Spring vent of tire vulcanizing mold

A spring vent for a tire vulcanizing mold comprises: a sleeve having a flow path vertically passing therethrough; a head opening/closing an inlet at an upper end of the flow path; a rod comprising a bar-type body formed below the head and disposed along the flow path and a stopper formed below the body to be hung to an outside of an outlet at a lower end of the flow path; and a spring inserted into the body. The stopper of the rod is formed to have a spherical shape. An elastic hole having an open bottom is formed in the stopper.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a spring vent of a tire vulcanizing mold for exhausting air between a tire and the vulcanizing mold during vulcanization, more particularly to a spring vent of a tire vulcanizing mold, in which, due to structural improvement of the spring vent, a rod is easily replaced at a sleeve in an assembled state of the spring vent and mold, thereby reducing maintenance costs and increasing work efficiency.

Description of the Related Art

Generally, a tire vulcanizing mold process includes inserting a green tire (raw tire) into a uniform mold, and applying heat and pressure inside and outside of the mold to perform a reaction between rubber and sulfur or other chemicals, thereby forming a tire.

During molding a tire, the spring vents for the tire vulcanizing mold are used to exhaust air between the green tire and the vulcanizing mold.

That is, a plurality of drill holes is formed at the vulcanizing mold and the spring vents are mounted in the drill holes. As a result, air is exhausted through the spring vents.

As a conventional art related to a spring vent for a tire vulcanizing mold, Korean Patent No. 10-0956242 (issued on Apr. 27, 2010, herein after referred as to “conventional art”) entitled “A MINI VENT STRUCTURE FOR TIRE MOLD” is disclosed.

Hereinafter, a configuration of the conventional art will be described.

As illustrated inFIGS. 2 to 4, a casing having a vent hole passing through a central part thereof in a vertical direction, and a valve structure elastically supported by a spring in the vent hole to open/close the vent hole of the casing are provided.

The valve structure includes a head disposed at an upper part thereof and a shaft disposed at a central part thereof. A stopper is provided at a lower part of the valve structure to be integrated with the shaft. The stopper has a diameter greater than that of the shaft to prevent the valve structure from being separated from the casing.

A plurality of engagement parts is provided at an inner diameter surface of a lower part of the casing to engage with an upper end of the stopper. The engagement parts are spaced apart a constant distance from one another.

Hereinafter, an operation method of the conventional art will be described.

When pressure is applied in the vulcanizing mold, air in the vulcanizing mold and green tire flows into the vent hole through an inlet at an upper end of the vent hole of the casing, and then air moving along the vent hole is exhausted through a space between a lower end of the casing and the stopper of the valve structure (each space formed between the engagement parts of the casing) to the outside of the vulcanizing mold.

Sequentially, as pressure is continuously applied to the green tire in the mold, the green tire and the head of the valve structure are in contact with each other. As a result, the head goes down by the green tire to close the upper inlet of the vent hole of the casing.

However, according to the mini vent including the above-described components, for replacement of the valve structure, the engagement parts protruding from the inner diameter of the casing are damaged using a tool so that the stopper of the valve structure is capable of passing through the vent hole of the casing, and then the valve structure is lifted upwards to separate the valve structure from the casing.

However, when the engagement parts are damaged using the tool, the casing and valve structure are damaged and are not restored to the original shape thereof, such that the entire mini vent should be replaced.

Thus, it is inconvenient to replace the valve structure in the casing, and, as such, maintenance costs are increased and work efficiency is decreased.

RELATED ART DOCUMENT

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a spring vent of a tire vulcanizing mold, in which due to structural improvement of the spring vent, a rod is easily replaced at a sleeve in an assembled state of the spring vent and mold, thereby reducing maintenance costs and increasing work efficiency.

In accordance with one aspect of the present invention, the above and other objects can be accomplished by the provision of a spring vent for a tire vulcanizing mold including a sleeve having a flow path vertically passing therethrough, a head opening/closing an inlet at an upper end of the flow path, a rod including a bar-type body formed below the head and disposed along the flow path and a stopper formed below the body to be hung to an outside of an outlet at a lower end of the flow path, and a spring inserted into the body.

