JP2012090842A - Needle piercing valve and hollow ball - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a needle piercing valve that has both high airtightness for maintaining the air pressure of a hydraulic ball and a smooth sliding property for an injection needle when air is injected, and a hollow valve having the same.SOLUTION: The needle piercing valve 1 is attached to a hollow ball and has a piercing hole 11 which is pierced with an injection needle for injecting air. The needle piercing valve 1 is made from silicone rubber containing silicone oil. The piercing hole 11 is formed of a guide hole 12 axially extended and having an outside diameter larger than that of the injection needle, and a piercing hole 13 axially extended from the bottom 14 of the guide hole 12 and having a cross-sectional shape similar to that of the injection needle. The hollow ball includes the needle piercing valve 1.

Description

  The present invention relates to a needle puncture valve and a hollow ball, and more particularly, needle piercing that achieves both high airtightness for maintaining the air pressure of the hollow ball and smooth slidability of the injection needle when air is injected. The present invention relates to a valve and a hollow ball provided with the needle insertion valve.

  For example, a hollow ball such as a soccer ball, volleyball, basketball, handball, rugby ball, or tennis ball has an internal space filled with air. However, since the air filled in the internal space may leak to the outside over time and / or depending on the usage state, it is necessary to replenish the internal space with air. Therefore, such a hollow ball includes a needle puncture valve connected to a pump or the like through which an injection needle for injecting air is pierced.

  An example of such a hollow ball is described in Patent Document 1. Specifically, the hollow ball described in Patent Document 1 is obtained by bonding a valve to the inner surface of a bladder formed by fusion-bonding two hollow hemispheres made of a thermoplastic elastomer into a hollow sphere. In the exercise ball, a small hole is formed in the inner surface of the bladder to which the valve is bonded, and a thick part is formed around the inner surface of the bladder in the small hole. A large diameter part having a larger diameter than the small hole located on the surface side bonded to the bladder inner surface, and an elastomer having a flat surface bonded to the through hole and the thick part. An exercise ball comprising a small diameter portion communicating with the bladder inner space.

  By the way, when air is injected into the hollow ball, if the needle is difficult to pierce the needle puncture valve, the needle piercing valve is damaged, and the sealing performance of the needle piercing valve, that is, the hollow ball is lowered. Air may easily leak from the outside.

  One method for avoiding such a problem is a method of applying a lubricant such as glycerin to the injection needle and inserting it into the needle puncture valve. However, this method is not efficient because a lubricant needs to be applied to the injection needle every time air is injected.

  On the other hand, a hollow ball provided with a needle piercing valve having a slit coated with a lubricant has been proposed. For example, as a method of manufacturing such a hollow ball, Patent Document 2 states that “in a method of manufacturing a soft tennis ball including an air supply valve composed of a cylindrical valve and a valve peripheral rubber, The valve peripheral rubber is vulcanized and bonded to a part of the inner wall of the ball body, a first hole is formed in the radial central portion of the valve peripheral rubber, and air is injected into the radial central portion of the valve. Forming a second hole for inserting the injection rod of the container, and forming a slit connected to the second hole at the central portion in the radial direction of the valve by the cutter in which a lubricant is applied to the blade edge of the cutter. The manufacturing method is characterized in that the lubricant is applied to the slit to form the valve, and the valve is inserted and bonded into the first hole of the peripheral rubber of the valve.

  In the needle piercing valve of Patent Document 2, a lubricant is applied in advance to the slit, but the lubricant gradually disappears, and its effect may fade with time.

