JP2003290400A - Manufacturing method of golf club head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a golf club head with superior productivity. <P>SOLUTION: In the manufacturing method of the golf club head, the golf club head having an undercut part UC is cast by using a wax model W. It includes a process of forming the wax model W by dividing it into a first model piece 11 divided at a dividing plane passing the undercut part and at least one second model piece 12 forming the wax model W by being integrated with the first model piece 11, and forming the wax model W by integrating each model piece 11 and 12. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a golf club head, which is useful for efficiently manufacturing a golf club head having an undercut portion.

[0002]

2. Description of the Related Art For example, FIG. 1 and FIG. 2 which is a sectional view thereof.
(Note that these drawings are for the head manufactured according to the present invention, but since the basic shape is the same as the conventional one, it will be used for the description here.) The golf club head 1 is mainly provided with an undercut portion UC which is recessed from the cavity C opened to the back surface to the club peripheral portion E between the face portion 2a and the head back portion 2b. Such a head 1 is
It provides ease to the average golfer by moving the center of gravity to the head back 2b side and increasing the moment of inertia.

Such a head 1 is generally manufactured by a forging or casting method, but it is generally manufactured by a casting method suitable for mass production. In the casting method, first, a wax model with a product shape that allows for the shrinkage amount of the metal material at the time of casting and the polishing amount at the time of finishing is molded by, for example, injection molding, and a mold material such as ceramics is formed around the wax model. After the adhered solidified by baking, the wax model inside is eluted to the outside to manufacture a mold. And
Molten metal is poured into this mold to cool and solidify, and the mold is crushed to take out the casting.

However, when a wax model of the head 1 having the above-described undercut portion UC is molded, if a mold Ma composed of split molds M1 and M2 as shown in FIG. As shown in (B), the undercut portion UC of the wax model Wo has a split mold M1.
It cannot be demolded because it engages with. Therefore, in the conventional case, as shown in FIG.
As shown in FIG. 8, in addition to using the split molds M1 and M2, a mold Mb using an assembly core M3 is adopted in the portion for molding the undercut portion UC.

The assembling core M3 has, for example, FIGS.
As shown in 0, a large number of core pieces M3a, M3b ... Which have almost the same thickness as the undercut portion UC and are vertically and horizontally divided.
Consists of. When the wax model Wo is released from the mold, for example, the central core piece M3a is pulled out toward the back side of the head, and the upper and lower cores M3b, M3c and the like are utilized by utilizing the empty space from which the core M3a has been removed. Undercut U
Extraction from C is performed.

[0006]

However, when the wax model Wo is formed by using the assembly core M3 as described above, the secant line of the assembly core M3 is formed in the wax model Wo as shown in FIG. It is transferred and becomes a so-called burr portion B protruding at a small height as shown in FIG. The burr portion B formed on such a wax model Wo is directly transferred to a cast product and appears as a convex portion having a small height, which is not preferable in appearance and causes stress concentration due to the notch effect.

Further, the assembling core M3 is required to have a high accuracy in manufacturing, and therefore the manufacturing cost is increased. Further, as shown in FIG. 20, the assembly core M3 has a large contact area with the wax model Wo in the undercut portion UC, and the wax model Wo shrinks and solidifies so as to surround the assembly core M3. There is a problem that removal of the piece requires a skilled technique and is inferior in productivity.

Therefore, for example, as shown in FIG. 23 (A), a method of using an integral core mold M4 made of a soluble material instead of the assembly core M3 can be considered. In this method, a wax model Wo is injection-molded using a mold Mc in which the core mold M4 is arranged inside the split molds M1 and M2 as shown in FIG. Then, the wax model Wo integrated with the core mold M4 is removed from the split molds M1 and M2. Then, as shown in (D) of the figure, the core type M4
Only the wax is melted to form a wax model Wo having an undercut portion UC.

According to such a method, it is possible to suppress the generation of the burr portion B which occurs when the assembled core M3 is used, but the molding step of the core mold M4 using a soluble material and the core M4. A new elution step of the mold M4 is required, so that there is a problem that the production efficiency is reduced.

The present invention has been devised in view of the above problems, and a first model piece obtained by dividing a wax model by a division plane passing through an undercut portion, and the first model piece. The method basically includes a step of forming the wax model by dividing it into at least one second model piece that forms the wax model by being integrated, and forming the wax model by integrating each model piece. Another object of the present invention is to provide a method for manufacturing a golf club head which can efficiently manufacture a golf club head having an undercut portion.

