JPS5827439B2 - Tire pressure injection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for injecting internal pressure into a tire using liquefied carbon dioxide gas.

Conventionally, it has been used as a simple tire pressure injection device for use when using foldable tires (Special Publication No. 45-27243, Special Publication No. 50-35957, etc.) or when repairing punctures, etc., to provide the necessary amount of internal pressure to the tire. It is known that liquefied Freon gas is sealed in a container with a valve mechanism.

This is intended to connect the valve of the container and the valve of the tire to introduce the Freon gas in the container into the tire air chamber, and to obtain the necessary tire internal pressure using the vapor pressure of the liquefied Freon gas.

However, Freon gas is generally expensive, and the vapor pressure at low temperatures does not reach the required internal tire pressure.
It has the disadvantage that it cannot be used in cold regions.

Furthermore, Freon gas poses a risk of causing air pollution if discharged into the atmosphere.

Liquefied carbon dioxide gas is known as being inexpensive, providing high vapor pressure even at low temperatures, and having no risk of air pollution.

The above-described disadvantages of injecting tire internal pressure with liquefied Freon gas can be overcome by using liquefied carbon dioxide gas, but since the vapor pressure of liquefied carbon dioxide gas is extremely high even at room temperature, there are many problems when using it.

First, as mentioned above, the vapor pressure of liquefied carbon dioxide gas is extremely high even at room temperature, so if a container filled with liquefied carbon dioxide gas is carelessly connected to a tire, a large amount of gas will instantly try to flow into the tire air chamber. , damage the tire valve,
Sudden pressure injection or excessive inflation can damage tires.

Furthermore, when using liquefied carbon dioxide, if a valve is installed like the Freon gas container mentioned above, the valve must be able to withstand high pressure, making the container expensive and having to be disposable. This results in a loss of practicality.

Therefore, when using liquefied carbon dioxide, the container is not designed to take out the gas with a valve, but rather to break the seal with an adapter with a needle rod before use, as is the case with gas cylinders for portable stoves. It can be said that a structure that allows for extraction is preferable.

However, when the adapter is used to break the seal, if the container is removed from the adapter during injection to stop the injection, high-pressure gas will gush out from the opening of the container, which is dangerous. The same is true because high-pressure residual gas still exists even after normal internal pressure injection.

In addition, the container must be strong enough to withstand high pressure.
There is also the problem that it becomes difficult to break the seal with an adapter.

The present invention solves the above-mentioned problems when using liquefied carbon dioxide gas to inject internal pressure into tires, and provides an easy-to-handle device that can safely and reliably inject internal pressure into tires using liquefied carbon dioxide gas. It is something.

That is, the present invention has a neck provided with a male thread on the outer periphery, and is filled with liquefied carbon dioxide necessary to give an appropriate internal pressure to the tire at a filling rate of 1.34 to 2.14 crn3/El. It has a container whose spout is sealed with a sealing plate, a container connection port at one end, and a tire valve connection port at the other end, and a female thread on the inner periphery of the container connection port that engages with the male thread of the container neck. A conical needle rod is provided at the bottom of the adapter's container connection port to break through the sealing plate when the container neck is screwed into the adapter's container connection port. In addition, a decompression hole leading to the outside is opened in the peripheral wall near the bottom of the container connection port, and a passage is further formed through the center of the needle rod to communicate the container connection port and the tire valve connection port. This is a tire internal pressure injection device in which the cross-sectional area of this passage is larger on the tire valve connection port side than on the container connection port side.

Hereinafter, the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of the present invention in a state where internal pressure is injected into a tire.

The device according to the present invention consists of a container 1 filled with liquefied carbon dioxide gas and an adapter 2.
It is connected to the tire valve 3 via.

The container 1 has a neck 7 provided with a male thread on the outer periphery.

The end of the neck γ is a spout 4.
is sealed by a sealing plate 5.

Further, a protrusion 6 is provided on the inner side of the shoulder of the container 1, and a gas spout hole 8 communicating with the spout 4 from inside the container 1 is formed.

