CAP UNIT FOR PUNCTURE REPAIR

A cap unit for puncture repair comprises a check valve 6 for preventing a backflow of a puncture repair liquid supplied from a bottle container 2. The check valve 6 is disposed in a first flow path 3 used for taking compressed air from a compressor 8 into a bottle container 2. The check valve is formed by a ball valve 21 disposed in a valve housing zone Y which is located in a vertical passage part 15 of the first flow path 3 and between an upper opening 3U and a valve seat portion 20. The ball valve 21 is formed by a rubber-like elastic body having a specific gravity of 1.1 or more, and a rebound resilience of 15% or less.

BACKGROUND OF THE INVENTION

The present invention relates to a cap unit used in a puncture repair kit for injecting a puncture repair liquid and compressed air sequentially into a punctured tire to temporary fix the puncture.

For example, in the following Patent Document 1, a cap unit for puncture repair has been proposed.

This cap unit has, as shown inFIG. 4, a first flow path (a) for taking compressed air supplied from a compressor into a bottle container, and a check valve (b) to prevent a puncture repair liquid from flowing backward.

The check valve (b) comprises a metal ball valve b1disposed in a valve housing zone (c) formed in the first flow path (a), a rubber valve seat b2disposed at the lower end of the valve housing zone (c), and a biasing spring b3for pressing the ball valve b1against the valve seat b2. Such structure leads to an increase in the cost.

On the other hand, in the following Patent Document 2, a check valve having a simple structure is disclosed, wherein a metal ball valve is inserted in a first flow path provided with a valve seat portion. In this check valve, the valve seat portion is closed by the weight of the ball valve.

In order to retain the ball valve, a locking pin is inserted in the upper end of the first flow path. This structure is simple, and the parts are less in number, therefore, the cost can be reduced.

However, since the ball valve is free to move in the first flow path during storage in a vehicle by the vibrations of the vehicle during traveling, there is a problem such that abnormal noise is caused, making the passenger uncomfortable.

Japanese Patent Application Publication No. 2011-189696

Japanese Patent Application Publication No. 2010-023244

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide a cap unit for puncture repair, in which abnormal noise occurring from a ball valve due to vibrations of the vehicle during traveling can be suppressed, while employing a simple structure to achieve a cost reduction.

According to the present invention, a cap unit for puncture repair comprises:

a cap main body which is attached to a mouth portion of a bottle container containing a puncture repair liquid, and which has a first flow path for taking compressed air from a compressor into the bottle container, and a second flow path for taking out the puncture repair liquid and the compressed air sequentially from the bottle container by the taking-in of the compressed air, and

a check valve which is disposed in the first flow path to prevent a back-flow of the puncture repair liquid supplied from the bottle container,

in a reference attitude of the bottle container whose mouth portion is directed downward, the first flow path has a vertical passage part extending downward from the top opening which opens within the bottle container, and

a valve seat formed in the vertical passage part,

the check valve is a ball valve disposed in a valve housing zone which is formed within the vertical passage part and on the upper side of the valve seat, and

the ball valve is made of a rubber-like elastic material having a specific gravity of 1.1 or more, and a rebound resilience of 15% or less.

In the cap unit for puncture repair according to the present invention, the rubber-like elastic material preferably has a low-temperature-embrittlement temperature of −30 degrees C. or below.

In the cap unit for puncture repair according to the present invention, the ratio Db/Da of the outer diameter Db of the ball valve and an inner diameter Da of the valve housing zone is preferably in the range from 0.75 to 0.9.

In the cap unit for puncture repair according to the present invention, the ratio Db/L of the outer diameter Db of the ball valve and a vertical length L of the valve housing zone is preferably 0.5 or more.

The “specific gravity” is measured in accordance with JIS K6268 “Rubber, vulcanized-Determination of density”.

The “rebound resilience” is measured in accordance with JIS K6255 “Rubber, vulcanized or thermoplastic-Determination of rebound resilience” at a temperature of 23 degrees C.

The “low-temperature-embrittlement temperature” is measured in accordance with JIS K6261 “Rubber, vulcanized or thermoplastic Determination of low temperature properties”, “Low-temperature brittleness test”.

In the cap unit according to the present invention, therefore, as the specific gravity of the ball valve is 1.1 or more, the ball valve can move down in the puncture repair liquid immediately by its own weight and can rapidly close the valve seat, which means that it can function as a check valve without using a biasing spring. Further, the ball valve is formed from the rubber-like elastic body of low repulsion. Therefore, even if the ball valve repeats collisions with the wall of the first flow path due to the vibrations during traveling of the vehicle, abnormal noise is hard to occur and quietness can be ensured.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, an embodiment of the present invention will be described in detail.

