JP7449100B2 - Diaphragm pump - Google Patents

Description

The present invention relates to a diaphragm pump including a diaphragm having a cup-shaped pump portion.

As a conventional diaphragm pump, there is one described in Patent Document 1, for example. The diaphragm pump disclosed in Patent Document 1 includes a diaphragm that converts rotation of a motor into reciprocating motion and transmits the reciprocating motion as driving force. This diaphragm has a cup-shaped pump part to which driving force is transmitted, and a plate-shaped clamping part provided around the pump part so that the pump part opens. The holding part is held between a first wall member that cooperates with the pump part to form a pump chamber, and a second wall member in which a hole into which the pump part is inserted is formed.

By the way, in this type of diaphragm pump, as shown in FIG. 6, an engagement consisting of a concave part 4 and a convex part 5 that engage with each other at the contact part between the clamping part 2 of the diaphragm 1 and the second wall member 3 is used. A structure 6 is often provided. In FIG. 6, reference numeral 7 indicates the pump portion of the diaphragm 1, and reference numeral 8 indicates the first wall member. A concave portion 4 is formed in the clamping portion 2 of the diaphragm 1 shown in FIG. 6, and a convex portion 5 is formed in the second wall member 3. The reason why the engagement structure 6 is provided in this way is that when the pump part 7 expands, the end part 2a of the clamping part 2 is pulled in the direction shown by the arrow by the pump part 7, which is shown by the two-dot chain line in FIG. This is to prevent the pump from expanding due to elastic deformation and being drawn into the pump chamber 9 from its normal position.

When the end portion 2a of the clamping portion 2 is drawn into the pump chamber 9, the following two problems occur. The first problem is that the end 2a of the clamping part 2 and the piston 7a forming the bottom of the pump part 7 may come into contact with each other during the contraction stroke of the pump part 7. The second problem is that the relatively thin rubber material forming the pump section 7 is bent excessively during the contraction stroke of the pump section 7, and the rubber materials come into contact with each other and are likely to wear out.

In recent years, there has been a demand for further miniaturization of the diaphragm pump configured as described above.

JP 2018-112127 Publication

However, with the conventional diaphragm pump configured as described above, further miniaturization could not be achieved. The reason for this is that if the thickness of the holding part 2 of the diaphragm 1 is made even thinner, the thickness of the part of the engaging structure 6 that forms the recessed part 4 will become extremely thin, and there is a risk that it will break. If the concave portion 4 is formed shallowly and the convex portion 5 is formed low in order to avoid such problems, the engagement structure 6 will no longer function, and it will become impossible to prevent the phenomenon in which the clamping portion 2 is drawn into the pump chamber 9. It ends up.

An object of the present invention is to provide a diaphragm pump that can be further downsized while preventing the pinching portion of the diaphragm from being drawn into the pump chamber.

A diaphragm pump according to the present invention includes a diaphragm having a cup-shaped pump part and a plate-shaped holding part provided around the pump part so that the pump part opens; a first wall member overlapping the diaphragm so as to cover an opening of the diaphragm and forming a pump chamber in cooperation with the pump section; and a hole into which the pump section is inserted; a second wall member that clamps the clamping portion of the diaphragm in cooperation with the second wall member; and a second wall member that is connected to the bottom of the pump portion and moves the bottom toward and away from the first wall member, so that the pump a drive body that increases or decreases the volume of the chamber; a suction passage formed through the first wall member through which fluid flows toward the pump chamber as the volume of the pump chamber increases; and the first wall a discharge passage formed through a member and through which fluid discharged from the pump chamber flows when the volume of the pump chamber is reduced; a suction valve that opens and closes the suction passage; and a discharge valve that opens and closes the discharge passage. The first wall member has a protruding wall that protrudes toward the inside of the pump section and fits into the opening of the pump section.

In the diaphragm pump of the present invention, the protruding wall may be formed in a disc shape, and the suction passage and the discharge passage may be formed to penetrate the protruding wall.

