JPH10218052A - Stand device suitable for bicycle for sport - Google Patents

Abstract

PROBLEM TO BE SOLVED: To park a bicycle easily in a condition in which it is erected by attaching a ground contact body which can be folded freely to a pedal supported on a free end of a crank by its shaft and making the crank at a stable support angle, the pedal, and the ground contact body act as a stand device. SOLUTION: When a bicycle is parked, a ground contact body 3 attached to a pedal 2 in such a manner that it can be folded freely is developed against a spring 7 from a storage condition along a rear surface of the pedal 2 so that a free end side can be brought into contact with the ground. At this time, a crank 1 is positioned at a stable support angle at which the bicycle can be supported stably. In this condition, the bicyle is tilted to bring the ground contact body 3 into contact with a road surface, and the bicyle is parked in a condition in which it is erected. The stable support angle which is an angle of the crank which is in a stable condition is expressed by a crank angle in the direction of stepping for the downward vertical direction, and its value is 15 deg. to 25 deg. when the bicyle is stopped on a horizontal road surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stand device having a lightweight, non-exposed shape suitable for a sports bicycle.

[0002]

2. Description of the Related Art Conventionally, many sport bicycles have no stand device. It was for the following reasons. (B) To prioritize weight reduction because of emphasis on running performance. (B) When running close to each other in competitions, etc., the shape of the stand device exposed to the outside may cause contact troubles and is dangerous. The bicycle cannot be stopped during parking or storage, which is inconvenient.

[0003]

SUMMARY OF THE INVENTION The present invention is to provide a stand device which achieves both low weight and a non-exposed shape and a good running performance in comparison with the prior art.

[0004]

SUMMARY OF THE INVENTION The present invention is a bicycle stand device comprising a crank (1) having a stable support angle (4), a pedal (2) and a grounding body (3).

[0005]

The method of use of the present invention is as follows. (A) Put the grounding body (3) in use so that the pedal (2) is grounded. (B) Position the crank (1) at the stable support angle (4). (C) Tilt the bicycle so that the grounding body (3) touches the road surface. The present invention is a stand device of a method for supporting a bicycle with a crank and a pedal, and a mechanism that balances a rotating and unstable crank with various external forces and is stable against temporary external force fluctuations such as wind. Is derived based on the dynamic principle peculiar to a bicycle. In the present invention, the angle of the crank in the stable state as described above is referred to as a stable support angle (4), and is represented by a crank angle in a stepping direction with respect to a downward vertical direction. Its value is 15 ° to 25 ° when stopping on a horizontal road surface. Hereinafter, a method of deriving the stable support angle will be described. When the pedal (2) is in contact with the road surface through the contact body (3), the following rotational moment acts on the crank (1). (A) The reaction force (W1) of a part (W) of the vehicle weight applied to the crank (1) and the pedal (2) is divided into a component (W2) in the crank direction and a component (W) in the direction perpendicular to the crank.
3), and further, the rotational moment (W
M). Here, WM is represented by the following equation. WM = W3 × L = WxLxSinθ (Equation 1) where, θ: crank angle with respect to the downward vertical direction L: crank rotation radius (b) Inclination of the road surface when stationary Acts on the bicycle as an external force (F), and a reaction force (F1) to the force becomes a component force (F2) in the crank direction and a component force (F3) in the direction perpendicular to the crank, and further generates a rotational moment (FM). The direction differs depending on the direction of the external force. Where FM
Is represented by the following equation. FM = F3 × L = F × L × Cos θ (Equation 2) (c) When the rotational moment in the stepping direction gradually increases, the bicycle attempts to move, but at the same time, the bicycle rotates at various parts. A reaction force is generated by a resistance force such as friction, and a counter-stepping direction rotational moment (RM) is generated. The two opposing rotational moments are initially balanced with the same magnitude, but when the counter-rotational direction rotational moment (RM) reaches the maximum value (RMmax), the stepping-direction rotational moment comes to prevail thereafter. The bicycle starts moving. The maximum value (RMma) of the rotational moment (RM) in the anti-stepping direction
x) changes greatly depending on the setting of the gear ratio of the bicycle transmission. The relationship between the above three rotational moments (WM, FM, RM) and the crank angle (θ) is shown in the figure, and the sum (W
M + FM + RM) is shown in FIG. 3, and the range of the crank angle at which the sum is zero is shown in FIG. The starting angle (θs)
Indicates the critical angle at which the user tries to rotate in the counter-stepping direction from the balanced state, and the rotational moment at that time is expressed as follows. WM + FM = 0 Here, when the rotational moment in the stepping direction is represented by “+” and the rotational moment in the counterstepping direction is represented by “−”, WM−FM = 0, and when represented by θs, F × cos θs = W × Sinθs · (Equation 3) Similarly, the end angle (θe) indicates a critical angle at which the user tries to rotate in the stepping direction from a balanced state,
The rotational moment at that time is expressed as follows. WM + FM + RM = 0 Here, when the rotational moment in the stepping direction is represented by “+” and the rotational moment in the counter-stepping direction is represented by “−”, WM−FM−RM = 0, and when represented using θe, F × Cosθe = W × Sin θe−R (Equation 4) Here, assuming that F is normalized and F / W and R / W are fixed values (K), Expressions 3 and 4 are expressed by the following functions of θ. F / W = f (θs) = f (θ) = Tan θ (Equation 5) F / W = g (θe) = g (θ) = Tan θ−K / Cos θ (Equation 6) 4) f (θ) and g (θ) are shown in the figure, and the range where the crank is balanced is represented as a portion (S) sandwiched between both functions. Here, a stable state of an arbitrary point (P) in the portion (S) of FIG. The point (P) can maintain the balance against the external force fluctuation in the range of Δh1 in the “+” direction and Δh2 in the “−” direction of the F / W axis, and the point (P) is represented by h (θ). And h (θ) = f (θ) −Δh1 (Equation 7) h (θ) = g (θ) + Δh2 (Equation 8) In addition, since the external force fluctuation has an arbitrary direction, the point (P) is most stable when | Δh1 | = | Δh2 | (Equation 9). Therefore, if Equation 9 is substituted into Equations 7 and 8, h (θ) indicates the most stable state, and is expressed by the following equation. h (θ) = (f (θ) + g (θ)) / 2 This equation is expressed as h (θ) = Tanθ−K / 2Cosθ from Equations 5 and 6. (Equation 10). Here, if the stable support angle (4) is defined to be expanded by ± 5 ° in consideration of the practical range with respect to the most stable crank angle given by Expression 10, the stable support angle (4) is as follows. Is represented by F / W = Tan θ−K / 2Cos θ (Equation 11) θm = θ ± 5 ° (Equation 12) where F: external force acting on the bicycle, W: a part of the weight of the bicycle F / W : Standard applied external force, K: Constant (R / W) R: Bicycle rotational frictional resistance θ: Crank angle θm: Stable support angle When calculated by the formula, when the vehicle is stopped on a horizontal road surface (F / W)
= 0), the stable support angle (4) is as follows. 15 ° ≦ θm ≦ 25 °

