JP6926418B2 - Golf club head, golf club, and method and device for measuring the load center position of the golf club head - Google Patents

Description

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

It is extremely important for manufacturers developing golf clubs and golf balls to analyze the exchange of force when hitting a ball with a golf club head. Conventionally, some 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 comes into contact with a collision plate. This method is a method for measuring the dynamic friction coefficient between the golf ball and the collision plate when the golf ball collides with the collision plate installed at an angle with respect to the flight direction of the golf ball. The contact force in the direction perpendicular to and the contact force in the shearing direction of the collision plate are simultaneously obtained, and the dynamic friction coefficient during contact is obtained.

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

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

Japanese Unexamined Patent Publication No. 2006-343139 JP-A-2010-257415

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

One aspect of the present invention is a golf club head, which is arranged between a head body, a face plate having a face for hitting a ball, and the head body and the face plate, and is placed on the face plate. The sensor comprises at least three force sensors capable of independently measuring the force, including a sensor for measuring the applied force, and in the front view of the face, the force sensor is: It is arranged so as to surround the main striking position of the face.

The main striking position can preferably include the centroid of the face.

The golf club head may preferably be formed in an iron shape.

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

A golf club may be formed by attaching a shaft to the golf club head.

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

The acquisition step is continuously performed at least from the moment when the ball comes into contact with the face until it is separated from the face, and the calculation step can continuously calculate the center position of the load.

A step of displaying the center position of the load on the display means as visual information may be further included.

Yet another aspect of the present invention is a device for measuring the center position of the load acting on the golf club head, wherein the golf club head according to any one of claims 1 to 4 and the respective force senses are described. It includes at least a control device that acquires information about the force measured by the sensor, and the control device includes a calculation unit that calculates a load center position acting on the face based on the information.

The golf club head according to the invention of claim 1 of the present application is arranged between a head body, a face plate having a face for hitting a ball, and the head body and the face plate, and acts on the face plate. Includes a sensor for measuring force. The sensor comprises at least three force sensors capable of independently measuring force, and in front view of the face, the force sensor is arranged so as to surround a main striking position 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 method of measuring the load center position of the golf club head and the measuring device according to claim 5 or 6, the load applied to the face of the golf club head is based on the information corrected mainly from each force sensor. The center position can be calculated.

It is a front view of the golf club head which shows one Embodiment of this invention. FIG. 1 is a cross-sectional view taken along the line AA of FIG. It is an exploded perspective view of the golf club head of this embodiment. It is a front view of the golf club head with the face plate removed. It is a perspective view which shows one Embodiment of the measuring device of the load center position of a golf club head. It is a front view which shows the arrangement state of the force sensor. (A) to (C) are graphs showing an example of measurement results obtained by using the load center position measuring device of the golf club head of the present embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a front view of the golf club head (hereinafter, may be simply referred to as “head”) 1 of the present embodiment, FIG. 2 is a cross section 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 to be parallel to 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 in addition to the iron type.

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

Further, the head 1 includes a head main body 10, a face plate 20, and a sensor 30 arranged between them and for measuring a force acting on the face plate 20.

The head body 10 constitutes the main part of the head 1, while the 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, a hosel 6, and a front wall portion 14 that constitutes a peripheral portion of the face 2 formed around the recess 12. The head body 10 of the present embodiment is integrally formed, but it goes without saying that two or more parts may be combined and configured.

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

The face plate 20 has a contour shape slightly smaller than the peripheral wall 12a of the recess 12 of the head body 10, as shown in FIGS. 1 and 2, for example. As a result, the face plate 20 can be arranged with a sufficient gap between the face plate 20 and the recess 12 of the head body 10 so as not to 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 thereof, and is formed to have 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 the main part of the face 2 that hits the ball. That is, the face 2 of the head 1 of the present embodiment is composed of 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 composed of a substantially flat surface. Regarding 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 the first plate 21. Further, the front surface and the rear surface of the second plate 22 of the present embodiment are both formed of a single plane. The first plate 21 and the second plate 22 are integrally fixed to each other, and as shown in FIGS. 1 and 3, for example, a screw 24 is integrally fixed to each other. As a result, 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 lines 23 or specific densities can be prepared and interchangeably attached to the second plate 22. Thereby, the head 1 of the present embodiment can be replaced with 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 a fixing means other than a screw such as an adhesive or caulking.

