JPH0449694Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a water pressure control valve used in a water supply pressure control device for a piping system in a building water supply system or the like.

[Prior art] For example, in a water supply system that uses a pressure tank and automatically operates a pump, the discharge pressure usually changes depending on the amount of water discharged by the pump, but if the water supply load fluctuates, the pressure fluctuations also occur, so it is difficult to boil water. This may cause equipment malfunctions or changes in shower water temperature. To prevent this, water supply devices with a constant discharge pressure using variable speed pumps have become popular.

However, the water supply system using the variable speed pump generally has high equipment costs, difficult to maintain the pump control equipment, etc., and high running costs.

Therefore, recently there has been a demand for an economical and compact water supply pressure control device with less pressure fluctuations in water supply systems for small and medium-sized buildings, and a device disclosed in Japanese Patent Publication No. 57-35483 was developed to meet this demand. A control valve as shown in FIG. 3 is known.

The control valve 14 consists of a housing 34, a slidable valve member 36, and a back pressure regulator 38. The suction waterway 40 is connected to the discharge port of the pump 10. One outlet waterway 42 is connected to the pressure tank 16, and another outlet waterway 46 is connected to the building's plumbing system through the pipe 28. A back pressure regulator 38 is connected to the lower portion of the housing 34 . Valve member 36 has a central shaft 70 with a counterbalance piston 72 at its lower end and a throttle valve 74 at its upper end. The counterbalancing piston 72 has a circumferential seal member 76 to provide a seal between the piston 72 and the inner surface 78 of the housing 34. An orifice 80 is provided through the counterbalance piston 72 to provide fluid communication between a central chamber 82 and a lower chamber 84 within the housing 34. The outer surface of the throttle valve 74 is shaped to restrict the flow of fluid between the central chamber 82 and the upper chamber 90, and the valve member 36
The flow rate increases as it moves upward. When valve member 36 is in its lowest position, fluid flow between central chamber 82 and upper chamber 90 is blocked. Furthermore, the valve member 36 has a check valve 98 at the upper part thereof. When the pressure in the upper chamber 90 is greater than the pressure in the central chamber 82, the check valve 98 is pressed against the valve seat 100 and fluid flow is closed.

The operation of this control valve is such that when a large amount of water is used, the pressure in the pipes 24 and 28 decreases to the operating setting value of the pressure switch 18, and the pressure switch 18 switches the motor 1.
2. The pump 10 is activated, and the fluid discharged from the pump 10 passes through the suction port waterway 40 to the control valve 14.
to go into. A portion of the fluid flows through orifice 80 to lower chamber 84 . Inside the lower chamber 84 is the piston 7
A fluid pressure is generated on the lower surface side of the piston 72, and the magnitude of the pressure applied to the lower surface side of the piston 72 is adjusted to a constant level by the pressure regulator 38. The above pilot pressure applied to the lower surface of the balance piston 72 causes the upper chamber 90 to
When the pressure in the piping system decreases, the valve member 36 moves upwardly and the throttle valve 74 opens. In this manner, the opening degree of the throttle valve is determined by the pressure difference between the upper chamber 90 and the lower chamber 84.

When the supply faucet 30 is closed, the pressure within the piping system increases until it is greater than the pilot pressure on the counterbalance piston 72, at which point the valve member 36 moves downwardly. The pressure in the upper chamber 90 gradually increases to the point where it completely closes the throttle valve 74, and the fluid pushes up the check valve 98 and drains the upper chamber 9.
0 into the pressure tank 16. pressure tank 1
When 6 is satisfied, the pressure in the piping system is changed to pressure switch 18.
motor 12 and pump 1 reach the cut-off level.
Stop 0. Check valve 98 then contacts valve seat 100 to prevent water from flowing back from upper chamber 90 to central chamber 82 . By operating as described above, the pressure within the piping system is controlled to be constant.

