TWI707087B - Diaphragm pump - Google Patents

Abstract

[Problem] The object of the present invention is to provide a diaphragm pump that can prevent the deterioration of the diaphragm and increase the compression ratio of the pump, thereby having a long life and high performance. [Solution] A diaphragm pump including a pump head 1, a diaphragm inside the pump head 1, a driving mechanism 3 connected to the diaphragm 2, and a pump chamber 4 divided by the diaphragm 2 inside the pump head 1. The diaphragm 2 is formed with a mountain-shaped portion 21 protruding in the thickness direction on the outer peripheral portion 2b. The peripheral end portion 2c is fixed to the pump head 1, and the driving mechanism 3 is connected to the central portion 2a. When the diaphragm 2 is driven in the thickness direction by When the mechanism 3 reciprocates, the first inclined portion 212 on the radially outer side of the vertex portion 211 of the ridge portion 21 is maintained in an inclined state, while the second inclined portion 212 on the radially inner side of the vertex portion 212 of the ridge portion 21 is maintained. The portion 213 swings with the vertex portion 211 as a fulcrum.

Description

Diaphragm pump

The present invention relates to a diaphragm pump (Diaphragm pump) that transmits fluid by swinging a diaphragm (Diaphragm).

A diaphragm pump has historically been known as a pump for transferring fluid. This diaphragm pump is equipped with a pump head, a flexible diaphragm arranged inside the pump head, a driving mechanism connected to the diaphragm, and a pump chamber divided by a diaphragm inside the pump head. As the diaphragm moves in the thickness direction by the driving mechanism The reciprocating movement changes the pressure in the pump chamber and transfers fluid (see, for example, Patent Document 1).

However, in many conventional diaphragm pumps, since the diaphragm is formed into a flat plate shape, whenever the diaphragm expands toward the pump chamber, the diaphragm generates a large tensile force in the radial direction and is stretched, and there is a problem that the diaphragm deteriorates in a short time. .

Therefore, in order to prevent the occurrence of such a pulling force on the diaphragm pump, it is also known that as shown in FIG. 4( b ), the diaphragm 102 is formed with a hanging portion 102 a that gently protrudes in the thickness direction. As a result, as shown in FIG. 4( a ), when the diaphragm 102 expands to the pump chamber 104 side, the hanging portion 102 a formed on the diaphragm 102 absorbs the tensile force, and the deterioration of the diaphragm 102 can be prevented. [Related Technical Documents] [Patent Documents]

[Patent Document 1] Japanese Patent Publication No. 7-14179

[Problem to be Solved by the Invention] However, when the diaphragm 102 swings, the sagging portion 102a of the diaphragm 102 often becomes an unstable shape. Specifically, as shown in FIG. 4(b), although the drooping portion 102a maintains a predetermined shape at the bottom dead center of the diaphragm 102, as shown in FIG. 4(c), the drooping portion 102a inherently has The influence of the shape is that the top dead center becomes a slightly curved shape on the side opposite to the pump chamber 104, and when the diaphragm swings repeatedly, as shown in Figure 4(d), the top dead center gradually becomes more curved shape. Therefore, a state where fluid remains (ineffective volume D) occurs in the curved portion, and the compression ratio expressed by the maximum capacity of the pump chamber 104 (capacity before compression)/the minimum capacity of the pump chamber 104 (capacity after compression) changes It is small, and there is a problem that the efficiency of fluid suction/discharge is reduced.

The present invention was proposed in view of the above-mentioned problems, and its object is to provide a diaphragm pump that can prevent the deterioration of the diaphragm and increase the compression ratio of the pump, thereby having a long life and high performance.

[Technical Means for Solving the Problem] In order to achieve the above-mentioned object, the present invention provides a diaphragm pump with a pump head, a flexible diaphragm provided inside the pump head, a driving mechanism connected to the diaphragm, and a diaphragm pump inside the pump head The pump chamber divided by the diaphragm changes the pressure of the pump chamber and transmits fluid as the diaphragm reciprocates in the thickness direction by the drive mechanism, and is characterized in that the diaphragm is formed on the outer periphery There is a mountain-shaped part protruding in the thickness direction, the peripheral end part is fixed to the pump head, and the driving mechanism is connected to the central part, when the diaphragm is reciprocated by the driving mechanism in the thickness direction , While the first inclined portion on the radially outer side of the apex of the ridge portion is maintained in an inclined state, the second inclined portion on the radially inner side of the apex of the ridge portion swings with the apex as a fulcrum .

