JPH11240481A - Drive assist device for electrically assisted bicycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce pedaling effort when ascending a slope without providing speed change gears to the rear wheel. SOLUTION: In the electrically assisted bicycle, power control of a motor 14 is executed according to the work amount of a crankshaft 4 which is driven by a pedal 3, and the rotation of the motor 14 is transmitted to a wheel drive shaft 13 via a reduction mechanism 21 to assist the rotation of the crankshaft 4. Further, a reduction mechanism 22 is provided between the crankshaft 4 and the wheel drive shaft 13. This reduces the pedaling effort when ascending a slope. Also, interposing the reduction mechanism 22 at this location makes it possible to realize appropriate assisted running wherein the assist power is cut off when the actual running speed reaches a predetermined speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive assist device for an electric assist bicycle.

[0002]

2. Description of the Related Art In general bicycles, it is necessary to depress a pedal with a large force at the time of starting, or a particularly large pedal is required when climbing a slope. Accordingly, an electric assisted bicycle has been developed to reduce the stepping force on the pedal.

As shown in FIG. 24, a motor-assisted bicycle has a bracket 1 formed on a bicycle frame and a drive assist device 2 in which a motor and a reduction gear are incorporated. When the crankshaft 4 is driven by the pedal 3 to drive the rear wheel 6 via the chain 5, the drive assist device 2 is configured to assist the drive. 7 is a drive assist device 2
Is a battery box in which a battery as a power source for driving the battery is stored.

The relationship between the configuration of the drive assist device 2 and the rear wheel 6 is configured as shown in FIG. When the pedal 3 is depressed to rotate the crankshaft 4, the one-way clutch 8
, The wheel 9 is rotated via the gears 10, 11, 12, and the rear wheel 6 is driven via the chain 5.

The drive assist device 2 has a built-in motor 14, and the rotation of the output shaft of the motor 14 is reduced via a planetary gear mechanism 15. This deceleration output is connected to the rotation shaft 17 of the gear 10 via the one-way clutch 16 to assist the rotation of the crankshaft 4. The power of the motor 14 is controlled by the control unit 18 in accordance with the rotation speed and the rotation torque of the crankshaft 4.

[0006] A drive assist device 2 of this type for an electric assist bicycle is disclosed in Japanese Patent Application Laid-Open No. 8-282575. By using this drive assist device 2,
The pedal depressing force when starting or climbing a hill has been reduced compared to ordinary bicycles, making it easier to ride.However, further reduction in pedal depressing force when climbing a hill is expected. I have.

Accordingly, there is an electric assisted bicycle in which a transmission 19 is provided on the rear wheel 6 as shown in FIG. 26 to reduce the pedal depressing force when climbing a slope.

[0008]

As shown in FIG. 26, the transmission 19 provided on the rear wheel 6 has a structure that can be manually switched by a user, and thus has poor operability.

Further, in order to distinguish the motor-driven bicycle from the motor-driven bicycle, the driving assist device 2 generates an assisting force until the running speed of the motor-driven bicycle reaches a specified speed (for example, 24 km / hour). The auxiliary power is turned off when the value exceeds. In this case, FIG.
The drive assist device 2 in the case of the conventional example shown in FIG. 1 detects that the wheel drive shaft 13 has reached the rotation speed at which the traveling speed in the state where the reduction ratio of the transmission 19 is 1: 1 reaches the specified speed, and 1
4 is turned off and the auxiliary force is turned off. Therefore, during traveling using the transmission 19, the actual traveling speed does not reach the specified speed. There is a problem that the assisting power is turned off and proper assist driving cannot be performed.

In order to solve this problem, it is conceivable to calculate the traveling speed from the actual rotational speed of the rear wheel 6 and turn off the assisting force when the traveling speed reaches a specified speed. In this case, there is a problem that a sensor (not shown) for counting the number of rotations of the rear wheel 6 needs to be added and the mounting of this sensor is troublesome.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a drive assist device for an electric assist bicycle that can reduce a pedal depressing force when climbing a hill or the like without providing a transmission on a rear wheel.

[0012]

A drive assist device for an electric assist bicycle according to the present invention is characterized in that a speed change mechanism is provided between a pedal-driven crankshaft and a wheel drive shaft.

According to this configuration, the stepping force on the pedal can be reduced without providing a transmission on the rear wheels.

[0014]

According to a first aspect of the present invention, there is provided a drive assist device for an electric assist bicycle, which controls electric power of a motor in accordance with a work amount of a crankshaft driven by a pedal, and includes a mechanism for reducing the rotation of the motor. An electric assist bicycle that transmits to a wheel drive shaft through a shaft to assist rotation of the crankshaft,
A transmission mechanism is provided between the crankshaft and the wheel drive shaft.

According to a second aspect of the present invention, there is provided a drive assist device for an electrically assisted bicycle, wherein a control unit for switching a speed change mechanism provided between a crankshaft and a wheel drive shaft in accordance with the work load of the crankshaft is provided. It is characterized by having.

According to a third aspect of the present invention, there is provided a drive assist device for an electrically assisted bicycle, wherein a control unit for switching a speed change mechanism provided between the crankshaft and the wheel drive shaft in accordance with a lapse of time from the start of traveling. It is characterized by having.

