Valve

Abstract

In a valve box in which the secondary-side communication flow path is integrated, the structure becomes complicated and post-adjustment of the secondary-side communication flow path cannot be performed. 【Solution means】 The upper end portion of the valve rod 10 is fixedly provided to the pressure displacement means 12 through the piston 9 in the cylinder 4, and the valve body 11 arranged in the secondary flow path 3 is fixedly provided at the lower end portion. By forming the secondary-side communication flow path 16 in the valve rod 10, without forming the secondary-side communication flow path 16 in the valve box 1, as the pressure on the secondary side increases, the fluid on the secondary flow path 3 side can be sent into the pressure-sensitive chamber 14 through the secondary-side communication flow path 16 of the valve rod 10, and it becomes possible to appropriately select the valve rod 10 having different diameters of the hollow portion 13 and the supply hole 15 constituting the secondary-side communication flow path 16.

Description

Technical Field

[0001] The present invention relates to a valve in which a secondary flow path and a space formed below pressure displacement means such as a diaphragm are communicated with each other by a secondary-side communication flow path.

Background Art

[0002] Conventionally, a typical example of such a valve is a pressure reducing valve. This pressure reducing valve is a valve in which the secondary-side end of the primary flow path and the primary-side end of the secondary flow path are arranged vertically, and a valve port is formed in a partition wall disposed therebetween. The opening degree of the valve body can be controlled according to the pressure fluctuation in the secondary flow path. For example, a form in which a space formed below pressure displacement means such as a diaphragm and the secondary flow path are communicated with each other by a secondary-side communication flow path formed on the valve box side is common (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above prior art, since the valve box is generally made by casting, forming a secondary-side communication flow path in this valve box causes complication of the valve box structure, and further problems such as inability to change the diameter of the secondary-side communication flow path after manufacturing have to be solved.

Means for Solving the Problems

[0005] In view of the problems based on the above prior art, such as the complication of the structure of the valve box and the inability to adjust the secondary-side communication flow path, the present invention has a valve box that forms a primary flow path and a secondary flow path inside, and includes a cylinder and a case that houses pressure displacement means. A valve port is formed in a partition wall disposed between the primary flow path and the secondary flow path. A valve mechanism portion penetrates through the cylinder, and the valve mechanism portion includes a piston that is reciprocally slidably housed in the cylinder, a valve rod that penetrates through the piston, a valve body that the lower end portion of the valve rod passing through the valve port penetrates through the center, and the pressure displacement means to which the upper end portion of the valve rod is fixed. The valve has a secondary-side communication flow path that communicates either the pressure-sensitive chamber formed below the pressure displacement means or one of the primary flow path and the secondary flow path. The valve rod has a hollow portion that is cylindrical and open downward. A supply hole that communicates the hollow portion and the pressure-sensitive chamber is formed on the upper end side of the valve rod. By forming the secondary-side communication flow path with the supply hole and the hollow portion, without forming a secondary-side communication flow path in the valve box, as the pressure on the secondary side rises, the fluid on the secondary flow path side can be sent into the pressure-sensitive chamber through the secondary-side communication flow path of the valve rod. By appropriately selecting valve rods with different diameters of the hollow portion and the supply hole, the adjustment of the secondary-side communication flow path is made possible, and the above problems are solved.

Advantages of the Invention

[0006] Briefly stated, the present invention has a valve box that forms a primary flow path and a secondary flow path inside, and includes a cylinder and a case that houses pressure displacement means. A valve port is formed in a partition wall disposed between the primary flow path and the secondary flow path. A valve mechanism portion penetrates the cylinder, and the valve mechanism portion includes a piston that is reciprocally slidably housed in the cylinder, a valve rod that penetrates the piston, a valve body through which the lower end portion of the valve rod passing through the valve port penetrates the center, and the pressure displacement means to which the upper end portion of the valve rod is fixed. The valve has a secondary-side communication flow path that communicates a pressure-sensitive chamber formed below the pressure displacement means with the secondary flow path. The valve rod has a hollow portion that is cylindrical and open at the bottom. A supply hole that communicates the hollow portion and the pressure-sensitive chamber is formed on the upper end side of the valve rod. Since the supply hole and the hollow portion form the secondary-side communication flow path, it is possible to provide the function of a pressure reducing valve or a constant flow rate valve without providing any special function on the valve box side. Further, since the valve rod is replaceable, it is possible to change the diameter of the secondary-side communication flow path even after manufacturing by replacing the valve rod with a valve rod having different dimensions of the hollow portion and the supply hole.

