JP2008180161A - Diaphragm pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent deformation of a diaphragm by heat generation by sufficiently radiating heat in laser welding, and to sufficiently extract characteristics of the diaphragm by setting an appropriate laser welding position. <P>SOLUTION: A laser welding part 9 jointing a resin diaphragm 21 to a case body 10 is arranged at a position with a non-welding region 13 separated from an edge 11a of a pump chamber 11, and heat generated in laser beam irradiation is sufficiently radiated toward a case body 10. The laser welding part 9 is arranged between the edge 11a of the pump chamber 11 and an outer peripheral edge 27a of a movable part 28 of a metal diaphragm 25, and vibration by a piezoelectric element 30 is surely exerted only in the movable part 28. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a diaphragm pump that draws fluid into a pump chamber and drives it by driving a diaphragm, and more particularly to a diaphragm pump suitable as a micro pump.

  In technical fields such as pharmaceutical administration in the medical field, fuel supply in fuel cells, and ink supply in printing equipment, micropumps that pump a fixed amount of fluid or gas with high accuracy are used. As such a pump, a pump that exhibits a pumping action by driving and vibrating a flexible thin film such as a diaphragm is suitably used.

  This type of so-called diaphragm pump is generally connected to a case having a fluid suction channel and a discharge channel, a diaphragm joined to the case to form a pump chamber between the case, and a diaphragm to which a voltage is applied. And a piezoelectric element that vibrates to actuate the diaphragm. In such a pump, by applying a voltage to the piezoelectric element to vibrate the diaphragm, the volume of the pump chamber is continuously expanded / reduced, and the suction of fluid into the pump chamber and the pump chamber to the outside of the pump are performed. Pump action such as fluid discharge occurs. A one-way valve corresponding to the flow path is provided in the suction flow path and the discharge flow path formed in the case. Patent Documents 1, 2 and the like describe a pump chamber in which these valves are fixed by being sandwiched between two parts constituting a case.

Japanese Patent No. 3707380 JP 2001-323879 A

  Some parts of the pump as described in each of the above patent documents are joined by laser welding or adhesion. In the case of laser welding, the material that absorbs the laser beam is irradiated with the laser beam, and the material is melted to join the counterpart component. Laser welding is employed where it is required to reliably prevent fluid leakage. However, when parts are joined together by laser welding, overheating occurs unless the heat generated during welding is effectively dissipated. For example, the resin diaphragm is deformed and the pump characteristics change. Moreover, if the location where laser welding is performed is not taken into consideration, the characteristics of the diaphragm cannot be sufficiently obtained, and the pump performance may be lowered.

  Therefore, the present invention effectively dissipates heat at the time of laser welding, suppresses deformation of the resin diaphragm due to heat generation, and sufficiently sets the characteristics of the diaphragm by setting an appropriate laser welding location. An object of the present invention is to provide a diaphragm pump capable of improving the pump performance.

  The diaphragm pump of the present invention includes a plate-shaped case main body, a pump chamber formed of a recess formed on one side of the case main body, and a fluid suction passage and discharge passage formed in the case main body and leading to the pump chamber. And a resin diaphragm that is disposed opposite to one side of the case body, covers the pump chamber and is welded to one side of the case body, and a diaphragm driving means that drives the resin diaphragm to change the substantial volume of the pump chamber In the diaphragm pump provided with the above, a flat case body-side joining surface is formed around the pump chamber on one side of the case body and at a position separating the non-welded region from the periphery of the pump chamber. A flat diaphragm side joining surface that is in close contact with the case body side joining surface is formed on the surface facing the body, and the case body side joining surface and the diaphragm Together and the arm-side bonding surface brought into close contact with each other, at least a portion of said seal adhesive portion is characterized in that it is joined by laser welding.

  According to the present invention, the laser welding portion for welding and joining the resin diaphragm to the case main body is disposed at a position separating the non-welding region from the peripheral edge of the pump chamber, which is a recess formed in the case main body. Moreover, the laser welding part is arrange | positioned in the part which contact | adhered the joining surface of the flat case main body side and the resin diaphragm side. By bringing flat joining surfaces into close contact, heat generated during laser welding is sufficiently transmitted from the melting side to the other side, whereby overheating is unlikely to occur and the heat is sufficiently dissipated. In addition, since a non-welding region is secured between the laser welding portion and the peripheral edge of the pump chamber in the recess, laser welding is reliably performed at a portion where the case body and the resin diaphragm are in close contact with each other.

