JP4971953B2 - Ball valve - Google Patents

Description

  The present invention relates to a ball valve that is attached to piping such as cold / hot water, air, and gas to open / close or control the flow of fluid.

  As this type of ball valve, there is a ball valve with excellent characteristics such as low pressure loss, simple flow rate controllability, and high operability for various industrial equipments and devices. (For example, refer to Patent Document 1). In this ball valve, a spherical ball is rotated by a stem, and this stem is inserted into a stem insertion hole provided in a burring portion or inserted into a stem insertion hole without a burring portion. is doing. When inserting a stem into a stem insertion hole with a burring part, the stem flange should be in contact with the tip of the burring part, while when inserting a stem into a stem insertion hole without a burring part The bearing is mounted between the periphery of the stem insertion hole and the flange of the stem. Thus, the rotational torque (thrust load) when the stem is rotated is reduced by abutting the flange portion and the tip of the burring portion or providing a bearing.

13 is a ball valve having a shaft seal structure different from that of Patent Document 1. In this ball valve 1, an annular flange 3 provided on the stem 2 is attached to a counterbore 6 formed on the inner wall of the stem insertion hole 5 of the valve body 4. Further, an annular bearing 7 formed of an elastic material is mounted between the annular flange 3 and the counterbore 6. This bearing 7 prevents the direct contact between the annular flange 3 and the counterbore 6 and reduces the thrust load by reducing the frictional resistance caused by torsional stress or the like during the rotation of the stem.
The rubber O-ring 8 is attached to the groove 2 a on the outer peripheral side of the stem 2, and the stem 2 and the valve main body 4 are sealed with a shaft by the self-elastic force of the O-ring 8.

  Furthermore, there is a ball valve 11 shown in FIG. 14 as another example of this type of ball valve. This ball valve is provided with a packing mounting portion 16 having a diameter larger than that of the stem insertion hole 15 of the valve main body 14, and the packing mounting portion 16 is formed in a substantially rectangular cross section by an elastic material having self-elasticity such as resin. A gland packing 18 is inserted, and the gland 19 is pressed from above the gland packing 18. The gland packing 18 has a repulsive force increased by the pressing of the gland 19 and presses the packing mounting portion 16 and the stem insertion hole 15 in a state in which the surface pressure is increased by the repelling force, whereby the stem 12 and the valve body 14 are pivoted. Sealed.

WO01 / 57423

However, in the ball valve of Patent Document 1, when an upward tensile stress due to tightening of the nut is applied to the stem when the valve is assembled, an excessive surface pressure is applied between the flange part and the tip of the burring part or between the flange part and the bearing. Join. When the stem is rotated in this state, the bearing is also worn and the frictional resistance between the buttock and the burring end increases, and this frictional resistance causes a so-called galling phenomenon between the stem and the valve body, resulting in an operating torque. As a result, the operability deteriorated.
Furthermore, there is a possibility that the annular flange portion may be damaged due to excessive surface pressure, or the stem may be damaged or broken due to application of a large torsional stress or tensile stress.

  On the other hand, in the ball valve 1 shown in FIG. 13, excessive surface pressure is generated between the annular flange portion 3 and the counterbore portion 6 due to excessive tightening of the nut 10, and the bearing 7 sandwiched between them is permanently deformed to externally. The seal function cannot be exhibited due to protrusion or breakage due to compression cracking.

  Further, when an O-ring 8 is provided at the shaft seal portion of the ball valve 1, there may be a case where fine foreign matter in the fluid enters and adheres to the O-ring 8 from the gap of the shaft seal portion. In addition, if there are machining roughness or gaps on the contact surface between the valve shaft 2 and the valve body 4, these are incorporated in a state of being offset, causing uneven wear or tearing during operation, reducing the self-elasticity of the O-ring 8. The sealing performance was lowered.

  Further, when the O-ring 8 is mounted in the groove 2a, the O-ring 8 may be damaged due to a load such as torsion, tension or compressive stress. When the stem 2 with the O-ring 8 is attached to the valve body 4, the stepped portion 5 a between the counterbore portion 6 and the inner diameter portion of the stem insertion hole 5, or the inner diameter of the valve body 4 and the counterbore portion 6. The O-ring 8 was easily damaged by contacting the corners of the step 5b between the portions.

