JPH11227666A - Assistant power device for bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform assistant power control with high precision by enabling stable and precise installation of an assistant power unit and a sensing device for pedal stamping force. SOLUTION: In this device, one end of a hollow shaft 22 to pivot a crank shaft 6 rotatably is connected with an output sprocket 8, while the other end is connected with a motor 12 through a one-way clutch 19 and also with a crank shaft through a ratchet 23. A case of this assistant power unit 4 is configured with an inner case and outer case perpendicularly intersecting the crank shaft in which a transmission system from the motor is accommodated and a cylindrical projection 25 which is concentrical with the crank shaft and hollow shaft and pivots the hollow shaft, and the projection is inserted into a hanger pipe 38 of a frame and the side faces of the inner case and outer case are abutted to the end face of the hanger pipe, and any part of the case is coupled with the frame, and thereby the assistant power device 4 is fixed to the frame.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle auxiliary power unit equipped with an auxiliary power unit such as an electric motor.

[0002]

2. Description of the Related Art Conventionally, as a bicycle auxiliary power unit provided with an auxiliary power unit such as an electric motor, FIGS.
There is one as disclosed in FIG. FIG.
Japanese Patent Application Publication No. 244496 discloses an electric assist unit having a configuration in which auxiliary power is added by a shaft different from a crankshaft. A motor stay 220 in which an electric motor 214 as auxiliary power is fixed to a seat tube 211 is disclosed. , The support shaft of the lever 212 is coaxial with the motor 214,
The center line O in the longitudinal direction of the lever 212 is arranged parallel to the chain 209. A drive pinion 221 is fixed to the output shaft of the motor 214 as a reduction gear to drive the large-diameter auxiliary gear 222. An auxiliary sprocket 213 integral with the gear 222 meshes with the chain 209. Thus, if the pedaling force by human power increases and the tension of the chain 209 increases, the lever 21
2, the pressure of the load cell 215 increases and the motor 214 operates.

FIG. 8 discloses the structure disclosed in Japanese Patent Application Laid-Open Nos. 8-295282 and 9-11970, in which the inner and outer cases 131 and 132 of the auxiliary power unit are orthogonal to the inner and outer cases 131 and 132. And crankshaft 180
Are provided, a manual driving force is applied by pedals 181 and 182, and auxiliary power from an electric motor or the like in an auxiliary power unit (not shown) is supplied to the crankshaft 180.
Is added to the hollow shaft 170 fitted to the shaft. The hollow shaft 17
0 is a regulating member 130 and a pair of mounting members 110 and 12
0 to the hanger 101 of the bicycle frame 107. The manual driving force from the crankshaft 180 is transmitted to a sprocket 117 connected to the outer periphery of the hollow shaft 170 via a ratchet or the like.

An auxiliary power unit for a bicycle having an auxiliary power unit such as an electric motor 315 is disclosed in Japanese Patent Application Laid-Open No. Hei 8-230757 in FIG. An electric motor 31
In order to automatically change the output such as 5
2 in addition to the speed detection mechanism 313 of the moving speed
Tension detection mechanism 314 for detecting 12 tensions
Is provided. The pedaling force acting on the pedal is detected from the type of the light receiving signal of the reflection type photosensor 353. When the pedaling force increases, the tension of the chain 312 increases, the speed detection gear is pushed up, and the drive shaft 328 bites into the rubber tire 317. Therefore, the driving force of the mobile device driving device 310, which is the auxiliary power, is efficiently transmitted to the rubber tire 317.

[0005]

FIG. 7 to FIG.
In the first prior art shown in FIG. 7, an auxiliary power unit can be retrofitted to the bicycle, and the auxiliary power unit can be manufactured at a low cost. Although it became
The tension of the chain, that is, the mounting position of the tension detecting device is extremely important for accurately detecting the pedaling force due to human power as described above. However, the auxiliary sprocket 21 which is also referred to as the main body of the tension detecting device is important.
3 is fixed to the seat tube 211. That is,
Since the tension detecting device such as the auxiliary sprocket 213 is mounted on the rear frame or the seat tube where the mounting position is likely to fluctuate with respect to the chain, a large error is likely to occur in the detected manual power, and high-precision control is achieved. It was impossible.

In the second conventional example shown in FIG. 8, a hollow shaft 170 for supporting a crankshaft 180 is separated from an inner and outer case in which a transmission system from an electric motor is housed, and a pair of mounting members 110 and 120 are provided. Through the bicycle frame 107
, The concentricity and roundness of the hanger 101 and the mounting members 110 and 120 need to be high precision. In this example, the inner and outer cases 131 and 132 (not shown) are used. Since the pedal depression force sensor is disposed inside the case, the axial bulk of the inner and outer cases 131 and 132 is increased, resulting in an increase in the size of the device.

Further, in the third conventional example shown in FIG. 9, since the rotation center position of the swinging idler sprocket arm cannot be determined accurately due to the fluctuation of the tension of the chain 312, the pedal depressing force due to the mounting variation. The relationship of the sensor output with respect to was not constant, and high-precision control was difficult. In addition, since the tension detecting mechanism 314 directly receives the chain tension, the swinging power of the idler sprocket arm becomes extremely large, and a large strength is required. In addition, an elastic body receiving the same has a large spring constant. The size of the apparatus.

The present invention solves the above-mentioned problems of the conventional auxiliary power device for a bicycle, and detects an auxiliary power unit and a pedal depression force without being affected by the roundness of a hanger pipe of a bicycle frame. It is an object of the present invention to provide an auxiliary power device for a bicycle which enables stable and high-precision mounting of a bicycle and can perform auxiliary power control with high accuracy.

[0009]

According to the present invention, one end of a hollow shaft rotatably supporting a crankshaft is connected to an output sprocket, and the other end is connected to an electric motor via a one-way clutch. A bicycle auxiliary power unit connected to the crankshaft via a ratchet together with
The case shape of the auxiliary power unit has an inner / outer case in which a transmission system from the electric motor is housed and which is orthogonal to the crankshaft, and a cylindrical convex portion which is concentric with the crankshaft and the hollow shaft and which supports the hollow shaft. By inserting the cylindrical projection into the hanger pipe of the frame and bringing the side surfaces of the inner and outer cases into contact with the end surfaces of the hanger pipe, and connecting any part of the case to the frame, The power unit is fixed to a frame. Further, according to the present invention, a sensor arm pedestal is fitted and mounted on an outer periphery of a cylindrical convex portion between the hanger pipe and the output sprocket, and a pair of arm pedestals extending from the sensor arm pedestal and a chain tension are attached to the sensor pedestal. And a displacement sensor for detecting an amount of swing of the idler sprocket. Further, the present invention is configured such that the end of the rotating shaft in the transmission system from the electric motor has a polygonal cross section, and the top of each of them is detected by a proximity switch to detect the crankshaft rotation speed. It is characterized by the following. Further, the present invention is characterized in that a ventilation hole is formed at a substantially central portion of the cylindrical convex portion so as to be able to ventilate inside the frame, and these are used as means for solving the problem. Things.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 show a first embodiment of a bicycle auxiliary power device according to the present invention. FIG. 1 is an overall side view of a bicycle equipped with the bicycle auxiliary power device according to the present invention.
FIG. 2A is an enlarged partial cross-sectional plan view of the auxiliary power unit,
FIG. 2B is an enlarged partial cross-sectional side view illustrating a tension detector in the auxiliary power unit, FIG. 3 is an exploded view of assembling the auxiliary power unit to a hanger pipe, and FIG. 4 is a cross-sectional view of a power transmission system. 5 is an explanatory diagram of an action tension in the tension detecting section, and FIG. 6 is an explanatory diagram of a power transmission system of the auxiliary power unit. In the present embodiment, as shown in FIG. 1, the bicycle auxiliary power unit of the present invention is configured as follows. The body 1 has a normal bicycle shape,
Vertical pipe 9 and lower pipe 1 with saddle inserted at upper end
At the hanger section (38, see FIG. 3) at the lower end of the intersection with 0,
A sensor arm pedestal 26 on which an auxiliary power unit 4, an idler sprocket 14 constituting a chain tension detecting device, and a displacement sensor 36 are installed is fitted and mounted together with the crankshaft 6. An output sprocket 8 driven by the crankshaft 6 as the pedal 5 is depressed, and a rear wheel pivotally supported at the intersection of a chain fork 11 and a back fork extending rearward from above and below the vertical pipe 9. The chain 7 is stretched between the rear wheel sprocket 28 installed on a hub such as an internal transmission and the like in the inside 3. A battery and a control unit 2 as a power source of an auxiliary power unit for a bicycle are provided on the back of a basket or the like above the front wheel.
Is mounted.

