JP2005337068A - Diaphragm pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a further thinner shape of a diaphragm pump. <P>SOLUTION: The pump is constituted such that the diaphragm (variable volume chamber) and a check valve are arranged at separate positions in plane. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a diaphragm pump.

A diaphragm pump forms a variable volume chamber by a diaphragm, and a pair of check valves having different flow directions (a suction side check valve that allows fluid flow to the variable volume chamber and a pair of flow paths connected to the variable volume chamber). A discharge-side check valve that allows fluid flow from the variable volume chamber is provided. When the diaphragm is vibrated, the volume of the variable volume chamber changes, and the suction side check valve opens in the stroke in which the volume increases, and the discharge side check valve opens in the stroke in which the volume decreases. can get. The diaphragm is made of an elastic (vibrating) material such as rubber or a piezoelectric vibrator.
JP 2001-173569 A JP 2001-323879 A

  Since this diaphragm pump can make the variable volume chamber including the diaphragm thin, it is being used as a cooling water circulation pump of, for example, a water-cooled notebook personal computer as a thin pump. However, according to the present inventors, the conventional diaphragm pump has room for further reduction in thickness.

  In addition, the diaphragm pump repeats the operation of opening the suction side check valve in the stroke in which the volume of the variable volume chamber is expanded and opening the discharge side check valve in the stroke in which the volume is reduced. Absent.

An object of the present invention is to further reduce the thickness of a diaphragm pump based on the above problem awareness.
Another object of the present invention is to obtain a diaphragm pump that can halve the period of pulsation at the discharge port.

  According to the present invention, in the conventional diaphragm pump, a check valve is arranged on the diaphragm, and the diaphragm (variable volume chamber), the check valve, It was concluded that a further reduction in thickness can be achieved by arranging the at a different position on a plane.

  That is, the diaphragm pump of the present invention is, in an aspect aiming at thinning, a variable volume chamber formed by the diaphragm and the variable volume chamber provided between the variable volume chamber and the suction port. Allowed fluid flow from the variable volume chamber to the discharge port, which is provided between the variable volume chamber and the discharge port, and a suction side check valve that allows fluid flow to the flow direction and does not allow fluid flow in the opposite direction. However, in a diaphragm pump having a discharge-side check valve that does not allow fluid flow in the opposite direction, the diaphragm and both check valves are arranged at different positions in plan view, that is, deviated from the area where the diaphragm exists. The suction-side check valve and the discharge-side check valve are arranged in the flat position.

  In addition, in order to halve the pulsation cycle, this diaphragm pump is provided with variable volume chambers at the top and bottom of the diaphragm, respectively, and a suction port and a discharge port are communicated with the pair of upper and lower variable volume chambers. Between the volume chamber and the suction port, there are provided first and second suction side check valves that allow fluid flow from the suction port to the pair of variable volume chambers and do not allow fluid flow in the opposite direction, First and second discharge-side non-returns that allow fluid flow from the pair of variable volume chambers to the discharge port and do not allow fluid flow in the opposite direction between the upper and lower variable volume chambers and the discharge port, respectively. An embodiment in which a valve is provided is possible.

  If the first and second suction-side check valves and the first and second discharge-side check valves are arranged at the same position as viewed in plan, it is advantageous for miniaturization.

  In order to reduce the thickness of the diaphragm, the diaphragm is sandwiched and supported by a pair of housings having recesses that form variable volume chambers facing the upper and lower sides of the diaphragm, and the pair of housings is opposite to the recesses. A suction-side flow channel and a discharge-side flow channel communicating with the recess are formed on the surface, and the inlet-side flow channel and the discharge-side flow channel are closed by a lid plate fixed to the housing. It is preferable to configure the flow path and the discharge side flow path.

  Further, the suction port and the discharge port are preferably formed at the same planar height as the planar height of the diaphragm. Further, the suction port and the discharge port can be further reduced in thickness by making the cross-sectional shape of the inner surface long in the plane direction of the diaphragm.

  The recesses of the pair of housings have a rotationally symmetric shape and have a stepped cross section in which the central portion is deepest and gradually becomes shallower toward the peripheral portion, thereby increasing pump efficiency.

