JPH0444947Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is a piston valve used in piping systems where the working fluid is mainly hot water or high-temperature steam, such as tire vulcanization plants and record presses. , especially regarding its gland part scale seal structure.

(Prior Art) The gland section of a conventional piston valve has not been provided with a means for removing scale that adheres to the valve stem and destroys the seal of the gland section. The gland seal structure includes a plurality of V-shaped packings inserted into the annular space formed between the gland and the valve stem, and the upper part of the V-shaped packing is connected to the gland via a packing holder. There is a structure in which each V-shaped gasket is constantly pushed out laterally and only sealed by pressing downward with a nut and upward with a gasket spring via a ring washer at the bottom. Are known.

(Problems to be Solved by the Invention) However, the conventional gland seal structure has the following problems.

In other words, the inner peripheral surface of the gasket always slides in close contact with the outer peripheral surface of the valve stem as the valve stem moves up and down, but the valve stem below the gasket is constantly exposed to hot water or high temperatures. Because the valve stem is exposed to steam, impurities contained in the hot water or high-temperature steam tend to adhere to the outer peripheral surface of the valve stem and form scale.

Since the gland part does not have a means for removing scale, when the valve stem moves up and down due to the operation of the piston, the inner circumferential surface of the seal is rubbed by the outer circumferential surface on which scale has adhered.
There was a problem in that the sealing performance of the inner circumferential surface of the packing was destroyed as the scale grew.

The present invention was made in order to solve the conventional problems as described above, and its purpose is to provide a piston valve that can maintain the sealing effect of the gasket over a long period of time. The purpose is to provide a scale seal structure for the gland section.

(Means for Solving the Problems) As a specific means for achieving the above object, the gland part scale seal structure of the piston valve of the present invention allows switching operation of the valve by pushing the piston using air pressure. At the same time, in a piston valve in which a plurality of V-shaped gaskets are used to seal between the gland part of the valve body and the valve stem, at least two or more thin plate-shaped blades formed in a substantially arc shape are slid into a circular shape. By movably overlapping each other, a circular opening appearing in the center is formed so as to be able to slide freely on the outer peripheral surface of the valve stem and to be in close contact with the valve stem at all times. The scale is attached to an inner circumferential groove provided on the inner circumferential surface of an annular body consisting of an arc-shaped portion, and a spring that biases the annular body inward is attached to an outer circumferential groove provided on the outer circumferential surface of the annular body. A scale removal ring formed by loosely fitting the scale seal member into a protection ring formed to form a seal portion and capable of surrounding the upper and lower surfaces and the outer circumferential surface of the scale seal portion on three sides is attached to the V-shaped piston valve. It has a structure in which it is interposed at the bottom of the packing.

(Function) In the gland part scale seal structure of the piston valve of the present invention, by having the structure as described above, when switching the valve, the valve stem for the pushing action of the piston is connected to the seal part by the V-shaped packing and the V It moves up and down through a scale removal ring installed at the bottom of the mold packing. The scale adhering to the outer peripheral surface of the valve stem portion below the scale removing ring is peeled off by the thin plate-shaped blade of the scale removing ring that is in close contact with the outer peripheral surface during the upward movement of the valve stem. Therefore, there is no harmful scale attached to the valve stem portion inserted into the seal portion formed by the V-shaped packing, and the sealing performance of the V-shaped packing is not destroyed by scale.

Furthermore, even if the shaft diameter of the valve stem fluctuates due to temperature changes, each thin plate blade is always pressed inward by the annular fluid biased inward by the spring. By sliding against each other according to changes in the shaft diameter, it is possible to always keep the opening in a circular shape and in close contact with the outer circumferential surface.

Further, even if the thin plate-like blade is worn out, the sealing effect of the packing can be maintained for a long period of time because the same effect is maintained to maintain a close contact state.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

First, the configuration of the embodiment will be explained.

As shown in FIG. 1, the piston valve A of this embodiment has a piston cylinder 3 connected to the upper part of a valve body 1 via a yoke 2, and a piston that is movable up and down inside the piston cylinder 3. 4
and the valve body 5 provided in the valve body 1 are connected by a valve stem 6, and the piston cylinder 3
The piston 4 is raised and lowered by the pressure balance between the repulsive force of the return spring 7 provided on the lower chamber side of the piston cylinder 3 and the high pressure air forced in from the air inflow hole 8 opened on the upper chamber side of the piston cylinder 3. , and is configured to perform a valve switching operation.

The sealing structure of the gland part includes three V-shaped packings 1 at the upper part of the annular space formed between the gland part 9 of the valve body 1 and the valve stem 6.
0, 10, 10 are inserted, and the V-shaped packing 10,
By pressing 10, 10, it is expanded laterally within the annular space, and its periphery is brought into close contact with the inner circumferential surface of the gland portion 9 and the outer circumferential surface 13 of the valve stem 6 for sealing. .

And, the gland part scale seal structure B is as follows.
As shown in FIGS. 2 to 5, a thin plate-like blade 20
The main components are an annular body 30 and a protective ring 40.

