JP4728112B2 - shoes - Google Patents

Description

  The present invention relates to shoes suitable for golf, tennis, squash, field hockey, basketball, aerobic exercises and the like.

The shoe is composed of an outsole, a midsole, an insole, an upper, and the like. The midsole is made of a polymer molded body containing bubbles. In an ordinary midsole, an ethylene-vinyl acetate copolymer (EVA) is used as a base polymer. The midsole contributes to shock absorption. The actual Hei 2-134003 discloses, includes a midsole having a multilayer structure, shock absorption and excellent shoes and traction properties is disclosed.

  When a golfer hits a golf ball, the golf ball is addressed so that the line connecting the left and right toes is substantially parallel to the target direction. At the address, the golf club head is located near the golf ball. From this state, the golfer starts taking back and swings the head up to the right and then up. The position where the head is most swung up is called the top position. A downswing is started from the top position, the head is swung down, and the head collides with the golf ball. After the collision, the golfer swings the golf club to the left and then up, and finishes.

From the top position to the finish, the golfer makes a body turn around the left foot. At the same time, the golfer kicks the ground with his right foot and transmits the force to the golf ball. In other words, right-handed golfers use their left foot as an axis foot and their right foot as a kick foot. For left-handed golfers, use the right foot as the axle and the left foot as the kick.
Japanese Utility Model Publication 2-134003

  When swinging, the golfer mainly kicks the ground with weight on the inside of the kick foot. Golfers also receive weight mainly inside the axle. At this time, the force is transmitted to the ground through the shoes. By applying a load to the inside of the foot, the swing is easily stabilized. Shoes suitable for swinging are desired.

  In other sports, an operation that puts weight on the inside of the foot can be seen. In tennis and squash, when the racket is swung, weight is applied to the inside of the foot. In field hockey, you take weight on the inside of your foot when you swing the stick. In basketball and aerobic exercises, the weight is applied to the inside of the foot during the left-right reversal operation. Also in these sports, shoes suitable for movement are desired.

  An object of the present invention is to provide a shoe in which a load is easily applied to the inside of a foot.

  The shoe according to the present invention includes a bottom portion, and the bottom portion includes a layer including a foam change portion where the foaming ratio gradually increases from the outside to the inside. There may be at least one layer including the foam change portion. A plurality of layers including the foam change portion may be provided.

  Another shoe according to the present invention includes a bottom portion, and the bottom portion includes a layer including an elastic change portion whose elastic modulus gradually decreases from the outside to the inside. There may be at least one layer including the elastic change portion. A plurality of layers including the elastic change portion may be provided.

  The method for manufacturing a shoe according to the present invention includes a step in which a foamable polymer material is placed in a mold in an unevenly distributed state, and foaming the polymer material that is unevenly distributed in the mold, so that the other side from the one side A step of forming a polymer molded body having a foam change portion where the foaming ratio gradually increases over time, and a step of providing the foam change portion at the bottom of the shoe so that the foaming ratio gradually increases from the outside to the inside And a step of producing a shoe from the bottom and the upper.

  In another shoe manufacturing method according to the present invention, a step in which a foamable polymer material is introduced into a mold and a heating temperature acting on the polymer material being foamed are partially different from each other. The step of forming a polymer molded body having a foam change part where the foaming ratio gradually increases from the other side to the other side, and this foam change part on the bottom of the shoe so that the foaming ratio gradually increases from the outside to the inside. A step of being provided, and a step of producing a shoe from the bottom and the upper.

  In another shoe manufacturing method according to the present invention, a step in which a foamable polymer material is introduced into a mold and a pressure acting on the polymer material being foamed are partially different from each other. A step of forming a polymer molded body having a foam change portion where the expansion ratio gradually increases toward the other side, and this expansion change portion is provided at the bottom of the shoe so that the expansion ratio gradually increases from the outside to the inside. And a step of making a shoe from the bottom and the upper.

  In the shoe according to the present invention, when the weight is added, the upper surface of the bottom portion tends to be inclined upward from the inside toward the outside. This inclination makes it easier for the wearer to put weight on the inside of the foot.

  Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

  FIG. 1 is a partially cutaway side view showing a golf shoe 2 according to an embodiment of the present invention. The golf shoe 2 includes an upper 4 and a bottom 6. The bottom portion 6 includes an insole 8, a midsole 10, and an outsole 12. The insole 8 is laminated with the midsole 10. The midsole 10 is laminated with the outsole 12. The outsole 12 includes a large number of projections 14 projecting downward on the lower surface thereof. The material and structure of the upper 4 are equivalent to those of the known upper. The material and structure of the insole 8 is the same as that of a known insole. The material and structure of the outsole 12 is equivalent to that of a known outsole.

  FIG. 2 is a plan view showing the midsole 10 of the golf shoe 2 of FIG. The midsole 10 includes a base 16. The base 16 includes a side wall 18 on the outer edge thereof. The midsole 10 is for the right foot. The shape of the midsole for the left foot is a shape in which the shape shown in FIG. A portion of the midsole 10 other than the foam change portion 20 described later is a base 16.

  3 is an enlarged sectional view taken along line III-III in FIG. 2, FIG. 4 is an enlarged sectional view taken along line IV-IV in FIG. 2, and FIG. 5 is taken along line V-V in FIG. FIG. 3 to 5, the left side is the inside, and the right side is the outside.

  The base 16 may be a polymer molded body that does not contain bubbles. Preferably, the base 16 is made of a polymer molded body containing bubbles. A typical base polymer for base 16 is EVA. The vinyl acetate content in EVA is preferably 10% by mass or more, and more preferably 15% by mass or more. The vinyl acetate content in EVA is preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 25% by mass or less. EVA and polyolefin are preferably used in combination as a base polymer for the midsole. Polyolefins can contribute to shock absorption and resilience. In this respect, the amount of polyolefin is preferably 5% by mass or more, and more preferably 10% by mass or more with respect to the total amount of the base polymer. From the viewpoint of cost and adhesiveness, the amount of polyolefin is preferably 80% by mass or less, more preferably 70% by mass or less, and particularly preferably 15% by mass or less. Preferred polyolefins include ethylene-octene copolymers, ethylene-butene copolymers, polypropylene and polyethylene.