  For this reason, for example, the resin diaphragm only melts at the time of laser welding, and the melted portion does not come into contact with the case main body to be bonded, thereby causing a problem that heat radiation becomes insufficient and the resin diaphragm is overheated and deformed. If a non-welding area is not secured and a portion corresponding to the periphery of the pump chamber is laser-welded, the portion of the resin diaphragm that is separated from the case body across the pump chamber may be overheated and deformed. In the present invention, such overheating does not occur and reliable heat dissipation is achieved.

  In the present invention, the metal diaphragm is overlapped and bonded to one side of the resin diaphragm, the peripheral edge of the pump chamber is disposed inside the outer peripheral edge of the metal diaphragm, and the laser welding portion of the resin diaphragm to the case body is provided in the pump chamber. It is preferable that it is disposed between the peripheral edge of the metal diaphragm and the outer peripheral edge of the metal diaphragm.

  According to this embodiment, the rigidity of the resin diaphragm is increased by joining the metal diaphragm to the resin diaphragm. For this reason, even if the resin diaphragm receives the pressure of the fluid, the resin diaphragm is not deformed by the pressure, and the state driven by the diaphragm driving means is reliably and accurately maintained, and an accurate pumping action can be obtained. In addition, since the laser welded portion is disposed inside the outer peripheral edge of the metal diaphragm, vibrations by the diaphragm driving means can be reliably exerted only in the region of the metal diaphragm, and the adhesion and heat dissipation of the laser welded portion can be achieved. Will improve.

  Further, the metal diaphragm has a movable part deformed by the diaphragm driving means and a fixed part formed around the movable part, and a void is formed between the movable part and the fixed part. The outer peripheral edge of the metal diaphragm is the outer peripheral edge of the movable part, and the metal diaphragm includes a form in which the metal diaphragm is joined to the resin diaphragm by an adhesive. In this embodiment, when the entire bonding surface of the metal diaphragm and the resin diaphragm is filled with the adhesive, the excess part leaks into the void. With this adhesive leakage phenomenon, it can be confirmed that the entire adhesive surface is in a normal adhesive state filled with the adhesive. Moreover, when there is no space, the excess amount of the adhesive comes out only from the outer peripheral edge, but the amount of surplus increases because there is no space. Therefore, the surplus amount from the outer peripheral edge can be reduced by forming the void.

  For example, when the metal diaphragm is smaller than the resin diaphragm and the outer peripheral portion of the resin diaphragm protrudes from the outer peripheral edge of the metal diaphragm, an excessive amount of adhesive appears on the surface of the protruding resin diaphragm. Here, if a void is not formed and the excessive amount of the adhesive is large, the excessive adhesive may exceed the height (thickness) of the metal diaphragm. That is, excess adhesive protrudes from the surface of the metal diaphragm. When the resin diaphragm is laser welded to the case body, a flat pressing jig such as glass is pressed against the metal diaphragm to bring the joint surfaces into close contact with each other. If the adhesive is excessive, the adhesive protrudes beyond the metal diaphragm. And a jig | tool will contact the surplus part of the adhesive agent, and a uniform pressure cannot be provided to a joining surface.

  Therefore, if the void is formed as in the present invention so that the excess adhesive comes out of the void, the surplus amount of the adhesive coming out from the outer peripheral edge of the metal diaphragm can be suppressed. Therefore, it is possible to prevent excess adhesive from protruding from the surface of the metal diaphragm, and the pressing jig can be brought into contact with the entire surface of the metal diaphragm during laser welding. As a result, a uniform pressure can be applied to the bonding surface, and laser welding can be performed soundly.

