Patent Publication Number: US-2018050241-A1

Title: Manufacturing method of golf iron head by combining different metal materials

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a manufacturing method of a golf club head, especially to a manufacturing method of a golf iron head by combining different metal materials. 
     2. Description of Related Art 
     A conventional golf iron head is mostly manufactured by forging or casting with one single steel material. Because the material properties lack diversity, the hitting performance of the club head is limited. Therefore, to enhance the hitting performance, the manufacture method of the conventional golf club head mostly adopts different metal materials. 
     A conventional golf iron head manufacturing method is disclosed with reference to  FIGS. 6 and 7 . In a pre-forming step, an iron head body  30  is made by a casting process and a strike plate  40  is made by a metal pressing process. The materials of the iron head body  30  and the strike plate  40  are different. A plate recess  31  is formed in the iron head body  30 . A flange  32  is formed around the plate recess  31 . An annular recess  41  is formed around a periphery of the strike plate  40 . 
     In a forming step, the strike plate  40  is placed in the plate recess  31  of the iron head body  30 . The flange  32  is blended toward the annular recess  41  by stamping press or hydraulic press, and the strike plate  40  and the iron head body  30  are fixed together and are formed as an iron head. 
     However, the strike plate  40  and the iron head body  30  are not really integrated as a one-piece structure, and a clearance still exists between the strike plate  40  and the iron head body  30 , which makes the combination force of the strike plate  40  and the iron head body  30  insufficient and easily generates noises upon striking. After the iron head hits a ball for several times, the strike plate  40  may fall down from the iron head body  30  or be loosened from the iron head body  30 , and the hitting performance of the iron head will get worse and noises are generated upon striking. 
     To overcome the shortcomings of the conventional manufacture method, the present invention provides a manufacturing method of a golf iron head to mitigate or obviate the aforementioned problems. 
     SUMMARY OF THE INVENTION 
     The main objective of the present invention is to provide a manufacturing method of a golf iron head comprising a pre-forming step, an engaging step, a pre-heating step and a forming step. 
     A head body and a strike plate are provided in the pre-forming step to combine together. The strike plate is engaged with the head body in the engaging step, and the strike plate and the head body are pre-heated together. The forming step combines the head body and the strike plate as a one-piece iron head without clearances. 
     Because the materials of the head body and strike plate are different and the connection force between the head body and the strike plate is increased, the mechanical properties and hitting performance are improved and noises upon hitting are eliminated. 
     Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a preferred embodiment of a manufacturing method of a golf iron head in accordance with the present invention; 
         FIG. 2  is a front view of a head body made by the method in  FIG. 1 ; 
         FIG. 3  is a cross sectional bottom view of the head body in  FIG. 2  with a strike plate; 
         FIG. 4  is a cross sectional bottom view of the head body with the strike plate in  FIG. 2  engaged with each other by an engaging step; 
         FIG. 5  is a cross sectional bottom view of a golf iron head made by the method in  FIG. 1 ; 
         FIG. 6  is a cross sectional bottom view of a golf iron head made by a conventional golf iron head manufacturing process; 
         FIG. 7  is cross sectional bottom view of the golf iron head in  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
     With reference to  FIG. 1 , a preferred embodiment of a manufacturing method of a golf iron head includes a pre-forming step S 1 , an engaging step S 2 , a pre-heating step S 3  and a forming step S 4 . 
     With reference to  FIGS. 2 and 3 , the pre-forming step S 1  further includes providing a head body and providing a strike plate. 
     A head body  10  is provided, is selectively made by a casting process or a forging process, and has a base  11 , a rod portion  12 , a plate recess  13  and at least one engaging recess  14 . The rod portion  12  is formed and integrated with one side of the base  11 . The plate recess  13  is formed in a front surface of the base  11  and has an inner wall. The at least one engaging recess  14  is formed in the inner wall of the plate recess  13 . Preferably, the inner wall of the plate recess  13  has four wall surfaces around the plate recess  13 , and each one of the wall surfaces is perpendicular to the bottom of the plate recess  13 . Four engaging recesses  14  are implemented and respectively defined in the four wall surfaces of the plate recess  13 . The engaging recesses  14  are inclined relative to the bottom of the plate recess  13  and formed triangular in cross section. 
