Tire with self-inflation device

Provided is a tire with self-inflation device. The tube is inserted inside the side portion where the extension and contraction movements of the tire are mostly occurring in order to further enhance the efficiency of the air supply to the tire cavity during driving. The air compressed towards the driving direction is injected to the tire cavity, and the air from the outside is charged to the tube due to the negative pressure formed in the tube located in the opposite side of driving. The durability is enhanced by reducing the exposed portion of the regulator.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This U.S. non-provisional patent application claims priority under 35 U.S.C. § 119 of Korean Patent Application No. 10-2016-0178250 filed on Dec. 23, 2016 in the Korean Patent Office, the entire contents of which are hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a tire capable of self-maintaining a proper air pressure by supplementing the leaking air pressure during tire operation through the air compression reaction induced by extension and contraction of the tube connected to the regulator.

BACKGROUND

Generally a minute portion of the air confined in the assembly of the tire and the rim is naturally leaking out as the time elapses.

When the air pressure of a tire is lower than the proper air pressure, steering, braking, and driving performance of a vehicle will be degraded.

In order to maintain the preset air pressure of a tire, the tire pressure detection system of the prior art measures the pressure or the temperature inside the tire using the tire pressure detection sensor mounted in the wheel and transmits this information to the control unit via the wireless communication.

However, the tire pressure detection system of the prior art simply alarm the driver when the tire pressure drops below the predetermined pressure, therefore, there has been a problem that still there is a risk of driving accident during driving to a vehicle service station, and intervening of the driver is necessary.

Further progressed from tire pressure monitoring system (TPMS), the necessity of development of an active tire safety device not requiring involvement of a driver when the tire pressure is decreased has been suggested.

Followings are the descriptions about a prior art related to tires capable of self-maintaining air pressure thereof.

(1) First, European Patent No. 1648721 (hereinafter refer to as ‘Prior Art 1’) is characterized in that a tube is installed between the tire and a rim flange1a, and a valve and a filter are installed at the both ends of the tube.

Generally, the tube supplying air into the tire is made of a flexible material such as a rubber which is a softer material compared to the rim flange1amade of a metallic material.

Thus, a problem exists in Prior Art 1 that the durability of the tube can be degraded as the tube is being contacted to the rim flange1acontinuously.

In addition, since the bead portion which is in the vicinity of the rim flange is unlikely to be deformed, there is a disadvantage that the compression and expansion of the tube supplying air into the tire are not performed smoothly.

However, compression of the tube may occur through the contact with the wheel, that is the rim flange, but in this case, disadvantages have been suggested that the durability of the tube is degraded including the problem as described above.

(2) U.S. Pat. No. 8,042,586 (hereinafter refer to as ‘Prior Art 2’) is characterized in that the bending region within a rolling tire footprint having a neutral axis, a compression sidewall, and an elongation sidewall, and a groove wherein the tube is installed is positioned within the compression sidewall, and a tube is positioned within the tube in contacting engagement with opposite groove surface.

Especially, in the case of Prior Art 2, it has been exemplary shown that the positions of the tube in the compression sidewall, wherein the compression of the tube is occurring during the rolling of the tire, are 200 in the outer surface, 202 in the inner surface, and 204 in the outer surface inFIG. 9Bof Prior Art 2.

Prior Art 2 is characterized by suggesting a technology wherein the air is forced by the compression of the tube during the rolling of the tire.

However, actually the movement of a tire is accomplished by the up-down movement of folding and unfolding thereof due to the compression at the surface of contact with the road surface, that is, an active extension and contraction movement.

Therefore, it is desirable to position the tube in a place where the most active extension and contraction movement is occurring in order to inject the air into the tire cavity.

In addition, the device for maintaining a proper air pressure of a tire should be made to be as light as possible, since the weight of a vehicle is closely related to the vehicle's performance.

(3) In U.S. Pat. No. 8,113,254 (hereinafter refer to as ‘Prior Art 3’), a circular type air tube is connected to the inlet and outlet devices which have the shape of a letter “T.”

It is characterized in that the inlet and outlet devices are positioned facing each other.

In the case of Prior Art 3, there are disadvantages as follows.

First, the inlet and the outlet are facing each other with 180 degree symmetry, that is, only half of the total length of the tube is used, therefore the performance is relatively lower when compared to the method having the inlet and outlet devices located in same position, and moreover, there is a difficulty in installing when compared to the technology comprising only one device for installing.

Besides, the external air is constantly introduced into the tube since no regulator is formed in the inlet device, and the process of exhausting the air via the outlet device is repeatedly performed even at the preset air pressure.

Therefore, since the inlet and outlet devices of the tire must be operating continuously during the operation of the tire, this may cause a big problem of degradation in the durability of the inlet and outlet devices.

