JP5859328B2 - Soft seal gate valve - Google Patents

Description

  The present invention relates to a soft seal gate valve that has a valve body that moves up and down in a crossing direction with respect to a flow path to open and close the flow path, and that performs a valve closing seal with a rubber seal material attached to the valve body.

  As this type of soft seal gate valve, for example, gate valves of Patent Document 1 and Patent Document 2 are known. In such a soft seal gate valve, when the diameter is small, such as 50A or 100A, a valve body in which an elastic material such as rubber is coated on the entire surface of a core material such as metal is usually used. A metal valve box that houses the valve body, a valve stem having a male screw threaded into a female screw provided on the valve body, a lid for sealing the valve box, and leakage of fluid from the stem of the valve stem. A packing to prevent is provided. Furthermore, the case where the handle or cap for rotating a valve stem is generally provided.

The soft seal gate valve has a structure in which the valve body moves in a direction crossing the pipe line (flow path) to stop the water, and in this case, the engagement convex portions or the engagement concave portions provided on both sides of the valve body are provided. The valve body moves up and down in the vertical direction by engaging with the guide recesses or guide protrusions provided on both sides of the valve box. When the valve body is lowered, the valve body comes into contact with the wedge-shaped valve seat of the valve box, so that the valve body moves in the closing direction with a compressive force acting on the sealing material. Thereby, when a valve body contact | abuts to the valve box bottom part, the sealing material by the side of a valve body bottom part is compressed, and a pipe line is stopped.
At this time, since the bottom side of the valve body is a water stop part that seals to the water stop surface provided on the bottom side of the valve box, the lining thickness of the seal material of this part may be thicker than other parts. Many. For example, in the case of Patent Document 1, a biting allowance is provided on the contact side surface of the valve body base that contacts the valve seat water stop surface and the outer peripheral surface of the valve body tip side that contacts the inner peripheral surface of the valve seat. The bottom side of the disc is thick due to the bite.

  Due to the above structure, in the soft seal gate valve, when the valve is closed, the compression force of the sealing material is applied to the valve seat and the bottom of the valve box to stop the flow of water. The water is made to flow by applying a force to release the compression force. Originally, when compressing the seal material or releasing the compression, it is preferable that the flow path can be opened and closed by operating the valve body with the minimum necessary force.

JP 2000-28015 A JP 7-151246 A

However, when the thickness of the rubber lining on the bottom side of the valve body is thick, the operating torque slowly increases corresponding to the increase in the number of rotations of the valve stem required until the water stops. Thus, since the force at the time of compression of the rubber-thick sealing material does not rapidly increase from the force at the time of completion of the cut-off, the operation force for completion of the cut-off becomes unclear. As a result, it is difficult to clearly confirm that the deadline has been completed, and thus there is a tendency to continue to apply force even after the deadline is completed. If the valve stem is rotated inadvertently, the lining surface may be damaged or peeled, the valve body or valve box may be damaged, the durability will deteriorate, and the sealing performance may deteriorate, leading to leakage. There is a possibility that the male and female screws may be damaged due to overtightening of the valve body, and the opening / closing operation cannot be performed normally.
In the soft seal gate valve of Patent Document 1, a bite allowance is provided on the contact side with the water stop surface of the valve element. This bite allowance is provided to prevent an increase in operating torque. It is not intended to prevent excessive tightening.

  Furthermore, in the case of a structure in which the valve body and the valve box are engaged by the rubber-lined engaging convex part (or engaging concave part) and the metal guide concave part (or guide convex part), A large frictional force is applied by these contacts during the up-and-down movement. Therefore, an extra opening / closing operation force is required, and it becomes difficult to understand the difference between the operation force until closing and the operation force when tightening from the completion of the closing. In addition, the frictional force between the valve body and the valve box further increases as the fluid pressure increases.

