JP6757903B2 - Non-circular bicycle gear with gear multiples for each left and right leg - Google Patents

Description

The present invention improves the efficiency when a human pedals a bicycle, and improves the running efficiency by changing the gear ratio more suitable for the difference in the force of the left and right legs or the crank angle, so that the bicycle can be run more quickly and efficiently. It invents gears.

Conventionally, there have been bicycle front gears that are perfectly circular, oval, or non-circular (Patent Document 1). The oval and non-circular ones had the outer contour shape that they intended, but they did not match the individuality of the individual who rides the bicycle, such as the physique and leg strength, and the outer contour shape proposed as a commercial product is It could not be said that it fits the individual's characteristics.
In addition, although there is a difference between the left and right leg strengths of the person who pedals, there is a problem that the conventional product cannot cope with this difference between the left and right leg strengths. In the past, there was no way for an individual to know the vector when pedaling a bicycle, but with the advent of Pioneer's in-vehicle pedaling monitor on the market in recent years, the vector when an individual player is pedaling himself is shown in Fig. 2. It has become easy to observe and record.
As a result, each individual's interest in and recognition of the vector direction and the magnitude of the force increased, and it became possible to individually examine the outer contour shape of the non-circular gear.

Conventionally, a perfect circular gear is the mainstream, and even if a large change in pedal pedal force occurs depending on the crank angle, it cannot cope with it, and the energy generated by the movement of the human body is wasted.
Various elliptical gears and non-circular gears have appeared to improve the situation, but the grounds for determining the outer contour shape are uniform and do not correspond to the individuality of the individual who pedals the bicycle. ..
Therefore, even if a gear other than a perfect circular gear is used, it is rare to take advantage of its effects and benefits.
The biggest reason why the outer contour shape was uniform and could not correspond to individuality due to mass production is that the tooth tip shape of the gear that drives the chain needs to be an involute curve etc., and each tooth becomes elliptical. This is because it was very difficult to draw along the non-circular contour line.
Further, even if drawing can be performed, in the manufacturing process, for example, a processing machine dedicated to the tooth tip of a gear has a mechanism corresponding to a perfect circle, and cannot correspond to an ellipse, much less a non-circular shape. Or, since it is manufactured by press working, it is not possible to change the mold according to individuality due to cost constraints. Further, even if CADCAM is used, it takes too much man-hours to change the shape each time, and the product price becomes expensive.
Due to the above three major factors, it has been extremely difficult to produce a wide variety of gears having an outer contour shape in small quantities, except for a perfect circular gear and a gear shape having a uniform contour shape.

Japanese Unexamined Patent Publication No. 09-020281

The present invention has been made in view of the above problems, and an object of the present invention is to provide a non-circular gear that is more suitable for individual individuality.

Each individual analyzes the results measured by a vector measuring device such as a pedaling monitor and reflects them when designing the outer contour shape of the non-circular gear with 3D-CAD. Individually or in small quantities and in many types, not by NC machine tools such as machining centers. It is characterized by manufacturing and selling circular gears.
In this way, the gear according to the present invention is reflected when each individual analyzes the result measured by a vector measuring device such as a pedaling monitor and designs the outer contour shape of the non-circular gear by 3D-CAD. It is characterized in that non-circular gears are manufactured and sold by NC machine tools such as machining centers.
In the present invention, it is preferable that the gear is mounted on the crankshaft of the center of the bicycle of the bicycle drive device, which is characterized in that the disk-shaped outer contour is not a perfect circle but an intended non-circular contour shape.
Further, it is preferable that the non-circular contour shape is designed so that the gear multiple that acts at the crank angle at which the right leg exerts the pedal pedal force and the gear multiple that acts at the crank angle at which the left leg exerts the pedal pedal force are different on the left and right. ..
Further, it is preferable that the leg has an outer contour shape in which the gear multiple changes according to the crank angle when the pedal is stepped on.

According to the present invention, it is possible to run a bicycle more efficiently by dealing with the difference in leg strength between the left and right legs of the player who pedals.

It is a vector diagram of a pedal effort. It is a vector resultant force diagram at each crank phase. The graph is a torque curve of the crankshaft of each player for each crank phase. It is a figure which shows the lever ratio of a crank length and a gear radius in a horizontal phase. It is a figure which shows the lever ratio of a crank length and a gear radius at the bottom dead center. The graph is a torque curve of the crankshaft for each of the left and right legs at each crank phase. The graph is a curve showing the angular velocity at each crank phase. It is the figure which explained the working principle which made the difference between the gear radius and the left leg when the right leg is a horizontal position in the crank horizontal position. It is a conceptual diagram which shows that the angular velocity of a right leg and a left leg was adjusted almost equal as a result of applying the principle of this embodiment. It is a flowchart which calculates the individual optimum shape from the measurement result of an individual player, and manufactures a non-circular gear.

