JP2007309292A - Diaphragm pump and flow passage structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diaphragm pump capable of eliminating a risk of deterioration of a liquid-tight structure of a flow passage in the diaphragm pump wherein a pump chamber is formed by a vibrating diaphragm and a housing, a pair of check valves of which directions flowing into the pump chamber are different from each other is formed, a suction flow passage recession and a delivery flow passage recession of which outer surfaces are opened are formed in the housing, the suction flow passage recession and the delivery flow passage recession are closed by a cover plate, and a suction flow passage and a delivery flow passage communicated with the pair of the check valves are formed. <P>SOLUTION: In the suction flow passage recession and the delivery flow passage recession of the housing, a shallow step part, a deep groove part, and an inside receiving wall are formed successively from the outer peripheral side. An outer periphery thin part fitted with the shallow step part, an insertion protrusion fitted to the deep groove part, and an O ring holding groove positioned on the outer periphery of the insertion protrusion are formed on the cover plate, the inside receiving wall is positioned on the inner side of the insertion protrusion, and deformation of the insertion protrusion to the inner side by an O ring inserted into the O ring holding groove is received by the inside receiving wall. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a diaphragm pump and a liquid-tight channel structure.

The diaphragm pump forms a pump chamber (variable volume chamber) by the diaphragm, and a pair of check valves (inlet side check allowing fluid flow to the pump chamber) in a pair of flow paths connected to the pump chamber. A discharge-side check valve that allows fluid flow from the valve and the pump chamber. When the diaphragm is vibrated, the volume of the pump chamber changes, and the suction side check valve opens in the stroke when the volume increases, and the discharge side check valve opens in the stroke when the volume decreases. It is done. The diaphragm is made of an elastic (vibrating) material such as rubber or a piezoelectric vibrator.
Registration No. 2510590 Utility Model Gazette JP 2005-337070 A

  In order to obtain the diaphragm pump with a simple and easily assembled configuration, the applicant forms a suction flow path recess and a discharge flow path recess that are open on the outer surface, and the suction flow path recess and the discharge flow path. Attempts have been made to form a suction flow path and a discharge flow path connected to a pair of check valves by closing the recesses with a lid plate.

  In such a flow channel formation mode, a highly reliable liquid-tight structure between the flow channel recess and the lid plate is a problem. For example, when a diaphragm pump is used as a cooling source for a personal computer, not only miniaturization but also long-term liquid-tight reliability is indispensable. However, along with downsizing, the lid plate is also inevitably downsized and thinned, and there is a concern about deterioration of the liquid-tight structure due to long-term use.

Accordingly, the present invention provides a diaphragm pump in which a suction-side and a discharge-side channel recess having an open outer surface are formed in a housing, and the channel recesses are covered with a lid plate, respectively. An object is to obtain a diaphragm pump with a low risk of occurrence.
It is another object of the present invention to obtain a flow path structure that is less likely to deteriorate the liquid-tight structure in a flow path structure in which a flow path is formed by a flow path recess and a lid plate.

  According to the present invention, a pump chamber is formed by a vibrating diaphragm and a housing, a pair of check valves having different flow directions are provided in the pump chamber, and a suction flow path recess and a discharge flow path recess that are open on the outer surface are provided in the housing. In the diaphragm pump in which the suction flow path recess and the discharge flow path recess are respectively closed with a lid plate to form a suction flow path and a discharge flow path connected to a pair of check valves, A shallow step portion, a deep groove portion, and an inner receiving wall are formed in order from the outer peripheral side of each channel recess, and the lid plate is fitted into the outer thin portion that engages with the shallow step portion and the deep groove portion. An insertion ridge portion to be joined and an O-ring holding groove located on the outer periphery of the insertion ridge portion are formed, and the inner receiving wall is positioned inside the insertion ridge portion and inserted into the O-ring holding groove. Inside of insertion ridge by O-ring It is characterized by undergoing deformation in inward support wall.

  The O-ring is preferably inserted in such a manner that it does not receive a compressive force in a direction that separates the thin outer peripheral portion of the lid plate and the shallow step portion of the housing.

  The lid plate and the housing can be joined at the contact portion between the thin outer peripheral portion and the shallow step portion. The joining means may be laser welding, ultrasonic welding, adhesive, or the like, and any means may be used.

  The suction channel recess and the discharge channel recess have the same shape, and the lid plate is preferably a common component.

