Fluid control valve and fluid control device

Abstract

To improve position stability of a displacement magnification mechanism that magnifies displacement of a valve body.SOLUTION: A fluid control valve comprises an actuator 4 for driving a valve body 3, and a displacement magnification mechanism 5 that is interposed between the valve body 3 and the actuator 4 and magnifies the displacement of the actuator 4 and transmits it to the valve body 3. The displacement magnification mechanism 5 has an input member 51 that is displaced by receiving a driving force from the actuator 4, and a plurality of lever members 52 that are arranged around a central axis 3C of the valve body 3 between the input member 51 and the valve body 3 and magnify the displacement of the input member 51 and transmit it to the valve body 3. The plurality of lever members 52 have a contact surface that comes in contact with the input member 51 to serve as a force point. The contact surface slopes downward toward the central axis 3C of the valve body 3.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a fluid control valve and a fluid control device. [Background technology]

[0002] A conventional fluid control valve uses a piezo stack as an actuator for driving a valve body, as shown in Patent Document 1. This fluid control valve is equipped with an actuation amount amplifier device to extend the actuation amount (stroke) of the actuation target part, which is the valve body, without increasing the size of the piezo stack, which has a small displacement amount.

[0003] This actuation amount amplification device is provided between the piezo stack and the actuated part, and comprises a pressure plate body arranged on the piezo stack side, a support plate body arranged on the actuated part side, and a lever body arranged so that the force point abuts against the pressure plate body and the action point abuts against the support plate body.

[0004] The upper end of the piezo stack is fixed to the case, and the lower end, which is the free end, displaces the pressing plate in the vertical direction. The pressing plate is flat, and the flat lower surface of the pressing plate is configured to contact the convex tip of the lever.

[0005] However, because the lower end of the piezo stack is a free end and the lower surface of the pressing plate is in contact with the convex tip of the lever, there is a risk that the pressing plate connected to the lower end of the piezo stack may shift laterally relative to the lever, resulting in a problem of poor reproducibility of the amplified displacement relative to the displacement of the piezo stack. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2003-199366 A Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, the present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to improve the positional stability of a displacement magnifying mechanism that magnifies the displacement of the valve body. [Means for solving the problem]

[0008] That is, the fluid control valve of the present invention comprises an actuator for driving a valve body, and a displacement magnification mechanism interposed between the valve body and the actuator for magnifying the displacement of the actuator and transmitting it to the valve body, the displacement magnification mechanism having an input member that is displaced by receiving a driving force from the actuator, and a plurality of lever members that are arranged around the central axis of the valve body between the input member and the valve body and magnify the displacement of the input member and transmit it to the valve body, the plurality of lever members having contact surfaces with which the input member comes into contact and which serve as force points, and the contact surfaces having a downward slope toward the central axis of the valve body.

[0009] In such a fluid control valve, a plurality of lever members arranged around the central axis of the valve body have contact surfaces that contact the input member and become the force points, and since the contact surfaces are inclined downward toward the central axis of the valve body, the input member is less likely to shift in position in a direction away from the central axis. As a result, the positional stability of the displacement magnification mechanism can be improved. By improving the positional stability of the displacement magnification mechanism, the reproducibility of the displacement amount magnified with respect to the displacement amount of the actuator can be improved. In addition, by improving the positional stability of the displacement magnification mechanism, the outflow (liquid leakage) in the fully closed state can be reduced. Furthermore, it is possible to prevent the margin at the time of full opening (the set value for the fully open state) from being exceeded, which leads to deterioration of controllability. In addition, since the reproducibility of the displacement amount can be improved, the responsiveness of the fluid control can be improved.

[0010] It is desirable that the contact surface slopes downwardly toward the central axis of the valve body regardless of expansion and contraction of the actuator. With this configuration, when the input member comes into contact with the multiple lever members, the contact surface always slopes downward, making it difficult for the input member to shift in position, thereby improving the positional stability of the displacement magnifying mechanism.

[0011] It is preferable that the input member has a plurality of pressing portions that press the contact surfaces of the plurality of lever members, each pressing portion making line contact with the corresponding contact surface. With this configuration, the pressing portion comes into line contact with the contact surface, so that the displacement of the actuator can be reliably input to the force point of the lever member.

