CN212898872U - Diaphragm pump - Google Patents

Abstract

An object of the utility model is to provide a diaphragm pump, its degradation that can prevent the diaphragm and enlarge the compression ratio of pump, and then can be longe-lived and high performance. A diaphragm pump is provided with: a pump head 1, a diaphragm 2 inside the pump head 1, a drive mechanism 3 connected to the diaphragm 2, and a pump chamber 4 inside the pump head 1 divided by the diaphragm 2. The diaphragm 2 has a ridge portion 21 protruding in the thickness direction formed 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, and when the diaphragm 2 reciprocates in the thickness direction by the driving mechanism 3, the 1 st inclined portion 212 radially outside the apex portion 211 of the ridge portion 21 is maintained in an inclined state, and the 2 nd inclined portion 213 radially inside the apex portion 212 of the ridge portion 21 swings with the apex portion 211 as a fulcrum.

Description

Diaphragm pump

Technical Field

The present invention relates to a diaphragm pump for transferring fluid by swinging a diaphragm.

Background

A diaphragm pump has been known as a pump for transferring a fluid. The diaphragm pump includes a pump head, a flexible diaphragm provided inside the pump head, a driving mechanism connected to the diaphragm, and a pump chamber partitioned by the diaphragm inside the pump head, and the pump chamber is configured to transmit a fluid by changing a pressure of the pump chamber as the diaphragm reciprocates in a thickness direction by the driving mechanism (see, for example, patent document 1).

However, in many conventional diaphragm pumps, since the diaphragm is formed in a flat plate shape, each time the diaphragm expands toward the pump chamber side, a large tensile force is generated in the radial direction of the diaphragm and the diaphragm is stretched, which causes a problem that the diaphragm deteriorates in a short time.

In order to prevent such a pulling force from being generated in the diaphragm pump, it is also known that a hanging portion 102a is formed in the diaphragm 102 so as to protrude gradually in the thickness direction as shown in fig. 4 (b). Thereby, as shown in fig. 4(a), when the diaphragm 102 expands toward the pump chamber 104, the hanging portion 102a formed in the diaphragm 102 absorbs the tensile force, and thus the deterioration of the diaphragm 102 can be prevented.

Documents of the prior art

Patent document

Patent document 1: japanese Kokai publication Hei-7-14179

SUMMERY OF THE UTILITY MODEL

Problems to be solved by the utility model

However, when the diaphragm 102 swings, the drooping portion 102a of the diaphragm 102 often becomes an unstable shape. Specifically, as shown in fig. 4(b), the hanging-down portion 102a is in a state of maintaining a predetermined shape at the operating bottom dead center of the diaphragm 102, but as shown in fig. 4(c), the hanging-down portion 102a has a shape slightly curved on the opposite side to the pump chamber 104 at the top dead center due to the influence of the original shape, and when the diaphragm is repeatedly swung, the hanging-down portion gradually becomes a shape having a larger curvature at the top dead center as shown in fig. 4 (d). Therefore, in a state (dead volume D) where fluid remains in the curved portion, a compression ratio represented by the maximum capacity (pre-compression capacity) of the pump chamber 104/the minimum capacity (post-compression capacity) of the pump chamber 104 is decreased, which may lower the efficiency of fluid suction/discharge.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a diaphragm pump which can prevent deterioration of a diaphragm and enlarge a compression ratio of a pump, and further can have a long life and high performance.

Means for solving the problems

In order to achieve the above object, the present invention provides a diaphragm pump comprising a pump head, a flexible diaphragm disposed inside the pump head, a driving mechanism connected to the diaphragm, and a pump chamber defined inside the pump head by the diaphragm, wherein the diaphragm reciprocates in a thickness direction by the driving mechanism to change a pressure in the pump chamber and transfer a fluid, characterized in that the diaphragm is formed with a ridge portion protruding in the thickness direction at the outer peripheral portion, the peripheral end portion 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, while the 1 st inclined part radially outside the apex part of the mountain-shaped part is maintained in an inclined state, the 2 nd inclined portion radially inside the apex portion of the mountain-shaped portion swings with the apex portion as a fulcrum.

Accordingly, since the 1 st inclined portion of the ridge portion of the diaphragm swings about the apex portion as a fulcrum while the 1 st inclined portion is maintained in an inclined state, a tensile force is hardly generated in the diaphragm, and thus the diaphragm can be prevented from extending in the radial direction. Therefore, deterioration of the separator can be prevented.

Further, since the 1 st inclined portion of the ridge portion of the diaphragm is maintained in an inclined state and the 2 nd inclined portion swings with the apex portion as a fulcrum, unnecessary deformation is less likely to occur in the outer peripheral portion of the diaphragm, and generation of dead volume in the outer peripheral portion of the diaphragm can be prevented or reduced. Therefore, the compression ratio expressed by the maximum capacity of the pump chamber (pre-compression capacity)/the minimum capacity of the pump chamber (post-compression capacity) can be expanded.

The pump head may be provided with a support member for maintaining an inclined state of the 1 st inclined portion of the mountain portion of the diaphragm. Accordingly, the 1 st inclined portion of the ridge portion of the diaphragm is reliably maintained in an inclined state, and the 2 nd inclined portion can stably swing with the apex portion as a fulcrum.

Further, the driving mechanism may be provided with a support member supporting the diaphragm, the support member constantly supporting a portion of the diaphragm other than the ridge portion, and supporting the 2 nd inclined portion of the ridge portion at the top dead center of the operation of the diaphragm to be separated at the bottom dead center of the operation of the diaphragm. Accordingly, the 2 nd inclined portion can stably swing with the apex portion as a fulcrum.

Further, a support-side cushion member may be provided between the diaphragm and the support member, and the support-side cushion member may extend radially outward from a peripheral end surface of the support member. Accordingly, the support member can be prevented from contacting the diaphragm and the inner wall of the pump head, and deterioration of the diaphragm can be reduced.

The drive mechanism may be provided with a restraining member that restrains the diaphragm, and a restraining-side cushion member may be provided between the diaphragm and the restraining member, the restraining-side cushion member extending radially outward from a peripheral end surface of the restraining member. Accordingly, the restraining member can be prevented from contacting the separator, and deterioration of the separator can be reduced.

The diaphragm may be made of polytetrafluoroethylene. Accordingly, the 1 st inclined portion and the 2 nd inclined portion of the ridge portion of the diaphragm can be flexibly deformed in the thickness direction while a certain degree of rigidity is imparted.

The support-side cushioning material and/or the restraint-side cushioning material may be made of polytetrafluoroethylene. When the diaphragm and the cushion material are made of the same material, the diaphragm can be smoothly deformed because a proper amount of sliding occurs in the radial direction between the diaphragm and the cushion material.

Effect of the utility model

Accordingly, the 1 st inclined portion of the ridge portion of the diaphragm swings about the apex portion as a fulcrum while the 1 st inclined portion is maintained in an inclined state, and therefore, almost no tensile force is generated in the diaphragm, and therefore, the diaphragm can be prevented from extending in the radial direction. Therefore, the deterioration of the diaphragm can be prevented, and the product life of the diaphragm pump can be extended.

Further, since the 1 st inclined portion of the ridge portion of the diaphragm is maintained in an inclined state and the 2 nd inclined portion swings with the apex portion as a fulcrum, unnecessary deformation is less likely to occur in the outer peripheral portion of the diaphragm, and generation of dead volume in the outer peripheral portion of the diaphragm can be prevented or reduced. Therefore, the compression ratio expressed by the maximum capacity of the pump chamber (pre-compression capacity)/the minimum capacity of the pump chamber (post-compression capacity) can be increased, and the performance of the diaphragm pump can be improved.

Drawings

FIG. 1 is a front sectional view of a diaphragm pump.

Fig. 2 is an enlarged front sectional view of an emphasized portion of the diaphragm of fig. 1.

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

Fig. 4(a), (b), (c), and (d) are front sectional views showing a conventional diaphragm pump, fig. 4(a) is a state when the diaphragm expands toward the pump chamber, fig. 4(b) is a state in which the hanging portion is maintained in a predetermined shape at the bottom dead center of the operation of the diaphragm, fig. 4(c) is a state in which the hanging portion is slightly curved at the opposite side to the pump chamber at the top dead center, and fig. 4(d) is a state in which the hanging portion is gradually changed into a more curved shape at the top dead center.

Detailed Description

Next, an embodiment of a diaphragm pump (hereinafter, referred to as a present pump) according to the present invention will be described with reference to fig. 1 to 3(a) and 3 (b). In the present specification, "upper" means an upper side with respect to the case of fig. 1, and "lower" means a lower side with respect to the case of fig. 1.

The pump includes a pump head 1, a diaphragm 2 provided inside the pump head 1, a drive mechanism 3 connected to the diaphragm 2, and a pump chamber 4 partitioned by the diaphragm 2, and the diaphragm 2 reciprocates in a thickness direction by the drive mechanism 3 to change a pressure of the pump chamber 4 and transmit a fluid.

