JP2004084504A - Diaphragm pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diaphragm pump free of pulsation at low cost in a simple configuration. <P>SOLUTION: The diaphragm pump is composed of a liquid feed part sucking in or discharging liquid, a diaphragm, a plurality of pump units concentrically arranged, a polyangular cam rotating at a center part of the pump unit and reciprocating on the diaphragm. The polyangular cam has angles so that the number of the angles does not coincide with the multiple of the number of the pump unit. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pump for transporting a liquid, and more particularly to a liquid feed pump using a diaphragm system (hereinafter, referred to as a diaphragm pump).
[0002]
[Prior art]
For example, pumps for conveying a fluid include the following. FIG. 5 is a sectional view of a main part showing an example of a conventional double diaphragm pump. Here, reference numeral 80 denotes a double diaphragm pump, 82 denotes a housing, 82a denotes an inflow-side liquid transfer section, 82b denotes a discharge-side liquid transfer section, 82c denotes a suction port, 82d denotes a discharge port, 84 denotes a diaphragm unit, and 84a denotes a suction valve. , 84b indicate a discharge valve, 84c indicates a first chamber, 84d indicates a second chamber, and 84e indicates a diaphragm.
[0003]
The double diaphragm pump 80 has a left-right symmetric structure, and an inflow-side liquid transfer section 82a and a discharge-side liquid transfer section 82b are provided at a lower portion and an upper portion of the housing 82, respectively. Here, the fluid to be conveyed is sucked into the inflow-side liquid transfer section 82a from the suction port 82c of the housing 82, and is distributed to one of the left and right diaphragm units 84. Then, the fluid discharged from the diaphragm unit 84 is collected in the discharge-side liquid transfer section 82b, and further discharged from the discharge port 82d.
[0004]
However, the double diaphragm pump has a drawback that when the pair of diaphragms stop at the top dead center and the bottom dead center of the stroke, the double diaphragm pump cannot be restarted. Since the fluid is alternately discharged from the diaphragm unit, pulsation cannot be avoided.
[0005]
Various measures have been proposed to solve this drawback. For example, Japanese Unexamined Patent Publication No. 8-338370 discloses a multiple diaphragm device, a multiple diaphragm pump, and a multiple diaphragm motor that can reliably restart and transport the fluid uniformly without pulsation. It has been disclosed.
FIG. 6 is a schematic longitudinal sectional view of one embodiment of the multiple diaphragm pump disclosed in the above-mentioned publication. Here, reference numeral 10 denotes a pump, 12 denotes a diaphragm unit, 12c denotes a first chamber, 12d denotes a second chamber, 12e denotes a diaphragm, 16 denotes a crankshaft member, and 20 denotes a connecting rod.
[0006]
That is, the first chamber 12c having the suction valve and the discharge valve, the second chamber 12d into which the pressurized fluid is periodically introduced, and the first chamber 12c and the second chamber 12d are liquid-tightly partitioned. A main body provided with at least three diaphragm units 12 having a diaphragm 12e; a connecting rod 20 having one end connected to each diaphragm 12e; a crankshaft member rotatably provided on the main body, wherein each connecting rod 20 The other end is rotatably connected to the crankshaft member 16 whose eccentric portions are mutually shifted in the rotation direction.
[0007]
In this multiple diaphragm device, the crankshaft member 16 is provided with at least three eccentric portions that are mutually deviated in the rotational direction. Since the connecting rod 20 of at least one diaphragm attempts to rotate the crankshaft member 16, it can be reliably restarted, and the next diaphragm can be discharged before the discharge of fluid from one diaphragm unit 12 is completely eliminated. Since the supply of the fluid to the unit 12 is started, the fluid can be relatively uniformly conveyed with little pulsation.
[0008]
However, since three or more units are required and the connecting rod and the crankshaft member are provided, there is a problem that the configuration is complicated and the cost is high.
Japanese Patent Laid-Open Publication No. Hei 8-170584 discloses a fixed-rate discharge device capable of discharging a fixed amount of liquid at a high pressure in proportion to the rotation speed with a simple structure and eliminating pulsation of the discharge amount.
