JP6967780B2 - Diaphragm pump - Google Patents

Description

The present invention relates to a diaphragm pump.

Generally, in a diaphragm pump having a pair of pump chambers and discharging a fluid by reciprocating the center rod, the working fluid is alternately supplied to the pair of working fluid chambers so that the center rod reciprocates. .. As such a diaphragm pump, a disc member connecting the diaphragm and the center rod comes into contact with the detector (see, for example, Patent Document 1). In the diaphragm pump described in Patent Document 1, the disk member abuts on the detector when the working fluid chamber contracts, and the detector moves to switch the fluid supply destination.

Japanese Unexamined Patent Publication No. 2014-214629

In a diaphragm pump as described in Patent Document 1, it is preferable to improve the detection sensitivity by the detector, that is, to reliably move the detector only when the disk member comes into contact with the diaphragm pump. Therefore, a configuration is conceivable in which the detector is urged toward the disc member and a compression spring is provided so as to protrude toward the disc member from the tip of the detector.

In such a configuration, the detector is pressed after the compression spring is compressed by the disc member. At this time, the detector does not move even if a force equal to or less than the urging force is applied to the detector. Further, when the disc member comes into contact with the detector, not only the pressing force of the disc member but also the restoring force of the compression spring is applied to the detector, so that the detector can be easily moved. In this way, the detector can be reliably moved only when the disc member comes into contact with the disc member, and the detection sensitivity can be improved.

However, when the detector is provided with the compression spring in this way, the compression spring expands and contracts, so that it may repeatedly come into contact with the detector and break. In particular, since the compression spring protrudes from the tip of the detector, it easily comes into contact with the tip of the detector. If the compression spring breaks, the above-mentioned effect of improving the detection sensitivity cannot be obtained.

An object of the present invention is to provide a diaphragm pump capable of sustaining an improvement in detection sensitivity.

The diaphragm pump of the present invention has a supply means for supplying a fluid to a pair of working fluid chambers, a diaphragm portion that separates the feed fluid chamber and the working fluid chamber, and a center that is connected to the pair of the diaphragm portions and reciprocates. The detection device is a diaphragm pump including a rod, a detection device for detecting the operation of the diaphragm portion, and a switching device for switching the fluid supply destination of the supply means according to the operation of the diaphragm portion. A rod-shaped detector that moves by contacting the contact portion of the diaphragm portion when the working fluid chamber contracts, an urging means that urges the detector toward the contact portion, and the detector. A compression spring that compresses and deforms before the contact between the contact portion and the detector, and a guide member that guides the compression spring along the moving direction of the detector . The guide member is formed in a tubular shape and is arranged between the detector and the compression spring, and the urging means makes the space behind the detector higher than that of the working fluid chamber. Therefore, the detector has a valve function for partitioning the working fluid chamber and the rear side space in a state where the detector does not abut on the contact portion, and the guide member has a valve function along the axial direction thereof. It is characterized in that a fluid passage portion through which a fluid can pass is formed.

According to the present invention as described above, by providing the guide member, the compression spring expands and contracts along the moving direction of the detector, and it is suppressed that the compression spring expands and contracts diagonally with respect to the moving direction. This makes it difficult for the compression spring and the detector to come into contact with each other, and it is possible to suppress the breakage of the compression spring. Therefore, the improvement of the detection sensitivity can be sustained by providing the urging means and the compression spring. Further, according to such a configuration, the compression spring is less likely to come into contact with the detector, and the breakage of the compression spring can be further suppressed. Further, according to such a configuration, when the detector is urged by the pressure difference and the detector has a valve function, when the contact portion abuts on the detector and the valve is opened, the rear side Fluid flows from the space into the working fluid chamber. At this time, if a fluid passage portion is formed in the guide member, the flow of the fluid is less likely to be obstructed by the guide portion.

