JP3568930B2 - Flow control device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a flow control device capable of attenuating pulsation of a pressure fluid flowing through a fluid passage and controlling the flow rate of the pressure fluid with high accuracy.
[0002]
[Prior art]
FIG. 6 shows a flow control system according to the related art for controlling the flow rate of a fluid flowing through a fluid passage.
[0003]
The flow control system 1 is connected to a pump 3 for sucking and feeding a pressure fluid stored in a tank 2 and connected to a downstream side of the pump 3 via a pipe 4 such as a tube. An on-off valve 5 for opening and closing a fluid passage of a supplied pressure fluid, and a flow control connected to a downstream side of the on-off valve 5 via a pipe 6 such as a tube to control a flow rate of the pressure fluid flowing through the fluid passage. And a valve 7.
[0004]
A flow sensor 8 for detecting the flow rate of the pressure fluid flowing through the fluid passage is provided downstream of the flow control valve 7, and the pressure fluid flowing through the fluid passage is determined based on a detection signal from the flow sensor 8. Is displayed on the display 9.
[0005]
An electro-pneumatic regulator 11 that regulates the pressure of air supplied from a compressed air supply source 10 and guides a predetermined pilot pressure to a pilot chamber of the flow control valve 7 is connected to the flow control valve 7 through a pipe 12 such as a tube. Connected via The electropneumatic regulator 11 controls the air supplied from the compressed air supply source 10 to a predetermined pressure based on a control signal derived from the controller 13 and derives it as a pilot pressure.
[0006]
The general operation of the flow control system 1 according to the prior art will be described. The pressure fluid stored in the tank 2 and supplied through the pump 3 is controlled by the on-off valve 5 being opened. Introduced to valve 7. In the flow control valve 7, a pilot pressure adjusted to a predetermined pressure via an electropneumatic regulator 11 is introduced into a pilot chamber, and is supplied via the on-off valve 5 to the pilot pressure introduced into the pilot chamber. By balancing the pressure of the pressure fluid (primary pressure), the valve opening of a valve body (not shown) is controlled.
[0007]
Therefore, in the flow control valve 7, the pilot pressure controlled based on the control signal derived from the controller 13 and the primary pressure of the pressurized fluid supplied through the on-off valve 5 are balanced, so that the valve The valve opening is adjusted, and the flow is controlled and derived to a flow rate corresponding to the valve opening of the valve body.
[0008]
The flow rate of the pressure fluid derived from the flow control valve 7 is detected by a flow rate sensor 8 and the flow rate is displayed on a display 9.
[0009]
[Problems to be solved by the invention]
However, in the flow control system according to the related art, the valve opening of the flow control valve is controlled by the air pressure (pilot pressure) derived from the electropneumatic regulator. In this case, a variation in flow rate occurs due to a delay in response, and stable flow control is difficult.
[0010]
Further, in the flow control system according to the related art, for example, the piping work between the fluid devices such as the on-off valve, the flow control valve, and the electropneumatic regulator is connected by a pipeline such as a tube, so that the piping work is complicated. At the same time, the installation area increases and the work space increases.
[0011]
The present invention has been made in view of the above points, and eliminates a delay in responsiveness when controlling a valve opening degree of a valve body, reduces the size of the entire apparatus, and reduces the installation space. It is an object of the present invention to provide a flow control device capable of controlling the flow rate.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention balances the regulated pilot pressure derived from the pressure regulating unit and the primary pressure of the pressure fluid flowing through the fluid passage, and pulsates the pressure fluid. A pulsation damping mechanism for damping pressure fluctuations,
A first valve body that opens and closes the fluid passage; a linear actuator that is controlled based on a control signal derived from a control unit to adjust a valve lift amount of the first valve body so that the first valve body flows through the fluid passage; A flow rate control mechanism for controlling the flow rate of the pressure fluid,
A joint part having one first port and the other second port communicating with the fluid passage, and integrally assembling the pulsation damping mechanism and the flow rate control mechanism;
With
The pulsation damping mechanism is disposed between the first diaphragm on the upper side and the second diaphragm on the lower side, between the first diaphragm and the second diaphragm, and is slidably provided along the vertical direction. A moving valve, a second valve body provided so as to face the fluid passage, connected to a lower side of the sliding plate, and opening and closing the fluid passage by being displaced integrally with the sliding plate; An intermediate member for connecting the sliding plate and the second valve body is included .
[0013]
In this case, a rotation detection unit that detects the amount of displacement along the axial direction based on the rotation amount of the drive shaft of the linear actuator is provided in the flow control mechanism, and a detection signal derived from the rotation detection unit is introduced into the control unit. Thus, feedback control may be performed, and the valve lift of the valve body may be controlled with high accuracy.
