JPS5829922Y2 - Insole for shoes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in shoe insole made of synthetic resin foam.

More specifically, the object is to provide a shoe insole that is lightweight and comfortable to wear.

Conventionally, some common shoe insoles made of synthetic resin foam are simply made to fit the shape of the shoe.

Since the compressive strength of this insole is the same in all parts, it cannot provide cushioning that corresponds to the degree of load applied to the toes, heel, and tread area. It had the drawbacks of being uncomfortable to wear, such as being too stiff at the tip of the toe.

To overcome this drawback, there are insoles made of composite materials with different compression properties.

This composite insole has extremely poor workability because it involves processing such as adhesion, and also has disadvantages such as increased costs due to the adhesive and increased weight of the insole due to the adhesive.

In addition, the polyurethane and rubber foam shoe insole disclosed in Japanese Utility Model Publication No. 142033/1977 is integrally shaped to fit the shape of the foot, and the insole is finished to match the amount of force applied during use. However, unfortunately, the polyurethane and rubber foams used as materials originally have low compressive strength, which causes them to bottom out, and strong compressive strength is required in areas such as the heel and front stepping areas. This requires a considerable amount of compression during molding, but it is technically difficult to achieve such a large compression rate with these materials.

Insoles that have improved on these points are made by laminating some molded parts molded in a separate process on top of some molded parts molded in a separate process to fit the shape of the foot. Although efforts have been made to do so, there have been disadvantages such as a reduction in cutting speed, increased cost of the adhesive, and increased weight due to the adhesive.

In addition, foams such as urethane and rubber require crosslinking agents, foaming agents,
Since other chemical additives are used, the decomposition products and residues of these agents remain on the molded insole, causing discomfort due to odor, and may even cause skin problems for some people. There is a drawback that users dislike it because it causes problems.

Separately, insoles made of open-cell materials such as urethane have water-absorbing properties, so sweat can soak in, leading to stuffiness, mold, and discomfort. .

Furthermore, since urethane and the like deteriorate quickly through oxidation, there is also a problem in durability.

In consideration of these shortcomings, we have developed the characteristics required for shoe insoles, such as compressive strength and recovery properties of each part that corresponds to the shape of the foot and stress on the foot, lightweight, and no unpleasant sensations such as odor. There was a strong demand for a shoe insole that could be more easily molded than a single piece of foam board and that could ensure a well-balanced combination of properties such as compatibility and non-irritation to the skin.

The insole of the present invention improves these conventional drawbacks and provides an insole that fully satisfies the above-mentioned required characteristics.

The content of the present invention will be explained in detail below using drawings and the like.

Figure 1 is a plan view of the insole for the right foot, viewed from below.
From the figure, FIG. 8 shows AA and BB in FIG.

Each cross-sectional view taken along line CC and line D-D is shown.

FIG. 4 shows a cross-sectional view taken along the line E--E of FIG. 2 as seen from the upper surface of the shoe midsole, and shows that the cross section is not flat as a whole.

FIG. 3 shows a side perspective view of the shoe insole.

Reference numerals 1, 2, and 3.4 indicate the heel part, the treading part, and the toe part, respectively, 5 and 6 indicate the outer peripheral wall part, 7 indicates the top edge of the outer peripheral wall part, and 8 and 9 indicate the top edge of the outer peripheral wall part. It shows a place where the top edge 7 is cut off near the front treading part 3, and the treading part layer edges 8', 9'
are formed at approximately the same height.

Further, there is no problem even if the top edge 7 is connected at the earth-shaft side g// and 9//.

The content of the present invention is that (a) a non-crosslinked PE system is selected as the foam board material, and (b) each part of the midsole of the shoe is made of non-crosslinked PE that occurs after pressing at different compression ratios. (c) Each of the characteristic values of each part of the shoe midsole satisfies the conditions for a lightweight and comfortable shoe midsole; It is completed by the combination of (a), (b), and (c) above.

The reasons for this will be explained in detail below.

First, the upper part (a) will be explained based on Table 1.

Table 1 shows the density of various foam boards and the compressive strength (kg) when the foam board is compressed (25% strain, 50% strain, 75% strain).
/cm2) is an experimental result table showing the relationship between

No. is the type of foam board, ■~■ is a non-crosslinked foamed polyethylene board, ■~■ is a crosslinked foamed polyethylene board, ■ is rubber foam, [phase], ◎ is two types of soft urethane foam, and O is vinyl chloride foam. .

