JP4762813B2 - Butterfly valve manufacturing method and butterfly valve structure - Google Patents

Description

  The present invention relates to a method for manufacturing a butterfly valve that does not require adjustment of the axial position of the valve shaft relative to the valve box, and a butterfly valve structure.

  The butterfly valve is an open / close valve installed in a pipeline such as a water supply. The configuration of the butterfly valve is such that, for example, as shown in FIG. A so-called butterfly valve body 3 is attached to the valve shaft 2.

  The upper part of the valve box 1 has an upper valve shaft support 9 that penetrates the valve box 1 in and out, and the lower part of the valve box 1 penetrates the valve box 1 in and out or has a bottomed lower valve shaft. A support portion 8 is provided, and the valve shaft 2 is fitted in the upper and lower valve shaft support portions 9 and 8 via bushes, liners and the like so as to be rotatable about the axis (see FIG. 7A).

  A valve seat 4 made of an annular rubber is fitted and fixed to the entire inner circumference of the pipe line of the valve box 1. As the valve shaft 2 rotates about its axis, the valve body 3 also rotates, and the peripheral edge portion 3a of the valve body 3 contacts and separates from the valve seat 4 to open and close the pipe line.

When assembling the butterfly valve, as shown in FIG. 8A, the valve shaft 2 is inserted into the valve shaft insertion hole 3b of the valve body 3, and the valve body 3 is inserted into the valve shaft 2 in a predetermined axial direction. After alignment with the position, pin holes 3d and 2d penetrating the valve body 3 and the valve shaft 2 are drilled.
After drilling, the valve shaft 2 is once removed from the valve shaft insertion hole 3b of the valve body 3, and only the valve body 3 is inserted into the valve box 1 (see FIG. 8B). The valve shaft 2 is inserted in the order of the upper valve shaft support portion 9 of the valve box 1, the valve shaft insertion hole 3b of the valve body 3, and the lower valve shaft support portion 8 of the valve box 1 (see FIG. 8C). 2 pin hole 2d and pin hole 3d of valve body 3 are aligned, pin 3c is inserted into pin holes 2d and 3d, and valve shaft 2 and valve body 3 are fixed together (FIG. 8 ( d) See step).

Since the valve box 1 used for the butterfly valve is generally a casting, an error is likely to occur in the inner surface dimension thereof. In particular, the vicinity of the upper and lower valve shaft support portions 9 and 8 has a complicated shape, and the thickness of the valve box 1 is not uniform over the entire circumference. It is considered that an error is likely to occur in the inner surface dimension.
For this reason, the inner surface of the valve hole is subjected to cutting and polishing in advance before its assembly, and the cross section of the valve hole in the direction perpendicular to the cylinder axis corresponds to the outer peripheral edge of the valve body 3 and the valve seat 4. Processed into a circle.

  However, the cutting and polishing of the inner surface of the valve hole cannot be performed in a state in which the valve box and the valve body are incorporated, so that the center of the processed surface does not match the center of the valve body 3 and the position is displaced in the radial direction. Sometimes it happens. Further, when the pin holes 2 d and 3 d penetrating the valve shaft 2 and the valve body 3 are drilled, the valve body 3 may be displaced in the axial direction from a predetermined fixed position with respect to the valve shaft 2.

The influence of this positional deviation will be described with reference to FIG. FIG. 7B shows the components of the butterfly valve shown in FIG. 7A separately for convenience of explanation. The symbol r in the figure indicates the outer diameter of the valve body 3, and the symbol s indicates the radial thickness of the valve seat 4.
Pipe axis direction center line p passing through the center between the uppermost end and the lowermost point b, b 'of the inner diameter surface of the valve seat 4 (or the uppermost end and the lowermost two points a, a of the inner surface of the valve box 1) The tube axis direction center line p) passing through the center between the center and the tube axis direction center line q passing through the center between the two points c and c ′ at the uppermost end and the lowermost end of the outer diameter surface of the valve body 3 Due to the influence of the displacement, the position of the lower surface 2b of the valve shaft 2 in the valve shaft direction varies depending on the valve. Conversely, if the position in the valve axis direction of the lower surface 2b of the valve shaft 2 is determined to be constant, the valve seat 4 and the valve body 3 are displaced in the radial direction by the valve due to the influence of the above-described positional deviation, and the valve seat There may be a state in which the inner diameter surface of the seat 4 and the outer peripheral edge of the valve body 3 do not come into watertight contact over the entire circumference.