  In an aspect in which the pulsation cycle is halved, the diaphragm pump of the present invention has a pair of variable volume chambers formed respectively above and below the diaphragm by the diaphragm, a single suction port, a single discharge port, The first and second suction sides, which are provided between the variable volume chamber and the suction port, respectively, allow fluid flow from the suction port to the pair of variable volume chambers but do not allow fluid flow in the opposite direction. A check valve and a first valve that is provided between the pair of variable volume chambers and the discharge port, respectively, permitting fluid flow from the pair of variable volume chambers to the discharge port and not allowing fluid flow in the opposite direction. And a second discharge-side check valve.

  In any embodiment, it is desirable that the check valve is composed of an umbrella. Moreover, it is practical that the diaphragm is composed of a piezoelectric vibrator or an electrostrictive vibrator. A bimorph type piezoelectric vibrator is particularly preferable.

According to the present invention, it is possible to further reduce the thickness of the diaphragm pump by changing the planar positions of the diaphragm and the check valve.
In addition, by forming a pair of variable volume chambers on the front and back of the diaphragm and using them alternately, the pulsation cycle at the discharge port can be halved.

  1 to 9 show an embodiment of the present diaphragm pump. The present diaphragm pump includes an upper housing 10, a lower housing 20, a piezoelectric vibrator (diaphragm) 30, and four umbrellas (check valves) 17, 18, 27, and 28 as basic components. The upper housing 10 and the lower housing 20 for sandwiching the piezoelectric vibrator 30 are flat as a whole, and have a substantially plane symmetrical shape. However, the lower housing 20 has a circular storage recess of the piezoelectric vibrator 30 having a planar circular shape. 21 (FIG. 4) is formed, and the circular convex portion 11 (FIG. 4) that fits into the circular housing concave portion 21 in the upper housing 10 and sandwiches the piezoelectric vibrator 30 between the circular housing concave portion 21. Is formed. Further, a suction port 31 and a discharge port 32 are formed in the lower housing 20.

  As shown in FIGS. 4 to 5, rotationally symmetrical recesses 12 and 22 concentric with the circular protrusion 11 and the circular storage recess 21 are formed in the upper housing 10 and the lower housing 20, respectively. Each of the rotationally symmetric recesses 12 and 22 has a stepped cross section that is deepest at the center and gradually becomes shallower toward the periphery. O-ring storage recesses 13a and 23a are formed outside the rotationally symmetric recesses 12 and 22, and the O-rings 13 and 23 fitted in the O-ring storage recesses 13a and 23a are stored in the circular storage recess 21. The variable volume chamber (pump chamber) 14 and the variable volume chamber (pump chamber) 24 are formed above and below the piezoelectric vibrator 30 in contact with the upper and lower sides (front and back) of the piezoelectric vibrator 30.

  The suction port 31 and the discharge port 32 formed in the lower housing 20 are parallel to each other with their centers positioned at the same planar height as the planar height of the piezoelectric vibrator 30, as is apparent from FIGS. ing. The inner ends of the suction port 31 and the discharge port 32 constitute a suction side alternating chamber 31a and a discharge side alternating chamber 32a. The thickness of the tube pipe (not shown) connected to cover the suction port 31 or the discharge port 32 by setting the plane height of the piezoelectric vibrator 30 and the centers of the suction port 31 and the discharge port 32 to substantially the same height. In consideration of the above, the height of the suction port 31 and the discharge port 32 can be maximized as long as the height of the pipe mounting does not exceed the height of the housing.

  The upper housing 10 is positioned on the opposite surface of the rotationally symmetric recess 12 in the same plane as the extension direction of the suction port 31 and the discharge port 32, and is parallel to the suction side flow channel 15 and the discharge side. A channel groove 16 is formed. The inner end portions of the suction-side flow channel 15 and the discharge-side flow channel 16 reach the deepest portion of the rotationally symmetric recess 12 in plan view, and the rotationally symmetric recess 12 ( It communicates with the variable volume chamber 14). Similarly, the lower housing 20 is positioned on the opposite surface of the rotationally symmetric recess 22 at the same plane position as the suction side flow channel 15 and the discharge side flow channel 16 and is parallel to each other. 25 and a discharge-side channel groove 26 are formed. The inner ends of the suction-side channel groove 25 and the discharge-side channel groove 26 reach the deepest portion of the rotationally symmetric recess 22 in plan view, and the rotationally symmetric recess 22 (variable through the through holes 25a and 26a). It communicates with the volume chamber 24).

