JP2021116708A - Diaphragm pump - Google Patents

Abstract

To provide a diaphragm pump which enables further downsizing while preventing a phenomenon in which a holding part of a diaphragm is drawn into a pump chamber.SOLUTION: A diaphragm pump includes: a diaphragm 23 having a cup shaped pump part 24 and a plate-like holding part 41; a diaphragm housing 32 (a first wall member) which cooperates with the pump part 24 to form a pump chamber 42; a diaphragm holder 31 (a second wall member) which holds the holding part 41 with the diaphragm housing 32; a driving body 20 connected to a bottom of the pump part 24; a suction passage 53; a discharge passage 55; a suction valve 36; and a discharge valve 103. The diaphragm housing 32 has a protruding wall 52 which protrudes to an interior of the pump part 24 and is fitted in an opening portion 24a of the pump part 24.SELECTED DRAWING: Figure 1

Description

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

As a conventional diaphragm pump, for example, there is one described in Patent Document 1. The diaphragm pump disclosed in Patent Document 1 includes a diaphragm in which the rotation of a motor is converted into a reciprocating motion and transmitted as a driving force. This diaphragm has a cup-shaped pump portion to which a driving force is transmitted, and a plate-shaped holding portion provided around the pump portion so that the pump portion opens. The sandwiching portion is sandwiched and held by a first wall member that forms a pump chamber in cooperation with the pump portion and a second wall member that has a hole into which the pump portion is inserted.

By the way, in this type of diaphragm pump, as shown in FIG. 6, the engagement including the concave portion 4 and the convex portion 5 which are engaged with each other in the contact portion between the holding portion 2 of the diaphragm 1 and the second wall member 3 is engaged. The structure 6 is often provided. In FIG. 6, reference numeral 7 indicates a pump portion of the diaphragm 1, and reference numeral 8 indicates a first wall member. A concave portion 4 is formed in the sandwiching 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 engaging structure 6 is provided in this way is that the end portion 2a of the sandwiching portion 2 is pulled by the pump portion 7 in the direction indicated by the arrow in the process of expanding the pump portion 7, and is shown by a chain double-dashed line in FIG. This is to prevent the pump chamber 9 from being drawn into the pump chamber 9 from a normal position by being stretched due to elastic deformation.

When the end portion 2a of the sandwiching portion 2 is pulled into the pump chamber 9, the following two problems occur. The first problem is that the end portion 2a of the holding portion 2 and the piston 7a forming the bottom of the pump portion 7 may come into contact with each other in the process of contracting the pump portion 7. The second problem is that the relatively thin rubber material forming the pump portion 7 is excessively bent in the process of contracting the pump portion 7, and the rubber materials come into contact with each other and easily wear.

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

Japanese Unexamined Patent Publication No. 2018-112127

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 sandwiching portion 2 of the diaphragm 1 is further reduced, the thickness of the portion forming the recess 4 of the engaging structure 6 becomes extremely thin and there is a risk of tearing. If the concave portion 4 is formed shallowly and the convex portion 5 is formed low in order to avoid such a defect, the engaging structure 6 does not function and the phenomenon that the holding portion 2 is pulled into the pump chamber 9 cannot be prevented. It ends up.

An object of the present invention is to provide a diaphragm pump capable of further miniaturization while preventing a phenomenon in which a holding portion of the diaphragm is drawn into the pump chamber.

The diaphragm pump according to the present invention has a diaphragm having a pump portion formed in a cup shape and having a plate-shaped holding portion provided around the pump portion so that the pump portion opens, and the pump portion. It has a first wall member which is overlapped with the diaphragm so as to cover the opening portion of the above and forms a pump chamber in cooperation with the pump portion, and has a hole into which the pump portion is inserted. The pump is connected to a second wall member that sandwiches the holding portion of the diaphragm in cooperation with the member and the bottom of the pump portion, and the bottom is brought into contact with and separated from the first wall member. A drive body that increases or decreases the volume of the chamber, a suction passage that is formed through the first wall member and allows fluid to flow toward the pump chamber by increasing the volume of the pump chamber, and the first wall. A discharge passage formed through a member and flowing a fluid discharged from the pump chamber by reducing the volume of the pump chamber, 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 portion and fits into the opening portion of the pump portion.

