US20070071615A1 - Diaphragm pump - Google Patents
Diaphragm pump Download PDFInfo
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- US20070071615A1 US20070071615A1 US11/526,366 US52636606A US2007071615A1 US 20070071615 A1 US20070071615 A1 US 20070071615A1 US 52636606 A US52636606 A US 52636606A US 2007071615 A1 US2007071615 A1 US 2007071615A1
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- Prior art keywords
- pump chamber
- plate
- pair
- diaphragm
- flow channel
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B43/00—Machines, pumps, or pumping installations having flexible working members
- F04B43/02—Machines, pumps, or pumping installations having flexible working members having plate-like flexible members, e.g. diaphragms
- F04B43/04—Pumps having electric drive
Definitions
- the present embodiments relate to a diaphragm pump.
- a diaphragm pump as disclosed in, for example, Japanese Unexamined Patent Application Publication No. 11-182413, is configured such that a pump chamber (variable volume chamber) is formed by a diaphragm.
- a pair of flow channels connected with the pump chamber is provided with a pair of check valves, which are different in the direction of flow (a suction-side check valve, which allows the flow of fluid to the pump chamber, and a discharge-side check valve, which allows the flow of fluid from the pump chamber).
- the diaphragm When the diaphragm is vibrated, since the volume of the pump chamber changes, and the operation of opening the suction-side check valve during the stroke in which the volume increases, and the operation of opening the discharge-side check valve during the stroke in which the volume reduces, are repeated, a pumping action is obtained.
- the diaphragm is made of elastic (vibrational) materials, for example, rubber and piezoelectric vibrator.
- a diaphragm pump with half the cycle of the pulsation has been disclosed (Japanese Patent Application No. 2004 -154991).
- an upper pump chamber and a lower pump chamber (a pair of pump chambers) are respectively formed above and below a diaphragm by the diaphragm.
- a single suction port and a single discharge port are provided.
- First and second suction-side check valves which allow the flow of fluid from the suction port to the pair of pump chambers and do not allow the flow of fluid in the reverse direction are provided between the pair of pump chambers, and the suction port.
- First and second discharge-side check valves which allow the flow of fluid from the pair of pump chambers to the discharge port and do not allow the flow of fluid in the reverse direction are provided between the pair of pump chambers and the discharge port (4-valve diaphragm pump).
- the 4-valve diaphragm pump can basically be configured by forming recessed parts, which define an upper pump chamber and a lower pump chamber, in upper and lower housings, which sandwich a diaphragm, stacking these housings in order, and forming flow channels which communicates a pair of pump chambers and the suction and discharges ports, in the upper and lower housings.
- a 4-valve diaphragm pump that ensures liquid tightness of connecting parts of the flow channels formed over the upper housing and the lower housing or the liquid tightness of the suction flow channel and the discharge flow channel, with high reliability and durability.
- One exemplary object of the present embodiments is to provide a 4-valve diaphragm pump that is liquid tight at the connecting parts of flow channels formed over an upper housing and a lower housing.
- a second exemplary object of the present embodiments is to provide a 4-valve diaphragm pump capable of ensuring the liquid tightness of a suction flow channel and a discharge flow channel with high reliability and durability.
- a diaphragm pump in a present embodiment, includes an upper housing, a diaphragm, and a lower housing which are stacked in order. Recessed parts are respectively formed in the surfaces of the upper and lower housings facing the diaphragm to define an upper pump chamber and a lower pump chamber above and below the diaphragm. A suction port and a discharge port are formed in the lower housing to communicate with the lower pump chamber. Branch channels are formed in the lower housing and the upper housing to communicate the suction port and the discharge port with the upper pump chamber. Suction-side check valves are respectively provided between the suction port and the upper pump chamber and between the suction port and the lower pump chamber.
- Discharge-side check valves are respectively provided between the discharge port and the upper pump chamber and between the discharge port and the lower pump chamber.
- the branch channels include holes formed in either the upper housing or the lower housing, a protruding cylindrical part fitted into the hole, and a sealing ring disposed in an annular gap formed between the hole and the protruding cylindrical part such that a compressive force is generated radially.
- the upper housing can theoretically be composed of one member, it is practical that the upper housing is composed of two members in a case where the upper housing is a molded article made of a resin material. If the upper housing is composed of two members, a problem occurs in the structure in which the liquid tightness of the suction flow channel and the discharge flow channel is ensured.
- the present embodiments disclose a suitable liquid-tight structure in a case where the upper housing is composed of two members.
- the upper housing is composed of two members.
- the upper housing is composed of a pump chamber plate, which is stacked on the diaphragm and has a recessed part for forming an upper pump chamber and a blind plate stacked on the pump chamber plate.
- a pair of an inter-plate suction flow channel and an inter-plate discharge flow channel, which communicates the suction port and the discharge port with the upper pump chamber, and which constitute parts of the branch channels is formed between the pump chamber plate and the blind plate.
- the inter-plate suction flow channel and the inter-plate discharge flow channel includes a pair of protruding parts formed in any one of the pump chamber plate and the blind plate, a pair of recessed groove parts which are formed in the other one of the pump chamber plate and the blind plate to allow the pair of protruding parts to fit thereinto, and a pair of sealing rings which are disposed in a pair of closed curve gaps between the pair of protruding parts and the pair of recessed groove parts such that a compressive force is generated radially.
- the upper housing is composed of two members.
- the upper housing is composed of an upper plate, which is stacked on the diaphragm and a pair of lid plates that are members separate from the upper plate.
- the upper plate is formed with recessed parts, which are opened to the front and back of the upper plate to form the upper pump chamber, and a pair of an open suction flow channel groove and an open discharge flow channel groove which communicates with the suction port and the discharge port with the upper pump chamber.
- Any one of the upper plates and the pair of lid plates is formed with protruding parts corresponding to the open suction flow channel groove and the open discharge flow channel groove.
- the other one of the upper plates and the pair of lid plates is formed with recessed groove parts to allow the pair of protruding parts to fit thereinto.
- a pair of sealing rings are interposed between the protruding parts and the recessed groove parts such that a compressive force is generated radially.
- the protruding parts, the recessed groove parts, and the sealing rings are elliptical.
- the liquid tightness can be ensured with high durability.
- FIG. 1 is a perspective view of an exploded state showing one exemplary embodiment of a diaphragm pump
- FIG. 2 is a sectional view of the exploded state according to FIG. 1 ;
- FIG. 3 is a plan view of an exemplary lower housing
- FIG. 4 is a sectional view taken along line IV-IV of FIG. 3 ;
- FIG. 5 is a sectional view taken along line V-V of FIG. 3 ;
- FIG. 6 is a plan view of an upper housing on the side of a pump chamber plate
- FIG. 7 is a plan view of the pump chamber plate on the side of a recessed part for forming a pump chamber
- FIG. 8 is an exploded perspective view of a bimorph-type piezoelectric vibrator
- FIG. 9 is a perspective view showing the relationship between the bimorph-type piezoelectric vibrator and a modified D-type sealing ring
- FIG. 10 is a plan view of principal parts of the piezoelectric vibrator
- FIGS. 11A and 11B are conceptual diagrams, in different vibrating directions, of a diaphragm of a 4-valve diaphragm pump to which the one exemplary embodiment is applied;
- FIG. 12 is a perspective view showing another embodiment, including a section corresponding to FIG. 4 ;
- FIG. 13 is an enlarged sectional view of principal parts of the embodiment of FIG. 12 ;
- FIG. 14 is a perspective view that illustrates a blind plate of the embodiment of FIG. 12 .
- FIG. 15 is a perspective view showing still another embodiment, including a section corresponding to FIG. 4 ;
- FIG. 16 is an enlarged sectional view of principal parts of the embodiment of FIG. 15 ;
- FIG. 17 is an enlarged perspective view of the principal parts of the embodiment of FIG. 15 .
- the diaphragm pump has an upper housing 10 , a lower housing 20 , and a piezoelectric vibrator 30 , and is in the shape of a flat rectangular parallelepiped as a whole.
- the upper housing 10 is composed of a blind plate 101 and a pump chamber plate 102 , and all the blind plate 101 , the pump chamber plate 102 , and the lower housing 20 are molded articles made of a resin material.
- the lower housing 20 is a member in the shape of a flat rectangular parallelepiped, which is most large-sized and has a complicate shape, among the molded articles.
- a recessed part 20 a for forming a pump chamber is formed so as to be open to the side opposing the piezoelectric vibrator 30 , and a suction port 31 and a discharge port 32 , which are molded integrally and parallel to each other, are formed so as to protrude from one surface of flat peripheral four surfaces of the lower housing (refer to FIGS. 1 to 5 ).
- the lower housing 20 is formed with a suction-side flow channel 24 H communicating with the suction port 31 , and a discharge-side flow channel 25 D communicating with the discharge port 32 .
- Inner ends of the suction-side flow channel 24 H and the discharge-side flow channel 25 D are respectively formed with flow channel enlarged parts 24 H a and 25 D a communicating with the recessed part 20 a for forming a pump chamber.