Moreover, each of ■ to ■, ■', and ■ is a foam board made by compressing (increasing the density) the foam boards of ■ and ■.

The meaning of Table 1 is that, for example, when looking at the compressive strength at 25% strain, the improvement in compressive strength of non-crosslinked foamed polyethylene plates that occurs when the compression changes from ■ to ■ (i.e., a 5-fold change in density) is , from 0.7 to 5.2 (i.e., 7.4 times), whereas in the case of the cross-linked foamed polyethylene board, this occurs due to the compression change from ■ to ■ (i.e., a 4 times density change). The improvement in compressive strength is only 0.6 to 1.8 (i.e. 3 times);
Even as an absolute value, this means that at a density of 200 kg/m3, a compressive strength that is less than that of a non-crosslinked product can be obtained.

Furthermore, in the case of the other foamed boards (G) and (3), considering the original density and its compressive strength values, this means that it is unlikely that the compressive strength can be improved by changing the compression.

In other words, according to the results in Table 1, the preferred foam board material to be used in the insole of the present invention, which has sections with different compression ratios, is a non-crosslinked foamed polyethylene board; This shows that it can be adopted as a lightweight shoe insole.

Next, the above (b) will be explained based on FIG. 14.

Fig. 14 is a graph showing the relationship between compressive strength and compressive strain of ■ to ■ explained in Table 1, with compressive strength on the vertical axis,
The amount of compressive strain of the material is plotted on the horizontal axis.

Also, for ease of explanation, 25% and 50% of the horizontal axis
, insert a vertical line at the position of 75% strain.

Here, the meaning of 25% compressive strain is that 25% of the deformation applied to the material has occurred, and it is said that it is best used within the range that gives this degree of deformation, and 50% A compressive strain of 75% means a range in which cushioning properties can be obtained without bottoming out even if more stress is applied, and a compressive strain of 75% represents a dangerous compressive strain where the eaves phenomenon begins to occur.

On the other hand, one of the meanings of the foam board density and 25% compressive strength of each part of the shoe insole, which are described as the constituent requirements of the present invention, is that the foam board that makes up the material has different compression changes in each part. This means that it is given.

That is, for example, if we take an example of the heel part where the compression changes the most and the foot tread part where the compression change the least, then ■ and ■ in Figure 14.
The density and compressive strength of the heel at 25% strain of the curves ,■,■ are approximately 135 to 2'OOkg/m3.
．． 2 kg/cm2) and the same upper and lower treads (approximately 40 to 65
kg/m3. Approximately 0.7 1.3 kg/crn2) means that a foam board with a density of 40 kg/m3 has a heel area of approximately 3.4 kg/m3.
It is shown that it is press-molded to ~5 times the density (■~■), and the soil tread part is press-molded to a density that is about 1 to 1.6 times (■~■).

Next, we will discuss the necessity of (b) and (c) above.

That is, most of the parts of the insole of the present invention utilize the characteristics that the non-crosslinked foamed polyethylene board exhibits after being compressed and deformed.

In relation to Figure 14, firstly, the need for a 25% compressive strength (kg/cm2) of approximately 3.8 to 5.2 at the center of the heel bottom of the present invention is the highest weight load (including exercise load).
Indicates that it has sufficient compressive strength to support.

In other words, the characteristics of the center of the heel bottom shown by the intersection of the curves ■ and ■ with the vertical line of 25% strain in Figure 14 change along the curves ■ and ■, so even when the maximum weight is loaded, the bottom will not reach the bottom. 75% generated
It never reaches the compression line.

Similarly, the need for the front stepping area to be approximately 2.4 to 3.8 mm is due to the support area being approximately 1.4 to 1.6 times that of the center of the heel bottom, which means that when bearing the same maximum weight, Even if there is, the compressive strength is about 60 to 70% of that value, which means that cushioning properties comparable to those of the heel region are maintained.

Similarly, the need for a compressive strength of approximately 0.7 to 1.3 for the ridged part of the foot means that the ridged part can provide cushioning that does not cause pain even when it comes into contact with the pedestal part of the foot. Along with this, it also serves to prevent the foot from moving inside the shoe.

Further, the compressive strength of the outer circumferential portion is about 0.7 to 1.3, which is used to wrap the sole periphery with a soft cushion and similarly prevent the foot from moving.

By having the above-mentioned characteristics, the insole of the present invention exhibits insole performance that is lightweight, has excellent durability, and has a good cushioning sensation.

A method for manufacturing a shoe insole according to the present invention will be explained by giving an example.

