Figure 10 , is provided on the cylinder outer shell 22 (roller frame 26) of the cylinder 20. The locking mechanism 50 has a locking piston 51 that is provided on the roller frame 26 so as to be able to advance and retreat relative to the cam frame 32, facing the cam frame 32 (first block 30). The locking piston 51 is housed inside a housing 52 provided on the roller frame 26.

[0080] In this embodiment, the housing 52 is detachably mounted on the cutout 22a of the lower front edge of the roller frame 26 via bolts or other fastening connections. The facing surface 52a of the housing 52 facing the cam frame 32 is disposed on the same surface as the facing surface 26a of the roller frame 26.

[0081] Containment Entity 52, such as Figure 10 As shown, a bottomed cylindrical receiving hole portion 53 is provided, which opens in the opposing surface 52a and extends toward the inner side of the cylinder housing 22. The locking piston 51 is received within the receiving hole portion 53. The receiving hole portion 53 extends from the opposing surface 52a toward the axis L2 relative to the cylinder 20 (see reference). Figure 2 (a) A large-diameter bore 53a and a small-diameter bore 53b, which are smaller in diameter than the large-diameter bore 53a, are continuously formed in an orthogonal direction (left-side direction). The large-diameter bore 53a and the small-diameter bore 53b are formed coaxially, and a movement limiting member for restricting the movement of the locking piston 51 in the forward / reverse direction (front end side) is fitted into the large-diameter bore 53a. A through hole 55a is provided at the radial center of the movement limiting member 55, extending along the forward / reverse direction of the locking piston 51. The shaft portion 51a on the front end side of the locking piston 51 is movably inserted into this through hole 55a.

[0082] On the bottom surface of the receiving hole portion 53, an annular stop surface 53c protruding radially inward is formed. The end of the locking piston 51 on the retraction side (base end side) in the retraction direction abuts against this stop surface 53c, restricting the movement of the locking piston 51 on the retraction side in the retraction direction. At the center of the stop surface 53c, a guide hole portion 56 extending to the left is formed. The guide hole portion 56 is formed as a bottomed cylindrical shape and extends coaxially with the receiving hole portion 53. The inner diameter of the guide hole portion 56 is smaller than the inner diameter of the small-diameter hole portion 53b. A test object 61 connected to the locking piston 51 is inserted into the guide hole portion 56, allowing for retraction. Details of the test object 61 will be described later.

[0083] Locking piston 51, such as Figure 10 As shown, a cylindrical shaft portion 51a is formed along axis L3 at the front end, and a cylindrical piston body portion 51b with a larger diameter than the shaft portion 51a is formed at the base end. The front end of the piston body portion 51b is connected to the base end of the shaft portion 51a, and the shaft portion 51a and the piston body portion 51b are formed coaxially.

[0084] The shaft portion 51a has a length such that, if the front end side end portion of the piston body portion 51b contacts the base end side end portion of the movement restriction member 55, the front end of the shaft portion 51a protrudes from the facing surface 52a of the housing body 52, and if the base end side end portion of the piston body portion 51b contacts the stop surface 53c of the housing hole portion 53, the front end of the shaft portion 51a is located on substantially the same plane as the facing surface 52a of the housing body 52. That is, the lock piston 51 is movable between a lock position Pr (refer to Figure 11 (b)) and a non-lock position Ph (refer to Figure 11 (a)), in the lock position Pr, the piston body portion 51b contacts the movement restriction member 55, and the front end of the shaft portion 51a protrudes toward the cam frame 32 side, in the non-lock position Ph, the piston body portion 51b contacts the bottom surface of the housing hole portion 53, and the front end of the shaft portion 51a is located on substantially the same plane as the facing surface 52a of the housing body 52.

[0085] As shown in Figure 10 , in the radial direction central portion of the end surface of the base end side of the piston body portion 51b, a bottomed cylindrical spring recessed portion 57 toward the front end side is formed. Inside this spring recessed portion 57, a load spring 58 for loading the lock piston 51 toward the front end side along the axis L3 is housed. In the present embodiment, the load spring 58 is, for example, a compression coil spring, and is housed in the spring recessed portion 57 in a state in which the front end portion of the load spring 58 contacts the bottom surface of the spring recessed portion 57, and the base end portion of the load spring 58 contacts the bottom surface of the housing hole portion 53. The load spring 58 is formed so as to load the lock piston 51 toward the cam frame 32 side even in a state in which the lock piston 51 is moved to the lock position Pr (refer to Figure 11 (b)).