- Valve-receiving recessed parts 24 H b and 25 D b are respectively formed at the ends of the flow channel enlarged parts 24 H a and 25 D a on the side of the recessed part 20 a for forming a pump chamber.
- a suction-side umbrella unit (suction-side check valve unit) 21 U and a discharge-side umbrella unit (discharge-side check valve unit) 22 U are adhesively fixed to the valve-receiving recessed parts 24 H b and 25 D b , respectively.
- the suction-side umbrella unit 21 U and the discharge-side umbrella unit 22 U have the same structure except that their mounting directions are different from each other.
- a central part of a unit plate 21 a (unit plate 22 a ) whose peripheral edge serves as an adhesive joint 21 b (adhesive joint 22 b ) to be adhered to the valve-receiving recessed part 24 H b (valve-receiving recessed part 25 D b ) is formed with an umbrella mounting hole 21 c (umbrella mounting hole 22 c ), and a peripheral edge of the umbrella mounting hole 21 c (umbrella mounting hole 22 c ) is formed with a plurality of flow channel holes 21 d (flow channel holes 22 d ).
- a pressure beyond a rated value is applied to the umbrella part 21 g (umbrella part 22 g ) from the flow channel holes 21 d (flow channel holes 22 d ) side, the umbrella part 21 g (umbrella part 22 g ) deforms elastically, and thus the flow channel holes 21 d (flow channel holes 22 d ) are opened.
- the adhesive joint 21 b ( 22 b ) is adhesively fixed to the valve-receiving recessed part 24 H b or 25 D b , with their front and back reversed.
- the suction-side umbrella unit 21 U allows the flow of fluid from the suction port 31 to the recessed part 20 a for forming a pump chamber (pump chamber 23 ), and does not allow the flow of fluid reverse thereto
- the discharge-side umbrella unit 22 U allows the flow of fluid from the recessed part 20 a for forming a pump chamber (pump chamber 23 ) to the discharge port 32 , and does not allow the flow of fluid reverse thereto.
- the unit plates 21 a and 22 a of the suction-side and discharge-side umbrella units 21 U and 22 U may be formed as one substrate.
- the lower housing 20 which is a single body that does not require a lid as a separate body, is formed with the suction-side flow channel 24 H and the discharge-side flow channel 25 D, which are closed between the suction port 31 and the recessed part 20 a for forming a pump chamber and between the discharge port 32 and the recessed part 20 a for forming a pump chamber.
- the lower housing 20 is formed with a sealing ring groove 20 b , which is located around the recessed part 20 a for forming a pump chamber.
- the sealing ring groove 20 b is in the shape of a modified letter “D” having a large circular-arc part 20 b 1 that is a partial circle larger than a semicircle, and a straight part 20 b 2 whose connects both ends of the large circular-arc part 20 b 1 together by a straight line.
- the suction-side umbrella unit 21 U and the discharge-side umbrella unit 22 U i.e., the valve-receiving recessed parts 24 H b and 25 D b (umbrella parts 21 g and 22 g ) are inclined (non-parallel) with respect to the plane of a piezoelectric vibrator 300 .
- the inclined direction is a direction in which the plane is separated apart from the piezoelectric vibrator 30 as it goes toward the inner end of the suction port 31 (discharge port 32 ) and approaches the piezoelectric vibrator as it goes to the near side. If the suction-side umbrella unit 21 U and the discharge-side umbrella unit 22 U are inclined in this way, the lower housing 20 can be made thin without sacrificing the channel sectional area of the suction port 31 and the discharge port 32 .
- a flow channel in a suction-side check valve (suction-side umbrella unit 21 U) is not orthogonal to the piezoelectric vibrator 30 .
- the axis of the suction port 31 (suction-side flow channel 24 H) is parallel to the plane of the piezoelectric vibrator 30 .
- the direction of the angle ⁇ is a direction in which the unit plate 21 a (umbrella part 21 g ) of the suction-side umbrella unit 21 U is separated from the piezoelectric vibrator 30 as it goes toward the inner end (left side of FIG. 4 ) of the suction port 31 (suction-side flow channel 24 H), and approaches the piezoelectric vibrator 30 as it goes to the near side (right side of FIG. 4 ).
- a flow channel in a discharge-side check valve (discharge-side umbrella unit 22 U) is not orthogonal to the piezoelectric vibrator 30 .
- the axis of the discharge port 32 (discharge-side flow channel 24 D) is parallel to the plane of the piezoelectric vibrator 30 .
- the direction of the angle ⁇ is a direction in which the unit plate 22 a (umbrella part 22 g ) of the discharge-side umbrella unit 22 U is separated from the piezoelectric vibrator 30 as it goes toward the inner end (left side of FIG. 5 ) of the discharge port 32 (discharge-side flow channel 25 D), and approaches the piezoelectric vibrator 30 as it goes to the near side (right side of FIG. 5 ).
- the lower housing 20 is further formed with branch channels 24 H d and 25 D d , which branch from the suction-side flow channel 24 H and the discharge-side flow channel 25 D, and which are opened toward the pump chamber plate 102 (upper housing 10 ).
- the pump chamber plate 102 is formed with communicating holes (branch channel) 41 and 42 communicating with the branch channels 24 H d and 25 D d .
- An inter-plate suction flow channel 14 H and an inter-plate discharge flow channel 15 D communicating with the communicating holes 41 and 42 are formed between the blind plates 101 and the pump chamber plate 102 which constitute the upper housing 10 .
- the pump chamber plate 102 is formed with protruding cylindrical parts 41 a and 42 a which fit into the branch channels 24 H d and 25 D d , and the communicating holes 41 and 42 are formed in the centers of the protruding cylindrical parts 41 a and 42 a.
- Open ends of the branch channels 24 H d and 25 D d of the lower housing 20 are respectively formed with large-diameter stepped parts 24 H e and 25 D e , which have a larger diameter than the outer diameter of the protruding cylindrical parts 41 a and 42 a .
- an annular gap 41 c or 42 c is formed between the protruding cylindrical part 41 a or 42 a , and the large-diameter stepped part 24 H e or 25 D e .
- An O-ring (sealing ring) 41 b or 42 b is inserted into the annular gap 41 c or 42 c.
- the inner diameter of the O-ring 41 b or 42 b is set to be smaller than the outer diameter of the protruding cylindrical part 41 a or 42 a , and the outer diameter thereof is set to be greater than the large-diameter stepped part 24 H e or 25 D e .
- the O-ring is kept in a state where it is brought into close contact with the protruding cylindrical part 41 a or 42 a and large-diameter stepped part 24 H e or 25 D e , thereby generating compressive force in its radial direction.
- the O-ring 41 b or 42 b keeps a space between the branch channel 24 H d or 25 D d and the protruding cylindrical part 41 a or 42 a (communicating hole 41 or 42 ) liquid-tight.
- the length (thickness) d 1 ( FIG. 4 or FIG. 5 ) of the annular gap 41 c or 42 c in the stacked direction is set to be greater than the thickness (diameter of a section) of the O-ring 41 b or 42 b .
- This length d 1 is ensured uniformly.
- the insertion (entrance) position of the protruding cylindrical part 41 a or 42 a is regulated.
- the O-ring 41 b or 42 b does not receive a compressive force in the stacked direction from the lower housing 20 and the pump chamber plate 102 . Any force that makes the lower housing 20 and the pump chamber plate 102 separated in the stacked direction from the O-rings 41 b and 42 b is not applied to the lower housing and the pump chamber plate.
- the surface of the pump chamber plate 102 which faces piezoelectric vibrator 30 becomes a recessed part 40 a for forming a pump chamber ( FIGS. 2, 4 , and 5 ).
- a substantially central part of the pump chamber plate is mounted with a suction-side umbrella 11 and a discharge-side umbrella 12 respectively corresponding to the suction-side umbrella unit 21 U and the discharge-side umbrella unit 22 U.
- the suction-side umbrella 11 and the discharge-side umbrella 12 are not drawn on FIG. 2 .
- the pump chamber plate 102 is formed with umbrella mounting holes 11 a and 12 a .
- the peripheral edges of the umbrella mounting holes 11 a and 12 a are respectively formed with a plurality of flow channel holes 11 b or 12 b.
- the suction-side umbrella 11 or the discharge-side umbrella 12 has a central shaft 11 c (central shaft 12 c ), which is mounted to the umbrella mounting hole 11 a (umbrella mounting hole 12 a ), and an umbrella part 11 d (umbrella part 12 d ) which plugs up the flow channel holes 11 b (flow channel holes 12 b ) normally.
- a pressure beyond a rated value is applied to the umbrella part 11 d (umbrella part 12 d ) from the flow channel holes 11 b (flow channel holes 12 b ) side, the umbrella part 11 d (umbrella part 12 d ) deforms elastically to open the flow channel holes 11 b (flow channel holes 12 b ).
- the suction-side umbrella 11 allows the flow of fluid from the blind plate 101 side to the recessed part 40 a for forming a pump chamber (pump chamber 13 ), and does not allow the flow of fluid reverse thereto, but the discharge-side umbrella 12 allows the flow of fluid from the recessed part 40 a for forming a pump chamber (pump chamber 13 ) to the blind plate 101 side, and does not allow the flow of fluid reverse thereto.
