JP6936470B2 - Diaphragm pump - Google Patents

Description

The present invention relates to a diaphragm pump having a drive body that converts rotation into reciprocating motion and an engaging structure that detachably connects the shaft of the drive body to a crank body on the motor side.

Conventional diaphragm pumps of this type are described, for example, in Patent Document 1. The diaphragm pump disclosed in Patent Document 1 includes a crank body fixed to a rotating shaft of a motor, a drive body connected to the crank body via an engaging structure, and a diaphragm connected to the drive body. It is equipped with a suction valve and a discharge valve. The crank body is formed in a columnar shape and is positioned on the same axis as the rotation axis of the motor. At one end of the crank body in the axial direction, an annular groove that opens on the shaft end surface of the crank body is formed coaxially with the crank body. In the annular groove, an engaging portion having a shape connecting the inner peripheral wall and the outer peripheral wall of the annular groove is provided. The inner peripheral wall of the annular groove is formed in a conical shape. The above-mentioned engaging structure is composed of an annular groove and an engaging portion.

The drive body has a shaft portion having one end detachably engaged in the above-mentioned annular groove, and an arm portion extending radially outward from the shaft portion. The other end of the shaft portion is swingably supported by the housing of the diaphragm pump at a position on the same axis as the rotation shaft of the motor. Therefore, the shaft portion is inclined with respect to the axis of the rotation shaft of the motor.
A plurality of deformed portions of the diaphragm are attached to the arm portion. The deformed part of the diaphragm forms a part of the pump chamber. The suction valve opens and closes the suction passage connected to the pump chamber. The discharge valve opens and closes the discharge passage connected to the pump chamber. When the pump chamber contracts, the discharge valve opens and the fluid in the pump chamber is discharged. On the other hand, when the deformed portion expands, the suction valve opens and the fluid is sucked into the pump chamber.

In this diaphragm pump, when the crank body rotates together with the rotating shaft of the motor, one end of the shaft portion of the driving body is pushed by the engaging portion, and the driving body swings around the other end of the shaft portion. Therefore, the drive body converts the rotation into a reciprocating motion and transmits it to the deformed portion of the diaphragm. The deformed portion contracts when pushed by the arm and expands when pulled by the arm.

The above-mentioned engagement structure of the diaphragm pump has a first function of transmitting the rotation of the crank body to one end of the shaft portion of the drive body and an engagement portion located at an eccentric position with respect to the axis of the rotation shaft of the motor. It has a second function of guiding one end of the shaft portion of the drive body. In this diaphragm pump, since the engaging structure has a second function, one end of the shaft portion is guided to the bottom of the annular groove at an eccentric position at the time of assembly, and the shaft portion is tilted. The assembly work of connecting the shaft portion of the drive body to the crank body can be easily performed.

Japanese Unexamined Patent Publication No. 2013-19295

In the diaphragm pump disclosed in Patent Document 1, a state in which one end of a shaft portion of a driving body and an engaging portion of a crank body are in contact with each other during operation and a state in which these members are separated from each other are alternately repeated. Sometimes. In such a case, the shaft portion may hit or separate from the engaging portion to generate noise.
In order to solve this noise problem, it is necessary to avoid lowering the workability when connecting the shaft portion to the crank body.

An object of the present invention is to provide a diaphragm pump in which noise caused by a collision between one end of a shaft portion and a crank body is reduced while adopting a configuration in which one end of the shaft portion is guided to an eccentric position during assembly. ..

In order to achieve this object, the diaphragm pump according to the present invention has a diaphragm having a deformed portion forming a part of a wall of a pump chamber, and one end in the axial direction is fixed to the rotating shaft of the motor in the axial direction. A crank body having a recess at the other end and eccentric with respect to the axis of the rotating shaft, and a shaft portion having one end rotatably engaged with the recess and inclined with respect to the axis of the rotating shaft. A drive body that has an arm portion that protrudes outward in the radial direction from the shaft portion and is connected to the deformed portion, converts the rotation of the crank body into a reciprocating motion, and transmits the rotation to the deformed portion. The recess is provided with a pump mechanism that alternately repeats a state in which fluid is discharged from the pump chamber and a state in which fluid is sucked into the pump chamber as the drive body reciprocates, and the recess is in the rotation direction of the crank body. An annular recess is formed at the other end of the crank body in the axial direction, and the plurality of recesses serve as outer peripheral walls. Is.

