JPS6222459Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a core material for a motorcycle seat particularly suitable for a motocross motorcycle.

Generally, as a motorcycle seat, one in which molded polyurethane is placed on a base as a cushion material and the entire seat is wrapped with synthetic leather or the like is widely used.

However, a seat in which only the polyurethane mat as the cushioning material is wrapped is often too flexible, giving a feeling of bottoming out when sitting on it, and has the disadvantage that it is uncomfortable to sit on, especially on rough roads. In addition, since the seat is easily deformed, it lacks a sense of stability when the seat is held between the crotches, and it also has the disadvantage of becoming unstable during sharp cornering.

For this reason, especially in motocross motorcycles and the like intended for riding on rough roads, attempts have been made to alleviate the above-mentioned drawbacks as much as possible by stuffing the motorcycle with a core material.

Conventional motorcycle seats mainly use palm locks made of intertwined foam rubber or coconut fibers as core materials.

It is true that the above drawbacks can be alleviated to some extent by using foam rubber or palm lock as a core material, but it is still not completely satisfactory. This gives rise to the following problems.

First, since foam rubber and palm locks do not have a fixed shape, it takes extra effort to cut out the bottom surface of the polyurethane mat placed on the pedestal to form a filling part, which complicates the manufacturing process. It is that it is giving rise to

Secondly, it is difficult to pack foam rubber and palm lock uniformly over the entire sheet, so it is necessary to concentrate the packing in the areas where the load is most likely to be applied, and it is difficult to pack foam rubber and palm lock uniformly over the entire sheet. This causes a difference in the hardness of the sheet between parts, causing a sense of discomfort.

Thirdly, the effectiveness as a core material varies greatly depending on the amount of foam rubber or palm lock packed in, making it difficult to provide a constant level of performance.

The present invention was developed in view of the above-mentioned current situation, and the purpose is to provide a core material for motorcycle seats that is easy to manufacture and process, and that can easily provide a certain level of satisfactory improvement. .

That is, the present invention is a polyolefin in-bead foam molded article having a shape roughly following the shape of a sheet,
At least in the center portions of both sides, a collar portion is formed that slightly bulges outward from both sides and is curved downward;
The present invention provides a core material for a motorcycle seat in which a recessed portion is formed on the lower surface to fit into a convex portion provided on a pedestal on which the core material is to be placed.

Hereinafter, the present invention will be described in more detail with reference to the drawings showing one embodiment of the present invention.

1 to 3 are views showing one embodiment of the present invention, in which FIG. 1 is a side view, FIG. 2 is a top view, FIG. 3 is a bottom view, and FIG. 4 is a rear view.

The core material is a polyolefin in-bead foam molded product made of polyethylene, polypropylene, etc., and has a shape roughly following the shape of the sheet. That is,
This core material has a relatively elongated planar truncated isosceles triangular shape, and is used to construct a seat with the front and rear portions of the top surface curved slightly upward to make it easier to sit on. It has a generally elongated triangular shape, and the front and rear portions of the upper surface are each curved upward, forming a front curved portion 1a and a rear curved portion 1b. Further, in order to provide the upper surface shape of the seat to suit the driving posture, the curvature of the rearward curvature portion 1b is relatively large.

This core material has flanges 2 formed at the central portions of both sides, which bulge slightly outward from both sides and are curved downward. This flange part 2 is intended to make it easier to pinch the seat between your crotches when driving.Since the flange part 2 bulges outward from the main body part, it is easy to firmly pinch the seat between your crotches and stabilize your body. Since the flange 2 is curved downward and exhibits appropriate elasticity like a leaf spring, it is also possible to prevent the clamping position from shifting due to direct transmission of vibrations during running.

If the flange portion 2 is formed near the center of both sides of the seat where the driver's knees will hit when the driver has to firmly pinch the seat between his/her crotches, such as when driving in a half-backed state, it will prevent other drivers from riding. Although it is not necessary to form them particularly toward the front or rear, they may be formed over the entirety of both sides in order to make it easier to pinch the seat in any position.

The rear lower surface of the core material projects downward from the central portion and the front lower surface to form a thick walled portion 3, in which three recessed portions 4 are provided. This recess 4
is fitted with a convex portion (not shown) provided on a pedestal (not shown) such as a metal plate on which the core material is to be placed. And the core material is
Because it is firmly fixed to the vehicle body via the pedestal, the core material does not shift during driving, and the seat's orientation is improved, making it easier for the driver to maintain balance even on rough roads. It is. Further, the reason why the thick part 3 is provided and the concave part 4 is formed therein is to maintain the strength of the concave part 4, and the influence of the fitting between the concave part 4 and the convex part of the base extends to the upper surface, which adversely affects sitting comfort. This is to prevent them from giving away. Furthermore, the reason why the recess 4 is provided at the rear is that in a normal driving position, the driver will sit down towards the rear of the seat, so the rear part, where the load is most likely to be applied, is fixed to the pedestal. This is to reliably prevent misalignment. However, recess 4
The formation position is not particularly limited to the rear side as long as it can be firmly fixed by fitting with the convex portion of the base.

