JPH10114294A - Bicycle with electric assist power unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide power assist without being influenced by a variation in an initial value which is inherent to torque detecting means. SOLUTION: In a bicycle A provided with an electric assist power unit, which involves a motor 40, the electric signal of a pedaling torque which is detected by torque detecting means 100 is converted by an A/D converter 110. A previously outputted voltage value E0 outputted previously is stored in minimum value storage means 210 as a minimum voltage value Es. If a subsequent outputted voltage value E1 outputted subsequently is smaller that the minimum voltage value Es, the minimum voltage value Es is updated by the subsequent outputted voltage value E1, and the subsequent outputted voltage value E1 and the minimum voltage value Es are compared by minimum comparing means 220. Based on a difference between them, pedaling torque is calculated by calculating means 230, and driving force is determined by driving force determining means 240. By assisting power corresponding to leg power of the pedal, it is possible to provide power assist without being influenced by a variation in the initial value of the torque detecting means 100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bicycle with an electric auxiliary power device that travels with the assistance of power from an electric auxiliary power device during manual driving.

[0002]

2. Description of the Related Art An electric auxiliary power unit including a motor and a speed reduction mechanism is provided on a bicycle, and power is supplied from the electric auxiliary power unit during traveling on an uphill or the like to enable easy traveling. Bicycles with equipment are widely known.
The method of assisting power during traveling is based on the rotational torque transmitted to the crankshaft during traveling, that is, the stepping torque generated by stepping on the pedal (hereinafter referred to as stepping).
Is detected by the torque detecting means, and the output of the motor is increased or decreased in accordance with the output of the torque detecting means, that is, the magnitude of the pedaling force. Is what you can do.

[0003] The torque detecting means is provided with a rotating member which rotates in accordance with a treading force, and detects a rotating angle of the rotating member by, for example, a resistance value change of a variable resistor. Alternatively, a deflection member that reciprocates according to the treading force is provided, and the deflection of the deflection member is caused to act on a strain-generating body in which a bridge is formed by a thin-film resistive film, thereby changing a resistance value that forms the bridge. Some are configured to take out as an electric signal, that is, a voltage.

[0004] However, although the former is advantageous in terms of cost because it is inexpensive, it has problems in terms of durability and corrosion resistance because it has mechanical contacts, that is, sliding contacts, and in terms of resistance characteristics. There is a problem that a linear resistance change characteristic cannot be obtained. In the latter case, there is a problem that the voltage at the time of zero load (initialization of the balance of the bridge and aging) is large and the setting is difficult.

In any case, in the configuration of the torque detecting means having the above-described configuration, when the torque sensor, that is, the sensor element is mounted on the torque detecting mechanism at the time of manufacturing, there is a variation in the mounting position, and this variation is different from the variation in the initial voltage. Therefore, the adjustment of the mounting position of the sensor element is indispensable, and even if this adjustment is made, the initial value cannot be determined uniformly, and it is necessary to adjust it again when mounting it on the bicycle body. Therefore, there is a problem that the assembling work is not easy. Further, since the torque detecting means receives a large vibration or impact during the running of the bicycle, the position of the sensor element attached to the torque detecting mechanism may be shifted in some cases, thereby changing the initial value, There is a problem that stable and accurate power cannot be assisted.

In order to solve such a problem, there is, for example, an auxiliary power control device for a power assisted vehicle described in Japanese Patent Application Laid-Open No. 8-175470. What is described in this publication is a tread force detecting means for detecting the magnitude of the tread force of the pedal, a tread force non-input time detecting means for detecting a state where the pedal tread force is not input, and a tread force detection value at the time of no tread force input. An auxiliary driving force control means for controlling the magnitude of the auxiliary power as a control reference value, wherein the pedal depression force is detected in a state where the pedal depression force is not input, and the auxiliary power is controlled based on the detected value. It is like that. Therefore, when an error occurs in the treading force detecting device due to a manufacturing and assembling error of the treading force detecting device or aging, the influence of the error is removed.

[0007] The auxiliary power control device for a power assisted vehicle described in this publication surely has a manufacturing and assembly error of the tread force detecting device, or an error in the tread force detecting device due to aging or the like. Although it has the effect of eliminating the influence of this error, it has the following problem. That is, since the detecting means for detecting the non-input of the pedaling force detects a state in which the speed detection value is zero or the pedaling force detection value does not fluctuate, for example, even if the pedal is depressed while the vehicle is stopped, the vehicle is stopped. The speed detection value is zero because of the presence of the pedal, and the pedal effort is not changed because the pedal is depressed while the vehicle is stopped. Since the magnitude of the auxiliary power is controlled using the detected treading force value as a control reference value, a situation occurs in which accurate power assist is not performed, and in some cases, the original power is not assisted.