- the blind plate 101 has substantially the same planar shape as the lower housing 20 so as to overlap the lower housing 20 .
- the blind plate 101 is formed with a recessed part 14 H a , which forms an inter-plate suction flow channel 14 H that communicates a communicating hole 41 with the suction-side umbrella 11 , and a recessed part 15 D a for forming an inter-plate discharge flow channel 15 D that communicates a communicating hole 42 with the discharge-side umbrella 12 , between itself and the pump chamber plate 102 (refer to FIG. 2 and FIGS. 4 to 6 ).
- Sealing ring grooves 14 H b and 14 D c for allowing elliptical O-rings (sealing rings) 15 D a and 15 D a to be fitted thereinto are formed around the recessed parts 14 H a and 15 D a , respectively.
- the blind plate 101 is also formed with a recessed part 10 a ( FIGS. 2 and 6 ) for allowing the pump chamber plate 102 to be fitted thereinto.
- the pump chamber plate 102 and the blind plate 101 are respectively formed with positioning fitting protrusions 40 c and fitting holes 10 c ( FIG. 1 ) which are fitted to each other in a state where the elliptical O-ring 14 H b and 15 D b are fitted into the recessed parts 14 H a and 15 D a , for example, respectively.
- the liquid-tight inter-plate suction flow channel 14 H that is liquid-tight from the communicating hole 41 to the suction-side umbrella 11 and the inter-plate discharge flow channel 15 D which is liquid-tight from the discharge-side umbrella 12 to the communicating hole 42 are formed.
- the positioning fitting protrusions 40 c are fitted into the recessed parts 10 a , for example, respectively, so that the blind plate 101 and the pump chamber plate 102 may be integrated in advance, thereby forming the inter-plate suction flow channel 14 H and the inter-plate discharge flow channel 15 D which are closed therebetween. Lid members other than the blind plate 101 and the pump chamber plate 102 in forming the inter-plate suction flow channel 14 H and the inter-plate discharge flow channel 15 D are not needed.
- a sealing ring groove 40 b corresponding to (having the same shape in plan view) the sealing ring groove 20 b of the lower housing 20 is formed around the recessed part 40 a for forming a pump chamber, which faces the piezoelectric vibrator 30 , in the pump chamber plate 102 .
- the sealing ring groove 40 b is in the shape of a modified letter “D” having a large circular-arc part 40 b 1 that is a partial circle larger than a semicircle, and a straight part 40 b 2 whose connects both ends of the large circular-arc part 40 b 1 together by a straight line.
- FIGS. 8 to 10 are schematic views of one embodiment of the bimorph-type piezoelectric vibrator, which is proposed in Patent Application No. 2004-192483 by the present applicant.
- This piezoelectric vibrator is provided with a circular shim 111 at the central part thereof, and piezoelectric elements 112 which are stacked on the front and back thereof.
- the shim 111 is made of a conductive metallic thin plate material, for example, a stainless steel thin plate having a thickness of about 0.2 mm.
- the piezoelectric elements 112 are made of, for example, PZT (Pb(Zr, Ti)O 3 ) having a thickness of about 3 mm, and they are subjected to polarizing treatment in the direction of the front and back thereof. This polarizing treatment is performed in the same direction in the pair of piezoelectric elements 112 located at the front and back of the shim 111 .
- PZT Pb(Zr, Ti)O 3
- the pair of front and back piezoelectric elements 112 in contact with the shim 111 exhibits polarization characteristics of different poles, respectively, and the exposed surfaces of the pair of piezoelectric elements 112 become different poles, respectively. If the front and back piezoelectric elements 112 are allowed to have the polarization characteristic of the same direction in this way, the displacement of the shim 111 can be increased when positive and negative voltages are applied alternately between the shim 111 and the exposed surfaces of the pair of piezoelectric elements 112 at the front and back of the shim 111 .
- the whole surfaces of the piezoelectric elements 112 on the side of the pair of shims 111 are adhered to the shim 111 so as to be electrically connected thereto, and a filmy electrode 113 is formed on each of the whole exposed surfaces of the piezoelectric elements opposite to the shim 111 .
- the filmy electrode 113 is formed, for example, by printing (screen-baking) conductive paste (silver paste).
- a power supply terminal 180 has a pair of contactors 1811 , a connection line 1812 which connects the contactors 1811 to each other, and a wiring connection 1813 .
- the pair of contactors 1811 and the connection line 1812 forms a U-shaped section.
- the pair of contactors 1811 has the same configuration having a substantially triangular part in plan view that is broader on the side of the wiring connection 1813 located outside the piezoelectric vibrator 30 , and becomes gradually narrower toward the central part of the piezoelectric vibrator 30 .
- each contactor 1811 is the narrowest on the side of a part 1131 soldered to the filmy electrode 113 of the piezoelectric vibrator 30 , and increases in width toward the outside of the piezoelectric vibrator 30 .
- a wiring connecting projection 114 which is formed in the shim 111 of the piezoelectric vibrator 30 and projects in the radial direction extends between the pair of contactors 1811 .
- This wiring connecting projection 114 is formed with an insulating recessed part 1141 , which ensures a gap from the connection line 1812 that connects the pair of contactors 1811 to each other.
- a pair of annular spacer insulating rings 115 are located above and below the circular shim 111 , for example, respectively, and striped insulating plate materials 1151 extends to between the pair of contactors 1811 and the wiring connecting projection 114 from the pair of spacer insulating rings 115 so that the short-circuiting between the shim 111 and the power supply terminal 180 can be prevented.
- Each striped insulating plate material 1151 prevents the connection line 1812 of the power supply terminal 180 from moving toward the insulating recessed part 1141 of the shim 111 , thereby ensuring insulation.
- the wiring connecting projection 114 of the shim 111 is formed with a pair of lead wire latching recessed parts 1143 and 1144 which are located further outside the piezoelectric vibrator 30 than the insulating recessed part 1141 and which are symmetrical with respect to each other on both sides of the wiring connecting projection 114 in the width direction thereof, and a soldering through hole 1145 is formed inwardly from one lead wire latching recessed part 1143 .
- the wiring connection 1813 of the power supply terminal 180 is formed with a soldering through hole 1814 corresponding to the soldering through hole 1145 of the wiring connecting projection 114 .
- the soldering through holes 1145 and 1814 are different in positions in plan view, and soldered to lead wires 211 and 221 , for example, respectively. Since the soldering through holes 1145 and 1814 increase soldering strength and are made different in positions in plan view, the whole diaphragm pump can be made thin.
- the lead wires 211 and 221 are hung on the lead wire latching recessed parts 1143 and 1144 , thereby increasing resistance against falling-off of the lead wires 211 and 221 .
- a PPS film (insulating films) 116 ( FIG. 8 ) is adhered to each surface of the piezoelectric vibrator 30 .
- the PPS film 116 has a radial tongue piece 116 a which extends onto the power supply terminal 180 to prevent disengagement between the contactors 1811 and the filmy electrode 113 of the piezoelectric vibrator 30 .
- wiring to the shim 111 and the filmy electrode 113 can be surely attained without obstructing movement of the piezoelectric vibrator 30 .
- the piezoelectric vibrator 30 whose basic shape is a planar circular shape as described above is sandwiched between the recessed part 20 a for forming a pump chamber of the lower housing 20 and the recessed part 40 a for forming a pump chamber of the pump chamber plate 102 .
- the upper and lower peripheries of the piezoelectric vibrator are sealed with the sealing rings 16 and 26 to form the pump chambers 13 and 23 .
- the sealing rings 16 and 26 have the same shape as the sealing ring groove 20 b of the lower housing 20 and the sealing ring groove 40 b of the pump chamber plate 102 , and have the large circular-arc part 16 a (large circular-arc part 26 a ) and the straight part 16 b (straight part 26 b ).
- the power supply terminal 180 of the piezoelectric vibrator 30 is located outside the sealing rings 16 and 26 , i.e., outside the straight part 16 b (straight part 26 b ). Since this arrangement prevents intersection of the power supply terminal 180 to the piezoelectric elements 112 of the piezoelectric vibrator 30 with the sealing rings 16 and 26 and local deformation of the sealing rings 16 and 26 , the durability can be improved.
- the lower housing 20 , and the blind plate 101 integrated in advance into the pump chamber plate 102 are combined with each other and integrated into one by fasteners (for example, bolt and nut), with the piezoelectric vibrator 30 sandwiched between the lower housing and blind plate, as described above.
- fasteners for example, bolt and nut
- an adhesive can be used additionally.
- FIGS. 12 to 14 illustrate an alternate embodiment of the diaphragm pump.
- the present embodiment is configured such that, even in the seal structure in the vicinity of the inter-plate suction flow channel 14 H and the inter-plate discharge flow channel 15 D, which are formed between the blind plate 101 and the pump chamber plate 102 (in the upper housing 10 ), a force in the direction in which the blind plate 101 and are separated from the pump chamber plate 102 is kept from being applied.