According to this, while the first inclined part of the mountain-shaped part of the diaphragm is maintained in an inclined state, the second inclined part swings with the apex part as a fulcrum. Since almost no tension is generated on the diaphragm, the diaphragm can be prevented from moving in the radial direction. extend. Therefore, the deterioration of the diaphragm can be prevented.

In addition, while the first inclined portion of the mountain-shaped portion of the diaphragm is maintained in an inclined state, the second inclined portion swings with the apex portion as a fulcrum. Since unnecessary deformation is difficult to occur in the outer peripheral portion of the diaphragm, it is possible to prevent or reduce The outer periphery of the diaphragm generates an ineffective volume. Therefore, the compression ratio expressed by the maximum capacity of the pump chamber (capacity before compression)/the minimum capacity of the pump chamber (capacity after compression) can be expanded.

In addition, the pump head may be provided with a supporting member for maintaining the inclined state of the first inclined portion of the mountain-shaped portion of the diaphragm. According to this, since the first inclined portion of the mountain-shaped portion of the diaphragm is surely maintained in an inclined state, the second inclined portion can stably swing with the vertex portion as a fulcrum.

In addition, the drive mechanism is provided with a support member that supports the diaphragm. While the support member always supports the portion of the diaphragm other than the ridge portion, it supports the diaphragm at the top dead center of the movement. The second inclined part of the mountain-shaped part can be separated at the bottom dead center of the movement of the diaphragm. According to this, the second inclined portion can stably swing with the vertex portion as a fulcrum.

In addition, a support side buffer material is provided between the diaphragm and the support member, and the support side buffer material may be provided in a form extending from the peripheral end surface of the support member toward the outer side in the radial direction. According to this, it is possible to prevent the support member from contacting the diaphragm and prevent contact with the inner wall of the pump head, thereby reducing the deterioration of the diaphragm.

In addition, the drive mechanism is provided with a restraining member that restrains the diaphragm, and a restraining side cushioning material is provided between the diaphragm and the restraining member, and the restraining side cushioning material may be provided from the circumference of the restraining member. A form in which the end surface extends outward in the radial direction. According to this, it is possible to prevent the suppression member from contacting the diaphragm and reduce the deterioration of the diaphragm.

Moreover, the diaphragm may be composed of polytetrafluoroethylene. According to this, the first inclined portion and the second inclined portion of the mountain-shaped portion of the diaphragm can be flexibly deformed in the thickness direction while generating a certain degree of rigidity.

In addition, the support side buffer material and/or the suppression side buffer material may be composed of polytetrafluoroethylene. When the diaphragm and the cushioning material are made of the same material, since moderate sliding occurs between the diaphragm and the cushioning material in the radial direction, the diaphragm can be deformed smoothly.

[Effects of the Invention] Accordingly, while the first inclined portion of the mountain-shaped portion of the diaphragm is maintained in an inclined state, the second inclined portion swings with the apex as a fulcrum, and since there is almost no tension on the diaphragm, it can be prevented The diaphragm extends in the radial direction. Therefore, the deterioration of the diaphragm can be prevented, and the product life of the diaphragm pump can be extended.

In addition, while the first inclined portion of the mountain-shaped portion of the diaphragm is maintained in an inclined state, the second inclined portion swings with the apex portion as a fulcrum. Since unnecessary deformation is difficult to occur in the outer peripheral portion of the diaphragm, it is possible to prevent or reduce The outer periphery of the diaphragm generates an ineffective volume. Therefore, the compression ratio expressed by the maximum capacity of the pump chamber (capacity before compression)/the minimum capacity of the pump chamber (capacity after compression) can be expanded, and the performance of the diaphragm pump can be improved.

Next, referring to FIGS. 1 to 3, an embodiment of the diaphragm pump of the present invention (hereinafter referred to as the present pump) will be described. In addition, in this specification, the "upper" means the upper side with respect to the case of FIG. 1, and the "lower" means the lower side with respect to the case of FIG.

The pump is equipped with a pump head 1, a diaphragm provided in the pump head 1, a driving mechanism 3 connected to the diaphragm 2, and a pump chamber 4 divided by the diaphragm 2, which is reciprocated by the driving mechanism 3 in the thickness direction through the diaphragm 2 The movement causes the pressure in the pump chamber 4 to change and transfer fluid.

As shown in FIG. 1, the pump head 1 is provided with a dome-shaped recess 11 with a circular cross section on the upper surface of the internal space. This pump head 1 is provided with a diaphragm 2 so as to cover the recess 11, forming a pump chamber 4 with the recess 11 as an upper wall and the diaphragm 2 as a bottom wall. In addition, a circulation port 12 through which fluid flows is provided in the center of the recess 11.

In addition, the pump head 1 is provided with a diaphragm fixing portion 13 on the side wall of the internal space, which fixes the peripheral end portion 2c of the diaphragm 2. The diaphragm fixing portion 13 includes a first fixing portion 13a provided on the front side of the diaphragm 2, a second fixing portion 13b provided on the side surface of the diaphragm 2, and a third fixing portion 13c provided on the back side of the diaphragm 2. The 1 to 3 fixing portions 13a, 13b, and 13c, and the peripheral end portion 2c of the diaphragm 2 are fixed so as to be surrounded from the front side, the back side, and the side surface. Thereby, when the diaphragm 2 reciprocates in the thickness direction, it is possible to prevent external air from entering the inside of the pump chamber 4 from the peripheral end 2c, or leakage of fluid from the peripheral end 2c to the outside of the pump chamber 4.

In addition, a protrusion 14 protruding downward is provided in the vicinity of the third fixing portion 13c, and the protrusion 14 pushes the end of the diaphragm 2 downward. As a result, it is possible to more reliably prevent external air from entering the pump chamber 4 from the peripheral end portion 2c of the diaphragm 2, or leakage of fluid from the peripheral end portion 2c to the outside of the pump chamber 4.

The diaphragm 2 is a flexible film-like member formed of polytetrafluoroethylene (registered trademark: Teflon) that is circular in plan view, and is set to be flexible and deformable in the thickness direction.

In addition, the diaphragm 2 is provided with an upper holder 33 as a restraining member on the upper side, and a lower holder 34 as a supporting member on the lower side. The upper holder 33 and the lower holder 34 are. The upper holder 33 and the lower holder 34 are substantially disc-shaped members formed of synthetic resin, and sandwich the diaphragm 2 from the vertical direction. In addition, the upper holder 33 is formed in a shape whose upper surface follows the inner surface of the recess 11 of the pump head 1.

In particular, in this embodiment, as shown in FIG. 3, a cushioning material 35 made of polytetrafluoroethylene (registered trademark: Teflon) is provided between the upper holder 33 and the diaphragm 2. Since this cushioning material 35 is provided in a form extending from the peripheral end surface of the upper holder 33 to the outside in the radial direction, it can prevent the upper holder 33 from contacting the diaphragm 2 and reduce the deterioration of the diaphragm 2.

In addition, as shown in FIG. 3, the lower retainer 34 is formed to be longer in the radial direction than the upper retainer 33, and while supporting the lower surface of the diaphragm 2 except for the portion 21 of the ridge portion, the diaphragm 2 moves The second inclined portion 213 of the mountain-shaped portion 21 is supported at the top dead center, and is in a separated state at the bottom dead center. Thereby, the second inclined portion 213 can stably swing with the vertex portion 211 as a fulcrum.

In addition, as shown in FIG. 3, between the lower holder 34 and the diaphragm 2, a cushion material 36 made of polytetrafluoroethylene (registered trademark: Teflon) is provided. Since this cushioning material 36 is provided in a form extending from the peripheral end surface of the lower holder 34 to the outside in the radial direction, it can prevent the lower holder 34 from contacting the diaphragm 2 and the inner wall of the pump head 1, thereby reducing the diaphragm 2. Deterioration.

