Valve

Abstract

To solve the problem in which a valve casing integrated with a secondary-side communication flow path has a complicated structure and does not allow ex post adjustment of the secondary-side communication flow path.SOLUTION: An upper end portion of a valve stem 10 is passed through a piston 9 in a cylinder 4 and fixed to pressure displacement means 12, and a valve body 11 arranged in a secondary flow path 3 is fixed to a lower end of the valve stem. By forming a secondary-side communication flow path 16 in the valve stem 10, the secondary-side communication flow path 16 does not have to be formed in a valve casing 1, and, as the secondary-side pressure increases, fluid on the secondary-flow-path 3 side can be fed into a pressure chamber 14 through the secondary-side communication flow path 16 of the valve stem 10. Thus, it is possible to appropriately select a valve stem 10 having a hollow portion 13 and a supply hole 15, which constitute the secondary-side communication flow path 16, with different diameters.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] A typical example of such a valve is a pressure reducing valve, which is a valve in which the secondary end of a primary flow path and the primary end of a secondary flow path are arranged above and below each other, with a valve port formed in a partition wall arranged between them, and which makes it possible to control the opening of the valve body in response to pressure fluctuations in the secondary flow path.A typical configuration of this valve is one in which a space formed below a pressure displacement means such as a diaphragm is connected to the secondary flow path by a secondary side connecting flow path formed on the valve box side (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-147724 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional technology, since the valve body is generally made of a cast material, forming a secondary communication passage in this valve body leads to a complicated structure of the valve body, and furthermore, there are problems that must be solved, such as the inability to change the diameter of the secondary communication passage after manufacturing. [Means for solving the problem]

[0005] In view of the problems of the complicated structure of the valve box and the inability to adjust the secondary side communication flow path based on the above-mentioned prior art, the present invention provides a valve box having a primary flow path and a secondary flow path formed therein, and including a cylinder and a case for accommodating pressure displacement means, wherein a valve port is formed in a partition wall arranged between the primary flow path and the secondary flow path, and a valve mechanism portion passes through the cylinder, the valve mechanism portion having a piston accommodated so as to be able to slide back and forth within the cylinder, a valve stem passing through the piston, a valve body through whose center the lower end portion of the valve stem that has passed through the valve port passes, and the pressure displacement means to which the upper end portion of the valve stem is fixed, and a valve having a secondary-side communicating flow path that communicates a pressure-sensing chamber with either the primary flow path or the secondary flow path, wherein the valve stem is cylindrical and has a hollow portion that opens downward, and a supply hole that communicates the hollow portion and the pressure-sensing chamber is formed at the upper end of the valve stem, and the supply hole and the hollow portion form the secondary-side communicating flow path.By doing so, it is possible to send fluid on the secondary flow path side to the pressure-sensing chamber via the secondary-side communicating flow path of the valve stem as the secondary-side pressure increases, without forming a secondary-side communicating flow path in the valve body, and by being able to appropriately select valve stems with different diameters of hollow portion and supply hole, it is possible to adjust the secondary-side communicating flow path, thereby solving the above-mentioned problem. [Effects of the Invention]

[0006] In short, the present invention provides a valve body having a primary flow path and a secondary flow path formed therein, and including a cylinder and a case accommodating pressure displacement means, a valve port formed in a partition wall arranged between the primary flow path and the secondary flow path, a valve mechanism penetrating the cylinder, the valve mechanism having a piston accommodated so as to be able to slide back and forth within the cylinder, a valve stem penetrating the piston, a valve body having a center through which the lower end of the valve stem that has passed through the valve port passes, and the pressure displacement means to which the upper end of the valve stem is fixed, and a pressure sensing chamber formed below the pressure displacement means. The valve has a secondary-side communicating flow path that communicates with the secondary flow path, and the valve stem is cylindrical and has a hollow portion that opens downward. A supply hole that communicates the hollow portion and the pressure-sensing chamber is formed at the upper end of the valve stem, and the supply hole and the hollow portion form the secondary-side communicating flow path. Therefore, the valve can function as a pressure reducing valve or a constant flow valve without providing any special function to the valve box. Furthermore, because the valve stem is replaceable, the diameter of the secondary-side communicating flow path can be changed even after manufacture by replacing it with a valve stem having different dimensions of the hollow portion and supply hole.