As shown in FIG. 3, in the present invention, the crankshaft 6 and the hollow shaft are orthogonal to the inner and outer cases 24 in which the transmission system from the electric motor 12 in the auxiliary power unit 4 described later is housed in detail. The cylindrical protrusion 25 of the case, which supports the shaft 22 concentrically, is inserted into the hanger pipe 38 of the frame, and the side surface of the inner / outer case 24 is brought into contact with the end surface of the hanger pipe 38 so that any one of the cases The auxiliary power unit 4 is fixed to the frame by connecting the unit and the frame.

At the same time, the hanger pipe 38 and
After the hanger pipe 38 is inserted, the sensor arm pedestal 26 is fitted and mounted on the outer periphery of the cylindrical projection 25 between the output sprocket 8 connected to one end of the hollow shaft 22 by the spline 33 at one end of the hollow shaft 22. A pair of arm pedestals 26A and sensor pedestals 26B extending from
(See (B)), an idler sprocket 14 for detecting the tension of the chain 7 and a displacement sensor 36 for detecting the amount of swing of the idler sprocket 14 are provided. Symbol 35A
And 35B are for preventing the output sprocket 8 from being pulled out from the hollow shaft 22 and for detecting the sensor from the cylindrical projection 25, respectively.
4 shows a retaining ring for retaining the arm base 26. And code 3
Reference numeral 0 denotes a pulley shaft that supports the idler sprocket 14 at the tip end of a swing arm 15 that is swingably supported by an arm base 26A by a bearing 32 (FIG. 2A). Further, reference numeral 34 denotes a ventilation hole formed substantially in the center of the cylindrical convex portion 25.

As shown in FIGS. 2 and 4, the auxiliary power unit 4 accommodates a transmission system from the electric motor 12, such as a speed reduction mechanism and a speed sensor, and is arranged in the width direction of the outer case 24A and the inner case 24B. Inner and outer case 2 divided into two
The sensor arm pedestal 26 serving as a tension detecting device for the chain 7 is fitted and mounted in a form having the base member 4 and being arranged on the opposite side to the inner and outer cases 24 with respect to the body frame, that is, the hanger pipe 38. FIG.
(A) and (B), as shown in FIG.
Of the pair of arm pedestals 26B and sensor pedestals 26A extending from the arm pedestal 26B, a swing arm 15 pivotally supported at the tip of the idler sprocket 14 is installed on the arm pedestal 26B by a swing arm rotating shaft 31.
A is provided with a displacement sensor 36 for detecting the swing amount of the idler sprocket 14. The swing amount of the idler sprocket 14 is detected by measuring the swing amount of the compression cylinder 27 protruding from the tip of the swing arm 15 that supports the idler sprocket 14 around the swing arm rotation shaft 31 by using the sensor base. This is performed by detecting the stroke amount of pushing back the slide shaft 37 urged by the coil spring 39 into the displacement sensor 36 installed at 26A.

