JP3023872B2 - Mechanical shift device and pneumatic auxiliary pilot valve for diaphragm pump - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to an improved fluid-operated dual diaphragm pump and, in particular, to the structure of a pilot valve for such a pump.

It is already known that double diaphragm pumps are used for transporting highly viscous liquids. A typical such pump consists of a pair of pump chambers with pressure chambers, the pressure champs being arranged in the housing parallel to each pump chamber. Each pressure chamber is separated from its connected pump chamber by a flexible diaphragm. When one pressure chamber is pressurized, it pushes the diaphragm and compresses the fluid in the associated pump chamber. In this way, the fluid is pushed out of the pump chamber. at the same time,
The diaphragm connected to the second pump chamber is curved so that fluid material is drawn into the second pump chamber. The two diaphragms are reciprocating simultaneously to alternately fill and evacuate the pump chamber. In fact, the two pump chambers are all in line so that the diaphragm can reciprocate in the axial direction simultaneously. The diaphragms are mechanically connected in this way, ensuring uniform operation and performance of the double-acting diaphragm pump.

Various types of control have been proposed for supplying pressurized fluid to a pump chamber associated with a double-acting diaphragm pump. It is important to provide a particular type of pilot valve device that appropriately shifts the flow of pressurized fluid to the pressure chamber. Many conventional diaphragm pump pilot valve designs emit an instantaneous signal to shift the fluid flow at the end of each pump stroke. Such instantaneous signals are usually rejected by reversing the movement of the diaphragm.

If the pump is operating at a very slow cycle rate or is pumping a very heavy or viscous material, diaphragm overshoot will be small. Also, the duration of the pilot or shift signal is reduced. This means that the pilot valve can only be partially shifted or the pilot valve can be stopped in the center position, so that the pump will not operate. The present invention is designed to overcome this shortcoming associated with conventional designs.

SUMMARY OF THE INVENTION The present invention, in brief, relates to a combined mechanical shift mechanism and pneumatic pilot valve structure for controlling the cycle of a dual diaphragm pump. A mechanical cycling or shifting mechanism is located between the two pressure chambers of the diaphragm pump in the pump housing;
It extends axially into one or the other pressure chamber. The shift mechanism moves axially as one of the diaphragms of the pump joins. When the diaphragms join, the mechanical shift opens the fluid pressure passage to the pneumatic pilot valve. The pilot valves control fluid flow to respective pressure chambers associated with the diaphragm pump. Thus, a positive pilot signal is emitted throughout the entire stroke or throughout the cycle of the diaphragm pump. The mechanical shifting mechanism is not directly connected to the diaphragm or to a connecting rod connected to the diaphragm.

Thus, it is an object of the present invention to provide an improved pilot valve structure for a diaphragm pump.

It is another object of the present invention to provide an improved combination of a mechanical shift mechanism and a pneumatic pilot valve for a diaphragm pump.

Yet another object of the present invention is to provide an improved combination of a mechanical shift mechanism and a pneumatic pilot valve for a diaphragm pump, wherein the pilot signal is transmitted over the entire cycle of the device. Is to be done.

It is a further object of the present invention to provide an improved mechanical shift mechanism and a pneumatically operated pilot valve device to provide a dual diaphragm with a simple structure, a functional design and improved reliability. The use of this in pumps.

These and other objects, advantages and features of the present invention will be described in the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS In the following detailed description, reference is made to the drawings, which are made up of the following figures.

FIG. 1 is a schematic cross-sectional view of a pilot valve structure of the present invention cooperating with a dual diaphragm pump in a first position.

FIG. 2 shows the FIG. 1 when the pump is moved to the next sequence of positions.
FIG.

FIG. 3 is a similar view of FIG. 2 showing further movement to show a shift of the pilot valve structure and a shift of the pump to the next sequential position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The drawings show a typical dual diaphragm pump of the present invention incorporating a combined mechanical shift and pneumatically operated pilot valve structure. 1, 2 and 3 show the sequential operation of the pump. In each drawing, the same members are denoted by the same reference numerals.

The pump has a main housing 10,
Form a first pressure chamber 12 and a second pressure chamber 14 which are arranged axially opposite to each other;
4 are essentially identical in size, shape and volume. The pressure chambers 12 and 14 have a generally conical shape. In other words, as shown in the cross-sectional view of FIG. 1, the cross-sections of these pressure chambers 12, 14 have the same outline regardless of the cutting position.

