JP4954964B2 - Fluid valve drive mechanism - Google Patents

Description

  The present invention relates to a valve control drive mechanism, and more particularly to an emergency safety device in a flow control valve for fuel supply in a gas turbine facility.

  Gas turbine technology is adopted as a core technology in LNG combined power generation (combined cycle), which is being rapidly introduced due to highly efficient power generation characteristics. In recent years, global warming countermeasures have been recognized as an important issue internationally. High-efficiency power generation technology for thermal power generation with a large amount of carbon dioxide emissions has become increasingly recognized, and gas turbine temperature (combustion) Technological development for further improvement in efficiency due to a rise in temperature) has been promoted, and in recent years, large-scale and highly efficient power generation equipment having a gas turbine temperature of 1500 ° C. has come into operation. Therefore, improvement of control reliability for the fuel fluid valve that controls the fuel supply to the gas turbine and realization of a reliable fail-safe function in an emergency are increasingly important issues.

  An example of a conventional fluid valve drive mechanism for controlling the fuel supply to the gas turbine is shown in FIG. The apparatus has a valve box 508, a connecting frame 507, and a spring box 506 as fixed parts, and a hydraulic actuator 501 that is a drive unit is fixed to the upper part of the spring box 506. A valve body 509 in the valve box 508 is connected to a hydraulic actuator 501 via a valve rod 510, a connecting rod 503, and an output shaft 502, and drives the output shaft 502 up and down by the oil pressure of a hydraulic supply unit (not shown). The valve body 509 is moved up and down to adjust the opening of the valve. The spring box 506 has a coil spring 504 whose upper end is fixed to the upper part of the spring box, and a lower end which is a free end of the coil spring 504 is fixed to the spring seat 505, and the spring seat 505 is connected to the connecting rod 503. Yes. In an initial state where no oil pressure is applied, the coil spring 504 is compressed to a predetermined length so that the valve body 509 keeps the valve closed state pressed against the valve seat with a predetermined pressing force. It is configured. During normal operation, the opening / closing operation of the valve is performed by raising the spring seat 505 and compressing the coil spring 504 via the output shaft 502 and the connecting rod 503 by the driving force of the hydraulic actuator 501. When the hydraulic pressure is cut off due to a failure of the hydraulic device, the valve is forcedly returned to the closed state by the spring reaction force of the coil spring 504 and has an emergency shut-off mechanism that shuts off the valve regardless of the external driving force.

  Moreover, the following prior art is disclosed regarding the emergency shut-off mechanism in the fluid valve of the type which moves a valve body back and forth.

  Patent Document 1 is a steam valve operating device that is used particularly in a steam turbine to open and close a valve by moving a valve body back and forth, and enables emergency shutoff by releasing spring energy stored in a disc spring 21. A steam valve operating device is disclosed. The apparatus includes a pressure accumulating device 7 including a disc spring 21 and a collet chuck 19, and a ram 49 of the driving unit 5 that engages with the collet chuck 19. During normal use of the apparatus, the collet chuck 19 is magnetized and fixed to the ram 49 by electromagnetic force generated by energizing the electromagnetic coil 13 in the ram 49, and the disc spring 21 in the collet chuck 19 is maintained in a compressed state. Open and close the valve. In an emergency, the energization of the electromagnetic coil 13 in the ram 49 is stopped, the magnetism of the collet chuck 19 with the ram 49 is released, the pressure-accumulated disc spring 21 is released, and the valve body is moved via the valve stem 3. It has a mechanism that moves forward and shuts off the steam valve urgently. Further, in order to mitigate the impact energy applied to the valve element and the valve seat by the sudden advance of the valve spring at the time of emergency shut-off, the valve stem 3 is not mechanically fixed directly to the ram 49 of the drive unit 5, The valve rod 3 is connected to a movable actuator plate 67 arranged in a state in which the valve is movable in a sealed chamber filled with fluid. When the valve rod 3 is moved suddenly, it is divided into two by the movable actuator plate 67. An operation device for a steam valve capable of absorbing impact energy by the resistance of fluid movement between sealed chambers is disclosed.

  Patent Document 2 relates to a valve displacement device, which performs an open / close operation of a valve during normal operation by forward and backward movement of a valve rod 4 by rotation of driving devices 2 and 3 and emergency shutoff by releasing spring energy stored in a spring spring 14. Disclosed is a valve displacement device that enables it. In this device, a shaft having a screw structure connected to a drive device is screwed into the rear end of the extension link type cartridge 16, and a spring 14 whose rear end is fixed in the cartridge 16 is accommodated in the extension link type cartridge 16. The tip of the spring 14 is connected to a flange connected to a valve stem connected to the valve body 23. During normal use of the displacement device, the flange is retracted and the spring 14 is compressed, and toggle mechanisms 10 and 11 are interposed between the front end of the flange and the front end of the cartridge 16 and maintained in an extended state by the latch pin 18. The spring 14 is maintained in a compressed state by the toggle link. During normal operation, while the spring 14 is in a compressed state, the cartridges 16 are moved forward and backward by the rotation of the shafts 2 and 3 by the driving device, and the valves are opened and closed. In an emergency, the power to the solenoid coil 27 is cut off, the latch pin 18 is pulled back by the pull-back spring, the toggle links 10 and 11 are bent and the spring 14 is extended, and the valve element is moved to the valve cutoff position by the spring energy. The displacement device is described.