[0009]
FIG. 7 is a schematic configuration diagram of the constant-rate discharge device disclosed in the above-mentioned patent publication. Here, reference numerals 51 and 52 denote double-acting plunger pumps, 53 denotes a cam mechanism, and 54 and 55 denote double-acting plungers.
That is, the two double-acting plunger pumps 51 and 52 and the double-acting plungers 54 and 55 of the double-acting plunger pumps 51 and 52 are accelerated at a constant acceleration from the bottom dead center to 90 °. A cam that decelerates at a constant acceleration from 90 ° to top dead center, accelerates at a constant acceleration from top dead center to 270 °, and decelerates at a constant acceleration from 270 ° to bottom dead center The cam mechanism 53 drives each of the plungers 54 and 55 with a phase shift of 90 ° to make the sum of the discharge amounts of the two double-acting plunger pumps 51 and 52 constant. .
[0010]
However, since a double-acting plunger pump and two cam mechanisms are required, there is a problem that the configuration is complicated and the cost is high.
[0011]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide a diaphragm pump that has a simple configuration and does not cost much in order to solve these problems.
[0012]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided a liquid supply unit for sucking / discharging a liquid and a diaphragm, wherein a plurality of pump units arranged concentrically, A polygonal cam that rotates at a central portion and reciprocates through the diaphragm, wherein the polygonal cam is a diaphragm pump having an angular number excluding a multiple of the number of the pump units.
[0013]
That is, the diaphragm pump is configured such that the polygonal cam rotating at the center of the plurality of pump units has an angular number excluding a multiple of the number of the pump units. With this configuration, the timing at which the polygon cam rotates and the vertex presses and deforms the diaphragm of the pump unit is shifted for each pump unit. The discharge operation corresponding to (number) × (number of pump units) is sequentially repeated, so that the liquid flows continuously without having a dead center.
[0014]
If the number of corners of the polygonal cam is a multiple of the number of pump units, a dead center occurs. To prevent pulsation, for example, when the number of pump units is three, the number of corners is not a multiple of three. It is necessary to use polygonal cams such as 5, 7, 8, 10, etc.
According to a second aspect of the present invention, there is provided a crankshaft comprising a plurality of the diaphragm pumps according to the first aspect, wherein the polygonal cams of each of the diaphragm pumps rotate coaxially. This is achieved by a diaphragm pump in which the vertices of each of the polygon cams are shifted in the rotational direction.
[0015]
With this configuration, the timing at which the polygonal cams of each of the plurality of diaphragm pumps rotate and the top portions press and deform the diaphragms of the pump units are shifted for each pump unit and each diaphragm pump, During one rotation of the crankshaft, the discharging operation corresponding to (number of polygon cam angles) × (number of pump units) × (number of diaphragm pumps) is sequentially repeated, so that the liquid has a dead center. The pulsation can be reduced without limit.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto.
〔Example〕
FIG. 1 is a top view showing one embodiment of the diaphragm pump according to the present invention. FIG. 2 is an AA 'side view showing an embodiment of the diaphragm pump according to the present invention. Here, a case of four pump units and a triangular polygon cam is illustrated.
[0017]
Reference numeral 101 indicates a polygonal cam, 102, 103, 104, and 105 indicate diaphragms, and 110, 111, 112, and 113 indicate liquid sending units. The vertex of the polygon cam may be a curved surface.
When the polygon cam rotates, the diaphragm is deformed by contact with the apex of the polygon cam, and the movement causes the liquid to be sent. Of course, a check valve is attached to the liquid sending section.
[0018]
For example, as shown in FIG. 1, when the diaphragm 102 of the liquid sending unit 110 is deformed by a vertex of the rotating polygonal cam 101 into a cam drive curve shown by a broken line, the pressure inside the liquid sending unit 110 increases, The liquid is drained.
On the other hand, since the diaphragm 104 of the liquid sending unit 112 is deformed in the opposite direction, the pressure inside the liquid sending unit 112 decreases, and the liquid is sucked.