This gas spout hole 8 is for preventing a sudden spout of carbon dioxide gas, and can be used when the pressure inside the container 1 is relatively low, or when the gas spout pressure can be sufficiently softened by an adapter 2, which will be described later. In some cases, there is no need to provide it.

Note that the size of the gas outlet hole 8 is such that its cross-sectional area is 0.
03 to Q, 3 ynm2 are preferred.

If it is too thick, it will not be possible to relieve the gas ejection pressure, and if it is too small, it will take too much time to inject the gas.

Considering safety etc., the liquefied carbon dioxide sealed in the container 1 has a filling rate of 1.34c1rL376;l ~ 2.1
4. It is necessary to be in the range of 3/g.

If the filling rate is less than 1.34 CrrL3/El, the internal pressure of the container 1 will become very high, and the internal pressure will increase rapidly, especially at high temperatures, which is not only dangerous but may also damage the tire valve 3 and the tire. There is a risk.

On the other hand, a filling rate of 2.14 means the critical specific volume of carbon dioxide gas, and if the filling rate is lower than this, the container 1 will not hold even at high temperatures.
Although the internal pressure does not increase, it is not efficient because the amount of carbon dioxide sealed is small.

Here, the filling rate means the ratio vc/gc of the internal volume Vc of the container 1 and the weight gc of the liquefied carbon dioxide gas sealed therein.

From the viewpoint of safety, it is preferable that the container 1 is configured to be able to sufficiently withstand the internal pressure generated when heated to about 80° C. with liquefied carbon dioxide gas sealed at the above-mentioned filling rate.

The container 1 is filled with liquefied carbon dioxide gas in an amount suitable for applying an appropriate internal pressure to the tire.

The amount of liquefied carbon dioxide to be sealed is determined with allowances for the amount of gas leakage that cannot be avoided during the injection operation and the amount of gas remaining in the container 1.

Considering the ease of handling of the container 1, the amount of gas leaked during internal pressure injection, and the accuracy of calculating the amount of gas remaining in the container 1, based on the filling rate and amount of liquefied carbon dioxide to be filled as described above, it is determined that it is suitable for the tire. The liquefied carbon dioxide necessary to provide a certain internal pressure is
Most preferably, the container is divided and sealed into 2 to 4 containers each having an internal volume of about 70 to 100 square meters.

If the capacity is increased too much, the container 1 will become large and inconvenient to handle.

Also, if the capacity is too small, the number of containers 1 will be too large, which will not only make the work complicated, but also reduce the amount of gas leakage and increase the number of containers 1.
The error in calculating the amount of gas remaining in the tank increases.

When liquefied carbon dioxide gas is dividedly sealed in the container 1 having the capacity as described above, the margin for the amount of gas leaking and the amount of gas remaining in the container 1 is 2 times the total amount of gas to be injected into the tire.
It is optimal to set it to good to 15%.

One end of the adapter 2 has a container connection port 9, and the other end has a tire valve 4 connection q1.
The inner periphery of the I-connector 9 is provided with a screw thread that engages with a male thread provided on the outer periphery of the neck 7 of the container 1. By screwing the neck 7 into the container connection port 9, the container 1 and adapter 2 are connected.

Furthermore, the container connection port 9 of the adapter 2 and the tire valve connection port 10 are communicated through a passage 11.

A gas reservoir 12 is formed in the middle of the passage 11, and a check valve 13 is provided here.

The gas reservoir 12 is used to relieve the pressure of carbon dioxide ejected from the container 1, and the diameter of the passage 11 is larger on the tire valve connection port 10 side than on the container connection port 9 side. It is for a similar purpose.

It is preferable that the formation of the gas reservoir 12 and the adjustment of the diameter of the passage 11 be performed in accordance with the internal pressure of the container 1.

In addition, the check valve 13 is for preventing the gas once injected into the tire from flowing back into the container 1. In particular, the present invention is designed to prevent the gas from flowing back into the container 1. Since it is preferable to divide and seal the four containers 1, it is convenient from the viewpoint of preventing gas leakage from inside the tire when replacing the containers 1.

The neck 7 of the container 1 is attached to the bottom of the container connection port 9 of the adapter 2.
A conical needle rod 17 is provided to protrude through the sealing plate 5 when it is screwed into the container connection port 9.