[0012] As a specific embodiment of each pressing portion, it is considered that each pressing portion is a linear protrusion formed so as to come into line contact with the corresponding contact surface.

[0013] It is desirable that the input member be formed on the inside of the plurality of pressing portions and have thick portions continuous with the apexes of the pressing portions. With this configuration, since the thick portion is located more inward than the multiple pressing portions, the mechanical strength of the input member is improved and the displacement of the actuator can be reliably input to the force point of the lever member.

[0014] It is preferable that the displacement magnifying mechanism further includes an output member that is interposed between the plurality of lever members and the valve body and that comes into contact with application points of the plurality of lever members. With this configuration, there is no need to increase the size of the valve body to accommodate multiple lever members, and it is possible to prevent the peripheral members from becoming larger as a result of increasing the size of the valve body.

[0015] It is preferable that the displacement magnifying mechanism further includes positioning members that are provided between the plurality of lever members in the circumferential direction and that position each of the lever members in the circumferential direction. With this configuration, it is possible to prevent the multiple lever members from becoming misaligned, to reliably receive the displacement input from the input member, and to reliably output the displacement to the valve body.

[0016] It is desirable that the surface of the input member facing the actuator be convex. With this configuration, the mechanical strength of the input member is improved, and the displacement of the actuator can be reliably input to the force point of the lever member.

[0017] In a fluid control valve (piezo valve) that uses a piezo stack as an actuator, the valve opening is small because the displacement of the piezo stack is small. In this way, it is desirable to apply the displacement magnifying mechanism of the present invention to a fluid control valve that uses an actuator having a piezo stack.

[0018] In addition, a fluid control device according to the present invention is characterized in that it comprises the above-mentioned fluid control valve, a fluid sensor provided upstream or downstream of the fluid control valve, and a valve control unit that controls the fluid control valve based on the output of the fluid sensor. Effect of the Invention

[0019] In this way, according to the present invention, it is possible to improve the positional stability of the displacement magnifying mechanism that magnifies the displacement of the valve element. [Brief description of the drawings]

[0020] [Figure 1] 1 is a diagram illustrating a schematic configuration of a fluid control device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of the fluid control valve of the embodiment. [Diagram 3] FIG. 2 is a perspective view showing a displacement magnifying mechanism of the embodiment. [Figure 4] 5 is a schematic diagram showing a positional relationship between a lever member and a positioning member in the embodiment; FIG. [Diagram 5]5A and 5B are schematic diagrams illustrating the displacement magnifying mechanism according to the embodiment in a contracted state and an expanded state of the actuator. [Figure 6] FIG. 4 is an enlarged cross-sectional view of a fluid control valve according to a modified embodiment. [Figure 7] FIG. 13 is a diagram illustrating a configuration of a fluid control device according to a modified embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of a fluid control device using a fluid control valve according to the present invention will be described with reference to the drawings. Note that in all of the drawings shown below, for ease of understanding, some parts are omitted or exaggerated as appropriate. The same components are given the same reference numerals and the description thereof will be omitted as appropriate.

[0022] <1. Basic configuration of the fluid control device 100> The fluid control device 100 according to this embodiment is a so-called mass flow controller used in a semiconductor manufacturing process. The fluid control device 100 can be used not only in the semiconductor manufacturing process but also in other processes.

[0023] The fluid control device 100 here is a pressure type device, as shown in Fig. 1. Specifically, the fluid control device 100 includes a flow path block B having a flow path L therein, a fluid control valve V installed in the flow path block B, a pair of pressure sensors PS1 and PS2 that are fluid sensors installed upstream or downstream of the fluid control valve V in the flow path block B, and a valve control unit C that feedback controls the fluid control valve V so that a flow rate value of the flow path L calculated based on pressure values ​​measured by the pair of pressure sensors PS1 and PS2 approaches a predetermined target value.

[0024] The flow path block B is, for example, rectangular parallelepiped-shaped, and has a fluid control valve V and a pair of pressure sensors PS1, PS2 disposed on a predetermined surface thereof. The flow path block B is also provided with a recessed accommodation portion B1 for accommodating the fluid control valve V on a predetermined surface thereof. The accommodation portion B1 divides the flow path L into an upstream flow path L1 and a downstream flow path L2. One end of the upstream flow path L1 opens on the bottom surface of the accommodation portion B1, and one end of the downstream flow path L2 opens on the side surface thereof.

