How to install a vent valve and a valve stem of the vent valve

Abstract

The present invention relates to a vent valve and a method for attaching a valve stem thereto. The vent valve (3) includes a valve body (4) having a vent channel (5) therein and a movable valve stem (6) including a valve member (7) and a collar (8) at the opposite end of the valve stem. A spring element (9) is disposed around the valve stem. Movement of the valve stem is limited by an external retaining ring (11) attached to an external retaining groove (12) in the valve body. The bottom of the retaining groove includes an opening extending to the vent channel, and the retaining ring protrudes partially through the opening into the vent channel, whereby the protruding portion of the retaining ring is configured to form a restriction surface (15) and prevent the collar from passing through the restriction surface.

Description

[Technical field]

[0001] The present invention relates generally to tire manufacturing processes and methods used therein.

[0002] More specifically, the disclosed solution relates to a venting valve for removing air from a vehicle tire vulcanising mould.

[0003] The present invention further relates to a method for attaching a valve stem of a vent valve.

[0004] The field of the invention is more particularly defined in the preambles of the independent claims. [Background technology]

[0005] When manufacturing pneumatic vehicle tires, vulcanization molds are used. It is known that the tire vulcanization mold must be breathable so that the green tire or tire blank can come into contact with the molding tool of the vulcanization mold during blowing from the inside. In this process, the outside of the green tire pushes air radially outwards. If this air cannot be evacuated, the contact between the inner contour of the vulcanization mold and the outer contour of the green tire may be misaligned, resulting in deviations from the designed shape and tire surface pattern. This is why tire manufacturers are particular about the breathability of the vulcanization mold. The vulcanization mold is provided with a large number of venting bores to evacuate the air in the mold. The mold is equipped with hundreds or even 1000-9000 individual venting bores, so that air pockets can be avoided. The venting bores can be equipped with vent valves that prevent tire material from entering the venting bores. An example of such a venting valve is disclosed in Patent Document 1. However, it has been shown that the known venting valves and their mounting principles contain several disadvantages. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] European Patent No. 0774333 Summary of the Invention [Problem to be solved by the invention]

[0007] SUMMARY OF THE PRESENT EMBODIMENT It is an object of the present invention to provide a new and improved vent valve and method of installing the vent valve.

[0008] The vent valve according to the invention is characterized by what is claimed in the independent device claim.

[0009] The method according to the invention is characterized by the characterizing parts and steps of the independent method claims.

[0010] The idea of ​​the disclosed solution is that the vent valve includes a movement of the valve stem, which is limited by a retaining ring relative to the valve body of the vent valve. The retaining ring is mounted in a retaining groove on the outer surface of the valve body. That is, the vent valve is provided with an external locking mechanism for the valve stem. The locking element is the external retaining ring. Furthermore, the bottom of the retaining groove has at least two slits or cuts forming openings, which extend to the venting channel and provide selective access for locking the locking ring. The retaining ring mounted inside the retaining groove can protrude into the slit inside the venting channel. The protruding portion of the retaining ring is configured to form a retaining surface that prevents the collar of the valve stem from passing through the retaining ring.

[0011] An advantage of the disclosed solution is that the structure of the outer retaining ring assembly allows the remainder of the vent valve structure to be simple, making it easier and cheaper to manufacture. The attachment of the retaining ring is facilitated by attaching it laterally and externally of the vent channel. Furthermore, the vent valve can be provided with a well-defined and relatively wide venting path which improves the air evacuation characteristics. [Means for solving the problem]

[0012] According to one embodiment, a retaining ring or locking ring is the only locking system provided on the valve stem.

[0013] According to one embodiment, the valve body includes two slits on either side of the valve body. The retaining ring can have two enlarged portions at its open end, the enlarged portions configured to protrude through the two slits or cuts.

[0014] According to one embodiment, the valve body comprises three or four slits, in which case the number of enlarged portions of the retaining ring may also be three or four, or alternatively two enlarged portions and more than two alternative mounting positions may be available.

[0015] According to one embodiment, the retaining ring is an elastically deformable element, in which case it can have a basic shape and be expandable to a larger dimension when subjected to an external force.

[0016] According to one embodiment, the retaining ring is made of a metallic material, such as steel.

[0017] According to one embodiment, the retaining ring is made of a plastic or other polymeric material.

[0018] According to one embodiment, the retainer ring is a retainer spring configured to snap into a retaining groove on the outside of the valve body when pressed laterally from the outside, in other words the retainer ring and the notched groove may have a snap fit.

[0019] According to one embodiment, the retaining ring is generally C-shaped, such that the retaining ring has a C-shaped configuration, with an enlarged portion at the end of the C-shape that can protrude through the groove cut.