  Next, the diaphragm pump of the present invention has a two-layer structure in which a metal diaphragm is joined to one side of a plate-like case main body and a resin diaphragm, and is disposed opposite to one side of the case main body, and a resin is provided on one side of the case main body. A diaphragm to which the diaphragm is welded and joined, a pump chamber formed between the diaphragm and the case body, a suction passage and a discharge passage for fluid that are formed in the case body and communicate with the pump chamber, and drive the diaphragm A diaphragm pump having a diaphragm drive means for changing the substantial volume of the pump chamber, and a flat case body that is a mutually opposed surface of the case body and the resin diaphragm and that is in close contact with the peripheral portion of the pump chamber A side joint surface and a resin diaphragm side joint surface are formed, and these joint surfaces are brought into close contact with each other. At least a portion of said seal adhesive portion is joined by laser welding, further the laser welding unit is characterized in that it is arranged on the inner side of the outer peripheral edge of the metal diaphragm.

  This diaphragm pump includes a form in which the pump chamber is not formed in the case body as a recess like the previous diaphragm pump. In this configuration, the volume of the pump chamber increases during fluid suction when the diaphragm is separated from the case body, and the volume of the pump chamber decreases when the diaphragm is in contact with or close to the case body. This diaphragm pump has a diaphragm in which a metal diaphragm is bonded to one side of a resin diaphragm.

  Even in the present invention, the flat case main body side and the resin diaphragm side joining surfaces are in close contact, and this close contact portion is laser welded, so heat generated during laser welding is sufficiently transmitted from the melting side to the other side. As a result, overheating is unlikely to occur and heat is sufficiently dissipated. Therefore, the resin diaphragm is not overheated and deformed, and laser welding is reliably performed at the portion where the case body and the resin diaphragm are in close contact.

  Similarly to the previous invention, the diaphragm of the present invention also has a movable part that is deformed by the diaphragm driving means and a fixed part formed around the movable part, and an empty space between the movable part and the fixed part. The metal diaphragm includes a form bonded to the resin diaphragm by an adhesive.

  According to the present invention, heat dissipation during laser welding is effectively performed, and deformation of the resin diaphragm due to heat generation is suppressed, and by setting an appropriate laser welding location, the characteristics of the diaphragm are sufficiently extracted, and these As a result, the pump performance can be improved.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[1] Configuration of Diaphragm Pump FIG. 1 is a perspective view of a diaphragm pump (hereinafter abbreviated as pump) 1A according to an embodiment, and FIG. 2 is a cross-sectional view of the pump 1A. 3 and 4 are a perspective view and a cross-sectional view, respectively, of the state in which the pump 1A is disassembled. As shown in these drawings, the pump 1A includes a diaphragm 20 and a piezoelectric element (diaphragm driving means) 30 on the upper side of the rectangular thin plate-like case body 10, and a flow path member 40 and a lower cover 50 on the lower side. It is a laminated structure.

  The case body 10 is formed of a laser beam transmitting material. As the laser light transmitting material, a transparent resin is suitable. A circular recess 11 is formed on the upper surface of the case body 10. This recess 11 is closed by a diaphragm 20 and is configured as a pump chamber. Around the recess 11 on the upper surface of the case body 10, an annular ridge 12 having a constant height is formed concentrically with the recess 11. A non-welded region 13 having a constant width is formed between the ridge 12 and the peripheral edge 11 a of the recess 11. The width of the non-welding region 13, that is, the distance between the peripheral edge of the recess 11 and the ridge 12 is ensured to be at least 0.2 mm. The upper surface (case body side joining surface) 12 a of the ridge 12 is formed on a flat surface parallel to the upper surface of the case body 10.

  On the other hand, a valve relief recess 14 and a valve housing recess 15 are formed on the lower surface of the case body 10 in a pair. Each of the recesses 14 and 15 has a rectangular shape, and is formed on both sides of the center of the case body 10 such that the longitudinal direction is along the radial direction. In this case, the valve housing recess 15 has a longer dimension than the valve escape recess 14. The case body 10 is formed with a suction passage 16 that leads from the valve relief recess 14 to the recess 11 and a discharge passage 17 that leads from the recess 11 to the valve housing recess 15.

