JP2006170361A - Valve device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve device having relatively simple construction for controlling the flow amount of fluid as required. <P>SOLUTION: The valve device comprises a first member 2 having a flow-in port 8, a valve element 20 stored in a valve housing 4, a coil spring 34 for elastically biasing the valve element 20 to be opened, an operating member 40 movably stored in a second member 6, a diaphragm 54 for sealing shut-off between a valve storage space 18 of the valve housing 4 and an operating member storage space 36 of the second member 6, and a driving means for moving the operating member 40. The driving means is constructed by an electric motor 60. Between the electric motor 60 and the operating member 40, a movement converting mechanism 80 is provided for converting the rotation of the electric motor 40 into the linear movement of the operating member 40. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a valve device for controlling a fluid supply amount.

  As a valve device for controlling the flow rate of liquid, a first member having an inlet, a valve housing attached to the first member, a valve body housed in the valve housing, and elastically opening the valve body Elastically biasing means for biasing, a second member attached to the valve housing, a flow rate control drive means accommodated in the second member, a valve accommodating space in the valve housing, and a drive in the second member There has been known one provided with a diaphragm for hermetically sealing off a member housing space and an opening / closing drive means attached to a second housing (see, for example, Patent Document 1). The opening / closing drive means is constituted by an opening / closing drive element and an opening / closing plunger, and the flow rate control drive means is constituted by a flow rate control plunger and a flow rate control drive element (for example, a flow rate control drive coil).

  In this valve device, when the fluid supply is stopped, the opening / closing drive means is in an activated state, and the flow rate controlling drive means is inactivated. In this operating state, the open / close plunger is moved in the closing direction by the open / close drive element (open / close drive coil), and the valve element is moved through the open / close plunger, the flow rate control plunger of the flow rate control drive means, and the diaphragm. Contact with the valve seat of the first member stops the supply of fluid from the inlet. Further, when the fluid is fed, the opening / closing drive means is deactivated, and the flow rate control drive means is activated. In this state, the open / close plunger is retracted and held in a non-operating state (a state where the open / close plunger is separated from the flow control plunger), and the flow control drive means moves toward the open / close drive means (for example, The drive current is supplied to the flow control drive coil, and the flow control plunger is magnetically attracted to the open / close drive means side). Thus, the valve body moves toward the opening / closing drive means by the action of the elastic biasing means, the space between the valve seat of the first member and the valve body is opened, and the fluid is fed through the inflow port. In this feeding state, the movement state of the flow rate control plunger is controlled by controlling the operating state of the flow rate control drive means (for example, the flow rate control plunger is controlled by controlling the drive current supplied to the flow rate control drive coil. The amount of suction between the valve seat of the first member and the valve body changes, thereby adjusting the amount of fluid fed through the inlet. it can.

JP-A-10-89532

  However, the conventional valve device described above has the following problems to be solved. Firstly, two drive means: an opening / closing drive means for controlling opening and closing of the valve body, and a flow rate control drive means for controlling the opening degree of the valve body (in other words, controlling the flow rate of the liquid). Therefore, there is a problem that the configuration of the valve device becomes complicated, the entire valve device becomes large, and the manufacturing cost thereof increases. Secondly, since the valve body is opened by operating the flow control drive element (for example, the flow control drive coil) of the flow control drive means, the flow control drive is used to keep the valve body open. It is necessary to keep the means in an operating state (for example, continue to supply drive current to the flow control drive coil). Accordingly, not only when the flow rate is adjusted, but also when the predetermined flow rate is maintained, the flow rate control drive element is maintained in the operating state (for example, the drive current is continuously supplied to the flow rate control drive coil), which is consumed. There is a problem that the energy (for example, power consumption) is large and the running cost when the fluid is supplied using the valve device is increased. Thirdly, since the drive current is supplied to the flow rate control drive element and the flow rate control plunger is magnetically attracted, it is difficult to obtain a large thrust for moving the valve body. Then, the drive element for flow control must be enlarged, and there is a problem that the valve device itself is enlarged. In addition, since the flow control drive element (drive coil) and the flow control plunger are combined, the air gap between them must be adjusted to a predetermined range. When the air gap increases, the valve element moves. There is a problem that the thrust for making it small.