In the present invention, in the diaphragm pump, the concave portion may be formed in a shape in which one end of the shaft portion is partially fitted, and the inner peripheral wall of the annular concave groove may be formed in a conical shape. ..

In the present invention, since one end of the shaft portion of the drive body is held in one of the plurality of recesses of the crank body, the one end of the shaft portion and the crank body do not come into contact with or separate from each other during operation. No.
Further, the plurality of recesses form the outer peripheral wall of the annular recessed groove, and when one end of the shaft portion of the drive body enters the recessed groove at the time of assembly, the recess is guided to the recess at an eccentric position.
Therefore, according to the present invention, it is possible to provide a diaphragm pump in which noise caused by a collision between one end of a shaft portion and a crank body is reduced without impairing assembling property.

It is sectional drawing of the diaphragm pump which concerns on this invention. It is a top view of the crank body. FIG. 2 is a cross-sectional view taken along the line III-III in FIG. It is sectional drawing for demonstrating the procedure at the time of connecting a drive body to a crank body.

Hereinafter, an embodiment of the diaphragm pump according to the present invention will be described in detail with reference to FIGS. 1 to 4.
The diaphragm pump 1 shown in FIG. 1 is attached to a motor 2 located at the lowest position in FIG. 1, and is driven by the motor 2 to operate. The diaphragm pump 1 according to this embodiment is a pump that sucks in and discharges the atmosphere (air). In this embodiment, air corresponds to the "fluid" in the present invention.
The diaphragm pump 1 includes a housing 3 fixed to a motor 2. The functional parts constituting the diaphragm pump 1 are held in the housing 3.

The housing 3 is formed in a columnar shape by combining a plurality of 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 plurality of members constituting the housing 3 include a bottomed cylindrical bottom body 5 attached to the motor 2, a diaphragm holder 6 attached to an opening portion of the bottom body 5, and a diaphragm to be described later in the diaphragm holder 6. A disk-shaped valve holder 8 attached via the valve holder 8, a lid body 9 attached so as to overlap the valve holder 8, and the like.

The diaphragm 7 is sandwiched and held by the diaphragm holder 6 and the valve holder 8. Further, the diaphragm 7 has a cup-shaped deformed portion 11 that opens toward the valve holder 8 and a suction valve 12.
The opening portion of the deformed portion 11 is closed by the valve holder 8. A pump chamber 13 is formed between the deformed portion 11 and the valve holder 8. That is, the diaphragm 7 forms a part of the wall of the pump chamber 13.
A connecting piece 14 projecting in the direction opposite to the pump chamber 13 is provided on the bottom wall 11a of the deformed portion 11 having a cup shape.

The suction valve 12 is formed in a plate shape extending in a direction orthogonal to the paper surface of FIG. 1, and is connected to another part of the diaphragm 7 at one end in the longitudinal direction. The suction valve 12 is housed in one end of a first fluid chamber 15 formed between the diaphragm holder 6 and the valve holder 8, and faces the first through hole 16 formed in the diaphragm holder 6. It is placed in the position to do.

The suction valve 12 comes into close contact with the diaphragm holder 6 in a state where the diaphragm 7 is sandwiched between the diaphragm holder 6 and the valve holder 8 and closes the opening of the first through hole 16. The first through hole 16 communicates the inside of the first fluid chamber 15 with the space S in the bottom body 5. The space S in the bottom body 5 communicates with the atmosphere through the second through hole 17 formed in the bottom body 5.
The other end of the first fluid chamber 15 communicates with the pump chamber 13. A discharge passage hole 18 is connected to the other end of the first fluid chamber 15. One end of the discharge passage hole 18 opens to the first fluid chamber 15, and the other end opens to the end surface of the valve holder 8 on the lid 9 side.

A discharge valve 21 is provided at the end of the valve holder 8 on the lid 9 side. The discharge valve 21 is housed in a second fluid chamber 22 formed in the lid 9. The second fluid chamber 22 is formed between the valve holder 8 and the lid 9, and communicates with the internal space 24 of the discharge pipe 23 provided in the lid 9. One end of the discharge pipe 23 is open to the inside of the lid 9, and the other end is open to the outer surface of the lid 9.
The discharge valve 21 is made of a rubber material and has a valve body 21a that is in close contact with the end surface through which the discharge hole 17 of the valve holder 8 opens. The valve body 21a naturally closes the opening portion of the discharge hole 17.

The discharge valve 21 and the suction valve 12 described above open and close as the volume of the pump chamber 13 increases or decreases. The discharge valve 21 is opened in a contraction stroke in which the volume of the pump chamber 13 is reduced, and is closed in other cases. The suction valve 12 opens in the expansion stroke in which the volume of the pump chamber 13 increases, and is closed otherwise. The volume of the pump chamber 13 changes when the deformed portion 11 of the diaphragm 7 is pushed or pulled by the drive mechanism 25 described later. In this embodiment, the suction valve 12, the discharge valve 21, the first fluid chamber 15, the first through hole 16, the space S in the bottom body 5, the second through hole 17, and the discharge. The pump mechanism 26 according to the present invention is configured by the passage hole 18, the second fluid chamber 22, the internal space 24 of the pipe 23, and the like.

The drive mechanism 25 includes a crank body 31 that rotates integrally with the rotating shaft 4 of the motor 2, and a drive body 33 that is connected to the crank body 31 via an engaging structure 32. The crank body 31 and the drive body 33 are each made of a plastic material.
The crank body 31 is formed in a columnar shape. As shown in FIG. 3, a shaft hole 34 formed of a non-through hole is provided at one end of the crank body 31 in the axial direction. The shaft hole 34 is formed in a shape extending in the axial direction of the crank body 31 at the axial center portion of the crank body 31.

An annular groove 35 forming the engaging structure 32 is formed at the other end of the crank body 31. The concave groove 35 is located on the same axis as the crank body 31 and is open to the other end surface 31a of the crank body 31. A conical protrusion 36 having a rounded top is formed in the central portion of the concave groove 35. Therefore, the inner peripheral wall 35a of the annular concave groove 35 is formed by the peripheral wall of the conical protrusion 36.

As shown in FIG. 2, the outer peripheral wall 35b of the recessed groove 35 is formed by a plurality of recesses 37 arranged at predetermined intervals in the circumferential direction of the crank body 31 when viewed from the axial direction of the crank body 31. Of the two recesses 37 adjacent to each other, the half portion 37a on the other end side of one recess 37 and the half portion 37b on the one end side of the other recess 37 form a mountain-shaped engaging portion 38. ..
As shown in FIG. 3, the recess 37 is connected to a straight line portion 41 extending parallel to the axis C1 of the crank body 31 toward one end side from the other end surface 31a of the crank body 31 and a circle connected to one end of the straight line portion 41. It is composed of a curved portion 42 forming the bottom of the annular concave groove 35.

As shown in FIG. 2, the straight portion 41 is formed by a concave curved surface extending in the axial direction of the crank body 31 in a shape that opens toward the axial center C1 of the crank body 31 when viewed from the axial direction of the crank body 31. .. The straight line portion 41 is provided at a position eccentric with respect to the axis of the crank body 31 (relative to the axis of the rotating shaft 4) by a predetermined length L. The straight portion 41 according to this embodiment is formed so that the opening shape is a part of the hole wall surface of a circular hole (not shown).

The curved portion 42 is formed in a shape that is curved so as to extend inward in the radial direction of the crank body 31 from one end of the straight portion 41 and extend to one end side (lower side in FIG. 3) of the crank body 31. The portion of the curved portion 42 connected to the straight portion 41 is formed by a concave curved surface having the same curvature as the straight portion 41. The curvature of the concave curved surface of the curved portion 42 gradually decreases toward the bottom of the concave groove 35. Therefore, the connecting portion between the curved portion 42 and the inner peripheral wall 35a of the concave groove 35 has a concave curved surface that does not have a concave curved surface that constitutes the concave portion 37, or is slightly recessed even if it exists.
As shown in FIG. 2, the engaging portion 38 is formed in a mountain shape that is convex toward the axial center of the crank body 31 when viewed from the axial direction of the crank body 31, and is a straight portion like the concave portion 37. It has 43 (see FIG. 3) and a curved portion 44.