According to a fourth aspect of the present invention, there is provided a drive assist device for an electrically assisted bicycle according to the first aspect, wherein a transmission mechanism provided between the crankshaft and the wheel drive shaft is used for the work amount of the crankshaft and the lapse of time from the start of running. It is characterized in that a control unit for switching according to is provided.

According to a fifth aspect of the present invention, there is provided a drive assist device for an electrically assisted bicycle, wherein a speed reduction mechanism for transmitting rotation of a motor to a wheel drive shaft is disposed in parallel with the axis of the crankshaft. A transmission mechanism provided between a shaft and the wheel drive shaft is arranged on the same axis as the axis of the crankshaft.

According to a sixth aspect of the present invention, there is provided the drive assist device for the electric assisted bicycle according to the fifth aspect, wherein a transmission mechanism for transmitting the rotation of the crankshaft to the wheel drive shaft is covered with the crankshaft and rotates integrally with the crankshaft. A hollow shaft to be rotated, a plurality of gear teeth rotatably arranged outside the hollow shaft with respect to the hollow shaft and arranged in the longitudinal direction of the crankshaft, and the hollow shaft and the gear teeth are selectively provided. And a clutch portion to be connected.

According to a seventh aspect of the present invention, there is provided the drive assist device for the electrically assisted bicycle according to the fifth aspect, wherein a transmission mechanism for transmitting the rotation of the crankshaft to the wheel drive shaft is covered with the crankshaft and rotates integrally with the crankshaft. A hollow shaft, and a transmission gear rotatable with respect to the hollow shaft outside the hollow shaft,
The clutch is configured to selectively connect the hollow shaft and the transmission teeth.

According to an eighth aspect of the present invention, there is provided a drive assist device for an electrically assisted bicycle, wherein the clutch portion is disposed between the crankshaft and a hollow shaft covered on the crankshaft. A clutch switching body that pushes an engaging body from a through hole slidably formed on the hollow shaft with respect to the crankshaft to a position where the engaging body engages with the inner peripheral surface of the transmission tooth;
An interlocking shaft provided inside the crankshaft so as to be slidable in the axial direction of the crankshaft and one end of which is connected to the clutch switching body, and is slidable in the axial direction of the clutch so as to cover the outside of the hollow shaft. A guide connected to the other end of the interlocking shaft through a hole formed in the hollow shaft and the clutch, and a rotation of the guide rotating with the rotation of the crankshaft and the hollow shaft. And an operating body engaged with the guide body and slidably driven in the axial direction of the crankshaft when the gear ratio is switched.

According to a ninth aspect of the present invention, there is provided a drive assist device for an electrically assisted bicycle according to the eighth aspect, wherein the actuator for changing a position of an operating body with respect to a crankshaft and the actuator are driven in accordance with a work amount of the crankshaft. It is characterized in that a control unit for switching the transmission rate of the transmission is provided.

According to a tenth aspect of the present invention, in the drive assisting device for an electrically assisted bicycle according to the eighth aspect, the actuator for changing the position of the operating body with respect to the crankshaft and the actuator are driven according to a lapse of time from the start of traveling. A control unit for switching the speed change rate of the speed change mechanism is provided.

According to an eleventh aspect of the present invention, in the drive assist device for an electrically assisted bicycle according to the eighth aspect, an actuator for changing the position of the operating body with respect to the crankshaft, and the work amount of the crankshaft and the time elapsed from the start of traveling. And a control unit for driving the actuator to change the speed ratio of the transmission.

Hereinafter, each embodiment of the present invention will be described with reference to FIG.
23 will be described. FIG. 2 shows a conventional example.
Components having the same functions as those of the fourth embodiment will be described with the same reference numerals.

(Embodiment 1) FIG. 1 is a power transmission diagram of a drive assist device of the present invention, and FIG. 2 is a sectional view. FIG. 1 will be described based on FIG.

Bracket 1 formed on bicycle frame
The crankcase 4 driven by the pedal 3, the motor 14, and the rotation of the motor 14 are reduced and the wheel drive shaft 13
And a speed change mechanism 22 provided between the crankshaft 4 and the wheel drive shaft 13.

The assisting force for assisting the rotation of the crankshaft 4 is:
It is transmitted as follows. The outer case 20 includes the motor 1
The shaft 23 is implanted coaxially with the output shaft 14a of No. 4.
The shaft 23 has a cup-shaped follower 2 via a bearing 24.
5 is rotatably mounted.

Gears 28 and 29 are mounted via one-way clutches 26 and 27 on the outer periphery on the distal end side of the driven body 25 whose base end is supported via a bearing 24. The gear 29 has a shaft 30 at every predetermined angle in the circumferential direction,
Are planted, and the shafts 30, 30,.
The gear 31 meshes with the output shaft 14a of the motor 14
Are rotatably mounted via bearings 32. The teeth of the gear 31 mesh with the teeth 33 formed on the inner peripheral surface of the outer case 20.

With this configuration, the driven body 25 rotates at a speed reduced by rotation of the motor 14 by the planetary gear mechanism. The wheel drive shaft 13 is rotatably supported by the outer case 20 via a bearing 34. Wheel drive shaft 1
3 has a base end of the driven body 25 (the outer case 2).
Gear 3 meshing with teeth 35 formed on the outer periphery of the
6 are formed.