  The diaphragm 20 has a two-layer structure in which a rectangular diaphragm-like metal diaphragm 25 is joined to the upper surface of a rectangular diaphragm-like resin diaphragm 21. The resin diaphragm 21 is formed of a laser light absorbing material. A black resin is suitable as the laser light absorbing material. As shown in FIG. 5, a plurality of arc-shaped slits (voids) 26 are formed in the metal diaphragm 25 so as to form an inscribed circle with a connecting portion 27 therebetween. In the metal diaphragm 25, the disk-shaped portion surrounded by the slit 26 is a movable portion 28, and the outside of the slit 26 is a fixed portion 29. The movable part 28 and the fixed part 29 are connected by a connecting part 27 formed between the slits 26. The resin diaphragm 21 and the metal diaphragm 25 are joined by an adhesive applied to the entire joining surface.

  The metal diaphragm 25 is slightly smaller in size than the resin diaphragm 21. The metal diaphragm 25 is joined to the upper surface of the resin diaphragm 21 so that an excess portion 22 having a uniform width that is not covered by the metal diaphragm 25 is formed at the periphery of the resin diaphragm 21. A disk-shaped piezoelectric element 30 having a smaller diameter than the movable portion 28 is concentrically fixed on the upper surface of the movable portion 28 of the metal diaphragm 25. The piezoelectric element 30 is fixed to the metal diaphragm 25 by means such as adhesion.

  In the diaphragm 20 in which the piezoelectric element 30 is bonded to the metal diaphragm 25, the flat lower surface of the resin diaphragm 21 is in close contact with the upper surface 12 a of the ridge 12 of the case body 10. In this case, the annular facing surface 21a of the lower surface of the resin diaphragm 21 to the ridge 12 is the diaphragm-side joint surface of the present invention which is in close contact with the case body 10 and welded. The close contact surfaces of the upper surface 12a of the ridges 12 of the case body 10 and the facing surface 21a of the resin diaphragm 21 are laser-welded to form an air-tight connection, thereby forming a laser weld 9. As shown in FIG. 2, in a state where the resin diaphragm 21 is welded and joined to the case body 10, the recess 11 of the case body 10 is covered with the diaphragm 20 to form a pump chamber. Further, the peripheral edge 11 a of the pump chamber 11 is disposed on the inner side (inner peripheral side) of the outer peripheral edge 27 a of the movable portion 28 in the metal diaphragm 25, and the laser welded portion 9 is disposed outside the peripheral edge 11 a of the pump chamber 11 and the movable portion 28. It arrange | positions between the periphery 27a.

  As with the resin diaphragm 21, the flow path member 40 is formed of a laser light absorbing material such as a black resin. The flow path member 40 has a disk part 41. From the lower surface of the disk portion 41, two pipe portions 42 and 43 (a suction side pipe portion 42 and a discharge side pipe portion 43) protrude perpendicularly to the lower surface. Channels 42 a and 43 a are formed inside the two pipe portions 42 and 43. On the upper surface of the disk portion 41, a valve housing recess 44 and a valve escape recess 45 are formed in a pair, similar to those formed in the case body 10. The disk portion 41 includes a suction passage 46 that leads from the passage 42 a of the suction side pipe portion 42 to the valve housing recess 44, and a discharge passage 47 that leads from the valve escape recess 45 to the passage 43 a of the discharge side pipe portion 43. Are formed.

  As shown in FIG. 2, in the flow path member 40, the upper surface of the disk portion 41 is concentrically joined to the lower surface of the case body 10. In this joined state, the valve accommodating recess 44 on the flow path member 40 side and the valve escape recess 14 on the case body 10 side face each other, and the valve escape recess 45 on the flow path member 40 side and the valve accommodation recess 15 on the case body 10 side are located. opposite. Any of the concavities 44 and 14 and concavities 45 and 15 that face each other face each other with the inner ends thereof aligned. Further, the suction flow path 46 on the flow path member 40 side and the suction flow path 16 on the case body 10 side communicate in a straight line via the recesses 44 and 14, and the discharge flow path 47 on the flow path member 40 side. The discharge flow path 17 on the case body 10 side also communicates linearly via the recesses 45 and 15. The communication between the suction channels 46 and 16 is opened and closed by a suction-side check valve 48 accommodated in the valve accommodating recess 44 of the channel member 40, and the communication between the discharge channels 47 and 17 is performed on the valve of the case body 10. The discharge side check valve 49 housed in the housing recess 15 is opened and closed. These check valves 48 and 49 are made of thin rubber having elasticity or the like.