  The outer ends of the suction side flow channel groove 15 and the discharge side flow channel groove 16 reach the suction side alternating chamber 31a of the suction port 31 and the discharge side alternating chamber 32a of the discharge port 32, respectively. In the discharge side alternating chamber 32a, umbrella mounting portions (communication holes) 15b and 16b are formed. As shown in FIG. 3, each of the umbrella mounting portions 15b and 16b includes a central portion of the umbrella mounting holes 15b1 and 16b1, and peripheral communication holes 15b2 and 16b2. The umbrella mounting holes 15b1 and 16b1 The shaft portion 17a and the shaft portion 18a of the umbrella 18 are fitted and locked. The umbrellas 17 and 18 are mounted in opposite directions at the umbrella mounting portions 15b and 16b. That is, the umbrella 17 allows the fluid flow from the suction side alternating chamber 31a to the suction side flow channel groove 15 (variable volume chamber 14) through the communication hole 15b2 by the elastic deformation of the umbrella portion 17b, and the flow in the opposite direction is allowed. It is a first suction side check valve which is not allowed. The umbrella 18 is elastic in the umbrella portion 18b in the fluid flow from the discharge side flow channel 16 (variable volume chamber 14) through the communication hole 16b2 to the discharge side alternating chamber 32a. This is a first discharge-side check valve that allows deformation and does not allow flow in the opposite direction.

  The suction side flow channel groove 25 and the discharge side flow channel groove 26 are formed in the same manner as the suction side flow channel groove 15 and the discharge side flow channel groove 16. That is, the outer ends of the suction-side flow channel 25 and the discharge-side flow channel 26 reach the suction-side alternating chamber 31a and the discharge-side alternating chamber 32a as viewed in a plan view. Umbrella mounting portions 25b and 26b are formed in the side alternating chamber 32a. Each of the umbrella mounting portions 25b and 26b includes an umbrella mounting hole 25b1 and 26b1 in the center portion and communication holes 25b2 and 26b2 in the peripheral portion. The portion 28a is fitted and locked. The umbrellas 27 and 28 have opposite mounting directions at the umbrella mounting portions 25b and 26b. The umbrella 27 permits the fluid flow from the suction side alternating chamber 31a to the suction side flow channel groove 25 (variable volume chamber 24) through the communication hole 25b2 by elastic deformation of the umbrella portion 27b and does not allow the flow in the opposite direction. This is a second suction side check valve. The umbrella 28 allows the fluid flow from the discharge-side flow channel 26 (variable volume chamber 24) to the discharge-side alternating chamber 32a through the communication hole 26b2 by elastic deformation of the umbrella portion 28b, and does not allow the flow in the opposite direction. This is a second discharge side check valve. The first and second suction side check valves (umbrellas) 17 and 27 are in the same position as viewed in plan, and the first and second discharge side check valves (umbrellas) 18 and 28 are viewed in plan. In the same position. An O-ring (not shown) that surrounds the umbrella mounting portions 25b and 26b is sandwiched between the upper housing 10 and the lower housing 20.

  The upper housing 10 is formed with a lid plate insertion recess 10a including areas where the suction side flow channel groove 15 and the discharge side flow channel groove 16 are formed, and the lid plate 19 is fitted into the lid plate insertion recess 10a. ing. Similarly, the lower housing 20 is formed with a cover plate insertion recess 20a including the formation area of the suction side flow channel groove 25 and the discharge side flow channel groove 26, and the cover plate 29 is formed in the cover plate insertion recess 20a. Is inserted. On the back surface of the lid plate 19 (29), a channel groove 19a (29a) is formed at a corresponding position of the suction side channel groove 15 (25) and the discharge side channel groove 16 (26). The channel groove 19a (29a) is effective for securing a channel area while reducing the thickness of the diaphragm pump.