  On the other hand, the gate valve of Patent Document 2 is provided with an overtightening prevention ring, and attempts to prevent overtightening of the valve by causing the overtightening prevention ring to abut against the abutting surface when the valve is fully closed. However, this gate valve has a structure that prevents the overtightening of the valve seat surface on the tip of the valve body by making the overtightening prevention ring attached to the valve stem abut against the abutting surface inside the body. Since the distance between the prevention position and the valve body abutting portion is increased, the accuracy of overtightening prevention is reduced. That is, even when the sealing material (packing) is deteriorated, the overtightening stop position on the valve shaft side does not change, so that there is a possibility that the valve body side is overtightened or tightening is not sufficient when tightening is completed. The accuracy when preventing overtightening may deteriorate due to an assembly error between the valve body and the valve stem. Furthermore, it is necessary to adjust and install the overtightening prevention ring at the valve closing position, and there is a problem that the number of parts increases due to this overtightening prevention ring.

  The present invention has been developed to solve the above-mentioned problems, and its purpose is to prevent excessive tightening after the valve body is cut off, and to deteriorate or damage the seal part, the valve body, and the valve box. It is an object of the present invention to provide a soft seal gate valve that can ensure high sealing performance at the time of closing and closing the valve, and can surely grasp the completion state of closing of the valve body during operation.

  In order to achieve the above object, the invention according to claim 1 is a valve body provided with a valve body provided with a rubber lining layer that moves up and down in a cross direction with respect to the flow path in the valve box, and the valve In a soft seal gate valve that seals the water stop surface provided at the bottom of the box and opens and closes the flow path of the valve box, the metal base material of the valve body provided with a rubber lining layer has a valve that seals at least the valve seat A stopper that applies a rubber lining layer to the body sealing portion and the water-stopping portion that seals against the water-stopping surface of the base material, and also provides an opening in the rubber lining layer of the water-stopping portion, with the base material facing the opening. This is a soft seal gate valve that prevents the valve body from being overtightened by the stopper portion by providing the portion.

  The invention according to claim 2 is the soft seal gate valve, wherein the opening is a pair of opening windows formed on the tapered surface of the water stop.

  The invention according to claim 3 is a soft seal gate valve in which a protruding stopper formed on the base material is exposed to the opening window, and the outer surface of the protruding portion is protruded to the middle of the rubber lining layer of the opening window. .

  The invention according to claim 4 is the soft seal gate valve in which the inner periphery of the opening window is a diameter-expanded taper surface extending along the outer side of the valve body.

  In the invention according to claim 5, the guide part of the valve box that moves the valve body up and down in the valve box and the guide part of the valve body are guided by the metal surfaces or the painted surfaces coated on the metal without rubber lining. This is a soft seal gate valve that is moved up and down.

  According to a sixth aspect of the present invention, there is provided a valve body guide concave portion provided in the valve box and a metal convex guide portion that protrudes from the base material of the valve body and is not subjected to rubber lining, This is a soft seal gate valve in which the convex guide portions are moved up and down between metal or painted surfaces.

  According to the first aspect of the present invention, the rubber lining layer applied to the valve body seal portion and the water stop portion ensures high sealing performance at the time of shutting off the valve body, and from the opening provided in the rubber lining layer of the water stop portion. By facing the stopper part and preventing the valve body from being overtightened by this stopper part, excessive tightening of the valve body after the shut-off is surely prevented, and the pressure contact of the seal part of the rubber lining is prevented. It is possible to avoid deterioration and damage of the seal part, the valve body, and the valve box, and to grasp the completion state of the valve body by feeling.

  According to the second aspect of the present invention, the tapered surface of the water stop portion is formed in a pair of pressure contact seals while exhibiting high sealing performance by sealing in a wedge shape to the water stop surface of the valve box when the valve body is closed. Since the opening is uniformly deformed and the stopper is brought into contact with the water stop surface through the opening, it is possible to reliably prevent overtightening of the valve body. Therefore, it is possible to prevent internal damage after the cut-off while preventing an excessive tightening force from acting on the valve body.

  According to the third aspect of the invention, the outer surface of the protrusion is made to protrude partway through the rubber lining layer of the opening window, so that the outer surface of the stopper portion can be reliably stopped by the deformation of the opening at the time of closing. Contact the water surface to prevent overtightening of the valve body.

