JP4162335B2 - Gate valve - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gate valve for opening and closing a pipe of a fluid pipe such as a water pipe or a gas pipe, and in particular, a gate valve having a valve body that moves in a direction perpendicular to the pipe axis of the fluid pipe, The valve body has a support member that moves up and down, and the support member relates to a gate valve of a type in which a deformable seal portion for sealing the valve box opening and the inner peripheral wall of the valve box is supported. .
[0002]
[Prior art]
As shown in FIG. 4, a conventional gate valve uses an existing fluid pipe A as a valve box. In this case, a valve pipe opening B is provided in the fluid pipe A as a valve box, A lid D for closing the valve box opening B and rotatably supporting the screw spindle C is coupled to the fluid pipe A via a split T-shaped pipe F in which a flange coupling portion E is formed. In the valve box of the lid D and the fluid pipe A, a valve body G is supported by a screw spindle C so as to be movable up and down. The valve body G seals a metal support member H that is screwed onto the screw spindle C, a rubber-made first annular seal portion I for sealing the valve box opening B, and a valve box inner peripheral wall J. And a second seal portion K made of rubber and deformable in a U-shaped radial direction.
[0003]
The operation of the gate valve having such a configuration will be described particularly with respect to the valve closing process. When the screw spindle C is rotated in the valve closing direction, the support member H screwed to the screw spindle C gradually descends with the first and second seal portions I and K, and eventually the second seal. The curved lower end surface of the portion K comes into contact with the bottom of the valve box inner peripheral wall J. After that, when the screw spindle C is further rotated and the support member H is forcibly pushed down, the second seal portion K is compressed in the vertical direction, so that the left and right side surfaces of both legs are in the lateral direction, that is, the radius. It is forced to bulge in the direction and comes into contact with the inner peripheral wall J of the valve box. The screw spindle C is further rotated so that the sealing surface of the second sealing portion K, that is, the lower end surface and the left and right side surfaces are pressed against the inner peripheral wall J of the valve box with sufficient force. When I is similarly crimped to the peripheral edge of the valve box opening B, the closing of the gate valve is completed.
[0004]
[Problems to be solved by the invention]
In the gate valve having such a configuration, both legs are indirectly bulged in the radial direction based on the compression in the vertical direction with respect to the second seal portion K, so that a sufficient seal pressure is obtained. Had to compress the second seal K in the vertical direction with considerable force. Therefore, due to such strong compression, an excessive load is applied not only to the second seal portion K but also to the fluid pipe A as the valve box, the screw spindle C, the support member H, and the lid D. There is a drawback that the service life of the respective members is extremely shortened.
[0005]
Further, when the valve is closed, the screw spindle C receives excessive compression resistance of the second seal portion K, so that the torque required to rotate the screw spindle C increases rapidly. This has been a cause of lowering the operability of the gate valve.
[0006]
The problem to be solved by the present invention has been made to solve the above-mentioned problem, and the overall compression amount of the seal portion is suppressed to the necessary minimum, the service life is sufficiently extended, and the operability is improved. The point is to provide an improved gate valve.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, the gate valve of the present invention has a valve body that enters and exits from the through hole formed in the fluid pipe, and the valve body moves forward and backward with respect to the fluid pipe. And a gate valve of a type comprising a support member that supports a first seal portion for sealing the periphery of the through-hole and a deformable second seal portion for sealing the inner peripheral wall of the fluid pipe. Is provided with an auxiliary member having a function of preventing the second seal portion from bulging in the inner diameter direction, and a widening member that moves in conjunction with the movement of the auxiliary member is provided in the second seal portion. The widening member is guided between the second seal portion and the auxiliary member by movement of the body in the valve closing direction, and both side portions of the second seal portion are bulged toward the inner peripheral wall of the valve box. Yes.
With this feature, when the valve body is lowered in order to close the gate valve, the support member, the auxiliary member, the widening member, and each seal portion are lowered following the downward movement. Eventually, when the lower end surface of the second seal part comes into contact with the bottom part of the inner peripheral wall of the fluid pipe and the downward movement of the second seal part and the widening member stops, only the support member and the auxiliary member descend thereafter. The support member compresses the second seal portion as it descends, and the auxiliary member contacts the inner surface of the second seal portion and prevents the expansion of the widening member while preventing expansion in the inner diameter direction due to the compression. It forcibly guides between the inner surfaces of the two seal portions and pushes the second seal portion outward.