Noto 2544929 Japanese Patent No. 4028910

  The present invention relates to a needle puncture valve that achieves both high airtightness for maintaining the air pressure of a hollow ball and smooth slidability of an injection needle when air is injected, and a hollow ball provided with this needle insertion valve The purpose is to provide

As means for solving the problems,
Claim 1 is a needle piercing valve mounted on a hollow ball and having a piercing hole through which an injection needle for air injection is pierced, and the needle piercing valve is made of silicone rubber containing silicone oil. Formed, the piercing hole is extended in the axial direction, continuously provided along the axial direction from the bottom of the guide hole, the guide hole having an outer diameter larger than the outer diameter of the injection needle, A needle puncture valve characterized by having an insertion hole having a cross-sectional shape similar to the cross-sectional shape of the injection needle,
The needle insertion valve according to claim 1, wherein the insertion hole contracts toward an axis when the insertion hole is attached to a hollow ball and closes.
The needle insertion valve according to claim 1 or 2, wherein the insertion hole has a substantially constant inner diameter along the axial direction.
According to a fourth aspect of the present invention, in place of the insertion hole, a slit formed along the axial direction from the bottom of the guide hole so as to be a trident or a cross in a plane perpendicular to the axial direction. The needle puncture valve according to any one of claims 1 to 3, wherein
A fifth aspect of the present invention is a hollow ball comprising the needle piercing valve according to any one of the first to fourth aspects.

  Since the needle puncture valve according to the present invention is formed of silicone rubber containing silicone oil and has a piercing hole having a guide hole and an insertion hole, the silicone oil oozes out on the inner surface of the insertion hole. When inserted in a hollow ball, the inner surfaces of the insertion holes are brought into close contact with each other through silicone oil to provide high airtightness, and the injection needle smoothly slides through the insertion holes with silicone oil inside the insertion holes. Easy to pierce. In addition, since the insertion hole has the cross-sectional shape, the injection needle inserted or pierced does not deteriorate the airtightness due to the close contact with the inner surface of the insertion hole. Therefore, according to the present invention, it is possible to provide a needle puncture valve that achieves both high airtightness for maintaining the air pressure of the hollow ball and smooth slidability of the injection needle when air is injected.

  Further, since the hollow ball according to the present invention includes the needle insertion valve according to the present invention, high airtightness for maintaining the air pressure of the hollow ball and smooth slidability of the injection needle when air is injected are provided. A hollow ball having a compatible needle piercing valve can be provided.

FIG. 1 is a view showing a needle puncture valve as an example of a needle puncture valve according to the present invention, and FIG. 1 (a) shows a needle puncture valve as an example of a needle puncture valve according to the present invention. FIG. 1B is a top view showing a needle puncture valve that is an example of a needle puncture valve according to the present invention. FIG. 2 is a view showing a needle puncture valve which is another example of the needle puncture valve according to the present invention, and FIG. 2A is a needle puncture which is another example of the needle puncture valve according to the present invention. FIG. 2B is a top view showing a needle puncture valve which is another example of the needle puncture valve according to the present invention. FIG. 3 is a schematic sectional view showing a hollow ball which is an example of the hollow ball according to the present invention.

  The needle puncture valve according to the present invention is a valve that is attached to a hollow ball and through which an injection needle for air injection is pierced. The hollow ball to which the needle puncture valve according to the present invention is attached may be any ball as long as it has a space inside and is filled with a gas such as air at a predetermined air pressure. A ball, specifically, a soccer ball, a volleyball, a basketball, a handball, a rugby ball, a tennis ball, etc. are mentioned. The needle puncture valve according to the present invention is attached to the hollow ball, particularly the inner surface thereof, such that a part thereof, for example, the opening of the guide hole is exposed on the surface of the hollow ball. Therefore, the needle puncture valve according to the present invention can be referred to as a hollow ball needle puncture valve.

  The needle puncture valve according to the present invention is pierced by an injection needle for air injection connected to a pump or the like. Since the needle puncture valve according to the present invention has an insertion hole, the injection needle is usually a tubular body, and the tip does not need to be pointed, and a flat tip surface is easy to handle and safe. Good nature. Although depending on the hollow ball to be mounted, such an injection needle generally has a circular or elliptical cross-sectional shape perpendicular to its axis, and its outer diameter (major diameter) is, for example, 1 to 1 4 mm.

  As shown in FIG. 1, a needle puncture valve 1 that is an example of a needle puncture valve according to the present invention has a tubular base 5 and a flange 8 formed on the outer peripheral surface of the base 5. .