  According to the invention which concerns on Claim 4, when the water stop part press-contacts to a water stop surface, the inner periphery vicinity of an opening window deform | transforms while expanding by an enlarged diameter taper surface, and an opening window may deform | transform into the stopper part side. Therefore, the outer surface of the stopper portion can be brought into contact with the water stop surface without fail when the valve body is cut off.

  According to the invention according to claim 5, the valve body can be moved up and down while providing the guide part of the valve body and the guide part of the valve box in an arbitrary combination structure, and between the painted surfaces coated with metals or between metals By moving the valve body up and down by the guide, the frictional force between the guide parts when the valve body is opened and closed is reduced. In particular, the frictional force is also reduced when the valve body is close to the shut-off state and a strong fluid pressure is applied. For this reason, the difference in the operating force between the operating force until the valve body is closed and the operating force at the time of closing the valve body can be increased, and the completion of the tightening can be surely grasped by clarifying the sense when the water stop is completed.

  According to the invention which concerns on Claim 6, the valve body is made to move up and down by guide of metal or painted surfaces by the valve body guide recessed part of a valve box, and the convex guide part of a valve body, and it is easy. While guiding the valve body reliably in the opening and closing direction with the structure, the frictional force at the time of opening and closing the valve body is reduced by these guide portions, and the frictional force is also reduced when a strong fluid pressure is applied at the time of closing the valve body. For this reason, the difference between the operating force up to the closing of the valve body and the operating force at the closing of the valve body can be increased, and the completion of the tightening can be surely grasped by clarifying the sense when the water stop is completed.

It is a principal part longitudinal cross-sectional view which shows embodiment of the soft seal gate valve of this invention. It is a front view which shows a valve body. It is a longitudinal cross-sectional view of FIG. (A) is a partially expanded sectional view of FIG. (B) is AA sectional drawing of FIG. (C) is a B arrow view of FIG. (A) is the principal part side surface sectional view which showed the cutoff state of the valve body. (B) is front sectional drawing of (a). It is EE sectional drawing of Fig.5 (a). It is sectional drawing which showed the other example of the attachment structure of a valve body. It is the graph which showed the measurement result of torque operation.

  Embodiments of a soft seal gate valve according to the present invention will be described below in detail with reference to the drawings. FIG. 1 shows an embodiment of the soft seal gate valve of the present invention, and FIG. 2 shows a valve body.

  As shown in the figure, the soft seal gate valve of the present invention is particularly suitable for a small-diameter gate valve such as 50A or 100A. The soft seal gate valve has a valve body 1, a valve box 2, a lid 3, and a valve stem 4. The valve body 1 is attached to a flow path 5 provided in the valve box 2 by a valve rod 4 so as to be movable up and down in the crossing direction.

  The valve body 1 is provided with a rubber lining layer 8 made of a rubber material such as EPDM or fluororubber. The rubber lining layer 8 provides a valve seat 6 provided in the valve box 2 and a water stop surface provided on the valve box bottom 2a. 7 is sealed to open and close the flow path 5 of the valve box 2.

  The valve body 1 has a base material 10 inside, and the base material 10 is made of a metal such as spheroidal graphite cast iron (for example, FCD450-10), stainless steel (SCS), bronze casting (CAC), or the like. Thus, it is cast-molded into a wedge shape having a symmetrical shape with respect to the flow path 5. A valve stem insertion hole 11 is provided through the center of the base material 10, and a female thread portion 12 is formed on the upper side of the valve stem insertion hole 11. A male thread portion 25 (to be described later) of the valve stem 4 is screwed onto the female thread portion 12, thereby enabling the valve body 1 to move up and down. When the base material 10 is made of cast iron, it is surface-treated with an appropriate coating material.

  A valve body seal portion 21 is provided in an upper arc portion of the base material 10, and the valve body seal portion 21 can be sealed to the valve seat portion 6 of the valve box 2. A water stop portion 20 having a tapered surface 24 is provided on the bottom 10 a side of the base material 10, and the water stop portion 20 can be pressure-contact sealed to the water stop surface 7 of the valve box 2. When the rubber lining layer 8 is applied to the base material 10, it is applied to at least the valve body seal portion 21 and the water stop portion 20.

