JPH0784022B2 - Racket frame manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to tennis, soft tennis,
The present invention relates to a racket frame manufacturing method for rackets that can be used for squash, badminton, racket balls, and the like.

[0002]

2. Description of the Related Art A conventional method for manufacturing a racket frame of this type is disclosed in, for example, Japanese Patent Laid-Open No. 56-168764.
The core member made of fiber reinforced plastic is used as a strength member,
There is provided a method of manufacturing a racket frame, the outer shell of which is injection-molded with a fiber-reinforced thermoplastic synthetic resin. In the above racket frame manufacturing method, a fitting recess is formed on the upper and lower surfaces of the core as a means for holding the fiber-reinforced plastic core in the mold space. Inserting and fixing the stop pin, and by mounting the inserted and fixed locking pin in the fitting holes provided on the inner surfaces of the upper and lower molds, the core body is held in the mold space,
A synthetic resin for forming an outer shell was injected.

[0003]

However, in the above-mentioned conventional racket frame manufacturing method, since the core body is held in the mold space only by the locking pins on the upper and lower surfaces, The pin has to be fitted not only in the fitting hole on the mold side but also in the fitting recess of the core body, so that it is necessary to form the fitting recess in the core body. However, since the core body is required to be light in weight and needs to be formed into a hollow tube shape, it is necessary to form the fitting recess in the core body having a small wall thickness. There were many problems in actual manufacturing in terms of equipment, work cost, strength, yield, etc., even when the fitting recess was formed in the core later or when it was integrally formed from the beginning. .

In view of the above, the present invention solves the above-mentioned drawbacks of the prior art by arranging the internal structural body of the frame in the mold space, and injection molding resin into the mold space around the internal structural body, whereby the internal structure is improved. An object of the present invention is to provide a manufacturing method of a racket frame which is easy to manufacture in a manufacturing method of molding a racket frame in which a resin outer component is coated around the body.

[0005]

In order to achieve the above object, in the method for manufacturing a racket frame of the present invention, the internal structure of the frame is arranged in the mold space, and the mold space around the internal structure is provided. A method of manufacturing a racket frame, comprising molding a resin-made outer component around the inner component by injection molding a resin to form a racket frame,
A resin positioning member is arranged so as to project from above and below and to the left and right of the inner surface of the mold into the mold space, and the internal component is positioned and held in the mold space in a manner of abutting against the resin positioning member. The first feature is that the resin positioning member is formed as a part of the meat of the resin external component by injecting resin into the mold space. Further, in the racket frame manufacturing method of the present invention, the inner structural body of the frame is disposed in the mold space, and the resin is injection-molded in the mold space around the inner structural body, so that the inner structural body is surrounded. A method for manufacturing a racket frame for molding a racket frame covered with a resin external component, wherein the internal component is integrally formed with vertical and horizontal positioning projections, and the positioning projections are Positioning and holding the internal component in the mold space so as to contact the inner surface of the mold, and injecting resin into the mold space to form a resin external component in which the resin positioning member remains. Second to do
It is a feature of.

[0006]

According to the first feature of the present invention described above, the internal structure is accurately held in the mold space by the resin positioning members on the upper, lower, left and right sides of the mold. And a resin outer component is formed around the inner component to form a racket frame. The resin positioning member becomes part of the flesh of the injection-molded resin outer structure, and is removed from the mold as a part of the racket frame. Since the inner structure is not provided with any fitting recesses for positioning pins or the like, the outer inner structure can be easily constructed or manufactured. Further, since the resin-made positioning member extends vertically and horizontally from the mold, the internal component can be positioned vertically and horizontally, and the positioning can be surely performed without inserting a positioning pin or the like. Further, when inserting the resin positioning member into the fitting hole of the mold, by removing the protruding portion after removing from the mold, and without inserting the resin positioning member into the fitting hole of the mold etc. When mounting on the inner surface of the mold, it is not necessary to grind the protruding portion after removing the mold. Further, according to the second aspect of the present invention, by disposing the internal component in the mold space, the positioning projections of the internal component come into contact with the inner surface of the mold vertically and horizontally, and the internal component is Accurately positioned in place. Then, in that state, the resin is press-fitted into the mold space, and the racket frame in which the resin external component is configured is formed around the internal component. Since the positioning protrusion of the inner structure does not protrude from the resin outer structure, it is not necessary to carry out a scraping operation later. In addition, integrally molding the positioning protrusion on the internal structure is superior in strength to forming a recess for fitting on the internal structure. Furthermore, when the positioning protrusion is integrally formed with the internal structure, the internal structure can be formed even if it is a thin body such as a hollow body. However, there are many molding restrictions in forming the recess for fitting in the internal structural body made of a thin hollow body.