[0011]

The invention according to claim 1 of the present invention is a method for manufacturing a golf club head in which a golf club head having an undercut portion is cast using a wax model, wherein the wax model is used. Is divided into a first model piece divided by a division plane passing through the undercut portion and at least one second model piece forming the wax model by being integrated with the first model piece. And then molding, and forming the wax model by integrating the model pieces together.

According to a second aspect of the present invention, the wax model is an iron type having an undercut portion that is recessed from the backside opening cavity between the face portion and the head back portion in the club peripheral portion, and the wax model is divided. By providing the surface at the end of the undercut portion on the face side, the first model piece is a model piece on the face side and the second model piece is a model piece on the back side of the head. The method for manufacturing a golf club head according to claim 1.

Further, the invention according to claim 3 is characterized in that the second model piece has a ring shape, and the wax model has an annular undercut portion around the cavity. Item 3. A method for manufacturing a golf club head according to item 3.

According to a fourth aspect of the present invention, the wax model comprises a head main body having a face opening whose front surface is open, and the head main body includes a hollow portion communicating from the face opening to the head back. The method of manufacturing a golf club head according to claim 1, further comprising an undercut portion that is recessed from the hollow portion to a peripheral portion of the head.

According to a fifth aspect of the present invention, in the first model piece and the second model piece, at the outer peripheral edge portion of the joint surface facing each other at the time of integration, there is provided a protruding portion protruding from the outer peripheral edge portion. Each molded, the first model piece and the second
5. The method for manufacturing a golf club head according to claim 1, wherein the ridge portion is smoothed after being integrated with the model piece.

Further, the invention according to claim 6 is characterized in that the wax model includes a fitting portion in which the first model piece and the second model piece are fitted with each other. The method for manufacturing a golf club head according to claim 1.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a golf club head (hereinafter, simply referred to as “head”) manufactured according to an embodiment of the present invention.
There is a thing. ) 1 is a perspective view of the same as seen from the back side, and FIG. 2 is a sectional view thereof.

The head 1 of this embodiment is exemplified by an iron type head. The head 1 includes, for example, a face portion 2a including a surface for hitting a ball, a head back portion 2b forming a back side of the head, a top portion 2c forming an upper portion of the head, a sole portion 2d forming a bottom surface of the head, and this sole portion. It has a toe part 2e, a heel part 2f, and a hosel 3 to which a shaft is attached, which connects between 2d and the top part 2c on the head tip side and the hand side, respectively.

Further, in the head 1, the head back portion 2b
At the same time, a cavity C whose rear surface is opened is formed by recessing the head back 2b from the opening 2bo toward the face side, and the cavity C is formed from the cavity C.
And a back portion 2b of the head, there is provided an undercut portion UC which is recessed to at least a part of the peripheral edge portion E of the club. The club peripheral portion E refers to the top portion 2c, the sole portion 2d, the toe portion 2e, or the heel portion 2f. In this example, the undercut portion UC is shown as being continuously formed in an annular shape around the cavity C, but it may be formed only partially.

FIGS. 3 and 4 show an example of a wax model W for casting the head 1 as described above. The wax model W has the same shape as the head 1. That is, the face portion 13a, the head back portion 13b,
It has a top portion 13c, a sole portion 13d, a neck portion 13d, and a hosel 14, and has a cavity C and an undercut portion UC (the cavity C and the undercut portion UC are given the same reference numerals as the head 1). It
The wax model W has a size (that is, the amount of shrinkage of the metal material at the time of casting and the amount of polishing at the time of finishing).
It is formed with a size slightly larger than the final product shape). Although not shown in FIGS. 3 and 4, the wax model W is appropriately provided to form a spout serving as a spout of the molten metal, a runner through which the molten metal flows, a gate leading to the wax model, and the like. The wax material is attached in advance or by retrofitting.

In the present invention, such a wax model W is used.
With a first model piece 11 divided by a division plane P passing through the undercut portion UC, and at least one of which forms the wax model W by being integrated with the first model piece 11 (this example). Then, it is divided into one second model piece 12 and individually molded. Then, the wax model W is formed by integrating the molded model pieces 11 and 12.

As shown in FIG. 4B, the dividing surface P of this embodiment is set as a single plane at the face side end Cb of the undercut portion UC, which is substantially the face. It is parallel to the plane. Due to such a division plane P, the first model piece 11 forms a model piece on the face portion side including the hosel 14. The second model piece 12 is
By including the top portion 13c, the sole portion 13d, the toe portion 13e, and the neck portion 13f on the head back side of the dividing surface P, the model piece on the head back side has a ring shape surrounding the cavity C.

