JPH0737134Y2 - Pressure reducing valve for water supply device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is a pressure reducing device for a water supply device capable of maintaining good flow characteristics without the secondary pressure fluctuating even if the primary pressure fluctuates a little. It is about valves.

[Conventional technology]

The water supply device is equipped with a pressure reducing valve for reducing the high pressure water supplied from the pump to a constant pressure.

In the past, as the pressure reducing valve, the one for hydraulic pressure was used as it was.

FIG. 8 is a schematic side sectional view showing the structure of this type of pressure reducing valve.

This pressure reducing valve is a primary pressure chamber that introduces the water supply from the pump.
85, a rod-shaped spool 86, and pressure adjusting chambers 84 and secondary pressure chambers 88 provided above and below the spool 86, respectively.

Here, a through hole 89 that connects the pressure adjusting chamber 84 and the secondary pressure chamber 88 is provided in the spool 86, and a spool spring 87 is inserted in the through hole 89.

Further, on the pressure regulating chamber 84 side, an adjusting screw 80, a pilot spring 81, a drain 82, and a poppet 83 for keeping the pressure inside the pressure regulating chamber 84 constant are provided.

And compared to the pressure in the pressure regulation chamber 84 where the pressure is constant, the secondary pressure chamber
When the pressure inside 88 becomes small, the spool 86 moves in the direction of the secondary pressure chamber 88 due to the pressure difference applied to both end faces of the spool 86, and the gap 90 between the primary pressure chamber 85 and the secondary pressure chamber 88 is reached. The high-pressure feed water in the primary pressure chamber 85 is introduced to the secondary pressure chamber 88 side, and the pressure in the secondary pressure chamber 88 is increased until it becomes equal to the pressure in the pressure adjusting chamber 84. .

FIG. 9 shows a water pressure reducing valve to which the hydraulic pressure reducing valve is applied, and in the same figure, it shows an open state.

As shown in the figure, this pressure reducing valve is provided with a first opening 1 and a second opening 1.
Pressure reducing valve body 4 having an opening 2 and a third opening 3
And a valve rod 9 provided with a throttle orifice 11 in its central portion,
A throttle valve 7 and a balancing piston 10 having the same diameter, which are mounted on the left and right sides of the valve rod 9, respectively, and the pressure reducing valve body 4
A lid 5 attached to the third opening 3 side, a pressure regulating valve 20 attached to the lid 5, and a spring 16 inserted in the third opening 3 for elastically pushing the balancing piston 10 to the left. It is equipped and configured.

And in this pressure reducing valve, the water supply discharged from the water supply pump flows into the pressure reducing valve main body 4 from the first opening portion 1,
It flows out from the gap a between the throat portion 6 of the pressure reducing valve body 4 and the throttle valve 7 to the second opening 2.

Here, the piston 10 balanced with the right side of the throttle valve 7
The primary pressure on the side of the first opening 1 is applied to each of the left surfaces of the. At this time, since the throttle valve 7 and the balancing piston 10 have the same diameter, the force for pushing the throttle valve 7 to the left and the force for pushing the balancing piston 10 to the right are the same and balanced.

On the other hand, the pressure in the third opening 3 is kept at a predetermined constant pressure by the pressure regulating valve 20, so that the set pressure is balanced and the force pressing the piston 10 to the left is constant.

Therefore, when the pressure in the second opening 2 (secondary pressure) is smaller than the set pressure in the third opening 3, the force that pushes the right surface of the balancing piston 10 to the left is the one of the throttle valve 7. Since the force is greater than the force that pushes the left surface to the right, the valve rod 9 moves to the left and the gap a increases, and
The amount of water supplied from the opening 1 to the second opening 2 of the
The pressure in the opening 2 is increased.

By the way, in the pressure reducing valve shown in FIG. 9, the throttle valve 7 and the balancing piston 10 have the same diameter, and since the areas that receive the pressure are the same, the secondary pressure in the second opening 2 and the secondary pressure in the second opening 2 are the same. When the set pressures in the openings 3 of the valve 3 are the same, the valve rod 9 is fixed at that position regardless of the position, and the opening amount of the gap a cannot be adjusted.

In such a case, a spring 16 is inserted in the third opening 3 in order to move the valve rod 9 to the left and open the gap a by a predetermined amount.

The spool spring 87 shown in FIG. 8 is also inserted for the same purpose.

