JP2009180163A - Diaphragm pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diaphragm pump can reducing pulsation with a very simple structure in diaphragm pumps which have a vibration diaphragm gripped between a pair of housings, have a pump chamber formed in at least one of an upper and a lower part of the vibration diaphragm, are provided with a suction side check valve allowing fluid flow from a suction port to the pump chamber and not allowing fluid flow in a reverse direction between the pump chamber and the suction port, are provided with a delivery side check valve allowing fluid flow from the pump chamber to a delivery port and not allowing fluid flow in a reverse direction between the pump chamber and the delivery port, and provide pump action by vibrating the vibration diaphragm. <P>SOLUTION: In this diaphragm pump, a pulsation reduction diaphragm composed of a pair of elastic materials corresponding to the suction port and the delivery port is gripped between the pair of housings with keeping different flat surface position from the vibration diaphragm, a recess part defining a variable volume liquid chamber and a variable volume air chamber at an upper and a lower part of the pair of pulsation reduction diaphragms is formed in the pair of housings respectively, and the pair of variable volume liquid chambers are communicated to the suction port and the delivery port respectively. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a diaphragm pump.

  An example of a pump that obtains a pump action by a vibrating diaphragm is a piezoelectric pump. In the piezoelectric pump, a piezoelectric vibrator is sandwiched between a pair of housings to form a pump chamber in at least one of the upper and lower sides of the piezoelectric vibrator, and the suction port is connected to the pump chamber between the pump chamber and the suction port. A suction-side check valve is provided that allows fluid flow in the reverse direction but does not allow fluid flow in the opposite direction, and allows fluid flow from the pump chamber to the discharge port between the pump chamber and the discharge port. A discharge check valve that does not allow flow is provided. When the piezoelectric vibrator vibrates, in the process of increasing the volume of the pump chamber, the inflow side check valve opens and the discharge side check valve closes, and fluid flows into the pump chamber from the suction port. In the smaller stroke, the discharge-side check valve opens and the suction-side check valve closes, and fluid is discharged from the pump chamber to the discharge port, thereby obtaining a pump action.

The present applicant is developing a water cooling system that cools a heat source (CPU, GPU, chipset, etc.) of a notebook PC using such a piezoelectric pump. The pump mounted on the notebook PC needs to satisfy the UL standard, which is a safety standard. In particular, the housing must be mainly made of synthetic resin so as to satisfy the voltage resistance. The housing made of synthetic resin is not easily elastically deformed as compared with the piping portion having a degree of freedom in design of the material, and thus is easily affected by pulsation (vibration) associated with opening and closing of the check valve. Conventionally, various pulsation prevention structures for this piezoelectric pump (diaphragm pump) have been proposed. However, the structure is complicated, obstructing the thinning, increasing the number of parts, causing problems in durability, or sacrificing the flow rate. There was a problem of becoming.
Japanese Patent Laid-Open No. 10-288160 Japanese Patent Laid-Open No. 10-331771 JP 2000-265964 A JP 2000-274374 A JP 2002-322986 JP Japanese Unexamined Patent Publication No. 2005-2208100 JP 2006-200524 Japanese Patent No. 3785656

  An object of this invention is to obtain the diaphragm pump which can reduce a pulsation with a very simple structure.

  According to the present invention, a pair of pulsation reduction diaphragms are sandwiched simultaneously by a pair of housings that sandwich a vibration diaphragm, and a variable volume liquid chamber that communicates with the suction port and the discharge port above and below the pair of pulsation reduction diaphragms, respectively. If the air chamber is formed, a thin diaphragm pump having a simple structure and excellent assemblability can be obtained.

  That is, according to the present invention, a vibration diaphragm is sandwiched between a pair of housings to form a pump chamber in at least one of the upper and lower sides of the vibration diaphragm, and the suction port is connected to the pump chamber between the pump chamber and the suction port. A suction-side check valve that allows fluid flow but does not allow fluid flow in the opposite direction is provided, and fluid flow from the pump chamber to the discharge port is allowed between the pump chamber and the discharge port, and fluid in the opposite direction is allowed. In a diaphragm pump that is provided with a discharge-side check valve that does not allow flow and that vibrates the vibration diaphragm to obtain a pumping action, the suction port and the discharge are disposed between a pair of housings with a plane position different from that of the vibration diaphragm. A pair of pulsation reduction diaphragms made of a pair of elastic materials corresponding to the ports are sandwiched, and the pair of pulsation reduction diaphragms are respectively disposed above and below the pair of housings. Each a recess defining a fluid chamber and an air chamber of variable volume, is characterized in that communicates the liquid chamber of the pair of variable volume, each suction port and a discharge port.