  As shown in FIG. 1, the base 5 is formed into a tubular body, and has a piercing hole 11 formed so as to penetrate along the axis thereof, preferably coaxially with the axis. The base body 5 usually has a circular or elliptical cross-sectional shape perpendicular to its axis. The base body 5 is adjusted to an appropriate outer diameter (long diameter) and axial length according to the type of hollow ball on which the needle puncture valve 1 is mounted, the air pressure filled in the internal space, and the like. The outer diameter (major diameter) of the base 5 is set to 1.5 to 10 mm when the needle puncture valve 1 is mounted on a volleyball, for example, and is set to 1 to 9 mm when mounted on a basketball. . Further, the axial length of the base 5 is set to 20 to 40 mm when the needle piercing valve 1 is mounted on a volleyball or basketball, for example.

  The piercing hole 11 of the base body 5 is formed so as to penetrate in the axial direction of the base body 5, and when the hollow ball is mounted, the inner space of the hollow ball and the outside of the hollow ball are hermetically closed, and air injection is performed. A needle is pierced to communicate the internal space of the hollow ball with the outside of the hollow ball. The piercing hole 11 extends in the axial direction and is continuously provided along the axial direction from the bottom of the guide hole 12 with a guide hole 12 having an outer diameter larger than the outer diameter of the injection needle. And an insertion hole 13 having a cross-sectional shape similar to the cross-sectional shape. The guide hole 12 is formed on the outer side of the hollow ball when the needle puncture valve 1 is mounted on the hollow ball, and the insertion hole 13 is formed on the inner part side of the hollow ball, that is, the inner space side. .

  As shown in FIG. 1, the guide hole 12 is drilled along the axis of the base 5 and is a bottomed hole having a bottom portion 14. The guide hole 12 has an outer diameter larger than the outer diameter of the injection needle, and guides the injection needle to the insertion hole 13. Accordingly, the inner diameter of the guide hole 12 only needs to be larger than the outer diameter of the injection needle. For example, the inner diameter is 101 to 300% of the outer diameter of the injection needle. The cross-sectional shape perpendicular to the axis of the guide hole 12 is not particularly limited, but considering the guide reliability of the injection needle, etc., it may be circular, elliptical or polygonal, and is similar to the cross-sectional shape of the injection needle Preferably, it is circular in this example. The bottom surface 14 of the guide hole 12 is formed in a substantially hemispherical shape so that the tip of the injection needle is substantially coaxial with an insertion hole 13 to be described later in consideration of the guide reliability of the injection needle. The depth of the guide hole 12 is appropriately set according to the axial length of the base 5 and is, for example, 1 to 15 mm.

  As shown in FIG. 1, the insertion hole 13 is drilled from the bottom 14 of the guide hole 12 to the opposite end of the base body 5 along the axial direction, preferably coaxially with the guide hole 12. That is, the piercing hole 11 includes a guide hole 12 that opens to one end face of the base 5 and an insertion hole 13 that is connected to the guide hole 12 and opens to the other end face of the base 5. The insertion hole 13 has a cross-sectional shape similar to the cross-sectional shape of the injection needle, and in this example, has a circular cross-sectional shape. The inner diameter of the insertion hole 13 is smaller than the outer diameter of the injection needle and is substantially constant, preferably constant along the axial direction, and contracts toward the axial line, that is, the central direction when mounted on the hollow ball. And set to dimensions that can be closed. Here, “substantially constant” does not need to be exactly constant, does not hinder the insertion of the injection needle, and has an error that causes the insertion hole 13 to be in a sealed state or a closed state when attached to the hollow ball. The error may be 1.5 mm or less, for example. For example, when the needle puncture valve 1 is mounted on a volleyball, the inner diameter of the insertion hole 13 is about 10%, so that the inner diameter of the insertion hole 13 is 0.1 to 3 mm. Is set. Thus, the insertion hole 13 is in a penetrating state when it is not attached to the hollow ball, whereas when it is attached to the hollow ball, it is contracted to be in a sealed state or a closed state. In particular, when the cross-sectional shape of the insertion hole 13 is the above-described shape, the adhesion between the outer peripheral surface of the injection needle and the inner surface of the insertion hole 13 increases, and the injection needle is inserted even if the injection needle is injected many times. Excellent airtightness.