In the diaphragm pump of the present invention, the protruding wall is formed in a cylindrical shape on a plate-shaped portion of the first wall member that constitutes the wall of the pump chamber, and the suction passage and the discharge passage are arranged in the first wall member. It may be formed to penetrate through a portion of the plate-shaped portion surrounded by the projecting wall.

In the diaphragm pump of the present invention, the opening portion of the pump portion has an annular recess formed such that the opening diameter is larger than the bottom side of the pump portion, and the protruding wall is arranged in the recess. It may be fitted to the

In the present invention, since the projecting wall of the first wall member restricts the movement of the clamping part of the diaphragm, it is possible to prevent the clamping part of the diaphragm from being drawn into the pump chamber without using an engagement structure. Therefore, according to the present invention, it is possible to provide a diaphragm pump that can be further downsized while preventing the pinching portion of the diaphragm from being drawn into the pump chamber.

FIG. 1 is a sectional view of a diaphragm pump according to a first embodiment. FIG. 2 is an enlarged cross-sectional view of a part of the diaphragm pump. FIG. 3 is an enlarged cross-sectional view of the main part. FIG. 4 is a cross-sectional view of a diaphragm pump according to a second embodiment. FIG. 5 is an enlarged cross-sectional view of the main part. FIG. 6 is an enlarged cross-sectional view of a part of a conventional diaphragm pump.

(First embodiment)
Hereinafter, one embodiment of a diaphragm pump according to the present invention will be described in detail with reference to FIGS. 1 to 3.
The diaphragm pump 11 shown in FIG. 1 is attached to a motor 12 located at the lowest position in FIG. 1, and is driven and operated by this motor 12 to suck in and discharge air.
The diaphragm pump 11 includes a drive section 13 fixed to a motor 12 and a valve section 14 attached to the drive section 13.

<Configuration of drive unit>
The drive unit 13 includes a drive unit housing 15 fixed to the motor 12 and a drive mechanism 16 housed within the housing 15.
The housing 15 is formed into a cylindrical shape with a bottom and is fixed to the motor 12 with a fixing bolt (not shown).
The drive mechanism 16 includes a crank body 18 attached to the rotating shaft 17 of the motor 12, a drive body 20 connected to the crank body 18 via a drive shaft 19, and the like.

The drive shaft 19 is inclined in a predetermined direction with respect to the rotation shaft 17.
The drive body 20 includes a cylindrical shaft portion 21 that is rotatably supported by the drive shaft 19 and a plurality of arm portions 22 that protrude outward in the radial direction from the shaft portion 21 .
The arm portion 22 is provided for each pump portion 24 of a diaphragm 23, which will be described later, and extends radially outward from the shaft portion 21.

A through hole 22a is bored in the arm portion 22. A connecting piece 25 of the diaphragm 23 is inserted into the through hole 22a. The connecting piece 25 is fixed to the arm portion 22 while passing through the arm portion 22 .
According to this drive mechanism 16, the crank body 18 and the drive shaft 19 rotate together with the rotation shaft 17 of the motor 12, so that the drive body 20 swings, and the pump portion 24 of the diaphragm 23 repeatedly contracts and expands. .

<Configuration of valve part>
As shown in FIG. 2, the valve section 14 includes a diaphragm 23 connected to the drive body 20, a diaphragm holder 31 attached to the opening of the drive section housing 15, and a diaphragm 23 between the diaphragm holder 31 and the diaphragm 23 connected to the drive body 20. The diaphragm housing 32 is attached to a diaphragm holder 31 in a state where the diaphragm housing 32 is sandwiched therebetween, and a cover 34 is attached to the diaphragm housing 32 via a partition wall 33. The diaphragm holder 31, the diaphragm housing 32, and the cover 34 are formed into a circular shape when viewed from the axial direction of the motor 12.

<Description of diaphragm holder>
The diaphragm holder 31 is formed in a disc shape that can be connected to the drive unit housing 15, and has a plurality of through holes. These through holes include a cylinder hole 35 for each pump section 24 into which a pump section 24 of a diaphragm 23 (described later) is inserted, and a suction hole 37 that is opened and closed by an umbrella-shaped suction valve 36. One ends of the cylinder hole 35 and the suction hole 37 open into a housing interior space S surrounded by the drive section housing 15 and the diaphragm holder 31, respectively. The housing interior space S is communicated with the atmosphere through a ventilation hole (not shown).
The other end of the suction hole 37 opens into a circular recess 38 that accommodates the suction valve 36. The suction valve 36 is made of a rubber material and has a valve body 36a that opens and closes the opening of the suction hole 37.

