JP2842126B2 - Racket molding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a racket forming method. In particular, the present invention relates to a racket forming method for connecting a pressurizing tube and a pressure source by a joint mechanism that is easily detachable and does not leak when a racket frame is formed by an internal pressure forming method using a pressurizing tube.

[0002]

2. Description of the Related Art A method called an internal pressure molding method has been developed as one of molding methods for producing a racket made of synthetic resin. This internal pressure molding method uses FRP or FRTP
When molding a racquet frame made of rubber, a pressure tube made of rubber or silicone is inserted into the hollow portion of an FRP or FRTP prepreg formed into an elongated hollow body, and this prepreg is flattened into an upper mold and a lower mold. This is a method in which a prepreg is set in a mold, a mold is heated, a pressurized fluid such as compressed air is introduced into a pressurizing tube, and the prepreg is pressed against an inner wall of the mold by expanding the pressurizing tube to be cured. By this internal pressure molding method, a racket frame excellent in surface smoothness and free from sink marks and voids can be obtained. One end of the pressure tube is sealed for pressurization, and a nozzle extending from a pressure source is inserted into the other end.
However, if the nozzle is simply inserted into the pressurizing tube, the nozzle is pushed out as the internal pressure increases when the pressure fluid is introduced, and eventually falls off from the pressurizing tube. Also,
In some cases, the gap between the pressurizing tube and the nozzle is widened and the pressurized fluid leaks. Conventionally, in order to prevent such "press leakage", the portion of the pressure tube into which the nozzle has been inserted has been tied with a string or the like from the outside, or wound with a tape and fixed by pressing.

[0003]

Since such a conventional nozzle fixing method is all performed by hand, it requires a lot of man-hours, resulting in poor work efficiency. The process was unstable, such as sudden leakage during molding. As a method of securely clamping the nozzle, at the tip of the nozzle, an annular convex portion formed with a diameter larger than the inner diameter of the pressure tube is provided, and this portion is inserted deeply into the pressure tube, and the subsequent nozzle There is a method in which the periphery of the portion where the cylindrical portion is inserted is fixed by fastening with a fastening band or the like. Although this method is more reliable than the above-described method of tying with a string, the fastening of the fastening band is manually performed, so that there remains a problem in work efficiency. The present invention has been made to solve this problem. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method of forming a racket using a joint mechanism of a pressure tube which can be easily attached and detached and does not cause pressure leakage during a molding operation.

[0004]

In order to solve the above-mentioned problems, the present invention provides a joint mechanism for connecting an end of a pressure tube and a pressure source when a racket is formed by the internal pressure forming method. A nozzle that extends from the pressure source and is inserted into the end of the pressure tube, and a sleeve that is integral with and separateable from the upper die and the lower die, respectively, surrounding the nozzle insertion portion of the pressure tube into which the nozzle is inserted; Formed at the tip of the nozzle to form an annular convex portion having a diameter larger than the inner diameter of the pressure tube, and the inner wall of the sleeve,
The annular convex portion is inserted and formed to have a smaller diameter than the outer diameter of the raised portion of the pressurized tube, and the nozzle is inserted into the pressurized tube before introducing the pressurized fluid into the pressurized tube. The present invention provides a method of forming a racquet in which a portion is surrounded by a sleeve, and a raised portion of the pressure tube is nipped between the annular convex portion and the inner wall of the sleeve to clamp the pressure tube to the nozzle. In the above, a stop ring is provided on the cylindrical portion of the nozzle, and a stopper is provided at the flat end to engage with the stop ring, and the stop ring comes into contact with the stopper to move the nozzle when introducing the pressurized fluid. Is preferably stopped. In the above, it is preferable that the inner wall of the sleeve is formed to have a gradually decreasing diameter toward the pressure source side.

[0005]

The joint mechanism in the racket forming method of the present invention has an annular convex portion at the tip of the nozzle, and a sleeve having a diameter smaller than the outer diameter of the raised portion of the pressurizing tube into which the nozzle is inserted is formed outside. The pressure tube is pinched between the annular convex portion of the nozzle and the sleeve and pressed against the nozzle to exhibit a packing effect to prevent pressure leakage and to cause the nozzle to fall out due to strong frictional resistance. Also prevent. Since this sleeve is integrated with the upper and lower molds of the flat type and can be divided, the above-mentioned nozzle is inserted into the end of the pressurizing tube, and the nozzle insertion portion of this pressurizing tube is referred to as the lower mold. Place it on one of the integrated sleeve pieces,
By simply overlapping the upper die with the other sleeve piece integrated with the lower die, the above-described pressing and upper / lower die alignment are achieved simultaneously, and the work efficiency of racket molding is significantly increased. Furthermore, if a stop ring is provided in the cylinder of the nozzle and a stopper is provided at the end of the mold to engage with the stop ring, when the pressure fluid is introduced, the direction in which the nozzle comes out of the mold due to strong fluid pressure. Even when the nozzle slides, the nozzle is stopped by this stopper and the nozzle does not fall out. Further, when the inner wall of the sleeve is formed with a gradually smaller diameter toward the pressure source side, when the nozzle is pressed toward the pressure source side by the internal pressure,
The raised portion is pushed into the gradually narrowing gap between the annular convex portion and the sleeve, and the effect of preventing pressure leakage is enhanced.

