JPH10175583A - Bicycle with auxiliary power - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bicycle with an auxiliary power to cause the occurrence of relative phase displacement in the rotation direction to a pedal mechanism according to rotation torque exerted on a rotating pedal mechanism, and detect displacement in a phase in the rotrationed direction in a non-contact manner by a sensor fixed on the frame side. SOLUTION: A drive shaft 40 on which a man power is applied and a power transmission wheel 60 to transmit a drive force to a 'drive wheel are intercoupled in a following rotatable state through an elastic body 70. A displacement detecting mechanism 32 is provided to detect relative displacement in rotation occurring between a drive shaft 40 and a power transmission wheel 60 through the generation of torque by means of sensors 43 and 63 fixed on the frame side. Based on a torque detecting signal from the displacement detecting mechanism 32, the output of an auxiliary power device is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle having an auxiliary power unit for assisting human power when the load of driving by human power exceeds a predetermined limit, and more specifically, a stepping torque applied to a pedal mechanism. The present invention relates to a bicycle with an auxiliary power that generates auxiliary power according to the following.

[0002]

2. Description of the Related Art A motor is connected to a driving wheel of a bicycle, and when driven manually, the motor is driven in accordance with the magnitude of a load applied to a crank pedal or a drive shaft to provide auxiliary power for driving the bicycle manually. There is known a bicycle with an auxiliary driving force that can be operated and run on a bicycle by light manual driving. As a method of measuring the driving force applied by human power, for example, Japanese Patent Application Laid-Open No. Hei 4-100790 discloses a method in which a torsion bar is used for a drive shaft, and the amount of torsion of the torsion bar is measured by a potentiometer, a strain gauge, or the like provided on the torsion bar. A method for detecting and measuring rotational torque is disclosed.

[0003]

However, since the potentiometer and the strain gauge are provided on a rotating shaft, their detected values must be taken out to the outside by using a slip ring, a brush, etc., resulting in friction and wear. Therefore, it is difficult to accurately detect the rotational torque.

An object of the present invention is to cause a relative phase shift in the rotational direction of a pedal mechanism in accordance with a rotational torque applied to a rotating pedal mechanism, and a phase difference in the rotational direction is determined by a sensor fixed to a frame side. It is an object of the present invention to provide a bicycle with an auxiliary power provided with a displacement detection mechanism capable of detecting the displacement of the bicycle without contact.

[0005]

In order to solve the above-mentioned problems, a bicycle with auxiliary power (10) of the present invention transmits a driving force to a driving wheel (12) to a drive shaft (40) to which human power is applied. The power transmission wheel (60) to be rotatably fitted and rotatably connected via an elastic body (70), and a relative torque generated between the drive shaft (40) and the power transmission wheel (60) due to torque generation. Sensor rotation (43) (6
3) a displacement detection mechanism (32) for detection is provided, and based on a detection signal from the displacement detection mechanism (32), an auxiliary power unit (2
It controls the output of 6).

The drive shaft (40) and the power transmission wheel (60)
As described later, the detection means (41) (61) in which one or a plurality of detected parts (42) (62) are formed on the circumferential surface or circumferential direction, respectively.
Is provided. The sensors (43) and (63) include the detected parts (42) and (6).
It is fixed to the frame side and arranged close to and facing the rotational transfer path of 2). In the detected means (41) (61), the detected parts (42) (62)
For example, a projection, a groove, a slit, a magnet, or the like is formed or arranged on the circumferential surface or circumferential direction. Detected part (42) (62)
Are provided on the drive shaft (40) and the power transmission wheel (60), respectively, at the same number and concentrically at equal intervals, and each of the detected parts (42) (62) is formed at a position equidistant from the shaft center. It is desirable that the detected portions (42) and (62) on the drive shaft side and the power transmission wheel side have the same phase as each other when no load is applied to the pedal mechanism (30). As described above, the sensors (43) and (63) approach the rotation transition path of the detected parts (42) and (62), are fixedly provided on the frame side, and pass through the detected parts (42) and (62). The signal is converted into an electric signal and transmitted to the control means (80) described later. The sensors (43) and (63) are also similar to the detected parts (42) and (62),
It is desirable to be mounted at a position equidistant from the axis of the drive shaft (40). Examples of the sensors (43) and (63) include a proximity sensor and a magnetoresistive element. The control means (80) is a means (89) for performing a torque calculation based on the detection signals from the sensors (43) and (63), and an auxiliary power unit (26) based on a calculation value of the torque calculation means (89). It is desirable to have output control means (85) for controlling the output. The torque calculating means includes a speed calculating unit (83) for calculating a running speed of the bicycle based on a detection signal from the sensor (63) and / or the sensor (43); a sensor (43); Phase difference calculation unit (82) that measures the phase shift of the detection signal of
(83) and a torque calculator (84) for performing a torque calculation based on the output from the phase difference calculator (82).