The objective of this invention is providing the valve apparatus which can obtain the big thrust for moving a valve body.
Another object of the present invention is to provide a valve device that can reduce power consumption during fluid supply and reduce running costs.

The valve device according to claim 1 of the present invention has an inflow port, a first member provided with a valve seat around the inflow port, a valve housing attached to the first member, and the valve A valve body that is housed in a housing and controls a flow rate of fluid according to an interval between the first member and the valve seat; elastic biasing means for elastically biasing the valve body in an opening direction; and the valve housing A second member attached to the valve member, an actuating member accommodated in the second member so as to be movable toward and away from the valve body, a valve accommodating space in the valve housing, and an operation in the second member A diaphragm for sealing and blocking between the member housing space and a driving means for moving the operating member;
The drive means is composed of an electric motor, and a movement conversion mechanism for converting rotation of the electric motor into linear movement of the operation member is provided between the electric motor and the operation member.
When the electric motor rotates in a predetermined direction, the rotation of the electric motor in the predetermined direction is converted into a movement in the closing direction of the operating member via the movement conversion mechanism, whereby the operating member causes the diaphragm to move. The valve body moves in the closing direction against the elastic biasing action of the elastic biasing means, and when the electric motor rotates in a direction opposite to the predetermined direction, The rotation in the direction opposite to the predetermined direction is converted into movement in the opening direction of the operating member via the movement conversion mechanism, whereby the valve body is moved in the opening direction by the elastic biasing action of the elastic biasing means. It is characterized by moving.

  Further, in the valve device according to claim 2 of the present invention, a speed reduction mechanism is drivingly connected to the output side of the electric motor, a female screw mechanism is provided on the operating member, and the movement converting means is the speed reduction mechanism. It is comprised from the external thread part provided in the output shaft of this, and the internal thread part provided in the said internal thread mechanism.

  In the valve device according to claim 3 of the present invention, the female screw mechanism includes a pair of female screw members provided with a female screw part and a spring member interposed between the pair of female screw members, and the operation A pair of contact portions are provided at both ends of the member, the pair of female screw members are arranged on the inner side in the axial direction of the pair of contact portions, and the spring member is spaced apart from the pair of female screw members. An elastic biasing force is applied, and one female screw member is in contact with the inner side in the axial direction of one contact portion, and the other female screw member is in contact with the inner side in the axial direction of the other contact portion.

  In the valve device according to claim 4 of the present invention, the electric motor is a stepping motor, and the speed reduction mechanism is drivingly connected to one end side of the output shaft of the stepping motor, and is connected to the other end side of the output shaft. An encoder for detecting a rotation angle is drive-coupled.

Further, in the valve device according to claim 5 of the present invention, a first member having an inlet, a valve seat provided around the inlet, a valve housing attached to the first member, A valve structure that is housed in the valve housing and controls a flow rate of fluid according to an interval between the first member and the valve seat; and a driving means for moving the valve structure;
The drive means is composed of an electric motor, and a movement conversion mechanism is provided between the electric motor and the valve structure to convert rotation of the electric motor into linear movement of the valve structure. ,
When the electric motor rotates in a predetermined direction, the rotation of the electric motor in the predetermined direction is converted into movement in the closing direction of the valve structure via the movement conversion mechanism, and the electric motor is moved in the predetermined direction. When rotating in the opposite direction, the rotation of the electric motor in the direction opposite to the predetermined direction is converted into movement in the opening direction of the valve structure via the movement conversion mechanism.