[Problems to be solved by the invention] As mentioned above, this type of constant pressure control valve is installed directly above the discharge side of the pump to control the water supply pressure in the piping flowing to the piping system at a constant level. In some cases, two pumps are installed in parallel due to the capacity, etc., so that one pump is always operated and when the amount of water used on the faucet side becomes large, the next pump is also operated. In such parallel operation, if the discharge amount on the faucet side decreases when two pumps are operating, one pump will stop operating. Even during operation, the pump may suddenly stop due to a power outage, and the constant pressure control valve directly above the pump on the side where operation has stopped does not close at the same time as the pump stops, and the throttle valve of the constant pressure control valve closes after a while. There was a problem. If the constant pressure control valve is not closed immediately after the pump stops, water pressure from the outlet waterway side of the constant pressure control valve will be applied to the foot valve installed on the water receiving tank side in the case of a suction operation water supply pump system, and this water pressure will close the foot valve. This may cause damage to the product.

The reason for this is that the pressure on the suction port waterway side 40 and the discharge port waterway side 42, 46 side of the constant pressure control valve throttle valve is balanced immediately after the pump is stopped, so the adjustment pressure in the piston chamber that adjusts the opening degree of the throttle valve is adjusted by the piston 72. This is because it takes time for the fluid to flow through the orifice 80 and into the central chamber 82, and there is also frictional resistance between the piston 72 and the inner surface 78 of the housing 34, so that the throttle valve does not lower immediately.

[Means for Solving the Problems] The gist of the present invention is to provide a valve connected to the discharge side of a pump to control the pressure of fluid at a constant pressure, which comprises a valve body provided with a suction port waterway and a discharge port waterway; A throttle valve is slidably housed in the valve body and controls the pressure of the discharge waterway at a constant level; a control valve body having a balance piston with which a sliding portion sealingly engages at its end and arranged to supply fluid from a suction waterway to an intermediate portion between the throttle valve and the balance piston; and an end face of the balance piston. A pressure regulating device is provided to allow fluid from the suction port waterway to flow into the side piston chamber, and to adjust the pressure to a constant level while discharging a portion of the pressure water in the piston chamber to the outside of the valve body. By adjusting the pressure, when the pressure on the outlet waterway side falls below a predetermined adjusted pressure, the balance piston increases the opening of the throttle valve so that fluid flows from the inlet waterway side to the discharge outlet waterway side, and the outlet water A constant pressure device characterized in that the balancing piston reduces the opening degree of the throttle valve via the valve stem so as to reduce the flow of fluid to the discharge port waterway side when the roadside pressure exceeds a predetermined adjustment pressure. It is a control valve.

[Function] As described above, in the present invention, the balance piston is slidably provided on the valve stem that is integrated with the throttle valve, and the sliding part with the balance piston is locked in a sealed state at the end of the valve stem. ing. For this reason, when the amount of water used on the faucet side is high and the pump is operating,
The pressure of the suction port waterway acts on the bottom surface of the throttle valve and the top surface of the piston, and the sliding part of the piston and valve stem is also locked to the end of the valve stem in a sealed state.
The opening degree of the throttle valve is determined based on the relationship between the pressure on the discharge port waterway side and the adjusted pressure in the piston chamber, and water at a constant pressure is supplied to the discharge port waterway side.

As mentioned in the problem section above, if one pump stops during parallel operation, or if the pump suddenly stops due to a power outage, etc., the pressure on the suction channel side will decrease compared to the pressure on the discharge channel side. Therefore, a force acts on the closing side of the throttle valve, and even if the balance piston does not go down immediately, the valve stem connected to the throttle valve is pushed downward, which seals the sliding part of the balance piston. is released, the pressure in the piston chamber on the piston end face side rapidly flows from the gap between the sliding parts to the suction port waterway side and decreases, and the resistance between the piston and the sliding part is also released, so the throttle valve immediately descends. and close it. Therefore, the throttle valve is closed at the same time as the pump is stopped, and the problem of back pressure being applied from the discharge port waterways 42, 46 side to the suction port waterway 40 side is prevented.

[Example] Next, an example according to the present invention will be described with reference to the drawings.

