JPH074532A - Butterfly valve - Google Patents

Abstract

PURPOSE:To enhance a water stopping property at the time of operation of a back pressure by preventing abrasion of a valve casing seat disposed in a valve casing of a butterfly valve and a valve body seat disposed in a valve body, and achieving a high sealing property when the valve body is fully closed. CONSTITUTION:A male type cam portion 4 disposed in a stem 2 is fitted to a female type cam portion 5 disposed in a valve body 3 within a predetermined range of a rotating angle in a relatively turnable manner. A function of a driver is applied to the male type cam portion 4, and a maximum projecting portion P1 interferes with the female type cam portion 5. Accordingly, the valve body 3 is kept in a fully closed position. When the stem 2 is turned from the fully closed position toward a fully opened direction, the valve body 3 is separated from a valve casing seat 1A by a moving quantity equivalent to a deviation quantity e1 of the male type cam portion 4, and is turned to the fully opened position. When the stem 2 is turned from the fully opened position to the fully closed position, the valve body 3 is first turned in the valve closing direction. Thereafter, the valve body 3 is pressed toward the valve casing seat 1A by the moving quantity equivalent to the deviation quantity e1 for sealing.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention prevents abrasion of the seats near the valve body boss and the valve box boss, ensures a high sealing property at the time of fully closing, and expects a high waterproofness at the time of back pressure action. Regarding butterfly valve.

[0002]

2. Description of the Related Art A conventional eccentric butterfly valve includes a valve body 1, a valve rod 2 and a valve body 3 as shown in FIGS. 8 and 9, and a valve body seat 3A is in close contact with the valve body seat 1A. Three
In the fully closed state, by rotating the valve rod 2 by 90 degrees in the opening direction of the valve body 3 shown by the arrow A, the valve body 3 is rotated together with the valve rod 2 to the position of the phantom line to be in the fully open state. In this fully opened state, by rotating the valve rod 2 by 90 degrees in the opposite direction to the closing direction of the valve body 3 shown by the arrow B, the valve body 3 is returned to the position of the solid line together with the valve rod 2 and is in the fully closed state. Is configured to be. However, in this type of butterfly valve, the sliding amount between the valve box seat 1A and the valve disk seat 3A due to the opening / closing motion of the valve disk 3 is such that the valve box seat 1A near the valve box boss 1B and the valve disk seat 3A near the valve disk boss 3B. Most often in.
Therefore, the valve box sheet 1A near the valve box boss 1B and the valve sheet 3A near the valve body boss 3B are significantly worn, and the sealability of this portion is deteriorated. Further, since it has a function of coping with a back pressure acting in a direction of separating the valve body sheet 3A from the valve box seat 1A, there is a drawback that high water shutoff cannot be expected when the back pressure acts.

Therefore, the valve box seat 1A near the valve box boss 1B and the valve body seat 3A near the valve body boss 3B are prevented from being worn, and a high sealing property at the time of fully closing is ensured, so that a back pressure is applied. The development of butterfly valves that can be expected to have high waterproofness is required.

[0004]

The problem to be solved is that there is a large amount of sliding between the valve case seat near the valve case boss and the valve body seat near the valve body boss, so that significant wear occurs and the seal at this portion is caused. Since it has the property of lowering the property and the function of coping with the back pressure, it is a point that a high water stop cannot be expected when the back pressure is applied.

[0005]

According to the present invention, a male cam portion provided on a valve rod is fitted to a female cam portion provided on a valve body so as to be relatively rotatable at a rotation angle within a predetermined range. The valve body is held at the fully closed position by interfering with the cam portion, and the valve body is moved from the valve box seat with a movement amount corresponding to the protrusion amount when the valve rod is rotated in the valve opening direction from the fully closed position to the fully opened position. The valve body is rotated in the valve closing direction when the valve rod is rotated in the valve closing direction from the fully opened position to the fully closed position while being separated from the fully opened position, and the valve is moved by a movement amount corresponding to the protrusion amount. The maximum protrusion that presses the body toward the valve box seat is formed on the male cam part, preventing wear of the valve box seat and valve body seat and ensuring high sealing performance when fully closed. As a result, the purpose of ensuring a high water-stopping property under the action of back pressure was achieved.

