JP2002071048A - Automatic pressure regulating valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress cavitation to a minimum, prevent hunting and wear of a valve rod and gland section, and actuate a small diameter valve and a large diameter valve quickly even when pressure of the discharge room is raised rapidly, in an automatic pressure regulating valve. SOLUTION: The automatic pressure regulating valve comprises a valve body which is divided into an inflow room 4 and a discharge room 5 by a partition 2 having a large diameter hole 3, a cylinder 21 which is divided into a pass room 20 and an accumulation room 7 by a piston 16, a large diameter valve 6 which is used to close the large diameter hole 3, a small diameter valve 10 which is used to close a small diameter hole 8 provided on the large diameter valve 6, and a valve rod 18. The inflow room 4 of the valve body is connected to the pass room 20 of the cylinder 21, and the discharge room 5 of the valve body is connected to the pass room 20 of the cylinder via an appropriate flow regulator, a pilot valve or the like, in order to link the inflow room of the valve body to the accumulation room of the cylinder. Besides, the piston in the cylinder is joined to the small diameter valve in the inflow room with a piston rod 13, in order to link the small diameter valve and the large diameter valve movably together, while permitting an independent movement in a prescribed range of the small diameter valve.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic pressure control valve used for, for example, water supply.

[0002]

2. Description of the Related Art For example, in water supply of a water supply system, in order to minimize water leakage from a water supply pipe, a water supply pressure is gradually reduced from a water supply source to a final water supply destination, and the water supply pressure is improved. 2. Description of the Related Art In order to obtain a proper water supply state, a pressure control valve that adjusts a supply amount of water from a water supply source according to use of water at a water supply destination is known.

[0003] Various types of such pressure regulating valves are supplied. Generally, the water supply side is set at a high pressure and the water supply side is set at a low pressure across the device, and the pressure difference is constant. When the pressure is in the range, the pressure regulating valve continues to maintain the closed state, for example, when the water pressure at the water supply destination side falls below a predetermined value due to water use in each household, the valve is opened to open the water supply destination. Water can be supplied from the water supply source according to demand.

[0004] However, the conventional pressure regulating valve which is opened due to the pressure drop at the water supply destination can appropriately cope with a sudden large pressure drop at the water supply destination, but has a small pressure drop at the water supply destination. To avoid the worst operating situation in the valve structure, the large valve structure is slightly opened to respond to a small pressure drop in order to respond by slightly opening the internal valve structure. Can not.

[0005] Such an operation causes cavitation very easily, and it cannot be denied that it is the largest cause of hunting, and if such a state continues continuously and repeatedly, the pressure regulating valve body may In addition, it has a great adverse effect on various device components connected thereto.

In order to reduce the occurrence of such troubles, the design of the pressure regulating valve is changed, and in order to achieve a delicate operation of the valve structure by incorporating more accurate parts, a separate valve body or its periphery is required. This forces the installation of components, which inevitably increases the cost of the finished product.

[0007] Japanese Patent Application Laid-Open No. 8-270806 discloses a solution to the above problem. This Japanese Patent Laid-Open No. 8-2
No. 70806 prepares a small diameter valve with a small diameter and a large diameter valve with a large diameter, drills a large diameter hole in the bulkhead of the valve body, closes it with a large diameter valve, and drills a small diameter hole in a large diameter valve However, the small-diameter hole can be independently moved within a certain range with respect to the large-diameter valve, and when exceeding the range, the large-diameter valve is closed by a small-diameter valve that moves integrally, and the small-diameter valve can be driven by appropriate control means. In this case, a small-diameter valve responds to a small pressure drop, and a small-diameter valve and a large-diameter valve operate and respond to a large pressure drop. After the small-diameter valve is opened and the capacity of the small-diameter valve is fully utilized, the large-diameter valve is opened in conjunction with the small-diameter valve.

