KR101999438B1 - Bicycle frame - Google Patents

Abstract

The front frame includes a head tube and a seat tube arranged in a longitudinal direction, and the head tube upper end portion and the seat tube upper end portion are disposed in a transverse direction, and the front frame and the rear frame are connected to the front frame. And a down tube disposed in the transverse direction, the down tube being connected to the lower end of the head tube and the lower end of the seat tube, wherein the rear frame includes a seat stay connected to the seat tube upper end portion and the rear wheel, And a chain stay connected to the seat tube lower end portion and the rear wheel, wherein the seat tube includes an upper seat tube, a middle seat tube and a lower seat tube, and the head tube, the top tube, the down tube, Wherein the seat tube and the lower seat tube are formed of a fiber-reinforced plastic, Portion seat tube, the seat stay and the chain stay is provided a bicycle frame formed of a metal.

Description

Bicycle frame {BICYCLE FRAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle frame, and more particularly to a bicycle frame in which a part of a frame is reinforced with a fiber-reinforced plastic.

Recently, bicycles have been designed and manufactured to be used for various purposes such as leisure activities besides transportation, and various kinds of bicycles having strength and weight suitable for the purpose of use are being released.

On the other hand, the bicycle frame, which is a main constituent for determining the strength and weight of the bicycle, is largely composed of a front frame and a rear frame. Generally, the front frame includes a head tube and a seat tube, Lt; / RTI >

Since bicycle frames must have a certain level of strength, they are usually made of materials such as chromium steel and stainless steel, which have high tensile strength and modulus of elasticity.

In recent years, bicycles made of carbon fiber reinforced plastic have been released to lighten bicycles. These bicycles are light in weight and excellent in driving feeling, and are highly satisfied with consumers.

However, the bicycle frame made of carbon fiber reinforced plastic has a problem that the production cost is high, the production cost is high due to low productivity, and mass production is difficult.

Accordingly, there is an increasing need to develop a bicycle frame capable of achieving mass production and light weight and sufficient mechanical strength.

A problem to be solved by the present invention is to provide a bicycle frame which can be mass-produced and lightweight and has excellent mechanical strength.

According to an aspect of the present invention, there is provided a head frame including a front frame and a rear frame joined to the front frame, wherein the front frame includes a head tube and a seat tube arranged in a longitudinal direction, And a down tube which is disposed in a transverse direction and which is joined to the lower end of the head tube and the lower end of the seat tube, And a chain stay connected to the seat tube lower end portion and the rear wheel, wherein the seat tube includes an upper seat tube, a middle seat tube, and a lower seat tube, and the head tube , The top tube, the down tube, the top sheet tube, Wherein the center tube, the seat tube and the chain stay are formed of a metal fiber reinforced plastic, and the central seat tube, the seat stay and the chain stay provide a bicycle frame formed of a metal.

The fiber-reinforced plastic may include a base resin and reinforcing fibers impregnated in the base resin.

The base resin may include at least one of a thermoplastic resin and a thermosetting resin.

Wherein the reinforcing fiber is selected from the group consisting of a metal fiber, a metalized inorganic fiber, a metalized synthetic fiber, a glass fiber, a polyester fiber, a polyamide fiber, a graphite fiber, a carbon fiber, a ceramic fiber, a mineral fiber, , Kenaf fibers, jute fibers, flax fibers, hemp fibers, cellulosic fibers, sisal fibers and coarse fibers.

The reinforcing fibers may include up to 85 wt% of the total weight of the fiber-reinforced plastic.

According to another aspect of the present invention, there is provided a head frame including a front frame and a rear frame joined to the front frame, wherein the front frame includes a head tube and a sheet tube arranged in the longitudinal direction, Wherein the rear frame includes a seat stay connected to an upper end of the seat tube and a rear wheel and a chain stay connected to a lower end of the seat tube and a rear wheel of the vehicle, The front frame is formed of fiber reinforced plastic, and the rear frame provides a bicycle frame formed of metal.

The center tube may be formed to be gradually wider from the center of the center tube toward the head tube and the seat tube.

The center tube may include a shell having a parabolic cross section, and a rib located inside the shell.

According to still another aspect of the present invention, there is provided a portable terminal including a front frame and a rear frame joined to the front frame, wherein the front frame includes a head tube and a sheet tube arranged in a longitudinal direction, And a center tube joined to the head tube and the seat tube, wherein the rear frame includes a seat stay connected to the seat tube upper end portion and the rear wheel, and a chain stay connected to the seat tube lower end portion and the rear wheel, Wherein the head tube, the center tube, and the center seat tube are formed of a fiber-reinforced plastic, and the upper sheet tube, the lower sheet tube, and the upper sheet tube, The rear frame provides a bicycle frame formed of metal.