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

In the present invention, in the diaphragm pump, the protruding wall is formed in a cylindrical shape in a plate-shaped portion constituting the wall of the pump chamber in the first wall member, and the suction passage and the discharge passage are the same. It may be formed through a portion of the plate-shaped portion surrounded by the protruding wall.

In the present invention, in the diaphragm pump, the opening portion of the pump portion has an annular recess formed so that the opening diameter is larger than that of the bottom side of the pump portion, and the protrusion wall is the recess. May be fitted to.

In the present invention, since the protruding wall of the first wall member restricts the movement of the holding portion of the diaphragm, it is possible to prevent the holding portion of the diaphragm from being drawn into the pump chamber without using an engaging structure. Therefore, according to the present invention, it is possible to provide a diaphragm pump capable of further miniaturization while preventing the phenomenon that the holding portion of the diaphragm is drawn into the pump chamber.

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

(First Embodiment)
Hereinafter, an 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, is driven by the motor 12 to operate, and sucks and discharges air.
The diaphragm pump 11 includes a drive unit 13 fixed to the motor 12 and a valve unit 14 attached to the drive unit 13.

<Structure of drive unit>
The drive unit 13 is composed of a drive unit housing 15 fixed to the motor 12 and a drive mechanism 16 housed in the housing 15.
The housing 15 is formed in a bottomed cylindrical shape and is fixed to the motor 12 by fixing bolts (not shown).
The drive mechanism 16 includes a crank body 18 attached to a 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 is composed of a columnar shaft portion 21 rotatably supported by the drive shaft 19, and a plurality of arm portions 22 protruding outward in the radial direction from the shaft portion 21.
The arm portion 22 is provided for each pump portion 24 of the 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 engaged in the through hole 22a. The connecting piece 25 is fixed to the arm portion 22 in a state of penetrating 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 repeats contraction and expansion. ..

<Valve configuration>
As shown in FIG. 2, the valve portion 14 has a diaphragm 23 between the diaphragm 23 connected to the drive body 20, the diaphragm holder 31 attached to the opening portion of the drive housing 15, and the diaphragm holder 31. It is provided with a diaphragm housing 32 attached to the diaphragm holder 31 in a state where the diaphragm housing 32 is sandwiched between the two, and a cover 34 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 in a circular shape when viewed from the axial direction of the motor 12.

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

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

The opening portion 24a of the pump portion 24 is closed by the diaphragm housing 32. A pump chamber 42 is formed between the pump portion 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 projecting in the direction opposite to the pump chamber 42 is provided. The connecting piece 25 is connected to the driving body 20 of the driving mechanism 16 as described above. Therefore, when the drive body 20 swings, the bottom (piston 43) of the pump portion 24 comes into contact with and separates from the diaphragm housing 32, and the volume of the pump chamber 42 increases or decreases.

The holding portion 41 of the diaphragm 23 is sandwiched and held between the diaphragm holder 31 and the diaphragm housing 32. In other words, the diaphragm holder 31 holds the holding portion 41 of the diaphragm 23 in cooperation with the diaphragm housing 32. In this embodiment, the diaphragm housing 32 corresponds to the "first wall member" in the present invention, and the diaphragm holder 31 corresponds to the "second wall member" in the present invention. As shown in FIG. 3, a first engaging structure 46 including a convex portion 44 on the diaphragm holder 31 side and a concave portion 45 on the diaphragm 23 side is provided between the diaphragm holder 31 and the diaphragm 23. Further, a second engaging structure 49 including a convex portion 47 on the diaphragm 23 side and a concave portion 48 on the diaphragm housing 32 side is provided between the diaphragm housing 32 and the diaphragm 23.

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. The first through hole 51 is provided for each pump portion 24 of the diaphragm 23.