Moreover, there is a disadvantage that the manufacturing and setting method for the valve comprising the combination of two balls and respective springs is difficult when compared to the piston method having one spring.

U.S. Pat. No. 9,205,714 (hereinafter refer to as ‘Prior Art 4’) has an advantageous structure capable of minimizing the height using a regulator utilizing the thin layer of a membrane method.

However, in the case of Prior Art 4, it not only uses two check valves in order to prevent reverse flow of the air, but also uses a separate spring for the design of the regulator considering the high pressure of the tire, therefore, the structure becomes rather complicated and there is a difficulty in miniaturization thereof.

And, a fine adjustment for setting the preset tire pressure becomes impossible.

Moreover, disadvantages have been suggested that since the connection between the compression tube and the inlet and outlet port is accomplished inside the bead portion of the tire, it is too difficult to apply to the actual tire.

In U.S. Pat. No. 8,573,270 (hereinafter refer to as ‘Prior Art 5’), the introduction of the air is controlled by the disc-like pressure membrane made of a flexible material, and it is about a technology for miniaturization of the valve (or regulator).

Although the objective of miniaturization of the valve (or regulator) can be partially achieved by Prior Art 5, the pressure membrane is continuously receiving the centrifugal force along the radial direction when the tire is rotating.

Therefore, while there is an advantage of miniaturization of the valve (or regulator), the problem of degradation in the durability of the pressure membrane has been suggested.

PATENT DOCUMENTS

SUMMARY

The objective of the present invention devised for solving the above described problems of the prior art is to provide a tire capable of maintaining air pressure thereof so that not only the further miniaturization of regulator becomes possible but also the efficiency of supplying air to the tire cavity can be further enhanced.

The present invention for solving the above described problem is characterized in that and comprising: a tire including a side portion; a tube disposed in the outer side of the side portion; and a regulator connected to the tube, wherein the regulator comprises: a main body having a space for accommodating a piston therein; a first port formed in the upper side of the main body, communicating with the external air; a second port located at the one side of the main body; a third port located at the other side of the main body; and a fourth port communicating with the third port, formed in the lower side of the main body, and wherein one end of the tube is connected to the second port, and the other end of the tube is connected to the third port, and the fourth port is penetrating through the side portion and being communicated with the tire cavity.

The present invention is characterized in that the piston moves back-and-forth along the circumferential direction of the tire.

The present invention is characterized in that a check valve interposed between the first port and the piston is further included.

The present invention is characterized in that: the equation D2<D1+2t1 is satisfied if the maximum outer diameter of the second port is D2, the maximum outer diameter of the one end of the tube is D1, and the thickness of the one end of the tube is t1, when the second port is connected to the one end of the tube; or the equation D4<D3+2t2 is satisfied if the maximum outer diameter of the third port is D4, the maximum outer diameter of the other end of the tube is D3, and the thickness of the other end of the tube is t2, when the third port is connected to the other end of the tube.

The present invention is characterized in that the height of the first port protrudedly formed from the upper surface of the main body is formed to be smaller than the width of the second port protrudedly formed from the one side of the main body, or the width of the third port protrudedly formed from the other side of the main body.

The present invention is characterized in that the tube is disposed in the outer side of the side portion along the circumferential direction, and the air compressing operation is accomplished through the extension and contraction movement of the side portion when the tire is rotating.

The present invention is characterized in that the tube is located between the end of the belt portion and the end of the apex.

The present invention is characterized in that: in the outer side of the side portion of the tire, a groove wherein the tube is inserted is further formed; wherein among the portions of the tube being connected to the second port, if the portion of the tube between the second port and the point where the tube is completely inserted into the groove is defined as a tube connecting portion160, it is satisfied that the inwardly bending angle of the tube connecting portion160towards the tire cavity is less than 90 degrees with respect to the center of the regulator; or wherein among the portions of the tube being connected to the third port, if the portion of the tube between the third port and the point where the tube is completely inserted into the groove is defined as a tube connecting portion170, it is satisfied that the inwardly bending angle of the tube connecting portion170towards the tire cavity is less than 90 degrees with respect to the center of the regulator.

The tire with self-inflation device of the present invention has advantages as follows.

(1) When compared to the prior art, in the present invention, among a plurality of ports, the second port connected with the one end of the tube, and a third port, located in the opposite side of the second port, connected with the other end of the tube, are formed in the side surface of the main body so that the overall size of the regulator can be significantly reduced.

Also, when connecting with the tube, the air flow inside the tube becomes smooth since the bending phenomenon of the flexible tube occurring at the port can be avoided.

(2) The second port is formed in the regulator, and the third port is located in the opposite side of the second port.

The one end of the tube is connected to the second port, and the other end of the tube is connected to the third port.