Further, the passage 11 passes through the center of the needle rod 17.

Furthermore, a pressure reduction hole 18 communicating with the outside is provided in the peripheral wall near the bottom of the container connection port 9.

This decompression hole 18 is used when removing the container 1 after injecting internal pressure.
This is to ensure safety by releasing residual gas.

Furthermore, safety is ensured by the decompression hole 18 even when the container 1 is removed midway to stop filling, such as when refilling when the internal pressure of the tire is somewhat low.

When the tire valve connection port 10 of the adapter 2 and the tire valve are connected with the screws provided on each, the protrusion 14 provided at the bottom of the tire valve connection port 10 presses the head 15 of the tire valve 3, and the valve 16 will be released.

Next, when the spout 4 portion of the container 1 is screwed into the container connection port 9, the needle rod 17 protruding from the bottom of the container connection port 9
The sealing plate 5 is broken and carbon dioxide gas is blown out and filled into the tire.

Here, as mentioned above, the needle rod 17 has a conical shape, and the sealing plate 5 of the container 1 is pressed against this needle rod 17 to break the seal, so as shown in the figure, the sealing plate 5 is The breaking piece protrudes inward of the container 1 in a shape that follows the shape of the needle rod 17, and the breaking piece sticks tightly to the needle rod 17 due to the pressure inside the container 1, thereby preventing gas leakage.

With this configuration, the container 1 can be opened simply by directly screwing the container 1 and the adapter 2 together, and no other means of unsealing the container 1 is required, making the unsealing operation extremely easy. Even the sealing plate 5 can be easily broken.

Further, the container 1 can be easily attached and detached, and safety can be sufficiently maintained especially when the container 1 is detached.

Since the gas pressure ejected from the container 1 can be sufficiently relaxed before being introduced into the tire air chamber, the tire valve 3 and the tire are not damaged, and appropriate internal pressure can be safely and reliably injected into the tire.

FIG. 2 shows another embodiment of the adapter, in which a container connection port 9 is formed at one end and a tire valve connection port 10 is formed at the other end, both of which are communicated through a passage 11.

A needle rod 17 similar to that described in FIG. 1 is protruded from the bottom of the container connection port 9, and a decompression hole 18 is bored in the peripheral wall near the bottom of the container connection port 9.

Furthermore, although this adapter 2' is not provided with a check valve like the one shown in Figure 1, the tire valve 3 is normally designed to open only when pressure is applied from the outside. Therefore, by utilizing this, backflow of gas from the tire to the container 1 direction can be prevented.

That is, the tire valve 3 connected to the container 1 via the adapter 2' is open while gas is being sent from the container 1, but when the pressure applied to the tire valve 3 is removed by removing the container 1, etc. It automatically closes to prevent gas from leaking from inside the tire.

If the adapter 2' is formed in this way, its structure will be extremely simple, making it easy to manufacture and reducing the risk of failure.

As described above, according to the present invention, internal pressure can be easily and safely injected into a tire regardless of time and place.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention in a state where internal pressure is injected into a tire, and FIG. 2 is a sectional view showing another embodiment of the adapter.

Claims (1)

[Claims] 1 It has a neck with a male thread on the outer periphery, and has a filling rate of 1.3 liquefied carbon dioxide, which is necessary to give the tire an appropriate internal pressure.
4 to 2.14crn3/&, and has a container with a spout at the end of the neck sealed with a sealing plate, a container connection port at one end, and a tire valve connection port at the other end, and an inner periphery of the container connection port. It consists of an adapter with a female thread that engages with a male thread on the container neck, and a seal plate is provided at the bottom of the container connection opening of the adapter that breaks through the sealing plate when the container neck is screwed into the adapter's container connection opening. A conical needle stick protrudes from the container connection port, and a decompression hole leading to the outside is opened in the peripheral wall near the bottom of the container connection port. A tire internal pressure injection device characterized in that a passage is formed to communicate the tire valve connection port, and the cross-sectional area of the passage is wider on the tire valve connection port side than on the container connection port side.