JP3187331U - spoke - Google Patents

Abstract

Provided is a spoke that can suppress air resistance and can efficiently receive a reduction in required power due to tailwind when the spoke is at the lower part of the wheel, and can also be reduced in weight. To do.
In a spoke comprising an attachment portion for fixing to a rim, an attachment portion for fixing to a hub, and a trunk portion existing between the two attachment portions, the cross-sectional shape of the trunk portion is changed to a tip portion 15. Is arcuate, and extends in a straight line in the direction in which the distance between the two ends away from both ends of the front end portion 15, and the cross-sectional shape presents a rear end portion 16 a in which the both ends extended in a straight line are connected in a straight line. Form. Or it forms in the cross-sectional shape which exhibits the rear-end part connected to the shape where the both ends extended in the above-mentioned linear shape curved toward the front-end | tip direction.
[Selection] Figure 1

Description

  The present invention relates to a spoke mounted on a bicycle wheel, and more particularly to a spoke capable of reducing air resistance during traveling.

  Common spokes equipped on bicycle wheels are made of metal such as hard steel wire or stainless steel, and the wire is interposed between the central part of the wheel that forms the hub and the rim to which the tire is attached. Shaped member.

  FIG. 1 shows a typical spoke 10. The head 11 is longer than the body 13 and has a function of fitting into a spoke hole provided in the hub so that the spoke 10 cannot be removed from the hub. The elbow 12 bends like an elbow and acts to direct the spoke 10 towards the rim. The body 13 is a portion existing between the hub and the rim, and the cross-sectional shape is variously formed depending on the application. The threaded portion 14 provided at the end of the body 13 is screwed with an exclusive nut called an nipple (not shown) to fix the spoke 10 to the rim and simultaneously set an initial tension.

  1 is a circular cross section having the same diameter as shown in FIG. 2a over the entire length of the body 13 in a general spoke called a long body spoke. .

  In the stepped spokes in which the middle part of the body 13 is thinned with a circular cross section, the middle part is thinned to reduce weight and at the same time reduce air resistance.

  In order to reduce the air resistance due to the rotation and running of the wheels, the cross-sectional shape of the middle part of the trunk 13 is elliptical as shown in FIG. 2b (elliptical spoke), or a plate shape (flat) as shown in FIG. There are also spokes called aerodynamic spokes.

  Patent Document 1 discloses a spoke mechanism for bending the outer end portion of a spoke and fitting the bent portion into the opening of the rim so that the outer end portion of the spoke is held in the opening of the rim, thereby reducing air resistance. It is disclosed.

JP-A-11-208201

  The figure shows the air resistance applied to the spoke when the wheel rotates in the direction of arrow A. When the spoke 10 is located at the upper part of the wheel 3, it receives air resistance from the direction indicated by the arrow 1, and when it is located at the lower part of the wheel 3, it receives air resistance from the direction indicated by the arrow 2.

  Therefore, the present invention can suppress the above-mentioned air resistance, and when the spoke is at the lower part of the wheel, it can efficiently reduce the necessary power due to the tailwind and can also be reduced in weight. The purpose is to provide spokes.

  The configuration of the present invention for achieving the above object is as follows.

  (1) The device according to claim 1, wherein the spoke includes a mounting portion for fixing to the rim, a mounting portion for fixing to the hub, and a trunk portion existing between the two mounting portions. The cross-sectional shape of the arc is formed in a cross-sectional shape in which the tip has an arc shape, extends linearly in a direction in which the distance between the two ends away from both ends of the arc, and the both ends extending in a straight line are connected in a straight line. .

  (2) The device described in claim 2 is a spoke according to claim 1, in which both end portions that extend in a straight line are formed in a cross-sectional shape that is connected to a shape that is curved toward the tip direction.

  It will be outlined with reference to the drawings how the present invention configured as described above works to solve the problems.

  FIG. 1 is a cross-sectional view of the body portion of the spoke according to claim 1, and FIG. 2 is a cross-sectional view of the body portion of the spoke according to claim 2.