According to the bicycle frame according to the embodiment of the present invention, a part of the frame is reinforced with a fiber-reinforced plastic, thereby achieving weight reduction and excellent mechanical strength, and also reducing production cost and mass production.

1 is a bicycle frame according to an embodiment of the present invention.
2 is a bicycle frame according to another embodiment of the present invention.
3 is a sectional view taken along the line III-III in Fig.
4 is a bicycle frame according to another embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: FIG. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the drawings, the thickness is enlarged to clearly represent the layers and regions. Like parts are designated with like reference numerals throughout the specification. It will be understood that when an element such as a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the element directly over another element, Conversely, when a part is "directly over" another part, it means that there is no other part in the middle.

Next, a bicycle frame according to an embodiment of the present invention will be described with reference to FIG.

1 is a bicycle frame according to an embodiment of the present invention.

Referring to FIG. 1, a bicycle frame according to an embodiment of the present invention includes a front frame 100 supporting the front of the bicycle and a rear frame 200 supporting the rear of the bicycle.

First, the front frame 100 will be described in detail.

The front frame 100 includes a head tube 110 and a seat tube 130 serving as a pillar of a bicycle and a head tube 110 and a seat tube 130 located between the head tube 110 and the seat tube 130, And a down tube 140 that supports the top tube 120 and the down tube 140, respectively.

The head tube 110 is a tube connected to a steering wheel of a bicycle and a fork on which a front wheel runs, and the seat tube 130 is a tube on which a seat of a bicycle can be mounted.

1, the head tube 110 and the seat tube 130 may be arranged in a longitudinal (y) direction in the bicycle frame. For convenience, the head tube 110 is relatively short in length and the seat tube 130 is relatively long But they may be arranged in various forms without being limited thereto.

The top tube 120 is joined to the head tube 110 and the seat tube 130 with the upper end of the head tube 110 and the upper end of the seat tube 130 interdigitated with each other.

The down tube 140 is joined to the head tube 110 and the seat tube 130 while connecting the lower end of the seat tube 130 and the lower end of the head tube 110 to each other.

The top tube 120 and the down tube 140 may be disposed in the transverse (x) direction in the bicycle frame.

The seat tube 130 includes an upper seat tube 130b on the upper portion of the seat tube 130, a middle seat tube 130a on the middle portion of the seat tube 130 and a lower seat tube 130c on the lower portion of the seat tube 130, . ≪ / RTI >

The head tube 110, the top tube 120, the down tube 140, the upper seat tube 130b, and the lower seat tube 130c of the front frame 100 of the bicycle frame according to the embodiment of the present invention, And the center seat tube 130a may be formed of a metal such as an aluminum alloy, iron (Fe), titanium, or the like.

The fiber reinforced plastic may include a base resin and reinforcing fibers impregnated with the base resin.

The base resin may include at least one of a thermoplastic resin and a thermosetting resin.

The thermosetting resin may include at least one of an epoxy resin, a phenolic resin, a unsaturated polyester resin, a vinyl ester, and a polyurethane.

The thermoplastic resin may be a polypropylene, a polyethylene, a low density polyethylene, a high density polyethylene, a polyester, a polystyrene, a polyvinyl chloride, a denatured Examples of such materials include modified polyphenylene oxide, polyamide 6, polyamide 610, polyamide 66, polyphenylene sulfide, ABS (acrylonitrile butadiene styrene), polycarbonate ), Polyurethane, polybutylene terephthalate, polyacetal, polysulfone, polyarylsulfone, polyphenylsulfone, polyethersulfone, polyether sulfone, polyether sulfone, ), Polyetheretherketone, polyamideimide, polyetherimide, polyetheretherketone, polyetheretherketone, And may include at least one of polytetrafluoroethylene (PTFE) and polyketone.

The reinforcing fiber is selected from the group consisting of a metal fiber, a metalized inorganic fiber, a metallized synthetic fiber, a glass fiber, a polyester fiber, a polyamide fiber, a graphite fiber, a carbon fiber, a ceramic fiber, a mineral fiber, Kenaf fibers, jute fibers, flax fibers, hemp fibers, cellulose fibers, sisal fibers and coir fibers.

Here, the reinforcing fiber may be 85% by weight or less based on the total weight of the fiber-reinforced plastic.

This is because the reinforcing fibers can achieve weight reduction while sufficiently securing the mechanical strength within the range of 85% by weight or less. When the reinforcing fibers exceed 85% by weight, mixing of the base resin and reinforcing fibers is difficult or the mold is damaged It is because.

Next, the rear frame 200 will be described.