- a pair of recessed groove parts 101 b 1 and 101 b 2 are respectively formed around the recessed parts 14 H a and 15 D a of the blind plate 101 , as shown in the enlarged view of FIG. 13 .
- the pump chamber plate 102 is formed with a pair of elliptical protruding parts 101 b 1 and 102 b 1 which are caused to project toward the blind plate 101 and fit into a pair of recessed groove parts 101 b 1 and 102 b 2 , for example, respectively.
- Sealing rings 141 b and 142 b are inserted into the pair of closed curve gaps 141 c and 142 c , for example, respectively.
- a compressive force is generated in the radial direction (the direction in the plane of the blind plate 101 and the pump chamber plate 102 ).
- the spaces between the blind plate 101 and the pump chamber plates 102 are held in liquid tightness by the sealing rings 141 b and 142 b.
- the length (thickness) d 2 ( FIGS. 12 and 13 ) of the pair of closed curve gaps 141 c and 142 c in the stacked direction of housings is set to be greater than the thickness (diameter of a section) of the sealing rings 141 b and 142 b . This length d 2 is ensured uniformly.
- any force that makes the blind plate 101 and the pump chamber plate 102 separated in the stacked direction from the sealing ring 141 b and 142 b is not applied to the blind plate and the pump chamber plate. Since a compressive force that is uniform as a whole is applied to the piezoelectric vibrator 30 from the stacked direction, vibration of the piezoelectric vibrator 30 is also uniformly generated in the stacked direction. The operation of the piezoelectric vibrator 30 can be stabilized, and a fluid can be generated efficiently.
- FIGS. 15 to 17 show still another embodiment of the diaphragm pump.
- This embodiment is an embodiment in which the upper housing 10 is composed of an upper plate 103 and a pair of lid plates 104 H and 104 D, a suction flow channel 14 H 1 is formed between this upper plate 103 and the lid plate 104 H, and a discharge flow channel 15 D 1 is formed between the upper plate 103 and the lid plate 104 D.
- the upper plate 103 is formed with an open suction flow channel groove 103 b 1 and an open discharge flow channel groove 103 b 2 whose top are opened.
- An inside end of the open suction flow channel groove 103 b 1 is provided with an umbrella 11 , and an outside end thereof is provided with a branch channel 41 .
- an inside end of the open discharge flow channel groove 103 b 2 is provided with an umbrella 12 , and an outside end thereof is provided with a branch channel 42 .
- the pair of lid plates 104 H and 104 D is provided with protruding parts 104 b 1 and 104 b 2 , respectively, which project toward the upper plate 103 and fit into the open suction flow channel groove 103 b 1 and the open discharge flow channel groove 103 b 2 .
- the length d 3 ( FIGS. 15 and 16 ) of the closed curve gaps 241 c and 242 c in the stacked direction is set to be greater than the thickness (diameter of a section) of the sealing rings 241 b and 242 b . This length d 3 is ensured uniformly.
- the sealing ring 241 b or 242 b does not receive a compressive force in the stacked direction from the upper plate 103 and the pair of lid plates 104 H and 104 D.
- any force that makes the upper plate 103 and the pair of lid plates 104 H and 104 D separated in the stacked direction from the sealing ring 241 b and 242 b is not applied to the upper plate and the lid plates.
- a compressive force that is uniform as a whole is applied to the piezoelectric vibrator 30 from the stacked direction, vibration of the piezoelectric vibrator 30 is also uniformly generated in the stacked direction. Therefore, the operation of the piezoelectric vibrator 30 can be stabilized, and a fluid can be generated efficiently.
- the present embodiments are aimed at the seal structure, which ensures the liquid tightness of the suction flow channel and discharge flow channel of the above embodiment, with high durability.
- the lower housing, the umbrella, or the piezoelectric vibrator only shows an example. Accordingly, although the umbrella is illustrated as a check valve, check valves other than the umbrella can also be used, and an electrostrictive vibrator may be used instead of the piezoelectric vibrator. Further, the present invention can also be applied to a 2-valve type diaphragm pump, i.e., a pump in which a pump chamber is formed only below a piezoelectric vibrator, and any pump chamber is not provided above the piezoelectric vibrator (an umbrella is not provided).
- the liquid tightness of the connecting parts of the flow channels formed over the upper housing and the lower housing can be ensured with high reliability and durability.
- the liquid tightness of the suction flow channel and discharge flow channel formed in the upper housing can be ensured with high reliability and durability.
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- Details Of Reciprocating Pumps (AREA)
Abstract
A diaphragm pump is provided. The diaphragm includes an upper housing, a diaphragm, and a lower housing. Recessed parts are formed in the surfaces of the upper and lower housings that face the diaphragm to define an upper pump chamber and a lower pump chamber above and below the diaphragm. A suction port and a discharge port are formed in the lower housing to communicate with the lower pump chamber. Branch channels are formed in the lower housing and the upper housing to communicate the suction port and the discharge port with the upper pump chamber. Suction-side check valves are respectively provided between the suction port and the upper pump chamber and between the suction port and the lower pump chamber. Discharge-side check valves are provided between the discharge port and the upper pump chamber and between the discharge port and the lower pump chamber.
Description
- This application claims the benefit of Japanese Patent Application No. 2005-280548 filed on Sep. 27, 2005 and Japanese Patent Application NO. 2006-136693 filed on May 16, 2006.
- 1. Field
- The present embodiments relate to a diaphragm pump.
- 2. Related Art
- A diaphragm pump, as disclosed in, for example, Japanese Unexamined Patent Application Publication No. 11-182413, is configured such that a pump chamber (variable volume chamber) is formed by a diaphragm. A pair of flow channels connected with the pump chamber is provided with a pair of check valves, which are different in the direction of flow (a suction-side check valve, which allows the flow of fluid to the pump chamber, and a discharge-side check valve, which allows the flow of fluid from the pump chamber). When the diaphragm is vibrated, since the volume of the pump chamber changes, and the operation of opening the suction-side check valve during the stroke in which the volume increases, and the operation of opening the discharge-side check valve during the stroke in which the volume reduces, are repeated, a pumping action is obtained. The diaphragm is made of elastic (vibrational) materials, for example, rubber and piezoelectric vibrator.
- In this diaphragm pump, as described above, since the operation of opening the suction-side check valve during the stroke in which the volume of the pump chamber increases, and the operation of opening the discharge-side check valve during the stroke in which the volume reduces, are repeated, pulsation in the discharge port is inevitable.
- A diaphragm pump with half the cycle of the pulsation has been disclosed (Japanese Patent Application No. 2004-154991). According to this diaphragm pump, an upper pump chamber and a lower pump chamber (a pair of pump chambers) are respectively formed above and below a diaphragm by the diaphragm. A single suction port and a single discharge port are provided. First and second suction-side check valves, which allow the flow of fluid from the suction port to the pair of pump chambers and do not allow the flow of fluid in the reverse direction are provided between the pair of pump chambers, and the suction port. First and second discharge-side check valves, which allow the flow of fluid from the pair of pump chambers to the discharge port and do not allow the flow of fluid in the reverse direction are provided between the pair of pump chambers and the discharge port (4-valve diaphragm pump).
- The 4-valve diaphragm pump can basically be configured by forming recessed parts, which define an upper pump chamber and a lower pump chamber, in upper and lower housings, which sandwich a diaphragm, stacking these housings in order, and forming flow channels which communicates a pair of pump chambers and the suction and discharges ports, in the upper and lower housings. However, there is a need for a 4-valve diaphragm pump that ensures liquid tightness of connecting parts of the flow channels formed over the upper housing and the lower housing or the liquid tightness of the suction flow channel and the discharge flow channel, with high reliability and durability.
- One exemplary object of the present embodiments is to provide a 4-valve diaphragm pump that is liquid tight at the connecting parts of flow channels formed over an upper housing and a lower housing. A second exemplary object of the present embodiments is to provide a 4-valve diaphragm pump capable of ensuring the liquid tightness of a suction flow channel and a discharge flow channel with high reliability and durability.
- In a present embodiment, a diaphragm pump includes an upper housing, a diaphragm, and a lower housing which are stacked in order. Recessed parts are respectively formed in the surfaces of the upper and lower housings facing the diaphragm to define an upper pump chamber and a lower pump chamber above and below the diaphragm. A suction port and a discharge port are formed in the lower housing to communicate with the lower pump chamber. Branch channels are formed in the lower housing and the upper housing to communicate the suction port and the discharge port with the upper pump chamber. Suction-side check valves are respectively provided between the suction port and the upper pump chamber and between the suction port and the lower pump chamber. Discharge-side check valves are respectively provided between the discharge port and the upper pump chamber and between the discharge port and the lower pump chamber. The branch channels include holes formed in either the upper housing or the lower housing, a protruding cylindrical part fitted into the hole, and a sealing ring disposed in an annular gap formed between the hole and the protruding cylindrical part such that a compressive force is generated radially.