[0086] The piston body portion 51b has an outer diameter that is formed larger on the base end side than on the front end side, and on the outer periphery of the portion where the outer diameter is formed larger, a recessed portion recessed toward the radial direction inner side is formed in a ring shape, and an O-ring 54a is fitted in this recessed portion. The O-ring 54a thus freely and airtightly supports the piston body portion 51b so as to be slidable in the axis L3 direction with respect to the housing hole portion 53. On the advance direction entry side of the lock piston 51, a lock release pressure chamber 59 for retraction of the lock piston 51 is formed. That is, the lock release pressure chamber 59 is formed between the advance direction entry side of the lock piston 51 and the housing hole portion 53. This lock release pressure chamber 59 communicates with a lock gas flow path 80 (refer to Figure 13 ), and the lock gas flow path 80 is connected to the first port 25a that supplies compressed air to the second pressure chamber 24b of the cylinder 20. The operation of the lock mechanism 50 will be described later.

[0087] Even in the case where such a lock mechanism 50 is provided on the gate valve 1, in the case where the load spring 58 fails, there is a risk that the lock piston 51 can no longer be brought into engagement with the engagement hole portion 32c. Therefore, the valve plate 4 becomes movable, and there is a risk that the cavity can no longer be hermetically closed by the gate opening 2. In this case, since the load spring 58 is provided in the housing 52, it is difficult to determine whether the lock mechanism 50 is in the engaged state with respect to the engagement hole portion 32c. Therefore, on the gate valve 1 of the present embodiment, a lock detection portion 60 is provided which can confirm whether the lock mechanism 50 is in the engaged state with respect to the engagement hole portion 32c.

[0088] (lock detection portion)

[0089] The lock detection portion 60, as shown in (a) and (b), has a detected body 61 and a detection body portion 63, the detected body 61 being provided at the base end side end portion of the lock piston 51 and extending into the guide hole portion 56, and the detection body portion 63 being able to detect the detected body 61 when the lock piston 51 is in the engaged state with the engagement hole portion 32c. The detected body 61 is made of a metal material of a magnetic body and is formed in a cylindrical shape. Figure 11 Figure 11 (b), has a detected body 61 and a detection body portion 63, the detected body 61 being provided at the base end side end portion of the lock piston 51 and extending into the guide hole portion 56, and the detection body portion 63 being able to detect the detected body 61 when the lock piston 51 is in the engaged state with the engagement hole portion 32c. The detected body 61 is made of a metal material of a magnetic body and is formed in a cylindrical shape.

[0090] Thus, the detection body portion 63 detects the detected body 61 which is linked to the lock piston 51 when the lock piston 51 is in the engaged state with the engagement hole portion 32c, and therefore, the detection body portion 63 does not need to directly detect the lock piston 51. Therefore, the degree of freedom of arrangement of the detection body portion 63 with respect to the lock piston 51 can be improved.

[0091] In the present embodiment, the detected body 61 extends coaxially with the lock piston 51 and has a threaded coupling portion 61a, a linking portion 61b, a small diameter portion 61c, and a large diameter portion 61d from the front end side linked to the lock piston 51 toward the base end side. The threaded coupling portion 61a is formed in a cylindrical shape, and an external thread portion is provided on the outer peripheral surface of the threaded coupling portion 61a. The threaded coupling portion 61a is threadedly coupled to an internal thread portion provided on the bottom surface of the spring recess portion 57 of the lock piston 51. The linking portion 61b is linked to the base end portion of the threaded coupling portion 61a and is formed in a cylindrical shape of a large diameter compared to the threaded coupling portion 61a. The linking portion 61b has an outer diameter smaller than the inner diameter of the spring recess portion 57 and larger than the inner diameter of the internal thread portion.

