JP4549794B2 - Ball valve - Google Patents

Description

  The present invention relates to a ball valve installed in the middle of piping for cold water, hot water, steam, oil, gas, etc., and in particular, has a one-piece structure formed of a single body part and has a flange-joint type body. It relates to a ball valve.

  Conventionally, this type of one-piece ball valve has a gasket for preventing the fluid flowing inside the valve from leaking to the outside as compared with the two-piece or three-piece ball valve divided into a plurality of body parts. There is no need to provide a seal. Therefore, the one-piece structure ball valve is suitable for a valve as a pressure vessel and is not easily affected by piping stress. Normally, a ball valve has a ball (spherical valve body) having a through-hole inside the body and is rotatably supported by a pair of ball seats. In this case, the ball seat on one side is inserted with various inserts. Screwed and fixed, and parts such as a spherical valve body and ball seat are incorporated into the body.

Since the insert is inserted into the body via a jig, the insert end surface is provided with two surface portions for engaging the jig, and the insert attaching / detaching jig is engaged with the two surface portions for rotation. However, in addition to the fact that the jig to be engaged with the two surfaces is a special jig, it requires labor and cost to manufacture the jig itself. When mounting the insert having the two surface portions, if the tightening torque is large, the sagging of the two surface portions or the jig may be damaged. Therefore, at present, as shown in Utility Model Registration No. 2598674 (see Patent Document 1), a hexagonal engagement section is provided on the inner surface of the opening end of the insert, and a hexagon bolt, nut, or the like is provided. An insert structure that enables attachment / detachment with a used jig is known.
Utility Model Registration No. 2598667 (Fig. 1)

  However, as shown in Patent Document 1, when an engaging portion having a hexagonal cross section is provided on the inner surface of the opening end of the insert, the engaging portion is easily formed by processing. When the inner shape (hexagonal diagonal dimension) is small, the engaging portion protrudes into the flow path. On the other hand, if the inner shape of the engaging part is formed larger than the inner diameter of the pipe, the engaging part comes close to the threaded part formed on the outer peripheral surface of the insert and the wall thickness is reduced, leading to insufficient strength of the threaded part. End up. In order to solve this problem, it is conceivable to increase the outer diameter of the insert. However, since the dimensions of the body flange adjacent to the open end of the insert, especially the position and dimensions of the pipe connection bolt hole, are specified, The gasket that seals between the flange of the pipe and the flange of the pipe has to have a large inner diameter while maintaining the outer diameter, and the area of the gasket is reduced. Therefore, a seal member such as an O-ring must be separately provided between the body and the insert so as to prevent fluid leakage from the connection portion between the valve and the pipe.

  When molding inserts used in reduced bore type ball valves, in which the diameter of the through hole (port diameter) of the spherical valve element is smaller than the nominal diameter of the valve (pipe port diameter), from the engaging part to the ball seat holding part The flow path is inclined from the inscribed circle of the engaging portion having a hexagonal cross section toward the inner diameter of the ball seat, and the flow path diameter is narrow due to the small inscribed circle, and the inclination angle is shallow. Therefore, when casting the insert using only the main mold (without using the core), it becomes difficult to remove the cast main mold from the flow path, resulting in casting sand chipping, or breaking the thin cast main mold. Had the problem of doing.

  The present invention has been developed as a result of earnest research in view of the above-described problems, and the object of the present invention is to provide a ball valve with few protrusions to the flow path without increasing the outer diameter of the insert. In addition, an object of the present invention is to provide a ball valve having an insert in which an engaging portion of a detachable jig can be cast.

