JP2001106163A - Power unit for motor assisted bicycle and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance assembling performance of a controller to improve productivity of a power unit with improving radiating performance of heat generating parts. SOLUTION: A heat sink 122 is mounted on a printed board 121. The controller 53 is constituted such as one assembly by fixing an FET 123 (a heat, generating part) on the heat sink 122. The controller 53 is fixed on a case 31 in a way that the heat sink 122 is closely contacted with an inner wall face of the case 31.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power unit for a power-assisted bicycle in which a wheel drive motor and a motor control controller having a printed circuit board on which heat-generating components are mounted are housed in a power unit case, and a method of manufacturing the same. It is.

[0002]

2. Description of the Related Art A conventional power unit for an electrically assisted bicycle of this type is disclosed, for example, in Japanese Patent Application Laid-Open No. H11-5584. The power unit for a power-assisted bicycle disclosed in this publication houses a controller for motor control at a position behind the motor in the power unit case and behind the vehicle. This controller is configured by mounting electronic components on a printed circuit board, and the printed circuit board is fixed to a power unit case by fixing screws. In addition, electronic components that generate heat among electronic components on a printed circuit board (hereinafter, simply referred to as heat-generating components)
The main body portion is contacted with the inner wall surface of the power unit case in a state where the leads are soldered to the printed circuit board, and is fixed with fixing screws. By fixing the heat generating component to the power unit case in this way, heat of the main body portion is transmitted to the power unit case by conduction, and the heat generating component is cooled.

[0003]

The conventional power unit constructed as described above has a problem that the operation of attaching the controller to the power unit case is complicated and the productivity is reduced. This is because the printed circuit board and the heat-generating component are respectively attached to the power unit case. That is, after the printed circuit board is attached to the power unit case, the heat-generating component must be attached to another place of the power unit case, which increases the number of assembly steps. In addition, since the heat-generating components are only supported on the printed circuit board by leads only before being attached to the power unit case, the controller can be transported,
When the operator grips the power unit case in order to assemble the power unit case, the lead must not be deformed due to an excessive load applied to the heat-generating component. The need to carefully transport and handle the controller as described above is one of the causes of a decrease in the productivity of the power unit. Furthermore, since the heat-generating component soldered to the printed circuit board is fixed to the power unit case at a place different from the printed circuit board with fixing screws, if there is an error in the mounting position of the heat-generating component, the heat-generating component is removed. When fixed to the power unit case, the lead is pulled or pressed and a load is applied to the soldered portion. If an excessive load is applied to the soldered portion, poor connection is likely to occur.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem. In addition to improving the heat radiation of heat-generating components, the assemblability of a controller is improved to improve the productivity of a power unit. An object of the present invention is to improve the reliability of a connection part of a heat generating component.

[0005]

In order to achieve this object, a power unit for a battery-assisted bicycle according to the present invention mounts a heat sink on a printed circuit board and fixes a heat-generating component to the heat sink to form a controller. The controller is fixed to a power unit case so that the heat sink is in close contact with the inner wall surface of the power unit case. According to the present invention, the heat of the heat generating component is transmitted to the power unit case via the heat sink, and is radiated from the power unit case to the atmosphere. Since the printed circuit board and the heat generating component are supported by the heat sink, the heat generating component can be fixed to the printed circuit board by assembling the controller.

According to a second aspect of the present invention, there is provided the power assisting bicycle power unit according to the first aspect, wherein the heat sinks are provided on both sides of one surface of the printed circuit board. Two opposing parallel side walls and a plurality of connecting walls connecting these side walls are integrally formed, and a heat-generating component is fixed to at least one of the side walls, and a printed circuit board is fixed between the side walls. The board-mounted component is disposed inside a range surrounded by the side walls, and at least one of the side walls is brought into contact with the power unit case and fixed to the power unit case. According to the present invention, since the electronic components on the printed circuit board are surrounded by the heat sink, the heat sink substantially functions as a protection member for protecting the electronic components.

A power unit for an electrically assisted bicycle according to a third aspect of the present invention is the power unit for an electrically assisted bicycle according to the second aspect, wherein the power unit case is formed with a recess for accommodating a controller. The case comprises a case body and a cover for closing the opening of the recess, and the heat sink is sandwiched between the case body and the cover with both side walls contacting the case body and the cover. According to the present invention, the heat of the heat generating component is dissipated from the side wall on which the heat generating component is fixed.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a power unit for an electrically assisted bicycle, comprising: a motor unit controller having a printed circuit board on which a heat-generating component is mounted; A manufacturing method, wherein the heat-generating component is fixed to a heat sink, the heat-sink is fixed to the printed circuit board, and then the heat-generating component is soldered to a printed circuit board, and then, the heat sink is fixed to a power unit case. carry out. According to the present invention, the lead of the heat generating member can be soldered to the printed circuit board without changing the position of the heat generating member relative to the printed circuit board, and no load is applied to the soldered portion after the soldering. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a power unit for an electric bicycle according to the present invention and a method of manufacturing the same.
This will be described in detail with reference to FIG. FIG. 1 is a side view of an electric bicycle equipped with a power unit according to the present invention, and FIG.
Is an enlarged side view of a power unit mounting portion, FIG. 3 is a side view of a power unit support portion in a vehicle body frame,
4 is a left side view of the power unit with the cover removed, FIG. 5 is a right side view thereof, FIG. 6 is a sectional view taken along line VI-VI in FIG.
FIG. 7 is a sectional view taken along line VII-VII in FIG. 8 is a left side view of the power unit housing, FIG. 9 is a right side view thereof, FIG. 10 is a cross-sectional view taken along line XX in FIG. 8, and FIG.
FIG. 12 is an enlarged plan view showing an electrode terminal mounting portion. 13 is a plan view of the controller, FIG. 14 is a side view thereof, FIG. 15 is a bottom view thereof, and FIG. 16 is a sectional view taken along line XVI-XVI in FIG. FIG.
18 is a bottom view of the heat sink, and FIG. 18 is XVII in FIG.
FIG. 8 is a sectional view taken along line I-XVIII.

FIGS. 19A and 19B are diagrams showing terminals. FIG. 19A is a plan view, FIG. 19B is a front view, and FIG. 19C is a side view. FIG. 20 is a side view of the battery support member, in which the connection between the load receiving member and the guide member is cut away. 21 is a plan view of a battery mounting portion, FIG. 22 is a bottom view of a power unit supporting bracket, FIG. 23 is a plan view of a load receiving member, and FIG. 24 is a cross-sectional view of a portion of the load receiving member into which terminals are inserted. 25 (a) is a rear view, FIG. 25 (b) is a sectional view taken along line BB in FIG. 25 (a), and FIG. 25 (c) is a sectional view taken along line C-B in FIG. It is C sectional drawing. FIG. 26 is a left side view of the battery,
27 is a rear view, FIG. 28 is a plan view, and FIG. 29 is a bottom view.

In these figures, the reference numeral 1 indicates an electric assist bicycle according to this embodiment. The electric assist bicycle 1 has a power unit 4 mounted on a hanger portion of a vehicle body frame 3 below a saddle 2 and driven by driving rear wheels 5 only by human power. And driving the rear wheel 5 with the resultant force. The body frame 3 includes a head pipe 7 that supports a front fork 6 so as to be steerable, a down tube 8 that extends rearward and downward from the head pipe 7, and a lower end of the down tube 8 as shown in FIGS. A seat tube 9 extending upward and having the saddle 2 attached to the upper end thereof, a seat stay 10 extending rearward and downward from the upper end of the seat tube 9, and a power unit support bracket 11 at a lower end of the seat tube 9. It is formed from a chain stay 12 and the like which are connected to each other. The seat stay 10 and the chain stay 12 are formed so as to form a pair in the left-right direction, and an end bracket (not shown) is provided at a rear end.
The rear wheel 5 is rotatably supported via the. In the middle of the seat stay 10, a wheel lock 10a (FIG. 1,
(See FIGS. 2 and 21).

The front fork 6 has a front wheel 13 rotatably mounted at a lower end thereof and a steering handle 14 mounted at an upper end thereof. The connection between the down tube 8 and the seat tube 9 is made via a lug 15. The lug 15 is formed so as to also serve as a bracket for supporting the front end of the power unit 4. As shown in FIG. 2, the saddle 2 provided at the upper end of the seat tube 9 raises the operation lever 2 a protruding from the lower rear portion upward, so that the rear portion of the saddle 2 moves upward about the front pivot 2 b. It has a structure that can be turned to move. By pulling up the rear portion of the saddle, the space between the seat tube 9 and the rear wheel 5 is opened upward. The battery 16 is provided in this space.

As shown in FIGS. 26 to 29, the battery 16 is a battery box 17 formed in a vertically long box shape.
A structure in which a large number of battery cells (not shown) are housed is adopted, and as shown in FIG. 2, the battery cells are detachably mounted on a battery support member 18 mounted on the upper surface of the power unit support bracket 11. The battery box 17
Has a handle 19, a charging terminal 20, and a battery fuel gauge 21 (see FIG. 28) attached to an upper end thereof, and a discharge terminal 22 attached to a lower end thereof. The battery cell is composed of a well-known Ni-MH cell or Ni-Cd.
Each unit is connected in series using a single cell.

As shown in FIG. 28, the handle 19 is formed in a U-shape in a plan view, and both ends are rotatably supported by the battery box 17 by support shafts 19a. With the handle 19 positioned at the storage position shown in FIG.
A connection port for the charging terminal 20 is formed at a position covered by the grip portion 19b of the battery 9. The fuel gauge 21 is
A plurality of indicator lamps 21a, a switch 21b
Is operated, the indicator lamps 21a are turned on by an amount corresponding to the remaining battery power when the is operated. The discharge terminal 22 has a female contact 22a (see FIGS. 2 and 29). This female contact 22a
A structure is adopted in which a male contact of a terminal on the power unit side described later is detachably fitted from below.

As shown in FIG. 20, the battery support member 18 is formed of a load receiving member 23 for supporting the battery 16 and a guide member 24 for holding a rear portion of the battery. The load receiving member 23 is formed of a synthetic resin, and as shown in FIGS. 23 and 24, a bottom plate 23a and side walls 23 at both ends in the left-right direction of the vehicle body.
b, 23c and the rear wall 23d of the rear end are integrally formed,
As shown in FIG. 21, the bottom plate 23a is
5 is fixed to the upper surface of the power unit supporting bracket 11. As shown in FIG. 23, an opening 23e for inserting the terminal 26 on the power unit 4 side is formed in the bottom plate 23a. As shown in FIG. 22, the power unit supporting bracket 11 is formed so that a portion corresponding to the terminal 26 is narrower than other portions.
The structure which avoids interference with the terminal 26 is adopted.

The side walls 23b, 23c and the rear wall 23d of the load receiving member 23 are formed so that the lower end of the battery box 17 can be fitted inside these walls. Further, a notch 23g is formed in the rear portion of the load receiving member 23 on the left side of the vehicle body, and as shown in FIG. 24, a key lock device 27 for locking the battery 16 with the battery 16 mounted thereon is looked up. I have. The key lock device 27
The power unit is fastened together with the load receiving member 23 on the upper surface of the unit supporting bracket 11. The guide member 2
As shown in FIG. 25, the upper part 4 is formed of a synthetic resin into a vertically long plate shape, and the locking piece 24 is attached to the lower end of the main body 24a.
b is formed integrally, and engaging pieces 24c are formed integrally with both ends and the upper end in the left-right direction of the main body 24a. The locking piece 24b has a structure in which it is engaged from above and fixed to an engagement hole 23f (see FIG. 23) formed in a rear wall 23d of the load receiving member 23. As shown in FIG. 2, the upper end of the guide member 24 is supported by the seat stay 10 via a guide member support bracket 28 and fastened together with the rear wheel fender. The guide member supporting bracket 28 has an upper end portion at the seat stay 10.
Welded.

As shown in FIG. 25 (a), the engaging piece 24c is formed in a downward U-shape as viewed from the rear, and is formed in a circular cross section so that the peripheral edge is thicker than other portions. A structure is adopted in which a guide groove 29 formed in the rear wall 17a of the battery box 17 as shown in FIGS. 27 and 29 is fitted. The guide groove 29 is provided on the rear wall 17a.
The opening is formed downward at the lower end of the rear wall 17a, and extends from the lower end of the rear wall 17a to the upper end of the rear wall along the rear wall 17a. That is, the guide member 2 is
By fitting the 4 engagement pieces 24c from below,
The rear part of the battery box 17 can be held by the guide member 24 in the left-right direction and the front-back direction.

The power unit 4 includes a power unit case (hereinafter simply referred to as a case) indicated by reference numeral 31 in FIGS. 4 to 12 and mounting bolts 32, 33 on the left side of the body of the case 31 as shown in FIG. Motor cover 34 and controller cover 35 detachably attached by
A gear cover 37 detachably attached to the right side of the vehicle body of the case 31 with the attachment bolts 36 as shown in FIG.
Is formed by assembling each member described later.

As shown in FIG. 2, the power unit 4 is fixed to the vehicle body frame 3 by fixing the front end of the case 31 to the lug 15 with fixing bolts 38.
The upper end and the rear end are fixed to the power unit support bracket 11 with fixing bolts 39 and 40. A bolt hole for inserting the fixing bolt 38 in the lug 15 is indicated by reference numeral 41 in FIG. 3, and a bolt hole for inserting the fixing bolts 39, 40 in the power unit supporting bracket 11 is indicated by reference numeral 42. In this embodiment, the power unit 4 is mounted on the vehicle body frame 3 as described above, and is covered with a synthetic resin outer cover 43 as shown in FIG. The outer cover 43 is a left half 43 that covers the left side of the vehicle body of the power unit 4.
a and a right half portion of the power unit 4 that covers the right side of the vehicle body, and is fixed to the vehicle body frame 3.

The case 31 and the covers 34, 35,
As shown in FIG. 6, the components to be assembled to the pedal 37 are a pedal crankshaft 51 that penetrates the case 31 in the left-right direction of the vehicle body.
A motor 52 disposed on the rear side of the vehicle body (lower side in FIG. 6) with respect to the pedal crankshaft 51;
A controller 53 disposed further in front of the vehicle body, a gear type power transmission device 54 disposed on the right side of the vehicle body of the case 31,
Sensor 55 for detecting the magnitude of human power (see FIG. 4)
And the terminal 26 (see FIGS. 4 and 5). The case 31 is formed by casting using an aluminum alloy as a material, and as shown in FIGS.
And a vertical wall 57 extending in the up-down direction and the front-rear direction inside the outer peripheral wall 56. The vertical wall 57
10, a cylindrical boss indicated by reference numeral 58 in FIGS. 10 and 11 and a partition wall having an arc shape in side view indicated by reference numeral 59 in FIG. 8 are integrally formed so as to protrude to the left side of the vehicle body. . In this embodiment, the partition wall 59 forms a part of the boss 58 and is formed so as to extend in the vertical direction behind the boss 58. The left end surfaces of the outer peripheral wall 56, the boss 58 and the partition wall 59 on the left side of the vehicle body are formed on the same plane as shown in FIGS.

The partition wall 59 and the rear end of the outer peripheral wall 56 form a circular motor storage chamber 60 as viewed from the left side of the vehicle body. The controller storage chamber is located forward of the vehicle body from the boss 58 and the partition wall 59. 61 are formed. That is, the boss 58 and the partition wall 59 are arranged such that the left side of the vehicle body in the case 31
And it is defined. The opening of the motor accommodation room 60 is closed by the motor cover 34, and the opening of the controller accommodation room 61 is closed by the controller cover 35. The motor cover 34 is formed in a disk shape as shown in FIG. 2, and is in contact with the partition wall 59 and the rear end of the outer peripheral wall 56 on the left side of the vehicle body via a seal member 62 (see FIG. 6). Let me. The controller cover 35 is formed in a shape substantially equal to the side surface shape of the controller accommodation chamber 61, and is in contact with the other end portions of the boss 58, the partition wall 59, and other portions of the outer peripheral wall 56 on the left side of the vehicle body via the seal member 62. Let me. The outer peripheral wall 56, the boss 58 and the partition wall 5
9 is formed on the same plane as described above, the motor cover 34 and the case 3 are formed by one seal member 62 in this embodiment.
1 and between the controller cover 35 and the case 31 are sealed. On the other hand, the vertical wall 5
7, on the right side of the vehicle body, as shown in FIG.
7, a gear housing chamber 63 is formed.

As shown in FIG. 6, the pedal crankshaft 51 is inserted through the boss 58 so as to penetrate the case 31 in the left-right direction of the vehicle body. In addition to being freely supported, the right end of the vehicle body is rotatably supported by the gear cover 37 via bearings 65 and 66 and a resultant shaft 67 described later.
A crank 69 having a pedal 68 (see FIG. 1) is fixed to both ends of the pedal crank shaft 51.

The resultant shaft 67 is connected to the pedal crankshaft 51.
A cylinder 71 interposed between the cylinder 71 and the gear cover 37, a disk 72 integrally formed so as to extend radially outward at a portion of the cylinder 71 inside the gear cover 37, and an outer peripheral portion of the disk 72. It comprises a ring gear 74 connected via a one-way clutch 73 and an annular stopper plate 75 fixed to the outer periphery of the disk 72. The one-way clutch 73 is moved from the ring gear 74 to the disc 72.
It has a structure to transmit power to. The stopper plate 75 is provided to prevent the ring gear 74 from coming off the disk 72. The cylinder 71 projects from the gear cover 37 to the right side of the vehicle body, and has a chain sprocket 76 for driving a rear wheel fixed to an end on the projecting side. A chain 77 is wound around the chain sprocket 76 and a freewheel (not shown) of the rear wheel 5. That is, when the resultant shaft 67 rotates, the rotation is transmitted to the rear wheel 5 via the chain 77, and the rear wheel 5 rotates.

The motor 52 is composed of an inner rotor type brushless DC motor. As shown in FIGS. 4 and 6, the motor 52 is placed in the motor housing chamber 60 of the case 31 in a state where the axial direction is parallel to the pedal crank shaft 51. I am wearing it.
More specifically, the motor 52 includes a stator 78 on the outer peripheral portion.
Is fitted and fixed to the partition wall 59 and the inner peripheral surface of the rear part of the outer peripheral wall of the case 31, and the end of the rotating shaft 79 a of the rotor 79 on the right side of the vehicle body is rotated on the vertical wall 57 of the case 31 via the bearing 80. The rotating shaft 79a is freely supported.
The left end of the vehicle body to the inner boss 34a of the motor cover 34.
Are rotatably supported via bearings 81. The coil 78a of the stator 78 is connected to the controller 53 via a power supply cable 82, as shown in FIG.
The power supply cable 82 passes through the rubber cable holder 83 fitted to the lower part of the partition wall 59 and is led out of the motor storage chamber 60 to the controller storage chamber 61. The cable holder 83 has a notch 84 formed in the partition wall 59 so as to open toward the left side of the vehicle body.
(See FIG. 8) from the left side of the vehicle body.

As shown in FIG. 4, a portion of the power supply cable 83 located in the controller housing 61 is wound at the lowermost portion of the controller housing 61 and fixed to the case 31 by a cable holding member 85. At the vertical wall 57 side. In this embodiment,
A connector 86 is interposed in the middle of the power supply cable 82 so that the power supply cable 82 can be divided into the motor 52 side and the controller 53 side. The right end of the rotating shaft 79a of the rotor 79 on the vehicle body penetrates the vertical wall 57 to face the gear housing chamber 63, and has a protruding end formed with a tooth 87 with which the ring gear 74 meshes. .
That is, the rotation of the rotor 79 is transmitted from the rotation shaft 79 a to the disk 72 of the resultant shaft 67 via the ring gear 74 and the one-way clutch 73.

As shown in FIGS. 5 and 6, the gear-type power transmission device 54 includes a planetary gear-type gearbox 91 provided coaxially with the pedal crankshaft 51, a ring gear 74 of a resultant shaft 67, and a motor 52. , And the like. The planetary gear type speed increaser 91 includes a carrier 93 that rotatably (rotates) the planetary gear 92.
Is connected to the pedal crankshaft 51 via a one-way clutch 94. The one-way clutch 94 has a structure for transmitting power from the pedal crankshaft 51 to the carrier 93. The sun gear 95 of the planetary gearbox 91
Is formed by forming teeth at the left end portion of the cylinder 71 of the resultant shaft 67 on the vehicle body. As shown in FIG. 5, the outer peripheral gear 96 includes a first lever 97 projecting downward from a lower portion on the front side of the vehicle body in an outer peripheral portion, and a second lever 98 projecting rearward and upward from a rear upper portion on the outer peripheral portion. Are integrally formed, and the outer peripheral portion is fitted to an annular recessed portion 99 formed in the vertical wall 57 of the case 31 so as to open toward the right side of the vehicle body, and is rotatably supported. Further, in FIG. 6, reference numeral 1 provided near the outer gear 96 on the right side of the vehicle body.
The reference numeral 00 indicates that the outer peripheral gear 96 has the annular recess 99.
It is a ring-shaped stopper for preventing it from coming off. The stopper 100 has a structure in which the outer peripheral portion of the outer peripheral gear 96 is fitted, and is fixed to the vertical wall 57 of the case 31 from the right side of the vehicle body. The stopper 100 and its fixed portion 100a are shown by two-dot chain lines in FIG.

The first lever 97 of the outer peripheral gear 96 is
As shown in FIG. 5, the second lever 98 is connected to a case 31 via a torque reaction force receiving device 101 disposed below a planetary gear type speed increaser 91, and the second lever 98 is brought into contact with a torsion spring 102. I have. The torque reaction force receiving device 10
1 receives a reaction force acting on the outer peripheral gear 96 when the pedal crankshaft 51 rotates in the forward direction (clockwise direction in FIG. 5) (a force for rotating the outer peripheral gear 96 in the same direction as the pedal crankshaft 51). As shown in FIGS. 5 and 7, a first spring receiving member 103 connected to the first lever 97, a second spring receiving member 104 supported by the case 31, and both springs are provided. Receiving member 103, 1
04 and a compression coil spring 105 elastically mounted. As shown in FIGS. 9 and 11, the torque reaction force receiving device 101 is housed in a concave portion 106 formed in the case 31 so as to open to the right side of the vehicle body. The first spring receiving member 103 is formed of a synthetic resin,
Guide plates 103a and 103b sandwiching the distal end of the first lever 97 from the right and left sides of the vehicle body, a cylinder 103c into which one end of the compression coil spring 105 is fitted, and an arc-shaped pressing piece 97a of the first lever 97. The pressure receiving plate 103d that makes sliding contact is formed integrally.

The second spring receiving member 104 is also made of synthetic resin, and is fitted to the cylinder 104a to which the other end of the compression coil spring 105 is fitted, the pressure receiving plate 104b which receives a load from the compression coil spring 105, and the case 31. Axis 104c
And are integrally formed. The pivot 104c is formed in a cylindrical shape on the rear side of the vehicle body (the left side in FIG. 5).
Is slidably fitted in a concave portion 107 having a semicircular cross section. By fitting the pivot 104c into the concave portion 107 of the case 31 in this manner, even if the position of the first lever 97 changes in the circumferential direction due to the rotation of the outer peripheral gear 96, the torque reaction force receiving device 101 can be used. The compression coil spring 105 can swing up and down around the pivot 104c so that it can easily expand and contract.

The torque reaction force receiving device 1 thus formed
In 01, the reaction force when the pedal crankshaft 51 rotates in the forward direction is transmitted from the first lever 97 to the first spring receiving member 103, and the compression coil spring 105 is deformed by an amount corresponding to the magnitude of the human power. Is compressed. Also,
The compression coil spring 105 expands to an initial size when the human force applied to the pedal crankshaft 51 disappears. Therefore, the outer peripheral gear 96 rotates clockwise in FIG. 5 by an angle corresponding to the magnitude of human power during traveling. In this embodiment, the first lever 9
The first and second spring receiving members 10 are so arranged that the contact between the first spring receiving member 103 and the first spring receiving member 103 and the contact between the second spring receiving member 104 and the case 31 can smoothly slide.
3, 104 are each formed of a synthetic resin material having self-lubricating properties, for example, polyacetal. Further, the pivot 104c of the second spring receiving member 104 is the same as that shown in FIG.
As shown in (1), when assembled into the case 31, the end surface on the right side of the vehicle body (the lower side in the figure) is formed so as to be located on the same plane as the mating surface of the case 31 and the gear cover 37. The gear cover 37 is formed so that a mating surface with the case 31 extends to a portion facing the pivot 104c. That is, the gear cover 37 prevents the second spring receiving member 104 from coming off the case 31.

The torsion spring 102 with which the second lever 98 of the outer gear 96 comes into contact is used to move the outer gear 96 clockwise in FIG. 5 so that the first lever 97 is not separated from the torque reaction force receiving device 101. It is for biasing in the direction. This torsion spring 10
2 is rotatably supported by a pin 108 erected on the vertical wall 57 of the case 31, one end of which is in contact with the second lever 98, and the other end of which is locked to the case 31. In the vicinity of the second lever 98 in the outer peripheral gear 96, a pin 109 for driving the sensor 55 is provided upright. The pin 109 is provided on the outer peripheral portion of the outer peripheral gear 96 so as to protrude toward the right side of the vehicle body, and makes the lever 110 of the sensor 55 abut. The sensor 55 is composed of a potentiometer, and the main body 55a is fitted into a circular hole 111 formed in the vertical wall 57 of the case 31 as shown in FIG. On the left side,
It is fixed between the boss 58 and the partition wall 59 and a controller 53 described later by a fixing bolt 112.

The lever 110 is bonded in advance to the tip of the input shaft 55b (see FIG. 5) of the sensor 55. That is, a structure is adopted in which the output of the sensor 55 increases or decreases as the outer peripheral gear 96 rotates and the pin 109 rotates the lever 110. In this embodiment, since the outer peripheral gear 96 rotates clockwise in FIG. 5 at an angle corresponding to the magnitude of human power, the lever 1
Reference numeral 10 rotates counterclockwise in FIG. 5 by an angle corresponding to the magnitude of human power. The position at the time when the lever 110 is rotated most counterclockwise is shown by a two-dot chain line in FIG. The rotation of the lever 110 to the position shown by the two-dot chain line is caused by the fact that the outer peripheral gear 96 rotates clockwise until the first spring receiving member 103 of the torque reaction force receiving device 101 comes into contact with the second spring receiving member 104. Is turned.

A controller 53, which will be described later, increases or decreases the output of the motor 52 so as to correspond to the increase or decrease of the output of the sensor 55. The controller 53 is shown in FIGS.
As shown in FIG. 18, the electronic component is mounted on the printed circuit board 121 and the heat sink 122 is attached to the printed circuit board 121. The main surface of the printed circuit board 121 is located at the front end of the controller housing 61 in the case 31 in the vehicle body. The heat sink 122 is fixed to the vertical wall 57 of the case 31 via the heat sink 122.

The printed circuit board 121 is mounted with six motor control FETs 123 arranged vertically, three on each end of the printed circuit board 121, and an electrolytic capacitor 124 and other components on the surface opposite to the FET 123. Electronic components and various cables are connected. FET
As shown in FIG. 14, each of the leads 123 has three leads 123a. The ends of these leads 123a are connected to through holes 121a of the printed circuit board 121 (see FIG. 16).
And soldered from the back side of the substrate. This F
ET123 constitutes the heat generating component according to the present invention. The printed circuit board 121 has a CPU 53 a on the mounting surface on which the FET 123 is mounted, outside the heat sink 122.
(See FIG. 13), and other electronic components (not shown) are mounted inside the heat sink 122. On both the front and back sides of the printed circuit board 121, in order to improve moisture resistance,
Silicon gel is applied after all the electronic components are mounted.

The heat sink 122 is formed by a die casting method using an aluminum alloy as a material, and is formed on both sides of the surface of the printed circuit board 121 on which the FET 123 is mounted (in FIG. 4, the left end of the vehicle body and the right end of the vehicle body). Two opposing parallel side walls 125, 125
And first to third connecting walls 126 to 128 for connecting the side walls 125 to each other are integrally formed (FIG. 1).
7, 18). The inner wall surface of the side wall 125 (the other side wall 12
5) on the heat-radiating portion 123b of the FET 123.
(See FIG. 16) is fixed by mounting screws 129. The mounting screw 129 passes through the heat radiating portion 123b and is screwed to the heat sink plate 129a. The heat sink plate 129a has three FETs 1
23 are formed in a narrow band shape. Further, as shown in FIG.
The outer peripheral wall 56 of the case 31 is
Is formed so as to be substantially along the inner peripheral surface of the vehicle body, in other words, to form an arc shape in which the side surface shape is convex toward the front of the vehicle body. The second connecting wall 127 is provided at a portion of the side wall 125 located closest to the front of the vehicle body, and the first connecting wall 127 is provided at both ends in the vertical direction.
And third connecting walls 126 and 128.

By providing the connecting walls 126 to 128 in this way, as shown in FIG.
6 and the second connecting wall 127 and the second connecting wall 127
A rectangular opening facing the printed circuit board 121 is formed between the third connection wall 128 and the third connection wall 128. Third connecting wall 1
As shown in FIGS. 17 and 18, the recess 28 is formed with a recessed portion 128 a that opens toward the printed circuit board 121 to reduce the weight. On the side wall 125, four columnar legs 125a protruding toward the printed circuit board 121 are integrally formed. The heat sink 122 is fixed to the printed circuit board 121 by the four mounting bolts 130 penetrating the leg 125 a and the side wall 125. By fixing the heat sink 122 to the printed circuit board 121 via the legs 125a in this manner, a space is provided between the side wall 125 and the printed circuit board 121. Although not shown, electronic components are also mounted in this space.
A space is provided between the first connection wall 126 and the printed circuit board 121 in the same manner as described above, and electronic components are mounted in this space.

The controller 53 is fixed to the case 31 by fixing bolts 131 penetrating through the side wall 125 near the lower first connecting wall 126 among the first and third connecting walls 126 and 128. The fixing bolt 132 penetrating the third connecting wall 128 is screwed into the screw hole 133 of the vertical wall 57.
(See FIG. 8) by screwing from the left side of the vehicle body. By fixing the controller 53 to the case 31, the side wall 125 of the heat sink 122 on the right side of the vehicle body comes into close contact with the vertical wall 57 as shown in FIG.
The heat of T123 can be dissipated to the case 31 by conduction. As shown in FIG. 4, the wiring connected to the printed circuit board 121 includes, in addition to a power supply cable 82 for supplying power to the motor 52, four cables 134 to 137 connected to the battery 16 and the sensor 55. 138, a cable connected to the switch box 139 (see FIG. 1) of the steering handle 14, and a cable connected to the headlamp 140 (see FIG. 1). Of these cables, the cables 134 to 137 connected to the battery 16 have the ends connected to the terminals 26. In this embodiment, the four cables 1
34 to 137, two relatively thick cables 13
The connector 141 is interposed in the middle of 5,136 (power cable). It should be noted that a connector can be interposed in the other two cables 134 and 137 (signal cables) which are relatively thin.

As shown in FIG. 19, the terminals 26 are connected to the ends of the cables 134 to 137, respectively.
It is formed of a male contact 142, a synthetic resin mold case 143 for holding the male contact 142, and a flange 144 for attaching to the case 31. The molded case 143 has a structure in which the male contact 142 and the distal ends of the cables 134 to 137 are integrally held by insert molding, and a flange 144 is integrally formed. Mold case 1
The material forming the 43 and the flange 144 employs synthetic rubber having insulating properties and elasticity. The flange 144 is formed in a series so that the groove 144a is not interrupted in the entire area of the side edge. Case 3 of terminal 26
12, the notch 145 is formed on the outer peripheral wall 56 of the case 31 so as to open toward the left side of the vehicle body. The notch 145 is fitted with the flange 144, and the controller cover 35 is fixed. It is performed by attaching to the case 31. When fitting the flange 144 into the notch 145, the edge of the notch 145 is fitted into the concave groove 144a.

The cable connected to the switch box 139 and the headlamp 140 is made of rubber which is routed inside the controller accommodating chamber 61 to the rear of the vehicle body and attached to the lower rear part of the case 31 as shown in FIG. Through the cable holder 146. The mounting structure of the cable holder 146 has the same structure as the mounting structure of the terminal 26. The cable led out of the cable holder 146 is denoted by reference numeral 14 in FIG.
Indicated by 7. A cable connected to the switch box 139 supplies power to a main switch (not shown) provided in the switch box 139 to detect opening / closing of a main switch (not shown) and to a battery remaining amount indicator lamp (not shown) provided in the switch box 139. Used to The cable connected to the headlamp 140 is used to turn on the headlamp 140 by the power of the battery 16.

Next, a procedure for assembling the power unit 4 configured as described above will be described. Power unit 4
Is assembled by assembling each member to the case 31 from both sides in the left-right direction of the vehicle body. The members to be assembled from the left side of the vehicle body are a motor 52, a controller 53, a sensor 5
5, the terminal 26, the motor cover 34, the controller cover 35, and the like. The members to be assembled from the right side of the vehicle body include the pedal crankshaft 51, the resultant shaft 67, the planetary gear type gearbox 9
1, a torque reaction force receiving device 101, a gear cover 37, and the like. To assemble the members from the left side of the vehicle body, first, the stator 78 of the motor 52 is attached to the case 31,
The rotor 79 is attached to the case 31. Then, the motor cover 34 is attached to the case 31 via the seal member 62. Further, as described later, a controller 5 pre-assembled is used.
3 is attached to the case 31, and the sensor 55 and the terminal 26 are attached to the case 31. At this time, the motor 5
Cable 82 for connecting the power supply 2 and the controller 53
Is wound in the controller accommodation chamber 61. By winding and arranging the relatively thick power supply cable 82 in this manner, the position of the controller 53 is not restricted by the power supply cable 82, so that the controller 53 can be easily assembled. After that, the controller cover 35 is attached to the case 31 via the seal member 62.

On the other hand, when assembling the members from the right side of the vehicle body, first, an assembly in which the carrier 93 and the planetary gear 92 of the planetary gear type speed increaser 91 are previously mounted on the pedal crankshaft 51 is mounted on the case 31. Then, the outer peripheral gear 96 of the planetary gear type speed increaser 91 is assembled together with the stopper 100. When the outer peripheral gear 96 is mounted, the lever 110 adhered to the input shaft 55 b of the sensor 55 is engaged with the pin 109, and the torque reaction force receiving device 101 and the torsion spring 10 are engaged.
Install 2. After that, the stopper 100 is fixed.
Thereafter, the resultant shaft 67 is assembled to the right end of the pedal crankshaft 51 on the vehicle body. Before the resultant force shaft 67 is mounted on the pedal crankshaft 51, a ring gear 74 is mounted on the disc 72 via a one-way clutch 73 before the ring gear 74 is mounted on the pedal crankshaft 51. To the rotating shaft 79a. Then, the gear cover 37 is attached to the case 31 via the seal member 151, and the rear wheel drive chain sprocket 76 is attached to the resultant shaft 67.
Attach to

In assembling the controller 53, first, six FETs 123 are fixed to the heat sink 122 by screws 129 and a heat sink plate 129a. Then, four printed circuit boards 121 are attached to the heat sink 122.
It is fixed with a bolt 130. Printed circuit board 12
1 is FET1 prior to mounting the heat sink 122.
All electronic components other than 23 are mounted on both front and back surfaces in advance. When attaching the heat sink 122 to the printed circuit board 121, the tips of the leads 123 a of the FET 123 are inserted into the through holes 121 a of the printed circuit board 121. After fixing the heat sink 122 to the printed circuit board 121, this assembly is loaded into a soldering device (not shown). This soldering apparatus has a structure in which the printed board 121 is held so that the back surface (the surface from which the leads 123a protrude) faces downward, and a solder tank in which molten solder is stored is brought into contact with and separated from the back surface from below. I am taking it. According to this soldering device, the lead 123a is soldered to the through hole 121a by the solder bath coming into contact with the back surface of the printed circuit board 121 from below. Solder tank has 3 F
Only a total of nine leads 123a of the ET123 are formed so that they can be soldered at one time.

After the soldering of the FET 123 is completed, the cables 134 to 138 and the power supply cable 82 are soldered to the printed circuit board 121, and silicon gel is applied to both sides of the printed circuit board 121. Printed circuit board 121
When the silicone gel is applied to the mounting surface on the heat sink side of the heat sink 122, the three connecting walls 126 to 1 of the heat sink 122 are applied.
28, the side walls 125 and the first connecting wall 126 of the heat sink 122 and the printed circuit board 1
The injection is performed by inserting an injection nozzle into a space provided between the injection nozzle and the injection nozzle. When the silicon gel hardens, the assembly process of the controller 53 ends. Controller 53
After the assembly as described above, the heat sink 122
The one side wall 122 is fixed to the case 31 by closely adhering to the vertical wall 57 of the case 31.

Accordingly, in the power unit 4 for an electrically assisted bicycle configured as described above, the heat sink 122 is mounted on the printed circuit board 121, and the controller 53 is fixed to the heat sink 122 by heating the FET 123 as a heat-generating component. Since the controller 53 is fixed to the case 31 so that the heat sink 122 is in close contact with the inner wall surface of the case 31, the heat of the FET 123 is
The light is transmitted to the case 31 through the case 22 and is emitted from the case 31 to the atmosphere. Printed circuit board 121 and FET12
Since 3 is supported by the heat sink 122, the FET 123 can be fixed to the printed circuit board 121 by assembling the controller 53. Therefore, when the operator holds the controller 53 to transport the controller 53 or assemble the controller 53 to the case 31, the FET 123 is used.
No excessive load is applied to the vehicle.

Also, both side walls 125 of the heat sink 122
In addition to fixing the FET 123, a plurality of legs 125a for mounting the printed board are protruded, and the printed circuit board 121 is fixed via the legs 125a. Side walls 12
Since the electronic components are arranged in the space between the printed circuit board 5 and the printed circuit board 121 and one of the side walls 125 is in contact with and fixed to the case 31, the electronic components on the printed circuit board 121 are surrounded by the heat sink 122. become. For this reason,
The heat sink 122 substantially functions as a protection member for protecting the electronic component. Further, despite the structure in which the component mounting surface of the printed circuit board 121 is surrounded by the heat sink 122, the connection wall 126 of the heat sink 122 is formed.
The moisture-proof silicon gel can be easily applied to the printed circuit board 121 by inserting an injection nozzle into the space between .about.128 and the space between the heat sink 122 and the printed circuit board 125.

Further, the controller 53 controls the FET 12
3 is fixed to the heat sink 122, and the heat sink 1
After fixing the FET 1 to the printed circuit board 121,
23 is soldered to the printed circuit board 121, and then the heat sink 122 is fixed to the case 31.
In the state where the position of 123 does not change,
Can be soldered to the printed circuit board 121. Therefore, no load is applied to the soldered portion after the soldering.

In this embodiment, the heat sink 122
Has a structure in which only the side wall 125 on the right side of the vehicle body is brought into close contact with the case 31. The heat sink 122 may be held at 35. By adopting this structure, the heat of the FET 123 is dissipated from the two side walls 125 to which the FET 123 is fixed.
The heat radiation can be further improved.

Power unit 4 shown in this embodiment
A motor 52 is disposed rearward of the vehicle body from the pedal crankshaft 51 with the axial direction parallel to the pedal crankshaft 51, and a controller 53 is disposed in front of the motor 52.
The motor 52 and the controller 53 are assembled to the case 31 from the left side of the vehicle body. A gear-type power transmission device 54 that transmits the rotation of the motor 52 and the pedal crankshaft 51 to the resultant shaft 67 is attached to the case 31 from the right side of the vehicle body. Since the mounting structure is adopted, the motor 52, the controller 53, and the gear type power transmission device 54 can be mounted in a direction parallel to the axial direction of the pedal crankshaft 51. Moreover, the processing of the member mounting portion of the case 31 can be performed from a direction parallel to the axial direction of the pedal crankshaft 51.

Further, since the motor 52 and the controller 53, which are the heat generating members, can be arranged separately from the front end and the rear end of the case 31, the heat transfer path between them can be lengthened. Further, the motor housing chamber 60 and the controller housing chamber 61 of the case 31 are defined by the boss 58 for supporting the pedal crankshaft and the partition wall 59 formed integrally with the boss 58, 5
The boss 58 and the partition wall 59 are located in the middle of a heat transfer path between the controller 2 and the controller 53, and the heat transmitted from the motor 52 toward the controller 53 and the heat transmitted from the controller 53 toward the motor 52. Heat can be blocked by the boss 58 and the partition wall 59. At the same time, the boss 58 and the partition wall 59 substantially function as a heat receiving member, and can transfer the heat to the case 31.

Further, the controller 53 has a structure in which electronic components are mounted on a printed circuit board 121, and the printed circuit board 121 is mainly attached to an end (front end) of the controller housing chamber 61 opposite to the pedal crankshaft 51. The printed circuit board 121 is disposed between the boss 58 and the partition wall 59 so that the surface faces in the front-back direction of the vehicle body.
Since the sensor 55, the electrolytic capacitor 124, and the cable are provided, the controller 53 can be provided near the outer peripheral wall 56 of the case 31 so that the occupied space is as small as possible. A large space for heat insulation can be formed between the partition wall 59 and the partition wall 59. Further, the sensor 55, the electrolytic capacitor 124, and the wiring can be accommodated by utilizing the space for heat insulation.

In addition, since the sensor 55 is assembled to the case 31 in a direction parallel to the axial direction of the pedal crankshaft 51, all the electric components housed in the case 31 are removed from the axial direction of the pedal crankshaft 51. Can be assembled in a direction parallel to Further, since the motor 52 is of an inner rotor type and the stator 78 is fixed to the outer peripheral wall 56 and the partition wall 59 forming the motor accommodation chamber 60 in the case 31, the heat of the stator 78 is radiated to the case 31 by conduction. be able to. Further, a resultant shaft 67 is rotatably supported coaxially on the pedal crankshaft 51,
The pedal crankshaft 51 is connected to the resultant shaft 67 via a planetary gearbox 91 provided coaxially with the pedal crankshaft 51. The planetary gearbox 91 includes a sun gear 95 provided on the resultant shaft 67, The outer peripheral gear 96 is connected to the case 31 via the torque reaction force receiving device 101 and the sensor 55, and the torque reaction force receiving device 101 is connected to the compression coil spring 105.
And the first and second spring receiving members 103 and 104 and assembled to the case 31 in a direction parallel to the axial direction of the pedal crankshaft 51, so that it is provided to detect the magnitude of human power. The torque reaction force receiving device 101 can also be assembled from the same direction as the pedal crankshaft 51 and the gear group. Furthermore, since the mating surfaces of the case 31, the motor cover 34, and the controller cover 35 are formed on the same plane, the space between the case 31 and the motor cover 34, the case 31, and the controller cover 35
Can be sealed with one seal member 62.

Although the mating surfaces of the two covers 34 and 35 are located on the same plane,
The reason why the motor 35 is not integrally formed is that the motor cover 34 that supports the left end of the rotor 79 on the vehicle body can be easily manufactured. That is, when the motor cover 34 is formed with the inner boss 34a for mounting the bearing 81 that supports the left end of the rotor 79 on the vehicle body, the motor cover 34 is rotated with a lathe or the like to rotate the inner boss 34a.
a can be easily formed by cutting. In this embodiment, the terminal 26 to which the battery 16 is detachably connected is provided integrally with the case 31, so that the terminal between the power unit 4 and the terminal is smaller than the structure in which the terminal is provided on the vehicle body frame 3 side. Therefore, a connector is not required, and the number of components can be reduced. In the above-described embodiment, an example is shown in which the planetary gear type gearbox 91 is used to increase the speed of rotation of the pedal crankshaft 51 and transmit the rotation to the resultant shaft 67, but instead of the planetary gearbox 91. A planetary roller type gearbox can also be used.

[0052]

As described above, according to the present invention, the heat of the heat generating component is transmitted to the power unit case via the heat sink, and is radiated from the power unit case to the atmosphere. For this reason, it is possible to improve the heat radiation of the heat-generating component while adopting a structure in which the controller is housed in the power unit case. Further, since the printed circuit board and the heat-generating component are supported by the heat sink, the heat-generating component can be fixed to the printed circuit board by assembling the controller. For this reason, the controller can be transported,
Since an excessive load is not applied to the heat-generating component when the operator grips the power unit case in order to assemble the power unit case, workability is improved in all operations for handling the controller. Therefore, it is possible to improve the assemblability of the controller and improve the productivity of the power unit while improving the heat radiation of the heat-generating components.

According to the second aspect of the present invention, since the heat sink functions substantially as a protection member for protecting the electronic components on the printed circuit board, the heat sink can be used when transporting the controller or assembling it to the power unit case. It is possible to prevent an excessive load from being applied not only to the heat-generating component but also to other electronic components.

According to the third aspect of the present invention, since the heat of the heat-generating component is dissipated from the two side walls to which the heat-generating component is fixed, the heat radiation of the heat-generating component can be further improved. According to the fourth aspect of the invention, the lead of the heat generating member can be soldered to the printed circuit board without changing the position of the heat generating member with respect to the printed circuit board, and a load is applied to the soldered portion after the soldering. Therefore, the reliability of the connection of the soldered portion of the heat-generating component can be improved.

[Brief description of the drawings]

FIG. 1 is a side view of an electric assist bicycle equipped with a power unit according to the present invention.

FIG. 2 is an enlarged side view showing a power unit mounting portion.

FIG. 3 is a side view of a power unit supporting portion of the vehicle body frame.

FIG. 4 is a left side view of the power unit with a cover removed.

FIG. 5 is a right side view of the power unit with a cover removed.

6 is a sectional view taken along line VI-VI in FIG.

FIG. 7 is a sectional view taken along line VII-VII in FIG.

FIG. 8 is a left side view of the power unit case.

FIG. 9 is a right side view of the power unit case.

FIG. 10 is a sectional view taken along line XX in FIG.

FIG. 11 is a sectional view taken along line XI-XI in FIG. 9;

FIG. 12 is an enlarged plan view showing a terminal mounting portion.

FIG. 13 is a plan view of the controller.

FIG. 14 is a side view of the controller.

FIG. 15 is a bottom view of the controller.

16 is a sectional view taken along line XVI-XVI in FIG.

FIG. 17 is a bottom view of the heat sink.

18 is a sectional view taken along line XVIII-XVIII in FIG.

FIG. 19 is a diagram showing terminals.

FIG. 20 is a side view of the battery support member.

FIG. 21 is a plan view of a battery mounting portion.

FIG. 22 is a bottom view of the power unit supporting bracket.

FIG. 23 is a plan view of a load receiving member.

FIG. 24 is a cross-sectional view of a portion of the load receiving member into which a terminal is inserted.

FIG. 25 is a view showing a guide member.

FIG. 26 is a left side view of the battery.

FIG. 27 is a rear view of the battery.

FIG. 28 is a plan view of a battery.

FIG. 29 is a bottom view of the battery.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electric assist bicycle, 4 ... Power unit, 31 ... Case, 34 ... Motor cover, 35 ... Controller cover,
2 ... motor, 53 ... controller, 61 ... controller accommodation room, 82 ... power supply cable, 121 ... printed circuit board, 122 ... heat sink, 123 ... FET, 124 ...
Electrolytic capacitor, 125 ... side wall, 125a ... leg, 12
6. First connection wall, 127 Second connection wall, 128 Third connection wall, 134 to 138 Cable.

Claims (4)

[Claims] 1. A power unit for an electric assist bicycle in which a wheel driving motor and a motor control controller having a printed circuit board on which a heat-generating component is mounted are housed in a power unit case, a heat sink is attached to the printed circuit board. The controller is configured to form one assembly by fixing the heat generating component to a heat sink, and the controller is fixed to a power unit case in a state where the heat sink is in close contact with the inner wall surface of the power unit case. Power unit for electric assisted bicycle. 2. The power unit according to claim 1, wherein the heat sink comprises two parallel side walls facing both sides of one surface of the printed circuit board, and a plurality of side walls connecting the side walls. A connecting wall is integrally formed, a heat-generating component is fixed to at least one of the side walls, a printed circuit board is fixed between the two side walls, and a board mounting component is arranged inside a range surrounded by the both side walls. A power unit for an electric assist bicycle, wherein at least one of the side walls is fixed to the power unit case by contacting the power unit case. 3. The power unit for an electrically assisted bicycle according to claim 2, wherein the power unit case includes a case main body having a controller receiving recess, and a cover for closing an opening of the recess. A power unit for an electric assist bicycle, wherein a side wall of a heat sink is brought into contact with the case body and the cover, and the heat sink is sandwiched between the case body and the cover. 4. A method of manufacturing a power unit for an electric assisted bicycle in which a motor control controller having a printed circuit board on which a heat generating component is mounted is housed in a power unit case, wherein the heat generating component is fixed to a heat sink. A method of manufacturing a power unit for a power-assisted bicycle, comprising fixing the heat-generating component to a printed circuit board after fixing the heat-generating component to the printed circuit board, and then fixing the heat sink to a power unit case.