Process for making a comfortable high-elasticity shoe sole midsole

Abstract

The application discloses a comfortable high-elastic shoe sole midsole manufacturing process method, and is especially suitable for high-heeled shoe midsoles. The method collects pressure data of a forefoot propulsion area and a heel contact area, generates a partition matrix containing vertical pressure of the forefoot, a shear direction component and impact pressure of the heel; and determines a forefoot support point, a reverse buckle locking groove and a pre-pressing amount of a heel air cushion according to the partition matrix. High-elastic polyether material enters the reverse buckle locking groove and is solidified to form a locking body, so that the midsole has the functions of forefoot anti-slip, interlayer anti-peeling, heel cushioning and high-elastic comfort.

Description

Technical Field

[0001] This invention relates to the field of shoe sole manufacturing technology, and more particularly to a manufacturing process for a comfortable and highly elastic shoe sole midsole. Background Technology

[0002] The midsole is a crucial component affecting the comfort, cushioning, support stability, and propulsion efficiency of footwear. Existing athletic, casual, and functional shoes typically employ multi-layered composite midsole structures to balance cushioning and support. For example, softer elastic shock-absorbing materials are combined with harder support materials, providing cushioning during heel strike and support during forefoot push-off. Chinese patent CN117377409A discloses a shoe sole with a double-layered midsole, comprising an elastic shock-absorbing layer and a base layer. The base layer's hardness can differ from the shock-absorbing layer, and the shock-absorbing layer can have laterally extending channels in the heel, midfoot, or forefoot areas to improve cushioning and deformation performance. While this approach enhances cushioning and support through the combination of soft and hard layers, its focus is primarily on the hardness difference between the mid and bottom layers, the channels in the shock-absorbing layer, and the regional structural arrangement. It often lacks further structural design regarding the synergistic relationship between shear direction support during forefoot propulsion, interlayer shear locking, and heel air cushion pre-compression.

[0003] With the development of plantar pressure testing technology, existing technologies have begun to apply plantar pressure data to the customized design of insoles or soles. For example, Chinese patent CN110693132A discloses a customized insole design method based on pressure acquisition. This method obtains plantar pressure area information and plantar pressure information, and combines the arch type and pressure information of each area to generate an insole design scheme, thereby improving the matching between the insole and the stress state of the foot. This type of solution can adjust the insole structure according to the differences in plantar pressure of different users, which is of positive significance for improving fit and local support. However, its technical focus is mainly on determining the regional shape of the insole or the local support method based on the plantar pressure distribution. It usually still focuses on the corresponding adjustment between the vertical pressure distribution and the insole support position, thickness or filling structure, without fully considering the tangential shear force direction during the forefoot push-off phase, the directional arrangement of forefoot support components, and the failure risk of the connection structure between the midsole and bottom layers under repeated shear loads.

[0004] In addition, existing shoe soles commonly feature columnar, strip-shaped, or rib-shaped support structures in the forefoot area and air cushions, cavities, or elastic buffers in the heel area to improve forefoot support and heel cushioning, respectively. While these structures can reduce impact, improve feel, or enhance local rebound to some extent, in most designs, the forefoot support, heel air cushion, and the connecting structure between the mid and bottom layers are often designed as relatively independent functional units. The forefoot support is mainly determined by spatial arrangement or appearance, the heel air cushion is mainly set according to cushioning requirements, and the soft upper layer and hard lower layer are mostly connected by bonding, covering, or ordinary interlocking. During long-term wear and exercise, the forefoot area will repeatedly bear bending, extension and shear loads. If the connection direction, locking depth and forefoot shear direction between the soft high-elastic layer and the hard bottom layer are not matched, problems such as local slippage, peeling, support loss or unstable foot feel may easily occur. If the heel air cushion is only assembled with a fixed thickness or fixed cavity, problems such as excessively soft cushioning, delayed rebound, air cushion displacement or incoordination with the forefoot support stiffness may also occur.

[0005] Therefore, while existing technologies have disclosed individual techniques such as dual-layer midsoles, customized insoles with plantar pressure, forefoot support protrusions, and heel cushioning, they still have the following shortcomings: First, plantar pressure data is mostly used for static or vertical support design, with less emphasis on incorporating shear direction information during the forefoot propulsion phase; second, there is a lack of mechanical direction correspondence between the forefoot support structure and the locking structure between the midsole and bottom layers, making it difficult to effectively resist interlayer displacement caused by push-off shear; third, the pre-compression and limiting of the heel cushioning are usually determined independently, without overall matching with the support requirements of the forefoot propulsion area; fourth, there is a lack of a unified manufacturing parameter linkage mechanism between the soft and hard dual-layer midsole, forefoot support, and heel cushioning, making it difficult to balance comfort, high elasticity, shear stability, and long-term durability. Based on this, there is an urgent need to improve the manufacturing process of comfortable, high-elasticity shoe midsoles, so that the midsole structure can achieve more coordinated overall performance in terms of forefoot propulsion support, interlayer connection stability, and heel cushioning consistency. Summary of the Invention

[0006] The technical objective of this invention is to provide a manufacturing process for a comfortable and highly elastic shoe midsole. By collecting pressure data from the forefoot propulsion area and heel area, a foot pressure zoning matrix is ​​established, which includes forefoot vertical pressure, forefoot shear direction, and heel impact pressure. Based on this matrix, the forefoot support point structure, the parameters of the inverted locking groove, and the pre-compression amount of the heel air cushion are determined. This ensures that the rigid bottom layer, the high-elastic polyether top layer, the forefoot irregular support array, and the heel air cushion are synergistically matched during the manufacturing process. This improves the problems of inaccurate forefoot support direction, insufficient interlayer shear stability, and incoordination between heel cushioning and forefoot propulsion support in existing midsoles.

[0007] To achieve the objectives of this invention, the following technical solution is adopted:

[0008] A manufacturing process for a comfortable and highly elastic shoe midsole includes the following steps: S1: Collecting pressure data of the forefoot propulsion zone and heel area of ​​the foot to generate a foot pressure zone matrix. ,in, For the first Normalized vertical pressure value of each forefoot propulsion zone For the first The shear direction component of the forefoot propulsion zone S2: Based on the normalized shock pressure value of the following region; Determine the projected area and height of the forefoot support point, and in When the shearing threshold is exceeded, vertical supports are formed, and the extension direction of the vertical supports is aligned with... The directional angle is no greater than 25°; S3: The bottom blank is formed using a hard material, and an undercut locking groove corresponding to the support point is formed in the forefoot area. The depth of the undercut locking groove is determined by... and The weighted determination is made, and the reverse bearing surface of the inverted locking groove faces the direction. In the opposite direction; S4: A hollow heel cavity with a pre-compression limiting step is formed in the heel area, the air cushion is embedded in the hollow heel cavity, and according to The air cushion preload is determined together with the average pressure in the forefoot propulsion area; S5: High-elastic polyether material is injected above the bottom blank, so that the high-elastic polyether material enters the inverted locking groove and covers the root of the support point, and is cured to form a high-elastic polyether upper layer that is mechanically locked with the hard bottom layer.

[0009] As a further improvement, in step S1, the shear direction component Using shear direction vector It means that the By the The tangential force vector of the forefoot propulsion zone during the push-off phase with vertical force Normalization yields the following, which satisfies:

[0010] ;

[0011] In the formula, For the first The shear direction vector of the forefoot propulsion zone. For the first The tangential force vector of the forefoot propulsion zone For the first The vertical force of the forefoot propulsion zone To prevent the correction factor from being zero in the denominator; the The direction is The direction, the The size is .