Further, in the diaphragm pump of the present invention, it is preferable that the guide member has a dropout control portion that regulates the dropout to the contact portion side by engaging with a part of the detector or the compression spring. According to such a configuration, when the contact portion moves away from the detector and the detector is moved by the urging force of the urging means or the compressed compression spring is restored, this momentum causes it. It is possible to prevent the guide member from falling off from the detector or the compression spring.

Further, in the diaphragm pump of the present invention, it is preferable that the guide member has a flange portion that covers the tip of the compression spring. According to such a configuration, the tip of the compression spring is protected by the flange portion, the contact portion and the tip of the compression spring do not come into direct contact with each other, and damage to the compression spring can be suppressed.

According to the diaphragm pump of the present invention as described above, the compression spring expands and contracts in the moving direction of the detection element by providing the guide member, so that the improvement of the detection sensitivity can be sustained.

It is sectional drawing which shows the pump main body of the diaphragm pump which concerns on embodiment of this invention. It is sectional drawing which shows the diaphragm pump. It is a partial cross-sectional view which shows the detection device of the diaphragm pump. It is sectional drawing which shows the guide member in the detection apparatus of the 1st modification of this invention. It is a perspective view which shows the guide member in the detection device of the 2nd modification of this invention. It is a perspective view which shows the guide member in the detection device of the 3rd modification of this invention. It is a partial cross-sectional view which shows the guide member in the detection device of the 4th modification of this invention.

Hereinafter, each embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, the diaphragm pump 1 of the present embodiment includes a pump main body 2, a switching device 3, and a supply means (not shown), and uses, for example, a gas such as air as a working fluid to prepare a liquid or the like. It discharges fluid. In the present embodiment, the vertical direction of the pump body 2 is the Z direction, and the two directions substantially orthogonal to the Z direction are the X direction and the Y direction, respectively. The pump main body 2 may be installed so that the Z direction is along the vertical direction, or may be installed with a slight inclination.

The pump main body 2 includes a pair of pump units 21A and 21B, a center rod 22, and a detection device 4. The pair of pump portions 21A and 21B are formed symmetrically with each other and include a diaphragm body 23 connected to the center rod 22, an inlet side check valve 24, and an outlet side check valve 25.

The diaphragm body 23 is fixed to the center rod 22 by being sandwiched by the discs 26 and 27. The pump main body 2 has a housing 28 and a main body portion 29 housed in the housing 28 and through which the center rod 22 penetrates, and the diaphragm body 23 has a space between the housing 28 and the main body portion 29. Is partitioned into a pump chamber A1 and a working fluid chamber A2. The diaphragm body 23 and the discs 26 and 27 form the diaphragm portion 230. Of the diaphragm portion 230, the disk 26 arranged in the working fluid chamber A2 serves as a contact portion that abuts on the detector 41 described later.

When the center rod 22 extending along the X direction moves in the X direction, the diaphragm portion 230 also moves, and when the pump chamber A1 expands (the working fluid chamber A2 contracts) in one pump portion 21A, the other pump The pump chamber A1 contracts in the portion 21B (the working fluid chamber A2 expands). Further, when the pump chamber A1 contracts in one pump portion 21A, the pump chamber A1 expands in the other pump portion 21B.

When the pump chamber A1 expands and is depressurized, the inlet side check valve 24 opens and the fluid is introduced into the pump chamber A1 from the inlet side opening 201. On the other hand, when the pump chamber A1 contracts and is boosted, the outlet-side check valve 25 opens and the fluid in the pump chamber A1 is discharged to the outside from the outlet-side opening 202.

As will be described later, the switching device 3 alternately supplies the working fluid to the working fluid chambers A2 of the pumps 21A and 21B, so that the center rod 22 reciprocates in the X direction and pumps the pumps 21A and 21B. The chamber A1 alternately expands and contracts repeatedly. As a result, the fluid introduced from the inlet side opening 201 is discharged from the outlet side opening 202, and the fluid is supplied to the outside.

As shown in FIG. 3, the detection device 4 has a detector 41, a compression spring 42, a guide member 43, and an accommodating portion 44.