As shown in FIG. 1, the drive body 33 includes a shaft portion 46 having a first shaft 4545 engaged with a recess 37 of the crank body 31, and an arm portion 47 protruding outward in the radial direction from the shaft portion 46. have. The first shaft 45 has a columnar main body portion 45a and a hemispherical tip portion 45b. The first shaft 45 according to this embodiment is formed in a shape that rotatably fits into the recess 37 of the crank body 31. In other words, the recess 37 is formed in a shape in which a part of the first shaft 45 is partially fitted. Further, among the plurality of engaging portions 38 provided on the crank body 31, the distance between the two engaging portions 38 adjacent to each other is equal to the outer diameter of the first shaft 45, or the first shaft 45 Slightly larger than the outer diameter of. In this embodiment, the first shaft 45 corresponds to the "one end" of the shaft portion in the present invention.

A second shaft 48 is projected from the other end of the shaft portion 46. The second shaft 48 is also composed of a columnar main body portion 48a and a hemispherical tip portion 48b. The second shaft 48 is inserted into the circular hole 49 of the diaphragm holder 6 and is rotatably held in the circular hole 49. The circular hole 48 constitutes a self-aligning spherical slide bearing, and is positioned on the same axis as the rotating shaft 4 of the motor 2. In the shaft portion 46, the first shaft 45 engages with the recess 37 of the crank body 31, and the second shaft 48 is inserted into and held in the circular hole 49, so that the axis of the rotating shaft 4 of the motor 2 is held. Tilt with respect to C2.
A through hole 47a is bored in the arm portion 47 of the drive body 33. The arm portion 47 is connected to the connecting piece 14 by engaging the connecting piece 14 of the diaphragm 7 into the through hole 47a.

In the drive mechanism 25 configured in this way, the rotation shaft 4 of the motor 2 rotates, so that the crank body 31 rotates integrally with the rotation shaft 4. At this time, when the engaging portion 38 connected to the recess 37 with which the first shaft 45 is engaged pushes the first shaft 45, the first shaft 45 moves with the rotation of the crank body 31. As the first shaft 45 moves, the direction in which the shaft portion 46 of the drive body 33 is inclined changes. By changing the tilting direction of the drive body 33 in this way, the position of the arm portion 47 changes in the axial direction of the rotating shaft 4. Therefore, the drive mechanism 25 including the drive body 33 and the crank body 31 described above converts the rotation of the motor 2 into a reciprocating motion and transmits the rotation to the deformed portion 11 of the diaphragm 7.

When the deformed portion 11 is pulled by the arm portion 47 to expand, air is sucked into the bottom body 5 through the second through hole 17 of the bottom body 5. Then, this air is sucked into the pump chamber 13 from the space S in the bottom body 5 through the first through hole 16 and the first fluid chamber 15. On the other hand, when the deformed portion 11 is pushed by the arm portion 47 and contracts, the air in the pump chamber 13 passes through the discharge passage hole 18, the second fluid chamber 22, and the internal space 24 of the pipe 23 to form a diaphragm pump. It is discharged from 1. As the crank body 31 rotates continuously, the pump mechanism 26 alternately repeats a state in which air is discharged from the pump chamber 13 and a state in which air is sucked into the pump chamber 13.

When assembling the diaphragm pump 1, for example, the diaphragm 7 can be sandwiched and held by the diaphragm holder 6 and the valve holder 8, and these members can be handled as one assembly. Then, in connecting the crank body 31 of the drive mechanism 25 and the drive body 33, the connecting piece 14 of the diaphragm 7 was passed through the arm portion 47 of the drive body 33, and the drive body 33 was supported by the above-mentioned assembly. Do it in the state. On the other hand, the crank body 31 is fixed to the rotating shaft 4 by, for example, press-fitting the rotating shaft 4 protruding into the bottom body 5 into the shaft hole 34 of the crank body 31 after attaching the bottom body 5 to the motor 2. ..