[0012] As a further improvement, in step S1, plantar pressure data is collected over at least three gait cycles, and the vertical pressure of each forefoot propulsion zone is stabilized to obtain... It satisfies:

[0013] ;

[0014] In the formula, For the first Normalized vertical pressure value of each forefoot propulsion zone For the first The average vertical pressure of each forefoot propulsion zone after removing the maximum and minimum values ​​over multiple gait cycles. For the first The average vertical pressure of each forefoot propulsion zone after removing the maximum and minimum values ​​over multiple gait cycles. The number of zones in the forefoot thrust zone. , All are partition numbers.

[0015] As a further improvement, in step S2, the first The projected area of ​​the support point within the forefoot propulsion zone and height Determine them respectively using the following formulas:

[0016] ;

[0017] ;

[0018] In the formula, For the first The total projected area of ​​the support points within the forefoot propulsion zone. To minimize the projected area of ​​the support, To maximize the supported projected area, For the first Normalized vertical pressure value of each forefoot propulsion zone The area response index ranges from 0.6 to 1.8. For the first The height of the support point within the forefoot propulsion zone. Minimum support height, For maximum support height, For the first The shear direction component of the forefoot propulsion zone This is the vertical pressure weighting coefficient. Here are the weighting coefficients for the shear component, and .

[0019] As a further improvement, in step S2, the current palm shear direction component Greater than the preset shear threshold At that time, vertical supports are set in the corresponding forefoot propulsion zone; when Not greater than and Greater than the preset vertical pressure threshold At that time, elliptical cylindrical supports or arc-shaped rib supports are set in the corresponding forefoot propulsion zone; when Not greater than and Not greater than At that time, cylindrical supports are set within the corresponding forefoot propulsion zone; among which, To determine the threshold of forefoot push-off shear concentration. To determine the threshold for vertical pressure concentration in the forefoot.

[0020] As a further improvement, in step S3, the first The depth of the inverted locking groove corresponding to the forefoot propulsion zone and inverted expansion width Determine them respectively using the following formulas:

[0021] ;

[0022] ;

[0023] In the formula, For the first The depth of the inverted locking groove corresponding to each forefoot propulsion zone. Minimum locking groove depth, For the maximum locking groove depth, For the first Normalized vertical pressure value of each forefoot propulsion zone For the first The shear direction component of the forefoot propulsion zone This is the vertical pressure weighting coefficient. Here is the shear direction weighting coefficient, and ; For the first The width of the inverted locking groove expansion section corresponding to the forefoot propulsion zone. To minimize the expansion width, This represents the maximum expansion width.

[0024] As a further improvement, in step S3, the inverted locking groove includes an inlet section, an expansion section, and a reverse bearing surface. The inlet section is located on the upper surface of the rigid substrate, the expansion section is located below the inlet section, and the reverse bearing surface is at an angle relative to the upper surface of the rigid substrate. The angle is 35° to 75°, and the inclination direction of the reverse bearing surface is the same as... The directions are opposite; after the high-elastic polyether material is cured, a reverse wedge-shaped locking body is formed in the inverted locking groove, and the filling rate of the reverse wedge-shaped locking body is... Not less than 85%, which satisfies:

[0025] ;

[0026] In the formula, For the first The filling rate of the high-elastic polyether material in the inverted locking groove. To proceed to the next stage after curing The volume of high-elastic polyether material within the inverted locking groove. For the first The volume of the cavity of the inverted locking groove. For the first The inclination angle of the reverse bearing surface of the inverted locking groove.

[0027] As a further improvement, in step S4, the air cushion pre-compression amount Determine by the following formula:

[0028] ;

[0029] In the formula, This refers to the pre-compression amount after the air cushion is inserted into the hollowed-out heel cavity. For minimum preload, For maximum preload, The normalized shock pressure value of the following region, Normalized vertical pressure values ​​for each part of the forefoot propulsion zone The average value; the pre-compression limiting step includes an annular pressure edge located at the upper edge of the hollow heel cavity and a support boss located at the bottom of the hollow heel cavity. The outer periphery of the air cushion is restricted between the annular pressure edge and the support boss, so that the maximum horizontal displacement of the air cushion relative to the hollow heel cavity under the pressure state of the heel. Not greater than 1.5mm, of which, This represents the maximum horizontal displacement of the air cushion after it is compressed.

[0030] As a further improvement, a molding feedback verification step is included after step S5: the cured midsole is subjected to forefoot shear displacement test, interlayer peel strength test, and heel impact peak test to obtain the forefoot shear displacement. interlayer peel strength and heel impact peak ;when greater than the preset displacement threshold At the same time, increase the depth of the inverted locking groove of the corresponding forefoot propulsion zone. Or deflect the width ;when Less than the preset peel strength threshold At the same time, increase the filling rate of the undercut locking groove. Or add surface activation treatment; when Greater than the preset impact threshold At the same time, increase the air cushion preload. Or increase the limiting contact area inside the hollow cavity.

[0031] Another aspect of the present invention provides a comfortable high-elasticity shoe sole midsole, manufactured using the aforementioned shoe sole midsole manufacturing process. The shoe sole midsole includes a rigid bottom layer, a high-elastic polyether top layer, a forefoot irregular support array, and a heel air cushion. The forefoot irregular support array includes at least three of the following: vertical support, elliptical cylinder support, arc-shaped rib support, and cylindrical support. The angle between the extension direction of the vertical support and the shear direction of the corresponding forefoot propulsion zone is no greater than 25°. The rigid bottom layer has an inverted locking groove corresponding to the forefoot irregular support array. The inverted locking groove is filled with a reverse wedge-shaped locking body formed by curing high-elastic polyether material, and the reverse pressure-bearing surface of the inverted locking groove faces the opposite direction of the shear direction. The heel air cushion is embedded in a hollow heel cavity with a pre-compression limiting step, and the outer periphery of the air cushion is limited by an annular pressing edge and a support boss.

[0032] This invention incorporates the normalized vertical pressure value, shear direction component, and normalized impact pressure value of the heel region into the same plantar pressure zoning matrix. This allows the projected area, height, shape, and arrangement of the forefoot support points, the depth of the undercut locking groove and the direction of the reverse bearing surface, and the pre-pressure amount and limiting method of the heel air cushion to be determined collaboratively under the same manufacturing logic. Consequently, zones in the forefoot region experiencing greater force can obtain support points of corresponding area and height, while zones with concentrated shear can form vertical supports matching the push-off direction. Furthermore, the undercut locking groove, with its reverse bearing surface facing the opposite side of the shear direction, transforms the interlayer shear tendency during forefoot push-off into a compressing and locking effect between the high-elasticity polyether upper layer and the hard lower layer, thereby reducing the relative slippage between the soft and hard layers. This reduces the risk of localized peeling and support attenuation. Simultaneously, the pre-compression of the heel cushioning is determined by both the heel impact pressure and the average pressure in the forefoot propulsion zone. This ensures that the heel cushioning performance is no longer designed in isolation, but rather matched with the forefoot propulsion support stiffness. This reduces the peak impact of heel strike, limits the horizontal displacement of the cushioning within the hollowed-out heel cavity, and improves rebound stability. During molding, the high-elastic polyether material enters the inverted locking groove and covers the root of the support point. After curing, it forms a reverse wedge-shaped locking body and a continuous high-elastic upper layer. This gives the midsole the structural support of a hard bottom layer, the soft rebound of the high-elastic polyether upper layer, the directional propulsion assistance of the forefoot irregular support array, and the cushioning and energy absorption effect of the heel cushioning. This improves the comfort, high elasticity, shear stability, and durability of the midsole under long-term repeated bending, extension, and impact conditions. Attached Figure Description

[0033] Figure 1 This is a schematic diagram illustrating the overall process of manufacturing the comfortable and highly elastic shoe sole midsole of the present invention;

[0034] Figure 2 A schematic diagram showing the direction of the irregular support array and vertical support bars in the forefoot;

[0035] Figure 3 A schematic diagram of the structure of the hollowed-out heel cavity, air cushion, and pre-compression limiting step;

[0036] Figure 4 This is a schematic diagram of the post-molding feedback verification and manufacturing parameter correction process;

[0037] Figure 5 This is a comparison chart of the peak forefoot pressure between Example 1 and Comparative Examples 1 to 4;

[0038] Figure 6 This is a comparison diagram of the forefoot sliding shear displacement and interlaminar peel strength between Example 1 and the comparative example. Detailed Implementation

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present invention.