This core material is attached to the vehicle body via the pedestal as described above, and the seat is constructed by covering it with a relatively thin cushioning material such as polyurethane mat and then wrapping it with an exterior material such as artificial leather. It is.

The upper surface of the main core material in the illustrated example is smooth, but fine irregularities are formed on the upper surface to improve compatibility with the cushion material that is placed over it and to prevent the cushion material from shifting. Also good.

In addition, the core material is a polyolefin in-bead foam molded product as described above, but preferably has a thickness of 2 to 2.
Beads with a foamed skin having a skin of 100μ, more preferably beads with a foamed skin having a skin that is three times or more thicker than the inner bubble film thickness of the beads made by the method of JP-A-57-70621. In a molded body,
Most suitable is a bead foam molded body made of skinned polyethylene beads. When beads with skin are used, the surface of the molded object has a continuous skin of each bead, and the state of fusion between the beads is good, making it stronger and more heat resistant than when beads without skin are used. will also be excellent. Therefore, if the core material is formed into a foam molded product using such beads, not only will the sheet not be crushed and the flange portion 2 in particular will not be cracked,
There is no fear that the core material will be damaged by the frictional heat between the core material and the cushion material during long-term continuous running, and it is durable. On the other hand, ordinary styrene bead foam moldings have poor flexibility, resilience,
Since it has poor abrasion resistance, it tends to be damaged by sheet crushing, cracking of the flange 2, and friction with the cushion material, resulting in poor durability.

In order to obtain suitable elasticity, stiffness, and resilience as a core material, the density of the bead foam molding that makes up this core material is 0.02 g/cm ³ (expansion ratio approximately 50 times) to 0.07.
g/cm ³ (foaming ratio approximately 15 times), optimally 0.03 g/cm ³
(Foaming ratio approx. 35 times) ~0.05g/cm ³ (Foaming ratio approx. 20 times)
preferably). If the density is too low, it will become too flexible and will be useless as a core material, while if it is too high, it will become brittle and break easily, or it will be too hard, causing a feeling of bottoming out when made into a sheet. The beads preferably have a relatively small diameter, and a particle diameter of 2 to 8 mm after foaming is optimal in order to obtain sufficient strength.

Next, the advantages of the present invention will be listed.

1. Since it is composed of a bead foam molded product, it can be easily obtained even in complex shapes without the hassle of cutting out.

2. Since the shape roughly follows the shape of the sheet, a sheet with a predetermined shape can be obtained simply by sequentially wrapping the core material with a cushion material and an exterior material, making it easy to manufacture the sheet. Furthermore, the reason why the core material can be made to conform to the shape of the sheet is that the core material is made of the above-mentioned molded body.

3. It is a bead foam molded product with appropriate elasticity, so even if the core material is incorporated into the sheet, it will not feel bottomed out, and the core material is incorporated into the entire sheet, making the hardness of the sheet uniform. The seat incorporates this core material to hold it in place, making it extremely comfortable to sit on.

4 Flanges are formed on both sides, and the core material is firmly fixed to the pedestal by the recess on the bottom surface, so when the core material is incorporated, it is easy to pinch the sheet strongly between the crotches, and the sheet itself does not shift. This makes it easier for the driver to maintain balance even on rough roads.

5. If the foam molding conditions are properly determined, core materials of a certain quality can be easily mass-produced, and there is no risk of quality variations occurring during the manufacturing process.

As explained above, according to the present invention, a motorcycle seat having excellent functions can be easily obtained.

[Brief explanation of the drawing]

Figures 1 to 4 show an embodiment of the core material according to the present invention, with Figure 1 being a side view, Figure 2 being a top view, Figure 3 being a bottom view, and Figure 4 being a rear view. It is. 1a: Front curved part, 1b: Back curved part, 2: Flange part, 3: Thick part, 4: Recessed part.

Claims (1)

[Scope of utility model registration request] It is a polyolefin bead foam molded article having a shape that roughly follows the shape of the sheet, and at least in the center portions of both sides, a collar portion that bulges slightly outward from both sides and is curved downward is formed, and on the lower surface, A core material for a motorcycle seat, characterized in that a concave portion is formed to fit into a convex portion provided on a pedestal on which the core body is placed.