  Specifically, the pulsation reducing diaphragm can be reduced in the number of parts by providing an annular bead sandwiched in a liquid-tight manner by a pair of housings on the periphery thereof as a flat circular shape.

  The present invention is not limited to a two-valve type diaphragm pump in which a pump chamber is formed only on one of the upper and lower sides of the vibration diaphragm, and a pump chamber is formed on each of the upper and lower portions of the vibration diaphragm. And a four-valve type in which a suction-side check valve and a discharge-side check valve are provided between the pump chamber and a single discharge port.

  In the 4-valve type, each of a pair of housings sandwiching the vibration diaphragm has a recess forming one of the pair of pump chambers, a suction side external opening hole communicating with the recess and opening on the outer surface of the housing, and a discharge side external A cylindrical flow path protrusion that forms an opening hole and forms a pair in which one of the pair of housings and the other of the housing are in a fitting relationship with each other so that the suction-side external opening hole and the discharge-side external opening hole communicate with each other; A connection hole is formed, and a suction port that communicates with the suction-side external opening hole and a discharge port that communicates with the discharge-side external opening hole are formed in the housing on the side having the cylindrical flow path protrusion of the pair of housings. Thus, a 4-valve type with a simple configuration can be obtained.

  Both the suction port and the discharge port can be provided in one of the pair of housings. Alternatively, a mode in which the suction port and the discharge port are provided on one and the other of the pair of housings is also possible.

  In a mass-produced product, the pair of housings are preferably formed from a molded product of a synthetic resin material.

  Further, in the 4-valve type, the cylindrical flow path is configured such that a liquid-tight free liquid flow path is configured simply by inserting the cylindrical flow path protrusion of the other housing into the connection hole of one housing of the pair of housings. The protrusion is provided with a large-diameter portion, a thin-diameter portion located above the large-diameter portion, and an annular slope that is not orthogonal to the axis that separates the large-diameter portion and the thin-diameter portion. An axis corresponding to the annular inclined surface of the cylindrical flow path protrusion, which is located at the boundary between the large diameter hole and the small diameter hole and communicates with the connection hole. It is preferable to provide an annular inclined surface that is not orthogonal to the O-ring, and an O-ring fitted to the narrow diameter portion of the cylindrical channel protrusion is compressed and sandwiched between both annular inclined surfaces to maintain liquid tightness. .

  Specifically, when the vibration diaphragm is composed of a piezoelectric vibrator having an alternately laminated structure of at least one shim made of a conductive metal thin plate and at least one piezoelectric layer, a thin diaphragm pump can be obtained. .

  The diaphragm pump of the present invention includes a pulsation reducing diaphragm made of a pair of elastic materials corresponding to the suction port and the discharge port between a pair of housings sandwiching the vibration diaphragm so that the plane position of the diaphragm is different from that of the vibration diaphragm. A pair of housings are formed on the top and bottom of the pair of pulsation-reducing diaphragms, respectively, to form recesses that define a variable volume liquid chamber and an air chamber. In addition, since the discharge port communicates with the discharge port, the pulsation reducing structure can be configured very easily.

  In this embodiment, the present invention is applied to a 4-valve diaphragm pump proposed by the present applicant in Japanese Patent Application No. 2007-275908, which can constitute a substantial flow path structure by assembling a pair of housings sandwiching a diaphragm. Is.