[0006]

Next, an embodiment of the present invention will be described with reference to the drawings. Embodiment 1 FIGS. 1A and 1B show an embodiment of a racket forming method of the present invention. In the figure, reference numeral 10 denotes a nozzle, 20
Reference numerals a and 20b denote flat upper and lower dies, respectively.
b denotes each piece of the sleeve integrated into the upper mold and the lower mold, 30 denotes a pressure tube, and 40 denotes a prepreg. Here, the joint mechanism used in the method of the first embodiment generally includes the nozzle 10 and the respective pieces 21a and 21b of the sleeve.

[0007] The nozzle 10 has an annular convex portion 11 at the tip of a cylindrical portion inserted into the end of the pressurizing tube. The diameter of the annular projection 11 is the inner diameter h of the pressure tube 30.
Molded to a larger diameter. Further, the nozzle 10 is provided with a stop ring 13 at a predetermined position of the cylindrical body. Each piece 21a, 21b of the sleeve is molded integrally with each piece 20a, 20b of the flat mold so that the sleeve is formed when the upper and lower molds 20a, 20b are overlapped. (The formed sleeve is indicated by reference numeral 21 hereinafter). The sleeve 21
The pressure tube is disposed at a position surrounding the nozzle insertion portion 31. The inner wall of the sleeve 21 has a raised portion 32 of the pressure tube into which the annular convex portion 11 of the nozzle is inserted and raised.
Is formed to have a smaller diameter than the outer diameter S. Thereby, as shown in FIG. 1B, when the annular convex portion 11 of the nozzle is arranged inside the sleeve 21, the raised portion 32 is pressed between the annular convex portion 11 and the inner wall of the sleeve 21. It is designed to be pressed. Stoppers 23a and 23b are provided at the ends of the dies 20a and 20b at positions where they engage with the stop rings 13 of the nozzles.

In this embodiment, first, a pressure tube 30 made of silicone is inserted into a hollow portion of an FRP prepreg 40 formed into an elongated hollow body forming a racket frame. One end of the pressure tube 30 is sealed, and the other open end is drawn out from the end of the prepreg 40 by a certain length. As shown in FIG. 1A, a nozzle 10 is attached to the end of the drawn pressure tube 30.
Is inserted until the end of the pressure tube 30 comes into contact with the stop ring 13 provided on the cylindrical body of the nozzle 10. The other end of the nozzle 10 is connected in advance to a pressure-resistant hose (not shown) of the air compressor. The prepreg 40 is set on the lower mold 20b. At this time, the nozzle insertion portion 31 of the pressure tube is arranged on the concave surface of the sleeve piece 21b formed on the lower mold 20b.
In this state, the stop ring 13 of the nozzle is in contact with the end surface of the sleeve piece 21b. Next, the upper mold 20a is connected to the lower mold 2
When overlapping with 0b, the sleeve piece 21a formed integrally with the upper mold 20a overlaps the sleeve piece 21b to form the sleeve 21.

Next, the upper and lower dies 20 a and 20 b are heated to the curing temperature of the prepreg 30, and a pressure fluid is introduced into the pressure tube 30 through the nozzle 10. When the internal pressure of the pressure tube 30 increases, as shown in FIG.
The pressurizing tube 30 expands and presses the prepreg 40 against the upper and lower mold surfaces 22a and 22b. At the same time, the nozzle 10 is also pressed, and slides inside the pressure tube 30 toward the pressure source. This sliding is performed by the stop ring 13
a, 23b to stop. At this time, since the annular convex portion 11 of the nozzle is shifted to the inside of the sleeve 21, the raised portion 32 is pinched between the annular convex portion 11 of the nozzle and the sleeve 21, exhibiting a packing effect and causing the nozzle 10. Closely clamped. Therefore, in this state, the nozzle 10 falls out, and the nozzle 10 and the pressure tube 30
No leakage of the pressurized fluid from between the two.