[0020] According to one embodiment, the retaining ring is an E-shaped retaining ring, also known as an E-ring or E-clip. All three branches of the retaining ring can then be provided with enlarged portions, and the retaining groove can have at least three cuts or slits to allow the enlarged portions to penetrate into the ventilation channel.

[0021] According to one embodiment, the collar is provided with a first conical surface, which faces away from the valve member of the valve stem, i.e. is located at the second end of the valve body. The conical surface expands the retaining ring when the valve stem is attached by a pushing movement in the vent channel. Thanks to the inclined surface of the conical surface, the attachment can be performed smoothly.

[0022] According to one embodiment, the collar is provided with a second conical surface, which faces the first end of the valve body, where the valve member is provided. The conical surface causes the retaining ring to expand when the valve stem is removed from the vent channel by pushing the valve stem towards the first end of the valve body. This embodiment allows the valve insert, including the valve stem and the opening spring, to be removed if necessary. Removal is easy thanks to the inclined surface.

[0023] According to one embodiment, the valve body comprises a support surface in the ventilation channel for the opening spring of the valve stem, the support surface facing the valve member of the valve stem, the opening valve or spring element being supported against said support surface.

[0024] According to one embodiment, the support surface is a shoulder surface having an annular surface facing towards the first end of the valve body. The shoulder is a fixed structural part of the valve body.

[0025] According to one embodiment, the retaining ring is configured to axially support the spring element, the retaining ring then having a dual purpose of retaining the collar and supporting the spring.

[0026] According to one embodiment, only the retaining ring is configured to axially support the spring element at the second end of the vent valve.

[0027] According to one embodiment, the retaining ring is configured to provide lateral support to the valve stem.

[0028] According to one embodiment, the retaining ring is configured to have three purposes: to retain the collar, to laterally support the valve stem, and to axially support the spring, thanks to which the other components are relatively simple, which allows them to be easily manufactured.

[0029] According to one embodiment, the retaining ring is the only physical element at the second end of the valve to provide lateral support, i.e., the valve body does not have a support surface for the valve stem at the second end of the valve body.

[0030] According to one embodiment, the valve stem and its collar have a solid configuration, in other words, the valve stem has no axial slits or gaps to allow it to be pressed to a smaller radial dimension.

[0031] According to one embodiment, the retaining ring includes two or more lugs projecting radially toward a central portion thereof.

[0032] According to one embodiment, the aforementioned lug is configured to protrude into the ventilation channel through a slit in the bottom of the retaining groove.

[0033] According to one embodiment, the disclosed solution relates to a method of mounting a valve stem of a vent valve having a valve body with a longitudinal vent channel, the method comprising applying an external mounting force to the valve stem longitudinally in the vent channel in a mounting direction against a spring force generated by a spring element, the method further comprising providing a collar on the valve stem and displacing the collar when the mounting force is removed and the spring force displaces the valve stem. the law of nature The valve stem includes preventing the valve stem from escaping the vent channel by an external retaining ring that supports against said collar when the valve stem is moved relative to the installation direction. The retaining ring is laterally mounted in a retaining groove formed in the outer surface of the valve body. The retaining ring is capable of radially expanding during assembly and returning to its original shape when released into the retaining groove. Furthermore, the retaining ring can selectively protrude into the vent channel, thereby forming a restricting surface that provides a shape lock to prevent the valve stem from leaving the vent channel. The retaining ring prevents the collar from passing the retaining ring when the retaining ring is in a normal, unexpanded state.

[0034] According to one embodiment, the method includes providing lateral support to the valve stem solely by the protruding portion of the retaining ring.

[0035] According to one embodiment, the method includes radially expanding the retaining ring with a conical surface of the collar when pushing the valve stem axially toward an installation direction, and / or correspondingly pushing the valve stem in the opposite direction when removing the valve stem.

[0036] The above disclosed embodiments and features can be combined to form the appropriate solution as required. [Brief description of the drawings]

[0037] [Figure 1] 1 is a schematic partial cross-sectional view of a vent valve installed in a vent hole of a vulcanization mold. [Diagram 2] FIG. 1 is a schematic cross-sectional side view of a vent valve with an external retaining ring mounted in an external retaining groove. [Diagram 3] FIG. 3 is a schematic diagram of a cross section taken along line AA in FIG. 2. [Figure 4] FIG. 1 is a schematic side view of a valve stem that can be mounted within the central vent channel of a vent valve. [Diagram 5] FIG. 2 is a schematic side view of a retaining ring. [Figure 6] 1 is a schematic side view of another vent valve in which a retaining ring supports a spring element. FIG. [Figure 7] FIG. 7 is a schematic diagram of a cross section taken along line AA in FIG. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0038] Some embodiments are explained in more detail in the accompanying drawings.

[0039] For clarity, the drawings illustrate some embodiments of the disclosed solutions in a simplified manner, in which like reference numbers identify similar elements.

[0040] FIG. 1 discloses a vent hole 1 of a vulcanization mold 2. The vent hole 1 has a first opening 1a on the inside of the mold and a second opening on a second side of the mold (not shown). The vent hole 1 is provided with a vent valve 3. Air in the mold can be vented to the outside of the mold through the vent valve 3 and the vent hole 1, and the vent valve 3 is intended to close before the tire material so that the tire material does not clog the vent hole 1.

[0041] Please note that in this document, the terms "tyre" and "tire" both mean "tire" and the terms "mold" and "mould" both mean "mold."

[0042] FIG. 2 discloses a vent valve 3 comprising a valve body 4 provided with a first end 4a and a second end 4b. The first end 4a faces towards the interior of the mould and the second end 4b faces away from the interior of the mould. The valve body 4 is further provided with a central vent channel 5 through which vent air is arranged to flow. In other words, the valve body is an elongated sleeve-like element with an outer surface and an inner surface. The outer surface can form a friction lock with the surface of the vent hole. A valve stem 6 is attached inside the vent channel 5. The valve stem 6 is axially movable relative to the valve body 4 by a limited distance. The valve stem 6 comprises a first end 6a provided with a valve member 7 for opening and closing the vent channel 5. The valve member 7 comprises an upper surface 7a and a conical sealing surface 7b. The second end 6b of the valve stem 6 is provided with a collar 8. The collar 8 is an enlarged portion of the distal end of the valve stem 6, and the collar 8 may be provided with a first conical surface 8a and a second conical surface. The spring element 9 is arranged to urge the valve stem 6 in an opening direction B towards an open position, in which air flow C is permitted through the ventilation channel 5. The spring element 9 may be, for example, a coil spring. Tire blank material fed into the mold urges the valve member 7 against the spring force generated by the spring element 9, closing the gap between the sealing surface 7b of the valve member 7 and the mating sealing surface of the valve body 4. In other words, the tire blank is moving the valve stem in a closing direction D. The valve stem 6 and the spring element 9 together form a valve insert 10 mounted inside the valve body 4.

[0043] The vent valve 3 further comprises a locking device 13 or system arranged at the second end 4b of the valve body 4 and configured to limit the movement of the valve stem 6 in the opening direction B. The locking device 13 comprises an external retaining ring 11 which serves as a mechanical locking element. The outer surface of the second end 4b of the valve body 4 is provided with a retaining groove 12 for receiving the retaining ring 11. The bottom of the retaining groove 12 is provided with two or more slits 14 which form an opening extending to the vent channel 5. The retaining ring 11 mounted in the retaining groove 12 can then partially protrude into the inside of the vent channel 5. The protrusion 11a of the retaining ring 11 is configured to form a regulating surface 15 which faces the collar 8 and prevents the collar 8 from passing through the regulating surface 15. The protrusion 11a of the retaining ring 11 is also shown in FIG. 3.

[0044] Collar 8 has a first conical surface 8a and a second conical surface 8b so that valve stem 6 can be easily installed by forcing it axially inside vent channel 5, and easily removed by forcing it axially in the opposite direction when the valve insert needs to be replaced. The conical surfaces 8a, 8b smoothly expand retaining ring 11 when valve stem 6 is forced to move axially by an external installation force. The outward expansion E is indicated in FIG. 3 by the arrows.

[0045] In the embodiment shown in FIG. 2, the spring element 9 is supported at the second end 4 b by a shoulder 16 of the valve body 4 .

[0046] In another embodiment shown in figure 6, the protrusion 11a of the retaining ring 11 is arranged not only to form a limiting surface 15 for the collar 8, but also to provide a support surface 17 for the spring element 9. In this solution the retaining ring 11 thus has a dual purpose: the construction of the valve body 4 can be even simpler if there is no need to arrange a fixing shoulder for the spring element.

[0047] In Fig. 3 the mounting direction M of the retaining ring 11 is indicated by an arrow. The retaining ring 11 may already be mounted on the valve body, and only afterwards the valve stem 6 is pressed along the ventilation channel towards the second end 4b. The first conical surface 8a facing the second end 4b then expands the retaining ring 11, allowing the collar 8 to pass through it.