For this reason, as shown in FIG. 7A, a through hole 5a is formed in the bottom cover 5 attached to the lower valve shaft holding portion 8 via the packing 7, and the adjusting bolt 6a can be screwed into the through hole 5a. It is said.
When the adjustment bolt 6a is screwed upward, the bottom cover 5 is raised while compressing the packing 7, and the tip of the adjustment bolt 6a slightly moves the valve shaft 2 upward in the axial direction. Further, if the adjusting bolt 6a is rotated in the reverse direction, the valve shaft 2 moves downward in the axial direction by its own weight.
By the movement of the valve shaft 2, both the center lines p and q are made coincident so that the outer diameter surface of the valve body 3 can maintain the water tightness over the entire circumference with respect to the inner diameter surface of the valve seat 4. Adjustment is performed (for example, refer to Patent Document 1).
JP-A-11-351414

  However, providing the valve shaft adjusting mechanism in the butterfly valve increases the number of parts. In addition, the adjustment work of the valve shaft is troublesome and requires skill, which is one of the factors that complicate the manufacturing process of the butterfly valve and increase the cost.

  Accordingly, an object of the present invention is to eliminate the need for a mechanism for adjusting the axial position of the valve shaft and the adjustment operation.

  In order to solve the above-described problems, the present invention supports an upper valve shaft support portion and a lower valve shaft support portion provided in a valve box so that the valve shaft can be freely rotated around the axis, and the valve shaft is a valve shaft of a valve body. In the method of manufacturing a butterfly valve that is inserted through the insertion hole and integrally fixes the valve shaft and the valve body, the valve body is inserted into the valve box, and the upper valve shaft support portion and the valve body The valve shaft is inserted into the valve shaft insertion hole and the lower valve shaft support portion, the lower end of the valve shaft is brought into contact with the bottom portion of the lower valve shaft support portion, and the valve shaft is made into the valve box by the contact. On the other hand, a method for manufacturing a butterfly valve in which the valve body is positioned in the axial direction with respect to the valve shaft in this state, and then the valve shaft and the valve body are integrally fixed is employed.

  In this way, the valve body can be integrally fixed to the valve shaft in accordance with the position of the inner surface of the valve hole of the valve box, so that the valve hole and the valve body do not shift in the radial direction, and the shaft of the valve shaft Adjustment of the direction position can be made unnecessary. That is, it is possible to eliminate the mechanism for adjusting the axial position of the valve shaft and the adjustment operation.

  As another means, in the present invention, the valve shaft is rotatably supported by the upper valve shaft support portion and the lower valve shaft support portion provided in the valve box, and the valve body is integrally fixed to the valve shaft. In the method of manufacturing a butterfly valve, a valve seat sheet that allows the valve body to contact and separate is bonded and formed in the valve box, and then the valve shaft is supported by the upper valve shaft support portion and the lower valve shaft support portion. In addition, a butterfly valve manufacturing method is adopted in which the lower end of the valve shaft is brought into contact with the bottom of the lower valve shaft support and the valve shaft is positioned in the axial direction with respect to the valve box by the contact.

The valve seat seat of the butterfly valve is bonded and molded inside the valve box, that is, the valve seat seat that is bonded to the inner surface of the valve box is cast and formed. The radial position can be determined based on the form position.
For this reason, the radial error of the position of the inner diameter surface of the valve seat decreases, and the tube axis center line passing through the center between the uppermost end and the lowermost end of the inner diameter surface of the valve seat, It is easy to match the tube axis direction center line passing through the center between the two points at the uppermost end and the lowermost end of the radial surface.

