JP2007215639A - Game ball - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a game ball capable of providing users with amusement of a sense closely similar to a snowball fight, used in a game in which the ball likened to a snowball is thrown at each other in simulation of the snowball fight. <P>SOLUTION: The game ball 10 comprises a spherical core body 11 consisting of a synthetic resin expanded body or a wooden piece and a cushion part 12 forming the periphery of the core body 11 and consisting of a polyurethane expanded body with a rebound modulus not more than 15%. The core body 11 comprises an impact absorbing body with a bulk density not less than that of the cushion part 12. The ball 10 never rebounds off so much even when it is hit to the user in contrast to a rubber ball filled with air or a polyethylene expanded ball and never bounces or rolls so much when it drops on a floor, being like the snowball. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a game ball that is made of a synthetic resin foam and is used in a game in which, for example, a ball that looks like a snowball is thrown to simulate a snowball battle.

  Conventionally, as this type of game ball, there is one disclosed in Patent Document 1, for example. This Patent Document 1 discloses a ball covering member made of a flexible polyurethane foam having a high coefficient of friction and used on a gate ball. If the ball covering member is placed on the ball when the gate ball is used indoors, the ball is prevented from rolling too much due to friction between the ball covering member and the floor. For this reason, a gate ball can be performed with the same feeling as the outdoors.

By the way, in recent years, a game has been proposed in which balls that look like snowballs are imitated in snowball fights. In this game, since the ball is used instead of a snowball, for example, a diameter of about 70 mm and a weight of about 50 to 70 g are required. Also, the ball needs to resemble a snowball that does not rebound so much when it hits a person and does not bounce or roll so much when it falls on the floor.
JP 2002-65901 A

  Conventionally, a soft tennis rubber ball, a foamed polyethylene resin ball, or a highly resilient foamed polyurethane resin ball has been used as the ball. However, soft tennis rubber balls and high-resilience foamed polyurethane resin balls bounce well when hit by people, for example, and often bounce and roll when dropped on the floor. It was similar to the jade and was not. Also, soft tennis rubber balls and foamed polyethylene resin balls have a small bulk density, so they did not reach 50 g at a diameter of about 70 mm, and could not be thrown so far unlike snow balls.

  An object of the present invention is to provide a game ball that can be enjoyed with a feeling close to that of a snowball fight, for example, in a game in which a ball that looks like a snowball fight is thrown.

  The invention according to claim 1, which achieves the above object, comprises a polyurethane foam having a rebound resilience of 15% or less. The rebound resilience is based on the standard of JIS K6400. According to such a configuration, due to the low rebound resilience, for example, even when hit by a person, it does not rebound so much, and even if it falls on the floor, it does not bounce or roll so much. Therefore, it becomes similar to a snowball, and can be enjoyed with a feeling of throwing snowballs in a snowball fighting game, for example. On the other hand, polyurethane foam with a rebound resilience of more than 15% rebounds well when hit by a person, and also bounces and rolls well when dropped on the floor, so it is far from the nature of snowballs. It becomes.

  The invention described in claim 2 is characterized in that, in the invention described in claim 1, a core body comprising an impact absorber having a bulk density equal to or higher than the bulk density of the polyurethane foam is provided. The “bulk density” of a polyurethane foam means the mass per unit volume of a sample containing both breathable and non-breathable voids. In addition, as the “core body”, for example, a foamed body such as polystyrene resin or polyurethane resin, wood, wood chips or synthetic resin pellets, which are hardened in an elastically deformable state by a flexible binder such as synthetic rubber, There are aggregates of grains, spheres or lumps made of a plurality of independent woods or synthetic resins. The “bulk density of the core” means the mass per unit volume of the sample including both air-permeable and non-air-permeable voids. According to such a configuration, it does not bounce, bounce, or roll so much, and it has a weight closer to the snowball than the weight of the ball without the core, and can be thrown as far as a snowball. it can.

  The invention according to claim 3 is characterized in that, in the invention according to claim 2, the core is arranged at a position eccentric from the center. According to such a configuration, since the core is located at a position shifted from the center of the ball, the ball is more difficult to roll.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the invention is used for a game in which a player looks like a snowball.