[0048] The inner surface of the lug 11a supports the valve stem 6 in the lateral direction L. There is an annular gap between the shoulder and the valve stem 6, allowing the removed air to pass through the shoulder. The shoulder therefore does not provide any lateral support to the valve stem in the solution disclosed in FIG. 2.

[0049] The drawings and the associated description are intended only to illustrate the principles of the invention. In its details, the invention may vary within the scope of the claims.

Claims

1. A vent valve (3) for removing air from a vehicle tire curing mold (2), the vent valve (3) comprising: a valve body (4) with a first end (4a) adapted to face the interior of said vulcanization mold (2) and a second end (4b) adapted to face away from said interior of said vulcanization mold (2); - a ventilation channel (5) passing longitudinally through said valve body (4); - a movable valve stem (6) arranged inside said ventilation channel (5) and having a first end (6a) provided with a valve member (7) for opening and closing said ventilation channel (5) and a second end (6b) provided with a collar (8); a spring element (9) for pushing said valve stem (6) in an opening direction (B) towards an open position in which air can flow through said ventilation channel (5); a locking element arranged at the second end (4b) of the valve body (4); It is equipped with The locking element is an outer retaining ring (11), the second end (4b) of the valve body (4) has an outer surface provided with a retaining groove (12) for receiving the outer retaining ring (11); The bottom of the retaining groove (12) is provided with two or more slits (14) forming an opening extending to the ventilation channel (5); the outer retaining ring (11) mounted in the retaining groove (12) is configured to partially protrude inside the ventilation channel (5), whereby the protruding portion of the outer retaining ring (11) forms a restricting surface (15) configured to limit the movement of the valve stem (6) in the opening direction (B) by preventing the collar (8) from passing over the restricting surface (15); Vent valve.

2. 2. The vent valve of claim 1, wherein the outer retaining ring (11) is an elastically deformable element having a basic shape and capable of expanding to a larger dimension.

3. The collar (8) is provided with a first conical surface (8a), 3. The vent valve of claim 1, wherein the first conical surface (8a) is formed to taper toward the second end (4b) of the valve body (4) and is configured to expand the outer retaining ring (11) when the first conical surface (8a) is inscribed in the outer retaining ring (11).

4. The collar (8) is provided with a second conical surface (8b); The vent valve according to any one of claims 1 to 3, wherein the second conical surface (8b) is formed to have a diameter that narrows toward the first end (4a) of the valve body (4) and is configured to expand the outer retaining ring (11) when the second conical surface (8b) is inscribed in the outer retaining ring (11) by pushing the valve stem (6) toward the first end (4a) of the valve body (4).

5. the second end (4b) of the valve body (4) is provided with a support surface (16a) in the ventilation channel (5) and faces the first end (4a) of the valve body (4); A vent valve as claimed in any one of the preceding claims, wherein the spring element (9) is supported against the support surface (16a).

6. A vent valve as claimed in any one of the preceding claims, wherein the outer retaining ring (11) is configured to axially support the spring element (9).

7. A vent valve as claimed in any one of the preceding claims, wherein the outer retaining ring (11) is configured to provide lateral support to the valve stem (6).

8. The vent valve according to any one of the preceding claims, wherein the valve stem (6) and the collar (8) have a solid construction.

9. A method for installing a valve stem (6) of a vent valve (3) having a valve body (4) with a longitudinal ventilation channel (5), comprising: - applying an external mounting force to press said valve stem (6) longitudinally in said ventilation channel (5) in a mounting direction against a spring force generated by a spring element (9); providing a collar (8) on the valve stem (6) to prevent the valve stem (6) from escaping from the ventilation channel (5) by a locking element bearing against the collar (8) when the external mounting force is removed and the spring force tries to move the valve stem (6) in the mounting direction; Including, using an external retaining ring (11) as the locking element; laterally mounting the outer retaining ring (11) in a retaining groove (12) formed in the outer surface of the valve body (4); moving the valve stem (6) in the installation direction to radially expand the outer retaining ring (11) as the collar (8) passes through the outer retaining ring (11), and allowing the outer retaining ring (11) to return to its original shape after the collar (8) passes through the outer retaining ring (11); allowing the outer retaining ring (11) to partially protrude at a selected location within the vent channel (5) and form a restricting surface (15) that prevents the valve stem (6) from escaping from the vent channel (5) when the outer retaining ring (11) is in its original unexpanded shape; The method further comprises:

10. 10. The method of claim 9, comprising the step of radially expanding the outer retaining ring (11) by means of conical surfaces (8a, 8b) of the collar (8) when the valve stem (6) is pressed longitudinally towards the installation direction.

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