  As shown in FIGS. 3 and 4, a protruding stopper 18 is formed at the position of the water stop 20 on the bottom 10 a side of the base material 10. The stopper portion 18 is formed integrally with the metal base material 10 and is provided as a pair on the left and right tapered surfaces 24, 24.

As shown in FIGS. 4A and 4C, when the rubber lining layer 8 is applied to the base material 10, an opening 22 is provided in the rubber lining layer 8 of the water stop portion 20, and the opening 22 Further, a stopper portion 18 facing the base material 10 is provided. When the valve is closed, the stopper portion 18 abuts against the water stop surface 7 to prevent the valve body 1 from being overtightened.
4A and 4B, the opening 22 is formed of an opening window formed in the tapered surface 24, and the protruding stopper 18 formed on the base material 10 is faced through the opening window 22. At the same time, the outer surface 19 of the stopper portion 18 which is the protruding portion protrudes partway through the rubber lining layer 8 of the opening window 22.

  A diameter-expanding tapered surface 23 that extends along the outside of the valve body 1 is provided on the inner periphery of the opening window 22. The diameter-enlarged taper surface 23 is deformed so that the vicinity of the inner periphery of the opening window 22 is expanded, and deformation of the stopper portion 18 toward the outer surface 19 is prevented.

  The opening window 22 is provided with a depth D. The depth D is a distance from the surface side of the rubber lining layer 8 to the outer surface 19 of the stopper portion 18, and this distance is a distance that allows the stopper portion outer surface 19 to contact the water stop surface 7 by elastic deformation of the opening 22. It has become.

  As shown in FIG. 6, metal convex guide portions 15 are formed on both sides of the base material 10 so as to protrude as guide portions. The rubber lining layer 8 is not applied to the convex guide portion 15, and the convex guide portion 15 that is a metal portion is exposed to the outside. The convex guide portion 15 is loosely fitted in a valve body guide concave portion 16 that is a guide portion provided in the metal valve box 2, and the convex guide portion 15 and the valve body guide concave portion 16 are made of metal. The valve body 1 is moved up and down by guidance by mutual contact. The convex guide portion 15 and the valve body guide concave portion 16 can move the valve body 1 up and down by guiding the painted surfaces.

  The valve body 1 can be moved to a position perpendicular to the direction of the flow path 5 of the valve box 2 via the convex guide portion 15 and the valve body guide concave portion 16, and when the valve body 1 is moved downward. The flow path 5 can be closed.

  When the rubber lining layer 8 is applied to the valve body 1, a rubber material is provided on the surface of the base material 10 by vulcanization molding. At that time, the stopper portion 18 and the convex guide portion 15 are exposed. By this vulcanization molding, at least the rubber lining layer 8 is provided to the water stop portion 20 on the bottom side of the valve body 1 and the valve body seal portion 21 in the upper arc portion. The rubber lining layer 8 is applied by integral molding.

  In FIG. 1, the valve box 2 and the lid 3 are made of, for example, a bronze casting such as CAC911, and the valve box 2 and the lid 3 are coupled by screws. Further, when spheroidal graphite cast iron such as FCD450-10 is formed as a material, the entire surface thereof is surface-treated with the same material as the coating material of the base material of the valve body 1. The valve seat portion 6 of the valve box 2 is formed in a wedge shape that can seal the valve body 1. The valve box 2 and the lid 3 may be fixed by a fixing member such as a bolt (not shown).

  The valve stem 4 is made of, for example, stainless steel, and a screw portion 25 is provided on the outer peripheral side thereof. The male screw portion 25 can be screwed to the female screw portion 12 of the valve body 1. An annular flange 26 is formed on the valve stem 4, and the valve rod 4 is inserted into an insertion hole 28 provided in the lid 3 in a state where the annular flange 26 is engaged with an engagement portion 27 formed on the lid 3. Mounted. Thereby, the valve stem 4 can be rotated in a state in which the vertical movement is prevented with respect to the valve box 2.