  Further, in order to solve the above-mentioned problems, the present invention supports the valve shaft so as to be rotatable about the shaft by the upper valve shaft support portion and the lower valve shaft support portion provided in the valve box, and the valve body is mounted on the valve shaft. The upper end of the valve shaft protrudes out of the valve box from the upper valve shaft support, and the lower end of the valve shaft contacts the bottom of the lower valve shaft support, and the valve shaft is Can be adopted a butterfly valve structure that is positioned in the axial direction.

Further, the lower valve shaft support portion is provided so as to penetrate the valve box inward and outward, and a bottom portion of the lower valve shaft support portion is fixed to the valve box so as to be stationary in the axial direction. A butterfly valve structure that is a bottom cover that closes the support portion may be employed.
The bottom cover fixed in the axial direction relative to the valve box is, for example, elastically deformable, such as an elastic body, between the facing surfaces where the bottom cover and the valve box are in contact (between the facing surfaces in the valve shaft axial direction). A mode in which both members are fixed with bolts or the like without interposing members is conceivable. If an elastic body or the like is not interposed, the axial position of the bottom cover with respect to the valve box does not change depending on the tightening degree of a fixture such as a bolt.

Further, a liner is interposed between the opposed surfaces of the lower end of the valve shaft and the bottom cover, and the valve shaft moves in the axial direction when the lower end of the valve shaft and the bottom cover come into contact with each other via the liner. A positioned configuration may be employed.
By appropriately selecting the shape and material of the interposed liner, it is possible to reduce the sliding resistance. Further, since the valve shaft does not directly contact the bottom cover, it is possible to suppress the bottom cover from being worn. If wear is suppressed, it is more preferable because it is less necessary to adjust the valve shaft in the axial direction.

Further, in the configuration in which the liner is provided, one or both of the opposing surfaces of the lower end of the valve shaft and the bottom cover are provided with a concave portion that gradually decreases in diameter as the distance from the opposing surface increases, and the liner is inserted into the concave portion. In addition to housing, a configuration in which the liner has a spherical surface that linearly contacts the inner peripheral surface of the concave portion may be employed.
In this way, since the liner and the inner peripheral surface of the recess are in line contact with each other, there is an advantage that the sliding resistance when the valve shaft rotates can be reduced.

In addition, the diameter which concerns on the said cyclic | annular line contact part can be arbitrarily set by adjusting the curvature of the spherical surface of the liner to be used. If the diameter related to the line contact can be arbitrarily set, it is possible to adjust the amount of wear predicted to occur on the contact surface.
Further, in the case where the tapered recess is provided in both the valve shaft and the bottom cover, if the sphere can be freely rotated using the liner as a sphere, the contact surface of the liner with the recess is the spherical surface of the liner. It is more preferable because it is not biased to a certain part.

  Since the present invention has been described above, it is possible to eliminate the mechanism for adjusting the valve shaft in the axial direction and the adjustment operation.

  An embodiment will be described with reference to the drawings. As shown in FIGS. 1 (a) and 1 (b), the butterfly valve of this embodiment has a stainless valve shaft 2 penetrating through a cylindrical valve box 1 in a direction perpendicular to the cylinder axis. A valve body 3 is attached.

In the vicinity of the valve hole, a valve seat 4 is provided on the entire inner circumference of the valve box 1 so that the peripheral portion 3a of the valve body 3 contacts and separates as the valve shaft 2 rotates. The valve seat 4 is formed by bonding (casting) by a method described later along a groove 1 a formed on the entire inner circumference of the valve box 1.
Since the rubber composition that is the material of the valve seat 4 is cast into the groove 1a around the inner surface, the valve seat 4 is prevented from being detached from the valve box 1. Further, the casting range is set to a predetermined length along the cylinder axis direction of the valve box 1, and both side edges in the cylinder axis direction of the valve seat 4 are not reached to the opening edge of the valve box 1. Yes.

As shown in FIG. 2 (a), the inner diameter surface of the valve seat 4 is symmetrical with respect to the axial center of the valve shaft 2 in the cylinder axis direction of the valve box 1, and the valve seats 4 are disposed above and below the valve seat 1 respectively. A hole through which the shaft 2 can be inserted is formed.
Further, an upper valve shaft support portion 9 and a lower valve shaft support portion 8 that penetrate the valve box 1 inward and outward are provided on the same shaft at the upper and lower portions of the valve box 1, respectively. The inner peripheral surfaces of the portions 9 and 8 are cylindrical surfaces.