  According to the valve device of the first aspect of the present invention, the first member is provided with the inlet, the valve body is accommodated in the valve housing, and the operation member for operating the valve body is accommodated in the second member. A diaphragm is disposed between the valve housing and the second member, and the diaphragm seals and shuts off the valve housing space in the valve housing and the actuating member housing space in the second member. The fluid that has flowed into the valve housing space does not flow into the actuating member housing space of the valve second member, and can reliably prevent the fluid from leaking to the outside. Further, since the driving means is composed of an electric motor and a movement conversion mechanism is provided between the electric motor and the operating member, the rotation of the electric motor is converted into a linear movement of the operating member via the movement conversion mechanism. It is possible to open and close the valve device and adjust its opening degree (in other words, control of the flow rate) using the rotation of the electric motor. In addition, since an electric motor is used to control the opening and closing of the valve body, a large thrust can be obtained. For example, a larger thrust can be obtained by combining with a speed reduction mechanism and a screw mechanism, thereby moving the valve body. A large range can be secured, and as a result, it can be applied over a wide range from small flow control to large flow control. Furthermore, the rotation of the electric motor only needs to move the valve body to control the flow rate (change the opening of the valve body), and no drive current is required to maintain the opening of the valve body, As a result, the power consumption can be reduced and the running cost can be reduced.

  According to the valve device of the second aspect of the present invention, the speed reduction mechanism is drivingly connected to the output side of the electric motor, the internal thread mechanism is provided on the operating member, and the movement converting means is the external thread of the output shaft of the speed reduction mechanism. And the female screw portion of the female screw mechanism, the rotation of the electric motor can be converted into the linear movement of the operating member by the male screw portion and the female screw portion screwed to each other. The valve body can be opened and closed.

  In the valve device according to claim 3 of the present invention, the female screw mechanism includes a pair of female screw members and a spring member interposed between the pair of female screw members, and the spring member includes one female screw member. Since it is elastically biased in the closing direction and is held in contact with one of the contact portions of the operating member, the male screw portion of the output shaft of the speed reduction mechanism and the female screw portion of the female screw mechanism when moving the moving member in the closing direction. There is no so-called play between them, and the rotation of the electric motor in a predetermined direction can be reliably converted into the linear movement of the actuating member in the closing direction, and the responsiveness of the valve body in the closing direction can be improved. Since the female screw member is elastically biased in the opening direction and is held in contact with the other contact portion of the operating member, the male screw portion of the output shaft of the speed reduction mechanism when the moving member is moved in the opening direction and the female screw mechanism There is no so-called play between the internal thread and the direction opposite to the predetermined direction of the electric motor. Reliably changing the direction of rotation into a linear movement the opening direction of the actuating member, it is possible to improve the response of the closing direction of the valve body.

  In the valve device according to claim 4 of the present invention, since the electric motor is composed of a stepping motor, the operation member is moved by a predetermined amount in the opening / closing direction by utilizing a predetermined angular rotation of the stepping motor. be able to. Moreover, control responsiveness can be improved by applying PID control to the control of the stepping motor. Further, when the drive current is not supplied, the output shaft is magnetically held at the angular position, so that the valve body can be moved to that position (for example, the closed position, the predetermined opening position, etc.) without supplying the drive current. The position holding effect can be further obtained by applying the magnetic circuit of the stepping motor, the speed reduction mechanism, and the screw mechanism. Further, since the encoder is drivingly connected to the other end of the output shaft of the stepping motor, the return of the valve body to the origin, that is, the positioning to the closed position can be reliably performed using the detection signal of the encoder.