As shown in fig. 1, the pump head 1 is provided with a dome-shaped recess 11 having 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, and forms a pump chamber 4 having the recess 11 as an upper wall and the diaphragm 2 as a bottom wall. A flow port 12 through which a fluid flows is provided in the center of the recess 11.

The pump head 1 is provided with a diaphragm fixing portion 13 for fixing a peripheral end portion 2c of the diaphragm 2 in a side wall portion of the internal space. The diaphragm fixing portion 13 includes a 1 st fixing portion 13a provided on the front surface side of the diaphragm 2, a 2 nd fixing portion 13b provided on the side surface side of the diaphragm 2, and a 3 rd fixing portion 13c provided on the back surface side of the diaphragm 2, and the peripheral end portion 2c of the diaphragm 2 is fixed so as to be surrounded from the front surface side, the back surface side, and the side surface by these 1 st to 3 rd fixing portions 13a, 13b, and 13 c. This prevents outside air from entering the pump chamber 4 from the peripheral end 2c or prevents fluid from leaking out of the pump chamber 4 from the peripheral end 2c when the diaphragm 2 reciprocates in the thickness direction.

Further, a projection 14 projecting downward is provided in the vicinity of the 3 rd fixing portion 13c, and the projection 14 presses the end portion of the diaphragm 2 downward. This prevents the outside air from entering the pump chamber 4 from the peripheral end 2c of the diaphragm 2 or the fluid from leaking out of the pump chamber 4 from the peripheral end 2c more reliably.

The diaphragm 2 is a flexible film-like member formed of polytetrafluoroethylene (registered trademark: teflon) and having a circular shape in plan view, and is provided so as to be flexibly deformable in the thickness direction.

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 substantially disk-shaped members formed of synthetic resin, and sandwich the diaphragm 2 from the top and bottom. In addition, the upper holder 33 is formed in a shape in which the upper surface follows the inner surface of the recess 11 of the pump head 1.

In particular, in the present embodiment, as shown in fig. 3(a) and 3(b), a buffer material 35 made of polytetrafluoroethylene (registered trademark: teflon) is provided between the upper holder 33 and the diaphragm 2. Since the cushion material 35 is provided in a form extending radially outward from the peripheral end surface of the upper holder 33, the upper holder 33 can be prevented from contacting the diaphragm 2, and deterioration of the diaphragm 2 can be reduced.

As shown in fig. 3(a) and 3(b), the lower holder 34 is formed to be longer than the upper holder 33 in the radial direction, and is formed to support the lower surface of the diaphragm 2 except for the ridge portion 21, and to support the 2 nd inclined portion 213 of the ridge portion 21 at the top dead center where the diaphragm 2 operates, and to be separated at the bottom dead center. Thereby, the 2 nd inclined portion 213 can stably swing with the apex portion 211 as a fulcrum.

As shown in fig. 3a and 3b, a cushion material 36 made of polytetrafluoroethylene (registered trademark: teflon) is provided between the lower retainer 34 and the diaphragm 2. Since the buffer material 36 is provided in a form extending radially outward from the peripheral end surface of the lower holder 34, the lower holder 34 can be prevented from contacting the diaphragm 2 and the inner wall of the pump head 1, thereby reducing deterioration of the diaphragm 2.

The diaphragm 2 is a connecting rod 31 having a central portion 2a connected to the drive mechanism 3 via an upper holder 33 and a lower holder 34. Therefore, the diaphragm 2 reciprocates in the thickness direction by the drive mechanism 3, so that the pressure of the pump chamber 4 is varied, and fluid is transferred via the communication port 12. Specifically, when the diaphragm 2 is moved downward by the drive 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 communication port 12. On the other hand, when the diaphragm 2 is moved upward by the drive mechanism 3, the volume of the pump chamber 4 decreases to generate a positive pressure, and the fluid is discharged from the pump chamber 4 through the flow port 12.

As shown in fig. 3(a) and 3(b), the diaphragm 2 has a flat central portion 2a sandwiched between an upper holder 33 and a lower holder 34. When the diaphragm 2 reciprocates in the thickness direction by the driving mechanism 3, the central portion 2a of the diaphragm 2 swings up and down while maintaining a flat state.

