JP7506613B2 - Diaphragm pump - Google Patents

Description

The present invention relates to a diaphragm pump equipped with a hat-shaped discharge valve.

An example of a conventional diaphragm pump of this type is described in Patent Document 1. The discharge valve of the diaphragm pump disclosed in Patent Document 1 is attached to the discharge passage side of a partition wall that separates the pump chamber from the discharge passage. A through hole is formed in the partition wall that connects the pump chamber to the discharge passage. The discharge valve has a disk-shaped valve body portion that covers the opening on the discharge passage side of the through hole, and a rib that is formed thicker than the valve body portion and extends radially from the center of the valve body portion. The rib is pressed against the partition wall by a cover body that cooperates with the partition wall to form the discharge passage. A groove extending along the rib is formed in the boundary between the rib and the valve body portion.

JP 2015-218581 A

The discharge valve of the diaphragm pump disclosed in Patent Document 1 is thick at the base of the valve body, i.e., the center, and thin at the outer edge, so that the thick part at the base creates a large resistance when the valve is opened and closed. In addition, the rib is elastically deformed by being pressed against the partition wall, and there is a risk that the valve body will also deform as a result of this rib deformation. If the valve body deforms, the seal will be incomplete when closing the opening of the through hole.

The object of the present invention is to provide a diaphragm pump that improves the opening and closing performance of the valve body of the discharge valve and improves the sealing performance when fully closed.

In order to achieve this object, the diaphragm pump of the present invention comprises a diaphragm having a cup-shaped deformation portion, a partition wall that closes the opening of the deformation portion and cooperates with the deformation portion to form a pump chamber, a suction passage connected to the pump chamber, a discharge passage connected to the pump chamber via a discharge through hole that penetrates the partition wall, a drive mechanism that converts the rotation of a motor into reciprocating motion to alternately deform the deformation portion in a direction that increases the volume of the pump chamber and a direction that decreases the volume of the pump chamber, a suction valve that opens the suction passage in a stroke in which the volume of the pump chamber increases and closes the suction passage in other strokes, and a valve that is disposed in the discharge passage and attached to the partition wall and opens the discharge passage in a stroke in which the volume of the pump chamber decreases. and a discharge valve that closes the discharge passage during the other stroke, and a pressing member that cooperates with the partition to hold the discharge valve. The discharge valve has a convex portion that fits into a protrusion that protrudes from the partition, a valve body portion that is formed in a disk shape that extends along the partition with the convex portion as the center and covers the opening of the discharge through hole, a plurality of ribs that protrude in the thickness direction from the valve body portion and extend radially from the convex portion to the outer periphery of the valve body portion and are pressed toward the partition by the pressing member, a first groove that is formed to extend along the rib at the boundary between the rib and the valve body portion, and a second groove that is formed to extend radially in the seal portion sandwiched between two adjacent ribs in the valve body portion.

In the diaphragm pump of the present invention, the second grooves may be formed radially from the convex portion as a center and may be formed in two places in the seal portion, and the discharge through hole may be positioned between the two second grooves when viewed in the thickness direction of the valve body portion.

In the present invention, the deformation transmitted from the rib to the seal portion is absorbed by the second groove. Also, the rigidity of the portion of the seal portion where the second groove is formed is reduced. Therefore, the seal portion bends at the second groove, facilitating elastic deformation during opening and closing.
Therefore, according to the present invention, it is possible to provide a diaphragm pump in which the opening and closing performance of the valve body of the discharge valve is improved and the sealing performance when fully closed is improved.

FIG. 1 is a cross-sectional view of a diaphragm pump according to the present invention. FIG. 2 is a plan view of the discharge valve. FIG. 3 is a side view of the discharge valve. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a diaphragm pump according to the present invention will now be described in detail with reference to FIGS.
The diaphragm pump 1 shown in Fig. 1 is attached to a motor 2 located at the bottom in Fig. 1, and is driven by the motor 2. The diaphragm pump 1 according to this embodiment is a pump that sucks in and discharges air.
The diaphragm pump 1 includes a housing 3 fixed to a motor 2. The functional components that constitute the diaphragm pump 1 are held in the housing 3.

The housing 3 is formed into a cylindrical shape by combining multiple members in the axial direction of the motor 2, and is positioned on the same axis as the rotating shaft 4 of the motor 2. The multiple members that make up the housing 3 are a bottomed cylindrical bottom body 5 attached to the motor 2, a diaphragm holder 6 attached to the opening of the bottom body 5, a disk-shaped valve holder 8 attached to the diaphragm holder 6 with a diaphragm 7 (described later) sandwiched between the diaphragm holder 6 and the diaphragm holder 6, and a lid body 9 attached so as to overlap the valve holder 8. In this embodiment, the valve holder 8 corresponds to the "partition wall" as defined in the present invention.

