JP3064454U - Constant pressure valve - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a simple check valve with a small number of parts. SOLUTION: In a constant pressure valve 1, a pressure receiving surface 15a of a secondary side pressure of a valve body 15 is concentric with the valve body 15 and is provided with a valve body 15
Circular orifice 41 with secondary side opening 39a of orifice 39
In the circular concave surface 41, the center of the check valve 40 made of a rubber disc having a larger diameter is fixed to the center of the circular concave surface 41, and the periphery of the circular concave surface 41 and the pressure receiving surface 15a are provided. The check valve 40 is warped at the step 43 so as to press it against it.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a constant pressure valve used for a pump unit of a pressure tank type water supply device.

[0002]

[Prior art]

 Conventionally, in the above pump unit, when water is used, the pump should be started to maintain a constant pressure.However, continuous operation of the pump even when water is not used shortens the life of the pump and reduces electricity costs. In such a situation, a means for stopping the pump is used, since this causes a problem such as wasting. As one example, there is a means for providing an orifice in a valve body of a constant pressure valve provided in a pump unit, in which a primary pressure chamber and a secondary pressure chamber of the constant pressure valve communicate with each other. In this method, water is flowing from the primary pressure chamber to the secondary pressure chamber through the orifice while the pump is running, and the amount of water used becomes less than a certain amount or the water is no longer used. In this case, the pressure in the secondary pressure chamber gradually increases due to the flow from the orifice, and when this pressure reaches the set value of the pressure switch provided in the unit, a pump stop signal is generated and the pump is stopped. It was made to stop. By the way, when using water, the discharge pressure of the pump is reduced by the constant pressure valve, and a constant pressure is maintained with respect to the flow rate change. Therefore, the primary pressure always becomes higher than the secondary pressure. However, when the pump is stopped as described above, the pressure in the primary side pressure chamber becomes 0 and the pressure in the secondary side pressure chamber has risen to the above-mentioned set value of the pressure switch. A back pressure is generated between the pressure and the downstream pressure. If this condition continues for a long time, the water in the secondary pressure chamber will flow back to the primary pressure chamber through the orifice, reducing the secondary pressure to the pump start pressure of the pressure switch. Despite the absence, the pump started to malfunction. Therefore, countermeasures such as installing a check valve on the discharge (secondary) side of the constant pressure valve or providing a check valve directly at the orifice have been taken.

[0003]

[Problems to be solved by the invention]

 However, all of the above check valves have a configuration in which a spring is press-fitted, and the number of parts is large, and the cost must be increased. Furthermore, if the check valve is caught by dust or the like, the check valve does not operate normally, and the check flow prevention function is impaired.

[0004]

[Means for Solving the Problems]

 In view of the above problem, the present invention provides a constant-pressure valve having a circular concave surface, which is concentric with the valve body and has a secondary opening of the orifice of the valve body, on the pressure receiving surface of the secondary side pressure of the valve body. In the circular concave surface, the center of a check valve made of a rubber disc having a larger diameter is fixed to the center of the circular concave surface, and at the step between the peripheral edge of the circular concave surface and the pressure receiving surface, By pressing the check valve such that the check valve is warped so as to press-contact the valve, the check valve is urged so as to close the secondary side opening, and a spring is not used. A check valve with a small number of parts and a simple structure is provided at the valve orifice. In addition, by forming the periphery of the secondary opening of the orifice at which the check valve closes and the above-mentioned step at which the check valve is pressed against the seat portion of the check valve, the pressure receiving surface of the valve body for the secondary pressure. In order to solve the above-mentioned problem, a double backflow prevention function is provided so that even if one of the sheet portions is damaged by dust or the like, the backflow prevention function is prevented by the other sheet portion. Solve.

[0005]

[Embodiment of the invention]

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of the constant pressure valve according to the present invention. The valve box 2 of the constant pressure valve 1 is formed in a substantially cylindrical shape, has a pair of inflow ports 3 and 3a on the left and right sides thereof, and has a lower opening as a discharge port 4. Further, a primary pressure chamber 5 communicating with the inflow ports 3 and 3a and a secondary pressure chamber 6 communicating with the discharge port 4 are provided inside the valve box 2 by partitioning the partition wall 7. A large-diameter hole 8 is opened, and the primary-side and secondary-side pressure chambers 5 and 6 communicate with each other through the large-diameter hole 8. Then, a substantially cylindrical inner box 10 is provided in the valve box 2 from the upper opening 9 of the valve box 2 to the large-diameter hole 8, and the primary-side pressure chamber 5 is partitioned into a nectar shape inside and outside. ing.

The inner box 10 has a plurality of communication ports 11 and 11a on its side, and communicates with the primary pressure chamber 5 (hereinafter, referred to as the primary pressure chamber 5 including the inside of the inner box 10). )doing. The lower opening of the inner box 10 is formed as a valve port 12 communicating with the primary side and the secondary side pressure chambers 5 and 6, and the end face of the opening side of the valve port 12 on the secondary side (of the inner box 10). And the valve seat 13.

A valve mechanism 14 is provided inside the inner box 10. The valve mechanism section 14 is configured by connecting a valve body 15 receiving primary pressure in the valve opening direction and a piston 16 receiving primary pressure in the valve closing direction of the valve body 15 via a valve rod 17, A valve element 15 is provided on the valve seat 13 so as to be detachable, and a piston 16 is slidably provided on an upper portion of an inner wall of the inner box 10. The upper part of the primary pressure chamber 5 defined by the piston 16 forms a cylinder chamber 18, and the cylinder chamber 18 is sealed by a cover 19 covering the upper opening 9 of the valve box 2 in a nectar-like shape. ing.

On the inner wall of the inner box 10, an annular piston stopper 20 is provided at the lower limit position of the piston 16. A guide ring 21 for slidingly guiding the valve stem 17 is fitted on an appropriate portion of the valve stem 17, and the guide ring 21 is supported by a plurality of guide bars 22, 22a protruding from the inner wall of the inner box 10. . The piston 16 is provided with an orifice 23 (hereinafter, referred to as a piston orifice 23) for communicating the cylinder chamber 18 and the primary pressure chamber 5, and a split pin 24 is loosely inserted into the piston orifice 23. The movement of the piston 16 causes the cotter pin 24 to move up and down in the piston orifice 23 so that water scale or the like does not adhere to the inside and does not block. A ring groove is cut out around the piston 16, and an O-ring 25 and a piston ring 26 are mounted in order from the inside of the ring groove.

The cylinder chamber 18 is connected in a watertight manner to a pilot valve 27 that regulates a constant pressure while discharging a part of the chamber pressure to the outside of the constant pressure valve 1. The pilot valve 27 includes a casing 30 that forms a flow path 29 that communicates the cylinder chamber 18 with the outside through a pilot valve port 28, and a pilot valve port 28 that has a predetermined pressure in the cylinder chamber 18. And a bonnet 32 in which a pressure adjusting mechanism 31 for adjusting the opening degree is provided. The pressure adjusting mechanism 31 includes a pilot valve element 33 that opens and closes the pilot valve port 28, a diaphragm 34 that provides the pilot valve element 33 at the center, and separates the casing 30 and the bonnet 32, and an outside of the bonnet 32. An adjusting screw 36 with a lock nut 35 screwed therein, and a spring 38 interposed with spring receivers 37 and 37a between the tip of the adjusting screw 36 protruding into the bonnet 32 and the diaphragm 34. Then, by adjusting the force of the spring 38 with the adjusting screw 36, the opening of the pilot valve port 28 is automatically adjusted so that the fluid pressure applied to the diaphragm 34 becomes the pressure adjusted by the spring 38. The fluid is adjusted to discharge the fluid.

As shown in FIG. 2 in an enlarged manner, the valve element 15 is provided with an orifice 39 (hereinafter, referred to as a valve element orifice 39) communicating with the primary and secondary pressure chambers 5, 6. A check valve 40 for a valve orifice 39 is provided on the pressure receiving surface 15a of the valve body 15 for receiving the secondary pressure. At the center of the pressure receiving surface 15a, a circular concave surface 41 which is concentric with the valve body 15 and in which a secondary opening 39a of the valve body orifice 39 is arranged is provided. The circular concave surface 41 has a smooth surface perpendicular to the valve stem 17 (a surface parallel to the pressure-receiving surface 15a of the valve element 15), and the smooth surface is flush with the secondary opening 39a of the valve element orifice 39. It is exposed to. At the center of the circular concave surface 41 (same as the center of the valve body 15), there is provided a cylindrical protrusion 15b through which the valve rod 17 is inserted, and a concave groove 42 is formed on the outer periphery of the base end of the protrusion 15b. Is formed. The check valve 40 is made of a rubber disk having a diameter larger than that of the circular concave surface 41, and is provided with a mounting hole 40a having a diameter slightly smaller than that of the concave groove 42 at the center thereof. It is externally fitted and fixed in the groove 42. In this state, since the check valve 40 has a larger diameter than the circular concave surface 41, the check valve 40 protrudes from the circular concave surface 41, and warps so as to be pressed against a step 43 between the peripheral edge of the circular concave surface 41 and the pressure receiving surface 15a. Due to this warping, the check valve 40 is urged so as to press the circular concave surface 41 and close the secondary opening 39a due to its material properties (elasticity). The first and second seat portions S1 and S2 respectively define the step portion 43 where the check valve 40 is pressed and the peripheral edge of the secondary opening 39a where the check valve 40 closes. Due to the second seat portions S1 and S2, the check valve 40 has a double backflow prevention function.