The detector 41 is formed of a metal member such as stainless steel into a rod shape extending along the X direction, is housed in a housing section 44 formed in the main body 29 as described later, and reciprocates along the X direction. .. The detector 41 has a constricted portion (a portion having an outer diameter smaller than other portions) 411 in the vicinity of the tip, and the surface of the step portion 412 on the tip side facing the base end side is engaged. It becomes a stop surface 413.

The compression spring 42 is a coil spring whose axial direction is the X direction, and a part of the detector 41 on the tip end side is inserted through the compression spring 42. The base end portion 421 of the compression spring 42 is fixed to the detector 41, and the tip end portion 422 thereof is arranged closer to the disk 26 than the tip end 414 of the detector 41. That is, the compression spring 42 is provided so as to project toward the disk 26 from the detector 41.

The guide member 43 is formed in a cylindrical shape with a resin such as polyethylene, and is arranged between the detector 41 and the compression spring 42. The guide member may be tubular or square tubular. The inner diameter of the guide member 43 is substantially equal to or slightly larger than the outer diameter of the portion of the detector 41 arranged inside the guide member 43 (the front and rear portions of the constricted portion 411), and has a rod shape extending in the X direction. It is regulated that the axial direction of the cylindrical guide member 43 is tilted with respect to the detector 41. Further, the outer diameter of the guide member 43 is substantially equal to or slightly smaller than the inner diameter of the compression spring 42, and the axial direction of the compression spring 42 is regulated to be inclined with respect to the axial direction of the guide member 43. Therefore, the compression spring 42 is prevented from being inclined in the axial direction with respect to the X direction, and expands and contracts along the X direction. That is, the guide member 43 guides the compression spring 42 so as to expand and contract along the moving direction (X direction) of the detector 41.

The guide member 43 has a locking projection 431 on its inner peripheral surface. The locking projection 431 may be continuous in the circumferential direction, or may be provided only in a part of the circumferential direction. The locking projection 431 has a locked surface facing the working fluid chamber A2 side, and the locked surface of the locking projection 431 and the locking surface 413 of the detector 41 come into contact with each other. The guide member 43 is restricted from moving toward the working fluid chamber A2 with respect to the detector 41. That is, the locking projection 431 functions as a dropout control unit that regulates the guide member 43 from falling off to the disk 26 side by engaging with a part of the detector 41.

Such a guide member 43 is assembled to the detector 41 by inserting the detector 41 through an opening on the opposite side of the working fluid chamber A2. The locking projection 431 has a tapered portion on a surface facing the opposite side of the working fluid chamber A2, so that the portion of the detector 41 on the tip side of the constricted portion 411 can be overcome.

The accommodating portion 44 is formed in the main body portion 29 and is a cylindrical hole-shaped recess as viewed from the working fluid chamber A2, and compressed air is always supplied by the supply means as described later. A valve seat portion is provided near the opening of the accommodating portion 44, and the space (rear side space) A3 in the accommodating portion 44 operates when the O-ring 415 provided on the outer peripheral surface of the detector 41 is seated. It is partitioned from the fluid chamber A2.

Compressed air is supplied to the rear side space A3 and the pressure becomes higher than that of the working fluid chamber A2, so that the detector 41 is urged to the working fluid chamber A2 side (disk 26 side). That is, the supply means and the accommodating portion 44 function as urging means. Further, the detector 41 is provided with an O-ring 415 seated on the valve seat portion, so that the working fluid chamber A2 and the rear space A3 can be partitioned and has a valve function.

As shown in FIG. 2, the switching device 3 includes a spool 31 having two constricted portions and a cylindrical housing 32 for accommodating the spool 31. The housing 32 has a working fluid supply port 321 and a working fluid discharge port 322, a first communication port 323 communicating with the working fluid chamber A2 of one pump part 21A, and a working fluid chamber A2 of the other pump part 21B. A second communication port 324 communicating with the pump unit 21A, a third communication port 325 communicating with the rear side space A3 of one pump unit 21A, and a third communication port 325 communicating with the rear side space A3 of the one pump unit 21A. A fourth communication port 326 communicating with the rear side space A3 of the other pump portion 21B is formed.

