JP5653286B2 - Check valve - Google Patents

Description

  The present invention relates to a check valve that is arranged in the middle of a flow path of a pump device or the like and closes an outlet by a valve body coming into contact with a valve seat provided with a fluid outlet from the downstream side in the fluid outlet direction.

  For example, Patent Document 1 discloses a check valve in which a valve body comes into contact with a valve seat provided with a fluid outlet from the downstream side in the fluid outlet direction to close the outlet. In Patent Document 1, the valve body includes a closing portion that faces the valve seat, and an annular protrusion that protrudes from the closing portion toward the valve seat and comes into contact with the periphery of the outlet. Is being energized. The valve seat is elastically deformable, and in a state where the valve body seals the outlet, the annular protrusion deforms the valve seat so that the valve body and the valve seat are brought into close contact with each other. In the check valve of this document, the outflow port is closed by the urging force of the urging means, so that it is easy to set a load (urging force) that urges the valve body to the valve seat. Moreover, since the outflow port can be closed in a state where the periphery of the outflow port is surrounded by the annular protrusion, the sealing performance of the outflow port by the valve body is high.

JP 2002-181213 A

  However, in Patent Document 1, in order to configure the valve seat so as to be elastically deformable, the valve seat is provided with a seat that can be elastically deformed on a surface facing the valve body, and the configuration of the valve seat becomes complicated. Yes.

  Here, if the seat provided on the valve seat can be omitted, the configuration of the valve seat becomes simple, and therefore it is easy to provide a check valve in the flow path. In this case, it can be considered that the seat is omitted from the valve seat by forming the valve body side so as to be elastically deformable. However, if the valve body is made of an elastic material, the valve body is attached to the valve seat by the biasing means. When energized, the shape of the annular protrusion that is compressed and deformed by the energizing force is not fixed, and there is a problem that the sealing performance is deteriorated.

  In view of the above problems, an object of the present invention is to provide a check valve having high sealing performance even when a valve body biased to a valve seat by a biasing means is formed from an elastic material.

In order to solve the above problems, the check valve of the present invention is
A valve seat provided with a fluid outlet;
A valve body made of an elastic material that is in contact with the valve seat from the downstream side in the fluid outflow direction and closes the outlet;
A biasing means that abuts the valve body from the downstream side of the valve body in a fluid outflow direction, and biases the valve body to the valve seat with a predetermined biasing force;
The valve body includes a closing portion facing the valve seat, and an annular protrusion protruding from the closing portion toward the valve seat and abutting around the outlet.
The annular protrusion has an inner peripheral inclined surface continuous radially inward with respect to the top, and an outer peripheral inclined surface continuous radially outward with respect to the top, and is formed over the entire circumference.
An inner contact angle formed between the valve seat and the inner inclined surface is smaller than an outer contact angle formed between the valve seat and the outer inclined surface.

  According to the present invention, since the check valve closes the outflow port with the elastic force of the valve body itself made of an elastic material and the urging force of the urging means, the sealing performance of the outflow port with the valve body is high. In addition, since the outlet is closed using the urging force of the urging means, the opening and closing operation of the outlet due to the variation in the shape of the valve body compared to the case where the outlet is closed only by the elastic force of the valve body itself. Can reduce the effect of Furthermore, since the valve body is urged to the valve seat by the urging means, it is easy to apply a predetermined load (biasing force) to the valve body. Moreover, since the outflow port can be closed in a state where the periphery of the outflow port is surrounded by the annular protrusion, the sealing performance of the outflow port by the valve body is high.

  Further, according to the present invention, the annular protrusion has an inner peripheral inclined surface and an outer peripheral inclined surface with respect to the top, and an inner peripheral contact angle formed by the valve seat and the inner peripheral inclined surface. However, it is formed smaller than the outer peripheral contact angle formed by the valve seat and the outer peripheral inclined surface. As a result, when the valve body is urged to the valve seat by the urging means, the deformation of the annular protrusion that is compressed and deformed by the urging force can be defined so as to be deformed in a direction in which the top portion is shifted to the outer peripheral side. Therefore, the sealing performance of the outlet port by the valve body is improved as compared with the case where the shape of the annular protrusion that is compressed and deformed by the urging force is not determined. In addition, since the inner contact angle formed by the valve seat and the inner inclined surface is smaller than the outer contact angle formed by the valve seat and the outer inclined surface, the outlet is closed by the biasing force. The valve body can be moved smoothly with respect to the pressure of the fluid to open the valve body.

  In this case, it is desirable that the inner peripheral contact angle is less than 45 °. In this way, it is possible to suppress the fluid pressure from acting in the direction of deforming the annular protrusion outward, so that the closed state of the outlet can be ensured.

  In the present invention, it is preferable that the valve body includes a positioning portion for positioning a contact position of the urging means on a surface of the closing portion that is located on a side opposite to the valve seat. In this way, the position and direction of the load (biasing force) applied to the closing portion by the urging means can be defined. Moreover, since it can suppress that a valve body fluctuates in the direction remove | deviated from the urging | biasing direction by an urging means, a sealing performance can be improved.

  In this case, it is preferable that the urging means is a coil spring having a diameter larger than that of the opening of the outlet, and the coil spring is disposed coaxially with the annular protrusion. If it does in this way, since a load can be uniformly given to the portion which contacts a valve seat in a valve element with a coil spring, seal nature improves.

  In this case, it is desirable that one circular end portion of the coil spring is in contact with a position corresponding to the annular protrusion on a surface of the closing portion on the opposite side to the valve seat. If it does in this way, since a load can be given to a portion in which an annular projection is formed in a closure part by a coil spring, sealing nature improves.

  According to the present invention, since the check valve closes the outflow port with the elastic force of the valve body itself made of an elastic material and the urging force of the urging means, the sealing performance of the outflow port with the valve body is high. In addition, since the outlet is closed using the urging force of the urging means, the opening and closing operation of the outlet due to the variation in the shape of the valve body compared to the case where the outlet is closed only by the elastic force of the valve body itself. Can reduce the effect of Furthermore, since the valve body is urged to the valve seat by the urging means, it is easy to apply a predetermined load (biasing force) to the valve body. Moreover, since the outflow port can be closed in a state where the periphery of the outflow port is surrounded by the annular protrusion, the sealing performance of the outflow port by the valve body is high.

  Further, according to the present invention, the annular protrusion has an inner peripheral inclined surface and an outer peripheral inclined surface with respect to the top, and an inner peripheral contact angle formed by the valve seat and the inner peripheral inclined surface. However, it is formed smaller than the outer peripheral contact angle formed by the valve seat and the outer peripheral inclined surface. As a result, when the valve body is urged to the valve seat by the urging means, the deformation of the annular protrusion that is compressed and deformed by the urging force can be defined so as to be deformed in a direction in which the top portion is shifted to the outer peripheral side. Therefore, the sealing performance of the outlet port by the valve body is improved as compared with the case where the shape of the annular protrusion that is compressed and deformed by the urging force is not determined. In addition, since the inner contact angle formed by the valve seat and the inner inclined surface is smaller than the outer contact angle formed by the valve seat and the outer inclined surface, the outlet is closed by the biasing force. The valve body can be moved smoothly with respect to the pressure of the fluid to open the valve body.

1 is an external perspective view of a positive displacement pump to which the present invention is applied. It is a longitudinal cross-sectional view of the positive displacement pump of FIG. It is a disassembled perspective view of the positive displacement pump of FIG. It is a fragmentary sectional view of the periphery of the electromagnetic actuator in a state where the moving body is in the raised position. It is sectional drawing of the electromagnetic actuator in the AA 'line of FIG. It is explanatory drawing for demonstrating the drive control and operation | movement of an electromagnetic actuator. It is a fragmentary sectional view around an electromagnetic actuator in a state where a moving body is in a lowered position. It is a time chart which shows the electric current value of the exciting current to an electromagnetic actuator. It is the graph which verified the relationship between the position of a moving body and thrust. It is the graph which verified the relationship between the position of a moving body in the state which considered the reaction force of the diaphragm, and thrust. It is a fragmentary sectional view around a valve chamber. It is a fragmentary sectional view around an active valve in a state where an inflow side channel is closed. It is explanatory drawing for demonstrating the force which acts on the valve body of an active valve. It is a fragmentary sectional view around an active valve in a state where an inflow side channel is opened. It is sectional drawing which shows the valve body and urging | biasing means of the non-return valve of a modification.

  A positive displacement pump to which a check valve according to the present invention is applied will be described with reference to the drawings.