[0092] ​Therefore, when the threaded engagement portion 61a is threaded into the internal thread of the locking piston 51, if the front end of the connecting portion 61b contacts the bottom surface of the spring recess 57, the object to be tested 61 can be positioned relative to the locking piston 51 in the axial direction of the locking piston 51. Furthermore, a space portion 62 for accommodating the loading spring 58 is formed between the outer surface of the connecting portion 61b and the inner surface of the spring recess 57, and the loading spring 58 is housed within this space portion 62. Moreover, the outer diameter of the connecting portion 61b is smaller than the inner diameter of the loading spring 58. Therefore, the connecting portion 61b can be inserted into the inner side of the loading spring 58 along the axis L3.

[0093] The small-diameter portion 61c extends from the end of the connecting portion 61b at the base end into the guide hole portion 56, and has an outer diameter smaller than the inner diameter of the guide hole portion 56. Therefore, there is no risk that the small-diameter portion 61c will come into contact with the inner surface of the guide hole portion 56 during the forward and backward movement of the locking piston 51.

[0094] The large-diameter portion 61d is connected to the base end of the small-diameter portion 61c. It has a larger diameter than the small-diameter portion 61c and an outer diameter slightly smaller than the inner diameter of the guide hole portion 56. Therefore, the large-diameter portion 61d can move within the guide hole portion 56 in conjunction with the forward and backward movement of the locking piston 51. The large-diameter portion 61d is detected by the detection body portion 63 when the locking piston 51 moves into the engagement hole portion 32c. Furthermore, the object being detected 61 is formed in a cylindrical shape, but is not limited to this; the small-diameter portion 61c and the large-diameter portion 61d may also be rectangular in cross-section and cuboid in the direction of the axis L3.

[0095] (Main testing unit)

[0096] In this embodiment, such as Figure 11 (a) and Figure 11 As shown in (b), the detection body 63 is, for example, an inductive proximity sensor 63', but it can also be a proximity sensor that can detect the large-diameter portion 61d of the object being detected 61 by other detection methods (e.g., capacitive proximity sensors, magnetic proximity sensors). The proximity sensor 63' is cylindrical in shape and is positioned orthogonal to the object being detected 61. The proximity sensor 63' is mounted in a mounting hole 52b formed on the housing 52.

[0097] The mounting hole portion 52b extends in a direction orthogonal to the guide hole portion 56 into which the detected object 61 is inserted. The mounting hole portion 52b is open on one end side in the length direction thereof, and extends to a position beyond the guide hole portion 56 on the other end side in the length direction thereof. The inner diameter of the mounting hole portion 52b is slightly larger than the outer diameter of the proximity sensor 63'. In addition, the length direction length of the mounting hole portion 52b is shorter than the length direction length of the proximity sensor 63'. Therefore, if the proximity sensor 63' is inserted from the opening of the mounting hole portion 52b, the proximity sensor 63' can be mounted in the mounting hole portion 52b from the opening thereof in a state in which the proximity sensor 63' protrudes from the opening on the base end side thereof.

[0098] In addition, in a state in which the proximity sensor 63' is inserted into the mounting hole portion 52b, a space portion is formed around the front end side of the proximity sensor 63'. Therefore, without the front end side of the proximity sensor 63' being covered by the housing 52, it is possible to prevent the range of the magnetic field generated from the front end of the proximity sensor 63' from becoming narrow. Therefore, it is possible to increase the sensitivity of the proximity sensor 63'.

[0099] In addition, in the middle portion in the length direction of the mounting hole portion 52b, a threaded hole portion 52c for a stop screw that extends in a direction orthogonal to the mounting hole portion 52b is provided. Therefore, in a state in which the proximity sensor 63' is inserted into the mounting hole portion 52b, by threadably coupling a stop screw to the threaded hole portion 52c, which is not shown, it is possible to fix the proximity sensor 63' in the mounting hole portion 52b.