  As shown in FIG. 1, the flange portion 8 is formed in an annular shape that radially bulges from the outer peripheral surface of the base body 5 toward the guide hole 12 side from the center in the axial direction of the base body 5. The flange portion 8 is fitted into a fitting concave portion of a mounting body provided in the hollow ball so that the needle piercing valve 1 does not easily fall off the hollow ball. Therefore, the formation position, the outer diameter, and the axial length of the collar portion 8 are set so as to fit the fitting recess. For example, the outer diameter of the collar portion 8 is 5 to 15 mm, and the axial length is 3 to 6 mm.

  The needle piercing valve 1 is made of silicone rubber containing silicone oil. When the needle puncture valve 1 is formed of such silicone rubber, silicone oil oozes out from the inner surface of the insertion hole 13 and contributes to both airtightness and slidability of the injection needle.

  The silicone rubber is not particularly limited, and various silicone rubbers can be used. Examples thereof include dimethyl silicone rubber, methylphenyl silicone rubber, and organosilicone rubber having an alkyl group having 1 to 6 carbon atoms.

  The silicone oil is not particularly limited, and various silicone oils can be used, and examples thereof include dimethyl silicone oil and methylphenyl silicone oil. The silicone oil preferably has a viscosity (25 ° C.) of 1 to 10 mPa · s, and preferably has a number average molecular weight of 500 to 1500 in terms of appropriate leaching on the surface of the silicone rubber. The number average molecular weight is a standard polystyrene equivalent molecular weight by GPC. The silicone rubber may contain various commonly used additives. Such additives include, for example, dispersants, foaming agents, vulcanizing agents, antioxidants, antioxidants, fillers, pigments, colorants, processing aids, plasticizers, flame retardants, release agents. Examples include molds.

  Among the silicone rubber and the silicone oil, a combination of dimethyl silicone rubber and dimethyl silicone oil is preferable in that the silicone oil is appropriately leached over a long period of time.

  The content of silicone oil in the silicone rubber containing silicone oil and the needle piercing valve 1 which is a molded product thereof is 1 with respect to 100 parts by mass of silicone rubber (including additives when containing additives). It is preferably -30 parts by mass, particularly preferably 5-10 parts by mass.

  The silicone rubber, that is, the needle puncture valve 1, has a rubber hardness (JIS A) of preferably 10 to 50 °, and particularly preferably 20 to 40 °. When the rubber hardness of the silicone rubber is within the above range, the insertion hole 13 of the needle puncture valve 1 can be closed with high airtightness. The rubber hardness (JIS A) is measured by preparing a silicone rubber composition that forms silicone rubber. Specifically, when the composition of the silicone rubber is known, a silicone rubber composition having that composition is prepared. Then, a test piece having a thickness of 6 mm and a length and width of 12 mm was prepared using the prepared silicone rubber composition, and the hardness of the test piece was measured in accordance with JIS K 6253 using a type A durometer. This is the value when

  The needle piercing valve 1 is made of silicone rubber containing silicone oil and has the piercing hole 11, so that both high airtightness and smooth slidability of air can be achieved. Therefore, even if lubricant such as glycerin is not applied to the injection needle, and the lubricant is not previously applied to the insertion hole 13 or the like, the injection needle can be easily applied to the insertion hole 11 while maintaining high airtightness. Can be pierced.

  As shown in FIG. 2 (a), a needle puncture valve 2, which is another example of the needle puncture valve according to the present invention, includes a tubular base body 6 and a flange 8 formed on the outer peripheral surface of the base body 6. have. This needle puncture valve 2 is basically the same as the needle puncture valve 1 except that it has a trident slit 16 instead of the insertion hole 13. Therefore, the trident slit 16 is formed along the axial direction of the piercing hole 11 from the bottom 14 of the guide hole 12 to the end surface on the opposite side of the base 6. The slits 16 extend radially in three directions so that a central angle formed by adjacent slits is about 120 ° on a plane perpendicular to the axial direction. The extending length in the radial direction of each slit at this time is appropriately set according to the outer diameter of the inserted injection needle and the like, and is, for example, 0.25 to 2.5 mm. As shown in FIG. 2A, the slit 16 is in a closed state even when not mounted on the hollow ball, unlike the needle puncture valve 1. Compared with the needle puncture valve 1, the needle puncture valve 2 is slightly inferior to the slidability of the injection needle. Therefore, it has excellent sliding durability. Therefore, the needle piercing valve 2 is preferably employed if the sliding durability is particularly focused.