[Problems to be solved by the device]

However, as described above, when the spring 16 is used to adjust the opening amount of the gap a by the throttle valve 7 at the time of balancing, it is difficult to keep the secondary pressure of the pressure reducing valve constant. This is because the elastic force of the spring 16 is applied to the place where the opening amount of the gap a of the throttle valve 7 should be adjusted based on the balance between the primary pressure, the secondary pressure and the set pressure in the pressure adjusting chamber 12. Conceivable.

FIG. 10 is a diagram showing the pressure reducing valve characteristics of the pressure reducing chamber shown in FIG. As shown in the figure, the secondary pressure P2 'not only changes its characteristics due to the difference in spring constant of the spring 16, but also
There is a problem that the secondary pressure is difficult to be maintained constant, and as the water supply amount Q increases (that is, as the primary pressure decreases), the secondary pressure does not become constant and sequentially decreases.

The present invention has been made in view of the above points, and it is possible to make the secondary pressure constant and to move the throttle valve at the time of balancing in a predetermined direction without using a spring to move the first opening and the second opening. Another object of the present invention is to provide a pressure reducing valve for a water supply device capable of ensuring a predetermined gap between the openings.

[Means for Solving the Problems]

In order to solve the above problems, the present invention forms a first opening 1, a second opening 2 and a third opening 3 in three directions, and the pump discharge liquid is discharged from the first opening 1. Inflow, the second
A pressure reducing valve main body 4 having a structure in which the liquid flows out from the opening 2, and a lid 5 is attached to the third opening 3 and a valve rod 9 is arranged in the pressure reducing valve main body 4. The second of the valve rod 9
A throttle valve 7 is attached to the opening 2 side end of the above, a balancing piston 10 having a diameter smaller than the diameter of the throttle valve 7 is attached to the third opening 3 side end, and the valve rod 9 is An orifice 11 for communicating the pressure adjusting chamber 12 between the balancing piston 10 and the lid 5 and the second opening 2 is passed through, and the pressure of the pressure adjusting chamber 12 is maintained at a predetermined constant pressure in the lid 5. A pressure reducing valve 20 for water supply was attached to form a pressure reducing valve for a water supply device.

[Action]

By configuring the pressure reducing valve for the water supply device as described above,
If (balance piston diameter) / (throttle valve diameter) is set to, for example, 0.93 to 0.95, the secondary pressure is (95 to 97% of the pressure set by the pressure regulating valve 20) + (about 3% of the pump discharge pressure). ~ 5%). Therefore, the influence of the fluctuation of the primary pressure on the secondary pressure is almost eliminated.

Further, by making the diameter of the throttle valve larger than the diameter of the balanced piston, it is possible to add a force for moving the valve rod in the direction of the throttle valve even at the time of balancing, so that the throttle valve can be opened by a predetermined amount. Therefore, the conventional spring is not required, and not only the number of parts can be reduced, but the throttle valve is not affected by the spring and only the balance of the primary pressure, the secondary pressure and the set pressure in the pressure adjusting chamber reduces the throttle. Since the amount is adjusted, the adjustment is accurate and reliable, and the secondary pressure can be kept constant.

〔Example〕

An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view showing a first embodiment of a pressure reducing valve for a water supply device according to the present invention.

As shown in the figure, this water supply device pressure reducing valve includes a pressure reducing valve body 4, a valve rod 9 inserted into the pressure reducing valve body 4, a throttle valve 7 attached to the left end of the valve rod 9, The valve rod 9
The balance piston 10 is attached to the right end of the pressure reducing valve, the lid 5 is attached to the pressure reducing valve body 4 on the side of the third opening 3, and the pressure regulating valve 20 is attached to the lid 5.

Each component will be described below.

The pressure reducing valve body 4 is formed in a substantially T shape, and a first opening 1, a second opening 2, and a third opening 3 are formed in three directions thereof.

Further, the pressure reducing valve body 4 is provided with a cylindrical throat portion 6 with which the throttle valve 7 and the outer peripheral surface of the balancing piston 10 are in sliding contact.

Next, the throttle valve 7 is formed in a disk shape having a diameter of DS, and an orifice 15 which connects the chamber between the throttle valve 7 and the balancing piston 10 and the second opening 2 is formed at a predetermined position thereof. Has been done. Further, the throttle valve 7 is provided with a guide 8 which is in sliding contact with the inner circumference of the throat portion 6.

Next, the balancing piston 10 is formed in a disc shape having a diameter of DP. Here, the diameter DP should be slightly smaller than the diameter DS of the throttle valve 7 (that is, DP <D
S) Composed. An O-ring 21 is attached to the outer periphery of the balancing piston 10 so as to closely seal the inner peripheral surface of the throat portion 6.