     Furthermore, the engaging recesses  14  are formed by molding when the head body  10  is made by a casting process, or the engaging recesses  14  are formed by machine cutting when the head body  10  is made by a forging process. 
     The material of the head body  10  could be applied to a casting process or a forging process, which are selected from stainless steel, carbon steel, alloy steel such as titanium alloys, aluminum bronze alloys, manganese bronze alloys, non-ferrous alloys or the combinations of them. Preferably, the stainless steel of the head body  10  can be JIS (Japanese Industrial Standards) No. SUS304, SUS303, SUS431, SUS15-5 or SUS17-4 stainless steel, or some other stainless steel alloys. The carbon steel of the head body  10  can be JIS No. 1020C, 1025C, 1035C or 1045C carbon steel. Or some other steel alloys with carbon contain as 4140 steel, 4130 steel or 4340 steel. 
     A strike plate  20  is provided to engage with the head body  10 . The material of the strike plate  20  is different from that of the head body  10 . Preferably, the strike plate  20  is made by a stamping press process or a forging process from metal sheets; the material of the strike plate  20  is selected from titanium alloys, aluminum alloys, bronze alloys, stainless steel and carbon steel or the combinations of them. 
     In the engaging step S 2  and with reference to  FIG. 3 , the strike plate  20  is placed in the plate recess  13  and protrudes out of the front surface of the base  11 . The shape of the strike plate  20  corresponds to the shape of the plate recess  13 . The thickness of the strike plate  20  is higher than the depth of the plate recess  13 . A height difference between a front surface of the strike plate  20  and the front surface of the head body  10  is from 0.1 mm to 3.0 mm. 
     In the pre-heating step S 3 , the head body  10  and the strike plate  20  are preheated to a forging temperature according to their materials. The range of the forging temperature is from 500° C. to 1200° C. 
     In the forming step S 4  and with reference to  FIGS. 4 and 5 , the head body  10  and the strike plate  20  are combined by a forging process. After the pre-heating process, the head body  10  and the strike plate  20  are placed in a forging mold. The forging pressure deforms the strike plate  20  to a strike plate  20 A, whose shape fits correspondingly with the plate recess  13  and the engaging recesses  14 . The forging pressure is controlled according to the material of the strike plate  20  and the temperature of the forging environment. A protrusion  21  is formed on the strike plate  20 A by the forging pressure, and the protrusion  21  is engaged with the engaging recesses  14 . After the forging process, the front surface of the strike plate  20  is flush with the front surface of the base  11  of the head body  10 , and the strike plate  20 A and the head body  10  are engaged integratedly and are formed as a complete iron head. 
     A surface treatment process can be applied to the iron head, and the iron head can be assembled with a golf rod in the rod portion  12  as a complete golf iron club. 
     The technique of the present invention adopts the pre-formed head body  10  to combine with the pre-formed strike plate  20 . To integrally connect the strike plate with the head body  10  and to engage the protrusion  21  on the strike plate with the engaging recesses  14 , the thickness of the strike plate  20  must be larger than the depth of the plate recess  13 . Hence, the material volume of the strike plate  20  is calculated correspondingly to the volume of the plate recess  13  of the head body  10 . The materials of the strike plate  20  can flow into the engaging recesses  14  and fill up the plate recess  13  by the forging pressure, and are formed integratedly and firmly with the head body  10  without clearances. Accordingly, the connection force between the head body  10  and the strike plate  20  is increased and is stronger than the conventional manufacturing method. Also, the hitting performance is better than that of the conventional iron club and noises upon hitting are eliminated. 
     Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.