[0008]

As described above, the torque detecting means in the conventional bicycle with the electric auxiliary power unit corrects the variation of the initial voltage caused by the variation of the mounting position when the sensor element is mounted on the torque detecting mechanism. It is necessary to adjust the mounting position of the sensor element to
Even if the adjustment is made, the initial value cannot be determined uniformly, and it is necessary to adjust it again when attaching it to the bicycle.Therefore, there is a problem that the assembly work is not easy. There is a problem that the sensor element attached to the torque detecting mechanism is displaced due to a large vibration or impact during traveling, thereby changing the initial value.

In the above-mentioned publication, which solves this problem, the detecting means for detecting no input of the pedaling force detects a state in which the speed detection value is zero or the pedaling force detection value does not fluctuate. There is a problem in that accurate power assist is not provided after the pedal is depressed inside, and in some cases, the original power is not assisted.

[0010]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above circumstances, and the invention according to claim 1 is to depress a pedal in a bicycle with an electric auxiliary power device that runs with power assist from a motor. Torque detecting means for converting a torque into a voltage signal, an A / D converter for A / D converting the voltage signal connected to the torque detecting means, and an A / D converter output first after power-on. Minimum value storage means for storing the first output voltage value E0 as a minimum voltage value Es at which the stepping torque is zero, and a second output voltage value E output following the first output voltage value E0 from the A / D converter.
And a minimum value comparing means for comparing 1 with the minimum voltage value Es stored in the minimum value storing means, and a minimum value when the output voltage value E1 is smaller than the minimum voltage value Es as a result of the comparison by the minimum value comparing means. The writing means for updating the minimum voltage value Es stored in the storage means by rewriting it to the post-output voltage value E1 and a step-down operation when the post-output voltage value E1 is smaller than the minimum voltage value Es as a result of the comparison by the minimum value comparing means. A stepping torque calculating means for calculating a predetermined voltage value determined to be zero torque and a difference between the two as a stepping torque voltage value when the subsequent output voltage value E1 is greater than the voltage value Es, and an output of the stepping torque calculating means. And a motor drive circuit for controlling the output of the motor based on the output of the motor drive force determining means. It is obtained by a bicycle with a dynamic auxiliary power unit.

According to the first aspect of the present invention, as the assisted power, the first output voltage value E0 output earlier from the A / D converter after the power is turned on is set to the minimum voltage value Es. When the post-output voltage value E1 is smaller than the minimum voltage value Es, the post-output voltage value E1 determines the minimum voltage value E1.
Since s is updated and the power to be assisted is determined based on the difference between the subsequently output voltage value E1 and the minimum voltage value Es, it does not depend on the initial value determined by the individual torque detecting means. Since the magnitude of the power to be assisted is determined, there is an effect that accurate power assist can be performed.

According to a second aspect of the present invention, in the first aspect of the present invention, when the minimum output value is determined by the minimum value comparing means to be smaller than the minimum voltage value Es, the difference between the two is eliminated. Comparing means for comparing with the tolerance value, the minimum value comparing means determines that the subsequent voltage value E1 is smaller than the minimum voltage value Es, and the difference compared by the comparing means is smaller than the noise tolerance value. At this time, the bicycle with the electric auxiliary power unit rewrites the minimum voltage value Es with the value of the rear output voltage value E1.

According to the second aspect of the present invention, the difference between the output voltage value E1 and the minimum value voltage value Es after the comparison by the minimum value comparing means is determined by the noise tolerance. Comparing means for comparing the output voltage value E1 with the output voltage value E1 is determined to be smaller than the minimum voltage value Es. Since the voltage is updated by E1, even if an abnormally low voltage is output due to noise, the voltage is not set to the minimum voltage value Es. It has the effect of preventing abnormal growth.

According to a third aspect of the present invention, in the first aspect of the invention, when the minimum output value is determined by the minimum value comparing means to be smaller than the minimum voltage value Es, the difference between the two is determined by noise. Comparing means for comparing with the withstand value; when the minimum value comparing means determines that the subsequent voltage value E1 is smaller than the minimum voltage value Es, and when the difference compared by the comparing means is larger than the noise withstand value. Is a bicycle with an electric auxiliary power unit in which the driving of the motor is stopped by the motor driving circuit.