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

As shown in FIGS. 2 and 3, the protrusion 52 is opened with a groove 54 that is a part of the suction passage 53 and one end of a second through hole 56 that is a part of the discharge passage 55. There is. The suction passage 53 and the discharge passage 55 are formed so as to penetrate the protrusion 52. The groove 54 is provided for each pump portion 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 portion 24. The suction passage 53 is composed of a space S inside the housing, a suction hole 37, a circular recess 38, a first through hole 51, and a groove 54.
As shown in FIG. 1, the other end of the second through hole 56 is connected to an input side space 71 formed between the diaphragm housing 32 and the partition wall 33 described later.

<Explanation of partition wall>
The partition wall 33 is sandwiched and held between the diaphragm housing 32 and the cover 34. Further, the partition wall 33 is formed in a plate shape by 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 separated from the input side space 71 by a partition wall 33. The 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 the cover 34. It is connected to the sub-exhaust passage 75 provided in the central portion of the above via a continuous 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 tubular 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 tubular valve body 64 constitutes a check valve 78 in cooperation with the cylinder 77 of the diaphragm housing 32.
The check valve 78 allows air in the input side space 71 to flow into the recess 34a of the cover 34 (output side space 72). The cylinder 77 constitutes the valve seat of the check valve 78. The tubular valve body 76 is formed in a cylindrical shape that covers the outer peripheral surface of the cylinder 77.

The protruding end of the tubular valve body 76 is in close contact with the outer peripheral surface of the cylinder 77 over the entire circumferential direction. The base end portion of the tubular valve body 76 is formed so as to have a diameter larger than that of the cylinder 77. The space between the base end portion of the tubular valve body 76 and the cylinder 77 is a part of the input side space 71. In this embodiment, the discharge passage 55 is composed of the input side space 71, the space in 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 valve body 82 of the differential pressure valve 81, which will be described later, and a third through hole 84 through which the columnar protrusion 83 of the diaphragm housing 32 is 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 in which the main exhaust passage 74 opens, and 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, the differential pressure valve 81 and the check valve 78 described above constitute the "discharge valve" referred to 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 with a minute gap. Therefore, the input side space 71 is open to the atmosphere through a minute gap between the columnar protrusion 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 internal space S passes through the suction passage 53. It is sucked into the pump chamber 42. In the process of expanding the pump unit 24 in this way, the pump unit 24 pulls the holding portion 41 of the diaphragm 23 toward the inside of the pump chamber 42. However, in this embodiment, the protruding wall 52 of the diaphragm housing 32 is fitted in the opening portion 24a of the pump portion 24, and the protruding wall 52 restricts the movement of the holding portion 41.
On the other hand, when the pump portion 24 of the diaphragm 23 contracts and the volume of the pump chamber 42 decreases, the air in the pump chamber 42 is sent to the input side space 71. When the pressure in the input side space 71 rises, 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 is stopped, the air in the input side space 71 is discharged to the outside of the pump through the sub-exhaust passage 75, so that 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, the continuous passage (not shown), and the main exhaust passage 74 to the outside of the pump. Is discharged to.

In the diaphragm pump 11, since the protruding wall 52 restricts the movement of the holding portion 41 in the process of expanding the pump portion 24 of the diaphragm 23, it is possible to prevent the holding portion 41 from being pulled into the pump chamber 42. Therefore, according to this embodiment, the holding portion 41 of the diaphragm 23 can be formed thin while preventing the phenomenon in which the holding portion 41 of the diaphragm 23 is drawn into the pump chamber 42, so that further miniaturization is achieved. A diaphragm pump capable of being provided can be provided.