  The fitting recess 10a (20a) and the lid plate 19 (29) are formed such that the surface of the lid plate 19 (29) fitted in the fitting recess 10a (20a) is flush with the surface of the upper housing 10. The cover plate 19 (29) is liquid-tightly fixed to the housing 10 (20) with an adhesive film 19b (29b) (shown in FIGS. 2 to 4 and 8) larger than the cover plate 19 (29). Has been. The adhesive film 19b (29b) can be formed from a synthetic resin material, a metal foil, or the like, and is bonded by an adhesive having high adhesiveness and water resistance. According to such an adhesive film 19b (29b), the suction side flow channel 15I (25I) and the discharge side flow channel 16 (26) can be easily formed in the suction side flow channel groove 15 (25) without requiring a special sealing member. ) Portion can be formed with discharge-side flow passage 16I (26I).

As the piezoelectric vibrator 30, for example, a bimorph type piezoelectric vibrator that is considered to be uniformly displaced up and down from the neutral position can be used. FIG. 9 is a schematic diagram of the bimorph type piezoelectric vibrator 30 and includes a shim 301 at the center and piezoelectric bodies 302 formed on the upper and lower sides (front and back). The shim 301 is made of a conductive metal thin plate material, for example, a stainless thin plate having a thickness of about 0.2 mm. The piezoelectric body 302 is made of, for example, PZT (Pb (Zr, Ti) O ₃ ) having a thickness of about 0.3 mm, and is polarized in the front and back directions. This polarization process is performed in the same direction in the pair of piezoelectric bodies 302 positioned on the front and back of the shim 301. That is, in FIG. 9, when the polarization direction of the pair of piezoelectric bodies 302 is represented by arrows a or b, the polarization direction is the same direction with the shim 301 interposed therebetween.

  The surfaces of the pair of piezoelectric bodies 302 on the shim 301 side are bonded so as to be fully conductive with the shim 301, and a film electrode 303 is formed on the entire exposed surface opposite to the shim 301 side. . The film electrode 303 can be formed, for example, by printing (screen baking) a conductive paste (silver paste). In addition, the membrane electrode may be formed on the shim side. Various materials and methods for forming these membrane electrodes are known.

  In the bimorph piezoelectric vibrator 30 described above, when an alternating electric field is applied using the shim 301 as one common electrode and the exposed surfaces (film electrodes 303) of the pair of piezoelectric bodies 302 as the other common electrode, The operation of extending the other side and contracting (reversibly elastically deforming) is repeated.

  The diaphragm pump having the above configuration operates as follows. When an alternating electric field is applied to the shim 301 and the membrane electrode 303 of the bimorph piezoelectric vibrator 30 by a power circuit (not shown), the piezoelectric vibrator 30 is elastically deformed (vibrated) in the forward and reverse directions. When the piezoelectric vibrator 30 is elastically deformed in the forward and reverse directions, the volume of one of the variable volume chambers 14 and 24 increases and the other volume decreases. The stroke in which the volume of the variable volume chamber 14 increases is the stroke in which the volume of the variable volume chamber 24 decreases. Since the volume of the variable volume chamber 14 increases, the umbrella (first suction-side check valve) 17 opens and sucks. Since fluid flows into the variable volume chamber 14 from the port 31 and the volume of the variable volume chamber 24 decreases, the fluid in the variable volume chamber 24 opens the umbrella (second discharge side check valve) 28 and discharge port 32. To leak. Conversely, the stroke in which the volume of the variable volume chamber 14 decreases is the stroke in which the volume of the variable volume chamber 24 increases, and the volume of the variable volume chamber 24 increases, so the umbrella (second suction side check valve) 27 opens. Then, the fluid flows from the suction port 31 into the variable volume chamber 24 and the volume of the variable volume chamber 14 decreases, so that the fluid in the variable volume chamber 14 opens the umbrella (first discharge side check valve) 18 and discharges it. Outflow to port 32. The configuration in which the rotationally symmetric recesses 12 and 22 are stepped and the deepest at the center is effective for moving the fluid sufficiently between the center and the periphery of the piezoelectric vibrator 30 and obtaining an efficient pumping action.