Such structure can reduce the degree of external exposure of the regulator significantly so that the damages to the ports formed in the regulator as well as the regulator itself can be greatly reduced.

(3) By inserting the tube inside the side portion wherein the extension and contraction movements of the tire are mostly occurring, the efficiency of the air supply to the tire cavity during driving can be enhanced further.

(4) The air compressed towards the driving direction is injected to the tire cavity, and the air from the outside is charged to the tube due to the negative pressure formed in the tube located in the opposite side of driving.

(5) Generally, it is known that the main parts vulnerable to damage are the ends of the belt and apex of the tire, therefore the present invention has a structure wherein the tube is located in a way that such parts vulnerable to damage are avoided.

Thus, the durability of the tire may not be seriously affected even if a groove for inserting the tube is formed in the side portion of the tire.

(6) The groove slightly protruded out of the side portion can be functioned as a rim protector protecting the wheel.

(7) The upper part and the lower part of the groove added to the side portion enhance the noise property of the tire and good for a comfortable ride due to the increase in damping of the side which is the major region of extension and contraction.

(8) In the present invention only the fourth port among the plurality of ports formed in the regulator is allowed to be communicating with the tire cavity.

Thus, when compared to the prior art, since the number of holes penetrating through the side portion of the tire can be reduced significantly, so the degradation in the durability of the side portion of the tire due to the formation of the holes can be minimized.

(9) Since connecting the regulator with the tube and mounting thereof to the tire can be accomplished from the outside of the tire, the assembling of the tire and the regulator becomes easy and the air pressure can be adjusted manually as well.

(10) Since the piston accommodated inside the regulator performs back-and-forth movement along the circumferential direction of the tire, the impact of centrifugal force along the radial direction according to the rotation of the tire becomes negligible.

Therefore, the durability of the piston being accommodated inside the regulator is excellent when compared to that of the prior art, and the basic role of maintaining air pressure can be faithfully practiced as well.

DETAILED DESCRIPTION OF EMBODIMENT

Hereinafter, firstly, the regulator50will be described as a main focus.

The tire10of the present invention includes a side portion.

A tube40is disposed in the outer side of the side portion15.

When the tire10is being driven, as an extension and contraction movement is occurring in the side portion15, accordingly, another extension and contraction movement is occurring in the tube40disposed in the side portion15.

Air injection into the tire cavity19due to such extension and contraction movements in the side portion15and the tube40will be described later.

The above described tube40is connected to the regulator50.

Hereinafter, the regulator50will be described with reference toFIGS. 1 to 3.

The overall shape of the regulator50of the present invention is like as follows.

The regulator50comprises a main body60.

In the main body60, a plurality of ports110,120,130, and140is formed protruded from the upper side, the side surfaces, and the lower surface of the main body.

The shape of the main body60excluding the plurality of ports110,120,130, and140is similar to the shape of a rectangle wherein a main body's space65is formed.

A piston70is accommodated by the main body's space65formed inside the main body65.

The piston70adopted by the present invention performs a back-and-forth movement inside the main body's space65formed inside of the main body60along the circumferential direction of the tire.

The piston70comprises a piston's first portion71and a piston's second portion72.

The piston's first portion71is formed to have a larger diameter than that of the piston's second portion72, but instead, the length of the former is shorter than that of the piston's second portion72.

For reference, the one surface of the piston's first portion71is in contact with the one end of the third port130(refer toFIG. 1).

In other words, the one end of the third port130plays the role of a stopper of the piston70.

A groove73is formed in a side surface74of the first portion of the piston along the circumference of the piston's first portion71.

A first O-ring75is located in the groove73of the side surface of the first portion of the piston.

The first O-ring75plays the role of hermetically sealing the space between the side surface74of the first portion of the piston and a main body's inner surface66of the space inside the main body.

The piston's second portion72is integrally formed with the piston's first portion71, and has a smaller outer diameter when compared to the piston's first portion71, and the length thereof is longer than that of the piston's first portion71.

The other side72bof the piston's second portion is inserted into a piston supporting portion67having a predetermined length and formed protrudedly from the main body's inner surface66of the main body's space, and supported thereby.

In the piston supporting portion67, a circular hole is formed so that the piston's second portion72having a circular cross-section can be movable along the lateral direction.

More specifically, a portion of the piston's second portion72is positioned protruded a predetermined length from the piston supporting portion67when viewed with reference to the cross-sectional view ofFIG. 1, but the other end76of the piston's second portion is positioned spaced apart from a second port's valve hole128a.

Within the piston's second portion72, a spring80is inserted in the remaining portion of the piston's second portion72except the other side72bof the second portion of the piston which is inserted into the piston supporting portion67and supported thereby.

A gap is formed between the piston supporting portion67and the other side72bof the second portion of the piston so as to allow the lateral movement of the piston70.