The spool 31 communicates the working fluid supply port 321 and one of the communication ports 323 and 324, and communicates the other of the communication ports 323 and 324 with the working fluid discharge port 322. That is, the working fluid is supplied to the working fluid chamber A2 communicating with the working fluid supply port 321 and expands, and the working fluid is discharged from the working fluid chamber A2 communicating with the working fluid discharge port 322 and contracts.

When the pump chamber A1 expands (the working fluid chamber A2 contracts) as described above, the disk 26 abuts on the detector 41 and the detector 41 moves backward, the working fluid chamber A2 provided with the detector 41 , One of the switching chambers 327 and 328 formed on both sides of the spool 31 in the Z direction communicates with each other. The contracting working fluid chamber A2 is connected to the working fluid discharge port 322, and the pressure is lower than that when expanding. Therefore, the switching chamber communicating with the contracting working fluid chamber A2 has a lower pressure than the other switching chamber, and the spool 31 moves in the Z direction toward the low pressure switching chamber side. As a result, the communication ports 323 and 324 that communicate with the working fluid supply port 321 or the working fluid discharge port 322 are switched, and the working fluid is supplied to the working fluid chamber A2 that has been contracted until then. In this way, the switching device 3 switches the fluid supply destination of the supply means according to the operation of the diaphragm unit 230.

The above operation will be described with a specific example. As shown in FIG. 2, the spool 31 is located at the first position (upper position in the Z direction), the working fluid supply port 321 and the second communication port 324 communicate with each other, and the working fluid discharge port 322 and the first communication port 323 communicate with each other. Upon communication, the working fluid is supplied to the working fluid chamber A2 in the other pump part 21B, and the working fluid in the working fluid chamber A2 in the one pump part 21A is discharged. That is, the center rod 22 moves toward the other pump portion 21B side. When the center rod 22 moves by a predetermined distance, the disk 26 comes into contact with the detector 41 at one of the pump portions 21A.

As a result, the working fluid chamber A2 of one of the pump portions 21A and the switching chamber 327 communicate with each other, and the switching chamber 327 has a lower pressure than the switching chamber 328. Due to this pressure difference, the spool 31 moves toward the switching chamber 327 side and is positioned at the second position (lower position in the Z direction), the working fluid supply port 321 and the first communication port 323 communicate with each other, and the working fluid discharge port. The 322 and the second communication port 324 will communicate with each other.

The third communication port 325 and the fourth communication port 326 communicating with the rear space A3 always communicate with the working fluid supply port 321 regardless of the position of the spool 31. As a result, compressed air is supplied to the rear space A3.

Here, the details of the operation of each part in the detection device 4 will be described. First, since compressed air is supplied to the rear space A3, the pressure of the rear space A3 is higher than that of the working fluid chamber A2, and the detector 41 is urged toward the working fluid chamber A2 by the pressure difference to close the valve. It becomes a state. When the working fluid chamber A2 contracts, the disc 26 first contacts the compression spring 42. As the disk 26 moves closer to the main body 29, the compression spring 42 is compressed.

When the disc 26 comes into contact with the tip 414 of the detector 41, the detector 41 is pushed by the disc 26 and starts moving against the urging force due to the pressure difference. The restoring force generated in the compression spring 42 before the disc 26 comes into contact with the tip 414 of the detector 41 is set to be smaller than the urging force due to the pressure difference, and the disc 26 comes into contact with the tip 414 of the detector 41. The detector 41 does not start moving before.

When the detector 41 starts moving, not only the pressing force of the disk 26 but also the restoring force of the compression spring is applied to the detector 41. Further, when the detector 41 moves to open the valve, the pressure difference between the working fluid chamber A2 and the rear space A3 decreases, and the urging force becomes smaller. As a result, the detector 41 starts moving vigorously. As described above, since the detection device 4 includes the urging means and the compression spring 42, the detector 41 moves reliably only when the disc 26 comes into contact with the disc 26, and high detection sensitivity can be obtained.

