JPH11201295A - Rubber sheet fixing structure in valve disc - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber sheet fixing structure in a valve disc which can maintain the sealing property between a rubber sheet and a valve box sheet stably. SOLUTION: A valve disc 11 to open and close the flow passage in a valve box 1 is provided rotatable around the shaft center of a valve rod, a rubber sheet 12 is arranged at the outer peripheral edge of the valve disc 11, and the rubber sheet 12 is fixed to the valve disc 11 by an installing bolt 6 through a sheet presser 13. And at the same time, a ring form projection 12a and a ring form recess 13a engaging each other are formed positioning near the outer peripheral edge of the rubber sheet 12, at the fitting surface of the rubber sheet 12 and the sheet presser 13. As a result, the valve disc 11 and the sheet presser 13 lock the rubber sheet 12 solidly in the diameter direction, to conduct the slip off preventive operation, and thereby, the damage of the rubber sheet 12 and the leaking of the fluid from the damaged position can be prevented. Consequently, the sealing property between the rubber sheet 12 and a valve box sheet 7 can be maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for fixing a rubber sheet in a valve element used for a butterfly valve or the like.

[0002]

2. Description of the Related Art Conventionally, in an eccentric butterfly valve as shown in FIGS. 4 and 5, a valve body 2 for opening and closing a flow path is provided inside a valve box 1 so as to be rotatable around the axis of a valve rod 3. I have. The valve body 2 has a seat 2a for arranging the rubber sheet 4 on the outer peripheral edge thereof over the entire circumference. The seat 2a is provided with a mating surface with the rubber sheet 4 on a pressing surface 2b having a corrugated cross section. Has formed.

A rubber sheet 4 is sandwiched between a seat 2a and a seat retainer 5, and is fixed to the valve body 2 with a plurality of mounting bolts 6 via the seat retainer 5. Sheet holder 5
Has a pressing surface 5a having a corrugated cross section on the mating surface with the rubber sheet 4. Rubber sheet 4 on the inner peripheral surface of valve box 1
And a valve box sheet 7 that is in sliding contact therewith.

[0004] According to the above-described conventional configuration, the rubber sheet 4 is provided with the sheet holder 5 and the respective holding surfaces 5 of the seat 2a.
a and 2b are fixed to the valve body 2 by being bitten into the rubber sheet 4 by the specified tightening force of the mounting bolts 6, and both members are pressed by the pressing surfaces 5a and 2b against the rubber sheet 4. In addition to ensuring the water stoppage between the rubber sheets, the rubber sheet 4 is prevented from coming off in the radial direction.

[0005]

However, in the conventional configuration described above, when the valve body 2 is opened and closed, a frictional force between the rubber sheet 4 and the valve box sheet 7 causes a radial force to be applied to the rubber sheet 4 in a radial direction. For this reason, in a configuration in which the pull-out force is resisted by the frictional force between the rubber sheet 4 and each of the pressing surfaces 2b and 5a, the pull-out force acts repeatedly when the valve body 2 is frequently opened and closed, so that the rubber sheet 4 When the valve body 2 is closed for a long time and then opened, the rubber body 4 may gradually come off due to an increase in frictional resistance between the rubber sheet 4 and the valve box sheet 7. A large exit force acts on the sheet 4 and the rubber sheet 4
Sometimes escaped. When the rubber sheet 4 comes off, the amount of protrusion of the rubber sheet 4 from the seat 2a increases, and the rubber sheet 4 may be in a state of being sandwiched between the valve box sheet 7 and the valve body 2 and may be damaged. May cause fluid leakage. An increase in the amount of protrusion of the rubber sheet 4 from the seat 2a acts as an increase in frictional resistance between the rubber sheet 4 and the valve box sheet 7, and an abnormally high torque is generated when the valve body 2 is opened and closed. However, there is a problem in that the valve element does not move.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rubber sheet fixing structure in a valve body which can stably maintain a sealing property between a rubber sheet and a valve box sheet.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, a rubber sheet fixing structure in a valve body of the present invention comprises:
A valve body that opens and closes a flow path is provided in the valve box so as to be rotatable around the axis of the valve rod, and an annular rubber sheet that is in sliding contact with the valve box sheet is arranged on the periphery of the valve body. An annular concavo-convex portion of the rubber sheet is engaged with the rubber sheet and the sheet retainer, or the mating surface of both the rubber sheet and the valve element. It is formed near the outer peripheral edge.