The dividing surface P can be variously set as long as it passes through the undercut portion UC without any particular limitation. That is, the dividing surface P in this example is shown as passing through the face-side end Cb of the undercut portion UC, but it may be the end surface on the head back portion 2b side or between these. Further, the dividing surface P can be freely set by a plurality of flat surfaces, curved surfaces, or a combination thereof, in addition to the case of being formed by a single flat surface as in this example. However, it is necessary that the dividing surface P does not make it difficult to form the first model piece 11 and the second model piece 12 that are divided by the dividing surface P. In other words, each model piece 11,
In No. 12, it is necessary to select so that there is no undercut portion.

The first model piece 11 and the second model piece 12 can be molded using simple dies Md, Me, etc., as shown in FIGS. 5 and 6, for example. The molds Md and Me are each composed of a pair of split molds that can be brought into and out of contact with each other, and the first model piece 11 and the second model piece 12 can be molded by combining them without using a core mold or the like inside. The model pieces 11 and 12 can be easily demolded by forming a space and separating them.

Then, the wax model W is formed by integrating the first model piece 11 and the second model piece 12 separately molded in this way. In order to integrate the first model piece 11 and the second model piece 12, for example, a method of using an adhesive, or a method of locally heating the periphery of the joint with a heating tool such as a soldering iron and fusing them together. For example, various methods can be adopted without particular limitation.
It should be noted that, when fusion is performed by heat, it is preferable in that both are firmly integrated, and in the case of an adhesive, the adhesive force is relatively reduced, but deformation of members such as heat fusion does not occur. It is preferable in that it does not occur (it is needless to say that even in the case of heat fusion, a wax material can be newly built up and repaired at the fusion bond if necessary). These are variously selected according to the shape of the member.

Further, as shown in FIG. 7, the wax model W preferably includes a fitting portion 22 in which the first model piece 11 and the second model piece 12 are fitted with each other. The fitting part 22 of this example is the first model piece 11 or the second model piece 1.
2 is provided on one side (the first model piece 11 in this example) and protrudes toward the other side (the second model piece 12 in this example), and the first model piece 11 or the second The model piece 12 which is provided on the other side (the second model piece 12 in this example) and includes the recess 21 into which the protrusion 20 can be fitted is exemplified. Thereby, when the first model piece 11 and the second model piece 12 are integrated, the positions of both members can be quickly and accurately adjusted efficiently.
As a result that productivity can be improved and alignment accuracy can be improved, it is useful for manufacturing the head 1 having excellent dimensional accuracy.
The protrusion 20 is provided on the first model piece 11 and the recess 21 is provided.
Can be provided on the first model piece 11, and further,
It is also possible to provide the protrusion 20 and the recess 21 on each of the first model piece 11 and the second model piece 12. Also, the convex portion 2
Needless to say, the shapes of the recesses 21 and the recesses 21 can be variously modified other than those illustrated.

Further, as shown in FIG. 8, the first model piece 11 and the second model piece 12 are formed on the outer peripheral edge portion Pe of the dividing surface P and are formed by protruding the outer peripheral edge portion Pe. 24
Can also be molded respectively. This ridge 24 is
For example, 0.1 to 0.1 mm more than the finished shape of the wax model W.
Small height h of 2.0 mm, more preferably 0.5-1.0 mm
And a thickness t in the direction perpendicular to the dividing plane P.
Is, for example, 0.5 to 2.0 mm, more preferably 0.8
It is desirable to set it to 1.2 mm. Then, such a ridge portion 24 is provided in the first model piece 11 and the second model piece 12
After integrating and, they are smoothed.

Such a ridge portion 24 can be used as, for example, a fusion portion for heating and fusing the first model piece 11 and the second model piece 12 with a soldering iron or the like. it can. In this case, the first model piece 11 and the second model piece 12 can be fused, and at the same time, the ridge portion 24 can be smoothed, and the shape of the wax model W can be adjusted. In addition, since the ridge portion 24 is formed to be raised more than the final finished shape of the wax model W, it is not necessary to newly build up the wax material in the recessed portion due to the fusion bonding, thereby improving the productivity. Help improve. Further, since the outer peripheral edge portion Pe of the split surface P is a split surface, there is a risk that the casting may form a line on the split surface as a burr. Therefore, it is also possible to provide a ridge portion 24 in this portion to make it thick in advance, and to polish it or melt it to smooth it and substantially eliminate the split surface. This can further improve the appearance of the head 1.