  As shown in FIG. 3, the suction-side check valve 48 is formed by integrally forming a tongue piece 48b on a rectangular base 48a, and the base 48a is sandwiched between the flow path member 40 and the case body 10. Is retained. The tongue 48b normally closes the opening 46a to the valve housing recess 44 in the suction flow path 46 on the flow path member 40 side. When the tongue piece 48b receives pressure toward the case body 10, the tongue piece 48b is elastically deformed into the valve escape portion 14. At this time, the opening 46a is opened and the suction flow paths 46 and 16 are communicated.

  Further, the discharge side check valve 49 is formed by integrally forming a tongue piece 49b on a rectangular base portion 49a, and the base portion 49a is sandwiched and held between the flow path member 40 and the case body 10. The tongue piece 49b normally closes the opening 17a to the valve housing recess 15 in the discharge flow path 17 on the case body 10 side. When the tongue piece 49b receives pressure toward the flow path member 40, the tongue piece 49b is elastically deformed into the valve escape portion 45. At this time, the opening 17a is opened and the discharge flow paths 17 and 47 are communicated.

  In the flow path member 40, the upper surface of the disk portion 41 is concentrically aligned with the lower surface of the case main body 10, and the portions around the valve housing recesses 44 and 15 on the joint surfaces are hermetically sealed. The laser welded portions 8 and 7 are formed by bonding.

  As shown in FIG. 3, the lower cover 50 has a rectangular outer shape and is formed with a fitting hole 51 at the center, and has a thickness similar to that of the disk portion 41 of the flow path member 40. It is. The diameter of the fitting hole 51 is slightly larger than the outer diameter of the disk portion 41. The lower cover 50 is joined to the lower surface of the case body 10 with an adhesive or the like in a state where the disk portion 41 is fitted in the fitting hole 51.

[2] Assembling the pump The above is the configuration of the pump 1A according to the present embodiment, and the pump 1A is assembled as follows.
First, the flow path member 40 is aligned and brought into close contact with the lower surface of the case body 10, and the laser welded portions 8 and 7 are formed by irradiating the laser beam from the case body 10 side (upper side in FIG. 2) through which the laser beam is transmitted. . The laser welding is performed by heating and melting the flow path member 40 made of a laser light absorbing material by the laser light transmitted through the case body 10 and welding the melted portion to the case body 10 which is a counterpart member. When laser welding is performed, a flat pressing jig such as a glass plate is used so that the case main body 10 and the flow path member 40 are in close contact with each other, and laser light is irradiated while the laser welding surfaces are in close contact with each other. .

  On the other hand, the metal diaphragm 25 is bonded to the resin diaphragm 21 using an adhesive to assemble the diaphragm 20, and the piezoelectric element 30 is bonded to the metal diaphragm 25 using an adhesive. Then, the lower surface of the resin diaphragm 21 is brought into close contact with the upper surface 12a of the ridge 12 of the case body 10, and the laser beam is irradiated from the case body 10 side (lower side in FIG. 2) through which the laser beam is transmitted. 9 is formed. In this case, the resin diaphragm 21 made of a laser light absorbing material is heated and melted by the laser light transmitted through the case main body 10, and the melted portion is welded to the case main body 10 which is a counterpart member. Further, when laser welding is performed, the upper surface of the metal diaphragm 25 is pressed against the case body 10 using a flat pressing jig such as a glass plate, and the lower surface of the resin diaphragm 21 is brought into close contact with the upper surface of the ridge 12, Irradiate with laser light. Finally, the lower cover 50 is joined to the flow path member 40 using an adhesive.