[0100] The proximity sensor 63' of the present embodiment is configured to output a detection signal that detects the large diameter portion 61d if the large diameter portion 61d approaches a position having a slight gap with respect to the other end (front end) in the length direction thereof, and not to output the above detection signal if the small diameter portion 61c approaches the front end of the proximity sensor 63'. Therefore, since the large diameter portion 61d moves in close proximity to the front end of the proximity sensor 63' while the lock piston 51 moves into the engagement hole portion 32c, the proximity sensor 63' outputs the detection signal, so it is possible to confirm that the lock piston 51 is in the engaged state with respect to the engagement hole portion 32c. In addition, in a case in which the detection signal is not output from the proximity sensor 63', it is possible to confirm that the lock piston 51 is not in the engaged state with respect to the engagement hole portion 32c.

[0101] Thus, since the detected object 61 has the small diameter portion 61c and the large diameter portion 61d, the proximity sensor 63' detects the large diameter portion 61d when the lock piston 51 is in the engaged state with respect to the engagement hole portion 32c, and does not detect the large diameter portion 61d when the lock piston 51 is not in the engaged state with respect to the engagement hole portion 32c, so it is possible to detect whether or not the lock piston 51 is in the engaged state with respect to the engagement hole portion 32c with a simple structure.

[0102] In addition, since the detection main body 63 detects the detected body 61 provided on the lock piston 51 when the lock piston 51 is in the state of engaging with the engagement hole portion 32c, the detection main body 63 does not need to directly detect the lock piston 51. Therefore, the degree of freedom of arrangement of the detection main body 63 with respect to the lock piston 51 can be improved.

[0103] Further, if the gap between the proximity sensor 63' and the large diameter portion 61d becomes larger than a prescribed value, there is a risk that the detection signal is not output. Therefore, it is necessary to make the gap between the front end of the proximity sensor 63' and the large diameter portion 61d a prescribed value. Therefore, as shown in FIG. 6, the lock piston 51 is removed from the housing hole portion 53, the load spring 58 is removed, and the position adjustment pin 66 is inserted into the guide hole portion 56. The diameter of the position adjustment pin 66 is made to be a value twice the radius calculated by adding the gap to the radius of the large diameter portion 61d of the detected body 61. Figure 12 The proximity sensor 63' is inserted into the mounting hole portion 52b so that the front end of the proximity sensor 63' protrudes against the side surface of the position adjustment pin 66. The position of the proximity sensor 63' with respect to the axial direction of the mounting hole portion 52b is adjusted. The proximity sensor 63' is fixed to the mounting hole portion 52b by a stop screw not shown in the drawing while the proximity sensor 63' is protruding against the position adjustment pin 66. The proximity sensor 63' is fixed to the prescribed position in the mounting hole portion 52b.

[0104] Further, by inserting the position adjustment pin 66 into the guide hole portion 56, inserting the proximity sensor 63' into the mounting hole portion 52b, and making the front end of the proximity sensor 63' protrude against the side surface of the position adjustment pin 66, the position of the proximity sensor 63' with respect to the axial direction of the mounting hole portion 52b can be adjusted. Further, by keeping the state in which the proximity sensor 63' is protruding against the position adjustment pin 66, and fixing the proximity sensor 63' to the mounting hole portion 52b by a stop screw not shown in the drawing, the proximity sensor 63' can be fixed to the prescribed position in the mounting hole portion 52b.

[0105] In addition, since the lock piston 51, the detected body 61, and the proximity sensor 63' are provided inside the housing 52 which is detachable with respect to the cylinder housing 22, in the case of adjusting the position of the proximity sensor 63', the housing 52 can be detached from the cylinder housing 22 and adjusted. In addition, in the case of failure of the load spring 58, the proximity sensor 63', and the like, the failed load spring 58, proximity sensor 63', and the like can be replaced by being detached from the housing 52. Therefore, the increase in cost can be suppressed.

[0106] ​Furthermore, as described above, the proximity sensor 63' is an inductive type. In this case, the housing 52 can be formed of a non-magnetic material, and the detected object 61 can be formed of a conductive magnetic material. By forming the housing 52 with a non-magnetic material, the danger of the magnetic field generated from the proximity sensor 63' passing through the housing 52 can be prevented, and the reduction in the strength of the magnetic field passing through the detected object 61 can be suppressed. In addition, by forming the detected object 61 with a conductive magnetic material, the magnitude of the eddy current generated in the large diameter portion 61d of the detected object 61 can be increased. As a result, the heat generated from the eddy current increases, which can improve the sensitivity of the inductive proximity sensor 63'.

