JP2013124489A - Tatami mat for judo having intermediate layer formed of elastic foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tatami mat for judo having an intermediate layer formed of an elastic foam for enhancing impact absorption, which maintains proper flexibility and hardness, not being too soft.SOLUTION: A tatami mat for judo includes an air gap at least at one of the top face and the bottom face of an intermediate layer which come in contact with a neighboring layer in a lamination structure constituting the tatami mat. The air gap has an area porosity of 10% to 50% relative to the whole contact surface at the top face and the bottom face of the intermediate layer.

Description

  The present invention relates to a tatami for judo that is laid on the floor of a building that is not normally used as a dojo, such as a dedicated dojo or gymnasium, and is used for practice or games of judo etc. The present invention relates to a tatami mat for judo having an intermediate layer formed of an elastic foam having.

Judo tatami mats on all or part of the floor when practicing martial arts such as judo, games and competitions in buildings that are not normally used as judo halls such as dedicated dojos, gymnasiums or auditoriums Is laid.
Conventionally, various structures have been known as such judo tatami mats. For example, in the column of the prior art in the cited document 1, a floor structure for a judo hall is disclosed. Moreover, in the cited document 2, the tatami mat frame used for the laying edge part of the flooring laid on the floor is described.
As a conventional judo tatami mat, a laminate in which a cushion layer, a plywood, a back sheet and the like are laminated as described above is known. For example, what laminated | stacked the back sheet | seat, the cushion layer by an elastic foam, the plywood, the cushion layer by an elastic foam, and a tatami surface from the floor surface is known.

And since the practice / game / competition etc. which were used with the throwing technique etc. are performed on the above-mentioned judo tatami, the judo tatami is required to have high shock absorption. On the other hand, if the elastic foam in the cushion layer itself is made flexible, the above-mentioned shock absorption will be increased, and the athlete's feet will sink into the tatami mat, which will in turn make it easier to suffer injuries such as sprains. Was known.
Therefore, when researching conventional judo tatami mats and flooring materials, it has been found that the above-mentioned judo tatami mats have a problem that the shock absorption must be enhanced while maintaining appropriate flexibility. However, simply increasing the thickness of the elastic foam itself constituting the cushion layer or increasing the elasticity of the elastic foam itself as described above has caused a problem that the foot struts do not work, resulting in injury.

JP-A-5-137828 JP 2008-194330 A

  The present invention provides an elastic foam that increases the shock absorption capacity while maintaining moderate flexibility and hardness without being too soft by providing a gap for releasing the impact force on the contact surface of the elastic foam in the cushion layer. An object is to provide a judo tatami mat having a formed intermediate layer.

In order to solve the above problems, the present inventor has adopted a tatami structure for judo having an intermediate layer formed of the following elastic foam.
(1) A judo tatami having an intermediate layer formed of an elastic foam, characterized in that a gap is formed in at least one of the contact surfaces of the upper surface and the lower surface of the intermediate layer with an adjacent layer. A judo tatami mat having an intermediate layer formed of elastic foam.
(2) The elastic foam as described in (1) above, wherein an area void ratio in a gap formed on the contact surface in the intermediate layer is 10% to 50% with respect to the entire contact surface A judo tatami mat with an intermediate layer formed.

(3) The intermediate layer is formed of the elastic foam as described in (1) or (2) above, wherein a contact surface in which a gap is formed is in contact with a wooden plate or a plastic plate. Judo tatami with an intermediate layer.
(4) The area void ratio in the gap formed on the contact surface is 22% to 36% with respect to the entire contact surface, as described in any one of (1) to (3) above Judo tatami mat having an intermediate layer formed of an elastic foam.
(5) The judo tatami mat having an intermediate layer formed of the elastic foam further includes another intermediate layer formed of an elastic foam in which no void is formed. Judo tatami having an intermediate layer formed of the elastic foam described in any one of (1).

  A judo tatami mat having an intermediate layer formed of an elastic foam according to the present invention is too soft, particularly when standing skill is active, by providing a gap for releasing an impact force on the contact surface of the intermediate layer formed of an elastic foam. It retains moderate flexibility and hardness, and has an excellent effect that the shock absorbency is remarkably increased as compared with the conventional judo tatami when passive such as passive.