FIG. 1shows an example of a puncture repair kit K employing a cap unit1according to the present invention.

The puncture repair kit K comprises the cap unit1, a bottle container2, and a compressor8so as to inject a puncture repair liquid and compressed air sequentially into a punctured tire to temporary fix the puncture.

FIG. 2is a sectional view of the cap unit1showing a state in which the bottle container2is mounted thereon.

The bottle container2has a well-known structure in which a small-diameter cylindrical mouth portion2A for taking out the puncture repair liquid is protruded from the lower end of the container portion2B for accommodating the puncture repair liquid.

Hereinafter, the cap unit1will be described in its reference attitude such that the mouth portion2A of the bottle container2is directed downward.

As shown inFIG. 2, the cap unit1has a cap main body5provided with a first flow path3and a second flow path4, and a check valve6disposed in the first flow path3.

The first flow path3is for taking the compressed air supplied from the compressor8in the bottle container2.

The second flow path4is for taking out the puncture repair liquid and the compressed air sequentially from the bottle container2by the taking-in of the compressed air.

The cap main body5in this example is provided at the upper end of a cylindrical body portion5A with a bottle mounting recess9for mounting the mouth portion2A of the bottle container2.

The inner circumferential surface of the bottle mounting recess9is provided with an internal threaded portion to which the mouth portion2A is attached by being screwed.

In the bottom surface of the bottle mounting recess9, there are disposed a boss portion10extending into the bottle container2, and an annular rib23surrounding the boss portion10so that they protrude from the bottom surface.

The boss portion10and the annular rib23in this example are formed concentrically with the bottle mounting recess9.

In the outer side surface of the cap main body5, there are disposed a first connecting portion11for the compressor, and a second connecting portion12for the tire so that they protrude therefrom.

The first connecting portion11in this example is a connection nozzle which can be coupled directly with a compressed air discharge port8A (shown inFIG. 1) of the compressor8without using a hose.

The second connecting portion12in this example is a hose connecting portion to which a hose to be connected to the tire T can be connected.

The first flow path3has a vertical passage part15and a horizontal passage part16.

The vertical passage part15extends downwardly from its upper opening3U which opens at the upper end of the boss portion10.

The horizontal passage part16extends substantially horizontally from a lower opening3L which opens at an end of the first connecting portion11, and intersects the vertical passage part15in the form of an L-shape.

The second flow path4has a vertical passage part17and a horizontal passage part18.

The vertical passage part17extends downwardly from its upper opening4U which opens in the bottom surface of the bottle mounting recess9and between the boss portion10and the annular rib23. The horizontal passage part18extends substantially horizontally from a lower opening4L which opens at an end of the second connecting portion12, and intersects the vertical passage part17in the form of an L-shape.

In the first flow path3, there is disposed the check valve6to prevent the backflow of the puncture repair liquid supplied from the bottle container2.

In the vertical passage part15of the first flow path3, as shown inFIG. 3(A), there are disposed a valve seat20, and a valve housing zone Y located on the upper side of the valve seat.

The valve seat20has a cone-shaped valve seat surface20swhose diameter is reduced toward the lower side.

The check valve6is formed by a ball valve21disposed in the valve housing zone Y.

The ball valve21is placed in the valve housing zone Y loosely to be movable up and down, and can close the valve seat20by the down motion due to its own weight.

Thereby, the reverse flow of the puncture repair liquid toward the compressor is prevented.

In this example, the upper opening3U is provided with a locking portion24for preventing the ball valve21from falling out therethrough. Accordingly, the valve housing zone Y is formed as a zone between the valve seat20and the locking portion24.

The locking portion24is, as shown inFIG. 3(B), formed by a plurality of (eg, three) projections protruding from the inner circumferential surface of the boss portion10.

In this example, the locking portion24is formed by melting the boss portion10partially by the use of, for example, a soldering iron or the like after the ball valve21has been inserted in the valve housing zone Y.

The ball valve21is made of a rubber-like elastic material having a specific gravity of 1.1 or more and a rebound resilience of 15% or less.

The specific gravity of the puncture repair liquid is usually about 1.03, and the ball valve21is heavier than the puncture repair liquid. Therefore, when the puncture repair liquid is going to flow back, the ball valve21moves down immediately, and it is possible to close the valve seat20. If the specific gravity is less than 1.1, the downward movement due to its own weight becomes slower, and the backflow of the puncture repair liquid can not be sufficiently prevented. Therefore, it is preferable that the specific gravity is 1.3 or more. The upper limit of the specific gravity is not particularly restricted.