The stopper of the rod is formed to have a spherical shape, an elastic hole having an open bottom is formed in the stopper, as plane surfaces are formed at opposite surfaces of the stopper, a first face short shaft and a second face are formed at the stopper, as a length of the second face of the stopper is greater than a diameter of the outlet, a length of the first face of the stopper is smaller than the diameter of the outlet,

The stopper is elastically deformed when the stopper passes through the outlet of the flow path. After passing through the outlet, the stopper is restored to the original shape thereof. As a result, when replacing the rod, the stopper is elastically restored, and, as such, it is easy to replace the rod.

In accordance with another aspect of the present invention, the above and other objects can be accomplished by the provision of a method of manufacturing the rod including mounting a round bar having a constant diameter on a lathe, shaping an end of the round bar using a drill to form the elastic hole, shaping the round bar using a bite to form the stopper, body, head and plane surfaces, and cutting the head of the rod shaped with the stopper, body, and head from the round bar.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, exemplary embodiments of the present invention are described in detail with reference to the accompanying drawings. Particular terms may be defined to describe the invention in the best manner. Accordingly, the meaning of specific terms or words used in the specification and the claims should not be limited to the literal or commonly employed sense, but should be construed in accordance with the spirit of the invention. The description of the various embodiments is to be construed as exemplary only and does not describe every possible embodiment of the invention. Therefore, it should be understood that various changes may be made and equivalents may be substituted for elements of the invention.

In addition, a direction toward a head1is referred to as an upper direction and a direction toward a stopper23is referred to as a lower direction in accordance withFIG. 1.

According to the illustrated embodiment of the present invention, the spring vent for the tire vulcanizing mold mainly includes a sleeve10, a rod20and a spring30. Hereinafter, the components of the spring vent will be described.

As illustrated inFIGS. 1 to 3, the sleeve10has a flow path11vertically passing through a central part therein while being formed to have a cylinder shape. An inlet12is formed at an upper end of the flow path11to communicate with an inside of the mold. An outlet13is formed at a lower end of the flow path11to communicate with an outside of the mold.

As illustrated inFIGS. 1 to 3, the rod20includes a head21for opening/closing the upper inlet12of the flow path, a bar-shaped body22formed at a lower part of the head21to be disposed along the flow path11, and a stopper formed at a lower part of the body22while being disposed at the outlet13at the lower end of the flow path11to be hung at an outside of the outlet.

As illustrated inFIGS. 1 to 3, the stopper23is formed to have a spherical shape. An elastic hole231having an open bottom is formed in the stopper23. Plane surfaces232are formed at opposite surfaces of the stopper such that the stopper23has a second face233and a first face234. A length of the second face233of the stopper23is greater than a diameter of the outlet13of the sleeve10. A length of the first face234of the stopper23is smaller than a diameter of the outlet13(seeFIG. 2and [A] ofFIG. 5).

Accordingly, due to the plane surfaces232, niche spaces235are formed between an inner diameter surface of the outlet13of the sleeve10and the plane surfaces232of the stopper23, respectively (see [A] ofFIG. 5). Namely, each niche space235is formed at each plane surface232of the stopper23.

Hereinafter, according to the illustrated embodiment of the present invention, an air exhaust process employing the above described configuration will be explained.

As illustrated inFIGS. 3 and 5, when pressure is applied in the vulcanizing mold, air in the vulcanizing mold and green tire is introduced into the flow path11through the inlet12of the sleeve10(seeFIG. 3). Air moving along the flow path11is exhausted through the niche space235to the outside (see [A] ofFIG. 5)

When pressure is continuously applied in the mold, the green tire and the head21of the rod20contact with each other, the head21of the rod20goes down and, as such, the head21closes the upper inlet12at the upper end of the flow path11.

Meanwhile, according to the conventional mini vent, for replacement of a valve structure disposed at a vent hole of a casing, engagement parts protruding from an inner diameter surface of the casing are damaged using a tool, so that a stopper of the valve structure passes through the vent hole. Then the valve structure is lifted upwards to be separated from the casing. However, when the engagement parts are damaged using the tool, the casing and valve structure are damaged and are not restored to the original shape thereof, and, as such, not only the valve structure but also the entire mini vent should be replaced.