That is, when the valve is closed, the left and right side portions of the second seal portion can be directly bulged in the radial direction by the auxiliary member and the widening member, so that the seal portion does not need to be excessively compressed beyond the necessary seal pressure. . Therefore, since an excessive load does not act on each member, the service life of the gate valve can be greatly extended.
[0008]
It is preferable that a pair of tapered taper surfaces are formed on the outer surface facing the second seal portion in the auxiliary member.
In this case, after the second seal portion and the widening member stop the descending movement, the auxiliary member further descends, and when the widening member is forcibly guided between the inner surface of the second seal portion. Since the auxiliary taper is guided without excessive compression by the tapered surface of the auxiliary member, the torque at the time of valve closing does not increase rapidly, and the operability is improved.
[0009]
The widening member is a pair of spheres or cylinders, and is preferably disposed at a predetermined position in the distal direction of the second seal portion when the valve body is open.
In this way, after the second seal portion and the widening member stop the downward movement, the auxiliary member further lowers, and when the widening member is forcibly guided between the inner surface of the second seal portion, Since the widening member is a sphere or a cylindrical body, it can be rotated when guided and moved, and since the area in contact with the auxiliary member is reduced, the movement resistance is reduced, and the torque at the time of closing the valve increases rapidly. The operability is improved.
Further, since the widening member is located in the distal direction of the second seal portion, the widening force does not work during the lowering of the second seal portion, so that the torque at the time of closing the valve does not increase rapidly, Operability is improved.
[0010]
In the second seal portion, it is preferable that an accommodation groove for positioning the widening member outside the tapered surface of the auxiliary member is formed.
In this case, since the widening member is always located outside the auxiliary member, the widening member is reliably guided between the second sealing portion and the inner surface of the second seal portion by the auxiliary member. The reliability with respect to stopping the water by expanding the seal part 2 and crimping it to the inner peripheral wall of the valve box is improved.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0012]
1, 2 and 3 show an embodiment of the valve body 1 of the present invention. The valve body 1 includes a support member 2, a pair of auxiliary members 3 positioned below the support member 2, a pair of opposing plates 4 sandwiching a second seal portion 6b described later from the tube axis direction, and the support member 2. A rubber piece comprising a screw piece 5 to which a screw spindle 8 to be moved up and down is screwed, a first seal part 6a for sealing a valve box opening (not shown) and a second seal part 6b for sealing an inner peripheral wall of the valve box. The seal part 6 and the widening member 7 are comprised. On the upper part of the support member 2, an engagement groove 2a for engaging the screw piece 5 is provided in a direction perpendicular to the tube axis.
[0013]
A concave portion to which the first seal portion 6a is attached is formed in the lower portion of the support member 2, and the opposing plates 4 and 4 sandwiching the second seal portion 6b are integrally provided with a predetermined interval in the tube axis direction. Yes. A spindle hole 2 b through which the screw spindle 8 is inserted is provided inside the support member 2.
[0014]
The counter plate 4 is formed with a width smaller than the opening of the valve box, and its tip is formed in an arc shape having a smaller diameter than the inner diameter of the fluid pipe used as the valve box.
[0015]
The auxiliary members 3, 3 are integrally provided in parallel with the tube axis between the opposing plates 4, 4 below the support member 2, and the outer surface at the tip of the auxiliary members 3, 3 is formed with a tapered surface 3 a inclined toward the center direction. Has been. Further, two grooves 3b for preventing movement of the widening member 7 described later in the tube axis direction are formed on the outer surface along the insertion direction of the valve body. The groove 3b is provided when the widening member 7 is spherical, and varies depending on the number of the widening members 7 arranged. When the widening member 7 is one on one side, the number of grooves 3b is one, and in the case of three, three are formed. It will be.
[0016]
The rubber seal 6 is attached to a recess provided in the lower portion of the support member 2 and seals the valve box opening. The rubber seal 6 is sandwiched between the opposing plates 4 and 4 and seals the inner peripheral wall of the valve box. It comprises a letter-shaped second seal portion 6b. The first seal portion 6a is formed in a shape corresponding to the shape of the valve box opening in order to seal a valve box opening (not shown) when the valve is closed.