(overall structure)
FIG. 1 is an external perspective view of a positive displacement pump to which the present invention is applied. FIG. 2 is a longitudinal sectional view of the positive displacement pump of FIG. The positive displacement pump 1 includes a pump unit 2 and an electromagnetic actuator 3 and an active valve 4 arranged in parallel below the pump unit 2. In the following description, the direction in which the electromagnetic actuator 3 and the active valve 4 are arranged is referred to as the device width direction (shown as the left-right direction in FIG. 1), and the direction orthogonal to the device width direction and the up-down direction is the device front-back direction. And The electromagnetic actuator 3 is disposed on the left side in the apparatus width direction, and the active valve 4 is disposed on the right side in the apparatus width direction.

  An outlet pipe 5 protruding upward is provided on the left side portion of the pump unit 2, and the upper end opening of the outlet pipe 5 is a fluid outlet 5a. An inflow pipe 6 is provided below the active valve 4, and a lower end opening of the inflow pipe 6 serves as a fluid inlet 6a.

  As shown in FIG. 2, a pump chamber 8 is formed inside the pump unit 2. An inflow channel (upstream channel) 9 is formed between the fluid inlet 6 a and the pump chamber 8, and an active valve 4 that opens and closes the inflow channel 9 is disposed in the inflow channel 9. Has been. An outflow channel (downstream channel) 10 is formed between the pump chamber 8 and the fluid outlet 5a. A check valve 11 for preventing a back flow of fluid is disposed in the outflow side channel 10. In the present embodiment, the check valve 11 functions as a passive valve with respect to the active valve 4.

  The bottom surface of the pump chamber 8 is defined by a diaphragm (movable body) 12, and the volume of the pump chamber 8 is changed by reciprocating the diaphragm 12 by the electromagnetic actuator 3. That is, the positive displacement pump 1 opens the active valve 4 to expand the volume of the pump chamber 8 to suck fluid from the fluid inlet 6a into the pump chamber 8, and closes the active valve 4 to reduce the volume of the pump chamber 8. By doing so, the fluid sucked into the pump chamber 8 is discharged from the fluid outlet 5a.

(Pumping unit)
FIG. 3 is an exploded perspective view of the positive displacement pump 1. The pump unit 2 will be described with reference to FIGS. The pump unit 2 includes an upper housing 21 and a lower housing 22 disposed below the upper housing 21.

  The upper housing 21 is made of PPS (polyphenylene sulfide) resin. The outflow pipe 5 protrudes upward from the left side portion of the upper end surface of the upper housing 21. As shown in FIG. 2, a circular first recess 211 that is recessed upward is provided on the left side of the lower end surface of the upper housing 21. A lower end opening 212 a of the first flow path 212 communicating with the outflow pipe 5 is exposed at the central portion of the ceiling surface of the first recess 211.

  The lower housing 22 is made of PPS (polyphenylene sulfide) resin. A circular upper protrusion 221 that fits into the first recess 211 of the upper housing 21 is formed on the left side of the upper end surface. A circular second recess 222 that is recessed downward is formed in the central portion of the upper protrusion 221. The upper protrusion 221 is fitted in the first recess 211, and the valve chamber 13 is formed coaxially with the outflow pipe 5 by the first recess 211 of the upper housing 21 and the second recess 222 of the lower housing 22. An O-ring 14 is disposed between the outer peripheral surface of the upper protrusion 221 and the inner peripheral surface of the first recess 211. A check valve (passive valve) 11 is configured in the valve chamber 13.

  A circular lower protrusion 223 is formed on the lower surface of the left portion of the lower housing 22. A circular third recess 224 that is recessed upward is provided at the center of the lower protrusion 223. The ceiling surface 224a of the third recess 224 is a tapered surface inclined upward toward the central portion, and the lower end opening 225a of the second flow path 225 communicating with the valve chamber 13 is exposed at the central portion. ing. An upper end opening 225 (outlet) b of the second flow path 225 is exposed at a central portion of the circular bottom surface 13 a of the valve chamber 13. The ceiling surface 224 a and the inner peripheral surface of the third recess 224 define the ceiling surface and the inner peripheral surface of the pump chamber 8. The pump chamber 8, the second flow path 225, the valve chamber 13, the first flow path 212, and the outflow pipe 5 are formed on the same axis, and the second flow path 225, the valve chamber 13, the first flow path 212, the outflow The pipe 5 constitutes the outflow side channel 10.

  A diaphragm 12 that defines the bottom surface of the pump chamber 8 is disposed below the lower protrusion 223. The diaphragm 12 is a rubber elastic body made of EPDM (ethylene propylene diene rubber) or the like, and has a circular planar shape when viewed from above. The diaphragm 12 has a central portion and an outer peripheral edge portion formed thick, and a connecting film portion having a constant thickness that curves so as to bulge upward is provided between the central portion and the outer peripheral edge portion. A connection portion 12 a for connecting the electromagnetic actuator 3 is provided at a lower portion of the central portion of the diaphragm 12.

  The electromagnetic actuator 3 is attached to the lower housing 22 using the outer peripheral side of the lower protrusion 223. When the electromagnetic actuator 3 is attached, the outer peripheral edge portion of the diaphragm 12 is sandwiched between the annular lower end surface of the lower protrusion 223 and the electromagnetic actuator 3 and is fixed.

  A circular fourth recess 226 that is recessed upward is formed on the lower surface of the right side portion of the lower housing 22. The fourth recess 226 includes, from below, a flat large-diameter portion 226a and a small-diameter portion 226b having a smaller diameter than the large-diameter portion. The upper end portion of the active valve 4 is inserted into the fourth recess 226 via the O-ring 15.

  In a state where the active valve 4 is inserted into the fourth recess 226, a space is formed in the upper end portion 226c of the small diameter portion 226b, and there is a space between the upper end portion 226c and the pump chamber 8. A third flow path 227 for communication is formed. The right end opening of the third channel 227 is exposed on the inner peripheral side surface of the upper end portion 226c of the small diameter portion 226b, and the left end opening of the third channel 227 is the ceiling surface of the pump chamber 8 and the lower end of the second channel 225. The part is exposed.

(Electromagnetic actuator)
The electromagnetic actuator 3 will be described with reference to FIGS. FIG. 4 is a partial cross-sectional view of the periphery of the electromagnetic actuator 3 with the moving body 33 in the raised position. FIG. 5 is a cross-sectional view of the electromagnetic actuator 3 taken along the line AA ′ of FIG.

  The electromagnetic actuator 3 has a box-shaped upper case 31 having an opening at the lower end, and a lower case 32 attached so as to close the opening at the lower end of the upper case 31. Inside the upper case 31 and the lower case 32, a movable body 33 that can move in the vertical direction and a fixed body 34 for moving the movable body 33 are arranged. The upper end portion of the moving body 33 is fixed to the connecting portion 12a of the diaphragm 12. When the moving body 33 reciprocates in the vertical direction, the diaphragm 12 reciprocates in the vertical direction to change the volume of the pump chamber 8. The fixed body 34 includes a first fixed body 35 disposed on the left side of the moving body 33 in the apparatus width direction and a second fixed body 36 disposed on the right side.

  As shown in FIG. 3, the moving body 33 includes a rectangular parallelepiped magnet 331 that has a side surface that is parallel to the moving direction of the moving body 33. The magnet 331 is two-pole magnetized, and magnetic pole surfaces 331a and 331b magnetized to different poles on the left and right sides facing the device width direction. In the present embodiment, the magnetic pole surface 331a is magnetized to the S pole, and the magnetic pole surface 331b is magnetized to the N pole (see FIG. 6). In addition, the moving body 33 includes a magnet holder 332 that holds an outer peripheral surface portion excluding the magnetic pole surfaces 331 a and 331 b of the magnet 331.

  The magnet holder 332 includes front and rear vertical frame portions 332a that hold the front and rear side surfaces of the magnet 331 from the front and rear direction of the apparatus, an upper frame portion 332b that connects upper end portions of the front and rear vertical frame portions 332a, The lower frame part 332c which has connected the lower end part of the vertical frame part 332a is provided. The front and rear vertical frame portions 332a are provided with guide protrusions 333 and 333 that protrude in parallel with the magnetic pole surfaces 331a and 331b, respectively. Each guide protrusion 333 has a rectangular parallelepiped shape and has a predetermined length in the vertical direction. A connection part 334 with the diaphragm 12 is provided on the upper frame part 332b so as to protrude upward. The lower frame portion 332c is provided with a guide shaft 335 protruding downward.

  The first fixed body 35 and the second fixed body 36 include yokes 37 and 37 and drive coils 38 and 38 wound around the yokes 37 and 37, respectively. As shown in FIG. 5, the first fixed body 35 is arranged such that the drive coil 38 faces the magnetic pole surface 331a of the moving body 33 with a certain gap therebetween, and the second fixed body 36 is The drive coil 38 is arranged to face the magnetic pole surface 331b with a certain gap.

