JP3138823B2 - Automotive disc wheels - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is intended to prevent a bead from falling into a disc wheel when the internal pressure of a puncture or the like is reduced while maintaining the assemblability of a tire at the same level as a conventional disc wheel. The present invention relates to an automobile disc wheel that can be prevented.

[Conventional technology]

Generally, when a pneumatic tire mounted on a normal automobile disc wheel receives a lateral force when the tire air pressure is reduced due to a puncture or the like, the bead portion moves inward from the bead seat of the disc wheel. , Into the drop center groove at the center of the disc wheel. As a result, since the bead portion of the tire moves freely during traveling, straight running stability is impaired.

In order to solve such a drawback, an annular groove is provided inside the bead seat of the disk wheel, and a ring made of a high-strength and non-stretchable material such as mild steel or glass fiber reinforced plastic is provided in the annular groove. There is a proposal to prevent the bead portion of the tire from dropping into the drop center groove portion by fitting (see Japanese Patent Application Laid-Open No. 50-149002).

However, according to this proposal, although the straight running stability can be improved when the internal pressure drops, the outer peripheral portion of the ring always projects from the annular groove. There was a problem that was troublesome.

[Problems to be solved by the invention]

The present invention has been made in order to solve such a conventional disadvantage, and an object of the present invention is to reduce the air pressure of a tire due to a puncture or the like while maintaining the assemblability of the tire at the same level as a conventional disk wheel. Another object of the present invention is to provide an automobile disk wheel capable of preventing a bead portion from dropping into a drop center groove of the disk wheel.

[Means for solving the problem]

That is, the vehicle disk wheel of the present invention is a vehicle disk wheel having a hump portion inside a bead seat on which the left and right bead portions of the tire are seated, and in the hump portion, at least a side corresponding to the outside of the vehicle body. The hump portion is provided with an annular groove, and an elastic ring made of an annular band material is attached to the annular groove. It is characterized by being made of a shape memory alloy that changes into a shape state larger than the rim diameter while sometimes increasing the distance between the ring fitting portions.

Thus, the elastic ring-shaped steel shape memory alloy, at the time of low temperature, and in a contracted state below the outer diameter D ₁ of the hump portion,
By changing the shape to a state larger than the rim diameter D at high temperatures, it does not hinder the insertion of the bead when assembling a tire in a low temperature state, so the assemblability is maintained at the same level as the conventional disk wheel When the air pressure of the tire decreases due to puncture or the like, since the inside of the tire is at a high temperature, it is possible to prevent the bead portion from being caught by the elastic ring and falling into the drop center groove portion of the disc wheel.

Here, as a boundary temperature at which a shape change of the shape memory alloy appears, it is preferable to select a temperature at or around 70 ° C. In general, the internal temperature of the tire is 70 ° C. or higher during traveling, so that the above-described object of the present invention can be reliably achieved by setting the above temperature.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a left-right symmetrical ordinary disk wheel for an automobile, which has flanges 2 at both outer ends in the axial direction and seats a bead portion 3 of a tire inside thereof. And a bead seat 4 for causing the bead seat 4 to move. The bead seat 4 has a hump portion 5 for holding the bead portion inside the bead seat 4 and a deep center drop center groove portion 6 in the center.

In the present invention, the hump portions 5 are provided with the respective annular grooves 7, and the respective annular grooves 7 are each provided with an elastic ring 8 made of a shape memory alloy. The ring 8 is at the room temperature, the outer diameter D ₂ is set in the storage state is smaller than or equal to the outer diameter D ₁ of the hump portion 5. But 70
℃ In the high temperature of above as shown in FIG. 2, an outer diameter D ₃ is set such that the memory shape to become larger than the rim diameter D of the disc wheel 1.

The shape of the elastic ring 8 at room temperature is an annular shape as shown in FIG. 3, but the shape under a high temperature condition is a non-annular shape in which the joining portion 8a of the ring is widened as shown in FIG. As shown in FIG. 5, it is possible to adopt a body or the like in which the joining portion 8a of the ring is widened and the outer periphery of the ring is wavy.