The diaphragm 7 is held by being sandwiched between the diaphragm holder 6 and the valve holder 8. The diaphragm 7 also has a plurality of cup-shaped deformation portions 11 that open toward the valve holder 8. These deformation portions 11 are provided at positions in the circumferential direction of the housing 3 that divide the diaphragm 7 into a plurality of portions.
The opening of the deformation portion 11 is closed by the valve holder 8 .

A pump chamber 12 is formed between the deformation portion 11 and the valve holder 8. Therefore, the diaphragm 7 constitutes a part of the wall of the pump chamber 12.
A connecting piece 13 is provided on a bottom wall 11a of the cup-shaped deformation portion 11, protruding in a direction opposite to the pump chamber 12. A drive mechanism 21 is connected to the connecting piece 13.

The drive mechanism 21 includes a crank body 22 attached to the rotating shaft 4 of the motor 2, and a driver 24 connected to the crank body 22 via a drive shaft 23. The crank body 22 is fixed to the rotating shaft 4 and rotates integrally with the rotating shaft 4. The crank body 22 and driver 24 are made of a plastic material. The drive shaft 23 is made of a metal material.

The drive shaft 23 is fixed to an eccentric portion of the crank body 22 in a state inclined relative to the rotating shaft 4 of the motor 2. The direction in which the drive shaft 23 is inclined is the direction in which the amount of eccentricity with respect to the rotating shaft 4 at the tip of the drive shaft 23 becomes smaller.

The driver 24 is composed of a cylindrical shaft portion 25 to which the drive shaft 23 is connected, and a plurality of arms 26 that protrude radially outward from the shaft portion 25 .
The shaft portion 25 is composed of a bearing member 25a that rotatably supports the drive shaft 23, and a cylindrical body 25b that covers the bearing member 25a.

The arms 26 of the driver 24 are provided for each deformation portion 11 of the diaphragm 7 and extend radially outward from the shaft portion 25. A through hole 26a is drilled in the arms 26. The connecting piece 13 of the diaphragm 7 is inserted into this through hole 26a. The connecting piece 13 is fixed to the arms 26 in a state where it penetrates the arms 26. Therefore, the arms 26 are connected to each of the multiple deformation portions 11 of the diaphragm 7.

According to this drive mechanism 21, the rotation of the rotating shaft 4 of the motor 2 causes the crank body 22 and the drive shaft 23 to rotate around the rotating shaft 4. At this time, the drive body 24 is restricted in rotation by the diaphragm 7, so it swings in response to changes in the tilt direction of the drive shaft 23. This swing causes the arm 26 to push and pull the deformation part 11. Therefore, the drive body 24 converts the rotation of the rotating shaft 4 into reciprocating motion and transmits it to the deformation part 11.

The deformable portion 11 of the diaphragm 7 is pulled toward the motor 2 by the arm 26 and expands, increasing the volume of the pump chamber 12. On the other hand, the deformable portion 11 of the diaphragm 7 is pushed toward the valve holder 8 by the arm 26, contracting the deformable portion 11 and decreasing the volume of the pump chamber 12. Therefore, as the crank body 22 continues to rotate, the volume of the pump chamber 12 alternates between increasing and decreasing.

The part of the valve holder 8 that constitutes the wall of the pump chamber 12 is provided with a suction valve 31, and a suction through hole 32 and a discharge through hole 33 are formed. The suction valve 31 is made of a rubber material and is provided for each pump chamber 12. Although two suction valves 31 are shown in FIG. 1, the number of suction valves 31, i.e., the number of pump chambers 12, is not limited to two. The suction valve 31 in this embodiment has a shaft portion 31a that passes through the valve holder 8 and is fixed to the valve holder 8, and a valve body 31b that is in close contact with the wall surface of the valve holder 8 on the pump chamber 12 side.

The suction through hole 32 is a hole that penetrates the valve holder 8 and communicates between the pump chamber 12 and a suction passage 34, which will be described later. The opening of the suction through hole 32 on the pump chamber 12 side is opened and closed by the valve body 31b of the suction valve 31. The suction passage 34 opens when the valve body 31b moves away from this opening, and closes the suction passage 34 when the valve body 31b closes this opening. That is, as shown on the right side of Figure 1, the suction valve 31 opens the suction passage 34 in a stroke in which the volume of the pump chamber 12 increases, and closes the suction passage 34 in other strokes.
The suction passage 34 is formed on the outer periphery between the valve holder 8 and the cover 9, and is separated from a discharge passage 36, which will be described later, by a cylindrical wall 35 that protrudes from the center of the valve holder 8. The tip of the cylindrical wall 35 is airtightly attached to the cover 9. The upstream end of the suction passage 34 in this embodiment is formed by a suction pipe 37 provided on the outer periphery of the cover 9.

