JP2018033700A - Golf club head, golf club, and measuring method and apparatus of golf club head load center position - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a golf club head, a golf club, and a measuring method and apparatus of a golf club head load center position.SOLUTION: A golf club head 1 includes: a head body 10; a face plate 20 having a face 2 for hitting a ball; and a sensor 30 disposed between the head body 10 and the face plate 20 and for measuring forces exerted onto the face plate 20. The sensor 30 is comprised of at least three force sensors 31, 32, 33, each being capable of measuring a force independently. The force sensors 31, 32, 33 are arranged to surround a main hitting position of the face 2 in a front view of the face plate 20.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a golf club head, a golf club, and a measuring method and measuring device for the load center position of the golf club head.

  For manufacturers developing golf clubs and golf balls, it is extremely important to analyze the exchange of force when the ball is hit with a golf club head. Conventionally, several techniques have been proposed in view of such a situation.

  For example, Patent Document 1 below proposes a method for measuring a force acting when a ball and a collision plate are in contact with each other. This method is a method for measuring a dynamic friction coefficient between a golf ball and a collision plate when the golf ball collides with a collision plate installed at a predetermined angle with respect to the flight direction of the golf ball. The contact force in the direction perpendicular to the contact force and the contact force in the shear direction of the impingement plate are obtained simultaneously to determine the dynamic friction coefficient during contact.

  Patent Document 2 below proposes a method for measuring the sliding speed of a ball when the ball contacts the collision plate. In this method, a process in which a ball contacts a collision plate is imaged from a side with a high-speed camera, and the ball sliding speed is obtained based on the image.

  However, none of the methods disclosed in Patent Documents 1 and 2 can measure the center position of the load acting on the face when the ball is hit with a golf club head.

JP 2006-343139 A JP 2010-257415 A

  The present invention has been devised in view of the above problems. A golf club head, a golf club, and a golf club capable of measuring a load center position acting on a face when a ball is hit with a golf club head. The main object is to provide a measuring method and measuring device for the load center position of the club head.

  One aspect of the present invention is a golf club head, comprising a head body, a face plate having a face for hitting a ball, the head body and the face plate, and the face plate. A sensor for measuring an applied force, and each of the sensors includes at least three force sensors capable of measuring the force independently, and in front view of the face, the force sensor includes: It is arranged so as to surround the main hitting position of the face.

  The primary striking position may preferably include the centroid of the face.

  The golf club head may preferably be configured as an iron type.

  The face plate may be provided so as to be replaceable with respect to the head body.

  A golf club may be configured by mounting a shaft on the golf club head.

  Another aspect of the present invention is a method for measuring a center position of a load applied to a golf club head, and hits a ball with the face of the golf club head according to any one of claims 1 to 5. A step of acquiring information relating to the force measured by each of the force sensors when hit, and a step of calculating a center position of a load acting on the face based on the acquired information. Can be included.

  The obtaining step is continuously performed at least until the ball leaves from the moment of contact with the face, and the calculating step can continuously calculate the center position of the load.

  You may further include the process of displaying the center position of the said load on a display means as visual information.

  According to still another aspect of the present invention, there is provided an apparatus for measuring a center position of a load acting on a golf club head, wherein the golf club head according to any one of claims 1 to 4 and the force sensations are provided. And a control unit that acquires information related to the force measured by the sensor, and the control unit includes a calculation unit that calculates a load center position applied to the face based on the information.

  A golf club head according to a first aspect of the present invention has a head main body, a face plate having a face for hitting a ball, and is disposed between the head main body and the face plate and acts on the face plate. And a sensor for measuring force. The sensor includes at least three force sensors that can measure force independently, and the force sensor is disposed so as to surround a major hitting position of the face in a front view of the face. ing. Such a golf club head can calculate the center position of the load acting on the face by using the outputs of the three force sensors.

  Further, according to the measurement method and the measurement device of the load center position of the golf club head according to claim 5 or 6, the load acting on the face of the golf club head based on the information corrected from each force sensor. The center position can be calculated.

1 is a front view of a golf club head showing an embodiment of the present invention. It is the sectional view on the AA line of FIG. It is a disassembled perspective view of the golf club head of this embodiment. FIG. 3 is a front view of the golf club head with a face plate removed. It is a perspective view showing one embodiment of a measuring device of a load center position of a golf club head. It is a front view which shows the arrangement | positioning state of a force sensor. (A)-(C) are graphs which show an example of the measurement result obtained using the measuring apparatus of the load center position of the golf club head of this embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1 is a front view of a golf club head (hereinafter, simply referred to as “head”) 1 of the present embodiment, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, and FIG. 3 is an exploded perspective view of the head. Each is shown. The front view of the head 1 is a state in which the face 2 of the head 1 is oriented in parallel with the paper surface. As shown in FIGS. 1 to 3, the head 1 of the present embodiment is configured as an iron type having a certain loft angle. The head 1 may be configured as a wood type or a putter type other than the iron type.

  The head 1 includes, for example, a face 2 for hitting a ball, a top 3 constituting the head upper surface, a sole 4 constituting the head bottom surface, a back 5 constituting the head rear surface, a hosel 6 for mounting the shaft S, a toe 7 and heel 8 are shown. The golf club 1G can be provided by fixing the shaft S to the hosel 6.

  The head 1 includes a head main body 10, a face plate 20, and a sensor 30 that is disposed between the head main body 10 and the face plate 20 and measures the force acting on the face plate 20.

  The head main body 10 constitutes a main part of the head 1, while a recess 12 is formed on the face 2 side. In a preferred embodiment, the head body 10 includes, for example, a top 3, a sole 4, a back 5, and a hosel 6, and a front wall portion 14 that forms a peripheral portion of the face 2 formed around the recess 12. Although the head main body 10 of this embodiment is configured integrally, it goes without saying that it may be configured by combining two or more parts.

  The recess 12 includes, for example, a peripheral wall 12a extending inward of the head from the front wall 14 and a bottom wall 12b positioned on the back 5 side of the peripheral wall 12a. The bottom wall 12 b is formed by a surface substantially parallel to the face 2. The recess 12 of the head body 10 provides a space that is open on the face 2 side and defined on the back 5 side by the bottom wall 12b. In this space, the face plate 20 and the sensor 30 are arranged. This will be described later. In a preferred embodiment, in order to arrange the face plate 20 having a sufficiently large hitting area, it is desirable that the recess 12 is formed along the contour of the face 2 and includes a portion in the front view of the head 1.

  For example, as shown in FIGS. 1 and 2, the face plate 20 has a contour shape slightly smaller than the peripheral wall 12 a of the recess 12 of the head body 10. Thus, the face plate 20 can be disposed with a sufficient gap between the face plate 20 and the recess 12 of the head body 10 so that the face plate 20 does not come into contact with the peripheral wall 12a of the recess 12 even when the ball is hit.

  The face plate 20 of the present embodiment includes, for example, a first plate 21 and a second plate 22 arranged on the back 5 side, and is formed with a substantially constant thickness.

  The first plate 21 is made of, for example, a metal material. The front surface of the first plate 21 constitutes a main part of the face 2 that hits the ball. That is, the face 2 of the head 1 of the present embodiment is constituted by the front surface of the face plate 20 and the front wall portion 14 of the head body 10. In a preferred embodiment, a plurality of score lines 23 are formed on the front surface of the first plate 21. On the other hand, the rear surface of the first plate 21 is a substantially flat surface. As for the head 1, the front side means the face 2 side, and the rear side means the back 5 side.

  The second plate 22 is made of, for example, a metal material and has substantially the same contour shape as that of the first plate 21. Moreover, as for the 2nd plate 22 of this embodiment, both the front surface and the rear surface are comprised by the single plane. The first plate 21 and the second plate 22 are integrally fixed, and as shown in FIG. 1 and FIG. Thereby, the face plate 20 is formed. According to this embodiment, for example, a plurality of types of first plates 21 having different surface roughness, score line 23 or specific gravity can be prepared, and these can be attached to the second plate 22 in a replaceable manner. Thereby, the head 1 of this embodiment can be exchanged for various face plates 20, and is useful for these evaluations. As another embodiment, the first plate 21 and the second plate 22 may be integrated by an adhering means other than a screw, such as an adhesive or caulking.

  FIG. 4 shows a front view of the head 1 with the face plate 20 removed so that the sensor 30 can be clearly seen. The sensor 30 includes at least three force sensors that can measure forces independently. An example in which the sensor 30 according to the present embodiment includes three sensors, that is, a first sensor 31, a second sensor 32, and a third sensor 33 is illustrated. The same sensor is used for each sensor 30, 31 and 32.

  As shown in FIGS. 2 to 4, each sensor 30 includes a substantially rectangular parallelepiped housing that is small and thin. Inside the housing, for example, a strain gauge (not shown) is arranged as a detection element (for example, “USL06-H5 Series” manufactured by Tech Technical Sales Co., Ltd.). Further, the housing is provided with a pressure receiving portion 35 for transmitting an external force to a strain gauge as a detection element. The pressure receiving portion 35 is provided, for example, at a substantially central portion of the housing and slightly protrudes from the housing to the front side. When an external force is applied to the pressure receiving portion 35, strain is generated in the strain gauge inside the housing of each sensor 30, and each sensor 30 can output an analog electric signal corresponding to this strain.

  As shown in FIGS. 3 and 4, a triaxial force sensor that can detect forces in the x, y, and z directions acting on the pressure receiving portion 35 is used for each sensor 30. An xyz coordinate system is associated with the head 1. In the present embodiment, the x-axis is a toe-heel direction parallel to the score line 23. The z-axis is the head front-rear direction perpendicular to the face 2. The y-axis is the vertical direction of the face 2 that is orthogonal to both the x-axis and the z-axis. Therefore, the force in the z direction is defined as a normal force Fz orthogonal to the face 2. The forces in the x and y directions are defined as shear forces Fx and Fy along the surface of the face 2, respectively.

  Each sensor 30 is disposed in the recess 12 of the head body 10. More specifically, each sensor 30 is fixed to the bottom wall 12b of the recess 12 with a screw 36 so that the pressure receiving portion 35 faces the front side. As shown in FIG. 2, each pressure receiving portion 35 of each sensor 30 is provided with a screw hole 37.

  A face plate 20 is fixed to each sensor 30. In the present embodiment, the second plate 22 of the face plate 20 is fixed to each pressure receiving portion 35 of each sensor 30 with screws 39. The first plate 21 is fixed to the second plate 22 with screws 24 after the second plate 22 is fixed to the pressure receiving portion 35. Therefore, in this embodiment, the force applied to the front surface of the face plate 20 is decomposed into three and input to the pressure receiving portions 35 of the sensors 30.

  As shown in FIG. 4, in the present embodiment, the first sensor 31 is disposed, for example, on the top 3 side. For example, the second sensor 32 is disposed on the sole 4 side and the heel 8 side of the first sensor. For example, the third sensor 33 is disposed on the sole 4 side and the toe 7 side of the first sensor.

  Therefore, when the face 2 is viewed from the front, the center of each pressure receiving portion 35 of each sensor 30 is located at each vertex of the polygon A (which is a triangle in this embodiment). Further, the polygon A is arranged so as to surround the main striking positions of the face 2 in the front view of the face 2. Here, the main hitting position is usually a position where the golfer tries to hit, and is preferably a region having a certain area including the centroid of the face 2 (or the sweet spot of the face). The

  In the present embodiment, the force applied to the face plate 20 is decomposed into three and measured by each sensor 30. Therefore, the normal force and shear force acting on the face 2 when the ball is hit with the face 2 can be obtained as the sum of the normal force and shear force detected by these three sensors 30.

  FIG. 5 shows an example of a measuring device 40 using the golf club 1G of the present embodiment. The measuring device 40 can measure the center position of the load acting on the face 2 of the golf club head 1. As shown in FIG. 5, the measuring device 40 includes at least a golf club 1G and a control device 42 that receives information on the force measured by each sensor 30 disposed on the golf club 1G.

  One end of a cable 43 for outputting the information as an electrical signal is connected to each sensor 30 (not shown in FIG. 5). For example, the cable 43 is taken out of the head through a hole 9 (shown in FIG. 2) provided on the back 5 side of the head body 10 and wired along the shaft S (shown in FIG. 1), for example. The other end of the cable 43 is connected to the control device 42 via various interfaces. Each sensor 30 outputs an analog electrical signal to the control device 42.

  The golf club 1G is attached to, for example, a swing robot 44. As is well known, the swing robot 44 can simulate a typical human golf swing by a robot (machine). In this embodiment, the golf club 1 </ b> G is swung by the swing robot 44, so that the ball B can be hit with the face 2 of the head 1. Therefore, in the present embodiment, it is possible to approximately provide a contact state (hit state) between the head 1 and the ball B that occurs in the course of an actual golf swing. Alternatively, it goes without saying that the golf club 1G may be swung by a human.

  The control device 42 is configured by a computer having display means 42a such as a display, for example. The controller 42 can receive and record information about the force output from each sensor 30 at a predetermined sampling rate. In order to start and stop measurement using the sensor 30, for example, trigger devices S1 and S2 as shown in FIG. 5 may be provided. Exploration light from the light projecting units S1a and S2a is input to the trigger devices S1 and S2, respectively. The position of the exploration light is adjusted so as to cross the swing path of the golf club 1G. In the present embodiment, when the search light input to the trigger device S1 is interrupted by the head 1 or the shaft S of the moving golf club 1G, the trigger device S1 generates a trigger signal for starting measurement recording. And output to the control device 42. Thereafter, when the search light input to the trigger device S2 is blocked by the head 1 or the shaft S of the moving golf club 1G, the trigger device S2 controls the trigger signal for completing the measurement (recording). Output to the device 42. Regarding the trigger devices S1 and S2, at least only one sensor S1 that controls the start of measurement may be provided. The control device 42 includes a calculation unit (program) that can calculate the center position of the load applied to the face 2 based on the signal received from the sensor 30.

  An example of a measuring method for measuring the center position of the load acting on the golf club head 1 at the time of hitting the ball using the apparatus 40 configured as described above will be described.

  First, by the swing of the golf club 1, the ball B is hit at the main hitting position of the face 2 (that is, in the present embodiment, in the area surrounded by the polygon A in the front view of the face 2). Thereby, the ball B and the face 2 start to contact each other, and a small contact area is generated. The contact area increases with time and then gradually decreases, so that the ball B is no longer separated from the face 2.

  In the present embodiment, at least while the ball B is in contact with the face 2, the force applied to the face plate 20 by the contact with the ball B is measured. Therefore, the control device 42 continuously acquires information from the state in which the output of each sensor 30 changes from zero to the time when the ball fluctuates, until the ball leaves the face 2 and becomes zero again. The information of each sensor 30 includes normal force Fz and shear forces Fx and Fy.

  The calculation unit of the control device 42 calculates the center position of the load acting on the face at each time based on the information acquired from the sensor 30. The calculation unit calculates the normal force Fz and shear forces Fx and Fy at each time according to the following equations. In addition, each direction of x, y, and z and a positive / negative sign are as having shown in FIG. Further, the subscripts 1, 2, and 3 of each force mean the forces detected by the first sensor 31, the second sensor 32, and the third sensor 33, respectively.

[Vertical force Fz acting on the face plate]
Fz = Fz1 + Fz2 + Fz3
[Shearing force Fx acting on the face plate]
Fx = Fx1 + Fx2 + Fx3
[Shearing force Fy acting on the face plate]
Fy = Fy1 + Fy2 + Fy3

  FIG. 6 shows a relationship between the arrangement state of each sensor 30 and the center of gravity G of the polygon A in the front view of the face. As shown in FIG. 5, the gravity center G of the polygon A connecting the centers of the pressure receiving portions 35 of the sensors 30 and the distances Lx2, Lx3, Ly1, Ly2 and Ly3 in the x and y directions to the pressure receiving portions 35 are obtained. Define. The thickness of the face plate 20 is t. In this case, the calculation unit at each time point x, y that passes through the center of gravity G of the polygon A on a plane that passes through the pressure receiving unit 35 of each sensor 30 (which is substantially equal to the rear surface of the face plate 20). And moments Mx, My and Mz about the z axis are calculated by the following equations.

[Moment about the x axis passing through the center of gravity G of the polygon]
Mx = Fz1, Ly1-Fz2, Ly2-Fz3, Ly3 + Fy1, (-t) + Fy2, (-t) + Fy3, (-t)
[Moment about the y-axis passing through the center of gravity G of the polygon]
My = -Fz2, Lx2 + Fz3, Lx3-Fx1, (-t) -Fx2, (-t) -Fx3, (-t)
[Moment about the z-axis passing through the center of gravity G of the polygon]
Mz = Fx1 / Ly1 + Fx2 / Ly2 + Fy2 / Lx2 + Fx3 / Ly3-Fy3 / Lx3

Further, the calculation unit calculates the x and y coordinates (ax, ay) of the center position of the load that has acted on the face plate 20 by the impact at each time by the following formula.
ax = My / Fz
ay = -Mx / Fz

  By the above procedure, the control device 42 can continuously calculate the center position of the load from the moment when the face 2 and the ball B come into contact until the end of the hitting.

  In a preferred embodiment, the control device 42 preferably further includes a step of displaying information such as the calculated center position of the load on the display means 42a as visual information such as a numerical value or a graph. In this step, not only the calculation result is displayed on a display, but also a step of printing on an information transmission member such as paper can be included. Thereby, the center position of the load acting on the face 2 of the head 1 can be visually observed. Hereinafter, an example of the display process will be described.

  7A to 7C show temporal changes in the vertical force Fz, the shear force Fy, and the position of the load center obtained using the measuring device 40 of the present embodiment. The time on the horizontal axis is the elapsed time when the hitting start (contact start) is zero.

  As shown in FIG. 7 (A), it was confirmed that the vertical force Fz increased with time, peaked after about 0.25 msec, and then gradually decreased.

  As shown in FIG. 7B, the shearing force Fy increases with the passage of time (a negative value means that the shearing force is upward), and peaks before the peak of the normal force Fz. After that, it was confirmed that it gradually decreased.

  In FIG. 7C, it can be confirmed that the position of the load center moves upward (a positive value means the top side of the face with respect to the center of gravity G) as time passes. This indicates that the ball B is moving to the top 3 side on the face 2 due to the influence of the loft angle of the face 2 during the contact with the face 2. In addition, it is understood that while the ball B and the face 2 are in contact with each other, the position of the load center changes in a step shape after maintaining a substantially constant position. This is presumed to indicate a phenomenon in which the ball is caught on the score line 23 provided on the face 2.

  As described above, by using the head 1 and the measuring device of the present invention, the exchange of force during contact between the ball B and the face can be examined in more detail, and as a result, it can be used for product development of golf equipment. it can. For example, at least two types of face plates 20 having different shapes of the score line 23 are prepared in advance, and a ball hitting test is performed while the face plate 30 is replaced, and changes in load centers on the respective face plates are examined. be able to. Thereby, the quality of the score line 23 can be evaluated. Further, it is possible to examine the center position of the load under various conditions by interposing a foreign object (lawn, water, soil, mud, etc.) between the ball B and the face 2.

  As mentioned above, although embodiment of this invention was described in detail, it cannot be overemphasized that this invention is not limited to said specific embodiment, and can be implemented in a various aspect.

DESCRIPTION OF SYMBOLS 1 Golf club head 1G Golf club 2 Face 10 Head main body 12 Recess 20 Face plate 21 First plate 22 Second plate 30 Sensor 31 First sensor 32 Second sensor 33 Third sensor 40 Measuring device 42 Control device 42a Display means A Square B ball

Claims (9)

A golf club head,
A head body, a face plate having a face for hitting a ball, and a sensor disposed between the head body and the face plate and for measuring a force acting on the face plate,
The sensor comprises at least three force sensors capable of measuring force independently of each other,
The golf club head, wherein the force sensor is disposed so as to surround a major hitting position of the face in a front view of the face.   The golf club head according to claim 1, wherein the primary hitting position includes a centroid of the face.   3. The golf club head according to claim 1, wherein the golf club head is of an iron type.   The golf club head according to claim 1, wherein the face plate is provided so as to be replaceable with respect to the head body.   A golf club in which a shaft is mounted on the golf club head according to claim 1. A method for measuring a center position of a load acting on a golf club head,
Hitting a ball with the face of the golf club head according to claim 1,
Obtaining information on the force measured by each of the force sensors when struck,
A method for measuring a load center position of a golf club head, comprising: calculating a center position of a load acting on the face based on the acquired information. The obtaining step is continuously performed at least until the ball leaves the moment of contact with the face,
The method of measuring a load center position of a golf club head according to claim 6, wherein the calculating step calculates the center position of the load continuously.   The method of measuring a load center position of a golf club head according to claim 6 or 7, further comprising a step of displaying the center position of the load as visual information on a display means. An apparatus for measuring the center position of a load acting on a golf club head,
Including at least a golf club head according to any one of claims 1 to 5 and a control device that acquires information about the force measured by each of the force sensors,
The said control apparatus is a measuring apparatus of the load center position of the golf club head containing the calculation part which calculates the load center position which acted on the said face based on the said information.

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