  Patent document 3 is disclosing the valve | bulb for steam turbines which can be act | operated quickly in the closing direction in the case of emergency interruption | blocking. In the valve, the drive mechanism 14 that operates the valve body 24 includes an electric motor 16, an electromagnetic coupling 18, a ball screw 20, and an accumulator 28. A bush 20 a constituting the ball screw 20 is connected to the electric motor 16 via the electromagnetic coupling 18, and a distal end portion of the rod 20 b constituting the ball screw 20 is connected to a base portion of the valve rod 22. An accumulator 28 composed of a spring is incorporated between the flange portion 26 at the tip of the rod 20b and the bush 20a. The valve is opened by driving the electric motor 16 and rotating the bush 20a via the electromagnetic coupling 18 to raise the rod 20c while accumulating the accumulator 28. In an emergency, the valve is opened and the pressure is accumulated by opening the electromagnetic coupling 18. Further, a steam turbine valve is disclosed in which the rod 20c is lowered while the bush 20a is rotated by the accumulator 28, and the valve is quickly shut off.

International Publication No. 02/035123 International Publication No. 2004/076899 JP 08-232607

  The present invention provides a fuel control valve for a gas turbine having a structure that is not easily affected by heat from a valve body that contacts a high-temperature fluid (fuel) flowing in the fuel control valve, and is a compact and simple structure, but in an emergency. The present invention relates to a fluid valve drive mechanism having a highly reliable fail-safe function capable of urgently shutting off a valve body with a strong pressing force.

  The present invention is a fluid valve drive mechanism for moving a valve body 12 of a fluid valve forward and backward with respect to a valve seat, the fluid valve drive mechanism having a drive means 1 and an emergency drive means, and the emergency drive means is , A spring unit (spring means) and an emergency release unit (spring holding means) 100, the spring unit comprising a spring 6, a sprung support part (upper spring box) 4, and an unsprung support part (lower spring box) 5. The unsprung support portion 4 and the unsprung support portion 5 are composed of a spring 6, which is connected to the driving means 1, and the unsprung support portion 5 is connected to the valve body 12. Connected, the emergency release unit 100 can fix the distance between the sprung support 4 and the unsprung support 5, and the driving means 1 raises and lowers the sprung support 4. A fluid valve drive mechanism, wherein the valve body 12 abuts against the valve seat, and the sprung support 4 and the spring The spring 6 is compressed to a predetermined length by reducing the distance between the sprung support portion 4 and the unsprung support portion 5 from an initial state in which the spring 6 is compressed by a predetermined length from the free length between the support portions 5. After the compression, the distance between the sprung support portion 4 and the unsprung support portion 5 is fixed by the emergency release unit, and the driving means 1 is driven, whereby the sprung support portion 4 and the unsprung support portion are driven. While holding the spring 6 in a compressed state between the parts 5, the valve body 12 is raised and lowered to control the opening and closing of the valve. In an emergency, the sprung support part 4 and the spring by the emergency release unit 100 The spacing between the lower support portions 5 is released, the spring 6 is extended from the compressed state, the valve body 12 is lowered via the unsprung support portion 5, and the valve body 12 is moved to the valve seat. By pressing, the fluid valve can be urgently driven to close. It is intended.

  In a further embodiment of the fluid valve drive mechanism of the present invention, the emergency release unit 100 includes an on-axis support part fixed to the sprung support part 4 and an under-axis support fixed to the unsprung support part 5. The emergency release unit shaft 104 extending through the portion, and the spring support capable of fixing the relative positions of the on-axis support portion, the under-axis support portion, and the emergency release unit shaft 104 to each other A part interval fixing means 101 is included.

  In a further embodiment of the fluid valve drive mechanism of the present invention, the emergency release unit shaft 104 is a shaft 104 having a screw structure, and one of the on-axis support portion and the under-axis support portion is a nut 111. The other of the on-axis support portion and the under-axis support portion is a support bearing 107, and the on-axis support portion and the shaft can be rotated while the shaft 104 is rotatable. The spring support portion interval fixing means 101 is fixed to the other of the lower support portions in the axial direction of the shaft 104, and the spring support portion interval fixing means 101 is capable of relative rotation between the shaft 104 and the nut 111. A rotation permission / inhibition control unit 101 that switches an impossible state, and a relative rotation between the shaft 104 and the nut 111 can change a distance between the sprung support portion 4 and the unsprung support portion 5. When the shaft 104 is rotatable, the sprung The shaft 104 and the nut 111 are relatively rotated by the pressing force by the driving device 1 or the spring reaction force of the spring 6 acting between the holding portion 4 and the unsprung support portion 5, and the spring The distance between the sprung support 4 and the unsprung support 5 is changed within the movable range of the upper support 4 and the unsprung support 5.