- Although the upper housing can theoretically be composed of one member, it is practical that the upper housing is composed of two members in a case where the upper housing is a molded article made of a resin material. If the upper housing is composed of two members, a problem occurs in the structure in which the liquid tightness of the suction flow channel and the discharge flow channel is ensured. The present embodiments disclose a suitable liquid-tight structure in a case where the upper housing is composed of two members.
- In a present embodiment, the upper housing is composed of two members. The upper housing is composed of a pump chamber plate, which is stacked on the diaphragm and has a recessed part for forming an upper pump chamber and a blind plate stacked on the pump chamber plate. A pair of an inter-plate suction flow channel and an inter-plate discharge flow channel, which communicates the suction port and the discharge port with the upper pump chamber, and which constitute parts of the branch channels is formed between the pump chamber plate and the blind plate. The inter-plate suction flow channel and the inter-plate discharge flow channel includes a pair of protruding parts formed in any one of the pump chamber plate and the blind plate, a pair of recessed groove parts which are formed in the other one of the pump chamber plate and the blind plate to allow the pair of protruding parts to fit thereinto, and a pair of sealing rings which are disposed in a pair of closed curve gaps between the pair of protruding parts and the pair of recessed groove parts such that a compressive force is generated radially.
- In another embodiment, the upper housing is composed of two members. The upper housing is composed of an upper plate, which is stacked on the diaphragm and a pair of lid plates that are members separate from the upper plate. The upper plate is formed with recessed parts, which are opened to the front and back of the upper plate to form the upper pump chamber, and a pair of an open suction flow channel groove and an open discharge flow channel groove which communicates with the suction port and the discharge port with the upper pump chamber. Any one of the upper plates and the pair of lid plates is formed with protruding parts corresponding to the open suction flow channel groove and the open discharge flow channel groove. The other one of the upper plates and the pair of lid plates is formed with recessed groove parts to allow the pair of protruding parts to fit thereinto. A pair of sealing rings are interposed between the protruding parts and the recessed groove parts such that a compressive force is generated radially.
- In one exemplary embodiment, the protruding parts, the recessed groove parts, and the sealing rings are elliptical.
- By keeping a compressive force in the stacked direction of the upper housing, the diaphragm, and the lower housing from being applied to any of the sealing rings, and allowing a compressive in a direction (radial direction) orthogonal to the stacked direction to be applied to the sealing rings, the liquid tightness can be ensured with high durability.
-
FIG. 1 is a perspective view of an exploded state showing one exemplary embodiment of a diaphragm pump; -
FIG. 2 is a sectional view of the exploded state according toFIG. 1 ; -
FIG. 3 is a plan view of an exemplary lower housing; -
FIG. 4 is a sectional view taken along line IV-IV ofFIG. 3 ; -
FIG. 5 is a sectional view taken along line V-V ofFIG. 3 ; -
FIG. 6 is a plan view of an upper housing on the side of a pump chamber plate; -
FIG. 7 is a plan view of the pump chamber plate on the side of a recessed part for forming a pump chamber; -
FIG. 8 is an exploded perspective view of a bimorph-type piezoelectric vibrator; -
FIG. 9 is a perspective view showing the relationship between the bimorph-type piezoelectric vibrator and a modified D-type sealing ring; -
FIG. 10 is a plan view of principal parts of the piezoelectric vibrator; -
FIGS. 11A and 11B are conceptual diagrams, in different vibrating directions, of a diaphragm of a 4-valve diaphragm pump to which the one exemplary embodiment is applied; -
FIG. 12 is a perspective view showing another embodiment, including a section corresponding toFIG. 4 ; -
FIG. 13 is an enlarged sectional view of principal parts of the embodiment ofFIG. 12 ; -
FIG. 14 is a perspective view that illustrates a blind plate of the embodiment ofFIG. 12 . -
FIG. 15 is a perspective view showing still another embodiment, including a section corresponding toFIG. 4 ; -
FIG. 16 is an enlarged sectional view of principal parts of the embodiment ofFIG. 15 ; and -
FIG. 17 is an enlarged perspective view of the principal parts of the embodiment ofFIG. 15 . - Illustrated embodiments are obtained by applying the present embodiments to a 4-valve diaphragm pump that the present applicant proposed the principle in Japanese Patent Application No. 2004-154991. One embodiment thereof will be described with reference to FIGS. 1 to 7. In one exemplary embodiment, the diaphragm pump has an
upper housing 10, alower housing 20, and apiezoelectric vibrator 30, and is in the shape of a flat rectangular parallelepiped as a whole. Theupper housing 10 is composed of ablind plate 101 and apump chamber plate 102, and all theblind plate 101, thepump chamber plate 102, and thelower housing 20 are molded articles made of a resin material. - The
lower housing 20 is a member in the shape of a flat rectangular parallelepiped, which is most large-sized and has a complicate shape, among the molded articles. In the lower housing, a recessedpart 20 a for forming a pump chamber is formed so as to be open to the side opposing thepiezoelectric vibrator 30, and asuction port 31 and adischarge port 32, which are molded integrally and parallel to each other, are formed so as to protrude from one surface of flat peripheral four surfaces of the lower housing (refer to FIGS. 1 to 5). - The
lower housing 20 is formed with a suction-side flow channel 24H communicating with thesuction port 31, and a discharge-side flow channel 25D communicating with thedischarge port 32. Inner ends of the suction-side flow channel 24H and the discharge-side flow channel 25D are respectively formed with flow channel enlarged parts 24Ha and 25Da communicating with the recessedpart 20 a for forming a pump chamber. Valve-receiving recessed parts 24Hb and 25Db are respectively formed at the ends of the flow channel enlarged parts 24Ha and 25Da on the side of the recessedpart 20 a for forming a pump chamber. - A suction-side umbrella unit (suction-side check valve unit) 21U and a discharge-side umbrella unit (discharge-side check valve unit) 22U are adhesively fixed to the valve-receiving recessed parts 24Hb and 25Db, respectively. The suction-
side umbrella unit 21U and the discharge-side umbrella unit 22U have the same structure except that their mounting directions are different from each other. A central part of aunit plate 21 a (unit plate 22 a) whose peripheral edge serves as an adhesive joint 21 b (adhesive joint 22 b) to be adhered to the valve-receiving recessed part 24Hb (valve-receiving recessed part 25Db) is formed with anumbrella mounting hole 21 c (umbrella mounting hole 22 c), and a peripheral edge of theumbrella mounting hole 21 c (umbrella mounting hole 22 c) is formed with a plurality offlow channel holes 21d (flow channel holes 22 d). - An
umbrella part 21 g (umbrella part 22 g) of anumbrella 21 f (umbrella 22 f) whosecentral shaft 21 e (central shaft 22 e is mounted into theumbrella mounting hole 21 c (umbrella mounting hole 22 c) plugs up the flow channel holes 21 d (flow channel holes 22 d) normally. When a pressure beyond a rated value is applied to theumbrella part 21 g (umbrella part 22 g) from the flow channel holes 21 d (flow channel holes 22 d) side, theumbrella part 21 g (umbrella part 22 g) deforms elastically, and thus the flow channel holes 21 d (flow channel holes 22 d) are opened. - In the suction-
side umbrella unit 21U or the discharge-side umbrella unit 22U, the adhesive joint 21 b (22 b) is adhesively fixed to the valve-receiving recessed part 24Hb or 25Db, with their front and back reversed. The suction-side umbrella unit 21U allows the flow of fluid from thesuction port 31 to the recessedpart 20 a for forming a pump chamber (pump chamber 23), and does not allow the flow of fluid reverse thereto, and the discharge-side umbrella unit 22U allows the flow of fluid from the recessedpart 20 a for forming a pump chamber (pump chamber 23) to thedischarge port 32, and does not allow the flow of fluid reverse thereto. Theunit plates side umbrella units - The
lower housing 20, which is a single body that does not require a lid as a separate body, is formed with the suction-side flow channel 24H and the discharge-side flow channel 25D, which are closed between thesuction port 31 and the recessedpart 20 a for forming a pump chamber and between thedischarge port 32 and the recessedpart 20 a for forming a pump chamber. Thelower housing 20 is formed with a sealingring groove 20 b, which is located around the recessedpart 20 a for forming a pump chamber. The sealingring groove 20 b is in the shape of a modified letter “D” having a large circular-arc part 20 b 1 that is a partial circle larger than a semicircle, and astraight part 20 b 2 whose connects both ends of the large circular-arc part 20 b 1 together by a straight line. - The suction-
side umbrella unit 21U and the discharge-side umbrella unit 22U, i.e., the valve-receiving recessed parts 24Hb and 25Db (umbrella parts piezoelectric vibrator 30, including the axis of the suction port 31 (discharge port 32), is considered, the inclined direction is a direction in which the plane is separated apart from thepiezoelectric vibrator 30 as it goes toward the inner end of the suction port 31 (discharge port 32) and approaches the piezoelectric vibrator as it goes to the near side. If the suction-side umbrella unit 21U and the discharge-side umbrella unit 22U are inclined in this way, thelower housing 20 can be made thin without sacrificing the channel sectional area of thesuction port 31 and thedischarge port 32. - For example, as shown in
