JPH07125677A - Motor control unit for moving body - Google Patents

Abstract

PURPOSE:To improve the assembling and cooling abilities of a motor control unit and to make its weight lighter by providing a circuit substrate where in the case where a lower case half body rises from the one side of a heat sink upward, and is attached to an upper case half body from a lower side, the lower case half body enters the upper case half body to make its upper edge lock on the inside of the upper case half body. CONSTITUTION:The rear upper face of a lower case half body 102 is applied to a flat plate-shaped heat sink attaching face 112, on the other hand, the front part of the lower case half body 102 is formed into an inclined face 114 inclining so as to be shallower toward the front. The inclined face 114 is provided with a groove 116 located below a gap between the opposite ribs 108a,108b of a rib group 108. Five sheets of longitudinally long radiating fins 118 are unitedly formed on the outside face of the heat sink attaching face 112. namely, the outer bottom of the lower case half body 102. These fins 118 protrude from an opening provided on a car body cover downward in a state where a control unit is attached to a main frame to facilitate the striking of a running wind against the control unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor control unit to which a moving body such as a bicycle with an electric motor is attached.

[0002]

2. Description of the Related Art A bicycle equipped with an electric motor is known in which the pedal effort is reduced by utilizing the assisting force of the electric motor. In addition, electric unmanned transport vehicles and robots, or human-powered transport vehicles and wheelchairs that use a combination of human power and auxiliary power provided by an electric motor are also considered.

In this type of small-sized moving body, vibration is applied to the motor control unit that accommodates the electric circuit.
It is necessary to increase the earthquake resistance, and it is also necessary to satisfy the requirements for cooling, assembling, and weight reduction. Conventionally, an electric component such as an IC or a semiconductor power element is mounted on a wiring circuit board of an electric circuit, and this board is screwed in a case.
Then, the case was sealed with a cover plate and fixed to the body frame.

[0004]

2. Description of the Related Art As described above, conventionally, since the wiring circuit board is fixed in the case and then the lid plate is fixed, there is a problem that the assemblability is poor and the inspection and maintenance are difficult. Further, since the case is hermetically sealed, there is a problem that the cooling performance of the electric circuit components, especially the switching elements such as the power transistors of the main circuit is deteriorated.

It is conceivable to make the entire case of metal in order to improve the cooling performance, but this increases the weight.
Therefore, it is conceivable that the case is made of resin and the heat sink is exposed to the outside through an opening provided in a part of the case, or cooling air is guided into the case. However, in this case, the waterproof property and the assembling property are deteriorated.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a motor control unit for a movable body, which has good assembling and cooling properties and is suitable for weight reduction.

[0007]

According to the present invention, an object of the present invention is to provide, in a motor control unit to be mounted on a moving body driven by an electric motor, a resin upper case half fixed to a vehicle body and having a lower surface opened, and this upper case half. A lower case half made of metal which is attached from below so as to close the lower surface opening, and at least a switching element of the main circuit of the electric motor fixed to the inner bottom surface of the lower case half. A plate-shaped heat sink, and upright from one side of the heat sink, and when the lower case half body is attached to the upper case half body from below, enters the upper case half body and the upper edge of the upper case half body is It is achieved by a motor control unit of a moving body, comprising: a circuit board locked to an inner surface.

[0008]

1 is a side view of an embodiment of the present invention, FIG. 2 is a power system diagram thereof, FIG. 3 is a block diagram showing the function of the controller, and FIG. 4 is a diagram showing a main circuit.

[0009]

[Vehicle Configuration] First, the overall configuration of the vehicle body will be described with reference to FIGS. In FIG. 1, reference numeral 10 denotes a main frame, a down tube 14 extending obliquely downward and rearward from the head pipe 12, and a pair of left and right chain stays 16 extending rearward from a lower end of the down tube 14 (only one is shown).
A seat tube 18 and a pair of left and right auxiliary stays 20 (only one of which is shown) that stand upright from the lower portion of the down tube 14, a seat tube 18 and an auxiliary stay 2
A pair of left and right back stays 22 (only one of which is shown) are connected to the rear end of the chain stay 16 at the upper end of 0.

A front fork 24 is rotatably held on the head pipe 12, and a front wheel 26 is attached to the lower end thereof and a bar handle 28 is attached to the upper end thereof. Seat tube 18
A seat post 30 is inserted from above and fixed so that its height can be adjusted, and a saddle 32 is attached to the upper end thereof.