According to the third aspect of the present invention, in addition to the operation of the first aspect, the output voltage value E1 after being compared by the minimum value comparing means is equal to that of the first aspect. When the voltage is smaller than the minimum voltage value Es and the difference between the two is larger than the noise tolerance value, the motor is stopped, so that an abnormally large power can be prevented from being assisted.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, a bicycle A with an electric auxiliary power device (hereinafter simply referred to as a bicycle) A includes a vehicle body B and an auxiliary power device (hereinafter simply referred to as a power device) C attached to the vehicle body B. The vehicle body B has a vertical pipe 2 and a lower pipe 3 having one end fixed to a hanger lug 1, a head pipe 4 fixed to the other end of the lower pipe 3, and one end fixed to a head pipe 4. A frame 6 comprising an upper pipe 5 fixed to a lower portion of the upright pipe 2; a chain stay 7 having one end fixed to the hanger lug 1; a front fork 8 attached to the head pipe 4; , A front wheel 10 attached to the lower end of the front fork 8, one end is fixed to the upper part of the standing pipe 2 and the other end is not shown as the other end of the chain stay 7. Backhawk 1 fixed via rear pawl
1, a rear wheel 12 attached to the other end of the chain stay 7, a saddle 13 attached above the standing pipe 2, a load receiving stand 14 provided above the rear wheel 12, and the like.

The hanger lug 1 is provided with a crankshaft 80 described later so as to be rotatable.
A left crank 81 and a right crank 82 provided with pedals 81a and 82a, respectively, are attached to both ends. A storage battery case 14a containing a storage battery 14b as a power supply is mounted on the upper part of the receiving table 14. The storage battery 14b is supplied with electric power via a lead 16 to a motor 40 and the like described later. In addition, a sprocket 1 for transmitting rotational force during traveling.
A chain 18 is hung around the sprocket 7 of the rear wheel 12 and 7.

Next, the structure of the power unit C will be described with reference to FIGS. As shown in FIG.
Is a case 2 composed of a case body 23 and a lid case 25.
0, the motor 40 attached to the case 20;
The case 20 is constituted by a speed reduction mechanism 50.
Is provided with a hollow shaft 70 which is mounted via a bearing and to which rotational force is transmitted from the speed reduction mechanism 50, and a crankshaft 80 penetrating through the hollow shaft 70. In the case 20, a microcomputer, a ROM,
The control device 200 including a RAM and the like is housed.

The case body 23 houses the speed reduction mechanism 50, the control device 200, and the like. The reduction mechanism 50 includes a gear 51 attached to a tip end of an output shaft 41 of the motor 40, a large-diameter gear 52 meshing with the gear 51, a small-diameter gear 53 provided integrally with the gear 52, A gear 54 composed of a large-diameter gear 54b and a bevel gear 54c meshing with the gear 53, a bevel gear 55 meshing with the bevel gear 54c, and a shaft 55a mounted on the same shaft as the shaft on which the bevel gear 55 is mounted. The gear 55b includes a drive gear 56 that meshes with the gear 55b.

The gear 55b is mounted on the shaft 55a via a one-way clutch 55f.
The one-way clutch 55f rotates the gear 55b so as to transmit the torque of the motor 40 to the drive gear 56 so that the bicycle travels normally, that is, travels in the forward direction, but idles in the opposite direction. It works like that. In other words, the one-way clutch 55f functions so as to idle when the cranks 81, 82 to which the pedals 81a, 82a are attached rotate in the traveling direction during manual driving described below.

A shaft hole 56a is formed in the center of the driving gear 56, and the shaft hole 56a has
2c are formed on the side surface of the drive gear 56 on the side of the lid case 25 and concentrically arranged on the outer periphery of the shaft hole 56a as shown in FIGS. 2 and 3 (three in the embodiment, FIG. 2). , FIG.
(Only one is shown in the figure), and the projection 57 is formed in the direction of the arrow shown in FIG.
As shown in the drawing, an inclined surface 57a that gradually rises upward along the direction in which the vehicle rotates during traveling is formed. On the side surface of the drive gear 56 on the side of the lid case 25, as shown in FIG. 3, a plurality (3 in this embodiment) disposed concentrically with the shaft hole 56a between the adjacent protrusions 57. An L-shaped regulating member 58 that regulates one end of a compression spring 60 described later (only one is shown in FIG. 3) is formed.

The hollow shaft 70 for transmitting the power of the motor 40, that is, the rotational force transmitted through the reduction mechanism 50, to the sprocket 17, is fitted into a shaft hole 56a formed in the drive gear 56. The hollow shaft 70 is rotatably provided on the hanger lug 1 and has a through hole 7 therein.
1 and at one end thereof, a concave / convex ridge 72 is formed to engage with the concave / convex ridge 56c formed in the shaft hole 56a. The shaft 70 is prevented from rotating in the direction, so that the hollow shaft 70 rotates integrally with the drive gear 56. Also,
A mounting member 17a to which the sprocket 17 is mounted is mounted on the other end of the hollow shaft 70.
The hollow shaft 70 is press-fitted into the inner race of the ball bearing 77 in the vicinity of the area where the concave and convex strips 72 are formed. Is attached to the case body 23.

A crankshaft 80 is rotatably provided through the through-hole 71 of the hollow shaft 70, and mounting portions 83 and 84 are formed at both ends of the crankshaft 80, respectively.