Fig. 1 is a longitudinal sectional view of this embodiment, and Fig. 2 is a longitudinal sectional view of the first embodiment.
The figure shows a constant pressure control circuit using the constant pressure control valve of the embodiment. The constant pressure control valve according to the present invention includes a main body 4 having an inlet channel 1 having a flange 3, a discharge channel 2 having a flange 3a, a central chamber 7, and a piston chamber 6 coaxially, a throttle valve 10, and a piston 14. , a control valve body 5 consisting of a valve stem 13, a valve 17, and a diaphragm 2.
6, a pressure adjustment section 30 consisting of a spring 19, an adjustment nut 20, and an adjustment screw 21, and a control valve body 5
It is composed of a stopper 9 that regulates the amount of sliding. The flanges 3 and 3a provided at the lower and upper ends of the main body 4 are connected to a discharge side flange of the pump and a secondary side of a water supply pipe or the like by bolts.

4a is a valve seat portion, and the throttle valve 10 of the control valve body 5 is set here so as to be slid upward.

The control valve body 5 has a throttle valve 10 having a guide bar portion 10b having a slit shape on the circumference fixed to one end of the valve stem 13, a valve seat 11 made of a flexible material, and an upper valve body 12, and the other end of the control valve body 5. A piston 14 is slidably connected to the outer periphery of the valve stem 13 at the end thereof, and is engaged with the valve stem 13 by a flange 52 on the lower surface side of the piston 14 via a packing 51 that seals the gap between the sliding parts. ing. The piston 14 is thus able to slide onto the top of the valve stem 13 but engages the valve stem 13 at its end.

The outer diameter of the throttle valve upper valve element 12 is approximately 1.5 times the inner diameter of the throttle valve seat 4a, which is relatively large compared to conventional control valves. The diameter is approximately 65% of the inner diameter of the enlarged diameter portion 2a of the outlet waterway 2, so that the fluid receives sufficient lift when passing through the outer circumference of the valve body 12.

Further, the throttle valve 10, the valve seat 11, and the upper valve body 12 are provided with at least one small hole 10a communicating with the central chamber 7 and the discharge port waterway 2.
A check gasket 61 and a check gasket housing 6 are provided on the top of the housing 6 to prevent the fluid from flowing from the outlet waterway 2 side to the center chamber 7 side through the small hole 10a.
2. A check valve 60 consisting of a check valve spring 63 and a check valve spring receiver 64 is assembled, and the throttle valve 10, valve seat 11,
It is tightened and fixed together with the upper valve body 12, and further prevents the nut from loosening and coming off from the split pin 23.

In the control valve body 5, the piston 14 engages with the sliding portion 6a of the piston chamber 6, and the throttle valve 10
is engaged with the valve seat portion 4a and is supported so as to be slidable up and down.

Further, an orifice 14a communicating with the inlet waterway 1 and the piston chamber 6 is bored in the piston 14. 14b is a wire inserted into the orifice 14a. Further, an O-ring 16a and a stopper ring surrounding the outer periphery of the O-ring are attached to a groove provided on the circumference of the piston 14 to slidably seal the piston 14 and the slide portion 6a. Discharge channel 2 on top of valve body 4
The stopper 9 provided inside has a plurality of ribs 9
It has a circular ring shape and a threaded portion 9a, and is screwed into the main body. Further, the cross-sectional area of the fluid passing through the stopper 9 is larger than the inner diameter cross-sectional area of the valve seat portion 4a. Further, by removing the stopper 9, the control valve body 5 can be easily removed from the main body 4.

The pressure adjustment section 30 has a spring 19 set between a diaphragm 26 with a valve 17 fixedly attached to the center and an adjustment nut 20, and is housed in a housing 22 of the pressure adjustment section 30, with one end extending outside from the housing 22. The force of the spring 19 is adjusted by turning the adjusting screw 21 and moving the adjusting nut 20.

The housing 22 is fixed to a pressure adjustment unit mounting seat 8 provided on the main body 4 via a diaphragm 26 with bolts 27 . A side portion of the pressure adjustment portion mounting seat 8 has a fluid discharge port 18 having a threaded portion.