In addition, the diaphragm 2 is a connecting rod (Connecting rod) 31 that is connected to the drive mechanism 3 through the upper holder 33 and the lower holder 34 through the central portion 2 a. Therefore, the diaphragm 2 reciprocates by the driving mechanism 3 in the thickness direction, so that the pressure of the pump chamber 4 changes, and the fluid is transferred through the flow port 12. Specifically, when the diaphragm 2 is moved downward by the driving mechanism 3, the volume of the pump chamber 4 increases to generate a negative pressure, and the fluid is sucked into the pump chamber 4 through the circulation port 12. On the other hand, when the diaphragm 2 is moved upward by the driving mechanism 3, the volume of the pump chamber 4 is reduced to generate a positive pressure, and the fluid is discharged from the pump chamber 4 through the flow port 12.

In addition, as shown in FIG. 3, the central portion 2 a of the diaphragm 2 is formed in a flat shape by being sandwiched by the upper holder 33 and the lower holder 34. Then, when the diaphragm 2 is reciprocated by the driving mechanism 3 in the thickness direction, the central portion 2a of the diaphragm 2 swings up and down while maintaining a flat state.

In addition, as shown in FIG. 3( b ), the diaphragm 2 is provided with a mountain-shaped part 21 that is bent into a mountain-shape so as to protrude toward the pump chamber 4 in the outer peripheral part 2 b. This mountain-shaped portion 21 includes an apex portion 211 located in the center portion, a first inclined portion 212 that rises from the peripheral end portion 2c of the diaphragm 2 obliquely upward in the radial direction, and a apex portion 211 facing The second inclined portion 213 that descends so as to extend diagonally downward on the inner side in the radial direction. Then, when the diaphragm 2 is reciprocated by the drive mechanism 3 in the thickness direction, while the first inclined portion 212 of the ridge portion 21 is maintained in an inclined state, the second inclined portion 213 of the ridge portion 21 becomes a vertex The part 211 swings as a fulcrum.

In particular, in this embodiment, the supporting member 15 for maintaining the inclined state of the first inclined portion 212 of the gable portion 21 of the diaphragm 2 is provided. This supporting member 15 is composed of a lower side supporting member 15a of the first inclined portion 212 supporting the mountain-shaped portion 21 of the diaphragm 2, and an upper side supporting member 15b supporting the first inclined portion 212, from the vertical direction The first inclined portion 212 is supported. Thereby, the inclined state of the first inclined portion 212 can be reliably maintained, and the second inclined portion 213 can stably swing with the vertex portion 211 as a fulcrum. In addition, the support member 15 and the first inclined portion 212 may be in close contact, or may be in a state where a predetermined gap is provided.

The drive mechanism 3 includes a motor (not shown) having a rotating shaft, an eccentric member 32 mounted on the rotating shaft of the motor, and a connecting rod 31 provided on the eccentric member 32 and connected to the diaphragm 2. The lower end of the eccentric member 32 is mounted on the rotating shaft of the motor at a position offset from the center. The connecting rod 31 is inserted into a hole provided in the center of the eccentric member 32 through a bearing metal piece, is connected to the upper holder 33 by a screw provided at the upper end, and is connected to the diaphragm 2 through the upper holder 33 and the lower holder 34的中心部 2a. Thereby, the rotational movement of the motor is converted into the vertical reciprocating movement of the connecting rod 31 through the eccentric member 32.

In this way, when the pump is discharging fluid, the connecting rod 31 moves upward to push up the center portion 2a of the diaphragm 2 upward. On the other hand, when the pump is sucking fluid, the connecting rod 31 moves downward to pull the central portion 2a of the diaphragm 2 downward.

Next, the operation of this pump will be described with reference to FIG. 3.

When the pump is discharging fluid, from the bottom dead center position of Fig. 3(b), the connecting rod 31 moves upward to push up the central portion 2a of the diaphragm 2 upward.

Then, as the central portion 2a is pushed upward by the connecting rod 31, the diaphragm 2 is maintained in an inclined state by the first inclined portion 212 of the mountain-shaped portion 21, and the second inclined portion 213 of the mountain-shaped portion 21 has an apex. 211 swings upward as a fulcrum, and the central portion 2a of the diaphragm 2 and the second inclined portion 213 are in a state where the cross-section is flat and connected on the same plane and has a slightly stepped shape, and moves to the top dead center position of Fig. 3(a) .

At this time, the upper holder 33 is in a state close to the inner surface of the recess 11 of the pump head 1, the volume of the pump chamber 4 is reduced to generate positive pressure, and the fluid is discharged from the pump chamber 4 through the flow port 12.