In order to achieve the above-mentioned object, the invention according to claim 1 is a ball valve in which a spherical valve body having a through hole in a body is supported by a pair of ball seats so as to be freely rotatable. The cylindrical insert that holds the ball seat at the tip is formed with a channel hole with a tapered cross section that increases in diameter from the tip that is substantially the same as the diameter of the through hole of the valve body toward the opening end. this on the inner peripheral surface in the vicinity of the tip of the flow path hole, an engagement portion which exhibited hexagonal shape composed of the engaging inner peripheral surface that does not protrude from the tapered surface of the passage hole in the centripetal direction, the The engaging portion is formed horizontally toward the opening end portion with the tip portion as a base point, and a step between the inner peripheral surface of the tip portion of the insert and the inner surface on the tip end side of the engaging portion is used as a tapered surface portion. thereby locking the insert-jig and adapted to be subjected to detachment of the insert Is Rubarubu.

According to the present invention , the engagement inner peripheral surface constituting the engagement portion is a surface that does not protrude in the centripetal direction from the tapered surface of the flow path hole, so that the outer diameter of the insert is not increased, A ball valve with few protrusions can be obtained. Since the open end of the insert can be formed without any restrictions due to the shape of the engaging part, the insert used for the reduced bore type ball valve is cast using only the main mold (without using the core). The angle of the taper surface of the passage hole can be deeply set to an appropriate angle as the casting gradient, and the casting main mold can be easily removed from the flow path. As a result, it is possible to obtain a ball valve that can be formed with a cast surface without separately processing the engaging portion, and the insert can be easily molded.

In addition to Te over path surface portion functions as cast punching gradient in manufacturing by casting inserts, suppression of pressure loss, it is possible to suppress the occurrence of burrs during internal machining, furthermore, the insert detachable tool It became possible to prevent over-insertion.

  Below, one embodiment of a ball valve in the present invention is described based on a drawing. FIG. 1 is a front view showing an example (50A in this example) of a ball valve according to the present invention, and FIG. 2 is a side view of the ball valve shown in FIG. 3 is a cross-sectional view taken along line AA in FIG. In the figure, 1 is a ball valve of the present invention, and 2 in the figure is a cast iron body having a one-piece structure formed by casting, for example, and flanges that can be connected to piping on both sides of the body 2 And a long neck 4 provided with a stem insertion hole 4a on the upper surface of the body 2 near the inflow side opening in this example. A stem 5 is rotatably attached to the long neck 4. As shown in FIG. 3, a grease space 6 is provided on the outer peripheral surface of the stem 5, and the grease can be enclosed in the space so that the effect can be maintained for a long time. In the figure, reference numeral 7 denotes an O-ring that seals between the stem 5 and the stem insertion hole 4a.

  On one side of the body 2, in this example, on the inner peripheral surface of the flow path on the outflow side, a protrusion 2a is integrally provided, and a seat surface 2g of the body 2 formed on the stepped surface of the protrusion 2a A spherical valve body 11 having a V-shaped outflow hole 10a on the outflow side of the cylindrical through hole 10 is mounted on the ball seat 9 and one of the ball sheets 9 (outflow side in this example) described later is mounted. The stem 5 and the spherical valve body 11 are joined to each other by inserting the lower end portion 5a of the stem 5 into the fitting groove 11a of the spherical valve body 11 while inserting the stem 5 to the contact position. In addition, in this example, it is set as the structure which has arrange | positioned internal components, such as the stem 5 and the spherical valve body 11, near the inflow side opening part, However, The structure which has arrange | positioned these internal components near the outflow side opening part according to implementation. It is also possible. Further, the ball valve in the present invention is a reduced bore type, and the inner diameter (port diameter) of the through hole 10 of the spherical valve body is formed smaller than the nominal diameter (pipe diameter) of the valve.

  In the figure, reference numeral 12 denotes a cylindrical insert having an annular seat surface portion 12a at the tip, and in this example, a cast iron insert 12 formed by casting is employed. A ball seat 8 on the other side (inflow side in this example), which will be described later, is mounted on the seat surface portion 12a of the insert 12, and a male screw portion 12b formed on the outer peripheral surface of the insert 12 is formed on the inner peripheral surface of the opening on the inflow side of the body 2. The insert 12 is inserted into the body 2 by being screwed into the female thread portion 2b. Further, a positioning step portion 12c is formed on the outer peripheral surface, and when the insert 12 is inserted, the positioning step portion 12c comes into contact with a step portion surface 2c formed on the inner peripheral surface of the body 2 of the opening. Therefore, an appropriate insertion position can be easily secured, and the spherical valve body 11 is properly supported by both the inflow side and outflow side ball seats 8 and 9.