30 cm x 30 cm, shown in II of Figure 11;
Density 40 kg/m with taper thickness from 12 to 200 mm
Approximately 6 portions of the homogeneous closed-cell non-crosslinked polyethylene foam board B of No. 3 were placed in a circulating air heating oven (not shown) at 130° C. to soften the core, and then cooled as shown in FIG. Placed between the male mold 10 and the female mold 11,
The heated foam board B is placed between molds as shown in FIG.
Each part of the shoe insole is press molded to have a different compression ratio, and after cooling the core part under pressure for about 2 minutes until it reaches about 50°C or less, it is taken out from the mold and is in a substantially non-foamed state. The insole is obtained by trimming the attached portion 13 along the resin layer 12 and the outer peripheral edge 7 of the insole.

The foam board B used in the present invention may have the same thickness or different thicknesses, as shown in Figure 11 and Figure II, making it easy to select the shape and compressive strength of the shoe insole. .

For example, if the thickness is different as shown in Fig. 11, the thicker side can be used as the heel, which requires compressive hardness, and the toe can be used to create a slope for tingling.

Further, a covering material 16 such as cloth is placed on the foam board B, and the first
It is also possible to obtain an insole that is integrally bonded and molded as shown in Figure 3.

Furthermore, if the female die 11 of the molding die is provided with wavy or lattice-like protrusions, it is possible to form wavy linear grooves 15 or lattice-shaped grooves 15' on the sole surface of the shoe as shown in FIG.

It is also possible to take out the molded product and drill a large number of small ventilation holes 14 therethrough as shown in FIG. 9.

In the present invention, the non-crosslinked closed-cell polyethylene foam is preferably a polyethylene homopolymer, but it also refers to a resin foam that contains other resin components within the scope of not significantly changing its essence. .

These foams are chemically inert so they do not deteriorate or irritate the skin, and are odorless so they do not cause discomfort.

In addition, since it is a closed-cell foam, it has recovery properties and can be used for long periods of time, and it is hygienic because it does not absorb moisture.

[Brief explanation of the drawing]

Fig. 1 is a bottom plan view of the insole of the right shoe according to the present invention, Fig. 2 is a top plan view of the right shoe insole, Fig. 3 is a perspective view of the insole of the right shoe, and Fig. 4 is E-- of Fig. 2. E-line sectional views, Figures 5 to 8 are A-A and B-B, respectively, with the bottom plan view of Figure 1 facing upward.
, a cross-sectional view taken along lines C-C and D-D, FIG. 9 is a bottom view showing a shoe midsole with a small hole passing through it, and FIG. 10 is a shoe midsole with wavy linear grooves or lattice grooves. Bottom view showing 1st
Figures I and II show the closed-cell foam board for the insole of the present invention having a uniform thickness and a tapered thickness, respectively. Figure 12 is a perspective view showing the state of insertion of the mold and material in the pressure molding machine for the insole of this shoe, and Figure 13 is a cross section showing the state where the foam board to be molded is pressed against the upper and lower molds shown in Figure 12. 14 are graphs showing the relationship between compressive strength and strain of various foams. 1...Heel part, 2...Touchi tread part, 3...
...Front stepping part, 4...Toe part, 5...
... Heel part outer peripheral wall part, 6 ... Terrain tread part outer peripheral wall part, 7 ... Top edge part, 8, 8', 8''...
・Intersection of top edge and front tread, 9, g/, 9//
,... Intersection of the top edge and the treading part, 10...
...Molding mold female mold, 11...Pa...Molding mold female mold,
12...Resin layer in substantially non-foamed state, 13...
... Adhesive part, 14 ... Small ventilation hole passing through, 15 ... Wavy linear groove, 15' ...
- Lattice groove, 16... Surface material.

Claims (1)

[Scope of utility model registration request] An insole made of a single substantially closed-cell non-crosslinked polyethylene foam board, wherein each component of the insole has a foam board density kg/m3 and a 25% compressive strength kg/cm2, respectively. About 135 to 200 kg/m3 at the center of the heel bottom, about 3.8 to 5.2 kg/cm2, about 90 to 1 at the stepping part
35kg/m3, about 2.4-3.8 kg/Cm2, about 40-65kg/m3, about 0.7-1.
3 kg/cm2, approximately 40 to 65 kg/m3 at the outer periphery,
An insole for shoes which is press-molded with a mold having parts with different compression ratios so as to satisfy a value relationship of about 0.7 to 1.3 kg/cm2.