[0107] Next, the flow path of compressed air when the valve plate 4 moves from the closed position P3 to the fully open position P1 and the flow path of compressed air when the valve plate 4 moves from the fully open position P1 to the closed position P3 will be briefly described.

[0108] As mentioned above, the first port 25a, such as Figure 13 As shown, a port for supplying and discharging compressed air relative to the head side of the cylinder 20 is connected to an annular flow path 81 defined by the groove on the outer periphery of the annular member 24d and the inner circumferential surface of the cylinder housing 22. Furthermore, the annular flow path 81 is connected to the second pressure chamber 24b via a supply and discharge airflow path 82 formed within the cylinder housing 22.

[0109] Furthermore, the annular flow path 81, and the pressure chamber 59 for releasing the lock-up relative to the compressed air (see reference) Figure 11 (a) The supply and discharge gas flow path 80 formed in the cylinder housing 22 is connected to the supply and discharge gas flow path 82. In addition, the supply and discharge gas flow path 82 extends further in the valve cap 10 and is connected to the supply and discharge gas flow path 82 formed in the cylinder housing 22 of the other cylinders 20.

[0110] On the other hand, the second port 25b, such as Figure 14 As shown, the port for supplying and discharging compressed air relative to the lever side of cylinder 20 is connected to an annular flow path 83 defined by the groove on the outer periphery of the annular member 24d and the inner circumferential surface of the cylinder housing 22. Furthermore, the annular flow path 83 is connected to the first pressure chamber 24a via a supply and discharge airflow path 84 formed within each cylinder housing 22, 22. Additionally, the locking release pressure chamber 59 of the locking mechanism 50 and the pressure chamber on the opposite side are open to the atmosphere via a connection path not shown.

[0111] Therefore, if compressed air is supplied to the first port 25a, then as Figure 13 As shown, the locking piston 51 moves in the retraction direction, releasing the locking of the valve plate 4, and the cylinder 20 extends. On the other hand, if compressed air is supplied to the second port 25b, then...Figure 14 As shown, the lock piston 51 is no longer supplied with compressed air to the lock release pressure chamber 59, and becomes a state in which the lock piston 51 is in contact with the inner side surface 32b of the cam frame 32 by the load spring 58. Therefore, the cylinder 20 performs a contraction movement.

[0112] Next, the basic operation of the gate valve 1 will be described in detail.

[0113] First, as shown in Figure 13 (a), by supplying compressed air from the first port 25a of the cylinder 20 to the second pressure chamber 24b, and discharging compressed air of the first pressure chamber 24a from the second port 25b, the drive piston 23 moves to the side (lower side) of the drive rod 21 (refer to Figure 2 (a)), and the drive rod 21 performs an extension movement. If the drive piston 23 is in abutment with the annular member 24d, as shown in Figure 1 and Figure 2 (a), the first block 30 (the lever arm 31 and the cam frame 32) and the second block 40 (the lever member 41) move to the lower position which is the maximum interval from the valve housing 3 and the valve bonnet 10. Along with this, the valve plate 4 moves from the gate opening 2 to the fully retracted open position PI in the direction of the axis LI of the valve shaft 5, and a passage is formed between the gate opening 2 and the back side opening 2a (refer to Figure 6 ). As a result, the work can be passed in and out of the cavity through this passage.

[0114] At this time, as shown in Figure 5 (b) and Figure 5 (d), in the guide groove 33 of the cam frame 32, only the second guide roller 27b shown by the arrow A is fitted, and the other first guide roller 27a is not yet fitted. In addition, in the first cam groove 34a and the second cam groove 34b, the first cam roller 42a and the second cam roller 42b move to the respective first positions CI.

