JP2007182922A - Method for manufacturing valve element of ball valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a valve element of a ball valve which is hard to generate a gap between a valve seat and it. <P>SOLUTION: A valve element of a ball valve having a through flow passage passing through the spherical outer surface, and a center, is shaped with a pair of molds 21, 22 which forms the outer surface and is divided into two by divided surfaces 21a, 22a inclined to a plane orthogonal to the through flow passage, and with a flow passage core 24 which forms the through flow passage by passing through at least one of the molds 21, 22. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a valve body of a ball valve.

  The ball valve uses a valve body that is formed in a substantially spherical body, has a flow path that passes through the center, and has a rotation axis that is orthogonal to the flow path. Conventionally, a valve body of a ball valve has been formed by a mold that is divided into two at a dividing surface orthogonal to the flow path. At the center of at least one of the hemispherical cavities of the mold, there is provided a columnar projection for forming a flow path that penetrates the valve element. After molding, the mold is divided by dividing the mold in the flow path direction. The valve body could be removed.

  Since the surface of the molded valve body is burred at the position of the dividing surface of the mold, polishing for removing the burr after molding is necessary. However, it is difficult to precisely remove only the burrs, and the surface of the valve body around the burrs is polished, so that the sphericity of the valve body decreases. Therefore, in a ball valve that uses a valve body molded by a conventional manufacturing method, when the flow path is closed, the portion with reduced sphericity is in close contact with the valve seat to seal the flow path, There has been a problem that a gap is easily formed between the valve body and the valve seat to cause leakage.

  In view of the above problems, an object of the present invention is to provide a method for manufacturing a valve body of a ball valve that is less likely to cause a gap with a valve seat.

  In order to solve the above-mentioned problems, according to the present invention, a method of manufacturing a valve body of a ball valve having an outer surface made of a spherical surface and a through-flow passage penetrating the center forms the outer surface, and the through-flow Molding is performed with a pair of molds that are divided into two by a split surface that is inclined with respect to a plane orthogonal to the path, and a flow path core that penetrates at least one of the molds and forms the through flow path.

  According to this method, burrs formed on the outer surface of the valve body at the time of molding can be generated at a position that does not contact the valve seat. For this reason, when opening and closing the valve, the flow path can be sealed with an outer surface having a high sphericity without contacting the valve seat at a portion where the sphericity has been lowered to deburr the outer surface of the valve body. As a result, a gap is hardly generated between the valve body and the valve seat, and the ball valve can obtain a high sealing ability.

  Moreover, in the manufacturing method of this invention, the said division surface is good to be located in the part which does not contact | abut the valve seat of the said outer surface.

  According to this method, not only when the valve is closed, but also when the valve is opened or during the operation of the valve, the valve body does not contact the part where the burr is generated due to the dividing surface with the valve seat. For this reason, the valve does not cause a leak between the valve body and the valve seat even in the open state. Further, even if the burrs are not polished, the burrs do not come into contact with the valve seat, so that the polishing step after molding can be omitted.

  Moreover, in the manufacturing method of this invention, the said division | segmentation surface may include the position in which the drive member which drives the said valve body is provided.

  According to this method, the position where the driving member is provided does not contact the valve seat, so that no gap is generated between the valve body and the valve seat. Furthermore, the drive member can be integrally molded with the valve body, or the engagement structure with the drive member can be formed on the valve body.

  In the manufacturing method of the present invention, the pair of molds may be provided with a groove for sandwiching a core that forms an engagement hole for inserting a drive member on the split surface.

  According to this method, it is possible to attach the shaft-like driving member made of a member separate from the valve body without machining the valve body.

  In the manufacturing method of the present invention, the pair of molds may be provided with a groove that forms a rotation shaft of the valve body on the dividing surface.

  According to this method, the rotating shaft of the valve body can be integrally formed.

  As described above, according to the present invention, the valve body of the ball valve includes the two-part mold for forming the outer surface of the valve body and the core that penetrates the mold for forming the flow path of the valve body. Therefore, when the ball valve is closed and the flow path is sealed, the valve body contacts the valve seat with the outer surface having a high sphericity, so there is a gap between the valve body and the valve seat. Is less likely to occur and fluid leakage is less likely to occur.