[3] Operation of Pump Next, the operation of the pump 1A will be described.
When an AC voltage is applied to the piezoelectric element 30, the diaphragm 20 continuously generates vibration that is a repeated operation of bending in the direction away from and close to the case body 10 (up and down in FIG. 2). The volume of the pump chamber 11 repeatedly increases and decreases. When the diaphragm 20 moves away from the case body 10, the volume of the pump chamber 11 increases and fluid is sucked into the pump chamber 11. When the diaphragm 20 moves in a direction approaching the case body 10, the volume of the pump chamber 11 decreases and fluid is discharged from the pump chamber 11. Hereinafter, the operation during inhalation and ejection will be described in detail.

(A) Fluid suction operation As shown in FIG. 6A, when the diaphragm 20 bends away from the case body 10 and the volume of the pump chamber 11 increases, the inside of the pump chamber 11 becomes negative pressure. Then, the tongue piece 48b of the suction side check valve 48 is separated from the flow path member 40, and the opening 46a of the suction flow path 46 is opened. On the other hand, the tongue piece 49b of the discharge side check valve 49 is in close contact with the case body 10, and the opening 17a of the discharge flow path 17 is kept closed. The fluid is sucked into the pump chamber 11 from the flow path 42 a of the suction side pipe portion 42 through the suction flow path 46 and the valve accommodating recess 44 of the flow path member 40, the valve escape recess 14 and the suction flow path 16 of the case body 10. The

(B) Fluid Discharge Operation As shown in FIG. 6B, when the volume of the pump chamber 11 decreases as the diaphragm 20 is bent in the direction approaching the case body 10, the inside of the pump chamber 11 becomes positive pressure. Then, the tongue piece 49b of the discharge side check valve 49 is separated from the case body 10, and the opening 17a of the discharge flow path 17 is opened. On the other hand, the tongue piece 48b of the suction side check valve 48 is in close contact with the flow path member 40, and the opening 46a of the suction flow path 46 is closed. The fluid in the pump chamber 11 passes through the discharge channel 17 and the valve housing recess 15 of the case body 10, the valve escape recess 45 and the discharge channel 47 of the channel member 40, and passes through the channel 43 a of the discharge side pipe unit 43. It is discharged outside.
By repeating the above suction / discharge operation, the pump action is continuously generated, and the fluid is pumped.

[4] Effects of this Embodiment According to the pump 1A of the present embodiment, the laser welding portion 9 that is a joint portion between the case main body 10 and the resin diaphragm 21 is formed in a recess (pump chamber) formed in the case main body 10. ) 11 is arranged at a position separating the non-welded region 13 from the peripheral edge 11a. Further, the laser welded portion 9 is disposed at a portion where the flat upper surface 12a of the ridge 12 on the case body 10 side and the flat facing surface 21a on the resin diaphragm 21 side are in close contact with each other. By bringing flat joint surfaces into close contact with each other in this manner, the heat generated during laser welding is sufficiently transmitted from the melting side to the other side (in this case, from the resin diaphragm 21 to the case body 10), thereby preventing overheating. Sufficient heat is dissipated. In addition, since the non-welded region 13 is secured between the laser welded portion 9 and the peripheral edge 11a of the recess 11, laser welding is reliably performed at the portion where the case body 10 and the resin diaphragm 21 are in close contact. The

  For these reasons, the resin diaphragm 21 only melts at the time of laser welding, and the melted portion does not come into contact with the case main body 10 to be bonded, so that heat radiation becomes insufficient, and the resin diaphragm 21 is overheated and deformed. Is unlikely to occur. When the non-welding region 13 is not secured and the portion corresponding to the peripheral edge 11a of the recess 11 is laser welded, the resin diaphragm 21 that is separated from the case body 10 with the recess 11 interposed therebetween is exposed to the recess 11. Although only the portion melts and overheats and may be deformed, in this embodiment, such overheating does not occur and reliable heat dissipation is performed.

  Moreover, since the diaphragm 20 is the structure by which the metal diaphragm 25 was joined to the resin diaphragm 21, it can be provided with high rigidity. For this reason, even if the diaphragm 20 receives the pressure of the fluid, the diaphragm 20 is not deformed by the pressure, and the state driven by the piezoelectric element 30 is reliably and appropriately maintained, and an accurate pumping action can be obtained. Further, since the laser welded portion 9 is disposed inside the movable portion 28 of the metal diaphragm 25, vibration due to the piezoelectric element 30 can be reliably exerted only on the movable portion 28, and the adhesion of the laser welded portion 9 can be achieved. And heat dissipation is improved.