[0115] Next, as shown in Figure 14 (a), by supplying compressed air from the second port 25b of the cylinder 20 to the first pressure chamber 24a, and discharging compressed air of the second pressure chamber 24b from the first port 25a, the drive piston 23 moves to the head direction (upper side), and the drive rod 21 performs a contraction movement into the cylinder housing 22 along the axis L2 thereof. At the same time, the lever arm 31, the cam frame 32, and the lever member 41 do not move in conjunction with the relative movement by the deformation (expansion, flexing, etc.) of the compression spring 6', but move integrally in the same direction as the moving direction of the drive rod 21 (the upper side direction of the axis LI of the valve shaft 5).

[0116] Along with this, the valve plate 4 moves from the fully retracted open position PI to the fully closed position P2 in the direction of the axis LI of the valve shaft 5, and the passage between the gate opening 2 and the back side opening 2a is closed. As a result, the work is prevented from passing in and out of the cavity through this passage. Figure 7 and Figure 14As shown, the valve plate 4 moves toward the gate opening 2 side along the axis L1 of the valve shaft 5. During this period, the valve plate 4 moves in parallel with respect to the face of the valve seat 8. Moreover, if the stop roller 71 of the lever member 41 abuts against the stop portion 72 of the lower face 10b of the valve cap 10, the movement of the lever member 41 in the axis L1 direction stops, the valve plate 4 moves to an intermediate position P2 at which the valve plate 4 is spaced from the gate opening 2 (i.e., the sealing member 9 is spaced from the valve seat 8), and the parallel movement of the valve plate 4 with respect to the face of the valve seat 8 stops.

[0117] Further, at this time, as shown in Figure 5 (b), both the first guide roller 27a and the second guide roller 27b shown by the arrow B are fitted in the guide groove 33 of the cam frame 32. In addition, the first cam roller 42a and the second cam roller 42b are disposed at the first position C1 of the first cam groove 34a and the second cam groove 34b, respectively.

[0118] Further, as shown in Figure 14 if the drive piston 23 is moved in the head direction (upward) by further supplying compressed air to the first pressure chamber 24a of the cylinder 20, the drive rod 21 (see Figure 2 (b)) is further moved in the contracting direction, the first block 30 composed of the lever arm 31 and the cam frame 32 moves in the axis L1 direction (upward) while compressing the compression spring 6', because the second block 40 composed of the lever member 41 is restricted in the movement in the axis L1 direction (upward) by the stop mechanism 70 (the stop roller 71 and the stop portion 72). Along with this, the lever member 41 is moved in a direction orthogonal to the axis L1 toward the valve seat 8 side by the vertical movement mechanism.

[0119] As a result, the valve plate 4 moves from the intermediate position P2 to the closed position P3 as shown in Figure 8 . Further, in the usual vacuum processing in the cavity, this position is used as the closed position.

[0120] Further, as shown in Figure 5 (b) and Figure 5 (d), when the valve plate 4 is in this closed position P3, both the first guide roller 27a and the second guide roller 27b are fitted in the guide groove 33 of the cam frame 32. In addition, the first cam roller 42a and the second cam roller 42b are disposed at the second position C2, respectively.

[0121] Next, the operation of the lock mechanism 50 and the lock detection portion 60 will be described in detail. If the valve plate 4 moves to the closed position P3, as shown in Figure 10As shown, the locking piston 51 of the locking mechanism 50 and the engaging hole portion 32c provided on the cam frame 32 are moved to the facing position, and the locking piston 51 is engaged with the engaging hole portion 32c by the load spring 58. Thus, the valve plate 4 can be locked in the closed position P3.

[0122] In this state where the valve plate 4 is locked by the locking mechanism 50, as shown in Figure 11 (b), the large diameter portion 61d of the detected body 61 of the locking detection portion 60 is moved to the position where the length direction front end of the proximity sensor 63' is approached. Thus, the proximity sensor 63' has outputted the detection signal of the large diameter portion 61d. Thus, it can be confirmed from the detection signal that the locking piston 51 is in the engaged state with respect to the engaging hole portion 32c.

[0123] In this state where the valve plate 4 is locked by the locking mechanism 50, as shown in Figure 11 (a), in the case where the load spring 58 is broken, the locking piston 51 can no longer enter to the engaging hole portion 32c side. Thus, the valve plate 4 becomes in the state where it is not locked in the closed position P3. However, in the state where the locking piston 51 does not enter to the engaging hole portion 32c side, since the small diameter portion 61c of the detected body 61 approaches the length direction front end of the proximity sensor 63', the proximity sensor 63' does not output the detection signal. Thus, it can be confirmed that the locking piston 51 is not in the engaged state with respect to the engaging hole portion 32c.