<Explanation of diaphragm>
The diaphragm 23 has a plurality of cup-shaped pump parts 24 that open toward the diaphragm housing 32, and a plate-shaped clamping part 41 provided around the pump part 24 so that the pump part 24 opens. There is.
The pump parts 24 are provided at positions dividing the diaphragm 23 into a plurality of parts in the circumferential direction of the cylindrical diaphragm holder 31. These pump parts 24 are inserted into cylinder holes 35 formed in the diaphragm holder 31.

The opening portion 24a of the pump portion 24 is closed by a diaphragm housing 32. A pump chamber 42 is formed between the pump section 24 and the diaphragm housing 32.
A piston 43 is provided at the bottom of the cup-shaped pump portion 24, and a connecting piece 25 that protrudes in a direction opposite to the pump chamber 42 is provided. This connecting piece 25 is connected to the driving body 20 of the driving mechanism 16 as described above. Therefore, as the driving body 20 swings, the bottom (piston 43) of the pump section 24 moves toward and away from the diaphragm housing 32, and the volume of the pump chamber 42 increases and decreases.

The holding portion 41 of the diaphragm 23 is held between the diaphragm holder 31 and the diaphragm housing 32. In other words, the diaphragm holder 31 cooperates with the diaphragm housing 32 to clamp the clamping portion 41 of the diaphragm 23 . In this embodiment, the diaphragm housing 32 corresponds to the "first wall member" according to the present invention, and the diaphragm holder 31 corresponds to the "second wall member" according to the present invention. As shown in FIG. 3, a first engagement structure 46 is provided between the diaphragm holder 31 and the diaphragm 23, and includes a protrusion 44 on the diaphragm holder 31 side and a recess 45 on the diaphragm 23 side. Further, a second engagement structure 49 is provided between the diaphragm housing 32 and the diaphragm 23, and includes a convex portion 47 on the diaphragm 23 side and a recess 48 on the diaphragm housing 32 side.

As shown in FIG. 2, a first through hole 51 is formed in a portion of the holding portion 41 of the diaphragm 23 that faces the circular recess 38. As shown in FIG. The first through hole 51 is provided for each pump portion 24 of the diaphragm 23 .

<Description of diaphragm housing>
The diaphragm housing 32 is formed in a plate shape, is stacked on the diaphragm 23 so as to cover the opening portion 24a of the pump section 24, and forms a pump chamber 42 in cooperation with the pump section 24.
The diaphragm housing 32 has a projecting wall 52 that projects toward the inside of the pump section 24 and fits into the opening portion 24a of the pump section 24. The projecting wall 52 according to this embodiment is formed into a disk shape. The outer diameter of the projecting wall 52 is the same as the inner diameter of the opening portion 24a of the pump section 24, or has an outer diameter such that it can be press-fitted into the pump section 24. The thickness of the protruding wall 52 (the length in the axial direction of the motor 12) is thinner than the thickness of the clamping part 41 of the diaphragm 23, and when the pump part 24 is most contracted, the bottom of the pump part 24 (piston 43) and the protruding wall 52 The thickness is such that a predetermined gap is formed between the two.

As shown in FIGS. 2 and 3, the projecting wall 52 has a groove 54 that becomes a part of the suction passage 53 and one end of a second through hole 56 that becomes a part of the discharge passage 55. There is. The suction passage 53 and the discharge passage 55 are formed to penetrate the projecting wall 52. The groove 54 is provided for each pump section 24 of the diaphragm 23, and communicates the inside of the pump chamber 42 with the inside of the first through hole 51 of each pump section 24. The suction passage 53 includes the housing inner space S, the suction hole 37, the circular recess 38, the first through hole 51, and the groove 54.
The other end of the second through hole 56 is connected to an input space 71 formed between the diaphragm housing 32 and a partition wall 33, which will be described later, as shown in FIG.