  Further, the ball valve 1 is adapted to support the stem by the outer peripheral side of the O-ring 8, but when the length of the stem is shortened, from the annular flange 3 to the mounting portion of the O-ring 8. The distance becomes shorter. For this reason, for example, if the gap between the stem 2 and the stem insertion hole 5 is large, the stem 2 may be wobbled due to a large axial deflection with the O-ring 8 as a fulcrum.

  On the other hand, in the ball valve 11 of FIG. 14, since the gland packing 18 is formed of an elastic material such as resin, if excessive tightening is performed, compression permanent deformation or compression cracking may occur.

  The present invention has been developed as a result of diligent research in view of the above circumstances, and its purpose is to prevent internal damage and deformation, and to smoothly rotate with excellent operability while suppressing operating torque. An object of the present invention is to provide a ball valve that can be operated and has excellent durability that can exhibit high sealing performance and alignment function.

  In order to achieve the above object, the invention according to claim 1 is a ball valve in which a ball having a through hole is provided in the valve body so as to be freely rotatable via a stem having a flange partway. A cylindrical burring portion formed between the burring portion and the stem, and a cylindrical packing portion mounted between the burring portion and the stem. A gland packing is formed with a hook-shaped packing part that is bent at the upper end of the packing part and abuts against the seating surface, and this gland packing is pressed with a ground member to bring the hooked packing part into close contact with the seating surface, and a cylindrical shape. In this ball valve, the lower end of the packing part is brought into close contact with the flange part, and a slight gap is maintained between the lower end of the burring part and the upper surface of the flange part.

  The invention according to claim 2 is a ball valve in which the gland packing is pressed through the gland member by the tightening force of the nut screwed into the stem and the collar portion of the stem is pulled up.

  The invention according to claim 3 is a ball valve in which an annular protrusion is formed on the outer periphery of the ground member, and the lower end of the annular protrusion is brought into contact with the seat surface of the valve body to limit the tightening force of the nut.

  The invention according to claim 4 is a ball valve in which a cylindrical burring portion has an inclined surface whose diameter is reduced inward, and the cylindrical packing portion of the gland packing is fitted in a wedge shape on the inclined surface.

  In the invention according to claim 5, the valve body is a pipe material, and a burring portion is formed at a stem insertion position of the pipe material to form a burring portion, and an insert member is inserted on both sides of the pipe material to connect the pipe material and the insert member. It is a fixed ball valve.

According to the first aspect of the present invention, the stem collar portion is prevented from coming into contact with the lower end of the burring portion, thereby preventing contact between the valve main body and the stem. It is a ball valve that can be operated with low torque while preventing galling with the main body, suppressing increase in frictional resistance and surface pressure, and can be smoothly rotated with excellent operability while preventing damage and breakage of the stem. Furthermore, it is a highly durable ball valve which can be operated while suppressing the wobbling of the stem while maintaining high shaft seal performance and exhibiting an excellent alignment function.
In addition, since this gland packing can be assembled from the outside and is excellent in assemblability, this ball valve is also suitable for automation at the time of manufacture and excellent in mass productivity. In addition, since this ball valve does not apply excessive torsional stress to the stem, it can be downsized as a whole, reducing the defective rate, reducing the number of man-hours, and reducing the cost by reducing the amount of material, while ensuring safety and man-hours. Can be manufactured while greatly reducing.

  According to the second aspect of the present invention, the gland packing can be assembled while being pulled up easily and reliably by the tightening force of the nut, and the gutter-like packing portion of the gland packing is brought into close contact with the seat surface. By bringing the lower end into close contact with the flange portion, the gland packing and the stem can be securely mounted at predetermined positions to exhibit excellent sealing performance, and the ball valve is also excellent in assemblability.

  According to the invention which concerns on Claim 3, it is a ball valve which can restrict | limit the clamping force of a nut and can prevent a gland packing and a stem from being damaged. In this case, even if the nut is tightened with an excessive tightening force, the gland packing and stem can be reliably prevented from being damaged. It is a ball valve that can

  According to the invention according to claim 4, the wedge effect can be exhibited by fitting the inclined surface of the burring portion and the wedge-shaped cylindrical packing portion of the gland packing, the gland packing is tightly sealed to the stem, and the gland packing, the stem, and the gland It is a ball valve capable of exhibiting an excellent shaft seal function by increasing the tight sealability between the packing and the insertion hole.

