JP2009270456A - Diaphragm pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively reduce pulsation by simple structure, in a diaphragm pump for providing pump action by the vibration of a vibrating diaphragm. <P>SOLUTION: This diaphragm pump is provided so that both the front and reverse of a pulsation reducing diaphragm are formed as liquid chambers, and one of these front and reverse liquid chambers is made to communicate with a suction port or a delivery port, and the other is made to communicate with the delivery port or the suction port, and liquid is introduced to the front and reverse of the pulsation reducing diaphragm, and the pulsation is reduced. <P>COPYRIGHT: (C)2010,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, a pump chamber is formed on at least one of the front and back surfaces 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.
Registered Utility Model No. 2535320 Japanese Utility Model Publication No. 61-144282 JP 2000-265963 A JP 2000-274374 A JP2002-202061 JP 2006-112368 A

  In the diaphragm pump having such an operation principle, pulsation in which the pressure in the suction port and the discharge port fluctuates due to vibration of the vibration diaphragm is unavoidable. The pulsation simultaneously causes loud driving sound (vibration, noise) and deterioration of durability of the piezoelectric vibrator provided in the diaphragm.

  Conventional diaphragm pump pulsation prevention structure generally has one chamber on the front and back of a pulsation reducing diaphragm made of an elastic material provided separately from the vibration diaphragm communicated with an intake port or a discharge port, and air is sealed in the other chamber. Yes. The idea is to absorb the pressure fluctuation of the suction port or the discharge port by the volume change of the sealed air chamber. According to the analysis of the present inventor, the volume change of the air chamber is about 10 to 20% of the volume change. It is difficult to effectively reduce the pulsation without increasing the volume of the air chamber. In addition, there is a problem that air is reduced by long-term use and the pulsation reducing effect is lowered.

  Further, the present applicant is developing a water cooling system for cooling 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.

  An object of the present invention is to obtain a diaphragm pump capable of effectively reducing pulsation with a simple structure.

  In the conventional apparatus, the front and back sides of the pulsation reducing diaphragm are liquid chambers and the other side is a sealed air chamber, whereas both front and back sides are liquid chambers, and one of the front and back liquid chambers is a suction port or The present invention has been completed by paying attention to the fact that the effect of reducing the pulsation is high if it is communicated with the discharge port, the other is communicated with the discharge port or the suction port, and the liquid is introduced into the front and back of the pulsation reduction diaphragm.

  According to the present invention, a pump chamber is formed on at least one of the front and back 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, and fluid flow in the opposite direction is allowed. There is no suction side check valve, and there is a discharge side check valve between the pump chamber and the discharge port that allows fluid flow from the pump chamber to the discharge port and does not allow fluid flow in the opposite direction. In a diaphragm pump that vibrates the diaphragm and obtains a pumping action, a pulsation reducing diaphragm made of at least one elastic material that forms a liquid chamber on each side is provided, and one of the liquid chambers on the front and back of the pulsation reducing diaphragm is connected to an intake port. A feature is that one of the discharge ports communicates with the other, and the other communicates with the other of the suction port and the discharge port.

  A vibration diaphragm and a pulsation reduction diaphragm whose plane position is different from that of the vibration diaphragm are sandwiched and supported by a pair of housings, and a pump chamber is formed in at least one of the front and back surfaces of the vibration diaphragm in each of the pair of housings. It is desirable to form recesses and recesses that define liquid chambers on the front and back sides of the pulsation reducing diaphragm.

  The pair of housings are further supported by sandwiching and supporting a perforated dummy diaphragm with a plane position different from that of the pulsation reducing diaphragm, and one of the liquid chambers on the front and back of the pulsation reducing diaphragm is provided with a flow path including the perforated diaphragm. And can communicate with either the suction port or the discharge port.

  The present invention is not only a two-valve type diaphragm pump in which a pump chamber is formed on only one of the front and back sides of the vibration diaphragm, but also a pump chamber is formed on each of the front and back surfaces 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 this four-valve type, a vibration diaphragm and a pair of pulsation reduction diaphragms are sandwiched and supported between a pair of housings, a recess that forms a pump chamber on the front and back of the vibration diaphragm, and a pair of pulsations A recess for forming a liquid chamber is formed on the front and back of the reduction diaphragm, and one of the liquid chambers on the front and back of the pair of pulsation reduction diaphragms is connected to the suction port and the discharge port, respectively, and the other is connected to the discharge port and the suction port. Each can communicate.

  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.