  In the above configuration, the umbrellas 17, 18, 27, and 28 and the piezoelectric vibrator 30 are arranged at different positions when seen in a plan view and do not overlap in a plan view. In other words, the umbrellas 17, 18 or 27, 28 are arranged at a planar position outside the region where the piezoelectric vibrator 30 exists. With this arrangement, the entire diaphragm pump can be reduced in thickness. In addition, the umbrellas 17 and 27 and the umbrellas 18 and 28 do not necessarily have to be at the same position when seen in a plan view, but can be reduced in size by being arranged at the same position when seen in a plan view as in the illustrated embodiment. it can.

  Furthermore, the suction port 31 and the discharge port 32 have a laterally long shape in which the cross-sectional shape of the passage is long in the plane direction of the piezoelectric vibrator 30 as shown in FIGS. By setting the passage cross-sectional shape in this way, the upper housing 10 and the lower housing 20 can be further reduced in size.

Further, according to the above embodiment, the fluid can be taken out from the discharge port 32 in both the forward and reverse deformation processes of the piezoelectric vibrator 30. In the conventional diaphragm pump, the fluid can be taken out only by one of the forward and reverse movements of the piezoelectric vibrator 30 and the pulsation was large (the peak interval of the extraction pressure was long). Accordingly, the pulsation can be reduced (the peak interval of the extraction pressure can be shortened).
In the passage cross section, the left and right wall thicknesses may be made smaller than the upper and lower wall thicknesses. While increasing the flow rate, rigidity can be secured at the thick part. The suction port 31 and the discharge port 32 are preferably formed integrally with each other as in the embodiment, and if there is a seam, there is a possibility of fluid leakage, and the wall is made thin in order to prevent leakage. It is difficult.

  However, for the purpose of reducing the thickness, it is also possible to take out the fluid from the discharge port 32 by only one of the forward and reverse deformation processes of the piezoelectric vibrator 30. This configuration corresponds to a configuration in which the umbrellas 17 and 18 (and related configurations) or the umbrellas 27 and 28 (and related configurations) are removed from the configurations of FIGS.

  From another viewpoint, in the above embodiment, the variable volume chamber 14 and the variable volume chamber 24 are formed above and below the piezoelectric vibrator 30, respectively, and the pulsation of the fluid taken out from the discharge port 32 can be reduced. There is an advantage. This advantage can be obtained without making the planar position of the umbrellas 17, 18 or 27, 28 different from the planar position of the piezoelectric vibrator 30. That is, although the illustrated embodiment has the greatest purpose of reducing the thickness, for the purpose of reducing the pulsation of the extracted fluid, the planar position of the umbrellas 17, 18, 27, and 28 and the planar position of the piezoelectric vibrator 30. May be overlapped. 10 (A) and 10 (B) depict such another embodiment with a skeleton, and the check valves 17, 18, 27, and 28 are depicted as flat valves.

  In the above embodiment, the suction port 31 and the discharge port 32 are arranged side by side in parallel, but the direction of both ports can be different. However, it is preferable to keep the height position the same even when the directions are different.

In the above embodiment, the piezoelectric vibrator is used as the diaphragm, but an electrostrictive vibrator may be used instead of the piezoelectric vibrator.

It is a top view which shows one Embodiment of the diaphragm pump by this invention. It is sectional drawing which follows the II-II line of FIG. It is a partially expanded sectional view of FIG. It is sectional drawing which follows the IV-IV line of FIG. It is a V arrow view of FIG. It is the perspective view which made the principal part of the diaphragm pump of FIG. 1 thru | or FIG. 5 the cross section. It is a skeleton figure which shows only the flow path of the diaphragm pump of FIG. 1 thru | or FIG. It is the perspective view seen from the back surface which shows the single-piece | unit shape of a cover plate. It is a model exploded perspective view of a bimorph type piezoelectric vibrator. It is a system | strain connection diagram which shows another embodiment of the diaphragm pump by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Upper housing 20 Lower housing 10a 20a Cover plate insertion recessed part 12 22 Rotationally symmetrical recessed part 13 23 O-ring 14 24 Variable volume chamber 15 25 Suction side flow path groove 15I 25I Suction side flow path 16 26 Discharge side flow path groove 16I 26I Side channel 15a 16a Through hole 15b 16b Umbrella mounting part 17 18 27 28 Umbrella 17a 18a 27a 28a Shaft part 17b 18b 27b 28b Umbrella part 19 29 Cover plate 19a 29a Channel groove 19b 29b Adhesive film 30 Piezoelectric vibrator (diaphragm)
31 Suction port 32 Discharge port 31a Suction side alternating chamber 32a Discharge side alternating chamber