  More generally, the present invention provides a flow path in which a flow path recess having an open outer surface is formed in a synthetic resin housing, and the flow path recess is closed with a synthetic resin lid plate to form a flow path. In the structure, a shallow step portion, a deep groove portion, and an inner receiving wall are formed in order from the outer peripheral side of the flow path recess of the housing, and the outer peripheral thin wall portion that engages with the shallow step portion is formed on the lid plate. An insertion ridge portion that fits into the deep groove portion and an O-ring holding groove located on the outer periphery of the insertion ridge portion are formed, and the inner receiving wall is positioned inside the insertion ridge portion to hold the O-ring. The inner receiving wall receives the inward deformation of the insertion protrusion by the O-ring inserted into the groove.

  According to the present invention, in a diaphragm pump in which an outer surface is opened in a housing to form a channel recess, the channel recess is covered with a lid plate, and the channel is connected to a check valve, the fluid tightness of the channel Reliability can be obtained over a long period of time. Further, even in a general channel structure using a lid plate, the liquid-tight reliability of the channel can be obtained over a long period of time.

  In the illustrated embodiment, the present invention is applied to a four-valve diaphragm pump whose principle was proposed in Japanese Patent Application Laid-Open No. 2005-337068. In this four-valve diaphragm pump, a pair of pump chambers are formed above and below the diaphragm by the diaphragm, while a single suction port and a single discharge port are provided, and the pair of pump chambers and the suction ports are respectively provided. First and second suction side check valves that allow fluid flow from the suction port to the pair of pump chambers but do not allow fluid flow in the opposite direction are provided between the pair of pump chambers and the discharge port. There are provided first and second discharge-side check valves that allow fluid flow from the pair of pump chambers to the discharge port but do not allow fluid flow in the opposite direction.

  1 to 9 show an embodiment of the present invention. This diaphragm pump has an upper housing 20U that sandwiches a piezoelectric vibrator (diaphragm) 10 at the center, and a lower housing 20L.

  The upper housing 20U and the lower housing 20L are made of a molded product of a resin material, and a suction port 21 and a discharge port 22 made of a completely cylindrical body and projecting from each other are provided on the lower housing 20L side. The upper housing 20U and the lower housing 20L basically have symmetrical shapes except for the structure around the suction port 21 and the discharge port 22. First, the common (symmetric) structure will be described. As shown in FIGS. 1, 4, and 5, the upper housing 20U (lower housing 20L) has an inner surface (the surface on the piezoelectric vibrator 10 side is the inner surface, and the opposite is the opposite). A pump chamber forming recess 23U (23L) is formed on the outer surface, and a suction flow path recess 24U (24L) and a discharge flow path recess (recess) 25U (25L) whose outer surfaces are opened on the outer surface. Is formed. A deformed O-ring holding groove 23U1 (23L1) is formed on the outer periphery of the pump chamber forming recess 23U (23L).

  The suction flow path recess 24U (24L) extends from the outer side of the upper housing 20U (lower housing 20L) toward the center, and the flow path communicates with the pump chamber forming recess 23U (23L) at the center side end. A hole 26U (26L) is formed. The discharge flow path recess 25U (25L) extends substantially in parallel with the suction flow path recess 24U (24L), and a flow path hole 27U (communication with the pump chamber formation recess 23U (23L) is provided at the center side end thereof. 27L) is drilled. A suction side umbrella (check valve) 28U (28L) is attached to the flow path hole 26U (26L), and a discharge side umbrella (check valve) 29U (29L) is installed in the flow path hole 27U (27L). Is installed.

  The suction flow path recess 24U (24L) and the discharge flow path recess 25U (25L) of the upper housing 20U (lower housing 20L) are liquid-tightly closed by the lid plate 42 (FIG. 1), thereby separating the suction flow path and the discharge flow path. Constitute. The lid plate 42 is a member made of a molded product of a synthetic resin material common to the suction flow path recess 24U (24L) and the discharge flow path recess 25U (25L), and its liquid-tight structure is taken as an example of the suction flow path recess 24U. This will be described with reference to FIGS.