[0007]

1 to 5 are views for explaining a first embodiment of the manufacturing method of the present invention, and FIG. 1 is an overall view of an internal structure,
2 is a view showing a mold, FIG. 3 is a view showing a state in which a resin positioning member is arranged in the mold, and FIG. 4 is a cross-sectional view showing a state in which an internal structural body is positioned and held in a mold space. 5 is a cross-sectional view showing a state in which the molded racket frame is taken out from the mold.

A first implementation method will be described with reference to FIGS. 1 to 4. For example, as shown in FIG. 4, the mold K is composed of split molds 10 and 20 which can be divided into two parts on a plane perpendicular to the thickness direction of the racket frame (plane parallel to the face surface of the racket). 20 is a groove for forming a mold space S, 21
Are formed. The mold space S is completed by combining the two grooves 11 and 21, and the entire inner structural body 30 shown in FIG. 1 is positioned and arranged in the space S. The inner structural body 30 is a core portion of the racket frame, and a resin S is injection-molded into a space S around the inner structural body 30 to form a resin outer structural body 40 around the inner structural body 30. Is formed. Therefore, the internal structure 30 needs to be held and positioned without contacting the inner surface of the mold.

In this embodiment, a resin-made positioning pin 50 is used as a positioning member for positioning the internal structure 30 in the mold space S, and the positioning pin 50 is arranged from above and below and on the left and right of the inner surface of the mold. It is arranged so as to project into the mold space S. Therefore, in this embodiment, one split mold 10 has a bottom surface 11a and a side surface 11a of the groove 11 as shown in FIG.
Insert holes 12a and 12b are provided in b at appropriate intervals, and the other split mold 20 is provided with insert holes 22a in the bottom surface 21a of the groove 21. These insertion holes 12a, 12b, 22
By inserting the resin-made positioning pin 50 into a, the positioning pin 50 comes into contact with the internal structure 30 from above, below, left and right, and the internal structure 30 can be positioned and arranged at a predetermined position in the mold space S. .

In the groove 11 of the one split mold 10, two fixing protrusions 13 are provided from the bottom surface 11a at a position corresponding to the grip position of the racket frame. This fixed protrusion 13
On the other hand, a mounting hole 33 is provided at a position corresponding to the grip of the internal structure 30. In FIG. 2, reference numeral 14 is a molten resin injection passage.

In order to manufacture the racket frame, first, the positioning pins 50 made of resin are inserted into the insertion holes 12a, 12b, 22a for the split molds 10, 20 of the mold K, and then the preformed internal parts are formed. The mounting body 33 is fitted into the fixing projection 13 of the split mold 10 of the structure 30, and the entire internal structure 30 is mounted in the groove 11 of the split mold 10. Then, the other split mold 20 is fitted to the split mold 10. This allows the internal structure
The upper and lower surfaces of 30 and the left and right surfaces are positioned and arranged in the mold space S while being in contact with the resin positioning pins 50 of the split molds 10 and 20. After that, by injecting the resin from the injection passage 14 into the mold space S, the resin-made outer structure 40 is molded around the inner structure 30. When the injection molding is completed, the split molds 10 and 20 are opened and the molded racket frame is taken out. At this time, the positioning pin 50 made of resin is also removed from the mold K together with the racket frame as a part of the meat of the outer structure 40 of the racket frame (see FIG. 5).
The portion of the positioning pin 50 protruding from the outer surface of the racket frame (the insertion holes 12a, 12b, 22 of the mold K)
Remove the part that was inserted into a).

In the above embodiment, the positioning pin 50 made of resin is used as a positioning member for positioning the internal structure 30 in the mold space S, and this is used as the insertion hole 12 of the mold K.
Although it is arranged to be inserted into a, 12b, and 22a, firstly, if the positioning member is made of resin, the pin described in the embodiment
It does not need to be 50, but may be anything that abuts on the surface of the internal structure 30 in a form projecting from the inner surface of the mold K to the space S side. Secondly, the resin positioning member is a mold K.
It may be attached to the inner surface of the mold K without being inserted into the insertion holes 12a, 12b and 22a of the mold K, or may be merely abutting and interposed between the inner surface of the mold K and the internal structure 30. It is possible. By constructing the resin positioning member in this way, the mold K is provided with the insertion hole on the inner surface.
Since it is not necessary to form things such as 12a, 12b, and 22a, and after the external component 40 is injection-molded, the positioning member does not project from the external component 40 of the racket frame. There is no need for subsequent processes such as taking. The present invention also includes a manufacturing method having such a resin positioning member and a mold as described above in its technical scope.