[0006]

According to the present invention, when the valve rod is rotated in the valve opening direction to open the valve body in the fully closed state, the male cam portion is also rotated, and the maximum protruding portion of the male cam portion is rotated. Interferes with the female cam to retract the valve body from the fully closed position to the half open position in the axial direction of the valve box, and rotate the squeeze rod in the valve opening direction to move the valve body from the half open position to the fully open position. Rotate to. When the valve rod is rotated in the valve closing direction to close the valve body in the fully open state, the male cam portion also rotates, and the maximum protruding portion of the male cam portion interferes with the female cam portion. By rotating the valve body in the fully closing direction and rotating the valve rod in the valve closing direction from the time point, the valve body moves forward in the axial direction of the valve box from the half open position to the fully closed position, and the valve seat To the valve box seat. That is, when the valve body is opened and closed, the valve body seat and the valve case seat do not slide. On the other hand, in the fully closed position of the valve body, the maximum protrusion of the male cam portion is directed toward the valve box seat side, and the valve body and the valve body seat are urged toward the valve box seat side via the female cam part. Since it can be retained by the above, the water stopping property at the time of back pressure action is improved.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing a butterfly valve to which the present invention is applied. It should be noted that the same or corresponding parts as those of the conventional example shown in FIGS.
In FIG. 1, the eccentric butterfly valve includes a valve box 1, a valve rod 2 and a valve body 3, and the valve rod 2 has a pair of male cam portions 4, 4 with a predetermined interval in the axial direction. Are provided, and the male cam portions 4 and 4 are fitted into the female cam portions 5 and 5 provided on the valve body 3 so as to be relatively rotatable, so that the valve rod 2 and the valve body 3 are integrally coupled. The fully closed state shown in the drawing is maintained by closely sealing the valve body seat 3A of the valve body 3 to the valve body seat 1A of the valve body 1 as in the conventional example.

Male cam portions 4, 4 and female cam portions 5, 5
Are configured as shown in FIG. That is, the male cam portions 4 and 4 (however, only one male cam portion 4 is shown in FIG. 2) are concentric base circles 4A having a radius equal to the radius R1 of the cross-section circular valve rod 2. And valve stem 2 and basic circle 4
A center of curvature O2 at a position eccentric from the center O1 of A by a distance e1
Is set, and the left half outer surface of the major axis C1 of the male cam part 4 passing through the centers O1 and O2 and having a radius R1 equal to the radius R1 and continuing to the base circle 4 is formed. The first cam surface 40 is used, and the right half outer surface is used as the second cam surface 41. The female cam portions 5 and 5 are the male cam portions 4
The first cam surface 5A having a shape with which the first cam surface 40 or the second cam surface 41 abuts, and the center O1 of the base circle 4A of the male cam portion 4 as the center of curvature, and the semi-axis located on the major axis C1 from O1. The second cam surface 5B formed by an arc from the maximum protrusion p1 to the intersection point p2 with the extension line of the minor axis C2 of the male cam portion 4A with the distance R3 to the maximum protrusion p1 of the circular convex portion 4B as the radius.
And the center O2 of the semi-circular convex portion 4B as the center of curvature, and the distance R4 (R4 from R2 to the intersection point p3 of the major axis C and the basic circle 4A
3 = R4) as a radius, and is constituted by a third cam surface 5C which is an arc from intersection point p3 to intersection point p2.

With such a construction, as shown in FIG. 2, the major axis C1 of the male cam portion 4 is parallel to the axis CB of the valve box 1 and the maximum protrusion p1 is located on the valve box seat 1A side. At the first position of the oriented male cam portion 4, the fully closed state in which the valve body seat 3A of the valve body 3 is in close contact with the valve housing seat 1A is firmly held. In order to open the valve body 3 from this fully closed state, the valve rod 1 is rotated in the forward direction, that is, the valve opening direction indicated by the arrow A, and the male cam portion 4 is shown from the first position in FIG. 3 (A). Rotation angle 45
3C, the position near the maximum protrusion p1 on the second cam surface 41 is the third cam surface 5C near the intersection point p2 of the female cam portion 5 immediately before the rotation angle of 90 degrees in FIG. 3B is reached. In a posture with a rotation angle of 90 degrees, the valve body 3 is moved by an amount corresponding to a half of the eccentric distance e1, that is, a half of the maximum protrusion p1. Retreat in the direction. From the posture of FIG.
By rotating to the second position with a rotation angle of 180 degrees as shown in FIG.
The parts up to 2 interfere with the third cam surface 5C of the female cam portion 5, and at the second position, the valve is moved by a moving amount corresponding to the eccentric distance e1, that is, a moving amount corresponding to the protruding amount of the maximum protruding portion p1. Body 3
Is retracted in the direction of the axis CB of the valve box 1 to the half-open position, and the valve body seat 3A is separated from the valve box seat 1A. Further, when the male cam portion 4 is rotated from the second position to the third position with the rotation angle of 270 degrees shown in FIG. 5, the entire surface of the second cam surface 41 is the first cam surface of the female cam portion 5. The valve body 3 rotates to the fully open position by interfering with 5A.

