JPH0133894Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention relates to an improvement of a pressure equalizing device for a rotary valve that almost equalizes the pressure upstream and downstream of the valve body to reduce the opening and closing torque when the rotary valve is opened and closed. It is.

(Prior art) A conventional device of this type is the one filed by the applicant of this invention (Japanese Patent Publication No. 12428/1983).
There is. This is constructed as shown in FIG. 1, and its operation will be explained as follows. That is, to open the valve from the fully closed state shown in the figure, by rotating the operating lever 28 in the direction of the arrow, one end surface of the sub-valve shaft 17 is pressed by the holding portion 28a against the biasing force of the spring 33. do. Then, the auxiliary valve body 16 fixed to the auxiliary valve shaft 17, which moves toward the inside of the valve body 1 due to this pressure, separates from the valve seat 18 and moves toward the inlet 2 side and the outlet 3 side in the valve body 1. and the annular groove 21 and the communication hole 2
2. They communicate through the annular groove 19 and the communication hole 23, and the pressures upstream and downstream of the main valve body 4 are approximately equal. When the operating lever 28 is rotated around the main valve shaft 7 while maintaining this communication, the main valve body 4 is gradually rotated to open the flow path, and becomes fully open when rotated approximately 90 degrees. When the operating lever 28 is rotated, the main valve body 4 is rotated with a small force since there is no differential pressure acting on the main valve body. After that, presser section 28
When the pressure by a is released, the auxiliary valve shaft 17 is moved by the spring 3.
3 to the opposite side from the above, and the sub valve body 16
comes into close contact with the valve seat 18 again.

To close the valve from the fully open state, first rotate the operating lever 28 in the direction of the arrow in the same manner as described above, press the one end surface of the sub-valve shaft 17 with the presser portion 28a, and press the sub-valve body 16 against the valve seat. 18 to establish communication between the inlet 2 side and the outlet 3 side in the valve box 1, and then rotate the operating lever 28 in the opposite direction while maintaining this communication.
As a result, the main valve body 4 is gradually reversely rotated to close the flow path, and when the main valve body 4 is rotated approximately 90 degrees in the reverse direction, the inclined surface 9 formed on the outer peripheral edge of the main valve body 4 comes into close contact with the inclined surface 13 formed on the valve body valve seat 10. do. After this, presser part 28a
When the pressure is released and the sub-valve body 16 is brought into close contact with the valve seat 18, it returns to its original fully closed state. Therefore, in this pressure equalizing device, the annular groove 21, the communication hole 22, the annular groove 19, and the communication hole 23 that communicate the inlet 2 side and the outlet 3 side in the valve body 1 are connected to the main valve shaft 7. Since it is provided in the valve body 4 and its length is short, the pressure loss is extremely small, and as a result, the pressure equalization time is shortened, improving operability. It becomes easy to form and the manufacturing cost becomes low.

(Problem to be solved by the invention) However, when the above-mentioned pressure equalization device is installed between the water supply pipe and the air valve as a stop valve for repairing the air valve as shown in the diagram (Fig. 1), When the pressure in the water supply pipe on the upstream side is high, a pressure difference occurs between the pressure in the valve box of the air valve on the downstream side, which is at atmospheric pressure, and in this state, the main valve body 4 cannot be opened or closed. Since the torque increases and the operability deteriorates, first, before opening the main valve body 4, the sub-valve body 16 is opened, and the water in the pipe is passed through the air valve to remove the float valve 41 and the floating valve body. 42 and close the large valve port 43 with the floating valve body 42 to eliminate the differential pressure, and even if the pressure on the upstream and downstream sides of the main valve body 4 is to be equalized, even if the sub valve body is opened. However, there is a problem in that it is difficult to eliminate this pressure difference.

That is, the communication hole 23 is connected from the mounting portion 5 to the main valve body 4.
When the main valve body 4 is fully closed, the center axis of the opening that opens on the surface of the main valve body 4 intersects with the center axis of the flow path in the valve box, and the opening opens into the valve body 45 of the air valve. Since it faces the annular flow path 47 formed between the bottomed cylindrical guide member 46, the water flowing from the communication hole 23 into the valve box 45 at the beginning of pressure equalization becomes a biased jet flow and flows into the annular flow path 47. The water is jetted from the water filling hole 50 provided at the lower end of the guide member 46 to the guide member 4.
6, the float valve 41 and the floating valve body 4
No buoyant force acts on 2, and the water that has entered the guide member 46 from the flow port 48 presses the floating valve body 42 downward due to the force of the jet flow, and flows from the large valve port to the outside of the valve box 45. This is because the valve box 45 is not filled with water due to water flowing out, and the floating valve body 42 cannot close the large valve port 43. Therefore, the upstream and downstream pressures of the main valve body 4 are not equalized and cannot be used as a pressure equalizing device. This means that it cannot work. Therefore, the technical problem of this invention is to make the float valve of the air valve produce a buoyancy effect due to the jet flow from the communication hole when the sub-valve body is opened.