The rear frame 200 may include a seat stay 210 and a lower seat tube 130c connected to the upper seat tube 130b and the rear wheel of the bicycle and a chain stay 220 connected to the rear wheel of the bicycle.

The seat stay 210 and the chain stay 220 may be formed by being divided into two pillars so as to connect the left and right sides of the rear wheel of the bicycle, respectively.

The seat stay 210 and the chain stay 220 may be formed of a metal such as an aluminum alloy, iron (Fe), or titanium.

That is, the bicycle frame according to the embodiment of the present invention includes the head tube 110, the top tube 120, the down tube 140, the top sheet tube 130b, and the bottom sheet tube 130c of the front frame 100 And the middle seat tube 130a and the rear frame 200 may be formed of metal.

When the bicycle frame is manufactured as described above, by using the fiber reinforced plastic and the metal material together, the weight of the bicycle frame can be reduced, the excellent mechanical strength of the existing metal material can be obtained, and the production cost can be drastically reduced.

Next, a bicycle frame according to another embodiment of the present invention will be described with reference to FIGS. 2 and 3. FIG.

FIG. 2 is a bicycle frame according to another embodiment of the present invention, and FIG. 3 is a sectional view taken along the line III-III of FIG.

The bicycle frame according to another embodiment of the present invention shown in FIGS. 2 and 3 has the same structure except for the bicycle frame, the center tube 160, and the seat tube 130 according to the embodiment of FIG. And the description thereof will be omitted.

Referring to FIG. 2, a bicycle frame according to another embodiment of the present invention includes a top tube 120 and a down tube (not shown) connecting the head tube 110 and the seat tube 130 of the bicycle frame according to the embodiment of FIG. Only one center tube 160 is disposed.

The center tube 160 is joined to and connected to the head tube 110 and the seat tube 130.

A bicycle frame according to another embodiment of the present invention includes a front frame 100 including a head tube 110, a seat tube 130 and a center tube 160 formed of fiber reinforced plastic, Aluminum, iron (Fe), titanium, or the like.

The center tube 160 may be formed gradually wider toward the head tube 110 and the seat tube 130 at an intermediate point of the center tube 160.

This is because the load applied to the bicycle frame is the largest at the portion where each constitution of the bicycle frame is joined so that the width of the center tube 160 in the area where the head tube 110 and the seat tube 130 meet So that the mechanical strength can be increased.

3, the center tube 160 includes a parabolic shell 160b and a rib 160a for reinforcing the mechanical strength of the center tube 160 inside the shell 160b .

The ribs 160a can reinforce the strength of the center tube 160 while reducing the thickness of the center tube 160. The ribs 160a can shorten the molding time and improve the dimensional stability of the center tube 160. In addition, It also functions to prevent deformation.

Further, though not shown, a plurality of holes may be formed in the rib 160a to reduce the weight of the rib 160a, thereby reducing the weight of the entire bicycle frame.

Next, a bicycle frame according to another embodiment of the present invention will be described in detail with reference to FIG.

4 is a bicycle frame according to another embodiment of the present invention.

The bicycle frame according to another embodiment of the present invention shown in FIG. 4 is the same as the bicycle frame according to the embodiment of FIGS. 2 and 3 described above except for the seat tube 130, .

4, the upper and lower seat tubes 130b and 130c of the seat tube 130 of the bicycle frame according to another embodiment of the present invention may be formed of a metal such as aluminum alloy, iron (Fe), titanium And the center seat tube 130a may be formed of a fiber-reinforced plastic.

For convenience, the bicycle frame shown in FIGS. 1 to 4 has been described by way of example, but the form of the bicycle frame is not limited thereto and can be manufactured in various known types.

Hereinafter, the structure and effect of the present invention will be described in more detail with reference to examples and comparative examples. However, this embodiment is intended to explain the present invention more specifically, and the scope of the present invention is not limited to these embodiments.

Example  One

1, the head tube, the top tube, the down tube, the upper seat tube and the lower seat tube are formed of carbon fiber-reinforced plastic, and the central seat tube and the rear frame are made of aluminum Respectively.

Example  2

4, the head tube, the center tube, and the center seat tube are made of carbon fiber-reinforced plastic, and the upper seat tube, the lower seat tube, and the rear frame are made of aluminum.

Comparative Example  One

A bicycle frame having the same shape as that of Embodiment 1 and having both the front frame and the rear frame formed of aluminum was produced.

Comparative Example  2

A bicycle frame having the same shape as that of the second embodiment and having both the front frame and the rear frame formed of aluminum was produced.

Experimental Example : Load test

The load test of the bicycle frame according to Examples 1 and 2 and Comparative Examples 1 and 2 was carried out by fixing the frame to a specially manufactured jig according to the European Standard Committee EN14764 and then applying a load.