According to the invention of claim 5, the valve body can be formed by press working, thereby preventing an increase in casting defects and weight such as nest cracking and poor water flow, which are problems in manufacturing by casting, and easy to manufacture and easy to assemble. It is possible to produce ball valves that can greatly reduce man-hours and costs. In addition, the burring part can be easily formed, and it is not necessary to perform subsequent processing, so the number of man-hours can be reduced, and a ball valve suitable for mass production by incorporating a gland packing into the burring part from the outside. It is.
In addition, this burring part prevents the torsional stress and excessive tensile / compressive stress from being applied to the gland packing when the stem is installed, and prevents the gland packing from being damaged and allows the ball valve to be assembled while maintaining a reliable seal. .

  Hereinafter, preferred embodiments and operations of the ball valve according to the present invention will be described in detail with reference to the drawings. 1 to 6 show a first embodiment of the ball valve of the present invention. This ball valve has a general ball valve structure, and rotates a valve body (ball) 35 by the rotational torque of a stem 30.

  In the figure, the ball valve main body 20 is formed in a substantially cylindrical shape by a tube material 21. The tube material 21 is formed by a thin (non-thick) type seamless pipe made of stainless steel or copper alloy, or the steel plate is formed into a roll shape and then joined into a tubular shape by means such as welding. Form with some type of seam. The valve body 20 deburrs both ends after the tube material 21 is cut into a predetermined length, that is, a length constituting the valve body 20.

  At the stem insertion position of the valve body 20 (pipe material 21), a flat seat surface 22 is formed on the outer peripheral side by drawing or tapping, and the position is bent inward so that the flange portion 31 of the stem is formed. A cylindrical burring portion 23 is formed by burring toward the side, and an insertion hole 24 is provided on the inner peripheral side of the burring portion 23. The burring portion 23 is formed at a substantially right angle with respect to the valve main body 20, whereby the burring portion 23 is substantially cylindrical. In addition, the burring portion 23 is highly accurate because it is not indirectly fixed such as welding, and improves the perpendicularity and concentricity of the shaft seal portion and the axial direction.

  In the circumferential direction of the valve body 20, a pair of cuts 26 a having appropriate lengths are formed to form a cut and bent portion 26, and the cut and bent portion 26 is deformed independently with respect to the axial direction of the tube material 21. It is possible. In the present embodiment, the cut and bent portions 26 are formed radially at equal intervals at four locations on the circumference of the tube material 21, but the number of cut and bent portions 26 can be arbitrarily changed. In that case, it is desirable to form at least two locations, and positioning can be performed reliably in the circumferential direction. Since the cut and bent portion 26 can be formed by plastic working, the accuracy at the time of incorporation is improved, and mechanical cutting can be reduced at the time of formation.

  The stem 30 is provided with a flange 31 in the middle of the vicinity of the lower portion, and the flange 31 is provided with a diameter larger than that of the insertion hole 24, so that the stem 30 is fluid pressure after the stem 30 is mounted. This prevents the valve body 20 from jumping out. Further, a non-circular protruding portion 32 is formed at the lower portion of the stem 30, and the protruding portion 32 can be joined to the ball 35.

The ball 35 has a through hole 36, and a stem fitting surface 37 is formed at the mounting position of the stem 30 so as to be parallel to the flow path (axial direction) when the valve is fully opened or fully closed. . The ball 35 is provided so that the protruding portion 32 of the stem 30 is engaged with the stem fitting surface 37 and is rotatable within the valve body 20 via the stem 30.
The ball 35 is formed so as to maintain high dimensional accuracy such as sphericity and eccentricity, and is made of, for example, amorphous metal (metal glass, for example, Zr—Al—Ni—Cu) as a material. By processing by die casting, high dimensional accuracy and surface smoothness can be obtained without post-processing. As a result, the valve seat sealing performance can be ensured without excessively increasing the pressing force of the ball seat 54 against the ball 35, so that the rotational torque of the stem can be suppressed, and the weight of the entire ball valve can be reduced. It becomes possible to plan.

  The gland packing 40 has a shape in which, for example, a cylindrical packing portion 42 and a flange-like packing portion 41 are provided by bending the upper end of the packing portion 42 with a resin material such as PFA or PTFE. The gland packing 40 is inserted into the insertion hole 24, and after insertion, the cylindrical packing portion 42 is mounted between the burring portion 23 and the stem 30, and the collar-shaped packing portion 41 can abut against the seat surface 22. It is like that. As a result, the gland packing 40 can function as a bearing that aligns the stem 30 in a coaxial state. Further, at this time, the gland packing 40 can work the shaft sealing function because the cylindrical packing portion 42 is in close contact with the insertion hole 24. For this reason, the valve body 20 can turn the stem 30 in a state where the thrust load is reduced.

