JPH04135063A - Manufacture of trim part of valve having spherical valve seat - Google Patents

Abstract

PURPOSE:To correctly bring a valve plug in line with the center of a valve stem by joining the valve plug to the valve stem on the same axis by welding and then, finish-working a spherical seat of the valve plug. CONSTITUTION:The valve stem 6 is joined integrally to the valve plug 21 by welding in advance. In welding, the lower end 6a of the valve stem 6 is fitted to the inside of an upper side bearing part 23 of the valve plug 21 and positioned and them, a welding torch 44 is inserted into the valve plug 21 from a lower side bearing part 24 of the valve plug 21 and in a state with the welding starting point position held, while the valve stem 6 and the valve plug 21 being rotated integrally, the lower end 6a is welded and fixed on the inside opening edge of the upper side bearing part 23 extending over the entire periphery thereof. Afterward, the peripheral surface of the valve plug 21 is finish-worked as serving to eliminate welding distortion as well and the spherical seat 25 having specified curvature is formed. According, the valve plug 21 does not cause eccentric deflection for the valve stem 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a trim part for a valve having a spherical valve seat, which is suitable for application to rotary valves and the like.

[Prior Art] In a rotary valve, a valve plug having a spherical valve seat and a valve stem to which this plug is attached form a trim part of the valve. FIG. 8 shows a conventional example of such a rotary valve. That is, the rotary valve 1 has a valve body #2.
A spherical valve plug 4 having a through hole 5 is installed in the flow path 3 of the valve It!, which is perpendicular to the center line of the valve body 2. By rotating by 16,
The flow path 3 is opened and closed, and the flow rate is controlled according to the effective angle. The outer circumferential surface of the valve plug 4 is a spherical surface whose spherical center coincides with the center of one lug, and is brought into close contact with the seating surface 8 of the seat ring 7 installed on the upstream side of the flow path 3 to form a spherical seating portion (spherical surface). Valve seat) 4A is formed. Furthermore, fitting holes 10.11 are formed in the upper and lower surfaces of the valve plug 4, into which the lower end corner head of the valve shaft 6 and the upper end of the stud 9 provided in the valve body 2 fit, respectively. The valve stem 6 forms a drive system of the rotary valve l together with the valve plug 4, and is inserted through a gland member 16 into a gland hole 15 of a top cover 13 that is fitted and fixed to the top opening 12 of the valve body 2. , its upper end protrudes above the upper lid 13.

In this case, the rotary valve 1 is assembled according to the following procedure.

■Install the valve body 2 on the assembly stand.

■Place the stud 9 inside the valve body 2.

(2) Insert the valve plug 4 into the valve body #2 and fit the fitting hole 11 into the upper end of the stud 9.

(2) Fit the lower end of the valve shaft 6 into the fitting hole 10 of the valve plug 4.

(2) Fit the upper part 1113 into the upper opening 12 of the valve body 2, and insert the valve shaft 6 into the gland hole 15.

■Gland member 16 is placed in the gap between the gland hole 15 and the valve stem 6.
, the retainer 18 and the like are fitted and inserted to seal the ground hole 15.

(2) Fit the seat ring 7 into the upstream opening 19 of the valve body 2 and screw the retainer 17 to bring the seating surface 8 of the seat ring 7 into close contact with the spherical seating portion 4A of the valve plug 4.

After this, the drive section is assembled to the upper end of the valve shaft 6.

[Lesson 61 that the invention attempts to solve! By the way, in most of such conventional rotary valves 1, the valve plug 4 and the valve shaft 6 are assembled in a loosely fitted state. The reason for this is that, in order to comfortably seat the seating surface 8 of the seat ring 7 on the spherical seating portion 4A, it is better to flexibly absorb the positional deviation between the two parts for better fitting. However, usually Benmoto #21
The seat ring 7 is fixed to the seat ring 1, and the plug side is often given a degree of freedom in its posture in the valve, and the engagement with the valve shaft 6 is often given some play.

However, with such a configuration, the spherical center of the valve plug 4 and the axis of the valve shaft 6 do not match correctly, and the valve plug 4 becomes eccentric, making smooth operation impossible. There was one problem.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and its purpose is to correctly align the centers of the valve plug and the valve stem, and to achieve smooth operation. An object of the present invention is to provide a method for manufacturing a trim part for a valve having a spherical valve seat.