  In a further embodiment of the fluid valve drive mechanism of the present invention, the shaft 104 having the screw structure is a ball screw shaft 104, and the nut 111 is a ball screw nut 111.

  In a further embodiment of the fluid valve drive mechanism of the present invention, the rotation availability control unit 101 is an electromagnetic clutch 101.

  In a further embodiment of the fluid valve drive mechanism of the present invention, the emergency drive means further includes a linear motion guide means (linear guide) 200, and the linear motion guide means 200 moves forward and backward in the valve body 12. The sprung support part 4 and the unsprung support part 5 are guided so as to slide smoothly with respect to the direction.

  In a further embodiment of the fluid valve drive mechanism of the present invention, the emergency drive means further includes an impact buffering means 300 between the unsprung support portion 5 and the valve body 12, and the impact buffer means. 300, the rapid rise and fall of the valve body 12 is mitigated by the fluid resistance of the fluid 301 contained in 300.

  In a further embodiment of the fluid valve drive mechanism of the present invention, the main frame 3 having the drive means 1 fixed and having the emergency drive means therein, a valve box including a valve body 12 and the main frame 3 It has a heat insulating frame 8 having a hollow structure therebetween, and further has a heat insulating connecting portion 7 between the heat insulating frame 8 and the main frame 3.

  In a further embodiment of the fluid valve drive mechanism of the present invention, the drive means 1 is a direct drive means (hydraulic linear servo motor).

  In a further embodiment of the fluid valve drive mechanism of the present invention, the drive means 1 is a rotation drive means (electric actuator, electric servo motor) 24, and a drive shaft 2 that rotates by the drive force of the rotation drive means. Is connected to the sprung support portion 4 and includes a rotation / linear motion conversion mechanism (drive shaft lifting nut) 23, and the rotation / linear motion conversion mechanism 23 is rotated by the drive shaft 2. 4 is raised and lowered.

  In a further embodiment of the fluid valve drive mechanism of the present invention, the rotational drive means is an electric servo motor 24, and the fluid valve drive mechanism further comprises cumulative load evaluation means 400, and the cumulative load evaluation means. Reference numeral 400 includes a rotation detection means (encoder) 401 that detects the rotation of the electric servomotor 24 and a drive current sensor 404 that detects a current that drives the electric servomotor 24, and is detected from the drive current sensor 404. The product of the motor thrust and the rotation speed is calculated and accumulated, and an alarm is issued when the accumulated value is larger than a predetermined value.

  Hereinafter, a fluid valve drive mechanism according to the present invention will be described with reference to the accompanying drawings.

  1 and 2 are a schematic front view and a schematic side view of a fluid valve drive mechanism according to a first embodiment of the present invention. FIG. 3 is a schematic front sectional view of the fluid valve drive mechanism as viewed from a cross section AA in FIG.

  The fluid valve drive mechanism according to the first embodiment includes main components of the drive unit 1, the main frame 3, the heat insulating frame 8, the valve box 13, the coil spring 6, the upper spring box 4, the lower spring box 5, and the spring holding unit 100. Have.

  The drive unit 1 is fixed to the upper part of the main frame 3, and the drive unit 1 drives the valve body 12 in the valve box 13 in the vertical direction (direction in which the valve body moves forward and backward with respect to the valve seat). Supply. The lower part of the main frame 3 is connected to the heat insulating frame 8 via the heat insulating connecting part 7, and the lower part of the heat insulating frame 8 is connected to the valve box 13. The main frame 3 has an upper spring box 4 and a lower spring box 5, and a coil spring 6 is installed between the upper spring box 4 and the lower spring box 5. The lower spring box 5 is connected to a valve rod 11 via a connecting rod 10, and the valve rod 11 is connected to a valve body 12 in the valve box 13. The drive unit 1 is connected to the upper spring box 4 via the drive shaft 2.

  In addition to the coil spring 6, the upper spring box 4 and the lower spring box 5 are connected by two spring holding units 100 arranged in a 180-degree symmetrical positional relationship on the outer periphery of the upper spring box 4 and the lower spring box 5. ing.