  In the valve device according to claim 5 of the present invention, the drive means is constituted by an electric motor, and the movement conversion mechanism is provided between the electric motor and the valve structure, so that the rotation of the electric motor Can be converted into a linear movement of the valve structure through the movement conversion mechanism, and the opening and closing of the valve device and the adjustment of the opening degree (in other words, the control of the flow rate) are performed using the rotation of the electric motor. Can do. Further, since an electric motor is used for opening / closing control of the valve structure, a large thrust can be obtained. For example, a larger thrust can be obtained by combining with a speed reduction mechanism and a screw mechanism. A large moving range can be secured. Furthermore, the electric motor can be rotated only when the valve structure is moved to control the flow rate, and the power consumption can be reduced.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best embodiment of a valve device according to the invention will be described with reference to the accompanying drawings. 1 is a cross-sectional view showing a valve device according to an embodiment, FIG. 2 is an exploded perspective view showing an exploded movement conversion mechanism in the valve device of FIG. 1, and FIG. 3 is a valve device of FIG. It is a fragmentary sectional view which shows a part of in the state which opened the valve body.

  In FIG. 1, the illustrated valve device includes a first member 2, a valve housing 4, and a second member 6. The valve housing 4 is attached to the first member 2, and the second member 6 is attached to the valve housing 4. ing. The first member 2 is provided with an inflow port 8 and an outflow port 10, and the inflow port 8 and the outflow port 10 are opened on one surface of the first member 2, the upper surface in FIG. 1. A liquid to be delivered, for example, a processing liquid, a reaction gas, or the like is supplied through the inlet 8 as indicated by an arrow 12, and the liquid supplied through the inlet 8 flows as indicated by an arrow 14 as described later. It is fed downstream through the outlet 10. A valve seat 16 is provided around the inlet 8 on the one surface of the first member 2.

  A valve housing space 18 is provided through substantially the center of the valve housing 4, and a valve body 20 is housed in the valve housing space 18. The valve body 20 includes a substantially cylindrical valve body 22, and a valve portion 24 is provided at one end of the valve body 22. In this embodiment, a circular concave portion 26 is provided on one end surface of the valve body 22 so as to face the inlet 8 of the first member 2, and an annular outer peripheral portion that defines the concave portion 26 functions as the valve portion 24.

  A mounting recess 28 that opens to the other end surface (upper surface in FIG. 1) is provided at the center of the valve body 22, and an action piece 30 is attached to the mounting recess 28, and the tip of the action piece 30 is the valve body. 22 slightly protrudes from the mounting recess 28 toward the second member 6 (upper side in FIG. 1). An annular flange 32 protruding radially outward is provided at the other end of the valve body 24, and an elastic biasing means is interposed between the annular flange 32 and the valve seat 16 of the first member 2. Yes. In this embodiment, the elastic biasing means is constituted by a coil spring 34 that is fitted between the annular flange 32 and the valve seat 16 so as to fit the valve main body 22. The coil spring 34 acts on the annular flange 32 to elastically bias the valve element 22 in the opening direction, that is, upward in FIG.

  In such a valve body 20, the valve body 22 and the annular flange 32 are formed from a synthetic resin material such as fluororesin (for example, PTFE, CPTFE), and the action piece 30 is formed from a metal material such as stainless steel. The entire valve body 20 may be integrally formed from a synthetic resin material or a metal material.

  An operation member accommodation space 36 is provided in a substantially central portion of the lower part of the second member 6, and a cylindrical space 38 connected to the operation member accommodation space 36 is provided in the upper part thereof. Referring also to FIG. 2, in this embodiment, the working member housing space 36 is formed in a rectangular shape, and the working member 40 is housed in the working member housing space 36 so as to be movable in the open / close direction, that is, in the vertical direction in FIG. 1. ing. The illustrated actuating member 40 includes a main body 44 provided with a substantially rectangular recess 42 that is released to the right side in FIG. 2, and one end of the main body 44 (the lower end in FIGS. 1 and 2) includes: A first plate piece 46 is provided so as to cover one end surface of the concave portion 42, and a second plate piece 48 is provided at the other end portion (upper end portion in FIGS. 1 and 2) so as to cover the end surface of the concave portion 42. Yes. The outer shape of the first plate piece 46 is substantially the same as the cross-sectional shape of the actuating member accommodation space 36 of the second member 6, and therefore, the first plate piece 46 extends along the actuating member accommodation space 36 in FIG. By moving in the direction, the actuating member 40 is moved in the opening and closing direction. On the outer surface (the lower surface in FIG. 1) of the first plate piece 46 is provided an action protrusion 50 that protrudes outward, and the second plate piece 48 is provided with a substantially U-shaped notch 52. . The 1st and 2nd plate pieces 46 and 48 function as a contact part with which the female screw mechanism mentioned later contacts.