  As shown in FIG. 4, each of the yokes 37 and 37 includes a shaft portion 371 extending in the vertical direction, first protrusions 372 and 372 projecting inward from the upper end portion of the shaft portion 371, and the shaft portion 371. 2nd protrusion part 373 and 373 which protrudes inward from the lower end part of this is provided.

  Each drive coil 38, 38 is disposed at a portion of the yokes 37, 37 between the first protrusions 372, 372 and the second protrusions 373, 373 in a direction orthogonal to the moving direction (vertical direction) of the moving body 33. It is wound. As shown in FIG. 5, each drive coil 38, 38 has a rectangular cross-sectional shape by a plane orthogonal to the moving direction of the moving body 33, and an outer peripheral surface portion 38 a that is one long side of the cross-sectional shape. , 38a are opposed to the magnetic pole surfaces 331a, 331b of the magnet 331.

  Here, the width dimension of the moving body 33 in the front-rear direction of the magnet 331 is set to be shorter than the width dimension of the outer peripheral surface portions 38a, 38a in the front-rear direction of the apparatus. In addition, the length dimension “a” of the moving body 33 in the vertical direction of the magnet 331 is shorter than the length dimension “b” between the first protrusions 372 and 372 and the second protrusions 373 and 373 in each yoke 37 and 37. The length is set (see FIG. 4). The length dimension a of the magnet 331 is such that when the moving body 33 moves within a predetermined moving range in the vertical direction, the magnet 331 is magnetic between the first protrusions 372 and 372 and the second protrusions 373 and 373. There is a region where the attractive force does not work or the influence of the magnetic attractive force is small. Specifically, it is a substantially linear range shown in FIG. 9 (displacement amount is about -0.3 mm to 0.2 mm).

  Further, as shown in FIG. 3, the lower ends of the yokes 37 and 37 are held by the lower case 32, and the upper ends of the yokes 37 and 37 are supported by a frame-shaped spacer 39. Accordingly, the drive coil 38 of the first fixed body 35 and the drive coil 38 of the second fixed body 36 are maintained at a constant interval along the moving direction of the moving body 33. Further, in the yokes 37 and 37, the ends of the first protrusions 372 and 372 and the second protrusions 373 and 373 on the moving body 33 side are closer to the moving body 33 than the outer peripheral surface portions 38 a and 38 a of the drive coils 38 and 38. The protrusions of the first protrusions 372 and 372 and the protrusions of the second protrusions 373 and 373 that are located on the side and protrude from the shafts 371 and 371 toward the moving body 33 are the same.

  The lower case 32 has a flat rectangular parallelepiped shape, and a pair of concave portions 322 and 322 serving as holding portions for the yokes 37 and 37 are formed on the upper end surface. A groove 323 extending in the longitudinal direction of the apparatus is formed between the pair of recesses 322 and 322 in the apparatus width direction, and a circular through hole 324 is formed in the central portion of the groove 323. The guide shaft 335 of the magnet holder 332 is inserted into the through hole 324. A pair of engaging protrusions 325 and 325 projecting upward are formed outside the pair of recesses 322 and 322 in the apparatus width direction.

  As shown in FIG. 3, the upper case 31 includes a rectangular upper plate 311 and four side plates 312 to 315 that extend downward from four edges of the upper plate 311. The upper plate 311 is provided with a rectangular connecting portion 316 that protrudes upward from its upper end surface. A through hole 316a is formed in the central portion of the connecting portion 316, and a stepped portion 316b extending outward is provided at the upper end portion of the through hole 316a. In the state where the electromagnetic actuator 3 is attached to the lower housing 22, as shown in FIG. 4, the lower protrusion 223 of the lower housing 22 is inserted inside the step 316b, and the circle of the lower protrusion 223 is inserted. The peripheral edge portion of the diaphragm 12 is sandwiched between the annular lower end surface and the annular end surface of the step portion 316b.

  Engaging recesses 317 and 317 extending in the vertical direction are formed in the two side plates 312 and 314 extending in parallel in the apparatus width direction. When the upper case 31 is put on the lower case 32, the pair of engagement protrusions 325 and 325 engage with the engagement recesses 317 and 317 of the side plates 312 and 314 to fix the upper case 31 to the lower case 32.

  The two side plates 313 and 315 extending in parallel in the apparatus front-rear direction are formed with guide grooves 318 and 318 extending upward with a certain width from the lower end edge of the central portion in the apparatus width direction. The guide grooves 318 and 318 are located at the center of the first fixed body 35 and the second fixed body 36 in the apparatus width direction. When the upper case 31 is put on the lower case 32, the front and rear guide protrusions 333 and 333 of the moving body 33 are inserted into the front and rear guide grooves 318 and 318 of the upper case 31, as shown in FIG. The Here, the guide protrusions 333 and 333 and the guide grooves 318 and 318 guide the moving body 33 in the vertical direction with the gap between the magnetic pole surfaces 331a and 331b and the drive coils 38 and 38 maintained constant. The moving mechanism 33 is arranged on the axis of the pump chamber 8, the second flow path 225, the valve chamber 13, the first flow path 212, and the outflow pipe 5 by the guide mechanisms 40, 40. Will be guided.

  Upper end edges 318 a and 318 a of the guide grooves 318 and 318 define an upper limit of the moving range of the moving body 33. That is, when the moving body 33 tries to move above the raised position (first position) 33A shown in FIG. 4, the guide protrusions 333 and 333 come into contact with the upper edges 318a and 318a of the guide grooves 318 and 318, respectively. To prevent the movement. At the raised position 33A, the upper end surface 331c of the magnet 331 of the moving body 33 is located below the upper end surfaces of the first protrusions 372 and 372 of the yokes 37 and 37. In the state where the moving body 33 is located at the ascending position 33A, the diaphragm 12 sets the volume of the pump chamber 8 to the minimum first volume. The movable body 33 is configured to be positioned at the raised position 33 </ b> A by the guide protrusions 333 and 333 of the movable body 33 coming into contact with the upper end edges 318 a and 318 a of the guide grooves 318 and 318 of the upper case 31. You can also. That is, the upper end edges 318a and 318a may be provided with a function as a moving body positioning unit that defines the upper limit of the moving range of the moving body 33.

  The upper end surfaces 32 a and 32 a of the lower case 32 define the lower limit of the moving range of the moving body 33. That is, when the moving body 33 tries to move downward from the lowered position (second position) 33B (see FIG. 7), the guide protrusions 333 and 333 come into contact with the upper end surfaces 32a and 32a of the lower case 32. , Stop that movement. In the lowered position 33 </ b> B, the lower end surface 331 d of the magnet 331 of the moving body 33 is positioned above the lower end surfaces of the second protrusions 373 and 373 of the yokes 37 and 37. Further, in the state where the moving body 33 is located at the lowered position 33B, the diaphragm 12 expands the volume of the pump chamber 8 to the maximum second volume. Note that the movable body 33 may be positioned at the lowered position 33B by the guide protrusions 333 and 333 of the movable body 33 coming into contact with the upper end surfaces 32a and 32a of the lower case 32. That is, the upper end surfaces 32a and 32a may be paired with the upper end edges 318a and 318a described above, and may have a function as a moving body positioning unit that defines the lower limit of the moving range of the moving body 33.

  Further, while the moving body 33 moves between the raised position 33A and the lowered position 33B, the state where the guide shaft 335 extending downward from the magnet holder 332 is inserted into the through hole 324 is maintained. Thereby, the moving body 33 moves linearly in a state in which the posture is maintained without being inclined with respect to the moving direction.

(Electromagnetic actuator drive control and operation)
The drive control and operation of the electromagnetic actuator 3 will be described with reference to FIGS. 2 and 6 to 10. FIG. 6 is an explanatory diagram for explaining drive control and operation of the electromagnetic actuator, and shows a state in which the moving body 33 is in the raised position 33A. FIG. 7 is a partial cross-sectional view around the electromagnetic actuator in a state where the moving body 33 is in the lowered position 33B. FIG. 8 is a time chart showing the current value of the excitation current applied to the electromagnetic actuator 3, and shows the current value of the excitation current while the movable body 33 is reciprocated between the rising position 33A and the lowering position 33B. Yes. FIG. 9 is a graph in which the relationship between the position of the moving body 33 and the thrust is verified by changing the current value of the excitation current supplied to the drive coils 38 and 38. FIG. 9 also shows a graph showing the relationship between the position of the moving body 33 and the reaction force acting on the moving body 33 from the diaphragm 12. FIG. 10 is a graph in which the relationship between the position of the moving body 33 and the thrust is verified by changing the current value of the excitation current supplied to the drive coils 38 and 38 in a state where the reaction force of the diaphragm 12 is taken into consideration.

  9 and 10, the moving body 33 and the diaphragm 12 are in the positions shown in FIG. 2, and the center of the magnet 331 and the drive coil 38 in the moving direction (vertical direction) of the moving body 33 are as follows. The center of 38 coincides. The movable body 33 is located at the raised position 33A shown in FIG. 6 at the position where the displacement is 0.6 mm, and the movable body 33 is located at the lowered position 33B shown in FIG. 7 at the position where the displacement is −0.6 mm. . Further, in FIG. 9, a graph rising to the right passing through a thrust of 0 mN and a displacement of 0 mm measured the thrust at each position (displacement) of the moving body 33 in a state where power is not supplied to the drive coils 38 and 38. Is. In FIG. 9, a downward-going graph passing through a thrust of 0 mN and a displacement of 0 mm indicates that the moving body 33 is moved from the diaphragm 12 to the moving body 33 at each position (displacement) of the moving body 33 in a state where power is not supplied to the drive coils 38 and 38. This is a measurement of the reaction force acting on. The sign of-given to the current value indicates the direction in which the excitation current flows, and means that the excitation current flows in the direction shown in FIG. The sign of + means that the exciting current is passed in the direction opposite to the direction shown in FIG. Further, the sign given to the thrust indicates the direction in which the thrust works, the + sign indicates the upper side, and the-sign indicates the lower side.

  First, as shown in FIG. 6, when the positive displacement pump 1 is operated and the electromagnetic actuator 3 is operating, power is not supplied to the drive coils 38, 38. 331 and the first protrusions 372 and 372 of the yokes 37 and 37 are stopped at the raised position 33A by the action of the magnetic attractive force F1 between the yokes 37 and 37 and the reaction force R1 of the diaphragm 12.

  Further, in this example, when the positive displacement pump 1 is not operating, power is not supplied to the drive coils 38, 38, so that the moving body 33 has the first protrusion of the magnet 331 and the yokes 37, 37. The raised position 33A is held by the action of the magnetic attractive force F1 with the portions 372 and 372 and the reaction force R1 of the diaphragm 12.

  In this example, when the moving body 33 is in the raised position 33A, the magnetic attraction between the magnet 331 and the first protrusions 372 and 372 of the yokes 37 and 37 as shown in the graph of the current value 0 mA in FIG. A thrust of about 200 mN is generated upward by the force F1. On the other hand, when the moving body 33 is in the raised position 33A, as shown in FIG. 6, the diaphragm 12 reduces the volume of the pump chamber 8 to the minimum first volume, and its central portion is smaller than the outer peripheral edge portion. The state is displaced upward. Therefore, the diaphragm 12 generates a reaction force R1 of about 100 mN downward. As a result, as shown in FIG. 10, the moving body 33 is directed upward by subtracting the reaction force R1 of the diaphragm 12 from the magnetic attractive force F1 between the magnet 331 and the first protrusions 372 and 372 of the yokes 37 and 37. Is stopped at the ascending position 33A by the force (about 100 mN).

  Next, when the moving body 33 is moved from the raised position 33A to the lowered position 33B, power is supplied to the drive coils 38, 38. In this example, as shown in FIG. 6, in the magnet 331 of the moving body 33, the left magnetic pole surface 331a is magnetized to the S pole and the right magnetic pole surface 331b is magnetized to the N pole. In the left drive coil 38 facing the magnetic pole surface 331a, the excitation current flowing through the winding portion constituting the outer peripheral surface portion 38a facing the magnetic pole surface 331a is excited in the direction from the front of the device toward the rear of the device. Will be washed away. The excitation current flowing through the winding portion facing the magnetic pole surface 331b is passed through the right drive coil 38 facing the right magnetic pole surface 331b in the direction from the front of the apparatus toward the rear of the apparatus.

  Here, since the magnet 331 of the moving body 33 is located on the outer peripheral side of the drive coils 38, 38, the direction of the excitation current flowing through the drive coils 38, 38 by feeding is orthogonal to the direction of the magnetic field by the magnet 331. As a result, when power is supplied to the drive coils 38, the Lorentz force acting between the drive coils 38, 38 and the magnetic field of the magnet 331 moves the moving body 33 downward according to Fleming's left-hand rule. Work as force F2.

  Further, the drive coils 38 and 38 and the yokes 37 and 37 function as electromagnetic coils (electromagnets) by supplying power to the drive coils 38 and 38 according to Ampere's right-handed screw law. That is, the first fixed body 35 disposed on the left side of the moving body 33 functions as an electromagnetic coil having the S pole on the upper side and the N pole on the lower side. The second fixed body 36 disposed on the right side of the moving body 33 functions as an electromagnetic coil having an N pole on the upper side and an S pole on the lower side. As a result, an electromagnetic repulsive force is generated on the upper side and an electromagnetic attractive force is generated on the lower side between the magnet 331 of the moving body 33 and the first fixed body 35 and the second fixed body 36. . The resultant force F3 of the electromagnetic repulsive force and the attraction force is a thrust for moving the moving body 33 downward together with the force F2 that moves the moving body 33 downward.

  The thrust generated by the force F2 for moving the moving body 33 downward and the resultant force F3 of the electromagnetic repulsive force and the attractive force appear in FIG. 9 as the difference in thrust between the current value graph and the current value graph. In this example, when an excitation current of -10 mA is supplied to the drive coils 38, 38, a downward thrust of a little less than 100 mN appears as a difference between the graph of the current value of 0 mA and the graph of the current value of -10 mA. can get. Similarly, when an excitation current of −30 mA is supplied to the drive coils 38, 38, a downward thrust exceeding 200 mN is obtained. When an excitation current of −50 mA is supplied to the drive coils 38, 38, a downward thrust exceeding 300 mN is obtained. The sign “−” given to the current value indicates the direction in which the excitation current flows, and means that the excitation current flows in the direction shown in FIG.

  Here, in this example, the moving body 33 is held at the raised position 33A by an upward force of about 100 mN at the raised position 33A. Therefore, in this example, in the first section P1 in which the moving body 33 moves away from the ascending position 33A as shown in FIG. 10, the first exciting current I1 of −30 mA is supplied to the drive coils 38 and 38 as shown in FIG. Generating downward thrust exceeding 100 mN. Thereby, the moving body 33 moves away from the ascending position 33A and moves downward.

  Next, when the moving body 33 moves away from the ascending position 33A, the magnet 331 moves away from the first protrusions 372 and 372 of the yokes 37 and 37. Therefore, as shown in the graph of the current value 0 mA in FIG. The magnetic attractive force F1 that has been acting on decreases in inverse proportion to the square of the distance. When the moving body 33 has a displacement of 0.2 mm to −0.2 mm, the magnet 331 and the first protrusions 372 and 372 of the yokes 37 and 37 are almost affected by the magnetic attractive force F1. That is, the magnetic attractive force F1 is substantially zero. In other words, in this range, the movement of the moving body 33 is controlled by the current supplied to the drive coils 38 and 38.

  Further, when the moving body 33 is at a position where the displacement amount is 0 mm, the diaphragm 12 is not displaced in the vertical direction as shown in FIG. Therefore, as shown in the graph of the reaction force R1 from the diaphragm 12 in FIG. 9 (elastic force possessed by the diaphragm 12), the reaction force R1 does not act from the diaphragm 12 to the moving body 33. Therefore, in the second section P2 where the moving body 33 passes in the vicinity of the position where the displacement amount is 0 mm, the moving body 33 can be lowered only by applying a slight thrust to the moving body 33.

  Therefore, in this example, as shown in FIGS. 8 and 10, in the second section P2 in which the moving body 33 passes in the vicinity of the position where the displacement amount is 0 mm, the drive coils 38 and 38 are supplied to the drive coils 38 and 38 more than the first excitation current I1. By supplying a small −10 mA second exciting current I2, a downward thrust of slightly less than 100 mN is generated, and thereby the moving body 33 is lowered. In FIG. 4, the vertical dimension “a” of the magnet 331 is set to be shorter than the dimension “b” between the first protrusions 372 and 372 and the second protrusions 373 and 373. It is possible to lengthen the second section P2 in which the magnetic attractive force acting between the first protrusions 372 and 372 and the second protrusions 373 and 373 is substantially zero.

  Thereafter, when the moving body 33 approaches the lowered position 33B, the magnet 331 approaches the second protrusions 373 and 373, so that the magnetic attractive force F4 between the magnet 331 and the second protrusions 373 and 373 works. The suction force F4 increases in inverse proportion to the square of the distance. Moreover, since the suction force F4 is a force that works downward, the suction force F4 is a thrust that moves the moving body 33 downward. Here, when the moving body 33 approaches the lowered position 33B, the center portion of the diaphragm 12 is displaced downward with respect to the outer peripheral edge portion as shown in FIG. As shown in the graph of the force R1, the reaction force R1 from the diaphragm 12 to the moving body 33 works upward. However, as shown in FIG. 9, the reaction force R1 acting on the moving body 33 from the diaphragm 12 is smaller than the magnetic attractive force F4 between the magnet 331 and the second protrusions 373 and 373. The moving body 33 is lowered to the lowered position 33B by the suction force F4.

  That is, in this example, in the third section P3 in which the moving body 33 approaches the lowered position 33B, the moving body 33 is lowered only by the suction force F4. Therefore, in this example, as shown in FIGS. 8 and 10, in the third section P3 in which the moving body 33 approaches the lowered position 33B, the third excitation current I3 supplied to the drive coils 38 and 38 is set to zero, That is, the power supply to the drive coils 38, 38 is stopped, and the moving body 33 is lowered only by the attractive force F4.

  Thereafter, when the moving body 33 reaches the lowered position 33B shown in FIG. 7, the magnetic body 331 and the magnetic attraction force F4 between the second protrusions 373 and 373 of the yokes 37 and 37 and the moving body 33 move downward. The movable body 33 stops because the reaction force R1 from the displaced diaphragm 12 is balanced.

  In the lowered position 33B, the diaphragm 12 expands the volume of the pump chamber 8 to the maximum second volume. That is, at the lowered position 33B, when the positive displacement pump 1 is operated and the electromagnetic actuator 3 is operating, power is not supplied to the drive coils 38, 38. The magnetic attractive force F4 and the reaction force R1 from the diaphragm 12 act between the second protrusions 373 and 373 of the yokes 37 and 37, and the moving body 33 stops. Further, in this example, when the positive displacement pump 1 is not operating, power is not supplied to the drive coils 38, 38, so that the moving body 33 has the second protrusion of the magnet 331 and the yokes 37, 37. The moving body 33 is held at the lowered position 33B by the action of the magnetic attractive force F4 with the parts 373 and 373 and the reaction force R1 of the diaphragm 12.

  When moving the moving body 33 from the lowered position 33B to the raised position 33A, the same force acts in the opposite direction as the moving body 33 is moved from the raised position 33A to the lowered position 33B. Therefore, as shown in FIG. 8, the first to third excitation currents I1 to I3 in the opposite directions to the case where the movable body 33 is moved from the raised position 33A to the lowered position 33B are supplied to the drive coils 38 and 38 in this order. . As a result, the moving body 33 has a Lorentz force generated by power feeding, an electromagnetic attractive force, and a resultant force of the electromagnetic attractive force, and a magnetic attractive force between the magnet 331 and the first protrusions 372 and 372. Ascending with F1 as a thrust, it reaches the ascending position 33A.

  Thereafter, when the moving body 33 is positioned at the raised position 33A, the magnetic attractive force F1 between the magnet 331 and the first protrusions 372 and 372 of the yokes 37 and 37, and the diaphragm displaced upward by the moving body 33 The reaction force R1 from 12 balances and the moving body 33 stops. Further, in this example, when the positive displacement pump 1 is not operating, power is not supplied to the drive coils 38, 38, and the magnet 331 of the moving body 33 and each yoke 37, Since the magnetic attractive force F1 is acting between the 37 first protrusions 372 and 372, the moving body 33 is held at the raised position 33A.

  Here, as shown in FIG. 10, in this example, in order to move the moving body 33 reliably, the first section P1 is a period until the moving body 33 moves from the raised position 33A to the position where the displacement amount is 0.2 mm. A first exciting current I1 of −30 mA is supplied. The second excitation current I2 of −10 mA is supplied as the second section P2 until the moving body 33 moves from the position of the displacement amount 0.2 mm to the position of the displacement amount −0.4 mm. Power supply is stopped as the third section P3 until the moving body 33 passes the displacement amount −0.4 mm and reaches the lowered position 33B.

  On the other hand, although description in FIG. 10 is omitted, when the moving body 33 is moved from the lowered position 33B to the raised position 33A, the moving body 33 moves from the lowered position 33B to the position where the displacement is −0.2 mm. The first excitation current I1 of 30 mA is supplied as the first section P1, and the 10 mA of 10 mA is set as the second section P2 until the moving body 33 moves from the position of the displacement amount −0.2 mm to the position of the displacement amount 0.4 mm. The two excitation currents I2 are supplied, and the power supply is stopped as the third section P3 until the moving body 33 passes the displacement amount 0.4 mm and reaches the rising position 33A. Here, when the moving body 33 is moved from the lowered position 33B to the raised position 33A, an exciting current is passed in a direction opposite to the direction shown in FIG.

  In this example, when moving the moving body 33 from the raised position 33A to the lowered position 33B, the first section P1 is -30 mA until the moving body 33 moves from the raised position 33A to a position with a displacement of 0.4 mm. The second excitation current I2 of -10 mA is supplied and moved until the moving body 33 moves from the position of the displacement amount 0.4 mm to the position of the displacement amount 0 mm as the second section P2. The power supply may be stopped after the body 33 has passed the displacement of 0 mm. Even in this case, since a thrust force for moving the moving body 33 downward can be obtained, the moving body 33 can be moved from the raised position 33A to the lowered position 33B. In this example, the third excitation current I3 is set to zero. However, in order to move the moving body 33 with certainty, a third excitation current I3 smaller than the second excitation current I2 is used as the third excitation current I3 as a drive coil. You may supply to 38,38.

(Check valve)
FIG. 11A is a partial cross-sectional view around the valve chamber 13, FIG. 11B is an explanatory view for explaining the cross-sectional shape of the annular protrusion of the valve body, and FIG. It is explanatory drawing for demonstrating the force of the fluid which acts on the inner side inclined surface of a cyclic | annular protrusion. In the present embodiment, the check valve 11 functions as a passive valve with respect to the active valve 4. As shown in FIG. 11A, the check valve 11 is in contact with the valve seat 111 in which the upper end opening 225b of the second flow path 225 is formed, and the valve seat 111 from the downstream side in the fluid flow direction. Are inserted between the valve body 112 closing the upper end opening 225b and the circular ceiling surface 13b of the valve body 112 and the valve chamber 13, and come into contact with the valve body 112 from the downstream side in the fluid flow direction. A spring member is provided as a biasing means that biases the body 112 toward the valve seat 111 with a predetermined biasing force. In this embodiment, the biasing means is a compression coil spring 113, and the valve seat 111 is a circular bottom surface 13 a of the valve chamber 13.

  The valve body 112 is made of a rubber elastic material such as EPDM (ethylene propylene diene rubber), and has a circular flat plate-shaped closing portion 114 facing the valve seat 111, and downward from the lower surface of the closing portion 114. And an annular projection 115 projecting out. The annular protrusion 115 is formed coaxially with the closing portion 114, and abuts around the upper end opening 225 b of the second flow path 225 in the valve seat 111.

  As shown in FIG. 11B, the annular protrusion 115 has a triangular radial cross section, and has a top 115a and an inner peripheral inclined surface 115b continuous radially inward with respect to the top 115a. , And an outer peripheral inclined surface 115c that is continuous radially outward with respect to the top 115a. The inner peripheral contact angle α formed by the valve seat 111 and the inner peripheral inclined surface 115b is smaller than the outer peripheral contact angle β formed by the valve seat 111 and the outer peripheral inclined surface 115c. In this example, the inner peripheral contact angle α is less than 45 °.

In addition, the radial cross section of the annular projection 115 shows that the inner peripheral contact angle α formed by the valve seat 111 and the inner peripheral inclined surface 115b is the outer peripheral contact angle formed by the valve seat 111 and the outer peripheral inclined surface 115c. What is necessary is just to be formed smaller than (beta), and it is not limited to a triangle shape, The shape (trapezoidal shape) with the top part having a certain amount of area may be sufficient. Further, the shape of the top is not limited to a flat surface, and may be a curved surface.

  Further, the valve body 112 includes a positioning portion 116 for positioning the contact position of the compression coil spring 113 on the upper surface of the closing portion 114 located on the side opposite to the valve seat 111. The positioning portion 116 is a cylindrical protrusion having an outer diameter corresponding to the inner diameter of the compression coil spring 113, and is formed coaxially with the annular protrusion 115.