Furthermore, to couple the casing and valve structure, the stopper of the valve structure is inserted through an inlet at an upper end of the vent hole of the casing, and the stopper passes through the vent hole to be disposed at an lower end of the vent hole, namely, at an outside of the casing. Sequentially, the engagement parts are formed at the lower end of the casing using a tool. This serves to prevent separation of the valve structure from the vent hole.

Thus, according to the conventional configuration, it is inconvenient to replace only the valve structure in the casing, and, as such, maintenance costs are increased and work efficiency is decreased.

Hereinafter, a coupling and replacement process of the sleeve10and rod20according to the illustrated embodiment of the present invention will be described.

As illustrated inFIGS. 4 and 5, to couple the rod20to the flow path11of the sleeve10, first, the stopper23of the rod20is introduced through the upper inlet12of the sleeve10. Then, as the stopper23passes through the flow path11of the sleeve10, the stopper23is disposed to go down to the lower end of the flow path11, namely, the outlet13. As illustrated in [A] ofFIG. 4and [A] ofFIG. 5, since the length of the second face233of the stopper23is greater that the diameter of the outlet13and the length of the first face234of the stopper23is smaller than the diameter of the outlet13, the stopper23is hung at the lower end of the flow path11, namely, the upper end of the outlet13.

According to the illustrated embodiment of the present invention, since the stopper23is entirely formed to have a spherical shape, the surface of the stopper23is curved. Furthermore, the stopper23is formed to have the elastic hole231having the open bottom and the plane surfaces232disposed at the opposite surfaces. Accordingly, due to the elastic hole231and the plane surfaces232, as seen in a cross-sectional view of the stopper23, elastic parts236are formed between the elastic hole231and the plane surfaces232, respectively, while each elastic part236includes a thin cross section (seeFIGS. 2 and 5).

Here, as illustrated in [A] ofFIG. 4and [A] ofFIG. 5, when pressure is applied to the head21of the rod20using a tool, due to the surface of the spherical-shaped stopper23, the stopper23goes down along the inner diameter surface of the outlet13of the sleeve. In this case, the second face233of the stopper23is pressurized along the inner diameter surface in the inward direction of the stopper23, while each elastic part236is deformed in the outward direction of the stopper23by elastic force, thereby deforming the elastic hole231. That is, the stopper23is deformed corresponding to a shape of the outlet13and, as such, the stopper23passes through the outlet13to be disposed at the outside of the sleeve10.

As illustrated in [C] ofFIG. 4and [C] ofFIG. 5, when the stopper23of the rod20passes through the outlet13of the sleeve10to be exposed at the outside of the sleeve10, the stopper23is restored to the original shape thereof by elastic force.

Meanwhile, as illustrated in [A] ofFIG. 6, to replace the rod20at the sleeve10, first, pressure is applied to a lower end of the stopper23disposed at the outside of the lower outlet13of the sleeve10using a tool.

As illustrated in [A] ofFIG. 6, due to the surface of the spherical-shaped stopper23, the stopper23is lifted along the inner diameter surface of the outlet13of the sleeve10. The second face233of the stopper23is pressurized by the outlet13in the inward direction of the stopper23, while each elastic part236is deformed in the outward direction of the stopper23by elastic force, thereby deforming the elastic hole231. Namely, as the stopper23is deformed corresponding to the shape of the outlet23, the stopper23passes through the outlet13to be introduced into the flow path11.

In addition, as illustrated in [C] ofFIG. 6, when the stopper23of the rod20passes through the outlet13of the sleeve10to be introduced into the flow path11, the stopper23is restored to the original shape thereof by elastic force. Accordingly, the rod20may be easily separated to the outside of the sleeve10through the inlet12of the sleeve10.

Finally, when the rod20is replaced, the stopper23is elastically deformed due to the spherical-shaped stopper23, the elastic hole231formed at the stopper23, the plane surfaces232formed at the opposite surfaces of the stopper23, and the elastic parts236formed between the elastic hole231and the plane surfaces232, respectively.

Accordingly, since it is easy to replace the rod20at the sleeve10, work efficiency of a user is increased. Furthermore, in a replacement process of the rod20, damage to the sleeve10is prevented and only the rod20is replaced, and, as such, maintenance costs are decreased. Hereinafter, a method of manufacturing the rod according to the illustrated embodiment of the present invention will be described.

As illustrated inFIGS. 7 to 11, according to the illustrated embodiment of the present invention, the method of manufacturing the rod20mainly includes a mounting process S10, a shaping process S20and a cutting process S30.