  In the suction flow path recess 24U, a shallow step portion 24U1, a deep groove portion 24U2, and a central middle-high portion (inner receiving wall) 24U3 are formed in a closed curve in order from the outside along the shape of the suction flow path recess 24U. . An O-ring guide taper portion 24U4 is formed between the shallow step portion 24U1 and the deep groove portion 24U2. On the other hand, on the lid plate 42, an outer peripheral thin plate portion 42a and an insertion protrusion portion 42b are formed in a closed curve so as to correspond to the shallow step portion 24U1 and the deep groove portion 24U2, and on the outer periphery side of the insertion protrusion portion 42b, An O-ring holding recess 42c is formed. The inner peripheral surface of the insertion protrusion 42b is in contact with the center middle / high part 24U3.

  An O-ring 43 is held in the O-ring holding recess 42c, and is held and compressed between the wall of the deep groove portion 24U2 and the insertion protrusion 42b to maintain liquid tightness. The repulsive force of the O-ring 43 tries to deform the insertion protrusion 42b inward, but the center middle / high part (inner receiving wall) 24U3 contacts the inner end of the insertion protrusion 42b, Deformation of the insertion protrusion 42b is prevented. In this way, the deformation force applied to the insertion protrusion 42b of the lid plate 42 by the O-ring 43 is received by the center middle / high portion 24U3 of the suction flow path recess 24U, so that the lid plate 42 is formed from a molded product of a thin resin material. Even in the case of the configuration, the liquid-tight reliability can be improved. The lid plate 42 is joined by an appropriate means such as laser welding or ultrasonic welding at the contact portion between the outer thin plate portion 42a and the shallow step portion 24U1.

  The lower housing 20L communicates with the suction port 21 and the discharge port 22, and communicates with the outer end portions of the suction flow path recess 24L and the discharge flow path recess 25L (FIGS. 2, 4, and 5). ) Is drilled. In the upper housing 20U, communication holes 33 and 34 (FIGS. 3, 4, and 4) are connected to the outer end portions of the suction flow path recess 24U and the discharge flow path recess 25U so as to match the positions of the communication holes 31 and 32. 5) is drilled.

  The communication holes 31 and 33 and the communication holes 32 and 34 are pipes that are liquid-tightly connected to each other. As shown in FIGS. 4, 5, and 6, the communication holes 33 and 34 are provided in the upper housing 20 </ b> U. And cylindrical projections 35 and 36 are formed so as to be coaxial with each other. On the other hand, fitting holes 37 and 38 for receiving the cylindrical projections 35 and 36 are formed in the lower housing 20L coaxially with the communication holes 31 and 32.

  The cylindrical protrusion 35 and the fitting hole 37 (cylindrical protrusion 36 and fitting hole 38) have the same structure. As best shown in FIG. 6, the cylindrical protrusion 35 (36) includes, in order from the tip, a small-diameter constant-diameter portion 35a (36a), a large-diameter tapered shaft portion 35b (36b), and a large-diameter constant-diameter portion 35c. (36c). On the other hand, the fitting hole portion 37 (38) has a small diameter constant diameter hole 37a (38a), a stepped enlarged diameter tapered hole portion 37b (38b) and a large diameter constant diameter hole portion 37c (38c) in order from the back. is doing. An O-ring 39 is provided between the diameter-expanded tapered shaft portion 35b (36b) of the cylindrical protrusion 35 (36) and the stepped diameter-expanded tapered hole portion 37b (38b) of the fitting hole 37 (38). Compressed and held.

  The O-ring 39 is connected in advance to the cylindrical protrusion 35 (36) when the upper housing 20U and the lower housing 20L are connected (see FIG. 7A). When the outer diameter of the O-ring 39 in this free state is d, the end diameter D of the fitting hole 37 (38) (large diameter constant diameter hole 37c (38c)) is set to D> d. (FIG. 7A). As described above, when the outer diameter of the O-ring 39 and the end diameter of the large-diameter constant-diameter hole 37c (38c) are set, the cylindrical protrusion 35 (36) of the upper housing 20U is made clear as shown in FIG. When inserting and coupling to the fitting hole 37 (38) of the lower housing 20L, the O-ring 39 is hardly caught. In the fully inserted state, the O-ring 39 is compressed and held between the enlarged diameter tapered shaft portion 35b (36b) and the stepped enlarged diameter tapered hole portion 37b (38b), thereby maintaining liquid tightness. . The small diameter constant diameter portion 35a (36a) and the large diameter constant diameter portion 35c (36c), and the small diameter constant diameter hole 37a (38a) and the large diameter constant diameter hole portion 37c (38c) are fitted to each other to ensure coaxiality. To do.