[0040] I. Terminology Explanation

[0041] 1. Midsole: The midsole is the load-bearing and cushioning component located between the outsole and the insole or the bottom of the upper. Its main functions are to provide support, cushioning, rebound, and wearing comfort. 2. Rigid Subsole: The rigid subsole is the structural support layer in the midsole closest to the outsole. It can be made of rigid TPU, nylon-reinforced TPU, rigid EVA, polypropylene, or composite materials thereof. Its function is to provide shape retention, torsional support, and a base for locking groove load-bearing.

[0042] 2. High-elastic polyether top layer: This refers to the elastic layer placed above the rigid bottom layer and closer to the foot contact side. It can be made of polyether-type polyurethane microporous elastomer, polyether-type TPU foam material or polyether ester elastomer foam material, and is used to provide soft rebound and cushioning feel.

[0043] 3. Forefoot Propulsion Zone: This refers to the area in the sole of the shoe that corresponds to the metatarsal heads and toe roots, and plays a major role in propulsion during the push-off phase of walking or running. This area can usually be divided into several zones, such as the medial metatarsal zone, the middle metatarsal zone, the lateral metatarsal zone, and the toe root transition zone.

[0044] 4. Heel area: This refers to the area in the sole that corresponds to the impact of the heel striking the ground. It is usually the center of the heel and its surrounding area, and is used to withstand the impact of the landing and generate cushioning deformation.

[0045] 5. Plantar Pressure Zoning Matrix: This refers to the data set formed after normalizing, zoning, and stabilizing the pressure, shear direction, and impact data collected from the forefoot propulsion zone and heel area of ​​the foot. It is denoted as... .

[0046] 6. Normalized vertical pressure value : refers to the The ratio of vertical pressure to total forefoot pressure in each forefoot propulsion zone across multiple gait cycles is used to determine the projected area and height of the zone's support point.

[0047] 7. Shear direction component : refers to the The normalized relationship between the tangential and vertical forces generated by the forefoot propulsion zone during the push-off phase. In this embodiment, Includes magnitude and direction; when direction needs to be expressed, a shearing direction vector is used. express.

[0048] 8. Followed by normalized impact pressure value : Refers to the normalized value of the impact pressure of the heel area during the landing phase, used to determine the heel air cushion preload.

[0049] 9. Inverted locking groove: This refers to a mechanical locking groove formed within the forefoot area of ​​the rigid sublayer, corresponding to the support point. It includes an inlet section, an expansion section, and a reverse bearing surface. After the high-elastic polyether material enters this groove, it solidifies to form a reverse wedge-shaped locking body, thereby improving the shear strength of the connection between the high-elastic polyether upper layer and the rigid sublayer.

[0050] 10. Reverse bearing surface: refers to the force-bearing surface in the inverted locking groove that is inclined to the opposite side of the forefoot shear direction. It is used to provide reverse blocking and clamping effect when the forefoot pushes out and generates shear load.

[0051] 11. Air cushion preload : refers to the initial compression amount generated under the action of the pre-compression limiting step after the air cushion is embedded in the hollow heel cavity. It is used to control the initial working state of the air cushion and the deformation space after being compressed.

[0052] 12. Pre-compression limiting step: refers to the structural limiting part set in the hollow heel cavity, including annular pressure edge, support boss or lateral limiting wall, used to limit the vertical pre-compression and horizontal displacement of the air cushion.

[0053] 13. Reverse wedge locking body: refers to the wedge-shaped filling structure formed after the high-elastic polyether material enters the inverted locking groove and solidifies. It cooperates with the expansion section and reverse bearing surface of the inverted locking groove to make the upper layer of high-elastic polyether less likely to detach from the hard bottom layer when subjected to forefoot shear load.

[0054] II. Overall Technical Route for Implementing the Method of the Invention

[0055] like Figure 1 As shown, the manufacturing process of this invention includes data acquisition, parameter mapping, rigid bottom layer molding, air cushion pre-pressing and embedding, high-elastic polyether top layer molding, and post-molding feedback verification. Specifically, pressure data of the forefoot propulsion area and heel area corresponding to the user or target shoe model are first collected to generate a foot pressure zoning matrix. Next, based on this matrix, determine the projected area, height, shape, and direction of the forefoot support point, and simultaneously determine the depth, expansion width, and reverse bearing surface direction of the undercut locking groove corresponding to the support point; then, use a hard material to form the bottom blank, forming an undercut locking groove in its forefoot area and a hollow heel cavity with a pre-compression limiting step in its heel area; then, based on the normalized impact pressure value of the heel... The air cushion preload is determined together with the average pressure in the forefoot propulsion area, and the air cushion is embedded into the hollow heel cavity. Finally, high-elastic polyether material is injected above the bottom blank, so that it enters the inverted locking groove and covers the root of the support point. After curing, it forms a high-elastic polyether upper layer that is mechanically locked with the rigid bottom layer.

[0056] The data processing involved in this invention includes partitioned normalization calculation, threshold judgment, and manufacturing parameter mapping based on sensor-collected data. Those skilled in the art can use pressure testing platforms, gait pressure plates, insole-type pressure sensors, or sports biomechanical testing systems to collect data, and utilize ordinary industrial computers, PLCs, host computer software, or mold parameter design software to complete matrix calculations and parameter mapping.

[0057] 1. S1: Plantar pressure data acquisition and generation of plantar pressure zoning matrix

[0058] In step S1, pressure data of the forefoot propulsion zone and heel area are first collected. The data can be collected from individual target users, or from a sample of people corresponding to a certain shoe size, shoe type, or sport. For mass-produced shoe types, plantar pressure data from at least 20 people within the same shoe size range can be selected, and stable statistical values ​​can be used as a standard matrix; for customized shoe types, plantar pressure data from a single user can be collected and an individualized matrix can be generated.

[0059] The data acquisition equipment can be a plantar pressure plate, an insole-type pressure sensor array, a three-dimensional force platform, or a gait testing platform with tangential force detection. To obtain forefoot shear direction information, a sensor array capable of simultaneously acquiring vertical and tangential forces is preferred, or a plantar pressure plate combined with a motion capture system can be used to estimate the tangential force direction during the push-off phase by analyzing the displacement direction of the plantar contact point over time. During data acquisition, the subject performs at least three gait cycles of natural walking, jogging, or the target movement. To reduce random errors, significant outliers are removed from each cycle; preferably, the maximum and minimum values ​​are removed before calculating the average.

[0060] The forefoot propulsion zone can be divided according to the anatomical location of the foot or the structure of the shoe sole. Each partition. For example, The values ​​can range from 4 to 8, specifically divided into the first metatarsal region, the second to third metatarsal regions, the fourth to fifth metatarsal regions, the medial toe root region, and the lateral toe root region. The heel region can be divided into the central heel region, the medial heel region, and the lateral heel region. In this embodiment, to facilitate parameter mapping, the impact pressure of each heel region can be combined into a normalized heel impact pressure value. .