On the other hand, by mounting the lid 5 so as to cover the third opening 3, a pressure adjusting chamber 12 is formed between the lid 5 and the balancing piston 10. The pressure regulating valve 20 attached to the lid 5 has a function of keeping the water pressure in the pressure regulating chamber 12 constant.

Further, an orifice 11 that allows the pressure adjusting chamber 12 and the second opening 2 to communicate with each other is provided at the center of the valve rod 9.

Next, the operation of the pressure reducing valve for the water supply device will be described with reference to FIGS.
It will be described with reference to the drawings.

Here, FIG. 1 shows a state in which the throttle valve 7 of the pressure reducing valve for the water supply device is opened most, and FIG. 2 shows a state in which the throttle valve 7 is closed most.

Here, a force for pushing the left side surface and a force for pushing the right side surface of the throttle valve 7, and a force for pushing the left side surface and the force for pushing the right side surface of the balancing piston 10 are applied to the valve rod 9, so that each will be described below.

First, the discharge liquid of a water supply pump (not shown) flows into the first opening portion 1, whereby the right side surface of the throttle valve 7 and the left side surface of the piston 10 are balanced by the pressure of the inflow liquid, that is, the primary Pressure is applied.

Since the diameter DP of the balancing piston 10 is smaller than the diameter DS of the throttle valve 7, the throttle valve 7
The force that pushes to the left is greater than the force that pushes the balancing piston 10 to the right. Therefore, a force is exerted on the valve rod 9 to move it to the left, that is, in the direction to open the gap a. This force corresponds to the above-mentioned conventional spring 16.

Next, the pressure applied to the left side surface of the throttle valve 7 is
Is the pressure (secondary pressure) after the primary pressure on the side of the opening 1 is throttled in the gap a between the throat portion 6 and the throttle valve 7, and the force due to this pressure is in the right direction.

On the other hand, as the pressure in the pressure adjusting chamber 12, a secondary pressure throttled by the throttle valve 7 is applied through the orifice 11 of the valve rod 9, and the pressure adjusting chamber 12 is adjusted by the pressure adjusting valve 20. That is, the pressure in the pressure adjusting chamber 12 is a desired set pressure adjusted by the pressure adjusting valve 20.

The force for pressing the valve rod 9 to the left and right is as described above.

First, in the balanced state, that is, in the operating state,
A case will be described in which the next pressure and the set pressure in the pressure adjusting chamber 12 are balanced and the valve rod 9 is stopped at a predetermined position.

In this case, PP: pump discharge pressure (primary pressure) P2: second opening 2 side pressure (secondary pressure) P1: pressure regulation chamber 12 pressure DP: balanced piston 10 diameter DS: throttle valve 7 diameter DS x (PP-P2) = DP x (PP-P1). Therefore, the secondary pressure P2 is P2 = P1 x (DP / DS) + PP x (1-DP / DS) ... equation (1).

Assuming that (DP / DS) is 0.95 to 0.97, (1-DP / DS)
Is 0.005 to 0.03.

That is, the pressure P2 of the second opening 2 is (95 to 97% of the pressure set by the pressure regulating valve 20) + (about 3 to 5% of the pump discharge pressure), which is the secondary pressure of the primary pressure PP. Almost no effect on P2.

That is, even if the primary pressure PP fluctuates, the secondary pressure P2 is not affected by this and is maintained at a constant pressure almost equal to the set pressure set by the pressure regulating valve 20.

Next, from the above-mentioned balanced state, the secondary pressure decreases and
When the secondary pressure becomes smaller than the set pressure in the pressure regulation chamber 12 and the balance state of both pressures is broken, the lowered secondary pressure rises to a pressure almost equal to the set pressure in the pressure regulation chamber 12. The valve rod 9 moves to the left by an amount necessary to open the gap a. The operation will be specifically described below.

First, let F be the initial pressure balance state, that is, the force for moving the throttle valve 7 to the left and the force for moving the balanced piston 10 to the right are the same. That is, DS x (PP-P2) = DP x (PP-P1) = F ... Formula (2).

Then, if the secondary pressure P2 then decreases by the pressure ΔP, the new secondary pressure P2 ′ will be P2 ′ = P2−ΔP.

At this time, the force to move the throttle valve 7 to the left is DS × {PP- (P2-ΔP)} = DS × (PP-P2) + DS × ΔP
= F + DS × ΔP Equation (3) is obtained.