[0025] The pair of pressure sensors PS1, PS2 are connected to the upstream and downstream sides, respectively, of a fluid resistance S1, such as a laminar flow element, provided in the flow path L, and both are connected to a flow rate calculation unit S2 that calculates the flow rate based on the outputs of the pair of pressure sensors PS1, PS2. The pair of pressure sensors PS1, PS2 are attached in a row together with the fluid control valve V on a predetermined surface of the flow path block B.

[0026] The valve control unit C has a so-called computer equipped with a CPU, memory, A / D and D / A converters, etc., and executes programs stored in the memory to realize various functions by various devices working together. Specifically, it feedback controls the valve opening of the fluid control valve V so that the flow rate value calculated by the flow rate calculation unit S2 approaches a target value previously stored in the memory.

[0027] <2. Specific configuration of the fluid control valve V> Next, the fluid control valve V of this embodiment will be described. For convenience of explanation, the valve seat member 2 side with respect to the valve body 3 will be referred to as the lower side, and the actuator 4 side with respect to the valve body 3 will be referred to as the upper side.

[0028] The fluid control valve V of this embodiment is, for example, a normally open type, and as shown in Figures 1 and 2, is equipped with a valve seat member 2 on which a valve seat 21 is formed, a valve body 3 arranged so as to be able to move toward and away from the valve seat 21, and an actuator 4 for driving the valve body 3.

[0029] The valve seat member 2 has a valve seat 21 for separating the upstream flow path L1 and the downstream flow path L2, and is accommodated in the accommodation portion B1 of the flow path block B. The valve seat member 2 of this embodiment has a circular valve seat 21. A first internal flow path 2a communicating with the upstream flow path L1 is formed inside the valve seat 21. Also, a second internal flow path 2b communicating with the downstream flow path L2 is formed outside the valve seat 21.

[0030] The valve body 3 has a seating surface 31 that seats on the valve seat 21 of the valve seat member 2. As shown in FIG. 2, the valve body 3 of this embodiment has a valve body main body 32 that is approximately cylindrical and extends in the direction of advancement and retreat by the actuator 4, and a diaphragm portion 33 that is approximately disk-shaped and provided around the valve body main body 32. The lower surface of the valve body main body 32 serves as the seating surface 31. The outer periphery of the diaphragm portion 33 is connected to a support portion 34 that is approximately cylindrical. This support portion 34 is fixed to the flow path block B via a seal member (not shown). In this embodiment, the valve body main body 32, the diaphragm portion 33, and the support portion 34 are integrally formed.

[0031] The actuator 4 is a piezoelectric actuator, and has one or more piezoelectric stacks in which piezoelectric ceramic layers and electrode layers are alternately laminated. The actuator 4 is housed in a casing 40, and an upper end portion of the actuator 4 (the end portion opposite the valve body 3) is fixed to the casing 40. In other words, the actuator 4 expands and contracts, and thereby the lower end portion (the end portion on the valve body 3 side) of the actuator 4 is displaced. The displacement of the lower end portion of the actuator 4 causes the valve body 3 to move via a displacement magnifying mechanism 5, which will be described later.

[0032] With the above-mentioned configuration, as the actuator 4 expands, the seating surface 31 of the valve body 3 comes into contact with the valve seat 21 of the valve seat member 2, blocking the upstream flow path L1 and the downstream flow path L2. As the actuator 4 contracts, the seating surface 31 of the valve body 3 moves away from the valve seat 21 of the valve seat member 2, connecting the upstream flow path L1 and the downstream flow path L2. Then, the position of the valve body 3 changes in response to the expansion and contraction of the actuator 4, and as a result, the distance between the valve seat 21 and the seating surface 31 changes, thereby controlling the flow rate.

[0033] <Displacement magnification mechanism 5> Thus, the fluid control valve V of this embodiment includes a displacement magnifying mechanism 5 that magnifies the displacement of the actuator 4 and transmits it to the valve element 3, as shown in FIGS.