As shown in fig. 3(b), the diaphragm 2 is provided with a mountain-shaped portion 21 bent in a mountain-shape so as to protrude toward the pump chamber 4 in the outer peripheral portion 2 b. The mountain-shaped portion 21 includes: the apex portion 211 at the central portion includes a 1 st inclined portion 212 rising upward so as to extend obliquely upward radially inward from the peripheral end portion 2c of the diaphragm 2, and a 2 nd inclined portion 213 descending so as to extend obliquely downward radially inward from the apex portion 211. Then, when the diaphragm 2 reciprocates in the thickness direction by the driving mechanism 3, the 1 st inclined portion 212 of the ridge portion 21 is maintained in an inclined state, and the 2 nd inclined portion 213 of the ridge portion 21 swings with the apex portion 211 as a fulcrum.

In particular, in the present embodiment, the support member 15 for maintaining the inclined state of the 1 st inclined portion 212 of the mountain-shaped portion 21 of the diaphragm 2 is provided. The support member 15 is composed of a lower support member 15a supporting the lower side of the 1 st inclined portion 212 of the mountain-shaped portion 21 of the diaphragm 2, and an upper support member 15b supporting the upper side of the 1 st inclined portion 212, and supports the 1 st inclined portion 212 from the up-down direction. With this, the inclination state of the 1 st inclined portion 212 can be reliably maintained, and the 2 nd inclined portion 213 can stably swing with the apex portion 211 as a fulcrum. Further, the supporting member 15 and the 1 st inclined part 212 may be in close contact with each other, 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 to the eccentric member 32 and connected to the diaphragm 2. The eccentric member 32 is mounted at a lower end portion on a rotation shaft of the motor at a position off-center. The connecting rod 31 is inserted into a hole provided in the center of the eccentric member 32 through a bearing metal, connected to the upper holder 33 by a screw provided at the upper end portion, and connected to the central portion 2a of the diaphragm 2 by the upper holder 33 and the lower holder 34. Thereby, the rotational motion of the motor is converted into the reciprocating motion of the connecting rod 31 in the up-down direction by the eccentric member 32.

In this way, when the pump discharges fluid, the connecting rod 31 moves upward to push up the central portion 2a of the diaphragm 2. On the other hand, when the pump sucks fluid, the connecting rod 31 moves downward, thereby pulling down the central portion 2a of the diaphragm 2.

Next, the operation of the present pump will be described with reference to fig. 3(a) and 3 (b).

When the pump discharges fluid, the connecting rod 31 moves upward from the bottom dead center position of fig. 3(b), and the center portion 2a of the diaphragm 2 is pushed upward.

Then, the diaphragm 2 is pushed up upward by the tie bar 31 with the central portion 2a, and is kept in an inclined state by the 1 st inclined portion 212 of the ridge portion 21, and the 2 nd inclined portion 213 of the ridge portion 21 swings upward with the apex portion 211 as a fulcrum, so that the central portion 2a and the 2 nd inclined portion 213 of the diaphragm 2 are flatly connected on the same plane, and are pushed to a position of the top dead center in fig. 3(a) while being in a substantially step-like state in cross section.

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

On the other hand, when the pump sucks the fluid, the connecting rod 31 moves downward from the top dead center position of fig. 3(a), and the center portion 2a of the diaphragm 2 is pulled downward.

Then, the diaphragm 2 is pulled down by the connecting rod 31 along with the central portion 2a, and the 1 st inclined portion 212 of the ridge portion 21 is maintained in an inclined state, and the 2 nd inclined portion 213 of the ridge portion 21 swings downward with the apex portion 211 as a fulcrum, so that the central portion 2a of the diaphragm 2 is maintained in a flat state, and the 1 st inclined portion 212 and the 2 nd inclined portion 213 return to an original ridge state and are pushed to a position of a bottom dead center in fig. 3 (b).

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 communication port 12.

In this way, when the diaphragm 2 reciprocates vertically in the thickness direction, the 2 nd inclined portion 213 swings about the apex portion 211 as a fulcrum while the diaphragm 2 is maintained in an inclined state at the 1 st inclined portion 212 of the ridge portion 21, and therefore, almost no tensile force is generated in the diaphragm 2, and extension in the radial direction can be prevented. In fact, in the present embodiment, the radius of the diaphragm 2 at the top dead center and the bottom dead center was measured, and it was confirmed that there was almost no difference in the radius of the diaphragm 2 at the top dead center and the bottom dead center, and the radius was 45.8mm at the top dead center and 45.9mm at the bottom dead center. Therefore, the deterioration of the diaphragm 2 can be prevented, and the product life of the pump can be extended.