The crankshaft 4 has one end supported by the outer case 20 via a bearing 37 and the other end connected to the wheel drive shaft 1.
3, and is rotatably supported with a bearing 38 interposed therebetween.

A hollow shaft 39 shown in FIG. 3 is put on the outside of the crankshaft 4, and the base end of the hollow shaft 39 is engaged with a flange 4 a of the crankshaft 4 so that the hollow shaft 39 is And rotate together. On the distal end side of the hollow shaft 39, a large-diameter portion 40 having an inner diameter larger than the outer diameter of the crankshaft 4 and a support flange portion 41 are formed on the outer periphery of the base end of the large-diameter portion 40. Small-diameter transmission teeth 43 are attached to the outer periphery of the support flange 41 via a one-way clutch 42. The teeth 43 mesh with the gear 29.

Outside the large diameter portion 40 formed on the hollow shaft 39, a large diameter transmission gear 44 and a medium diameter transmission gear 45 forming the transmission mechanism 22 are rotatably inserted. The large-diameter transmission gear 44 is formed by a large-diameter central portion 44a and teeth 44b attached to the outer periphery thereof via a one-way clutch 46. The tooth 44b of the large-diameter transmission gear 44 is
Are meshed with the teeth 35 formed at the base end portion.

The medium-diameter transmission gear 45 meshes with the teeth 28 attached to the leading end of the driven body 25 via a one-way clutch 26. Recesses 47 are formed in the inner peripheral surfaces of the large-diameter transmission gear 44 and the medium-diameter transmission gear 45 in correspondence with the through holes 40a and 40b formed in the large-diameter portion 40 formed in the hollow shaft 39. And the through holes 40a, 4 of the hollow shaft 39
A steel ball 48 is arranged at 0b.

In order to switch the projecting state of the steel ball 48 from the through holes 40a and 40b of the hollow shaft 39, the crankshaft 4
, A cylindrical clutch switching body 49 that is slidable with respect to the crankshaft 4 is disposed between the clutch switching body 49 and the hollow shaft 39.
A projection 49a is formed on the outer peripheral surface of the clutch switching body 49.

The clutch switching body 49 is driven by a clutch switching motor 50 as follows. As shown in FIG. 4, the crankshaft 4 has an internal passage 4b at the center.
The interlocking shaft 51 is inserted into the internal passage 4b. The clutch switching body 49 and the interlocking shaft 51
Is connected to the interlocking shaft 51 by inserting a connecting pin 52a from a hole 49b formed in the clutch switching body 49 to a first long hole 4c formed in the crankshaft 4. I have.

The crankshaft 4 is also provided with a second long hole 4d in addition to the first long hole 4c, and the hollow shaft 39 corresponds to the second long hole 4d of the crankshaft 4. A long hole 39a is formed. An annular guide 53 is slidably covered outside the long hole 39a of the hollow shaft 39, and the long hole 39 of the hollow shaft 39 is inserted through a hole 53b formed in the guide 53.
The linking shaft 51 and the guide 53 are connected by inserting a connecting pin 52b toward the second elongated hole 4d of the crankshaft 4 with the connecting shaft 51a.

The hole 49b of the clutch switching body 49 into which the connecting pin 52a is inserted and the hole 53b of the guide body 53 into which the connecting pin 52b is inserted are shown in FIG. I have.

As described above, the clutch switching body 49 and the guide body 5
The clutch switching member 49 slides inside the hollow shaft 39 by sliding the guide body 53 in the longitudinal direction of the crankshaft 4.

The guide 53 provided on the rotating crankshaft 4 is slid by the switching motor 50 as an actuator provided on the fixed side (the outer case 20 side) as follows. .

The base end of the operating body 54 meshes with a feed screw 50a formed on the output shaft of the switching motor 50. When the switching motor 50 is rotated, the operating body 54 is turned on in accordance with the rotation direction. It moves in the axial direction of the crankshaft 4. A concave portion 54a is formed at the tip of the operating body 54,
The concave portion 54a is engaged with a convex portion 53a formed on the outer periphery of the guide 53 so as to allow the guide 53 to rotate.

Therefore, the clutch switching body 49 is advanced as shown in FIG. 4, and the steel ball 48 located in the through hole 40a of the hollow shaft 39 is pushed outward by the projection 49a of the clutch switching body 49, and this steel ball is pushed out. The hollow shaft 39 and the large-diameter transmission gear 44 are connected via 48. In this state, the hollow shaft 39 and the medium-diameter transmission gear 45 are not connected.

In the clutch switching state shown in FIG. 4, the rotation of the crankshaft 4 generated by depressing the pedal 3 drives the driven body 25 via the large-diameter transmission gear 44.

The control unit 18 shown in FIG.
The amount of work of the crankshaft 4 is calculated based on the number of rotations and the torque acting on the hollow shaft 39, and the power control of the motor 14 is executed to adjust the magnitude of the assisting force by the motor 14. . Specifically, the rotational speed is detected from the number of teeth passing per unit time by a magnetic sensor (not shown) arranged close to the teeth of the wheel drive shaft 13, and the torque acting on the hollow shaft 39 is A ribbon of an amorphous magnetic alloy is attached to the peripheral surface of the hollow shaft 39, and the magnetic sensor 5
5 is arranged in close proximity to read the magnitude of the torque.