[0007] Since a primary-side communication flow path that communicates the pressure-sensitive chamber with the primary flow path is formed in the valve box, the primary-side communication flow path must be formed in the valve box. However, since the secondary-side communication flow path is formed in the valve rod, in addition to having substantially the same effect as the above-described effect, by communicating the primary-side communication flow path formed in the valve box via the pressure-sensitive chamber with the secondary-side communication flow path formed in the valve rod, the fluid in the primary flow path can flow into the secondary flow path via the primary-side communication flow path, the pressure-sensitive chamber, and the secondary-side communication flow path. Therefore, the practical effect is very great, such as being able to provide the function of a pilot valve in a direct-acting valve.

Brief Description of the Drawings

[0008]

Fig. 1

Fig. 2

Fig. 3

Fig. 4(a)

Fig. 4(b)

Mode for Carrying Out the Invention

[0009] The valve box 1 of the valve according to the present invention is made of metal, resin, etc., and in particular, those made by casting are common. Basically, a primary flow path 2 and a secondary flow path 3 are formed inside, and a cylinder 4 and a pressure displacement means 12 and a case 5 for housing are provided. The inner diameter of the case 5 is made larger than the inner diameter of the cylinder 4, and a boundary portion to is provided as a step portion 5a, and a valve port 7 is formed in a partition wall 6 arranged between the primary flow path 2 and the secondary flow path 3.

[0010] The valve mechanism portion 8 penetrating the inside of the cylinder 4 includes a piston 9 housed in the cylinder 4 so as to be reciprocally slidable, a valve rod 10 penetrating the piston 9, and a valve body 11 arranged in the secondary flow path 3 through which the lower end portion of the valve rod 10 penetrating the valve port 7 penetrates the center, and a pressure displacement means 12 in which the upper end portion of the valve rod 10 is fixed and housed in the case 5.

[0011] The valve rod 10 has a secondary-side communication flow path 16 constituted by a hollow portion 13 opening downward and a supply hole 15 opening on the side surface near the upper end, and enables the pressure-sensitive chamber 14 formed below the pressure displacement means 12 in the case 5 and the secondary flow path 3 to communicate with each other through the secondary-side communication flow path 16.

[0012] A cover 17 is attached to the upper part of the case 5, and 17 a downward biasing means 18 of the pressure displacement means 12 such as a spring is provided inside.

Example

[0013] Figure 1 is a schematic cross-sectional view of a diaphragm valve which is Example 1 of the valve according to the present invention. The pressure displacement means 12 is a diaphragm, and the outer peripheral portion is sandwiched between the case 5 and the cover 17.

Embodiment

[0014] Figure 2 is a schematic cross-sectional view of a piston valve which is Example 2 of the valve according to the present invention. The pressure displacement means 12 is a piston that is reciprocally slidably accommodated in the case 5.

[0015] When used as a pressure reducing valve or a constant flow rate valve, the downward biasing means 18 (spring) is adjusted to a predetermined opening during operation, and a fluid with a predetermined pressure or a predetermined flow rate is sent to the secondary flow path 3 side. As the pressure on the secondary side rises, the fluid on the secondary flow path 3 side is sent into the pressure sensing chamber 14 through the secondary side communication flow path 16 (hollow portion 13 and supply hole 15) of the valve rod 10. Thus, in the case of Example 1, the diaphragm (pressure displacement means 12) is deformed, and in the case of Example 2, the piston (pressure displacement means 12) rises to expand the pressure sensing chamber 14. Accordingly, the valve body 11 rises and the opening degree of the valve port 7 becomes narrower, thereby reducing the pressure on the secondary side to the set value.

Embodiment

[0016] Figure 3 is a schematic cross-sectional view of a valve having a forced closing valve function which is Example 3 of the valve according to the present invention. Basically, it has the same configuration as Example 2, but a plunger 20 is mounted at the opposing portion of the cylinder 4 below the valve box 1. The plunger 20 has a spindle 21 arranged coaxially with the valve rod 10, and the upward and downward movement of the spindle 21 can open and close the lower opening of the valve rod 10, and the upward movement of the spindle 21 can forcibly move the valve rod 10 upward to close the valve port 7 with the valve body 11.

[0017] During the pressure resistance test, the valve body 11 is in the lowest state, the pressure displacement means 12 is seated on the step portion 5a, and there is no pressure sensing chamber 14 below the pressure displacement means 12. If the lower opening of the valve rod 10 is closed by the spindle 21 of the plunger 20, the pressure sensing chamber 14 will not be formed even if the fluid pressure acts.

[0018] When used as a flow control valve, by bringing the tip of the spindle 21 of the plunger 20 into contact with the lower end of the valve rod 10, it becomes possible to maintain the valve body 11 at a predetermined opening degree.