The detected means (41) on the drive shaft side is connected to the drive shaft (40) via a one-way clutch (46), and the power transmission wheel (60) is connected to the detected means (41) on the drive shaft side. 41)
It is desirable to be mounted so as to be able to follow and rotate via an elastic body (70). This is because when the crank pedals (31) and (31) are reversely rotated, the detected means (41) on the drive shaft side is reversely rotated integrally with the crank pedal (31), and an error is detected from the sensor (41). This is to prevent the detection signal from being transmitted.

In a state where almost no load is applied to the pedal mechanism (30), the drive shaft (40) and the power transmission wheel (60)
Since there is no deviation in the rotation direction, the detection means (4) that rotates integrally with the drive shaft (40) and the power transmission wheel (60)
1) No rotation deviation occurs between (61). Accordingly, the detected parts (42) and (62) are also detected by the sensors (43) and (63) in the same phase, and the detection signals are transmitted to the control means (80).
When the phases of the detection signals from the sensors (43) and (63) match, the control means (80) does not drive the auxiliary power unit (26).

However, when a load exceeding a predetermined limit exceeding the urging force of the elastic body (70) acts on the pedal mechanism (30), such as when the bicycle (10) starts, climbs, or accelerates, the elastic body (70) becomes The power transmission wheel (60) is elastically deformed and is displaced in the rotation delay direction relative to the drive shaft (40). The relative displacement between the two in the rotation direction is substantially proportional to the torque applied to the drive shaft (40). When a relative rotational deviation occurs between the drive shaft (40) and the power transmission wheel (60), the sensor (43) (6
The phase of the detected parts (42) and (62) detected in 3) is also shifted. Each of the sensors (43) and (63) detects a phase shift between the detected parts (42) and (62) and transmits the detected phase to the control means (80). Control means
(80) calculates the torque acting on the pedal mechanism (30) from the phase difference between the transmitted detection signals, drives the auxiliary power unit (26) with an output corresponding to the torque, and ) Is auxiliary-driven. In the control means (80), as described above, the speed calculation unit (83)
And a torque calculating means (89) including a phase difference calculating section (82) and a torque calculating section (84), and an output control means (85) for controlling the auxiliary power unit (26). When the detection signals of the sensors (43) and (63) are input to (89), the speed calculation unit (83)
Calculates the speed of the bicycle based on the signal from the sensor (63) or the sensor (43), and the phase difference calculation unit (83)
The phase shift of the signal between the sensor (43) and the sensor (63) is measured. The measurement results of these two are input to the torque calculation section (84), and the torque calculation section (84) calculates the rotation torque acting on the pedal mechanism (30). The output control means (85) drives the auxiliary power unit (26) with an output corresponding to the rotational torque to perform power assist of the bicycle.

[0010]

Embodiments of the present invention will be described. Hereinafter, an example in which the present invention is applied to a two-wheeled bicycle (10) having a rear wheel (13) as a drive wheel (12) will be described. However, the present invention is also applied to a front-wheel drive bicycle and other human-powered driving devices. Is applicable. In the embodiment, the rotation of the drive shaft (40) and the power transmission wheel (60) refers to the rotation direction of the bicycle (10) when traveling.

Structure Description As shown in FIG. 1, a bicycle with auxiliary power (10) has a frame.
The front part of (15) is provided with a front wheel (14) and a handle (16), and the rear part is provided with a rear wheel (13) to be a driving wheel (12). Frame (1
At approximately the center of 5), a seat tube (18) with a saddle (17) is located at the upper end, and at the lower end of the seat tube (18),
A cylindrical frame (19) pivotally supporting the pedal mechanism (30) is located. The seat tube (18) includes an auxiliary power device (26) such as a motor, a battery (25) serving as a power source of the auxiliary power device (26), and control means for controlling output of the auxiliary power device (26).
(80) is deployed.

The pedal mechanism (30) includes a drive shaft (40) pivotally supported by the cylindrical frame (19), and opposite directions perpendicular to the drive shaft (40) from both ends of the drive shaft (40). A power transmission wheel (60) is rotatably fitted to the protruding crank pedals (31) and (31) and the drive shaft (40). The power transmission wheel (60) has a sprocket (28) formed on the outer periphery, and a sprocket (22) mounted on an axle (21) of the rear wheel (13).
An endless chain (23) is stretched between them. Also,
A reduction gear (27) is provided on the cylindrical frame side of the power transmission wheel (60), and the auxiliary power unit is provided via a reduction mechanism (35).
Linked to (26). In the present embodiment, the reduction gear (27) is
As will be described later, the detection means (61) on the power transmission wheel side
Also serves as. The power transmission wheels (6
0) and a casing (29) surrounding the means to be detected (41) (61) described later are attached. The drive shaft (40) penetrates through the casing (29), and openings are provided on the upper surface and the rear surface of the casing (29) to pass the speed reduction mechanism (35) and the chain (23), respectively.

FIG. 2 is a partial cross-sectional view around the drive shaft (40) on the power transmission wheel side of the pedal mechanism (30), and FIG.
It is arrow sectional drawing in alignment with line XX. In the vicinity of the end of the drive shaft (40), the detected means is connected via a one-way clutch (46).
(41) is deployed. The detected means (41) can rotate integrally with the drive shaft (40) only in the traveling direction, and when the drive shaft (40) rotates reversely, power transmission to the detected means (41) is not performed. The detection is not performed, and the detection target means (41) remains stopped. In the present embodiment, a gear (45) is used for the detection target (41). The gear (45) has N teeth (44) as a detected part (42).
Is a gear with a tip radius R engraved on the peripheral surface. Detected means
On the power transmission wheel side of (41), two elastic pressing members (47) (47) are protruded at symmetrical positions with respect to the drive shaft (40). Each of the pressing members (47) and (47) is screwed with a pressing screw (48) or (48) that penetrates the pressing member in the rotation direction. It is protruding.

The power transmission wheel (60) has a sprocket (28) formed on the outer periphery, and is rotatably fitted to the drive shaft (40) via a bearing (66). Power transmission wheel (60)
An elastic body support member (67) to which an elastic body (70) is attached is fixedly provided on the power transmission wheel (60) between the power transmission wheel (60) and the detection means (41) on the drive shaft side. The support member (67) is
As shown in FIG. 3, two notches are provided at positions corresponding to the pressing members (47) protruding from the detection means (41) on the drive shaft side.
(68) and (68) are provided, and the pressing member (47) is fitted in the rotation direction with a little margin. An elastic body (70) is embedded in the notch (68) (68) at the end face in the rotation direction so as to be able to expand and contract in the direction opposite to the rotation direction. The tip of the elastic body (70) on the side opposite to the rotation direction is in contact with the tip of the pressing screw (48). Also,
End faces (69) (6) of the notch (68)
9a) are detents of the pressing member (47), respectively.
When the power transmission wheel (60) is at a predetermined angle or more, the drive shaft (40)
To prevent rotation. In a state where no load is applied to the crank pedal, the pressing member (47) is urged by the elastic body (70) in a direction opposite to the rotation direction, so that the end face of the elastic body support member (67) on the opposite side to the rotation direction ( 69a). On the cylindrical frame side of the power transmission wheel (60), a reduction gear (27) connected to the auxiliary power device (26) via a reduction mechanism (35) is provided. In this embodiment, the reduction gear (27) also serves as the detected means (61) on the power transmission wheel side, and has a tip radius at which N teeth (64) are carved as the detected part (62). R gear (65), and the detected means (6
1) has the same number of teeth as the detected means (41) on the drive shaft side,
This is the tip radius. Of course, the detection means (61) and the reduction gear (27) may be formed separately. If the state in which the pressing member (47) is pressed against the end surface (69a) of the support member (67) on the opposite side in the rotation direction is the initial state, in the initial state, the detection means (41) (61) facing The phases of the detected parts (42) and (62) are adjusted so as to match.