The thin plate-shaped blade 20 is designed to exfoliate the scale 14 attached to the outer circumferential surface 13 of the valve stem 6, and is formed in an arc shape from a phosphor bronze plate approximately 0.3 mm thick, and its inner circumferential edge 21 is The diameter is the same as that of the valve stem 6, and the outer peripheral edge 2
2 is formed into a semicircle with a width several mm larger than the inner circumferential edge 21, and both tip portions 23, 23 have an inner width equal to the diameter of the valve stem 6 and protrude by several mm. and the thin plate-like blade 2
0 is made by stacking three pieces of the same shape in a ring shape, evenly spaced at 120 degrees each. At this time, a circular opening 24 having the same inner diameter as the outer diameter of the valve stem 6 is formed in the center.

Further, the annular body 30 includes the thin plate-like blade 20
It is designed to stably press the valve stem 6 against the valve stem 6, and consists of three arcuate parts 31 of the same shape, and when these are arranged in a circle, each joint part 32,
32, 32 are formed to have the same distance. The inner peripheral surface of the annular body 30 has the above-mentioned 3
An inner circumferential groove 33 is provided with a width that allows the thin plate-shaped blade 20 to fit loosely thereinto. The diameter of the groove bottom of this inner circumferential groove 33 is formed to be the same as the outer diameter dimension of the outer circumferential edge 22 when the thin plate-like blade 20 is in close contact with the valve stem 6.

Furthermore, an outer circumferential groove 34 is provided on the outer circumferential surface of the annular body 30, into which a ring-shaped spring 35 having a small outer diameter is fitted over the entire circumference.

The scale seal portion 15 is formed by loosely fitting the thin plate-like blade 20 into the inner circumferential groove 33 of this annular body 30 and fitting it into the outer circumferential groove 34 with the spring 35 in a tightened state.

Further, the protective ring 40 accommodates the scale seal portion 15 to ensure expansion and contraction of the scale seal portion, and also serves as a ring washer that relays the pressing force of the packing spring 12 to the V-shaped packing 10. The upper ring 41 is formed in a ring shape with an inwardly and downwardly opened state by a member having an inverted L-shaped cross section and has a hole diameter suitably larger than the diameter of the valve stem 6, and an outer diameter of the upper ring 41. and a flat lower ring 42 having the same size as the inner diameter. Further, the inner portion of the upper ring 41 is formed in a size that allows the scale seal portion 15 to fit loosely therein.

Then, insert the scale seal part 15 into the upper ring 41, and insert the lower open part into the lower ring 41.
The descaling ring 45 is assembled by closing it with the .

The valve stem 6 is inserted into the opening 24 of this scale removal ring 45, and the upper ring 41 is
It is brought into contact with the lower surface of a packing receiving ring 16 that engages with the lower surface of the mold packing 10, and is interposed between the packing receiving ring 16 and the packing spring 12. In the opening 24 into which the valve stem 6 is inserted, the inner peripheral edge 21 of the thin plate-shaped blade 20 pressed by the annular body 30 contracted by the spring 35 is connected to the outer peripheral surface 1 of the valve stem 6.
3. It forms a circular shape and comes into close contact with 3.

Next, the operation of this embodiment will be explained.

Since the present embodiment has the above-mentioned configuration, the piston 4 is lowered by the high-pressure air forced in from the air inlet 8 and disengaged from the valve seat of the valve body 5, thereby allowing hot water to flow. At this time, since the hot water always penetrates into the annular space, the portion of the valve stem 6 that protrudes downward from the scale removal ring 45 is exposed to the hot water. Therefore, impurities in the hot water adhere to the outer circumferential surface 13 of the valve stem 6, forming a thin film-like scale 14. After this, when the injection of high pressure air is stopped, the valve stem 6
is raised by the repulsive force of the return spring 7. At this time, the outer peripheral surface 13 of the valve stem 6 is
Since it slides in close contact with the inner peripheral edge 21 of the thin plate-shaped blade 20, the scale seal portion 14 formed on the outer peripheral surface 13 is peeled off by this inner peripheral edge 21. Then, the portion of the valve stem 6 from which the scale 14 has been removed is inserted into the V-shaped packing 10. Scale 1 formed on this valve stem 6
4 is peeled off by the thin plate-like blade 20 each time the piston valve A is operated, so it does not grow large.

Furthermore, when the shaft diameter of the valve stem 6 is reduced due to a temperature change inside the piston valve A, the tightening force of the spring 35 causes each of the thin plate-like blades 20, 20 to
20 move in the axial direction while sliding against each other to maintain the close contact state of the inner peripheral edge 21. Furthermore, when the shaft diameter expands, each of the thin plate-like blades 20, 20, 20 is pressed outward with the inner circumferential edge 21 in close contact with the outer circumferential surface 13, but the annular body 30 is affected by the tightening force of the spring 35. By resisting and expanding, each of the thin plate-like blades 20, 20, 20 can be brought into close contact without being distorted. Incidentally, even when the inner circumferential edge 21 of the thin plate-like blade 20 is worn out, the same effect as in the case of reducing the shaft diameter occurs.