  As shown in FIG. 2B, a needle puncture valve 3 which is another example of the needle puncture valve according to the present invention includes a tubular base body 7 and a collar portion formed on the outer peripheral surface of the base body 7. 8. This needle puncture valve 3 is basically the same as the needle puncture valve 1 except that it has a cross-shaped slit 17 instead of the insertion hole 13, and the needle puncture valve 3 has the same shape except for the slit shape. This is basically the same as the valve 2. The slits 17 extend radially in four directions so that the central angle formed by the adjacent slits is about 90 ° on a plane perpendicular to the axial direction.

  A method for manufacturing the needle puncture valve according to the present invention will be described by taking the needle puncture valve 1 as an example. The needle puncture valve 1 can be manufactured, for example, by molding a silicone rubber composition that forms silicone rubber into a predetermined shape. The silicone rubber composition to be prepared contains a rubber precursor that forms the silicone rubber, the silicone oil, and various additives as required. Examples of the rubber precursor include polyorganosiloxane and polydimethylsiloxane. The silicone oil content in the silicone rubber composition is preferably 1 to 30 parts by mass, particularly preferably 5 to 10 parts by mass with respect to 100 parts by mass of the silicone rubber composition. Among the silicone rubber compositions, a silicone rubber composition containing dimethyl silicone rubber and dimethyl silicone oil is preferable.

  The prepared silicone rubber composition is molded into a predetermined shape by various molding methods, for example. For example, injection molding using a mold, compression molding, or the like is preferably employed. In this way, a needle puncture valve can be manufactured. In addition, after forming the needle piercing valves 2 and 3 having the slits 16 and 17, the slits 16 and 17 can be formed later using a cutter or the like.

  The hollow ball according to the present invention includes the needle insertion valve according to the present invention. The hollow ball according to the present invention includes a spherical shell formed in a spherical shape, a valve mounting portion provided on the spherical shell, and a needle insertion valve mounted on the valve mounting portion. The spherical shell may have a single-layer structure or a multi-layer structure, and the layer structure is appropriately selected according to the use of the hollow ball. Examples of the layer constituting the multilayered spherical shell include a reinforcing layer that reinforces the strength of the spherical shell, and a skin layer. The valve mounting portion is provided inside the spherical shell by bonding or the like, and stores the needle insertion valve in its storage space. Therefore, the valve mounting portion is a tubular hollow housing. In this valve mounting portion, the storage space usually has a smaller radial dimension than the needle insertion valve, and the needle insertion valve is formed in the storage recess in a state compressed in the radial direction in the storage space. In this case, the needle insertion valve is stored in a state in which the collar portion is fitted. By being stored in the storage space in this way, the needle insertion valve, in particular, the insertion hole and the slit maintain a high close state. The hollow ball according to the present invention can adopt a known configuration as appropriate except for the needle insertion valve according to the present invention. For example, the configuration of Patent Document 1 can be adopted. The configuration other than the needle insertion valve in the hollow ball according to the present invention is appropriately configured according to the type of the hollow ball, for example, soccer ball, volleyball, basketball, handball, rugby ball, tennis ball and the like.