The bottom portion of the lower valve shaft support portion 8 is closed by a metal bottom cover 5 fixed by screwing a bolt 15 into a screw hole 18 in the lower portion of the valve box 1.
The valve box 1 is a casting, and the metal surfaces of the upper surface of the bottom cover 5 and the lower surface of the valve box 1 are in direct contact with each other, and the bolt 15 is provided so as to penetrate between both contact surfaces. Further, the valve box 1 and the bottom cover 5 are kept watertight by a packing 19 in contact with the entire inner periphery of the lower valve shaft support portion 8.

  The valve shaft 2 is inserted into the valve shaft support portions 9 and 8 and the upper and lower holes of the valve seat 4, and the upper end of the valve shaft 2 extends from the upper valve shaft support portion 9 to the outside of the valve box 1. A cylindrical metal liner 2a provided at the lower end of the bottom cover 5 fits into a circular recess 5c formed on the upper surface 5b of the bottom cover 5 and is supported rotatably around the axis. A sleeve 20 is inserted between the lower valve shaft support 8 and the valve shaft 2.

  A method for manufacturing this butterfly valve will be described. First, a method for forming the valve seat 4 in the valve box 1 will be described below.

The valve seat 4 is cast by using a mold 10 shown in FIGS. The first mold 10a and the second mold 10b are respectively inserted from the opening on both sides in the cylinder axis direction of the valve box 1, and the valve shaft support part molds are respectively inserted into the upper and lower valve shaft holding parts 9 and 8 of the valve box 1. Insert molds 11 and 12.
The valve shaft support molds 11 and 12 include rod-shaped molds 11a and 12a each having a columnar shape, and flange portions 11b and 12b fixed to one end thereof. The rod-shaped molds 11a and 12a are inserted, and the inserts 13 and 13 are interposed between the pair of molds 10a and 10b.
The inserts 13 and 13 are disk-shaped, and are formed by combining half pieces 13a and 13a. At the center, a recess is provided in which the tips of the rod-shaped molds 11a and 12a fit snugly.

  As shown in FIG. 3B, the front surfaces of the pair of molds 10 a and 10 b are in close contact with each other with the hook-shaped portions engaged with each other, and are fixed to the valve box 1 via the spacers 17 in that state. For this fixing, a well-known fastener using a bolt or the like may be used.

A cavity for the valve seat 4 is formed between the pair of molds 10a and 10b, the double bar-shaped molds 11a and 12a, and the inserts 13 and 13, and the inner surface of the valve box 1. Since the pair of molds 10a and 10b are in close contact with the inner surface of the valve box 1 except for the part facing the cavity, there is no need to adjust the radial position with respect to the valve box 1, and both molds If 10a, 10b is inserted into the valve box 1, its radial position is naturally determined.
Further, the inserts 13 and 13 are fixed between the molds 10a and 10b and the inner surface of the valve box 1 in a stationary state in a state where the front surfaces of the molds 10a and 10b are in close contact with each other.

  Next, the unvulcanized rubber G is filled into the recess 14 formed on the back side of the first mold 10a. When the ram 10c of the mold 10 is pushed in the cylinder axis direction, the unvulcanized rubber G is passed through the runners 16a, 16b formed by the pair of molds 10a, 10b (unvulcanized rubber G injection paths). It is press-fitted into the cavity. With the unvulcanized rubber G being press-fitted, the valve seat 4 is formed through a predetermined vulcanization process.