Further, the control unit 18 operates the switching motor 50 in accordance with the elapsed time from the start of traveling, the torque acting on the hollow shaft 39 and the rotation speed of the wheel drive shaft 13 to change the speed of the transmission mechanism 22. The rate switching control is being executed.

More specifically, the control unit 18 is configured to operate as shown in FIG.
The switching control of the gear ratio is executed based on the program table of (b). When the speed at the time of starting is zero, the transmission rate of the transmission mechanism is switched to a low-speed position where the gear ratio for driving the driven body 25 by connecting the large-diameter transmission gear 44 to the hollow shaft 39 as shown in FIG. Have been.

Immediately after the start, when the speed is low and the torque is large, the start can be started by depressing the pedal easily by maintaining the low-speed position indicated by P1 in the table of FIG.

When the speed is low and the torque is reduced to a medium level, the control unit 18 sets P2 in the table of FIG.
Switch to the middle speed position (gear ratio: medium) indicated by.
In this middle position, the clutch switching body 49 moves rightward from the state shown in FIG.
9a releases the pushing of the steel ball 48 set in the through hole 40a of the hollow shaft 39, and the protrusion 49a of the clutch switching body 49 pushes out the steel ball 48 set in the through hole 40b of the hollow shaft 39. Is carried out. As a result, the medium-diameter transmission gear 45 and the hollow shaft 39 are connected to the steel ball 4 as shown in FIG.
8, the rotation of the crankshaft 4 is controlled by the medium-diameter transmission gear 4
5, the driven body 25 is driven.

When the speed increases to a middle speed and the torque further decreases and decreases, the control unit 18 switches to the high-speed position (gear ratio: small) indicated by P3 in the table of FIG. In this high-speed position, the clutch switching body 49 moves further to the right as compared with the case where the clutch switching body 49 is in the middle-speed position, and moves to the position shown in FIG. As a result, the projection 49a of the clutch switching body 49
Does not push out the steel balls 48 set in any of the through holes 40 a and 40 b of the hollow shaft 39, and the rotation of the crankshaft 4 causes the one-way clutch 42 to rotate on the outer periphery of the support flange 41 of the hollow shaft 39. Small-diameter transmission teeth 4 mounted via
The driven body 25 is driven via the control unit 3. As described above, the high-speed position, the medium-speed position, and the low-speed position are automatically and appropriately switched to realize comfortable driving performance.

Further, in this embodiment, during continuous running, for example, when a predetermined time (about 30 minutes) has elapsed from the start, the control unit 18 operates the switching motor 50 according to the table in FIG. Then, the clutch portion of the transmission mechanism 22 is switched according to the amount of work acting on the crankshaft 4, and the high-speed position, the medium-speed position, and the low-speed position are automatically and appropriately switched, thereby reducing user fatigue. It is configured to reduce.

Thus, the crankshaft 4 and the wheel drive shaft 13
The transmission mechanism 22 is provided in between, so that the pedal depressing force can be reduced when climbing a slope, etc.
When the speed change mechanism 22 is interposed at this position, it is possible to realize a proper assist traveling in which the assisting force is turned off when the actual traveling speed reaches the above-mentioned specified speed.

The control unit 18 of the above embodiment switches the speed of the transmission mechanism 22 in accordance with the amount of work of the crankshaft 4 and the lapse of time from the start of running. Even in the case where the speed change rate of the speed change mechanism 22 is switched according to the amount of work or the lapse of time from the start of traveling, the effect is more effective than the conventional example.

The speed change mechanism of the above-described embodiment has been described in terms of three-stage switching in which the driven body 25 is driven via one of the large-diameter transmission gear 44, the medium-diameter transmission gear 45, and the small-diameter transmission gear 43. In the case of two-stage switching in which the driven body 25 is driven through one of the large-diameter transmission gear 44 and the small-diameter transmission tooth 43, or the driven body 25 is driven through one of the medium-diameter transmission gear 45 and the small-diameter transmission tooth 43. In the case of two-stage switching to drive,
The same applies to a case where the number of stages is changed to a higher number.

(Embodiment 2) FIG. 7 shows (Embodiment 2).
And FIG. 8 to FIG. 10 show the configuration of the drive assist device.

FIG. 7 will be described with reference to FIGS.
The assisting force of the rotation of the motor 14 is transmitted from the motor shaft 14a to the spur gear 56, and from the spur gear 56 to the spur gear 57, the hollow shaft 3
9 and a hollow shaft 39 via a one-way clutch 59.
Transmitted from the spur gear 57 to the spur gear 60 provided in
Stepped down.

The rotational force of the pedal 3 is applied to the hollow shaft 39 via the crankshaft 4, and the auxiliary force reduced by three steps is combined with the human power. Motor 1 due to battery discharge
When the wheel 4 does not rotate, the one-way clutch 59 idles and the spur gears 57 and 56 do not rotate, so that the user can pedal the pedal 3 with a small force when only human power is used.

At a low speed, the power is transmitted from the teeth 61 of the hollow shaft 39 to the rotating body 63 of the idle gear 62 via the one-way clutch 64. The teeth 65 of the rotating body 63 mesh with the teeth 68 of the transmitting body 67 to which the front gear 66 is fitted.