  The hollow ball according to the present invention will be specifically described with reference to the drawings. As shown in FIG. 3, a hollow ball 70 as an example of a hollow ball according to the present invention includes a spherical shell 71 formed in a spherical shape, a valve mounting portion 72 provided in the spherical shell 71, and the valve mounting. The needle insertion valve according to the present invention, for example, the needle insertion valve 1, mounted on the portion 72 is included. The spherical shell 71 has a three-layer structure including a base layer 71a, a reinforcing layer 71b, and a skin layer 71c. The base layer 71a is formed in a hollow shape with an air impermeable rubber such as butyl rubber. The reinforcing layer 71b is a layer formed by winding a fiber such as nylon on the outer peripheral surface of the base layer 71a, and the skin layer 71c is formed of natural leather or synthetic leather. The spherical shell 71 defines an internal space 73 filled with air. As shown in FIG. 3, the valve mounting portion 72 is a tubular hollow casing bonded to the inside of the base layer 71a, and the needle insertion valve is formed by fitting the collar portion 8 into the fitting recess therein. It has a storage space 72a for storing 1 compressed in the radial direction.

  Since the hollow ball according to the present invention includes the needle insertion valve according to the present invention, the hollow ball has high airtightness for maintaining the air pressure of the hollow ball and smooth slidability of the injection needle when air is injected. is doing. Therefore, according to the present invention, the object of providing a hollow ball that achieves a high level of both high airtightness for maintaining the air pressure of the hollow ball and smooth slidability of the injection needle when air is injected is achieved. it can.

  The needle piercing valve and the hollow ball according to the present invention are not limited to the above-described embodiments, and various modifications can be made within a range in which the object of the present invention can be achieved. For example, each of the needle piercing valves 1 to 3 includes the bases 5 to 7 and the collar portion 8, but in this invention, the needle piercing valve does not include other engagement means instead of the collar portion. Alternatively, only the base may be provided.

  The piercing hole 11 has a guide hole 12 and an insertion hole 13 or a slit 16 or 17. In this invention, the piercing hole may have only an insertion hole or a slit, You may have a guide hole, an insertion hole, or a slit and a large-diameter hole formed in the insertion hole or slit on the opposite side of the guide hole.

  Although the insertion hole 13 has a circular cross-sectional shape, in this invention, the insertion hole may have a plurality of slits cut radially from the inner surface thereof. In this case, for example, it is preferable that three or four slits are formed at equal intervals in the circumferential direction of the insertion hole on a plane perpendicular to the axial direction of the insertion hole.

Example 1
A silicone rubber composition containing dimethyl silicone oil was prepared. In addition, content of the silicone oil in this silicone rubber composition exists in the said range.

The prepared silicone rubber composition was injected into a mold capable of forming the piercing hole 11 having the insertion hole 13 and molded at a molding temperature of 175 ° C. for 10 minutes to produce the needle piercing valve 1 shown in FIG. . The needle piercing valve 1 had a rubber hardness of 40 ° and the following dimensions.
Base 5: Axis length 27 mm, outer diameter 7 mm
Ridge part 8: axial length 5 mm, outer diameter 10 mm
Guide hole 12: depth 10mm, inner diameter 2.5mm, curvature radius R1.25 of bottom 14
Insertion hole 13: axis length 17 mm, inner diameter 0.5 mm

(Example 2)
Basically the same as Example 1 except that the silicone rubber composition was molded using a mold capable of forming only the guide hole 12 instead of the mold, and then the trident slit 16 was formed with a cutter. Similarly, the needle piercing valve 2 shown in FIG. This needle puncture valve 2 had the following dimensions.
Base 5: Axis length 27 mm, outer diameter 7 mm
Ridge part 8: axial length 5 mm, outer diameter 10 mm
Guide hole 12: depth 10mm, inner diameter 2.5mm, curvature radius R1.25 of bottom 14
Slit 16: Axis length 17mm, radial extension length 0.75mm

(Example 3)
A needle piercing valve 3 shown in FIG. 2B was manufactured basically in the same manner as in Example 2 except that a cross-shaped slit 17 was formed with a cutter instead of the trident slit 16. This needle puncture valve 3 had the following dimensions.
Base 5: Axis length 27 mm, outer diameter 7 mm
Ridge part 8: axial length 5 mm, outer diameter 10 mm
Guide hole 12: depth 10mm, inner diameter 2.5mm, curvature radius R1.25 of bottom 14
Slit 17: Axis length 17mm, radial extension length 0.75mm