  Further, when the metal diaphragm 25 is joined to the resin diaphragm 21 with an adhesive, as shown in FIG. 7A, excess of the adhesive P can be leaked from the slit 26. With this adhesive leakage phenomenon, it can be confirmed that the entire adhesive surface is in a normal adhesive state filled with the adhesive.

  When the slit 26 is not formed, as shown in FIG. 7B, the excessive adhesive P leaks from the outer peripheral edge of the metal diaphragm 25. However, the surplus amount also corresponds to the absence of the slit 26. As shown in the figure, it may protrude upward from the surface of the metal diaphragm 25 as shown. In this case, when the resin diaphragm 21 is laser-welded to the case body 10, a pressing jig such as glass that presses against the surface of the metal diaphragm 25 hits the cured adhesive P and applies a uniform pressure to the bonding surface. I can't.

  Therefore, if the slit 26 is formed as in the present embodiment so that the excess adhesive P comes out of the slit 26 as well, the excess amount of the adhesive coming out from the outer peripheral edge of the metal diaphragm 25 can be suppressed. it can. Therefore, it is possible to prevent the excess adhesive from protruding from the surface of the metal diaphragm 25, and the pressing jig can be brought into contact with the entire surface of the metal diaphragm 25 during laser welding. As a result, a uniform pressure can be applied to the bonding surface, and laser welding can be performed soundly.

[5] Other Embodiments FIG. 8 shows a pump according to another embodiment of the present invention, which is a modification of the above embodiment.
In the pump 1B, the recess 11 is not formed on the upper surface of the case body 10, and only the ridges 12 are formed on the flat upper surface. As shown in FIG. 9A showing the fluid suction state, the pump chamber 19 in this case has an increased volume of the pump chamber 11 during fluid suction when the diaphragm 20 is separated from the case body 10, and during fluid discharge, As shown in FIG. 9B, the resin diaphragm 21 of the diaphragm 20 comes into contact with the upper surface of the case body 10 and the volume of the pump chamber 11 is reduced. The pump action by the vibration of the diaphragm 20 is the same as that of the above embodiment.

  Even in the pump 1B, the lower surface of the resin diaphragm 21 is brought into close contact with the flat upper surface 12a of the ridge 12 of the case main body 10, and the laser welded portion 9 is formed by laser welding of the close contact portion. For this reason, the heat generated during laser welding is sufficiently transmitted from the resin diaphragm 21 on the melt side to the case body 10, thereby preventing overheating and sufficiently dissipating heat. Therefore, the resin diaphragm 21 is not overheated and deformed, and laser welding is reliably performed at a portion where the case body 10 and the resin diaphragm 21 are in close contact with each other. Further, since the laser welding portion 9 between the case body 10 and the resin diaphragm 21 is disposed inside the outer peripheral edge 27a of the movable portion 28 in the metal diaphragm 25, the vibration due to the piezoelectric element 30 can be reliably ensured only by the movable portion 28. It can be demonstrated.

[6] Modifications of the Present Invention The above are the embodiments of the present invention, but the present invention includes the following modifications in addition to these embodiments.

  In the pumps 1A and 1B, the ridge 12 is formed on the case body 10 side, the flat upper surface 12a of the ridge 12 and the flat facing surface 21a on the resin diaphragm 21 side are brought into close contact with each other, and laser light is applied to the contact portion. To form a laser weld 9. Contrary to this configuration, a protrusion is provided on the lower surface of the resin diaphragm 21, the upper surface on the case body 10 side is a flat surface flush with the non-welded region 13, and the surface of the protrusion is in close contact with the flat upper surface of the case body. Then, the close contact portion is laser welded to form a laser welded portion. Further, in the pump 1A, the facing surface of the resin diaphragm 21 and the case body 10 may be a flat surface without forming a ridge, and a laser welding portion may be formed around the pump chamber.