[0019]
As described above, while the polygon cam 101 makes one rotation, the diaphragms 102, 103, 104, and 105 sequentially repeat suction and discharge three times while shifting the phase.
FIG. 3 is a diagram showing the configuration of four single pump units each having a liquid sending unit shown in FIG. 1 and the discharge amount according to the rotation angle of the polygon cam. Here, the pump unit denoted by reference numeral 100 is shown. .
[0020]
The trajectory of the diaphragm deformed by the contact with the apex of the polygonal cam and reciprocating is indicated by a thick broken line. As can be seen, a single pump unit produces three pulsations during one revolution of the triangular polygon cam and has three top dead centers and three bottom dead centers.
FIG. 4 is a diagram showing the discharge amount of each pump unit in the embodiment according to the present invention. Since the discharge amount of each pump unit changes during one rotation of the polygon cam, a dead point occurs in the diaphragm pump. And the flow rate can be averaged.
[0021]
That is, a total of 12 discharges are performed by the four pump units during one rotation of the triangular polygon cam, so that as shown in FIG. , The liquid is sent at a very stable flow rate.
In this embodiment, the case of four pump units and a triangular polygonal cam has been exemplified. However, when the pump unit is composed of n units, a polygonal cam having an angle which is not a multiple of n, for example, n + 1 or n-1 is used. Any polygonal cam having an angle may be used, and there are many combinations thereof.
[0022]
Further, a plurality of diaphragm pumps are provided side by side, and the polygonal cams of each of the diaphragm pumps are arranged on a crankshaft that rotates coaxially, and the vertexes of each of the polygonal cams are shifted from each other in the rotational direction. Thus, it is possible to convey a substantially uniform liquid with less pulsation than in the embodiment.
[0023]
【The invention's effect】
As described above, according to the present invention, the timing at which the polygon cam rotates and the vertex of the polygon cam presses and deforms the diaphragm of the pump unit is shifted for each pump unit, so that the polygon cam rotates one rotation. In this way, a large number of discharge operations are repeated in sequence during the operation.Therefore, with a simple configuration, there is no dead center, so that restart can be performed reliably and uniform liquid transfer with almost no pulsation is possible. It becomes.
[Brief description of the drawings]
FIG. 1 is a top view showing one embodiment of a diaphragm pump according to the present invention.
FIG. 2 is an AA ′ side view showing one embodiment of the diaphragm pump according to the present invention.
FIG. 3 is a diagram showing a configuration and a discharge amount of a single pump unit.
FIG. 4 is a diagram showing a discharge amount of each pump unit in the embodiment according to the present invention.
FIG. 5 is a sectional view of a main part showing an example of a conventional double diaphragm pump.
FIG. 6 is a schematic longitudinal sectional view of one embodiment of a multiple diaphragm pump.
FIG. 7 is a schematic configuration diagram of a fixed-rate discharge device.
[Explanation of symbols]
10 Pump 12, 84 Diaphragm unit 12c, 84c First chamber 12d, 84d Second chamber 12e, 84e, 102, 103, 104, 105 Diaphragm 16 Crankshaft member 20 Connecting rod 51, 52 Double-acting plunger pump 53 Cam mechanism 54, 55 Double-acting plunger 80 Double diaphragm pump 82 Housing 82a Inlet-side liquid sending section 82b Outlet-side liquid sending section 82c Suction port 82d Discharge port 84a Suction valve 84b Discharge valve 100 Pump unit 101 Polygon cams 110, 111, 112, 113 Liquid sending section

Claims (2)

It has a liquid sending section that sucks or discharges liquid and a diaphragm, and has a plurality of pump units arranged concentrically, and a polygonal cam that rotates at the center of the pump unit and reciprocates through the diaphragm. And
A diaphragm pump, wherein the polygonal cam has an angular number excluding a multiple of the number of the pump units. A plurality of the diaphragm pumps according to claim 1, wherein the polygonal cams of the respective diaphragm pumps are disposed on a crankshaft that rotates coaxially, and vertexes of the polygonal cams are mutually connected in the rotational direction. A diaphragm pump characterized by being shifted.

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