[0061] No. Normalized vertical pressure value of each forefoot propulsion zone It can be calculated using the following formula:

[0062] ;

[0063] In the formula, For the first Normalized vertical pressure values ​​for each forefoot propulsion zone; For the first The average vertical pressure of each forefoot propulsion zone after removing the maximum and minimum values ​​over multiple gait cycles; For the first The average vertical pressure of each forefoot propulsion zone after removing the maximum and minimum values ​​over multiple gait cycles; The number of zones in the forefoot propulsion zone; , All are partition numbers.

[0064] Shear direction vector can be used express, The size is , The direction is The direction of shearing. The shearing direction vector can be determined by the following formula:

[0065] ;

[0066] In the formula, For the first The shear direction vector of the forefoot propulsion zone; For the first The tangential force vector of the forefoot propulsion zone during the push-off phase; For the first Vertical force of the forefoot propulsion zone during the push-off phase; To prevent the correction factor from being zero in the denominator, it can be taken as 0.001N to 0.1N, or as a positive number corresponding to the minimum resolution of the sensor.

[0067] Followed by normalized impact pressure value It can be determined based on the peak impact pressure or impact integral value of the following region during the landing phase. As one possible implementation method, Calculate using the following formula:

[0068] ;

[0069] In the formula, This is the normalized shock pressure value for the following regions; This refers to the peak vertical impact pressure in the following region during the landing phase; This represents the average vertical pressure across multiple zones in the forefoot propulsion area.

[0070] in, This can be further expressed as:

[0071] ;

[0072] In the formula, The average vertical pressure in the forefoot propulsion zone; The number of zones for the forefoot propulsion area; For the first Stable average vertical pressure in each forefoot propulsion zone.

[0073] After the above processing, a plantar pressure zone matrix is ​​formed:

[0074] ;

[0075] In the formula, Plantar pressure zone matrix; For the first Normalized vertical pressure values ​​for each forefoot propulsion zone; For the first The shear direction component of the forefoot propulsion zone, its direction is determined by... It indicates that the size is determined by express; This is the normalized shock pressure value for the following regions.

[0076] 2. S2: Determination of forefoot support point parameters and support pattern

[0077] like Figure 2 As shown, in step S2, according to Determine the projected area and height of the forefoot support point, and in When the shearing threshold is exceeded, vertical supports are formed, and the extension direction of the vertical supports is aligned with... The directional angle is no greater than 25°.

[0078] No. The total projected area of ​​the support points within the forefoot propulsion zone It can be determined by the following formula:

[0079] ;

[0080] In the formula, For the first The total projected area of ​​the support points within the forefoot propulsion zone; The minimum support projection area can be determined based on shoe size and forefoot area. To provide the maximum supporting projected area; For the first Normalized vertical pressure values ​​for each forefoot propulsion zone; This is the area response index, with values ​​ranging from 0.6 to 1.8. When... When the value is less than 1, even areas with lower pressure can obtain a certain support area; when When the value is greater than 1, the support area of ​​the high-pressure zone increases more significantly.

[0081] support point height It can be determined by the following formula:

[0082] ;

[0083] In the formula, For the first The height of the support point within the forefoot propulsion zone; Minimum support height; Maximum support height; For the first Normalized vertical pressure values ​​for each forefoot propulsion zone; For the first The shear direction component of the forefoot propulsion zone; The magnitude of the shear direction component; This is the vertical pressure weighting coefficient; These are the weighting coefficients for the shear component; and For regular flat shoes or low-heeled shoes, the forefoot primarily bears vertical pressure. A value of 0.60 to 0.70 is acceptable. A value of 0.30 to 0.40 is acceptable; for shoe types with significant push-off shear or forward slip shear, A value of 0.45 to 0.60 is acceptable. A value of 0.40 to 0.55 is acceptable. For high heels, due to the simultaneous presence of high vertical pressure and forward slip shear tendency in the forefoot metatarsal region, a value of 0.40 to 0.55 is preferred. , In practice, A thickness of 1.5mm to 3mm is acceptable. A thickness of 4mm to 10mm is acceptable; It can be taken as 5% to 12% of the corresponding zone area. It can be taken as 20% to 45% of the corresponding zone area.

[0084] The shape of the support point according to and Determined jointly. Current palm shear direction component. Greater than the preset shear threshold At that time, vertical supports are installed in the corresponding zones. The length direction of the vertical supports is along... The directional arrangement ensures that the extension direction of the vertical supports is consistent with... Direction angle The angle should not exceed 25°, and preferably be between 0° and 15°. This structure provides support continuity along the main shear direction during push-off, reducing local lateral curling or collapse of the forefoot elastic layer.

[0085] Current palm shear direction component Not greater than and Greater than the preset vertical pressure threshold When, elliptical cylindrical supports or arc-shaped rib supports are set in the corresponding zones; when Not greater than and Not greater than At that time, cylindrical supports are set in the corresponding zones. Here, To determine the threshold of forefoot push-off shear concentration. To determine the threshold for vertical pressure concentration in the forefoot. As an example, A value of 0.12 to 0.35 is acceptable. The value can be between 0.18 and 0.30, and the specific value is determined by the test population and the purpose of the shoe sole.

[0086] Length of vertical support With width ratio 3 to 10 can be selected, height The spacing between adjacent support points can be 2mm to 8mm. The thickness can range from 3mm to 15mm. The vertical supports can be entirely formed of high-elastic polyether material, or a rigid core can be formed on a rigid substrate and then covered with high-elastic polyether material. Preferably, the root of the support point is correspondingly provided with an undercut locking groove, so that when the support point is subjected to shear load, the interlaminar shear tendency generated at its root can be borne by the undercut locking groove.

[0087] 3. S3: Forming of the hard bottom blank and the undercut locking groove

[0088] In step S3, a hard material is used to form the bottom blank, and an undercut locking groove corresponding to the support point is formed in the forefoot area. The depth of the undercut locking groove is determined by... and The weighted determination is made, and the reverse bearing surface of the inverted locking groove faces the direction. The opposite direction.

[0089] The rigid subsole can be fabricated using injection molding, compression molding, thermoforming, or 3D printing followed by thermosetting. Materials can include rigid TPU, glass fiber reinforced TPU, nylon reinforced TPU, rigid EVA, polypropylene, or polyamide elastomer composites. To ensure midsole support, the rigid subsole's hardness can range from 55 Shore D to 80 Shore D, and its thickness from 1.5 mm to 6 mm. For athletic shoe midsoles, the forefoot subsole thickness can be slightly less than the heel thickness to facilitate flex; for casual or work shoes, the midfoot and heel thickness can be relatively increased to improve stability.

[0090] No. The depth of the inverted locking groove corresponding to the forefoot propulsion zone It can be determined by the following formula:

[0091] ;

[0092] In the formula, For the first The depth of the inverted locking groove corresponding to the forefoot propulsion zone; Minimum locking groove depth; This is the maximum locking groove depth; For the first Normalized vertical pressure values ​​for each forefoot propulsion zone; For the first The shear direction component of the forefoot propulsion zone; The magnitude of the shear direction component; This is the vertical pressure weighting coefficient; The shear direction weighting coefficient; and For regular flat shoes or low-heeled shoes, the forefoot primarily experiences vertical pressure. A value of 0.60 to 0.70 is acceptable. A value of 0.30 to 0.40 is acceptable; for shoe types such as athletic shoes and dance shoes that exhibit significant push-off shear, A value of 0.45 to 0.60 is acceptable. A value of 0.40 to 0.55 is acceptable; for high heels, due to the simultaneous presence of high vertical pressure and a significant forward slippage shearing tendency in the forefoot area, the preferred value is... , This ensures that the depth of the inverted locking groove simultaneously provides both pressure support and shear-resistant locking. A thickness of 0.5mm to 1.5mm is acceptable. A thickness of 2.5mm to 5mm is acceptable.

