JP2001099345A - Contaminated fluid vent valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict the influence of the viscosity of hydraulic fluid on valve operation in an air vent valve for discharging the air contaminated in the hydraulic fluid for transmitting the driving force to a diaphragm of a diaphragm pump. SOLUTION: A sleeve 22 has a shaft hole 28 for communicating a fluid pressure chamber with an atmospheric air side. A valve element 38 has a spool 34 to be slid along the shaft hole 28 and valve heads 30 arranged in both end of the spool 34 so as to regulate the sliding range of the valve element 38. Any one of the valve heads can be seated in a valve seat 32 provided in each sleeve end so as to cut the communication between the fluid pressure chamber and the atmospheric air side. Flow passages 40, 42 are provided in the spool 34, and when the valve element 38 exists within the predetermined range, this flow passage communicates both the ends of the sleeve 22 with each other. When pressure of the fluid pressure chamber rises, the valve element is moved upward, and the contaminated air inside of the fluid pressure chamber is discharged through the flow passage on the way of the upward movement of the valve element 38.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a drain valve for draining a fluid mixed in a fluid (hereinafter referred to as a working fluid) for transmitting a driving force to a diaphragm of a diaphragm pump from a fluid pressure chamber.

[0002]

2. Description of the Related Art A diaphragm pump for driving a diaphragm through a fluid is provided with a drain valve for removing a fluid, for example, air, which has entered or generated inside the working fluid.

FIG. 7 shows an example of a schematic configuration of a conventional mixed fluid drain valve used for a diaphragm pump, in particular, an air vent valve. The movement of a piston that reciprocates by a crank mechanism or the like is transmitted to the diaphragm of the diaphragm pump via a working fluid. Therefore, the pressure of the working fluid serving as the transmission medium of the driving force pulsates in response to the movement of the piston. The working fluid is sealed in the fluid pressure chamber. The fluid pressure chamber housing 100 is provided with an air vent valve 102 for venting another fluid, for example, air mixed with the internal fluid.

The air release valve 102 has a bolt 104 for fixing the entire air release valve 102 to the housing 100. An axial hole 106 is provided in the bolt 104 in the axial direction.
This hole is open only to the fluid pressure chamber side. Further, a lateral hole 108 reaching the shaft hole 106 is provided on a side surface of the bolt 104. Housing 100
An open hole 110 whose other end is open to the atmosphere is provided at a position corresponding to the horizontal hole 108. A small diameter portion of the sleeve 112 is accommodated in the shaft hole 106, and a large diameter portion of the sleeve 112 is formed on a gasket 114 disposed on the shoulder 113 of the housing 100 by the lower end of the bolt 104.
Is joined to. The sleeve 112 is provided with a shaft hole 116 penetrating the sleeve 112 in the axial direction. This shaft hole 11
6 includes a check ball 11 for preventing backflow of the working fluid.
8. A valve body 120 is provided to release mixed fluid such as air to the atmosphere and prevent leakage of working fluid. Valve body 12
0 is urged downward in the figure by a spring 122. Further, the inside of the handle of the valve body 120 has an axial hole 123 in the axial direction.
And an orifice 124 is provided therein. Further, the shaft hole 123 of the valve body does not reach the valve head portion, and communicates with the lateral hole 126 just before this.
Housing 100 corresponding to the lower end of sleeve 112 in the drawing.
Is provided with a pressure hole 128 connected to the fluid pressure chamber.

When the entrained fluid is separated from the working fluid and has a lower density than the working fluid, a valve for removing the same is provided at the highest position of the housing 100. In many cases, the working fluid is liquid and the entrained fluid is a gas, and the gas of the entrained fluid is air. The air mixed in the working fluid passes through the pressure hole 128 and moves to the air vent valve 102 provided at the top of the housing. When the pressure inside the fluid pressure chamber starts to rise above the atmospheric pressure, the air pushes up the check ball 118 through the lateral hole 126, the shaft hole 123, and the orifice 124 in the valve body. Furthermore, it reaches the outside of the sleeve 112, from which the side hole 10 of the bolt
8. Open to the outside through the opening hole 110. The accumulated air is discharged, and the working fluid enters the valve body 120 and reaches the orifice. Since the passage of the orifice 124 is extremely narrow, air can easily pass through, but the working fluid experiences a large flow resistance. This resistance causes the valve element 120 to
The valve head is moved upward against the urging force, and the shaft hole 116 of the sleeve is closed by the valve head. Thereby, the outflow of the working fluid is prevented, and the pressure in the fluid pressure chamber increases.
On the other hand, when the pressure in the fluid pressure chamber decreases, the check ball 118 closes the shaft hole 116 of the sleeve to prevent air from entering from outside.

[0006]

In the above-described air vent valve, the working fluid slightly leaks at the end of the process of discharging the entrained air. The amount of leakage depends on the movement of the valve body 120,
This movement is affected by the flow resistance of the working fluid passing through the orifice 124. The flow path resistance is determined by the viscosity of the working fluid,
It changes depending on the flow velocity, pressure change in the fluid pressure chamber, and the like. Therefore, there is a problem that the amount of leakage of the working fluid changes due to a change in the operating conditions, and the performance of the air vent valve changes.

Further, since the diameter of the flow path of the orifice 124 is very small, there is a problem that if foreign matter (dust or the like) is mixed in the working fluid, the foreign matter is clogged.

Further, there is a problem that both the valve body and the sleeve are complicated in shape and high precision is required, and the processing cost is high.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a simple and highly reliable valve for removing a mixed fluid.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a mixed fluid drain valve according to the present invention uses a mixed fluid mixed in a working fluid for transmitting a driving force of a diaphragm of a diaphragm pump. A valve for forming a communication passage communicating with the fluid pressure chamber and the atmosphere side, and protruding respective ends to the fluid pressure chamber and the atmosphere side so that the fluid pressure inside the communication passage is reduced. A spool that moves in accordance with a pressure difference between the chamber and the atmosphere side, and a valve body that is provided at a portion of the spool that protrudes toward the fluid pressure chamber and the atmosphere side and that can close an open end of the communication path; In the spool,
During the movement of the spool, the fluid pressure chamber communicates with the atmosphere side, and a flow path capable of allowing movement of the working fluid is provided.

The flow path resistance of the flow path connecting the fluid pressure chamber and the atmosphere side is sufficiently small to allow the movement of the working fluid, and the influence of the change in the flow path resistance can be reduced.

Further, the flow path may be closed by a sleeve when at least one of the valve elements is blocking the communication path.

[0013] Further, there may be provided an urging means for urging the sleeve from the atmosphere side toward the fluid pressure chamber side.

[0014]

Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of the present embodiment. Housing 1 forming a fluid pressure chamber filled with a working fluid for driving a diaphragm of a diaphragm pump
At 0, an air vent valve 12 for discharging mixed fluid mixed into the working fluid from the fluid pressure chamber is attached. The mixed fluid is mainly air, but is not limited to this.
The working fluid is a liquid that is usually an incompressible fluid, and if the mixed fluid is a gas such as air, the air vent valve 12
It is arranged at the highest position of the housing 10. As a result, the mixed air naturally gathers at the position of the air vent valve 12 due to the difference in density. In the opposite case, i.e., assuming that the density of the entrained fluid is higher than that of the working fluid, the valve for removing the fluid is arranged at the lowest position of the housing. In such a case, for example, the working fluid is oil, and the mixed fluid is water separated from the oil.

The air release valve 12 has a bolt 14 which is screwed to a screw portion of the housing to fix the entire air release valve to the air release hole 11 of the housing 10. The air vent hole 11 is provided to connect the inside and outside of the housing, that is, the fluid pressure chamber and the atmosphere side. An axial hole 16 is provided in the bolt 14 in the axial direction.
It is open only to the fluid pressure chamber side. Further, the bolt 14 is formed with a lateral hole 18 communicating between the bolt side surface and the shaft hole 16 in a direction perpendicular to the axis. At a position corresponding to the side hole 18 of the housing 10, an open hole 20 whose other end is open to the atmosphere is provided.
Is provided.