The ground member 45 is mounted above the gland packing 40 so that it can be tightened by the tightening force of the nut 34 screwed into the stem 39. When the nut 34 is tightened, the gland packing 40 is interposed via the gland member 45. And the collar 31 of the stem 30 is pulled up.
Further, when the gland packing 40 is pressed by the gland member 45, the flange-shaped packing portion 41 is in close contact with the seat surface 22, and the lower end 43 of the cylindrical packing portion 42 is in close contact with the upper surface 31 a of the flange portion 31. .

  Further, as shown in FIG. 2, the length L of the cylindrical packing portion 42 is set to have a relationship of L> M with respect to the length M of the burring portion. A slight gap is maintained between the lower end 23 a and the upper surface 31 a of the flange 31. The gap at this time is indicated by G in FIG. A washer 49 is mounted on the upper surface of the ground member 45. In addition, when excessive tightening of the nut is performed, the lower end 46a is brought into contact with the seat surface 22 to limit the tightening force of the nut.

  The disc spring 48 is mounted on the upper surface side of a handle 58 to be described later so that the pressure applied to the gland packing 40 when the ball valve is assembled can be corrected to an appropriate pressure. Accordingly, for example, even when the gland packing 40 contracts when the ball valve is used in a cold region, the surface pressure can be maintained at an appropriate level by the elastic force of the disc spring 48.

  The insert member 50 is formed in a substantially cylindrical shape, and the insert members 50 and 50 are inserted from both sides of the tube material 21 to fix the tube material 21 and the insert member 50 together. The insert member 50 is formed into a shape as shown in the figure by precision casting such as lost wax casting, and has a strength that does not deform even when a strong force is applied during insertion into the tube material 21.

  A concave locking groove 51 is provided on the outer periphery of the insert member 50, and a cut and bent portion 26 of the valve body 20 is formed in advance at a position corresponding to the locking groove 51. The valve body 20 and the insert member 50 are fixed by pressing the portion 26 in the centripetal direction of the valve body 20 and dropping the cut and bent portion 26 into the locking groove 51.

  A female thread 52 that is a pipe joint is formed on the outer end side of the insert member 50. Further, a mounting portion 53 is provided at the tip of the insert member 50, and a ball seat 54 is mounted on the mounting portion 53. The ball sheet 54 is formed of a material that can ensure a constant torque and sealability when the ball 35 rotates. For example, the ball sheet 54 is processed by ultra-high density resin molding and the ball sheet 54 is brought into contact with the ball 35. , Heat expansion and contraction due to changes in outside air temperature can be suppressed, high elasticity can be maintained, and uneven wear due to deformation and displacement during assembly due to variations in dimensional accuracy of each part can be prevented. .

  An outer peripheral groove 55 for attaching an O-ring is formed on the outer periphery on the tip side of the insert member 50, and an O-ring 56 made of resin or the like is attached to the outer peripheral groove 55. The O-ring 56 seals between the outer peripheral surface of the insert member 50 and the inner peripheral surface of the valve main body 29.

  A positioning protrusion 57 is formed on the outer peripheral surface of the outer end side of the insert member 50, and when the insert member 50 is inserted into the valve body 20, the positioning protrusion 57 becomes a pipe end of the valve body 20. An appropriate surface pressure is applied to the ball surface 38 of the ball 35 by the ball seat 54 fitted to the insert member 50 and engaged with 20a. For this reason, the positioning protrusion 57 needs to be formed at an accurate position with respect to the axial direction of the insert member 50.

The handle 58 has a fitting hole 58 a that can be fitted to the parallel two-surface portion 33 on the top of the stem 30, and the fitting hole 58 a is fitted to the parallel two-surface portion 33 so that it does not rotate with respect to the stem 30. It can be installed in the state.
As shown in FIGS. 4 to 6, the handle 58 is formed with two protruding pieces 59, 59 by cutting and bending, and this protruding piece 59 is a shaft (not shown) of the fitting hole 58a. They are formed at an interval of approximately 90 ° with respect to the heart. Moreover, the protruding piece 59 is formed at a position corresponding to the cut and bent portion 26 of the valve body 20 when the handle 58 is mounted on the stem 30 and the handle 58 is rotated, and the handle 58 is closed or opened. When one of the projecting pieces 59 is locked to the locking surface 26b of the cut and bent portion 26 when operated to the state, the rotation of the handle 58 can be restricted to approximately 90 °.