  A diaphragm 54 is provided between the valve housing space 18 of the valve housing 4 and the operating member housing space 36 of the second member 6. The diaphragm 54 is composed of a thin metal plate formed of a metal material such as stainless steel, and is fixed to the end surface of the valve housing 4 by means such as welding. By providing the diaphragm 54 in this manner, the valve housing space 18 of the valve housing 4 and the operating member housing space 36 of the second member 6 are hermetically cut off, and the fluid flowing into the valve housing space 18 is operated as described later. Leakage into the member accommodating space 36 can be reliably prevented. The diaphragm 54 may be provided on the second member 6 side, or may be attached using a rubber seal or the like instead of welding.

  The operating member 40 is configured to be moved in the opening / closing direction by the rotation of the electric motor 60. More specifically, a cover member 62 is attached so as to cover the cylindrical space 38 of the second member 6, and a speed reduction mechanism housing 64 containing a speed reduction mechanism (not shown) is attached to the outside of the cover member 62, An electric motor 60 constituting drive means is attached to the speed reduction mechanism housing 64. The electric motor 60 is preferably composed of a stepping motor, and by using the stepping motor, the valve body 20 is opened and closed in the opening / closing direction (vertical direction in FIG. 1) by utilizing a predetermined angle rotation of its output shaft (not shown). Accordingly, the amount of fluid supplied through the inlet 8 can be accurately controlled. Further, due to the characteristics of the magnetic circuit of the stepping motor, when the drive current is not supplied, the output shaft is held at the stop angle position, and the valve body 20 is moved to its open / close position (ie, without consuming drive power). The closed position can be held in the closed state, and the predetermined open position in the predetermined open state.

  An output shaft (not shown) of the electric motor 60 is drivingly connected to an input side of a speed reduction mechanism (not shown), and an output shaft portion 66 of the speed reduction mechanism passes outward (in FIG. 1) through an end wall of the speed reduction mechanism housing 64. Projecting downward) and extending into the cylindrical space 38 of the second member 6 through an opening 68 provided in the cover member 62. A screw shaft portion 70 is attached to the output shaft portion 66 and constitutes an output shaft of the speed reduction mechanism together with the output shaft portion 66. For example, the screw shaft portion 70 is provided with a connection recess 74 in the screw shaft portion 70, the connection shaft portion 76 of the output shaft portion 66 is inserted into the connection recess 74, and a fixing screw 78 is screwed into the screw shaft portion 70. By acting on the connecting shaft portion 76, the output shaft portion 66 is connected. With this configuration, when the electric motor 60 rotates in a predetermined direction (the direction opposite to the predetermined direction), the rotation speed is reduced as required through the reduction mechanism, and output with the reduced rotation speed. The shaft portion 66 and the screw shaft portion 70 are rotated in a predetermined direction (a direction opposite to the predetermined direction).

  Between the output shaft (screw shaft portion 70) of the speed reduction mechanism and the operating member 40, there is provided a movement conversion mechanism 80 for converting the rotation of the output shaft into a linear movement in the opening / closing direction (vertical direction in FIG. 1). It has been. The movement conversion mechanism 80 includes a male screw portion 72 provided on the screw shaft portion 70 of the speed reduction mechanism and a female screw mechanism 82 provided on the operating member 40. The screw shaft portion 70 may be omitted, and the male screw portion 72 may be directly provided on the output shaft portion 66 of the speed reduction mechanism.