FIG. 4 , the surface (unit plate 21 a (umbrella part 21 g) of the suction-side umbrella unit 21U) of the valve-receiving recessed part 24Hb and the plane of thepiezoelectric vibrator 30 in a free state, which are non-parallel, forms an angle α. A flow channel in a suction-side check valve (suction-side umbrella unit 21U) is not orthogonal to thepiezoelectric vibrator 30. The axis of the suction port 31 (suction-side flow channel 24H) is parallel to the plane of thepiezoelectric vibrator 30. The direction of the angle α is a direction in which theunit plate 21 a (umbrella part 21 g) of the suction-side umbrella unit 21U is separated from thepiezoelectric vibrator 30 as it goes toward the inner end (left side ofFIG. 4 ) of the suction port 31 (suction-side flow channel 24H), and approaches thepiezoelectric vibrator 30 as it goes to the near side (right side ofFIG. 4 ). - As shown in
FIG. 5 , the surface (unit plate 22 a (umbrella part 22 g) of the discharge-side umbrella unit 22U) of the valve-receiving recessed part 24Db and the plane of thepiezoelectric vibrator 30 in a free state, which are non-parallel, forms an angle α. For example, a flow channel in a discharge-side check valve (discharge-side umbrella unit 22U) is not orthogonal to thepiezoelectric vibrator 30. The axis of the discharge port 32 (discharge-side flow channel 24D) is parallel to the plane of thepiezoelectric vibrator 30. The direction of the angle α is a direction in which theunit plate 22 a (umbrella part 22 g) of the discharge-side umbrella unit 22U is separated from thepiezoelectric vibrator 30 as it goes toward the inner end (left side ofFIG. 5 ) of the discharge port 32 (discharge-side flow channel 25D), and approaches thepiezoelectric vibrator 30 as it goes to the near side (right side ofFIG. 5 ). - The
lower housing 20 is further formed with branch channels 24Hd and 25Dd, which branch from the suction-side flow channel 24H and the discharge-side flow channel 25D, and which are opened toward the pump chamber plate 102 (upper housing 10). Thepump chamber plate 102 is formed with communicating holes (branch channel) 41 and 42 communicating with the branch channels 24Hd and 25Dd. An inter-platesuction flow channel 14H and an inter-platedischarge flow channel 15D communicating with the communicatingholes blind plates 101 and thepump chamber plate 102 which constitute theupper housing 10. For example, thepump chamber plate 102 is formed with protrudingcylindrical parts holes cylindrical parts - Open ends of the branch channels 24Hd and 25Dd of the
lower housing 20 are respectively formed with large-diameter stepped parts 24He and 25De, which have a larger diameter than the outer diameter of the protrudingcylindrical parts cylindrical parts FIGS. 4 and 5 , anannular gap cylindrical part annular gap - The inner diameter of the O-
ring cylindrical part cylindrical part ring cylindrical part hole 41 or 42) liquid-tight. - The length (thickness) d1 (
FIG. 4 orFIG. 5 ) of theannular gap ring cylindrical parts entrance regulating surface pump chamber plate 102 abuts on an abutting surface 24Hi or 25Di, which faces theentrance regulating surface cylindrical part ring lower housing 20 and thepump chamber plate 102. Any force that makes thelower housing 20 and thepump chamber plate 102 separated in the stacked direction from the O-rings - Since a compressive force that is uniform as a whole is applied to the
piezoelectric vibrator 30 from the stacked direction, vibration of thepiezoelectric vibrator 30 is also uniformly generated in the stacked direction. The operation of thepiezoelectric vibrator 30 can be stabilized, and a fluid can be generated efficiently. - The surface of the
pump chamber plate 102, which facespiezoelectric vibrator 30 becomes a recessedpart 40 a for forming a pump chamber (FIGS. 2, 4 , and 5). A substantially central part of the pump chamber plate is mounted with a suction-side umbrella 11 and a discharge-side umbrella 12 respectively corresponding to the suction-side umbrella unit 21U and the discharge-side umbrella unit 22U. The suction-side umbrella 11 and the discharge-side umbrella 12 are not drawn onFIG. 2 . For example, in the positions vertically corresponding to the suction-side umbrella unit 21U and the discharge-side umbrella unit 22U, thepump chamber plate 102 is formed withumbrella mounting holes umbrella mounting holes - The suction-
side umbrella 11 or the discharge-side umbrella 12 has a central shaft 11 c (central shaft 12 c), which is mounted to theumbrella mounting hole 11 a (umbrella mounting hole 12 a), and anumbrella part 11 d (umbrella part 12 d) which plugs up the flow channel holes 11 b (flow channel holes 12 b) normally. When a pressure beyond a rated value is applied to theumbrella part 11 d (umbrella part 12 d) from the flow channel holes 11 b (flow channel holes 12 b) side, theumbrella part 11 d (umbrella part 12 d) deforms elastically to open the flow channel holes 11 b (flow channel holes 12 b). - The suction-
side umbrella 11 allows the flow of fluid from theblind plate 101 side to the recessedpart 40 a for forming a pump chamber (pump chamber 13), and does not allow the flow of fluid reverse thereto, but the discharge-side umbrella 12 allows the flow of fluid from the recessedpart 40 a for forming a pump chamber (pump chamber 13) to theblind plate 101 side, and does not allow the flow of fluid reverse thereto. - The
blind plate 101 has substantially the same planar shape as thelower housing 20 so as to overlap thelower housing 20. Theblind plate 101 is formed with a recessed part 14Ha, which forms an inter-platesuction flow channel 14H that communicates a communicatinghole 41 with the suction-side umbrella 11, and a recessed part 15Da for forming an inter-platedischarge flow channel 15D that communicates a communicatinghole 42 with the discharge-side umbrella 12, between itself and the pump chamber plate 102 (refer toFIG. 2 and FIGS. 4 to 6). Sealing ring grooves 14Hb and 14Dc for allowing elliptical O-rings (sealing rings) 15Da and 15Da to be fitted thereinto are formed around the recessed parts 14Ha and 15Da, respectively. Theblind plate 101 is also formed with a recessedpart 10 a (FIGS. 2 and 6 ) for allowing thepump chamber plate 102 to be fitted thereinto. - The
pump chamber plate 102 and theblind plate 101 are respectively formed with positioningfitting protrusions 40 c andfitting holes 10 c (FIG. 1 ) which are fitted to each other in a state where the elliptical O-ring 14Hb and 15Db are fitted into the recessed parts 14Ha and 15Da, for example, respectively. By bonding the positing fitting protrusions and the fitting holes together after they are fitted to each other, the liquid-tight inter-platesuction flow channel 14H that is liquid-tight from the communicatinghole 41 to the suction-side umbrella 11 and the inter-platedischarge flow channel 15D which is liquid-tight from the discharge-side umbrella 12 to the communicatinghole 42 are formed. For example, thepositioning fitting protrusions 40 c are fitted into the recessedparts 10 a, for example, respectively, so that theblind plate 101 and thepump chamber plate 102 may be integrated in advance, thereby forming the inter-platesuction flow channel 14H and the inter-platedischarge flow channel 15D which are closed therebetween. Lid members other than theblind plate 101 and thepump chamber plate 102 in forming the inter-platesuction flow channel 14H and the inter-platedischarge flow channel 15D are not needed. - As shown in
FIG. 7 , a sealingring groove 40 b corresponding to (having the same shape in plan view) thesealing ring groove 20 b of thelower housing 20 is formed around the recessedpart 40 a for forming a pump chamber, which faces thepiezoelectric vibrator 30, in thepump chamber plate 102. The sealingring groove 40 b is in the shape of a modified letter “D” having a large circular-arc part 40 b 1 that is a partial circle larger than a semicircle, and astraight part 40 b 2 whose connects both ends of the large circular-arc part 40 b 1 together by a straight line. - Both of a unimorph-type piezoelectric vibrator and a bimorph-type piezoelectric vibrator can be used as the
piezoelectric vibrator 30. FIGS. 8 to 10 are schematic views of one embodiment of the bimorph-type piezoelectric vibrator, which is proposed in Patent Application No. 2004-192483 by the present applicant. This piezoelectric vibrator is provided with acircular shim 111 at the central part thereof, andpiezoelectric elements 112 which are stacked on the front and back thereof. Theshim 111 is made of a conductive metallic thin plate material, for example, a stainless steel thin plate having a thickness of about 0.2 mm. - The
piezoelectric elements 112 are made of, for example, PZT (Pb(Zr, Ti)O3) having a thickness of about 3 mm, and they are subjected to polarizing treatment in the direction of the front and back thereof. This polarizing treatment is performed in the same direction in the pair ofpiezoelectric elements 112 located at the front and back of theshim 111. For example, referring toFIG. 8 , when the polarization direction of the pair ofpiezoelectric elements 112 are denoted by arrow “a” or “b”, the polarizing treatment in the same direction as the thickness direction of theshim 111 is performed. The pair of front and backpiezoelectric elements 112 in contact with theshim 111 exhibits polarization characteristics of different poles, respectively, and the exposed surfaces of the pair ofpiezoelectric elements 112 become different poles, respectively. If the front and backpiezoelectric elements 112 are allowed to have the polarization characteristic of the same direction in this way, the displacement of theshim 111 can be increased when positive and negative voltages are applied alternately between theshim 111 and the exposed surfaces of the pair ofpiezoelectric elements 112 at the front and back of theshim 111. - The whole surfaces of the
piezoelectric elements 112 on the side of the pair ofshims 111 are adhered to theshim 111 so as to be electrically connected thereto, and afilmy electrode 113 is formed on each of the whole exposed surfaces of the piezoelectric elements opposite to theshim 111. Thefilmy electrode 113 is formed, for example, by printing (screen-baking) conductive paste (silver paste). - A
power supply terminal 180 has a pair ofcontactors 1811, aconnection line 1812 which connects thecontactors 1811 to each other, and awiring connection 1813. The pair ofcontactors 1811 and theconnection line 1812 forms a U-shaped section. The pair ofcontactors 1811 has the same configuration having a substantially triangular part in plan view that is broader on the side of thewiring connection 1813 located outside thepiezoelectric vibrator 30, and becomes gradually narrower toward the central part of thepiezoelectric vibrator 30. For example, eachcontactor 1811 is the narrowest on the side of apart 1131 soldered to thefilmy electrode 113 of thepiezoelectric vibrator 30, and increases in width toward the outside of thepiezoelectric vibrator 30. - A