  In addition, in this embodiment, a pair of the cylindrical protrusion 35 and the fitting hole 37, and the cylindrical protrusion 36 and the fitting hole 38 are present in parallel with each other. For this reason, as shown in FIG. 8, the manufacturing error of the inter-axis distance X also causes the pinching. According to this embodiment, it is possible to absorb an error in the distance between the axes. The outer diameter d of the O-ring 39 in the free state and the size of the end diameter D of the fitting hole 37 (38) (large diameter constant diameter hole 37c (38c)) are specifically manufactured by these. Determined in consideration of errors and assembly errors.

  When the O-ring 39 is compressed between the enlarged diameter tapered shaft portion 35b (36b) and the stepped enlarged diameter tapered hole portion 37b (38b), the repulsive force of the O ring 39 causes the upper housing 20U and the lower housing to be compressed. A force in the separation direction acts between 20L. This force should be as small as possible. For this reason, it is preferable that the inclination | tilt angle (alpha) (FIG. 6, FIG. 7) with respect to the axis line of the diameter expansion taper shaft part 35b (36b) and the step diameter expansion taper hole part 37b (38b) shall be 20 degrees-45 degrees.

  The piezoelectric vibrator 10 is sandwiched and held between the two housings with the deformed O-ring 41 inserted into the deformed O-ring holding groove 23U1 (23L1) of the upper housing 20U (lower housing 20L). The piezoelectric vibrator 10 is composed of a bimorph-type piezoelectric vibrator, and vibrates when an alternating electric field is applied between a shim at a central portion in the thickness direction and piezoelectric bodies stacked on the front and back of the shim. Such a piezoelectric vibrator 10 is well known and has nothing to do with the gist of the present invention, so further description including the feeding structure will be omitted.

  In the diaphragm pump having the above-described configuration, the chamber formed between the piezoelectric vibrator 10 and the pump chamber forming recess 23U of the upper housing 20U is defined as the pump chamber A, and the pump chamber forming recess 23L of the piezoelectric vibrator 10 and the lower housing 20L. Assuming that the chamber formed between the two chambers is a pump chamber B, the operation is as follows. That is, when the piezoelectric vibrator 10 is elastically deformed (vibrated) in the forward and reverse directions, the volume of one of the pump chambers A and B increases and the other volume decreases. In the process of increasing the volume of the pump chamber A (decreasing the volume of the pump chamber B), the suction side umbrella 28U is opened, fluid flows into the pump chamber A from the suction port 21, and fluid in the pump chamber B is discharged. The side umbrella 29L is opened and flows out to the discharge port 22 (see FIG. 11B). Conversely, in the stroke in which the volume of the pump chamber A decreases (the volume of the pump chamber B increases), the suction-side umbrella 28L is opened and fluid flows into the pump chamber B from the suction port 21, and the fluid in the pump chamber A Opens the discharge-side umbrella 29U and flows out to the discharge port 22 (see (A)). Therefore, the pulsation cycle in the discharge port 22 can be shortened (halved compared to the case where the pump chamber is formed only in one of the upper and lower sides of the piezoelectric vibrator 30).

  FIG. 10 shows another shape example of the lid plate 42 and the suction flow path recess 24U. FIG. 6A shows an example in which the outer peripheral surfaces of the deep groove portion 24U2 of the suction flow passage recess 24U and the insertion protrusion portion 42b of the lid plate 42 are inclined surfaces inward, and FIG. In the example in which the vertical surface of the insertion protrusion 42b of the plate 42 is the same inclined surface, (C) shows the deep groove 24U2 and the outer peripheral surface of the insertion protrusion 42b and the vertical surface of the insertion protrusion 42b. This is an example in which the inward side is an inclined surface facing inward and tapered. In any embodiment, the repulsive force by the O-ring 43 is generated in the direction along the contact surface between the outer peripheral thin plate portion 42a and the shallow step portion 24U1, and does not work in the direction of separating the two.

  The present invention is directed to a flow path structure including a suction flow path recess 24U (24L) and a discharge flow path recess 25U (25L), and a lid plate 42 used in common, and the overall structure of the housing, The formation mode of the umbrella (check valve), the piezoelectric vibrator, and the like is merely an example. Of course, the present invention is also applicable to a diaphragm pump in which the piezoelectric vibrator is a unimorph type and the pump chamber is formed only on one surface thereof.