[0006]

Embodiments of the present invention will be described below. The present invention provides a crank (1) having a stable support angle (4),
It is composed of a pedal (2) and a grounding body (3). When using this, (a) Put the grounding body (3) in use so that the pedal (2) is grounded. (B) Position the crank (1) at the stable support angle (4). The stable support angle (4) varies depending on the inclination angle of the road surface, but is 15 ° to 25 ° in a horizontal case. (C) Tilt the bicycle and put the pedal (2) on the road surface through the grounding body (3). In this way, the bicycle is stopped on the road surface, supported by the crank and the pedal and the grounding body. This state is stable without falling down even if some external force fluctuation such as wind occurs. Further, in the case of a bicycle having a transmission, the higher the gear ratio, the higher the stability. Here, the grounding body (4) broadly means a body that functions to ground the pedal (2) to the road surface. Hereinafter, as one example, a method in which the leg (5) provided at the end of the pedal (2) indirectly grounds the pedal (2) on the road surface will be described. (A) Attach the leg (5) to the frame (6) of the pedal (2). (B) The leg (5) rotates around the support shaft (9). (C) A spring (7) is attached to the support shaft (9), and the leg (5)
Gives a turning force to make it easy to open. (D) A magnet (8) is provided inside the frame (6) so that the leg (5) can be fixed. The configuration is as described above, and the operation method is as follows. (A) The leg (5) is housed in the frame (6) during traveling and is fixed by the magnet (8). (B) To stop and make the leg (5) usable,
The foot (10) is stepped on with the foot to separate the leg (5) fixed to the magnet (8). The separated leg (5) opens naturally by the rotational force of the spring. (D) In order to store the legs (5) when traveling, the legs (5) are rotated with their feet so as to be folded into the frame (6). The legs (5) folded inside the frame (6) are magnets (8)
Is fixed by As described above, all operations can be performed with feet while sitting on the bicycle. In addition to the above method, there are the following types of grounding bodies. (A) A method in which the pedal (2) is deformed to directly contact the ground (b) A method in which the crank (1) expands and contracts to directly contact the pedal (2)

[0007]

The effects of the present invention are as follows. (A) Since most of the device is constituted by the crank (1) and the pedal (2), the weight is significantly reduced as compared with the conventional device. Therefore, the effect on running performance is small even if it is mounted on a sports bicycle. (B) During traveling, the shape of the present device is only the crank (1) and the pedal (2), and there is no danger due to the shape exposed to the outside as in the conventional device. (C) Since the operation can be performed with the foot while sitting on the bicycle, it can be used with a lighter operation than the conventional device. The same effect can be obtained by applying the invention to a general bicycle. However, when applied to a general-purpose bicycle, a bicycle having a heavy vehicle body or a bicycle having a low speed ratio may not be applicable due to the characteristic of the stable support angle.

[Brief description of the drawings]

FIG. 1 is a use side view of the present invention.

FIG. 2 is a perspective view of use of the present invention.

FIG. 3 is a diagram showing a relationship between a rotational moment acting on a crank and a crank angle.

FIG. 4 is a diagram showing a stable state of a crank in a relationship between an external force and a crank angle.

FIG. 5 is a perspective view of a grounding body of a type in which a leg is in contact with the ground when the leg is stored.

FIG. 6 is a perspective view of a landing body of a type in which a leg is in contact with the ground when the leg is opened.

FIG. 7 is an exploded perspective view of a grounding body of a type in which a leg is grounded.

FIG. 8 is a perspective view showing the use of a grounding body in which a pedal is deformed.

FIG. 9 is a perspective view of the use of a grounding body of a type in which a crank expands and contracts.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Crank 2 Pedal 3 Grounding body 4 Stable support angle 5 Leg 6 Frame 7 Spring 8 Magnet 9 Support shaft 10 Projection

Claims (1)

[Claims] Crank (1) with a stable support angle (4)
And a bicycle stand device comprising a pedal (2) and a grounding body (3).