The discharge through hole 33 is a hole that passes through the valve holder 8 and communicates the pump chamber 12 with the discharge passage 36 .
The discharge passage 36 is composed of a discharge fluid chamber 38 formed inside the cylindrical wall 35 at the center between the valve holder 8 and the cover 9, and a discharge pipe 39 protruding from the axial center of the cover 9. A discharge valve 41 is provided in the discharge fluid chamber 38. This discharge valve 41 is a so-called hat-shaped valve, as shown in Figures 2 to 4, and is made of a rubber material.

The discharge valve 41 has first to third functional parts. The first functional part is a convex part 42 that is attached to the valve holder 8. The convex part 42 is formed to fit into a protrusion 43 that protrudes from the valve holder 8. In this embodiment, the convex part 42 is formed in an elliptical shape in a plan view, as shown in FIG. 2. The protrusion 43 of the valve holder 8 is also formed in the same shape as the convex part 42.

The second functional portion is a valve body 44 that opens and closes the opening of the discharge through hole 33 on the discharge passage 36 side. The valve body 44 is formed in a disk shape extending along the valve holder 8 with the protrusion 42 as its center. The valve body 44 covers the opening of the discharge through hole 33 when the discharge valve 41 is attached to the valve holder 8.
The third functional portion is a rib 45 for pressing the valve body portion 44 against the valve holder 8. The rib 45 is formed so as to protrude from the valve body portion 44 in the thickness direction and extend radially from the convex portion 42 to the outer periphery of the valve body portion 44. The direction in which the rib 45 protrudes from the valve body portion 44 is the direction away from the valve holder 8.

As shown in FIG. 2, the ribs 45 in this embodiment are provided so as to protrude from four points on the valve body portion 44. More specifically, the four ribs 45 are provided two on one end side of the longitudinal direction of the convex portion 42, and two on the other end side of the longitudinal direction of the convex portion 42. In the following, the two ribs 45 located on one end side of the longitudinal direction of the convex portion 42 are collectively referred to as the first rib group 46, and the two ribs 45 located on the other end side of the longitudinal direction of the convex portion 42 are collectively referred to as the second rib group 47. The angle a between a pair of ribs 45 in the first rib group 46 is the same as the angle b between a pair of ribs 45 in the second rib group 47.

The angle c between one rib 45 of the first rib group 46 and one rib 45 of the second rib group 47 adjacent to this rib 45 is greater than the angles a and b. In the following, the portion of the valve body portion 44 located between the first rib group 46 and the second rib group 47 is referred to as the seal portion 51. The valve body portion 44 in this embodiment has two seal portions 51. The discharge valve 41 is configured so that these seal portions 51 cover the discharge through hole 33 of the valve holder 8.

When the discharge valve 41 is attached to the valve holder 8, the four ribs 45 are pressed toward the valve holder 8 by a pressing member 52 (see FIG. 1 ) of the cover 9, and are compressed and elastically deformed. The pressing member 52 is provided on the cover 9 so as to protrude toward the valve holder 8, and cooperates with the valve holder 8 to clamp the discharge valve 41.
When the rib 45 is pressed by the pressing member 52 , the portion of the valve body 44 on which the rib 45 is formed is brought into close contact with the valve holder 8 .

A first groove 53 extending along the rib 45 is formed at the boundary between the rib 45 and the valve body portion 44. The first groove 53 in this embodiment is formed at the boundary between the seal portion 51 of the valve body portion 44 and the rib 45.
A second groove 54 is formed in the seal portion 51. The second groove 54 is formed to extend radially in the seal portion 51 sandwiched between two adjacent ribs 45 (the rib 45 of the first rib group 46 and the rib 45 of the second rib group 47) in the valve body portion 44.

More specifically, the second grooves 54 are formed radially from the convex portion 42 as a center, and are formed in two locations so as to divide the seal portion 51 into three equal parts. The second grooves 54 extend from the outer peripheral edge of the valve body portion 44 to the vicinity of the convex portion 42. For this reason, the outer peripheral portion of the seal portion 51 according to this embodiment is divided into two outer seal portions 51a, 51b connected to the rib 45 via the first grooves 53, and an inner seal portion 51c connected to these outer seal portions 51a, 51b via the second grooves 54.
The discharge through hole 33 of the valve holder 8 is positioned between the two second grooves 54 (the portion facing the inner seal portion 51c) when viewed in the thickness direction of the valve body portion 44.