As explained above, the gland part scale seal structure B in the piston valve A of this embodiment
Now, with the configuration as described above, the scale 14 attached to the outer circumferential surface of the valve stem 6 below the gland V-shaped packing 10 can be removed by the scale removal ring 45 interposed at the lower part of the V-shaped packing 10.
Because it is removed every time the valve is switched,
The sealing performance of the V-shaped gland packing 10 is not destroyed by the scale 14.

Furthermore, the thin plate-shaped blade 20 for scale removal provided in the removal ring 45 is always in close contact with the outer circumferential surface 13 of the valve stem 6 even if the shaft diameter of the valve stem 6 changes due to temperature changes. The scale 14 can be removed at all times. In addition, the sealing effect of the V-shaped gland packing 10 can be maintained for a long period of time because the thin plate-shaped blade 20 can be operated in the same manner even if it is worn out.

Although the embodiment of the present invention has been described above based on the drawings, the specific configuration is not limited to this embodiment, and the present invention may be modified without departing from the gist of the present invention. included in the idea.

For example, the thin plate-shaped blade 20 is formed of a phosphor bronze plate approximately 0.3 mm thick, and three plates are formed into a circular shape. can be set arbitrarily.

Further, although the annular body 30 is made up of three arcuate portions 31, the present invention is not limited thereto, and the number of divisions of the annular body 30 can be set arbitrarily.

Further, although the spring 35 that urges the annular body 30 inward is a coil spring, the spring shape etc. can be set arbitrarily.

(Effect of the invention) As explained above, in the gland part scale seal structure of the piston valve of the invention, at least two thin plate-shaped blades formed in a substantially arc shape can be slid freely in a circular shape. By overlapping each other, a circular opening appearing in the center is formed so as to be able to slide freely on the outer circumferential surface of the valve stem and to be in close contact with the valve stem at all times. The scale seal portion is attached to an inner circumferential groove provided on the inner circumferential surface of the annular body, and a spring that biases the annular body inward is attached to the outer circumferential groove provided on the outer circumferential surface of the annular body. A scale removal ring formed by loosely fitting the scale seal member into a protective ring formed to be able to surround the upper and lower surfaces and the outer circumferential surface of the scale seal portion on three sides is attached to the lower part of the V-shaped packing of the piston valve. As a result, scale attached to the outer circumferential surface of the valve stem below the V-shaped gland packing is removed every time the valve is switched by the scale removal ring inserted below the V-shaped packing. Therefore, the sealing performance of the V-shaped gland packing is not destroyed by the scale.

In addition, the thin plate-shaped blade for scale removal provided in the removal ring always remains in close contact with the outer circumferential surface of the valve stem, even if the shaft diameter of the valve stem fluctuates due to temperature changes. You can make it happen. In addition, the sealing effect of the V-shaped gland packing can be maintained for a long period of time because the thin plate blade can be operated in the same way even if it is worn out.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the gland part scale seal structure of a piston valve according to an embodiment of the present invention;
Figure 2 is an enlarged vertical cross-sectional view of the main part showing details of the gland scale seal structure, Figure 3 is a cross-sectional view of the same,
FIG. 4 is an assembly procedure diagram of the thin plate blade, and FIG. 5 is an exploded view of the gland scale seal structure. A...Piston valve, B...Gland part scale seal structure, 1...Valve body, 4...Piston, 6...Valve stem, 9...Gland part,
10... V-shaped packing, 13... Outer peripheral surface, 14...
...Scale, 15...Scale seal part, 20...
... Thin plate-shaped part, 24 ... Opening blade, 30 ... Annular body, 31 ... Arc-shaped part, 33 ... Inner circumferential groove, 34
...Outer groove, 35...Spring, 40...Protection ring, 45...Scale removal ring.

Claims (1)

[Scope of Claim for Utility Model Registration] A valve switching operation is performed by the pushing action of a piston using air pressure, and a plurality of V-shaped packings are used to seal between the gland part of the valve body and the valve stem. In this piston valve, at least two thin plate-like blades formed in a substantially arc shape are slidably overlapped in a circular shape, so that the circular opening appearing in the center is connected to the outer periphery of the valve stem. The thin plate-shaped blade is formed so as to be able to freely slide on the surface and to be in close contact with the surface at all times, and the thin plate-shaped blade is installed in an inner circumferential groove provided on the inner circumferential surface of an annular body consisting of at least two or more circular arc parts, and A scale seal portion is formed by attaching a spring that biases the annular body inward to an outer circumferential groove provided on the outer circumferential surface, so that the scale seal portion can be surrounded on three sides, the upper and lower surfaces and the outer circumferential surface. A gland part scale seal structure for a piston valve, characterized in that a scale removal ring formed by loosely fitting the scale seal member into a protective ring is interposed at the lower part of the V-shaped packing of the piston valve.