(Comparative Example 1)
A needle piercing valve of Comparative Example 1 was manufactured in basically the same manner as in Example 2 except that one single-letter slit was formed by a cutter instead of the trident slit 16. The needle puncture valve had the following dimensions:
Base 5: Axis length 27 mm, outer diameter 7 mm
Ridge part 8: axial length 5 mm, outer diameter 10 mm
Guide hole 12: depth 10mm, inner diameter 2.5mm, curvature radius R1.25 of bottom 14
Slit: Axis length 17mm, cutting depth 1.5mm

(Manufacture of hollow balls)
Using the manufactured needle puncture valves of Examples 1 to 3 and Comparative Example 1, hollow balls shown in FIG. 3 were manufactured. That is, a base layer 71a formed hollow with butyl rubber, a reinforcing layer 71b formed by wrapping nylon on the outer peripheral surface of the base layer 71a, and a skin layer 71c formed by attaching natural leather to the outer peripheral surface of the reinforcing layer 71b A hollow ball was manufactured by mounting the manufactured needle puncture valve on the valve mounting portion 72 of the spherical shell 71 having the above. The internal pressure inside the hollow of each hollow ball was adjusted to 300 hPa.

(Slidability of injection needle)
Each hollow ball manufactured as described above is attached to a measuring terminal of a tensile testing machine (trade name “Tensilon Universal Material Testing Machine”, model number: RTM-100, manufactured by A & D Co., Ltd.). A metal rod (outside diameter 1.5 mm) simulating an injection needle for air injection was pressed until it penetrated through the needle insertion valve, and then extracted. The maximum stress generated at the time of press-fitting and withdrawal was measured with a tensile tester. This measurement was performed 50 times to obtain an arithmetic average value of stress. As a result, Example 1 was 7.2N, Example 2 was 8.0N, and Example 3 was 7.8N, while Comparative Example 1 was 10.2N, and the slidability was extremely poor. It was.

(air tightness)
One cycle of insertion / removal operation to insert / extract after inserting a metal rod (outside diameter 1.5mm) imitating an injection needle for air injection into the needle insertion valve of each manufactured hollow ball until it penetrates the needle insertion valve As described above, continuous insertion and removal operations of 50 cycles were repeated. After 50 cycles of insertion and removal operations were completed, the internal pressure of each hollow ball was measured using a “dial-type ball internal pressure gauge” (trade name “Digital Pressure Gauge”, manufactured by Molten Co., Ltd.). As a result, Example 1 was 260 hPa, Example 2 was 250 hPa, and Example 3 was 240 hPa, whereas Comparative Example 1 was 190 hPa, and the airtightness was extremely low.

1, 2, 3 Needle piercing valve 5, 6, 7 Substrate 8 Gutter part 11 Puncture hole 12 Guide hole 13 Insertion hole 14 Bottom part 16, 17 Slit 70 Hollow ball 71 Spherical shell 71a Base layer 71b Reinforcement layer 71c Skin layer 72 Valve Mounting part 72a Inner part 73 Inner space

Claims (5)

A needle puncture valve mounted on a hollow ball and having a piercing hole through which an injection needle for air injection is pierced,
The needle piercing valve is formed of silicone rubber containing silicone oil,
The piercing hole extends in the axial direction, and is continuously provided along the axial direction from the bottom of the guide hole with a guide hole having an outer diameter larger than the outer diameter of the injection needle. A needle insertion valve having an insertion hole having a cross-sectional shape similar to the cross-sectional shape.   The needle insertion valve according to claim 1, wherein the insertion hole contracts and closes toward an axis when mounted on a hollow ball.   The needle insertion valve according to claim 1 or 2, wherein the insertion hole has a substantially constant inner diameter along the axial direction.   Instead of the insertion hole, it has a slit formed along the axial direction from the bottom of the guide hole so as to form a trident or a cross in a plane perpendicular to the axial direction. The needle puncture valve according to any one of claims 1 to 3.   The hollow ball provided with the needle puncture valve of any one of Claims 1-4.

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