  The compression coil spring 113 has a cylindrical shape, and its inner diameter is larger than the opening diameter of the upper end opening 225b of the second flow path 225, and is set to a size that allows the positioning portion 116 to be inserted. When the check valve 11 is disposed in the valve chamber 13 with the compression coil spring 113 inserted into the positioning portion 116, the upper end of the compression coil spring 113 is the first flow path 212 of the circular ceiling surface 13 b of the valve chamber 13. The lower end opening 212a is in contact with the lower end, and the circular end of the lower end is in contact with the upper surface of the closing portion 114 to be compressed. Note that the compression coil spring 113 is preferably disposed so that the circular end portion at the lower end is in contact with or near the position corresponding to the annular protrusion 115 on the upper surface of the closing portion 114. As a result, the compression coil spring 113 biases the valve body 112 toward the valve seat 111.

  Here, as shown in FIG. 11C, by setting the inner circumferential contact angle α to be less than 45 °, the pressure F0 of the fluid flowing into the valve chamber 13 from the upper end opening 225b is changed to the annular protrusion. It can suppress acting in the direction which deform | transforms 115 outside. That is, if the inner peripheral contact angle α is reduced, the component force F01 in the direction perpendicular to the axial direction of the annular projection 115 is suppressed to a small level at the pressure F0 of the fluid flowing into the valve chamber 13 from the upper end opening 225b. Therefore, the outward deformation of the annular projection 115 due to the fluid pressure F0 is suppressed, and the closed state of the upper end opening 225b can be ensured.

  The check valve 11 has a predetermined pressure equal to or higher than a predetermined urging force by the compression coil spring 113 in the outflow side passage 10 when the volume of the pump chamber 8 is reduced by the diaphragm 12 and the pump chamber 8 becomes high pressure. Is applied in the outflow direction, the upper end opening 225b of the second flow path 225 is opened, and the outflow side flow path 10 is opened. When pressure is applied to the outflow side channel 10 in the direction opposite to the outflow direction, the upper end opening 225b of the second channel 225 is closed and the outflow side channel 10 is closed.

(Active valve)
Next, the active valve 4 will be described in detail with reference to FIG. 2, FIG. 3, and FIG. FIG. 12 is a partial cross-sectional view of the periphery of the active valve 4 in a state where the inflow channel 9 is closed. As shown in FIG. 3, the active valve 4 includes a cylindrical body 41, an orifice component 42 extending coaxially upward from the body 41, and an inflow pipe extending coaxially downward from the body 41. 6 is provided.

  The orifice constituting part 42 has a smaller diameter than the body part 41, and the inflow pipe 6 has a smaller diameter than the orifice constituting part 42. The inflow pipe 6 also serves as the inflow pipe 6 of the positive displacement pump 1, and the downstream end is a fluid inlet 6a. As shown in FIG. 2, in the active valve 4, the orifice component 42 is inserted into the small diameter portion 226b of the fourth recess 226 of the lower housing 22, and the upper end portion of the body portion 41 is inserted into the large diameter portion 226a. And attached to the lower housing 22.

  As shown in FIG. 12, the orifice component 42 includes a columnar portion 421 and an annular flange portion 422 formed on the outer peripheral side of the lower end of the columnar portion 421. The cylindrical portion 421 is formed with an orifice 423 penetrating in the vertical direction along the central axis. A lower end opening 423 a of the orifice 423 is exposed at the lower end surface of the cylindrical portion 421. In addition, an annular recess 424 is formed around the lower end opening 423a of the orifice 423 on the lower end surface of the columnar portion 421, whereby the peripheral edge of the lower end opening 423a of the orifice 423 is an annular protrusion. . The annular protrusion serves as a valve seat 44 of the valve body 43 that opens and closes the lower end opening 423a of the orifice 423.

  The body portion 41 includes a fluid flow path 45 that allows the inflow pipe 6 and the orifice 423 to communicate with each other. The fluid channel 45 is provided coaxially with the orifice 423 and the inflow pipe 6. When the active valve 4 is fixed to the lower housing 22, the inflow side flow path 9 from the pump chamber 8 to the fluid inlet 6a is constituted by the third flow path 227, the upper end portion 226c of the fourth recess 226 and the active valve 4. Is done. A valve element 43 is inserted into the fluid flow path 45 so as to be reciprocally movable in the axial direction. The valve body 43 opens and closes the inflow channel 9 by opening and closing a lower end opening 423a on the fluid channel 45 side of the orifice 423.

  The valve body 43 has a cylindrical shape. The valve element 43 includes a stainless steel pipe 431, three circular magnets 432 arranged in the vertical direction inside the pipe 431, and three disc-shaped magnets arranged between adjacent magnets 432, respectively. The plate 433, two disk-shaped magnetic plates 434 arranged at the upper end and the lower end, a stainless steel lid plate 435 arranged on the upper magnetic plate 434, and the lower magnetic plate 434, respectively. A stainless steel bottom plate 436 is provided. In addition, the thing made from resin can also be used as the pipe 431, the cover board 435, and the baseplate 436. FIG. A circular rubber sheet 437 is attached to the upper surface of the cover plate 435 by a method such as adhesion. Here, the adjacent magnets 432 have the same poles facing the other magnet. More specifically, the upper end magnet 432 is arranged so that the upper side is the S pole and the lower side is the N pole, and the magnet 432 adjacently arranged below the upper side is the N pole and the lower side is the S pole. Further, the magnet 432 arranged below is arranged so that the upper part is an S pole and the lower part is an N pole, and the lower end magnet 432 is an N pole on the upper side and an S pole on the lower side. It is arranged to become. As a result, in the valve body 43, the magnetic lines of force are concentrated at the location where the magnetic plate 433 is located.

  The fluid channel 45 is formed inside a coil bobbin 47 around which a drive coil 46 for driving the valve body 43 is wound. A cylindrical yoke 48 is disposed on the outer peripheral side of the coil bobbin 47.

  The coil bobbin 47 is made of resin, and an annular engagement recess 471 for attaching the orifice component 42 is formed at the upper end portion of the coil bobbin 47. The flange portion 422 of the orifice constituting portion 42 is inserted into and fixed to the engaging recess 471 through the rubber packing 49. An annular holding plate 50 is fitted from above on the outer peripheral side of the columnar portion 421 of the orifice component 42, and the holding plate 50 is fixed to the upper end surface of the coil bobbin 47 and the upper end surface of the yoke 48. The orifice component 42 is fixed to the coil bobbin 47 and the yoke 48. The holding plate 50 is made of a magnetic material. The presser plate 50 is formed of a magnetic material, so that the presser plate 50 can generate a magnetic attractive force with the magnet 432 mounted on the valve body 43. . That is, the pressing plate 50 made of a magnetic material constitutes a first urging means 51 that magnetically urges the valve body 43 to the valve seat 44 together with the magnet 432.

  In addition, the coil bobbin 47 includes a cylindrical body part 472 extending in the vertical direction and six flange parts 473 that increase in diameter on the outer peripheral surface of the cylindrical body part 472. The five spaces surrounded by the cylindrical body portion 472 and the six flange portions 473 of the coil bobbin 47 are five winding portions around which the drive coil 46 is wound. In the present embodiment, the five drive coils 46 wound around the coil bobbin 47 constitute a drive mechanism 52 for moving the valve body 43 together with the magnet 432 of the valve body 43.

  The five drive coils 46 wound around the coil bobbin 47 have the winding directions of adjacent drive coils 46 reversed in order to reverse the direction of the excitation current. Further, the five drive coils 46 are electrically connected in series, for example. Alternatively, a configuration is adopted in which three drive coils 46 located on the inner side in the axial direction are electrically connected in parallel, and the drive coils 46 on both sides in the axial direction are electrically connected in series to those connecting portions. You can also In this example, the vertical dimension of the upper and lower drive coils 46 is ½ of the vertical dimension of the three drive coils 46 positioned therebetween. In the valve body 43, the vertical dimension of the upper and lower magnets 432 is ½ of the vertical dimension of the two magnets 432 therebetween. As a result, when the valve body 43 is in contact with the valve seat 44 and the lower end opening 423a of the orifice 423 is closed, the magnetic plate 433 and the magnetic plate 434 are both positioned at the center of the drive coil 46 in the vertical direction. positioned.

  Here, the outer diameter dimension of the valve body 43 is slightly smaller than the inner diameter dimension of the cylindrical body portion 472 of the coil bobbin 47, and the valve body 43 is inserted into the space inside the cylindrical body portion 472 of the coil bobbin 47. In the state, the fluid flows between the outer peripheral side surface of the valve body 43 and the inner peripheral surface of the cylindrical body portion 472 of the coil bobbin 47.