However, Japanese Patent Application Laid-Open No. Hei 8-270806 discloses that a small-diameter valve is opened when a required flow rate is small, and a valve corresponding to the small-diameter valve is opened by reducing the opening of a large-diameter valve. As compared with the conventional type corresponding to, turbulence around the valve is less likely to occur, cavitation can be suppressed as much as possible, and hunting which causes a failure of the valve element can be almost completely prevented. However, the valve stem and the gland contact each other violently each time the valve stem moves up and down, so that the valve stem sometimes wears out, causing the valve stem to lose its function.

[0009] This is because the central axis of the valve stem and the central axis of the gland portion are not installed concentrically, or the valve stem and the piston rod are connected while the central axis of the valve stem and the gland portion are not perpendicular. In this state, even if it enters the grant part, the valve stem causes axial misalignment and makes large contact with the gland part, or the valve stem contacts the gland part obliquely, Water is leaked out of the main body due to the one-sided reduction of the valve stem and the sharpening of the grant part, and the pressure decreases, and control becomes impossible.

Further, the conventional automatic pressure regulating valve has a problem that it is difficult to close the small-diameter valve and the large-diameter valve quickly when the pressure in the outflow chamber rises sharply. The use of springs has assisted the operation of small-diameter and large-diameter valves, but the use of this spring has eliminated the repulsive force and has the problem that small-diameter and large-diameter valves do not operate quickly. .

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to minimize the occurrence of cavitation, prevent hunting which may cause a failure of a valve body, and prevent wear of a valve stem and a gland. I do.

[0012]

According to a first aspect of the present invention, there is provided an automatic pressure regulating valve having a valve body divided into an inflow chamber and an outflow chamber by a partition having a large-diameter hole, and a flow chamber and a storage chamber by a piston. Cylinder, a large-diameter valve for closing a large-diameter hole, a small-diameter valve for closing a small-diameter hole drilled in the large-diameter valve, and a valve stem, so that the small-diameter valve can be driven by appropriate control means. The small-diameter valve operates for a small pressure drop, the small-diameter valve and the large-diameter valve operate for a large pressure drop, the center axis of the valve rod is arranged concentrically and perpendicularly to the gland, By contacting the upper surface of the valve shaft, wear of the valve stem and the gland portion due to axial misalignment and oblique contact is prevented.

According to a second aspect of the present invention, there is provided an automatic pressure regulating valve provided with an upper lid on an upper surface of a lid, a stopper movable up and down on the upper lid, and an upper cylinder provided in the upper lid. The valve stem is introduced into the upper cylinder at right angles to the lid, and the valve stem is provided with a portion protruding in the outer peripheral direction at a portion penetrating the gland portion, and the projecting portion is used as an upper piston, so that the valve stem is It is possible to push the piston down. As a solution to the problem that it is difficult to close the small-diameter valve and the large-diameter valve promptly when the pressure of the outflow chamber generated by the conventional automatic pressure regulating valve suddenly rises, a small-diameter valve and a large-diameter valve are provided in the flow chamber. It is possible to solve the problem that the small-diameter valve and the large-diameter valve do not operate promptly because the spring used to assist the quick operation of the valve is not required and the spring loses the repulsive force. It is possible.

According to a third aspect of the present invention, there is provided an automatic pressure regulating valve, wherein a space defined by an upper piston, an upper cylinder, and an upper bottom surface of the upper cylinder is defined as an upper piston chamber, and a flow passage communicating the upper piston chamber and the flow chamber is provided with a valve stem. When the pressure in the flow chamber increases or decreases, the pressure in the upper piston chamber also increases or decreases through the flow path, so that the vertical movement of the valve rod can be linked to the vertical movement of the piston.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific embodiment of the present invention will be described with reference to FIGS. 1 to 4. In the drawings, reference numeral 1 denotes a valve device main body, 2 denotes a partition wall having a large-diameter hole 3 formed therein, and the valve device main body 1 is provided in an inflow chamber. 4 (water supply source side) and outflow chamber 5 (water supply destination side). 6 is a large diameter valve,
On the periphery of the small diameter hole 8, a protruding edge installed upward forms a valve seat 9, and the large diameter valve 6 is in the inflow chamber 4 and closes the large diameter hole 3 of the partition 2.