  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 is provided with a pulsation reducing diaphragm made of at least one elastic material that forms liquid chambers on the front and back sides separately from the vibrating diaphragm that controls the pump action, and one of the liquid chambers on the front and back sides of the pulsation reducing diaphragm is provided. Since the communication with one of the suction port and the discharge port and the other with the other of the suction port and the discharge port, the pressure fluctuation in the suction port (discharge port) is changed in the discharge port (suction port). Absorbs with liquid pressure and can reduce pulsation (vibration, noise).

  The embodiment of FIGS. 1 to 6 is a four-valve diaphragm pump proposed by the present applicant in Japanese Patent Application No. 2007-275908 that can constitute a substantial flow path structure by assembling a pair of housings sandwiching a diaphragm. The present invention is applied.

  First, the principle of operation 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 the 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. 9B). 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. 9A). Therefore, the pulsation cycle in the discharge port 32 can be shortened (halved compared to the case where the pump chamber is formed only on one of the front and back 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 pulsation is further reduced. One embodiment of the present invention will be described with reference to FIGS. In FIG. 1 to FIG. 6, the same reference numerals are given to the same components as those in FIG.

  1 to 6 show a first embodiment of a four-valve diaphragm pump according to the present embodiment. As shown in FIG. 2, the upper housing 10 made of a synthetic resin material (for example, PBT (polybutylene terephthalate) resin, PPS (polyphenylene sulfide) resin) is formed on the opposite surface (mating surface) to the lower housing 20 as shown in FIG. A recess 13a that forms the upper pump chamber 13 is formed, and a suction-side external opening hole 16 and a discharge-side external opening hole 17 that communicate 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 in FIG. 9, 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 the discharge side external opening hole 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, as shown in FIG. 2, the lower housing 20 made of a synthetic resin material (same product) is provided with a recess 23 a that forms the lower pump chamber 23 on the surface facing the upper housing 10 (the mating surface). In addition, a suction-side external opening hole 26 and a discharge-side external opening hole 27 communicating with the recess 23a 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. 9 and open to the outer surface of the lower housing 20.

  Further, the lower housing 20 has a flat circular discharge side liquid chamber (concave portion) 201 that coincides with the suction side liquid chamber 101 of the upper housing 10 on a surface (mating surface) facing the upper housing 10, and a discharge side. A flat circular suction-side liquid chamber (concave portion) 202 whose position matches that of the liquid chamber 102 is formed. In the lower housing 20, as shown in FIG. 3, an annular groove corresponding to the annular protrusion 103 (104) of the upper housing 10 is concentric with the discharge side liquid chamber 201 (suction side liquid chamber 202) on the suction side and the discharge side. 203 (204) is formed.

  The peripheral bead portion 303 (304) of the pulsation reducing diaphragm 301 (302) made of an elastic material 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 a discharge-side liquid chamber 201 (suction-side liquid chamber 202) are formed on the front and back sides (upper and lower in the drawing), respectively.

  As shown in FIG. 6, the discharge side liquid chamber 201 communicates with the discharge side external opening hole 17 (discharge side flow path 15D) via the liquid flow path 205, and the suction side liquid chamber 202 has a liquid flow path. It communicates with the suction side external opening hole 16 (suction side flow path 14H) via 305.

  FIG. 6 shows a liquid flow path 205 for communicating the discharge side liquid chamber 201 and the discharge side external opening hole 17 (discharge side flow path 15D), and a liquid flow path for communicating the suction side liquid chamber 202 and the suction side external opening hole 16. In order to show the relationship of 305, the two VI-VI cross sections of FIG. 1 are drawn on the II-II cross sectional view of FIG. The flow path lengths of the liquid flow paths 205 and 305 are drawn long in FIG. 6, but the discharge side liquid chamber 201 and the discharge side external opening hole 17, and the suction side liquid chamber 202 and the suction side external opening hole 16 are shown in FIG. As shown in Fig. 2, they are adjacent and are actually short (of course, they do not ask for length).

  The pulsation reducing diaphragm 301 (302) is made of a vulcanized molded product of rubber material or a metal thin film, and includes a suction side liquid chamber 101 (discharge side liquid chamber 102) and a discharge side liquid chamber 201 (suction side liquid chamber 202). It elastically deforms according to the pressure difference and changes the volume of the suction side liquid chamber 101 (discharge side liquid chamber 102) and the discharge side liquid chamber 201 (suction side liquid chamber 202).

  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, 22 in the illustrated embodiment are umbrella valves of the same form, and as shown in FIG. 2, perforated substrates 11 a, 12 a, 22 a, which are bonded or welded to the flow path, Umbrellas 11b, 12b, 22b, and 23b made of an elastic material are attached to the recess 23a.