Hereinafter, an example of the outer contour shape of the non-circular gear using the pedaling monitor device will be described with reference to FIGS. 1 to 10.

FIG. 1 shows a vector diagram of the pedal depression force when the bicycle operator steps on the arm 20 of the crank. The bicycle gear plate 10 rotates in a predetermined direction about the center 00 of the shaft. On the bicycle gear plate 10, a pair of left and right crank arms 20 extend in opposite directions from the center 00. A pedal shaft center 30 is provided near the tip of the arm 20, and a pedal (not shown) is rotatably attached thereto. Reference numeral 40 is a virtual line indicating the outline of a virtual perfect circular gear plate. In the present embodiment, the gear plate 10 has a predetermined non-circular contour shape instead of a perfect circle.
When the operator steps on the pedal, the pedal stepping force acts as a resultant force 52. The resultant force 52 is in the direction of rotation of the crank (direction perpendicular to the extension direction of the arm 20) and the normal component force 50 acting in the direction perpendicular to the direction of rotation of the crank (direction of extension of the arm 20). It can be decomposed into the acting tangential component force 51 and shown.

Ideally, the vector resultant force 52 shows the highest efficiency in the same direction as the tangential component force 51 that rotates the gear plate 10, that is, the normal component force 50 is not working. However, even bicycle athletes have been found to show considerable loss. FIG. 2 shows the results of experimental measurement of the vector resultant force when a cycling athlete steps on a pedal using a measurement system (for example, a pedaling monitor sensor manufactured by Pioneer Corporation). The measurement system can measure the resultant force of the pedal effort separately on the left and right. As shown by the arrows in FIG. 2, the vector resultant force 52 shows a considerable inclination with respect to the rotation direction (tangential direction). In each crank phase, the ideal efficient vector resultant force 52 (that is, the direction along the rotation direction) is only 60 ° near the horizontal crank in FIG. 2 in 360 ° of one rotation of the crank. Limited to a degree of angle range.

FIG. 3 shows the torque acting on the crankshaft (of which only the right leg) was measured at each crank phase for two players, A player and B player. Assuming that the position where the crank faces the upper end is 0 °, the strongest pedaling force is in the vicinity of 90 ° and on the rear side (180 ° to 360 ° (position where it becomes 0 ° again)). Sometimes it has a negative pedaling force (at this time, the pedaling force of the opposite leg maintains the rotation of the crank). Although the big tendency is the same, as can be seen from the comparison between A player and B player, it can be seen that there is a large individual difference in the torque curve generated when a human pedals.

In addition, FIG. 6 shows the results of measuring the treading force of both the left and right legs of the same person. Usually, an individual has a dominant foot, and the treading force on the dominant foot side is stronger (in the person in FIG. 6, the right leg is the dominant foot). In order to run the bicycle at high speed, it is preferable that the difference in pedaling force between the left and right legs is small and the pedaling force is applied evenly to the left and right as much as possible.
How to eliminate the difference in pedaling force between the left and right legs as shown in FIG. 6 with a non-circular gear will be described with reference to FIGS. 4 and 5. The chain 60 is always treated as the gear plate 10 around 12:00 in FIG. Regardless of which phase the crank moves by stepping on the pedal, the position of the contact point where the chain 60 treats the gear plate 10 does not change. In the present invention, the independence of the crank phase and the portion treated by the chain 60 and the gear plate 10 is utilized.
That is, the gear ratio can be arbitrarily changed by adjusting the radius from the crankshaft core 00 to the contact point treated with the chain 60 for each crank phase.

It can be seen from the measurement results that the stepping force of the left foot is weaker than that of the right leg at a crank angle of around 90 ° for the person shown in FIG.
Therefore, as shown in FIG. 8, when the right side of the crank is at a crank angle of 90 °, the solid gear radius line B is eccentric to the dotted line B'(the position where B <B'and C>C'are formed), so that the right leg A ÷ B> A ÷ B'
Left foot A ÷ C <A ÷ C'
As such, the load torque of the left leg with weak pedaling force can be reduced.
On the contrary, this also increases the load torque of the right leg, which has a strong stepping force. By such a means for adjusting the gear radius, it is possible to increase the crank angular velocity on the left leg side where the pedaling force is weak and suppress the acceleration / deceleration of the acceleration when the bicycle is running, so that the bicycle can be run more efficiently. You can. Specifically, as a result of the eccentricity 70, as shown in FIG. 9, the angular velocity at the time of stepping on the left and right legs could be corrected to the extent that a difference between the left and right legs is hardly recognized. As a result, the time during the competition was also shortened.

