JPH0487893A - Driving device for bicycle - Google Patents

Abstract

PURPOSE:To lessen the fluctuation of torque so as to go up a slope easily by converting the reciprocation of a pedal to the rotary motion of a crank through a pedal arm, and driving a bicycle by the rotating force. CONSTITUTION:Shafts 2 are respectively projected on both right and left side surfaces of a frame 9 of a bicycle, and one end of a pedal arm 1 is rotatably fitted to each shaft 2. A pedal 3 is fitted to the other end of the pedal arm 1. The lower surface 7 of the pedal arm 1 is formed as a sliding surface where a rotary cylinder 6 slides. A cover 4 is fitted to the side of the arm 1 not to separate the arm 1 from a ring 6. On the other hand, a rotating ring 6 is annularly installed on the forward end portion 5 of a crank 8 to lessen the sliding friction. That is, the lower surface 7 of the arm is brought into contact with the forward end of the crank to convert the reciprocation of the arm 1 to the rotary motion. Thus, a driving device having no fluctuation of torque is formed so as to go up a slope easily.

Description

[Detailed Description of the Invention] (a) Field of Industrial Application This invention relates to a bicycle drive device, and relates to a bicycle drive device that reduces fatigue when climbing a slope and allows the bicycle to climb the slope easily. .

(b) Conventional technology Conventional bicycles run by pressing the pedals and transmitting the rotation to the wheels. When the road becomes uphill, the pedals become heavier, the speed slows down, and the rider becomes fatigued, the speed changer is used to change the gear ratio to reduce the speed and increase the rotational force. It was climbing.

(c) Problems to be solved by the invention When riding a conventional bicycle up a hill, the rider had to press the pedals hard, slowing down, and becoming fatigued, making it difficult for the rider. The reason you run poorly is because when you convert leg force into rotation, you don't average it out. The torque curve of the conventional bicycle is shown in FIG. 4, and the torque changes in a wave pattern depending on the rotational position of the crank.

When going up a hill with a torque curve like this, where the torque is low, you have to use all the force to press the pedal in order to proceed, and even where the torque is high, you have to increase the speed and build up inertia to keep it from stopping. Because of this, I ended up getting tired from pushing the pedals as hard as I could. Even if a transmission was used, it was equally tiring as the legs rotated quickly. The problem that this invention aims to solve is what measures should be taken to make it easier to climb up hills on a bicycle than now.

(d) Means for Solving the Problems As a means for solving the above-mentioned problems, the bicycle drive device according to the present invention is as follows.

That is, the bicycle drive device according to the present invention is made up of a combination of an arm and a crank. Conventionally, the crank was rotated by turning it directly with the foot, but in this invention, an arm intervenes in the meantime, and the lower surface of the arm (7)
The arm (1) is brought into contact with the tip of the crank, and the reciprocating motion of the arm (1) is turned into a rotational motion. In this way, a drive device with less fluctuation in torque as shown in FIG. 3 can be obtained. A drive system with little torque fluctuation can withstand low speeds, making it easier to climb up hills. Note that various methods can be considered for abutting the arm and the crank.

(E) Operation The bicycle drive device according to the present invention functions as follows. FIG. 2 is a diagram showing the operating state.

A rotating ring (6) is attached to the tip (5) of the crank (8) to reduce friction on the sliding surface.

The lower surface (7) of the pedal arm (1) is in contact with it from above. When the pedal is depressed from above, the pedal arm (1) also lowers and the rotating ring (6) in contact with the pedal is pushed forward, simultaneously rotating the crank (8). When it reaches the lowest position, the pedal arm (1) is lifted by the rotation of the crank and returns to its original position. Second
The lower surface of the pedal arm (1) (
7) and the crank tip (5) are at right angles, and this position is the top dead center of this invention, and at this time the pedal is at its highest position. From this position, pedal (
When you step down on the rotating ring (6)
) is pushed out by the lower surface (7) of the pedal arm and moves forward while descending, simultaneously rotating the crank (8) in the direction of the arrow to generate torque. When the pedal reaches its lowest point, bottom dead center, no torque is generated.

The bottom dead center is located at the imaginary line in Figure 2. From that position, the pedal moves back and the pedal arm (1) is now supported by the rotating ring (6) and lifted back to its original top dead center position. The rotation continues by repeating the same action. Now, the positions of the top dead center and bottom dead center of this invention are further forward and further back than the positions of the conventional top dead center and bottom dead center. Therefore, the angle at which torque is generated during one rotation of the crank was conventionally generated within 180 degrees, which is half of the rotation from top to bottom, but in the case of this invention, the angle at which torque is generated is approximately 240 degrees. Wide angle in degrees. The half-plane return is approximately 120 degrees, which is an included angle. Therefore, the torque curve becomes a torque diagram as shown in FIG. 3, where the height is low but the width of the hem is wide from side to side. Since the left and right pedals generate torque, as shown in the figure, the hem of the mountain overlaps and the torque of the left and right pedals is combined and generated. Then, as shown in FIG. 3, the torque curve is corrected by the dotted line, and the drop in torque is smaller than in the conventional case, resulting in torque generation with less fluctuation.