"Means for Solving the Problems" The present invention has been made to achieve the above object, and the first invention is to coaxially join a valve plug whose outer circumferential surface is roughly processed into a spherical surface and a valve shaft by welding. The valve shaft to which the valve plug is connected is chucked and the spherical surface is finished while the valve plug is rotated to obtain a spherical seating portion having a predetermined curvature.

In addition, the second invention is such that the valve shaft is coaxially fitted into the valve shaft side bearing part of the valve plug, which is provided with cylindrical bearing parts at both the upper and lower ends, and whose outer peripheral surface is roughly processed into a spherical surface. A welding torch is inserted into the shaft-side bearing, and while maintaining the welding starting position of the torch, the valve shaft and the valve plug are rotated around their central axes so that the entire periphery of the bearing-side end of the valve shaft is covered as described above. The valve shaft is welded to the bearing part, and then the valve shaft joined to the valve plug is chucked, and the spherical surface is finished processed while the valve plug is rotated to obtain a spherical seating part having a predetermined curvature. .

[Operation] In the present invention, the valve plug is integrally and coaxially joined to the valve shaft by welding, and does not swing eccentrically with respect to the valve shaft. The welding torch is inserted into the valve plug, and the valve shaft and valve plug are rotated around their central axis while maintaining the starting position, so that the entire circumference of the end of the valve shaft is uniformly welded.

[Example] Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIG. 1 is a sectional view showing an embodiment of a rotary valve equipped with a trim part manufactured by the method of the present invention, and FIG. 2 is a perspective view of a valve plug and a valve stem. In the figure, the same components as in FIG. 8 are designated by the same reference numerals.

First, the structure of the rotary valve will be explained based on FIG. 1 and FIG. 2. In these figures, the rotary valve 20 includes a valve plug 21 attached to the inner end of the valve stem 6 and disposed within the valve body 2.

The valve plug 21 is composed of a valve body 22 made of a substantially hemispherical shell structure with a hollowed out inside, and cylindrical bearing portions 23 and 24 integrally provided on the upper and lower surfaces of the valve body 22, respectively. A long band-shaped spherical seat 25 is formed protrudingly on the outer peripheral surface of the valve body 22 in the direction of rotation of the valve shaft 6, and an opening 26 forming an equal percentage characteristic portion overlaps one end of the spherical seat 25. It is formed like this. The width of the spherical seating portion 25 is equal to the inner diameter A of the seating surface 8 of the seat ring 7.
It is set slightly thicker (D>A).

The inner end 6a of the valve shaft 6 is fitted into the upper bearing part 23 and integrally joined by welding or the like, and the lower bearing part 24 is connected to the upper part of the stud 9 provided on the inner surface of the valve body 2*M. It is rotatably fitted and supported by the shaft. The outer end 6b of the valve shaft 6 is
It passes through the ground hole 15 of the lid 13 that closes the upper opening 12 of the valve body 2 and projects to the outside.

In addition, the outer end of the valve stem 6 is provided with a tapered surface 6A and a square head 6B to which a drive portion such as a handle is attached.

The gland hole 15 is formed by making the upper half of the center hole 28 provided in the upper M13 a large diameter hole 15, and a gland member 30 is provided in the gap between this hole and the valve shaft 6. It is fitted.

In this case, in this embodiment, the gland member 30 includes a packing 31, a spring washer 32, backing (preferably a yarn-shaped molded packing) 33a, 33b, and an O-ring 34.
, a ground member 35 and a retainer (a metal ring for maintaining the shape of the packing 33) 18 are used. However, the gland member 30 is not limited to the above-mentioned members, and any gland member may be used as long as it satisfies both the movability of the valve shaft 6 and the liquid sealing property of the gland hole 15.

On the other hand, an O-ring 36 and a guide bush 37 are fitted into the center hole 28 of the upper lid 13. The guide bushing 37 is made of a lining material made of fluororesin as a base material combined with carbon or the like, and is made by lining the inside of a stainless steel perforated plate.