Further, when the working fluid chamber A2 expands, the disk 26 moves away from the detector 41, but since compressed air is always supplied to the rear space A3, it is different from the working fluid chamber A2. The detector 41 moves to the disk 26 side due to the pressure difference and closes the valve.

According to the present embodiment as described above, there are the following effects. That is, by providing the guide member 43, the compression spring 42 expands and contracts along the X direction, which is the moving direction of the detector 41, and is suppressed from expanding and contracting diagonally with respect to the X direction. As a result, the compression spring 42 and the detector 41 are less likely to come into contact with each other, and breakage of the compression spring 42 can be suppressed. Therefore, the improvement of the detection sensitivity can be sustained by providing the urging means and the compression spring 42.

Further, since the guide member 43 is arranged between the detector 41 and the compression spring 42, the compression spring 42 is less likely to come into contact with the detector 41, and the breakage of the compression spring 42 can be further suppressed. ..

Further, since the guide member 43 has the locking projection 431 as a dropout restricting portion, the disk 26 moves away from the detector 41, and when the detector 41 moves due to the atmospheric pressure difference, the guide member 43 due to this momentum. Can be prevented from falling off from the detector 41.

Although the present invention has been described above with reference to embodiments, the present invention is not limited to the above-described embodiment, and includes other configurations and the like that can achieve the object of the present invention, and modifications and the like as shown below. Is also included in the present invention.

For example, in the above embodiment, the guide member 43 has a locking projection 431 so as not to fall off from the detector 41, that is, the guide member 43 is attached to the detector 41. As shown in the above, the guide member 45 may be attached to the compression spring 42. The guide member 45 has a protrusion 451 as a dropout restricting portion on the outer peripheral surface thereof, and the protrusion 451 is arranged between the coils of the compression spring 42 to engage with the guide member 45. That is, the guide member 45 is attached to the compression spring 42 so that the guide member 45 is prevented from falling off. In such a configuration in which the guide member is attached to the compression spring, the detector does not have to have a constricted portion.

Further, in the above-described embodiment, the guide member 43 has a cylindrical shape, but a flange portion 452 may be provided at the tip of the cylinder as in the guide member 45 shown in FIG. The flange portion 452 is formed in an annular plate shape extending radially outward from the tip of the cylinder, and covers the tip of the compression spring 42. According to such a configuration, the tip of the compression spring 42 is protected by the flange portion 452, the disc 26 and the tip of the compression spring 42 do not come into direct contact with each other, and damage to the compression spring 42 can be suppressed.

Further, the guide member may or may not be formed in the shape of a square cylinder. For example, the guide member may be formed in a C-shaped cross section and may have a shape extending in the X direction.

Further, in the above embodiment, the compression spring 42 is assumed to protrude toward the disk 26 from the detector 41, but the compression spring does not have to protrude from the tip of the detector. As shown in FIG. 4, in the configuration in which the guide member 45 is attached to the compression spring 42, the compression spring 42 is compressed and deformed when the disk comes into contact with the guide member 45. In such a configuration, the compression spring 42 can be compressed and deformed before the contact between the disk and the detector even if the compression spring 42 does not protrude from the tip of the detector.

Further, the guide member may be formed with a fluid passing portion through which the fluid can pass along the axial direction thereof. For example, as shown in FIG. 5, the guide member 46 may have a recess 461 as a fluid passage portion formed on the outer peripheral surface. In the illustrated example, four recesses 461 are formed, and these recesses 461 extend continuously across both ends of the guide member 46 in the axial direction. The outer diameter of the outer peripheral surface of the guide member 46 passing through the portion where the recess 461 is not formed is substantially equal to or slightly smaller than the inner diameter of the compression spring 42.