  First, the operation principle of the 4-valve diaphragm pump will be described with reference to FIG. This diaphragm pump includes an upper housing 10, a lower housing 20, a piezoelectric vibrator (diaphragm) 30, and four umbrellas (check valves) 11, 12, 21, and 22 as basic components. An upper pump chamber (variable volume chamber) 13 and a lower pump chamber (variable volume chamber) 23 are formed between the upper housing 10 and the piezoelectric vibrator 30, and between the lower housing 20 and the piezoelectric vibrator 30, respectively. The single suction port 31 communicates with the suction side flow paths 14H and 24H, the suction side flow path 14H communicates with the upper pump chamber 13 via the suction side check valve 11, and the suction side flow path 24H It communicates with the lower pump chamber 23 via the side check valve 21. The single discharge port 32 communicates with the discharge-side flow paths 15D and 25D, and the discharge-side flow path 15D communicates with the upper pump chamber 13 via the discharge-side check valve 12, and the discharge-side flow path 25D. Communicates with the lower pump chamber 23 via the discharge check valve 22.

  In the four-valve diaphragm pump, when the piezoelectric vibrator 30 is elastically deformed (vibrated) in the forward and reverse directions, the volume of one of the upper pump chamber 13 and the lower pump chamber 23 increases and the other volume decreases. The stroke in which the volume of the upper pump chamber 13 increases is a stroke in which the volume of the lower pump chamber 23 decreases. Since the volume of the upper pump chamber 13 increases, the suction side check valve 11 opens and fluid flows from the suction port 31 into the upper pump chamber 13. Flows in and the volume of the lower pump chamber 23 decreases, so that the fluid in the lower pump chamber 23 opens the discharge-side check valve 22 and flows out to the discharge port 32 (FIG. 7B). Conversely, the stroke in which the volume of the upper pump chamber 13 decreases is a stroke in which the volume of the lower pump chamber 23 increases. Since the volume of the lower pump chamber 23 increases, the suction side check valve 21 opens and the suction port 31 opens into the lower pump chamber 23. Since the fluid flows into the upper pump chamber 13 and the volume of the upper pump chamber 13 decreases, the fluid in the upper pump chamber 13 opens the discharge-side check valve 12 and flows out to the discharge port 32 (FIG. 7A). Therefore, the pulsation cycle at the discharge port 32 can be shortened (halved compared to the case where the pump chamber is formed only on one of the upper and lower sides of the piezoelectric vibrator 30).

  In the present embodiment, the four-valve diaphragm pump having the above operation principle is realized with a simple structure, and the pulsation is further reduced. One embodiment of the present invention will be described with reference to FIGS. In FIG. 1 to FIG. 5, the same reference numerals are given to the same components as those in FIG.

  1 and 2 show the overall structure of the present four-valve diaphragm pump. An upper pump chamber 13 is formed on the upper housing 10 made of a synthetic resin material (for example, PBT (polybutylene terephthalate) resin, PPS (polyphenylene sulfide) resin) on the surface facing the lower housing 20 (mating surface). A recess 13a is formed, and a suction-side external opening hole 16 and a discharge-side external opening hole 17 communicating with the recess 13a are formed. The suction-side external opening hole 16 and the discharge-side external opening hole 17 constitute the suction-side flow path 14H and the discharge-side flow path 15D shown in FIG. 7, and open to the outer surface of the upper housing 10 and have an opening end thereof. A suction port 31 and a discharge port 32 are configured.

  Further, the upper housing 10 has a planar circular suction side liquid chamber (concave portion) 101 communicating with the suction side external opening hole 16 via a communication passage 16a on a surface (mating surface) facing the lower housing 20 and a communication surface. A flat circular discharge side liquid chamber (concave portion) 102 communicating with 17 through the passage 17a is formed. As shown in FIG. 3, the upper housing 10 is formed with an annular protrusion 103 (104) concentric with the suction side liquid chamber 101 (discharge side liquid chamber 102).

  Similarly, the lower housing 20 formed of a synthetic resin material (same product) is provided with a recess 23a that forms a lower pump chamber 23 on the surface (mating surface) facing the upper housing 10, and communicates with the recess 23a. A suction-side external opening hole 26 and a discharge-side external opening hole 27 are formed. The suction-side external opening hole 26 and the discharge-side external opening hole 27 constitute the suction-side flow path 24H and the discharge-side flow path 25D in FIG. 7 and open to the outer surface of the lower housing 20.

  Further, the lower housing 20 has a plane circular air chamber (recessed portion) 201 corresponding to the suction side liquid chamber 101 of the upper housing 10 and a discharge side liquid chamber 102 on the surface (mating surface) facing the upper housing 10. A corresponding flat circular air chamber (concave portion) 202 is formed. As shown in FIG. 3, an annular groove 203 (204) corresponding to the annular protrusion 103 (104) of the upper housing 10 is formed in the lower housing 20 concentrically with the air chamber 201 (202).

  The peripheral bead portion 303 (304) of the pulsation reducing diaphragm 301 (302) having a flat circular shape is fitted into the annular groove 203 (204) of the lower housing 20. Then, the upper housing 10 is overlapped on the lower housing 20, the annular protrusion 103 (104) is fitted into the annular groove 203 (204), and the annular bead portion 303 (304) is compressed, so that the pulsation reducing diaphragm 301 (302) is compressed. A suction-side liquid chamber 101 (discharge-side liquid chamber 102) and an air chamber 201 (202) are formed above and below the figure, respectively. The air chamber 201 (202) may be sealed or opened to the atmosphere.

  The pulsation reducing diaphragm 301 (302) is made of a vulcanized molded product of rubber material, and elastically deforms according to the pressure difference between the suction side liquid chamber 101 (discharge side liquid chamber 102) and the air chamber 201 (202), The volumes of the suction side liquid chamber 101 (discharge side liquid chamber 102) and the air chamber 201 (202) are changed.

  The check valves 11 and 12 are provided at the end of the suction side external opening hole 16 and the discharge side external opening hole 17 on the recess 13a side, and the check valves 21 and 22 are provided with the suction side external opening hole 26 and the discharge side external opening hole. It is provided at the end of the opening hole 27 on the recess 23 a side. The check valves 11, 12, 21, and 22 in the illustrated embodiment are umbrella valves of the same form, and are made of elastic material on the perforated substrates 11 a, 12 a, 22 a, and the recesses 23 a that are bonded or welded to the flow path. Umbrellas 11b, 12b, 22b, and 23b are mounted.

  The piezoelectric vibrator 30 is held in a liquid-tight manner between the upper housing 10 and the lower housing 20 via O-rings 33 and 34, and constitutes an upper pump chamber 13 between the upper housing 10 and the lower housing 20, and is connected to the concave portion 23a. A lower pump chamber 23 is formed therebetween. The piezoelectric vibrator 30 is a well-known one that is formed by laminating a piezoelectric body on at least one of the front and back sides of a shim made of a conductive metal thin plate, and vibrates in the direction perpendicular to the surface of the shim by applying an alternating electric field. In the present embodiment, the configuration of the piezoelectric vibrator 30 does not matter. For example, any type of unimorph and bimorph may be used.

  The external opening hole 16 (suction side flow path 14H) of the upper housing 10 and the external opening hole 26 (suction side flow path 24H) of the lower housing 20 are formed integrally with the upper housing 10 as shown in FIG. The suction side tubular channel protrusion 43H communicates with the suction side connection hole 42H formed in the lower housing 20, and the outer opening hole 17 (discharge side channel 15D) of the upper housing 10 and the outer opening hole 27 of the lower housing 20 are communicated. The (discharge side flow path 25D) communicates with a discharge side cylindrical flow path projection 43D formed integrally with the upper housing 10 and a discharge side connection hole 42D formed in the lower housing 20. That is, the suction side cylindrical flow path protrusion 43H and the suction side connection hole 42H are in a fitting relationship with each other, and the external opening holes 16 and 26 (suction side flow paths 14H and 24H) communicate with each other. The protrusion 43D and the discharge side connection hole 42H are in a fitting relationship with each other, and connect the discharge side flow paths 15D and 25D (discharge side flow paths 15D and 25D). The cylindrical channel protrusion 43H (43D) and the connection hole 42H (42D) have a bilaterally symmetric structure, and details thereof will be described with reference to FIGS. 2 and 4 are shown upside down.

  As shown in detail in FIG. 4, the outer opening hole 26 (27) formed in the lower housing 20 includes a large-diameter hole 26a (27a) that opens to the outer surface of the lower housing 20, and the large-diameter hole 26a (27a). A small-diameter hole 26b (27b) located on the inner side, and an annular inclined surface 26c (27c) that is not orthogonal to the axis located at the boundary between the large-diameter hole 26a (27a) and the small-diameter hole 26b (27b) Yes. Further, the connection hole 42H (42D) formed in the lower housing 20 is positioned at the annular inclined surface 26c (27c) portion of the external opening hole 26 (27) and communicates perpendicularly with the external opening hole 26 (27). It is formed to do. The external opening hole 26 (27) and the connection hole 42H (42D) are integrally formed with the lower housing 20 by a forming die (punch die).