It is the partial cross section figure which showed the tatami for judo which concerns on Embodiment 1 of this invention. It is a top view of the intermediate | middle layer which concerns on Embodiment 1 of this invention. It is the perspective view which showed the laminated structure of the tatami for judo which concerns on Embodiment 2 of this invention. It is the figure which showed the intermediate | middle layer used for the tatami for judo which concerns on Embodiment 3 of this invention. It is the perspective view which showed the intermediate | middle layer which concerns on Embodiment 4 used for the tatami for judo of this invention. It is sectional drawing which showed the intermediate | middle layer and wooden board which concern on Embodiment 5 used for the tatami for judo of this invention. Fig. (A) is a cross-sectional view showing a structure in which the upper surface of the intermediate layer and the wooden board are in contact with each other at a point, and Fig. (B) shows a structure in which voids and protrusions are formed on the lower surface of the intermediate layer. It is sectional drawing. It is sectional drawing which shows the illustration of the other tatami for judo which concerns on Embodiment 6 of this invention.

Hereinafter, a judo tatami mat having an intermediate layer formed of an elastic foam according to the present invention will be described in detail. However, the form shown below is an example of the tatami mat for judo according to the present invention, and the tatami mat for judo according to the present invention is not limited to the following mode.
Examples of the elastic foam used for the intermediate layer having cushioning properties of judo tatami mats according to the present invention include rigid polyurethane foam, polystyrene foam, polyethylene foam, polypropylene foam, EVA foam, foam rubber, polyolefin composite resin foam, and phenol foam. Etc. Of course, materials other than the above materials may be used as long as they can be used as an intermediate layer having cushioning properties in judo tatami mats. Among the above materials, the most suitable for forming shock absorption and voids is polypropylene foam, and the next most suitable is polystyrene and polyolefin composite resin foam.
The judo tatami according to the present invention is characterized in that voids are formed on the contact surfaces of the upper surface and / or the lower surface of the intermediate layer formed of the elastic foam.

Members made of other materials are laminated on the upper and lower surfaces of the intermediate layer formed of the judo tatami mat elastic foam according to the present invention. A gap is formed on the contact surface of the intermediate layer formed of the elastic foam that contacts at least the member that contacts the intermediate layer formed of the elastic foam. Such voids may be formed on the upper surface and / or the lower surface of the intermediate layer formed of elastic foam and on the surface that comes into contact with another adjacent member, but the upper surface of the intermediate layer formed of elastic foam. Further, it may be formed on both the lower surface and the lower surface, and an aspect of penetrating the lower surface from the upper surface of the intermediate layer formed of elastic foam is also included. Among these, the gap in the judo tatami mat according to the present invention is preferably a concave shape formed by hollowing out a part of the upper surface or the lower surface of the intermediate layer formed of elastic foam. A particularly preferable form of the void is a concave shape in which the upper surface of the elastic foam is hollowed out.
When used as a tatami for judo, the athlete's weight on the tatami is applied to an intermediate layer formed of elastic foam from above. Since the intermediate layer formed of elastic foam has a surface that is in contact with other members and an air gap with respect to the load from above, the middle of the entire load formed of elastic foam downward It will take to press the layer from above. In such a case, by providing a gap in the contact surface of the intermediate layer, the same load applied to the entire contact surface is supported in a narrow area other than the gap. Then, the edge part of an elastic foam will be extruded to the plane direction of the space in which the space | gap is formed. That is, the impact force can be reduced by dispersing the load received on the small contact surface of the intermediate layer in the gap direction.
In the present invention, the area void ratio in the gap formed in the contact surface is 10% to 50% with respect to the entire contact surface. Here, the interview porosity is a value obtained by dividing the total area of the portion that does not directly abut against other members that abut due to the void formed in the intermediate layer by twice the area of the intermediate layer. It is not preferable that the porosity is less than 10% because the effect of shock absorption is hardly obtained. On the other hand, if the area porosity exceeds 50%, a problem may occur in terms of supportability. Further, the area porosity in the gap formed on the contact surface is more preferably 22% to 36% with respect to the entire contact surface.
The voids are preferably dispersed on the upper and lower surfaces of the elastic foam at an appropriate interval. In particular, it is preferable that the voids are dispersed and formed at the same interval.