wiring connecting projection 114, which is formed in theshim 111 of thepiezoelectric vibrator 30 and projects in the radial direction extends between the pair ofcontactors 1811. Thiswiring connecting projection 114 is formed with an insulating recessedpart 1141, which ensures a gap from theconnection line 1812 that connects the pair ofcontactors 1811 to each other. - A pair of annular
spacer insulating rings 115 are located above and below thecircular shim 111, for example, respectively, and striped insulatingplate materials 1151 extends to between the pair ofcontactors 1811 and thewiring connecting projection 114 from the pair ofspacer insulating rings 115 so that the short-circuiting between theshim 111 and thepower supply terminal 180 can be prevented. Each striped insulatingplate material 1151 prevents theconnection line 1812 of thepower supply terminal 180 from moving toward the insulating recessedpart 1141 of theshim 111, thereby ensuring insulation. - The
wiring connecting projection 114 of theshim 111 is formed with a pair of lead wire latching recessedparts piezoelectric vibrator 30 than the insulating recessedpart 1141 and which are symmetrical with respect to each other on both sides of thewiring connecting projection 114 in the width direction thereof, and a soldering throughhole 1145 is formed inwardly from one lead wire latching recessedpart 1143. - The
wiring connection 1813 of thepower supply terminal 180 is formed with a soldering throughhole 1814 corresponding to the soldering throughhole 1145 of thewiring connecting projection 114. The soldering throughholes wires holes lead wires parts lead wires - A PPS film (insulating films) 116 (
FIG. 8 ) is adhered to each surface of thepiezoelectric vibrator 30. ThePPS film 116 has aradial tongue piece 116 a which extends onto thepower supply terminal 180 to prevent disengagement between thecontactors 1811 and thefilmy electrode 113 of thepiezoelectric vibrator 30. - According to the wiring structure in the vicinity of the
wiring connecting projection 114 of theshim 111 and thepower supply terminal 180 which have been described hitherto, wiring to theshim 111 and thefilmy electrode 113 can be surely attained without obstructing movement of thepiezoelectric vibrator 30. - The
piezoelectric vibrator 30 whose basic shape is a planar circular shape as described above is sandwiched between the recessedpart 20 a for forming a pump chamber of thelower housing 20 and the recessedpart 40 a for forming a pump chamber of thepump chamber plate 102. The upper and lower peripheries of the piezoelectric vibrator are sealed with the sealing rings 16 and 26 to form thepump chambers ring groove 20 b of thelower housing 20 and the sealingring groove 40 b of thepump chamber plate 102, and have the large circular-arc part 16 a (large circular-arc part 26 a) and thestraight part 16 b (straight part 26 b). Thepower supply terminal 180 of thepiezoelectric vibrator 30 is located outside the sealing rings 16 and 26, i.e., outside thestraight part 16 b (straight part 26 b). Since this arrangement prevents intersection of thepower supply terminal 180 to thepiezoelectric elements 112 of thepiezoelectric vibrator 30 with the sealing rings 16 and 26 and local deformation of the sealing rings 16 and 26, the durability can be improved. - The
lower housing 20, and theblind plate 101 integrated in advance into thepump chamber plate 102 are combined with each other and integrated into one by fasteners (for example, bolt and nut), with thepiezoelectric vibrator 30 sandwiched between the lower housing and blind plate, as described above. In an alternate embodiment, an adhesive can be used additionally. - In the diaphragm pump having the above configuration, when alternating electric fields are applied to between the
power supply terminal 180 and the shim 111 (wiring connecting projection 114) to elastically deform (vibrate) thepiezoelectric vibrator 30 forward and backward, the volume of one of thepump chambers pump chamber 13 increases, since the suction-side umbrella 11 opens and a fluid flows into thepump chamber 13 from thesuction port 31 and simultaneously the volume of thepump chamber 23 decreases, the fluid in thepump chamber 23 opens the discharge-side umbrella (unit) 22, and flows into thedischarge port 32. - During the stroke in which the volume of the
pump chamber 13 decreases, since the suction-side umbrella (unit) 21 opens and a fluid flows into thepump chamber 23 from thesuction port 31, and the volume of thepump chamber 13 decreases, the fluid in thepump chamber 13 opens the discharge-side umbrella 12 and flows into thedischarge port 32. The cycle of the pulsation in thedischarge port 32 can be shortened (reduced to half as compared with a case where a pump chamber is formed only in one of the upper and lower sides of the piezoelectric vibrator 30). Flow channels of the above-described 4-valve diaphragm pump are skeletonized inFIG. 1 . - FIGS. 12 to 14 illustrate an alternate embodiment of the diaphragm pump. The present embodiment is configured such that, even in the seal structure in the vicinity of the inter-plate
suction flow channel 14H and the inter-platedischarge flow channel 15D, which are formed between theblind plate 101 and the pump chamber plate 102 (in the upper housing 10), a force in the direction in which theblind plate 101 and are separated from thepump chamber plate 102 is kept from being applied. - For example, instead of the sealing ring groove 14Hc and 15Dc, a pair of recessed groove parts 101 b 1 and 101 b 2 are respectively formed around the recessed parts 14Ha and 15Da of the
blind plate 101, as shown in the enlarged view ofFIG. 13 .Thepump chamber plate 102 is formed with a pair of elliptical protruding parts 101 b 1 and 102 b 1 which are caused to project toward theblind plate 101 and fit into a pair of recessed groove parts 101 b 1 and 102 b 2, for example, respectively. When the pair of protruding parts 102 b 1 and 102 b 2 and the pair of recessed groove part 101 b 1 and 101 b 2 are caused to fit into each other, a pair ofclosed curve gaps - Sealing rings 141 b and 142 b are inserted into the pair of
closed curve gaps closed curve gaps blind plate 101 and the pump chamber plate 102). For example, the spaces between theblind plate 101 and thepump chamber plates 102 are held in liquid tightness by the sealing rings 141 b and 142 b. - The length (thickness) d2 (
FIGS. 12 and 13 ) of the pair ofclosed curve gaps pump chamber plate 102 abut on abutting surfaces 101 a 1 and 101 a 2, respectively, thereby regulating the insertion (entrance) position of the protruding parts. The sealing rings 141 b and 142 b do not receive a compressive force in the stacked direction from theblind plate 101 and thepump chamber plate 102. Any force that makes theblind plate 101 and thepump chamber plate 102 separated in the stacked direction from the sealingring piezoelectric vibrator 30 from the stacked direction, vibration of thepiezoelectric vibrator 30 is also uniformly generated in the stacked direction. The operation of thepiezoelectric vibrator 30 can be stabilized, and a fluid can be generated efficiently. - FIGS. 15 to 17 show still another embodiment of the diaphragm pump. This embodiment is an embodiment in which the
upper housing 10 is composed of anupper plate 103 and a pair oflid plates upper plate 103 and thelid plate 104H, and a discharge flow channel 15D1 is formed between theupper plate 103 and thelid plate 104D. - Any force in the direction in which both are separated from each other (force in the direction in which the
upper plate 103 and thelid plate 104H (lid plate 104D) are separated from each other) is kept from being applied by the seal structure between theupper plate 103 and thelid plates 104H and between theupper plate 103 and thelid plate 104D. For example, theupper plate 103 is formed with an open suction flow channel groove 103 b 1 and an open discharge flow channel groove 103 b 2 whose top are opened. An inside end of the open suction flow channel groove 103 b 1 is provided with anumbrella 11, and an outside end thereof is provided with abranch channel 41. - Although not shown in
FIG. 15 , an inside end of the open discharge flow channel groove 103 b 2 is provided with anumbrella 12, and an outside end thereof is provided with abranch channel 42. Alternatively, the pair oflid plates upper plate 103 and fit into the open suction flow channel groove 103 b 1 and the open discharge flow channel groove 103 b 2. - When the protruding parts 104 b 1 and 104 b 2 are caused to fit into the open suction flow channel groove 103 b 1 and the open discharge flow channel groove 103 b 2, respectively,
closed curve gaps FIG. 16 . The sealing rings 241 b and 242 b are inserted into theclosed curve gaps closed curve gaps lid plates lid plates upper plate 103 are held in liquid tightness by the sealing rings. - The length d3 (
FIGS. 15 and 16 ) of theclosed curve gaps lid plates - The sealing
ring upper plate 103 and the pair oflid plates upper plate 103 and the pair oflid plates ring piezoelectric vibrator 30 from the stacked direction, vibration of thepiezoelectric vibrator 30 is also uniformly generated in the stacked direction. Therefore, the operation of thepiezoelectric vibrator 30 can be stabilized, and a fluid can be generated efficiently. - The present embodiments are aimed at the seal structure, which ensures the liquid tightness of the suction flow channel and discharge flow channel of the above embodiment, with high durability. The lower housing, the umbrella, or the piezoelectric vibrator only shows an example. Accordingly, although the umbrella is illustrated as a check valve, check valves other than the umbrella can also be used, and an electrostrictive vibrator may be used instead of the piezoelectric vibrator. Further, the present invention can also be applied to a 2-valve type diaphragm pump, i.e., a pump in which a pump chamber is formed only below a piezoelectric vibrator, and any pump chamber is not provided above the piezoelectric vibrator (an umbrella is not provided).