More specifically, spring's one end81is in contact with the step between the piston's first and the second portions79, and supported thereby.

Meanwhile the spring's other end82is in contact with one surface of the piston supporting portion67and supported thereby.

Hereinafter, a plurality of ports110,120,130, and140will be described.

The first port110, having a predetermined height, is formed protrudedly on the main body's upper surface61in a shape similar to a cylinder.

As the first port110plays the role of communicating with the outside air, a certain degree of protrusion at the side portion15cannot be avoided, and the risk of damages of the externally exposed first port110is higher than that of the other ports, for example, the second port120and the third port130that are connected to the tube40and that are accommodated by a groove35.

Therefore, the height of protruded portion of the first port110from the main body's upper surface61is formed to be smaller than the width of the second port120protrudedly formed from the main body's one side63.

In this way, the degree of exposure of the first port110towards the outside can be reduced.

The first port110includes a cover115.

The cover115has been formed removable from a cover supporting portion114which is protrudedly formed to have a predetermined height.

The cover supporting portion114is formed to have a larger diameter than that of the cover115.

That is, the cover's lower end116is inserted into the groove (not shown) formed in the cover supporting portion114, thereby forming a structure wherein the cover115is fixed to the main body60and supported thereby.

Meanwhile, a check valve150is located in the lower side of the cover115.

The check valve150may further be formed in order to prevent the air, introduced into the main body's space65through a first pathway111which will be described later, from reverse flowing towards the outside through the first pathway111again.

More specifically, the check valve150is interposed between the spring80and the first port110, and communicating with the first pathway111.

For reference, a filter (not shown) may further be located between the check valve150and the lower portion of the cover115.

The filter (not shown) plays the role of preventing foreign substances, which may be included in the air introduced through the first pathway111via the first port110, from infiltrating into the inside of the regulator50.

The first pathway111formed in the first port110and communicating with the check valve150is communicating with the main body's space65.

In the exemplary embodiment of the present invention, the first pathway111is communicating with a through-hole117formed in the center of the cover115, and also comprised of a straight line pathway communicating with the main body's space65.

Since the first port110is communication with the outside air, eventually, the main body's space65can be communicating with the outside air via the first pathway111.

Hereinafter, the second port120located in the main body's one side63will be described.

The second port120is protrudedly formed to have a predetermined width from the main body's one side63.

More specifically, the shape of the second port120can be described as follows.

First, second port's one end124is protrudedly formed to have a predetermined width from the main body's one side63, and integrally formed with the second port's other end127.

The outer diameter of the second port's other end127is formed to be smaller than that of the second port's one end124.

For reference, a second port connecting portion122is interposed between the main body's one side63and the second port120.

Referring to the cross-section ofFIG. 1as a reference, it is integrally formed in the order of the second port connecting portion122, a step123between the second port connecting portion and the one end of the second port, the second port's one end124, a second port's horizontal portion125, a second port's inclined portion126, and the second port's other end127towards the outer direction.

The maximum value of the outer diameter of the second port120is same as that of the second port's one end124or the second port's horizontal portion125.

The outer diameter of the second port120is gradually decreasing as it passes the second port's horizontal portion125and passing through the second port's inclined portion126.

The second port's other end127has the minimum value of the outer diameter of the second port120.

The reason why the second port's other end127has the minimum outer diameter of the second port120is to facilitate the connection with a tube40, more specifically with tube's one end41.

In other words, the second port's other end127formed to have the smallest value of the outer diameter of the second port120and the second port's inclined portion126play the role of connecting the second port120to a flexible tube smoothly as the tube's one end41is expanding.

Referring to the cross-section ofFIG. 1as a reference, the difference between the height of a second port connecting portion120aand the outer diameter of the second port's one end124forms a step123between the second port connecting portion and the one end of the second port.

It is preferred that the tube's one end41connected to the second port120is located and in contact with the step123between the second port connecting portion and the one end of the second port.

Meanwhile, a second pathway121of the second port120is formed penetrating the second port120.

A second port's valve128is formed between the second pathway121and the above mentioned other end76of the second portion of the piston.

The second port's valve128comprises a second O-ring129and a second port's valve hole128a.

The second O-ring129is located in the side surface of the second port connecting portion122.

That is, the second O-ring129is located between the other end76of the second portion of the piston and the side surface of the second port connecting portion122.

Meanwhile, referring toFIG. 1as a reference, the second port's valve hole128ais formed in the right side of the second O-ring129.

The second port's valve hole128ais formed penetrating the second port connecting portion122along the lateral direction so as to be communicating with the second pathway121.

Hereinafter, the third port130formed in the main body's other side64will be described.

Referring toFIG. 1as a reference, since the shape of the third port130is same as the second port120previously described, the detailed description thereof will be omitted.