The small-diameter valve 10 for closing the small-diameter hole 8 is a large-diameter valve 6.
And a piston rod 13 protrudes from the upper surface thereof. The corners present on the lower surface of the small-diameter valve 10 and the upper edge of the valve seat 9 are all curved surfaces, and are designed so as to attenuate cavitation generated when the water flow is disturbed by the corners.

The connecting plate 14 is a connecting plate through which the piston rod 13 penetrates and is fixed to the large-diameter valve 6 by a connecting leg 15. The small-diameter valve 10 is independent between the large-diameter valve 6 and the connecting plate 14 by a certain range. When the piston rod 13 rises while the two large and small valves are closed as shown in FIG. 1, first the small diameter valve 10 starts to rise, the small diameter hole 8 is opened, and the small diameter hole 8 is opened. When the valve 10 comes into contact with the connecting plate 14 and raises it, the large-diameter valve 6 rises and the large-diameter hole 3 is opened.

Reference numeral 16 denotes a piston which slides in a cylinder 21 disposed above the valve device main body 1 in a vertical direction in the figure.
On its lower surface, a piston rod 13 of the small diameter valve 10 is fixed to the center of the piston 16. The cylinder 21 is divided into upper and lower chambers by the piston 16.
The upper opening of the piston 1 is closed by a lid 19.
6 and the lid 19 form a flow chamber 20. The lower bottom surface 21 ′ of the cylinder 21 and the piston 16 form the storage chamber 7.
Are formed.

A ground portion 11 is screwed into the center of the lid 19, and a valve stem 18 penetrates the ground portion 11, and the lower end of the valve stem 18 is in contact with the upper part of the piston rod 13. 17
Is an upper cylinder, in which the upper piston 12 is a portion protruding from the valve stem 18 in the outer peripheral direction. The upper piston 12 is located inside the upper cylinder 17, and the upper cylinder 17 and the upper cylinder which is the upper bottom surface of the upper cylinder 17. 17
′ And the upper piston 12 form an upper piston chamber 32. The upper lid 33 has a window for confirming the operation state from the outside. The upper lid 33 is provided with a stopper 27 which can be moved up and down at the upper part.
9 is provided so as to cover the valve stem 18 that penetrates the gland part 11 in the central part. Reference numeral 31 denotes a flow passage in the valve stem,
0 and the upper piston chamber 32 are communicated by the flow path 31.

A through hole 2 is formed in the lower bottom surface 21 'of the cylinder 21.
2, the inflow chamber 4 and the storage chamber 7 communicate with each other, and the flow chamber 20 above the cylinder 21 is connected to an inflow conduit 23.
Is connected to the inflow chamber 4 of the valve body 1 by the
To the outflow chamber 5.

The inflow conduit 23 is provided with a control section 25 at an intermediate portion thereof. The control section 25 is constituted by an orifice, a needle valve, a strainer, etc., and flows from the inflow chamber 4 of the valve body 1 to the flow chamber 20 of the cylinder 21. Adjustment of the degree of inflow of pressurized water to be performed.

The outflow conduit 24 is provided with a pilot valve 26 having a pre-set pressure at an intermediate portion thereof. When the pressure acting on the pilot valve 26 becomes lower than a set value, the pilot valve 26 opens to open the cylinder 21. The water in the flow chamber 20 flows out through the outflow conduit 24 into the outflow chamber 5 of the valve body 1.

Reference numeral 28 denotes an exhaust valve provided on the lid 19, which is used for exhausting air in the flow chamber 20 of the cylinder 21 when making settings for starting the apparatus.