The connection between the crank body 31 and the drive body 33 is performed by superimposing the diaphragm holder 6 of the above-mentioned assembly having the drive body 33 on the bottom body 5. At this time, as shown in FIG. 4, when the diaphragm holder 6 is close to the bottom body 5, the first shaft 45 of the drive body 33 is inserted into the annular groove 35 of the crank body 31. Then, when the diaphragm holder 6 comes into contact with the bottom body 5, the first shaft 45 engages (fits) with any one of the plurality of recesses 37.

As shown by the alternate long and short dash line in FIG. 4, when the first shaft 45 is located on the same axis as the axis C2 of the crank body 31, the diaphragm holder 6 approaches the bottom body 5. In the process, the first shaft 45 comes into contact with the protrusion 36 of the crank body 31. Then, as the diaphragm holder 6 approaches the bottom body 5, the first shaft 45 moves along the inner peripheral wall 35a (the peripheral wall of the protrusion 36) of the concave groove 35 of the crank body 31, and the plurality of recesses 37 It is guided to any one of the recesses 37.

Therefore, in the diaphragm pump 1 according to this embodiment, one end (first shaft 45) of the shaft portion 46 of the drive body 33 is held by one of the plurality of recesses 37 of the crank body 31. The phenomenon that one end of the shaft portion 46 and the crank body 31 hit or separate during rotation is not alternately repeated.
Further, the plurality of recesses 37 form an outer peripheral wall 35b of the annular recessed groove 35, and one end (first shaft 45) of the shaft portion 46 of the drive body 33 enters the recessed groove 35 at the time of assembly. Leads to a recess 37 at an eccentric position.
Therefore, according to this embodiment, it is possible to provide a diaphragm pump in which noise caused by a collision between one end of the shaft portion 46 and the crank body 31 is reduced without impairing the assembling property.

The recess 37 according to this embodiment is formed in a shape in which a part of the first shaft 45 is partially fitted. Further, the inner peripheral wall 35a of the annular concave groove 35 is formed in a conical shape.
Therefore, since one end of the shaft portion 46 of the drive body 33 is securely held in the recess 37 in the fitted state, the generation of noise can be prevented even more reliably. Further, at the time of assembly, the first shaft 45 of the drive body 33 is guided to one of the plurality of recesses 37 along the conical inner peripheral wall 35a of the recessed groove 35, so that the first shaft 45 is recessed. Despite the configuration of fitting to 37, the assembly work can be easily performed.

The diaphragm pump 1 shown in the above-described embodiment is provided with only one pump chamber 13. However, the present invention is not bound by such limitations. The present invention can also be applied to a diaphragm pump provided with a plurality of pump chambers.

1 ... Diaphragm pump, 2 ... Motor, 4 ... Rotating shaft, 7 ... Diaphragm, 11 ... Deformed part, 13 ... Pump chamber, 26 ... Pump mechanism, 31 ... Crank body, 33 ... Drive body, 35 ... Recessed groove, 36 ... Protrusions, 37 ... recesses, 46 ... shafts, 47 ... arms.

Claims (2)

A diaphragm with a deformed part that forms part of the wall of the pump chamber,
A crank body in which one end in the axial direction is fixed to the rotating shaft of the motor and the other end in the axial direction has a recess at a position eccentric to the axis of the rotating shaft.
One end rotatably engages with the recess to have a shaft portion inclined with respect to the axis of the rotating shaft, and an arm portion protruding outward in the radial direction from the shaft portion and connected to the deformed portion. Then, the drive body that converts the rotation of the crank body into a reciprocating motion and transmits it to the deformed portion,
It is provided with a pump mechanism that alternately repeats a state in which a fluid is discharged from the pump chamber and a state in which the fluid is sucked into the pump chamber in accordance with the reciprocating motion of the drive body.
The recesses are provided at a plurality of positions arranged at predetermined intervals in the circumferential direction of the crank body, respectively.
A diaphragm pump in which an annular recess having a plurality of recesses as an outer peripheral wall is formed at the other end of the crank body in the axial direction. In the diaphragm pump according to claim 1,
The recess is formed in a shape in which one end of the shaft portion is partially fitted.
A diaphragm pump characterized in that a conical protrusion is formed at the center of the annular concave groove.

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