(Third Embodiment)
When the clutch switching body 49 is switched in the direction away from the front gear 66 as shown in FIG. 11, the steel ball 48 is pushed out from the through hole 40a of the hollow shaft 39, and the teeth 70 are A hollow shaft 39 on the inner periphery
The extruded steel ball 48 engages with the spherical recess of the transmission spur gear 71 idling around the outer periphery of the hollow shaft 39 and the transmission spur gear 7.
1 and 1 rotate together. Here, the diameter of the teeth 70 is larger than the diameter of the teeth 61 and the speed is increased. Note that the teeth 61 do not rotate even if they are engaged by the clutch 64.

In this (Embodiment 2), the motor shaft 14
a, a switching gear is provided in parallel with the crankshaft 4, and a resultant shaft for transmitting a rotational force to the front gear 66 is disposed. In Embodiment 1, the reduction mechanism is a planetary gear mechanism. However, when the reduction mechanism is a spur gear as in this (Embodiment 2), the structure is simple and it can be manufactured at low cost.

(Embodiment 3) FIG. 11 shows a power transmission diagram of the drive assist device of (Embodiment 3).
3 shows the configuration.

FIG. 11 will be described based on FIG. 12 and FIG. In this (Embodiment 3), the motor shaft and the crankshaft are orthogonal to each other, have a switching gear in parallel with the crankshaft, and have a resultant shaft for transmitting torque to the front gear.

The auxiliary force of the motor shaft 14a is
(Built-in one-way clutch), spur gear 73, spur gear 7
4. It is transmitted to the bevel tooth 75. It is transmitted from the bevel 75 to the bevel 76 of the hollow shaft 39.

The rotational force of the pedal 3 is transmitted from the crankshaft 4 to the hollow shaft 39 via the one-way clutch 77.
Accordingly, when the pedal 3 is stopped, the reverse rotation is light, and the pedal 3 is easily rotated to the depressed position.

The teeth 78 formed on the hollow shaft 39 are
9 meshed. After the combined force with the electric assist force, the driving force is transmitted to the front gear 66 via the transmission mechanism.

(Third Embodiment)
Is the same as The spur gear 79 transmits rotation through a one-way clutch 83 to a rotating body 82 rotatably supported by an idle shaft 80 fixed to the outer case 20 and a bearing 81. This rotation is transmitted to the teeth 68 of the transmission body 67 meshing with the gear 84.

When the hollow shaft 39 and the transmission spur gear 71 rotate integrally with each other by the engagement of the steel ball 48, the rotation is transmitted to the teeth 85 of the rotating body 82, and the spur gear 79 is rotated by the one-way clutch 83.
Spins.

(Embodiment 4) FIG. 14 shows a power transmission diagram of the drive assist device of (Embodiment 4).
6 shows the structure.

FIG. 14 will be described with reference to FIG. 15 and FIG. This (Embodiment 4) includes the crankshaft 4 and the front gear 66
Of the crankshaft 4, the resultant shaft 91, the motor shaft 14a, and the idle shaft 100 are respectively arranged in parallel. The rotational force of the motor is directly transmitted to the resultant shaft 91 without going through the transmission mechanism.

The auxiliary force is applied to the motor shaft 14a, the spur gear 92,
The power is transmitted to the spur gear 93, the spur gear 94, the one-way clutch 95, the resultant shaft 91, and the front gear 66. The resultant shaft 91 is arranged parallel to the crankshaft 4 and coaxially with the motor shaft 14a.

The rotational force of the pedal 3 is transmitted from the crankshaft 4 to the hollow shaft 39 via the one-way clutch 96.
One of the spur gears 98 and 99 rotates with the hollow shaft 39 by the steel ball 48 pushed up by the clutch switching body 49 whose position is controlled by using the human torque measured by the magnetostrictive sensor 97 as one control factor.

The idle shaft 100 has two sets of teeth 1 having different diameters.
01 and 102 mesh with the spur gear 99. Since the idle shaft 100 is fixed to the case 2 and meshes with the corresponding teeth of the internal tooth body 103, the internal tooth body rotates at an increased speed, and a one-way clutch 104 is mounted on the side with a lower rotation speed, and idles at the time of shifting to the speed increasing side. .

The teeth 105 on the outer periphery of the internal tooth body 103 are
Of the gear 1 through the one-way clutch 106
07. The torque detection / transmission mechanism is the same as in the first embodiment.

(Embodiment 5) FIG. 17 shows a power transmission diagram of the drive assist device of (Embodiment 5).
9 shows the structure.

FIG. 17 will be described with reference to FIG. 18 and FIG. The rotational force of the motor is directly transmitted to the resultant shaft 91 without going through the transmission mechanism, as in (Embodiment 4).

The auxiliary force is applied to the motor shaft 14a, the spur gear 116,
Spur gear 117, spur gear 118, one-way clutch 11
9, the resultant shaft 91, the teeth 121, the transmission body 67, and the front gear 66 are transmitted. The human power after the speed change is applied to the resultant shaft 91.