Then, as shown in FIG. 9A, the wax model W formed by the above-described method has a mold material 25 (slurry of ceramic mud or sand of ceramics) on the surface thereof. Stucco, which is the body, etc.) is attached and solidified. Then, by heating to about 100 to 200 ° C., the wax model W is melted and discharged to the outside, and further heated to about 800 to 1200 ° C. to form the mold 26 as shown in FIG. 9B. . Then, a molten metal is poured into the mold 26 according to a conventional method to solidify the molten metal, and thus the head 1 having the undercut portion UC is obtained.
Can be cast molded. After molding, the mold 26 is crushed and the head 1 is demolded.

Next, another embodiment of the present invention will be described. FIG. 10 is an exploded perspective view of a head 1 of another embodiment to which the present invention can be applied, and FIG. 11 is a sectional view thereof. The head 1 includes a face plate 1a and a head body 1b having the face plate 1a on the front surface. The head body 1b includes a face edge portion 30a surrounding the face opening O whose front surface is open, and a head back portion 30b.
A top portion 30c forming a head upper surface, a sole portion 30d forming a head bottom surface, and a toe portion 30e and a heel portion 30f connecting the sole portion 30d and the top portion 30c at the head tip side and the hand side, respectively. And a hosel 31 to which the shaft is attached. Then, the head 1 having a hollow interior is formed by fixing the face plate 1a to the face opening.

The head body 1b has a face opening O.
Has a hollow portion i extending from the head back portion 30b to at least a part of the head peripheral portion E (which indicates the top portion 30c, the sole portion 30d, the toe portion 30e or the heel portion 30f) from the hollow portion i. It has a cut portion UC. That is, in this example, an undercut portion UC which is invisible from the outside after the head 1 is completed is formed annularly between the face edge portion 30a and the head back portion 30b. As described above, "a golf club head having an undercut portion" includes an undercut portion during the manufacturing process of the head, in addition to the case where the undercut portion has a final product shape as shown in FIG. Includes.

A wax model W for casting such a head body 1b is shown in FIG. 12, its exploded view is shown in FIG. 13, and its sectional view is shown in FIG. As described above, the wax model W has a size and shape in which the shrinkage amount and the polishing amount of the metal material during casting are taken into consideration in advance, but the outer shape is substantially the same as that of the head 1 shown in FIG. In this example, the wax model W is the first model piece 3 on the face side divided by the division plane P passing through the face side end (Cb) of the undercut portion UC as shown in FIG.
4 and a second model piece 35 on the back side of the head that forms the wax model W by being integrated with the first model piece 34, and is molded.
It is formed by integrating 35.

The model pieces 34 and 35 are shown in FIGS.
As shown in FIG. 5, any of them can be molded by using molds Mf, Mg and the like. The molds Mf and Mg are each composed of a pair of split molds that can be brought into contact with and separated from each other.
The model piece 34 or 35 can be easily released from the mold by having a space in which the model piece 12 of FIG. Although not shown in detail, in this embodiment as well, similarly to the above-described embodiment, the protrusion portion in which the outer peripheral edge portion Pe of the dividing surface P is raised is provided, and the fitting portion 22 is further provided. Can also divide the second model piece 35 in two.

As described above, although the iron type is illustrated in each of the above embodiments, the present invention is not limited to wood type, utility type, and putter type as long as it has an undercut portion. It can be applied regardless of the type of head. Needless to say, the dividing surface P is not limited to the one shown in the example and can be variously modified.

[0035]

EXAMPLES Iron type golf club heads having undercut portions shown in FIGS. 1 and 10 were manufactured based on the specifications shown in Table 1, and the total number of days required for mold production, wax model production time, and product were obtained. The appearance and the like were evaluated. The head shapes are the same, and the metallic material is SUS63.
0 was used uniformly. The results of the test are shown in Table 1, and it was confirmed that the method of the present invention can improve the appearance of the product while improving the productivity.

[0036]

[Table 1]

[0037]

As described above, according to the invention of claim 1, the wax model having the undercut portion is
A first model piece and a first model piece are divided by a dividing surface that passes through the undercut portion and molded, and then these are integrated, so that a complicated wax model can be formed by a simple process. . Therefore, the manufacturing time can be shortened and the productivity can be improved. Further, unlike the conventional case, since it is not necessary to use an assembly core die for the undercut portion, it is possible to prevent the secant line of the assembly core from being transferred to the wax model and further to the cast product, thereby improving the appearance of the head. Also useful for.

When the wax model is an iron type having an undercut portion which is recessed from the back opening cavity to the peripheral portion of the club between the face portion and the head back portion, as in the invention described in claim 2, By providing the dividing surface at the face side end of this undercut portion, the first model piece can be used as the face side model piece and the second model piece can be divided into a simple shape as the head back side model piece. Increase productivity. Further, as in the invention according to claim 3,
If the second model piece has a ring shape, the wax model can easily form an annular undercut portion around the cavity.

Further, as in the invention described in claim 4, a head main body having a face opening whose front surface is opened can be manufactured by the same method.

According to the fifth aspect of the present invention, in the first model piece and the second model piece, the projecting portions are formed on the outer peripheral edge of the dividing surface, and the first model piece is formed. After the piece and the second model piece are integrated, the ridge portion is smoothed to eliminate the boundary line of the outer peripheral edge portion,
Transfer to the casting can be prevented.

When the wax model is provided with a fitting portion in which the first model piece and the second model piece are fitted to each other, the wax model can be quickly and positionally aligned. Since it can be performed with high accuracy and efficiency, productivity can be improved, and alignment accuracy can be improved. As a result, it is useful for manufacturing a head having excellent dimensional accuracy.

[Brief description of drawings]

FIG. 1 is a rear perspective view showing an example of a head manufactured according to the present invention.

FIG. 2 is a sectional view thereof.

FIG. 3 is a rear perspective view showing an example of a wax model used in the present invention.

FIG. 4A is an exploded perspective view of a wax model, and FIG.
Is a sectional view thereof.

FIG. 5 is a cross-sectional view showing injection molding of a second model piece.

FIG. 6 is a cross-sectional view showing injection molding of a first model piece.

FIG. 7 is an exploded cross-sectional view showing another form of the wax model.

FIG. 8 is an exploded cross-sectional view showing another form of the wax model.

9A and 9B are cross-sectional views illustrating a process of manufacturing a mold from a wax model.

FIG. 10 is an exploded perspective view showing an example of a head manufactured according to the present invention.

FIG. 11 is a sectional view thereof.

FIG. 12 is a perspective view of a wax model.

FIG. 13 is an exploded view thereof.

FIG. 14 is a sectional view of FIG.

FIG. 15 is a cross-sectional view showing injection molding of a second model piece.

FIG. 16 is a cross-sectional view showing injection molding of a first model piece.

17A and 17B are cross-sectional views showing an example of injection molding of a wax model.

FIG. 18 is a cross-sectional view showing an example of injection molding of a wax model using an assembly core.

FIG. 19 is a perspective view illustrating an assembly core.

FIG. 20 is a cross-sectional view illustrating removal of the assembly core.

FIG. 21 is a perspective view seen from the back side, for explaining the drawbacks of the conventional wax model.

FIG. 22 is a sectional view thereof.

23 (A) to (D) are cross-sectional views showing another embodiment of manufacturing a wax model.

[Explanation of symbols] 1 golf club head 2a, 30a Face part 2b, 30b head back 11 First model piece 12 Second model piece 22 Fitting part 24 Projections W wax model C cavity UC undercut part P division plane Pe Peripheral edge of split surface

Claims (6)

[Claims] 1. A method of manufacturing a golf club head in which a golf club head having an undercut portion is cast using a wax model, wherein the wax model is divided by a dividing surface passing through the undercut portion. A model piece and at least one second model piece forming the wax model by being integrated with the first model piece are divided and molded, and the model pieces are integrated with each other. A method of manufacturing a golf club head, comprising the step of forming a wax model. 2. The wax model is an iron type having an undercut portion which is recessed in a club peripheral portion between a face portion and a head back portion from a cavity which is opened from the back surface, and the divided surface has an undercut portion. 2. The first model piece is a model piece on the face side and the second model piece is a model piece on the back side of the head by being provided at the end on the face side. Golf club head manufacturing method. 3. The golf club head according to claim 3, wherein the second model piece has a ring shape, and the wax model has an annular undercut portion around the cavity. Manufacturing method. 4. The wax model comprises a head body having a face opening whose front surface is open, and the head body has a hollow portion communicating from the face opening portion to the head back portion, and the hollow portion from the hollow portion. 2. The method for manufacturing a golf club head according to claim 1, further comprising an undercut portion recessed in the portion. 5. The first model piece and the second model piece each have a protruding portion formed by protruding the outer peripheral edge portion at the outer peripheral edge portion of the dividing surface, and the first model piece. 5. The method for manufacturing a golf club head according to claim 1, wherein the ridge portion is smoothed after the piece and the second model piece are integrated. 6. The golf club according to claim 1, wherein the wax model includes a fitting portion in which the first model piece and the second model piece fit together. Head manufacturing method.