  On the other hand, as shown in detail in FIGS. 4 and 5, the cylindrical channel protrusion 43 </ b> H (43 </ b> D) formed integrally with the upper housing 10 has a large-diameter portion 43 a and a thin portion positioned above the large-diameter portion 43 a. A diameter portion 43b, and an annular inclined surface 43c that separates (defines the boundary) between the large diameter portion 43a and the small diameter portion 43b and is not orthogonal to the axis, and the external opening hole 16 (17) is formed in the shaft portion. An internal flow path 44 that communicates is formed. The cylindrical channel protrusion 43H (43D) is also integrally formed with the upper housing 10 by a molding die (punch die).

  The annular slope 26c (27c) of the external opening hole 26 (27) and the annular slope 43c of the cylindrical channel protrusion 43H (43D) have a corresponding relationship. In the illustrated example, the annular slope 26c (27c) (annular slope 43c). Is 45 ° with respect to the axis of the external opening 26 (27) (cylindrical channel protrusion 43H (43D)). This angle can be changed within a range of about 30 ° to 60 °. An O-ring 46 is fitted around the small-diameter portion 43b of the cylindrical channel protrusion 43H (43D) (on the annular inclined surface 43c), and the cylindrical channel projection 43H (43D) is connected to the connection hole 42H (42D). ), The O-ring 46 is sandwiched and compressed between the annular inclined surface 26c (27c) of the external opening hole 26 (27) and the annular inclined surface 43c of the cylindrical channel protrusion 43H (43D), The external opening holes 16 and 26 (external opening holes 17 and 27) communicate with each other through the flow path 44.

  Therefore, the four-valve diaphragm pump of the present embodiment combines the upper housing 10 and the lower housing 20 as shown in FIG. 2, and the cylindrical flow path protrusion 43H (43D) of the upper housing 10 is connected to the connection hole 42H ( 42D), the O-ring 46 is compressed between the annular inclined surface 26c (27c) of the external opening hole 26 (27) and the annular inclined surface 43c of the cylindrical flow path protrusion 43H (43D), and the internal flow path 44 is compressed. Thus, the external opening holes 16 and 26 (external opening holes 17 and 27) can be communicated to obtain a liquid-tight structure.

  Between the upper housing 10 and the lower housing 20, a piezoelectric vibrator 30 and a pulsation reducing diaphragm 301 (302) are sandwiched. That is, the piezoelectric vibrator 30 is liquid-tightly sandwiched and held between the upper housing 10 and the lower housing 20 via O-rings 33 and 34, and constitutes the upper pump chamber 13 between the recess 13a and the recess 23a. A lower pump chamber 23 is formed between the two. The peripheral bead portion 303 (304) of the pulsation reducing diaphragm 301 (302) is fitted in the annular groove 203 (204) of the lower housing 20, and the annular protrusion 103 (104) of the upper housing 10 is inserted into the annular groove 203 (204). The peripheral bead portion 303 (304) is compressed by being fitted into the. As a result, a liquid-tight (air-tight) suction-side liquid chamber 101 (discharge-side liquid chamber 102) and an air chamber 201 (202) are formed above and below the pulsation reducing diaphragm 301 (302), respectively.

  In the above piezoelectric pump, when the piezoelectric vibrator 30 is elastically deformed (vibrated) in the forward and reverse directions, as described above, the volume of either the upper pump chamber 13 or the lower pump chamber 23 increases and the other volume decreases. The stroke in which the volume of the upper pump chamber 13 increases is a stroke in which the volume of the lower pump chamber 23 decreases. Since the volume of the upper pump chamber 13 increases, the suction side check valve 11 opens and fluid flows from the suction port 31 into the upper pump chamber 13. Flows in and the volume of the lower pump chamber 23 decreases, so that the fluid in the lower pump chamber 23 opens the discharge side check valve 22 and flows out to the discharge port 32. Conversely, the stroke in which the volume of the upper pump chamber 13 decreases is a stroke in which the volume of the lower pump chamber 23 increases. Since the volume of the lower pump chamber 23 increases, the suction side check valve 21 opens and the suction port 31 opens into the lower pump chamber 23. Since the fluid flows into the upper pump chamber 13 and the volume of the upper pump chamber 13 decreases, the fluid in the upper pump chamber 13 opens the discharge-side check valve 12 and flows out to the discharge port 32.