On the other hand, the force to move the balancing piston 10 to the right side is DP x (PP-P1) = F (Equation 4) and does not change (the primary pressure PP and the pressure adjusting chamber pressure P1 change. Not).

From the equations (3) and (4), the force to move the throttle valve 7 to the left side is larger than the force to move the balancing piston 10 to the right side by the force (DS × ΔP).

Therefore, the force (DS × ΔP) acts on the valve rod 9 and the valve rod 9 moves to the left side (throttle valve 7 side).

As the valve rod 9 moves to the left, the gap a shown in FIG. 1 gradually increases and the throttling effect of the gap a decreases. When the value for reducing the primary pressure decreases by ΔP due to the reduction of the throttling effect, the secondary pressure P2 ″ increases correspondingly, and P2 ″ = P2 ′ + ΔP = (P2-ΔP) + ΔP = P2.

As a result, the balance state of the equation (2) is again established.
Therefore, the valve rod 9 becomes stationary again after the movement. That is, the secondary pressure is always maintained at a pressure almost equal to the set pressure set by the pressure regulating valve 20.

Next, when the secondary pressure becomes higher than the set pressure in the pressure adjusting chamber 12, the secondary pressure on the second opening 2 side is the pressure adjusting chamber 12
The valve rod 9 moves to the right by an amount necessary to make it equal to the set pressure inside, and narrows the gap a to reduce the secondary pressure.
Also in this case, if the valve rod 9 is stopped due to the balance between the two, the secondary pressure becomes a value represented by the above mathematical formula.

Here, FIG. 3 is a diagram showing the pressure reducing valve characteristics of the pressure reducing valve for a water supply apparatus according to the above embodiment.

The secondary pressure P2 indicated by the dotted line in the figure remains constant until the predetermined feed water flow rate is reached, even if the primary pressure PP indicated by the solid line gradually decreases as the feed water flow rate increases.

Here, this secondary pressure P2 is equal to the set pressure P1 in the pressure control chamber 12 (DP / D
The value obtained by multiplying the pump discharge pressure PP by (1-DP / DS) (a minute amount) is added to the two-dot chain line multiplied by S).

That is, according to the present invention, the secondary pressure does not depend on the fluctuation of the primary pressure, and the throttle valve 7 and the throttle valve 7 are set so that the secondary pressure becomes almost the same as the set pressure set by the pressure regulating valve 20. The amount of diaphragm between the throat portions 6 is adjusted.

Further, according to the present invention, by making the diameter of the throttle valve 7 larger than the diameter of the balancing piston 10, a force for moving the valve rod 9 toward the throttle valve 7 can be added even at the time of balancing, so that the spring as in the conventional spring is used. Is unnecessary.

When the outlet of the second opening 2 is closed, the secondary pressure rises, so the valve rod 9 moves to the right and closes the gap a as shown in FIG. Then, in this case, the primary pressure gradually pressurizes the chamber closed by the second opening through the orifice 15 until the primary pressure is reached.

FIG. 4 is a sectional view showing a second embodiment of the present invention.

The second embodiment is different from the first embodiment in that the throttle valve 7'is not provided with the guide 8 and instead the throat portion 6 is extended so as to extend over the entire movement range of the throttle valve 7 '. And a cutout portion that communicates between the first opening portion 1 and the second opening portion 2 with the extended throat portion 6.
This is the point where 30 is provided. Note that the diameter of the throttle valve 7'is made slightly larger than the diameter of the balanced piston 10 as in the first embodiment.

The secondary pressure can be adjusted in the same manner as in the first embodiment by the amount by which the throttle valve 7'blocks the notch 30 and throttles it.

FIG. 5 is a sectional view showing a third embodiment of the present invention.

The third embodiment is different from the above-mentioned first embodiment in that the throttle valve 7, the balancing piston 10 and the valve rod 9 are integrally incorporated in a cylindrical adapter 17, and the outside of the adapter 17 is provided. The point where the pressure reducing valve main body 4 is attached and the gap a (closed in the figure) for reducing the secondary pressure to the second opening 2 are defined by the circumferential end face on the right side of the adapter 17 and the throttle valve 7. And the orifice 15 'is provided in the pressure reducing valve body 4. The diameter of the throttle valve 7 is made slightly larger than the diameter of the balancing piston 10 in the same manner.

The secondary pressure can be adjusted in the same manner as in the first embodiment according to the throttle amount of the gap a formed between the left side surface of the throttle valve 7 and the right end surface of the adapter 17.

