JPH11270710A - Molding of ball for ball valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for molding a ball for a ball valve relatively easily and stably accurately, wherein the material and machining costs are not so expensive, the ball is to be rigid and relatively lightweight, fluid resistance is low, foreign matter is prevented from accumulating and precipitating inside, and a metal mold is not complicated. SOLUTION: In this method of molding a ball for a ball valve, an intermediate shape unit having an inner cylinder 3 forging a forging material consisting of metal material to be provided with a disk-shaped partition wall 4 on the upper end side, a bottom part 3b connected to a lower end of the inner cylinder 3, and an outer cylinder 6 with an external shape on the side of the bottom part 3b forming a surface 5 of circular arc section, is molded, the intermediate shape unit is press worked, an opening end of the outer cylinder 6 is closely abutted to the inner cylinder 3, at least an opening end side of the outer cylinder 6 is molded into the surface 5 forming the circular arc section, and the disk- shaped partition wall 4 on the upper end side is cut off from the inner cylinder 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a ball for a ball valve which is mounted on a pipe of water, oil, gas or the like and used for controlling the fluid.

[0002]

2. Description of the Related Art There are various types of balls 22 used for a ball valve 21 as shown in a vertical sectional view of FIG. 4, and they are made by different molding methods.
The ball 23 shown in the vertical cross-sectional view of FIG. 5 is made by cutting a round bar or a forged material. The ball 23 formed by this forming method has many portions to be shaved, and the material is wasted. More and more expensive. Also, since there is no hollow portion, it is heavy, and particularly large diameter one is extremely heavy.

The ball 24 shown in the longitudinal sectional view of FIG. 6 is made by casting or welding a plate or tube by pressing or the like, and has a hollow portion 24a, so that the ball 24 is lighter. Has become. However, when casting is used, defects such as cavities are often found after spherical processing, and in this case, material and processing time are wasted. Also, since the shape is complicated, it is necessary to thicken the meat to improve the flow of hot water,
Therefore, the processing cost is so large that much time is required for the processing.

[0004] When a plate or pipe is made by welding such as press working, the relationship between the pipe diameter and the wall thickness is limited, and the pipe or pipe is generally soft, easily deformed, and difficult to handle. . Welding is also a very cumbersome operation because the welds are relatively thin and therefore easily deformed by heat.

The ball 25 shown in the vertical sectional view of FIG. 7 is made by casting or pressing a plate material or a tube material.
Although it can be made lightweight and inexpensive, this ball 25
The flow of the fluid flowing through the inside of the ball 25 is disturbed to increase the fluid resistance, and foreign matter in the fluid is accumulated or deposited in the inside 25a of the ball 25, which is caught between the ball and the seat and hinders the operation of the valve. Or spills may have an adverse effect on the piping system. In the case of making by casting, there is a problem due to a cavity as in the case of the ball 24 shown in FIG. 6, and when making a plate material or a tube material by pressing or the like, it is soft and easily deformed. become.

Further, the hollow spherical body disclosed in Japanese Patent Application Laid-Open No. 9-314267 and a molding method thereof relate to a ball used as a plug of a ball valve. This is a solution to the problem in. FIG. 8 is a longitudinal sectional view showing the intermediate body in the molding method, and FIG. 9 is a longitudinal sectional view showing the intermediate body in a state where the outer diameter is made spherical thereafter.

The intermediate body 26 shown in FIG. 8 is obtained by forming a forging material such as a round bar by hot forming or the like.
The inner cylinder part 26a and the outer cylinder part 26b are connected at the lower part,
The outer shape below the outer cylinder part 26b is hemispherical. The partition 26c remains inside the inner cylinder 26a. The outer shape of the outer cylindrical portion 26b of the intermediate shape body 26 is deformed so that the outer shape is continuous with the lower outer shape.
The tip of 6b and the tip of the inner cylinder 26a are brought into close contact with each other to form the intermediate body 27 shown in FIG.