  FIG. 4 shows an enlarged cross-sectional view of the spring holding unit (emergency release unit) 100. Each of the spring holding units 100 includes a support bearing 107 fixed to the upper spring box 4 via an upper bracket 106, and the support bearing 107 rotatably holds the ball screw shaft 104. An electromagnetic clutch 101 is provided above the support bearing 107, and an upper end 112 of the ball screw shaft 104 is fixed to the armature 103 of the electromagnetic clutch 101. The electromagnetic clutch 101 is fixed to an upper bracket 106 that is fixed to the upper spring box 4. Each of the spring holding units 100 includes a ball screw nut 111 fixed to the lower spring box 5 via a lower bracket 110, and the nut 111 is screwed with a threaded portion 105 of the corresponding ball screw shaft 104. Yes.

  Hereinafter, the characteristic configuration of the first embodiment of the fluid valve driving mechanism according to the present invention will be described based on the operation of the fluid valve.

  In the initial state (FIG. 3), the driving force by the drive unit 1 is not applied, the electromagnetic clutch 101 is not energized, the clutch 101 is in an open state, and the ball screw shaft 104 rotates with respect to the ball screw nut 111. It is possible. The coil spring 6 is in the maximum length within the movable range of the upper spring box 4 and the lower spring box 5 in the main frame (the interval between the upper spring box 4 and the lower spring box 5 is shown in FIG. This is a state of length L1). Further, the valve body 12 is in a closed state in which the valve spring 12 is pressed against the valve seat by the coil spring 6 with a predetermined pressure.

  The drive unit 1 is driven from this initial state, the drive shaft 2 is moved downward, and the upper spring box 4 is pushed down. Since the valve body 12 is in contact with the valve seat and the lower spring box 5 cannot be lowered, the positions of the lower spring box 5, the connecting rod 10, and the valve rod 11 do not change, and the upper spring box 4 compresses the coil spring 6. Then, it is lowered to a predetermined position (FIG. 5). The ball screw shaft 104 is supported by the support bearing 107 and is fixed in the vertical direction (the axial direction of the ball screw shaft) while being rotatable with respect to the upper spring box 4, so that the upper spring box 4 is lowered. While the coil spring 6 is being compressed, the ball screw shaft 104 is rotated by the screw portion 105 engaged with the ball screw nut 111 fixed to the lower bracket 110 while the upper spring box 4 and the lower spring box 5 are rotated. The interval of is narrowed.

  When the upper spring box 4 is lowered to a predetermined position, the lowering of the upper spring box 4 by the drive unit 1 is stopped, the electromagnet inside the stator 102 of the electromagnetic clutch 101 is energized, and the armature 103 is fixed to the stator 102 by electromagnetic force. Then, by restraining the rotation of the ball screw shaft 104, the compression reaction force of the coil spring 6 is maintained, and the distance between the upper spring box 4 and the lower spring box 5 is fixed to the length L2 (<L1) (FIG. 5).

  In such a state that the coil spring 6 is compressed and the elastic energy of the spring is kept high, the drive unit 1 is operated, and the distance between the upper spring box 4 and the lower spring box 5 is fixed to the length L2 The body 12 is moved up and down to control the opening of the fluid valve (FIG. 6).

(Coil spring compression maintenance mechanism by electromagnetic clutch)
In the present invention, the distance between the upper spring box 4 and the lower spring box 5 in a state where the coil spring 6 is compressed is maintained by the spring holding mechanism 100. The spring reaction force of the coil spring 6 may be as strong as 8 tons in the case of a valve body having a diameter of 250 mm, for example. In the spring holding mechanism 100 of the present invention that resists this spring reaction force acting in the vertical direction, when the lead of the screw portion 105 is assumed to be 10 mm and the screw efficiency is assumed to be 1, the screw portion 105 of the ball screw shaft 104 causes the 12. It is possible to hold a spring reaction force of 8 tons with a small torque of 7 kg · m, and there is an advantage that a device necessary for holding the spring reaction force can be simplified and made compact.

  When an abnormality occurs in the drive unit 1 and the fluid valve cannot be controlled by the drive unit 1, it is necessary to shut off the fluid valve urgently. In that case, energization of the electromagnetic clutch 101 is stopped and the electromagnetic clutch is released. Thereby, the ball screw shaft 104 can be rotated. During normal operation, the coil spring 6 is held in a compressed state, so that in an emergency, regardless of the position of the valve body 12, the coil spring 6 expands rapidly and rotates the ball screw shaft 104 while rotating the upper spring. The distance between the box 4 and the lower spring box 5 is increased and the valve element 11 is pressed against the valve seat to urgently shut off the valve (FIG. 3).

  In the conventional fluid valve drive mechanism illustrated in FIG. 12, the drive unit is operated with a force corresponding to the sum of the fluid force applied to the valve body and a spring reaction force much larger than that to expand and contract the coil spring. However, it was necessary to open and close the valve during normal operation. However, by adopting the configuration of the present invention, it is possible to open and close the valve in the normal operation by operating the drive unit only with a force corresponding to the fluid force applied to the valve body, so that the drive necessary for the normal operation of the valve is required. The steady load of the part is reduced, and the drive part can be made compact.