[0093] Width of the undercut locking groove expansion section It can be determined by the following formula:

[0094] ;

[0095] In the formula, For the first The width of the inverted locking groove expansion section corresponding to the forefoot propulsion zone; Minimum expansion width; Maximum expansion width; For the first The shear direction component of the forefoot propulsion zone; This represents the magnitude of the shear direction component. As an example... A thickness of 0.3mm to 0.8mm is acceptable. A thickness of 1.2mm to 3mm is acceptable.

[0096] The inverted locking groove includes an inlet section, an expansion section, and a reverse bearing surface. The inlet section is located on the upper surface of the rigid substrate, facilitating the entry of the high-elastic polyether material into the groove during injection or casting. The expansion section is located below the inlet section, with a lateral width greater than that of the inlet section, thus forming an inverted structure. The reverse bearing surface is located on one or both sides of the expansion section, with the main bearing surface facing... Inclined in the opposite direction. The angle between the reverse bearing surface and the upper surface of the hard subgrade. The angle can be 35° to 75°, and preferably 45° to 65°.

[0097] 4. S4: Hollowed-out heel cavity, air cushion pre-compression and limiting assembly

[0098] like Figure 3 As shown, in step S4, a hollow heel cavity with a pre-compression limiting step is formed in the heel area of ​​the hard bottom layer. The air cushion is embedded into the hollow heel cavity, and according to... The air cushion preload is determined together with the average pressure in the forefoot propulsion zone.

[0099] The hollowed-out cavity can be integrally formed during the hard base molding process, or it can be formed after the hard base blank is formed by CNC milling, thermal cutting, or punching. The hollowed-out cavity preferably has an upper or side opening structure to facilitate air cushion insertion. The pre-compression limiting step includes an annular pressure edge located at the upper edge of the hollowed-out cavity and a support boss located at the bottom of the hollowed-out cavity. The annular pressure edge is used to limit the upward movement of the air cushion, the support boss is used to define the bottom position of the air cushion, and the lateral limiting wall is used to limit the horizontal displacement of the air cushion.

[0100] The air cushion can be made of TPU film heat-sealed air, TPE film air, or polyurethane elastic air bladder. The air cushion can contain two or more independent or semi-connected air chambers to prevent excessive localized bulging when a single air chamber is compressed. The air cushion thickness can range from 5mm to 22mm, and the initial inflation gauge pressure can range from 0.01MPa to 0.18MPa. For running shoes with high heel impact, a thicker air cushion and higher pre-compression can be used; for everyday casual shoes, a thinner air cushion and lower pre-compression can be used.

[0101] Air cushion preload It can be determined by the following formula:

[0102] ;

[0103] In the formula, The pre-compression amount after the air cushion is inserted into the hollowed-out heel cavity; This is the minimum preload; This is the maximum preload. This is the normalized shock pressure value for the following regions; Normalized vertical pressure values ​​for each part of the forefoot propulsion zone The average value.

[0104] in, It can be determined by the following formula:

[0105] ;

[0106] In the formula, The average normalized vertical pressure value of the forefoot propulsion zone; For the first Normalized vertical pressure values ​​for each forefoot propulsion zone; This refers to the number of zones in the forefoot propulsion zone.

[0107] When the impact pressure of the heel When the average forefoot pressure is relatively low and the heel pressure is relatively high, the air cushion preload should be increased to ensure effective support from the initial impact point. Conversely, when the average forefoot pressure is high, it indicates a strong need for overall propulsion support. In this case, excessive preload of the heel air cushion should be avoided to prevent a significant difference in stiffness between the forefoot and heel. Therefore, the air cushion preload should be determined jointly by heel impact and forefoot propulsion support, rather than solely based on experience.

[0108] The dimensions of the preload limiting step can be determined according to Determined. For example, if the free height of the air cushion is... The effective height between the annular pressure edge inside the hollow cavity and the supporting boss. It can be determined by the following formula:

[0109] ;

[0110] In the formula, The effective height for holding the air cushion in the hollowed-out cavity; This refers to the free height of the air cushion in its unassembled state. This is the pre-compression amount of the air cushion.

[0111] The maximum horizontal displacement of the air cushion relative to the hollow heel cavity under heel pressure. The gap should not exceed 1.5mm. This can be achieved by reducing the gap between the outer periphery of the air cushion and the lateral limiting wall, setting an annular pressure edge, or setting a positioning flange on the outer periphery of the air cushion. The assembly gap between the outer periphery of the air cushion and the side wall of the hollow heel cavity can be from 0.2mm to 1.5mm.

[0112] 5. S5: High-elastic polyether material injection, locking filling and integrated curing

[0113] In step S5, a high-elastic polyether material is injected above the bottom blank, so that the high-elastic polyether material enters the inverted locking groove and covers the root of the support point, and is cured to form a high-elastic polyether upper layer that is mechanically locked with the rigid bottom layer.

[0114] The preferred high-elasticity polyether material is a polyether-type polyurethane microporous elastomer. It can be composed of polyether polyol, isocyanate, chain extender, foaming agent, catalyst, and foam stabilizer; it can also be formed by compression molding of polyether-type TPU foam particles. The hardness of the high-elasticity polyether material can be from 35 Asker C to 55 Asker C, the resilience rate is not less than 55%, and the apparent density after foaming can be from 0.12 g / cm³ to 0.45 g / cm³. These parameters can be adjusted according to the intended use in footwear.

[0115] Before injecting the high-elasticity polyether material, it is preferable to perform surface activation treatment on the upper surface of the rigid substrate and the inner wall of the inverted locking groove. Surface activation can be performed using plasma treatment, flame treatment, corona treatment, roughening treatment, or primer treatment. The purpose of surface activation is to improve the interfacial bonding ability between the high-elasticity polyether material and the rigid substrate. For rigid TPU substrates, plasma treatment for 10 to 60 seconds can be used; for polypropylene materials, corona treatment can be performed first, followed by coating with a polyurethane primer.

[0116] High-elastic polyether materials can be molded through casting foaming, secondary injection, in-mold foaming, or hot-press foaming. The specific steps are as follows: place the rigid bottom blank and air cushion pre-assembled part in the midsole molding mold, with the undercut locking groove opening facing the mold cavity; inject the mixed high-elastic polyether reactant into the mold cavity; under injection pressure or self-flowing action, the high-elastic polyether material enters the inlet and expansion sections of the undercut locking groove and covers the root of the support point; then cure at 35℃ to 90℃ for 3 to 30 minutes; after demolding, trimming, post-curing, and dimensional inspection are performed.

[0117] To ensure the inverted locking groove functions effectively, the filling rate of the high-elastic polyether material within the inverted locking groove must be... The filling rate should be no less than 85%, preferably no less than 90%. The filling rate can be determined using the following formula:

[0118] ;

[0119] In the formula, For the first The filling rate of high-elastic polyether material in the inverted locking groove; To proceed to the next stage after curing The volume of high-elastic polyether material within the inverted locking groove; For the first The volume of the inverted locking groove cavity.

[0120] when When the viscosity is below 85%, it can be corrected by increasing the injection pressure, reducing the initial viscosity of the reactant, adding venting grooves, or increasing the width of the inlet section. To facilitate venting, a micro-venting groove can be provided on the side of the inverted locking groove away from the inlet section. The width of the venting groove can be 0.05mm to 0.2mm, and the depth can be 0.02mm to 0.1mm.