On the other hand, when the pump is sucking fluid, from the top dead center position of FIG. 3(a), the connecting rod 31 moves downward to pull the central portion 2a of the diaphragm 2 downward.

Then, as the central portion 2a is pulled down by the connecting rod 31, the diaphragm 2 is maintained in the inclined state by the first inclined portion 212 of the mountain-shaped portion 21, and the second inclined portion 213 of the mountain-shaped portion 21 has a vertex. 211 swings downward as a fulcrum, the central portion 2a of the diaphragm 2 maintains a flat state, and the first inclined portion 212 and the second inclined portion 213 return to the original mountain-shaped state, and move to the bottom dead center of Fig. 3(b) position.

At this time, the upper holder 33 is separated from the inner surface of the recess 11 of the pump head 1, the volume of the pump chamber 4 increases to generate a negative pressure, and the fluid is sucked into the pump chamber 4 through the flow port 12.

In this way, when the diaphragm 2 reciprocates up and down in the thickness direction, the first inclined portion 212 of the ridge portion 21 is maintained in an inclined state by the diaphragm 2 while the second inclined portion 213 uses the apex portion 211 as a fulcrum. Since the swinging force hardly generates a pulling force on the diaphragm 2, it can be prevented from extending in the radial direction. In fact, in this embodiment, the radius of the diaphragm 2 at the top dead center and the bottom dead center is measured. The top dead center is 45.8mm and the bottom dead center is 45.9mm. The top dead center and the bottom dead center are confirmed There is almost no difference in the radius of the diaphragm 2 at. Therefore, the deterioration of the diaphragm 2 can be prevented, and the product life of the pump can be extended.

In addition, by maintaining the inclined state of the first inclined portion 212 of the mountain-shaped portion 21 of the diaphragm 2 while the second inclined portion 213 swings with the apex portion 211 as a fulcrum, it is difficult to cause unnecessary occurrence in the outer peripheral portion 2b of the diaphragm 2. Therefore, it is possible to prevent or reduce the generation of ineffective volume in the outer peripheral portion 2b of the diaphragm 2. Therefore, the compression ratio expressed by the maximum capacity of the pump chamber 4 (capacity before compression)/the minimum capacity of the pump chamber 4 (capacity after compression) can be expanded, and the performance of the pump can be improved.

In addition, although it has been described that the diaphragm 2 is provided with the mountain-shaped part 21 in advance, the mountain-shaped part 21 may be provided later by the support member 15.

In addition, the diaphragm 2 is supported by the support member 15 from the vertical direction to the first inclined portion 212 of the ridge portion 21, but it may be supported only by one of the upper or lower sides of the support member 15, or not supported It is also possible. However, when the first inclined portion 212 of the mountain-shaped portion 21 is not supported by the support member 15, it is preferable to increase the rigidity of the first inclined portion 212 so that the first inclined portion 212 can be maintained during the reciprocating movement of the diaphragm 2. 1 The structure of the inclined state of the inclined portion 212.

In addition, the diaphragm 2 is made of polytetrafluoroethylene, but it may be made of other materials. However, in the case where the diaphragm 2 is composed of polytetrafluoroethylene, the first inclined portion 212 and the second inclined portion 213 of the mountain-shaped portion 21 of the diaphragm 2 generate a certain degree of rigidity at the same time, in the thickness direction It can be softly deformed, so it is preferable.

In addition, the buffer materials 35 and 36 are made of polytetrafluoroethylene, but they may be other materials. However, when the diaphragm 2 and the cushioning materials 35 and 36 are made of the same material, since moderate sliding occurs in the radial direction between the diaphragm 2 and the cushioning materials 35 and 36, the diaphragm 2 can be deformed smoothly, so it is more good.

Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the illustrated embodiments. With respect to the illustrated embodiment, various corrections and modifications can be added within the same range as the present invention or within an equal range.