[0034] As shown in Figures 2 to 5, the displacement magnification mechanism 5 has an input member 51 that is displaced upon receiving a driving force from the actuator 4, a plurality of lever members 52 that amplify the displacement of the input member 51 and transmit it to the valve body 3, and an output member 53 that is displaced upon receiving a driving force from the plurality of lever members 52.

[0035] The input member 51 is connected to the lower end, which is the free end, of the actuator 4 via the intermediate connector 6. The input member 51 has a convex upper surface, which faces the actuator 4, and a recess 51c in which the intermediate connector 6 is provided is formed in the center. When the actuator 4 expands or contracts, the input member 51 is displaced together with the actuator 4 via the intermediate connector 6. The input member 51 displaces together with the actuator 4 and inputs a driving force (displacement of the actuator 4) to a plurality of lever members 52. The input member 51 is accommodated in a accommodating block 7 connected to the support portion 34 of the valve body 3 (see FIG. 2).

[0036] The multiple lever members 52 are disposed around the central axis 3C of the valve body 3 between the input member 51 and the valve body 3. The central axis 3C of the valve body 3 is specifically the central axis of the valve body main body 32 and is also the central axis of the actuator 4. The multiple lever members 52 in this embodiment are disposed at equal intervals in the circumferential direction around the central axis 3C of the valve body 3. Here, an example in which three lever members 52 are disposed is shown, but a configuration using one or two lever members 52, or a configuration using four or more lever members 52 may also be used.

[0037] Specifically, the multiple lever members 52 are accommodated in the accommodation block 7 (see FIG. 2). A roughly cylindrical space is formed inside the accommodation block 7 to accommodate the input member 51 and the multiple lever members 52 (see FIGS. 2 and 4). The multiple lever members 52 are arranged at equal intervals in the circumferential direction on the upper surface (the surface facing the actuator 4) of, for example, an annular protrusion 7a formed inside the accommodation block 7. The multiple lever members 52 come into contact with an inner peripheral surface 7b of the accommodation block 7, and their radial positions are regulated.

[0038] 2, each of the lever members 52 has a contact surface 52a with which the input member 51 comes into contact to form the force point X. Specifically, the upper surface (the surface facing the actuator 4) of each of the lever members 52 has the contact surface 52a with which the input member 51 comes into contact to form the force point X. Moreover, each of the lever members 52 has the same shape.

[0039] Furthermore, a protrusion 52b serving as a fulcrum Y is formed on the outer side of the lower surface (the surface facing the valve body 3) of each lever member 52, and a tip 52c serving as a point of action Z is formed on the inner side of the lower surface. Note that the outer side of the lower surface refers to the side away from the central axis 3C of the valve body 3, and the inner side of the lower surface refers to the side facing the central axis 3C of the valve body 3.

[0040] 5, the positions of the fulcrum Y, force point X, and action point Z are set in each lever member 52 in order to magnify the displacement input from the input member 51 and output it to the output member 53. Specifically, the distance between the fulcrum Y and the action point Z is set to be larger than the distance between the fulcrum Y and the force point X.

[0041] As shown in FIG. 2 and FIG. 5, the contact surface 52a of each lever member 52 has a downward inclination toward the central axis 3C of the valve body 3. Here, "having a downward inclination toward the central axis 3C" means that the contact surface 52a is inclined toward the valve body side (the opposite side to the actuator 4) as it approaches the central axis 3C. The contact surface 52a has a downward inclination toward the central axis 3C of the valve body 3 regardless of the expansion and contraction of the actuator 4. In a state in which the multiple lever members 52 are arranged on the protruding portion 7a of the accommodation block 7, the contact surface 52a has a downward inclination toward the central axis 3C of the valve body 3. The contact surface 52a in this embodiment is a flat surface, but may be a curved surface or a bent surface. Note that the inclination angle of the downward inclination of the contact surface 52a is greater than 0 degrees, for example, 20 degrees or less, with respect to the horizontal plane (plane perpendicular to the central axis 3C) before the actuator 4 is extended.