The opening of the discharge through hole 33 on the discharge fluid chamber 38 side is opened and closed by the valve body 44 of the discharge valve 41. When the valve body 44 moves away from this opening, the discharge passage 36 opens, and when the valve body 44 closes this opening, the discharge passage 36 closes. That is, as shown on the right side of Figure 1, the discharge valve 41 closes the discharge passage 36 during the stroke in which the volume of the pump chamber 12 increases, and opens the discharge passage 36 during the other strokes.

The valve body 44 of the discharge valve 41 according to this embodiment has a first groove 53 and a second groove 54 formed therein, so that even though the rib 45 is pressed by the pressing member 52 and elastically deforms, the valve body 44 is less susceptible to the effect of the deformation of the rib 45. When the rib 45 is pressed by the pressing member 52 and elastically deforms, the deformation of the rib 45 is also propagated to the seal portion 51 of the valve body 44. This deformation is not completely absorbed by the first groove 53, and is transmitted, albeit slightly, to the outer seal portions 51a and 51b. However, the deformation transmitted to the outer seal portions 51a and 51b is absorbed by the second groove 54.

Therefore, the inner seal portion 51c of the seal portion 51 is hardly affected by the deformation of the rib 45, and when fully closed, it comes into close contact with the valve holder 8 and reliably closes the opening of the discharge through hole 33. Also, the rigidity of the portion of the seal portion 51 where the second groove 54 is formed is reduced. Such a seal portion 51 is bent at the second groove 54, facilitating elastic deformation when opening and closing.
Therefore, according to this embodiment, it is possible to provide a diaphragm pump in which the opening and closing performance of the valve body portion 44 of the discharge valve 41 is improved and the sealing performance when fully closed is improved.

The second grooves 54 in this embodiment are formed radially from the convex portion 42 as the center, and are formed in two places in the seal portion 51. The discharge through hole 33 is positioned between the two second grooves 54 when viewed from the thickness direction of the valve body portion 44. Therefore, the inner seal portion 51c of the seal portion 51 is formed in a fan shape, and when the valve body portion 44 opens due to the pressure of the air discharged from the discharge through hole 33, the outer periphery of the fan-shaped inner seal portion 51c moves significantly away from the valve holder 8. As a result, air is discharged smoothly, and discharge efficiency is increased.

1...diaphragm pump, 2...motor, 7...diaphragm, 8...valve holder (partition), 11...deformation portion, 12...pump chamber, 33...discharge through hole, 34...suction passage, 36...discharge passage, 21...drive mechanism, 31...suction valve, 41...discharge valve, 42...projection, 43...protrusion, 44...valve body portion, 45...rib, 51...seal portion, 52...pressure member, 53...first groove, 54...second groove.

Claims (2)

A diaphragm having a cup-shaped deformation portion;
a partition wall that closes an opening portion of the deformation portion and forms a pump chamber in cooperation with the deformation portion;
a suction passage communicating with the pump chamber;
a discharge passage communicating with the pump chamber via a discharge through hole penetrating the partition wall;
a drive mechanism that converts rotation of a motor into reciprocating motion to alternately deform the deformation portion in a direction in which the volume of the pump chamber increases and in a direction in which the volume of the pump chamber decreases;
a suction valve that opens the suction passage during a stroke in which the volume of the pump chamber increases and closes the suction passage during other strokes;
a discharge valve disposed in the discharge passage and attached to the partition wall, the discharge valve opening the discharge passage during a stroke in which the volume of the pump chamber decreases and closing the discharge passage during other strokes;
a pressing member that cooperates with the partition wall to hold the discharge valve,
The discharge valve is
a protrusion that fits into a protrusion provided on the partition wall;
a valve body portion formed in a disk shape extending along the partition wall with the protrusion as a center and covering an opening of the discharge through hole;
a plurality of ribs formed to protrude from the valve body in a thickness direction, extend radially from the protrusion to an outer periphery of the valve body, and be pressed toward the partition wall by the pressing member;
a first groove formed at a boundary between the rib and the valve body portion so as to extend along the rib;
a second groove formed in the valve body portion so as to extend radially in a seal portion sandwiched between two adjacent ribs. 2. The diaphragm pump according to claim 1, wherein the second groove is formed radially from the convex portion as a center and is formed at two locations in the seal portion,
The diaphragm pump according to claim 1, wherein the discharge through hole is located between two of the second grooves when viewed in a thickness direction of the valve body portion.

Images