The stud 9 is formed in a cylindrical shape, and a flange 9a is integrally protruded from the middle part of the outer peripheral surface of the stud 9, and the lower end of the flange 9a is fitted into a recess 38 formed in the inner surface of the valve body 2. There is.

The upper M13 is fitted into the upper end opening 12 of the valve body 2 via the gas get 40, and fastened with a plurality of bolts (not shown).

After the seat ring 7 is inserted into the valve body 2, the retainer 17 is screwed into the upstream 1llWRO portion 19 of the valve body 2 via the seat spring 41 and O-ring 42, and the seat ring 7's seating surface 8 is inserted into the valve body 2. 22 spherical seating part 2
Close to 5.

Now, the manufacturing method and assembly procedure of the trim in the rotary valve 20 having such a structure will be explained in detail with reference to FIGS. 3 to 7.

First, the valve plug 2 that forms the trim part on the workbench
1, the valve stem 6, and the upper cover 13 are placed. The outer peripheral surface of the valve 1 lug 21 is a rough spherical surface and has not been finished yet. The valve stem 6 and the valve plug 21 are integrally joined in advance by welding, as shown in FIG. During welding, after fitting and positioning the inner end 6a of the valve shaft 6 into the upper bearing part 23 of the valve plug 21, the welding torch 44 is inserted from the lower bearing part 24 of the valve plug 21 into the valve plug 21.
the lower end 6a while rotating the valve shaft 6 and the valve plug 21 together while maintaining the welding starting point posture.
is welded and fixed to the inner opening edge of the upper bearing part 23 over its entire circumference.

Here, the welding torch 44 is inserted into the valve 1 from the lower bearing part 24.
It is also possible to direct the welding arc toward the welding location from the hemispherical split surface direction of the valve plug 21 (direction of arrow A in Figure 3) without inserting it into the lug 21, but in that case, Since the angle of the torch is different all around, the bead is not evened out, causing the valve plug 21 to bend, which is not practical.

After welding the valve stem 6, the outer circumferential surface of the valve plug 21 is finished to remove welding distortion, and the finishing of the 0-spherical seating portion 25, which is a spherical seating portion 25 with a predetermined curvature, is performed according to well-known methods. Machining, NC machining, etc. may be used, but according to a new valve plug machining method (Japanese Patent Application No. 1-215724) already proposed by the same applicant as another machining method, it is possible to obtain a spherical surface with high sphericity. It is possible.

This processing method involves rotating and feeding the valve plug along its center line, while advancing a cutting blade that is attached eccentrically to a rotating shaft that is perpendicular to the center line and rotates together with the rotating shaft. The outer peripheral surface is cut into a spherical shape.

Next, the ground hole 15 of the top cover 13 prepared on the workbench.
In other words, as shown in FIG. 4, the gland member 35 and the backing 3 are sealed from above into the gland hole 15 by the spring washer 32, the packing 31, the backing 33a, and the O-ring 34.
3b, and finally the retainer 18 consisting of an E ring etc.
is inserted into the groove formed on the inner circumferential surface of the ground hole 15. In addition, a guide bush 3 is inserted into the center hole 28 from below.
7 and the O-ring 36 are inserted.

Next, the upper end of the valve shaft 6 is inserted into the upper lid 13 in which the gland member 30 is incorporated from the opposite side of the seal structure, that is, from the lower end opening side via the thrust ring 46 (fifth
figure).

In the process of assembling the gland member 30 and the valve stem 6, the retainer 18 is slightly hammered in using a tool while it is in contact with the entrance of the gland hole 15.

However, although the yarn-like packing 31 bulges inward to some extent, it is press-fitted by applying an appropriate external force such as applying a rotational force when inserting the valve stem 6, and the dimensions of each part are adjusted so that a suitable liquid sealing effect can be obtained. decide. At this time, the valve stem 6 acts as a gripping part, making it easy to apply force.

Next, the valve 1 lug 21 and the valve stem 6 are inserted into the valve body 2, and the upper cover 13 is fitted to the upper end opening a112 of the valve body 2 via the gas get 40, and fastened with bolts (sixth
figure).