(Active valve operation)
The operation of the active valve 4 will be described with reference to FIGS. FIG. 13 is an explanatory diagram for explaining the force acting on the valve body 43 of the active valve 4. FIG. 14 is a partial cross-sectional view of the periphery of the active valve 4 in a state where the inflow side passage 9 is open. The active valve 4 is driven and controlled by controlling power feeding to the drive coil 46 by a drive control mechanism (not shown).

  As shown in FIG. 13, the valve body 43 is held in the closed position 43 </ b> A by the magnetic attractive force F <b> 5 between the magnet 432 of the valve body 43 and the presser plate 50 in a state where power is not supplied to the drive coil 46. Has been. In the closed position 43A, the valve body 43 has moved to the upper end of the fluid flow path 45 inside the coil bobbin 47, the rubber sheet 437 on the upper end surface of the valve body 43 abuts the valve seat 44, and the lower end opening of the orifice 423 is opened. 423a is blocked. Thereby, the inflow side flow path 9 will be in a closed state. Further, the magnetic plate 433 and the magnetic plate 434 of the valve body 43 are both positioned at the center position of the drive coil 46 in the vertical direction.

  Here, the valve body 43 is located upstream of the valve seat 44 in which the lower end opening 423 a of the orifice 423 is provided in the fluid flow direction, and is a fluid flow path 45 formed coaxially with the orifice 423. It is comprised so that it may move in the distribution direction of the fluid in the inside. For this reason, the fluid pressure (back pressure) of the fluid flowing into the active valve 4 from the fluid inlet 6a exerts the force F6 in the direction of moving the valve body 43 toward the closed position 43A.

  Next, when the inflow channel 9 is opened, power is supplied to the drive coil 46. In the active valve 4, the drive coil 46 wound in a cylindrical shape is disposed on the outer peripheral side of the magnet 432, so that the direction of the excitation current flowing through the drive coil 46 by feeding is orthogonal to the direction of the magnetic field by the magnet 432. As a result, as shown in FIG. 14, when power is supplied to the drive coil 46, the Lorentz force acting between the magnetic flux of the magnet 432 and the drive coil 46 causes the valve element 43 to move downward from the closed position 43A. Work as F7. Here, at the start of power supply to the drive coil 46, the magnetic plate 433 and the magnetic plate 434 of the valve body 43 are both positioned at the center position of the drive coil 46 in the vertical direction and are linked to the drive coil. Since the magnetic field is efficiently formed, a large thrust is generated as the force F7. Therefore, the valve body 43 resists the magnetic attraction force F5 between the holding plate 50 and the force F6 caused by the fluid pressure of the fluid flowing into the active valve 4 from the fluid inlet 6a. To the lower open position 43B.

  When the valve body 43 moves to the open position 43B, the valve body 43 is separated from the valve seat 44 to the upstream side in the fluid flow direction, and the rubber sheet 437 is separated from the lower end opening 423a of the orifice 423. Thereby, the inflow side flow path 9 will be in an open state. In the open position 43 </ b> B, the valve body 43 reaches the open position where the lower end of the valve body 43 abuts against the protruding portion 474 formed inside the coil bobbin 47 or balances and stops without abutting. In the open position 43B, the fluid that flows in from the fluid inlet 6a through the inflow pipe 6 flows between the outer peripheral surface of the valve body 43 of the fluid flow path 45 and the cylindrical body 472 of the coil bobbin 47, and passes through the lower end opening 423a. Through the orifice 423 and toward the pump chamber 8.

  Further, when the inflow side channel 9 is closed, the power supply to the drive coil 46 is stopped. When the power supply to the drive coil 46 is stopped, the force F6 caused by the magnetic attraction force F5 between the holding plate 50 and the fluid pressure of the fluid flowing into the active valve 4 from the fluid inlet 6a shown in FIG. Thus, the valve body 43 moves to the closed position 43A, the valve body 43 comes into contact with the valve seat 44, and returns to the state where the upper end rubber sheet 437 closes the lower end opening 423a of the orifice 423. Accordingly, the inflow channel 9 is closed.

  When the inflow channel 9 is closed, an excitation current in the opposite direction to the case where the valve body 43 is moved from the closed position to the open position may be supplied to the drive coil 46. In this way, the valve body 43 has a Lorentz force generated between the magnet 432 of the valve body 43 and the drive coil 46, a magnetic attractive force F5 between the valve body 43 and the holding plate 50, and a fluid inlet. It moves upward by a force F6 caused by the fluid pressure of the fluid flowing into the active valve 4 from 6a. After the valve body 43 reaches the closed position, if the power supply to the drive coil 46 is stopped, the valve body 43 is held at the closed position 43A.

(Operation of positive displacement pump)
Next, the operation of the positive displacement pump 1 will be described. The electromagnetic actuator 3 and the active valve 4 of the positive displacement pump 1 are driven and controlled in synchronization by a drive control mechanism (not shown).

  In a state where power is not supplied to the drive coil 38 of the electromagnetic actuator 3 and the drive coil 46 of the active valve 4, the valve body 43 of the active valve 4 is held at the closed position 43A as shown in FIG. 4 closes the inflow side flow path 9. Further, as shown in FIG. 4, the moving body 33 of the electromagnetic actuator 3 is held at the raised position 33 </ b> A, and the diaphragm 12 sets the volume of the pump chamber 8 to the minimum first volume. The check valve (passive valve) 11 closes the outflow side flow path 10 by closing the upper end opening 225 b of the second flow path 225 by the urging force of the compression coil spring 113.

  When the fluid is sucked into the pump chamber 8, the valve element 43 is driven from the closed position 43 </ b> A to the open position 43 </ b> B by supplying power to the drive coil 46 of the active valve 4, and the inflow side flow path 9 is opened. It is said. That is, the active valve 4 is in the state shown in FIG. In parallel with this, power is supplied to the drive coils 38 of the electromagnetic actuator 3, whereby the moving body 33 is driven from the raised position 33A to the lowered position 33B. As a result, as shown in FIG. 7, the volume of the pump chamber 8 is expanded to the maximum second volume.

  When the moving body 33 is lowered and the diaphragm 12 is displaced downward, a negative pressure is generated in the pump chamber 8, so that the fluid is sucked into the pump chamber 8. In a state where negative pressure is generated in the pump chamber 8, the check valve (passive valve) 11 closes the upper end opening 225 b of the second flow path 225 and closes the outflow side flow path 10.

  Next, when the fluid is discharged from the pump chamber 8, the power supply to the drive coil 46 of the active valve 4 is stopped. As a result, as shown in FIG. 13, the valve body 43 rises from the open position 43B to the closed position 43A, and the inflow side flow path 9 is closed. In parallel with this, power is supplied to the drive coils 38 of the electromagnetic actuator 3. That is, an excitation current in the direction opposite to that during fluid suction is supplied to the drive coils 38, 38, and the moving body 33 is driven from the lowered position 33B to the raised position 33A. As a result, as shown in FIGS. 4 and 6, the volume of the pump chamber 8 is reduced to the minimum first volume.

  Here, when the volume of the pump chamber 8 is reduced, the pressure in the pump chamber 8 becomes high. Therefore, in the outflow side channel 10, a force greater than a predetermined pressure corresponding to the urging force of the valve body 112 by the compression coil spring 113 is in the outflow direction. It takes. As a result, the fluid moves the valve body 112 in the outflow direction, flows out from the upper end opening 225b of the second flow path 225, and is discharged from the fluid outlet 5a.

  Thereafter, when the positive displacement pump 1 enters a standby state, the valve body 43 of the active valve 4 is held at the closed position 43A, and the active valve 4 closes the inflow side flow path 9. The moving body 33 of the electromagnetic actuator 3 is held at the raised position 33A, and the diaphragm 12 sets the volume of the pump chamber 8 to the first volume. The check valve (passive valve) 11 closes the upper end opening 225 b of the second flow path 225 by the urging force of the compression coil spring 113 and closes the outflow side flow path 10.

(Effects of check valve)
According to this example, the check valve 11 closes the upper end opening 225 b of the second flow path 225 with the elastic force of the valve body 112 itself made of an elastic material and the urging force of the compression coil spring 113. Therefore, the sealing performance of the upper end opening 225b by the valve body 112 is high. In addition, since the upper end opening 225b is closed using the urging force of the compression coil spring 113, the upper end opening 225b is closed only by the elastic force of the valve body 112 itself. The influence which the opening / closing operation | movement of the upper end opening 225b of the two flow paths 225 receives can be reduced.