[0017]
In the non-compressed state, the second seal portion 6b is slightly smaller in width than the valve box opening and can be inserted through the valve box opening, and its length is longer than the inner diameter of the fluid pipe used as the valve box. Have been long. A locking portion 6c is formed at the center of the bottom portion of the inner peripheral surface of the second seal portion 6b, and a pair of widening members 7 are disposed in the receiving grooves 6d provided on the left and right.
[0018]
In this embodiment, the widening member 7 disposed in the housing groove 6d of the seal portion 6 is a rigid sphere made of plastic or metal. However, instead of this sphere, a rigid cylinder having a length slightly shorter than the distance between the opposing plates 4 and 4 can be used. In that case, since the opposing plates 4 and 4 prevent the cylindrical body from moving in the tube axis direction, the groove 3b of the auxiliary member 3 does not need to be provided. (Fig. 3 (b))
[0019]
In addition, in the engaging groove 2a formed in the upper part of the support member 2, the screw piece 5 is disposed so as not to rotate, and the screw spindle 8 is screwed into the female screw portion formed in the screw piece 5, and the screw spindle By rotating 8, the valve body 1 moves up and down.
[0020]
Next, the operation of this embodiment will be described.
[0021]
First, in the valve open state, the widening member 7 is disposed in the housing groove 6 d of the rubber seal portion 6, and the auxiliary member 3 is positioned above the width of the widening member 7.
[0022]
Next, in order to close the gate valve from this state, when the screw spindle 8 is rotated and the support member 2 is lowered, the lower end surface of the second seal portion 6b of the seal portion 6 eventually becomes a valve box (not shown). In contact with the bottom of the inner peripheral wall, the downward movement of the second seal portion 6b stops.
[0023]
Thereafter, the support member 2 and the auxiliary member 3 are lowered according to the rotation of the screw spindle 8, and the lower portion of the support member 2 compresses the second seal portion 6b. In this case, the inner peripheral surface of the second seal portion 6b comes into contact with the outer peripheral surface of the auxiliary member 3 to prevent the inner member from expanding in the inner diameter direction. As the auxiliary member 3 is lowered, the widening member 7 in the housing groove 6d is It moves along the tapered surface 3a and is pushed outward against the elastic force of the seal portion 6 while engaging the groove 3b.
[0024]
Accordingly, the second seal portion 6b of the seal portion 6 is gradually pushed down and simultaneously bulged in the lateral direction, that is, toward both sides of the inner peripheral wall of the valve box (not shown) (right side in FIG. 2). Thus, when the second seal portion 6b of the seal portion 6 is pressed against the inner peripheral wall of the valve box (not shown) with a sufficient force, the first seal portion 6a of the seal portion 6 simultaneously opens the valve box opening (not shown). It will come to be crimped | bonded with sufficient force similarly to a peripheral part. Here, based on the proper compression action of the seal portion, the rotational torque of the screw spindle is kept relatively small when the valve is closed, so that the operability of the gate valve is improved.
[0025]
Next, in order to open the gate valve from this closed state, the screw spindle 8 may be rotated in the reverse direction. In this case, the movement of each member of the valve body 1 is completely opposite to the movement when the valve is closed. That is, the widening member 7 that has been pushed outward from the housing groove 6d is gradually pushed back inward by the elastic force of the seal portion 6 as the auxiliary member 3 is lifted, and thus the second seal portion 6b of the seal portion 6 The sealing surfaces on both sides are separated from both sides of the inner peripheral wall of the valve box (not shown). At the same time, the first seal portion 6a is also separated from the valve box opening, and the support member 2, that is, the valve body 1 is similarly raised in accordance with the rotation of the screw spindle 8.
[0026]
While the embodiments of the present invention have been described with reference to the drawings, the specific configuration of the present invention is not limited to this.
[0027]
In the embodiment, the auxiliary member is provided integrally with the support member. However, the auxiliary member is disposed inside the second seal portion as a separate member, and the auxiliary member is also pressed when the second seal portion is compressed. You may make it move to the bottom part of a part.