  During this pumping action, the pressure in the suction side external opening hole 16 and the discharge side external opening hole 17 varies. This pressure fluctuation reaches the suction-side liquid chamber 101 and the discharge-side liquid chamber 102 via the communication passages 16a and 17a. When the pressure in the suction-side liquid chamber 101 (discharge-side liquid chamber 102) increases, the pulsation reducing diaphragm 301 When (302) elastically deforms toward the air chamber 201 (202) and descends, it elastically deforms toward the suction side liquid chamber 101 (discharge side liquid chamber 102). Therefore, the pulsation (vibration) appearing in the liquid pressure in the suction port 31 and the discharge port 32 is reduced.

  In the above embodiment, there is an advantage that a liquid-tight structure can be achieved simply by fitting the cylindrical flow path protrusion 43H (43D) of the upper housing 10 into the connection hole 42H (42D) of the lower housing 20. It is also possible to maintain the liquid tightness by closing the opening end of 26 (27) with another member. In this case, the liquid tightness of the cylindrical flow path protrusion 43H (43D) and the connection hole 42H (42D) is maintained. For example, it may be secured by an O-ring.

  In the above embodiment, both the suction port 31 and the discharge port 32 are provided in the upper housing 10, but both ports are formed in the lower housing 20, or one port is provided in each of the upper housing 10 and the lower housing 20. It can also be provided. The rule at that time is a rule that a suction port is provided in the housing on the side having the suction side cylindrical flow path projection, and a discharge port is provided in the housing on the side having the discharge side cylindrical flow path projection. In the illustrated embodiment, the suction port 31 and the discharge port 32 (the suction side external opening hole 16 (26) and the discharge side external opening hole 17 (27)) are extended to the opposite side of the housing 10 (20). You may extend to the side.

  In the above embodiment, the present invention is applied to a four-valve diaphragm pump, but the present invention can also be applied to a two-valve diaphragm pump. FIG. 6 shows an embodiment thereof. In FIG. 2, the suction side check valve 21, the discharge side check valve 22 and the related components are removed, and a recess 23a and an air chamber 201 (202) are formed in the lower housing 20. This corresponds to an embodiment in which only the above is formed. The air chamber A is configured by the recess 23 a and the piezoelectric vibrator 30. Other configurations are the same as those in the embodiment of FIG. 2, and the same reference numerals are given to the same elements.

  Further, in the above embodiment, the pulsation reducing diaphragm 301 (302) is provided between the cylindrical flow path protrusion 43H (43D) and the check valves 11, 12, 21, 22; 43H (43D) may be provided between the suction port 31 and the discharge port 32.

  In the above embodiment, the piezoelectric vibrator is exemplified as the diaphragm. However, the present invention can be widely applied to liquid pumps using other vibrating diaphragms.

  In the above embodiment, the housing and related elements are named “upper” and “lower” for convenience, but it is obvious that the housing and the elements are not limited to those in use.