  Here, the ball sheet employed in this example will be described. As shown in FIG. 3, the inflow side and outflow side ball sheets 8 and 9 have different shapes. Of the ball sheets 8 and 9, the lip portion 8a provided on the inner diameter side of the inflow side ball sheet 8 is supported by the seat surface portion 12a at the tip of the insert 12, so that the body 2, the ball sheet 8, 9. Even when the processing dimensions of the spherical valve body 11 or the insert 12 vary, the lip portion 8a absorbs this and functions to stabilize the operation torque. On the other hand, in this example, the ball sheet 9 on the outflow side does not have a lip portion, and the elastic deformation amount of the ball sheet 9 on the outflow side is set to be smaller than the elastic deformation amount of the ball sheet 8 on the inflow side. Thus, the ball sheet 9 on the outflow side functions to reduce the creep deformation of the ball sheet when a load is applied for a long time in the fully closed state.

  As shown in FIG. 3, the cylindrical insert 12 has a tapered cross-section that expands from the tip end portion 12 d that is substantially the same diameter as the through hole 10 of the spherical valve body 11 toward the opening end portion 12 e. A channel hole 13 is provided, and an engagement portion 12f having a polygonal shape is provided on the inner surface near the tip of the channel hole 13, and an insert attaching / detaching jig is engaged with the engagement portion 12f. The insert can be attached and detached. The engagement inner peripheral surface 12h that constitutes the engagement portion 12f is a surface that does not protrude in the centripetal direction from the tapered surface of the flow path hole 13, so that the pressure loss is small and a predetermined flow rate characteristic is realized. .

  4 is a perspective view showing an example of the insert in the present invention, FIG. 5 is a side view when the insert shown in FIG. 4 is viewed from the open end side, and FIG. It is B line sectional drawing. As shown in FIG. 5, the engaging portion 12 f has a hexagonal shape in this example when viewed from the opening end side. As described above, the engaging portion 12 f protrudes inward from the inner diameter of the flow path hole 13. The structure that does not. In addition, since the engaging portion 12f is formed horizontally with respect to the tip end portion 12d with respect to the flow path hole 13 having a tapered cross section, it is possible to secure a large amount of a hooking portion with the insert attaching / detaching jig. It is possible to easily and reliably attach and detach, and a special tool is not required, and a jig made of existing hexagon bolts and nuts can be used as an insert detaching jig.

  Further, since the engaging portion 12f is formed on the tip end side (ball seat mounting side) of the insert, the opening end portion can be formed without restriction due to the shape of the engaging portion. Therefore, it is possible to ensure a large inner diameter of the opening end without changing the outer diameter of the insert, thereby making it possible to set the angle of the taper surface of the flow path hole deeply to an appropriate angle as the casting gradient, and reducing the reduced bore When the insert used for the ball valve of the mold is cast using only the main mold (without using the core), the cast main mold for forming the flow path hole is thick and can be easily removed from the flow path. Thereby, it can form with a casting surface without processing an engaging part separately, and shaping | molding of an insert becomes easy. In the present embodiment, the inner diameter of the opening end is substantially the same as the inner diameter of the pipe.

  Further, a step between the inner peripheral surface of the distal end portion 12d of the insert 12 and the inner surface of the engaging portion 12f having a hexagonal shape is a tapered surface portion 12g, thereby suppressing pressure loss, and the insert 12 , It can function as a casting gradient when manufacturing by casting, can suppress the generation of burrs during inner diameter processing, and further functions to prevent over-insertion of the insert attaching / detaching jig.