Flexible diaphragms 16 and 18 are connected to each pressure chamber 12 and 14, respectively. Diaphragms 16 and 18 are generally circular in shape and are held in place by lid members 20 and 22, respectively, to seal housing 10. 1, the housing 10, the diaphragm 18 and the lid member 20 form a pressure chamber 14 and a pump chamber 29. Similarly, as shown on the left side of FIG.
The diaphragm 16 and the lid member 22 form the pressure chamber 12 and the pump chamber 23.

Each diaphragm 16 and 18 is made from an elastomeric material known to those skilled in the art.

Diaphragms 16 and 18 are mechanically coupled by a shaft 24, which passes through the center point of each diaphragm 16 and 18 and extends axially along axis 26. Shaft 24 is attached to diaphragm 18 by opposed plates 28 and 30, which are held in place by bolts 32 on shaft 24. For diaphragm 16, plates 34 and 36 or bolts screwed into shaft 24
Held by 38. In other words, the diaphragm 16 and
18 is axially movable in harmony with the movement of the pump.

During exercise, the pressure chamber 12 is first pressurized,
14 is connected to the outlet. This or diaphragm 16
At the left side, thereby compressing the fluid in the fluid chamber 23, so that the fluid is
Forcibly flows out of the check valve 25. A second check valve 27 located at the opposite end of the pump chamber 23 is closed by pumping. At the same time, as the diaphragm 16 moves to the left in FIG. 1, the diaphragm 18 also moves to the left. The compressed fluid is exhausted from chamber. At the same time, pumped fluid or pump passes through check valve 31 and into pump chamber 29. During this operation, the second check valve 33 is closed.

When the shaft 24 moves in the opposite direction or to the right in FIG. 1, the pumping and filling actions of the pump chambers 23 and 29 are reversed. In each case, the outflow of fluid takes place through outlet 25 or outlet 35. Fluid flow into the pump is at inlet 27 or
Done through 31.

The particular configuration of the present invention provides for the construction of a mechanically or hydraulically operated pilot valve structure that controls the flow of pressurized fluid into the pressure chambers 12 and 14 and thus controls the operation of the dual diaphragm pump. Involved.

Referring first to FIG. 1, the pilot structure is an axially slidable mechanical pilot member or moving rod.
40 and an air-actuated actuator 42.
As shown in the embodiment, the actuator 42 is also movable in the axial direction. However, the direction of movement of the valve 42 relative to the diaphragms 16, 18 is not a limiting feature of the present invention.

With respect to the mechanical pilot member 40, the member 40 is typically a cylindrical rod,
It extends through 10 and into pressure chambers 12 and 14.
As shown in FIG. 1, the length of member 40 is less than the length of shaft 24 extending between diaphragms 16 and 18. The member 40 is
At substantially the center of both ends of the member 40, an annular groove 44 having a reduced diameter is provided. Member 40 comprises a series of O-rings 48, 49, 50 and 51.
The O-ring is inserted into a groove in the cylindrical passage (opening) 46 and is sealed with respect to the member 40. I agree. That is, the passages intermediate the respective O-rings 48, 49, 50 and 51 are sealed and separated from each other so that no fluid leakage occurs between them. At opposite ends of the member 40, cylindrical washers 52 and 54 are held in the grooves. Washers 52 and 54 allow the movement of member 40 as it slides through cylindrical passage 46 in response to the engagement of member 40 with plate 28 or plate 36 and in response to air pressure as described below. Acts as a restriction.

Actuator 42 is a generally cylindrical valve member having a series of different diameters adapted to operate in response to a pressure differential. That is, the actuator 42 is connected to the first end surface 56 located in the constant diameter chamber 58.
have. The chamber 58 is connected to the atmosphere via a passage 60. Actuator 42 has an annular groove 62 with a seal 64 engaged against the wall of chamber 58. The diameter of the chamber 58 is the first end portion of the actuator 42
It is almost equal to 56 diameter. The actuator 42 also has an annular groove 68 for receiving a slidable D-valve 70. Actuator 42 has a neck 72 with the same diameter as portion 56 and is coupled to an enlarged head 74 that has an annular groove 76 that receives a seal 78. The end face 80 of the actuator 42 defines the surface of the working surface described below. The diameter of the head 74 is approximately equal to the diameter of the enlarged chamber 82, through which the head 74 slides. The chamber 82 limits the movement allowed for the head 74, that is, the movement of the actuator 42. The diameter of chamber 82 is next adjacent, chamber 58 and
It is larger than the diameter of the central chamber 84 between 82. Fluid pressure inlet 86 is connected to chamber 84 and supplies fluid pressure to operate a double-acting diaphragm pump.