  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 allow the external opening holes 17 and 27 (discharge-side flow paths 15D and 25D) to communicate with each other. 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, the liquid-side (air-tight) suction-side liquid chamber 101 (discharge-side liquid chamber 102) and the discharge-side liquid chamber 201 (suction-side liquid chamber 202) on the front and back (upper and lower sides) of the pulsation reducing diaphragm 301 (302), respectively. ) Is formed. Further, sealing means is appropriately provided on the liquid flow paths 205 and 305 straddling the upper housing 10 and the lower housing 20.

  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) is elastically deformed toward the discharge side liquid chamber 201 (suction side liquid chamber 202) and descends, it is elastically deformed toward the suction side liquid chamber 101 (discharge side liquid chamber 102).

  What is characteristic in this embodiment is that the discharge-side liquid chamber 201 (suction-side liquid chamber 202) communicates with the discharge-side external opening hole 17 (suction-side external opening hole 16) via the liquid flow path 205 (305). It is that. That is, when the pressure of the liquid in the discharge side liquid chambers 102 and 201 rises in the process of moving the piezoelectric vibrator 30 toward the upper housing 10 side, the suction side liquid chambers 202 and 101 on the opposite side of the pulsation reducing diaphragms 302 and 301 are used. Therefore, the pulsation reducing diaphragms 302 and 301 are elastically deformed toward the suction side liquid chambers 202 and 101, respectively, to absorb the pulsation. Similarly, when the pressure of the liquid in the suction side liquid chambers 101 and 202 decreases in the process of moving the piezoelectric vibrator 30 toward the lower housing 20, the discharge side liquid chamber 201 on the opposite side of the pulsation reducing diaphragms 301 and 302. Since the pressure at 102 increases, the pulsation reducing diaphragms 301 and 302 elastically deform toward the discharge side liquid chambers 101 and 202, respectively, to absorb the pulsation. 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. 7 and 8 show the embodiment.

  The embodiment of FIGS. 7 and 8 is the same as that of FIGS. 2 and 6 except that the suction side check valve 21, the discharge side check valve 22 and related components are removed, and the lower housing 20 has a recess 23, a discharge side liquid chamber. This is common in that a (recess) 201 and a suction-side liquid chamber (recess) 202 are formed and the discharge-side liquid chamber 201 and the suction-side liquid chamber 202 are communicated with each other through a liquid flow path 206. The air chamber A is configured by the recess 23 a and the piezoelectric vibrator 30. The shapes and specifications of the recesses 201 and 202 are the same. The difference is that, in the embodiment of FIG. 7, a pulsation reducing diaphragm 301 similar to that of the embodiment of FIGS. 1 to 6 is positioned between the discharge side liquid chamber 201 and the suction side liquid chamber 101, and the discharge side liquid chamber 102 and Whereas a perforated diaphragm 302H having a hole H is located between the discharge side liquid chamber 202 and the discharge side liquid chamber 202, in the embodiment of FIG. The pulsation reducing diaphragm 302 similar to the embodiment of FIG. 6 is positioned, and a perforated diaphragm 301H having a hole H is positioned between the discharge side liquid chamber 201 and the suction side liquid chamber 101. Other configurations are the same as those in the embodiment of FIG. 2, and the same reference numerals are given to the same elements.

  In the embodiment of FIG. 7, the discharge side liquid pressure is exerted on the discharge side liquid chamber 201 by the flow path 206 including the perforated diaphragm 302H on the back surface of the pulsation reducing diaphragm 301 of the suction side liquid chamber 101. In the inhalation step, the pulsation reducing diaphragm 301 is deformed in the direction of the suction side liquid chamber 101 due to the decompression of the suction side liquid chamber 101, and the pulsation mitigating action is obtained by reducing the decompression on the suction side liquid chamber 101 side. On the other hand, in the discharge process of the pump, the pressure on the discharge side liquid chamber 201 is increased, and the pulsation reducing diaphragm 301 is similarly deformed in the direction of the suction side liquid chamber 101 to reduce the pressure rise, thereby obtaining a pulsation reducing action. Further, in the embodiment of FIG. 8, the suction side liquid pressure is exerted on the suction side liquid chamber 202 by the flow path 206 including the perforated diaphragm 301H on the back surface of the pulsation reducing diaphragm 302 of the discharge side liquid chamber 102. In the discharge process of the pump, the pulsation reducing diaphragm 302 is deformed to the suction side liquid chamber 202 side due to the pressure increase in the discharge side liquid chamber 102 to reduce the pressure increase, thereby obtaining the pulsation reducing action. On the other hand, in the pump suction process, the suction side liquid chamber 202 side is depressurized, and the pulsation reducing diaphragm 302 is similarly deformed to the suction side liquid chamber 202 side to reduce the pressure reduction of the suction side liquid chamber 202, thereby obtaining a pulsation reducing action. It is done. The pulsation reducing effect leads to a driving noise (vibration, noise) reduction effect at the same time.