[0042] The input member 51 inputs the displacement of the actuator 4 to the multiple leverage members 52, and the input member 51 of this embodiment has multiple pressing portions 51a that press the contact surfaces 52a of the multiple leverage members 52, as shown in Figures 2, 3 and 5. Specifically, the input member 51 has multiple branched portions 511 on which the respective pressing portions 51a are formed, as shown in Figure 3. In other words, the input member 51 is provided so that the multiple branched portions 511 correspond to the multiple leverage members 52.

[0043] Each pressing portion 51a is in line contact with the corresponding contact surface 52a. Here, line contact means that the pressing portion 51a is in line contact with the contact surface 52a over a predetermined range. Also, each pressing portion 51a is a linear protrusion formed to be in line contact with the corresponding contact surface 52a. By making the pressing portion 51a in line contact with the contact surface 52a in this way, stress concentration can be reduced and wear of the contact surface 52a can be reduced compared to when the pressing portion 51a is in point contact.

[0044] The input member 51 has a thick portion 51b formed inside the pressing portions 51a and continuing to the tops of the pressing portions 51a. The lower surface of the thick portion 51b, which faces the lever member 52, is flat. The thick portion 51b increases the mechanical strength of the input member 51.

[0045] Here, positioning members 54 for positioning each of the lever members 52 in the circumferential direction are provided between the respective lever members 52 in the circumferential direction. Note that the circumferential direction is the direction around the central axis 3C of the valve body 3.

[0046] 2 and 4, the positioning member 54 is disposed between the multiple lever members 52 that are disposed apart in the circumferential direction. The positioning members 54 are disposed with some wobble between the adjacent lever members 52 so that each lever member 52 can rotate around a fulcrum portion. The positioning members 54 also position the input member 51 with respect to the multiple lever members 52. For this reason, the positioning members 54 are also disposed between the branch portions 511 of the input member 51.

[0047] As shown in Figs. 2 to 5, the output member 53 is in contact with the tip portions 52c, which are the action points Z of the multiple lever members 52, and transmits the driving force received from the action points Z to the valve body 32 of the valve body 3. The output member 53 is connected to the upper end portion, which is the end portion opposite to the seating surface 31 of the valve body 32 of the valve body 3. The output member 53 of this embodiment is connected by screwing to the valve body 32, and has a male screw portion 531 that screws into a female screw portion formed in the valve body 32, and a receiving portion 532 provided at the upper end portion of the male screw portion 531. The receiving portion 532 is in contact with the action points Z of the multiple lever members 52 on its upper surface, and is approximately disk-shaped. The receiving portion 532 of the output member 53 can receive the force from the multiple lever members 52 without increasing the radial size of the valve body 32.

[0048] In addition, the output member 53 is biased in a direction (opening direction) to open the valve body 3 by the elastic body 55. As a specific configuration, as shown in FIG. 2, the elastic body 55 is provided between the support ring 8 provided on the support portion 34 and the output member 53, so that the output member 53 is biased in the opening direction. By biasing the output member 53 in the opening direction, the valve body main body 32 of the valve body 3 is also biased in the opening direction. The support ring 8 has a through hole in the center, and the valve body main body 32 moves inside the through hole. In addition, the elastic body 55 is formed of, for example, a leaf spring. By forming the elastic body 55 from a leaf spring, the installation space can be made smaller than when a spring is used.

[0049] In the above configuration, when the fluid control valve V is assembled, the output member 53, the multiple lever members 52, the input member 51, and the intermediate connector 6 are pressed against the lower end of the actuator 4 by the elastic force of the diaphragm portion 33 and the elastic force of the elastic body 55. That is, when the fluid control valve V is assembled, the input member 51 and the multiple lever members 52 are in pressing contact with each other. In this state, the contact surface 52a of each lever member 52 slopes downward toward the central axis 3C of the valve body 3 (see FIG. 2). Also, each lever member 52 is in contact with the inner peripheral surface 7b of the containing block 7, and its position is restricted.

[0050] <Operation of fluid control valve V> Next, the operation of the fluid control valve V according to this embodiment will be described.

[0051] The fluid control valve V is set so that the valve opening degree (the distance between the valve seat 21 of the valve seat member 2 and the seating surface 31 of the valve body 3) is a predetermined value when no voltage is applied to the actuator 4. The state in which the valve opening degree is the predetermined value is the fully open state of the fluid control valve V.