A passage 88 extends from the inlet 86 to the passage 46 between the O-rings 48 and 49.
Is led to. Passageway 90 includes a forward end of chamber 82,
It connects the passage 46 with the middle between the O-rings 49 and 50. Passage 92 is connected from passage 46 to the atmosphere between O-rings 50 and 51. The pressure chamber 12 is connected to a chamber 84 through a manifold plate 96 by a passage 94.
Passage 98 is connected from atmosphere to chamber 84. The pressure chamber 14 is connected to the chamber 84 through the passage 100 and also through the plate 96. Of course, the D-type valve (D-va
lve) or slide valve 70 is configured to connect only two of the defined passages through plate 96.
That is, the D-valve performs connection between the passages 98 and 100 or connection between 98 and 94 depending on the position of the actuator 42. D-valve arrangement and position,
The structure of the actuator and the relative positions of all the passages described so far are well suited to the operation of the device described hereinafter.

First, please refer to FIG. 1 for the operation. Air enters through an inlet 86 and pressurizes a passage 88 to form a chamber 82
And chamber 84 are pressurized. Actuator 42
When is in the position shown in FIG. 1, surface 80 or surface 80 of head 74 is connected to exhaust through passageway 90, annular groove 44 and passageway 92. At this same moment, the pressure chamber 12 is connected through passage 94 to chamber 84, a source of pressurized fluid. At the same time, due to the position of valve 70, pressure chamber 14 is connected to atmosphere or exhaust through passages 100 and 98. That is, the air pressure acting on the diaphragm 16 causes the diaphragm 16 to move to the left in FIG. Similarly axis 24
Moves to the left as the diaphragm 18 moves.
The driving fluid, air, is of course exhausted from the chamber 14. The pumped-up fluid is pump chamber 29
Drawn into. Fluid is pumped out of the pump chamber 23.

The actuator 42 is held in the position shown in FIG. 1 because the pressure in the chamber 84 acts on the back of the head 74. The front or front side 80 is connected to the atmosphere. That is, the actuator 42 is always maintained at the position shown in FIG. 1 during pressurization of the pressure chamber 12. The pressure in the pressure chamber 12 also acts on the surface or surface of the member 40 projecting into the pressure chamber 12, which presses the member 40 to the far right end in FIG. The washer 52 holds the member 40 and prevents the member 40 from coming out of the cylindrical opening (passage) 46. The pressure over the surface of member 40 is O-ring 48,
Sufficient pressure to overcome the frictional engagement of 49, 50 and 51. The air pressure applied to seals such as seals 64 and 78 is
This prevents air from leaking into the chamber at the end of member 42. Chamber 58 is connected to atmosphere or exhaust through passage 60.

As we move left to diaphragms 16 and 18, the members
The movement of 40 is affected based on engagement with plate 28. As the diaphragm 18 moves to the left in FIG. 1, the diaphragm 18 eventually becomes a member 40, more specifically a member
It engages the head of 40 and pushes the member 40 to the left.

According to FIG. 2, it can be seen that the member 40 has been mechanically moved to the left. During this movement, the exhaust passage 90 is closed. Moving further to the left, the passages 88 and 90 are connected as shown in FIG. In this condition, the fluid or air pressurized will
Flowing into 82, the face 80 drives the valve to the left based on different surface areas, as shown in FIG. D-type valve (D-
valve) (D-shaped valve insert) 70, as shown in FIG.
It moves axially to connect the passages 94 and 98. The pressure chamber 12 is then connected to the exhaust, and the pressure chamber 14 has an inlet
From 86, it is connected to pressurized air through a chamber 84 and a passage 100 connected through the plate 96. Air is again exhausted from chamber 58 via passage 60.

As the pressure chamber or cavity 14 is pressurized, the pressure in the pressure chamber acts on the right end of the member 40 so that the member 40 can maintain the position shown in FIG. Become. This ensures that pressure is maintained against the end 80 of the valve 42. This, in turn,
This ensures that pressurized air is supplied through passage 100 and that exhaust is performed continuously from pressure chamber 12 via passage 94. In that case, like the diaphragm 16 and the shaft 24, the diaphragm 18 also moves to the right in FIG. 3, achieving pump-up from the pump chamber 29 and drawing fluid into the pump chamber 23.

The movement of the plate 36 to the right in FIG. 3 eventually causes the plate 36 to engage the end of the member 40, so that a reversal of the operation of the pump is again achieved.
In this way, the member 40 is connected to the diaphragms 16, 18 and the shaft 24.
Again to the left, and eventually return to the position shown in FIG. The pump will continue to vibrate or cycle as long as air is supplied through inlet 86.

Positive pressure is always supplied to the actuator 42 until the actuator 42 is actually shifted based on the structure of the present invention. The positive pressure then acts on the actuator 42 at the shifted position. Thus, the mechanical member 40 defines a constant and positive shift of the pilot valve mechanism. Because the end of member 40 is pressurized by fluid pressure, the pilot valve structure maintains a positive pressure even after mechanical startup in the cycle has been completed.

Here, advantageous embodiments of the invention have been described. However, the present invention can be changed or replaced without departing from the spirit and scope of the present invention. Accordingly, the invention is to be limited only by the following claims and equivalents thereof.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kozamprik, Nicholas Jr. United States 43506 Ohio Brian Route 1 Box 201 (56) References JP-A-57-188788 (JP, A) JP-A-55-135802 (JP, A) U) US Pat. No. 4,545,551 (US, A) US Pat. No. 3,791,768 (US, A)

Claims (4)

(57) [Claims] 1. A combined mechanical and fluid operated pilot valve structure for a dual diaphragm pump, comprising: a housing, first and second diaphragms, a pilot valve device, and first and second fluid pressure passages. And a mechanically shiftable pilot member, wherein the housing defines an axis with first and second fluid pressure chambers axially spaced within the dual diaphragm pump; A second diaphragm is disposed in the first and second pressure chambers, respectively, forming a flexible wall in each of the pressure chambers, wherein the diaphragm extends transversely to the axis; Mechanically coupled so as to reciprocate substantially simultaneously in the axial direction, and each of the diaphragms provides a flexible wall for an adjacent pump chamber. The pilot valve device has a single fluid inlet, a first outlet to a first chamber, and a second outlet to a second chamber, and the pilot valve device has a fluid inlet. First
Or a fluid actuated slide valve reciprocating for connection to the second outlet, said fluid actuated slide valve comprising a differential surface area fluid actuator having a small surface area and a large surface area; A pilot member that is mechanically shiftable, protrudes axially into the pressure chamber and is slidable axially in response to engagement of one of the diaphragms; And the actuator has an elongated spool valve axially movable within the housing, the spool valve having a slide member on one side, wherein the slide member has a first or second outlet and an intermediate. Cooperates with the discharge passage so that when one or the other outlet is connected to the pressurized fluid inlet, only the other or one outlet is connected to the exhaust passage. Wherein the first and second fluid pressure passages communicate with a small surface area and a large surface area, respectively, of the fluid actuator, the first fluid pressure passage directly communicating with the small surface area, and a second fluid pressure passage. Communicates with a large surface area via a mechanically shiftable pilot member, and wherein the mechanically shiftable pilot member has a fluid connection passage which is engaged by engagement with the other diaphragm. Interconnecting the first and second fluid pressure passages to provide a flow of pressurized fluid into the second fluid pressure passage when the pilot member is mechanically shifted axially toward only one of the diaphragms. A pilot valve structure. 2. The combination according to claim 1, wherein the pilot member protruding into the pressure chamber has a surface area in which pressurized fluid in the pressure chamber acts to bias the pilot member. body. 3. A mechanically shiftable pilot member,
2. The combination according to claim 1, further comprising a stop for limiting the axial travel. 4. The translation of the pilot member in the axial direction,
2. The combination according to claim 1, further comprising an exhaust passage connectable to the large surface area via a mechanically shiftable pilot member.