A sleeve 22 is provided at the lower end of the bolt 14 in the drawing.
Is arranged. The sleeve 22 has a large-diameter portion and a small-diameter portion, and the lower end of the bolt 14 abuts on the large-diameter portion.
The sleeve 22 is pressed and fixedly held.

The sleeve 22 has a shaft hole 28 which extends in the axial direction and is open at both ends. Opening portions at both ends are formed with valve seats 32 to be in contact with a valve head 30 described later. A spool 34 is disposed in the shaft hole 28 of the sleeve so as to be inscribed therein without any gap. The spool 34 forms a valve body 38 together with the aforementioned valve head 30 fixed at both ends by screws 36. The spool 34 has a shaft hole 40 extending along the central axis and two lateral holes 42 that are substantially orthogonal to the shaft hole 40 and penetrate the spool 34. The shaft hole 40 and the lateral hole 42 provided in the spool 34 form a flow path that allows communication between the fluid pressure chamber side and the atmosphere side. The flow paths 40 and 42 communicate or block the fluid pressure chamber side and the atmosphere side depending on the position of the valve body 38. More specifically, at least a part of the range where the valve head 38 is located at the position of the valve body 38 not in contact with the valve seat 32, the flow paths 40,
The length of the shaft hole 28 of the sleeve and the position of the lateral hole 42 of the flow path are determined so that the fluid communication side 42 communicates between the fluid chamber side and the atmosphere side. When one of the valve heads 30 is seated on the valve seat 32, the shaft hole 28 of the sleeve and the lateral hole 4 of the flow path are so arranged that at least the flow paths 40 and 42 are closed.
2 are defined.

As described above, the air vent hole 1 of the housing
Reference numeral 1 denotes a state where the air vent valve 12 blocks the air side. On the other hand, the air vent hole 11 communicates with the pressure chamber through a pressure hole 44. Further, the shaft hole 28 of the sleeve is formed with the pressure hole 44 and the shaft hole 16 of the bolt.
It functions as a communication path that connects the fluid pressure chamber side and the atmosphere side via the lateral hole 18 and the open hole 20. A spring 46 for biasing the valve body 38 toward the pressure chamber is disposed in the shaft hole 16 of the bolt.

Before the pressure in the fluid pressure chamber rises above the atmospheric pressure, the valve head 30a on the upper side in the figure is seated on the valve seat 32. Also, the lateral hole 42 of the upper flow path in the drawing
a is closed by the sleeve 22. In the process of increasing the pressure in the fluid pressure chamber, if the force due to the pressure applied to the valve body 38 from the fluid pressure chamber side becomes larger than the sum of the force due to the pressure applied to the valve body 38 from the atmosphere side and the urging force of the spring 46, This difference causes the valve body 38 to start moving upward in the drawing against the urging force of the spring 46. By the movement of the valve body 38, the two valve heads 30a and 30b are separated from the valve seat 32, and when further moved, the upper side hole 42a and the lower side hole 42b are both opened. At this time, the channels 40 and 42 communicate the fluid pressure chamber with the atmosphere. In this state, the air mixed with the working fluid flows through the flow passages 40 and 42 into the shaft hole 16 of the bolt, and is further discharged to the atmosphere through the lateral hole 18 of the bolt and the open hole 20 of the housing. Further, when the valve body 28 rises, the side hole 42b is closed by the sleeve 22, and the channels 40 and 42 are closed,
Finally, the lower valve head 30b is seated on the valve seat 32 to prevent further outflow of mixed air and working fluid. This further increases the pressure in the fluid pressure chamber,
The diaphragm is driven.

When the piston reaches the top dead center and the discharge of the handling liquid of the pump stops, the pressure of the handling liquid and the working fluid in the pump decreases to substantially the atmospheric pressure. When the pressure inside the fluid pressure chamber decreases and cannot withstand the urging force of the spring 46 and the atmospheric pressure, the valve body 38 moves downward in the figure, and the upper valve head 30a is seated. Backflow of the working fluid and suction of air are prevented. Also, in the course of the movement of the valve body 38, a passage communicating with the fluid pressure chamber and the atmosphere side is formed in the valve body 38. However, as described above, the pressure in the fluid pressure chamber at this time is substantially equal to the atmospheric pressure, and therefore, no air flows from the atmosphere side to the fluid pressure chamber. The spring 46 can be omitted if the valve body 38 can move downward only by its own weight to prevent the backflow of the working fluid and the suction of air.