[0052] Next, when a voltage is applied to the actuator 4, the actuator 4 expands. The driving force associated with this expansion of the actuator 4 is transmitted to the valve body 32 of the valve body 3 via the displacement magnifying mechanism 5, and the valve body 32 moves in a direction in which it comes into contact with (approaches) the valve seat 21. This causes the valve opening to become smaller than a predetermined value. Note that the actuator 4 expands more as the applied voltage increases, so the valve opening can be controlled by adjusting the magnitude of the voltage.

[0053] Here, the displacement caused by the expansion of the actuator 4 is magnified by a predetermined magnification by the displacement magnifying mechanism 5 as shown in FIG.

[0054] Specifically, when the actuator 4 extends, the input member 51 is displaced in a direction to contact (approach) the valve seat 21 via the intermediate connector 6. When the input member 51 is displaced in a direction to contact the valve seat 21, each pressing portion 51a of the input member 51 presses a contact surface 52a, which is a force point portion X of each lever member 52.

[0055] Here, the contact surface 52a of each of the lever members 52 slopes downward toward the central axis 3C of the valve body 3, eliminating positional deviation of the input member 51 in a direction away from the central axis 3C. Note that, since each of the lever members 52 contacts the inner peripheral surface 7b of the containing block 7, each of the lever members 52 does not shift outward.

[0056] As shown in FIG. 5, when the contact surface 52a, which is the force point X of each lever member 52, is pressed, each lever member 52 rotates around the protrusion 52b, which is the fulcrum Y, as the rotation center, and the tip portion 52c, which is the action point Z, presses the output member 53 in the direction of contacting the valve seat 21. As a result, the output member 53 moves in the direction of contacting (approaching) the valve seat 21. The multiple lever members 52 magnify the displacement of the output member 53 by a predetermined magnification with respect to the displacement of the input member 51. As a result, the displacement of the actuator 4 is magnified and transmitted to the valve body main body 32 of the valve body 3. When the voltage applied to the actuator 4 becomes equal to or greater than a predetermined value, the valve seat 21 of the valve seat member 2 and the seating surface 31 of the valve body 3 come into contact with each other.

[0057] Subsequently, when the voltage applied to the actuator 4 decreases, the actuator 4 contracts. As the actuator 4 contracts, the valve body 32 of the valve body 3 moves in a direction away from (away from) the valve seat 21 due to the pressure of the elastic body 55. This causes the valve opening degree to increase.

[0058] <3. Effects of this embodiment> Thus, according to the fluid control device 100 of this embodiment, the multiple lever members 52 arranged around the central axis 3C of the valve body 3 have contact surfaces 52a that contact the input member 51 and become the force points X, and since the contact surfaces 52a have a downward slope toward the central axis 3C of the valve body 3, the input member 51 is less likely to be displaced in a direction away from the central axis 3C. As a result, the positional stability of the displacement magnification mechanism 5 can be improved. By improving the positional stability of the displacement magnification mechanism 5, the reproducibility of the displacement amount magnified with respect to the displacement amount of the actuator 4 can be improved. In addition, by improving the positional stability of the displacement magnification mechanism 5, the outflow (liquid leakage) in the fully closed state can be reduced. Furthermore, it is possible to prevent the margin at the time of full opening (the set value at the fully open state) from being exceeded, which leads to deterioration of controllability. In addition, since the reproducibility of the displacement amount can be improved, the responsiveness of the fluid control can be improved.

[0059] <4. Other embodiments> For example, the input member 51 may be, for example, disk-shaped, instead of having a plurality of branched portions 511. In this case, a plurality of pressing portions 51a corresponding to the plurality of lever members 52 are formed on the lower surface of the input member 51.

[0060] Furthermore, the lever member 52 has the protrusion 52b serving as the fulcrum Y, but may have no protrusion 52b. In this case, it is conceivable to form a convex portion on the upper surface of the protrusion 7a of the storage block 7, and make the lever member 52 rotatable via the fulcrum Y that comes into contact with the convex portion.