Embodiment

[0019] In Embodiments 1 to 3, only the secondary-side communication flow path 16 can communicate with the pressure-sensitive chamber 14, but in Embodiment 4, the secondary-side communication flow path 16 can communicate the pressure-sensitive chamber 14 with the secondary flow path 3, and the pressure-sensitive chamber 14 can communicate with the primary flow path 2 through the primary-side communication flow path 23 formed in the valve box 1. FIG. 4(a) is a schematic cross-sectional view showing the open state of a float-type valve which is an example of Embodiment 4 of the valve according to the present invention, and FIG. 4(b) is a schematic cross-sectional view showing the closed state of the float-type valve of FIG. 4(a). It has a plunger 20 as in Embodiment 3, but a float 22 is connected to the base end portion of the spindle 21, and the primary-side communication flow path 23 is opened at the step portion 5a.

[0020] Then, as shown in FIG. 4(a), the valve body 11 is in the lowest state, the opening degree of the valve port 7 is the maximum, the pressure displacement means 12 is seated on the step portion 5a, the primary-side communication flow path 23 is closed, there is no pressure-sensitive chamber 14 below the pressure displacement means 12, the tip of the spindle 21 is separated from the lower end portion of the valve rod 10, and the lower opening is in an open state. When water flow starts, first, only the float 22 and the spindle 21 rise, the tip of the spindle 21 abuts against the lower end portion of the valve rod 10 to close the lower opening, the secondary-side communication flow path 16 (hollow portion 13 and supply hole 15) and the secondary flow path 3 are put into a non-communication state, and the valve rod 10, the valve body 11, and the pressure displacement means 12 also rise together with the float 22 and the spindle 21. Along with this, the pressure-sensitive chamber 14 is formed and gradually expands, and the primary flow path 2 and the pressure-sensitive chamber 14 are put into a communication state through the primary-side communication flow path 23. Finally, as shown in FIG. 4(b), the valve port 7 is closed by the valve body 11 and the water flow is stopped.

[0021] When the water level drops, first only the float 22 and the spindle 21 start to descend accordingly. When the lower opening of the valve rod 10 opens, the primary flow path 2 and the secondary flow path 3 communicate with each other through the primary-side communication flow path 23, the pressure sensing chamber 14, and the secondary-side communication flow path 16. Next, the valve rod 10, the valve body 11, and the pressure displacement means 12 descend, the valve port 7 opens, and water flow starts.

Explanation of Reference Numerals

[0022] 1 Valve box 2 Primary flow path 3 Secondary flow path 4 Cylinder 5 Case 5a step portion 6 Partition wall 7 Valve port 8 Valve mechanism section 9 Piston 10 Valve rod 11 Valve body 12 Pressure displacement means 13 Hollow part 14 Pressure sensing chamber 15 Supply hole 16 Secondary-side communication flow path 17 cover 20 plunger 21 spindle 22 float 23 Primary-side communication flow path

Claims

1. a valve having a valve body which defines a primary flow path and a secondary flow path therein, and which includes a cylinder and a case which houses a pressure displacement means, a valve port being formed in a partition wall disposed between the primary flow path and the secondary flow path, a valve mechanism which passes through the cylinder, the valve mechanism having a piston housed so as to be able to slide back and forth within the cylinder, a valve rod which passes through the piston, a valve body whose center is penetrated by a lower end of the valve rod which passes through the valve port, and the pressure displacement means to which an upper end of the valve rod is fixed, and a secondary side communicating flow path which communicates between the secondary flow path and a pressure sensing chamber formed below the pressure displacement means within the case, The valve stem has a cylindrical hollow portion that opens downward, and a supply hole is formed at the upper end side of the valve stem to connect the hollow portion and the pressure sensing chamber, and the supply hole and the hollow portion form the secondary side communicating flow path.

2. A valve as described in claim 1, characterized in that the pressure displacement means is a diaphragm whose outer periphery is sandwiched between the case and a cover attached to the top of the case.

3. A valve as described in claim 1, characterized in that the pressure displacement means is a piston accommodated in the case so as to be capable of reciprocating sliding movement.

4. A valve as described in claim 1, 2 or 3, characterized in that a plunger is attached to the lower part of the valve box at the opposing position to the cylinder, the spindle of the plunger is arranged coaxially with the valve stem, the lower opening of the valve stem can be opened and closed by up and down movement of the spindle, and the valve stem is forcibly moved upward by upward movement of the spindle, thereby enabling the valve orifice to be closed by the valve body.

5. A valve as described in claim 1, characterized in that a primary side communicating passage is formed in the valve body to connect the pressure sensing chamber and the primary passage.

6. A valve as described in claim 5, characterized in that a plunger is attached to the lower part of the valve box at the opposing position to the cylinder, the spindle of the plunger is arranged coaxially with the valve stem, a float is connected to the base end of the spindle, the inner diameter of the case is larger than the inner diameter of the cylinder, and the primary side communicating flow passage is opened at a step portion at the boundary.

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