The procedure for inserting the valve body 1 into the water supply circuit will be briefly described. The upstream pipe 29 connected to the inflow chamber 4 and the downstream pipe 3 connected to the outflow chamber of the valve body 1 are described.
Gate valves (not shown) are installed at 0, respectively.
Work is performed after closing these gate valves to cut off water supply.

When the valve body 1 is installed, the stopper 27 is lowered to completely close the large-diameter hole 3 and the small-diameter hole 8 and close the pilot valve 26. When the valve body 1 is fixed in a liquid-tight manner between the upstream pipe 29 and the downstream pipe 30 and the gate valve on the upstream side is opened, the water on the water supply side flows downward from the inflow chamber 4 to the cylinder 17. To the storage chamber 7 of the cylinder 17 through a through hole 22 formed in the bottom surface 17 ',
It flows into the flow chamber 20 of the cylinder 17 via the inflow conduit 23.

At this time, the exhaust valve 28 is opened and the flow chamber 20 is opened.
The remaining air in the inside is exhausted, and when the inflow of water into the inflow chamber 4 and the circulation chamber 20 is stabilized, the downstream gate valve is opened, and the water in the downstream pipe 30 flows into the outflow chamber 5 of the valve body 1. Fulfill. In this state, the upstream pipe 29
Then, the water pressure in the downstream pipe 30 is measured, and the pilot valve 26 is adjusted so that the pilot valve 26 opens when the water pressure in the downstream pipe 30 falls below a predetermined value.

When the above procedure is completed, the stopper 27 is lifted to release the fixing of the valve stem 18, and the large-diameter valve 6 and the small-diameter valve 10 are completely removed from the large-diameter hole 3 and the small-diameter hole 8, thereby completely closing the large-diameter hole 3 and the small-diameter hole 8. Close and complete the installation.

In operation, when the water pressure in the outflow chamber 5 of the valve body 1 falls below a predetermined pressure, the closed pilot valve 26 is opened and the water in the flow chamber 20 is discharged through the outflow conduit 24 to the outflow chamber. 5 flows into. Although the supply of water to the flow chamber 20 is performed by the inflow conduit 23, since the inflow amount is adjusted by the interposed control unit 25 to be smaller than the outflow amount by the outflow conduit 24, the piston 16
Is received by the water in the flow chamber 20, the piston 16
Becomes lower than the pressure received by the water in the storage chamber 7, and the piston 16 is raised in the cylinder 21 by the pressure of the water continuously supplied from the through hole 22 to the storage chamber 7.

At this time, the valve rod 18 is
Rises because it is in pressure contact with
Since the water is supplied to the upper piston chamber 32 through the valve 1, the valve rod 18 is slowly raised in conjunction with the piston 16.

When the piston 16 rises, the small diameter valve 10 connected to the piston 16 by the piston rod 13
Rises to open the closed small-diameter hole 8 and gradually feeds the water in the inflow chamber 4 into the outflow chamber 5. In this case, the large-diameter valve 6 in which the small-diameter hole 8 is bored does not move and continues to close the large-diameter hole 3 of the partition wall 2.

As described above, when the pressure in the outflow chamber 5 does not increase to a desired value even when water is supplied from the small-diameter hole 8 (the supply of a small amount of water is insufficient because the water pressure in the outflow chamber 5 is extremely low). In this case, since the pilot valve 26 continues to be opened and the water in the flow chamber 20 continues to flow through the outflow conduit 24, the pressure in the outflow chamber 20 further decreases, and the decrease in the pressure causes the piston 16 to further rise. produce. The elevation of the valve stem 18 is as described above.

When the piston 16 further rises, the small-diameter valve 1
0 continues to rise, and when it contacts the connecting plate 14, the small-diameter valve 10 raises the large-diameter valve 6 integrated with the connecting plate 15, so that the large-diameter valve 6 rises and closes the large partition wall 2. Diameter hole 3
Gradually open. This allows the inflow chamber 4 to move out of the outflow chamber 5
The supply of water to the outlet is greatly increased, resulting in a rapid increase in the pressure in the outlet chamber 5.