There are two possible assembly methods at this time, one of which is to drop the stud 9 into the valve body 2 in advance, fit its lower end into the recess 38, and then attach the gas get 40 to the upper end opening 12. Lift it up while it is still placed on the stepped surface! Insert the valve plug 21 unitized with the i13 and the valve stem 6 into the valve body 2, fit the bearing flange 24 of the valve plug 21 to the upper end of the stud 9, and then press the top! 113 between upper ends O section 1
2 and secure it.

Another option is to turn the top cover 13 upside down and use the valve 1 lug 2.
1 facing upward, fit the stud 9 into the lower bearing part 24, place the gas get 4o on the upper part 1113, turn the valve body 2 upside down and place it over the valve plug 21 from above, and then fit the stud 9 into the valve body #1. 2, and the upper lid 1 is fitted into the upper end opening 12.
3 are fitted through the gas get 40 and fastened and fixed with bolts. Then, return the bento book #2 to its original position.

In this case, the latter assembly method is more suitable for automatic assembly, but
Either is fine here.

After the drive system consisting of the valve 116 and the valve plug 21 is assembled into the valve body 2 in this way, the seat ring 7 is fitted into the upstream m opening 19 of the valve body #2 as shown in FIG. At the same time, the retainer 17, which is the fixing means, is fitted through the seat spring 41 and the O-ring 42, and the seating surface 8 of the seat ring 7 is fitted onto the spherical seating portion 2 of the valve plug 21.
Close to 5. After this, a drive section (handle) for applying rotational force to the outer end of the valve shaft 6 is installed, thereby completing the assembly work of the rotary control valve 20.

[Effects of the Invention] As described above, according to the method for manufacturing a trim part for a valve having a spherical valve seat according to the present invention, the valve plug and the valve shaft are coaxially joined by welding, and then the spherical surface attachment of the valve plug is performed. Since the MfjJ is finished, it is possible to correctly align the plug ball center with the valve stem, and the valve assembly also rotates concentrically, so the valve plug does not run out eccentrically, and the operation is smooth. It is smooth and suitable for use in continuously operating automatic regulating valves. In addition, when welding the valve stem, the welding torch is inserted into the bearing part on one end of the valve plug, and the valve stem is rotated while maintaining the welding starting position, so that the circumferential surface of the end of the valve stem can be welded uniformly around the entire circumference. Furthermore, even though the valve plug and the valve stem are concentric, the fitting portion between the two can be machined only roughly, making the work very easy.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of a rotary valve equipped with a trim part manufactured by the method of the present invention, Fig. 2 is a perspective view of the valve stem and valve plug, and Figs. FIG. 8, which is a diagram for explaining the manufacturing method and assembly procedure according to the invention, is a sectional view showing a conventional example of a rotary valve. 2...Valve body, 6...-valve shaft, 6a...-tapered surface,
7...- Seat ring, 9-... Stud, 12-...
Upper end opening, 13...Top lid, 15--Gland hole,
17.18-1 Retainer, 21- Valve plug,
23.24... Bearing part, 25... Spherical seating part, 30
-...Gland member, 44...-Welding torch. Patent applicant Yamatake Honeywell Co., Ltd.

Claims (2)

[Claims] (1) A valve plug whose outer peripheral surface has been machined into a rough spherical surface is coaxially joined to the valve shaft by welding, and the valve shaft to which the valve plug is joined is chucked and the spherical surface is finished while rotating the valve plug. A method for manufacturing a trim part for a valve having a spherical valve seat, characterized in that a spherical seat portion having a predetermined curvature is obtained by using a spherical valve seat. (2) The valve shaft is coaxially fitted into the valve shaft side bearing section of the valve plug, which has cylindrical bearing sections at both the upper and lower ends, and whose outer circumferential surface is roughly machined into a spherical surface, and the valve shaft is fitted coaxially into the valve shaft side bearing section, and the valve plug has cylindrical bearing sections at both the upper and lower ends, and the outer peripheral surface is roughly machined into a spherical surface. Insert a welding torch, and while maintaining the welding starting position of the torch, rotate the valve shaft and valve plug around their central axes to weld the entire circumference of the peripheral edge of the bearing side end of the valve shaft to the bearing. and then chucking the valve shaft joined to the valve plug and finishing the spherical surface while rotating the valve plug to obtain a spherical seat having a predetermined curvature. A method for manufacturing a valve trim part having the following.