FIG. 3 is a schematic view of a pump unit using the constant pressure valve 1 according to the present invention. In the figure, reference numeral 44 denotes a pipe from a water main or a water receiving tank, and the pipe 44 is connected to the inflow ports 3 and 3a of the constant pressure valve 1 via a pump 45. The discharge port 4 of the constant pressure valve 1 is connected to each water tap 46 by a water supply pipe 47, and a pressure switch 48 for starting and stopping the pump 45 in the water supply pipe 47, and a pressure tank 49 storing water are interposed. I have. The pilot valve 27 is connected to a suction side of a pump 45 by a drain tube 50.

Next, the operation of the constant pressure valve 1 will be described with reference to FIGS. When the water with the water tap 46 opened is used, water is supplied from the pressure tank 49. Thereafter, when the pressure in the water supply pipe 47 drops to the pump starting pressure of the pressure switch 48, the pump 45 is started by the pressure switch 48. By discharging water from the pump 45, the valve body 15 and the piston 16 of the constant pressure valve 1 receive the primary pressure, and a part of the fluid in the primary pressure chamber 5 flows into the cylinder chamber 18 through the piston orifice 23. . Then, the pressure in the cylinder chamber 18 eventually rises above the pressure in the secondary pressure chamber 6, and the piston 16 moves in the valve opening direction of the valve body 15, whereby the valve body 15 is separated from the valve seat 13, and The primary-side pressure chamber 5 and the secondary-side pressure chamber 6 communicate with each other, and the fluid is supplied to a water tap 46 through a water supply pipe 47. When the pressure in the cylinder chamber 18 exceeds the set value of the pilot valve 27, the pilot valve body 33 opens and discharges the pressurized fluid, so that the pressure is kept constant. Is adjusted to keep the secondary pressure constant. Next, when the water tap 46 is closed to stop using water, the secondary side pressure rises above the pressure in the cylinder chamber 18, so that the valve body 15 closes. The fluid in the primary pressure chamber 5 passes through the valve body orifice 39 to open the check valve 40, flows to the secondary pressure chamber 6, is stored in the pressure tank 49, and is stored in the pressure tank 49. When the pressure of the water supply pipe 47 pressurized by the pressure rises to the pump stop pressure of the pressure switch 48, the pressure switch 48 stops the pump 45. Thereafter, the check valve 40 receives the increased secondary pressure and closes.

[0013]

[Effect of the invention]

 In short, according to the present invention, the check valve 40 can be formed only by attaching the rubber disc to the circular concave surface 41 as described above without providing a check valve using a spring on the valve body as in the conventional case. Since the assembly work is simple and easy, and the number of parts is only the check valve 40 having the above configuration, the cost can be reduced as compared with the conventional constant pressure valve.

Further, the check valve 40 has a double backflow preventing function of the outer first seat portion S1 surrounding the circular concave surface 41 and the inner second seat portion S2, so that the first, Even if dust is caught in the second sheet portions S1 and S2 and the backflow prevention function is impaired, the backflow prevention function can be maintained by the other first or second sheet portions S1 and S2. It is big.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a constant pressure valve.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is a schematic view showing an example of a pump unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Constant-pressure valve 2 Valve box 3, 3a Inflow port 4 Discharge port 5 Primary pressure chamber 6 Secondary pressure chamber 12 Valve port 13 Valve seat 15 Valve body 15a Pressure receiving surface 16 Piston 17 Valve rod 18 Cylinder chamber 23 Piston orifice 27 Pilot valve 39 Valve body orifice 39a Secondary opening 40 Check valve 41 Circular concave surface 43 Step

Claims (1)

[Utility model registration claims] 1. A valve body for opening / closing a valve port provided inside a valve box so as to communicate with a primary pressure chamber and a secondary pressure chamber communicating with an inflow port and a discharge port through a valve port. The valve seat is detachably provided on the valve seat so as to receive the primary pressure in the valve opening direction.
An orifice communicating the secondary pressure chamber and the secondary pressure chamber is provided in the valve body, and a piston that receives the primary pressure in the valve closing direction via a valve rod is connected to the valve body. In a constant pressure valve in which a separate orifice communicating the cylinder chamber and the primary pressure chamber is provided, and a pilot valve for adjusting the chamber pressure to a constant level is connected to the cylinder chamber, the pressure receiving of the secondary pressure of the valve body is performed. A circular concave surface provided concentrically with the valve element and having a secondary opening of the orifice of the valve element, the check valve comprising a rubber disc having a larger diameter than the circular concave surface. Is fixed to the center of the circular concave surface, and at the step between the peripheral edge of the circular concave surface and the pressure receiving surface, the non-return valve is warped so as to press against the same, thereby closing the secondary opening. A constant pressure valve characterized in that a check valve is biased in the above manner.