<Description of bulkhead>
The partition wall 33 is held between the diaphragm housing 32 and the cover 34. Further, the partition wall 33 is formed into a plate shape of an elastic material such as a rubber material containing synthetic rubber, and partitions the diaphragm housing 32 and the cover 34. An input side space 71 is formed between the partition wall 33 and the diaphragm housing 32, and an output side space 72 is formed between the partition wall 33 and the cover 34.

The output side space 72 is partitioned from the input side space 71 by a partition wall 33. This output side space 72 includes an outlet passage 73 provided on one side of the cover 34 (the left side in FIG. 1), a main exhaust passage 74 provided on the other side of the cover 34, and a main exhaust passage 74 provided on the other side of the cover 34. It is connected to a sub-exhaust passage 75 provided in the center of the exhaust gas via a communication passage (not shown). The outlet passage 73 communicates the inside of the recess 34a of the cover 34 with the outside of the cover 34.

A cylindrical valve body 76 that protrudes into the recess 34a of the cover 34 is provided on one side of the partition wall 33 (the left side in FIG. 1). The cylindrical valve body 64 cooperates with the cylinder 77 of the diaphragm housing 32 to form a check valve 78.
The check valve 78 allows air in the input space 71 to flow into the recess 34a of the cover 34 (output space 72). The cylinder 77 constitutes a valve seat of a check valve 78. The cylindrical valve body 76 is formed into a cylindrical shape that covers the outer peripheral surface of the cylinder 77.

The protruding end of the cylindrical valve body 76 is in close contact with the outer peripheral surface of the cylinder 77 over the entire circumferential area. The base end portion of the cylindrical valve body 76 is formed to have a larger diameter than the cylinder 77 . The space between the base end of the cylindrical valve body 76 and the cylinder 77 is a part of the input side space 71. In this embodiment, the discharge passage 55 is constituted by the input side space 71, the space within the recess 34a of the cover 34, the outlet passage 73, and the second through hole 56 of the diaphragm holder 31.

The partition wall 33 is provided with a third through hole 84 through which a valve body 82 of a differential pressure valve 81 (described later) and a columnar projection 83 of the diaphragm housing 32 are passed. The third through hole 84 is connected to the sub exhaust passage 75.
The differential pressure valve 81 is composed of a valve body 82 and a valve seat 85 through which the main exhaust passage 74 opens, and when the valve body 82 moves due to the pressure difference between the input side space 71 and the output side space 72, The main exhaust passage 74 is opened and closed. In this embodiment, this differential pressure valve 81 and the above-mentioned check valve 78 constitute a "discharge valve" in the present invention.
The columnar protrusion 83 inserted into the third through hole 84 is formed so as to be separated from the hole wall surface of the third through hole 84 by a small gap. Therefore, the input side space 71 is open to the atmosphere via the small gap between the columnar projection 83 and the third through hole 84 and the sub-exhaust passage 75 of the cover 34 .

<Explanation of operation>
In the diaphragm pump 11 configured in this way, when the pump portion 24 of the diaphragm 23 expands and the volume of the pump chamber 42 increases, the suction valve 36 opens and the air in the housing inner space S passes through the suction passage 53. It is sucked into the pump chamber 42. In the stroke in which the pump section 24 expands in this manner, the pump section 24 pulls the clamping section 41 of the diaphragm 23 toward the inside of the pump chamber 42 . However, in this embodiment, a projecting wall 52 of the diaphragm housing 32 is fitted into the opening portion 24a of the pump section 24, and this projecting wall 52 restricts the movement of the clamping section 41.
On the other hand, when the pump portion 24 of the diaphragm 23 contracts and the volume of the pump chamber 42 decreases, air within the pump chamber 42 is sent to the input side space 71. As the pressure in the input side space 71 increases, the differential pressure valve 81 closes, and the air in the input side space 71 is supplied to the outlet passage 73 through the check valve 78 and the recess 34a.
When the motor 12 stops, the air in the input side space 71 is discharged to the outside of the pump through the auxiliary exhaust passage 75, so the pressure in the input side space 71 decreases, and the differential pressure valve 81 opens accordingly. By opening the differential pressure valve 81 in this way, the air in the output side space 72, that is, the air in the outlet passage 73, passes through the recess 34a, a communication passage (not shown), and the main exhaust passage 74 to the outside of the pump. is discharged.