Next, a method of operating the water supply pressure reducing valve in combination with a water supply pump will be described with reference to FIG.

As shown in the figure, the water in the water receiving tank E enters the water supply pump P through the suction pipe P-1, is pressurized by the water supply pump P, and then is supplied to the water supply device pressure reducing valve B according to the present invention at a predetermined level. The pressure is reduced, passes through the check valve C, and the water supply pipe F-1
It is consumed from the faucet F1, F2, F3 connected to.

Figure 7 shows the amount of water used (J1, J
2, J3) and the discharge pressure (primary pressure) of the water supply pump P and the secondary pressure of the water supply device pressure reducing valve B.

According to the present invention, as shown in the figure, the water consumption is J1, J2, J3.
In either case, the secondary pressure is constant.

If all of the faucets F1 to F3 are closed here, the secondary pressure of the pressure reducing valve B for the water supply device accumulates water in the pressure tank D shown in FIG. 6, while the shutoff pressure Ps of the water supply pump P shown in FIG. However, when the secondary pressure reaches the OFF line in the middle, the pressure switch G shown in FIG. 6 operates to send a signal to the control panel H and stop the motor M.

Next, when the faucets F1 to F3 are used again, first the pressure tank D
The water accumulated in is used and the secondary pressure is ON as shown in Fig. 7.
When the line is reached, the pressure switch G is activated to send a signal to the control panel H to start the motor M.

[Effect of device]

As described in detail above, according to the pressure reducing valve for a water supply device according to the present invention, even if the primary pressure fluctuates, the secondary pressure is not affected by this, and it is possible to maintain a constant pressure. Have the effect.

Also, by making the diameter of the throttle valve larger than the diameter of the balanced piston, it is possible to add a force to move the valve rod in the direction of the throttle valve even during balancing and to open the throttle valve by a predetermined amount. No spring is needed. Therefore, not only can the number of parts be reduced, but the throttle valve is not affected by the spring, and its throttle amount is adjusted only by the balance between the primary pressure, the secondary pressure, and the set pressure in the adjustment chamber. It is accurate and reliable, and the secondary pressure can be kept constant.

Further, since the third opening is provided, the entire valve rod (including the throttle valve and the balancing piston), the pressure regulating valve and the lid can be easily removed without removing other pipes.

[Brief description of drawings]

1 and 2 are sectional views showing a first embodiment of a pressure reducing valve for a water supply device according to the present invention, FIG. 3 is a diagram showing characteristics of the pressure reducing valve of the above embodiment, and FIG. FIG. 5 is a sectional view showing a second embodiment, FIG. 5 is a sectional view showing a third embodiment of the present invention, and FIG. 6 is a view showing a method of operating the pressure reducing valve for a water supply device according to the present invention in combination with a water supply pump, Figure 7 shows the amount of water used (J
1, J2, J3) and the discharge pressure (primary pressure) of the water supply pump P and the secondary pressure of the water supply device pressure reducing valve B, and FIG. 8 is a schematic side sectional view showing the structure of a conventional pressure reducing valve. Fig. 9 and Fig. 8
Sectional drawing which shows the pressure reducing valve for water which applied the pressure reducing valve for hydraulics shown in FIG. 10, FIG. 10 is a figure which shows the pressure reducing valve characteristic of the pressure reducing valve shown in FIG. In the figure, 1 ... first opening, 2 ... second opening, 3 ... third
, 4 ... Pressure reducing valve body, 5 ... Lid, 7 ... Throttle valve, 9 ... Valve rod, 10 ... Balancing piston, 11 ... Orifice, 12 ... Pressure adjusting chamber, 20 ... Pressure adjusting valve.

Claims (1)

[Scope of utility model registration request] 1. A first opening, a second opening and a third opening are formed in three directions, and pump discharge liquid flows in through the first opening, and the second opening opens from the second opening. A pressure reducing valve body having a structure for allowing the liquid to flow out is provided, a lid is attached to the third opening, and a valve rod is arranged in the pressure reducing valve body.
A throttle valve is attached to the opening side end of the valve, a balancing piston having a diameter smaller than the diameter of the throttle valve is attached to the third opening side end, and the valve rod has a balancing piston and a lid. A water supply device characterized in that a pressure regulating valve for maintaining the pressure of the pressure regulating chamber at a predetermined constant pressure is attached to the lid by penetrating an orifice for communicating the pressure regulating chamber between the second opening and the pressure regulating chamber. Pressure reducing valve.