[0014]
In addition, the pulsation damping mechanism and the flow rate control mechanism are integrally assembled via a joint having a fluid passage that connects one of the first port and the other of the second port. And the whole device may be easily miniaturized.
[0015]
According to the present invention, the pulsation damping mechanism and the flow rate control mechanism are integrally assembled via a joint portion, so that the size of the entire apparatus can be reduced as compared with the related art, and a control signal derived from the control means. By controlling the linear actuator based on the (electric signal), the valve lift amount of the first valve body, that is, the valve opening of the first valve body that opens and closes the fluid passage can be adjusted.
[0016]
Therefore, there is no variation in responsiveness when adjusting the valve opening of the first valve body, and the flow rate of the pressure fluid flowing through the fluid passage can be controlled stably.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
A preferred embodiment of a flow control device according to the present invention will be described below in detail with reference to the accompanying drawings.
[0018]
In FIG. 1, reference numeral 20 indicates a flow control device according to an embodiment of the present invention.
[0019]
The flow control device 20 includes a joint portion 22 to which a tube (not shown) is detachably connected at a predetermined interval, a pulsation damping mechanism 24 provided on one upper side of the joint portion 22 along the axial direction, And a flow rate adjusting mechanism 26 provided on the other upper part of the joint part 22 along the axial direction.
[0020]
The joint 22, the pulsation damping mechanism 24, and the flow rate adjusting mechanism 26 are integrally assembled.
[0021]
The joint portion 22 has a first joint body 30 having a first port 28 formed at one end thereof, and a second joint body 34 having a second port 32 formed at the other end thereof. The first and second joint bodies 30, 34 connected substantially coaxially are provided with a fluid passage 36 for communicating the first port 28 and the second port 32.
[0022]
Further, the joint portion 22 engages with the first port 28 and the second port 32, respectively, and the inner member 40 inserted into the opening of the tube 38 and the first and second joint bodies 30, 34 A lock nut 42 is provided to maintain the liquid-tightness of the connection portion of the tube 38 by screwing into a thread groove formed at the end.
[0023]
A pulsation damping mechanism 24 is disposed above the joint portion 22 close to the first port 28, and the pulsation damping mechanism 24 is configured by integrally connecting a plurality of blocks including an upper bonnet 44. It has a housing 46.
[0024]
Air is supplied to the inside of the bonnet 44 via a pressure fluid supply port 50 connected to a compressed air supply source 48, and the air supplied from the pressure fluid supply port 50 is adjusted to a predetermined pressure. A pressure adjusting unit 54 is provided for guiding the adjusted air toward the passage 52.
[0025]
In the pressure adjusting section 54, air supplied from the pressure fluid supply port 50 is introduced into a diaphragm chamber (not shown), and the spring force of a spring member adjusted by a pressure adjusting handle (not shown) is introduced into the diaphragm chamber. The pressure of the pressure fluid supply port 50 is adjusted by balancing the pressing force for pressing a diaphragm (not shown) by the pressure of the pressurized fluid and displacing a stem and a valve body (not shown) under the bending action of the diaphragm (not shown). Can be adjusted to a desired pressure.
[0026]
On the other hand, on the lower side of the housing 46, there is provided a pulsation equilibrium part 58 for performing an on / off operation of a valve body 56 that opens and closes the fluid passage 36 based on the air derived from the pressure regulating part 54.
[0027]
As shown in FIG. 2, the pulsation equilibrium portion 58 is formed with a pressure chamber 60 into which air (pilot pressure) derived from the pressure adjusting section 54 through the passage 52 is introduced. The valve member 62 facing the fluid passage 36 is provided so as to be displaced under the action of air introduced into the fluid passage 36.
[0028]
The valve member 62 is disposed between an upper first diaphragm 64 and a lower second diaphragm 66, and is provided with a sliding plate 68, which is displaceable in a vertical direction, and the sliding plate 68. A valve body (second valve body) 56 connected to a lower central portion of the housing 68 via a screw member 70 and provided so as to be able to approach or separate from a seating portion 72 formed in the housing 46; By contacting a sealing member 74 mounted on the outer peripheral surface of the moving plate 68 via an annular groove, and a slope 76 formed on the housing 46 between the sliding plate 68 and the valve body 56. And an intermediate member 78 functioning as a stopper.