The fluid passes from the piston chamber 6 through the water passage 24 and applies fluid pressure to the diaphragm 26, causing the spring 1
The openings of the valve seat 4b and the valve 17 are automatically adjusted so that the pressure adjusted by 9 is reached.
and is discharged to the fluid outlet 18. Since the inlet waterway 1 and the outlet waterway 2 are provided on the same shaft plug, piping can be easily performed.

FIG. 2 systematically shows an example of a water supply device using the constant pressure control valve according to the present invention. 4 is a constant pressure control valve, 40 is a water receiving tank, 41 is a suction pipe, 42 is a pump, 45 is a water supply pipe to each faucet 50, 49 is a pressure tank, and 46 is a connection pipe for the pressure tank 49. Also, 47 is the pump 42.
It is a pressure switch for turning on and off, and 48 is a pressure gauge. Further, a hose 4 is connected from the pressure adjustment part 30 of the constant pressure control valve 4 to the suction side of the pump 42.
3. For this reason, pressure adjustment section 3
0 The pressure on the secondary side is almost constant, and since the pressure regulator 30 can maintain a sufficient pressure difference between the primary side pressure and the secondary side pressure, it is almost the same as the pressure on the inlet waterway 1 side of the constant pressure control valve. It is possible to control the pressure until the pressure on the discharge port waterway 2 side reaches a certain level.

Next, the operation will be explained using FIGS. 1 and 2. First, in FIG. 2, when all the faucets 50 are closed and no water is used, the pump 42 is stopped, the check valve 60 in the constant pressure control valve 4 is closed, and the pressure tank 49 is connected to an appropriate level. Water is stored and the water supply piping system 45 is pressurized by a pressure tank. At this time, the control valve body 5 is also closed.

When the faucet 50 is used, water is first supplied from the pressure tank 49, and the pressure inside the pipe decreases to a pressure 0.2 to 0.5 lower than the adjusted pressure.
Pressure switch 47
The pump 42 is started.

Immediately after the pump 42 is started, the pump discharge pressure is applied to the lower surface of the throttle valve 10 and the upper surface of the piston 14, and the piston 14 is locked to the end of the valve rod with its sliding portion sealed. and inlet waterway 1
The water sent from the piston passes through the orifice 14a of the piston 14 and generates back pressure on the lower surface of the piston 14, which becomes higher than the pressure on the discharge port waterway 2 side, so the control valve body 5 moves upward and the throttle Valve 1
Water is supplied to the water supply pipe 45 through 0. When the pump is in operation, water entering the constant pressure control valve 4 is supplied through the throttle valve 10 and passes from the orifice 14a of the piston chamber 6 through the water passage 24 in the piston chamber 6 and hits the diaphragm 26, where the force exceeds the force of the spring 19. Once reached, the valve 17 is pushed open and the water is returned from the fluid outlet 18 through the hose 43 to the pump suction side, creating a nearly constant and regulated pressure on the underside of the piston 14.

At this time, the throttle valve upper valve body 12 and the valve seat 4a
As the degree of opening increases, the water on the inlet waterway side flows to the outlet waterway side, so the pressure applied to the lower surface of the valve body 12 decreases compared to the pressure when the valve body is closed. The control valve body 5 is balanced at a certain position in the body 4 due to the force relationship between the pressure on the discharge port waterway 2 side, which is generated by the lifting force that pushes up the body 12, and the pressure difference on the piston chamber 6 side. The opening degree of the valve seat 4a is determined.

When the pressure on the outlet waterway 2 side is small, the valve body 12
The degree of opening becomes large, and when the pressure on the side of the outlet waterway 2 is large, the degree of opening becomes small, and the pressure on the side of the outlet waterway 2 of the constant pressure control valve is kept almost constant.

Next, when the faucet 50 is closed and the use of water is stopped, the pressure in the outlet waterway rises above the adjusted pressure in the piston chamber, so a downward force is applied to the control valve body 5, causing it to descend and stop the throttle valve. . Since the pump continues to operate, water passes through the small hole 10a of the throttle valve 10 and reaches the check gasket 6 of the check valve 60.
1 is pushed up, flows to the discharge port waterway 2 side, and is sent into the pressure tank 49.

