JP5123310B2 - Active check valve in diaphragm pump with solenoid drive - Google Patents

Abstract

The invention refers to a diaphragm pump (1) for use as a detergent dosage pump. The diaphragm pump (1) according to the invention comprises a pump housing (2), a working fluid chamber, at least one intake (3), at least one outlet (4) and one diaphragm (6) defining a wall of the working fluid chamber and reciprocatingly moveable, diaphragm driving means for reciprocating said diaphragm (6) and at least one check valve (7) including a spring biassed valve body (7a) for controlling ingress of the fluid into the working fluid chamber. The diaphragm pump is characterized by means for mechanically pushing the valve body (7a) into its valve seat.

Description

  The present invention relates generally to diaphragm pumps, and more particularly to a pump housing, a working fluid chamber, at least one inlet, at least one outlet, and a wall of the working fluid chamber and reciprocally movable. And having at least one diaphragm, diaphragm driving means for reciprocating said diaphragm, and at least one check valve including a spring-biased valve body for controlling fluid entry into the working fluid chamber. In particular, the present invention relates to a diaphragm pump used as a detergent administration pump.

  Diaphragms and piston pumps are used to deliver metered amounts of liquid with various characteristics. Depending on the field of application, various requirements are imposed on the pump operation in order to ensure that the metered medium supply is as accurate as possible and remains constant for as long as possible. .

  Diaphragm pumps are common industrial pumps that transfer liquids using positive displacement. These devices typically include a single diaphragm and chamber, and a discharge check valve to prevent backflow. A piston is coupled to or used to drive the diaphragm utilizing pressurized oil. Diaphragm pumps are usually very reliable because they do not contain internal parts that rub against each other. Because the drive means is typically completely separate from the hydraulic portion of the pump, the diaphragm pump can handle a variety of media including abrasive materials, acids, chemicals, or the like. Diaphragm pumps are particularly suitable as dosing pumps because they can supply a small volume of fluid at the maximum flow rate.

  Another reason for using diaphragm pumps as dosing pumps is that these pumps have two strokes, an inhalation stroke in which the medium is drawn from the reservoir, and a metered medium supply into the metered line, for example. And a compression stroke or a supply stroke. For example, diaphragm pumps known in the art have an intake check valve and a discharge check valve to prevent backflow. These check valves are normally spring-biased and opened and closed by the pressure difference of the medium to be pumped.

  Especially when pumping high concentrations of detergents, known diaphragm pumps often fail due to crystallization and particles in the check valve. The valve body of the check valve is usually held in a sealed relationship with the valve seat by a compression spring. The check valve normally operates only by the differential pressure of the fluid. This compression spring applies a relatively small spring force to ensure easy opening of the check valve. This is especially true for the check valve on the suction side of the pump.

  Diaphragm pumps known in the art often have the disadvantage that a small amount of contaminants prevents proper placement of the valve body within the valve seat to ensure the function of the check valve. As a result, the function of the pump is completely stopped. Accordingly, it would be desirable to provide a diaphragm pump that is not affected by small particles of contaminants and crystallization in the metered medium.

  According to one aspect of the invention, a pump housing, a working fluid chamber, at least one inlet, at least one outlet, and a diaphragm defining a wall of the working fluid chamber and reciprocating. A diaphragm drive means for reciprocating said diaphragm, and at least one check valve including a spring-biased valve body for controlling the entry of fluid into the working fluid chamber, particularly as a detergent dispensing pump A diaphragm pump is provided that features additional means for mechanically pressing the valve body into its valve seat.

  The diaphragm pump according to the present invention forces the valve body into the valve seat so that the basic function of the diaphragm pump is guaranteed even when small particles or crystals collect between the valve body and the valve seat. It has the advantage of being pressed. In particular, when supplying a very high concentration of detergent, it is possible for small crystals to grow in the medium to be weighed. In such a case, when the valve body is pushed into the valve seat, the small crystals are broken, resulting in the valve body being placed in the valve seat in a sealed relationship. According to the design according to the invention, the check valve can be closed with a relatively large force, but the spring load acting on the valve body is still relative so that the valve can be easily actuated by the fluid pressure May be small.