In the above-mentioned embodiment, since the internal structure 30 is required to have strength and light weight, it is preferable to use a hollow body made of fiber reinforced resin. However, as long as it is a resin or other material excellent in strength, it is not necessarily required to be a fiber reinforced resin, and it is preferable that it is lightweight, but it need not be a hollow body. When the internal structure 30 is a hollow body made of the fiber reinforced resin, for example, after making a prepreg made of a thermosetting resin into a tube shape, the internal structure is heated by applying an internal pressure in a mold. Cure into shape. Of course, the hollow internal component may be formed of a fiber-reinforced thermoplastic resin.

In the above embodiment, it is preferable that the resin-made external component 40 to be injection-molded is made of a thermoplastic resin reinforced with short fibers, but if the strength is high, it is not necessary to be a fiber reinforced resin. Absent.

In the above embodiment, the resin positioning pin
The resin positioning member including 50 is made of resin in order to facilitate compatibility with the external component 40 formed by injection molding, but the type of resin is the same resin as the external component 40, and the external component Various thermosetting resins and thermoplastic resins can be selected, except for the resin whose softening and melting temperature is extremely lower than the melting temperature of the resin of the body 40. It may be reinforced with glass fiber or carbon fiber.
Of course, provided that the resin positioning member can play the role of positioning, the resin positioning member does not re-melt during the injection molding of the external component 40 to form an interface with the tissue of the external component 40. Can be said to be preferable.

6 to 9 are views for explaining the second embodiment of the manufacturing method of the present invention. FIG. 6 is an overall view of the internal structure, and FIG. 7 is a partially enlarged perspective view of the internal structure. 8 is a sectional view showing a state in which the internal structure is positioned and held in the mold space, and FIG. 9 is a sectional view showing a state in which the molded racket frame is taken out from the mold.

In the second embodiment, the positioning projection 3 in the vertical direction (thickness direction of the racket frame) is formed on the surface.
4 and a positioning protrusion 35 in the left-right direction (direction of the racket frame width) are integrally formed in advance, and an internal structure 30 is used. Further, the inner surface of the mold K is not provided with the insertion hole for the positioning pin as in the first embodiment. The positioning projections 34, 35 are drawn in a pin-like shape in the drawing, but they do not have to be pin-shaped, and the important point is that they are inside the mold space S of the internal structure 30. It suffices if the positioning is possible, and it may be a bulging portion that contacts the inner surface of the mold K at several points in the vertical and horizontal directions. The positioning protrusions 34 and 35 may be formed of the same material as the main body of the internal structure 30 at the same time as the main body is formed, or those formed in advance with another material may be It may be integrally fixed at the same position at the time of molding. However, since the external structural body 40 is made of resin, it is preferable that the same resin or the same resin as that is used.

As described above in the first embodiment, the internal structure 30 is required to be strong and lightweight, so that it is preferable to use a hollow body made of fiber reinforced resin. The fiber-reinforced resin is not always required as long as it is an excellent resin or another material. It is also preferably lightweight, but need not be hollow. When the internal structure 30 is a hollow body made of the fiber reinforced resin, for example, after making a prepreg made of a thermosetting resin into a tube shape, positioning protrusions 34, 35 made of the same resin are used for the tube. It is attached to a predetermined position with glue or other method, and by heating while applying internal pressure in the mold, the positioning protrusion 34,
It is possible to integrally mold the internal structure 30 in which 35 is completely bonded. Alternatively, the molded positioning protrusions 34 and 35 may be attached to the molded internal structure 30.

The racket frame is manufactured by first fitting the preformed internal structure 30 with the positioning projections 34 and 35 into one split mold 10 of the mold K, and then the other split mold.
Match 20 to the split mold 10. As a result, the internal structure 30
The upper and lower and left and right positioning protrusions 34, 35 contact the inner surface of the mold, and the internal structure 30 is positioned and arranged in the mold space S. After that, by injecting the resin from the injection passage 14 into the mold space S, the resin-made outer structure 40 is molded around the inner structure 30. After injection molding, split mold 10,
Open 20 and take out the molded racket frame. As shown in FIG. 9, the positioning protrusions 34 and 35 become part of the meat of the outer structure 40 of the racket frame. Positioning protrusion
Since the parts 34 and 35 only contact the inner surface of the mold K, they do not project from the racket frame even after the injection molding, so that the work of scraping is not necessary.