In this diaphragm pump 11, since the projecting wall 52 restricts the movement of the clamping part 41 during the expansion stroke of the pump part 24 of the diaphragm 23, the clamping part 41 can be prevented from being drawn into the pump chamber 42. Therefore, according to this embodiment, the clamping part 41 of the diaphragm 23 can be formed thin while preventing the clamping part 41 of the diaphragm 23 from being drawn into the pump chamber 42, so that further miniaturization can be achieved. diaphragm pumps can be provided.

The projecting wall 52 according to this embodiment is formed into a disk shape. The suction passage 53 and the discharge passage 55 are formed to penetrate the projecting wall 52. According to this embodiment, since the substantial volume of the pump chamber 42 is reduced by the volume of the projecting wall 52, the compression ratio can be increased by utilizing the projecting wall 52.

(Second embodiment)
The projecting wall according to the present invention can be constructed as shown in FIGS. 4 and 5. In FIGS. 4 and 5, the same or equivalent members as those explained with reference to FIGS. 1 to 3 are given the same reference numerals, and detailed explanations will be omitted as appropriate. FIG. 5 is an enlarged cross-sectional view of section A in FIG. 4. FIG.
The diaphragm pump 101 shown in FIG. 4 differs from the diaphragm pump 11 according to the first embodiment in the configuration of the valve portion 14. In the valve part 14 of the diaphragm pump 101 according to the second embodiment, a cover 34 is stacked on a diaphragm housing 32, and one discharge fluid is provided in a discharge fluid chamber 102 formed between the diaphragm housing 32 and the cover 34. A valve 103 is provided.

The discharge fluid chamber 102 is connected to the pump chamber 42 via the fourth through hole 104 of the diaphragm housing 32, and is also connected to a hollow portion of a discharge pipe 105 protruding from the cover 34. In this embodiment, a discharge passage 55 is constituted by the fourth through hole 104, the discharge fluid chamber 102, and the hollow portion of the discharge pipe 105.
The discharge valve 103 is made of a rubber material and has a valve body 103a that is in close contact with the wall surface of the diaphragm housing 32 on the discharge fluid chamber 102 side. This valve body 103a closes the opening portion of the fourth through hole 104 so as to be openable and closable.

The fourth through hole 104 is provided in a plate-shaped portion 111 that constitutes the wall of the pump chamber 42 in the diaphragm housing 32 . The plate-shaped portion 111 is provided with a suction valve 112 and a fifth through hole 113 that is opened and closed by a valve body 112a of the suction valve 112. The fourth and fifth through holes 104 and 113 and the suction valve 112 are provided for each pump chamber 42. The fifth through hole 113 communicates the pump chamber 42 with a suction fluid chamber 114 formed in an annular shape within the cover 34 . The suction fluid chamber 114 is connected to the hollow part of the suction pipe 115 of the cover 34 . In this embodiment, the suction passage 53 is constituted by the fifth through hole 113, the suction fluid chamber 114, and the hollow portion of the suction pipe 115.

The plate portion 111 of the diaphragm housing 32 according to this embodiment has a cylindrical projecting wall 121. On the other hand, the opening portion 24a of the pump portion 24 of the diaphragm 23 has an annular recess 122 formed such that the opening diameter is larger than the bottom side of the pump portion 24, as shown in FIG. The cylindrical projecting wall 121 fits into the annular recess 122 . The outer diameter of the projecting wall 121 is the same as the inner diameter of the recess 122, or has an outer diameter such that it can be press-fitted into the recess 122. The height of the protruding wall 121 (length in the axial direction of the motor 12) is thinner than the thickness of the clamping part 41 of the diaphragm 23, and has a height such that the valve body 112a of the suction valve 112 is housed inside the protruding wall 121. It is.

