JPH0519081U - Bicycle seat pillar - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a seat pillar that is both lightweight and strong and suitable for road racing bicycles and mountain bikes. [Structure] In a bicycle seat pillar including a column portion made of a metal pipe whose lower end is fixed to a bicycle frame, and a seat mounting portion continuously provided at the upper end of the column portion, the wall thickness of the pipe of the column portion is made uniform. Instead, the thickness of the lateral peripheral surface is reduced with respect to the traveling direction so that the outer surface shape of the horizontal cross section is circular and the inner surface shape is elliptical. In other words, the wall thickness of the front and rear peripheral surfaces of the column part, which is subjected to a large bending load during traveling, is made large, so sufficient strength can be secured,
And it can be made lighter.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bicycle seat pillar, and further to a seat pillar suitable for road racing bicycles and mountain bikes.

[0002]

[Prior art and its problems]

 In the bicycle seat pillar, as shown in FIG. 5, a seat mounting portion 2 is integrally connected to an upper end of a column portion 1 made of a metal pipe at a predetermined angle. The seat mounting portion 2 is fixed by a lower clamp 3 and an upper clamp 4 or clamp bolts 5, and a rod-shaped spring portion on the back side of a seat (saddle) not shown is clamped by the lower clamp 3 and the upper clamp 4. , The seat is fixed to the seat pillar. Then, the lower end of the column part 1 is inserted into and fixed to a frame (not shown) of the bicycle, but the column part 1 is fixed in a slightly inclined state.

By the way, recently, cycle sports have become widespread, and bicycles for road racing and mountain bikes that run off-road under severe conditions have become popular. These bicycles are used in competitions for records and run on rough roads with a lot of ups and downs, so weight reduction is strongly required. The seat pillars installed on these bicycles, which are very small, should also be light. On the other hand, these bicycles are also subject to a larger load on the seat pillars while traveling than ordinary bicycles, and there is a higher risk of falling. Therefore, if a thin-walled pipe is used for the column in order to reduce the weight, the seat pillar may bend in the front-rear direction due to a repeated load during traveling or an impact due to a fall. In other words, it is required to be lightweight and strong, but it is difficult to achieve both.

[0004]

[The purpose of the device]

 Therefore, an object of the present invention is to provide a seat pillar that is both lightweight and strong and suitable for road racing bicycles and mountain bikes.

[0005]

[Constitution of the device and its action]

 In order to achieve such an object, the present invention provides a bicycle seat pillar comprising a column part made of a metal pipe whose lower end is fixed to a bicycle frame, and a seat mounting part continuously connected to the upper end of the column part. The thickness of the pipe is not uniform, and the thickness of the lateral surface is thin with respect to the traveling direction so that the outer surface of the horizontal cross section is circular and the inner surface is elliptical.

Since the column portion of the seat pillar is fixed in a slightly inclined state, a bending load is mainly applied to the column portion in the traveling direction during traveling. In other words, a large amount of compressive tensile stress is applied to the front and rear peripheral surfaces of the column in the running direction, but the column of the present invention does not make the pipe wall thickness uniform, and is lateral to the running direction. Since the wall thickness of the peripheral surface is thin and the inner surface is oval, the wall thickness of the front and rear peripheral surfaces is large, and it is possible to withstand a large bending load. Further, since the thickness of the lateral peripheral surface is reduced, the weight can be reduced accordingly, and the weight reduction and the strength can be compatible.

[0007]

【Example】

 The present invention will be described in detail below with reference to the embodiments shown in the drawings. 1 is a partial cross-sectional view as seen from the front peripheral surface in the traveling direction, and FIG. 2 is a partial cross-sectional view as seen from the lateral peripheral surface in the traveling direction. As shown in FIG. 3, the boundary portion of No. 2 is made of a pipe with a uniform thickness, and the outer surface shape and the inner surface shape of the horizontal cross section are both circular. However, in the column portion 1 below this boundary portion, the wall thickness is not uniform, and as shown in FIG. 4, the horizontal peripheral surface 1a is thin in the traveling direction, and the front peripheral surface 1b and the rear peripheral surface 1b are thin. Surface 1c is thicker. Therefore, the outer surface of the horizontal cross section is circular, but the inner surface is elliptical. To give a specific example, the column part 1 is made of an aluminum alloy pipe with an outer diameter of 27 mmφ, the front peripheral surface 1b and the rear peripheral surface 1c have a wall thickness of 2.6 mm, and the lateral peripheral surface 1a has a wall thickness of 1.7 mm. Is.

Although such a seat pillar is mounted on a mountain bike or a road race bicycle, a large compressive tensile stress is applied to the front peripheral surface 1b and the rear peripheral surface 1c of the column portion 1 during traveling. However, since the front peripheral surface 1b and the rear peripheral surface 1c are thick, they can withstand a large compressive tensile stress and are strong against impact, and the column portion 1 does not bend. On the other hand, since the lateral circumferential surface 1a is thin, the lateral circumferential surface 1a is lighter than the lateral circumferential surface 1a having the same thickness as the front circumferential surface 1b. In addition, since the outer shape of the column portion 1 is circular, it is compatible and can be attached to any bicycle.

[0009]

[Effect of the device]

 As described above, in the bicycle seat pillar of the present invention, the wall thickness of the pipe of the column part is not uniform, and the wall thickness of the lateral peripheral surface is reduced with respect to the traveling direction, and the outer surface shape of the horizontal cross section is reduced. Since it has a circular shape and the inner surface has an elliptical shape, it is lightweight and strong at the same time, making it a seat pillar suitable for road racing bicycles and mountain bikes.

[Submission date] April 15, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction content]

By the way, recently, cycle sports have become widespread, and bicycles for road racing and mountain bikes that run off road under harsh conditions have become popular. These bicycles are used in competitions for records and run on rough roads with a lot of ups and downs, so weight reduction is strongly required. The seat pillars installed on these bicycles, which are very small, should also be light. On the other hand, these bicycles are also subject to a larger load on the seat pillars during running than normal bicycles, and there is a higher risk of falling. Therefore, if a thin-walled pipe is used for the column in order to reduce the weight, the seat pillar may bend in the front-rear direction due to a repeated load during traveling or an impact due to a fall. In other words, it is required to be light and strong, but it is difficult to achieve both.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a seat pillar viewed from a front peripheral surface in a traveling direction.

FIG. 2 is a partial cross-sectional view of a seat pillar viewed from a lateral peripheral surface with respect to a traveling direction.

3 is a sectional view taken along the line AA of FIG.

FIG. 4 is a sectional view taken along line BB in FIG.

FIG. 5 is an explanatory diagram of a seat pillar.

[Explanation of symbols]

 1 column part 1a lateral peripheral surface 1b front peripheral surface 1c rear peripheral surface 2 seat mounting part 3 lower clamp 4 upper clamp 5 clamp bolt

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[Procedure amendment]

[Submission date] September 4, 1992

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 3]

[Figure 4]

[Figure 1]

[Fig. 2]

[Figure 5]

Claims (1)

[Scope of utility model registration request] 1. A bicycle seat pillar comprising a column portion made of a metal pipe having a lower end fixed to a bicycle frame, and a seat mounting portion connected to an upper end of the column portion, wherein the column portion is arranged in a traveling direction. The bicycle seat pillar is characterized in that the lateral circumferential surface has a small thickness, the horizontal cross-section has a circular outer shape, and the inner surface has an elliptical shape.