[0061] Furthermore, although the contact surface 52a of the lever member 52 in the above embodiment is formed on substantially the entire upper surface of the lever member 52, it is sufficient that it is formed in an area that can be contacted by the pressing portion 51a of the input member 51. Here, the area that can be contacted by the pressing portion 51a refers to a range from a portion that the pressing portion 51a contacts when the actuator 4 is contracted to a portion that the pressing portion 51a contacts when the actuator 4 is extended, and also includes a portion that the pressing portion 51a contacts even if the input member 51 is shifted in the lateral direction.

[0062] In addition, although the input member 51 in the above embodiment has the thick portion 51b, it may have no thick portion 51b as shown in Fig. 6. In this case, the input member 51 has a pressing portion 51a protruding downward.

[0063] Moreover, in the above embodiment, the fluid control device 100 has been described as a differential pressure type, but it may be a thermal type as shown in Fig. 7. Specifically, this device includes a capillary tube T connected in parallel to a flow path L so that a predetermined ratio of fluid flowing through the flow path L is guided by a fluid resistance S1, a heater H provided in the capillary tube T, and a pair of temperature sensors TS1 and TS2, which are fluid sensors provided before and after the heater H. When a fluid flows through the capillary tube T, a temperature difference corresponding to the mass flow rate is generated between the two temperature sensors TS1 and TS2, and the device is configured to measure the flow rate based on this temperature difference.

[0064] In the above embodiment, the present invention has been described by taking the normally open type fluid control valve V as an example, but the present invention can also be applied to a normally closed type fluid control valve.

[0065] In the above embodiment, a piezoelectric element (piezo stack) is used as the actuator 4 of the fluid control valve V, but a solenoid or the like may also be used.

[0066] In addition, various modifications and combinations of the embodiments may be made as long as they do not go against the spirit of the present invention. [Explanation of symbols]

[0067] 100... Fluid control device V...Fluid Control Valve PS1, PS2: Pressure sensor (fluid sensor) C···Valve control section 3. Valve body 3C: Central axis of valve body 4. Actuator 5. Displacement magnification mechanism 51... Input member 51a... Multiple pressing parts 51b...Thick part 52... Plural lever members X...Emphasis point Y: Support Z...Action point 52a...Contact surface 53 Output member 54 Positioning member

Claims

1. An actuator for driving the valve body, The valve body and the actuator are interposed, and the displacement amplification mechanism amplifies the displacement of the actuator and transmits it to the valve body. The displacement amplification mechanism is, An input member that is displaced by receiving a driving force from the actuator, The valve body has a plurality of lever members arranged between the input member and the valve body, around the central axis of the valve body, which amplify the displacement of the input member and transmit it to the valve body. The plurality of lever members have contact surfaces that the input member contacts and which become the point of force application. A fluid control valve in which the contact surface has a downward slope toward the central axis of the valve body.

2. The fluid control valve according to claim 1, wherein the contact surface slopes downward toward the central axis of the valve body regardless of the extension or retraction of the actuator.

3. The input member has a plurality of pressing parts that press against the contact surface of each of the plurality of lever members, The fluid control valve according to claim 1, wherein each of the pressing portions makes line contact with the corresponding contact surface.

4. The fluid control valve according to claim 3, wherein each of the pressing portions is a linear projection formed to make line contact with the corresponding contact surface.

5. The fluid control valve according to claim 3, wherein the input member is formed inward from the plurality of pressing portions and has a continuous thickened portion at the top of each of the pressing portions.

6. The fluid control valve according to claim 1, wherein the displacement amplification mechanism further comprises an output member interposed between the plurality of lever members and the valve body, and which is in contact with the points of action of the plurality of lever members.

7. The fluid control valve according to claim 1, wherein the displacement amplification mechanism further comprises a positioning member provided between each of the plurality of lever members in the circumferential direction for positioning each of the lever members in the circumferential direction.

8. The fluid control valve according to claim 1, wherein the input member has a convex shape on the surface facing the actuator.

9. The fluid control valve according to claim 1, wherein the actuator has a piezo stack.

10. A fluid control valve according to any one of claims 1 to 9, A fluid sensor provided on the upstream or downstream side of the fluid control valve, A fluid control device comprising a valve control unit that controls the fluid control valve based on the output of the fluid sensor.

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