Next, a method for attaching the valve shaft 2 and the valve body 3 will be described.
As described above, after the valve seat 4 is cast and formed in the valve box 1, the valve body 3 is inserted into the valve box 1 as shown in FIG. The position, orientation, and orientation of the valve body 3 are adjusted so that the valve shaft 2 can be inserted into the upper valve shaft support portion 9, the valve shaft insertion hole 3 b of the valve body 3, and the lower valve shaft support portion 8 of the valve box 1. To do. As shown in FIG. 5 (b), the valve shaft 2 is inserted into the valve shaft insertion hole 3b of the valve body 3 and simultaneously through the valve shaft support portions 8 and 9 via the sleeve 20, and the valve shaft 2 is brought into contact with the bottom cover 5 at the bottom of the lower valve shaft support 8.
At the time of this contact, the liner 2 a is interposed between the lower surface 2 b of the valve shaft 2 and the upper surface 5 b of the bottom cover 5. When the valve shaft 2 and the bottom cover 5 abut on each other via the liner 2a, the valve shaft 2 is positioned in the axial direction with respect to the valve box 1. Moreover, since the liner 2a fits into the recessed part 5c formed in the upper surface 5b of the bottom cover 5, the horizontal position is hold | maintained.

  At this time, the axial direction position of the valve shaft 2 passes through the center between the uppermost end and the lowermost end of the inner diameter surface of the valve seat 4 (see symbols b and b ′ in FIG. 7B showing the conventional example). The tube axis direction center line is set so that the tube axis direction center line passing through the center between the uppermost end and the lower end of the outer diameter surface of the valve body 3 (same as c and c ′) coincides. Therefore, it is not necessary to adjust the axial position of the valve shaft 2 thereafter.

  The valve shaft 2 and the valve box 1 are held so that the valve shaft 2 does not move at this position. Next, after the valve body 3 is aligned at a predetermined position in the axial direction with respect to the valve shaft 2, pin holes 2d and 3d passing through the valve shaft 2 and the valve body 3 are drilled, and the pin holes 2d, A pin 3c is inserted into 3d, and the valve shaft 2 and the valve body 3 are fixed together. The positioning of the valve body 3 is performed based on the position of the valve seat 4. Finally, a predetermined opening / closing device is attached to the upper end of the valve shaft 2 outside the valve box 1.

In addition, the aspect of the bottom cover 5 is not limited to this embodiment, The structure which does not provide the recessed part 5c is also employable. Moreover, when the effect of the liner 2a is not desired, a configuration in which the liner 2a is omitted may be employed.
Further, the valve box 1 and the bottom cover 5 are fixed to each other without interposing an elastically deformable member such as an elastic body between the opposed surfaces in contact with each other (between the opposed surfaces in the axial direction of the valve shaft 2). What is necessary is just to be fixed in a state where the metal surfaces are in direct contact with each other. This is because if the elastic body or the like is not interposed, the axial position of the bottom cover 5 with respect to the valve box 1 does not change depending on the tightening degree of a fixing tool such as a bolt.
Alternatively, the bottom portion of the lower valve shaft holding portion 8 may be cast integrally with the valve box 1 without using the bottom cover 5, and the lower end of the valve shaft 2 may be brought into direct contact with the bottom portion.

  In addition, when using the said liner 2a, you may employ | adopt the aspect shown to FIG.2 (b) (c), for example. FIG. 2 (b) has tapered inner surfaces that gradually decrease in diameter as they move away from the opposing surfaces 2b and 5b, respectively, on both the lower surfaces of the valve shaft 2 and the opposing surfaces 2b and 5b of the bottom cover 5. Recesses 2c and 5c are provided. The recesses 2c and 5c are conical spaces each having the same diameter and height. The liner 2a is a sphere, and the spherical surface of the liner 2a comes into annular contact with the inner peripheral surfaces of the recesses 2c and 5c by storing the liner 2a made of the sphere in the recesses 2c and 5c. For this reason, the sliding resistance at the time of rotation of the valve shaft 2 can be made small.

  Further, the tapered recess may be provided on either the valve shaft 2 or the bottom cover 5. When the tapered concave portion is provided on either the valve shaft 2 or the bottom cover 5, a concave portion having a circular cross section as shown in FIG. 2C may be formed in the other concave portion, for example. At this time, the liner 2a can adopt a configuration having a spherical surface that makes an annular line contact with the tapered concave portion and a cylindrical portion that is fitted and held in the concave portion having a circular cross section.