Embodiments of the present invention will now be described with reference to the drawings.
FIG. 1 shows a ball joint built-in pipe joint 1 using a valve body manufactured by a manufacturing method according to an embodiment of the present invention. The pipe joint 1 includes a socket 2 and a plug 3, and the socket 2 includes a main body 4 and a sleeve 5 that can slide on the outer periphery of the main body 5.

  The main body 4 accommodates therein a substantially spherical valve body 6 and valve seats 7 sandwiched between the inner wall of the main body 4 and the outer surface of the valve body 6 on both sides of the valve body 6. The valve body 6 has a rotating shaft 8 that is pivotally supported by the main body 4, and a drive member 9 is attached to the eccentric position. The drive member 9 is engaged with a drive ring 10 fitted to the inner surface of the sleeve 5, and can move the valve body 6 around the rotation shaft 8 by moving together with the sleeve 5.

  The sleeve 5 is biased toward the plug 3 by a sleeve biasing spring 11. As shown in the drawing, the plug 3 can be inserted into the main body 4 at the tip. The main body 4 is provided with an inflow passage 12 that opens to the opposite side of the plug 3. The valve body 6 is provided with a through-flow passage 13 penetrating through the center. As shown in the drawing, the through-flow passage 13 is arranged concentrically with the inflow passage 12 when the sleeve 5 is located on the plug 3 side, and the valve seat 7 To the inflow passage 12 via The plug 3 is provided with an outflow path 14 that is inserted into the main body 4 and arranged concentrically with the introduction path 12, and the outflow path 14 can communicate with the inflow path 12 through the through flow path 13 of the valve body 6 and the valve seat 7. It is.

  2 and 3 show the valve body 6 in detail. The valve body 6 has an outer surface 15 formed in a spherical surface, and an engagement hole 16 into which the driving member 9 is fitted is provided. Further, the valve body 6 is formed with a slight plane perpendicular to the through flow path 13 around the opening of the through flow path 13.

  FIG. 4 shows a mold configuration for molding the valve body 6. The outer surface 15 of the valve body 6 is formed of two molds 21 and 22 that are joined and separated by the dividing surfaces 21a and 22a. The molds 21 and 22 are respectively formed with cavities 21b and 22b corresponding to the outer surface 15, and together form a substantially spherical inner space. Further, the molds 21 and 22 are provided with half-pipe-shaped shaft grooves 21c and 22c extending from the cavities 21b and 22b onto the dividing surfaces 21a and 22a, respectively, and forming the rotating shaft 8 of the valve body 6. Further, the molds 21 and 22 have split surfaces 21a and 22a so that the rod-like engagement hole core 23 can be inserted into the internal space formed by the cavities 21b and 22b in order to form the engagement holes 16 of the valve body 6. Half-pipe-shaped core grooves 21d and 22d are provided on the top. Further, a core hole 21e that penetrates the mold 21 is opened in the mold 21 at the back of the cavity 21b, and a flow path core 24 that forms the through flow path 13 of the valve body 6 is inserted into the core hole 21e. The The flow path core 24 is provided with a step so as to form the inside of the plane around the opening of the through flow path 13 of the valve body 6, and penetrates the core hole 21 e to the back of the cavity 22 b of the mold 22. Reach up to.

  The valve body 6 is molded by aligning the mold 21 and the mold 22 with the dividing surfaces 21a and 22a so that the engagement hole core 23 is sandwiched between the core grooves 21d and 22d, and the engagement hole core 23 is formed in the core grooves 21d and 22d. In a state where the flow path core 24 is inserted into the core hole 21e, a molten metal material is poured from a gate (not shown) and molded. When the metal material cools and hardens, the engagement hole core 23 is pulled out along the core grooves 21d and 22d, and the flow path core 24 is pulled out from the core hole 21e. If the molds 21 and 22 are divided by the dividing surfaces 21a and 22a, the valve body 6 is taken out.