  Furthermore, since the valve body 112 is urged toward the valve seat 111 by the compression coil spring 113, it is easy to apply a predetermined load (biasing force) to the valve body 112. Further, the valve body 112 includes an annular protrusion 115 that protrudes from the closing portion 114 toward the valve seat 111 and abuts around the upper end opening 225 b of the second flow path 225. The upper end opening 225b can be closed while surrounding the upper end opening 225b. Therefore, the sealing performance of the upper end opening 225b by the valve body 112 is high.

  Here, the annular protrusion 115 has a triangular radial cross section in which the top 115a, the inner peripheral inclined surface 115b, and the outer peripheral inclined surface 115c are formed over the entire circumference, The inner peripheral contact angle α formed by the peripheral inclined surface 115b is smaller than the outer peripheral contact angle β formed by the valve seat 111 and the outer peripheral inclined surface 115c. As a result, when the valve body 112 is urged against the valve seat 111 by the compression coil spring 113, the annular projection 115 is deformed in a direction in which the top 115a of the triangular radial cross section is shifted to the outer peripheral side. Can be specified. Accordingly, the sealing performance of the upper end opening 225b by the valve body 112 is improved as compared with the case where the shape of the annular protrusion that is compressed and deformed by the urging force of the compression coil spring 113 is not determined. Further, the inner peripheral contact angle α formed by the valve seat 111 and the inner peripheral inclined surface 115b is set smaller than the outer peripheral contact angle β formed by the valve seat 111 and the outer peripheral inclined surface 115c. The closed state of the upper end opening 225b can be ensured by the urging force, and the valve body 112 can be smoothly moved with respect to the pressure of the fluid for opening the valve body 112.

  Further, in this example, since the inner peripheral contact angle α formed by the valve seat 111 and the inner peripheral inclined surface 115b is set to be less than 45 °, the fluid pressure is deformed into the annular protrusion 115. It can suppress working in the direction. Therefore, the closed state of the upper end opening 225b by the valve body 112 can be ensured.

  Further, the valve body 112 includes a positioning portion 116 for positioning the contact position of the compression coil spring 113 on the surface of the closing portion 114 that is located on the opposite side of the valve seat 111. As a result, the position and direction of the load (biasing force) applied to the closing portion 114 by the compression coil spring 113 can be defined. In addition, since the valve body 112 can be prevented from wobbling in a direction deviating from the urging direction by the compression coil spring 113, the sealing performance is improved.

  Furthermore, the compression coil spring 113 has a larger diameter than the opening of the upper end opening 225 b of the second flow path 225 and is disposed coaxially with the annular protrusion 115. Further, the circular end 143a at the lower end of the compression coil spring 113 is in contact with a position corresponding to the annular protrusion 115 on the surface of the closing portion 114 located on the side opposite to the valve seat 111. As a result, the compression coil spring 113 can uniformly apply a load to the portion of the valve body 112 that contacts the valve seat 111, so that the sealing performance is improved.

(Modification of check valve)
FIG. 15 is a cross-sectional view showing a valve body and urging means of a check valve according to a modification. In the modification shown in FIG. 15A, a recess 117 is provided inside the annular projection 115 of the valve body 112. In a state where the valve body 112 is disposed in the valve chamber 13, the upper end opening 225 b of the second flow path 225 and the recess 117 are opposed to each other.

  In the modification shown in FIG. 15B, an annular protrusion is used as the positioning portion 116A. The inner diameter of the annular protrusion is a dimension corresponding to the outer diameter of the compression coil spring 113.

  In the modified examples of FIG. 15C and FIG. 15D, the urging means is changed from the compression coil spring 113. The compression coil spring 113A of the urging means in FIG. 15C has an inner diameter that increases upward. The biasing means in FIG. 15D is a leaf spring 113B. Even when the leaf spring 113B is used, the closing portion 114 can be provided with a positioning portion 116 that defines a contact position with which the leaf spring abuts. Here, the shape of the positioning portion 116 for positioning the leaf spring 113B is not limited to a cylindrical shape or an annular shape.

  In any example, the annular projection 115 has a triangular radial cross section in which the top, the inner peripheral inclined surface, and the outer peripheral inclined surface are formed over the entire circumference. Since the inner peripheral contact angle formed by the side inclined surface is smaller than the outer peripheral contact angle formed by the valve seat and the outer peripheral inclined surface, the sealing performance of the upper end opening 225b by the valve body 112 is high. . Further, the closed state of the upper end opening 225b can be ensured by the urging force, and the valve body 112 can be smoothly moved with respect to the pressure of the fluid for opening the valve body 112.

1 · Positive displacement pump 2 · Pump unit 3 · Electromagnetic actuator 4 · Active valve 5 · Outlet tube 5a · Fluid outlet 6 · Inflow tube 6a · Fluid inlet 8 · Pump chamber 9 · Inflow Side flow path, 10. Outflow side flow path, 11 Check valve, 12 Diaphragm, 12a Connection portion, 13 Valve chamber, 13a Circular bottom, 13b Circular ceiling surface, 1415 O-ring, 21 -Upper housing, 22-Lower housing, 31-Upper case, 32-Lower case, 32a-Upper end surface, 33-Moving body, 33A-Raised position, 33B-Lowered position, 34-Fixed body, 35-First Fixed body, 36, second fixed body, 37, yoke, 38, drive coil, 38a, outer peripheral surface part, 39, spacer, 40, guide mechanism, 41, body, 42, orifice component, 43, valve body, 43A, closed position, 43B Open position, 44, valve seat, 45, fluid flow path, 46, drive coil, 47, coil bobbin, 48, yoke, 49, rubber packing, 50, pressing plate, 51, biasing means, 52, drive means, 111, Valve seat, 112, valve body, 113, 113A, compression coil spring, 113B, leaf spring, 114, closing part, 115, annular projection, 115a, top part, 115b, inner peripheral inclined surface, 115c, outer peripheral inclined surface 116, 116A, positioning portion, 211, first recess, 212, first flow path, 212a, lower end opening, 221, upper projection, 222, second recess, 223, lower projection, 224, third recess 224a, ceiling surface, 225, second flow path, 225a, lower end opening, 225b, upper end opening (outlet), 226, fourth recess, 226a, large diameter portion, 226b, small diameter portion, 226c, upper end portion, 22・ 3rd flow path, 311, upper plate, 312 to 315, side plate, 316, connecting portion, 316a, through hole, 316b, stepped portion, 317, engaging recess, 318, guide groove, 318a, upper edge, 322, Recess, 323, groove, 324, through hole, 325, engagement protrusion, 331, magnet, 331a, 331b, magnetic pole surface, 332, magnet holder, 332a, vertical frame, 332b, upper frame, 332c, lower frame , 333 · Guide projection, 334 · Connection portion, 335 · Guide shaft, 371 · Shaft, 372 · First projection, 373 · Second projection, 421 · Column-shaped part, 422 · Flange part, 423 · Orifice, 423a, lower end opening, 424, annular recess, 431, pipe, 432, magnet, 433, magnetic plate, 434, magnetic plate, 435, lid plate, 436, bottom plate, 437, rubber sheet 471, engagement recess, 472, cylindrical body, 473, flange, 474, protrusion, I1-I3, excitation current, P1-P3, section, α, inner contact angle, β, outer contact angle

Claims (5)

A valve seat provided with a fluid outlet;
A valve body made of an elastic material that is in contact with the valve seat from the downstream side in the fluid outflow direction and closes the outlet;
A biasing means that abuts the valve body from the downstream side of the valve body in a fluid outflow direction, and biases the valve body to the valve seat with a predetermined biasing force;
The valve body includes a closing portion facing the valve seat, and an annular protrusion protruding from the closing portion toward the valve seat and abutting around the outlet.
The annular protrusion has an inner peripheral inclined surface continuous radially inward with respect to the top, and an outer peripheral inclined surface continuous radially outward with respect to the top, and is formed over the entire circumference.
A check valve characterized in that an inner contact angle formed between the valve seat and the inner inclined surface is smaller than an outer contact angle formed between the valve seat and the outer inclined surface. In claim 1,
The check valve according to claim 1, wherein the inner peripheral side contact angle is less than 45 °. In claim 1 or 2,
The check valve includes a positioning portion for positioning a contact position of the urging means on a surface of the closing portion on a side opposite to the valve seat. In any one of claims 1 to 3,
The biasing means is a coil spring having a larger diameter than the opening of the outlet.
The check valve, wherein the coil spring is arranged coaxially with the annular protrusion. In claim 4,
The check valve according to claim 1, wherein one circular end of the coil spring is in contact with a position corresponding to the annular protrusion on a surface of the closing portion on a side opposite to the valve seat.

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