Further, as shown in FIG. 6, the guide member 47 may have a recess 471 as a fluid passage portion formed on the inner peripheral surface. In the illustrated example, four recesses 471 are formed, and these recesses 471 extend continuously over both ends in the axial direction of the guide member 47. The inner diameter of the inner peripheral surface of the guide member 47 passing through the portion where the recess 471 is not formed is substantially equal to or slightly larger than the outer diameter of the portion of the detector 41 before and after the constricted portion 411.

Further, when the guide member has a sufficient wall thickness, a through hole extending at both ends in the axial direction may be formed as a fluid passage portion.

Further, in the above embodiment, the guide member 43 is arranged between the detector 41 and the compression spring 42, but as shown in FIG. 7, the guide member 48 is arranged outside the compression spring 42. It may be configured as such. In the configuration shown in FIG. 7, a cylindrical guide wall 291 fixed to the main body 29 and extending along the X direction is arranged outside the detector 41B and the compression spring 42. The outer diameter of the cylindrical guide member 48 is substantially equal to or slightly smaller than the inner diameter of the guide wall 291 so that the guide member 48 moves in the X direction along the guide wall 291. The guide member 48 has a protrusion 481 as a dropout restricting portion on its inner peripheral surface, and can be attached to the compression spring 42. Further, the inner diameter of the guide member 48 is substantially equal to or slightly larger than the outer diameter of the compression spring 42.

Even in the configuration in which the guide member 48 is arranged outside the compression spring 42 in this way, the compression spring 42 can be expanded and contracted along the X direction to suppress breakage, as in the above embodiment. Therefore, the improvement of the detection sensitivity can be sustained by providing the urging means and the compression spring 42.

In addition, the best configuration, method, and the like for carrying out the present invention are disclosed in the above description, but the present invention is not limited thereto. That is, the present invention is primarily illustrated and described with respect to a particular embodiment, but without departing from the scope of the technical idea and object of the present invention, with respect to the embodiments described above. Various modifications can be made by those skilled in the art in terms of material, quantity, and other detailed configurations. Therefore, the description limiting the shapes, materials, etc. disclosed above is merely an example for facilitating the understanding of the present invention, and does not limit the present invention. Therefore, those shapes, materials, etc. The description by the name of the member excluding a part or all of the limitation such as is included in the present invention.

1 Diaphragm pump 22 Center rod 230 Diaphragm part 26 Disc (contact part)
3 Switching device 4 Detection device 41 Detector 42 Compression spring 43, 45-48 Guide member 431 Locking protrusion (drop-off control part)
452 Flange part 461, 471 Recessed part (fluid passage part)

Claims (3)

A supply means for supplying fluid to a pair of working fluid chambers, a diaphragm portion that separates the fluid feeding chamber and the working fluid chamber, a center rod connected to the pair of the diaphragm portions and reciprocating, and the diaphragm portion. A diaphragm pump including a detection device for detecting an operation and a switching device for switching a fluid supply destination of the supply means according to the operation of the diaphragm unit.
The detection device includes a rod-shaped detector that moves by contacting the contact portion of the diaphragm portion when the working fluid chamber contracts, and an urging means that urges the detector toward the contact portion. A compression spring that is compressed and deformed before the contact between the contact portion and the detector when the detector is inserted, and a guide member that guides the compression spring along the moving direction of the detector. and, with a,
The guide member is formed in a cylindrical shape and is arranged between the detector and the compression spring.
The urging means makes the space behind the detector higher than that of the working fluid chamber.
The detector has a valve function for separating the working fluid chamber and the rear side space in a state where the detector does not abut on the contact portion.
A diaphragm pump characterized in that the guide member is formed with a fluid passing portion through which a fluid can pass along its axial direction. The diaphragm pump according to claim 1, wherein the guide member has a dropout restricting portion that regulates the dropout to the contact portion side by engaging with a part of the detector or the compression spring. .. The diaphragm pump according to claim 1 or 2 , wherein the guide member has a flange portion that covers the tip of the compression spring.

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