A one-way clutch 85 is attached to the crankshaft 80 at a position close to the drive gear 56 attached to the hollow shaft 70, and is connected to the crankshaft 80 via the one-way clutch 85. Has a drive plate 90 attached. The one-way clutch 85
Are pedals 81a, 82 when the crankshaft 80 is running manually.
In the case where the drive plate 90 is rotated in the traveling direction by the left and right cranks 81 and 82 to which the a is attached, the drive plate 90 is rotated. It works like that. A disc-shaped flange portion 91 is formed on the cover case 25 side of the drive plate 90 at a predetermined distance so as to form a space between the drive plate 90 and a side surface of the drive gear 56.
A compression portion 92 is formed on the surface of the flange portion 91 on the side of the drive gear 56, as shown in FIG. And
The compression spring 60 is disposed between the L-shaped regulating member 58 and the compression section 92.

The magnitude of the biasing force of the compression spring 60 is adjusted so that the compression spring 60 is compressed in accordance with the rotational force applied to the drive plate 90 via the crankshaft 80 and the one-way clutch 85 during manual driving. Is set. That is, in the case of manual running, the driving gear 56 is set so as to move relative to the driving gear 56 in accordance with the rotational force of the driving plate 90 which rotates together with the one-way clutch 85 with the rotation of the crankshaft 80. It is.

The flange portion 91 of the driving plate 90 has
As shown in FIGS. 2 and 4, three through holes 93 (only one is shown in FIGS. 2 and 5) are formed at portions corresponding to the protrusions 57 formed on the side surface of the drive gear 56.

An offset plate 95 made of an annular plate is provided so as to be able to contact and separate from the flange portion 91, and the offset plate 95 is provided with the through holes 9 respectively.
A slide shaft 96 is provided at a position corresponding to 3 and integrally fixed so as to penetrate an end on one end side into the through hole 93. A spherical projection 96a is formed at the other end of the slide shaft 96. The spherical projection 96a is formed on the inclined surface 57a of the projection 57 formed on the drive gear 56.
The coil spring 97 is biased so as to be pressed against the deflection plate 95. That is, the eccentric plate 95 allows the slide shaft 96 fixed to the eccentric plate 95 to pass through the through hole 93 of the flange portion 91 and is urged by the coil spring 97 so that the spherical projection 96a is formed on the inclined surface 57a. It is arranged between the drive gear 56 and the drive plate 90 so as to be able to move in the axial direction of the crankshaft 80 in a state of being pressed.

When the pedaling force of the pedals 81a, 82a is applied to the crankshaft 80 via the left and right cranks 81, 82, the rotational force is transmitted via a one-way clutch 85 mounted on the crankshaft 80 to the driving plate. When the driving plate 90 is transmitted to the motor 90 and the driving plate 90 is rotated, and the vehicle is in an acceleration state such as traveling on an uphill, the pedals 81a and 82a are more strongly depressed than before, so that the pedals 81a and Crankshaft 8 rotated by pedaling force of 82a
0 and a driving gear 5 that rotates integrally with the hollow shaft 70.
6, a relative movement corresponding to the pedaling force occurs.
That is, to accelerate the bicycle A, the pedals 81a, 82
By strongly depressing “a” and increasing the stepping force, the compression spring 60 provided between the driving plate 90 and the driving gear 56 is compressed, and the driving plate 90 precedes the driving gear 56 by an amount corresponding to the stepping force. As a result, the spherical projection 96 of the slide shaft 96 fixed to the deflection plate 95 is rotated.
a moves upward along the inclined surface 57a of the projection 57 provided on the drive gear 56, and along with this movement, the coil spring 97 is compressed, and the deflection plate 95 moves in a direction away from the drive gear 56, that is, Will be deviated.

Then, the deflection plate 95 is connected to the drive gear 56.
When the deflection plate 95 is displaced in a direction away from the
The operating rod 140 of the torque sensor 100 as a torque detecting means described later operates in accordance with the amount of deviation of the torque sensor 100, and the torque sensor 100 outputs an electric output according to the pedaling force. (Analog / digital value) The analog value is converted into a digital value by the converter, that is, A / D converted and sent to the control device 200.

A start switch 15 is provided on the lid case 25 of the power unit C as shown in FIG.
The start switch 15 is provided with a key insertion hole 15a, and a key (not shown) is inserted into the key insertion hole 15a to perform a closing / opening operation.
The electric power is supplied to and stopped from the motor 40 and the like. When the start switch 15 is closed, the vehicle can travel easily with the assistance of the rotational force from the power unit C. When the start switch 15 is opened, the vehicle travels manually using only human power.