The outer diameter of the other end137of the third port130is formed to be smaller than that of the one end (not shown) of the third port.

The third port130is protrudedly formed to have a predetermined width from the main body's other side64, and located there to.

A third pathway131formed in the third port130is formed penetrating through the third port130.

Tube's other end42is connected to the third port130.

More specifically, we may consider that the tube's other end42is connected to the inlet131aof the third pathway.

Meanwhile, a second outlet131cis formed in the third pathway131.

That is, a portion of the lower side of the third pathway131is cut off and a second outlet131cis formed thereby.

A fourth pathway141which will be described later and the third pathway131are communicating with each other through the second outlet131cof the third pathway. Hereinafter, the fourth port140wherein the fourth pathway141is formed will be described.

The fourth pathway140is formed from a main body's lower surface62.

Similar to the above described ports110,120, and130, the fourth port140is protrudedly formed to have a predetermined height (width).

The fourth pathway141is formed vertically penetrating the fourth port140.

More specifically, a fourth pathway's inlet141ais communicating with the second outlet131cof the third pathway previously described.

Therefore, the air supplied from the tube's other end42can be introduced into the fourth pathway141via the fourth pathway's inlet141apassing through the third pathway131.

The air introduced through the fourth pathway141can be injected to the tire cavity19through an outlet141bof the fourth pathway.

Meanwhile, when the air passed through the third pathway131is entering into the fourth pathway141the flow direction of the air is switched 90 degrees.

The air whose flow direction is switched 90 degrees is injected into the tire cavity19from the fourth pathway141.

The diameter of the fourth port140is formed to be smaller than the diameter of the second port120where the tube40is connected to, or the third port130, so that the impact to the durability of the side portion15can be minimized as possible when the fourth port140is penetrating the side portion15.

In this way, in the present invention, the injection of the air into the tire cavity19is performed by using only one port, that is, the fourth port140, among the plurality of ports110,120,130, and140formed in the regulator50.

When compared to the prior art, this structure significantly reduces the number of through-holes formed for the communication between the ports and the side portion15.

Thus, there are advantages that the productivity can be enhanced due to the reduction of the number of processes, and also the degradation in the durability of the side portion of the tire caused by forming through-holes can be minimized.

Meanwhile, a groove35is formed along the circumferential direction of the tire10, and the tube40is inserted in to the groove35.

Specifically, the groove35is formed in the outer side15aof the side portion15.

It is preferred that the length of the circumference of the groove35is formed to be slightly shorter than the circumference of the side portion15, more specifically the length is to be reduced by the length of the regulator50.

As described above, the tube's one end41is connected to the second port120of the regulator50, and the tube's other end42is connected to the third port130.

In the present invention, when the regulator50is coupled to the side portion15of the tire, the second port120where the tube's one end41is connected to, or the third port130where the tube's other end42is connected to may be accommodated by the groove35.

Therefore, while driving a vehicle, the damages to the port connected to the tube40by the external impact can be significantly reduced.

Such effect can be accomplished by miniaturizing the sizes of the second port120and the third port130compared to the prior art.

Meanwhile, when the tube40is being connected to the port, it is preferred that the following requirements are satisfied in order to accommodate the second port120or the third port130into the groove35.

When the second port120is connected to the tube's one end41, the maximum value of the outer diameter of the second port120is defined as D2.

Meanwhile, the maximum outer diameter of the tube's one end41is defined as D1, and the thickness of the tube's one end41is defined as t1.

At this time, it is preferred to satisfy the requirement that the maximum value D2 of the outer diameter of the second port120is smaller than the value wherein two times of the thickness t1 of the tube's one end41is added to the maximum value D1 of the outer diameter of the tube's one end41.

When this requirement is satisfied, after the tube40is connected to the second port120, the tube's one end41can have similar height of the second port120.

This arrangement can prevent the excessive protrusion from the groove35when the tube40and the second port120are connected.

Similarly, when the third port130is connected to the tube's other end42, the maximum value of the outer diameter of the third port130is defined as D4.

The maximum outer diameter of the tube's other end42is defined as D3, and the thickness of the tube's other end42is defined as t2.

At this time, it is preferred to satisfy the requirement that the maximum value D4 of the outer diameter of the third port is smaller than the value wherein two times of the thickness t2 of the tube's other end42is added to the maximum value D3 of the outer diameter of the tube's other end42.

Hereinafter, the operation principle of a regulator50in a tire with self-inflation device of the present invention will be described.

First, air is introduced into the main body's space65through the first port110communicating with the outside air.

The air introduced into the main body's space65is moved to the tube40through the second pathway121of the second port120via the second port's valve hole128a.

The air introduced into the tube40is moving along the tube40, and moved to the third pathway131passing through the tube's other end42.