As shown in FIGS. 4 and 6, an inner / outer case housing a transmission system from an electric motor 12, such as a speed reduction mechanism and a speed sensor, is divided into two in an outer case 24A and an inner case 24B in the vehicle width direction. In the approximate center of 24,
A shaft 20 that constitutes a speed sensor 29 is arranged in parallel with the electric motor 12 and the crankshaft 6, and a speed reduction mechanism composed of a gear train is formed. Auxiliary power control is performed by the electric motor 12 by receiving a sensor output from the displacement sensor 36 which detects the magnitude of the pedaling force by human power, that is, the magnitude of the tension of the chain 7 and receiving a control signal from the control unit 2. . Motor shaft 1
A gear 16 is fixed to 2A, and its rotation is
The rotation is transmitted to the one-way clutch 1 because the gear 17 is fixed to the flange body 18 with bolts.
9 is transmitted. The one-way clutch 19 transmits rotation from the gear 17 side to the shaft 20 when the electric motor 12 rotates forward. That is, conversely, rotation cannot be transmitted from the shaft 20 to the gear 17. Therefore, even if the power of the electric motor 12 is lost during the control process, even if the chain is driven by manually depressing the pedal, the rotational driving force is not transmitted to the one-way clutch 19 first, and the electric motor 12 Can be prevented from being forcibly rotated from the motor shaft 12A side.

The shaft 20 has a speed sensor 29
And the shaft end 40 of the rotating shaft has a polygonal cross section,
As shown in FIG. 2B, the crankshaft rotation speed is detected by sensing each of the tops with a proximity switch. The rotation of the shaft 20 is transmitted to a gear 21 that meshes with a gear 20A formed on the outer periphery of the shaft 20. A hollow shaft 22 extends concentrically through a hanger pipe 38 so as to support the crankshaft 6 inside the boss portion of the gear 21. The output sprocket 8 is connected to the outer periphery of one end of the hollow shaft 22, and the inner periphery of the other end is connected to the crankshaft 6 via a ratchet 23 and a pawl 13 constituting a one-way clutch. The hollow shaft 22 is connected to the inner case 2.
An auxiliary power unit body is accurately and preliminarily supported as an auxiliary power unit body on the inner peripheral portion of a cylindrical convex portion 25 extending concentrically with the crankshaft 6 from the inner side surface of 4B. The cylindrical convex portion 25 is provided in the inner case 24B.
And the inner case 2 as shown in the figure.
It may be formed separately from 4B. Therefore, there is no need for high accuracy between the outer peripheral portion of the cylindrical convex portion 25 and the inner peripheral portion of the hanger pipe 38, and it is possible to manufacture the bicycle at low cost. The shaft end of the polygonal section constituting the speed sensor may be provided on the rotation shaft of the idler sprocket.

FIG. 5 is an explanatory diagram of the action tension in the tension detecting section. When the pedaling force R is increased by human power and the tension T of the chain 7 is increased, the chain suspended between the output sprocket 8 and the idler sprocket 14. The swing arm 15 that supports the idler sprocket 14 swings around the swing arm rotation shaft 31 by the component force F2 of the force F1 that tries to make the 7 straight. Projecting compression cylinder 27
Presses the slide shaft 37 of the displacement sensor 36 with the force F3. Therefore, the torque detected as the tension of the chain 7, that is, the movement amount of the slide shaft 37 is converted into an electric signal, and the appropriate control unit 2 controls the electric motor 1 according to the pedaling force by human power.
2, the auxiliary power control is performed. When a force that tries to straighten the chain 7 acts on the idler sprocket 14, a part of the force can be borne by the shaft support of the idler sprocket 14 with respect to the swing arm 15. Since the force of the displacement sensor 36 in the measurement direction of the slide shaft 37 in the displacement sensor 36 can be relatively small due to the swing of the displacement sensor 36, the capacity of the coil spring 39 and the like in the displacement sensor 36 shown in FIG. Is possible.