Next, the structure of the torque sensor 100 will be described with reference to FIGS. As shown in FIG. 5, the torque sensor 100 includes a case main body 101 including a lower case 110 and an upper case 120 attached to the lower case 110, a strain gauge 130 as a sensor disposed in the case main body 101, Actuating rod 140 which receives the pedaling force of the detected torque, that is, the acting force of the rotational torque of crankshaft 80, and operating rod 140
And a coil spring 150 for transmitting the acting force received to the strain gauge 130.

The upper case 120 has a bottom wall 1.
21 is formed with a cylindrical portion 125 protruding inward and outward, respectively. The cylindrical portion 125 is formed with a guide hole 126 at a portion from the outer end portion to a substantially intermediate portion, and is formed from the intermediate portion to the inner side. Guide hole 1 at the end
A hole 127 larger in diameter than 26 is formed.

Then, the sensor, that is, the strain gauge 1
Reference numeral 30 denotes four thin-film resistors R1 formed on a surface of a strain body 131 made of, for example, aluminum through an insulating film.
To R4 (not shown in FIG. 5) by sticking or so-called semiconductor technology, and these four resistors R1 to R4 are connected by conductors to form a bridge W as shown in FIG. It is configured.
The connection point between the resistors R1 and R3 and the connection point between the resistors R4 and R2 of the bridge W are connected to the lead wire 132a.
And 132b are connected to a power supply, and the connection point between the resistors R1 and R4 and the connection point between the resistors R2 and R3 are output ends. A corresponding electrical output is output, and the electrical output is sent to the control device 200 via the A / D converter 110 through the leads 133a and 133b.

The free end 131a of the strain body 131 fixed to the lower case 110 and the upper case 120 with the fixed end sandwiched therebetween is located below the inner end of the cylindrical portion 125 and has a guide hole 126. A pin 134 having an axis coinciding with the axis of the guide hole 126 is attached to the distal end portion.

The operating rod 140 is connected to the guide hole 1.
A shaft 141 which is guided by 26 and slidably fits in the axial direction, and a large diameter formed at one end of the shaft 141 and rotatably fitted with a steel ball 142a to reduce friction. The coil spring 150 is disposed between the operating rod 140 and the pin 134 in a state where the coil spring 150 is compressed by a predetermined amount.

The operation of the torque sensor 100 is based on the same principle as that of a conventionally known torque sensor using a strain gauge. That is, the pedals 81a, 8
The pedaling force 2a is transmitted to the crankshaft 80, and a bending force corresponding to the amount of deflection of the deflection plate 95 that changes according to the magnitude of the rotational force of the crankshaft 80 is applied to the flexure element 131. The bridge W outputs an electrical output corresponding to a change in the resistance value of the resistors R1 to R4. In this embodiment, the maximum bending force is applied to the strain body 131 when the deflection plate 95 is not deflected.

As shown in FIG. 3, a speed sensor 160 as a vehicle speed detecting means for detecting the speed of the bicycle A is provided inside the case 20, and a known magnetic sensor is used as the speed sensor 160. And
A detection unit (not shown) of the speed sensor 160 is disposed close to the teeth of the drive gear 56, and is generated each time each tooth of the drive gear 56 approaches the detection unit by the rotation of the drive gear 56. The vehicle speed is detected based on the number of pulses per unit time of the pulse signal.

Next, the rear wheel 1 of the driving force of the motor 40
2 will be described.

The pedals 81a, 82a are adapted to accelerate the bicycle A as in the case of running uphill or the like in manual running.
a, the pedals 81a, 82a
The driving force increases to exceed a predetermined value, and the driving plate 90 rotates ahead of the driving gear 56 to cause relative movement of the driving plate 56 and the driving gear 56 by an amount corresponding to the pressing force. Is a protrusion 5 provided on the drive gear 56.
7 is moved upward, and the deflection plate 95 is shifted in a direction away from the driving gear 56 by a deflection amount corresponding to the magnitude of the pedaling force. As a result, the maximum bending force applied to the flexure element 131 via the operating rod 140 and the coil spring 150 decreases, and the flexure element 131 is restored. With this restoration, the resistance values of the resistors R1 to R4 of the bridge W are restored. Is changed, and an electrical output corresponding to the change is sent to the control device 200. Then, the control device 200 drives the motor 40 as described later, and the power of the motor 40 is transmitted from the gear 42 provided on the output shaft 41 to the drive gear 56 via the speed reduction mechanism 50, and the drive gear 56 And transmitted to the rear wheel 12 via the sprocket 17 and the chain 18 attached to the hollow shaft 70. That is, the pedals 81a, 8
By stepping on 2a, the bicycle travels by adding or assisting the rotational force of the motor 40, that is, the power, to the rotational force of the human power transmitted to the crankshaft 80 by being depressed.