  The illustrated female screw mechanism 82 includes a pair of female screw members 84 and 86 and a spring member 88 interposed between the female screw members 84 and 86. The female screw members 84 and 86 are constituted by rectangular members provided with the female screw portion 90, and the outer shape thereof corresponds to the shape of the rectangular concave portion 42 of the operating member 40, and the spring member 88 is constituted by a coil spring. Has been. The pair of female screw members 84 and 86 are screwed into the male screw portion 72 of the screw shaft portion 70 of the speed reduction mechanism, and one female screw member 84 is mounted so as to contact the contact portion 46 (first plate piece) of the operating member 40. The other female screw member 86 is mounted so as to contact the other contact portion 48 (second plate piece) of the actuating member 40, and the spring member 88 extends in a direction separating the pair of female screw members 84 and 86 from each other. Elastically biased. Such a female screw mechanism 82 is mounted so as to be accommodated in the rectangular recess 42 of the operating member 40, and the female screw portion 90 of the pair of female screw members 84 and 86 and the male screw portion 72 of the screw shaft portion 70 constitute the movement converting mechanism 90. To do. A nut member can also be used as the pair of female screw members 84 and 86.

  With this configuration, when the output shaft (the output shaft portion 6 and the screw shaft portion 70) of the speed reduction mechanism rotates in a predetermined direction (or a direction opposite to the predetermined direction), the second member 6 and the operating member 40 1 and the relative rotation of the actuating member 40 and the female screw mechanism 82 (the pair of female screw members 84 and 86) are restricted, so that the female screw mechanism 82 and the actuating member 40 are integrally closed, that is, FIG. Is moved downward (or in the opening direction, ie upward in FIG. 1). At this time, since the spring member 88 acts on the pair of female screw members 84 and 86, play (so-called looseness) in the closing direction movement of the female screw member 84 acting on one of the contact portions 46, and the other female screw There is substantially no play when moving in the opening direction when the member 86 acts on the other abutting portion 48, and the actuating member 40 can be reliably moved in the opening and closing direction. Responsiveness can be improved.

  In this valve device, an encoder 92 is attached to the other end of the output shaft (not shown) of the electric motor 60. The encoder 92 may be known per se, and is configured to detect the rotation angle of the electric motor 60 with the encoder 92. The detection signal of the encoder 92 is used when the origin of the valve body 20 is returned, that is, when the valve body 20 is positioned at the closed position shown in FIG. 1 (the position where the valve portion 24 of the valve body 20 is seated on the valve seat 16 of the first member 2). By using this detection signal, it is possible to reliably position the valve body 20 in the closed position and stop the fluid supply.

  The opening / closing operation of this valve device will be described as follows. When the fluid supply is stopped, the valve body 20 is held in the state shown in FIG. That is, the output shaft of the electric motor 60 is held at the origin angle position (this origin angle position is an angle position where the valve body 20 is positioned at the origin return position, and is performed using the detection signal of the encoder 92. ) In this state, as shown in FIG. 1, the action protrusion 50 of the actuating member 40 acts on the action piece 30 of the valve body 20 via the diaphragm 54, and the valve part 24 is seated on the valve seat 16 and flows into the inlet. 8 is closed and the fluid from the inlet 8 is stopped.

  When supplying fluid, the electric motor 60 is rotated in a predetermined direction. Thus, the rotation of the electric motor 60 is transmitted to the screw shaft portion 70 via the speed reduction mechanism, and the screw shaft portion 70 is rotated in a predetermined direction. Thus, since the rotation of the operating member 40 and the female screw mechanism 82 is restricted, the operating member 40 is moved in the opening direction (upward in FIG. 1) via the female screw mechanism 82, and accompanying this movement in the opening direction. The valve body 20 is moved in the opening direction by the elastic biasing action of the coil spring 34. When moving in the opening direction in this way, the valve portion 24 of the valve body 20 is separated from the valve seat 16 of the first member 2, the inlet 8 is released, and the fluid from the inlet 8 flows into the valve housing space 18, The fluid thus introduced is fed downstream through the outlet 10.