[0124] Thus, it can provide the gate valve 1 where it can be confirmed whether the locking piston 51 of the locking mechanism 50 is in the engaged state with respect to the engaging hole portion 32c.

[0125] The embodiment of the gate valve 1 of the present application has been described in detail above, but the present application is not limited to the above-described embodiment, and various design changes can of course be made within the scope of the gist of the present application.

[0126] For example, in the above-described embodiment, the case where the valve moving mechanism 29 makes the valve plate 4 reciprocate through the intermediate position P2 between the closed position P3 and the fully open position PI has been described, but the valve moving mechanism can also make the valve plate 4 reciprocate between the closed position P3 and the fully open position PI without providing the intermediate position P2. In this case, the link member 6 is removed, the lower end portion of the valve shaft 5 is connected to the lever arm 31, the upper end of the cam frame 32 is connected to the lower surface 10b of the bonnet 10, and the lower end of the cam frame 32 is removed from the lever arm 31. In addition, the first cam groove 34a and the second cam groove 34b of the cam frame 32 are formed so as to be inclined to the valve seat 8 side (front side) as going from the upper side to the lower side. Thus, if the drive rod 21 of the cylinder 20 is extended and contracted, the lever member 41 is moved in the up and down direction and in the front and back direction, and the valve plate 4 can be reciprocated between the fully open position PI and the closed position P3.

[0127] In addition, the lock mechanism 50 forms the length of the shaft portion 51a of the lock piston 51 to be long, and in the state where the valve plate 4 is moved to the closed position P3, a through-hole that penetrates in the left-right direction is provided on the cam frame 32 facing the front end of the shaft portion 51a, and a engagement hole portion 32c is provided on the side of the lever member 41 facing the through-hole. Therefore, the shaft portion 51a is able to advance and retreat with respect to the engagement hole portion 32c through the through-hole in the state where the valve plate 4 is moved to the closed position P3. Therefore, if the shaft portion 51a engages with the engagement hole portion 32c, the valve plate 4 can be locked.

[0128] In addition, in the above-described embodiment, the case where the proximity sensor 63' outputs a detection signal when the lock piston 51 is in the engaged state with respect to the engagement hole portion 32c and does not output a detection signal when it is not in the engaged state with respect to the engagement hole portion 32c is described, but is not limited thereto. For example, the proximity sensor 63' can not output a detection signal when the lock piston 51 is in the engaged state with respect to the engagement hole portion 32c and output a detection signal when it is in the engaged state with respect to the engagement hole portion 32c. In this case, the outer diameter of the large diameter portion 61d of the above-described detection body 61 is made equal to the outer diameter of the small diameter portion 61c, and the outer diameter of the small diameter portion 61c is made equal to the outer diameter of the large diameter portion 61d.

[0129] [Explanation of Symbols]

[0130] 1: gate valve

[0131] 2: gate opening

[0132] 3: valve housing

[0133] 4: valve plate

[0134] 5: valve shaft

[0135] 6: link member

[0136] 20: cylinder

[0137] 21: drive rod

[0138] 22: cylinder housing

[0139] 22a: cutout portion

[0140] 23: drive piston

[0141] 24a: first pressure chamber

[0142] 24b: second pressure chamber

[0143] 25a: first port (port)

[0144] 26: roller frame (facing wall)