Claims (11)

A variable volume chamber formed by a diaphragm;
A suction-side check valve provided between the variable volume chamber and the suction port, which allows fluid flow from the suction port to the variable volume chamber and does not allow fluid flow in the opposite direction;
A discharge-side check valve provided between the variable volume chamber and the discharge port, which allows fluid flow from the variable volume chamber to the discharge port and does not allow fluid flow in the opposite direction;
In a diaphragm pump having
A diaphragm pump, wherein the suction-side check valve and the discharge-side check valve are arranged at a planar position deviating from a region where the diaphragm exists. 2. The diaphragm pump according to claim 1, wherein the variable volume chambers are respectively provided above and below the diaphragm, and the suction port and the discharge port communicate with the pair of upper and lower variable volume chambers, respectively. A first and second suction-side check valves that allow fluid flow from the suction port to the pair of variable volume chambers and do not allow fluid flow in the opposite direction, respectively, between the suction port and the suction port; First and second discharge-side check valves that allow fluid flow from the pair of variable volume chambers to the discharge port and do not allow fluid flow in the opposite direction between the upper and lower variable volume chambers and the discharge port, respectively. Diaphragm pump provided with 3. The diaphragm pump according to claim 2, wherein the first and second suction side check valves are in the same position when viewed in plan, and the first and second discharge side check valves are at the same position when viewed in plan. Diaphragm pump in 4. The diaphragm pump according to claim 1, wherein the diaphragm is sandwiched between a pair of housings each having a concave portion that forms a variable volume chamber facing the upper and lower sides of the diaphragm, respectively. A diaphragm pump in which the port and the discharge port are formed at the same plane height as the plane height of the diaphragm. 5. The diaphragm pump according to claim 4, wherein the pair of housings have a suction-side flow channel groove and a discharge-side flow channel communicating with the concave portion on a surface opposite to the concave portion, and the inlet-side flow channel groove. And a diaphragm pump in which the discharge-side channel groove is closed via a lid plate fixed to the housing to constitute the suction-side channel and the discharge-side channel. 6. The diaphragm pump according to claim 4 or 5, wherein the suction port and the discharge port have a horizontally long cross-section on the inner surface and are long in the planar direction of the diaphragm. The diaphragm pump according to any one of claims 4 to 6, wherein the recesses of the pair of housings have a rotationally symmetric shape, and have a stepped cross-sectional shape in which the central part is deepest and gradually becomes shallower toward the peripheral part. . A pair of variable volume chambers respectively formed above and below the diaphragm by the diaphragm;
A single inlet port;
A single discharge port;
The first and second fluid passages, which are provided between the pair of variable volume chambers and the suction port, respectively, allow fluid flow from the suction port to the pair of variable volume chambers and do not allow fluid flow in the opposite direction. A suction check valve,
First and second discharges, which are provided between the pair of variable volume chambers and the discharge port, respectively, allow fluid flow from the pair of variable volume chambers to the discharge port but do not allow fluid flow in the opposite direction. A side check valve,
A diaphragm pump characterized by comprising: The diaphragm pump according to any one of claims 1 to 8, wherein the check valve is an umbrella. 10. The diaphragm pump according to claim 1, wherein the diaphragm is a piezoelectric vibrator or an electrostrictive vibrator. 10. The diaphragm pump according to any one of claims 1 to 9, wherein the diaphragm is a bimorph type piezoelectric vibrator.

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