The inner surfaces of both sides of the casing (29) surrounding the power transmission wheel (60) approach the rotation transition paths of the detected parts (42) and (62), and move to the proximity sensors (43) and (63). Are deployed respectively. 2 and 3, the proximity sensors (43) and (63) are mounted at corresponding positions above the rotational transition path of the detected parts (42) and (62). Both sensors (43) and (63) are to be detected (42)
The passage of the teeth (44) and (64) serving as (62) is detected, and the signal is transmitted to the control means (80).

The control means (80) for receiving signals from the sensors (43) and (63) and controlling the output of the auxiliary power unit (26) will be described. The control means (80), as shown in FIG.
Signals transmitted from both sensors (43) and (63) are received by the sensors (43) and (63) interface (81). The interface (81) is connected to a torque calculating means (89).
The torque calculator (89) includes a phase difference calculator (82), a speed calculator (83), and a calculator connected to the interface (81).
(82) A torque calculating section (84) connected to the calculating section (83). The phase difference calculation unit (82) measures the phase difference between the signals of the two sensors (43) and (63), and the speed calculation unit (83) calculates the phase difference of the detected portion (62) on the power transmission wheel side. From the detection interval, the bicycle
The running speed of (10) is calculated. The measurement and calculation results of the phase difference calculator (82) and the speed calculator (83) are transmitted to the torque calculator (84). The torque calculator (84) calculates the torque generated in the pedal mechanism (30) from the signal phase difference between the two sensors (43) and (63) and the detection interval of the detected part (62) on the power transmission wheel side, as described later. Calculate and transmit the torque signal to the output control means (85). The output control means (85) determines the output of the auxiliary power unit (26) based on these signals, and drives the auxiliary power unit (26). The output determination process in the output control means (85) is not particularly limited, and various known methods can be used. For example, the auxiliary power unit (2) corresponding to the input torque signal and the traveling speed information is output to the output control means (85).
Deploy a memory (not shown) that stores the output of 6) in advance,
The output may be determined, or the output of the auxiliary power unit (26) may be calculated from the torque signal and the information on the traveling speed of the bicycle (10).

Description of Operation The operation of the assisted powered bicycle (10) provided with the displacement detecting mechanism (32) having the above-described configuration will be described. The initial state described above, that is, a state in which a load equal to or more than a predetermined limit is not acting on the pedal mechanism (30), for example, a state in which the crank pedal is not depressed, or even if the crank pedal is depressed, the pedal mechanism (30) is actuated. When the load applied is smaller than the biasing force of the elastic body (70) and the power transmission wheel (60) is not displaced relative to the drive shaft (40) in the rotational direction, the There is no shift between the detecting means (41) and the detected means (61) on the power transmission wheel side. Therefore, the detection signals of the sensors (43) and (63) are not detected when the crank pedal is stopped, and when the crank pedal is rotating, as shown in FIG. (63)
Have the same phase. At this time, the control means (80)
Determines that the torque is zero and does not drive the auxiliary power means. In this embodiment, since the detected means (41) on the drive shaft side is connected to the drive shaft (40) via the one-way clutch (46), even if the crank pedal is rotated in the opposite direction, The detected means (41) does not rotate, and no erroneous detection signal is issued.