[0121] After the high-elastic polyether upper layer is molded, its upper surface can form a flat foot contact surface, or it can form a micro-protrusion or flexible covering layer corresponding to the support point in the forefoot area. The base of the support point is locked by an inverted locking groove, and the upper part is covered by the high-elastic polyether upper layer, so that the forefoot support does not form a hard abrupt feeling, while maintaining the directionality of the support.

[0122] 6. Molding feedback verification and manufacturing parameter correction

[0123] like Figure 4 As shown, after step S5, further molding feedback verification can be performed.

[0124] After molding, the midsole underwent forefoot shear displacement testing, interlayer peel strength testing, and heel impact peak testing to obtain the forefoot shear displacement. interlayer peel strength and heel impact peak The testing method can be as follows:

[0125] Forefoot shear displacement test: The forefoot area of ​​the midsole was fixed on a fixture, and an application was made along the high-elastic polyether upper layer. A horizontal shear load is applied in the direction of the substrate, and the maximum displacement of the upper layer relative to the rigid lower layer is measured and denoted as . .

[0126] Interlayer peel strength test: Standard samples were cut along the forefoot area or arch transition zone. The peel strength between the high-elastic polyether upper layer and the rigid underlayer was determined using a 180° peel or T-shaped peel method, and recorded as _____. .

[0127] Heel impact peak test: Using a drop hammer impact test or sole cushioning impact test, a specified mass impact head is dropped from a specified height onto the heel area, and the peak acceleration or peak impact force is measured and recorded as follows. .

[0128] when greater than the preset displacement threshold If the forefoot shear locking is insufficient, the depth of the inverted locking groove in the corresponding forefoot propulsion zone can be increased. Or deflect the width ;when Less than the preset peel strength threshold If the interlayer bonding is insufficient, the filling rate of the undercut locking groove can be improved. , Add surface activation treatment or adjust the primer; when Greater than the preset impact threshold If the heel cushioning is insufficient, the preload of the air cushion can be increased. Adjust the air cushion inflation pressure or increase the limiting contact area inside the hollow heel cavity.

[0129] in, This represents the relative displacement of the forefoot after shearing. The peel strength between the high-elastic polyether top layer and the rigid bottom layer; The peak acceleration or peak impact force in the heel impact test; The permissible forefoot shear displacement threshold; The minimum permissible interlayer peel strength threshold; The maximum allowable peak heel impact threshold.

[0130] III. Specific application examples and experimental data:

[0131] To verify the applicability of the comfortable high-elasticity midsole manufacturing process described in this invention to high heels, test samples were prepared using size 38 women's high heels. Unlike ordinary athletic shoes, high heels raise the heel, significantly shifting the body's load towards the forefoot. The metatarsal area of ​​the forefoot bears high vertical pressure for extended periods. Simultaneously, the heel elevation creates a tendency for the foot to slide forward, generating significant tangential shear forces in the forefoot propulsion area and toe root area. This can easily lead to forefoot pain, forward foot slippage, displacement between the soft midsole layers, and unstable heel support. Therefore, this application example focuses on verifying the technical effects of this invention in distributing forefoot pressure, resisting forefoot forward slippage shear, preventing peeling between the soft and hard layers, and providing small-area cushioning and restraint in the heel of high heels.

[0132] 1. Sample preparation

[0133] This application example uses a women's high-heeled shoe with a heel height of 70mm and a forefoot platform thickness of 8mm as the test shoe model. The midsole consists of a rigid bottom layer, a high-elastic polyether top layer, a forefoot irregular support array, and a hollow air cushion structure in the heel. The rigid bottom layer is made of rigid TPU injection molding with a hardness of 68 Shore D, a thickness of 2.2mm in the forefoot area, 3.0mm in the arch transition area, and 4.0mm in the heel support area. The high-elastic polyether top layer is formed by casting and foaming of polyether-type polyurethane microporous elastomer with a hardness of 42 Asker C, an apparent density of 0.26g / cm³, and a rebound rate of 64%.

[0134] For comparison, the following samples were prepared:

[0135] Comparative Example 1 is a regular high-heeled shoe midsole, made of a single layer of EVA foam material, without a hard bottom layer, forefoot irregular support array, inverted locking groove and heel air cushion.

[0136] Comparative Example 2 is a typical double-layer high-heeled shoe midsole, consisting of a hard TPU bottom layer and a high-elastic polyether top layer. However, the forefoot support points are all equally spaced cylindrical supports. The area, height, and direction of the support points are not determined according to the foot pressure zoning matrix, and no inverted locking groove is set.

[0137] Comparative Example 3 is a high-heeled shoe midsole with a forefoot support point and a heel air cushion. The forefoot support point includes cylindrical support and strip support, but the direction of the strip support is uniformly set along the longitudinal direction of the sole. The heel air cushion is fixedly embedded in the heel cavity, and the pre-compression amount is not determined based on the heel impact pressure and the average pressure of the forefoot.

[0138] Comparative Example 4 is a high-heeled shoe midsole with an inverted buckle groove and a heel air cushion, but the depth of the inverted buckle groove is uniformly 1.3mm, the reverse bearing surface is not set according to the forefoot shear direction, and the pre-compression amount of the heel air cushion is fixed at 1.0mm.

[0139] Example 1 is a high-heeled shoe midsole manufactured using the complete process of the present invention. Its forefoot support point, inverted locking groove, and heel air cushion pre-pressure amount are all determined by the same foot pressure zoning matrix.

[0140] 2. Generation of the foot pressure matrix of high heels

[0141] Ten female participants, all wearing shoe sizes 37 to 38 and weighing between 48 kg and 62 kg, were selected. Wearing 70mm high heels with identical lasts, they performed standing and slow-walking tests on a flat indoor surface. Foot pressure data were collected using insole-type pressure sensors and a tangential force measurement module. Five stable gait cycles were collected for each participant, and obviously abnormal data were discarded.

[0142] Because high heels concentrate pressure on the forefoot, this application example divides the forefoot propulsion zone into six areas: the first metatarsal zone, the second metatarsal zone, the third metatarsal zone, the fourth and fifth metatarsal zones, the medial toe root zone, and the lateral toe root zone. The heel area is divided into the central heel support zone and the peripheral heel stability zone, and these are combined to form a normalized heel impact pressure value. .

[0143] No. Normalized vertical pressure value of each forefoot propulsion zone Determine by the following formula:

[0144] ;

[0145] In the formula, For the first Normalized vertical pressure values ​​for each forefoot propulsion zone; For the first The average vertical pressure of each forefoot propulsion zone after removing the maximum and minimum values ​​over multiple gait cycles; For the first The average vertical pressure of each forefoot propulsion zone after removing the maximum and minimum values ​​over multiple gait cycles; To determine the number of zones for the forefoot propulsion area, in this application example... ; , All are partition numbers.

[0146] In high heels, the forefoot shear direction is mainly characterized by the tendency of the foot to slide towards the forefoot relative to the shoe cavity. Therefore, the shear direction vector... Determine by the following formula:

[0147] ;

[0148] In the formula, For the first The shear direction vector of the forefoot propulsion zone; For the first The tangential force vector of each forefoot propulsion zone during the standing or walking forward glide phase; For the first Vertical force of the forefoot propulsion zone; To prevent the correction factor from being zero in the denominator, it is set to 0.01N in this application example; The direction is direction, The size is .

[0149] The main parameters obtained in Example 1 are shown in Table 1.

[0150] Table 1. Forefoot Pressure Matrix and Support of High Heels

[0151]

[0152] Among them, the supporting area Determine by the following formula:

[0153] ;

[0154] In the formula, For the first The total projected area of ​​the support points within the forefoot propulsion zone; To minimize the projected area, a value of 22 mm² is used in this application example; To maximize the supported projected area, 82 mm² is used in this application example; For the first Normalized vertical pressure values ​​for each forefoot propulsion zone; This is the area response index, which is set to 1.15 in this application example.