When the curing of the prepreg 40 is completed, the pressure in the pressure tube 30 is removed and the upper mold 20a is removed, and at the same time, the sleeve portion 21a is also removed. Therefore, the formed racket frame can be easily attached to the lower mold 20 with the pressure tube 30 and the nozzle 10 attached.
b can be released from the mold. At this time, since the pressurizing tube 30 is contracted, it can be easily pulled out from the racket frame. Since the pressure tube 30 and the nozzle 10 can be used as they are for the next molding operation, there is no need to separate them.

(Embodiment 2) FIG. 2 shows another embodiment of the present invention. Also in the joint mechanism used here, the sleeve 21 is formed integrally with the upper and lower flat molds 20a and 20b for internal pressure forming as in the first embodiment. However, the inner wall of the sleeve 21 is formed so as to have a gradually decreasing diameter on the pressure source side, and a stop ring is removed from the nozzle 10 and a stopper is removed from the mold. The operation of this embodiment is the same as that of the first embodiment. However, when an internal pressure is applied to the pressurizing tube 30, the sliding of the nozzle 10 toward the pressure source side progresses to a certain extent and stops because the inner wall of the sleeve 21 is gradually narrowed toward the pressure source side. The protruding portion 32 at this time is pushed into a narrow gap formed by the annular convex portion 11 and the sleeve 21, and is pinched to exhibit a packing effect, and is tightly pressed against the nozzle 10. Therefore, in this state, the nozzle 10 does not fall out and the pressurized fluid does not leak from between the nozzle 10 and the pressurizing tube 30.

In any of the molding methods of the first and second embodiments, since the sleeve is integrated with the upper and lower dies and is divided, it is extremely easy to set and release the molded product, and to apply the pressure. There is no dropout or pressure leakage of the nozzle during molding.

[0013]

According to the racket forming method of the present invention, when the racket frame is formed by the internal pressure forming method, a joint mechanism for connecting the end of the pressurizing tube and the pressure source is extended from the pressure source to extend the pressurizing tube. And a splittable sleeve which is integrated with the upper and lower molds surrounding the nozzle insertion portion of the pressure tube into which the nozzle is inserted, and which can be divided. Since the annular convex portion formed to have a larger diameter than the inner diameter of the pressurizing tube is formed, and the inner wall of the sleeve is formed to have a smaller diameter than the outer diameter of the raised portion of the pressurized tube in which the annular convex portion is inserted and raised. The pressure of the pressurizing tube at the time does not cause the nozzle to fall off or leak, and the molded article can be easily attached and detached, thereby improving the working efficiency.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.
(A) shows a state before pressurization, and (b) shows a state during pressurization.

FIG. 2 is a sectional view showing another embodiment of the present invention.
(A) shows a state before pressurization, and (b) shows a state during pressurization.

[Explanation of symbols]

10 ... nozzle, 11 ... annular convex part, 21 ... sleeve, 30
… Pressure tube, 32 ridge, h… Pressure tube inner diameter.

Claims (3)

(57) [Claims] 1. An elongated hollow forming a racket frame.
Of FRP or FRTP prepreg
Insert rubber or silicone pressure tube into hollow section
Then, set this prepreg into a flat type consisting of an upper die and a lower die.
And heat the flat mold and put it in the pressure tube.
Introducing pressure fluid and inflating this pressurized tube
Press the prepreg against the flat inner wall to cure it
When forming a racket, a joint mechanism that connects the end of the pressure tube and the pressure source,
A nozzle extending from the pressure source and inserted into the end of the pressure tube, and whether the nozzle is integrated with an upper die and a lower die surrounding the nozzle insertion portion of the inserted pressure tube, respectively.
One is composed of a split sleeve, forming an annular convex portion than the inner diameter of the pressure tube is formed into a large diameter at the tip of the nozzle, and an inner wall of said sleeve
And the annular convex portion is formed smaller in diameter than the outer diameter of the raised portion of the raised pressure tube is inserted, the pressure in the pressure tube
Insert the nozzle into the pressurized tube before introducing the fluid.
Insert the nozzle, surround the nozzle insert with a sleeve, and
The raised portion of the tube is sandwiched between the annular convex portion and the inner wall of the sleeve.
Racket molding that presses and presses the pressure tube to the nozzle
How . 2. A stop ring is provided in the cylinder of the nozzle.
And the flat end is fitted with a stop ring.
Provide a topper and stop ring abuts this stopper
Stops the nozzle movement during pressure fluid introduction.
The method for molding a racket according to claim 1, wherein the racket is formed. 3. The inner wall of the sleeve is gradually raised toward the pressure source side.
The racket according to claim 1, wherein the racket is formed to have the next smaller diameter.
Molding method.