FIGS. 2 and 3 show other forms of the sleeve and the valve body. The sleeve 48 has a shaft hole 50 having a predetermined length, similarly to the sleeve 22 shown in FIG.
The valve body 52 has a spool 54 that fits into the shaft hole 50 of the sleeve, and a valve head 56 is fixed to each end of the spool 54 by a nut 58. The spool 54 is provided with a through hole 60 penetrating therethrough in a direction orthogonal to the axis. The diameter of the through-hole 60 is slightly longer than the length of the shaft hole 50, whereby the through-hole 60 functions as a flow path communicating the fluid pressure chamber with the atmosphere. Sleeve 48 and valve element 52
Can be used in place of the sleeve 22 and the valve body 38 shown in FIG. 1, and can constitute an air vent valve.

FIGS. 4 and 5 show still another embodiment of the sleeve and the valve body. The sleeve 62 has a shaft hole 64 of a predetermined length, similarly to the sleeve 22 shown in FIG. The valve body 66 has a spool 68 that fits into the shaft hole 64 of the sleeve.
0 is fixed by a nut 72. An axially extending groove 74 is provided on the side surface of the spool 68. The length of the groove 74 is slightly longer than the length of the shaft hole 64, so that the groove 74 functions as a flow path communicating the fluid pressure chamber with the atmosphere. The sleeve 62 and the valve element 66 can be used instead of the sleeve 22 and the valve element 38 shown in FIG. 1, and can constitute an air release valve.

FIG. 6 shows the valve element 66 shown in FIGS.
A part of the valve body 76 which can be replaced with the above is shown. Valve body 76
Is formed by integrally forming a spool 68 and one valve head 70 shown in FIG. 4 and the like. Further, a valve head 70 shown in FIG.
2 and functions in the same manner as the above-described respective valve elements.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of the present embodiment.

FIG. 2 is a view showing a modified example of a valve body and a sleeve.

FIG. 3 is a view showing a spool of the valve body of FIG. 2;

FIG. 4 is a view showing another modification of the valve element and the sleeve.

FIG. 5 is a view showing a spool of the valve body shown in FIG. 4;

FIG. 6 is a view showing still another modified example of the valve body.

FIG. 7 is a schematic configuration diagram of a conventional air vent valve.

[Explanation of symbols]

Reference Signs List 10 housing, 12 air release valve, 22 sleeve, 30 valve head, 34 spool, 38 valve body, 4
0 shaft hole, 42 side hole (flow path), 46 spring.

Claims (4)

[Claims] 1. A valve for removing a mixed fluid mixed in a working fluid transmitting a driving force of a diaphragm of a diaphragm pump from a fluid pressure chamber, wherein the communication passage communicates with the fluid pressure chamber and an atmosphere side. A spool that protrudes each end to the fluid pressure chamber and the atmosphere side, and moves in the communication passage according to a pressure difference between the fluid pressure chamber and the atmosphere side; and a fluid pressure chamber of the spool and the atmosphere. A valve body provided at a portion protruding to the side, and capable of closing an open end of the communication passage, wherein the spool communicates a fluid pressure chamber with the atmosphere during movement of the spool, A mixed fluid drain valve provided with a flow path capable of permitting movement of a working fluid. 2. The mixed fluid drain valve according to claim 1, wherein the flow path is closed by a sleeve when at least one of the valve elements closes the communication passage. . 3. The mixed fluid drain valve according to claim 1 or 2, further comprising a biasing means for biasing the sleeve from the atmosphere side to the fluid pressure chamber side. 4. The mixed fluid drain valve according to claim 1, wherein the working fluid is a liquid, and the mixed fluid is a gas.