  As a result, the locking surface 26b of the cut and bent portion 26 can be used as a rotation restricting portion for purposes other than the insert member 50 and the stopper of the valve body 20, and the ball can be formed without forming the rotation restricting portion on the valve body 20 side. 35 can be accurately regulated for rotation. For this reason, rationalization of the function can be achieved using the cutting and bending portion 26 and the locking groove 51 as a stopper and a rotation restricting portion while reducing the number of processing steps.

  Further, when the protruding piece 59 of the handle 58 is formed by a precise cutting and bending technique in order to match the position of the cutting and bending portion 26, this excellent dimensional accuracy improves the bending rigidity and provides the width dimension accurately. It is done. Further, as shown in FIGS. 4 and 5, the protruding piece 58 is set so as to be locked to the locking surface 26 b of the cut and bent portion 26 provided on the upper portion of the valve body 20. Since the length of 58 can be shortened, it is possible to prevent twisting due to insufficient rigidity at the time of punching, and to prevent breakage such as cracks from the root portion, thereby improving dimensional accuracy and ensuring rigidity. For this reason, the defect rate at the time of forming the handle 58 can be reduced, and the yield can be improved.

In addition, when the handle 58 is rotated, the contact surface 59a with which the protruding piece 59 comes into contact with the locking surface 26b is a surface positioned in a direction perpendicular to the bending direction of the protruding piece 59, so that the rigidity is increased. Can do. For this reason, even if the handle 58 is rotated with high torque by an excessive operation load and the protruding piece 59 comes into contact with the locking surface 26b with a strong force, the protruding piece 59 does not bend. The bending shape is maintained, and the rotation restriction angle can be accurately maintained. Further, by bringing the protruding piece 59 into contact with the cut and bent portion 26, the length of the protruding piece can be made shorter than when contacting the body side surface of the valve main body.
The ball valve in this embodiment is manually rotated by the handle 58, but may be automatically rotated by an actuator (not shown) or the like.

Next, the procedure and operation when assembling the ball valve of the present invention will be described.
When assembling the ball valve, first, after inserting one insert member 50 from the pipe end 20a on one side of the valve body 20, the stem 30 is inserted from below the insertion hole 24. The part 32 is fitted to the stem fitting surface 37 of the ball 35 so that the ball 35 is non-rotatably joined to the stem 30.
In this state, the gland packing 40 is mounted from above the stem 30, and the cylindrical packing portion 42 is inserted into the insertion hole 24 until the lower surface 41 b of the flange portion 41 is in close contact with the seat surface 22. At this time, the lower end 43 of the cylindrical packing portion is in contact with the flange portion 31 of the stem, and the flange portion 31 is separated from the lower end 23a of the burring portion 23 and is separated from the flange portion 31. The valve body 20 is in a non-contact state.

  Next, the other insert member 50 is inserted from the tube end 20 a on the other side of the valve body 20. After both the insert members 50, 50 are inserted, the positioning protrusion 57 is engaged with the pipe end 20a of the valve body 20, so that the insert members 50, 50 are disposed at the correct position of the valve body 20. Thus, the seal surface pressure applied to the ball surface 38 by the ball sheet 54 can be ensured in an appropriate state. In this state, the cut and bent portion 26 of the valve body 20 is pressed in the centripetal direction, and the cut and bent portion 26 is dropped into the locking groove 51 of the insert members 50 and 50, and the valve body 20 and the insert members 50 and 50 are moved. Fix it.

  In this case, it is preferable that the cutting and bending portion 26 simultaneously performs the formation of the cut and the bending process by a single pressing process after inserting the insert member 50 into the valve body 20. You may make it bend by pressing the notch 26a provided beforehand. In any of the processing methods, the cut and bent portion 26 can be reliably dropped into the locking groove 51 in a state where the positioning protrusion 57 and the pipe end 20a are securely positioned.

  Further, the cut and bent portion 26 is preferably formed by a processing method applying fine blanking (precision punching), for example, and in this case, a thick metal can be formed without burrs only by punching, Moreover, it can be formed with higher accuracy than a general press die.

  Next, the gland member 45 is mounted from above the gland packing 40. When the ground member 45 is mounted, it is mounted in a state where the inner peripheral surface side of the annular protrusion 46 is fitted to the flange 41. Further, a washer 49 is attached to the stem 30 from above.