[0155] Support height Determine by the following formula:

[0156] ;

[0157] In the formula, For the first The height of the support point within the forefoot propulsion zone; The minimum support height is set at 1.8mm in this application example; For the maximum support height, 6.8mm is used in this application example; This is the vertical pressure weighting coefficient, which is set to 0.55 in this application example; This is the weighting coefficient for the shear component; in this application example, it is set to 0.45. For the first Normalized vertical pressure values ​​for each forefoot propulsion zone; For the first The magnitude of the shear direction component of the forefoot propulsion zone.

[0158] Inverted locking groove depth Determine by the following formula:

[0159] ;

[0160] In the formula, For the first The depth of the inverted locking groove corresponding to the forefoot propulsion zone; The minimum locking groove depth is 0.7mm in this application example; The maximum locking groove depth is 3.6mm in this application example; This is the vertical pressure weighting coefficient, which is set to 0.50 in this application example; This is the shear direction weighting coefficient, which is set to 0.50 in this application example; For the first Normalized vertical pressure values ​​for each forefoot propulsion zone; For the first The magnitude of the shear direction component of the forefoot propulsion zone.

[0161] For the first metatarsal region, the second metatarsal region, and the third metatarsal region, due to All are greater than the preset shear threshold This application example sets up vertical supports and aligns the extension direction of the vertical supports with the corresponding... The directional angle is 8° to 18°, and not greater than 25°.

[0162] 3. Determine the pre-compression amount of the heel air cushion.

[0163] High heels have a small impact area at the heel, and due to their height, the heel support area needs to balance cushioning and stability. In this application example, the normalized impact pressure value of the heel area is... The average pressure in the forefoot propulsion zone is 0.48. It is 0.167. Air cushion preload. Determine by the following formula:

[0164] ;

[0165] In the formula, The pre-compression amount after the air cushion is inserted into the hollowed-out heel cavity; The minimum preload is 0.8 mm in this application example; The maximum preload is 3.0 mm in this application example; This is the normalized shock pressure value for the following regions; Normalized vertical pressure values ​​for each part of the forefoot propulsion zone The average value.

[0166] Calculations show that the air cushion preload in Example 1... It is 2.38mm. Air cushion free height. The effective height between the annular pressure edge inside the hollowed-out cavity and the bottom support boss is 8.0mm. The diameter is 5.62mm. The heel air cushion uses a TPU film heat-sealed air cushion with two semi-connected air chambers inside. The outer perimeter of the air cushion is held by an annular pressing edge and a support boss, with a lateral assembly gap of 0.6mm.

[0167] 3. Experimental testing methods

[0168] 1) Peak pressure test for the forefoot

[0169] Test subjects wore high heels with different midsoles and walked 10m at a natural pace on a pressure test treadmill, recording the peak pressure in the forefoot metatarsal region.

[0170] 2) Forefoot forward sliding shear displacement test

[0171] The high heels were fixed on a simulated high-heel standing platform with an inclination angle of 18°. A vertical load of 500N was applied to the standard foot last inside the shoe cavity, and the displacement of the upper layer of high-elastic polyether in the forefoot relative to the rigid bottom layer in the forward sliding direction was recorded. .

[0172] 3) Interlayer peel strength test

[0173] A 20mm wide midsole sample was cut near the second metatarsal region of the forefoot, and the peel strength between the high-elastic polyether upper layer and the hard bottom layer was measured using a 180° peel method. .

[0174] 4) Peak heel impact test

[0175] Using a high-heeled shoe heel impact simulation device, the sole assembly with the midsole was mounted on an inclined support, and a 6kg impact head was dropped from a height of 40mm to measure the peak acceleration of the heel support area. .

[0176] 5) Air cushion horizontal offset test

[0177] A cyclic compressive load of 50N to 500N is applied to the heel support area at a frequency of 2Hz. After 10,000 cycles, the maximum horizontal displacement of the air cushion relative to the hollow heel cavity is measured. .

[0178] 6) Subjective comfort rating

[0179] After walking indoors for 30 minutes wearing the sample shoes, testers rated the forefoot pressure, forefoot slippage, heel cushioning, and overall stability on a scale of 1 to 10, with higher scores indicating a better experience. This subjective rating is for illustrative purposes only and should not be considered the sole basis for assessing the technical performance.

[0180] 5. Experimental Results

[0181] Table 2. Results of forefoot pressure and anti-slip shear test on high heels

[0182]

[0183] From Table 2 and Figure 5As shown in Figure 6, Comparative Example 1, with its ordinary single-layer EVA midsole, exhibits a peak forefoot pressure of 462 kPa and a forefoot forward slip shear displacement of 2.16 mm, indicating deficiencies in both forefoot pressure concentration and forefoot slippage in high heels. Comparative Example 2, while employing a double-layer structure and ordinary cylindrical support, suffers from insufficient support points... and The zoned design limits the forefoot pressure distribution. Comparative Example 3 uses a standard strip support and heel air cushion, but the strip support's direction is fixed and doesn't match the actual shear direction, resulting in a forward sliding shear displacement of 1.21mm. Comparative Example 4, while featuring an undersnap groove, doesn't match the groove's depth or the direction of the reverse bearing surface. It was determined that its shear resistance was weaker than that of Example 1. In Example 1, the peak forefoot pressure was reduced to 342 kPa, the forefoot forward slip shear displacement was reduced to 0.52 mm, and the interlayer peel strength was increased to 2.61 N / mm, indicating that the present invention can effectively improve the problems of forefoot pressure concentration and forward slip displacement of the high-elastic polyether layer in high heels.

[0184] Table 3. Test results of heel cushioning, air cushion stability, and wearing performance of high heels.

[0185]

[0186] As shown in Table 3, although Comparative Example 3 included a rear air cushion, the air cushion's horizontal displacement reached 1.84 mm after cyclic loading due to the lack of pre-compression calculation and insufficient limiting structure. Comparative Example 4, using fixed pre-compression and a standard limiting structure, reduced the air cushion displacement somewhat, but still less than Example 1. In Example 1, the air cushion pre-compression amount was... and Through joint analysis and by using annular pressing edges and support bosses for limiting, the peak heel impact was reduced to 7.1g, and the horizontal offset of the air cushion was reduced to 0.58mm. Wearing rating results also showed that Example 1 was superior to all the other pairs in terms of overall comfort and control of forward slippage.

[0187] Table 4 Results of the midsole cycle durability test for high heels

[0188]

[0189] As shown in Table 4, high-heeled shoe midsoles are prone to forefoot collapse and rebound attenuation after prolonged pressure. In Example 1, because the high-elastic polyether material enters the inverted locking groove and forms a reverse wedge-shaped locking body, and the height and area of ​​the forefoot support point are determined by the plantar pressure matrix, the rebound retention rate after cycling reaches 90.4%, the compression set rate is 8.7%, and the forefoot support height attenuation is only 0.23 mm, which is superior to the comparative examples.

[0190] The foregoing description of embodiments of the present invention, through which those skilled in the art are able to implement or use the present invention, will be readily apparent to those skilled in the art. Various modifications to these embodiments will be readily apparent to those skilled in the art. The general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novelty disclosed herein.