On the other hand, in order to close the valve body 3 from the fully opened state of FIG. 5, the valve rod 1 is rotated in the opposite direction, that is, the valve closing direction shown by the arrow B, and the male cam portion 4 is moved to the first position shown in FIG. By rotating from the position before the third position to the fourth position shown in FIG. 7, the first cam surface 40 interferes with the second cam surface 5B to rotate the valve body 3 in the valve closing direction, and the fourth position 3 to the position of FIG. 3 (A) through the state of FIG. 3 (B), the valve body seat 3A is brought into a fully closed state in which the valve body seat 3A is in close contact with the valve box seat 1A, and further rotated to the first position of FIG. By moving, the fully closed state is firmly held as described above.

As described above, according to the present invention, when the valve body 3 is opened and closed, the valve body seat 3A and the valve box seat 1A do not slide. Therefore, the wear of the valve body seat 3A and the valve box seat 1A can be reliably prevented. Further, the long axis C1 of the male cam portion 4 is made parallel to the axis CB of the valve box 1, and the maximum protrusion p1 is directed to the valve box seat 1A side.
In the first position, the fully closed state of the valve body 3 is firmly held, so that a high sealing property at the time of fully closed can be secured, and the water stopping property at the time of the back pressure action can be significantly improved.

[0012]

As described above, according to the present invention, the valve body seat and the valve body seat do not slide when the valve body is opened and closed. Therefore, the wear of the valve body seat and the valve box seat can be reliably prevented. In addition, the fully closed state of the valve body can be firmly held by the interference between the male cam part and the female cam part, so a high sealing performance is ensured when fully closed, and the water stoppage during back pressure is greatly improved. To do.

[Brief description of drawings]

FIG. 1 is a front view of a butterfly valve to which the present invention has been applied.

FIG. 2 is an enlarged cross-sectional view of the male cam in a first position.

3 (A) and 3 (B) are enlarged cross-sectional views of an initial state of rotation of the male cam in the valve opening direction.

FIG. 4 is an enlarged cross-sectional view of the male cam in the second position.

FIG. 5 is an enlarged cross-sectional view of the male cam in the third position.

FIG. 6 is an enlarged cross-sectional view showing a state in which the male cam is in front of the third position.

FIG. 7 is an enlarged sectional view of the male cam in a fourth position.

FIG. 8 is a front view showing a conventional butterfly valve.

9 is a sectional view taken along the line Aa of FIG.

[Explanation of symbols]

 1 Valve box 1A Valve box seat 2 Valve rod 3 Valve body 3A Valve body seat 4 Male cam part 5 Female cam part e1 Eccentricity (protruding amount) p1 Maximum protruding part

Claims (1)

[Claims] 1. A male cam part provided on a valve rod is fitted to a female cam part provided on a valve body so as to be relatively rotatable within a predetermined range of rotation angle, and interferes with the female cam part to interfere with the valve body. Is held at the fully closed position, and when the valve rod is rotated in the valve opening direction from the fully closed position to the fully open position, the valve body is moved away from the valve box seat by the amount of movement corresponding to the protrusion amount to the fully open position. In addition, the valve body is rotated in the valve closing direction when the valve rod is rotated in the valve closing direction from the fully open position to the fully closed position, and the valve body is pressed in the valve box seat direction by a movement amount corresponding to the protrusion amount. A butterfly valve, wherein the maximum protruding portion is formed on the male cam portion.