  Subsequently, similarly to the gland packing 40 and the gland member 45, the handle 58 is attached so that the fitting hole 58 a is fitted to the parallel two-surface part 33 from above the washer 49. Next, the disc spring 48 is mounted on the handle 58, and the nut 34 is tightened while the female screw portion 34 a is screwed onto the male screw portion 30 a formed on the stem 30. By tightening the nut 34, the stem 30 tends to be pulled up to the upper portion (centrifugal direction) of the valve body 20. However, because of this tightening force, surface pressure is applied to the upper surface 45a of the ground member 45. The member 45 is compressed downward with respect to the stem 30, whereby the flange portion 41 is pressed against the seat surface 22, and the inner and outer peripheral sides of the cylindrical packing portion 42 are tightly sealed to the stem outer peripheral surface 30 b and the insertion hole 24. To do.

  At this time, the gland packing 40 moves to the tip side of the burring portion 23 and the lower end 43 of the cylindrical packing portion abuts on the upper surface 31a of the heel portion, thereby separating the heel portion 31 and the lower end 23a of the burring portion. The ball valve is assembled together with the state secured. This state is also maintained when the stem 58 is rotated by operating the handle 58.

  In the ball valve of the present invention, a seating surface 22 is formed at a stem insertion position of the valve body 20, and the cylindrical burring portion 23 is bent toward the flange 31 side of the stem 30 by bending the position inward. A gland packing 40 is formed by a cylindrical packing portion 42 formed and attached between the burring portion 23 and the stem 30 and a flange-shaped packing portion 41 which is bent at the upper end of the packing portion 42 and abuts against the seat surface 22. The gland packing 40 is pressed by the gland member 45 to bring the flange-shaped packing portion 41 into intimate contact with the seat surface 22 and the lower end 43 of the cylindrical packing portion 42 is in intimate contact with the flange portion 31. The lower end 23a and the flange portion 31 of the stem do not contact each other, and the frictional resistance and galling phenomenon can be suppressed to prevent an increase in operating torque.

Since this cylindrical packing part 42 can ensure a large volume along the outer periphery of the stem as compared with the thin annular bearing 7 as shown in the prior art (see FIG. 13), it is difficult to wear. Accordingly, the lower end of the packing can be continuously brought into close contact with the flange portion of the stem, and the gap G can be maintained.
Moreover, since the clamping force of the gland packing 40 by the nut 34 is limited by the gland member 45, it is possible to prevent an excessive surface pressure from being applied to the flange portion 31, and the nut 34 is temporarily tightened with an excessive clamping force. Even if tightened, breakage of the collar 31 can be prevented.

  Further, the gland packing 40 can bearing the stem 30 when the stem 30 rotates, and this bearing function suppresses an increase in torque at the time of operation, and even if an external force such as external stress or vibration at the time of pipe joining is applied. It is possible to prevent the shaft 30 from swinging and maintain the shaft seal function. Further, since the concentric state of the stem 30 and the insertion hole 24 can be maintained, it is possible to prevent the sealing performance from being damaged due to uneven wear or the like. Further, since the gland packing 40 can be brought into close contact with each other at a long distance in the axial direction, the stem 30 can be prevented from falling and the ball 35 can be prevented from being eccentric. With these shaft sealing functions, the ball valve of the present invention can exhibit excellent sealing performance by preventing fluid from leaking between the valve body 20 and the stem 30.

  Further, the gland member 45 extends around the outer periphery of the gland member 45 and surrounds the flange part 41 of the gland packing 40 from the outer peripheral side by an annular protrusion 46 bent toward the valve body 20 side. Even if the packing surface pressure is increased by the tightening force of the nut 34, the outer peripheral surface 41c of the flange portion 41 abuts against the inner peripheral surface 46b of the annular protrusion 46 to prevent the diameter from expanding. It can suppress that the shape packing part 41 protrudes outside. Further, as described above, the gland member 45 can be pressed from the upper side while surrounding the flange portion 41 by the annular protrusion 46, and therefore, due to this synergistic effect, the gland packing is effectively pressed to the lower side with a strong force. Can be pressed. Thereby, the seal surface pressure by the gland packing 40 is maintained, the seal surface pressure of the lower end 43 abutting against the flange portion 31 of the stem is maintained, and the contact between the lower end 23a of the burring portion 23 and the flange portion 31 is surely prevented. Yes.