  In this embodiment, the valve seat 4 is cast and formed, the accuracy of the radial position of the inner diameter surface of the valve seat 4 with respect to the valve box 1 is increased, and the valve shaft 2 and the bottom cover 5 are connected to the liner 2a. , The valve shaft 2 is positioned at a predetermined axial position with respect to the valve box 1. Therefore, for example, even when the butterfly valve manufacturing method shown in FIG. 8 of the conventional example is used, if the mounting accuracy of the valve body 3 with respect to the valve shaft 2 is maintained at a predetermined level, an error caused by other elements may occur. Since there are few, adjustment of the axial direction position of the valve shaft 2 can also be made unnecessary.

  In addition, for example, when the valve seat 4 is not formed by casting on the butterfly valve, that is, a valve seat 4 made of rubber or the like that is molded in advance is fixed in the valve box 1 so as not to be removed, Alternatively, in the case where a seat ring is provided around the valve body 3, the valve body 3 is disposed on the valve hole inner surface position (radial position) of the valve box 1 or the valve seat 4 fixed to the valve hole. As long as the position adjustment is performed along the axial direction of the valve shaft 2 in accordance with the inner diameter surface position (radial position), the operation of adjusting the axial position of the valve shaft 2 can be made unnecessary thereafter.

1 shows an embodiment, (a) side view, (b) front view. (A) is a principal part enlarged view of FIG.1 (b), (b) (c) is a principal part enlarged view which shows other embodiment. It is explanatory drawing which shows the formation method of a valve seat, (a) is a longitudinal cross-sectional view, (b) is a cross-sectional view. The perspective view which shows the structure of the metal mold | die used when forming a valve seat sheet Explanatory drawing which shows the manufacturing method of a butterfly valve Perspective view of butterfly valve A prior art example is shown, (a) is a front view, (b) is an explanatory view showing a configuration of a valve box, a valve shaft and a valve body. Explanatory drawing which shows the manufacturing method of the butterfly valve of a prior art example

Explanation of symbols

1 Valve box 2 Valve shaft 2a Liner 2b Lower surface (opposite surface)
2c Recess 3 Valve body 4 Valve seat 5 Bottom cover 5a Through hole 5b Upper surface (opposing surface)
5c Recess 6a, 6b Adjustment bolt 7 Packing 8 Lower valve shaft support 9 Upper valve shaft support 10 Mold 10a First mold 10b Second mold 10c Ram 11, 12 Valve shaft support mold 11a, 12a Rod mold 11b, 12b Flange part 13 Nest 13a Half piece 14 Recess 15 Bolt 16a, 16b Runway
18 Screw hole 19 Packing 20 Sleeve G Rubber

Claims (1)

Upper valve shaft support portion provided in the valve box (1) (9) and its valve stem while supporting the valve shaft (2) freely about the axis rotation by the lower valve shaft support portion (8) and (2) the valve body ( 3 ) in the method for manufacturing a butterfly valve, wherein the valve shaft ( 2 ) and the valve body ( 3 ) are integrally fixed by being inserted into the valve shaft insertion hole ( 3b ) .
The valve seat (4) that allows the valve body (3) to come into contact with and separate from the valve box ( 1 ) is adhesively molded, and then the valve body ( 3 ) is inserted into the valve box ( 1 ) . , the upper valve shaft support portion (9), the valve shaft insertion hole of said valve body (3) (3b), and the valve shaft (2) is inserted into the lower valve shaft support portion (8), the valve shaft The upper end of (2) is projected out of the valve box (1) from the upper valve shaft support (9), and the lower end of the valve shaft ( 2 ) is in contact with the bottom of the lower valve shaft support ( 8 ). is not the valve shaft (2) is positioned axially relative to the valve casing (1) by its contact with the positioning the valve body in its state (3) relative to the valve shaft (2) in the axial direction after, the valve shaft (2) and the valve body (3) and integrally fixed to the bottom of the lower valve shaft support portion (8) is axially non relative to said valve body (1) Method for manufacturing a butterfly valve, characterized in that a bottom cover that closes the lower valve shaft support portion is fixed (8) (5).

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