Next, the bicycle A in this embodiment
An embodiment of the first control for assisting the power according to the pedaling force of the vehicle will be described with reference to a control block diagram shown in FIG. 7 and a flowchart shown in FIG.

In the figure, reference numeral 200 denotes the control device described above. The control device 200 includes a minimum value storage unit 210 including a memory, a minimum value comparison unit 220 connected to the minimum value storage unit 210, and a minimum value comparison unit 22.
0, the read / write means 215 provided between the minimum value storage means 210, and a stepping torque calculation means (hereinafter referred to as calculation means) 2 connected to the minimum value comparison means 220.
30, a motor driving force determining means (hereinafter referred to as driving force determining means) 240 connected to the calculating means 230, a motor driving circuit 250 connected to the driving force determining means 240,
Storage means 260 connected to the driving force determination means 240
And control means (not shown).

The A / D converter 110 connected to the torque sensor 100 is connected to the minimum value storage means 210, the minimum value comparison means 220 and the calculation means 230. The motor drive circuit 250 is connected to the motor 40 and the storage battery 14b. The motor drive circuit 250 controls the current supplied from the storage battery 14b based on the output from the driving force determination means 240. The output of the motor 40, that is, the rotational force is controlled. Further, the storage means 260 stores the calculation means 230
The driving force information corresponding to the pedaling force voltage value calculated by the above is stored.
The driving force information corresponding to this output is read out from the storage means 260 based on the output from the storage means 260, the driving force is determined, and the result is output to the motor driving circuit 250.

Next, the control based on the control block diagram configured as described above will be described with reference to the flowchart shown in FIG. First, when the bicycle A travels, the start switch 15 provided on the driving device C is closed by a key (not shown) to turn on the power. When the power is turned on, the torque sensor 100 outputs a stepping torque applied to the pedal at this time, that is, a voltage corresponding to the stepping force (this is also output when the power is turned on even when the pedal is not depressed). This voltage is A / D converted by an A / D converter 110 and output. The output is read at predetermined time intervals by reading means (not shown) controlled by the control means (not shown). The read voltage, that is, the output voltage value E0 is determined in step 1
(Hereinafter, this is described as S1. Also, Steps 2, 3 and so on described below are S2, S3 and so on, respectively.)
) Is stored in the minimum value storage means 210 as the minimum voltage value Es at which the pedaling force is zero. Next, after the first output voltage value E0 in S2, the output of the A / D converter 110, that is, the second output voltage E1 is read by the reading means (not shown). After this read, the output voltage value E1 is S
In step 3, the minimum value comparing means 220 compares the minimum voltage value Es read out from the minimum value storing means 210 by the read / write means 215, and compares the value in step S4. As a result, when the rear output voltage value E1 is larger than the minimum voltage value Es, a difference between the rear output voltage value E1 and the minimum voltage value Es is calculated, and this difference voltage is set as a tread force voltage value Et, which is transmitted to the driving force determination means 240. Output. Then, in S5, the driving force determination unit 240 stores the driving force information corresponding to the treading force voltage value Et in the storage unit 260.
From the motor drive circuit 2
50, and based on this output, the motor drive circuit 25
Numeral 0 controls the motor 40 to assist the power corresponding to the pedaling force of the pedal.

If the output voltage value E1 is smaller than the minimum voltage value Es as a result of the comparison by the minimum value comparison means 220, the read / write means 215 determines the minimum output voltage value E1 by the read / write means 215 in S6. The minimum voltage value Es is updated by rewriting Es.

After the result of the comparison, the output voltage value E1 is smaller than the minimum voltage value Es.
The reference numeral 30 designates a driving force determining means 240 assuming that the pedaling force is zero and using a predetermined voltage value as a pedaling force voltage value Et.
The driving force determination means 240 reads the driving force information corresponding to the treading force voltage value Et from the storage means 260 in S5 based on the output to determine the driving force, and outputs this to the motor drive circuit 250. Based on this output, the motor drive circuit 250 controls the motor 40 to assist power.

As described above, the minimum voltage value Es is constantly updated to the minimum value because of the control, and the subsequent output sequentially output from the A / D converter 110 in accordance with the depression force generated by depressing the pedal. Since the voltage value E1 is compared with the updated minimum voltage value Es, and the assisting power is determined by the relative value of the two, the voltage value E1 depends on the unique initial value of each torque sensor 100. Therefore, stable and accurate power assist over a long period of time can be achieved without being affected by a change in characteristics due to a manufacturing error of the torque sensor 100, an aging change, a displacement during assembly to the vehicle body B, and the like. You can do it.

Further, since the pedal is rotated by depressing, there is always a position where the pedaling force becomes zero during one rotation, and the output of the A / D converter 110 at this time is defined as the minimum voltage value Es. Since the treading force is stored in the minimum value storage means 210, the treading force voltage Et is calculated using the minimum voltage value Es based on the state where the treading force is set to zero as a reference value, and power assist is performed based on the treading force voltage value Et. As a result, proper power is assisted and safe driving is performed.