  At the time of shaft seal, the inner bottom surface 45c of the ground member 45, the flange upper surface 41a of the gland packing 40, the inner peripheral surface 46b of the annular protrusion 46, the outer peripheral surface 41c of the flange 41, the lower surface 41b of the flange 41, and the valve body 20 The seat surface 22, the cylindrical portion outer peripheral surface 42a and the insertion hole 24, the cylindrical portion distal end surface 43 and the flange upper surface 31a, the cylindrical portion inner peripheral surface 42b and the stem outer peripheral surface 30b are in close contact with each other. Thus, fluid leakage can be prevented in a state where the seal surface pressure between the seal surfaces is made uniform.

  Further, the wear of the cylindrical inner peripheral surface 42 b and the stem outer peripheral surface 30 b can be allowed by allowing the ground member 45 to move by the gap between the valve body 20 and the load by the disc spring 48. In addition, the disc spring 48 prevents the gland packing 40 from being applied with a force exceeding the allowable surface pressure, so that the gland packing 40 is permanently deformed and protrudes to the outside, or is compressed and cracked or broken to provide a sealing function. It can be prevented from being damaged.

  As described above, since the gland packing 40 exerts a sealing force by the external elastic force of the disc spring 48, it is possible to prevent the sealing performance from being adversely affected by foreign matters in the fluid. Further, since the self-elastic force of the gland packing 40 is not required at the time of assembly, there is a processing roughness or a gap on the contact surface of the stem 30 or the valve body 20, and even if these are assembled in a state of being offset, Can prevent uneven wear and tears, and can maintain high sealing performance over a long period of time.

  In addition, when the gland packing 40 is assembled, the gland packing 40 can be simply installed and prevented from being damaged by only inserting the gland packing 40 into the burring portion 23 while preventing a load such as torsion, tension, and compression stress from being applied. In addition, since the gland packing 40 can be molded with a resin material such as PFA at an ultra-high density, it is difficult to expand and contract against the heat of the fluid and the internal pressure even after retightening by the nut 34, so that compression permanent deformation and compression cracking are prevented. It becomes possible to prevent.

  Subsequently, FIG. 7 shows a second embodiment of the ball valve according to the present invention, in which a main part is disassembled. In the following embodiments, the same parts as those in the above embodiments are denoted by the same reference numerals, and the description thereof is omitted. In this ball valve, a cylindrical burring portion 61 of the valve body 60 is formed into an inclined surface with a diameter gradually reduced inward, and the cylindrical packing portion 42 of the gland packing 40 is fitted into the inclined surface 61 in a wedge shape. It is combined. As a result, a wedge effect can be exerted between the burring portion 61 and the cylindrical packing portion 42, and by this wedge effect, the gland packing 40 is compressed downward with respect to the stem 30, and the burring portion 61 is slightly inclined. Combined with the spring effect by the surface, the sealing performance between the cylindrical packing portion 42 and the burring portion 61 of the gland packing 40 and the cylindrical packing portion 42 and the stem 30 can be improved, and the stem 30 is more effective. Can be automatically aligned.

  8 to 10 show a third embodiment of the ball valve of the present invention. In this ball valve, the handle 65 is formed in the shape shown in the figure, a fitting hole 66 into which the stem 30 can be fitted is provided inside the handle 65, and a part of the fitting hole 66 is provided in the inner circumferential direction. Protruding protrusions 67 are provided, and the protrusions 67 are provided so as to be able to be engaged with the recessed parts 30c provided on the stem 30, so that the handle 65 can be easily attached and detached with one touch.

  The locking ring 68 is provided with a hole-like insertion portion 68a provided on the inner diameter side by a slit 69a so that the diameter can be increased, and the taper protrusion 69 can be formed on the inner diameter side by the diameter increase of the insertion portion 68a. ing. The locking ring 68 is attached to the stem 30 as an alternative to the nut 34. At the time of attachment, the inner lower surface is brought into contact with the flange upper surface 41a of the gland packing 40, and the edge portion of the insertion portion 68a is located above the stem 30. It is made to engage with the enlarged diameter step portion 30d.