The torque of the pedal 3 is transmitted from the crankshaft 4 to the hollow shaft 39 via the one-way clutch 122. Using the human torque measured by the magnetostrictive sensor 97 as one control factor, the gear teeth 123 are rotated by the steel balls 48 pushed up by the clutch switching body 49 moved to the position.

The hollow shaft 39 rotated by the transmission teeth 123
As shown in FIG. 19, eight spherical recesses for accommodating the steel balls 48 and concave portions 47 serving as guide grooves are formed on the rotating surface of the transmission gears 123, 124, 124, and 91 at high speed.
The power is transmitted to the transmission body 67 and the front gear 66.

(Third Embodiment)
Is the same as The teeth 126 rotate integrally with the hollow shaft 39, and at low speed, the resultant shaft 91 through a one-way clutch 127.
To communicate.

(Embodiment 6) FIG. 20 is a power transmission diagram of the drive assist device of (Embodiment 6), and FIGS.
2 shows the configuration.

FIG. 20 will be described with reference to FIG. 21 and FIG. In this (Embodiment 6), a cylinder 136 is provided coaxially on the outer periphery of the crankshaft 4 and a magnetostrictive torque sensor is arranged. The cylinder 136 also serves as a transmission mechanism.

The rotational force of the motor is reduced by the motor shaft 14a to about 1/40 through a cyclo reducer (K-H-V type planetary gear unit, hypocycloid reducer) 137, and through a one-way clutch 138. Resultant shaft 139,
The power is transmitted to the front gear 66. A man-powered resultant portion is provided between the cyclo reduction device 137 of the resultant shaft 139 and the front gear 66.

The rotational force of the pedal 3 is applied to the crankshaft 4, one-way clutch 140, guide 141, interlock pin 142,
The power is transmitted to the resultant shaft 139 via the spur gear 143a, the spur gear 143b, and the one-way clutch 143c.

The guide 141 is movable along the crankshaft 4 in the direction of arrow A while transmitting torque.
The operating body 54 which is driven by the motor 50 and moves in the direction of the arrow A engages with the guide 141, and
Slide 1.

The three spur gears 143a, 144a, 145
“a” is rotatably mounted on the crankshaft 4 via a bearing 146, and an interlocking pin 142 fixed to the guide body 141 is inserted into the hole 147 of each spur gear to rotate integrally.

The transmission gears of the interlocking pin 142 are sequentially idled by the one-way clutches 143c and 144c in the order of low speed, medium speed and high speed. (Embodiment 7) FIG. 23 is a power transmission diagram of the drive assist device of (Embodiment 7).

In this (Embodiment 7), the front gear shaft, the transmission gear shaft, the motor reduction shaft, and the motor shaft are coaxially arranged, and these are arranged parallel to the crankshaft 4. The switching unit is disposed on the crankshaft and the transmission gear shaft.

The planetary gears are set in two stages by a motor reduction mechanism (flat gear reduction) and a torque detection mechanism (sun fixed planetary mechanism), and the transmission mechanism switches gears to change gears. The auxiliary force is the motor shaft 14a, the spur gear 155, the one-way clutch 15
6, transmitted to the spur gear 157, the external teeth 158, the internal teeth 159, and the front gear 66.

The torque of the pedal 3 is transmitted to the crankshaft 4, the one-way clutch 160, the planetary shaft 161, the planetary teeth 162 or 163, the internal gear 159, and the front gear 66.
The sun shaft 164 has an arm 165 and a potentiometer 16
6. The torque is measured by the reaction force fixed through the spring 167.

The low speed side of the planet is a one-way clutch 168,
The planetary rotation guide is provided by the teeth 163. The high-speed side is guided by a mechanical or electric transmission mechanism 169 and teeth 162.

[0090]

According to a first aspect of the present invention, there is provided a drive assist device for an electrically assisted bicycle that controls power of a motor in accordance with a work amount of a crankshaft driven by a pedal, and controls rotation of the motor via a speed reduction mechanism. An electric assist bicycle that transmits to a wheel drive shaft to assist the rotation of the crankshaft, and a transmission mechanism is provided between the crankshaft and the wheel drive shaft, so that the pedal depressing force is applied when climbing a hill. When the speed change mechanism is interposed at this position, it is possible to realize an appropriate assisted traveling in which the assisting force is turned off when the actual traveling speed reaches the specified speed.

[0091] Specifically, the control unit includes a transmission mechanism provided between the crankshaft and the wheel drive shaft as described in claim 2 or 3 or 4. It is configured to switch according to the amount, or to change the transmission mechanism provided between the crankshaft and the wheel drive shaft according to the passage of time from the start of traveling, or between the crankshaft and the wheel drive shaft. Since the provided speed change mechanism is configured to be switched in accordance with the work amount of the crankshaft and the lapse of time from the start of traveling, appropriate automatic switching can be realized, so that operability is also good.

According to a fifth aspect of the present invention, there is provided a drive assist device for an electric assisted bicycle according to the first aspect, wherein a reduction mechanism for transmitting rotation of a motor to a wheel drive shaft is disposed in parallel with the axis of the crankshaft. Since the transmission mechanism provided between the shaft and the wheel drive shaft is disposed on the same axis as the axis of the crankshaft, the size can be reduced.