In the judo tatami according to the present invention, in the intermediate layer formed of the elastic foam, a contact surface in which a gap is formed may be in contact with a wooden board. Since the intermediate layer formed of elastic foam contacts the wooden board, the load from above can be distributed over the entire contact surface of the intermediate layer formed of elastic foam. This is because even when all loads are applied to the area (toes), the load can be dispersed to some extent on the contact surface of the intermediate layer formed of elastic foam.
Here, examples of the wooden board include an insulation board, a medium density fiber board, and a hard board. These wooden boards are a kind of wood board in which wood fibers are mixed with an adhesive and hot pressed. Unused waste wood or low-quality wood may be used as the raw material wood.

Embodiment 1
FIG. 1 is a partial cross-sectional view illustrating a judo tatami mat according to Embodiment 1 of the present invention. As shown in FIG. 1, a judo tatami mat 10 according to the first embodiment is composed of a tatami mat 1, an intermediate layer 2 made of elastic foam, a wooden board 3, another cushion layer 4, and a back sheet 6. ing. Here, a gap 7 is formed on the contact surface of the upper surface of the intermediate layer 2 formed of the elastic foam.
The intermediate layer 2 is made of polypropylene foam. Moreover, the said wooden board 3 is formed from the MDF board (medium density fiber board). Further, the cushion layer 4 is made of polypropylene foam.
The space 7 formed on the contact surface has a depth (H) of 25 mm, a length (L1) of 60 mm, and a length (L4) from the end of the elastic foam to the space forming portion of 40 mm. .

FIG. 2 is a plan view of the intermediate layer 2 according to Embodiment 1 of the present invention. The four sides are projecting frames and are in contact with a wooden board 3 (not shown). Similarly, a plurality of protrusions 5 are arranged at equal intervals in the intermediate layer 2. A gap 7 is formed in the frame and on the outer periphery of the protrusion 5. As for the size in each part, L1 is 60 mm, L2 is 50 mm, L3 is 60 mm, L4 is 45 mm, L5 is 50 mm, and L6 is 40 mm. Further, no gap is formed on the contact surface on the lower surface of the intermediate layer 2. The entire plane of the intermediate layer 2 is 920 mm × 910 mm.
Therefore, the total area of the contact surface is 1,674,400 mm ^{2 in} total for the upper surface and the lower surface of the intermediate layer 2. Also, the area of the outer frame in contact with the wood plate 3 on the upper surface of the intermediate layer 2 is 274,700Mm ^2, the total area of the protruding portion 5 is 122,500Mm ^2. Therefore, the area in contact with the adjacent layer is 1,234,400 mm ² on the entire upper surface and lower surface of the intermediate layer 2, and 73.7% of the total area of the upper surface and lower surface of the intermediate layer 2 is in contact with it. .
Therefore, the area porosity in the intermediate layer according to the first embodiment is 26.3% of the entire contact surface on the upper surface and the lower surface of the intermediate layer 2.

Embodiment 2
FIG. 3 is a perspective view showing a laminated structure of judo tatami mats according to Embodiment 2 of the present invention. As shown in FIG. 3, the judo tatami 20 according to the second embodiment includes an intermediate layer 12 made of elastic foam, a wooden board 13, another cushion layer 14, a back sheet 16, and an elastic foam layer 18. ing. Here, a gap 17 is formed in the contact surface of the upper surface of the intermediate layer 12 formed of the elastic foam, and is in contact with the lower surface of the elastic foam layer 18.
The intermediate layer 12 is made of polypropylene foam. Moreover, the said wooden board 13 is formed from the MDF board (medium density fiber board). The back sheet 16 is formed of a Matron (registered trademark of Ueno Systec Co., Ltd.) sheet. Further, the cushion layer 14 is made of polypropylene foam. The gap 17 formed on the contact surface is formed to a depth of 25 mm.