[0008]

However, according to this method, when the outer cylindrical portion 26b is deformed into a spherical shape as described above and its tip is brought into close contact with the tip of the inner cylindrical portion 26a, the deformation occurs. The tip of the outer cylinder 26b is the inner cylinder 2
6a is excessively pushed downward in the drawing to buckle the inner cylinder portion 26a, and the inner cylinder deforms toward the space with the outer cylinder, and the tip of the outer cylinder portion 26b becomes the tip of the inner cylinder portion 26a. , Or the outer cylindrical portion 26b may not be spherical. This phenomenon is particularly noticeable during hot forming.

The method of molding a ball for a ball valve according to the present invention solves the above-mentioned problems of the conventional ball as shown in FIGS. 5 to 7 and a diagram for solving these problems. The purpose of the present invention is also to solve the problems in the ball molding method shown in FIG. 8 and FIG. 9, and the purpose is to reduce material costs and processing costs, improve yield, and reduce weight, It is to form a ball that improves the function of the valve without causing turbulence in the fluid or accumulating or depositing foreign matter in the ball. The object of the present invention is to provide a molding method which does not cause the problem.

[0010]

Means for Solving the Problems To solve the above-mentioned problems, the present invention provides an inner cylinder having a disk-shaped partition wall provided at the upper end by forging a forging material made of a metal material. An intermediate body having a bottom connected to the lower end of the inner cylinder, and an outer cylinder having a bottom-side outer surface forming an arc-shaped cross section is formed, and the intermediate body is pressed to form an outer cylinder opening end. By bringing the outer cylinder into close contact with the cylinder, the opening end side of the outer cylinder was formed into a surface having a circular cross section, and the disk-shaped partition was cut off from the inner cylinder.

Further, a part of the outer cylinder of the ball formed by the above method, which is not in contact with the seat, may be cut off.

The ball for a ball valve formed by the forming method of the present invention is obtained by forging a forging material and performing machining or the like to form the outer shape of the ball and a cylindrical through hole. There is no defect such as
An economical ball that is strong, not too heavy and does not require excessive material and processing.

In the ball for a ball valve of the present invention, if a part of the outer cylinder of the ball that does not contact the seat (see the seat 22a in FIG. 4) is cut off, the weight of the ball can be further reduced, and the stem can be further reduced. Even if cutting chips and the like generated when cutting the mounting portion enter the hollow portion of the ball, they can be easily removed.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing a ball valve forming method according to an embodiment of the present invention. FIG. 1 is a longitudinal sectional view showing an example of the ball for a ball valve of the present invention, FIG. 2 is a longitudinal sectional view showing a first intermediate body in the process of molding the same, and FIG. It is a longitudinal section showing the 2nd intermediate figure.

The first intermediate body 2 shown in the longitudinal sectional view of FIG.
Is formed by forging a forging material made of a metal material, and has a disk-shaped partition wall 4 on the upper end 3a of the inner cylinder 3.
The bottom 3b connected to the open lower end has
A surface 5 having an arc cross-section located outside the inner cylinder 3 is connected, and a large-diameter end portion 5a of the surface 5 having an arc cross-section is connected to an outer cylinder 6. The surface 5 which becomes the circular arc of the cross section is the bottom 3
Formed to form part of a sphere in combination with the outer shape of b.

FIG. 3 shows an opening of the outer cylinder 6 of the first intermediate body 2 shown in FIG. 2 formed on a surface 6a having an arcuate cross section. It is a longitudinal cross-sectional view of the 2nd intermediate-shaped body 7 shape | molded closely outside the upper end 3a which has this. The outer cylinder 6 is formed into a spherical shape in combination with the outer shape of the bottom portion 3b and the surface 5 having a circular arc cross section.

In the case where at least both ends of the ball are formed into an arcuate surface, the sheet contact surfaces at both ends of the ball may be formed into an arcuate surface, and an intermediate portion connecting the two arcuate surfaces may be a flat surface. Forms the sealing surfaces at both ends of the ball (outer cylinder) into arcuate surfaces.

Next, the partition wall 4 of the second intermediate body 7 shown in FIG.
The stem mounting portion 9 is formed by cutting, and a portion of the outer shell 10 of the outer cylinder 6 that is not in contact with the sheet is cut to form a cutout hole 11. The ball shown in FIG. 1 is completed by polishing the surface and, if necessary, plating or the like.