  In the fluid valve drive mechanism illustrated in the present embodiment, the spring holding unit (emergency release unit) 100 including the ball screw shaft 104 and the ball screw nut 111 is illustrated, but the present invention is not limited to this. However, it should be noted that the same effect can be obtained by a shaft and nut having any screw structure, such as a roller screw shaft and a roller screw nut, or a trapezoidal screw shaft and a trapezoidal screw nut.

  In the fluid valve drive mechanism exemplified in the present embodiment, the emergency drive means having the coil spring 6 is exemplified, but the present invention is not limited to this, and any elasticity such as a disc spring, a leaf spring, an air spring, etc. It should be noted that a similar effect can be achieved by a spring element that can store energy.

  In the present embodiment, the spring holding unit 100 has a structure in which the electromagnetic clutch 101 is fixed to the upper spring box 4 and the ball screw nut 111 is fixed to the lower spring box 5 side. The structure is not limited, and in the spring holding unit 100 having the electromagnetic clutch 101 on the lower spring box 5 side and the ball screw nut 111 on the upper spring box side and reversed in the vertical direction with this embodiment, Similar effects can be obtained.

(Shock buffer mechanism)
If the electromagnetic clutch 101 is released and the coil spring 6 rapidly expands and the valve body 12 collides with the valve seat at the time of emergency disconnection, the valve body 12 and the valve seat may be damaged or broken. In order to prevent this, the fluid valve drive mechanism of the present invention includes an impact buffer mechanism 300 (FIG. 7). The shock buffering mechanism 300 is an oil damper and has a shock buffering pot 305 fixed to the main frame 3 or the heat insulating frame 8. The shock buffering pot 305 is filled with oil 301 (viscous fluid) and connected. The rod 10 is slidably connected to the shock absorbing pot 305 via an O-ring 304 (seal member). A plate 302 having an orifice 303 is fixed to a portion of the connecting rod 10 located in the shock buffering pot 305. When the plate 302 moves up and down in the shock buffer pot 305 by opening and closing the valve, that is, by raising and lowering the connecting rod 10, the plate 302 receives fluid resistance through which the oil 301 passes through the orifice 303. Since the fluid resistance is proportional to the square of the flow velocity of the fluid passing through the orifice, the rapid lowering speed of the valve body 12 at the time of the emergency shutoff of the valve is relaxed by the plate 302 fixed to the connecting rod 10 and given to the valve. The risk of damage and breakage can be reduced.

  Further, when the electromagnetic clutch 101 is opened due to an emergency interruption of electric power when the drive unit 1 is abnormal, the upper spring box 4 is also rapidly moved up by the spring reaction force of the coil spring 6. The main frame 3 has an impact buffer 9 so that the upper end does not collide with the main frame 3 and damage the apparatus.

(Insulation structure)
In an environment where the fuel temperature of the gas turbine can reach up to 280 ° C, to prevent the early deterioration of grease that is likely to deteriorate at high temperatures, suppressing the temperature rise of the valve drive mechanism is the maintainability of the device. It is extremely important to improve reliability and maintain reliable file safe function in emergency. For this reason, the valve box 13 of the conventional fluid control valve for gas turbine fuel is often provided with fins 511 for cooling the valve body (FIG. 12). For this reason, there is a problem that the height of the entire control valve device is increased and the size is increased. In the present invention, a heat insulating frame 8 having a hollow structure is configured to be interposed between the main frame 3 and the valve box 13, and a structure in which heat is not easily transferred from the valve box 13 to the main frame 3 side is adopted. Further, the connecting portion between the main frame 3 and the heat insulating frame 8 is provided with a heat insulating connecting portion 7 in order to reduce the heat transfer cross-sectional area, thereby increasing the heat resistance and making it difficult to transfer heat from the valve box 13 to the main frame 3 side (see FIG. 1, 2) The functional reliability of the apparatus can be further improved by increasing the heat insulation effect.

(Reliable file safe mechanism with linear guide)
Even if the fluid valve needs to be urgently closed for some reason, such as an abnormality in the drive unit 1 or when an abnormality occurs in one of the two electromagnetic clutch 101 devices, the valve can be reliably shut off. Therefore, the fluid valve drive mechanism of the present invention includes a linear guide (linear motion guide mechanism) mechanism 200. FIG. 8 (BB cross section in FIG. 2) is a cross-sectional view showing the arrangement and structure of the linear guide mechanism 200. FIG. The linear guide mechanism 200 is provided on the main frame 3 and extends in the axial direction (vertical direction) of the drive shaft 2, the upper slider 202 provided on the upper spring box 4, and the lower provided on the lower spring box 5. And a slider 203. The slider engages with the rail, and generally has a steel ball 204 in the groove between the rail and the slider. Each of the upper spring box 4 and the lower spring box 5 moves in the vertical direction (the valve body 12 in the main frame 3). Is guided so that it can slide smoothly in the forward and backward direction). When an abnormality occurs in any of the electromagnetic clutches 101, the spring reaction force of the coil spring 6 is held by the spring holding mechanism 100 on one side, but the rail 201 of the linear guide mechanism 200 is fixed to the strong main frame 3. Therefore, although the spring reaction force may be as much as 8 tons, there is less deformation than in the case of a guide mechanism that uses a bush or the like with a cylindrical column, and the moment load due to support on only one side is reduced. Even if it works, the upper spring box 4 and the lower spring box 5 do not incline from the predetermined angle with respect to the main frame 3, and the emergency guide with high reliability can be realized by the linear guide mechanism 200.