Next, a second embodiment of the control of the bicycle A will be described with reference to a control block diagram shown in FIG. 9 and a flowchart shown in FIG. As shown in FIG. 9, the configuration of the control block differs from the configuration of the control block shown in FIG. 7 only in that a comparison unit 221 and a noise tolerance value storage unit 222 connected to the comparison unit 221 are added. Are the same, the same reference numerals are given to the same components and the description thereof will be omitted. Also, as shown in FIG. 10, when the minimum voltage value Es is larger than the post-output voltage value E1 between S3 and S6 in the flowchart shown in FIG.
The only difference is the configuration in which S3-1 for comparing K with the comparing means 222 is provided, and the other configurations are the same. Therefore, the same components are denoted by the same reference numerals and description thereof is omitted.

Then, the noise tolerance value K is stored in the noise tolerance value storage means 222 in the block diagram shown in FIG.
When it is determined that the subsequent output voltage value E1 is initially smaller than the voltage value Es, the difference between the two is compared with the noise tolerance value K. The noise withstand value refers to the magnitude of noise that cannot be removed from the entire torque sensor 100.

Next, this control will be described with reference to the flowchart of FIG. In FIG. 10, the minimum voltage value Es
And the post-output voltage value E1 is the minimum value comparing means 2 in S3.
As a result of the comparison at S20, when it is determined that the subsequent output voltage E1 is smaller than the minimum voltage value Es, the difference between the two and the noise tolerance value K are compared by the comparing means 221 at S3-1. As a result, when the difference is smaller than the noise tolerance value K, the minimum voltage value is updated by rewriting the minimum voltage value Es with the subsequent output voltage value E1 in S6, and the tread force voltage is determined to be zero in step S7. The driving force is determined by the value Et, and the motor 40 is controlled based on this determination. When the difference is determined to be larger than the noise tolerance value K, the minimum voltage value Es is rewritten by the subsequent output voltage value E1. The driving force is determined based on the pedaling force voltage value Et that determines that the pedaling force is zero without proceeding to S7, and the motor 40 is controlled based on this determination.

By this, when the post-output voltage value E1 is based on noise and is abnormally small, it is possible to prevent the minimum voltage value Es from being updated by this abnormal value, so that abnormally large power is assisted. Can be prevented.

Next, an embodiment of the third control of the bicycle A will be described. Since the configuration of the control block according to the third embodiment is the same as the configuration of the control block shown in FIG. 9, the description thereof will be omitted, and only the control will be described based on the flowchart shown in FIG. . Also, the flowchart of the second embodiment shown in FIG. 10 is different from the flowchart of the third embodiment only in the configuration provided with S3-2 in FIG. 10 and the other configurations are the same. The same components are denoted by the same reference numerals, and description thereof is omitted.

In FIG. 11, when the minimum voltage value Es and the subsequent output voltage value E1 are compared by the minimum value comparing means 220 in S3, it is determined that the subsequent output voltage E1 is smaller than the minimum voltage value Es. At -1, the comparing means 221 compares the difference between the two and the noise tolerance value K. As a result, when the difference is smaller than the noise tolerance value K, the minimum voltage value is updated by rewriting the minimum voltage value Es with the subsequent output voltage value E1 in S6, and the tread force voltage is determined to be zero in step S7. The driving force is determined by the value Et, and the motor 40 is controlled based on this determination.
When it is determined that the difference between the minimum voltage value Es and the subsequent output voltage value E1 is larger than the noise tolerance value K, the result is output to the driving force determination means 240 via the calculation means 230, and S
In 3-2, the driving force determination unit 240 outputs stop information for stopping driving of the motor to the motor drive circuit 250, and based on this output, the motor drive circuit 250 controls the motor 40 to stop. Then, by stopping the motor 40, if the rear output voltage value E1 is based on noise and the value is abnormally small, based on the abnormal value due to the noise and the rear output voltage value E1 to be output next. It is possible to prevent the abnormally large power from being assisted by the determined driving force information, and to perform safe driving.

[0054]

According to the first aspect of the present invention, the power to be assisted is such that the first output voltage value E0 previously output from the A / D converter is the minimum voltage value Es,
When the subsequent output voltage value E1 is smaller than the minimum voltage value ES, the minimum voltage value Es is updated by the subsequent output voltage value E1, and the assist is performed based on the difference between the next output voltage value E1 and the minimum voltage value Es to be output next. Since the power to be determined is determined, it is possible to determine the power to be assisted without depending on the unique initial value determined by the individual torque detecting means. This has an effect that stable and accurate power can be assisted. Things.