  The valve body 6 molded in this way is located at the position indicated by the alternate long and short dash line in FIGS. 2 and 3 with the center of the rotary shaft 8 and the engagement hole 16 corresponding to the divided surfaces 21a and 22a of the molds 21 and 22. As a result, a burr 17 is formed so as to go around the outer surface 15. Further, as shown in FIG. 3, an annular burr 18 is formed on the plane around the opening of the through passage 13 of the valve body 6 by the joint between the flow path core 24 and the mold 21. Similarly, the burr 19 formed by the joint between the flow path core 24 and the mold 21 is formed at the inner edge of the opening of the through flow path 13.

  As shown in FIG. 2, the burr 17 is positioned between the two valve seats 7 in a state where the valve is opened, and does not contact the valve seat 7. Further, since the burrs 18 and 19 are formed in a flat portion retreated from the spherical outer surface 15, they do not contact the valve seat 7.

  FIG. 5 shows a state where the valve of the pipe joint 1 is closed. The valve body 6 rotates about 65 ° counterclockwise from the state shown in FIG. 2 so that the spherical outer surface 15 contacts the valve seats 7 on both sides. Thus, the valve body 6 separates the inflow path 12 and the outflow path 14 and blocks the flow path.

  The rotation of the valve body 6 is performed within a range where the burr 17 does not come into contact with both valve seats 7, so that when the burr 17 or the burr 17 is polished, the outer surface 15 with reduced sphericity contacts the valve seat 7. There is no risk of forming a gap with the valve body 6 in contact therewith. Further, since the burrs 18 and 19 are formed at a position retreated from the outer surface 15, they do not come into contact with the valve seat 7 unless they are very large. Since it should just polish, the sphericity of the outer surface 15 is not reduced.

  As described above, according to the present invention, polishing for removing the burrs 17, 18, and 19 formed on the molded valve body 6 can be omitted, and even if the burrs 17, 18, and 19 are removed. As a result, the sphericity of the portion of the outer surface 15 that comes into contact with the valve seat 7 is not lowered, so that high sealing performance can be secured.

  Further, since the flow passage core 24 and the engagement hole core 23 can form the through flow passage 13 and the engagement hole 16, and the shaft grooves 21 c and 22 c can simultaneously form the rotary shaft 8 when the valve body 6 is molded. It is not necessary to perform processing that requires high accuracy after molding.

Sectional drawing of the pipe joint which has the valve body of the ball valve manufactured by embodiment of this invention. The side view of the valve body at the time of the ball valve release of FIG. The front view of the valve body of FIG. The schematic of the mold for shape | molding the valve body of FIG. The side view of the valve body at the time of the ball valve closure of FIG.

Explanation of symbols

1 Fitting (Built-in ball valve)
6 Valve body 7 Valve seat 8 Rotating shaft 9 Drive member 12 Introduction path 13 Movable flow path 14 Outflow path 15 Outer surface 16 Engagement hole 17 Burr 18 Burr 19 Burr 21, 22 Mold 21a, 22a Dividing surface 21b, 22b Cavity 21c, 22c Shaft groove 21d, 22d Core groove 21e Core hole 23 Engagement hole core 24 Flow path core

Claims (5)

A method of manufacturing a valve body of a ball valve having an outer surface made of a spherical surface and a through channel that passes through the center,
A pair of molds that form the outer surface and are divided into two by a dividing surface inclined with respect to a plane orthogonal to the through-flow path;
A ball valve valve body manufacturing method comprising molding with a flow path core that penetrates at least one of the molds to form the through flow path.   2. The ball valve valve body manufacturing method according to claim 1, wherein the dividing surface is located at a portion of the outer surface that does not contact the valve seat. 3.   The method of manufacturing a valve body according to claim 2, wherein the dividing surface includes a position where a driving member for driving the valve body is provided.   The pair of molds are provided with a groove for sandwiching an engagement hole core that forms an engagement hole for inserting a drive member on the split surface. A method of manufacturing a valve body of a ball valve.   5. The ball valve valve body manufacturing method according to claim 1, wherein the pair of molds are provided with a groove that forms a rotating shaft of the valve body on the dividing surface. Method.

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