As shown in FIG. 3, the intermediate layer 12 according to the second embodiment of the present invention has a protruding frame, and the upper surface of the frame is bonded to the elastic foam layer 18. Similarly, a plurality of protrusions 15 are arranged at equal intervals in the intermediate layer 12. The upper surface of the protrusion 15 is also bonded to the elastic foam layer 18. A gap 17 is formed on the outer periphery of the frame and the protrusion 15. Further, no gap is formed on the contact surface on the lower surface of the intermediate layer 12. The lower surface of the intermediate layer 12 is bonded to the back sheet 16.
Furthermore, the lower surface of the cushion layer 14 is bonded to the upper surface of the wooden board 13, and the upper surface of the elastic foam layer 18 is bonded to the lower surface of the wooden board 13 to manufacture the judo tatami mat 20 according to Embodiment 2 of the present invention. Can do. The judo tatami 20 manufactured in this way may be covered with a tatami mat (not shown).

Embodiment 3
FIG. 4 is a view showing an intermediate layer used in the judo tatami according to Embodiment 3 of the present invention. Fig. (A) is a plan view of the intermediate layer, and Fig. (B) is a cross-sectional view of the intermediate layer in Fig. (A). As shown in FIG. 4, the intermediate layer according to the third embodiment is formed of an elastic foam, and a gap 27 is formed on the contact surface of the upper surface of the intermediate layer.
The intermediate layer according to the third embodiment is made of polypropylene foam which is a kind of elastic foam. The gap 27 formed in the contact surface has a depth (H) of 20 mm.

As shown in FIG. 4, the intermediate layer according to the third embodiment of the present invention has a size of one tatami mat (910 mm × 1,820 mm). The four sides are protruding frames and are bonded to a wooden board (not shown). Similarly, a plurality of protrusions 25 are arranged at equal intervals inside the intermediate layer. A gap 27 is formed in the frame and on the outer periphery of the protruding portion 25. The size of each part is 50 mm for L1, 50 mm for L2, 50 mm for L3, 80 mm for L4, 50 mm for L5, and 85 mm for L6. Further, no gap is formed on the contact surface on the lower surface of the intermediate layer.
Therefore, the total area of the contact surface is 3,312,400 mm ^{2 in} total for the upper surface and the lower surface of the intermediate layer. Also, the area of the outer frame abutting the wooden plate (not shown) in the upper surface of the intermediate layer is 154,700Mm ^2, the total area of the protruding portion 25 is 280,000mm ^2. Therefore the area and adjacent layers abutting the upper surface of the projecting portion and the frame on the upper surface side of the intermediate layer is 698,700Cm ^2, the lower surface side is 1,656,200Mm ^2, the total area of the upper surface and lower surface of the intermediate layer 71 1% is the contact area.
Therefore, the area porosity in the intermediate layer according to the third embodiment is 28.9% of the entire contact surface on the upper surface and the lower surface of the intermediate layer.

Note that L1 to L6 and H described above are merely examples, and other numerical values may naturally be used depending on the design. For example, L1 is 30 mm, L2 is 70 mm, L3 is 70 mm, L4 is 70 mm, L5 is 30 mm, and L6 is 70 mm. Further, no gap is formed on the contact surface on the lower surface of the elastic foam.
In this case, the total area of the contact surface is 3,312,400 mm ^{2 in} total for the upper surface and the lower surface of the intermediate layer. Moreover, the area of the outer frame which contacts the wooden board (not shown) on the upper surface of the intermediate layer is 362,600 mm ² , and the total area of the projecting portions 25 is 100,800 mm ² . Therefore the area and adjacent layers abutting the upper surface of the projecting portion and the frame on the upper surface side of the intermediate layer is 463,400Cm ^2, the lower surface side is 1,656,200Mm ^2, the upper and lower surfaces of the total area of the intermediate layer 64 0.0% is the contact area.
Therefore, the area porosity in the intermediate layer in this case is 36.0% of the entire contact surface on the upper surface and the lower surface of the intermediate layer.

In addition, L1 is 50 mm, L2 is 52.5 mm, L3 is 52.5 mm, L4 is 70 mm, L5 is 50 mm, and L6 is 70 mm. Further, no gap is formed on the contact surface on the lower surface of the elastic foam.
In this case, the total area of the contact surface is 3,312,400 mm ^{2 in} total for the upper surface and the lower surface of the intermediate layer. Also, the area of the outer frame abutting the wooden plate (not shown) in the upper surface of the intermediate layer is 362,600Mm ^2, the total area of the protruding portion 25 is 280,000mm ^2. Therefore the area and adjacent layers abutting the upper surface of the projecting portion and the frame on the upper surface side of the intermediate layer is 642,600Cm ^2, the lower surface side is 1,656,200Mm ^2, the total area of the upper surface and lower surface of the intermediate layer 69 4% is the contact area.
Therefore, the area porosity in the intermediate layer in this case is 30.6% of the entire contact surface on the upper surface and the lower surface of the intermediate layer.

In addition, L1 is 70 mm, L2 is 35 mm, L3 is 35 mm, L4 is 70 mm, L5 is 70 mm, and L6 is 70 mm. Further, no gap is formed on the contact surface on the lower surface of the elastic foam.
In this case, the total area of the contact surface is 3,312,400 mm ^{2 in} total for the upper surface and the lower surface of the intermediate layer. In addition, the area of the outer frame that abuts against a wooden board (not shown) on the upper surface of the intermediate layer is 362,600 mm ² , and the total area of the protrusions 25 is 548,800 mm ² . Therefore the area and adjacent layers abutting the upper surface of the projecting portion and the frame on the upper surface side of the intermediate layer is 911,400Cm ^2, the lower surface side is 1,656,200Mm ^2, the upper and lower surfaces of the total area of the intermediate layer 77 5% is the contact area.
Therefore, the area porosity in the intermediate layer in this case is 22.5% of the entire contact surface on the upper surface and the lower surface of the intermediate layer.

Embodiment 4
FIG. 5 is a perspective view showing an intermediate layer 40 according to Embodiment 4 used in the judo tatami of the present invention. As shown in FIG. 5, the intermediate layer 40 according to the fourth embodiment is formed of an elastic foam made of polypropylene foam. A gap 37 is formed on the contact surface of the upper surface of the intermediate layer 40 formed of the elastic foam, and protrusions 32 and 33 are formed. A space 38 is formed on the contact surface of the lower surface, and the protrusion 35 and 36 is formed. The intermediate layer 40 has a thickness of 35 mm, and the gaps 37 and 38 formed on the contact surface are each formed to a depth of 10 mm.

As shown in FIG. 5, the size of each part in the intermediate layer 40 according to Embodiment 4 of the present invention is as follows: L1 is 50 mm, L2 is 50 mm, L3 is 60 mm, L4 is 60 mm, L5 is 25 mm, L6 is 25 mm, L7 Is 800 mm and L8 is 960 mm.
Therefore, the total area of the contact surface is 1,536,000 mm ^{2 in} total for the upper and lower surfaces of the intermediate layer. Further, the total area of the contact surfaces of the protrusions 32 and 33 that contact a wooden board (not shown) on the upper surface of the intermediate layer is 384,000 mm ² . The total area of the abutment surfaces of the protrusions 35 and 36 that abut the adjacent layers on the lower surface of the intermediate layer is 384,000 mm ² , and 50.0% of the total area of the upper and lower surfaces of the intermediate layer is in contact. Become an area.
Therefore, the area porosity in the intermediate layer according to the fourth embodiment is 50.0% of the entire contact surface on the upper surface and the lower surface of the intermediate layer.

Embodiment 5
FIG. 6: is sectional drawing which showed the intermediate | middle layer and wooden board which concern on Embodiment 5 used for the tatami for judo of this invention. Fig. (A) is a cross-sectional view showing a structure in which the upper surface of the intermediate layer and the wooden board are in contact with each other at a point, and Fig. (B) shows a structure in which voids and protrusions are formed on the lower surface of the intermediate layer. It is sectional drawing. The effects of the present invention can also be achieved by forming the intermediate layer in such a structure.

Embodiment 6
FIG. 7: is sectional drawing which shows the illustration of the tatami for other judo which concerns on Embodiment 6 of this invention. Fig. (A) shows from the upper layer, antibacterial tatami surface 61, intermediate layer 62 formed of elastic foam, wooden board 63 by hard board made of honeycomb plastic board, insulation board 68, hard styrene foam 69, cushion layer 64, and back A sheet 66 is used. In the judo tatami shown in FIG. 1 (a), a gap 67 is formed on the contact surface of the lower surface of the intermediate layer 62 formed of the elastic foam with the wooden board 63.