  The diaphragm pump according to a preferred embodiment of the invention is characterized in that the additional means for pushing the valve body into its associated valve seat is driven by the diaphragm drive means.

  According to another aspect of the present invention, the diaphragm pump has first and second check valves, and the second check valve opens in a direction opposite to the first check valve.

  For example, the first and second check valves may be configured such that when the second valve body is pulled up to its open position, the second valve body presses the first valve body into its associated valve seat. It is advantageous to arrange the check valves in such a way that the movement paths of the first and second valve bodies cross each other. In other words, in all compression strokes, the second valve body pushes the first valve body into its closed position.

  According to still another aspect of the present invention, the second valve body described above constantly holds the first valve body in the closed position when the pump is not operating. According to this aspect of the present invention, a safety shut-off valve is provided. This is particularly advantageous, for example, in that the detergent container can be placed higher than the pump. The shut-off function very effectively prevents flow through the pump when the pump is not operating.

  According to still another aspect of the present invention, the second valve body is coupled to the diaphragm driving means and reciprocates in a state synchronized with the stroke of the diaphragm.

  In a preferred embodiment, the aforementioned second check valve forms part of the aforementioned diaphragm.

  This design is particularly small in dead space or dead volume (the difference between the total volume of the working fluid chamber and the volume of displacement in the compression stroke) such that the pump according to the invention is not affected by the intake air at start-up. It has the advantage of being realized. Due to the minimization of the dead volume, the compressibility of the air taken into the system does not affect the operation of the pump.

  The second valve body can be compliantly held in a sealed relationship with respect to the diaphragm, thereby closing the aperture in the diaphragm and at least in the first stroke (intake stroke) of the diaphragm, and In the second stroke (compression stroke), fluid communication is established between the aforementioned working fluid chamber and the aforementioned outlet.

  Due to this design, the hydraulic effective surface of the pump increases to a maximum value.

  In a preferred embodiment of the diaphragm pump according to the invention, said second valve body and said diaphragm are relative to each other such that the pressure generated in the diaphragm compression stroke is determined by the elastic restoring force of the spring. Spring biased.

  When the pressure generated in the compression stroke in the working fluid chamber reaches a certain level, the second valve body is slightly lifted from its valve seat so that the diaphragm has a very effective pressure ratio. .

  Advantageously, said diaphragm drive means is a solenoid drive.

  Alternatively, a bend lever drive, hydraulically actuated drive or pneumatically actuated drive can be provided.

  According to yet another aspect of the present invention, the second valve body has a stem coupled to the armature of the solenoid drive described above.

  Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

FIG. 3 shows a cross-sectional view of an exemplary diaphragm pump according to the present invention during the suction stroke. 2 shows the diaphragm pump of FIG. 1 in the compression stroke. 1 shows a diaphragm pump according to the invention at the end of a compression stroke.

  Referring initially to the drawings, FIG. 1 illustrates an exemplary embodiment of a diaphragm pump 1 according to the present invention. The diaphragm pump 1 has a pump housing 2 having a suction port 3 and a discharge port 4, where the suction port 3 is a suction port and the discharge port 4 is a pressure port.

  In the pump housing 2, pump chambers 5a and 5b are defined. The pump chambers 5a and 5b accommodate a main diaphragm 6 that divides the pump chamber into first and second compartments 5a and 5b. The suction port 3 communicates with a first compartment 5a of the pump chamber that defines the working fluid chamber, and the discharge port 4 communicates with a second compartment 5b of the working fluid chamber.

  The diaphragm pump 1 according to the present invention has first and second check valves 7 and 8, as will be described in detail later. The first check valve 7 controls the suction port 3, and the second reverse valve. The stop valve 8 is arranged in series with the first check valve 7.

  The first check valve 7 has a bowl-like first valve body 7a that is spring-biased with respect to the first valve seat 7b by a first compression spring 7c. The first valve body 7a is sealed against the first valve seat 7b by a sealing ring 7d, which is preferably an O-ring sealing.

  The diaphragm 6 is driven to reciprocate in the pump housing 2 by a solenoid driving device in which only the armature 9 is shown. The solenoid drive armature 9 is coupled to the stem 10 of the second rod-like valve body 8a. The stem 10 a of the second valve body 8 a passes through the aperture 11 at the center of the main diaphragm 6. In the state shown in FIG. 1, the second valve body 8a is held in a spring-biased state in a sealed relationship with respect to the main diaphragm 6, thereby closing the aperture 11 in a sealed state. doing. For this purpose, the second compression spring 8c located on the base 12 of the stem 10 presses the main diaphragm 6 against the sealing surface 13 of the second valve body 8a. An annular sealing rib 14 is provided on the surface of the main diaphragm forming the inner wall of the first compartment 5a for sealing against the corresponding sealing surface 13 of the second valve body 8a.

  A hard holding member 15 having a peripheral collar portion 16 for contact with the second compression spring 8c is provided on the surface of the main diaphragm 6 facing the second compartment 5b of the pump chamber.

  As can be easily understood from the drawing, the main diaphragm 6 having the central aperture 11 forms a part of the second check valve 8. As will be described later, the armature 9 of the solenoid driving device is provided with an auxiliary diaphragm 17 having only a sealing function as the auxiliary diaphragm 17 reciprocates in synchronization with the main diaphragm during the operation of the diaphragm pump 1. , Sealed against the second compartment 5b of the pump chamber.

  As can be seen from the drawing, the stem 10 of the second valve body 8 a passes through the holding member 15 and the aperture 11 of the main diaphragm 6. The first and second compartments between the stem 10 and the aperture 11 and between the stem 10 and the aperture 18 in the holding member 15 that is in alignment with the aperture 11 when the second check valve 8 is opened. An annular gap 19 is formed between 5a and 5b that establishes fluid communication.

  Hereinafter, the function of the diaphragm pump 1 will be described with reference to the accompanying drawings.

  As already explained above, FIG. 1 shows the diaphragm pump according to the invention in the intake stroke. In the intake stroke, the armature 9 of the solenoid driving device moves backward (that is, moves to the right in FIG. 1). Due to the reciprocating motion of the armature 9 coupled to the stem 10, the main diaphragm 6 and the auxiliary diaphragm 17 are also moved in synchronization with the armature 6. The volume of the first compartment 5a is increased so that the suction input is applied to the suction port 3. As a result, the first valve body 7a is lifted from the associated first valve seat 7b against the pressure of the first compression spring 7c. The first compartment 5a of the pump chamber is now in fluid communication with the inlet 3 so that the entered medium can be pumped into the first compartment. The fluid can enter the first compartment 5a through an annular gap 20 between the first valve body 7a and the first valve seat 7b.

  The compression force applied by the first compression spring 7c is compared so that only a slight pressure difference between the first compartment 5a and the suction port 3 can sufficiently pump the medium into the compartment 5a. Small.

  Referring now to FIG. 2, a diaphragm pump 1 according to the present invention in the compression stroke is shown.

  As described above, the armature 9 connected to the stem 10 of the second valve main body 8b reciprocates in the pump housing by the operation of the solenoid driving device. As a result, the pumping operation is executed mainly by the main diaphragm 6. In the compression stroke, the volume of the first compartment 5a is reduced, and pressure is generated in the compartment 5a. The spring force of the first compression spring 7c moves the first valve body 7a into its associated valve seat 7b. This movement is supported by the rising pressure in the compartment 5a. Furthermore, the rising pressure in the first compartment 5a acts on the main diaphragm, and the main diaphragm 6 is a spring of the second compression spring 8c that is relatively strong compared to the first compression spring 7c. The result is that it is pressed against force. The pressure generated in this first compartment 5 a causes a relative movement between the second valve body 8 a and the main diaphragm 6, and the second valve body 8 a has its associated second formed by the main diaphragm 6. The result is that the two valve seats are lifted. As a result, the fluid taken into the first compartment 5 a can enter the second compartment 5 b through the annular gap 19.