  When the valve stem 4 is rotated in the valve closing or valve opening direction, the convex guide portion 15 is restricted in rotation by the valve body guide concave portion 16, so that the valve body 1 is connected to the male screw portion 25 and the female screw portion 12. It moves up and down with respect to the valve stem 4 through screwing. The valve stem 4 is manually rotated by a handle (not shown), but can be automatically operated by an electric actuator (not shown).

  As described above, in the soft seal gate valve of the present invention, the rubber lining layer 8 may be applied to at least the valve body seal portion 21 and the water stop portion 20 of the base material 10, and thus the above embodiment. Then, the convex guide part 15 for making the valve box 2 contact with metal, rubber | gum on the base material surface side other than the valve body neck part 29 which does not contact the valve seat part 6 and the water stop surface 7 at the time of raising / lowering motion A lining layer 8 was applied. The present invention is particularly suitable when the valve body 1 has a small diameter and the rubber lining layer 8 is applied to the surface of the base material 10 other than the opening 22, the convex guide portion 15, and the neck portion 29. In the case of a base material with a large lining layer, or when a rubber lining layer is partially applied to the surface of the flow path side valve body other than the valve body seal part and the water stop part, and a rubber seal material is attached by fitting into the base material It is also applicable to.

  Further, as shown in FIG. 1, in this soft seal gate valve, the male thread portion 25 of the valve stem 4 is hidden in the valve box 2, and the valve stem 4 rotates at a fixed position when the valve body 1 is opened and closed. Although it is an internal screw type gate valve, an external screw type gate valve structure (not shown) may be used. The externally threaded gate valve has a structure in which the threaded portion of the valve stem is outside the valve box, the valve stem is raised by opening the valve, and the valve stem is lowered by closing.

  When the wedge-shaped valve body 1 (base material 10) is moved up and down with respect to the valve box 2 to close the flow path 5 with the valve body 1, the soft seal gate valve has a valve body seal portion 21 and water stop. Although the gate valve is a so-called wedge-shaped structure that seals the portion 20 to the valve seat portion 6 and the water stop surface 7, the valve body is not limited to the wedge shape. For example, although not shown in the drawings, a so-called pressure-bonding type in which a valve body in which the upstream side surface and the downstream side surface are substantially parallel is moved up and down so that the valve body seal portion is pressure-bonded to the valve seat portion of the valve body to close the valve. May be provided.

  In FIG. 7, the other example of the attachment structure of a valve body is shown. In this case, the valve body guide convex part 30 is provided in the valve box 2, while the metal concave guide part 31 not provided with rubber lining is provided on the base material of the valve body 1, and the valve body guide convex part 30 is concave. The guide part 31 is moved up and down by metal guides. As described above, the combination of the concave and convex portions of the valve box 2 and the valve body 1 may be exchanged, and if the valve body can be slid in the vertical direction while the valve body is stopped by rotating the valve rod, The combination structure between the guide portions is not limited. In any case, the valve box side and the valve body side can be moved up and down by the guidance of the painted surfaces.

Next, the operation in the above embodiment of the soft seal gate valve of the present invention will be described.
In the fully open state of the valve body 1 in FIG. 1, there is no contact portion between the rubber lining layer 8 of the valve body 1 and the valve box 2. When the handle is rotated in the closing direction from this state, the valve rod 4 is rotated, and the valve body 1 slides in the closing direction while the convex guide portion 15 and the valve body guide concave portion 16 are in contact with each other by a metal guide. . Thus, since the valve body 1 moves up and down by contact of metals with respect to the valve box 2, the frictional force at the time of opening and closing of the valve body is reduced, and the increase in operating force is prevented.

  When the valve body 4 is further rotated to move the valve body 1 from the fully open position to the closing direction, the wedge-shaped valve seat section 6 comes into contact with the rubber-lined valve body seal section 21 and the water stop surface 7 is stopped. It will be in the state which the part 20 contacted. When the valve stem 4 is rotated in this state, the valve body 1 moves in the closing direction while compressive force mainly acts on the valve body seal portion 21 and the water stop portion 20. Therefore, the operation force starts to increase from this state.