  FIG. 7 (b) shows an antibacterial tatami surface 71, a cushion layer 74 made of EVA foam rubber, a wooden board 73 made of a honeycomb plastic board hard board, an insulation board 78, a hard styrene foam 79, and an intermediate layer made of an elastic foam. 72, a cushion layer 70 made of urethane microchip, and a back sheet 76. In the judo tatami shown in FIG. (B), voids 77 are formed on the contact surfaces of the upper surface and the lower surface of the intermediate layer 72 formed of the elastic foam. As described above, the judo tatami mat according to the present invention may have another cushion layer laminated on the upper part of the intermediate layer in which the gap is formed.

  FIG. 7C shows an antibacterial tatami surface 81, an EVA foam rubber cushion layer 84, a honeycomb board 83 made of a hard board made of honeycomb plastic board, an insulation board 88, a wooden board 85 made of a hard board made of honeycomb plastic board, and an elastic layer. It is comprised from the intermediate | middle layer 82 formed with foam, the cushion layer 84 by a urethane microchip, and the back sheet | seat 86. FIG. In the judo tatami shown in FIG. (C), a gap 87 is formed so as to penetrate from the upper surface to the lower surface of the intermediate layer 82 formed of the elastic foam. By adopting such a structure, the cushion layer 84 retains moderate flexibility without being too soft when the standing technique is active, and the shock absorption is enhanced by the intermediate layer 82 formed of elastic foam when passive such as passive. be able to.

Example 1
A judo tatami mat (910 mm × 920 mm) of Example 1 having the structure shown in Embodiment 1 (FIGS. 1 and 2) was produced. Further, as Comparative Example 1, a judo tatami mat having the same size was manufactured. The judo tatami mat according to Comparative Example 1 has the same layered structure as that of Example 1, but no gap is formed in the intermediate layer and has the same structure as before.
Each of the judo tatami mats was set in a drop impact tester SDST-700B (manufactured by Shinei Technology Co., Ltd.), and a drop test was performed. As an acceleration measurement analysis system, Omniace RA1200 (manufactured by NEC Avio Infrared Technologies) was used.
In the drop test, a weight of 6.0 kg was placed on the tatami mat and the test was made to drop from a height of 80 cm four times. Each impact value and recovery time were measured, and the average value was calculated. After comparing the results. Table 1 below shows the test results.
The comparison in Table 1 shows the ratio between the impact value of the developed product and the average value of time when the judo tatami mat of Comparative Example 1 is 100.

  As is clear from the results in Table 1 above, the impact value of the judo tatami mat according to Example 1 is significantly lower than that of the judo tatami mat according to comparative example 1 which is a conventional product. On the other hand, the time required for the surface of the tatami to return to the original state after dropping is longer in Example 1, while maintaining appropriate flexibility and the judo tatami according to Example 1 is a conventional judo. It has been found that the tatami mat has an excellent effect that the shock absorption is much higher than that of the tatami mat.

1, 61, 71, 81 Tatami 2, 12, 40, 62, 72, 82 Intermediate layer 3, 13, 63, 73, 83 Wooden board 4, 14, 64, 74, 84 Other cushion layers 5, 15, 25 , 32, 33, 35, 36 Protruding part 6, 16, 66 Back sheet 7, 17, 27, 37, 38, 67, 77, 87 Air gap 18 Elastic foam layer 10, 20 Judo tatami mat

Claims (5)

  A judo tatami mat having an intermediate layer formed of an elastic foam, wherein a void is formed in at least one of the contact surfaces of the upper surface and the lower surface of the intermediate layer with an adjacent layer. Judo tatami with an intermediate layer formed of   2. The intermediate formed of the elastic foam according to claim 1, wherein an area void ratio in a gap formed on the contact surface in the intermediate layer is 10% to 50% with respect to the entire contact surface. Judo tatami with layers.   3. A judo having an intermediate layer formed of an elastic foam according to claim 1 or 2, wherein a contact surface in which a gap is formed in the intermediate layer is in contact with a wooden plate or a plastic plate. Tatami mat.   4. The elastic foam according to claim 1, wherein an area void ratio in the gap formed on the contact surface is 22% to 36% with respect to the entire contact surface. Judo tatami mat with an intermediate layer.   5. The judo tatami mat having an intermediate layer formed of the elastic foam further includes another intermediate layer formed of an elastic foam in which no void is formed. A judo tatami mat with an intermediate layer formed of the described elastic foam.

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