[0007] A primary side communicating passage that connects the pressure sensing chamber and the primary flow passage is formed in the valve body. Therefore, while the primary side communicating passage must be formed in the valve body, the secondary side communicating passage is formed in the valve stem. This provides substantially the same effects as those described above. In addition, by connecting the primary side communicating passage formed in the valve body with the secondary side communicating passage formed in the valve stem via the pressure sensing chamber, the fluid in the primary flow passage can be made to flow to the secondary flow passage via the primary side communicating passage, the pressure sensing chamber, and the secondary side communicating passage. This provides a direct acting valve with a function similar to that of a pilot valve, and has other significant practical effects. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view of a diaphragm-type valve according to a first embodiment of the valve of the present invention. [Figure 2] FIG. 10 is a schematic cross-sectional view of a piston-type valve according to a second embodiment of the valve of the present invention. [Figure 3] FIG. 10 is a schematic cross-sectional view of a valve having a forced valve-closing function, which is a third embodiment of a valve according to the present invention. [Figure 4(a)] FIG. 10 is a schematic cross-sectional view showing an open state of a float-type valve according to a fourth embodiment of the present invention. [Figure 4(b)] FIG. 5 is a schematic cross-sectional view showing the float valve of FIG. 4(a) in a closed state. DETAILED DESCRIPTION OF THE INVENTION

[0009] The valve body 1 of the valve according to the present invention is generally made of metal or resin, and is particularly generally made of casting. Basically, a primary flow path 2 and a secondary flow path 3 are formed inside the valve body 1, and the valve body 1 has a case 5 that houses a cylinder 4 and a pressure displacement means 12, which will be described later. The inner diameter of the case 5 is larger than that of the cylinder 4, with a step 5a at the boundary between the primary flow path 2 and the secondary flow path 3, and a valve port 7 is formed in a partition wall 6.

[0010] The valve mechanism 8 that passes through the cylinder 4 has a piston 9 that is accommodated in the cylinder 4 so that it can slide back and forth within the cylinder 4, a valve stem 10 that passes through the piston 9, a valve body 11 that is disposed in the secondary flow path 3 and through which the lower end of the valve stem 10 that passes through the valve port 7 passes through the center, and a pressure displacement means 12 to which the upper end of the valve stem 10 is fixed and which is accommodated in the case 5.

[0011] The valve rod 10 has a secondary-side communicating flow passage 16 consisting of a hollow portion 13 that opens downward and a supply hole 15 that opens on the side surface near the upper end, and the secondary-side communicating flow passage 16 allows communication between the pressure-sensing chamber 14 formed below the pressure displacement means 12 inside the case 5 and the secondary flow passage 3.

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

[0013] FIG. 1 is a schematic cross-sectional view of a diaphragm-type valve which is a first embodiment of a valve according to the present invention, in which pressure displacement means 12 is a diaphragm, and the outer periphery is sandwiched between a case 5 and a cover 17. [Example]

[0014] FIG. 2 is a schematic cross-sectional view of a piston-type valve that is a second embodiment of the valve according to the present invention, in which pressure displacement means 12 is a piston accommodated in case 5 so as to be reciprocally slidable.

[0015] When used as a pressure reducing valve or a constant flow valve, the downward biasing means 18 (spring) is adjusted to achieve a predetermined opening during operation, and fluid at a predetermined pressure or 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 to the pressure sensing chamber 14 through the secondary side communicating flow path 16 (hollow portion 13 and supply hole 15) of the valve stem 10, which in the case of Example 1 deforms the diaphragm (pressure displacement means 12), and in the case of Example 2, the piston (pressure displacement means 12) rises and expands the pressure sensing chamber 14, and as a result, the valve body 11 rises and the opening of the valve port 7 narrows, thereby reducing the pressure on the secondary side to the set value. [Example]

[0016] FIG. 3 is a cross-sectional schematic diagram of a valve with a forced valve-closing function, which is a third embodiment of the valve according to the present invention. This valve has basically the same configuration as the second embodiment, except that a plunger 20 is attached to the lower part of the valve body 1, facing the cylinder 4, and the plunger 20 has a spindle 21 arranged coaxially with the valve stem 10. The vertical movement of the spindle 21 opens and closes the lower opening of the valve stem 10, and the upward movement of the spindle 21 forcibly moves the valve stem 10 upward, allowing the valve body 11 to close the valve orifice 7.

[0017] During a pressure test, the valve body 11 is lowered to its lowest position, the pressure displacement means 12 is seated on the step portion 5a, and there is no pressure-sensitive chamber 14 below the pressure displacement means 12. If the lower opening of the valve stem 10 is closed by the spindle 21 of the plunger 20, the pressure-sensitive chamber 14 will not be formed even if fluid pressure acts on it.

[0018] When used as a flow rate adjusting valve, the tip of the spindle 21 of the plunger 20 is brought into contact with the lower end of the valve stem 10, thereby making it possible to maintain the valve body 11 at a predetermined opening. [Example]

[0019] In Examples 1 to 3, only the secondary side communicating flow path 16 is capable of communicating with the pressure sensing chamber 14, but in Example 4, the pressure sensing chamber 14 is capable of communicating with the secondary flow path 3 via the secondary side communicating flow path 16, and the pressure sensing chamber 14 is capable of communicating with the primary flow path 2 via a primary side communicating flow path 23 formed in the valve box 1. Figure 4(a) is a cross-sectional schematic diagram showing the open state of a float type valve, which is an example of Example 4 of the valve according to the present invention, and Figure 4(b) is a cross-sectional schematic diagram showing the closed state of the float type valve of Figure 4(a). Like Example 3, this valve has a plunger 20, but a float 22 is connected to the base end of the spindle 21, and the primary side communicating flow path 23 opens at a step portion 5a.

[0020] As shown in FIG. 4(a), the valve body 11 is in the lowest position, the valve port 7 is at its maximum opening, 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 sensing chamber 14 below the pressure displacement means 12, the tip of the spindle 21 is separated from the lower end of the valve stem 10, and the lower opening is open. When water starts to flow, first, only the float 22 and spindle 21 rise, and the tip of the spindle 21 comes into contact with the lower end of the valve stem 10. The valve stem 10, valve body 11 and pressure displacement means 12 rise together with the float 22 and spindle 21, forming a pressure-sensing chamber 14 which gradually expands until the primary flow path 2 and the pressure-sensing chamber 14 are connected by the primary-side communicating flow path 23. Finally, as shown in Figure 4(b), the valve port 7 is closed by the valve body 11, and water flow is stopped.

[0021] As the water level drops, first only the float 22 and spindle 21 begin to descend, and the lower opening of the valve stem 10 opens, so that the primary flow path 2 and the secondary flow path 3 are connected via the primary side communicating flow path 23, the pressure-sensing chamber 14, and the secondary side communicating flow path 16. Next, the valve stem 10, valve body 11, and pressure displacement means 12 descend, opening the valve port 7 and starting the flow of water. [Explanation of symbols]

[0022] 1 Valve box 2 Primary flow path 3 Secondary flow path 4 cylinders 5 cases 5a Step part 6 Bulkhead 7. Orifice 8 Valve mechanism 9 pistons 10 Valve stem 11 Valve body 12 Pressure displacement means 13 Hollow part 14 Pressure-Sensing Chamber 15 Supply hole 16 Secondary 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 formed in a partition wall arranged between the primary flow path and the secondary flow path, a valve mechanism which passes through the cylinder, the valve mechanism having a piston which is housed so as to be able to slide back and forth within the cylinder, a valve stem which passes through the piston, a valve body whose center is penetrated by the lower end of the valve stem which has passed through the valve port, and the pressure displacement means to which the upper end of the valve stem is fixed, a secondary-side communicating flow path which communicates between a pressure-sensing chamber formed below the pressure displacement means in the case and the secondary flow path, the valve stem having a cylindrical hollow portion which opens downward, a supply hole which communicates between the hollow portion and the pressure-sensing chamber formed at the upper end of the valve stem, A valve 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.

2. 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 formed in a partition wall arranged between the primary flow path and the secondary flow path, a valve mechanism which passes through the cylinder, the valve mechanism having a piston which is housed so as to be able to slide back and forth within the cylinder, a valve stem which passes through the piston, a valve body whose center is penetrated by the lower end of the valve stem which has passed through the valve port, and the pressure displacement means to which the upper end of the valve stem is fixed, a secondary-side communicating flow path which communicates between a pressure-sensing chamber formed below the pressure displacement means in the case and the secondary flow path, the valve stem having a cylindrical hollow portion which opens downward, a supply hole which communicates between the hollow portion and the pressure-sensing chamber formed at the upper end of the valve stem, A valve characterized in that the pressure displacement means is a piston accommodated in the case so as to be able to slide back and forth.

3. 3. A valve according to claim 1, wherein a plunger is attached to a portion of the lower part of the valve body facing 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 can be forcibly moved upward by up movement of the spindle, so that the valve port can be closed by the valve body.

4. 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 formed in a partition wall arranged between the primary flow path and the secondary flow path, a valve mechanism which passes through the cylinder, the valve mechanism having a piston which is housed so as to be able to slide back and forth within the cylinder, a valve stem which passes through the piston, a valve body whose center is penetrated by the lower end of the valve stem which has passed through the valve port, and the pressure displacement means to which the upper end of the valve stem is fixed, a secondary-side communicating flow path which communicates between a pressure-sensing chamber formed below the pressure displacement means in the case and the secondary flow path, the valve stem having a cylindrical hollow portion which opens downward, a supply hole which communicates between the hollow portion and the pressure-sensing chamber formed at the upper end of the valve stem, A valve characterized in that a primary side communication flow path that communicates the pressure sensing chamber and the primary flow path is formed in the valve body.

5. 5. A valve according to claim 4, wherein a plunger is attached to a portion of the lower part of the valve body facing the cylinder, a 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 path is opened at a step portion at the boundary.

Images