The ball valve21is formed by the rubber-like elastic body of low repulsion. Therefore, during storage, even if the ball valve21repeats collisions with the wall of the first flow path3due to vibrations of the vehicle during traveling, abnormal noise is hard to occur and quietness can be ensured. If the rebound resilience is more than 15%, the occurrence of abnormal noise can not be sufficiently prevented.

Although the lower limit of the rebound resilience is not particularly restricted, it is difficult at present to produce a rubber-like elastic body whose rebound resilience is less than 2%. On the other hand, since the ball valve21is formed by the rubber-like elastic body, even if the valve seat20is formed from a plastic as a part of the cap main body5, the sealing can be assured.

There is a tendency that the puncture repair kits K are stored or used in a temperature range of from −30 degrees C. to +60 degrees C. Therefore, it is preferable for the cap unit1that the ball valve21does not cause brittle fracture at least down to −30 degrees C. Accordingly, as the ball valve21, the rubber-like elastic body having the low-temperature-embrittlement temperature of under −30 degrees C. is preferably used.

In the check valve6, it is preferable that the ratio Db/Da of the outer diameter Db of the ball valve21and the inner diameter Da of the valve housing zone Y is set in a range of from 0.75 to 0.9.

If the ratio Db/Da is less than 0.75, then the movement of the ball valve21in the valve housing zone Y becomes large, and the collision with the wall of the valve housing zone Y becomes strong. Thus, this is disadvantageous for suppressing the generation of abnormal noise.

If the ratio Db/Da is more than 0.9, the flow rate of the high pressure air passing by the ball valve2is reduced, and the time required for injecting the puncture repair liquid and increasing the pressure becomes longer, which is disadvantageous to the puncture repair work.

In the check valve6, it is also preferable that the ratio Db/L between the outer diameter Db of the ball valve21and the length L of the valve receiving area Y is 0.5 or more. If the ratio Db/L is less than 0.5, the movement of the ball valve21within the valve housing zone Y becomes large, which is disadvantageous for suppressing the generation of abnormal noise.

As shown inFIG. 1, the cap unit1is further provided with a guide stopper30. The housing of the compressor8is provided with a slot. At the time of attaching the cap unit1to the compressor8, the guide stopper30is inserted in the slot, and as a result, the bottle container2is held in the above-mentioned reference attitude by the housing.

As shown inFIG. 2, the cap unit1is further provided with an inner lid25for preventing the puncture repair liquid from flowing out of the upper openings3U and4U before actuating the compressor8when the puncture repair kit K has been set up. This inner lid25has a first sealing portion25A and a second sealing portion25B. The first seal portion25A hermetically contacts with the outer circumferential surface of the boss portion10to thereby seal the upper opening3U.

The second sealing portion25B hermetically contacts with the outer circumferential surface of the annular rib23to thereby seal the upper opening4U.

During the puncture repair kit K is operating, the compressed air from the compressor8pushes up the inner lid25, and the inner lid25is automatically removed to break the seal.

While detailed description has been made of a particularly preferred embodiment of the present invention, the present invention can be embodied in various forms without being limited to the illustrated embodiment.

WORKING EXAMPLES

In order to confirm the effects of the present invention, cap units having structures based on the structure shown inFIG. 2and having the specifications shown in Table 1, were experimentally manufactured, and each of the cap units was tested for the injecting and inflating time, and about whether the puncture repair liquid was flowed backward or not, and whether abnormal noise was generated from the ball valve or not.

The specific gravity, rebound resilience, and low-temperature-embrittlement temperature of the ball valve were changed by changing the rubber-like elastic material.

(1) Injecting and inflating time: using a same compressor, the time required to inject 400 cc of a puncture repair liquid into the tire (195/65R15) and to inflate the tire from zero pressure to 250 kPa was measured. The ambient temperature was −30 degrees C. The results are indicated in Table 1.
(2) whether the puncture repair liquid was flowed backward or not: After the injecting work of the puncture repair liquid was done, the cap unit was removed, and the presence or absence of the reverse flow into the first flow path was visually checked. The results are indicated in Table 1.
(3) whether abnormal noise was generated or not: During traveling in the city streets, each cap unit put on the floor of the rear seat was checked by the driver whether abnormal noise due to the ball valve was generated or not. The results are indicated in Table 1, wherein,
A denotes that abnormal noise was not generated,
B denotes that abnormal noise was slightly generated, and
C denotes that abnormal noise was generated.

As shown in Table, it was confirmed that, in the working examples, abnormal noise generated from the ball valve due to vibrations of the vehicle during traveling can be effectively suppressed.

DESCRIPTION OF THE SIGNS