In detail, as illustrated inFIGS. 7 and 8, the mounting process S10is a preparation for the shaping process, in which a round bar40made of a metal material which is the basis of the rod20is mounted on a lathe.

The shaping process S20includes a shaping process S21of the elastic hole231and a shaping process S22of the stopper23, the body22, the head21, and the plane surfaces232.

As illustrated inFIGS. 7 and 8, the shaping process S21is a formation process of the elastic hole231at a central part of an end of the round bar40using a drill.

As illustrated inFIGS. 7 and 8, the shaping process22is a formation process of the stopper23, the body22, the head21, and the plane surfaces232, in which, while the round bar40having the elastic hole231is rotated on the lathe, the stopper23, the body22, the head21, and the plane surfaces232are sequentially formed using a bite. In this case, the stopper23is shaped to have a spherical shape. A diameter of the stopper23is smaller than the diameter of the flow path11of the sleeve10and greater than the diameter of the outlet13of the sleeve10. Accordingly, the elastic hole231is formed in the stopper23and is formed to have an open bottom. In addition, the plane surfaces232are formed at opposite surfaces of the stopper23, respectively.

The cutting process S30is a cutting process of the head21of the rod20including the stopper23, the body22, the head21and the plane surfaces232from the round bar40. In a conventional mini vent, after shaping the valve structure and casing and coupling the valve structure to the casing, a plurality of engagement parts is formed at the lower part of the casing using a tool in order to prevent the valve structure from being separated from the casing. Whereas, in the illustrated embodiment of the present invention, after shaping the rod20, the rod20is inserted into the sleeve10to be coupled with the sleeve10. Upon replacement of the rod20, the sleeve10is not reprocessed but the rod20is reprocessed to be coupled, such that it is easy to manufacture the spring vent. Furthermore, in the conventional mini vent, for replacement of the valve structure, the engagement parts protruding from the inner diameter of the casing are damaged using a tool such that the stopper of the valve structure passes through the vent hole of the casing, and then the valve structure is lifted upwards to separate the valve structure from the casing. However, when the engagement parts are damaged, the casing and the valve structure are damaged and are not restored to the original shape thereof, and, as such, the entire mini vent is replaced.

According to the conventional configuration, since it is inconvenient to replace the valve structure, maintenance costs are increased and work efficiency is decreased. Furthermore, it is inconvenient to manufacture the casing. However, in the illustrated embodiment of the present invention, it is easy to couple and separate the sleeve10and the rod20. In terms of replacement of the rod20, the sleeve10is not damaged and, as such, maintenance costs are decreased and work efficiency is increased.

Meanwhile, as illustrated inFIGS. 12 and 13, the plane surfaces232are formed at opposite surfaces of the stopper23, respectively. In this case, a plurality of elastic grooves232amay be formed at each plane surface232as the stopper23passes through the outlet13of the flow path11to elastically contract and expand. As a result, the stopper23may be easily deformed due to the elastic holes232a.

As illustrated inFIG. 13, the elastic grooves232aor a boundary groove250may be formed at the first face24of the stopper23. Thus, the stopper23may easily contract or expand due to the elastic grooves232aand the boundary groove250. As illustrated inFIG. 14, an elastic recessed groove234aand an air vent groove234bmay be further formed at the surface of the second face233of the stopper23. Accordingly, when being exhausted, air may be rapidly exhausted through the air vent groove234bas well as the niche spaces235. As illustrated inFIG. 15, to easily deform the stopper23, auxiliary holes231amay be further formed at opposite surfaces of the elastic hole231of the stopper23. Accordingly, the stopper23is elastically deformed, namely, contracts and expands well, and, as such, the stopper23may easily pass through the outlet13.

As is apparent from the above description, in accordance with the present invention, the spring vent for the tire vulcanizing mold is provided. Due to structural improvement of the spring vent, it is easy to replace the rod at the sleeve. As a result, maintenance costs are decreased and work efficiency is increased.

Although the present invention has been described using limited embodiments of “a spring vent for a tire vulcanizing mold” having specific shape and structure and drawings, it should be understood that many variations and modifications of the basic concept described herein will still fall within the scope of the present invention as defined in the appended claims.