  As can be more clearly observed in FIG. 3, the first and second valve bodies 7a and 8a are arranged so that their movement paths intersect. That is, at the end of the compression stroke, the second valve body 8a presses the first valve body 7a to its closed position. For example, if the first valve body becomes immobile in its open position due to particles or crystals gathering between the sealing ring 7d and the associated sealing surface of the valve body, the second valve body 8a Will push the first valve body 7a into its closed position.

  FIG. 3 shows the initial state of the pump when the solenoid drive is not operating. In other words, in this situation, the first valve body 7a is constantly held in its closed position by the second valve body 8a so that the first and second check valves function like a safety shut-off valve. Yes.

  It should be understood that in the subsequent stroke of the diaphragm pump 1, the volume of the second compartment 5b will decrease so that fluid moves into the discharge port 4 (pressure port).

  From the above description, it is clear that the second valve body 8a reciprocates the main diaphragm 6 in the pump housing 2, and therefore the second valve body 8a forms part of the diaphragm drive mechanism. It is.

  The embodiments described herein are not intended to be limiting, but are intended to be exemplary. It will be apparent that many other embodiments readily apparent to those skilled in the art can be practiced without substantially departing from the spirit and scope of the invention.

DESCRIPTION OF SYMBOLS 1 Diaphragm pump 2 Pump housing 3 Inlet port 4 Outlet port 5a, 5b First and second compartments of pump chamber 6 Main diaphragm 7 First check valve 7a First valve body 7b First valve seat 7c First compression spring 7d Sealing Ring 8 Second check valve 8a Second valve body 8c Second compression spring 9 Armature 10 Stem 11 Aperture 12 Stem base 13 Sealing surface 14 Sealing rib 15 Holding member 16 Collar 17 Auxiliary diaphragm 18 Aperture 19 Annular gap 20 Annular gap

Claims (5)

A diaphragm pump used as a detergent administration pump in particular,
A pump housing (2);
A working fluid chamber comprising first and second compartments (5a, 5b) in the pump housing (2) ;
At least one inlet (3) in communication with said first compartment (5a) ;
At least one outlet (4) in communication with the second compartment (5b) ;
A main diaphragm (6) that divides the working fluid chamber into the first and second compartments (5a, 5b) and is capable of reciprocating;
Diaphragm driving means for reciprocating the main diaphragm (6);
An auxiliary diaphragm (17) for sealing the diaphragm driving means with respect to the second compartment, wherein the auxiliary diaphragm (17) reciprocates in synchronization with the main diaphragm (6) in the operation of the diaphragm pump. The auxiliary diaphragm (17) having only a sealing function;
A first check valve (7) including a spring-biased first valve body (7a) for controlling the entry of working fluid into the first compartment (5a) ;
A second check valve (8) including a second valve body (8a) for controlling the entry of the working fluid into the second compartment (5b);
Diaphragm pump, characterized in that it comprises an additional means for mechanically pushing the first valve body (7a) and the valve seat (7b) in. The diaphragm pump according to claim 1, wherein the additional means for pressing the first valve body (7a) into its associated valve seat (7b) is driven by the diaphragm drive means. The second check valve (8) opens in a direction opposite to the first check valve (7), and the second valve body (8a) is opened when the diaphragm pump is not operating. The diaphragm pump according to claim 1 or 2 , wherein the first valve body (7a) is constantly held in a closed position .   The diaphragm pump according to any one of claims 1 to 3, wherein the diaphragm driving means is a solenoid driving device.   5. A diaphragm pump according to claim 4, wherein the second valve body (8a) has a stem (10) coupled to an armature (9) of the solenoid drive.

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