[0029]
In this case, the first diaphragm 64 is formed of, for example, a rubber material, and has a function of protecting the sliding plate 68. The second diaphragm 66 maintains the liquid tightness of the pressure fluid and collects the liquid. In order to remove, it is preferable to use a resin material such as polytetrafluoroethylene (PTFE).
[0030]
In this case, even if there is pressure fluctuation such as pulsation in the pressure fluid flowing through the fluid passage 36, the pressure fluctuation of the pressure fluid flowing through the fluid passage 36 is attenuated by the pressure of the air supplied to the pressure chamber 60, A pressure fluid maintained at a substantially constant pressure can flow.
[0031]
The flow rate adjusting mechanism 26 includes a housing 80 integrally connected to the second joint body 34, a first piston 82 that is displaced along a chamber formed inside the housing 80 along the arrow X <b> 1 or X <b> 2 direction, and And a second piston 84.
[0032]
As shown in FIG. 3, the first piston 82 is formed with a large-diameter first protrusion 86a on the lower side and a small-diameter second protrusion 86b on the upper side. The portion 86a is slidably inserted into the housing 80. A piston packing 88a is mounted on the outer peripheral surface of the first piston 82 via an annular groove.
[0033]
The second piston 84 is formed to have a substantially U-shaped cross section. The second protrusion 84b of the first piston 82 is engaged with a recess formed below, and is slidably inserted into the housing 80. A pair of piston packings 88b and 88c are mounted on the outer peripheral surface through an annular groove.
[0034]
A spring member 90 is interposed between the inside of the second piston 84 and the second projecting portion 86b, and the first piston 82 and the second piston 84 are separated from each other by the spring force of the spring member 90. Being energized.
[0035]
Further, a through screw hole 96 is formed in a substantially central portion of the second piston 84 to be screwed with a shaft portion of a drive shaft 92 described later.
[0036]
A pin member 98 is mounted on the side surface of the second piston 84 so as to protrude by a predetermined length through a groove, and the pin member 98 is provided so as to engage with an engagement groove 100 formed on the side surface of the housing 80. ing. That is, when the second piston 84 is displaced in the axial direction, the pin member 98 has a function of preventing rotation of the second piston 84 in the circumferential direction.
[0037]
A valve body (first valve body) 102 formed of a flexible material such as a resin material or a rubber material is connected to a lower end of the first piston 82, and the valve body 102 is a first valve body. It is provided so as to be displaced integrally with the piston 82. The valve body 102 includes a thick portion 104a formed substantially at the center and a thin portion 104b formed integrally with the thick portion 104a, and is formed to be freely bendable.
[0038]
In this case, the valve body 102 is separated from the seating portion 106 formed on the second joint body 34 or is seated on the seating portion 106 to open and close the fluid passage 36 and to open and close the valve of the valve body 102. The function of controlling the flow rate of the pressurized fluid flowing through the fluid passage 36 with high accuracy based on the lift amount (displacement amount of the valve body 102 along the axial direction).
[0039]
A ring-shaped buffer member 108 for protecting the thin portion 104b of the valve body 102 is provided on the upper surface of the valve body 102, and the buffer member 108 is formed of, for example, an elastic member such as rubber. 80 is held by the lower surface.
[0040]
As shown in FIG. 1, on the upper side of the flow rate adjusting mechanism 26, there is provided a bonnet 110 integrated with an upper portion of a housing 80, and a power source (not shown) is energized in the bonnet 110. A linear actuator 112 for driving the valve element 102 by the actuator and a rotation detecting unit 114 for detecting the amount of displacement of the valve element 102 based on the amount of displacement of the linear actuator 112 are provided.
[0041]
Note that a connector 120 for guiding a detection signal to the controller 118 via the lead wire 116 is disposed close to the rotation detection unit 114.
[0042]
The linear actuator 112 is composed of a linear stepping motor that is energized and deactivated by a rotation drive control signal (pulse signal) derived from a controller 118, and includes a stator and a rotor (not shown) provided in a casing, and a power supply (not shown). A rotor (not shown) is provided so as to rotate in a predetermined direction under the action of an exciting current supplied from the motor.
[0043]
The drive shaft 92 of the linear actuator 112 is provided so as to be displaceable along the axial direction (the direction of the arrow X1 or X2) under its rotation.
[0044]
On the other hand, the drive shaft 92 of the linear actuator 112 is provided with a first shaft portion 122 and a second shaft portion 124 in which screw portions having a predetermined pitch are engraved, respectively. Is set to be larger than the diameter of the lower second shaft portion 124.