In order to process the non-circular gear of the present invention, it is necessary to continuously process on a non-circular track having a distance obtained by multiplying the roller spacing by an integer.
This is a process that cannot be done by a conventional gear processing machine.
Therefore, as shown in FIG. 10, a mathematical shape model is calculated using 3D CAD, and the 3D model data derived from the calculation is used to calculate a tool path for commanding a numerically controlled machine tool using 3D CAM. .. Specifically, each bicycle operator first measures data including the pedaling force of the left and right legs as shown in FIG. 6 using a pedaling monitor (Step 10), and analyzes this data to obtain a pedaling force vector and a torque curve. , The individuality of the athlete such as the angular velocity is analyzed (Step 20). At present, portable measuring devices (for example, in-vehicle pedaling monitors manufactured by Pioneer Corporation) are widely used, and measurement / analysis can be performed using them.
Next, the contour of the non-circular gear is designed according to the characteristics of each player. At this time, the eccentricity 70 is added to such an extent that the difference in pedaling force between the left and right legs can be reduced or eliminated. Based on this data, the shape of the sprocket tooth tip is made non-circular by 3D-CAD, and arithmetic processing is performed so as to follow the contour shape of the gear (Step 30). Next, based on this arithmetic processing, three-dimensional data is output (Step 40), the tool path for the machining machine is calculated by 3D-CAM (Step 50), and then the material is cut by the machining center (Step 60). In this way, using 3D-CAMCAD and a machine tool equipped with a high degree of computing power, it was possible to manufacture a bicycle gear having a complicated shape that could not be manufactured in the past.
This makes it possible to process a non-circular gear plate required by an individual player in a processing time that is almost the same regardless of whether it is a single piece or mass production.
As described above, according to the present embodiment, it has become possible to provide a non-circular gear that is more suitable for individual individuality. As a result, it was possible to run the bicycle more efficiently by responding to the difference in leg strength between the left and right legs of the player who pedals.

00 ... Center of bicycle crankshaft Pedal and gear rotate around here.
10 ... Bicycle gear plate The shape of this is a perfect circle, an ellipse, a non-circle, or the like.
20 ... Bicycle crank arm 30 ... Bicycle pedal shaft center Athletes step on the pedal of this shaft core.
40 ... Contour line of perfect circular gear plate 50 ... Force in the normal direction of crankshaft rotation of pedaling force The unit is kgf
51 ... The tangential force unit of the crankshaft rotation of the pedaling force is kgf.
52 ... The direction and magnitude of the combined force of 50 and 51 when the pedal is pressed.
60 ... Line segment of drive chain ⇒Move in the direction.
70 ... The center of the gear plate is eccentric from 00 in order to improve the laterality of the leg force.
A ... Crank length B ... Gear radius that acts when the right leg crank is in the horizontal position B'... Gear radius that increases the gear magnification when the right leg crank is in the horizontal position C ... Acts when the left leg crank is in the horizontal position Gear radius C'... Gear radius that lowered the gear magnification when the left leg crank is in the horizontal position D ... Gear radius that acts when the right leg crank is in the bottom dead center position

Claims (1)

The disc-shaped outer contour is not a perfect circle but an intended non-circular (excluding elliptical) contour shape. The rear wheel gear is mounted on the central crank shaft of a general bicycle drive device that runs idle. It is a method of manufacturing gears, and each bicycle operator measures data including the pedaling force of the left and right legs using a measuring system, and by analyzing this data, the individuality of the pedaling force vector, torque curve, and angular speed of the athlete. According to the characteristics of each athlete, eccentricity is added to the extent that the difference in pedaling force between the left and right legs can be reduced or eliminated , and the gear multiple that acts at the crank angle where the right leg exerts pedal pedaling force and the left leg are pedals. The contour of the non-circular gear is designed so that the gear multiple acting on the crank angle that exerts the pedaling force is different on the left and right, and based on this data, the shape of the sprocket tooth tip is made non-circular by 3D-CAD, and the contour shape of the gear is made. A gear manufacturing method in which three-dimensional data is output based on this arithmetic processing, a tool path for a processing machine is calculated by 3D-CAM, and then a material is cut by a machining center.

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