JP2001295250A - Pressure reducing valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure reducing valve capable of reducing energy more than the conventional pressure reducing valve. SOLUTION: This pressure reducing valve is provided with a water guide tube 3 having an inlet 1 of high-pressure water at one end section and an opening section 2 for splashing at the other section, a gate 4 slidably assembled to the other end section of the water guide tube 3 to open or close the opening section 2, and an opening/closing means 5 vertically moving the gate 4. An energy reducing means 9 formed with a spiral fin 9A is provided in the water guide tube 3 so that the spiral fin 9A interferes with the water flowing down toward the opening section 2 from the inlet 1 to reduce energy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve for attenuating water at a high head of a dam to a downstream irrigation channel and discharging the water with a small flow rate, and a valve for discharging the deenergized water from a discharge port of a pressure water pipe. As a pressure reducing valve.

[0002]

2. Description of the Related Art Heretofore, for example, as a valve that attenuates water at a high head of a dam to a downstream irrigation channel and discharges the water at a small flow rate, or a valve that discharges deenergized water from a discharge port of a pressure water pipe. As a suitable pressure reducing valve, a pressure reducing valve called a sleeve valve is known. As shown in FIGS. 5 and 6, this type of pressure reducing valve is provided with a vertically extending water pipe 3 having an upper end provided with an inlet 1 for high-pressure water and a lower end provided with an opening 2 for discharge. 2
The energy dissipating tank includes a gate 4 that is freely slidably mounted on the lower end of the water pipe 3 so that the gate 4 can be opened and closed, and opening and closing means 5 for moving the gate 4 up and down, that is, up and down. 6 is installed.

The inlet 1 of the water pipe 3 is opened laterally by disposing an elbow 3A. The opening 2 of the water pipe 3 is formed by forming a large number of small holes 2B, 2B,... At predetermined intervals in the circumferential direction and the vertical direction all around the annular wall 2A. Is fitted to the annular wall 2A so as to be able to move up and down while sliding on the inner surface of the annular wall 2A. The lower end of the annular wall 2A is closed by the bottom plate 2a.

The opening / closing means 5 includes a spindle 5 extending vertically.
A and an elevating device 5B. The spindle 5A communicates with the center axis of the water pipe 3 and the elbow 3A.
The lower end is connected to the gate 4, and the upper end is connected to the elevating device 5 B above the ceiling 6 A of the energy dissipation tank 6. I have. In the figure, reference numeral 8 denotes a high-pressure water pipe, which is connected to the inlet 1 of the water pipe 3.

According to the pressure reducing valve constructed as described above, when the water in the high-pressure water supply pipe 8 flows down into the water supply pipe 3 with the gate 4 opening a large number of small holes 2B, 2B. The water is turned downward by the elbow 3A, descends vertically inside the water pipe 3, and is converted into a radial flow from the many small holes 2B, 2B,.
Squirt into the interior.

When passing through the plurality of small holes 2B, a pressure loss occurs, and the energy is reduced. Further, the flow spouted radially from the large number of small holes 2B into the inside of the deenergizing tank 6 collides with the standing wall of the deenergizing tank 6, and the energy is secondarily reduced. The ejection flow rate into the deenergization tank 6 is adjusted by automatic or manual operation of the lifting / lowering device 5B of the opening / closing means 5. That is, when the opening 2 is fully closed, the gate 4 is lowered to the fully closed position shown in FIG. , 2B... Can be obtained by closing all of the small holes 2B, 2B,. By holding the gate 4 at an arbitrary position between the fully closed position and the fully open position, it is possible to obtain the ejection flow rate according to the opening degree of the gate 4.

[0007]

However, the above-mentioned conventional pressure reducing valve has a structure in which only a large number of small holes 2B, 2B formed in the opening 2 are energized to reduce the energy. Is limited. Therefore, it is not possible to expect even greater energy reduction.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a pressure reducing valve capable of performing a larger deenergization than a conventional pressure reducing valve.

[0009]

In order to achieve the above object, a pressure reducing valve according to the present invention is provided with a high pressure water inlet at one end and a discharge opening at the other end. A pressure reducing valve comprising a water pipe, a gate slidably assembled to the other end of the water pipe so as to open and close the opening, and opening and closing means for moving the gate in the opening and closing direction of the opening. In addition, a deenergizing means is provided inside the water guide pipe for interfering with water flowing down from the inlet toward the opening to reduce the energy.

According to the present invention, the water flowing down the inside of the water pipe is deenergized by interfering with the deenergizing means. Since this deenergizing action is added to the known deenergizing action performed at the opening, the total deenergizing action of the pressure reducing valve can be greatly increased.