The air moved to the third port130is moved to the fourth pathway141of the fourth port140through the fourth pathway's inlet141acommunicating with the second outlet131cof the third pathway.

The fourth port140is penetrating through the side portion15, and communicating with the tire cavity19, therefore, the air moved to the fourth pathway141of the fourth port140can be supplied to the tire cavity19.

Meanwhile, in the present invention, the second port's valve128opens only when the air pressure inside the tire cavity19is lower than the preset air pressure.

When the regulator50is not operating, as previously described, the tensile strength of the spring80of the tire reacts in a way that it pushes the piston70towards the third port130.

Thus, the piston70is located spaced apart from the second port's valve hole128a.

That is, the second port's valve hole128ais opened without being blocked by the piston70.

Therefore, the air introduced into the main body's space65via the first port110can be moved to the tube40through the second port120.

The movement of the air introduced into the main body's space65towards the third port130or the fourth port140is blocked by the first O-ring75.

Eventually, the air introduced into the main body's space65via the first port110must have a pathway wherein the air is moved via the second port120, via the tube40, via the third port130, and towards the fourth port140.

If the air pressure inside the tire cavity19is equal to or greater than the preset air pressure, the regulator50blocks the air injection into the tire cavity19.

The air inside the tire cavity19is pushing the piston70through the fourth port140which is communicating with the air.

The air inside the tire cavity19is pushing the first portion71of the piston towards the right side with respect toFIG. 1via the fourth port140which is communicating with the air.

The piston70being pushed towards the right side is being moved towards the direction of the second port120overcoming the tensile strength of the spring80.

Therefore, the piston70being pushed towards the direction of the second port120blocks the second port's valve128, more specifically, the second port's valve hole128a.

When the second port's valve hole128ais blocked by the piston70, the outside air cannot be introduced through the first port110even if a negative pressure is generated inside the tube40due to the rotation of the tire, therefore the cannot be charged into the tire cavity19.

The structure of a tire10adopting the aforementioned regulator50in a tire with self-inflation device of the present invention will be described as follows.

FIG. 5illustrates a cross-sectional view of the tire10of the present invention wherein the side portion15is reinforced, and for reference,FIG. 11illustrates a cross-sectional view of the tire1011of the prior art wherein the side portion1511is not reinforced.

The terms used in the description hereinafter will be defined as follows.

A tread portion11means a portion of a tire10which directly contacts the ground and forming a ground contact surface.

A body ply12forming the frame of the tire10is located in the lower side of the tread portion11.

The body ply12is a portion forming the skeleton of the tire10enduring the air pressure, weight, and impact inside of the tire and also called as a carcass.

Since the tensile strength is reacting on the body ply12from the all directions, cords made of mainly nylon, polyester, rayon, and the like are provided in order to maintain such tensile strength.

A tire cord fabric is formed by arranging a plurality of fabric cords with a predetermined gap and coating thereof with a thin rubber sheet along the up-down direction.

A belt portion13made by stacking a plurality of belt layers is located between the tread portion11and the body ply12.

A cap ply17is located at an end13aof the belt portion.

The cap ply17has a structure which covers the end13aof the belt portion, and plays the role of preventing the delamination and separation of the belt having a multi-layered structure.

Meanwhile, an inner liner14which prevents the leaking of the air is located inner side of the body ply12.

Meanwhile, a side portion15, which protects the body ply12forming the skeleton of the tire10and allows a flexible contraction and expansion movement, is located in the side surface of the tire10.

Such side portion15connects the tread portion11and a bead portion16.

The bead portion16means a portion for mounting the tire10to the rim.

The tire cavity19means a space formed by the inner surface of the tread portion11, the inner surface of the side portion15, and the outer surface of the rim (not shown).

Meanwhile, an extension and contraction movement of a tire in the present invention means an up-down movement wherein the tire10is folded at the ground contact surface due to the contact with the ground and then unfolded again.

The tire10is mounted to the rim (not shown), and the assembling of the rim and the tire10is accomplished by the bead portion16.

During driving, since the bead portion16is the portion receiving much impact from the rim (not shown), an apex18surrounding the bead portion16is formed for alleviating the impact being received by the bead portion16.

Meanwhile, a rim protector20, a portion which is coupled to the rim (not shown), is located close to the rim (not shown), therefore the high temperature heat generated during driving or from the disk brake is transferred thereto, so that it requires a superior heat resistance so that the change in the tensile strength and hardness of the rubber due to the heat is minimized, and it plays the role of reducing the damage, scratches, and the like to the rim caused by an external physical impact.

It is preferred that the tube40in a tire with self-inflation device is located as described as follows.

In a tire with self-inflation device, the tube40is located in the outer side15aof the side portion15wherein extension and contraction of the tire is mostly occurring during driving.