The inner cylinder 3 of the ball 1 shown in FIG.
A through hole communicating the body cavity with the flow path may be provided. This through-hole causes the temperature of the fluid (especially liquid) in the body cavity to rise due to the flow of high-temperature fluid in the open valve or the heating of the fluid from the outside, causing the body cavity to abnormally increase in pressure. This is for preventing the ball 1 from being deformed.

As described above, the ball 1 formed by the molding method of the present invention is a forged product having no defects such as cavities and the like. An economical ball that is not too heavy and does not require excessive material or processing.

Further, since a cylindrical flow path is formed by the through holes 8, the flow of the fluid is not disturbed and the flow path resistance is not increased, and foreign matter is accumulated or deposited in the ball 1, This does not enter the body of the valve and hinder the operation of the valve, and does not flow out and adversely affect the piping system.

When the outer cylinder 6 of the first intermediate body 2 is deformed and its opened end is brought into close contact with the outside of the upper end 3a having the partition wall 4 of the inner cylinder 3, the inner cylinder 3 Since it is not buckled and deformed by being supported by the disk-shaped partition wall 4, reliable close contact can be achieved, and a complete spherical outer shell portion 10 can be formed.

Further, since the ball 1 is provided with a cutout hole 11 by cutting a part of the outer shell 10, the weight of the ball 1 can be further reduced, and the ball 1 is generated when the stem mounting portion 9 is cut. Even if cutting chips enter the hollow portion 13 of the ball 1, they can be easily removed.

In addition, the method of forming the ball of the ball valve of the present invention is relatively simple, the mold and the like are not complicated, a high-precision ball material can be produced, and a high-quality ball can be produced.

[0025]

As described above, the method for forming a ball for a ball valve of the present invention is relatively simple, the mold is not complicated, and a uniform and high-precision ball material can be produced. Can be made. Also, this ball
Material cost, processing cost, etc. can be reduced, and the wall thickness is optimal, strong, lightweight, and extremely economical. In addition, a cylindrical flow path is formed, the fluid resistance is small,
No foreign matter accumulates or accumulates in the ball, and the outflow does not adversely affect the ball valve or the piping system.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a ball formed by a method for forming a ball for a ball valve of the present invention.

FIG. 2 is a vertical sectional view showing a first intermediate body in the molding of the ball shown in FIG. 1;

FIG. 3 is a longitudinal sectional view showing a second intermediate body in the molding of the ball shown in FIG. 1;

FIG. 4 is a longitudinal vertical sectional view showing an example of a normal ball valve.

FIG. 5 is a longitudinal sectional view showing an example of a conventional ball for a ball valve.

FIG. 6 is a longitudinal sectional view showing an example of a conventional ball for a ball valve.

FIG. 7 is a longitudinal sectional view showing an example of a conventional ball for a ball valve.

FIG. 8 is a longitudinal sectional view showing an intermediate body in a conventional method for molding a ball for a ball valve.

FIG. 9 is a longitudinal sectional view showing an intermediate body in a conventional method for molding a ball for a ball valve.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ball 2 Intermediate-shaped body 3 Inner cylinder 3b Bottom part 4 Partition wall 5 Surface which becomes circular arc 6 Outer cylinder 11 Cut-out hole

Claims (2)

[Claims] 1. A forging material made of a metal material is forged, and has an inner cylinder provided with a disk-shaped partition wall on an upper end side, a bottom connected to a lower end of the inner cylinder, and a bottom-side outer shape having a cross section. By molding an intermediate body having an outer cylinder that forms an arc-shaped surface, and pressing the intermediate body so that the outer cylinder opening end is in close contact with the inner cylinder, the opening end side of the outer cylinder is formed into a circular cross section. A method for forming a ball for a ball valve, wherein the disk-shaped partition is cut off from an inner cylinder. 2. A method for forming a ball for a ball valve, wherein a part of the outer cylinder of the ball according to claim 1 is cut off.