[0045]
The rotation detecting unit 114 is provided with a light emitting unit and a light receiving unit (not shown) arranged at positions facing each other with a predetermined space therebetween, and is connected to a drive shaft 92 of a linear actuator 112 and integrally rotates. No rotor is provided. In this case, the light emission of the light emitting element passing through the inside of the rotor is received by the light receiving element, so that the rotation angle and the number of rotations of the drive shaft 92 of the linear actuator 112 are detected, and the detection signal is output to the controller 118 as a detection signal. .
[0046]
In the controller 118, a displacement amount along the axial direction of the drive shaft 92 is calculated based on the pitch data of the drive shaft 92 of the linear actuator 112 and the detection signal such as the number of revolutions, and based on the calculation result, The separation distance between the valve element 102 and the seat 106, that is, the valve lift of the valve element 102 is calculated.
[0047]
Accordingly, the controller 118 obtains a deviation from a preset lift amount of the valve body 102, and adjusts the lift amount of the valve body 102 so that the deviation becomes zero, thereby controlling the pressure fluid flowing through the fluid passage 36. Can be controlled with high precision.
[0048]
The flow control device 20 according to the embodiment of the present invention is basically configured as described above. Next, the operation and the operation and effect will be described.
[0049]
As shown in FIG. 4, the pressure fluid stored in the tank 132 under the suction action of the pump 130 is supplied to the joint portion 22 of the fluid control device 20, and is transmitted through the first port 28 of the joint portion 22. Pressure fluid is introduced into the pulsation balance 58. In this case, in the pressure adjusting section 54, the air supplied from the pressure fluid supply port 50 is introduced into a diaphragm chamber (not shown), and is introduced into the spring chamber, the spring force, and the diaphragm chamber under the bending action of the diaphragm (not shown). By balancing the pressure of the air, the pressure of the air is adjusted to a desired pressure.
[0050]
Accordingly, the air adjusted to a desired pressure by the pressure adjusting unit 54 is introduced into the pressure chamber 60 of the pulsation equilibrium unit 58 through the passage 52, and the primary pressure of the pressure fluid flowing through the fluid passage 36 and the pressure The pressure of the air introduced into the chamber 60 is balanced. Therefore, even if there is a pressure fluctuation such as pulsation in the pressure fluid flowing through the fluid passage 36, the pressure fluctuation of the pressure fluid flowing through the fluid passage 36 is attenuated by the air supplied to the pressure chamber 60, The pressure of the pressure fluid flowing through the passage 36 can be kept substantially constant.
[0051]
In other words, when the pressure fluid flowing through the fluid passage 36 has pressure fluctuation such as pulsation, the pressure fluctuation of the pressure fluid is transmitted to the sliding plate 68 via the second diaphragm 66, and the sliding plate 68 It moves up and down slightly. At this time, the pressure fluctuation of the pressurized fluid is attenuated and suitably absorbed by being buffered by the air in the pressure chamber 60 provided on the opposite side of the fluid passage 36 with the slide plate 68 therebetween.
[0052]
The pressure fluid led out of the pulsation balance part 58 flows along the fluid passage 36 and is introduced into the flow rate adjusting mechanism 26. The flow rate adjusting mechanism 26 adjusts the distance between the valve body 102 and the seat 106 by biasing and deactivating the linear actuator 112 based on a rotational drive control signal derived from the controller 118. Is set. The valve opening of the valve body 102 is adjusted, and the pressure fluid flowing through the fluid passage 36 is controlled to a flow rate corresponding to the valve opening of the valve body 102.
[0053]
In this case, the controller 118 derives an urging signal to the linear actuator 112 and displaces the first and second shaft portions 122 and 124 that are the drive shaft 92 of the linear actuator 112 in the direction of the arrow X1. Accordingly, the second piston 84 and the first piston 82 screwed to the second shaft portion 124 through the through screw holes 96 under the rotation of the drive shaft 92 are displaced upward, whereby the valve body 102 is moved. It rises integrally and separates from the seat 106.
[0054]
The amount of displacement of the valve body 102 along the axial direction is detected by a rotation detector 114 via the amount of rotation of a linear actuator 112, and based on a detection signal (pulse signal) derived from the rotation detector 114, The controller 118 controls the linear actuator 112 so that the valve body 102 stops at a preset position.
[0055]
That is, the controller 118 counts the pulse signal derived from the rotation detecting unit 114 and, when the pulse signal reaches a predetermined number of pulses set in advance, derives a deenergization signal to the linear actuator 112 and drives the linear actuator 112 in a driving state. To stop. The controller 118 calculates the amount of displacement of the drive shaft 92 from the amount of rotation such as the number of rotations and the angle of rotation of the drive shaft 92 and the thread pitch of the second shaft 124 screwed to the second piston 84. Can be calculated. As a result, the lift amount of the valve body 102 can be controlled with high accuracy, and the flow rate of the pressure fluid corresponding to the lift amount of the valve body 102 can be controlled with high accuracy.