  Furthermore, the fluid valve drive mechanism of the present invention is normally operated in a state in which the space between the upper spring box 4 and the lower spring box 5 is fixed by the spring holding mechanism 100 while the coil spring 6 is compressed. Therefore, even when an abnormality occurs in the one-side spring holding mechanism 100, the coil spring 6 can be reliably maintained in a compressed state only by the other spring holding mechanism 100 operating normally, except when necessary. There is also an effect that the shut-off operation of the valve can be prevented in advance.

  In the fluid valve drive mechanism of the conventional gas turbine shown in FIG. 12, as described in the first embodiment, during normal operation, the fluid force applied to the valve body and the compression reaction of a spring much larger than that are applied. The opening / closing operation of the valve must be performed with a force corresponding to the sum of the forces. Therefore, the driving unit requires a large driving force constantly during normal operation. The change from the hydraulic actuator of the drive unit to the electric actuator is a major operational and design advantage that avoids potential oil leakage problems and avoids the complexity of installing hydraulic piping. Have However, in order to obtain the necessary driving force against the compression reaction force of the strong coil spring as described above by the electric actuator, the electric actuator itself becomes enormous, so it is not practical especially in application to a large valve. It was difficult to realize. However, in the present invention, during normal operation, the valve can be opened and closed only with a force corresponding to the fluid force applied to the valve body, so that the driving force for constantly adjusting the opening of the valve is reduced. In addition, it has a special effect that the design of the drive unit with an electric actuator can be made realistic.

  FIG. 9 shows a schematic front sectional view of a fluid valve drive mechanism that is Embodiment 2 of the present invention. In the figure, the same members as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the present embodiment, an electric actuator 24 that is a rotational drive means is used for the drive unit 1, and the drive shaft 2 of the drive unit 1 rotates without moving up and down. The drive shaft 2 is fixed to the main frame 3 so as not to move in the vertical direction and to be rotatable by a main support bearing 21 and a nut 22 fixed to the main frame 3. FIG. 10 shows an enlarged cross-sectional view of the support portion of the drive shaft 2. The drive shaft 2 has a threaded portion 20 and is screwed into a drive shaft elevating nut 23 fixed to the upper spring box 4.

  In the operation of the fluid valve in the first embodiment, when the drive unit 1 is driven from the initial state, the drive shaft 2 is lowered and the upper spring box 4 is lowered, but in the second embodiment, the electric actuator 1 is driven. The drive shaft 2 rotates. Due to the rotation of the drive shaft 2, the drive shaft lifting nut 23 screwed with the screw portion 20 of the drive shaft 2 is pushed down, and the upper spring box 4 is lowered. Other basic operations are the same as in the first embodiment, and the same effects of the invention as in the first embodiment can be obtained. Furthermore, in the second embodiment, in particular, by using the electric servo motor 24 in the drive unit 1, it is possible to always control to the optimum drive current by detecting the angle of the rotor, and highly accurate positioning without step-out. Therefore, the opening degree of the fluid valve can be controlled with high accuracy.

(Accumulated load detection of screw part and bearing part)
Further, in the second embodiment in which the electric servo motor 24 is used for the drive unit 1, the mechanical load of the screw portion and the bearing portion can be detected using the characteristics of the electric servo motor. The accumulated load detection will be described with reference to the schematic configuration diagram of the accumulated load detection unit shown in FIG.

  When the electric actuator is used for the drive unit 1 as in the second embodiment, maintaining the screw unit 20 and the main support bearing 21 used for the opening / closing operation of the fluid valve in a state in which the device can function normally is It is very important to maintain reliability.

  The rotation angle of the rotor of the electric servo motor 24 is detected by a built-in encoder (rotation detection means) 401. The electric servo motor 24 has a driver 402, and the driver 402 generates an optimum rotating magnetic field that generates a maximum torque in accordance with the rotation angle of the rotor of the electric servo motor based on the position signal fed back from the encoder 401. Electric current is supplied to the electric servomotor 24 so that it occurs. The host controller 403, which is the host of the driver 402, controls the vertical position of the valve body 12 while monitoring the vertical position signal of the valve body 12 from the linear position sensor 406, and controls the fluid flow rate to an appropriate fluid flow rate. The driver 402 has a built-in motor drive current sensor 404 and monitors the drive current of the motor.