According to a second aspect of the present invention, in the first aspect, the difference between the output voltage value E1 and the minimum voltage value Es after comparison by the minimum value comparing means is compared with the noise immunity value. Means are provided, and the minimum value comparison means updates the minimum voltage value Es with the rear output voltage value E1 only when the post-output voltage value E1 is smaller than the minimum voltage value Es and the difference between the two is smaller than the noise tolerance value. Therefore, even if an abnormally low voltage is output due to noise, the voltage is not set to the minimum voltage value Es. In addition to the effect of the invention described in claim 1, it is possible to prevent the assisted power from becoming abnormally large. It has the effect of being able to run safely.

According to a third aspect of the present invention, when the difference between the output voltage value E1 and the minimum voltage value Es after the comparison by the minimum value comparing means is larger than the noise tolerance value in the first aspect of the invention. Is stopped, so that abnormally large power can be prevented from being assisted, and an effect that the vehicle can travel safely can be achieved.

[Brief description of the drawings]

FIG. 1 is an overall view of an embodiment of a bicycle with an electric auxiliary power device according to the present invention.

FIG. 2 is a sectional view showing a configuration of the auxiliary power unit according to the embodiment.

FIG. 3 is a side view showing the auxiliary power unit of the embodiment.

FIG. 4 is a partial view showing the relationship between the depression force of the pedal and the operation of the torque detecting means in the embodiment.

FIG. 5 is a cross-sectional view of the torque detecting means (torque sensor) of the embodiment.

FIG. 6 is a circuit diagram of a torque detecting means (torque sensor) of the embodiment.

FIG. 7 is a control block diagram of a first embodiment of the control in the above embodiment.

FIG. 8 is a flowchart of the first embodiment of the control.

FIG. 9 is a control block diagram according to a second embodiment of the control in the embodiment.

FIG. 10 is a flowchart of a second embodiment of the control.

FIG. 11 is a flowchart of a third embodiment of the control in the above embodiment.

[Explanation of symbols]

A Bicycle with electric auxiliary power unit. B vehicle body C auxiliary power unit 14b storage battery 40 motor 80 crankshaft 81a, 82a pedal 100 torque sensor (torque detecting means) 110 A / D converter 160 speed sensor (vehicle speed detecting means) 200 controller 210 minimum value storage means 215 Writing means 220 Minimum value comparison means 221 Comparison means 222 Noise tolerance value storage means 230 Calculation means (stepping torque calculation means) 240 Driving force determination means (Motor drive determination means) 250 Motor drive circuit 260 Storage means

Claims (3)

[Claims] 1. A bicycle with an electric power assisting device that travels with power assist from a motor, a torque detecting means for converting a stepping torque of a pedal into a voltage signal, and the voltage signal connected to the torque detecting means is converted to an A signal. A for / D conversion
A / D converter; a minimum value storage means for storing a first output voltage value E0 previously output from the A / D converter after the power is turned on as a minimum voltage value Es at which the stepping torque is zero;
Minimum value comparing means for comparing a subsequent output voltage value E1 outputted from the / D converter following the preceding output voltage value E0 with a minimum voltage value Es stored in the minimum value storing means; When the output voltage value E1 is smaller than the minimum voltage value Es as a result of the comparison by the comparing means, the minimum voltage value Es stored in the minimum value storage means is rewritten with the post-output voltage value E1 to update the minimum voltage value Es; When the output voltage value E1 is smaller than the minimum voltage value Es as a result of the comparison by the value comparing means, the predetermined voltage value determined to be zero in the stepping torque is replaced with the rear output voltage value E1.
When 1 is greater than the voltage value Es, stepping torque calculating means for calculating the difference between the two as a stepping torque voltage value, and motor driving force determining means for determining the driving force of the motor based on the output of the stepping torque calculating means. A motor drive circuit for controlling the output of the motor based on the output of the motor drive force determining means. 2. The invention according to claim 1, wherein said minimum value comparing means compares said difference with a noise immunity value when said subsequent output voltage value E1 is determined to be smaller than said minimum voltage value Es. The minimum voltage value Es is determined by the minimum value comparison means to be smaller than the minimum voltage value Es, and the difference compared by the comparison means is smaller than the noise immunity value. A bicycle with an electric auxiliary power unit, which is rewritten according to the value of the rear output voltage value E1. 3. The comparing means according to claim 1, wherein when the minimum value comparing means determines that the post-output voltage value E1 is smaller than the minimum voltage value Es, the comparing means compares the difference between the two with the noise immunity value. When the minimum value comparing unit determines that the subsequent voltage value E1 is smaller than the minimum voltage value Es, and the difference compared by the comparing unit is larger than the noise tolerance value, the motor driving circuit controls the motor by the motor driving circuit. A bicycle with an electric auxiliary power unit, wherein driving is stopped.