[0093] Specifically, as set forth in claim 6 or 7, the above-mentioned transmission mechanism has a hollow shaft which is put on a crankshaft and rotates integrally with the crankshaft, and a hollow shaft provided outside the hollow shaft. A plurality of transmission teeth rotatably arranged in the longitudinal direction of the crankshaft with respect to the hollow shaft, and a clutch unit for selectively connecting the hollow shaft and the transmission teeth, or A hollow shaft which is put on the crankshaft and rotates integrally with the crankshaft, a speed change gear rotatable with respect to the hollow shaft outside the hollow shaft, and selectively connecting the hollow shaft and the speed change tooth And a clutch unit.

More specifically, the clutch portion according to claim 6 or 7 is disposed between a crankshaft and a hollow shaft covered on the crankshaft, and is slidable with respect to the crankshaft. A clutch switching body that pushes an engagement body from a through hole formed in the hollow shaft to a position where the engagement body engages with the inner peripheral surface of the transmission tooth; and a first end provided inside the crankshaft so as to be slidable in the axial direction of the crankshaft. Are interlocked with the interlocking shaft connected to the clutch switching body, and the interlocking shaft is placed on the outside of the hollow shaft so as to be slidable in the axial direction of the clutch through a hole formed in the hollow shaft and the clutch. A guide connected to the other end, and a shaft center of the crankshaft which is engaged with the guide so as to allow rotation of the guide rotating with the rotation of the crankshaft and the hollow shaft and switches the speed ratio. Slide in direction Composed of an actuating body which is moving.

According to a ninth aspect of the present invention, there is provided a drive assist device for an electrically assisted bicycle according to the eighth aspect, wherein the actuator for changing a position of an operating body with respect to a crankshaft and the actuator are driven according to a work amount of the crankshaft. It is characterized in that a control unit for switching the transmission rate of the transmission is provided.

According to a tenth aspect of the present invention, in the drive assist device for an electrically assisted bicycle, the actuator for changing the position of the operating body with respect to the crankshaft and the actuator are driven in accordance with the lapse of time from the start of traveling. A control unit for switching the speed change rate of the speed change mechanism is provided.

According to the eleventh aspect of the present invention, there is provided a drive assist device for an electrically assisted bicycle according to the eighth aspect, wherein the actuator for changing a position of an operating body with respect to a crankshaft is provided in accordance with a work amount of the crankshaft and a lapse of time from the start of running. And a control unit for driving the actuator to change the speed ratio of the transmission.

As described above, according to the present invention, comfortable assist traveling performance can be realized.

[Brief description of the drawings]

FIG. 1 is a power transmission diagram of a drive assist device according to an embodiment of the present invention and peripheral components thereof;

FIG. 2 is a sectional view of the drive assist device according to the embodiment;

FIG. 3 is an exploded perspective view of a transmission mechanism and a clutch according to the embodiment.

FIG. 4 is an overall sectional view of a transmission mechanism and a clutch according to the embodiment;

FIG. 5 is a sectional view of a medium-diameter transmission tooth and a clutch part according to the embodiment;

FIG. 6 is a table diagram of a control unit that switches the transmission mechanism of the embodiment.

FIG. 7 is a power transmission diagram of the drive assist device according to the second embodiment.

FIG. 8 is a cross-sectional plan view of the drive assist device according to the second embodiment.

FIG. 9 is a side sectional view of a main part of the drive assist device according to the second embodiment.

FIG. 10 is an exploded perspective view of a main part of the drive assist device according to the second embodiment.

FIG. 11 is a power transmission diagram of the drive assist device according to the third embodiment.

FIG. 12 is a cross-sectional plan view of the drive assist device according to the third embodiment.

FIG. 13 is a side sectional view of a main part of the drive assist device according to the third embodiment;

FIG. 14 is a power transmission diagram of the drive assist device according to the fourth embodiment.

FIG. 15 is a cross-sectional plan view of the drive assist device according to the fourth embodiment.

FIG. 16 is a side sectional view of a main part of the drive assist device according to the fourth embodiment.

FIG. 17 is a power transmission diagram of the drive assist device according to the fifth embodiment.

FIG. 18 is a cross-sectional plan view of the drive assist device according to the fifth embodiment.

FIG. 19 is a side sectional view of a main part of the drive assist device according to the fifth embodiment.

FIG. 20 is a power transmission diagram of the drive assist device according to the sixth embodiment.

FIG. 21 is a cross-sectional plan view of the drive assist device according to the sixth embodiment.

FIG. 22 is a side sectional view of a main part of the drive assist device according to the sixth embodiment;

FIG. 23 is a power transmission diagram of the drive assist device according to the seventh embodiment.

FIG. 24 is a front view of the electric assisted bicycle.

FIG. 25 is a diagram of a conventional drive assist device and a power transmission diagram around it.

FIG. 26 is a power transmission diagram of another conventional drive assist device and its periphery.