  The base 16 may include closed cells or open cells. From the viewpoint of shape restoring force and non-water absorption, closed cells are preferable. Bubbles are usually formed by foaming of a pyrolytic foaming agent. Examples of the thermally decomposable foaming agent used include azo compounds (for example, azodicarbonamide), nitroso compounds (for example, dinitrosopentamethylenetetramine), and triazole compounds. The average foaming ratio of the midsole 10 is preferably 2 times or more, and more preferably 3 times or more. The average expansion ratio is preferably 30 times or less, more preferably 15 times or less, and particularly preferably 10 times or less. The expansion ratio means the ratio of the density when bubbles are not present to the density when bubbles are present.

  The midsole 10 includes a foam change portion 20. In the foam changing portion 20, the foaming ratio gradually increases from the outside to the inside. In the present embodiment, the foam change portion 20 is a separate molded body 22 that is molded separately from the base 16. In the present embodiment, the whole of the separate molded body 22 is the foam change portion 20. The foam changing portion 20 may be integrally formed with the base 16. Further, a part of the separate molded body 22 may be the foam change portion 20. In addition, the average foaming ratio of the entire foam change part 20 may be higher or lower than the average foaming ratio of parts other than the foam change part 20.

  The foam change portion 20 is made of a polymer molded body containing bubbles. A typical base polymer of the foam change part 20 is EVA. The vinyl acetate content in EVA is preferably 10% by mass or more, and more preferably 15% by mass or more. The vinyl acetate content in EVA is preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 25% by mass or less. EVA and polyolefin are preferably used in combination as a base polymer for the midsole. Polyolefins can contribute to shock absorption and resilience. In this respect, the amount of polyolefin is preferably 5% by mass or more, and more preferably 10% by mass or more with respect to the total amount of the base polymer. From the viewpoint of cost and adhesiveness, the amount of polyolefin is preferably 80% by mass or less, more preferably 70% by mass or less, and particularly preferably 15% by mass or less. Preferred polyolefins include ethylene-octene copolymers, ethylene-butene copolymers, polypropylene and polyethylene.

  The foam change part 20 may include closed cells or open cells. From the viewpoint of shape restoring force and non-water absorption, closed cells are preferable. Bubbles are usually formed by foaming of a pyrolytic foaming agent. Examples of the thermally decomposable foaming agent used include azo compounds (for example, azodicarbonamide), nitroso compounds (for example, dinitrosopentamethylenetetramine), and triazole compounds. The average foaming ratio of the foam change part 20 is preferably 2 times or more, and more preferably 3 times or more. The average expansion ratio is preferably 30 times or less, more preferably 15 times or less, and particularly preferably 10 times or less.

  The foam change part 20 is also an elastic change part. In the foam change part 20, the elastic modulus is lower as the foaming ratio is higher, and the elastic modulus is higher as the foaming ratio is lower. The elastic modulus of the portion having the highest elastic modulus in the foam change portion 20 is also referred to as the maximum elastic modulus below. An inside high elasticity portion 26 having an elastic modulus equal to or higher than the maximum elastic modulus is provided on the inside of the foam change portion 20. In addition, an outer high elastic portion 27 having an elastic modulus equal to or higher than the maximum elastic modulus is provided on the outside of the foam change portion 20.

  When the golfer wears the golf shoes 2 and the weight of the golfer is added to the bottom portion 6, the midsole 10 is compressed. Since the expansion ratio of the foam change portion 20 is large on the inside, the amount of compressive deformation on the inside tends to increase. Since the expansion ratio of the foam change portion 20 is small on the outside, the amount of compressive deformation on the outside tends to be small. In the midsole 10, a biased deformation occurs due to the addition of weight. Due to the deformation of the midsole 10, the position of the upper surface 28 (see FIG. 1) of the insole 8 is displaced. The downward displacement of the upper surface 28 on the inside tends to be larger than the downward displacement of the upper surface 28 on the outside. The upper surface 28 tends to tilt upward from the inside toward the outside. Due to the inclination of the upper surface 28, the soles of the golfers are also inclined upward from the inside toward the outside. The weight of the golfer is mainly on the inside. As mentioned above, the golfer kicks the ground on the inside of the kick foot when swinging. Because the legs are tilted, the golfer can easily transfer power to the ground. The midsole 10 is suitable for a right-handed golfer's right foot. This golf shoe 2 contributes to a large head speed. A large head speed produces a large flight distance. Even in the left foot shoe, the weight of the golfer is mainly on the inside. As described above, in the case of a right-handed golfer, the left foot is the shaft foot. The weight is applied to the inside of the shaft foot so that the shaft foot is stabilized. The stability of the shaft foot contributes to a large flight distance and an improvement in shot accuracy.

  In the midsole for the left foot and the right foot, it is preferable that a biased deformation of the midsole is achieved. The biased deformation of the midsole may be achieved with only one of the midsole for the left foot and the right foot.

  In the foam change portion 20, the foaming ratio is gradually changing. This change may be a continuous change or a step change. That is, in the foam change portion 20, the change in the foaming ratio from the outside to the inside may be continuous or stepwise. Preferably, the change in the expansion ratio is continuous. Due to the continuous change in the expansion ratio, the amount of compressive deformation of the midsole 10 continuously changes from the inside to the outside. The amount of compressive deformation does not change abruptly. The continuous change contributes to the stability of the swing. A stable swing suppresses variation in flight distance. A stable swing further suppresses variations in the flight direction of the golf ball. The midsole 10 in which the amount of compressive deformation changes continuously does not cause a sense of incongruity during walking. As the foam change part in which the change in the expansion ratio is gradual, for example, a foam change part formed by sequentially joining members having different expansion ratios from the outside to the inside can be employed. This joining is performed by, for example, an adhesive.

  As is clear from FIG. 2, the planar shape of the foam change portion 20 is substantially an ellipse. In the midsole 10 provided with the elliptical foam changing portion 20, the amount of compressive deformation does not change abruptly in the front-rear direction. The elliptical foam change part 20 contributes to the stability of the swing. The foam change part 20 whose planar shape is an ellipse also contributes to the stability of the swing.

  2 is a length line of the midsole 10. The length line A is the longest line segment that can be drawn within the contour of the midsole 10. The length line A extends from the toe side end 30 to the heel side end 32. In FIG. 2, the length of the length line A is indicated by the symbol L. A two-dot chain line indicated by a symbol B in FIG. The width line B is orthogonal to the length line A. The distance from the toe side end 30 to the width line B is (L / 4). The width line B passes through the foam change portion 20. In other words, the foam change part 20 exists at a point where 25% of the distance L of the length line is moved from the toe side end 30 to the heel side end 32 along the length line A. It is in the vicinity of the main baseball that the most force is applied in the swing. Due to the presence of the foam change portion 20 at the aforementioned position, the golfer can easily transmit force to the ground. The length L is usually 150 mm to 320 mm.

  From the viewpoint that the golfer can easily transmit the force to the ground, the distance of the foam change portion 20 along the length line A is preferably 5 mm or more, more preferably 20 mm or more, and particularly preferably 50 mm or more. Although there is no restriction | limiting in this upper limit of the distance from an effect viewpoint, Usually, it is 200 mm or less, Furthermore, it is 105 mm or less.

  In FIG. 4, what is indicated by a double-pointed arrow Wa is the width in the left-right direction of the foam change portion 20. The width Wa is measured in a cross section along the width line B. The width Wa is preferably 5 mm or greater and 100 mm or less. By setting the width Wa to 5 mm or more, the effect of tilting so that the weight is applied to the inside (hereinafter also referred to as tilt effect) is further increased. From this viewpoint, the width Wa is more preferably 15 mm or more, more preferably 20 mm or more, more preferably 30 mm or more, and particularly preferably 50 mm or more. In the golf shoe 2 in which the width Wa is set to 100 mm or less, the golfer can easily transmit the force to the ground. In this respect, the width Wa is more preferably equal to or less than 80 mm, and particularly preferably equal to or less than 70 mm. In addition, the width W of the midsole 10 along the width line B is usually 80 mm or more and 120 mm or less.

  In FIG. 4, what is indicated by a double-headed arrow Wb is the width of the portion of the inner high elasticity portion 26 whose upper surface is flat. The width Wb is measured along the width line B. The width Wb is preferably 3 mm or greater and 25 mm or less. By setting the width Wb to 3 mm or more, a sufficient force is transmitted from the foot to the ground. In this respect, the width Wb is more preferably equal to or greater than 5 mm, further preferably equal to or greater than 7 mm, and particularly preferably equal to or greater than 10 mm. By setting the width Wb to 25 mm or less, the foot is sufficiently inclined. In this respect, the width Wb is more preferably equal to or less than 22 mm, and particularly preferably equal to or less than 18 mm.

  In FIG. 4, what is indicated by a double-headed arrow Wc is the width of the inner high elasticity portion 26. The width Wc is measured along the width line B. The width Wc is preferably 13 mm or greater and 35 mm or less. By setting the width Wc to 13 mm or more, a sufficient force is transmitted from the foot to the ground. In this respect, the width Wc is more preferably 15 mm or more, further preferably 17 mm or more, and particularly preferably 20 mm or more. By setting the width Wc to 35 mm or less, the foot is sufficiently inclined. In this respect, the width Wc is more preferably equal to or less than 32 mm, and particularly preferably equal to or less than 28 mm.

  In FIG. 4, what is indicated by a double-headed arrow Wd is the width of the outer high elasticity portion 27. The width Wd is preferably 13 mm or more, more preferably 15 mm or more, further 17 mm or more, and further preferably 20 mm or more. The width Wd is preferably 35 mm or less, more preferably 32 mm or less, and even more preferably 28 mm or less.

  In FIG. 4, what is indicated by a double arrow T is the thickness of the midsole 10. The thickness T is measured in a cross section along the width line B. The thickness T is the maximum thickness of the portion excluding the side wall 18. The thickness T is 2 mm or more, and further 5 mm or more. The thickness T is 25 mm or less, further 20 mm or less, and further 15 mm or less. In FIG. 4, what is indicated by a double arrow t is the maximum thickness of the foam change portion 20. The thickness t is measured in a cross section along the width line B. From the viewpoint that the upper surface of the insole 8 is sufficiently inclined, the ratio of the thickness t to the thickness T is preferably 30% or more, more preferably 40% or more, further 50% or more, and more preferably 80% or more. In the embodiment shown in FIG. 4, this ratio is 100%. In other words, the foam change portion 20 is slightly exposed on the bottom surface 34 of the midsole 10. As is clear from FIG. 3, the foam change portion 20 is not exposed on the bottom surface 34 in the cross section along the line III-III. As is clear from FIG. 5, the foam change portion 20 is not exposed on the bottom surface 34 even in the cross section along the line VV. From the viewpoint of durability, the ratio of the thickness t to the thickness T is preferably less than 100%, more preferably 98% or less, and particularly preferably 95% or less. From the viewpoint of enhancing the tilt effect, the thickness t is preferably 3 mm or more, more preferably 5 mm or more, and particularly preferably 7 mm or more. From the viewpoint of suppressing an excessive tilting effect, the thickness t is preferably 20 mm or less, more preferably 15 mm or less, and particularly preferably 12 mm or less.

  FIG. 6 is a cross-sectional view for explaining an example of a method for manufacturing the midsole 10 of FIG. In this manufacturing method, first, the foam change portion 20 (separately formed body 22) and the base 16 are prepared. The foam change portion 20 is a polymer molded body having bubbles. The base 16 is also a polymer molded body having bubbles.

  The foam change portion 20 is previously thermoformed with a mold dedicated to the foam change portion 20. After thermoforming, the contour shape of the foam change part 20 may be adjusted by punching or polishing.

  The base 16 is formed in advance by a die dedicated to the base 16. The base 16 has a fitting portion 36. The fitting portion 36 may be a hole or a recess. The shape of the fitting portion 36 corresponds to the shape of the foam change portion 20.

  With the foam change portion 20 fitted into the fit portion 36, the foam change portion 20 and the base 16 are joined. This joining is performed by, for example, an adhesive. The foam change part 20 and the base 16 may be fused. The midsole 10 is formed by joining the foam changing portion 20 and the base 16.

  The manufacturing method of the insole 8 and the outsole 12 is the same as that known. The midsole 10, the insole 8, and the outsole 12 are joined to manufacture the bottom 6. This joining method is the same as that known. This joining is performed by, for example, an adhesive or sewing. Further, the bottom 6 and the upper 4 are joined to manufacture the golf shoe 2. This joining method is the same as the known one. This joining is performed by, for example, an adhesive or sewing.

  Next, the manufacturing method of a foam change part is demonstrated. FIG. 7 is a cross-sectional view for explaining a first manufacturing method of the foam change portion. In addition, the following 1st-4th manufacturing methods are a manufacturing method of a foam change part, and are also a manufacturing method of an elastic change part.

  The foam change portion is formed by thermoforming with a mold 38. The mold 38 has an upper mold 40 and a lower mold 42. In the first manufacturing method, first, the polymer material P1 is charged into the opened mold 38 (see FIG. 7A). The polymer material P <b> 1 is arranged in a state of being offset on the cavity surface 44 of the lower mold 42.

  Next, the mold 38 is closed (see FIG. 7B). A cavity 39 is formed inside the closed mold 38. The cavity 39 is a space defined by the cavity surface 46 of the upper mold 40 and the cavity surface 44 of the lower mold 42. The polymer material P <b> 1 is offset in the cavity 39. The polymer material P1 is filled only on one side of the cavity 39 (the right side in FIG. 7B). The polymer material P1 is not filled on the other side of the cavity 39 (left side in FIG. 7B). Inside the cavity 39, there are a filling portion J filled with the polymer material P1 and a space portion K not filled with the polymer material P1. In this way, the polymer material P1 is charged into the mold in an unevenly distributed state.

  Next, pressurization and heating are performed. The polymer material P1 is foamed by heating. Due to this foaming, the volume of the polymer material P1 expands and the space K disappears. The foamed molded product P2 is molded by foaming. As shown in FIG. 7C, the foamed molded product P <b> 2 fills the cavity 39. The shape of the foam molded body P2 is the same as the shape of the cavity 39. An object to be molded from the state before the heating to the foamed molded product P2 is referred to as a polymer material P1.

  In the process until the foam molding P2 is formed, the portion on the space K side of the polymer material P1 before filling filled in the filling portion J expands toward the space K. Of the polymer material P1, the space K side tends to expand. The space K can partially vary the pressure acting on the polymer material P1 during foaming. Due to the uneven distribution of the polymer material P1 in the cavity 39, the pressure acting on the polymer material P1 during foaming results in partially different results. The pressure acting on the polymer material P1 during foaming becomes smaller toward the space K side. Therefore, the expansion ratio in each part of the foam molded product P2 gradually increases from one side (right side in FIG. 7C) to the other side (left side in FIG. 7C).

  Next, the foamed molded product P <b> 2 is taken out from the mold 38. By taking out, the foam molded product P2 becomes a polymer molded product P3 having a larger volume than the foam molded product P2. Needless to say, the expansion ratio also changes in the polymer molded body P3. That is, the expansion ratio in each part of the polymer molded body P3 gradually increases from one side (right side in FIG. 7 (d)) to the other side (left side in FIG. 7 (d)).

  A foam change part is produced from this polymer molded object P3. For example, a foam change part is produced by punching out the polymer molding P3. Further, the polymer molded body P3 may be secondarily molded by a mold for secondary molding. The polymer molded body P3 may be used as it is as the foam change portion. In this case, the cavity 39 of the mold 38 is designed in consideration of the volume increase from the foamed molded product P2 to the polymer molded product P3. A skin layer may be formed on the surface of the polymer molded body P3. The skin layer is not substantially foamed. This skin layer may be removed by sanding or the like. It may be attached to the bottom of the shoe with the skin layer.

  The foam change portion is provided at the bottom of the shoe so that the expansion ratio gradually increases from the outside to the inside. That is, the foam change portion is arranged so that one side (side with a low expansion ratio) of the polymer molded body P3 is the outside side of the shoe. In other words, the foam change portion is arranged so that the other side (the side with the higher expansion ratio) of the polymer molded body P3 is the inside side of the shoe.

  FIG. 8 is a cross-sectional view for explaining a second manufacturing method of the foam change portion. The structure of the mold 38 is the same as that of the first manufacturing method described above.

  In the second manufacturing method, first, the polymer material P4 is charged into the opened mold 38 (see FIG. 8A). Similarly to the first manufacturing method described above, also in this second manufacturing method, the polymer material P1 is put into the mold in a state of being unevenly distributed. However, the uneven distribution is different from the first manufacturing method. As shown in FIG. 8B, the polymer material P1 is arranged so that the thickness in the vertical direction of the mold gradually changes. The subsequent steps are the same as those in the first manufacturing method described above.

  Also in the second manufacturing method, the expansion ratio in each part of the foam molded product P5 gradually increases from one side (right side in FIG. 8C) to the other side (left side in FIG. 8C). Yes. The reason why the expansion ratio is changed is the same as that of the first manufacturing method. In the process until the foamed molded product P5 is formed, the portion on the space K side of the polymer material P4 before foaming filled in the filling portion J expands toward the space K. Of the polymer material P4, the space K side tends to expand. In the cross-sectional view of FIG. 8, the proportion of the space portion K at each position in the longitudinal direction of the cavity 39 (left and right direction in FIG. 8B) is larger on the other side of the cavity 39 (left side of FIG. 8B). Therefore, the pressure acting on the polymer material P <b> 4 during foaming increases toward one side of the cavity 39. The method of forming the foam change part from the polymer molded body P6 is also the same as the first manufacturing method described above.

  The aspect of uneven distribution of the polymer material in the first and second production methods is merely an example. Various modes of uneven distribution of the polymer material are conceivable. In the stage before foaming the polymer material, when the filling portion J and the space portion K exist in the cavity 39, the polymer material is unevenly distributed in the mold. Further, the expansion ratio may be gradually changed in the entire polymer molded body, or the expansion ratio may be gradually changed in a part of the polymer molded body. Of the polymer molded body, the portion where the expansion ratio is gradually changed may be the expanded portion.

  FIG. 9 is a cross-sectional view for explaining a third manufacturing method of the foam change portion. In the third manufacturing method, the polymer material P7 is not unevenly distributed in the state of being put in the mold (see FIGS. 9A and 9B).

  The shape of the mold 50 in the third manufacturing method is the same as that used in the first and second manufacturing methods described above. However, a temperature gradient is applied to the mold 50. As shown in FIG. 9C, the mold temperature is gradually increased from one side (right side of the drawing) to the other side (left side of the drawing). This temperature gradient can be achieved, for example, by varying the degree of heating by a heating means (not shown) for heating the mold for each part of the mold.

  In the third manufacturing method, first, the polymer material P7 is charged into the opened mold 50 (see FIG. 9A). Next, the mold 50 is closed (see FIG. 9B). The polymer material P7 is filled throughout the cavity 51. The polymer material P7 is put in the mold without being unevenly distributed.

  Next, pressurization and heating are performed. By heating, the polymer material P7 tends to foam. However, in the state before foaming, the polymer material P7 fills the cavity 39 without a gap, so the polymer material P7 does not expand in the cavity 39.

  Next, the upper mold 52 and the lower mold 54 are separated, and the foamed molded product P8 is taken out from the mold 50. By taking out, the foamed molded product P8 is placed under normal pressure to become a polymer molded product P9. At this time, foaming proceeds at a stretch. The expansion ratio of the polymer molded body P9 decreases on the side heated at a low temperature and increases on the side heated at a high temperature. As a result, the thickness of the polymer molded body P9 is thin on the side heated at a low temperature and thick on the side heated at a high temperature (see FIG. 9D). Therefore, the expansion ratio in each part of the polymer molded body P9 gradually increases from one side (right side in FIG. 9 (d)) to the other side (left side in FIG. 9 (d)). The subsequent manufacturing process is the same as the first to third manufacturing methods described above. When the thickness is desired to be uniform when used as the foam change portion, the polymer molded body P9 is cut so that the thickness is uniform (see the broken line in FIG. 9D).

  FIG. 10 is a cross-sectional view for explaining a fourth manufacturing method of the foam change portion. In this embodiment, a planar mold is used. The mold includes a press upper plate 56 and a press lower plate 58. In this manufacturing method, first, the polymer material P10 before foaming is put into a mold. Next, the first heating and pressurization are performed (see FIG. 10A). This is the primary press. Next, in the middle of foaming, the position of the polymer material P10 is changed. The position of the polymer material P10 is a position where only a part of the polymer material P10 is between the press upper plate 56 and the press lower plate 58 (see FIG. 10B). The second heating and pressurization is performed in a state where only a part of the polymer material P10 is sandwiched between the press upper plate 56 and the press lower plate 58. This is a secondary press. In the secondary press, only the portion sandwiched between the press upper plate 56 and the press lower plate 58 is heated and pressurized. Therefore, in the secondary press, the pressure acting on the polymer material P10 during foaming is partially different. That is, the portion sandwiched between the upper press plate 56 and the lower press plate 58 is pressurized at a predetermined pressure, while the portion not sandwiched between the upper press plate 56 and the lower press plate 58 is added. It is not pressed. In this way, by partially varying the pressure acting on the polymer material during foaming, the obtained polymer molded body (not shown) has a foam changing portion where the foaming ratio gradually increases from one side to the other side. It becomes the polymer molding which has this.

  In addition to the first to fourth manufacturing methods described above, as a manufacturing method for partially varying the pressure acting on the polymer material during foaming, a gold pressure capable of partially varying the press pressure acting on the cavity is used. A manufacturing method using a mold may be used. As such a mold, for example, a mold having a divided structure in which each of an upper mold and a lower mold is divided into a plurality of molds and a plurality of press machines can be exemplified.

  In the embodiment shown in FIGS. 2 to 5, a part of the midsole 10 is a foam change portion. The entire midsole may be a foam change part. In addition, as in the cross-sectional view shown in FIG. 11, at least a part of the midsole may be provided with the foam changing portion 60 over the entire width of the midsole in the left-right direction.

  From the viewpoint of improving the tilting effect and reducing the weight, the foaming ratio S1 at the inner position of the foam change portion is preferably 3.0 or more, more preferably 3.5 or more, and particularly preferably 4.0 or more. From the viewpoint of weight reduction, the foaming ratio S2 at the middle position of the foam change portion is preferably 2.5 or more, more preferably 3.0 or more, and particularly preferably 3.5 or more. From the viewpoint of weight reduction, the expansion ratio S3 at the outer position of the foam change portion is preferably 2.0 or more, more preferably 2.5 or more, and particularly preferably 3.0 or more.

  From the viewpoint of improving the durability by suppressing the sagging, the foaming ratio S1 at the inner position of the foam change portion is preferably 10.0 or less, more preferably 9.0 or less, and particularly preferably 8.0 or less. From the viewpoint of improving the durability by suppressing the sagging, the foaming ratio S2 at the middle position of the foam change portion is preferably 9.0 or less, more preferably 8.0 or less, and particularly preferably 7.0 or less. From the viewpoint of enhancing the tilting effect and improving durability by suppressing sag, the expansion ratio S3 at the outer position of the foam change portion is preferably 8.0 or less, more preferably 7.0 or less, and 6.0 or less. Is particularly preferred.

  From the viewpoint of enhancing the tilt effect, the expansion ratio S1 at the inner position of the foam change portion, the expansion ratio S2 at the middle position of the foam change portion, and the expansion ratio S3 at the outer position of the foam change portion are related to each other [S1> S2> S3 It is preferable that

  From the viewpoint of enhancing the inclination effect, the ratio (S1 / S3) of the foaming ratio S1 at the inner position of the foam change part and the foaming ratio S3 at the outer position of the foam change part is preferably 1.2 or more, and 1.3 or more. More preferably, 1.4 or more is particularly preferable. The ratio (S1 / S3) is 5.0 from the viewpoint of suppressing an uncomfortable feeling due to an excessive tilt effect and suppressing the tilt of the upper surface 28 (see FIG. 1) of the bottom 6 during normal walking to facilitate walking. The following is preferable, 4.0 or less is more preferable, and 3.0 or less is particularly preferable.

  From the viewpoint of enhancing the tilting effect, the ratio (S1 / S2) of the foaming ratio S1 at the inner position of the foaming change part and the foaming ratio S2 at the middle position of the foaming change part is preferably 1.1 or more, and 1.2 or more. More preferably, 1.3 or more is particularly preferable. The ratio (S1 / S2) is 4.0 from the viewpoint of suppressing an uncomfortable feeling due to an excessive tilt effect and suppressing the tilt of the upper surface 28 (see FIG. 1) of the bottom 6 during normal walking to facilitate walking. The following is preferable, 3.0 or less is more preferable, and 2.0 or less is particularly preferable.

  From the viewpoint of enhancing the inclination effect, the ratio (S2 / S3) of the expansion ratio S2 at the middle position of the foam change portion and the expansion ratio S3 at the outer position of the foam change portion is preferably 1.1 or more, and is 1.2 or more. More preferably, 1.3 or more is particularly preferable. The ratio (S2 / S3) is 4.0 from the viewpoint of suppressing a sense of incongruity due to an excessive inclination effect and suppressing the inclination of the upper surface 28 (see FIG. 1) of the bottom 6 during normal walking to facilitate walking. The following is preferable, 3.0 or less is more preferable, and 2.0 or less is particularly preferable.

  Each expansion ratio S1, S2, and S3 is defined as follows. At the position where the width along the width line B (see FIG. 2) is the maximum width (position in the length line A direction), when the foam change portion is equally divided into three in the width line B direction, it is located most inside. The average expansion ratio of the divided body is the expansion ratio S1, the average expansion ratio of the divided body located most outside is the expansion ratio S3, and the divided body located most inside and the divided body located most outside The average expansion ratio of the divided bodies positioned between them is the expansion ratio S2. In addition, the partition surface which partitions off divided bodies turns into a surface along the length line A (refer FIG. 2).

  The inner hardness HL, the intermediate hardness HM, and the outer hardness HH can be defined at a position where the width in the direction along the width line B of the foam change portion or the elastic change portion is greater than 10 mm (position in the length line A direction). The inner hardness HL is a hardness at a position 5 mm away from the inside edge of the foam change portion or the elastic change portion in the width line B direction. The intermediate hardness HM is the hardness at the center position of the width along the width line B direction of the foam change portion or the elastic change portion. The outer hardness HH is a hardness at a position 5 mm away from the outside edge of the foam change portion or the elastic change portion in the width line B direction.

  From the viewpoint of enhancing the tilt effect, preferably, at the position where the width in the width line B (see FIG. 1) direction is the maximum width, the inner hardness HL, the intermediate hardness HM, and the outer hardness HH are [HL <HM <HH]. It is good to satisfy the relationship.

  From the viewpoint of suppressing stability deterioration and uncomfortable feeling due to excessive softness, the inner hardness HL is preferably 20 or more, more preferably 30 or more, and particularly preferably 35 or more. In light of enhancing the gradient effect, the inner hardness HL is preferably equal to or less than 70, more preferably equal to or less than 60, and particularly preferably equal to or less than 55.

   From the viewpoint of enhancing the gradient effect by setting the intermediate hardness HM as an intermediate between the inner hardness HL and the outer hardness HH, the intermediate hardness HM is preferably 30 or more, more preferably 40 or more, and particularly preferably 45 or more. From the viewpoint of enhancing the gradient effect by setting the intermediate hardness HM as an intermediate between the inner hardness HL and the outer hardness HH, the intermediate hardness HM is preferably 80 or less, more preferably 70 or less, and particularly preferably 65 or less.

   From the viewpoint of enhancing the tilt effect, the outer hardness HH is preferably 40 or more, more preferably 50 or more, and particularly preferably 55 or more. From the viewpoint of suppressing a decrease in cushioning property due to excessive hardness, the outer hardness HH is preferably 85 or less, more preferably 80 or less, and particularly preferably 75 or less.

  The ratio (HL / HH) of the inner hardness HL to the outer hardness HH is preferably 0.20 or more and 0.90 or less. By setting the ratio (HL / HH) to 0.20 or more, a rapid change in the amount of compressive deformation is suppressed. In this respect, the ratio (HL / HH) is more preferably equal to or greater than 0.30 and particularly preferably equal to or greater than 0.40. By setting the ratio (HL / HH) to 0.90 or less, the tilt effect is improved and the golfer can easily transmit the force to the ground. In this respect, the ratio (HL / HH) is more preferably equal to or less than 0.85, and particularly preferably equal to or less than 0.80.

  The ratio (HL / HM) of the inner hardness HL to the intermediate hardness HM is preferably 0.30 or more and 0.93 or less. By setting the ratio (HL / HM) to 0.30 or more, a rapid change in the amount of compressive deformation is suppressed. In this respect, the ratio (HL / HM) is more preferably equal to or greater than 0.40, and particularly preferably equal to or greater than 0.50. By setting the ratio (HL / HM) to 0.93 or less, the tilt effect is improved. In this respect, the ratio (HL / HM) is more preferably equal to or less than 0.92, and particularly preferably equal to or less than 0.90.

  The ratio (HM / HH) of the intermediate hardness HM to the outer hardness HH is preferably 0.30 or more and 0.95 or less. By setting the ratio (HM / HH) to 0.30 or more, a rapid change in the amount of compressive deformation is suppressed. In this respect, the ratio (HM / HH) is more preferably equal to or greater than 0.40, and particularly preferably equal to or greater than 0.50. By setting the ratio (HM / HH) to 0.95 or less, the tilt effect is enhanced. In this respect, the ratio (HM / HH) is more preferably equal to or less than 0.93, and particularly preferably equal to or less than 0.90.

  The inner hardness HL, intermediate hardness HM, and outer hardness HH are measured with an Asker C type hardness meter of Kobunshi Keiki Co., Ltd. in accordance with the Japan Rubber Association standard.

  FIG. 12 is a plan view showing a midsole 70 of a golf shoe according to another embodiment of the present invention. In FIG. 12, a length line A and a width line B are shown. The midsole 70 includes a base 72 and a side wall 74 provided on the outer edge of the base 72. The midsole 70 is for the right foot. The midsole for the left foot has a shape in which the shape shown in FIG. The cross-sectional shape along the width line B of the midsole 70 is equivalent to the cross-sectional shape of the midsole 10 shown in FIG. The midsole 70 includes a foam change portion 76. This foam change part 76 is also an elastic change part. The difference between the foam change part 20 and the foam change part 76 described above is a planar shape.

  As is clear from FIG. 12, the planar shape of the foam change portion 76 is an octagon. In the midsole 70 including the octagonal foam change portion 76, the amount of compressive deformation does not change abruptly in the front-rear direction. The octagonal foam change part 76 contributes to the stability of the swing. Foam change portions having a hexagonal shape, heptagonal shape, nine-sided shape, and decagonal shape in plan can also contribute to the stability of the swing.

  FIG. 13 is a plan view showing a midsole 78 of a golf shoe according to still another embodiment of the present invention. In FIG. 13, a length line A and a width line B are shown. The midsole 78 includes a base 80 and a side wall 82 provided on the outer edge of the base 80. This midsole 78 is for the right foot. The midsole for the left foot has a shape in which the shape shown in FIG. The cross-sectional shape along the width line B of the midsole 78 is equivalent to the cross-sectional shape of the midsole 10 shown in FIG. The midsole 78 includes a foam change portion 84. The foam change portion 84 is also an elastic change portion. The difference between the foam change portion 20 and the foam change portion 84 described above is a planar shape.

  As is clear from FIG. 13, the planar shape of the foam change portion 84 is substantially semi-elliptical. In the midsole 78 provided with the substantially semi-elliptical foam change portion 84, the amount of compressive deformation does not change abruptly in the front-rear direction. The substantially semi-elliptical foam change part 84 contributes to the stability of the swing.

  FIG. 14 is a plan view showing a midsole 86 of a golf shoe according to still another embodiment of the present invention. In FIG. 14, a length line A and a width line B are shown. The midsole 86 includes a base 88 and a side wall 90 provided on the outer edge of the base 88. This midsole 86 is for the right foot. The midsole for the left foot has a shape in which the shape shown in FIG. The cross-sectional shape along the width line B of the midsole 86 is equivalent to the cross-sectional shape of the midsole 10 shown in FIG. The midsole 86 includes a foam change portion 92. The foam change portion 92 is also an elastic change portion. The difference between the foam change portion 20 and the foam change portion 92 described above is a planar shape.

  As is clear from FIG. 14, the planar shape of the foam change portion 92 is a rectangle. In the midsole 86 including the rectangular foam changing portion 92, the amount of compressive deformation does not change abruptly in the front-rear direction. The rectangular foam change part 92 contributes to the stability of the swing.

  The material of the foam change portion is a polymer molded product having bubbles. The base polymer of this polymer molded product is not particularly limited, and ethylene-vinyl acetate copolymer (EVA), RB (syndiotactic 1,2-polybutadiene), polystyrene, rubber and the like can be used.

  The foam change portion or the elastic change portion may be provided on the insole or may be provided on the outsole. From the viewpoint of suppressing the wear of the shoe sole, it is preferable not to expose the foam change portion or the elastic change portion to the shoe sole. From the viewpoint of suppressing wear inside the shoe and preventing the user from feeling uncomfortable at the time of walking, it is preferable not to expose the foam change portion or the elastic change portion to the inside of the shoe. From these viewpoints, it is preferable to provide the foam change portion or the elastic change portion in the midsole.

  Hereinafter, the effects of the present invention will be clarified by examples. However, the present invention should not be construed in a limited manner based on the description of the examples.

[Example 1]
A midsole was created by the first manufacturing method described above. The polymer material P1 is a base polymer composed of ethylene-vinyl acetate copolymer (EVA) and ethylene-octene, which is a polyolefin, mixed with a crosslinking agent, a pigment and a foaming agent, and kneaded with an open roll and a kneader. Obtained. The blowing agent was azodicarbonamide. This polymer material P1 was put into the mold 38 in an unevenly distributed state in accordance with the first manufacturing method described above. The mold temperature of the mold 38 was 155 ° C., and the press pressure of the mold press was 150 (kg / cm ² ). The press time was 30 minutes. The obtained polymer molded product P3 was punched to obtain a foam change portion having an elliptical planar shape. A midsole was obtained by adhering the foam change portion to a separately molded base. In this midsole, the length L is 290 mm, the width W is 100 mm, and the thickness T is 6 mm. The midsole includes a foam change portion. This midsole has the same structure as the midsole 10 described above. The width Wa of the foam change portion is 50 mm. The width Wb is 15 mm. In this midsole, the ratio of the thickness t to the thickness T is 100%. An outsole, an insole, and an upper were attached to the midsole to obtain a golf shoe of Example 1.

  In the polymer molded product P3 according to Example 1, the expansion ratio gradually increased from one side to the other side. Therefore, the foam change part was able to be produced from the polymer molding P3. Moreover, the polymer molded body P3 according to Example 1 had a gradually decreasing elastic modulus from one side to the other side. Therefore, the foaming change part obtained from the polymer molding P3 was an elastic change part.

[Example 2]
The manufacturing method is the above-described third manufacturing method, the mold temperature during molding at one end of the mold 50 is 145 ° C., and the mold during molding at the other end of the mold 50 is performed. A golf shoe of Example 2 was obtained in the same manner as Example 1 except that the mold temperature was 160 ° C.

  In the polymer molded product P9 according to Example 2, the expansion ratio gradually increased from one side to the other side. Therefore, a foam change part was able to be produced from the polymer molded object P9. In addition, the polymer molded body P9 according to Example 2 had an elastic modulus that gradually decreased from one side to the other side. Therefore, the foaming change part obtained from the polymer molded object P9 was an elastic change part.

[Example 3]
The manufacturing method is the above-described fourth manufacturing method, and the mold temperature, press pressure, and press time of the primary press are 155 ° C., 150 (kg / cm ² ), and 10 minutes, respectively. A golf shoe of Example 3 was obtained in the same manner as in Example 1 except that the mold temperature, the pressing pressure, and the pressing time were 155 ° C., 150 (kg / cm ² ), and 20 minutes, respectively.

  In the polymer molded body according to Example 3, the expansion ratio gradually increased from one side to the other side. Therefore, a foam change part was able to be produced from this polymer molding. In addition, the polymer molded body according to Example 3 gradually decreased in elastic modulus from one side to the other side. Therefore, the foam change part obtained from this polymer molding was an elastic change part.

  Shoes that can tilt their feet are suitable for various sports other than golf.

FIG. 1 is a partially cutaway side view showing a golf shoe according to an embodiment of the present invention. FIG. 2 is a plan view showing a midsole of the golf shoe of FIG. FIG. 3 is an enlarged cross-sectional view taken along line III-III in FIG. FIG. 4 is an enlarged cross-sectional view taken along line IV-IV in FIG. FIG. 5 is an enlarged cross-sectional view taken along line VV in FIG. FIG. 6 is a cross-sectional view for explaining an example of a method for manufacturing the midsole of FIG. FIG. 7 is a cross-sectional view for explaining an example of a method for producing a foam change portion (elastic change portion) according to the present invention. FIG. 8 is a cross-sectional view for explaining an example of another manufacturing method of the foam change portion (elastic change portion) according to the present invention. FIG. 9 is a cross-sectional view for explaining an example of another manufacturing method of the foam change portion (elastic change portion) according to the present invention. FIG. 10 is a cross-sectional view for explaining an example of another manufacturing method of the foam change portion (elastic change portion) according to the present invention. FIG. 11 is a cross-sectional view illustrating a midsole of a golf shoe according to another embodiment of the present invention. FIG. 12 is a plan view showing a midsole of a golf shoe according to still another embodiment of the present invention. FIG. 13 is a plan view showing a midsole of a golf shoe according to still another embodiment of the present invention. FIG. 14 is a plan view showing a midsole of a golf shoe according to still another embodiment of the present invention.

Explanation of symbols

2 ... Golf shoes 4 ... Upper 6 ... Bottom 8 ... Insole 10, 70, 78, 86 ... Midsole 12 ... Outsole 14 ... Projection 16 ... Base 18 ... Side wall 20, 76, 84, 92 ... Foam change part 38, 50 ... Mold 39, 51 ... Cavity P1, P4, P7, P10 ... Polymer material

Claims (8)

With a bottom,
This bottom part is a foam change part where the expansion ratio gradually increases from the outside to the inside, and a high elastic part having an elastic modulus higher than the maximum elastic modulus in the foam change part on each of the inside and outside of the foam change part And a shoe having a layer comprising. The dimension along the width line of the bottom of each highly elastic part formed on the inside and outside of the foam change part is 13 mm or more and 35 mm or less,
The width line is a straight line in the width direction of the bottom, is at a distance of 1/4 of the length line from the toe side end of the length line of the bottom, and is orthogonal to the length line,
The shoe according to claim 1, wherein the length line is a longest line segment that can be drawn within a contour of a bottom portion. With a bottom,
This bottom part has an elastic change part whose elastic modulus gradually decreases from the outside to the inside, and a high elastic part having an elastic modulus higher than the maximum elastic modulus in the elastic change part on each of the inside and outside of the elastic change part And a shoe having a layer comprising. The dimension along the width line of the bottom of each highly elastic part formed on the inside and outside of the elastic change part is 13 mm or more and 35 mm or less,
The width line is a straight line in the width direction of the bottom, is at a distance of 1/4 of the length line from the toe side end of the length line of the bottom, and is orthogonal to the length line,
The shoe according to claim 3, wherein the length line is a longest line segment that can be drawn within a contour of the bottom. A step in which a foamable polymer material is placed in a mold in an unevenly distributed state;
A step of forming a polymer molded body having a foam change part in which the foaming ratio gradually increases from one side to the other side by foaming the unevenly distributed polymer material in the mold; and
A step in which the foam change portion is provided at the bottom of the shoe so that the foaming ratio gradually increases from the outside to the inside;
A step in which a high elastic portion having an elastic modulus higher than the maximum elastic modulus in the foam change portion is provided on the inside of the foam change portion and the outside, respectively, on the bottom of the shoe;
A method for manufacturing a shoe including a step of producing a shoe from the bottom and the upper. A process in which a foamable polymer material is put into a mold;
A step of forming a polymer molded body having a foam change portion in which the foaming ratio gradually increases from one side to the other side by partially varying the heating temperature acting on the polymer material during foaming;
A step in which the foam change portion is provided at the bottom of the shoe so that the foaming ratio gradually increases from the outside to the inside;
A step in which a high elastic portion having an elastic modulus higher than the maximum elastic modulus in the foam change portion is provided on the inside of the foam change portion and the outside, respectively, on the bottom of the shoe;
A method for manufacturing a shoe including a step of producing a shoe from the bottom and the upper. A process in which a foamable polymer material is put into a mold;
A step of forming a polymer molded body having a foam change part in which the foaming ratio gradually increases from one side to the other side by partially varying the pressure acting on the polymer material during foaming;
A step in which the foam change portion is provided at the bottom of the shoe so that the foaming ratio gradually increases from the outside to the inside;
A step in which a high elastic portion having an elastic modulus higher than the maximum elastic modulus in the foam change portion is provided on the inside of the foam change portion and the outside, respectively, on the bottom of the shoe;
A method for manufacturing a shoe including a step of producing a shoe from the bottom and the upper. The dimension along the width line of the bottom of each highly elastic part formed on the inside and outside of the foam change part is 13 mm or more and 35 mm or less,
The width line is a straight line in the width direction of the bottom, is at a distance of 1/4 of the length line from the toe side end of the length line of the bottom, and is orthogonal to the length line,
The method for manufacturing a shoe according to any one of claims 5 to 7, wherein the length line is a longest line segment that can be drawn in a contour of a bottom portion.

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