[0011]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing a partial cross section of an embodiment of the present invention, and FIG. 2 is an enlarged half sectional view of an opening. The same parts as those in the conventional example shown in FIGS. 5 and 6 are denoted by the same reference numerals, and the description of the overlapping structure and operation will be omitted.

In FIG. 1 and FIG. 2, a series of spiral fins 9 surrounding a spindle 5A on the inner peripheral surface and abutting the outer peripheral surface on the inner peripheral surface of the water conduit 3 are provided inside the water conduit 3.
A energy reducing means 9 is provided.

According to the above configuration, when the water in the high-pressure water pipe 8 flows down into the water pipe 3, the introduced water is turned downward by the elbow 3A and descends vertically inside the water pipe 3. The water descending inside the water pipe 3 interferes with the spiral fin 9 </ b> A constituting the energy reducing means 9 and turns inside the water pipe 3. As a result, pressure loss occurs and energy can be reduced.

The water whose energy has been depressurized by the deenergizing means 9 inside the water pipe 3 generates a pressure loss when passing through a number of small holes 2B, 2B,. Energy is reduced. That is, to the conventionally known deenergizing action performed by the opening 2, the deenergizing action by the deenergizing means 9 constituted by the spiral fin 9A can be added. For this reason, compared with the conventional pressure reducing valve,
The total deenergizing action can be greatly increased.

As described above, since the total deenergizing action is greatly increased, the primary pressure ejected from the opening 2 into the deenergization tank 6 is reduced, and the secondary pressure determined by the water depth of the deenergization tank 6 is reduced. The pressure, that is, the differential pressure from the secondary pressure determined by the opening depth of the opening 2 can be reduced, and the cavitation coefficient can be increased to exert an effect of suppressing the occurrence of cavitation. The water introduced into the water pipe 3 is
Since it descends while turning inside, the turning of water continues inside the opening 2, that is, the inner peripheral area of the annular wall 2A. Since the swirling flow S can be accompanied by solid foreign matter on the upper surface of the bottom plate 2a of the annular wall 2A and guided to the large number of small holes 2B, 2B, it is possible to prevent solid foreign matter from being deposited on the upper surface of the bottom plate 2a.

In the above-described embodiment, a description has been given of a configuration in which the energy reducing means 9 composed of a series of spiral fins 9A is provided. However, the spiral fins 9A are provided in a plurality in the axial direction of the water pipe 3. The energy dissipating means 9 may be configured by being provided separately. Instead of the spiral fin 9A, as shown in FIG. 3, a plurality of punching metals or mesh members 9B, 9B,... You may comprise. Further, the pitch of the spiral fins 9A and the arrangement interval of the punched metal or mesh members 9B, 9B,... Are set uniformly in the axial direction of the water pipe 3, but are coarse in the upper part of the water pipe 3 in the axial direction. The lower part in the axial direction of the water pipe 3 may be set densely.

Further, according to the present invention, as shown in FIG. 4, a cone 3B is provided at the lower end of the water pipe 3 so that the outside of the opening 2 can be opened and closed by the gate 4, and the spindle 5A is guided. The present invention can also be applied to a pressure reducing valve arranged outside the water pipe 3.

[0018]

As described above, since the pressure reducing valve according to the present invention is constituted, the following special effects can be obtained.

That is, the energy of the water flowing down the inside of the water pipe can be reduced by the energy reducing means and added to the known energy reducing action performed at the opening. Can be greatly increased.

[Brief description of the drawings]

FIG. 1 is a front view showing a partial cross section of an embodiment of the present invention.

FIG. 2 is an enlarged half sectional view of an opening.

FIG. 3 is a longitudinal sectional view showing a modified example of the energy-reducing means.

FIG. 4 is a partially enlarged sectional view of an opening showing another embodiment of the present invention.

FIG. 5 is a front view showing a conventional example with a partial cross section.

FIG. 6 is an enlarged half sectional view showing an opening of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inlet 2 Opening 3 Water pipe 4 Gate 5 Opening / closing means 9 Energy reduction means

Claims (1)

[Claims] 1. A water pipe having an inlet for high-pressure water at one end and an opening for discharge at the other end, and a slide at the other end of the water pipe so that the opening can be opened and closed. In a pressure reducing valve having a movably assembled gate and an opening / closing means for moving the gate in the opening / closing direction of the opening, water is supplied to the water flowing down from the inlet toward the opening inside the water pipe. A pressure reducing valve provided with a deenergizing means for deenergizing energy by interference.