Subsequently, when the valve body 1 is tightened, the pressure contact portion of the rubber lining layer 8 is elastically deformed by the lowering of the valve body 1 and the valve is closed.
In FIG. 5, in order to bring the valve body 1 into the shut-off state while sealing the water stop portion 20 to the water stop surface 7, the valve rod 4 is further rotated to move the valve body 1 in the closing direction. At that time, since the compressive force acts on the rubber lining layer 8 in the vicinity of the water stop portion 20, the operating force is further increased.
When the stopper portion 18 comes into contact with the water stop surface 7 through the pair of opening windows 22 and 22 formed on the tapered surface 24 of the water stop portion 20, the movement of the valve body 1 in the closing direction is restricted by the stopper portion 18. . As a result, the movement of the valve body 1 is surely stopped, and it becomes impossible to operate even if an operation force is further applied.
In this way, when the stopper portion 18 abuts against the water stop surface 7, excessive deformation of the press contact portion in the water stop portion 20 and the valve body seal portion 21 is prevented, and these burdens are reduced to be damaged or broken. Can be prevented.

  Moreover, since the stopper portion 18 is provided from the opening 22 provided in the rubber lining layer 8 of the water stopping portion 20, the valve body 1 stops at a predetermined closing position without being affected by the rubber lining layer 8. Therefore, the valve stem 4 can be rotated with high accuracy to the tightening completion state while preventing leakage, regardless of the deterioration state of the water stop portion 20 or the valve body seal portion 21, and separate parts are used to prevent overtightening. It is not used and the structure is simple.

  When the stopper portion 18 is in contact with the water stop surface 7, it can be confirmed with a feeling during operation that the stopper portion 18 is in a fully closed state. At that time, the stopper 18 made of metal, which is harder than the rubber lining layer 8 constituting the water stop portion 20, abuts against the water stop surface 7, so that the shut-off torque is larger than when the water stop portion 20 is gently deformed. It changes rapidly. For this reason, it is easy to convey a sense of completion of the deadline, and the deadline state of the valve body 1 can be reliably grasped.

  By causing the outer surface 19 of the stopper portion 18 to project partway along the rubber lining layer 8 of the opening window 22, the opening portion 22 is deformed, so that the stopper portion 18 abuts against the water stop surface 7 and the valve body 1 is moved. It can be stopped at the shut-off position, and the inner periphery of the opening window 22 is an enlarged diameter tapered surface 23, so that the peripheral portion of the opening window 22 is deformed inward when the water stopping portion 20 is pressed against the water stopping surface 7. At this time, the outer surface 19 of the protrusion 18 is exposed to the water stop surface 7 side.

Next, in the soft seal gate valve described above, in order to investigate the relationship between the rotational speed of the valve stem and the operating torque, the operating torque with respect to the rotational speed of the valve stem was measured using the soft seal gate valve.
In this case, the number of rotations of the valve stem 4 when the valve stem 4 is rotated from the valve opening direction to the valve closing direction while applying pressure by a predetermined test device from the primary side of the flow path 5 of the soft seal gate valve of 50A. The relationship between the valve body 1 and the operating torque of the valve body 1 at a predetermined number of revolutions was measured. The depth D to the stopper part 18 of the test piece of the soft seal gate valve was set to 0.5 mm, 1.0 mm, and 2.0 mm, respectively. When the upper surface side of the valve body 1 is in contact with the inner side of the lid 3, the valve body 1 is rotated from the fully open state to the closing direction. A position where there was no leakage to the secondary side when the fluid pressure was continuously applied for 15 seconds was defined as a water stop position (water stop point). Table 1 shows the relationship between the rotational speed and operating torque when the differential pressure is 0.1 MPa and 0.3 MPa, and the relationship between the rotational speed and operating torque when the differential pressure is 0.5 MPa and 0.75 MPa. Is shown in Table 2. Among these, FIG. 8 shows a graph showing the relationship between the rotational speed and torque when the differential pressure is 0.3 MPa as an example.