  According to the present invention, for example, it is possible to provide a game ball that is used in a game in which a ball that looks like a snowball game and throws a ball that looks like a snowball game and that can be enjoyed with a feeling close to that of a snowball game.

Next, an embodiment in which the present invention is embodied in a snowball game ball will be described with reference to FIGS.
As shown in FIG. 1, a ball 10 having a spherical shape includes a spherical core body 11 and a cushion portion 12 that encloses the core body 11. The diameter of the ball 10 is about 70 mm, and its weight is in the range of 50 to 70 g, preferably in the range of 55 to 65 g. The core 11 has a diameter of about 25 to 35 mm and is disposed at the center of the cushion portion 12.

  The core 11 is made of a synthetic resin foam such as a polystyrene foam resin or a polyurethane foam resin, or an impact absorber such as wood. Moreover, the cushion part 12 consists of a soft foaming polyurethane resin, and the resilience elastic modulus based on the specification of JIS K6400 of this resin is made into the value of 15% or less. The rebound resilience of the flexible foamed polyurethane resin is more preferably in the range of 3 to 8%. In addition, the cushion part 12 has the skin layer 13 without the bubble formed naturally at the time of shaping | molding. The skin layer 13 makes it difficult for the surface of the ball 10 to get dirty. The core 11 has a bulk density equal to or higher than the bulk density of the cushion portion 12.

Next, a method for manufacturing the ball 10 configured as described above will be described.
As shown in FIG. 2A, the ball 10 is molded using a lower mold 20 and an upper mold 21 each having hemispherical cavities 20a and 21a. A support needle 22 for supporting the core body 11 is installed in the cavity of the lower mold 20.

  First, after the core body 11 is stabbed and held at the tip of the support needle 22 of the lower mold 20, the upper mold 21 is aligned with the lower mold 20. Next, a polyurethane raw material is injected into the cavities 20a and 21a and heated to be foamed and cured. Finally, after removing the upper mold 21 from the lower mold 20, the ball 10 as a molded and hardened product is extracted from the tip of the support needle 22, thereby completing the molding of the ball 10.

  According to the embodiment configured as described above, the cushion portion 12 made of polyurethane foam having a rebound resilience of 15% or less, preferably 3 to 8% is provided. Unlike a rubber ball or foamed polyethylene resin ball, it does not rebound so much when it hits it. Also, it doesn't bounce or roll that much when it falls on the floor. Therefore, since the ball 10 becomes closer to the snowball, it can be used for a snowball fighting game and can be enjoyed as if the snowballs were actually thrown.

  Moreover, since the core body 11 made of an impact absorber having a bulk density equal to or higher than the bulk density of the cushion portion 12 is provided at the center portion of the cushion portion 12, it does not rebound, bounce, or roll so much. The weight is closer to the snowball than the weight of the ball 10 without the core body 11. For this reason, since it can be thrown away like a snowball, it can be enjoyed with a feeling closer to a snowball fight. Furthermore, since the thing cheaper than an expensive soft foaming polyurethane resin can be used as the core 11, the cost cost of the ball | bowl 10 can be reduced.

  Next, an example of the ball 10 according to this embodiment configured as described above will be described together with a comparative example.

  (Evaluation methods)

上記の表１に示すように、実施例１〜４は、上記実施形態のように、クッション部１２の内側に芯体１１を有するものである。実施例１，２は、ビーズ法ポリスチレン発泡体（Expanded Poly-Styrene ：ＥＰＳ）からなる芯体１１を備え、また、実施例３，４は、木材からなる芯体１１を備えている。また、クッション部１２は、ポリオールを主剤とし、イソシアネートを硬化剤とするポリウレタン樹脂発泡体からなる。なお、実施例５は、図３（ａ）に示すように、芯体１１を備えない構成とされ、その重量が５５ｇに達していない。実施例１〜４は、上記の製造方法によって製作され、実施例５は、上記製造方法において、支持針２２を用いず、芯体１１をキャビティ２０ａ，２１ａに入れない点のみが異なる。

As shown in said Table 1, Examples 1-4 have the core 11 inside the cushion part 12, like the said embodiment. Examples 1 and 2 include a core 11 made of expanded polystyrene (EPS), and Examples 3 and 4 include a core 11 made of wood. Moreover, the cushion part 12 consists of a polyurethane resin foam which uses a polyol as a main ingredient and uses isocyanate as a hardening | curing agent. In addition, Example 5 is set as the structure which is not provided with the core 11 as shown to Fig.3 (a), The weight has not reached 55g. Examples 1 to 4 are manufactured by the above manufacturing method, and Example 5 is different from the above manufacturing method only in that the support needle 22 is not used and the core body 11 is not put into the cavities 20a and 21a.