  In the embodiment of FIG. 7 and the embodiment of FIG. 8, the pulsation reducing diaphragm 301 (302) is provided on the suction port 31 side or the discharge port 32 side, so that the pulsation reduction effect is more effectively exhibited in the pump suction process. There is an advantage that it is possible to select whether to make it more effective in the discharge process. Of course, the perforated diaphragm does not function as a diaphragm, but substantially functions as a seal member. It is possible to form a similar flow path without using a perforated diaphragm.

  In the above embodiment, the pulsation reducing diaphragm 301 (302) (and the perforated diaphragms 301H and 302H) are provided between the cylindrical flow path protrusion 43H (43D) and the check valves 11, 12, 21, and 22. However, it may be provided between the cylindrical flow path protrusion 43H (43D), 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 cross-sectional view drawn corresponding to FIG. 2, showing a communication relationship between a discharge side liquid chamber and a discharge side external opening hole, and a suction side liquid chamber and a suction side external opening hole. 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). FIG. 4 is a developed sectional view corresponding to FIG. 2, showing another 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 Liquid chamber (concave)
203 204 Annular groove 205 305 Liquid flow path 301 302 Pulsation reduction diaphragm 303 304 Peripheral bead portion

Claims (10)

A pump chamber is formed on at least one of the front and back sides of the vibration diaphragm, and a suction side reverse that does not allow a fluid flow from the suction port to the pump chamber between the pump chamber and the suction port and does not allow a reverse fluid flow. A stop valve is provided, and a discharge-side check valve is provided between the pump chamber and the discharge port to permit fluid flow from the pump chamber to the discharge port and not to reverse fluid flow, and to vibrate the vibration diaphragm. In a diaphragm pump that obtains a pumping action,
A pulsation reducing diaphragm made of at least one elastic material that forms a liquid chamber on each side is provided.
A diaphragm pump characterized in that one of the liquid chambers on the front and back sides of the pulsation reducing diaphragm is connected to one of the suction port and the discharge port, and the other is connected to the other of the suction port and the discharge port. 2. The diaphragm pump according to claim 1, wherein the vibration diaphragm and the vibration reduction diaphragm whose plane positions are different from each other are sandwiched between a pair of housings, and each of the pair of housings is vibrated. A diaphragm pump in which a recess for forming a pump chamber is formed on at least one of the front and back sides of the diaphragm, and a recess for defining a liquid chamber on the front and back sides of the pulsation reducing diaphragm. 3. The diaphragm pump according to claim 2, wherein a hole-shaped dummy diaphragm is sandwiched and supported by the pair of housings so that a planar position is different from that of the pulsation reducing diaphragm, and liquid chambers on the front and back sides of the pulsation reducing diaphragm are provided. A diaphragm pump in which one of the two is connected to either the suction port or the discharge port through a flow path including the perforated diaphragm. 3. The diaphragm pump according to claim 2, wherein the pump chambers are respectively formed on the front and back sides of 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 discharge port. A diaphragm pump provided with the suction-side check valve and the discharge-side check valve, respectively. 5. The diaphragm pump according to claim 4, wherein the vibration diaphragm and a pair of pulsation reduction diaphragms are sandwiched and supported between the pair of housings, and a pump chamber is provided on the front and back of the vibration diaphragm in the pair of housings. A concave portion to be formed and a concave portion for forming a liquid chamber are formed on the front and back sides of the pair of pulsation reducing diaphragms, and one of the liquid chambers on the front and back sides of the pair of pulsation reducing diaphragms communicates with the suction port and the discharge port, respectively. A diaphragm pump in which the other communicates with the discharge port and the suction port. The diaphragm pump according to any one of claims 1 to 5, wherein the pulsation reducing diaphragm has a flat circular shape and an annular bead sandwiched liquid-tightly by a pair of housings on a peripheral edge thereof. 7. The diaphragm pump according to claim 2, wherein a pair of housings sandwiching the vibration diaphragm includes a recess that forms one of the pair of pump chambers, and the housing communicated with the recess. A suction-side external opening hole and a discharge-side external opening hole are formed on the outer surface of the
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. 8. The diaphragm pump according to claim 7, wherein the suction port and the discharge port are both provided in one of a pair of housings. 9. The diaphragm pump according to claim 7, wherein the cylindrical flow path protrusion has a large diameter portion, a small diameter portion positioned above the large diameter portion, and an axis that divides the large diameter portion and the small diameter portion. An annular slope that is not orthogonal to the
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. The diaphragm pump according to any one of claims 1 to 9, wherein the vibration diaphragm is a piezoelectric vibrator.

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