  The spoke according to the present invention has a tip 15 provided in an arc shape in its cross section. If the spoke is attached to the wheel so that the tip 15 is directed toward the traveling direction when the spoke is on the upper part of the wheel, the air resistance received due to the arc shape is small.

  On the other hand, the rear end portion 16 opposite to the front end portion 15 is a straight rear end portion 16a in the device according to claim 1, and is curved toward the front end portion 15 side in the device according to claim 2. It becomes the rear end 16b.

  If the front end portion 15 is attached so as to face the traveling direction side when the spoke is on the upper portion of the wheel, the rear end portion 16 faces the traveling direction side when the spoke is on the lower portion of the wheel. At this time, the rear end portion 16 receives a head wind, but the lower portion of the wheel rotates toward the opposite side in the traveling direction, so that the head wind becomes a tailwind. That is, in order to promote the rotation of the wheel, it is preferable to form the rear end portion 16 in a shape that can receive the required power reduction, and therefore the rear end portion 16a in the device according to claim 1 is formed in a straight line shape. The rear end portion 16b in the device according to claim 2 is provided with a curved shape on the front end portion 15 side, so that the area for receiving the tailwind can be increased and the required power can be reduced more efficiently. It will be. Moreover, since the rear end portion 16b is recessed in a curved shape toward the front end portion 15 side, the spoke itself can be reduced in weight.

Sectional view of the device of claim 1 Sectional view of the device according to claim 2 Spoke perspective view AA line sectional view in FIG. Explanatory diagram showing the relationship between wheel rotation and air resistance

  Hereinafter, an embodiment of a preferred device will be outlined with reference to the drawings. The embodiments of the present invention are not limited to the following embodiments, and various forms can be adopted as long as they belong to the technical scope of the present invention.

  The spoke according to the present invention has a shape substantially similar to that of the conventional spoke shown in FIG. 3, and is an attachment portion which is a screw portion 14 for fixing to a rim and an attachment which is a head 11 for fixing to a hub. And the body part 13 existing between the two attachment parts are configured as an integral member.

  The material is formed of a conventional metal material such as sheet metal, stainless steel, aluminum, or a carbon fiber composite material. Of course, from the present disclosure, other suitable materials can be used as needed and / or desired.

  The feature of the present invention resides in the cross-sectional shape of the trunk. Here, the cross-sectional shape refers to a shape appearing in the cross-section taken along the line AA shown in FIG.

  In the device according to claim 1, the tip portion 15 is arcuate, and extends linearly in a direction in which the distance between the two ends away from both ends of the tip portion 15 and the both ends extending in a straight line form a straight line. It is formed in the cross-sectional shape which exhibits the rear-end part 16a connected in a shape. At this time, both the straight portions 17 and 17 are provided symmetrically with respect to the center line B. However, this is only an example, and a shape suitable for efficiently reducing the air resistance can be arbitrarily adopted. Is.

  In the device according to claim 2, the tip portion 15 has an arc shape, extends linearly in a direction in which the distance between the two ends away from both ends of the tip portion 15 and the both ends extended in the straight line form the tip. It is formed in a cross-sectional shape exhibiting a rear end portion 16b connected to a shape curved in the direction. At this time, both the straight portions 18 and 18 are provided symmetrically with respect to the center line C, but this is only an example, and a shape suitable for efficiently reducing the air resistance can be arbitrarily adopted. Is.

15 .. Tip 16..

Claims (2)

In the spoke consisting of an attachment part for fixing to the rim, an attachment part for fixing to the hub, and a body part existing between the two attachment parts,
A spoke in which the cross-sectional shape of the body is arc-shaped at the tip, extends linearly from both ends of the arc to the rear, and both ends extending in a straight line are connected in a straight line.   The spoke according to claim 1, wherein both end portions extending in a straight line have a cross-sectional shape connected to a shape curved toward the front end direction.

Images