1‧‧‧Pump head 11‧‧‧Concave part 12‧‧‧Circulation port 13‧‧‧Diaphragm fixing part 13a‧‧‧The first fixing part 13b‧‧‧The second fixing part 13c‧‧‧The third fixing part 14‧ ‧‧Protrusion 15‧‧‧Supporting member 15a‧‧‧Lower supporting member 15b‧‧‧Upper supporting member 2‧‧‧Diaphragm 2a‧‧‧Central part 2b‧‧‧Outer peripheral part 2c‧‧‧Circumferential end 21 ‧‧‧Mountain part 211‧‧‧Vertex part 212‧‧‧First inclined part 213‧‧‧Second inclined part 3‧‧‧Drive mechanism 31‧‧‧Connecting rod 32‧‧‧Eccentric member 33‧‧‧ Upper retainer 34‧‧‧Lower retainer 35, 36‧‧‧Buffer material 4‧‧‧Pump chamber

Figure 1 is a front sectional view of the diaphragm pump.

Fig. 2 is an enlarged front sectional view of an important part of the diaphragm of Fig. 1.

Fig. 3 is a front cross-sectional view showing (a) the state of the top dead center and (b) the state of the bottom dead center of the diaphragm of Fig. 1.

Fig. 4 is a front sectional view showing a conventional diaphragm pump.

1‧‧‧Pump head

11‧‧‧Concave

12‧‧‧Circulation port

13‧‧‧Diaphragm fixing part

13a‧‧‧The first fixed part

13b‧‧‧Second fixed part

13c‧‧‧The third fixed part

14‧‧‧Protrusion

15‧‧‧Supporting member

15a‧‧‧Lower side support member

15b‧‧‧Upper support member

2a‧‧‧Central part

2b‧‧‧peripheral part

2c‧‧‧week end

21‧‧‧Mountain Department

211‧‧‧Vertex

212‧‧‧The first inclined part

213‧‧‧Second Incline

31‧‧‧Connecting rod

33‧‧‧Upper retainer

34‧‧‧Lower side retainer

35、36‧‧‧Buffer material

4‧‧‧Pump Room

Claims (7)

A diaphragm pump is provided with a pump head, a flexible diaphragm arranged inside the pump head, a driving mechanism connected to the diaphragm, and a pump chamber divided by the diaphragm inside the pump head. The diaphragm is reciprocated in the thickness direction by the drive mechanism to change the pressure in the pump chamber and transfer fluid. The diaphragm is characterized in that the diaphragm has a mountain-shaped portion protruding in the thickness direction formed on the outer periphery of the diaphragm. The end is fixed to the pump head, and the drive mechanism is connected to the central portion. When the diaphragm is reciprocated by the drive mechanism in the thickness direction, it is located between the apexes of the chevron While the first inclined portion on the outer side in the radial direction is maintained in an inclined state, the second inclined portion on the inner side in the radial direction of the vertex of the mountain-shaped portion swings with the vertex as a fulcrum, and the driving mechanism is provided with a support for the diaphragm The support member, which always supports the part of the diaphragm other than the mountain-shaped part, supports the second inclined part of the mountain-shaped part at the top dead center of the movement of the diaphragm, and The movement of the diaphragm is separated at the bottom dead center, and at the top dead center, the central portion of the diaphragm and the second inclined portion are connected flatly on the same plane. The diaphragm pump according to claim 1, wherein the pump head is provided with a supporting member for maintaining the inclined state of the first inclined portion of the mountain-shaped portion of the diaphragm. The diaphragm pump according to claim 1 or 2, wherein a support side buffer material is provided between the diaphragm and the support member, and the support side buffer material is provided so as to face the diameter from the peripheral end surface of the support member The shape extends outward in the direction. The diaphragm pump according to claim 1 or 2, wherein the drive mechanism is provided with a suppression member that suppresses the diaphragm, and a suppression side cushioning material is disposed between the diaphragm and the suppression member, and the suppression side cushioning The material is provided so as to extend from the peripheral end surface of the suppression member toward the outside in the radial direction. The diaphragm pump according to claim 3, wherein the driving mechanism is provided with a restraining member that restrains the diaphragm, and a restraining side buffer material is provided between the diaphragm and the restraining member, and the restraining side buffer material is It is provided in the form extended from the peripheral end surface of the said suppression member toward the radial direction outer side. The diaphragm pump according to claim 1 or 2, wherein the diaphragm is composed of polytetrafluoroethylene. In the diaphragm pump according to claim 5, the support side buffer material and/or the suppression side buffer material are composed of polytetrafluoroethylene.

Images