  Further, the metal diaphragm 25 has the movable portion 28 and the fixed portion 29 with the slit 26 interposed therebetween, but may have a simple disk shape without the fixed portion 29. In this case, since the slit is not formed, an excess of the adhesive leaks from the outer peripheral edge, and although there is a possibility of interfering with the holding jig used at the time of laser welding, there is a diaphragm having a configuration in which a metal diaphragm is joined to a resin diaphragm. The effects it has (exact pump action due to high rigidity, etc.) are fully exhibited.

It is a perspective view of the diaphragm pump which concerns on one Embodiment of this invention. It is sectional drawing of the same diaphragm pump. It is a disassembled perspective view of the same diaphragm pump. It is an exploded sectional view of the same diaphragm pump. It is a top view of the metal diaphragm with which the diaphragm pump is provided. It is sectional drawing at the time of (a) inhalation and (b) discharge of the diaphragm pump. (A) is sectional drawing explaining the effect of the slit formed in the metal diaphragm of one Embodiment, (b) is sectional drawing explaining the problem in case the slit is not formed in the metal diaphragm. It is sectional drawing of the diaphragm pump which concerns on other embodiment of this invention. It is sectional drawing at the time of (a) inhalation and (b) discharge of the diaphragm pump of other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1A, 1B ... Diaphragm pump 9 ... Laser welding part 10 ... Case main body 11 ... Recess (pump chamber)
12a ... Upper surface of the ridge (joint surface on the case body side)
DESCRIPTION OF SYMBOLS 13 ... Non-welding area | region 16 ... Inhalation flow path of case main body 17 ... Discharge flow path of case main body 10 21 ... Resin diaphragm 21a ... Opposite surface (diaphragm side joining surface)
25 ... Metal diaphragm 26 ... Slit (vacant)
27 ... movable part 28 ... fixed part 30 ... piezoelectric element (diaphragm driving means)

Claims (4)

A plate-shaped case body;
A pump chamber consisting of a recess formed on one side of the case body;
A suction passage and a discharge passage for the fluid formed in the case body and communicating with the pump chamber;
A resin diaphragm disposed opposite to one side of the case body, and covering the pump chamber and welded to one side of the case body,
In a diaphragm pump comprising a diaphragm driving means for driving the resin diaphragm to change the substantial volume of the pump chamber,
Around the pump chamber on one side of the case body, a flat case body side joining surface is formed at a location separating the non-welded region from the periphery of the pump chamber,
On the surface facing the case body of the resin diaphragm, a flat diaphragm side joining surface that is in close contact with the case body side joining surface is formed,
The diaphragm pump, wherein the case body side joining surface and the diaphragm side joining surface are brought into close contact with each other, and at least a part of the contact portion is joined by laser welding.   A metal diaphragm is overlapped and joined to one surface of the resin diaphragm, a peripheral edge of the pump chamber is disposed inside an outer peripheral edge of the metal diaphragm, and a laser weld portion of the resin diaphragm to the case body is provided in a pump chamber. The diaphragm pump according to claim 1, wherein the diaphragm pump is disposed between a peripheral edge of the metal diaphragm and an outer peripheral edge of the metal diaphragm. A plate-shaped case body;
A diaphragm having a two-layer structure in which a metal diaphragm is joined to one side of a resin diaphragm, arranged opposite to one side of the case body, and a resin diaphragm is welded and joined to one side of the case body;
A pump chamber formed between the diaphragm and the case body;
A suction passage and a discharge passage for the fluid formed in the case body and communicating with the pump chamber;
In a diaphragm pump comprising diaphragm driving means for driving the diaphragm and changing a substantial volume of the pump chamber,
The case body and the resin diaphragm are opposed to each other, and a flat case body side joining surface and a resin diaphragm side joining surface that are in close contact with each other are formed around the pump chamber. In addition to being adhered, at least a part of the adhesion portion is joined by laser welding,
Further, the laser welding portion is disposed inside the outer peripheral edge of the metal diaphragm.   The metal diaphragm has a movable part deformed by the diaphragm driving means and a fixed part formed around the movable part, and a void is formed between the movable part and the fixed part. 4. The diaphragm pump according to claim 2, wherein an outer peripheral edge of the metal diaphragm is an outer peripheral edge of the movable portion, and the metal diaphragm is bonded to the resin diaphragm with an adhesive.

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