  When the flow rate of the fluid supplied through the inflow port 8 is controlled, the electric motor 60 may be rotationally controlled. For example, when the electric motor 60 is rotated in a predetermined direction (or a direction opposite to the predetermined direction), the screw shaft portion 70 of the speed reduction mechanism and The operating member 40 is moved in the opening direction (or the closing direction) via the female screw mechanism 82, whereby the valve body 20 is moved in the opening direction by the elastic biasing action of the coil spring 34 (or the operating member 40 moves the diaphragm 54. Via the valve body 20 and moves in the closing direction against the elastic biasing action of the coil spring 34), and thus the supply amount of the fluid supplied from the inlet 8 is increased (or decreased).

  Further, when stopping the supply of the fluid supplied from the inflow port 8, the electric motor 60 may be rotated in a direction opposite to the predetermined direction. By rotating the electric motor 60 as described above, as described above, the screw shaft portion 70 of the speed reduction mechanism. The operating member 40 is moved in the closing direction via the female screw mechanism 82, and the operating member 40 acts on the valve body 20 via the diaphragm 54 to move in the closing direction. Thus, the valve portion 24 of the valve body 20 is moved in the first direction. The inflow port 8 is closed by sitting on the valve seat 16 of the one member 2, and the supply of fluid from the inflow port 8 is stopped.

  In the valve device using the electric motor 60, when the supply of current to the electric motor 60 is stopped due to a power failure or the like, the valve body 20 cannot be controlled to open and close. For example, when a power failure occurs when the valve body 20 is in the open state, the valve body 20 is kept in the open state, and the supply of fluid through the inflow port 8 is continued. In order to eliminate the occurrence of such a situation, it is preferable to provide power storage means for storing drive power, for example, a capacitor, in association with the electric motor 60. The capacity of the power storage means may be sufficient to operate the electric motor 60 and move the valve body 20 to, for example, the origin return position (closed position in this embodiment). By providing such power storage means, When the opening / closing control of the valve body 20 becomes impossible, such as during a power failure, the valve body 20 can be forcibly returned to the origin return position and the fluid supply to the downstream side can be stopped.

  The valve device described above can further enhance the responsiveness of the opening / closing operation of the valve body by applying the PID control to the opening / closing control. PID is proportional to the proportional action (Proportional Action) that produces an output proportional to the deviation between the current value and the set value, the integral action that produces an output proportional to the integral of the deviation (Integral Action), and proportional to the derivative of the deviation. This is a control method of outputting the sum of the differential action (Derivative Action) for outputting the output and controlling toward the target value.

  As mentioned above, although one Embodiment of the valve apparatus according to this invention was described, this invention is not limited to this Embodiment, A various deformation | transformation thru | or correction | amendment are possible without deviating from the scope of the present invention.

For example, although the outlet 10 is provided in the first member 2 in the illustrated embodiment, such an outlet may be provided in the valve housing.
Further, for example, in the illustrated embodiment, the actuating member 40 and the valve body 20 are configured separately, and the actuating protrusion 50 of the actuating member 40 is configured to act on the valve body 20 via the diaphragm 54. However, the present invention is not limited to such a configuration, and the valve structure is formed by integrating the actuating member 40 and the valve body 20, and the valve structure is opened and closed by a movement conversion mechanism (a screw shaft portion and a female screw mechanism of a speed reduction mechanism). In this case, it is necessary to seal between the diaphragm 54 and the valve structure that penetrates the diaphragm 54, but the coil spring 34 as the elastic biasing means can be omitted. In addition, the structure which moves such a valve structure body with an electric motor is applicable also to the other normal valve apparatus which is not provided with a diaphragm.

  Further, for example, in the illustrated embodiment, the description has been made by applying to the normal / closed type in which the valve body 20 is normally closed, but the present invention is not limited thereto, and the valve body is normally maintained in the open state. It can be similarly applied to the normal open type. In this case, the elastic biasing means may be positioned at the open position (origin return position).