When the pressure in the outflow chamber 5 increases, the pilot valve 2
6, the pilot valve 26 is first closed, the outflow of water from the flow chamber 20 is stopped, the water in the inflow chamber 4 is supplied from the inflow conduit 23 to the flow chamber 20, and the flow chamber 20 The pressure inside the piston 16 increases, and the pressure applied to both the upper and lower surfaces of the piston 16 becomes equal.
6 is lowered by the pressure of the water applied to the large diameter valve 6 and the small diameter valve 10, and after the large diameter valve 6 closes the large diameter hole 3, the small diameter valve 10 closes the small diameter hole 8 and flows in. The movement of water from the chamber 4 to the outflow chamber 5 is stopped.

At this time, the increased pressure in the flow chamber 20 gently pushes the upper piston 12 downward through the flow path 31, and the valve stem 18 gradually descends in accordance with the piston 16.

In the valve device of the present invention thus closed, only the small-diameter valve 10 operates to open the small-diameter hole 8 when the required water volume is small, and when the large water volume is required, the small-diameter valve is opened. In addition to 10, the large-diameter valve 6 is operated to open the large-diameter hole 3, each corresponding to a required situation.

According to the present invention, the water flowing out of the flow chamber 20 due to the opening of the pilot valve 26 is controlled by the inflow conduit 23.
Can be controlled by the control unit 25, the movement of the piston 16 for opening the small-diameter valve 10 can be freely adjusted, and when the pilot valve 26 is opened, the small-diameter valve 10 can be controlled. Can be adjusted to move very slowly and smoothly, so that the occurrence of cavitation can be minimized.

Also, the upper surface edges of the small valve seat 9 and the large valve seat 34,
Since the lower edges of the small diameter valve 10 and the large diameter valve 6 are all sharply angled so as to be curved, the water flow is not immediately caused by the sharp corners and cavitation is generated. Even so, it will occur at a place away from such an edge, and will not cause hunting or the like, and it will be possible to almost completely eliminate the wear caused by cavitation on the valve device.

Further, the valve stem 18 is disposed perpendicular to the gland portion 11, and the lower end of the valve stem 18 is
Since the abutment 3 is in contact with the upper surface, there is no fear that both the valve stem 18 and the gland portion 11 are greatly worn.

The valve stem 18 has the upper piston 12 inside.
By providing the flow path 31 that connects the upper piston chamber 32, which is the upper space, with the flow chamber 20, the valve rod 18 can be gently linked to the vertical movement of the piston 16.

As for the assembling, a projection is provided in the portion where the valve stem 18 penetrates the lid 19 in the outer peripheral direction, and the projection is used as the upper piston 12, so that the pressure in the outflow chamber 5 has been sharply increased. As a means for solving the problem that the small-diameter valve 10 and the large-diameter valve 6 are difficult to close promptly when the air-fuel ratio rises, the small-diameter valve 10 and the large-diameter valve 6 are used in the circulation chamber 20 to assist the quick operation of the small-diameter valve 10 and the large-diameter valve 6. The small-diameter valve 10 caused by the loss of the repulsive force without the need for a spring
It is possible to solve the problem that the large-diameter valve 6 does not operate quickly.

[0041]

As described above, in the case where the required flow rate is small, the small-diameter valve is released to cope with the small flow rate. Compared to the type, turbulence around the valve is less likely to occur, and the occurrence of cavitation can be suppressed as much as possible,
The hunting that causes the failure of the valve body can be almost completely prevented, and the pressure receiving area of the small-diameter valve and the large-diameter valve and the pressure receiving area of the piston are appropriately adjusted and designed. The ideal balance of the water supply destination pressure can be achieved, and the pilot valve and the flow rate control device are further adjusted, and the movement of the water in the circulation chamber of the cylinder is adjusted appropriately, so that the smaller-diameter valve can be opened more gently. Therefore, there is an effect that cavitation can be largely suppressed and hunting can be removed together with a change in the cross-sectional shape of the valve seat installed in the small-diameter hole.