It is a perspective view of the disassembled state which shows one Embodiment of the diaphragm pump by this invention. It is an inner surface figure of a lower housing. It is an external view of an upper housing. It is sectional drawing which follows the IV-IV line of FIG.2 and FIG.3 in an assembly state. It is sectional drawing which follows the same VV line. It is a disassembled cross-sectional perspective view of a connection pipe line part. (A), (B), (C) is sectional drawing which shows the assembly process of a connection pipe line part. It is sectional drawing before the coupling | bonding of an upper housing and a lower housing which follows the VIII-VIII line of FIG. It is a cross-sectional perspective view showing the relationship between a suction channel recess (discharge channel recess) and a lid plate that closes the recess liquid-tightly. (A), (B), (C) is sectional drawing of the principal part which shows another embodiment of the flow-path structure by this invention. (A), (B) is a conceptual diagram in the vibration direction from which the diaphragm of the 4-valve diaphragm pump to which this invention is applied is different.

Explanation of symbols

10 Piezoelectric vibrator (diaphragm)
20U Upper housing 20L Lower housing 21 Suction port 22 Discharge port 23U 23L Pump chamber forming recess 24U 24L Suction flow path recess 25U 25L Discharge flow path recess 24U1 Shallow step portion 24U2 Deep groove portion 24U3 Center middle and high portion (inner receiving wall)
24U4 O-ring guide taper portion 26U 26L Channel hole 27U 27L Channel hole 28U 28L Suction side umbrella 29U 29L Discharge side umbrella 31 32 Communication hole (lower housing side)
33 34 Communication hole 35 36 Cylindrical protrusion 35a 36a Small diameter constant diameter part 35b 36b Large diameter tapered shaft part 35c 36c Large diameter constant diameter part 37 38 Fitting hole part 37a 38a Small diameter constant diameter hole 37b 38b Stepped large diameter tapered hole Portion 37c 38c large-diameter constant-diameter hole 39 O-ring 41 deformed O-ring 42 lid plate 42a outer peripheral thin plate portion 42b insertion protrusion 42c O-ring holding recess 43 O-ring

Claims (5)

A pump chamber is formed by a vibrating diaphragm and a housing, a pair of check valves having different flow directions are provided in the pump chamber, and a suction flow channel recess and a discharge flow channel recess having an open outer surface are formed in the housing, In the diaphragm pump in which the suction flow path recess and the discharge flow path recess are respectively closed with a lid plate to form a suction flow path and a discharge flow path connected to the pair of check valves,
A shallow step portion, a deep groove portion, and an inner receiving wall are formed in order from the outer peripheral side of the suction flow channel recess and the discharge flow channel recess of the housing,
The lid plate is formed with an outer peripheral thin wall portion that engages with the shallow step portion, an insertion ridge portion that fits into the deep groove portion, and an O-ring holding groove that is positioned on the outer periphery of the insertion ridge portion,
The inner receiving wall is positioned on the inner side of the insertion protrusion, and the inward deformation of the insertion protrusion by the O-ring inserted into the O-ring holding groove is received by the inner reception wall. Diaphragm pump. 2. The diaphragm pump according to claim 1, wherein the O-ring is inserted in such a manner that it does not receive a compressive force in a direction in which the outer peripheral thin portion of the lid plate and the shallow step portion of the housing are separated from each other. 3. The diaphragm pump according to claim 1, wherein the lid plate and the housing are joined at a contact portion between the outer peripheral thin portion and the shallow step portion. The diaphragm pump according to any one of claims 1 to 3, wherein the suction flow path recess and the discharge flow path recess have the same shape, and the lid plate is a common part. In a flow path structure in which a flow path recess having an open outer surface is formed in a synthetic resin housing, and the flow path recess is closed with a synthetic resin lid plate to form a flow path.
In the flow path recess of the housing, in order from the outer peripheral side, a shallow step portion, a deep groove portion, and an inner receiving wall are formed,
The lid plate is formed with an outer peripheral thin wall portion that engages with the shallow step portion, an insertion ridge portion that fits into the deep groove portion, and an O-ring holding groove that is positioned on the outer periphery of the insertion ridge portion,
The inner receiving wall is positioned on the inner side of the insertion protrusion, and the inward deformation of the insertion protrusion by the O-ring inserted into the O-ring holding groove is received by the inner reception wall. Channel structure.