Claims

1. A manufacturing process for a comfortable and highly elastic shoe sole midsole, characterized in that, The steps include: S1: Collect pressure data of the forefoot propulsion zone and heel area of ​​the foot, and generate a plantar pressure zone matrix. ,in, For the first Normalized vertical pressure value of each forefoot propulsion zone For the first The shear direction component of the forefoot propulsion zone S2: Based on the normalized shock pressure value of the following region; Determine the projected area and height of the forefoot support point, and in When the shearing threshold is exceeded, vertical supports are formed, and the extension direction of the vertical supports is aligned with... The directional angle is no greater than 25°; S3: The bottom blank is formed using a hard material, and an undercut locking groove corresponding to the support point is formed in the forefoot area. The depth of the undercut locking groove is determined by... and The weighted determination is made, and the reverse bearing surface of the inverted locking groove faces the direction. In the opposite direction; S4: A hollow heel cavity with a pre-compression limiting step is formed in the heel area, the air cushion is embedded in the hollow heel cavity, and according to The air cushion preload is determined together with the average pressure in the forefoot propulsion area; S5: High-elastic polyether material is injected above the bottom blank, so that the high-elastic polyether material enters the inverted locking groove and covers the root of the support point, and is cured to form a high-elastic polyether upper layer that is mechanically locked with the hard bottom layer.

2. The manufacturing process of the shoe sole midsole according to claim 1, characterized in that, In step S1, the shear direction component Using shear direction vector It means that the By the The tangential force vector of the forefoot propulsion zone during the push-off phase with vertical force Normalization yields the following, which satisfies: ； In the formula, For the first The shear direction vector of the forefoot propulsion zone. For the first The tangential force vector of the forefoot propulsion zone For the first The vertical force of the forefoot propulsion zone To prevent the correction factor from being zero in the denominator; the The direction is The direction, the The size is .

3. The manufacturing process of the shoe sole midsole according to claim 1, characterized in that, In step S1, plantar pressure data are collected over at least three gait cycles, and the vertical pressure of each forefoot propulsion zone is stabilized to obtain... It satisfies: ； In the formula, For the first Normalized vertical pressure value of each forefoot propulsion zone For the first The average vertical pressure of each forefoot propulsion zone after removing the maximum and minimum values ​​over multiple gait cycles. For the first The average vertical pressure of each forefoot propulsion zone after removing the maximum and minimum values ​​over multiple gait cycles. The number of zones in the forefoot thrust zone. , All are partition numbers.

4. The manufacturing process of the shoe sole midsole according to claim 1, characterized in that, In step S2, the first The projected area of ​​the support point within the forefoot propulsion zone and height Determine them respectively using the following formulas: ； ； In the formula, For the first The total projected area of ​​the support points within the forefoot propulsion zone. To minimize the projected area of ​​the support, To maximize the supported projected area, For the first Normalized vertical pressure value of each forefoot propulsion zone The area response index ranges from 0.6 to 1.

8. For the first The height of the support point within the forefoot propulsion zone. Minimum support height, For maximum support height, For the first The shear direction component of the forefoot propulsion zone This is the vertical pressure weighting coefficient. Here are the weighting coefficients for the shear component, and .

5. The manufacturing process of the shoe sole midsole according to claim 1, characterized in that, In step S2, the current palm shear direction component Greater than the preset shear threshold At that time, vertical supports are set in the corresponding forefoot propulsion zone; when Not greater than and Greater than the preset vertical pressure threshold At that time, elliptical cylindrical supports or arc-shaped rib supports are set in the corresponding forefoot propulsion zone; when Not greater than and Not greater than At that time, cylindrical supports are set within the corresponding forefoot propulsion zone; among which, To determine the threshold of forefoot push-off shear concentration. To determine the threshold for vertical pressure concentration in the forefoot.

6. The manufacturing process of the shoe sole midsole according to claim 1, characterized in that, In step S3, the first The depth of the inverted locking groove corresponding to the forefoot propulsion zone and inverted expansion width Determine them respectively using the following formulas: ； ； In the formula, For the first The depth of the inverted locking groove corresponding to each forefoot propulsion zone. Minimum locking groove depth, For the maximum locking groove depth, For the first Normalized vertical pressure value of each forefoot propulsion zone For the first The shear direction component of the forefoot propulsion zone This is the vertical pressure weighting coefficient. Here is the shear direction weighting coefficient, and ; For the first The width of the inverted locking groove expansion section corresponding to the forefoot propulsion zone. To minimize the expansion width, This represents the maximum expansion width.

7. The manufacturing process of the shoe sole midsole according to claim 1, characterized in that, In step S3, the inverted locking groove includes an inlet section, an expansion section, and a reverse bearing surface. The inlet section is located on the upper surface of the rigid substrate, the expansion section is located below the inlet section, and the reverse bearing surface is at an angle relative to the upper surface of the rigid substrate. The angle is 35° to 75°, and the inclination direction of the reverse bearing surface is the same as... The directions are opposite; after the high-elastic polyether material is cured, a reverse wedge-shaped locking body is formed in the inverted locking groove, and the filling rate of the reverse wedge-shaped locking body is... Not less than 85%, which satisfies: ； In the formula, For the first The filling rate of the high-elastic polyether material in the inverted locking groove. To proceed to the next stage after curing The volume of high-elastic polyether material within the inverted locking groove. For the first The volume of the cavity of the inverted locking groove. For the first The inclination angle of the reverse bearing surface of the inverted locking groove.

8. The manufacturing process of the shoe sole midsole according to claim 1, characterized in that, In step S4, the air cushion pre-compression amount Determine by the following formula: ； In the formula, This refers to the pre-compression amount after the air cushion is inserted into the hollowed-out heel cavity. For minimum preload, For maximum preload, The normalized shock pressure value of the following region, Normalized vertical pressure values ​​for each part of the forefoot propulsion zone The average value; the pre-compression limiting step includes an annular pressure edge located at the upper edge of the hollow heel cavity and a support boss located at the bottom of the hollow heel cavity. The outer periphery of the air cushion is restricted between the annular pressure edge and the support boss, so that the maximum horizontal displacement of the air cushion relative to the hollow heel cavity under the pressure state of the heel. Not greater than 1.5mm, of which, This represents the maximum horizontal displacement of the air cushion after it is compressed.

9. The manufacturing process of the shoe sole midsole according to claim 1, characterized in that, Following step S5, a molding feedback verification step is also included: performing forefoot shear displacement testing, interlayer peel strength testing, and heel impact peak testing on the cured midsole to obtain the forefoot shear displacement. interlayer peel strength and heel impact peak ;when greater than the preset displacement threshold At the same time, increase the depth of the inverted locking groove of the corresponding forefoot propulsion zone. Or deflect the width ;when Less than the preset peel strength threshold At the same time, increase the filling rate of the undercut locking groove. Or add surface activation treatment; when Greater than the preset impact threshold At the same time, increase the air cushion preload. Or increase the limiting contact area inside the hollow cavity.

10. A comfortable, highly elastic shoe sole midsole, characterized in that, The shoe sole is manufactured using the manufacturing process described in any one of claims 1 to 9. The shoe sole includes a rigid bottom layer, a high-elastic polyether top layer, a forefoot irregular support array, and a heel air cushion. The forefoot irregular support array includes at least three of the following: vertical support, elliptical cylinder support, arc-shaped rib support, and cylindrical support. The angle between the extension direction of the vertical support and the shear direction of the corresponding forefoot propulsion zone is no greater than 25°. The rigid bottom layer has an inverted locking groove corresponding to the forefoot irregular support array. The inverted locking groove is filled with a reverse wedge-shaped locking body formed by curing high-elastic polyether material, and the reverse bearing surface of the inverted locking groove faces the opposite direction of the shear direction. The heel air cushion is embedded in a hollow heel cavity with a pre-pressing limiting step, and the outer periphery of the air cushion is limited by an annular pressing edge and a support boss.

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