The embodiments of the present invention have been described above. However, within the scope of the present invention, the type of the auxiliary power unit, the type of the reduction mechanism in the auxiliary power unit, the type of the motor such as an electric motor as the auxiliary power, and the like. The arrangement, the shape of the sensor arm pedestal, the configuration of the idler sprocket, the type of the displacement sensor, the type of detection of the swing amount of the idler sprocket relative to the displacement sensor, the form of support of the hollow shaft and the cylindrical convex portion, the auxiliary power unit, The attachment form of the sensor / arm pedestal to the frame or the like can be appropriately selected.

[0018]

As has been described in detail above, according to the bicycle auxiliary power unit of the present invention, a crankshaft is built in as an auxiliary power unit assembly, and a combined driving force of human power and electric power is output to the output sprocket. As the hollow shaft for transmission is covered, the cylindrical convex portion provided in the case portion of the auxiliary power unit is inserted into the hanger pipe and mounted, so that the crankshaft, the hollow shaft and the cylindrical convex portion are concentric. Since no particular precision is required for the roundness and concentricity between the outer peripheral portion of the cylindrical convex portion and the inner peripheral portion of the hanger pipe, which is out of the scope of the rotary drive system, the inner peripheral portion of the hanger pipe is not required. Stable drive rotation with low rotational resistance of the crankshaft or hollow shaft is realized without being affected by the circularity or concentricity. In addition, since the cylindrical convex portion of the auxiliary power unit is inserted into the hanger pipe of the frame and the side surface of the case is brought into contact with the end surface of the hanger pipe, and any part of the case is connected to the frame. Along with the radial positioning of the concentric rotary drive system by the crankshaft, the hollow shaft and the cylindrical projection in the auxiliary power unit, the axial positioning can also be accurately performed.

Further, since the arm that swings due to the fluctuation of the tension of the chain and the base of the sensor that detects the displacement are configured as a common sensor arm base, the distance between the sensors is guaranteed, so that the distance between the sensors is assured. Detection is possible. Also, regarding the positional relationship between the idler sprocket at the tip of the swing arm, the output sprocket and the rear wheel sprocket on the frame side, fixing of the sensor arm pedestal, the outer periphery of the cylindrical projection concentric with the output sprocket, and the output Since a chain stay connecting the centers of the sprocket and the rear wheel sprocket is used, the positional relationship among the output sprocket, the rear wheel sprocket, and the idler sprocket is guaranteed despite the variation in frame accuracy. Therefore, the torque detection characteristic of the swing arm rotation force of the idler sprocket with respect to the chain tension (pedal force) is:
Stable without being affected by variations in the frame body or assembly.

Further, since the end of the rotating shaft in the transmission system from the electric motor has a polygonal cross section, and the top of each of them is detected by a proximity switch, the crankshaft rotation speed is detected. An appropriate speed sensor can be configured by arbitrarily selecting the number of vertices per one rotation of the crankshaft, and a close-up can be achieved by using relatively large gear teeth in a reduction mechanism as seen in a conventional one. Installing the switch does not increase the radius of the device.

Further, by forming a ventilation hole at a substantially central portion of the cylindrical convex portion, communication between the inside of the frame pipe and the inside of the auxiliary power unit is made with a simple structure, and a sudden temperature difference between the inside and outside of the case is reduced. Even if they are encountered, there is no danger of water droplets penetrating into the case or condensing and adhering due to changes in atmospheric pressure. In addition, since the ventilation hole is formed in the substantially central portion of the cylindrical projection, it is exposed inside the frame pipe, so that dust and the like from the outside do not enter. As described above, according to the bicycle auxiliary power device of the present invention, it is possible to stably and accurately mount the auxiliary power unit and the pedal depression force detection device without being affected by the roundness of the hanger pipe of the bicycle frame. Thus, an auxiliary power device for a bicycle that can perform auxiliary power control with high accuracy is provided.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of a bicycle auxiliary power device of the present invention, and is an overall side view of a bicycle on which the bicycle auxiliary power device of the present invention is mounted.

2 shows a first embodiment of an auxiliary power unit for a bicycle according to the present invention, wherein FIG. 2 (A) is an enlarged partial cross-sectional plan view of the auxiliary power unit, and FIG. FIG. 3 is an enlarged partial cross-sectional side view illustrating a tension detection unit.