  In general, the mechanical cumulative load on the threaded portion 20 and the main support bearing 21 can be estimated by the product of thrust and rotational speed. Since the thrust is proportional to the motor current, the cumulative load calculation unit 405 built in the host controller 403 calculates the mechanical cumulative load that is the product of the motor current, the thrust calculated from the encoder 401, and the rotation speed, respectively. And accumulate. When the accumulated load calculation value exceeds a predetermined value, an alarm is displayed on the alarm display unit 407, so that even if there is a variation in the operating state of each device, it is appropriate depending on the operation results of the device. Can recognize proper maintenance timing.

  In addition, although the fluid valve drive mechanism illustrated in the embodiment has the two spring holding mechanisms 100, the present invention is not limited to this, and the same is achieved by having three or more spring holding mechanisms. Note that the following effects can be obtained. In this case, the three or more spring holding mechanisms are preferably arranged symmetrically with respect to the central axis of the drive shaft 2. Further, when the number of the spring holding mechanisms is increased, the holding force against the reaction force of the coil spring 6 required for one spring holding mechanism is reduced, so that the electromagnetic clutch, the support bearing, etc. can be made compact. .

  Furthermore, although the fluid valve drive mechanism illustrated in the embodiment has two linear guide mechanisms 200, the present invention is not limited to this, and the same is achieved by having three or more linear guide mechanisms. Note that the following effects can be obtained. In this case, the three or more linear guide mechanisms are preferably arranged symmetrically with respect to the central axis of the drive shaft 2.

  Moreover, although the fluid valve drive mechanism illustrated in the embodiment has been described on the assumption that the valve is closed in an emergency, the present invention is not limited to this and opens the fluid valve in an emergency. It should be noted that the present invention can be applied to an operation in which it operates. When the valve is opened urgently in the event of an emergency, it is possible to prevent damage or breakage of the valve due to a collision with the valve case at the valve opening limit position by an impact buffering mechanism. Similar effects can be achieved.

  In the description of the present invention in the specification, the invention is described by designating the direction by expressions such as up, down, left, and right, but this is for convenience to explain based on the description of the drawings attached to the specification. It should be noted that the description is not intended to define the direction in which the apparatus of the present invention is installed.

1 is a schematic front view of a fluid valve drive mechanism according to Embodiment 1. FIG. 1 is a schematic side view of a fluid valve drive mechanism according to Embodiment 1. FIG. It is the schematic which shows the initial state (state after emergency interruption | blocking) of the fluid valve drive mechanism which concerns on Example 1, and shows the front schematic sectional drawing seen from the cross section AA of FIG. It is the elements on larger scale which show a spring holding mechanism. In the fluid valve drive mechanism according to Embodiment 1, the drive shaft is lowered to a predetermined position and the electromagnetic clutch is closed. In the fluid valve drive mechanism according to Embodiment 1, it is a schematic diagram showing a state of normal valve operation in which an electromagnetic clutch is operating. It is a partial expanded sectional view which shows an impact buffer mechanism. It is an expanded sectional view which showed the linear guide mechanism and was seen from the cross section AA of FIG. The front schematic sectional drawing of the fluid valve drive mechanism which concerns on Example 2 is shown. FIG. 6 is an enlarged cross-sectional view of a support bearing of a drive shaft and an upper spring box portion in a fluid valve drive mechanism according to a second embodiment. The schematic block diagram of the accumulation load detection unit in the fluid valve drive mechanism which concerns on Example 2 is shown. It is the schematic which shows an example of the fluid control valve used with the conventional gas turbine.

Explanation of symbols

1: Drive unit 2: Drive shaft 3: Main frame 4: Upper spring box 5: Lower spring box 6: Coil spring 7: Thermal insulation connecting part 8: Thermal insulation frame 9: Shock absorber 10: Connecting rod 11: Valve rod 12: Valve body 13: Valve box 20: Screw part 21: Main support bearing 22: Nut 23: Drive shaft lifting nut 24: Rotation drive means (electric servo motor)
100: Spring holding mechanism 101: Electromagnetic clutch 102: Stator 103: Armature 104: Ball screw shaft 105: Screw part 106: Upper bracket 107: Support bearing 108: Bearing cover 109: Nut 110: Lower bracket 111: Ball screw nut 112: Ball screw shaft upper end 200: linear guide mechanism 201: rail 202: upper slider 203: lower slider 204: steel ball 300: shock buffer mechanism 301: oil 302: baffle plate 303: orifice 304: O-ring 305: shock buffer pot 400: Cumulative load estimation unit 401: Encoder 402: Driver 403: Host controller 404: Motor drive current sensor 405: Cumulative load calculation unit 406: Linear position sensor 407: Alarm display unit 501: Hydraulic actuator 502: Output shaft 503: Connection rod 504: Coil spring 505: Spring seat 506: Spring box 507: Connection frame 508: Valve box 509: Valve body 510: Valve rod 511: Valve box cooling fin