[0145] 29: valve moving mechanism

[0146] 30: first block

[0147] 32c: engagement hole portion

[0148] 40: second block

[0149] 50: lock mechanism

[0150] 51: lock piston

[0151] 52: housing body

[0152] 53: housing hole portion

[0153] 58: load spring

[0154] 59: lock release pressure chamber

[0155] 60: lock detection portion

[0156] 61: detected body

[0157] 61c: small diameter portion

[0158] 61d: large diameter portion

[0159] 63: detection main body portion

[0160] 63': proximity sensor

[0161] 80: lock gas flow path

[0162] P1: fully open position

[0163] P2: intermediate position

[0164] P3: closed position

Claims

1. A gate valve, wherein a gate opening on a valve box is opened and closed by a valve plate disposed within the valve box, characterized in that, Equipped with the aforementioned valve plate, valve shaft, cylinder, and valve moving mechanism, One end of the valve shaft is mounted on the valve plate, and the other end extends from the valve housing and is supported so as to be movable relative to the valve housing. The cylinder is located on the outside of the valve box and has a drive rod. The valve moving mechanism, in accordance with the telescopic movement of the drive rod of the cylinder, moves the valve plate via the valve shaft, causing the valve plate to reciprocate between a sealed position that airtightly closes the gate opening and a fully open position that fully opens the gate opening. The valve moving mechanism described above has a first block, a second block, and a connecting component. The first piece is fixed to the aforementioned drive rod. The second piece is fixed to the valve shaft extending from the valve box. The connecting component connects the second block relative to the first block so that they can move relative to each other. The aforementioned cylinder has a cylinder housing that can retractably support the aforementioned drive rod. A locking mechanism and a locking detection unit are provided on the aforementioned cylinder outer shell. The locking mechanism is used to lock the valve plate when it has been moved to the aforementioned sealed position. The locking detection unit can detect whether the valve plate is locked by the locking mechanism. The aforementioned locking mechanism includes a locking piston, which is retractably disposed relative to the first block on the opposing wall of the cylinder housing opposite to the first block. An engaging hole is provided on the first block, which is used to engage the locking piston that enters towards the first block when the valve plate is moved to the sealed position. The aforementioned locking detection unit can detect whether the aforementioned locking piston is in an engaged state relative to the aforementioned engaging hole.

2. The gate valve according to claim 1, characterized in that, The aforementioned locking detection unit has a detected object and a detection main body. The object to be tested is located at the retraction-side end of the aforementioned locking piston, extending towards the retraction side. The detection body detects the object being tested when the locking piston is engaged with the engagement hole.

3. The gate valve according to claim 2, characterized in that, The aforementioned detection main body is a proximity sensor. The object being tested extends along the forward and backward direction of the locking piston, forming a small-diameter portion on the entry side in the forward and backward direction, and a large-diameter portion larger than the small-diameter portion on the retraction side in the forward and backward direction. When the locking piston is engaged with the engagement hole, the proximity sensor detects the large diameter portion of the object being detected.

4. The gate valve according to claim 3, characterized in that, The aforementioned locking piston, the aforementioned object being detected, and the aforementioned proximity sensor are disposed inside a housing, which is mounted on the aforementioned cylinder housing. The aforementioned housing can be detachably installed in the cutout formed on the aforementioned cylinder shell.

5. The gate valve according to claim 4, characterized in that, The aforementioned proximity sensor is an inductive type. The aforementioned containment body is formed of a non-magnetic material. The object being tested is formed of a magnetic material that has electrical conductivity.

6. The gate valve according to any one of claims 1 to 5, characterized in that, A drive piston, fixed to the drive rod, is provided inside the cylinder housing of the aforementioned cylinder. Compared to the drive piston inside the cylinder housing, a first pressure chamber is provided on the drive rod side to drive the valve plate from the fully open position to the closed position. Conversely, compared to the drive piston, a second pressure chamber is provided on the cylinder housing on the opposite side of the drive rod to drive the valve plate from the closed position to the fully open position. The locking piston of the aforementioned locking mechanism is housed within a receiving hole provided on the opposing wall of the aforementioned cylinder housing. On the retraction side of the aforementioned locking piston in the forward and backward direction, a loading spring is provided to cause the locking piston to move towards the first block side. On the inward / outward direction of the aforementioned locking piston, a locking release pressure chamber is formed for retracting the aforementioned locking piston. The aforementioned locking release pressure chamber is connected to a locking gas passage that connects to the port that supplies compressed air relative to the aforementioned second pressure chamber.

7. The gate valve according to any one of claims 1 to 6, characterized in that, The valve moving mechanism causes the valve plate to reciprocate between the closed position and the fully open position through an intermediate position opposite to the gate opening.

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