FIG. 3 is an exploded view of the auxiliary power unit for a bicycle according to the first embodiment of the present invention, in which the auxiliary power unit is attached to a hanger pipe.

FIG. 4 is a cross-sectional view of a power transmission system according to a first embodiment of the bicycle auxiliary power device of the present invention.

FIG. 5 is a diagram illustrating a first embodiment of an auxiliary power device for a bicycle according to the present invention, and is an explanatory diagram of an action tension in a tension detection unit.

FIG. 6 shows the first embodiment of the bicycle auxiliary power device of the present invention, and is an explanatory diagram of a power transmission system of the auxiliary power unit.

FIG. 7 is a side view of a main part showing a first conventional example of an auxiliary power device for a bicycle.

FIG. 8 is an exploded view of a main part showing a second conventional example of an auxiliary power device for a bicycle.

FIG. 9 is a side view of a main part showing a third conventional example of a bicycle auxiliary power unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bicycle body 2 Battery and control unit 3 Rear wheel 4 Auxiliary power unit 5 Pedal 6 Crankshaft 7 Chain 8 Output sprocket 9 Vertical pipe 10 Lower pipe 11 Chainstay 12 Electric motor 12A Motor shaft 13 Claw 14 Idler sprocket 15 Swing arm 16 , 17 Gear 18 Flange Body 19 One-way Clutch 20 Shaft 20A Gear 21 Gear 22 Hollow Shaft 23 Ratchet 24 Inner / Outer Case 24A Outer Case 24B Inner Case 25 Cylindrical Convex Part 26 Sensor / Arm Base 26A Sensor Base 26B Arm Base 27 Compressed Cylinder 28 Rear Wheel sprocket 29 Speed sensor 30 Pulley shaft 31 Swing arm rotation axis 32 Bearing 33 Spline 34 Vent hole 35A Retaining ring 35B Retaining ring 36 Displacement center Sir 37 slide shaft 38 hanger pipe 39 coil spring 40 shaft end

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Toshiharu Furukawa 3-1-1 Nakatsuma, Ageo-shi, Saitama Bridgestone Cycle Co., Ltd. (72) Inventor Yuki Sato 3-1-1 Nakatsuma, Ageo-shi, Saitama Bridge Toncycle Co., Ltd.

Claims (4)

[Claims] 1. One end of a hollow shaft rotatably supporting a crankshaft is connected to an output sprocket, the other end is connected to an electric motor via a one-way clutch, and is connected to the crankshaft via a ratchet. In the bicycle auxiliary power unit, the case shape of the auxiliary power unit is
A transmission system from the electric motor is housed, the inner and outer cases are orthogonal to the crankshaft, and the crankshaft and the hollow shaft have a cylindrical protrusion that is concentric with the hollow shaft and supports the hollow shaft. The auxiliary power unit was fixed to the frame by inserting it into the hanger pipe of the frame and making the side surfaces of the inner and outer cases abut against the end surface of the hanger pipe, and connecting any part of the case to the frame. An auxiliary power unit for a bicycle, comprising: 2. A sensor arm pedestal is fitted and mounted on the outer periphery of a cylindrical projection between the hanger pipe and the output sprocket, and a pair of arm pedestals extending from the sensor arm pedestal and a chain tension are attached to the sensor pedestal. 2. An auxiliary power device for a bicycle according to claim 1, further comprising an idler sprocket for detecting the rotational speed and a displacement sensor for detecting a swing amount of the idler sprocket. 3. The crankshaft rotation speed is detected by detecting the end of a rotating shaft in a transmission system from the electric motor in a polygonal cross section and sensing the top of each of them by a proximity switch. The auxiliary power unit for a bicycle according to claim 1 or 2, wherein: 4. The bicycle according to claim 1, wherein a ventilation hole is formed at a substantially central portion of the cylindrical convex portion so as to be able to ventilate inside the frame. Auxiliary power unit.