- According to the present embodiments, in a 4-valve diaphragm pump, the liquid tightness of the connecting parts of the flow channels formed over the upper housing and the lower housing can be ensured with high reliability and durability. The liquid tightness of the suction flow channel and discharge flow channel formed in the upper housing can be ensured with high reliability and durability.
Claims (16)
1. A diaphragm pump comprising:
an upper housing, diaphragm, and lower housing;
recessed parts thatare respectively formed in the surfaces of the upper and lower housings opposing the diaphragm to define an upper pump chamber and a lower pump chamber above and below the diaphragm;
a suction port and a discharge port that are formed in the lower housing to communicate with the lower pump chamber;
branch channels that are formed in the lower housing and the upper housing to communicate the suction port and the discharge port with the upper pump chamber;
suction-side check valves that are provided between the suction port and the upper pump chamber and between the suction port and the lower pump chamber; and
discharge-side check valves that are provided between the discharge port and the upper pump chamber, and between the discharge port and the lower pump chamber,
wherein the branch channels include at least one hole, a protruding cylindrical part fitted into the hole, and a sealing ring disposed in an annular gap formed between the hole and the protruding cylindrical part such that a compressive force is generated in the radial direction of the sealing ring.
2. The diaphragm pump according to claim 1 ,
wherein the upper housing includes a pump chamber plate that is stacked on the diaphragm and has the recessed part, and a blind plate stacked on the pump chamber plate.
3. The diaphragm pump according to claim 2 , wherein a pair of inter-plate suction flow channels and an inter-plate discharge flow channel that communicate the suction port and the discharge port with the upper pump chamber and that constitute parts of the branch channels are formed between the pump chamber plate and the blind plate.
4. The diaphragm pump according to claim 3 , wherein the inter-plate suction flow channel and the inter-plate discharge flow channel includes a pair of protruding parts formed in any one of the pump chamber plate and the blind plate.
5. The diaphragm pump according to claim 4 , wherein a pair of recessed groove parts that are formed in the another pump chamber plate and the blind plate to allow the pair of protruding parts to fit thereinto.
6. The diaphragm pump according to claim 5 , wherein a pair of sealing rings which are disposed in a pair of closed curve gaps between the pair of protruding parts and the pair of recessed groove parts such that a compressive force are generated radially.
7. The diaphragm pump according to claim 1 ,
wherein the upper housing is composed of an upper plate stacked on the diaphragm and a pair of lid plates.
8. The diaphragm pump according to claim 7 , wherein the upper plate is formed with recessed parts that are opened to the front and back of the upper plate to form the upper pump chamber.
9. The diaphragm pump according to claim 8 , wherein a pair of open suction flow channel grooves and an open discharge flow channel groove that constitute parts of the branch channels that communicate the suction port and the discharge port with the upper pump chamber, any one of the upper plate and the pair of lid plates is formed with protruding parts corresponding to the open suction flow channel groove and the open discharge flow channel groove.
10. The diaphragm pump according to claim 9 , wherein the other one of the upper plates and the pair of lid plates is formed with recessed groove parts to allow the pair of protruding parts to fit thereinto.
11. The diaphragm pump according to claim 9 , wherein a pair of sealing rings are interposed between the protruding parts and the recessed groove parts such that a compressive force is generated radially.
12. The diaphragm pump according to claim 2 ,
wherein the protruding parts, the recessed groove parts, and the sealing rings are elliptical.
13. The diaphragm pump according to claim 3 ,
wherein the protruding parts, the recessed groove parts, and the sealing rings are elliptical.
14. The diaphragm pump according to claim 1 ,
wherein a compressive force in the stacked direction of the upper housing, the diaphragm, and the lower housing is not applied to any of the sealing rings.
15. The diaphragm pump according to claim 1 , wherein the at least one hole is formed in the upper housing.
16. The diaphragm pump according to claim 1 , wherein the at least one hole is formed in the lower housing.
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2005280548 | 2005-09-27 | ||
JP2005-280548 | 2005-09-27 | ||
JP2006136693A JP2007120488A (en) | 2005-09-27 | 2006-05-16 | Diaphragm pump |
JP2006-136693 | 2006-05-16 |
Publications (1)
Publication Number | Publication Date |
---|---|
US20070071615A1 true US20070071615A1 (en) | 2007-03-29 |
Family
ID=37894214
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/526,366 Abandoned US20070071615A1 (en) | 2005-09-27 | 2006-09-25 | Diaphragm pump |
Country Status (2)
Country | Link |
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US (1) | US20070071615A1 (en) |
JP (1) | JP2007120488A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20120085949A1 (en) * | 2010-10-12 | 2012-04-12 | Microjet Technology Co., Ltd | Fluid transportation device |
US9169837B2 (en) | 2010-12-21 | 2015-10-27 | Pentair Flow Technologies, Llc | Diaphragm pump and motor system and method |
EP3060806A4 (en) * | 2013-10-11 | 2017-07-12 | Checkpoint Fluidic Systems International, Ltd. | Scalable pumping mechanism utilizing anti-synchronized poly-diaphragm stack |
TWI627354B (en) * | 2017-05-31 | 2018-06-21 | 研能科技股份有限公司 | Fluid transmitting device |
US12031534B2 (en) | 2022-01-25 | 2024-07-09 | Pentair Flow Technologies, Llc | Diaphragm pump and motor system and method |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5107767B2 (en) * | 2007-10-24 | 2012-12-26 | アルプス電気株式会社 | 4-valve diaphragm pump |
JP5000571B2 (en) * | 2008-04-01 | 2012-08-15 | アルプス電気株式会社 | 4-valve piezoelectric pump with built-in driver |
JP6061054B2 (en) * | 2014-03-07 | 2017-01-18 | 株式会社村田製作所 | Blower |
-
2006
- 2006-05-16 JP JP2006136693A patent/JP2007120488A/en not_active Withdrawn
- 2006-09-25 US US11/526,366 patent/US20070071615A1/en not_active Abandoned
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20120085949A1 (en) * | 2010-10-12 | 2012-04-12 | Microjet Technology Co., Ltd | Fluid transportation device |
US8579606B2 (en) * | 2010-10-12 | 2013-11-12 | Microjet Technology Co., Ltd. | Fluid transportation device |
US9169837B2 (en) | 2010-12-21 | 2015-10-27 | Pentair Flow Technologies, Llc | Diaphragm pump and motor system and method |
US11231027B2 (en) | 2010-12-21 | 2022-01-25 | Pentair Flow Technologies, Llc | Diaphragm pump and motor system and method |
EP3060806A4 (en) * | 2013-10-11 | 2017-07-12 | Checkpoint Fluidic Systems International, Ltd. | Scalable pumping mechanism utilizing anti-synchronized poly-diaphragm stack |
TWI627354B (en) * | 2017-05-31 | 2018-06-21 | 研能科技股份有限公司 | Fluid transmitting device |
US12031534B2 (en) | 2022-01-25 | 2024-07-09 | Pentair Flow Technologies, Llc | Diaphragm pump and motor system and method |
Also Published As
Publication number | Publication date |
---|---|
JP2007120488A (en) | 2007-05-17 |
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Owner name: ALPS ELECTRIC CO., LTD., JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:NAKAJIMA, JIRO;YAMADA, SATOSHI;REEL/FRAME:018346/0578 Effective date: 20060904 |
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