Magnesium alloy club shaft

Abstract

A magnesium alloy golf club shaft is disclosed. The magnesium alloy golf club shaft is manufactured by a production process by means of an apparatus for forming a magnesium alloy pipe, comprising the steps of: heating a workpiece of a magnesium alloy pipe to a preset temperature by a heater unit and maintaining the heated temperature; rotating a die unit and varying a size of a forming space of the die unit by means of a rotational force generated by the rotation; moving the heated workpiece into the forming space; and adjusting a rotational angular velocity of the die unit in response to a reduced size of the pipe of the heated workpiece, forming the workpiece according to the size of the forming space that varies in response to the rotational angular velocity, and controlling heating performance of the heater unit in response to the rotational angular velocity.

Description

Magnesium alloy golf club shaft

[0001] The present invention relates to a magnesium alloy golf club shaft, and more specifically, to a magnesium alloy golf club shaft produced through a device that forms a magnesium alloy pipe to have a tapered shape in the longitudinal direction.

[0002] Magnesium alloys are lightweight metals with low density among available structural materials, and are gaining attention for their excellent properties such as high specific strength, machinability, and vibration absorption.

[0003] Recently, the use of these magnesium alloys is gradually increasing as they replace aluminum alloys in response to the demand for lighter transportation equipment to improve fuel efficiency. Additionally, their application is increasing in products such as mobile phones and laptops due to the demand for lightweight, compact, and excellent electromagnetic shielding properties.

[0004] However, magnesium alloys have the problem of relatively lower strength, ductility, and corrosion resistance compared to aluminum alloys, and although the ductility of magnesium alloys can be improved by increasing the processing temperature, there was a problem that there were limitations to their commercialization because compression forming was difficult for products with complex shapes or sharp corners.

[0005] Accordingly, in order to improve the formability of magnesium alloy processed materials, warm forming is performed at a temperature of 200°C or higher where non-basal slip is activated.

[0006] As such warm forming is performed on magnesium alloys, there is an increasing demand for the development of various technologies to make the forming of magnesium alloys more precise and accurate.

[0007] In particular, golf club shafts have a tapered shape in which their diameter gradually decreases along their length, and because very high dimensional precision is required for the shaft in terms of golf club performance, very special means are required to form a golf club shaft from a magnesium alloy pipe.

[0008] Japanese prior art patent document JP 2003-111876 discloses a metal shaft for a golf club made of magnesium or a magnesium alloy containing 90 mass% or more of magnesium.

[0009] The method for manufacturing a metal shaft using magnesium or a magnesium alloy disclosed in the Japanese patent document involves forming a magnesium alloy plate into a pipe shape and welding it, then annealing it to make it easier to process, drawing it to form a pipe of a desired outer diameter, grinding it, repeating the drawing process sequentially starting from the butt side to attach steps (joints) one by one, performing quenching and annealing, correcting the bending, and then plating to complete the process.

[0010] This method cannot produce a seamless shaft because it manufactures a shaft with a constant diameter equal to the step length of the drawn stage.

[0011] Korean prior art patent document Registered Patent 10-1237171 discloses a shaft made of a magnesium alloy material composed of magnesium, aluminum, zinc, and manganese.

[0012] The Korean patent document describes a shaft in which the core is made of magnesium alloy and a graphite layer is formed on the outer surface by wrapping it with a carbon graphite material or coating it with carbon graphite resin. The configuration of such a golf club shaft is similar to the configuration of an archery arrow in which carbon fiber is wrapped around an aluminum alloy core.

[0013] However, the relevant Korean patent document discloses characteristics such as the composition of the material and the physical properties resulting therefrom, but does not disclose how it is molded.

[0014] The present invention was invented based on the above recognition, and the object of the present invention is to provide a magnesium alloy golf club shaft produced by a device for forming a magnesium alloy pipe to have a tapered shape in the longitudinal direction.

[0015] A magnesium alloy golf club shaft according to one embodiment of the present invention for achieving the above objectives is manufactured through a magnesium alloy pipe forming device, wherein the manufacturing process through the magnesium alloy pipe forming device comprises the steps of: raising the workpiece of the magnesium alloy pipe to a preset temperature by a heater unit and maintaining the raised temperature; rotating a mold unit and varying the size of the forming space of the mold unit by the rotational force generated by the rotation; moving the raised workpiece into the forming space; adjusting the rotational angular velocity of the mold unit in correspondence with the shaft size of the raised workpiece; forming the workpiece according to the size of the forming space that varies in correspondence with the rotational angular velocity; and adjusting the heating performance of the heater unit in correspondence with the rotational angular velocity.

[0016] Here, the mold part includes a plurality of mold frames, and the step of varying the size of the molding space of the mold part may be such that as the plurality of mold frames rotate, the distance separated from the axis of rotation by the rotational force is changed, and the size of the molding space surrounded by the plurality of mold frames is varied due to the changed separation distance.

[0017] In this case, the adjustment of the rotational angular velocity of the mold part can adjust the size of the molding space, which varies due to the spacing distance of the plurality of mold frames that changes according to the rotational angular velocity.

[0018] Specifically, the adjustment of the rotational angular velocity of the mold part may be such that as the shaft tube size of the heated workpiece increases, the rotational angular velocity of the mold part increases to increase the distance separated from the rotation axis, and as the shaft tube size of the heated workpiece decreases, the rotational angular velocity of the mold part decreases to decrease the distance separated from the rotation axis.

[0019] In this case, the heater unit includes a high-frequency heater unit, an air heater unit, and a coil heater unit, and the step of raising the workpiece to a preset temperature and maintaining the raised temperature is such that, before the workpiece is placed at the front end of the mold unit and enters the molding space, the workpiece is raised to the preset temperature by the high-frequency heater unit and the raised temperature is maintained, and when the workpiece enters the molding space of the mold unit, the temperature of the workpiece is raised and maintained by the coil heater unit placed around the mold unit and the air heater unit placed on one side of the mold unit and on one side of the workpiece entering the mold unit, and the air heater unit may be capable of cooling the workpiece.

[0020] In this case, the step of adjusting the heating performance of the heater unit in response to the rotational angular velocity may be to increase the heating performance of the air heater unit as the rotational angular velocity of the mold unit increases, and to decrease the heating performance of the air heater unit as the rotational angular velocity of the mold unit decreases.

[0021] In this case, the step of controlling the heating performance of the heater unit in response to the rotational angular velocity may be to increase and maintain the temperature of the high-frequency heater unit in a range of 200°C or higher and 400°C or lower and to increase and maintain the temperature of the coil heater unit in a range of 200°C or higher and 500°C or lower and to increase and maintain the temperature of the air heater unit in a range of 200°C or higher and 400°C or lower and to maintain the temperature.

[0022] In this case, the rotational angular velocity of the mold part may be adjusted within a range of 20 RPM or more, 400 RPM or less, and 1500 RPM or less.

[0023] In addition, the heating performance of the heater part of the magnesium alloy pipe forming device can be adjusted according to the length of the workpiece.

[0024] The magnesium alloy golf club shaft according to the present invention has a precisely and continuously tapered shape without bending, despite the special properties of the magnesium alloy material. In particular, the magnesium alloy golf club shaft according to the present invention has a long tapered section. The present invention allows for the design of a free change in diameter along the longitudinal direction of the shaft as needed.

[0025] FIG. 1 is a drawing illustrating a magnesium alloy pipe and a magnesium alloy golf club shaft formed therefrom according to an embodiment of the present invention;

[0026] FIG. 2 is a drawing illustrating a magnesium alloy golf club shaft according to a modified embodiment of the present invention;

[0027] FIG. 3 is a block diagram illustrating the configuration of a magnesium alloy pipe forming device according to one embodiment of the present invention;

[0028] FIG. 4 is a drawing illustrating an example of a magnesium alloy pipe forming device according to one embodiment of the present invention;

[0029] FIG. 5 is a drawing for explaining the change in size of the molding space according to the rotation of the mold part according to an embodiment of the present invention;

[0030] FIG. 6 is a diagram illustrating the operation process of a high-frequency heater unit and an air heater unit according to an embodiment of the present invention; and,

[0031] FIG. 7 is a flowchart illustrating the process of manufacturing a magnesium alloy golf club shaft through a magnesium alloy pipe forming device according to one embodiment of the present invention.

[0032] The present invention will be described in more detail below with reference to the drawings. Furthermore, in describing the present invention, detailed descriptions of related known functions or configurations are omitted if it is determined that such detailed descriptions would unnecessarily obscure the essence of the invention. Additionally, the terms described below are defined considering their functions in the present invention, and these may vary depending on the intentions or relationships of the user or operator. Therefore, their definitions should be based on the content throughout this specification.

[0033]

[0034] FIG. 1 is a drawing illustrating a magnesium alloy pipe and a magnesium alloy golf club shaft formed therefrom, according to one embodiment of the present invention.

[0035] Referring to FIG. 1, a pipe made of magnesium alloy material having a predetermined length (L) and outer diameter (D) is a workpiece (10) for making a magnesium alloy golf club shaft. The workpiece (10) is formed into a golf club shaft having a desired diameter and shape by a forming device (100) disclosed in the present invention.

[0036] For example, the workpiece (10) may be formed by an extrusion process using an extruder that presses a billet of magnesium alloy with a ram and pushes it through a die. Alternatively, the workpiece (10) may be formed by a drawing process in which a billet of magnesium alloy is pulled axially through a die. The workpiece (10) may be designed by the die of the extruder or the drawing machine to have a suitable mass, thickness, and diameter.

[0037] The golf club shaft (20) according to the present invention is made of magnesium alloy. The magnesium alloy golf club shaft (20) is manufactured by forming a workpiece (10) using a forming device (100).

[0038] A golf club shaft (20) has a butt section with a thick diameter and a tip section with a thin diameter at both ends. The golf club shaft (20) is divided into a ferrule butt section (21) and a ferrule tip section (23) with a constant diameter. The lengths of the ferrule butt section (21) and the ferrule tip section (23) may vary depending on the product design. The shaft (20) has a transition section (22) between the ferrule butt section (21) and the ferrule tip section (23). The transition section (22) is a part that has a gradual change in diameter to offset the difference in diameter between the two end sections (21, 23). To form a transition section (22) with a gradually decreasing diameter from a pipe (10) with a constant diameter, a tapering process is required to gradually decrease the diameter over the desired forming length.

[0039] The magnesium alloy golf club shaft (20) according to the present invention has a transition region (22) formed by tapering by the magnesium alloy pipe forming device (100) according to the present invention. That is, the magnesium alloy pipe forming device (100) according to the present invention can provide a tapering process necessary to manufacture such a shaft (20).

[0040]

[0041] FIG. 2 is a drawing illustrating a magnesium alloy golf club shaft according to a modified embodiment of the present invention.

[0042] The shaft (20') of FIG. 2 has a different shape of the transition section (20') from the shaft (20) of FIG. 1. The diameter of the transition section (20') increases or decreases along the length or repeats the increase and decrease. Such a shaft design can be recognized by consumers as a unique feature of a specific brand product. The magnesium alloy pipe forming device (100) according to the present invention can provide a variable axial pipe forming process capable of producing such a shaft (20').

[0043]

[0044] FIG. 3 is a block diagram illustrating the configuration of a magnesium alloy pipe forming device according to one embodiment of the present invention.

[0045] Referring to FIG. 1, a magnesium alloy pipe forming device (100) includes a heater part (110), a mold part (120), a moving part (130), and a processor (140).

[0046] The workpiece (10) that is the subject of the magnesium alloy pipe forming device (100) is a cylindrical pipe made of magnesium alloy material, and undergoes a pipe reduction process to reduce the diameter or radius of the pipe, and the diameter or radius size of the pipe that undergoes the pipe reduction process is defined as the pipe reduction size.

[0047] The magnesium alloy pipe forming device (100) heats the workpiece (10), i.e., the magnesium alloy pipe, using a heater part (110) and maintains the heated temperature, while performing plastic forming by applying pressure to the high-temperature magnesium alloy pipe while rotating it with a mold part (120) to be described later.

[0048] Specifically, the heater unit (110) raises the workpiece (10) to a preset temperature and maintains the raised temperature. To this end, the heater unit (110) is positioned along the path of the workpiece (10) so that the raised temperature is maintained from before the workpiece (10) is injected into the magnesium alloy pipe forming device (100) until it is discharged to the outside after undergoing the forming process.

[0049] The mold part (120) rotates around a rotation axis and defines a molding space through which the workpiece (10) passes and is formed. The size of the molding space of the mold part (120) varies in response to the rotational force.

[0050] In a specific embodiment, the mold part (120) is composed of a plurality of mold frames, and the plurality of mold frames surround the molding space with respect to a rotation axis. Then, when the mold part (120) rotates, each of the plurality of mold frames moves away from the rotation axis due to the rotational force, that is, centrifugal force. In other words, the plurality of mold frames are gathered around the rotation axis, but as the rotational force becomes stronger, they move further away from the rotation axis and the gap between neighboring mold frames widens.

[0051] As the multiple mold frames spread apart due to the rotational force, the size of the molding space surrounded by the multiple mold frames changes. The workpiece (10) moves into this molding space, and the workpiece (10), while maintaining the raised temperature, is plastically molded within the molding space through the pressure of each of the multiple mold frames.

[0052] The moving part (130) moves the workpiece (10) into the molding space. As an example, the moving part (130) moves the workpiece (10) axially within a moving speed range of 5 mm / s to 100 mm / s. The moving part (130) may be a piston, a linear motor, etc., positioned opposite the entrance of the mold part (120) and capable of pushing and pulling the workpiece (10) in the longitudinal direction.

[0053] The processor (140) adjusts the rotational angular velocity of the mold part (120) in correspondence with the shaft size of the heated workpiece (10), thereby enabling the workpiece (10) to be molded according to the size of the molding space that varies in correspondence with the rotational angular velocity.

[0054] And, the processor (140) can adjust the heating performance of the heater unit (110) in response to the rotational angular velocity.

[0055] Here, the shaft size of the heated workpiece refers to the size of the cross-section to be formed of the heated workpiece, and can be defined as a radius size or a diameter size according to the length in the forming direction.

[0056] For example, if the target product formed from the workpiece (10), which is a pipe, is in the shape of a tapered cone, the size of the shaft becomes smaller as the workpiece (10) moves in the direction of travel.

[0057] Then, the processor (140) adjusts the rotational angular velocity of the mold part (120) according to the shrinking shaft size, and the workpiece (10) is formed into a shaft according to the size of the molding space created by varying in response to the rotational angular velocity.

[0058] Specifically, the processor (140) can increase the rotational angular velocity of the motor that rotates the mold part (120) so that as the aforementioned plurality of mold frames rotate, they gradually spread further away from the rotation axis and the size of the molding space they form increases, thereby increasing the size of the shaft tube in which the heated workpiece (10) is molded.

[0059] Additionally, as the processor (140) gradually lowers the rotational angular velocity of the mold part (120), the aforementioned plurality of mold frames are brought closer to the rotation axis, and as the size of the molding space they form becomes smaller, the size of the shaft tube in which the heated workpiece (10) is molded can also be reduced.

[0060] For example, if the molded product of the heated workpiece (10) is a magnesium alloy golf club shaft having a conical shape or a conical transition section (22), the shaft tube size must become smaller as the workpiece (10) moves in the direction of travel. Therefore, the processor (140) increases the rotational angular velocity of the mold part (120) when the heated workpiece (10) enters the molding space so that the shaft tube size of the workpiece (10) is formed larger, and as the workpiece (10) moves in the molding direction after entering the molding space, the processor (140) gradually decreases the rotational angular velocity of the mold part (120) so that the shaft tube size of the workpiece (10) becomes smaller, thereby making the shape of the workpiece (10) conical.

[0061] Meanwhile, the processor (140) can adjust the performance of the heater unit (110) in response to the rotational angular velocity, and this will be described later.

[0062]

[0063] FIG. 4 is a drawing illustrating an example of a magnesium alloy pipe forming device according to one embodiment of the present invention.

[0064] Referring to FIG. 4, in a magnesium alloy pipe forming device (100) according to one embodiment of the present invention, a heater unit (110) is positioned at one side of the workpiece (10), the entrance to the forming space within the mold unit (120), and the exit of the forming space within the mold unit (120) respectively before the workpiece (10) enters the forming space within the mold unit (120), and a moving unit (130) moves the workpiece (10) so that the workpiece (10) can enter the forming space within the mold unit (120).

[0065] And, the processor (140) controls the heater unit (110) to raise the workpiece (10) to a preset temperature and maintain the raised temperature, and controls the moving unit (130) to move the workpiece (10) at a speed of 5 mm / s to 100 mm / s, and can form the workpiece (10) into an axial tube while adjusting the rotational angular velocity of the mold unit (120) according to the axial tube size of the target workpiece (10).

[0066]

[0067] FIG. 5 is a drawing illustrating the change in the size of the molding space according to the rotation of the mold part according to one embodiment of the present invention.

[0068] Referring to FIG. 5, the mold portion (120) may include a plurality of mold frames (121, 122, 123, 124). The mold portion (120) of the representative embodiment illustrated in FIG. 5 includes four mold frames (121, 122, 123, 124). The four mold frames (121, 122, 123, 124) define a molding space (125) in the center surrounding the axis of rotation. The plurality of mold frames (121, 122, 123, 124) have cross-sections that are evenly divided radially around the axis of rotation. In the illustrated example, the four mold frames (121, 122, 123, 124) have cross-shaped cross-sections that are divided into four equal parts in an X-shape with respect to the axis of rotation. By analogy, the multiple mold frames (121, 122, 123, 124) are similar to a four-part clamp fitting or chuck that clamps a workpiece (10) or pipe accommodated in a molding space (125).

[0069] Meanwhile, there may be two of the plurality of mold frames (121, 122, 123, 124). For example, if there are two of the plurality of mold frames, one mold frame may form half of the entire cross-shaped mold part (120) and may be implemented in an upwardly convex shape (hat shape), and the part forming the internal molding space (125) may be an arc corresponding to 1 / 2 of the circle, rather than an arc corresponding to 1 / 4 of the circle as shown in FIG. 5.

[0070] A plurality of mold frames (121, 122, 123, 124) are gathered around a rotation axis to form a molding space (125) inside. When the mold part (120) rotates clockwise (127) with a rotational angular velocity (ω) around the rotation axis, the plurality of mold frames (121, 122, 123, 124) move away from the rotation axis by rotational force, that is, centrifugal force, and the distance (126) separated from the rotation axis changes according to the strength of the rotational force.

[0071] And, the processor (140) can adjust the size of the molding space (125) based on the distance (126) from the rotation axis that changes according to the rotational angular velocity by adjusting the rotational angular velocity (ω) of the mold part (120).

[0072] For example, if the target shaft size of the workpiece (10) is larger than the size of the molding space of the current mold part (120), the processor (140) increases the rotational angular velocity (ω) of the mold part (120) to increase the distance (126) at which a plurality of mold frames (121, 122, 123, 124) are separated from the rotation axis, thereby expanding the size of the molding space (125) and allowing the shaft size of the workpiece (10) to be molded to be larger.

[0073] Additionally, if the target shaft size of the workpiece (10) is smaller than the shaft size of the molding space (125) of the current mold part (120), the processor (140) reduces the rotational angular velocity (ω) of the mold part (120) to reduce the distance (126) between the plurality of mold frames (121, 122, 123, 124) and the rotation axis, thereby narrowing the size of the molding space (125) and making the shaft size of the workpiece (10) smaller.

[0074] That is, the processor (140) can increase the rotational angular velocity (ω) of the mold part (120) to increase the distance (126) separated from the rotation axis as the shaft tube size of the heated workpiece (10) increases, and decrease the rotational angular velocity (ω) of the mold part (120) to decrease the distance (126) separated from the rotation axis as the shaft tube size of the heated workpiece (10) decreases.

[0075]

[0076] FIG. 6 is a diagram illustrating the operation process of a high-frequency heater unit and an air heater unit according to an embodiment of the present invention.

[0077] A heater unit (110) according to one embodiment of the present invention includes a high-frequency heater unit (111), an air heater unit (112), and a coil heater unit (113). In the embodiment illustrated in FIG. 6, there are multiple air heater units (112).

[0078] Here, the high-frequency heater (111) is positioned at the front of the mold part (120), that is, around the entrance, so that the workpiece (10) can be heated to a preset temperature using high frequency before the workpiece (10) enters the molding space (125) and the heated temperature can be maintained.

[0079] Additionally, each of the plurality of air heater sections (112) is positioned on one side of the mold section (120) and on one side of the workpiece (10) entering the mold section (120) to maintain the increased temperature of the workpiece (10).

[0080] Additionally, the coil heater (113) is positioned around the mold part (120), that is, inside the main body of the molding device (100) that surrounds the mold part (120), and raises and maintains the workpiece (10) and the mold part (120), which are cooled inside the molding device (100) when in contact with the mold part (120), to a preset temperature.

[0081] This is because, due to the characteristics of magnesium alloys, the crystal structure of the structure can only change at a specific temperature, and plastic forming becomes possible at this specific temperature. Additionally, since magnesium alloys have excellent thermal conductivity and a very fast cooling rate, it is very important to maintain the elevated temperature when the forming distance is long (e.g., 100 mm or more).

[0082] Accordingly, as shown in FIG. 6, a high-frequency heater unit (111) is positioned around the entrance of the mold unit (120), an air heater unit (112) is positioned on the discharge side of one side of the workpiece (10) and the opposite side of the mold unit (120), and a coil heater unit (113) is positioned inside the main body of the molding device (100) around the mold unit (120), so that the temperature can be raised and isothermally maintained, that is, the raised temperature, from the time the workpiece (10) enters the mold unit (120) until it is discharged after molding processing.

[0083] Meanwhile, in the above embodiments, the high-frequency heater unit (111) and the coil heater unit (113) are used together, but they may be used alternatively or complementarily as needed. For example, if the temperature of the environment in which the shaft is manufactured is low, the high-frequency heater unit (111) irradiated from the outside is useful. However, if sufficient temperature increase and maintenance for forming the magnesium alloy pipe (10) is possible with only one of the high-frequency heater unit (111) or the coil heater unit (113), it is possible to use only one of them.

[0084] Meanwhile, the air heater unit (112) can be used to lower the temperature of the workpiece (10). For example, to reduce the risk of the molded product, which has become soft and overheated at the discharge side of the mold unit (120) of the molding device (100), being deformed by external forces such as gravity, the air heater unit (112) can turn off the air heating function and air cool with natural wind.

[0085] Meanwhile, the processor (140) can increase the heating performance of the air heater part (112) as the rotational angular velocity (ω) of the mold part (120) increases, and decrease the heating performance of the air heater part (112) as the rotational angular velocity (ω) of the mold part (120) decreases.

[0086] Specifically, as the rotational angular velocity (ω) of the mold part (120) increases, the distance between each of the plurality of mold frames (121, 122, 123, 124) and the rotation axis increases, and as the size of the molding space (125) increases, the shaft tube size of the workpiece (10) increases, and accordingly, the cross-sectional area and surface area of ​​the workpiece (10) increase.

[0087] And, in order to maintain the increased temperature of the workpiece (10) with a wider cross-sectional area, the processor (140) increases the performance of the air heater unit (112) so that a larger amount of heated air is discharged, thereby maintaining the temperature so that the workpiece (10) does not cool down as much as the cross-sectional area has increased.

[0088] Additionally, as the rotational angular velocity (ω) of the mold part (120) decreases, the distance between each of the plurality of mold frames (121, 122, 123, 124) and the rotation axis decreases, and as the size of the molding space (125) decreases, the shaft tube size of the workpiece (10) decreases, and accordingly, the cross-sectional area of ​​the workpiece (10) becomes narrower.

[0089] And, in order to maintain the increased temperature of the workpiece (10) with a narrowed cross-sectional area, the processor (140) can maintain the temperature of the workpiece (10) by reducing the performance of the air heater unit (112) so that a smaller amount of heated air is discharged.

[0090] As described above, the processor (140) can adjust the rotational angular velocity (ω) of the mold part (120) in accordance with the shaft tube size of the workpiece (10), and increase or decrease the heating performance of the heater part (110) according to the adjusted rotational angular velocity (ω).

[0091] Additionally, the processor (140) can adjust the heating performance of the heater section (110), namely the high-frequency heater section (111), the air heater section (112), and the coil heater section (113), according to the length of the workpiece (10). When manufacturing golf club shafts of various lengths, the magnesium alloy pipe, which is the workpiece (10), may have different lengths, and since the workpiece (10) is exposed to the outside and the amount of heat dissipated increases, the heating performance of the heater section (110) increases as the length of the workpiece (10) increases by the control of the processor (140) in order to maintain the increased temperature.

[0092] Meanwhile, the processor (140) controls the high-frequency heater unit (111) to raise and maintain the temperature in the range of 200°C or higher and 400°C or lower, thereby raising and maintaining the workpiece (10) to a preset temperature in the range of 200°C or higher and 400°C or lower, and controls the air heater unit (112) to maintain the temperature in the range of 200°C or higher and 400°C or lower, and controls the coil heater unit (113) to raise and maintain the temperature in the range of 200°C or higher and 500°C or lower, thereby raising and maintaining the workpiece (10) to a preset temperature in the range of 200°C or higher and 400°C or lower. Additionally, the processor (140) can adjust the rotational angular velocity (ω) of the mold part (120) in the range of 20 RPM or more, 400 RPM or less, and as described above, can adjust the rotational speed by increasing or decreasing the rotational angular velocity (ω).

[0093]

[0094] FIG. 7 is a flowchart illustrating the process of manufacturing a magnesium alloy golf club shaft using a magnesium alloy pipe forming device according to one embodiment of the present invention.

[0095] Referring to FIG. 7, a method for manufacturing a magnesium alloy golf club shaft using a magnesium alloy pipe forming device according to one embodiment of the present invention includes the step (S710) of first raising the workpiece of the magnesium alloy pipe to a preset temperature by a heater unit and maintaining the raised temperature.

[0096] The heater section of the forming device includes a plurality of components, such as a high-frequency heater section and an air heater section, and can be arranged to raise and maintain the temperature of a long workpiece.

[0097] Next, the method for manufacturing a magnesium alloy golf club shaft using a magnesium alloy pipe forming device includes the step (S720) of rotating the mold part and varying the size of the forming space of the mold part using the rotational force generated by the rotation. The mold part is composed of a plurality of mold frames, and the plurality of mold frames arranged in a circumferential direction around a rotation axis form a forming space whose size varies as the distance from the rotation axis changes due to the rotational force generated by the rotational angular velocity.

[0098] Next, the method for manufacturing a magnesium alloy golf club shaft using a magnesium alloy pipe forming device includes the step (S730) of moving the heated workpiece into the forming space. The movement of the workpiece can be performed by a moving part (130) of the forming device.

[0099] And, a method for manufacturing a magnesium alloy golf club shaft using a magnesium alloy pipe forming device includes the step (S740) of adjusting the rotational angular velocity of the mold part in correspondence with the shaft tube size of the heated workpiece, forming the workpiece according to the size of the forming space that varies in correspondence with the rotational angular velocity, and adjusting the heating performance of the heater part in correspondence with the rotational angular velocity.

[0100] The adjustment of the rotational angular velocity of the mold section controls the size of the molding space, which varies due to the separation distance between multiple mold frames that changes according to the rotational angular velocity. Specifically, the adjustment of the rotational angular velocity of the mold section is achieved by increasing the rotational angular velocity as the shaft size of the heated workpiece increases, thereby increasing the separation distance between multiple mold frames from the rotation axis, and by decreasing the rotational angular velocity as the shaft size of the heated workpiece decreases, thereby reducing the separation distance between multiple mold frames from the rotation axis.

[0101] The heating performance is adjusted so that as the rotational angular velocity of the mold part increases, the heating performance of the air heater part increases, and as the rotational angular velocity of the mold part decreases, the heating performance of the air heater part decreases.

[0102]

[0103] Meanwhile, a non-transitory computer-readable medium may be provided that stores a program for sequentially performing the method of manufacturing a magnesium alloy golf club shaft using a magnesium alloy pipe forming device according to the present invention.

[0104] A non-transient readable medium refers to a medium that stores data semi-permanently and can be read by a device, rather than a medium that stores data for a short period of time, such as a register, cache, or memory. Specifically, the various applications or programs described above may be stored and provided on non-transient readable media such as CDs, DVDs, hard disks, Blu-ray discs, USBs, memory cards, and ROMs.

[0105] Furthermore, although preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above. It is understood that various modifications can be made by those skilled in the art without departing from the essence of the invention as claimed in the claims, and such modifications should not be understood individually from the technical spirit or perspective of the present invention.

Claims

1. In a magnesium alloy golf club shaft manufactured through a magnesium alloy pipe forming device, The manufacturing process using the above magnesium alloy pipe forming device is, A step of raising the workpiece of a magnesium alloy pipe to a preset temperature by means of a heater and maintaining the raised temperature; A step of rotating the mold part and varying the size of the molding space of the mold part using the rotational force generated by the rotation; A step of moving the heated workpiece into the molding space; and A magnesium alloy golf club shaft comprising the step of: adjusting the rotational angular velocity of the mold part in correspondence with the shaft tube size of the heated workpiece; forming the workpiece according to the size of the forming space that varies in correspondence with the rotational angular velocity; and adjusting the heating performance of the heater part in correspondence with the rotational angular velocity.

2. In Paragraph 1, The above mold part includes a plurality of mold frames, and The step of varying the size of the molding space of the above-mentioned mold part is, A magnesium alloy golf club shaft in which the distance separated from the axis of rotation by the rotational force changes as the plurality of mold frames rotate, and the size of the molding space surrounded by the plurality of mold frames varies due to the changed separation distance.

3. In Paragraph 2, The adjustment of the rotational angular velocity of the above mold part is, A magnesium alloy golf club shaft that adjusts the size of the molding space, which varies due to the spacing distance of the plurality of mold frames that changes according to the rotational angular velocity.

4. In Paragraph 3, The adjustment of the rotational angular velocity of the above mold part is, A magnesium alloy golf club shaft that increases the rotational angular velocity of the mold part to increase the distance separated from the rotation axis as the shaft tube size of the heated workpiece increases, and decreases the rotational angular velocity of the mold part to decrease the distance separated from the rotation axis as the shaft tube size of the heated workpiece decreases.

5. In Paragraph 4, The above heater unit includes a high-frequency heater unit, an air heater unit, and a coil heater unit, and The step of raising the workpiece to a preset temperature and maintaining the raised temperature is Before the above workpiece is placed at the front end of the mold part and enters the molding space, the workpiece is heated to the preset temperature by the high-frequency heater part and the heated temperature is maintained. When the above workpiece enters the molding space of the mold part, the temperature of the workpiece is raised and maintained by the coil heater part disposed around the mold part and the air heater part disposed on one side of the mold part and on one side of the workpiece entering the mold part. A magnesium alloy golf club shaft in which the air heater portion is capable of cooling the workpiece.

6. In Paragraph 5, The step of adjusting the heating performance of the heater unit in response to the above rotational angular velocity is, A magnesium alloy golf club shaft that increases the heating performance of the air heater as the rotational angular velocity of the mold part increases, and decreases the heating performance of the air heater as the rotational angular velocity of the mold part decreases.

7. In Paragraph 6, The step of adjusting the heating performance of the heater unit in response to the above rotational angular velocity is, A magnesium alloy golf club shaft that controls the temperature of the high-frequency heater section to be raised and maintained in a range of 200°C or higher and 400°F or lower, and the temperature of the air heater section to be raised and maintained in a range of 200°C or higher and 400°F or lower.

8. In Paragraph 7, A magnesium alloy golf club shaft in which the rotational angular velocity of the above-mentioned mold part is adjusted within a range of 20 RPM or more and 400 RPM or less.

9. In Paragraph 1, A magnesium alloy golf club shaft, wherein the heating performance is adjusted according to the length of the workpiece.

Images