In Table 1, σmax denotes the maximum stress, X denotes the safety factor, and Λ denotes the maximum deformation amount.

The results are shown in Table 1 below.

weight
(kg) Pedal load (1100N) Vertical load (1500N) Front load (1200N) sigma max
(MPa) X Λ
(mm) sigma max
(MPa) X Λ
(mm) sigma max
(MPa) X Λ
(mm) Example 1 1.20 90 0.33
(safety) 0.73 160 0.58
(safety) 0.98 156 0.56
(safety) 9.6 Example 2 1.19 155 0.56
(safety) 3.2 132 0.48
(safety) 1.5 164 0.58
(safety) 11.3 Comparative Example 1 1.33 89.3 0.32
(safety) 1.1 249 0.90
(unrest) 1.2 286 1.04
(Fracture) 7.8 Comparative Example 2 1.30 132 0.51
(safety) 4.5 202 0.76
(safety) 2.1 179 0.67
(safety) 11.8

As shown in Table 1, the bicycle frame according to Examples 1 and 2 achieves a weight reduction of about 10% as compared with the bicycle frame according to Comparative Examples 1 and 2, and excellent results in the pedal load, vertical load and front load test .

As described above, according to the bicycle frame of the embodiment of the present invention, a part of the frame is reinforced with a fiber reinforced plastic, so that it is lightweight and has excellent mechanical strength, and also it is possible to reduce the production cost and mass production.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

110: head tube 120: top tube
130: seat tube 140: down tube
210: Seat stay 220: Chain stay
100: front frame 200: rear frame

Claims (12)

A front frame and a rear frame joined to the front frame,
Wherein the front frame includes a head tube and a sheet tube arranged in a longitudinal direction and a center tube disposed in a transverse direction and bonded to the head tube and the seat tube,
The rear frame includes a seat stay connected to an upper end portion of the seat tube and a rear wheel, and a chain stay connected to a lower end portion of the seat tube and a rear wheel,
The seat tube includes an upper seat tube, a middle seat tube, and a lower seat tube,
Wherein the head tube, the center tube, and the center seat tube are formed of a fiber-reinforced plastic, the upper seat tube, the lower seat tube, and the rear frame are made of metal,
Wherein the center tube is formed at an intermediate point of the center tube so as to be gradually wider toward the head tube and the seat tube and has a parabolic cross section and a plurality of holes Wherein the bicycle frame comprises a rib formed therein. The method of claim 1,
Wherein the fiber-reinforced plastic comprises a base resin and reinforcing fibers impregnated in the base resin. 3. The method of claim 2,
Wherein the base resin comprises at least one of a thermoplastic resin and a thermosetting resin. 4. The method of claim 3,
Wherein the reinforcing fiber is selected from the group consisting of a metal fiber, a metalized inorganic fiber, a metalized synthetic fiber, a glass fiber, a polyester fiber, a polyamide fiber, a graphite fiber, a carbon fiber, a ceramic fiber, a mineral fiber, , Kenaf fibers, jute fibers, flax fibers, hemp fibers, cellulosic fibers, sisal fibers and coir fibers. 5. The method of claim 4,
Wherein the reinforcing fibers are less than or equal to 85 weight percent of the total weight of the fiber-reinforced plastic. A front frame and a rear frame joined to the front frame,
Wherein the front frame includes a head tube and a sheet tube arranged in a longitudinal direction and a center tube disposed in a transverse direction and bonded to the head tube and the seat tube,
The rear frame includes a seat stay connected to the seat tube upper end portion and the rear wheel, and a chain stay connected to the seat tube lower end portion and the rear wheel,
Wherein the front frame is made of fiber-reinforced plastic, the rear frame is made of metal,
Wherein the center tube is formed at an intermediate point of the center tube so as to be gradually wider toward the head tube and the seat tube and has a parabolic cross section and a plurality of holes Wherein the bicycle frame comprises a rib formed therein. delete delete The method of claim 6,
Wherein the fiber reinforced plastic comprises a base resin and reinforcing fibers impregnated in the base resin,
Wherein the base resin comprises at least one of a thermoplastic resin and a thermosetting resin,
Wherein the reinforcing fiber is selected from the group consisting of a metal fiber, a metalized inorganic fiber, a metalized synthetic fiber, a glass fiber, a polyester fiber, a polyamide fiber, a graphite fiber, a carbon fiber, a ceramic fiber, a mineral fiber, , Kenaf fibers, jute fibers, flax fibers, hemp fibers, cellulosic fibers, sisal fibers and coir fibers. delete delete delete

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