  In the first and third embodiments, the center of the cushion portion 12 and the center of the core body 11 coincide. On the other hand, in the second and fourth embodiments, as shown in FIG. 3B, the center C2 of the core body 11 is disposed at a position eccentric from the center C1 of the cushion portion 12, and the amount of eccentricity is about 10 mm. Yes.

  About each of Examples 1-5, the ball 10 was dropped on the concrete floor from a position of 150 cm in height, and the initial height when the ball 10 bounced off the floor and the number of times of rebound were measured. Moreover, the same evaluation as Examples 1-5 was performed about the comparative examples 1 and 2 shown in Table 2.

（評価結果）
実施例１〜５によれば、１５０ｃｍから落下させたときの初回跳ね返り高さが６ｃｍ以下となった。さらに、芯体１１を備えた実施例１〜４によれば、同初回跳ね返り高さが４ｃｍ以下となった。また、実施例１〜５によれば、１５０ｃｍから落下させたときの跳ね返り回数が２回以下となった。さらに、木材の芯体１１を備えた実施例３，４によれば、同跳ね返り回数が１回となった。

(Evaluation results)
According to Examples 1 to 5, the initial rebound height when dropped from 150 cm was 6 cm or less. Furthermore, according to Examples 1-4 provided with the core 11, the same initial rebound height became 4 cm or less. Moreover, according to Examples 1-5, the number of rebounds when dropping from 150 cm became 2 or less. Furthermore, according to Examples 3 and 4 provided with the wood core 11, the number of rebounds was one.

On the other hand, according to Comparative Examples 1 and 2, the initial rebound heights were 100 cm and 45 cm, respectively, and the numbers of rebounds were 20 times and 10 times, respectively.
Therefore, as in Examples 1 to 5, the ball 10 including the cushion portion 12 made of a low-rebound polyurethane foam having a rebound resilience within a range of 15% is made of a pneumatic rubber ball or a high-repulsion polyurethane foam. Unlike a ball, it does not bounce, bounce, or roll so much that it is close to a snowball.

It should be noted that the present invention can be modified and embodied as follows.
A core 11 made of wood chips or synthetic resin pellets that are elastically deformed by a flexible binder such as synthetic rubber, or a plurality of independent wood or synthetic resin grains, spheres or lumps Assume an aggregate. Here, in order to use a plurality of independent wood or synthetic resin grains, spheres, or a collection of mold pools as a core, the assembly is wrapped with, for example, a polyethylene resin film or cloth, and this is used as a cushion part. What is necessary is just to put in the center part at the time of 12 shaping | molding. Also in this case, the bulk density should just be more than the bulk density of the cushion part 12. FIG.

The present invention is not limited to a spherical ball, and is embodied in other rugby ball-like oval and egg-shaped balls.
-The present invention is not limited to a snowball game ball, but is embodied in, for example, a dodge ball.

The front view which fractured | ruptured a part which shows the ball | bowl of one Embodiment. (A), (b) is a figure which shows the formation process of a ball | bowl both. (A), (b) is a front view which shows the ball | bowl of other embodiment.

Explanation of symbols

  10 ... ball, 11 ... core, 12 ... cushion part, C1 ... center.

Claims (4)

  A game ball comprising a polyurethane foam having a rebound resilience of 15% or less.   2. The game ball according to claim 1, further comprising a core made of an impact absorber having a bulk density equal to or higher than the bulk density of the polyurethane foam.   The game ball according to claim 2, wherein the core is arranged at a position eccentric from a center.   The game ball according to any one of claims 1 to 3, wherein the game ball is used in a game in which the ball is thrown like a snowball.

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