【The invention's effect】
According to the invention, when the valve body is lowered in order to close the gate valve, the support member, the auxiliary member, the widening member, and each seal portion are lowered following the downward movement. Eventually, when the lower end surface of the second seal part comes into contact with the bottom part of the inner peripheral wall of the fluid pipe and the downward movement of the second seal part and the widening member stops, only the support member and the auxiliary member descend thereafter. The support member compresses the second seal portion as it descends, and the auxiliary member contacts the inner surface of the second seal portion and prevents the expansion of the widening member while preventing expansion in the inner diameter direction due to the compression. It forcibly guides between the inner surfaces of the two seal portions and pushes the second seal portion outward.
That is, when the valve is closed, the left and right side portions of the second seal portion can be directly bulged in the radial direction by the auxiliary member and the widening member, so that the seal portion does not need to be excessively compressed beyond the necessary seal pressure. . Therefore, since an excessive load does not act on each member, the service life of the gate valve can be greatly extended.
[0028]
According to the second aspect of the present invention, after the second seal portion and the widening member stop the descending movement, the auxiliary member further descends, and the widening member is forcibly guided between the inner surface of the second seal portion. When this is done, it is guided without excessive compression by the tapered surface of the auxiliary member, so that the torque at the time of valve closing does not increase rapidly, and the operability is improved.
[0029]
According to the invention of claim 3, after the second seal part and the widening member stop the descending movement, the auxiliary member further descends and forcibly guides the widening member between the inner surface of the second seal part. Since the widening member is a sphere or a cylinder, the widening member can be rotated when guided and moved, and since the area in contact with the auxiliary member is reduced, the movement resistance is reduced, and the torque when closing the valve is suddenly increased. Therefore, the operability is improved.
Further, since the widening member is located in the distal direction of the second seal portion, the widening force does not work during the lowering of the second seal portion, so that the torque at the time of closing the valve does not increase rapidly, Operability is improved.
[0030]
According to the invention of claim 4, since the widening member is always located outside the auxiliary member, it is ensured that the widening member is guided between the inner surface of the second seal portion by the auxiliary member. Thus, the reliability with respect to stopping the water by expanding the second seal portion and pressing the second seal portion on the inner peripheral wall of the valve box is improved.
[Brief description of the drawings]
FIG. 1 is a side view including a partial longitudinal section of a valve body in an embodiment of the present invention.
FIG. 2 is also a vertical sectional view of 1-1, wherein the left side shows a valve open state and the right side shows a valve closed state.
3 is a cross-sectional view taken along the line 2-2. FIG. 3A is a case where the widening member is a sphere, and FIG. 3B is a case where the widening member is a cylindrical body.
FIG. 4 is a longitudinal sectional view of a conventional gate valve, the left side showing a valve open state and the right side showing a valve closed state.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Valve body 2 Support member 2a Engaging groove 2b Spindle hole 3 Auxiliary member 3a Tapered surface 3b Groove 4 Opposite plate 5 Screw top 6 Seal part 6a First seal part 6b Second seal part 6c Engagement part 6d Housing groove 7 Widening member 8 Screw spindle

Claims (4)

A first seal portion that has a valve body that enters and exits the fluid pipe from a through-hole formed in the fluid pipe; the valve body moves forward and backward relative to the fluid pipe and seals the periphery of the through-hole; In the gate valve of the type comprising a support member that supports a deformable second seal portion for sealing the inner peripheral wall of the fluid pipe, the support member has a bulge in the inner diameter direction of the second seal portion. An auxiliary member having a function of preventing is provided, and a widening member that moves in conjunction with the movement of the auxiliary member is provided in the second seal portion. A gate valve, wherein the gate valve is guided between a seal portion and an auxiliary member, and both side portions of the second seal portion are bulged toward an inner peripheral wall of the valve box. 2. The gate valve according to claim 1, wherein a pair of tapered tapered surfaces are formed on an outer surface side of the auxiliary member facing the second seal portion. The gate valve according to claim 1 or 2, wherein the widening member is a pair of spheres or cylinders, and is disposed at a predetermined position in the distal direction of the second seal portion when the valve body is open. The gate valve according to claim 3, wherein the second seal portion is formed with an accommodation groove for positioning the widening member outside the tapered surface of the auxiliary member.

Images