When a load exceeding a predetermined limit acts on the pedal mechanism (30), such as when the bicycle (10) starts, accelerates, or climbs a hill, the elastic body (70) is elastically deformed, and the power transmission wheel (60) Against the urging force of the elastic body (70), the elastic body (70) is displaced in the rotation delay direction relative to the drive shaft (40). This displacement amount depends on the magnitude of the load applied to the pedal mechanism (30). The relative displacement of the power transmission wheel (60) in the rotation delay direction is detected on the drive shaft side that rotates integrally with the drive shaft (40).
This corresponds to the displacement of the detection means (61) on the power transmission wheel side that rotates integrally with the power transmission wheel (60) in the rotation delay direction with respect to (41). When a rotation shift occurs between the detected means (41) and (61), a phase shift as shown in FIG. 6B occurs in the detection signals of the sensors (43) and (63). The difference of the rising part of this signal waveform is calculated by the phase difference calculation unit (82).
Is measured as the time difference. Further, in the speed calculation unit (83), based on the detection interval of the detected portion (62) on the power transmission wheel side, specifically, based on the interval of the rising portion of the signal waveform,
Calculate the speed of the bicycle (10). In the torque calculator (84),
The torque applied to the pedal mechanism (30) is calculated from these detection results, the output control means (85) determines the output of the auxiliary power unit (26), and the output of the auxiliary power unit (26) is controlled by PWM control or the like. Change and drive. The driving force of the auxiliary power unit (26) is
The power is transmitted to the power transmission wheel (60) via the reduction gear (27), and the rear wheel (13), which is the drive wheel (12), is driven. An example of the method of calculating the torque is shown in an embodiment described later.

In the above description, the deceleration gear (27) also serves as the detected means (61) on the power transmission wheel side for simplification of the configuration, but the driving force of the auxiliary power unit (26) is Wheel (12)
May be added directly to the chain (23). The detected means (41) and (61) are the detected parts (42) (6
As 2), a projection or a slit may be formed side by side in the circumferential direction, or a configuration in which a magnet is attached to the circumferential surface or the circumferential direction may be adopted. The sensors (43) and (63) are
According to 2), a proximity sensor, a magnetoresistive element, or the like may be used. The elastic body (70) for urging the power transmission wheel (60) against the drive shaft (40) is not limited to a coil spring, but may be a leaf spring, rubber, or the like. Further, the traveling speed of the bicycle (10) can be detected by separately attaching a speed sensor to the driving wheel (12) or the like.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a method for calculating a torque will be described. Hereinafter, among the torques acting on the pedal mechanism, the torque acting on the elastic body will be calculated. In addition, each constant and variable are set as follows (see FIGS. 3 and 6). · The number of the detecting means detected portion (number of teeth of the gear): radius of the N-axis to the heart detected portion (addendum radius): phase difference between the R portion to be detected (time): T ₁ power transmission wheel side Pulse interval (time) of the part to be detected: T
_2. Elastic body Radius from axis to elastic body: r Spring constant: k

Since the number of detected parts is N in the circumferential direction, the interval is represented by 2πR / N. Therefore,
The rotation of the detected means on the power transmission wheel side, that is, the phase difference displacement X in the rotational direction of both detected means taking into account the traveling speed of the bicycle is approximately expressed by the following equation 1.

[0022]

(Equation 1)

Therefore, the displacement amount at the position where the elastic body is attached, that is, the contraction amount x of the elastic body is expressed by the following equation (2).

[0024]

(Equation 2)

Therefore, the detected torque τ at the elastic portion
Is represented by the following equation 3.

[0026]

(Equation 3)

By driving the auxiliary power unit with a driving force corresponding to the detected torque τ, power assist can be performed.

[0028]

According to the bicycle with an auxiliary power provided with the displacement detecting mechanism of the present invention, since the torque acting on the rotating pedal mechanism can be detected in a non-contact manner, there is no detection error due to the entry of noise or the like. Furthermore, since there is no contact, there is no mechanical connection between the sensor and the detected part, and no mechanical loss is involved in torque detection. Further, the present invention can be easily implemented only by attaching a sensor instead of a known pedal mechanism of an auxiliary powered bicycle to the above-mentioned pedal mechanism. Further, by connecting the detected means on the drive shaft side to the drive shaft via a one-way clutch, even if the user rotates the crank pedal in the reverse direction, the detected means does not rotate in the reverse direction. No signal is sent.

[Brief description of the drawings]

FIG. 1 is a side view of a bicycle with an auxiliary power provided with a displacement detection mechanism according to the present invention.

FIG. 2 is a partial cross-sectional view around a drive shaft on a power transmission wheel side of a pedal mechanism.

FIG. 3 is a sectional view taken along line XX of FIG. 2;

FIG. 4 is a cross-sectional view showing a state in which the power transmission wheel has shifted in the rotational direction relative to the drive shaft.

FIG. 5 is a circuit diagram of a control unit.

FIG. 6 is a graph showing a detection signal of a sensor,
(a) shows a detection signal when there is no relative rotation between the power transmission wheel and the drive shaft, and (b) shows a detection signal when there is a relative deviation.

[Explanation of symbols]

 (10) Bicycle with auxiliary power (26) Auxiliary power unit (30) Pedal mechanism (32) Displacement detection mechanism (41) Detected means (43) Sensor (61) Detected means (63) Sensor

Claims (7)

[Claims] 1. A pedal mechanism having a power transmission wheel fitted to a drive shaft having crank pedals at both ends to which human power is applied, and an auxiliary power device for performing auxiliary driving of a driving wheel pivotally supported by a frame, In an auxiliary powered bicycle that controls the output of an auxiliary power device based on human power applied to a pedal mechanism, the bicycle is rotatably fitted to a drive shaft (40), and is attached to the drive shaft (40) via an elastic body (70). A plurality of detected parts (42) (62) are formed so as to be integrally rotatable concentrically with the power transmission wheel (60), the drive shaft (40), and the power transmission wheel (60), which are connected so as to be capable of following rotation. )
Detected means (41) and (61) each including the detected part (42) and (62), which are fixed to the frame side close to the rotational transition path and the detected part (4
2) A displacement detecting mechanism (32) including sensors (43) and (63) for detecting displacement in the rotational direction of (62), and an auxiliary power unit (26) based on detection signals from the sensors (43) and (63). And a control means (80) for controlling the output of (1). 2. The detecting means (41) on the drive shaft (40) side comprises:
The drive shaft (40) is linked to the drive shaft (40) via a one-way clutch (46), and the power transmission wheel (60) is attached to the detection means (41) on the drive shaft side so as to be able to follow and rotate via an elastic body (70). The assisted powered bicycle according to claim 1, wherein The control means (80) includes means (89) for performing a torque calculation based on the detection signals from the sensors (43) and (63), and an auxiliary based on a calculation value of the torque calculation means (89). Power unit (2
The auxiliary powered bicycle according to claim 1 or 2, further comprising output control means (85) for controlling the output of (6). 4. A torque calculating means (89) for calculating a running speed of a bicycle based on a detection signal from the sensor (63) and / or the sensor (43), and a sensor (43).
Difference calculation unit (82) that measures the phase shift between the detection signal of the sensor and the sensor (63), and a torque calculation unit that calculates the torque based on the output from the speed calculation unit (83) and the phase difference calculation unit (82). The auxiliary powered bicycle according to claim 3, comprising (84). The detected means (41) and (61) are connected to the detected parts (42) (6).
Gears with the same number of teeth (44) and (64) on the peripheral surface as 2)
(45) (65), characterized in that they are (65)
An auxiliary powered bicycle according to any one of the above. 6. The detected parts (42) and (62) are respectively connected to the detected means (4
1) The bicycle with auxiliary power according to any one of claims 1 to 4, characterized in that the slits are formed at equal intervals in the circumferential direction of (61). 7. The detected parts (42) and (62) are connected to the detected means (41) (6).
The auxiliary powered bicycle according to any one of claims 1 to 4, wherein the magnet is a magnet arranged in the circumferential direction of (1).