JPH0449029A - Manufacture of monolithic-molded ball valve - Google Patents

Abstract

PURPOSE:To avoid defective sealing performance due to the deformation of ball, etc. and the partial fusion, etc. of the ball, etc. and a valve casing by previously mixing a fixed quantity of a forming agent with a resin material molding the valve casing, foam-molding the resin material while being injected into a molded at low pressure by using the mold and manufacturing the title ball valve. CONSTITUTION:A proper quantity of a foaming agent is injected previously to a resin liquid injected into a mold, and the resin liquid is injected at a pressure lower than that of normal injection molding. Uniform pressure is applied from the inside to the whole by the foaming agent in the mold in the resin liquid injected at that time, and smooth surfaces are formed at positions brought into contact with each section of a ball, a seal 5, a spindle section 3b, an O ring 4 and upper and lower molds 1a, 1b. The resin is solidified, the upper and lower molds 1a, 1b are released, a valve box is extracted, and left and right holding inserts 6 are rotary removed.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method of manufacturing an integrally molded ball valve.

(Prior art) A conventional ball valve has a ball that serves as a valve body, as shown in Figure 1.
tv1' and a sea area surrounding the inlet/outlet side of the flow path 1'a.
In order to insert L/2' into the pulp casing 31, attach two pieces of pulp casing 3'a on the left and right.

It is assembled by dividing it into parts 3'b, attaching the bow zLz 1' and the seal 2', and then screwing them together.

In the drawings, 4' is a steering wheel, 51 and 6' are circles, and 71 is a handle.

(Problems to be Solved by the Invention) Conventional products are bonded products as described above, and therefore have drawbacks such as complicated manufacturing problems and sealing problems, as well as increased cost.

The present invention aims to provide a new method for manufacturing integrally molded pole bulbs that eliminates these drawbacks.

(Means for Solving the Problems) The present invention provides a ball having a flow path in the center and having a handle attachment spindle ρ formed in a direction perpendicular to the flow path;
A certain amount of foaming agent is mixed in advance into the resin material used to mold the resin pulp casing, which is integrally molded with the seal surrounding the inlet and outlet sides of the flow path of the ball, and the foaming agent is mixed into the resin material using a mold. It is characterized by being manufactured by foam molding while being injected into a mold at low pressure.

The operation of the present invention will be specifically explained with reference to the following examples.

(Example) FIGS. 2A and 2B show the manufacturing state, and FIG. 3 shows the ball, with A being a front view and B being a side view of the same.

1a is an upper mold, 1b is a lower mold, and a female mold of the pulp casing 2, which is divided into two parts with desired dimensions and shapes, is formed at the center of each mold. Reference numeral 3 denotes a valve part 3 which is made of metal or resin in advance and has a spherical shape.
A and Nupindo, y8b and Nanashi, and a flow path 3C is bored in the center of the valve part. 4. The O-ring and the ring are seals that are brought into contact with the inlet and outlet sides of the flow path 3C.

On the other hand, numeral 6 denotes a pair of holding inserts to be held and fixed symmetrically at the boundary between the 1-metal gold 5ia and the lower mold 1b, which are held between the upper mold 1a and the lower mold 1b, respectively. The large step part 6b1 has a male thread S carved on its outer periphery, and the small step part 6bz has a fixed part 6a to be fixed and a large and small stepped projection 6b protruding into the female die forming the valve body. The outside of the valve portion 3a is the same as the inside of the flow path 3C of the valve portion 3a.

On the other hand, 7 is a resin injection gate, which is connected to the lower mold 1 on the opposite side to the spindle part 8b so that the flow of molten plum fat is symmetrical.
It is provided at the bottom position of b.

By the way, an appropriate amount of foaming agent is not injected into the resin liquid injected into the mold in advance, and the resin liquid is injected at a pressure lower than that in normal injection molding. The resin liquid injected into the mold is heated by a foaming agent inside the mold, and a uniform pressure is applied to the entire mold from inside, forming a mold of Pole L/3.
, the seal lv5, the spindle part 3b10, the ring 4, and the upper and lower molds 1a, 1b, etc., form smooth surfaces at the points where they come into contact with each other.

Then, the upper and lower molds 1a and tb for solidification and removal of the resin liquid are opened, the valve box is taken out, and the left and right holding inserts 6 are rotated and removed. Fig. 4 shows a cross section of the product manufactured in this way. It is a diagram.

The balls used in the practice of the present invention are made of metal, resin, or the like, and in the case of resin, they are made of a resin that has a higher melting point than the resin used for pulp casings and has non-layer properties. Note that the holding insert 6 is made of metal and is used repeatedly.

(Achievements of the invention) In the present invention, a foaming agent is mixed into the injected resin liquid and injected at low pressure, so high local pressure is not applied to balls etc. built into the mold. In other words, it is possible to inexpensively and efficiently manufacture ball valves of extremely excellent quality by avoiding poor sealing performance due to deformation of balls, etc., and partial fusion of balls and valve casings, etc. It becomes something that can be done.

[Brief explanation of drawings]

Figure 1 shows the manufacturing state of the conventional product, Figure 2 A, 13
3 shows the manufacturing state according to the present invention, FIG. 3 shows the ball used in the present invention, A is a front view, B is a side view, and FIG. 4 is a sectional view of the product. la, -0 upper mold 1b...lower mold 2...
・Pulp casing 3...Ball 5...Seal I
v 6...Holding insert 7...Resin injection gate Patent applicant: Kyokuto Shokai Co., Ltd., -V Nee'' -MP Drawing of C drawing in Figure C

Claims (1)

[Claims] (1) A resin that is integrally molded by embedding a ball that has a flow path in the center and a spindle for attaching a handle in a direction perpendicular to the flow path, and a seal that surrounds the inlet and exit sides of the flow path of the ball. manufactured by mixing a certain amount of foaming agent into the resin material used to mold the valve casing in advance, and foam-molding this by injecting it into the mold at low pressure using a mold. A method for manufacturing an integrally molded ball valve featuring: