A method for preparing carbon plate for running shoes

Abstract

The present invention relates to a method for preparing a carbon plate for running shoes, which belongs to the field of shoe accessories. The method sets different elastic moduli according to the stress conditions of each metatarsal area during running, sets a smaller elastic modulus at the weakly stressed area, and sets a larger elastic modulus at the strongly stressed area. The elastic moduli of the first metatarsal area, the second metatarsal area, the fourth metatarsal area, and the fifth metatarsal area are all smaller than the elastic modulus of the third metatarsal area. The present invention designs elastic moduli according to the force generation process and stress of each area of ​​the sole of the foot, so that different areas have different mechanical responses. A lower elastic modulus is designed for the weakly stressed area so that the carbon plate at this area can respond quickly and bend and deform; a larger elastic modulus is designed for the strongly stressed area so that this area can provide sufficient support. The arrangement of carbon fiber layers and polyimide fiber layers forms a carbon plate with different properties in different areas, which can take into account both the support and rapid response of the carbon plate.

Description

[0001] The present invention is a divisional application of the Chinese invention patent application with application number CN202210577319.5 and titled "A carbon plate for running shoes and a preparation method thereof." Technical Field

[0002] The invention relates to a method for preparing a carbon plate for running shoes, belonging to the field of shoe accessories. Background Art

[0003] There is a type of shoe on the market that has pedals added to the soles to enhance support and rebound performance, thereby making up for the support and rebound performance of the soles and assisting foot propulsion more efficiently.

[0004] For example, in the Chinese utility model with the authorization announcement number CN215532060U and the name “A new type of boosting and shock-absorbing sole”, a carbon fiber plate is provided between the first midsole and the second midsole. Another example is the Chinese utility model with the authorization announcement number CN213487263U and the name “A sports shoe containing a racing carbon plate”, in which a racing carbon plate is provided in the sole. The so-called “carbon plate” in the industry is a carbon fiber reinforced resin composite material, which is mainly composed of fiber material and resin material. Carbon fiber has the characteristics of high specific strength, tensile strength, low bending and low elongation, so the carbon plate has the characteristics of high elastic modulus and high tensile strength, but it is not resistant to shearing and bending, and has poor toughness. It is difficult to take into account both support and rapid response according to the force characteristics of running, which affects the propulsion performance and user experience.

[0005] In view of this, the inventors of this case conducted in-depth research on the above-mentioned issues, which led to the emergence of this case. Summary of the Invention

[0006] The object of the present invention is to provide a method for manufacturing a carbon plate for running shoes that can take into account both support and response speed.

[0007] In order to achieve the above object, the present invention adopts such technical solution:

[0008] A method for preparing a carbon plate for running shoes includes a carbon plate body, wherein areas of the carbon plate body corresponding to each metatarsal bone are set as metatarsal regions, and the metatarsal regions are sequentially set as a first metatarsal region, a second metatarsal region, a third metatarsal region, a fourth metatarsal region, and a fifth metatarsal region. Different elastic moduli are set according to the stress conditions of each metatarsal region during running, with a smaller elastic modulus being set at a weakly stressed area and a larger elastic modulus being set at a strongly stressed area. The elastic moduli of the first metatarsal region, the second metatarsal region, the fourth metatarsal region, and the fifth metatarsal region are all smaller than the elastic modulus of the third metatarsal region.

[0009] As an improvement of the present invention, the resin-impregnated carbon fiber layer and / or polyimide fiber layer is arranged in the left-right direction to form a first ply, the resin-impregnated carbon fiber layer and / or polyimide fiber layer is arranged in the up-down direction to form a second ply, and the first ply and the second ply are molded and cured to form the carbon plate body.

[0010] As an improvement of the present invention, the carbon plate body is laid out in seven layers, and the fibers are respectively the first to seventh layers from the bottom layer to the top layer, CF represents the carbon fiber layer, and PI represents the polyimide fiber layer. In the first metatarsal area and the second metatarsal area, the fiber arrangement is CF / PI / CF / CF / CF / PI / PI; in the third metatarsal area and the fourth metatarsal area, the fiber arrangement is CF / CF / CF / CF / CF / CF / PI; in the fifth metatarsal area, the fiber arrangement is CF / PI / PI / CF / PI / PI / PI.

[0011] As an improvement of the present invention, the fibers in a same layer are continuous and uninterrupted.

[0012] As an improvement of the present invention, 12K CF and 1500D PI are interlaced and layered when the fibers are spread and formed.

[0013] As an improvement of the present invention, the carbon plate body also includes a toe area corresponding to the toes, a midfoot area corresponding to the human arch, and a heel area corresponding to the heel. The carbon plate has a smooth first curvature when transitioning from the toe area to the metatarsal area, and the curvature ρ1 of the first curvature is between 10-12; the carbon plate has a smooth second curvature in the length direction of the metatarsal area, and the curvature ρ2 of the second curvature is between 5.5-8.3; the carbon plate has a smooth second curvature in the length direction of the metatarsal area, and the curvature ρ2 of the second curvature is between 5.5-8.3; the carbon plate has a smooth second curvature in the length direction of the metatarsal area. The transition from the metatarsal area to the fifth metatarsal area has a smooth third curvature, and the curvature ρ3 of the third curvature is between 9-11; the carbon plate has an upward fourth curvature in the length direction of the midfoot area, and the curvature ρ4 of the fourth curvature is between 4-6; the carbon plate has a smooth fifth curvature from the outside to the inside in the midfoot area, and the curvature ρ5 of the fifth curvature is between 3-6; the carbon plate has a sixth curvature in the length direction of the heel area, and the curvature ρ6 of the sixth curvature is between 4-6.

[0014] As an improvement of the present invention, the width of the toe area is 3-6 cm, the width of the metatarsal area is 5-8 cm, the width of the midfoot area is 4-5 cm, the width of the heel area is 4-7 cm, the width of the first metatarsal area is 1-1.5 cm, the width of the second metatarsal area is 1-1.5 cm, the width of the third metatarsal area and the fourth metatarsal area are both 3-4 cm, and the width of the fifth metatarsal area is 1-1.5 cm.

[0015] As an improvement of the present invention, the carbon fiber layer and the polyimide fiber layer are both multi-layered.

[0016] As an improvement of the present invention, the carbon fiber layer and the polyimide fiber layer both extend in the front-to-back direction.

[0017] As an improvement of the present invention, the first metatarsal area and the second metatarsal area are each provided with at least three layers of the polyimide fiber layer, the third metatarsal area and the fourth metatarsal area are each provided with at least one layer of the polyimide fiber layer, and the fifth metatarsal area is provided with at least five layers of the polyimide fiber layer.

[0018] After adopting the technical solution of the present invention, the carbon plate structure is designed according to the force generation process and the different forces in different areas of the sole of the foot, so that different parts have different mechanical responses. A lower elastic modulus is designed in the weakly stressed areas, so that the carbon plate in these areas can respond quickly and bend and deform; a higher elastic modulus is designed in the strongly stressed areas, so that these areas can provide sufficient support. The present invention also proposes a method for manufacturing the carbon plate, which forms a carbon plate with different properties in different areas by arranging carbon fiber layers and polyimide fiber layers, which can balance the support and rapid response of the carbon plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a top view of the present invention.

[0020] Figure 2 It is a side view of the present invention.

[0021] Figure 3 for Figure 1 Cross-sectional view at A-A in the middle.

[0022] Figure 4 for Figure 1 Cross-sectional view at B-B in the middle.

[0023] Figure 5 Schematic diagram of fiber laying in step 1 of the present invention.

[0024] Figure 6 Schematic diagram of fiber laying in step 2 of the present invention.

[0025] Figure 7 Schematic diagram of fiber laying in step three of the present invention.

[0026] Figure 8 Schematic diagram of fiber laying in step 4 of the present invention.

[0027] Figure 9 Schematic diagram of fiber laying in step five of the present invention.

[0028] Figure 10Schematic diagram of fiber laying in step six of the present invention.

[0029] Figure 11 Schematic diagram of fiber laying in step seven of the present invention.

[0030] Figure 12 Schematic diagram of the cross section of the fiber layer in the present invention.

[0031] In the picture:

[0032] Carbon plate body 100 First region 101

[0033] Second region 102 First metatarsal region 201

[0034] Second metatarsal region 202 Third metatarsal region 203

[0035] Fourth metatarsal region 204 Fifth metatarsal region 205

[0036] Mid-foot area 301 Third area 401

[0037] Fourth region 402 carbon fiber layer 10

[0038] Polyimide fiber layer 20 DETAILED DESCRIPTION

[0039] In order to further explain the technical solution of the present invention, it is described in detail below with reference to embodiments.

[0040] Reference Figures 1 to 12 A carbon plate for running shoes includes a carbon plate body 100. The areas of the carbon plate body 100 corresponding to the metatarsal bones are designated as metatarsal regions. The metatarsal regions (also known as Region II) are sequentially designated as a first metatarsal region 201, a second metatarsal region 202, a third metatarsal region 203, a fourth metatarsal region 204, and a fifth metatarsal region 205. The elastic moduli of the first metatarsal region 201, the second metatarsal region 202, the fourth metatarsal region 204, and the fifth metatarsal region 205 are all smaller than the elastic modulus of the third metatarsal region 203. The carbon plate of the present invention can be used in running shoes and placed between two midsoles, as in the prior art.

[0041] As a preferred embodiment of the present invention, the elastic modulus of the fifth metatarsal region 205 is smaller than the elastic modulus of the fourth metatarsal region 204. As a preferred embodiment of the present invention, the carbon plate body 100 further includes a toe region (i.e., region I) corresponding to the toes, and the toe region includes a first region 101 corresponding to the big toe and a second region 102 corresponding to the second toe to the fifth toe.

[0042] In the present invention, the carbon plate body 100 can be provided only for the front portion of the sole of the foot. In an embodiment, its shape corresponds to the entire sole of the foot. The length of the carbon plate body 100 is 80%-90% of the actual sole length of the adult wearer's foot. In the present invention, the carbon plate body 100 also includes a midfoot area 301 (also known as Area III) provided for the arch of the human foot and a heel area (also known as Area IV) provided for the heel. The side of the carbon plate body 100 corresponding to the inner side of the instep of the human foot is designated as the inner side, and the side corresponding to the outer side of the instep is designated as the outer side. The heel area is divided into a third area 401 provided for the inner side of the carbon plate body 100 and a fourth area 402 provided for the outer side of the carbon plate body 100.

[0043] This study analyzes the force generated by the sole of the foot during running from a biomechanical perspective, dividing the sole of the foot into four major regions and ten minor regions. During running, the sole of the foot contacts the ground, transitioning from the heel to the forefoot and from the lateral to the medial side of the foot, and the forces acting on the sole of the foot are generated accordingly. However, analysis of sole pressure reveals significant differences in the pressure generated by each area of ​​the sole during running. As the force-generating area transitions from the fifth metatarsal to the first metatarsal, the force initially increases and then decreases, reaching a peak at the third metatarsal before decreasing. This reflects the distinct roles played by each area of ​​the sole during running.

[0044] As a preferred embodiment of the present invention, the carbon plate body 100 includes a carbon fiber layer 10 and a polyimide fiber layer 20 compounded together by a resin adhesive, and the carbon fiber layer 10 and the polyimide fiber layer 20 are both multi-layered. The so-called "carbon plate" within the industry is a carbon fiber reinforced resin composite material, which is mainly composed of fiber material and resin material. The performance of the composite material can be effectively regulated by regulating the performance and stacking structure of the fiber material. Carbon fiber has the characteristics of high specific strength, tensile strength, low bending and low elongation, so the carbon plate has a high elastic modulus and high tensile strength, but it is not resistant to shearing and bending, and has poor toughness; polyimide fiber has a higher specific strength, better tensile strength, and at the same time has a larger elongation and better toughness. It can make up for the shortcomings of carbon fiber's high rigidity and poor toughness.

[0045] During running, the carbon plate embedded in the sole will bend, especially in the metatarsal area of ​​the forefoot, where the bending variable is the largest. According to experimental analysis, for sports shoes with implanted carbon plates, the maximum bending angle of the metatarsal area can reach about 15°. Therefore, running has higher requirements for the bending performance of the carbon plate.

[0046] As a preferred embodiment of the present invention, with the inner and outer directions of the carbon plate body 100 as the left and right directions, the toe area of ​​the carbon plate body 100 as the front, and the heel area of ​​the carbon plate body 100 as the back, the carbon fiber layer 10 and the polyimide fiber layer 20 both extend in the front-to-back direction, and the carbon fiber layer 10 and the polyimide fiber layer 20 are arranged in the left and right directions in the left and right direction areas of the carbon plate body 100 to form different elastic moduli, and the carbon fiber layer 10 and the polyimide fiber layer 20 are stacked in the up and down directions to form the carbon plate body 100 with a thickness of 0.8-1.2 mm.

[0047] As a preferred embodiment of the present invention, the width of the toe area is 3-6 cm, the width of the metatarsal area is 5-8 cm, the width of the midfoot area 301 is 4-5 cm, the width of the heel area is 4-7 cm, the width of the first metatarsal area 201 is 1-1.5 cm, the width of the second metatarsal area 202 is 1-1.5 cm, the width of the third metatarsal area 203 and the fourth metatarsal area 204 are both 3-4 cm, and the width of the fifth metatarsal area 205 is 1-1.5 cm.

[0048] As a preferred embodiment of the present invention, the first metatarsal region 201 and the second metatarsal region 202 are each provided with at least three layers of the polyimide fiber layer 20, the third metatarsal region 203 and the fourth metatarsal region 204 are each provided with at least one layer of the polyimide fiber layer 20, and the fifth metatarsal region 205 is provided with at least five layers of the polyimide fiber layer 20. The toe region transitions to the metatarsal region through a smooth arc with a curvature range of 9-12. The metatarsal region is substantially flat in length. The metatarsal region has a smooth curvature with a curvature range of 5-9. The metatarsal region transitions from the first metatarsal region 201 to the fifth metatarsal region 205 through a smooth curvature with a curvature range of 8-12. The midfoot region 301 has a smooth curvature along its length with a curvature range of 4-7. The midfoot region 301 has a smooth curvature from the outside to the inside with a curvature range of 2-6. The heel region has a smooth curvature along its length with a curvature range of 4-6. In the present invention, each region does not operate independently, but rather forms a continuous whole, ensuring smooth force transmission.

[0049] The present invention also proposes a method for preparing a carbon plate for running shoes, including a carbon plate body 100, wherein the areas of the carbon plate body 100 corresponding to each metatarsal are set as metatarsal areas, and the metatarsal areas are sequentially set as a first metatarsal area 201, a second metatarsal area 202, a third metatarsal area 203, a fourth metatarsal area 204 and a fifth metatarsal area 205. Different elastic moduli are set according to the force conditions of each metatarsal area during running, a smaller elastic modulus is set at a weakly stressed area, and a larger elastic modulus is set at a strongly stressed area. The elastic moduli of the first metatarsal area 201, the second metatarsal area 202, the fourth metatarsal area 204 and the fifth metatarsal area 205 are all smaller than the elastic modulus of the third metatarsal area 203.

[0050] As a preferred embodiment of the present invention, the resin-impregnated carbon fiber layer 10 and / or polyimide fiber layer 20 are arranged in the left-right direction to form a first ply, that is, the first ply can be entirely carbon fiber layers 10 or polyimide fiber layers 20, or the carbon fiber layers 10 and polyimide fiber layers 20 are arranged alternately, and the resin-impregnated carbon fiber layer 10 and / or polyimide fiber layer 20 are arranged in the up-down direction to form a second ply, and the first ply and the second ply are molded and cured to form the carbon plate body 100.

[0051] Preferably, the carbon plate body 100 of the present invention is laid with at least seven layers. Taking seven layers as an example, it is manufactured in the following manner:

[0052] This embodiment plans to arrange seven layers of fibers, from the bottom to the top, from the first to the seventh layers. CF represents the carbon fiber layer 10, and PI represents the polyimide fiber layer 20. These are represented by blocks of varying packing densities in the figure. In the first metatarsal region 201 and the second metatarsal region 202, the fiber arrangement is CF / PI / CF / CF / CF / PI / PI; in the third metatarsal region 203 and the fourth metatarsal region 204, the fiber arrangement is CF / CF / CF / CF / CF / CF / PI; and in the fifth metatarsal region 205, the fiber arrangement is CF / PI / PI / CF / PI / PI / PI.

[0053] To ensure smooth force transmission and the integrity of the carbon plate, the fibers in the same layup are continuous and uninterrupted. The fiber arrangement of the first, second, third, fourth, and fifth metatarsals is used as a foundation, and then extended to achieve the fiber arrangement of the entire carbon plate. A compression molding and curing process then forms the carbon plate into a three-dimensional, contoured structure. The plate exhibits a smooth curvature from Zone I to Zone II, with a curvature ρ1 ranging from 10 to 12 degrees. Zone II also exhibits a smooth curvature along its length, with a curvature ρ2 ranging from 5.5 to 8.3 degrees. Zone II also exhibits a smooth curvature from the first metatarsal region 201 to the fifth metatarsal region 205, with a curvature ρ3 ranging from 9 to 11 degrees. Zone III also exhibits an upward curvature along its length, providing support for the arch of the foot, with a curvature ρ4 ranging from 4 to 6 degrees. The carbon plate has a smooth curvature from the outside to the inside in zone III, and the curvature ρ5 of the curvature smoothly transitions between 3 and 6. The carbon plate has a curvature in the length direction in zone IV to provide support for the heel, and the curvature ρ6 of the curvature smoothly transitions between 4 and 6.

[0054] The arrangement of each layer of fibers is customized according to the design requirements during the preparation of prepreg. When the fibers are spread and formed, 12K CF and 1500D PI are interlaced and laid. Figure 5 The middle is a full carbon fiber layup (approximately the width of 6 CF fiber bundles); Figure 6 From left to right in the middle, first lay PI with a width of about 2.5 cm (the width of about 8 PI fiber bundles), then lay CF with a width of about 2 cm (the width of about 2 CF fiber bundles), and then lay PI with a width of about 1.5 cm (the width of about 4 PI fiber bundles); Figure 7 From left to right, first lay a 5 cm wide CF (the width of about 5 CF fiber bundles), and then lay a 1.5 cm wide PI (the width of about 4 PI fiber bundles); Figure 8 The middle is a full carbon fiber layup (approximately the width of 6 CF fiber bundles); Figure 9 From left to right, first lay a 5 cm wide CF (the width of about 5 CF fiber bundles), and then lay a 1.5 cm wide PI (the width of about 4 PI fiber bundles); Figure 10 From left to right in the middle, first lay PI with a width of about 2.5 cm (the width of about 8 PI fiber bundles), then lay CF with a width of about 2 cm (the width of about 2 CF fiber bundles), and then lay PI with a width of about 1.5 cm (the width of about 4 PI fiber bundles); Figure 11 The middle layer is a full polyimide fiber layer (approximately 18 PI fiber bundles). Each layer of prepreg is pre-impregnated with epoxy resin, stacked according to the ply order, and press-cured at 120°C for 30 minutes to obtain the finished carbon board (single fiber layer thickness is 0.1-0.12mm).

[0055] According to calculations, the bending modulus of the area corresponding to the fifth metatarsal bone is approximately 40% lower than that of the third and fourth metatarsal bones, and the bending failure strain is approximately three times higher, reaching approximately 5.5%. This means that the fifth metatarsal bone can achieve a large deformation effect under a small stress.

[0056] The product form of the present invention is not limited to the embodiments of this case. Any appropriate changes or modifications made by anyone with similar ideas should be deemed to be within the patent scope of the present invention.

Claims

1. A method for preparing a carbon plate for running shoes, comprising a carbon plate body, wherein the areas of the carbon plate body corresponding to the metatarsal bones are defined as metatarsal regions, the metatarsal regions including, in sequence, a first metatarsal region, a second metatarsal region, a third metatarsal region, a fourth metatarsal region, and a fifth metatarsal region, characterized in that: Different elastic moduli are set for each metatarsal region according to the stress conditions during running. A smaller elastic modulus is set for the weakly stressed area, and a larger elastic modulus is set for the strongly stressed area. The elastic moduli of the first, second, fourth, and fifth metatarsal regions are all smaller than that of the third metatarsal region. The carbon plate body is laid out in seven layers, with the fibers from the bottom layer to the top layer being the first to the seventh layer respectively, with CF representing the carbon fiber layer and PI representing the polyimide fiber layer. In the first metatarsal area and the second metatarsal area, the fiber arrangement is CF / PI / CF / CF / CF / PI / PI; in the third metatarsal area and the fourth metatarsal area, the fiber arrangement is CF / CF / CF / CF / CF / CF / PI; in the fifth metatarsal area, the fiber arrangement is CF / PI / PI / CF / PI / PI / PI.

2. The method for preparing a carbon plate for running shoes according to claim 1, wherein: The resin-impregnated carbon fiber layer and / or polyimide fiber layer are arranged in the left-right direction to form a first ply, the resin-impregnated carbon fiber layer and / or polyimide fiber layer are arranged in the up-down direction to form a second ply, and the first ply and the second ply are molded and cured to form the carbon plate body.

3. The method for preparing a carbon plate for running shoes according to claim 1 or 2, wherein: The fibers in the same ply are continuous and uninterrupted.

4. The method for preparing a carbon plate for running shoes according to claim 1, wherein: When the fibers are spread and formed, 12K CF and 1500D PI are interlaced and layered.

5. The method for preparing a carbon plate for running shoes according to claim 1, wherein: The carbon plate body also includes a toe area set corresponding to the toes, a midfoot area set corresponding to the human arch, and a heel area set corresponding to the heel. The carbon plate has a smooth first curvature when transitioning from the toe area to the metatarsal area, and the curvature ρ1 of the first curvature is between 10-12; the carbon plate has a smooth second curvature in the length direction of the metatarsal area, and the curvature ρ2 of the second curvature is between 5.5-8.3; the carbon plate has a smooth third curvature in the transition from the first metatarsal area to the fifth metatarsal area in the metatarsal area, and the curvature ρ3 of the third curvature is between 9-11; the carbon plate has an upward fourth curvature in the length direction of the midfoot area, and the curvature ρ4 of the fourth curvature is between 4-6; the carbon plate has a smooth fifth curvature from the outside to the inside in the midfoot area, and the curvature ρ5 of the fifth curvature is between 3-6; the carbon plate has a sixth curvature in the length direction of the heel area, and the curvature ρ6 of the sixth curvature is between 4-6.

6. The method for preparing a carbon plate for running shoes according to claim 5, wherein: The width of the toe area is 3-6 cm, the width of the metatarsal area is 5-8 cm, the width of the midfoot area is 4-5 cm, the width of the heel area is 4-7 cm, the width of the first metatarsal area is 1-1.5 cm, the width of the second metatarsal area is 1-1.5 cm, the width of the third metatarsal area and the fourth metatarsal area are both 3-4 cm, and the width of the fifth metatarsal area is 1-1.5 cm.

7. The method for preparing a carbon plate for running shoes according to claim 2, wherein: The carbon fiber layer and the polyimide fiber layer are both multi-layered.

8. The method for preparing a carbon plate for running shoes according to claim 7, wherein: The carbon fiber layer and the polyimide fiber layer both extend in a front-to-back direction.

9. The method for preparing a carbon plate for running shoes according to claim 8, wherein: The first metatarsal region and the second metatarsal region are both provided with at least three layers of the polyimide fiber layer, the third metatarsal region and the fourth metatarsal region are both provided with at least one layer of the polyimide fiber layer, and the fifth metatarsal region is provided with at least five layers of the polyimide fiber layer.

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