Next, the operation of the above-described vehicle disk wheel will be described.

As shown in FIG. 6, the tire is assembled in an atmosphere at room temperature (approximately 20 ° C.), and one bead portion 3 of the tire T is dropped into the drop center groove 6 of the disc wheel 1. The other bead portion 3 is mounted on the bead seat 4, and then the bead portion 3 falling into the drop center groove 6 gets over the hump portion 5 and is seated on the bead seat 4. This time, the outer diameter D ₂ of the elastic ring 8 mounted on the annular groove 7 of the hump portion 5 is equivalent to the outer diameter D ₁ of the hump portion 5, assembly of the tire in the ease of comparable conventional disk wheel It can be carried out.

When the tire T mounted on the disk wheel 1 is mounted on a vehicle (not shown) and travels, the inside of the tire T generates heat at 70 ° C. or higher, and the elastic ring 8 is also heated. Under such a high temperature, as shown in FIG. 7, the elastic ring 8 changes to the shape set at the high temperature,
An outer diameter D ₃ is larger than the rim diameter D of the disc wheel 1.

As described above, when the elastic ring 8 becomes larger than the rim diameter D, the bead portion 3 is prevented from moving by the elastic ring 8 even if the air pressure of the tire T decreases due to puncture and receives a lateral force. Don't be depressed.

In the disk wheel 1, the elastic ring 8 is formed of a band member made of a shape memory alloy formed in an annular shape, and the shape memory structure changes to a shape state larger than the rim diameter D while widening the gap between the joining portions 8a at high temperature. Therefore, the thickness in the wheel width direction can be arbitrarily set. Therefore, by forming the elastic ring 8 to be thick in the wheel width direction, it is possible to support even an automobile tire.

In the above description, the case where the annular groove 7 is provided in each of the humps 5 on the left and right sides and the elastic ring 8 is attached to each annular groove 7 has been described. In the case of the asymmetric disk wheel 1 ′ in FIG. The annular groove 7 and the elastic ring 8 may be arranged only on the right hump 5 (the side corresponding to the outside of the vehicle body) where the drop center groove 6 is suddenly deepened. This is because the drop center groove 6 gradually becomes deeper on the left side of the disc wheel 1 ', and the bead portion 3 hardly falls into the drop center groove 6.

〔The invention's effect〕

As described above, the present invention is, in an annular groove provided on the hump portion of the disc wheel, forming varying shape memory in a condition to be larger than the state and the rim diameter D contracted to the outer diameter D ₁ less the hump portion By installing an alloy elastic ring, the tire's bead fits into the disc wheel's drop center groove when the tire pressure decreases due to puncture etc. while maintaining the tire's assemblability as the conventional disc wheel. Be able to prevent falling.

[Brief description of the drawings]

1 and 2 are cross-sectional views of an automobile disk wheel according to the present invention, FIG. 3 is a plan view of an elastic ring in a contracted state at a low temperature, and FIGS. 4 and 5 are elastic views at a high temperature. 6 to 8 are explanatory views of the operation of the vehicle disk wheel according to the present invention, and FIG. 9 is a sectional view of another embodiment of the vehicle disk wheel according to the present invention. 1,1 '... Disc wheel, 3 ... Bead part, 4 ...
Bead seat, 5 ... Hump section, 7 ... Circular groove, 8 ... Elastic ring, T ... Tyre.

Claims (1)

(57) [Claims] 1. An automobile disk wheel having a hump portion inside a bead seat for seating left and right bead portions of a tire, wherein at least a hump portion of the hump portion corresponding to the outside of the vehicle body has an annular groove. And an elastic ring made of a band formed in an annular shape is attached to the annular groove, and the elastic ring is in a state of contracting to an outer diameter of the hump portion at a low temperature or less, and an interval between ring joining portions at a high temperature. An automotive disc wheel made of a shape memory alloy that changes to a shape larger than the rim diameter while expanding the shape.