According to this embodiment, even if the suction valve 112 is provided in the pump chamber 42 , the projecting wall 121 can prevent the holding portion 41 from being drawn into the pump chamber 42 . Therefore, by adopting this embodiment, in the diaphragm pump 101 in which the suction valve 112 is provided in the pump chamber 42, the holding portion 41 of the diaphragm 23 can be made thinner, thereby achieving further miniaturization.

The projecting wall 121 according to this embodiment fits into an annular recess 122 formed in the opening portion 24a of the pump portion 24 so that the opening diameter is larger than that at the bottom side of the pump portion 24. Therefore, since the protruding wall 121 is accommodated in the holding portion 41 of the diaphragm 23, the inner diameter of the pump portion 24 can be made smaller than when the annular recess 122 is not formed. As a result, the diameter of the pump portion 24 can be reduced, and a diaphragm pump that is even more compact can be realized.

DESCRIPTION OF SYMBOLS 11, 101... Diaphragm pump, 20... Drive body, 23... Diaphragm, 24... Pump part, 24a... Opening part, 32... Diaphragm housing (1st wall member), 31... Diaphragm holder (2nd wall member), 35... Cylinder hole (hole), 36, 112... Suction valve, 41... Sandwiching part, 42... Pump chamber, 52, 121... Projection wall, 53... Suction passage, 55... Discharge passage, 78... Check valve, 81... Differential pressure valve, 103...Discharge valve, 111...Plate-shaped portion, 122...Recessed portion.

Claims (3)

a diaphragm having a cup-shaped pump part and a plate-shaped holding part provided around the pump part so that the pump part opens;
a first wall member that is stacked on the diaphragm so as to cover the opening of the pump section and cooperates with the pump section to form a pump chamber;
a second wall member having a hole into which the pump portion is inserted, and which cooperates with the first wall member to sandwich the holding portion of the diaphragm;
a drive body that is connected to the bottom of the pump section and increases or decreases the volume of the pump chamber by moving the bottom toward and away from the first wall member;
a suction passage formed through the first wall member, through which fluid flows toward the pump chamber by increasing the volume of the pump chamber;
a discharge passage formed through the first wall member, through which fluid discharged from the pump chamber flows as the volume of the pump chamber decreases;
a suction valve that opens and closes the suction passage;
and a discharge valve that opens and closes the discharge passage,
The first wall member has a protruding wall that protrudes toward the inside of the pump section and fits into the opening of the pump section ,
The projecting wall is formed in a disc shape,
A diaphragm pump characterized in that a groove is formed in an outer circumferential portion of the projecting wall, opening into the pump chamber, extending in the radial direction of the projecting wall, and communicating between the inside and outside of the pump chamber. The diaphragm pump according to claim 1 ,
A diaphragm pump, wherein the suction passage is formed using the groove, and the discharge passage is formed by penetrating the projecting wall. a diaphragm having a cup-shaped pump part and a plate-shaped holding part provided around the pump part so that the pump part opens;
a first wall member that is stacked on the diaphragm so as to cover the opening of the pump section and cooperates with the pump section to form a pump chamber;
a second wall member having a hole into which the pump portion is inserted, and which cooperates with the first wall member to sandwich the holding portion of the diaphragm;
a drive body that is connected to the bottom of the pump section and increases or decreases the volume of the pump chamber by moving the bottom toward and away from the first wall member;
a suction passage formed through the first wall member, through which fluid flows toward the pump chamber by increasing the volume of the pump chamber;
a discharge passage formed through the first wall member, through which fluid discharged from the pump chamber flows as the volume of the pump chamber decreases;
a suction valve that opens and closes the suction passage;
and a discharge valve that opens and closes the discharge passage,
The first wall member has a protruding wall that protrudes toward the inside of the pump section and fits into the opening of the pump section,
The projecting wall is formed in a cylindrical shape on a plate-shaped portion of the first wall member that constitutes the wall of the pump chamber,
The suction passage and the discharge passage are formed through a portion of the plate portion surrounded by the projecting wall ,
The opening part of the pump part has an annular recess formed so that the opening diameter is larger than the bottom side of the pump part,
The diaphragm pump is characterized in that the projecting wall fits into the recess .

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