(Means for solving the problem) In the pressure equalizing device as described above, the center axis of the opening of the communication hole provided in the main valve body that opens on the surface of the main valve body is such that when the main valve body is fully closed, It almost coincides with the center axis of the flow path of the valve box, and the inside of the air valve.
The central axis of the water filling hole formed in the lower part of the bottomed cylindrical guide member incorporating the float valve is also made to substantially coincide with the center axis.

(Function) Water flowing into the valve box from the communication hole at the beginning of pressure equalization is jetted toward the water filling hole formed in the guide member of the air valve, and does not become a biased jet toward the annular flow path. As the water level in the valve box gradually rises, a buoyant force acts on the float valve and the floating valve body. Therefore, the large valve port can be smoothly closed by the floating valve element, and pressures upstream and downstream of the main valve element can be equalized.

(Effect of the invention) When the pressure is equalized, the pressure equalizing jet from the communication hole is almost aligned with the central axis of the flow path of the valve box, and the air valve operates reliably, so it can not only be used as a stop valve for repairing the air valve. When filling the water pipe with water after installation, or when starting water supply after stopping water supply, the main valve body should be closed and the sub-valve body open. This has the advantage that the floating valve body of the air valve gently closes the large valve port, thereby preventing water hammer.

(Example) Examples of this invention will be described below.

In this embodiment, the same parts as in the conventional one will be given the same reference numerals, and the explanation will be omitted, and only the new parts will be explained.

Reference numeral 53 denotes a communication hole provided in the main valve body 54, and an opening 55 of the communication hole 53 that opens on the lower side surface of the main valve body 54 is a protrusion provided at the center of the surface of the main valve body 54. 56. Further, this protrusion 56 faces a water filling hole 50 formed at the lower part of a bottomed cylindrical guide member 46 containing a float valve 41 in an air valve disposed on the downstream side with respect to the main valve body 54. In addition, the central axis of the opening 55 coincides with the flow path central axis of the valve box 1 and the central axis of the water filling hole 50 when the main valve body 54 is fully closed.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view showing a case where a conventional rotary valve pressure equalization device is used as a stop valve for repairing an air valve;
FIG. 2 is a partially omitted longitudinal sectional front view showing an example of the use of the rotary valve pressure equalizing device of this invention as a stop valve for repairing an air valve. 1... Valve box, 2... Inlet, 3... Outlet, 4
...Main valve body, 7...Main valve shaft, 16...Sub-valve body, 1
7... Sub-valve shaft, 19, 21... Annular groove, 22, 2
3...Communication hole, 28...Operation lever, 33...Compression spring, 53...Communication hole, 54...Main valve body, 55
...Opening, 56...Protrusion.

Claims (1)

[Scope of Claim for Utility Model Registration] A main valve body that opens and closes a flow path is rotatably disposed within the valve body, and a rotary main valve shaft is supported on the main valve body by a bearing portion of the valve body. The ends are fixed, and a sub-valve shaft is provided at the center of the main valve shaft, which is slidable in the axial direction of the main valve shaft. A communication hole communicating with the upstream side is bored in the valve body, a sub-valve body for opening and closing this communication hole is fixed to the inner end of the sub-valve shaft, and a main valve is attached to the outer end of the main valve shaft. An operating lever for the main valve body that rotates the shaft, and an operating lever for the auxiliary valve body that slides the auxiliary valve shaft are provided at the outer end of the auxiliary valve shaft at positions close to each other outside the valve box, and the auxiliary valve body Provided with a biasing member that always biases in the direction of closing,
A rotary valve having a second communication hole bored in the main valve body that communicates the communication hole with the downstream side of the main valve body in the valve box, between the water supply pipe and the air valve, In a pressure equalizing device arranged so that the downstream side of the main valve body in the valve box communicates with the inside of the air valve, the center axis of the opening of the second communication hole that opens on the surface of the main valve body is aligned with the main valve body. When the valve body is fully closed, it almost coincides with the center axis of the flow path of the valve box, and also almost coincides with the center axis of the water filling hole formed at the bottom of the bottomed cylindrical guide member that houses the float valve inside the air valve. A rotary valve pressure equalizing device characterized in that: