JP2009066071A - Manufacturing method of golf club head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a golf club head by strongly bonding a head main body and a weight member by brazing. <P>SOLUTION: The method of manufacturing the golf club head comprising the head main body composed of a metallic material and provided with a recessed part and the weight member mounted on the recessed part and composed of a metallic material whose specific gravity is larger than the head main body includes: a preparation process of preparing a head assembly for which the weight member is fitted to the recessed part of the head main body and a brazing filler metal is disposed at the boundary part of both; and a heating process of heating the head assembly and fusing the brazing filler metal. The heating process includes a main heating stage of continuously heating the head assembly at Tc+80(°C) to Tc+100(°C) for 15 to 60 minutes when the melting point of the brazing filler metal is defined as Tc(°C). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a golf club head manufacturing method for manufacturing a golf club head by joining a head body and a weight member by brazing.

  In recent years, the position of the center of gravity of a golf club head has been optimized to improve the directionality and flight distance of the hit ball. For example, an iron-type golf club head is known in which a weight member made of a high specific gravity material such as a tungsten alloy is fixed to the sole portion side of a head body such as soft iron that has an excellent feel at impact.

By the way, the head main body and the weight member are usually a combination of metal materials that cannot be welded in many cases. In such a case, the head body and the weight member are usually fixed by a bonding method such as adhesive or brazing. However, when the adhesive is used, since the bonding strength is small, there is a problem that the weight member is detached from the head main body while the ball is hit repeatedly. On the other hand, brazing is a method of joining dissimilar metals by melting a brazing material, which is a metal or alloy having a melting point lower than that of the base material, and filling and solidifying the gaps between the base materials using, for example, capillary action. It is. Such brazing can increase the bonding strength as compared with the case of bonding using an adhesive, but further improvement of the bonding strength has been desired.
Related literature includes the following:

JP 2006-25903 A

  The present invention has been devised in view of the above problems, and a preparation process for preparing a head assembly in which a weight member is fitted in a concave portion of a head body and a brazing material is disposed at the boundary between the two, A main heating step of continuously heating the head assembly for 15 to 60 minutes at a temperature 80 to 100 (° C.) higher than the melting point Tc (° C.) of the brazing material. The main object of the present invention is to provide a method for manufacturing a golf club head capable of sufficiently enhancing the mutual reaction and thus firmly fixing the head body and the weight member.

  The invention according to claim 1 of the present invention includes a head body made of a metal material and provided with a recess, and a weight member made of a metal material attached to the recess and having a specific gravity greater than that of the head body. A method for manufacturing a club head, comprising: preparing a head assembly in which the weight member is fitted in the recess of the head body and a brazing material is disposed at the boundary between the two; and heating the head assembly And a heating step for melting the brazing material. The heating step takes 15 to 60 minutes at a temperature of Tc + 80 (° C.) or more and Tc + 100 (° C.) or less when the melting point of the brazing material is Tc (° C.). And a main heating step of continuously heating the head assembly.

  According to a second aspect of the present invention, in the heating step, the head assembly is preheated for 50 to 100 minutes at a temperature not lower than Tc-100 (° C.) and not higher than Tc (° C.) prior to the main heating step. 2. A method of manufacturing a golf club head according to claim 1, comprising a preheating step.

  According to a third aspect of the present invention, the heating step includes a cooling step of slowly cooling the temperature from Tc (° C.) to Tc-100 (° C.) over 60 to 120 minutes after the main heating step. Item 3. A method for manufacturing a golf club head according to Item 1 or 2.

  According to a fourth aspect of the present invention, one of the recess or weight member is provided with a protrusion that protrudes toward the other, and the other of the recess or weight member has a bottomed hole into which the protrusion is inserted. 4. The golf club head manufacturing method according to claim 1, wherein a portion is provided, and the weight member is positioned and fitted into the recess of the head body by inserting the protrusion into the hole. 5. is there.

  In the manufacturing method of the present invention, the head assembly in which the weight member is fitted in the concave portion of the head main body and the brazing material is disposed at the boundary between the two is 80-100 (° C.) higher than the melting point Tc (° C.) of the brazing material. It includes a main heating stage that is continuously heated at an elevated temperature for 15-60 minutes. Thereby, the element of the brazing material can be sufficiently diffused in the head main body and the weight member, and the element on the base material side of the head main body and the weight member is dissolved in the brazing material to obtain a strong alloy part. Can do. Therefore, it is possible to manufacture a golf club head in which the head main body and the weight member are firmly fixed as compared with the related art.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a rear view of an iron-type golf club head 1 manufactured by the manufacturing method of the present embodiment. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. FIG. 4 is an exploded perspective view of FIG.

  A golf club head (hereinafter, also simply referred to as “head” or “club head”) 1 of the present embodiment is composed of a head body 2 made of a metal material and a metal material having a specific gravity greater than that of the head body 2. And a weight member 3. In this embodiment, the weight member 3 includes a toe weight 3t provided on the toe side and a heel weight 3h provided on the heel side. Thus, the number of weight members 3 can be determined arbitrarily.

  The head body 2 constitutes a main part of the club head 1. In this embodiment, the head base 2A and a hosel part 2B connected to the heel side of the face base 2A and into which a shaft (not shown) is inserted. Are integrally formed.

  As shown in FIGS. 2 and 3, the face base portion 2A includes a face 2a that is a surface for hitting a ball, a peripheral surface 2b that continues to the face 2a and extends rearward of the head, and a face 2a that extends to the peripheral surface 2b. And a back surface 2c that forms the opposite surface.

  Further, as shown in FIG. 1, the peripheral surface 2b includes a top surface 2b1 that forms the upper portion of the head, a sole surface 2b3 that extends from the bottom of the head, and a space between the top surface 2b1 and the sole surface 2b3 on the toe side. And a toe surface 2b2 extending up and down.

  A cavity C that is recessed toward the face 2a is formed on the back surface 2c. As a result, the weight of the face base portion 2A is suitably distributed to the peripheral portion thereof, and as a result, the moment of inertia of the club head 1 increases.

  The head body 2 is made of various metal materials. In the case of an iron type golf club head as in this embodiment, for example, carbon steel, stainless steel, chrome molybdenum steel or maraging steel is suitable. In particular, carbon steel and stainless steel are preferable from the viewpoint of improvement in feel at impact and ease of processing. Needless to say, when the club head 1 is a wood-type club head, a titanium alloy, an aluminum alloy, or the like can be employed in addition to the above metal.

  As shown in FIG. 4, the head body 2 is provided with a recess 4 for fixing the weight member 3. The recess 4 includes a toe side recess 4t to which the toe weight 3t is fixed and a heel side recess 4h to which the heel weight 3h is fixed. Each recess 4 is provided on the bottom surface side of the head and is provided so as to extend over the peripheral surface 2b and the back surface 2c (in other words, the weight member 3 extends over the peripheral surface 2b and the back surface 2c of the head body 2 and Part of each).

  As shown in FIGS. 1 to 4, each recess 4 of the present embodiment includes a receiving surface 4a extending substantially parallel to the face 2a, and an inner wall surface 4b rising from the outer edge of the receiving surface 4a to the back surface 2c. , And a bottomed hole 4c that is recessed in a substantially cylindrical shape from the receiving surface 4a. As is apparent from FIG. 1, each concave portion 4 of the present embodiment is formed to be inclined and tapered from the bottom surface of the head toward the top surface of the head toward the center of the face when viewed from the back surface 2c side. Is done. However, it is not limited to such an aspect. Further, as apparent from FIGS. 2 and 3, the inner wall surface 4b rises substantially vertically from the receiving surface 4a.

  Each weight member 3 includes a back surface 3a that constitutes a part of the back surface 2c of the head body 2, a downward surface 3b that is connected to the back surface 3a and constitutes a part of the sole surface 2b3 (peripheral surface 2b), Constructed in a lump shape including an inward surface 3c facing the receiving surface 4a of the recess 4, an outer peripheral surface 3d facing the inner wall surface 4b of the recess 4, and a protrusion 3e inserted into the hole 4c of the recess 4 from the inward surface 3c. Is done. Such a weight member 3 is accurately positioned and fitted into the recess 4 as shown in FIGS. 2 and 3 by inserting the protrusion 3e into the hole 4c of the recess 4.

  The weight member 3 is not particularly limited as long as the weight member 3 is a metal material having a specific gravity larger than that of the head main body 2, but preferably the specific gravity is 12 or more in order to efficiently move the position of the center of gravity of the head. More preferably, 14 or more, and even more preferably 15 or more metal materials are desirable. On the other hand, if the specific gravity of the weight member 3 is too large, workability and productivity may be reduced. From such a viewpoint, the specific gravity of the weight member 3 is preferably 20 or less, more preferably 19 or less, and still more preferably 18 or less. As the metal material constituting the weight member 3, for example, a tungsten alloy, particularly W—Ni—Cu, W—Ni—Fe, W—Ni—Co or W—Mo—Ni—Fe, which is relatively easy to process, is desirable. .

  In such a club head 1, the weight member 3 is provided separately on the head bottom side and on the toe side and the heel side, so that the weight can be efficiently distributed to a deeper and lower position. Therefore, in addition to helping to set the center of gravity of the head deeper and lower, it is possible to increase the moment of inertia of the head and stabilize the directionality of the hit ball.

Next, a method for manufacturing such a club head 1 will be described.
First, as partially shown in FIGS. 5A and 5B, the weight member 3 is fitted in each concave portion 4 of the head main body 2, and the brazing material 9 is arranged at the boundary j between the head assembly. A preparation process for preparing the solid 1m is performed. The protrusion 3 e of the weight member 3 is inserted into the hole 4 c of the recess 4.

  In the manufacturing method of the present embodiment, when the weight member 3 and the recess 4 are fitted, the space between the outer peripheral surface 3d of the weight member 3 and the inner wall surface 4b of the recess 4 is larger than the other portions. A gap 7 is provided. In the present embodiment, the gap 7 has a depth that reaches the receiving surface 4 a of the recess 4. The gap 7 is preferably formed over 50% or more, more preferably 60 to 90% of the length along the outer peripheral surface 3d of the weight member 3. As described above, it is desirable to provide the gap 7 that improves the penetration of the brazing material 9 into at least a part of the joint between the weight member 3 and the recess 4.

  Further, the weight member 3 has fitting portions 8 on both sides of the downward surface 3b, the outer peripheral surface 3d of which is closely fitted to the inner wall surface 4b of the recess 4. The weight member 3 is positioned and fitted into the recess 4 with high accuracy by the fitting portion 8 and the protrusion 3e. At this time, the width G of the gap 7 is formed substantially constant. In addition, in order to position with sufficient precision, it is good to provide the said fitting part 8, but in order to reduce manufacturing cost, without providing the said fitting part 8, the outer peripheral surface 3d of the weight member 3, and the recessed part 4 are provided. It is desirable to provide the gap 7 in the entire range between the inner wall surface 4b.

  The width G of the gap 7 is not particularly limited. However, if the width G is too small, it is difficult to sufficiently penetrate the brazing material 9 deep inside. From such a viewpoint, the width G of the gap 7 is preferably 0.03 mm or more, more preferably 0.05 mm or more, and preferably 0.3 mm or less, more preferably 0.2 mm or less. In addition, in order to ensure the positioning of the weight member 3 and the recessed portion 4 and to prevent deterioration of the mountability, the width GL of the gap between the weight member 3 and the recessed portion 4 in the fitting portion 8 is set to the gap 7. It is desirable that the width G is less than 1.0 times, preferably 0.8 times or less, more preferably 0.5 times or less. Further, the lower limit of the width GL is preferably 0.01 mm or more, more preferably 0.02 mm or more in order to ensure the mountability of the weight member 3 to the recess 4. Note that the gap between the protrusion 3e and the hole 4c is preferably in the same range as the width GL.

  Further, the brazing material 9 is continuously arranged at all the boundary portions j between the weight member 3 and the recess 4. In this embodiment, a viscous paste-like brazing material 9 is used, and the gap at the boundary between the weight member 3 and the recess 4 including the gap 7 is sufficiently filled. As the brazing material 9, various types such as copper brazing, brass brazing, silver brazing, phosphor copper brazing, gold brazing, palladium brazing, nickel brazing or aluminum brazing can be adopted. In particular, when the weight member 3 is made of a tungsten alloy, nickel brazing having a high bonding force with the tungsten member is desirable.

  The nickel brazing is a brazing material in which boron or phosphorus as a melting point lowering element is blended with nickel, and a joint portion by this is also preferable in terms of excellent oxidation resistance and corrosion resistance. Further, nickel brazing can be broadly classified into Ni-B-Si ternary eutectic system and Ni-P binary eutectic system when classified by alloy system. In particular, BNi-2 having a low melting point and good flow is suitable.

  In the manufacturing method of this embodiment, brazing is performed in a vacuum furnace. Therefore, it is not necessary to consider the growth of an oxide film or the like on the surface of the base material being heated, and it is not necessary to use a flux. However, depending on the brazing method, the brazing surface of the base material may be cleaned using a flux. As such a flux, for example, borides such as borax, boric acid, boron, fluoride, chloride or the like is used, and “FB3D” in the AWS standard is particularly preferable.

  Prior to the placement of the brazing material 9, the flux is applied to the boundary portion j in advance and liquefied by being heated, and can flow deeply between the weight member 3 and the recess 4 to clean the surface of the base material. Thereafter, the brazing material 9 is disposed again on the brazing portion cleaned with the flux, and heating is performed for brazing. Further, both the flux and the brazing material 9 can be placed on the boundary j, and the flux can be dissolved together with the brazing material 9.

  Next, a heating step is performed in which the head assembly 1m obtained as described above is heated to melt the brazing material 9. In the heating process of the present embodiment, the head assembly 1m is put into a vacuum furnace and heated. In the furnace, the head assembly 1m can be placed, for example, on a horizontal mounting table with the face 2a in contact (not shown).

  FIG. 6 shows a time chart of the heating process of the present embodiment, where the vertical axis indicates the temperature in the furnace and the horizontal axis indicates time. In the heating process of the present embodiment, the furnace temperature is gradually raised. When the melting point of the brazing material 9 is Tc (° C.), the temperature of T1 is at a temperature of Tc−100 (° C.) or more and Tc (° C.) or less. A preheating step of preheating the head assembly 1m for a minute is performed.

  In order to increase the bonding strength between the weight member 3 and the recess 4 by uniform brazing, it is necessary to reduce the temperature difference between the head main body 2 and the weight member 3 during brazing and to maintain substantially the same temperature. However, since the specific heat of the weight member 3 and the concave portion 4 is different, there is a possibility that uniform brazing cannot be performed due to a temperature difference between the members 2 and 3 when heated for a short time. In this embodiment, prior to actual brazing (which means a main heating stage to be described later, heating at a temperature at which the brazing material is completely and sufficiently melted), the head body 2 and the weight member 3 are sufficiently time-consuming. By preheating, the temperature difference between the members 2 and 3 is reduced, and as a result, uniform brazing can be realized.

  In order to exert such an action reliably, the preheating stage time t1 is preferably 50 minutes or more, more preferably 60 minutes or more, and even more preferably 70 minutes or more continuously. On the other hand, if the time t1 of the preheating stage is too long, the productivity may be lowered. Therefore, it is preferably 100 minutes or less, more preferably 90 minutes or less, and still more preferably 80 minutes or less.

  Further, the temperature in the preheating stage needs to be Tc-100 (° C.) or higher and Tc (° C.) or lower. When the temperature is lower than Tc-100 (° C.), there is a large difference up to the temperature when the brazing material 9 is melted, and as a result, there is a possibility that a temperature difference will occur again during actual brazing. On the other hand, when the temperature exceeds Tc, the brazing material 9 may melt before the temperature difference among the head body 2, the weight member 3, and the recess 4 is reduced.

  After finishing the preheating step, the furnace temperature is gradually raised. In this embodiment, the head assembly 1m is continuously heated at a temperature of Tc + 80 (° C.) or higher and Tc + 100 (° C.) or lower for 15 to 60 minutes. The main heating stage takes place. By the main heating step, the brazing material 9 is sufficiently dissolved, and the element can diffuse into both the head body 2 and the weight member 3 (base material). Further, part of the elements of the head main body 2 and the weight member 3 are also dissolved in the brazing material 9. Such a mutual reaction forms a strong alloyed joint between the weight member 3 and the recess 4.

  Further, in the conventional brazing, the temperature and time are sufficient for the brazing material to be completely melted. For example, the temperature is about Tc + 30 (° C.) and the heating time is about 5 minutes at most. On the other hand, in the main heating stage of the present embodiment, the above-mentioned reaction is surely performed by performing at a temperature not lower than Tc + 80 (° C.) and not higher than Tc + 100 (° C.) for 15 to 60 minutes under sufficient temperature and time conditions. Thus, a uniform and strong joint can be obtained between the weight member 3 and the recess 4.

  Here, it is desirable that the main heating step is performed at a time t2 of more preferably 20 minutes or more, and even more preferably 30 minutes or more. Thereby, the said interaction can be expressed more reliably. On the other hand, if the time t2 is too long, not only will the effect reach its peak, but productivity may be reduced. Further, when the head main body 2 is made of carbon steel, the crystal grains become large and the strength may be reduced. From such a viewpoint, the time T2 for performing the main heating stage is preferably 50 minutes or less, more preferably 45 minutes or less.

  The temperature in the main heating stage needs to be at least Tc + 80 (° C.) or more. Thereby, the brazing material 9 can be surely melted, and the brazing material 9 can be penetrated deeper into the boundary j between the weight member 3 and the recess 4. On the other hand, if the temperature of the main heating stage is too high, the metal structure of the base metal may be adversely affected, and therefore, it is set to Tc + 100 (° C.) or less.

  Also, when the main heating step is finished, the furnace temperature is gradually lowered. At this time, the temperature inside the furnace is decreased from Tc (° C.) to Tc-100 (° C.) over a period of time 60 to 120 minutes, so that the head assembly 1 m in the furnace is gradually cooled. It is desirable to include. Such a cooling step can prevent rapid contraction and deformation of the head main body 2 and the weight member 3 by preventing a rapid temperature drop of the heated head assembly 1m. Accordingly, cracks and the like are effectively prevented from occurring in the brazing material filled between the members 2 and 3.

  Here, when the time t3 required for the cooling stage is less than 60 minutes, the rapid contraction deformation of the head main body 2 and the weight member 3 cannot be suppressed, and cracks are likely to occur in the brazing material 9 during the curing. Conversely, if the time t3 exceeds 120 minutes, the productivity may be significantly reduced. From this point of view, the cooling step is preferably performed for 70 minutes or more, more preferably 80 minutes or more, and preferably for 110 minutes or less, more preferably 100 minutes or less. Since most of the brazing filler metal 9 melted in the main heating stage starts to be cured by cooling from the temperature Tc to Tc-100 (° C.), the brazing filler metal is cooled sufficiently over the temperature range so that the brazing filler metal 9 is cooled. 9 cracks can be reliably prevented.

  After the above heating process, the head assembly 1m is taken out from the furnace, and excess brazing material remaining on the surface is removed. Further, the club head 1 is manufactured by performing surface finishing of the head assembly 1m, necessary painting, and the like according to the custom.

  Here, the melting point Tc of the brazing material 9 is not particularly limited, but if it is too low, the bonding force with the weight member 3 made of a tungsten alloy tends to be low. In addition to requiring a large amount of heat energy, the productivity is reduced and the head body 2 and the weight member 3 may be affected by heat. From such a viewpoint, the melting point Tc of the brazing material 9 is preferably 850 ° C. or higher, more preferably 870 ° C. or higher, further preferably 900 ° C. or higher, preferably 1050 ° C. or lower, more preferably 1030 ° C. or lower. More preferably, 1010 ° C. or lower is desirable.

  Also, the melting point Th of the head body 2 is not particularly limited, but if it is too low, it cannot be heated to a high temperature, so brazing itself may not be possible, and conversely if too high, the material cost may increase. . From this point of view, the melting point Th of the head body 2 is preferably 1300 ° C. or higher, more preferably 1350 ° C. or higher, further preferably 1400 ° C. or higher, preferably 2500 ° C. or lower, more preferably 2000 ° C. or lower. More preferably, 1800 ° C. or lower is desirable. When the weight member 3 is made of, for example, a sintered tungsten alloy, the melting point Tw is about 2500 to 3500 ° C., and thus is not affected at all by the heat during brazing.

  Further, at the time of brazing, the melting point Tm of the base material (that is, the melting point Th of the head body 2 or the melting point Tw of the weight member 3) so as not to impair the mechanical strength of the base material (head body 2 and weight member 3). The difference (Tm−Tc) between the lower temperature of the brazing material and the melting point Tc of the brazing material is desirably at least 200 ° C., more preferably 300 ° C. or more, and even more preferably 500 ° C. or more.

  In a particularly preferred embodiment of the club head 1, as shown in FIG. 3, the ratio (A / B) between the opening length A and the depth B of the recess 4 is regulated within a certain range. Here, the opening length A of the recess 4 is the length of a straight line L connecting the end point P1 on the head upper side of the recess 4 and the end point P2 on the head bottom side of the recess 4 as shown in FIG. . Further, the depth B of the recess 4 is the maximum depth of the recess 4 in the direction perpendicular to the straight line L.

  As a result of various experiments by the inventors, when the ratio (A / B) is decreased, the depth B of the recess 4 is relatively increased with respect to the volume of the weight member 3, and a crack or the like is generated in the brazed portion. It has been found that poor bonding is likely to occur. On the other hand, when the ratio (A / B) is increased, the fitting property between the weight member 3 and the recessed portion 4 is lowered, or it is difficult to confirm whether the weight member 3 is correctly fitted into the recessed portion 4, for example. Become. From such a viewpoint, the ratio (A / B) is preferably 1.00 or more, more preferably 1.20 or more, still more preferably 1.25 or more, and preferably 5.0 or less, more It is preferably 4.0 or less, more preferably 3.0 or less.

  Further, the opening length A of the recess 4 is preferably 5 mm or more, more preferably 7 mm or more, and further preferably 10 mm or more in order to securely hold a sufficiently large weight member 3 within a limited head volume. Desirably, it is preferably 20 mm or less, more preferably 15 mm or less, and still more preferably 12 mm or less. From the same viewpoint, the depth B of the recess 4 is preferably 3 mm or more, more preferably 4 mm or more, further preferably 5 mm or more, and preferably 15 mm or less, more preferably 12 mm or less, still more preferably 10 mm or less. Is desirable.

  The dimensions A and B are obtained by cutting the club head 1 along a plane that passes through the center of gravity of the weight member 3 and is perpendicular to the face 2a when the weight member 3 is fitted in the recess 4. The cross section where the height A is maximum is determined, and the value measured at the cross section is taken.

  In the cross section, the thickness d1 of the head body 2 and the thickness d2 of the weight member 3 measured in a direction perpendicular to the face 2a, the height h1 of the weight member 3 measured in parallel with the face 2a, etc., respectively. It is also desirable to regulate.

  That is, if the thickness d1 of the head main body 2 is too small, the center of gravity of the head becomes high, which may deteriorate the flight distance performance and directionality of the club head. On the other hand, if the thickness d1 is too large, the head weight may increase and the swing balance may deteriorate. From such a viewpoint, the thickness d1 of the head body 2 is preferably 13 mm or more, more preferably 15 mm or more, further preferably 16 mm or more, preferably 25 mm or less, more preferably 24 mm or less, and still more preferably. Is preferably 22 mm or less.

  On the other hand, if the thickness d2 of the weight member 3 (not including the protrusion 3e) is too small, the weight of the weight member 3 may be reduced and the center of gravity of the head cannot be moved effectively. In addition, the recess 4 becomes excessively deep, and as a result, the bonding strength may be reduced. From this point of view, the thickness d2 of the weight member 3 is preferably 3 mm or more, more preferably 4 mm or more, further preferably 5 mm or more, preferably 10 mm or less, more preferably 9 mm or less, and still more preferably. 8mm or less is desirable. From the same viewpoint, the height h1 of the weight member 3 is preferably 3 mm or more, more preferably 4 mm or more, further preferably 5 mm or more, and preferably 10 mm or less, more preferably 9 mm or less, still more preferably 8 mm. The following is desirable.

  In order to improve both the durability and the increase in the moment of inertia of the head, the ratio (d2 / d1) between the thickness d1 of the head body 2 and the thickness d2 of the weight member 3 is preferably 0.12 or more. More preferably, it is 0.14 or more, more preferably 0.16 or more, preferably 0.50 or less, more preferably 0.45 or less, and further preferably 0.40 or less.

  The embodiment of the present invention has been described by taking the iron type golf club head as an example. However, the present invention is not limited to this, and is applied to various heads such as a wood type, a utility type, or a putter type. Needless to say, it is possible. In the above embodiment, the weight member 3 has a protrusion and the recess 4 has a hole, but conversely, the weight member 3 has a hole and the recess has a protrusion. good. Furthermore, in the above embodiment, brazing is performed by in-furnace brazing, but there are various other methods such as gas brazing, high frequency brazing, arc brazing, or light beam brazing. It may be adopted.

  A wood type golf club head was manufactured based on the specifications shown in Table 1, and the presence or absence of cracks in the brazed portion was tested. As a common specification of each head, a forged product of S25C (specific gravity 7.9, melting point 1510 ° C.) is used for the head body, W: 98 wt%, Ni: 1.5 wt%, Fe: 0.5 wt% A sintered material of W—Ni—Fe alloy composed of inevitable impurities (specific gravity 18.0, melting point 3000 ° C. or higher) and nickel brazing (BNi-2, melting point 970 ° C.) were used.

  And after manufacturing each test head, the presence or absence of the crack of a brazing part was observed by the penetration | inspection flaw test before hit | damaging the ball | bowl. The test heads without cracks were each prototyped as an iron type golf club with the same shaft (MP-400 manufactured by SRI Sports Co., Ltd.), each club was attached to a swing robot, and a head speed of 42 m / s. After hitting 5000 pieces of 3 piece golf balls at, the presence or absence of cracks was again observed by the penetration test. Table 1 shows the test results.

  As a result of the test, it was confirmed that the club head of the example had no cracks in the brazed portion after production. Moreover, it was also confirmed that no cracks occurred after the impact test except for Examples 1 and 5.

It is a rear view which shows the golf club head of this embodiment. It is the AA sectional view. It is BB sectional drawing of FIG. FIG. 2 is an exploded perspective view of FIG. 1. (A), (b) is a fragmentary perspective view which shows the state which fitted the weight member in the recessed part. It is a graph which shows the relationship between the furnace temperature and time in a vacuum furnace.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Golf club head 2 Head main body 2A Face base 2B Hosel part 2a Face 2b Peripheral surface 2c Back surface 3 Weight member 4 Concave part 9 Brazing material

Claims (4)

A method of manufacturing a golf club head comprising a head body made of a metal material and provided with a recess, and a weight member mounted on the recess and made of a metal material having a specific gravity greater than that of the head body,
A preparation step of preparing a head assembly in which the weight member is fitted in the concave portion of the head body and a brazing material is disposed at a boundary portion between the two,
Heating the head assembly to melt the brazing material, and
The heating step includes a main heating step of continuously heating the head assembly for 15 to 60 minutes at a temperature not lower than Tc + 80 (° C.) and not higher than Tc + 100 (° C.) when the melting point of the brazing material is Tc (° C.). A method of manufacturing a golf club head, comprising:   The heating step includes a preheating step of preheating the head assembly for 50 to 100 minutes at a temperature of Tc-100 (° C) or more and Tc (° C) or less prior to the main heating step. Golf club head manufacturing method.   3. The golf club head according to claim 1, wherein the heating step includes a cooling step of slowly cooling the temperature from Tc (° C.) to Tc-100 (° C.) over 60 to 120 minutes after the main heating step. Manufacturing method. One of the recess or weight member is provided with a protrusion protruding toward the other,
The other of the concave portion or the weight member is provided with a bottomed hole portion into which the protrusion is inserted, and the weight member is positioned and fitted into the concave portion of the head body by inserting the protrusion into the hole portion. A method of manufacturing a golf club head according to claim 1.

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