  Further, for example, in the illustrated embodiment, a stepping motor is used as the electric motor, but a brushless DC servo motor can be used for more precise required specifications.

Sectional drawing which shows one Embodiment of a valve apparatus. The disassembled perspective view which decomposes | disassembles and shows the movement conversion mechanism in the valve apparatus of FIG. The fragmentary sectional view which shows a part of valve apparatus of FIG. 1 in the state which open | released the valve body.

Explanation of symbols

2 First member 4 Valve housing 6 2nd member 8 Inlet 10 Outlet 16 Valve seat 18 Valve accommodating space 20 Valve body 34 Coil spring 36 Actuating member accommodating space 40 Actuating member 54 Diaphragm 60 Electric motor 80 Movement conversion mechanism 82 Female screw mechanism 92 Encoder

Claims (5)

A first member having an inlet and a valve seat around the inlet; a valve housing attached to the first member; and the valve of the first member housed in the valve housing. A valve body for controlling a flow rate of fluid according to a distance from the seat, elastic biasing means for elastically biasing the valve body in an opening direction, a second member attached to the valve housing, and the second member And a diaphragm for hermetically sealing between a valve housing space in the valve housing and a working member housing space in the second member. And drive means for moving the actuating member,
The drive means is composed of an electric motor, and a movement conversion mechanism for converting rotation of the electric motor into linear movement of the operation member is provided between the electric motor and the operation member.
When the electric motor rotates in a predetermined direction, the rotation of the electric motor in the predetermined direction is converted into a movement in the closing direction of the operating member via the movement conversion mechanism, whereby the operating member causes the diaphragm to move. The valve body moves in the closing direction against the elastic biasing action of the elastic biasing means, and when the electric motor rotates in a direction opposite to the predetermined direction, The rotation in the direction opposite to the predetermined direction is converted into movement in the opening direction of the operating member via the movement conversion mechanism, whereby the valve body is moved in the opening direction by the elastic biasing action of the elastic biasing means. A valve device characterized by moving.   A reduction mechanism is drivingly connected to the output side of the electric motor, a female screw mechanism is provided on the operating member, and the movement converting means is connected to a male screw portion provided on the output shaft of the reduction mechanism, and the female screw mechanism. The valve device according to claim 1, wherein the valve device comprises a female screw portion provided.   The female screw mechanism is composed of a pair of female screw members provided with a female screw part and a spring member interposed between the pair of female screw members, and a pair of contact parts are provided at both ends of the operating member, The pair of female screw members are disposed on the inner side in the axial direction of the pair of contact portions, the spring member applies an elastic biasing force in a direction away from each other to the pair of female screw members, and one female screw member 3. The valve device according to claim 2, wherein the valve device is in contact with an inner side in the axial direction of the contact portion, and the other female screw member is in contact with an inner side in the axial direction of the other contact portion.   The electric motor is a stepping motor, the speed reduction mechanism is drivingly connected to one end side of the output shaft of the stepping motor, and an encoder for detecting a rotation angle is drivingly connected to the other end side of the output shaft. The valve device according to claim 2. A first member having an inlet and a valve seat around the inlet; a valve housing attached to the first member; and the valve of the first member housed in the valve housing. A valve structure that controls the flow rate of fluid according to the distance from the seat, and drive means for moving the valve structure,
The drive means is composed of an electric motor, and a movement conversion mechanism is provided between the electric motor and the valve structure to convert rotation of the electric motor into linear movement of the valve structure. ,
When the electric motor rotates in a predetermined direction, the rotation of the electric motor in the predetermined direction is converted into movement in the closing direction of the valve structure via the movement conversion mechanism, and the electric motor is moved in the predetermined direction. When rotating in the opposite direction, the rotation of the electric motor in the direction opposite to the predetermined direction is converted into movement in the opening direction of the valve structure via the movement conversion mechanism.

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