  When the insert 12 is mounted on the body 2, an insert attaching / detaching jig inserted from the opening end side is engaged with the engaging portion 12f provided in the flow path hole 13, and the jig is rotated by a predetermined amount. Thus, the insert 12 can be smoothly mounted. The insert 12 abuts on a stepped surface 2c formed on the inner peripheral surface of the opening of the body 2 by the positioning stepped portion 12c, and is fixed by proper mounting. The opening end surface 12i of the insert 12 properly mounted in the body 2 is located slightly on the spherical valve body 11 side with respect to the opening end surface 2h of the body 2. Thereby, the gasket 14 mounted between the ball valve 1 of the present invention and the pipe 15 is sandwiched between the flange portion 3 (opening end portion 2 h) of the body 2 and the flange portion of the pipe 15, and the gap between both flanges is sandwiched. It has a pipe connection structure that seals liquid tightly. Therefore, even if fluid enters between the body 2 and the insert 12, there is no need to interpose a seal member such as an O-ring between both parts, and fluid leakage from the connection between the ball valve 1 and the pipe 15 is prevented. Can be prevented.

  Further, the gasket 14 is not sandwiched between the opening end face 12i of the insert 12 and the flange portion of the pipe 15, and fluid can enter between the two parts. As a result, the space X between the body 2 and the insert 12 and the space Y between the insert 12 and the pipe 15 communicate with each other and have the same pressure, so that the fluid can be prevented from flowing into this space. it can.

  Moreover, the ball valve of the present invention shown as an example is a flange joint type in which flange parts 3 and 3 having bolt insertion holes 3a and 3a are provided on both sides of the body 2, and a body part and a flange part 3 for pipe joining, Are connected by a rib 2d. The body 2 in this example has a one-piece structure composed of a single body portion, and the thickness of the body portion is set to be equal to or greater than the thickness of the pipe to be connected. In addition, as shown in FIG. 1, a plurality of ribs 2d are provided in the radial direction on the minimum outer diameter portion 2e of the trunk portion, and in this example, four ribs are projected in the cross direction to further increase the rigidity of the trunk portion, and casting. Consideration is also given to the ease with which the body 2 is molded. The outer diameter of the rib 2d is approximately the same as the maximum outer diameter portion 2f of the body portion.

  Further, the long neck 4 and the inflow side flange portion 3 adjacent to the long neck 4 are connected by a rib 2i, thereby improving the castability of the long neck 4 and reinforcing it, and at the time of casting finishing, the upper surface of the rib 2i. The deburring between the long neck 4 and the inflow side flange portion 3 can be performed only by grinding and finishing.

  FIG. 7 is an explanatory view showing a state where the ball valve according to the present invention is subjected to a surface treatment. In the ball valve of the present invention, dacrotized surface treatment is applied to the entire surface of the body 2 having a one-piece structure composed of a single body and the insert member 12 to be inserted into the body 2. The dacrotized surface treatment refers to a treatment with a dacrotized treatment liquid (manufactured by Nippon Dacro Shamrock). Specific examples include a treatment with a dispersion solution of metallic zinc flakes, chromic anhydride, glycol, etc. After dipping the body 2 or the insert 12 which is a liquid member, the remaining drops are removed by centrifugation and heated to about 300 ° C. in a baking furnace, whereby hexavalent chromium is reduced by an organic substance such as glycol and is insoluble in water. Amorphous nCr03 · mCr203 is produced, which acts as a binder and bonds the laminated zinc flakes together to form a coating. At the same time, chromic anhydride in the treatment liquid oxidizes and chemically bonds the surface of the metal substrate to produce a strong adhesion.

  The anti-corrosion mechanism of the dacrotized coating consists of controlled self-sacrificial protection of zinc particles, passivation of the ground by chromic acid and zinc flakes, and the barrier action of chromium compounds, realizing excellent corrosion resistance Will do. Therefore, in this example, first, the pretreated body 2 and the insert 12 are put in a mesh container and subjected to dip coating, and as shown in FIG. A surface treatment is applied to the wetted member that is prone to the occurrence of corrosion to ensure excellent corrosion resistance.