FIG. 4 shows a front view of the head 1 from which the face plate 20 has been removed so that the sensor 30 can be clearly seen. The sensor 30 is composed of at least three force sensors capable of independently measuring force. An example in which the sensor 30 of the present embodiment is composed of the first sensor 31, the second sensor 32, and the third sensor 33 is shown. The same sensors 30, 31 and 32 are used.

As shown in FIGS. 2 to 4, each sensor 30 includes a small and thin housing having a substantially rectangular parallelepiped shape. Inside the housing, for example, a strain gauge (not shown) is arranged as a detection element (for example, "USL06-H5 series" manufactured by Tech Gihan Co., Ltd.). Further, the housing is provided with a pressure receiving portion 35 for transmitting an external force to a strain gauge which is a detection element. The pressure receiving portion 35 is provided, for example, in a substantially central portion of the housing, and slightly protrudes forward from the housing. When an external force acts on the pressure receiving unit 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, each sensor 30 uses a three-axis force sensor capable of detecting forces in each of the x, y, and z directions acting on the pressure receiving unit 35. The xyz coordinate system is associated with the head 1. In this embodiment, the x-axis is the toe-heel direction parallel to the scoreline 23. The z-axis is in the front-rear direction of the head 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 the 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 arranged in a 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. Further, 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, respectively. 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 the present embodiment, the force applied to the front surface of the face plate 20 is decomposed into three and input to the pressure receiving portion 35 of each sensor 30.

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

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 apex of the polygon A (which is a triangle in this embodiment). Further, the polygon A is arranged so as to surround the main striking position 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 center of gravity of the face 2 (or the sweet spot of the face). NS.

In the case of 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 the shearing force acting on the face 2 when the ball is hit by the face 2 are obtained as the sum of the normal force and the shearing force detected by these three sensors 30.

FIG. 5 shows an example of the 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 about the force measured by each sensor 30 arranged in the golf club 1G.

One end of a cable 43 for outputting the information as an electric signal is connected to each sensor 30 (omitted in FIG. 5). The cable 43 is taken out of the head from a hole 9 (shown in FIG. 2) provided on the back 5 side of the head body 10, and is 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 electric signal to the control device 42.

The golf club 1G is attached to, for example, the swing robot 44. As is well known, the swing robot 44 can simulate a typical human golf swing by a robot (machine). In the present embodiment, the ball B can be hit by the face 2 of the head 1 by swinging the golf club 1G with the swing robot 44. Therefore, in the present embodiment, it is possible to approximately provide the contact state (striking state) between the head 1 and the ball B that occurs in the process 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 composed of, for example, a computer having a display means 42a such as a display. The control device 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 the measurement using the sensor 30, for example, the trigger devices S1 and S2 as shown in FIG. 5 may be provided. The exploration light from the light projecting units S1a and S2a is input to the trigger devices S1 and S2, respectively. The exploration light is positioned so as to cross the swing trajectory of the golf club 1G. In the present embodiment, when the input of the exploration light to the trigger device S1 is blocked by the head 1 or the shaft S of the moving golf club 1G, the trigger device S1 sends a trigger signal for starting recording of the measurement. , Output to the control device 42. After that, when the input of the exploration light 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 ending the measurement (recording). Output to device 42. Regarding the trigger devices S1 and S2, at least one sensor S1 that controls the start of measurement may be provided. The control device 42 includes a calculation unit (program) capable of calculating the center position of the load acting on the face 2 based on the signal received from the sensor 30.

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

First, the swing of the golf club 1 causes the ball B to be hit at the main hitting position of the face 2 (that is, in the present embodiment, in the region surrounded by the polygon A in the front view of the face 2). As a result, the ball B and the face 2 start contacting each other, and a small contact area is generated. This contact area increases with the passage of time and then gradually decreases, and finally the ball B does not separate from the face 2.

In the present embodiment, the force applied to the face plate 20 by the contact with the ball B is measured at least while the ball B is in contact with the face 2. Therefore, the control device 42 continuously acquires information from the state where the output of each sensor 30 is zero until the ball hits the ball and fluctuates, and the ball leaves the face 2 and becomes zero again. The information of each sensor 30 includes a normal force Fz and a shear force 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 the shear forces Fx and Fy at each time by the following formula. The directions of x, y and z and the positive and negative signs are as 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.

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

FIG. 6 shows the 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 center of gravity G of the polygon A connecting the centers of the pressure receiving portions 35 of each sensor 30 and the distances Lx2, Lx3, Ly1, Ly2 and Ly3 to each pressure receiving portion 35 in the x and y directions are set. Define. Further, the thickness of the face plate 20 is t. In this case, the calculation unit passes through the center of gravity G of the polygon A on a plane (which is substantially equal to the rear surface of the face plate 20) passing through the pressure receiving unit 35 of each sensor 30 at each time x, y. And the moments Mx, My and Mz around the z-axis are calculated by the following formulas.

[Moment around 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 around 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 around 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 acting 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 with each other until the end of the hit.

In a preferred embodiment, it is desirable that the control device 42 further includes a step of displaying the calculated information such as the 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 or the like, but also a step of printing on an information transmission member such as paper can be included. As a result, the central position of the load acting on the face 2 of the head 1 can be visually observed. An example of the display process is shown below.

7 (A) to 7 (C) show the time change of the normal force Fz, the shear force Fy, and the position of the load center obtained by using the measuring device 40 of the present embodiment. The time on the horizontal axis is the elapsed time with the start of striking (start of contact) as zero.

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

As shown in FIG. 7 (B), the shear force Fy increases with the passage of time (a negative value means that the shear 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 was confirmed that the position of the center of load moved upward (a positive value means the top side of the face with respect to the center of gravity G) with the passage of time. This indicates that the ball B is moving on the face 2 toward the top 3 due to the influence of the loft angle of the face 2 during the contact with the face 2. Further, it is understood that the position of the center of load is changed in a stepped manner after maintaining a substantially constant position while the ball B and the face 2 are in contact with each other. It is presumed that this indicates 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, it is possible to investigate the exchange of force during contact between the ball B and the face in more detail, which is useful for the product development of golf equipment. can. For example, at least two types of face plates 20 having different shapes of score lines 23 are prepared in advance, a ball striking test is performed while exchanging the face plates 30, and changes in the load center on each face plate are examined. be able to. As a result, the quality of the score line 23 can be evaluated. Further, it is also possible to check the center position of the load under various conditions by interposing a foreign substance (lawn, water, soil, mud, etc.) between the ball B and the face 2.

Although the embodiments of the present invention have been described in detail above, it goes without saying that the present invention is not limited to the above-mentioned specific embodiments and can be implemented in various embodiments.

1 Golf club head 1G Golf club 2 Face 10 Head body 12 Recess 20 Face plate 21 1st plate 22 2nd plate 30 Sensor 31 1st sensor 32 2nd sensor 33 3rd sensor 40 Measuring device 42 Control device 42a Display means A Many Square B ball

Claims (4)

It is a method for measuring the center position of the load applied to the golf club head.
The golf club head
It includes a head body, a face plate having a face for hitting a ball, and a sensor arranged between the head body and the face plate and for measuring a force acting on the face plate.
The sensors consist of at least three force sensors, each capable of independently measuring force.
In the front view of the face, the force sensor is arranged so as to surround the main striking position of the face.
The head body includes a recess formed on the face side.
The sensor is fixed in the recess and
The process of hitting a ball with the face of the golf club head and
The process of acquiring information on the force measured by each of the force sensors when hit, and
Including the step of calculating the center position of the load acting on the face based on the acquired information.
The information is a method for measuring a load center position of a golf club head including a normal force Fz orthogonal to the face, a shear force Fx in the toe-heel direction, and a shear force Fy in the vertical direction of the face. The acquisition step is continuously performed at least from the moment when the ball comes into contact with the face until it is separated from the face.
The calculation step is the method for measuring the load center position of a golf club head according to claim 1, wherein the load center position is continuously calculated. The method for measuring a load center position of a golf club head according to claim 1 or 2, further comprising a step of displaying the load center position as visual information on a display means. A device for measuring the center position of the load acting on the golf club head.
The golf club head
It includes a head body, a face plate having a face for hitting a ball, and a sensor arranged between the head body and the face plate and for measuring a force acting on the face plate.
The sensors consist of at least three force sensors, each capable of independently measuring force.
In the front view of the face, the force sensor is arranged so as to surround the main striking position of the face.
The head body includes a recess formed on the face side.
The sensor is fixed in the recess and
The golf club head and at least a control device for acquiring information on the force measured by each force sensor include.
The information includes a normal force Fz orthogonal to the face, a shear force Fx in the toe-heel direction, and a shear force Fy in the vertical direction of the face.
The control device is a device for measuring the load center position of a golf club head, including a calculation unit that calculates the load center position acting on the face based on the information.

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