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

(Second Embodiment)
The protruding wall according to the present invention can be configured as shown in FIGS. 4 and 5. In FIGS. 4 and 5, the same or equivalent members as those described with reference to FIGS. 1 to 3 are designated by the same reference numerals, and detailed description thereof will be omitted as appropriate. FIG. 5 is a cross-sectional view showing an enlarged portion A in FIG.
The diaphragm pump 101 shown in FIG. 4 has a valve portion 14 different from that of the diaphragm pump 11 according to the first embodiment. In the valve portion 14 of the diaphragm pump 101 according to the second embodiment, the cover 34 is overlapped with the diaphragm housing 32, and one discharge is made to the 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 the hollow portion of the discharge pipe 105 projecting from the cover 34. In this embodiment, the discharge passage 55 is composed of 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. The 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 the plate-shaped portion 111 forming 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 is formed with a fifth through hole 113 that is opened and closed by the 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 the suction fluid chamber 114 formed in a ring shape in the cover 34. The suction fluid chamber 114 is connected to the hollow portion of the suction pipe 115 of the cover 34. In this embodiment, the suction passage 53 is composed of the fifth through hole 113, the suction fluid chamber 114, and the hollow portion of the suction pipe 115.

The plate-shaped portion 111 of the diaphragm housing 32 according to this embodiment has a cylindrical protruding wall 121. On the other hand, as shown in FIG. 5, the opening portion 24a of the pump portion 24 of the diaphragm 23 has an annular recess 122 formed so that the opening diameter is larger than that of the bottom side of the pump portion 24. The cylindrical protruding wall 121 is fitted in the annular recess 122. The outer diameter of the protrusion 121 is the same as the inner diameter of the recess 122, or is an outer diameter that is press-fitted into the recess 122. The height of the protrusion 121 (the length in the axial direction of the motor 12) is thinner than the thickness of the holding portion 41 of the diaphragm 23, and the height is such that the valve body 112a of the suction valve 112 is accommodated inside the protrusion 121. Is.

According to this embodiment, even when the suction valve 112 is provided in the pump chamber 42, the protrusion 41 can prevent the holding portion 41 from being pulled 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 sandwiching portion 41 of the diaphragm 23 can be formed thinly to further reduce the size.

The protruding wall 121 according to this embodiment is fitted in an annular recess 122 formed in the opening portion 24a of the pump portion 24 so that the opening diameter is larger than that on the bottom side of the pump portion 24. Therefore, since the protruding wall 121 is accommodated in the sandwiching portion 41 of the diaphragm 23, the inner diameter of the pump portion 24 can be reduced as compared with the case where the annular recess 122 is not formed. As a result, the diameter of the pump unit 24 can be reduced, and a diaphragm pump that is even smaller can be realized.

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

Claims (4)

A diaphragm having a pump portion formed in a cup shape and having a plate-shaped holding portion provided around the pump portion so that the pump portion opens.
A first wall member that is superposed on the diaphragm so as to cover the opening portion of the pump portion and cooperates with the pump portion to form a pump chamber.
A second wall member having a hole into which the pump portion is inserted and sandwiching the sandwiching portion of the diaphragm in cooperation with the first wall member.
A driving body that is connected to the bottom of the pump portion and that increases or decreases the volume of the pump chamber by bringing the bottom into contact with or separating from the first wall member.
A suction passage formed through the first wall member and allowing a fluid to flow toward the pump chamber by increasing the volume of the pump chamber.
A discharge passage formed through the first wall member and flowing a fluid discharged from the pump chamber by reducing the volume of the pump chamber.
A suction valve that opens and closes the suction passage,
A discharge valve that opens and closes the discharge passage is provided.
The diaphragm pump is characterized in that the first wall member has a protruding wall that protrudes toward the inside of the pump portion and fits into an opening portion of the pump portion. In the diaphragm pump according to claim 1,
The protruding wall is formed in a disk shape,
A diaphragm pump characterized in that the suction passage and the discharge passage are formed so as to penetrate the protrusion. In the diaphragm pump according to claim 1,
The protruding wall is formed in a cylindrical shape on a plate-shaped portion constituting the wall of the pump chamber in the first wall member.
A diaphragm pump characterized in that the suction passage and the discharge passage are formed so as to penetrate a portion of the plate-shaped portion surrounded by the protrusion. In the diaphragm pump according to claim 3,
The opening portion of the pump portion has an annular recess formed so that the opening diameter is larger than that of the bottom side of the pump portion.
A diaphragm pump characterized in that the protruding wall is fitted in the recess.

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