(f) Examples Example 1 FIG. 1 is a perspective view showing a first embodiment.

A shaft (2) is provided protruding from both left and right sides of a bicycle frame (9), and one end of a pedal arm (1) is rotatably attached to the shaft (2). A pedal (3) is attached to the other end of the pedal arm (1). The pedal arm (1) rotates forward and backward through an angle of about 60 degrees about the axis (2). Pedal arm (1
) is a sliding surface on which the rotating ring (6) slides. A cover (4) is attached to the side of the arm (1) to prevent the arm and ring from separating. The tip (5) of the crank (8) is equipped with a rotating ring (6) to reduce friction during sliding.

(g) Effects of the Invention To climb a hill easily on a bicycle, it is easier to climb up a hill if you take your time and go up slowly, albeit at a slower speed.However, with conventional bicycles, it was difficult to climb up a hill slowly. Because the crank is rotated directly by the foot, the generation of torque is the fourth
As shown in the conventional torque curve diagram shown in the figure, when the fluctuations are large, and the positions where no torque is generated and the positions where the highest torque occurs alternately, and the position is about to stop due to lack of torque, the speed must be increased before and after that. It was necessary to build up inertia to drive the vehicle, and it was not possible to run very slowly; it was tiring to use force to maintain the speed it had achieved by forcing itself up the slope.

However, with this invention, as shown in the torque curve shown in Figure 3, a relatively average torque is generated, so even on uphill slopes, it is possible to drive relatively slowly at an average speed.
Since you can drive without forcing yourself to increase your speed, you can climb hills more easily than before.

In order to climb a hill easily, more force is required, and this invention increases the number of rotations to increase the force. The idea is to minimize unnecessary pedal movement by minimizing pedal movement. The pedals used to move in a circular motion, but now they move in a reciprocating motion.

Therefore, even if the pedal speed is the same, the rotation can be completed faster because the distance is shorter. Furthermore, in the conventional pedal movement, it takes the same amount of time to go back and forth, but with this invention, it takes half the time to return. This is achieved by the action shown in FIG. 2, which shows the operating state. Since the top dead center of this invention is about 30 degrees ahead of the conventional top dead center, the crank reaches the top dead center about 30 degrees earlier and rotates while generating torque, but the bottom dead center is about 30 degrees earlier.
0 degrees, further back than before, and the crank rotates about 30 degrees more than before to reach bottom dead center. When you press the pedal all the way down, the crank rotates approximately 240 degrees.

It takes about 120 degrees of rotation for the pedal to return from the bottom to the top. If you compare the time it takes to pedal from top to bottom to the time it takes to pedal from the bottom, it takes half the time. Comparing one round trip of the pedal of this invention with that of a conventional pedal, the pedal of this invention is three-fourths
It takes one round trip. This means that the pedals of the present invention can make five reciprocations while the conventional bicycle pedals make four reciprocations. Since one reciprocation of the pedal is one rotation of the crank, the rotation of the crank can be further increased, so when power is required when climbing a slope, the rotation speed of the crank can be increased to increase the output.

As described above, this bicycle drive device allows the bicycle to run even at low speeds when going up a slope, and the strong force obtained by fast rotation makes it possible to go up a slope easily.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a first embodiment of the present invention, FIG. 2 is a diagram showing an operating state, FIG. 3 is a characteristic diagram of the present invention, and FIG. 4 is a characteristic diagram of a conventional invention. (1) --- Pedal arm (2) --- (axis) (3
)--1 (pedal) (4)-1~(cover) (
5) --- (crank tip) (6) - direct rotation ring) (7) -- (bottom of arm) (8) --- (crank) (9) --- (frame') (to) --- (
Chain) Fig. 1 ``Rarely rotated ring Pedal arm lower surface Crank frame Chain Fig. 2 Fig. 3r2 $4 Fig.

Claims (1)

[Claims] 1. Provide a shaft (2) protruding from the side of the bicycle frame (9), attach one end of the pedal arm (1) to it, and bring the bottom surface (7) of the pedal arm into contact with the crank tip (5). the other end of the pedal arm (1) is attached to the pedal (3).
) to control the reciprocating motion of the pedal.
A bicycle drive device that converts the rotational motion of the crank into rotational power and runs the bicycle using that rotational force.