  In Tables 1 and 2, the water stop point is when the rotation speed is approximately 11 rotations, and the operating torque suddenly increases from around 11 rotations. By confirming this increase in operating torque, it was confirmed that the deadline was completed. Comparing the relationship between the number of rotations due to the difference in differential pressure and the operating torque, the operation due to the difference in differential pressure until reaching the water stop point in any case of depths of 0.5 mm, 1.0 mm, and 2.0 mm There is little change in torque. On the other hand, as the pressure is further tightened from the water stop point, the operating torque tends to increase slightly when the differential pressure is large at any depth.

  In any case of the differential pressure, when the depth D to the surface of the stopper portion 18 is reduced, the number of rotations required until the fully closed state is reduced, and as the depth D is increased, the number of rotations until the fully closed state is reached. Will increase. From this, by reducing the depth D, the tightening allowance (clearance) until completion of the cut-off can be reduced, and by increasing the depth D, the allowance until completion of the cut-off can be increased.

  Among these, in the case of the differential pressure of 0.3 MPa shown in FIG. 8, the operating torque at the water stop point is 7.5 N · m, 7 N · m respectively at the depths of 0.5 mm, 1.0 mm, and 2.0 mm. m, 5.5 N · m. The relationship between the rotational speed at each depth and the operating torque is as follows. When the depth is 0.5 mm, the rotational speed increases rapidly after the water stop point, and the numerical values of the rotational speed 11 and 1/8 rotation are 25 N · m. Became. In the case of a depth of 1.0 mm, the number of revolutions rapidly increased after the water stop point, and the values of the number of revolutions 11 and 5/16 were 30 N · m. In the case of a depth of 2.0 mm, the number of revolutions rapidly increased after the water stop point, and the values of the number of revolutions 11 and 6.5 / 16 were 27.5 N · m. In this way, it was possible to confirm a sudden increase in the operating torque, and thereby it was possible to grasp the completion of the deadline.

DESCRIPTION OF SYMBOLS 1 Valve body 2 Valve box 2a Bottom part 5 Flow path 6 Valve seat part 7 Water stop surface 8 Rubber lining layer 10 Base material 15 Convex guide part (guide part)
16 Recess for valve body guide (guide part)
18 Stopper (protrusion)
19 External surface 20 Water stop part 21 Valve body seal part 22 Opening window (opening part)
23 Tapered surface with increased diameter 24 Tapered surface

Claims (6)

  A valve body provided with a rubber lining layer that moves up and down in a crossing direction with respect to the flow path in the valve box and seals the valve seat provided in the valve box and the water stop surface provided in the bottom of the valve box. In the soft seal gate valve for opening and closing the flow path of the box, the metal base material of the valve body provided with a rubber lining layer includes at least a valve body seal part that seals the valve seat part and the water stop surface of the base material This stopper is formed by providing a rubber lining layer on the water-stopping portion that is pressure-contact sealed to the water-stopping portion, providing an opening in the rubber lining layer of the water-stopping portion, and providing a stopper portion facing the base material from the opening. Soft seal gate valve characterized by preventing overtightening of the valve body at the part.   The soft seal gate valve according to claim 1, wherein the opening is a pair of opening windows formed on a tapered surface of the water stop portion.   3. The soft seal gate valve according to claim 2, wherein a protruding stopper formed on the base material faces the opening window, and an outer surface of the protruding portion protrudes partway through a rubber lining layer of the opening window.   The soft seal gate valve according to claim 2 or 3, wherein the inner periphery of the opening window is a diameter-expanding tapered surface that extends along the outside of the valve body.   5. The valve body guide part for raising and lowering the valve body in the valve box and the guide part for the valve body are moved up and down by metal without applying rubber lining. Soft seal gate valve as described in 1.   A concave part for valve body guide provided in the valve box and a metal convex guide part that protrudes from the base material of the valve body and is not subjected to rubber lining are provided, and the convex guide is provided in the concave part for valve body guide. The soft seal gate valve according to claim 5, wherein the part is moved up and down by guidance between metal parts or painted surfaces.

Images