When specifically explained, the tube40is located in the opposite side of the cavity19which is a space formed by the inner surface of the tread portion11, the inner surface of the side portion15, and the outer surface of the rim.

FIG. 7compares the performance of air pressure increase depending on the location of the tube40, and shows that it is advantageous in air pressure increase when the tube is located in the side portion15.

That is, it is shown that the performance of air injection into the tire cavity19is superior when the tube40is located in the side portion15, more specifically, in the outer side15aof the side portion15than when the tube40is located in the bead portion16, regardless of the tube material.

Meanwhile, the thickness of the side portion15needs to be increased in order to prevent the degradation in the durability due to the groove35wherein the tube40is inserted.

In this way, when the thickness of the side portion15is increased, not only the noise property of the tire is enhanced due to the increase in damping of the side portion15, but also the comfortable feeling of the vehicle riding is also enhanced thereby.

FIG. 10shows the result of experiments wherein the noise property is enhanced due to the increase in the thickness of the side portion15, and it is shown that the noise in the booming region is reduced about 2 dB due to the increase in damping of the side portion15.

Meanwhile, the groove35, formed in the outer side15aof the side portion15in order to insert a tube40in the side portion15, also performs actions as follows.

(1) The groove35slightly protruded towards the outer side15aof the side portion15may play the role of a protector protecting the wheel (not shown).

(2) An upper portion35aand the lower portion35bof the groove35which is formed to insert a tube40into the outer side15aof the side portion15are protruded towards the outer side15aof the side portion15when compared to the prior art, and thus, the noise property of the tire is enhanced due to the increase in damping of the side portion15which is a major area of extension and contraction, and it is also acts advantageously for a comfortable ride.

The tire with self-inflation device of the present invention includes a tube40for compressing air through the extension and contraction movement of the side portion15during the tire rotation, and also may further include the regulator50which will be described later.

The tube40disposed in the outer side15aof the side portion15along the circumferential direction compresses air through the extension and contraction movement of the side portion15when the tire is rotating.

According to the extension and contraction movement of the side portion15, a force is applied towards the radial direction of the tube40.

When the tire10is driving while in contact with the road surface, the air inside the tube40is being compressed (refer to the arrow drawn in a continuous line inFIG. 4).

Meanwhile, when the tire10is driving while in contact with the road surface, a negative pressure is generated inside the tube40located in the opposite side of driving direction due to an instant vacuum, and thus, an outside air is introduced into the tube40.

Meanwhile, in a preferred exemplary embodiment, a groove35wherein a tube40is inserted along the circumferential direction of the tire10is formed in the outer side15aof the side portion15.

More specifically, the groove35is formed by cutting out a portion of the outer side15aof the side portion.

It is preferred that the length of the circumference of the groove35formed in the side portion15is shorter than the circumference of the side portion15, and this is for mounting of a regulator50which will be described later.

The groove35formed in the side portion15will be specifically described with reference to the cross-sectional view ofFIG. 5as follows.

It is preferred that the tube40is located between the end13aof the belt portion and an end18aof the apex.

For reference, the apex18means a portion which surrounds the bead portion16and alleviates the impact to be received by the bead portion16, and generally the end18aof the apex18and the end13aof the belt are considered as main portions of a tire vulnerable to damages.

Meanwhile, the apex18is encompassed by the body ply12which protects the bead portion16and supports the side portion15of the tire, and has a high stiffness characteristic among the rubber materials.

That is, similarly, the end18aof the apex18also becomes an area vulnerable to damage as the heat is concentrated thereon because the movement of the end18aof the apex is converted into the heat energy due to the dissimilar material bonding with the body ply12and the characteristics of high stiffness material.

Thus, in the present invention, the tube40is located between the end13aof the belt portion and the apex18avoiding the major areas vulnerable to damage (that is, the end18aof the apex and the end13aof the belt portion) in order to obtain the durability of the tire10.

In the present invention, the experiment was performed by inserting the tube40between the end18aof the apex and the end13aof the belt portion with reference to the experiment tire (265/35R20) as an area most active in compression and expansion of the tire40, and wherein the major areas of the tire vulnerable to damage are avoided.

When the groove35wherein the tube40is inserted is formed according to the present invention, the thickness increase in the entire or a portion of the side portion15is necessary in order to prevent the degradation in the durability of the side portion15due to the formation of the groove35.

Accordingly, there are two types of configurations in the present invention as follows.

(1) The diameter of the groove35is formed to be 6 mm, and the inlet of the groove35formed with an opening is formed to be 3 mm.

The location of the groove35is determined to have a distance of 9 mm from the rim protector20to the center of the groove35.