Reference numeral 34 denotes a power unit, which is a unit in which a bottom bracket case (hereinafter referred to as a BB case) 36 and a permanent magnet type DC electric motor 38 are integrated. The BB case 36 is a bracket 40,
It is fixed to the lower rear part of the down tube 14 by 42. A crankshaft 44 is inserted through the BB case 36 of the power unit 34, and cranks 46 are fixed to both ends thereof. Crank pedals 48, 48 are attached to the crank 46.

The power unit 34 is internally provided with gears, sprockets and the like (not shown) for transmitting the rotation of the crankshaft 44 to the chain 52 via the one-way clutch 50 on the crankshaft side (FIG. 2). A planetary gear mechanism is interposed between the crankshaft 44 and the chain 52.

In this planetary gear mechanism, pedaling force is input from the planetary gear and pedaling force is output from the ring gear to the chain 52. Then, the pedaling force F is detected by detecting the torque applied to the central sun gear by the pedaling force detection mechanism 54 including a potentiometer. The rotation of the motor 38 is transmitted to the chain 52 via the planetary roller reducer 56 and the motor-side one-way clutch 57.

Reference numeral 58 denotes a rear wheel, which is attached to a rear end of the chain stay 16, that is, a connecting portion between the chain stay 16 and the back stay 22. Here, the hub of the rear wheel 58 is a free wheel 60, and the chain 52 drives the rear wheel 58 only in the forward direction. In FIG. 1, reference numeral 62 denotes a rechargeable battery such as a lead battery, and the seat tube 18
And the auxiliary stay 20 are mounted in a vertically long battery case 64 arranged vertically from above.

A rotation sensor 66 is attached to the BB case 36 to detect the rotation speed of a crankshaft-interlocking rotating portion (not shown). The rotation sensor 66 also serves as vehicle speed detecting means for detecting the vehicle speed S. Reference numeral 68 denotes a control unit, which is mounted below the front portion of the down tube 14. The control unit 68 and the power unit 34 are covered with a vehicle body cover 70.

A pedaling force detection mechanism 5 composed of a potentiometer
The pedaling force F detected in 4 and the vehicle speed S detected by the vehicle speed sensor 66 are input to a motor control unit 68, and the control unit 68 controls the motor current based on the pedaling force F and the vehicle speed S to output a motor output, that is, a motor. Generate torque T _M.

[0017]

[Circuit Configuration of Motor Control Unit] The circuit of the motor control unit 68 is constructed as shown in FIG. Motor 38
The battery 62 and the battery 62 form a closed circuit together with the switching circuit 72, and this closed circuit serves as the main circuit 74. The switching circuit 72 is composed of switching elements such as two MOS-FETs 72A and 72B having the same characteristics connected in parallel as shown in FIG. 4, for example. A flyhole diode 76 is connected in parallel to the motor 38, a shunt 78 for current detection is attached to the main circuit 74, and a battery 62
A capacitor 79 for absorbing surge is attached in parallel with. The number of switching elements is not limited to two and may be three or more.

Reference numeral 80 denotes a CPU, which outputs a command value i for the output (torque) T _M of the motor 38 based on the pedaling force F and the vehicle speed S.
Is output. That is, the command value i is output so that the output (torque) T _M of the motor 38 is periodically increased / decreased in synchronization with the periodic increase / decrease of the pedal effort F. Further, when the vehicle speed S becomes constant, the motor output T _M may be limited to limit the vehicle speed S.

Reference numeral 82 is a gate circuit, which outputs a gate signal g for driving the switching circuit 72 in response to a command value i supplied from the CPU 80, which changes the duty ratio. That is, when increasing the motor output T _M , the value of (ON time) / (OFF time + ON time) (referred to as duty) of the command value i is increased.

The gate signal g output by the gate circuit 82 based on the command value i is the FET 7 of the switching circuit 72.
2A, 72B sent to the gate of each FET 72A, 72
Turn B on and off at the same time.

In FIG. 3, reference numeral 84 denotes a main key switch. When the main switch 84 is turned on, the CPU 8
0 is the main relay 8 interposed in the main circuit 74 after initial setting
6, the power supply unit 88, the auxiliary device control unit 90,
The gate circuit 82 and other parts of the control unit 68 are all activated. The power supply unit 88 steps down the voltage of the battery 62 for traveling by, for example, a switching regulator,
The power supply voltage of the CPU 80, the drive voltage of the auxiliary device 92, and the like are created.