It is a top view which shows embodiment which applied this invention to the 4-valve diaphragm pump (piezoelectric pump). FIG. 2 is a developed sectional view taken along line II-II in FIG. 1. FIG. 3 is an enlarged cross-sectional view of a part III in FIG. 2. FIG. 4 is an enlarged cross-sectional view of a part IV in FIG. 2. (A), (B) is the perspective view which changed the view direction which shows the relationship between the example of the shape of the cylindrical flow path protrusion protruded from the lower housing, and an O-ring. FIG. 3 is a developed sectional view corresponding to FIG. 2, showing an embodiment in which the present invention is applied to a two-valve diaphragm pump (piezoelectric pump). (A) and (B) are skeleton diagrams showing the principle of a four-valve diaphragm pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Upper housing 11 12 21 22 Check valve 13 Upper pump chamber 13a Recess 14H 24H Suction side flow path 15D 25D Discharge side flow path 16 26 Suction side external opening hole 17 27 Discharge side external opening hole 20 Lower housing 23 Lower pump chamber 23a Recess 30 Piezoelectric vibrator (diaphragm)
31 Suction port 32 Discharge port 33 34 O-ring 40 Free liquid flow path 40 External opening hole 26a 27a Large diameter hole 26b 27b Small diameter hole 26c 27c Annular slope 42H 42D Connection hole 43H 43D Cylindrical flow path protrusion 43a Large diameter part 43b Small diameter Portion 43c Annular slope 44 Internal channel 46 O-ring 101 Suction side liquid chamber (recess)
102 Discharge side liquid chamber (concave)
103 104 Annular projection 201 202 Air chamber (concave)
203 204 Annular groove 301 302 Pulsation reduction diaphragm 303 304 Peripheral bead portion

Claims (8)

A vibration diaphragm is sandwiched between a pair of housings to form a pump chamber on at least one of the upper and lower sides of the vibration diaphragm, and fluid flow from the suction port to the pump chamber is allowed between the pump chamber and the suction port. A suction-side check valve that does not allow fluid flow in the reverse direction is provided, and the fluid flow from the pump chamber to the discharge port is allowed between the pump chamber and the discharge port, and discharge is not allowed in the reverse direction. In a diaphragm pump that has a side check valve and obtains a pump action by vibrating a vibrating diaphragm,
A pulsation reducing diaphragm made of a pair of elastic materials corresponding to the suction port and the discharge port is sandwiched between the pair of housings with a plane position different from that of the vibration diaphragm, and
The pair of housings are respectively formed with concave portions defining a variable volume liquid chamber and an air chamber above and below the pair of pulsation reducing diaphragms, and the pair of variable volume liquid chambers are respectively connected to the suction port and the discharge port. Diaphragm pump characterized by being connected to 2. The diaphragm pump according to claim 1, wherein the pulsation reducing diaphragm includes a circular bead having a circular shape and a liquid crystal sandwiched between a pair of housings on the periphery thereof. 3. The diaphragm pump according to claim 1, wherein the pump chambers are respectively formed above and below the vibration diaphragm, and between the pair of pump chambers and a single suction port and between the same pair of pump chambers and a single pump chamber. A diaphragm pump provided with the suction side check valve and the discharge side check valve, respectively, between the discharge ports. 4. The diaphragm pump according to claim 3, wherein each of the pair of housings sandwiching the vibration diaphragm includes a recess that forms one of the pair of pump chambers, and a suction side that communicates with the recess and opens to the outer surface of the housing. External opening hole and discharge side external opening hole are formed,
One of the pair of housings and the other are formed with a cylindrical flow path projection and a connection hole that form a pair and are connected to each other so that the suction side external opening hole and the discharge side external opening hole of both housings communicate with each other. And
A diaphragm pump in which the suction port that communicates with the suction-side external opening hole and the discharge port that communicates with the discharge-side external opening hole are formed in a housing on the side having the cylindrical flow path protrusion of the pair of housings. 5. The diaphragm pump according to claim 4, wherein the suction port and the discharge port are both provided in one of a pair of housings. 6. The diaphragm pump according to claim 4, wherein both of the pair of housings are formed of a synthetic resin material. The diaphragm pump according to any one of claims 4 to 6, wherein the cylindrical flow path protrusion includes a large diameter portion, a small diameter portion located above the large diameter portion, and the large diameter portion and the small diameter. An annular slope that is not orthogonal to the axis that divides the part,
The external opening hole is a large-diameter hole, a small-diameter hole located inside the large-diameter hole, and the cylindrical flow path protrusion of the cylindrical flow-path protrusion that is located at the boundary between the large-diameter hole and the small-diameter hole and communicates with the connection hole. An annular slope that is not orthogonal to the axis corresponding to the annular slope,
A diaphragm pump in which an O-ring fitted to the narrow diameter portion of the cylindrical flow path projection is compressed and sandwiched between the two annular inclined surfaces to maintain liquid tightness. 8. The diaphragm pump according to claim 1, wherein the vibration diaphragm is a piezoelectric vibrator.

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