Further, since the diaphragm 2 is swung with the apex portion 211 as a fulcrum while the 1 st inclined portion 212 of the mountain-shaped portion 21 is maintained in an inclined state and the 2 nd inclined portion 213 is kept in an inclined state, unnecessary deformation is less likely to occur in the outer peripheral portion 2b of the diaphragm 2, and therefore, generation of dead volume in the outer peripheral portion 2b of the diaphragm 2 can be prevented or reduced. Therefore, the compression ratio expressed by the maximum capacity of the pump chamber 4 (pre-compression capacity)/the minimum capacity of the pump chamber 4 (post-compression capacity) can be increased, and the performance of the pump can be improved.

Although the ridge portion 21 is provided in advance in the diaphragm 2, the ridge portion 21 may be provided later by the support member 15.

The diaphragm 2 is supported by the 1 st inclined portion 212 of the ridge portion 21 from the up-down direction by the support member 15, but may be supported only by one of the upper side and the lower side of the support member 15, or may not be supported. However, when the 1 st inclined portion 212 of the chevron portion 21 is not supported by the support member 15, a structure capable of maintaining the inclined state of the 1 st inclined portion 212 during the reciprocating motion of the diaphragm 2 is preferable such that the rigidity of the 1 st inclined portion 212 is increased.

The diaphragm 2 is made of polytetrafluoroethylene, but may be made of other materials. However, when the diaphragm 2 is made of polytetrafluoroethylene, it is preferable that the 1 st inclined portion 212 and the 2 nd inclined portion 213 of the ridge portion 21 of the diaphragm 2 are flexible in the thickness direction while having a certain degree of rigidity.

The cushioning materials 35 and 36 are made of polytetrafluoroethylene, but may be made of other materials. However, when the diaphragm 2 and the cushioning materials 35 and 36 are made of the same material, it is preferable that the diaphragm 2 be smoothly deformed because a proper amount of sliding occurs in the radial direction between the diaphragm 2 and the cushioning materials 35 and 36.

While 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. Various modifications and variations can be added to the illustrated embodiments within the same or equivalent ranges as the present invention.

Description of the reference numerals

1 Pump head

11 recess

12 flow port

13 diaphragm fixing part

13a 1 st fixing part

13b second fixing part

13c No. 3 fixing part

14 projecting part

15 support member

15a lower support member

15b upper side support member

2 diaphragm

2a central part

2b outer peripheral portion

2c peripheral end portion

21 mountain-shaped part

211 vertex part

212 st inclined part

213 nd inclined part 2

3 drive mechanism

31 connecting rod

32 eccentric component

33 upper holder

34 lower retainer

35. 36 buffer material

4 pump chamber

Claims (8)

1. A diaphragm pump comprising a pump head, a flexible diaphragm provided inside the pump head, a drive mechanism connected to the diaphragm, and a pump chamber partitioned by the diaphragm inside the pump head, wherein a pressure in the pump chamber is changed and a fluid is transferred as the diaphragm reciprocates in a thickness direction by the drive mechanism,

a diaphragm having a ridge portion formed on an outer peripheral portion thereof so as to protrude in a thickness direction, a peripheral end portion fixed to the pump head, and the driving mechanism connected to a central portion,

when the diaphragm reciprocates in the thickness direction by the drive mechanism, the 1 st inclined portion on the radially outer side of the apex portion of the ridge portion is maintained in an inclined state, and the 2 nd inclined portion on the radially inner side of the apex portion of the ridge portion swings with the apex portion as a fulcrum.

2. The diaphragm pump according to claim 1, wherein the pump head is provided with a support member for maintaining an inclined state of a 1 st inclined portion of the mountain-shaped portion of the diaphragm.

3. The diaphragm pump of claim 1 wherein said drive mechanism is provided with a support member supporting said diaphragm,

the support member supports the 2 nd inclined portion of the ridge portion at the top dead center of the operation of the diaphragm while constantly supporting the portion of the diaphragm other than the ridge portion, and separates at the bottom dead center of the operation of the diaphragm.

4. The diaphragm pump according to claim 3, wherein a support-side cushioning material is provided between the diaphragm and the support member,

the support-side cushioning material is provided so as to extend radially outward from the peripheral end surface of the support member.

5. The diaphragm pump according to claim 1, wherein the driving 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,

the restraining-side cushioning material is provided in a form extending radially outward from a peripheral end surface of the restraining member.

6. The diaphragm pump according to claim 4, wherein the driving 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,

the restraining-side cushioning material is provided in a form extending radially outward from a peripheral end surface of the restraining member.

7. The diaphragm pump of claim 1 wherein said diaphragm is comprised of polytetrafluoroethylene.

8. The diaphragm pump according to claim 6, wherein the support-side damper and/or the suppression-side damper is composed of polytetrafluoroethylene.

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