Further, since the valve stem is not connected to the piston rod, there is no fear that both the valve stem and the gland will be greatly worn, and a flow path communicating the flow chamber and the upper piston chamber is provided in the valve stem. This makes it possible for the valve stem to be gently interlocked with the up and down movement of the piston, and to provide a projection in the outer peripheral direction at a portion where the valve stem penetrates the upper part of the gland portion, and makes the projection an upper piston. As a result, when the pressure in the outflow chamber suddenly rises with the conventional automatic pressure regulating valve, the small-diameter valve and the large-diameter valve are required to close the spring quickly, which is used as an auxiliary valve in the flow chamber. Instead, it is possible to solve the problem that the small-diameter valve and the large-diameter valve do not operate promptly due to the spring losing the repulsive force.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a state in which a small-diameter valve and a large-diameter valve are closed in a cross section of the present invention.

FIG. 2 is a conceptual diagram in which a valve body portion of FIG. 1 is enlarged.

FIG. 3 is a conceptual diagram showing a state in which a small-diameter valve and a large-diameter valve are opened in a cross section of the present invention.

FIG. 4 is a partial sectional view of a small valve seat and a small diameter valve according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve apparatus main body 2 Partition wall 3 Large diameter hole 4 Inflow chamber 5 Outflow chamber 6 Large diameter valve 7 Storage room 8 Small diameter hole 9 Valve seat 10 Small diameter valve 11 Ground part 12 Upper piston 13 Piston rod 14 Connecting plate 15 Connecting leg 16 Piston 17 Upper cylinder 17 ′ Upper bottom surface 18 Valve stem 19 Lid 20 20 Flow chamber 21 Cylinder 22 Through hole 23 Inflow conduit 24 Outflow conduit 25 Controller 26 Pilot valve 27 Stopper 27 ′ Lock nut 28 Exhaust valve 29 Upstream pipe 30 Downstream pipe 31 Flow path 32 Upper piston chamber 33 Upper lid 34 Large valve seat 35 Seal material

Claims (3)

[Claims] 1. A valve body divided into an inflow chamber and an outflow chamber by a partition having a large-diameter hole, a cylinder divided into a flow chamber and a storage chamber by a piston, and a large-diameter valve closing the large-diameter hole. And a small-diameter valve for closing a small-diameter hole formed in a large-diameter valve, and an automatic pressure regulating valve composed of a valve rod, wherein an inflow chamber of a valve body, a flow chamber of a cylinder, an outflow chamber of a valve body, and a flow chamber of a cylinder. Are connected via an appropriate flow control device or a pilot valve, etc., to communicate the inflow chamber of the valve body with the storage chamber of the cylinder, and the piston in the cylinder and the small diameter valve in the inflow chamber are connected by a piston rod. The small-diameter valve and the large-diameter valve are movably connected in a state that allows independent movement within a certain range, and the valve stem is arranged coaxially with the center axis of the lid while abutting on the upper surface of the piston rod. And automatic pressure regulating valve. 2. An upper lid having a window for confirming an operation state from the outside is provided on an upper surface of the lid, and a stopper which is movable up and down is provided on the upper lid, and the upper lid is provided in the upper lid. An upper cylinder is provided, a valve stem is introduced into the upper cylinder orthogonally to the lid, and a projection is provided in an outer peripheral direction at a portion where the valve stem penetrates the lid, and the projection is used as an upper piston. The automatic pressure regulating valve according to claim 1, wherein 3. An upper piston chamber is provided between the upper piston, the upper cylinder, and the upper bottom surface of the upper cylinder, and a flow passage communicating the upper piston chamber and the flow chamber is provided in the valve stem. Item 6. The automatic pressure regulating valve according to Item 1.