  In particular, when extra drops of the dacrotizing liquid remain and solidify on the seat surface portion 12a of the insert 12 to which the ball sheets 8 and 9 are mounted and the seat surface portion 2g of the body 2, the ball seat and each seat surface portion become convex portions. There is a risk that the adhesiveness (sealability) to the glass will be impaired. Therefore, for example, in the case of the body 2, as shown in FIG. 7, the seat surface portion 2 g of the body 2 is arranged in the container so as to be inclined by 45 degrees with respect to the rotation radius, and this is centrifuged, The extra droplets of the dacrotizing treatment liquid remaining on the seat surface portion 2g are shaken off, surface treatment with an appropriate film thickness can be performed, and adhesion with the ball sheet can be ensured.

  In the ball valve 1 of the present invention, the long neck 4 is disposed as close to the inflow side opening as possible while avoiding interference with connection bolts and nuts with the pipe 15 attached to the flange 3 of the body 2. As a result, the seating surface portion 2g for mounting the ball seat 9 is disposed near the inflow side opening, and the machining can be performed easily and accurately, and the eccentricity is such that the assembly of the valve components is facilitated. The structure is adopted. On the other hand, some actuators (not shown) having a gear mechanism have an eccentric structure in which the output shaft is arranged at a position eccentric from the center in the longitudinal direction of the actuator. Accordingly, by mounting the ball valve 1 of the present invention and the actuator having the eccentric structure so that the eccentric directions thereof coincide with each other, a suitable arrangement balance between the valve and the actuator is realized. That is, the protrusion of the actuator with respect to the valve is minimized, and it is not necessary to secure a large piping space for the ball valve 1 of the present invention on which the actuator is mounted.

  The ball valve in the present invention can also be applied to piping including a fan coil unit, adjusting the supply amount balance of cold water or hot water as a heat medium to the heat exchanger (coil) of each fan coil unit. It can be installed in the pipe to be supplied, and its excellent function can be demonstrated over a long period of time. Furthermore, the present invention can be applied not only to a structure in which a stem is rotated by an actuator but also to a structure in which a stem is manually rotated, and can be provided as a ball valve that can be applied to piping in various fields including the air conditioning piping. It is.

It is the front view which showed an example (50A) of the ball valve which is this invention. It is a side view when the ball valve shown in FIG. 1 is seen from the primary side. It is the sectional view on the AA line in FIG. It is the perspective view which showed an example of the insert in this invention. It is a side view when the insert shown in FIG. 4 is seen from the opening end side. It is the BB sectional view taken on the line in FIG. It is explanatory drawing which showed the state which surface-treats to a body.

1 Ball valve 2 Body 5 Stem 8 Ball seat (inflow side ball seat)
9 Ball sheet (outflow side ball sheet)
DESCRIPTION OF SYMBOLS 10 Through-hole 11 Spherical valve body 12 Insert 12d Tip part 12e Open end part 12f Engagement part 12g Tapered surface part 12h Engagement inner peripheral surface 13 Channel hole

Claims (1)

A ball valve having a spherical valve body having a through-hole inside the body and rotatably supported by a pair of ball seats, the cylindrical insert holding at least one ball seat at the tip includes the valve A flow path hole having a tapered cross section that expands from the tip end that is substantially the same diameter as the through hole of the body toward the opening end is formed. an engagement portion which exhibited hexagonal shape composed of the engaging inner peripheral surface does not project centripetal direction from the tapered surface of Michiana, the engagement portion, toward the open end side of the base to tip while being horizontally formed Te, a step between the tip end side inner surface of the engaging portion and the distal end portion inner peripheral surface of the insert engaging was locked insert detachable tool engaging portion a tapered face portion, obtain perform attachment and detachment of the insert A ball valve characterized by that.

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