[0056]
As described above, in the present embodiment, since the lift amount of the valve body 102 is controlled based on the rotation drive control signal derived from the controller 118, there is no variation in responsiveness unlike the related art, and The valve opening can be adjusted, and the flow rate of the pressure fluid flowing through the fluid passage 36 can be controlled stably.
[0057]
Further, in the present embodiment, since the on-off valve 5, the flow control valve 7, the electropneumatic regulator 11, and the like according to the related art are integrally assembled, piping work such as a tube connecting each fluid device is performed. Is unnecessary, and there is no risk of liquid leakage from the piping material, and the entire apparatus can be reduced in size and the installation space can be reduced.
[0058]
Further, as shown in FIG. 5, a flow sensor 140 is disposed in the fluid passage on the downstream side of the flow control device 20, and a sensor detection signal from the flow sensor 140 is introduced into the controller 118 to perform feedback control. Thus, the flow rate flowing through the fluid passage 36 can be monitored in real time.
[0059]
In this case, the controller 118 compares the preset flow rate data with the sensor detection signal derived from the flow rate sensor 140, and adjusts the valve lift amount of the valve body 102 so that the deviation becomes zero. The flow rate actually flowing through the fluid passage 36 can be controlled with high accuracy.
[0060]
【The invention's effect】
According to the present invention, the following effects can be obtained.
[0061]
That is, by controlling the linear actuator based on a control signal (electric signal) derived from the control means, it is possible to eliminate a delay in responsiveness when controlling the valve opening of the first valve body.
[0062]
In addition, by integrally providing the pulsation damping mechanism and the flow control mechanism via the joint portion , the pipe connection work is simplified, and the overall configuration of the apparatus can be reduced in size to reduce the installation space. .
[Brief description of the drawings]
FIG. 1 is a partially omitted longitudinal sectional view of a flow control device according to an embodiment of the present invention.
FIG. 2 is a partially enlarged longitudinal sectional view of a pulsation equilibrium section constituting the flow control device of FIG.
FIG. 3 is a partially enlarged longitudinal sectional view of a flow rate adjusting mechanism constituting the flow rate control device of FIG. 1;
FIG. 4 is a block diagram of a flow control system incorporating the flow control device shown in FIG. 1;
FIG. 5 is a block diagram showing a modified example of the flow control system of FIG. 4;
FIG. 6 is a block diagram of a flow control system according to the related art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 20 ... Flow control device 22 ... Coupling part 24 ... Pulsation damping mechanism 26 ... Flow rate adjusting mechanism 28, 32 ... Port 36 ... Fluid passage 54 ... Pressure regulating part 56,102 ... Valve 58 ... Pulse balancing part 60 ... Pressure chamber 64 66, diaphragm 68, sliding plate 72, 106, seating portion 82, 84, piston 90, spring member 92, drive shaft 96, through screw hole 112, linear actuator 114, rotation detector 118, controller 122, 124 ... shaft Part 140 ... flow rate sensor

Claims (2)

A pulsation damping mechanism that balances the regulated pilot pressure derived from the pressure regulator and the primary pressure of the pressure fluid flowing through the fluid passage, and attenuates pressure fluctuations due to pulsation of the pressure fluid;
A first valve body that opens and closes the fluid passage; a linear actuator that is controlled based on a control signal derived from a control unit to adjust a valve lift amount of the first valve body so that the first valve body flows through the fluid passage; A flow rate control mechanism for controlling the flow rate of the pressure fluid,
A joint part having one first port and the other second port communicating with the fluid passage, and integrally assembling the pulsation damping mechanism and the flow rate control mechanism;
With
The pulsation damping mechanism is disposed between the first diaphragm on the upper side and the second diaphragm on the lower side, between the first diaphragm and the second diaphragm, and is slidably provided along the vertical direction. A moving valve, a second valve body provided so as to face the fluid passage, connected to a lower side of the sliding plate, and opening and closing the fluid passage by being displaced integrally with the sliding plate; A flow control device comprising an intermediate member for connecting a sliding plate and the second valve body . The device of claim 1,
The flow rate control device is characterized in that the flow rate control mechanism is provided with a rotation detector that detects a displacement amount along an axial direction based on a rotation amount of a drive shaft of a linear actuator.

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