In this ball valve, after the locking ring 68 is mounted, the locking ring 68 repels between the flange upper surface 41a of the gland packing 40 and the enlarged diameter step portion 30d of the stem 30, and the force lifts the stem 30 upward ( It is possible to obtain a pulling force in the centrifugal direction. Therefore, it is possible to maintain a state in which the flange-shaped packing portion 41 is in contact with the seat surface 22, the lower end 43 of the cylindrical packing portion 42 is in close contact with the flange portion 31, and the lower end 23a of the burring portion 23 and the flange portion 31 are separated. It can exhibit an excellent shaft seal function.
Further, since the engagement ring 68 is maintained in the fitted state to the stem 30 even when the handle 65 is removed from the ball valve, the shaft seal function can be maintained.

  Although not shown, when burring is performed on the insertion hole 24, a part of the burring portion 23 is protruded in the centrifugal direction to form a stopper piece, while the flange portion 31 of the stem 30 is engaged with the stopper piece. A stopper mechanism may be provided by forming a notch groove that can stop and restrict its rotation, and the ball may be restricted at an angle of approximately 90 ° by this stopper mechanism.

11 and 12 show a fourth embodiment of the ball valve of the present invention. In this ball valve, a handle 70 having a shape different from that of the ball valve of the first embodiment is mounted, and the handle 70 can be operated.
The handle 70 has a shape having two operation portions 71 and 71 centering on a fitting hole portion 70a to the stem 30, and the stem 30 is rotatably provided by operating each operation portion 71. . Thereby, even when this ball valve is installed in a narrow place, it can be easily operated by operating any one of the operation portions 71, and this ball valve can be installed in any place.
Further, the handle 70 has a projecting piece 72 corresponding to the position of the cut and bent portion 26 of the valve body 20 as in the case of the first embodiment, and when the handle 70 is operated to the closed or open state. Since the protruding piece 70 is locked to the locking surface 26b of the cutting and bending portion 26, the rotation of the handle 70 can be restricted to about 90 °.

It is sectional drawing which showed 1st Embodiment of the ball valve of this invention. It is a principal part enlarged view of FIG. It is a top view of the ball valve of FIG. It is a perspective view which shows an example of the stopper structure of a handle. It is a perspective view which shows the closed state of the handle | steering-wheel of FIG. It is the perspective view which showed the handle | steering-wheel. It is principal part sectional drawing which showed 2nd Embodiment of the ball valve of this invention. It is sectional drawing which showed 3rd Embodiment of the ball valve of this invention. It is a top view of FIG. It is a top view which shows a locking ring. It is the fragmentary sectional view which showed 4th Embodiment of the ball valve of this invention. It is a top view of the ball valve of FIG. It is principal part sectional drawing of the conventional ball valve. It is principal part sectional drawing of the other conventional ball valve.

Explanation of symbols

20 Valve body 21 Tubing material 22 Seat surface 23 Burring portion 23a Lower end 30 Stem 31 Gutter 31a Upper surface 34 Nut 35 Ball (valve element)
36 Through-hole 40 Gland packing 41 Gutter-shaped packing part 42 Cylindrical packing part 43 Lower end 45 Ground member 46 Annular protrusion 46a Lower end 50 Insert member G Gap

Claims (5)

  In a ball valve in which a ball having a through hole in the valve body is rotatably provided through a stem having a flange partway, a seating surface is formed at the stem insertion position of the valve body, and the position is inward A cylindrical burring portion is formed toward the flange side of the stem, and the seating surface is formed by bending the cylindrical packing portion mounted between the burring portion and the stem and the upper end of the packing portion. The gland packing is composed of the gutter-shaped packing part abutting on the gland, and the gland packing is pressed by the gland member so that the gutter-shaped packing part is brought into close contact with the seat surface, and the lower end of the cylindrical packing part is brought into close contact with the gutter part. And a slight gap is maintained between the lower end of the burring portion and the upper surface of the flange portion.   2. The ball valve according to claim 1, wherein the gland packing is pressed through the gland member by a tightening force of a nut screwed into the stem, and the flange portion of the stem is pulled up.   The ball valve according to claim 1 or 2, wherein an annular protrusion is formed on an outer periphery of the ground member, and a lower end of the annular protrusion is brought into contact with a seating surface of the valve body to limit a tightening force of the nut. .   The cylindrical burring portion is formed into an inclined surface having a diameter reduced inward, and the cylindrical packing portion of the gland packing is fitted into the inclined surface in a wedge shape. Ball valve.   The valve body is a pipe material, burring processing is performed at a stem insertion position of the pipe material to form a burring portion, and insert members are inserted on both sides of the pipe material to fix the pipe material and the insert member. The ball valve according to any one of the above.

Images