Claims (9)

A fluid valve drive mechanism for moving the valve body 12 of the fluid valve forward and backward with respect to the valve seat, the fluid valve drive mechanism having a drive means 1 and an emergency drive means,
The emergency drive means includes a spring unit and an emergency release unit 100,
The spring unit includes a sprung support 4, an unsprung support 5, and a spring 6 disposed between the sprung support 4 and the unsprung support 5. Connected to the drive means 1, the unsprung support 5 is connected to the valve body 12,
The emergency release unit 100 includes an on-axis support portion fixed to the sprung support portion 4, an under-axis support portion fixed to the unsprung support portion 5, the on-axis support portion and the under-axis support portion. And an emergency release unit shaft 104 having a screw structure and a spring support portion interval fixing means 101,
One of the on-axis support portion and the under-axis support portion is a nut 111 that is screwed with the emergency release unit shaft 104, and the other is the emergency release unit with the emergency release unit shaft 104 being rotatable. A bearing 107 that is fixed in the axial direction of the shaft 104;
The spring support portion interval fixing means 101 fixes the interval between the on-axis support portion and the under-axis support portion by restricting relative rotation between the emergency release unit shaft 104 and the nut 111. By fixing the distance between the sprung support portion 4 and the unsprung support portion 5 and enabling the relative rotation between the emergency release unit shaft 104 and the nut 111, the shaft The distance between the upper support part 4 and the unsprung support part 5 can be changed by changing the distance between the upper support part and the lower support part .
The valve body 12 abuts against the valve seat, and the spring 6 is compressed between a free length and a predetermined length between the sprung support portion 4 and the unsprung support portion 5 from the initial state. After the spring 6 is compressed to a predetermined length by reducing the distance between the portion 4 and the unsprung support portion 5, the distance between the sprung support portion 4 and the unsprung support portion 5 is fixed by the emergency release unit. By driving the driving means 1, the valve body 12 is moved up and down while the spring 6 is held in a compressed state between the sprung support 4 and the unsprung support 5 to open and close the valve. Control
In an emergency, the fixing of the distance between the sprung support portion 4 and the unsprung support portion 5 by the emergency release unit 100 is released, and the spring 6 is extended from the compressed state, and the unsprung support portion 5 The valve body 12 is lowered, and the valve body 12 is pressed against the valve seat to urgently drive the fluid valve to be closed.
Fluid valve drive mechanism. The fluid valve drive mechanism according to claim 1 , wherein the emergency release unit shaft is a ball screw shaft and the nut is a ball screw nut. The spring support portion interval fixing means 101 is an electromagnetic clutch 101, claim 1 or 2 of the fluid valve drive mechanism. The emergency drive means further includes a linear motion guide means 200. The linear motion guide means 200 smoothly slides the sprung support portion 4 and the unsprung support portion 5 in the direction in which the valve body 12 moves forward and backward. Guide you to move,
The fluid valve drive mechanism according to any one of claims 1 to 3 . The emergency drive means includes an impact buffer means 300 between the unsprung support portion 5 and the valve body 12,
The rapid rise and fall of the valve body 12 is mitigated by the fluid resistance of the fluid 301 contained in the shock absorbing means 300.
The fluid valve drive mechanism according to any one of claims 1 to 4 . A main frame 3 which fixes the driving means 1 and has the emergency driving means inside;
A heat insulating frame 8 having a hollow structure between the valve box including the valve body 12 and the main frame 3;
A heat insulating connection 7 between the heat insulating frame 8 and the main frame 3
The fluid valve drive mechanism according to any one of claims 1 to 5 , further comprising: The drive means 1 is a linear drive means, the fluid valve drive mechanism according to any one of claims 1 to 6. The driving means 1 is a rotational driving means,
A rotation / linear motion conversion mechanism 23 is provided at a connection portion between the drive shaft 2 rotated by the driving force of the rotation driving means and the sprung support portion 4,
The rotation / linear motion conversion mechanism 23 moves the sprung support 4 up and down by the rotation of the drive shaft 2.
The fluid valve drive mechanism according to any one of claims 1 to 6 . The rotation driving means is an electric servo motor 24;
The fluid valve drive mechanism further includes cumulative load evaluation means 400,
The cumulative load evaluation unit 400 includes a rotation detection unit 401 that detects the rotation of the electric servo motor 24 and a drive current sensor 404 that detects a current that drives the electric servo motor 24. The product of the motor thrust and the number of revolutions is calculated and accumulated, and if the accumulated value is greater than a predetermined value, an alarm is issued.
The fluid valve drive mechanism according to claim 8 .

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