In the case of the present invention, the upper portion35aand the lower portion35bof the groove35are further protruded towards the outer side15aof the side portion15than the rim protector20which is considered as the outmost portion of a tire of the prior art.

At this time, the thickness of the side portion15is increased by 6 mm from the thickness of the prior art.

(2) The depth of the groove35is formed to be 8 mm, and at this time, the height of the groove35is formed to be 4 mm, and the inlet of the groove35wherein an opening is formed is formed to be 2 mm.

At this time, the thickness of the side portion15is increased by 8 mm from the thickness of the prior art.

Specifically, the groove35is located between the end18aof apex and the end13aof the belt portion.

In addition, the groove35has a depth corresponding to a value from 50% (min.) to 90% (max.) of the remaining section (distance illustrated by the arrow inFIG. 5) excluding the thickness including the body ply12from the outmost portion of the tire which is on the same line as the inner portion of the tire.

In here, the outmost portion of the tire means the upper portion35aof the groove35and the lower portion35bof the groove35protruded towards the outer side15aof the side portion15when compared to the prior art.

As the exemplary embodiment of the present invention, when the depth of the groove35is formed to be greater than 50% of the remaining section (distance illustrated by the arrow inFIG. 5) excluding the thickness (dotted line inFIG. 5) including the body ply12from the outmost portion of the tire which is on the same line as the inner portion of the tire, it will not affect the compression property of the tube40since the center point of the tube40is not deviating off from the outer periphery of the tire.

In addition, when the depth of the groove35is formed to be maximum 90% of the remaining section (distance illustrated by the arrow inFIG. 5) excluding the thickness (dotted line inFIG. 5) including the body ply12from the outmost portion of the tire which is on the same line as the inner portion of the tire, tire damages due to the exposure of the cords can be prevented.

For the compression performance of the tube40, the center point of the tube40should be inwardly located from the tangential line drawn at the outmost portion of the tire (continuous line inFIG. 5).

In the exemplary embodiment of the present invention, the section (distance illustrated by the arrow inFIG. 5) wherein the groove35may possibly formed is the region between the continuous line and the dotted line in theFIG. 5

Meanwhile, in the case ofFIG. 11illustrating a cross-section of a tire of the prior art, the outmost portion of the tire becomes the rim protector20.

Therefore, the section (distance illustrated by the arrow inFIG. 11) wherein the groove35may possibly formed is the region between the continuous line inFIG. 11which is the tangential line at the rim protector20and the dotted line which is the tangential line of the outmost portion of the body ply12.

It can be seen that when the side portion15is not reinforced, the section wherein the groove35may possibly formed is formed narrower than that of the present invention.

Meanwhile, when connecting the tube40and the regulator50, it is necessary to avoid the stacking point which is a flow bottleneck interfering the air flow inside the tube40.

When a stacking point which is a flow bottleneck is occurring, the air cannot be smoothly supplied into the tire cavity19through the extension and contraction movement of the tube40.

In the present invention, an exemplary embodiment for preventing or reducing the stacking point phenomenon, which is a flow bottleneck, is suggested as follows.

As previously described, a groove35wherein a tube40is inserted is further formed in an outer side of the side portion15of a tire10.

Tube's one end41is connected to a second port120.

At this time, among the tube40whose one end41is connected to the portions of the second port120the portion between the second port120and the point where the tube40is starting to be inserted into the groove35is defined as a tube connecting portion160.

Specifically, the tube connecting portion160could mean the portion between the second port's other end127and the tube40inserted into the groove35within the tube40.

The inwardly bending angle A of the tube connecting portion160towards the tire cavity19in order to prevent the stacking point phenomenon should be less than 90 degrees with respect to the center of the regulator50(dot-and-dash line inFIG. 6).

Same goes to the third port130.

That is, the tube's other end42is connected to a third port130.

At this time, among the tube40whose other end42is connected to the portions of the third port130the portion between the third port130and the point where the tube40is starting to be inserted into the groove35is defined as a tube connecting portion170.

Specifically, the tube connecting portion170could mean the portion between the other end137of the third port and the tube40inserted into the groove35among the portions of the tube40.

The inwardly bending angle B of the tube connecting portion170towards the tire cavity19in order to prevent the stacking point phenomenon should be less than 90 degrees with respect to the center of the regulator50(dot-and-dash line inFIG. 6).

A person who has common knowledge in this technical field shall understand that the present invention may be embodied in various modified forms without departing from the fundamental characteristics of the present invention.

In addition, various exemplary embodiments disclosed in the present invention may be implemented through a variety of combinations thereof.

INDUSTRIAL APPLICABILITY

According to a tire with self-inflation device of the present invention, (1) the air leaking as the time elapses during operation can be supplemented without driver's intervention, and (2) the outside air introduced through the regulator can be smoothly guided into the tire cavity via the tube.