Thereafter, when the pressure in the water supply piping system 45 reaches the pump stop pressure, the pressure switch 47 switches the pump 42
stops, the check valve 60 of the constant pressure control valve closes, and returns to its original state. Normally, the pressure in the piping system is controlled to be constant in this way.

On the other hand, if one pump is stopped during parallel operation of pumps, or if one pump is suddenly stopped due to a power outage, etc., the control valve's inlet waterway 1 side The pressure decreases compared to the pressure on the outlet waterway 2 side. However, unless the adjusted pressure in the piston chamber 6 is released, it will not immediately decrease, but the lifting force on the throttle valve due to the flow of water that was passing through the throttle valve during pump operation will disappear, so a downward force will be exerted on the throttle valve 10 and the valve stem will Press down on 13. At this time, the seal of the gasket 51 that seals the gap between the sliding part of the valve stem 13 and the piston 14 is released, and when the valve stem descends, the adjustment pressure water in the piston chamber 6 that should be removed is removed by the sliding part of the piston 14. It flows from the gap between the moving parts to the inlet waterway 1 side. Therefore, the pressure in the piston chamber 6 rapidly decreases, and the throttle valve 10, which is integrated with the valve rod 13, rapidly descends, and the throttle valve 10 closes the valve seat 4a. After this, the piston 14 descends regardless of the descent of the valve stem 13. Therefore, the conventional problem in which the pressure water on the discharge outlet waterway 2 side flows to the inlet waterway 1 side when the pump is suddenly stopped is solved.

[Effects] As mentioned above, the constant pressure control valve of the present invention allows the throttle valve to close suddenly following the stop of the pump, even when one pump is stopped during parallel operation or when the pump is suddenly stopped during a power outage. Therefore, the conventional problems such as water in the piping flowing back to the pump side and damage to the foot valve provided in the water suction pump device for suction operation are solved, and constant pressure control can be performed.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a constant pressure control valve according to an embodiment of the present invention, Figure 2 is a schematic diagram of a water supply system using the constant pressure control valve of the present invention, and Figure 3 is a conventional constant pressure control valve and water supply. It is a schematic system diagram of an apparatus. 4... constant pressure control valve body, 5... control valve body,
10... Throttle valve, 12... Valve body, 13...
Valve stem, 14...piston, 14a...orifice, 17...valve, 19...spring, 21...
Adjustment screw, 30... Pressure adjustment section, 42... Pump, 43... Hose, 49... Pressure tank, 51
...Putskin, 52...Flange, 60...Check valve.

Claims (1)

[Scope of utility model registration request] A valve that is connected to the pump discharge side to control the pressure of fluid at a constant pressure, and includes a valve body provided with a suction port waterway and a discharge port waterway, and a valve body that is slidably housed within the valve body and is provided with a discharge port waterway. A throttle valve for controlling pressure at a constant level, and a counterbalance piston on the opposite side of the throttle valve, which is slidable on a valve stem shaft via a valve stem, and whose sliding part sealingly engages at the end of the valve stem. a control valve body arranged to supply fluid from the suction port waterway to an intermediate portion between the throttle valve and the balance piston, and a control valve body arranged to supply fluid from the suction port waterway to the piston chamber on the end face side of the balance piston. A pressure adjustment device is provided to adjust the pressure to a constant pressure while discharging a portion of the pressure water in the piston chamber to the outside of the valve body, and by adjusting the pressure in the piston chamber, the pressure on the discharge port waterway side is adjusted to a predetermined value. The balancing piston increases the opening degree of the throttle valve so that fluid flows from the inlet channel side to the discharge outlet channel side when the pressure drops below the pressure, and when the pressure on the discharge outlet channel side exceeds a predetermined adjusted pressure, the balance piston opens the throttle valve. A constant pressure control valve characterized in that the balancing piston reduces the opening degree of the throttle valve via a valve stem so as to reduce the flow of fluid to the inlet waterway side.