[Explanation of symbols]

Reference Signs List 1 bracket 2 drive assist device 3 pedal 4 crankshaft 4b internal passage of crankshaft 4 4c first elongated hole of crankshaft 4 4d second elongated hole of crankshaft 4 13 wheel drive shaft 13a through hole of wheel drive shaft 13 DESCRIPTION OF SYMBOLS 14 Motor 14a Output shaft of motor 14 18 Control part 20 Outer case 21 Reduction mechanism 22 Transmission mechanism 23 Shaft 24 Bearing 25 Follower 26, 27 Unidirectional clutch 28, 29 Gear 30, 30, ... Shaft 31 Gear 32 Bearing 33 tooth 34 bearing 35 tooth 36 gear 37 bearing 38 bearing 39 hollow shaft 39a long hole of hollow shaft 39 4a flange portion of crankshaft 4 large diameter portion 40a, 40b of hollow shaft 39 through hole 41 formed in hollow shaft 39 Support flange portion of hollow shaft 39 42 One-way clutch 43 Small diameter transmission gear 44 Transmission mechanism 2 The large-diameter transmission gear 44a that forms the large-diameter transmission gear 44 The large-diameter central portion 44b of the large-diameter transmission gear 44 The teeth 45 of the large-diameter transmission gear 44 The medium-diameter transmission gear that forms the transmission mechanism 22 46 The one-way clutch 47 The recess 48 The steel ball 49 The clutch switching Body 49a Protrusion 49b of clutch switching body 49b Hole of clutch switching body 49 50 Clutch switching motor 50a Feed screw 51 formed on output shaft of switching motor 50 Interlocking shaft 52a Connection pin 52b Connection pin 53 Guide 53b Guide 53 holes

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masato Yata 13-13, Katayama-cho, Kashiwara-shi, Osaka National Bicycle Industry Co., Ltd. (72) Inventor Yasuo Enomoto 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (11)

[Claims] An electric power control of a motor is performed in accordance with a work amount of a crankshaft driven by a pedal, and rotation of the motor is transmitted to a wheel drive shaft via a speed reduction mechanism to assist rotation of the crankshaft. A drive assist device for an electrically assisted bicycle, comprising a transmission mechanism between the crankshaft and the wheel drive shaft. 2. The drive assist device for an electrically assisted bicycle according to claim 1, further comprising a control unit that switches a transmission mechanism provided between the crankshaft and the wheel drive shaft in accordance with a work amount of the crankshaft. 3. The drive assist device for an electrically assisted bicycle according to claim 1, further comprising a control unit that switches a transmission mechanism provided between the crankshaft and the wheel drive shaft in accordance with a lapse of time from the start of traveling. 4. A drive assist device for an electric power-assisted bicycle according to claim 1, further comprising a control unit for switching a transmission mechanism provided between the crankshaft and the wheel drive shaft in accordance with a work amount of the crankshaft and a running start time. . 5. A speed reduction mechanism for transmitting rotation of a motor to a wheel drive shaft is provided in parallel with the axis of the crankshaft, and a speed change mechanism provided between the crankshaft and the wheel drive shaft is provided on the crankshaft. The drive assist device for an electric assist bicycle according to claim 1, wherein the drive assist device is disposed on the same axis as the axis of the bicycle. 6. A transmission mechanism for transmitting rotation of a crankshaft to a wheel drive shaft, a hollow shaft covered by the crankshaft and rotating integrally with the crankshaft, and a hollow shaft outside the hollow shaft with respect to the hollow shaft. 6. The electric assist bicycle according to claim 5, comprising: a plurality of rotatable gear teeth arranged in the longitudinal direction of the crankshaft; and a clutch unit for selectively connecting the hollow shaft and the gear teeth. Drive assist device. 7. A transmission mechanism for transmitting rotation of a crankshaft to a wheel drive shaft, a hollow shaft covered with the crankshaft and rotating integrally with the crankshaft, and a hollow shaft outside the hollow shaft with respect to the hollow shaft. The drive assist device for an electrically assisted bicycle according to claim 5, comprising: a rotatable transmission tooth; and a clutch unit that selectively connects the hollow shaft and the transmission tooth. 8. A clutch having a clutch portion disposed between a crankshaft and a hollow shaft covered by the crankshaft, and having a transmission gear slidable with respect to the crankshaft through a through hole formed in the hollow shaft. A clutch switching body that pushes an engagement body to a position where the engagement body engages with an inner peripheral surface of the clutch switching body; A guide body which is slidable in the axial direction of the clutch and is connected to the other end of the interlocking shaft via a hole formed in the hollow shaft and the clutch so as to be slidable in the axial direction of the clutch; An actuating body is engaged with the guide so as to allow rotation of the guide that rotates with the rotation of the shaft and the hollow shaft, and is slid in the axial direction of the crankshaft when the gear ratio is switched. Claim 6 or A drive assist device for an electric assist bicycle according to claim 7. 9. An actuator according to claim 8, further comprising an actuator for changing a position of an operating body with respect to a crankshaft, and a control unit for driving the actuator in accordance with a work amount of the crankshaft to switch a transmission gear ratio. Drive assist device for electric assist bicycle. 10. The apparatus according to claim 8, further comprising an actuator for changing the position of the operating body with respect to the crankshaft, and a control unit for driving the actuator in accordance with a lapse of time from the start of traveling to switch the speed change rate of the speed change mechanism. Drive assist device for electric assist bicycle. 11. An actuator for changing a position of an operating body with respect to a crankshaft, and a control unit for driving the actuator in accordance with a work amount of the crankshaft and a lapse of time from the start of traveling to switch a gear ratio of a transmission. The drive assist device for the electric assist bicycle according to claim 8, wherein the drive assist device is provided.