[0020]

According to the method of manufacturing the racket frame of the present invention, the present invention has the above-described structure and operation.
A resin positioning member is arranged so as to project into the mold space from above and below and on the left and right of the inner surface of the mold, and the internal component is positioned and held in the mold space in such a manner as to abut against the resin positioning member, Since the resin positioning member is configured as a part of the meat of the resin external component by injecting the resin into the mold space, the internal component has a fitting recess for a positioning pin or the like. Since it is not necessary to mold any of them, it is possible to make the internal structure very easily. Further, since the resin positioning member is projected from the mold in the left-right and up-down directions, the internal component is positioned in the left-right up-down direction,
Positioning can be surely performed without inserting a positioning pin or the like into the internal structure. When inserting the resin positioning member into the fitting hole of the mold, simply remove the protruding portion after removing it from the mold, and insert the resin positioning member into the fitting hole of the mold. When it is attached to the inner surface of the mold without using it, it is not necessary to grind the protruding portion after removing it from the mold, so that the post-treatment of injection molding becomes very easy. According to the racket frame manufacturing method of the second aspect of the present invention, the positioning protrusions in the vertical and horizontal directions are integrally formed in the internal structure, and the positioning protrusions are in contact with the inner surface of the mold. Since the internal structure is positioned and held in the mold space and a resin is injected into the mold space to form a resin external structure in which the resin positioning member remains, the internal structure The protrusion for positioning the body does not protrude from the resin-made external component, so that there is an advantage that no scraping work is required after injection molding. In addition, integrally molding the positioning protrusion on the internal structure is superior in strength to forming a recess for fitting on the internal structure. Furthermore, when the positioning protrusion is integrally formed with the internal structure, the internal structure can be formed even if the internal structure is a thin body such as a hollow body. There are less molding restrictions than molding a recess for fitting.

[Brief description of drawings]

FIG. 1 is an overall view of an internal structure used in a first embodiment of the manufacturing method of the present invention.

FIG. 2 is a view showing a mold used in the first embodiment of the manufacturing method of the present invention.

FIG. 3 is a view showing a state in which a resin positioning member is arranged on the mold in the first embodiment of the manufacturing method of the present invention.

FIG. 4 is a cross-sectional view showing a state in which the internal structure is positioned and held in the mold space in the first embodiment of the manufacturing method of the present invention.

FIG. 5 is a cross-sectional view showing a state in which the molded racket frame is taken out from the mold in the first embodiment of the manufacturing method of the present invention.

FIG. 6 is an overall view of an internal structure used in a second embodiment of the manufacturing method of the present invention.

FIG. 7 is a partially enlarged perspective view of an internal structure used in a second embodiment of the manufacturing method of the present invention.

FIG. 8 is a cross-sectional view showing a state in which the internal structure is positioned and held in the mold space in the second embodiment of the manufacturing method of the present invention.

FIG. 9 is a cross-sectional view showing a state in which the molded racket frame is taken out of the mold in the second embodiment of the manufacturing method of the present invention.

[Explanation of symbols] 10, 20 Split mold 10, 21 Grooves 12a, 12b, 22a Insert hole 30 Internal component 34 Vertical positioning protrusion 35 Horizontal positioning protrusion 40 Resin external component 50 Resin Positioning pin K mold S mold space

Claims (2)

[Claims] 1. A resin outer component is provided around the inner component by arranging the inner component of the frame in the mold space and injection-molding a resin into the mold space around the inner component. A method for manufacturing a racket frame for molding a covered racket frame, comprising arranging a resin positioning member so as to project into a mold space from above and below and on the left and right of an inner surface of the mold, wherein the internal structure is The resin positioning member may be positioned and held in the mold space so as to be in contact with the resin positioning member, and the resin may be injected into the mold space to form the resin positioning member as a part of the meat of the resin external component. Characteristic racket frame manufacturing method. 2. The resin-made external component is formed around the internal component by arranging the internal component of the frame in the mold space and injection-molding resin into the mold space around the internal component. A method for manufacturing a racket frame for molding a covered racket frame, wherein positioning projections for vertical and horizontal directions are integrally formed on the internal structure, and the projections for positioning come into contact with an inner surface of a mold. The internal structure is positioned and held in the mold space in a shape, and a resin external structure in which the resin positioning member remains is formed by injecting resin into the mold space. Racket frame manufacturing method.