According to the above construction, the rubber sheet is sandwiched between the seat of the valve body and the seat retainer, and the convex (recess) on the outer peripheral side of the rubber sheet and the concave (convex) of the seat retainer are fitted. By fixing in the fitted state, the valve body and the seat retainer firmly lock the rubber sheet in the radial direction and prevent the rubber sheet from coming off.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rubber sheet fixing structure according to an embodiment of the present invention will be described below with reference to the drawings. Members performing the same operations as those described above with reference to FIGS. 4 and 5 are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIGS. 1 to 3, the eccentric butterfly valve 10 has a valve body 11 that opens and closes a flow path inside a valve box 1, which is rotatable around the axis of a valve rod 3. The valve body 11 has a seat 11a for arranging an annular rubber sheet 12 on the outer peripheral edge thereof over the entire circumference.
Has a mating surface with the rubber sheet 12 formed on a pressing surface 11b having a corrugated cross section.

The rubber sheet 12 is sandwiched between a seat 11a and a seat retainer 13, and is fixed to the valve body 11 with a plurality of mounting bolts 6 via the seat retainer 13. On both mating surfaces of the rubber sheet 12 and the sheet retainer 13,
An annular convex portion 12a and concave portion 13a that engage with each other are formed near the outer peripheral edge of the rubber sheet 12. The sheet retainer 13 is a mating surface with the rubber sheet 12,
A mating surface on the inner peripheral side with respect to the concave portion 13a is formed as a pressing surface 13b having a wavy cross section. A valve box sheet 7 slidably in contact with a rubber sheet 12 is disposed on the inner peripheral surface of the valve box 1.

According to the above configuration, the rubber sheet 12
Is sandwiched between the seat 11a of the valve body 11 and the seat retainer 13, and the protrusion 12a on the outer peripheral edge side of the rubber sheet 12 is provided.
The valve body 11 and the sheet retainer 13 firmly lock the rubber sheet 12 in the radial direction and prevent the rubber sheet 12 from coming off by fixing the rubber sheet 12 with the mounting bolt 6 in a state where the rubber sheet 12 and the recess 13a of the sheet retainer 13 are fitted to each other.

When the frequency of opening and closing of the valve element 11 is high,
When the valve is closed for a long time and then opened, the valve body 11 and the seat retainer 13 are firmly locked in the radial direction against the pull-out force acting on the rubber sheet 12 to prevent the rubber sheet 12 from coming off. The rubber sheet 12
The sealing property between the valve case 7 and the valve box sheet 7 can be stably maintained.

In the above configuration, the rubber sheet 12
A convex portion 12a is formed on the
However, a concave portion may be formed in the rubber sheet 12 and a convex portion may be formed in the sheet retainer 13.

In the above configuration, the rubber sheet 12
An annular concave / convex portion that engages with each other is formed on the mating surface of both the rubber seat 12 and the seat retainer 13. It may be formed on a surface.

[0016]

As described above, according to the present invention, the rubber sheet is sandwiched and fixed between the valve body and the sheet retainer, and the mating surface of both the rubber sheet and the sheet retainer, or the rubber On the mating surfaces of both the seat and the valve element, an annular concave and convex portion that engages with each other is formed near the outer peripheral edge of the rubber sheet, and the valve element and the seat are engaged by engaging the concave and convex portion. The retainer firmly locks the rubber sheet in the radial direction and prevents it from falling off. Therefore, damage to the rubber sheet and leakage of fluid from the damaged portion can be prevented, and the sealing property between the rubber sheet and the valve box sheet can be stably maintained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a rubber sheet fixing structure according to an embodiment of the present invention.

FIG. 2 is a sectional view of an eccentric butterfly valve employing the rubber sheet fixing structure.

FIG. 3 is a perspective view of the rubber sheet.

FIG. 4 is a sectional view of a butterfly valve employing a conventional rubber sheet fixing structure.

FIG. 5 is a schematic sectional view showing the rubber sheet fixing structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve box 3 Valve stem 10 Butterfly valve 11 Valve body 12 Rubber sheet 12a Annular convex part 13 Seat retainer 13a Annular concave part

Claims (1)

[Claims] 1. A valve body for opening and closing a flow path is provided in a valve box so as to be rotatable around an axis of a valve rod, and an annular rubber sheet is provided on a peripheral portion of the valve body so as to be in sliding contact with the valve box sheet. The sheet is sandwiched and fixed between the sheet retainer and the valve body, and the annular unevenness is engaged with the mating surface of both the rubber sheet and the sheet retainer, or the mating surface of both the rubber sheet and the valve body. A rubber sheet fixing structure in a valve body, wherein the portion is formed near an outer peripheral edge of the rubber sheet.