A small-capacity battery (not shown) other than the battery 62 is connected to the power source 88, and the voltage of the battery 62 is reduced by a switching regulator to charge the small-capacity battery. Is also good. The auxiliary device 92 includes lamps and meters, which are driven by the electric power of the power supply part 88 in accordance with a command from the auxiliary device control part 90.

[0023]

[Housing Structure of Motor Control Unit] Next, the housing structure of the motor control unit 68, that is, the mechanical structure will be described. 5 is a left side view showing the appearance of the control unit 68, FIG. 6 is a rear view of the same, FIG. 7 is a left side view of the upper case half thereof, FIG. 8 is a bottom view of the inside thereof seen from below, and FIG. Figure 7
9 is a sectional view taken along line IX-IX in FIG.

FIG. 10 is a side sectional view showing a preassembly in which a substrate and a heat sink are assembled to the lower case half body, FIG. 11 is an exploded perspective view thereof, and FIG. 12 shows the upper edge of the substrate on the inner surface of the upper case half body. FIG. 6 is a partially enlarged cross-sectional view showing a group of ribs for locking to. Further, FIG. 13 is a side view showing the vicinity of the heat sink mounting portion under the substrate and the concept of wiring of the main circuit, and FIG. 14 is a plan view showing the actual wiring of the main circuit.

The control unit 68 has a resin upper case half 100 and a metal lower case half 102. The upper case half body 100 has a box-like shape that is long in the front-rear direction and has an open lower surface, and has flanges 104 and 106 projecting forward and backward on the upper part thereof so as to be offset to the right. Upper case half 100
Are fixed to the down tube 14 of the main frame 10 by the flanges 104 and 106 (FIG. 1).

The flange 10 of this upper case half 100
Rib groups 108 and 110, into which the upper edge of a wiring board 120, which will be described later, is inserted from below, are integrally formed on the upper portion of the inner surface on the side of 4 and 106. Since these rib groups 108 and 110 have the same structure, only one of them will be described with reference to FIG. The rib group 108 is a facing rib 108 that faces the longitudinal direction (front-back direction) of the upper case half body 100 at a predetermined interval.
a and 108b, and support ribs 108c and 108d that are orthogonal to these and support from the outside.

The angle θ sandwiched by the facing surfaces of the facing ribs 108a and 108b is tapered upward as shown in FIG. 12, and the lower edges of the supporting ribs 108c and d are facing ribs 10.
8a, 108b are inclined so as to gradually become higher toward the lower edges thereof. Therefore, when the substrate 120 is pushed up from below, the substrate 120 smoothly enters between the facing ribs 108c and 108b and is held therein.

As shown in FIGS. 10 and 11, the lower case half 102 is formed in a substantially dish shape by die casting of a metal such as an aluminum alloy. The upper surface of the rear part of the lower case half 102 serves as a flat heat sink mounting surface 112, while the front part has an inclined surface 1 inclined so as to become shallower toward the front.
It is 14.

The rib group 108 is formed on the inclined surface 114.
A groove 116 is formed below the gap between the facing ribs 108a and 108b. Heat sink mounting surface 112
On the outer surface of the outer surface of the lower case half 102,
Five radiating fins 118 that are long in the front-rear direction are integrally formed. These fins 118 are attached to the vehicle body cover 70 when the control unit 68 is attached to the main frame 10.
It protrudes downward from the opening provided in the and the running wind easily hits.

Reference numeral 120 denotes a printed wiring circuit board, the lower side of which is formed along the inner bottom surface of the lower case half body 102. A thick plate-shaped heat sink 122 is fixed to the lower edge of the rear portion of the substrate 120 at a right angle, that is, horizontally. Reference numerals 124 and 124 in FIG. 13 denote bolt holes provided in the substrate 120 for fixing the heat sink 122.

The heat sink 122 is made of an aluminum plate or the like, and the FETs 72A and 72B as the switching elements, the diode 76 and the shunt resistor 78 are screwed to the upper surface thereof. F used here
The ETs 72A, 72B, the diode 76, and the shunt resistor 78 are in the shape of a rectangular block, and have a package in which three or two terminals project in parallel at one end face thereof. These are screwed to the upper surface of the heat sink 122 as shown in FIG.

These FETs 72A, 7 are provided on the substrate 120.
A through hole into which three terminals of a source S, a drain D and a gate G of 2B are inserted (S, D and G are attached to corresponding through holes respectively), a through hole into which terminals R ₁ and R _{2 of} a resistor 78 are inserted, a diode Through holes are provided respectively for the terminals D _{1 and} D _{2 of} 76. Also the substrate 12
At 0, large-diameter through-holes are formed in the vicinity of the upper side of these through-holes, and these large-diameter through-holes are connected to the corresponding small-diameter through-holes by the printed circuit pattern 126 coated with solder. These large-diameter through holes are large-diameter lead wires J1 to J4.
And J5, J6, etc. are connected in place.

Lead wires J1 to J4 connect the drains D and sources S of the FETs 72A and 72B shown in FIG. 4 to the terminal D _{2 of the} diode 76 and the terminal R _{1 of the} resistor 78, respectively. The portions indicated by J1 to J4 in FIG. 10 are cross sections of these lead wires J1 to J4. The lead wire J5 is connected to the motor 38, and the lead wire J6 is grounded.

In this embodiment, two FETs 72A, 7
Since 2B are connected in parallel to increase the current capacity,
It is necessary to make the circuit conditions uniform so that the currents of both FETs 72A and 72B become uniform. That is, FIG.
And both FET72A from terminals D _2, the resistance value of the circuit leading to the drain D of 72B in the same shown in, Similarly terminals R ₂
To the source S of each of the FETs 72A and 72B have the same resistance value. Therefore, the lead wires J1 to J4 have the same diameter and substantially the same length. FIG. 14 shows the arrangement of these lead wires J1 to J4.

A heat sink 122 is provided on the substrate 120.
The capacitor 79, the CPU 80 (see FIG. 10) and other discrete components are attached to the side surface, and then fixed to the lower case half body 102. That is, the heat sink 122 is attached to the heat sink mounting surface 11 of the lower case half body 102.
Then, the screws 128, 128 (FIG. 10) are screwed into the heat sink 122 from below. At this time, the front part of the substrate 120 is engaged and held in the groove 116 of the inclined surface 114. In this way, the preassembly 130 in which the substrate 120 and the heat sink 122 are assembled to the lower case half body 102 is formed.

This preliminary assembly 130 is made up of the upper case 100.
Is inserted from below. At this time, the upper edge of the substrate 120 is locked by the rib groups 108 and 110, and the vibration of the substrate 120 is prevented. Then, the opening edges of the upper and lower case halves 100 and 102 are sealed and joined with screws. The main relay 86 (FIGS. 3, 5, 6) is provided on the rear surface of the upper case half 100.
Is fixed. The main relay 86 is connected to the substrate 120 by a lead wire that penetrates the grommet 134 fitted in the opening 132 in the rear surface of the upper case half body 100.

In this embodiment, the heat sink 122 has F
Not only ET72A, 72B but also diode 76, resistor 7
Although 8 is also attached, the present invention may be one in which the heat generation amount is the largest, for example, only the switching element such as FET is attached to the heat sink. Also, the substrate 120
Is deviated to the side of the flanges 104 and 106, the impact applied to the substrate 120 is reduced when the entire control unit 68 sways left and right due to vehicle body vibration.

[0038]

As described above, according to the first aspect of the present invention, the heat sink which is substantially orthogonal to the lower edge of the substrate is fixed, and the heat sink is preliminarily fixed to the metal lower case half body to form the preassembly. This is inserted into the upper case half from below, and the lower case half is fixed to the upper case half while the upper edge of the substrate is locked to the inner surface of the upper case half from below.

Therefore, the electric circuit portion including the substrate can be attached and detached together with the lower case half body, and the assembling property is good. Further, since the heat sink is fixed to the lower case half made of metal, heat of the switching element of the main circuit attached to the heat sink can be satisfactorily transferred from the heat sink to the lower case half and radiated well from the outer surface thereof. Therefore, heat dissipation is improved. Furthermore, since the upper case half is made of resin, it is also suitable for weight reduction.

[Brief description of drawings]

FIG. 1 is a side view of a bicycle with a motor according to an embodiment of the present invention.

[Fig. 2] Power system diagram

FIG. 3 is a functional block diagram of a controller

FIG. 4 is a diagram showing a main circuit.

FIG. 5 is a left side view showing the appearance of the control unit.

FIG. 6 is a rear view of the same.

FIG. 7 is a left side view of the upper case half body.

FIG. 8 is a bottom view of the inside viewed from below.

9 is a sectional view taken along line IX-IX in FIG.

FIG. 10 is a side sectional view showing a preliminary assembly.

FIG. 11 is an exploded perspective view of the same.

FIG. 12 is a partially enlarged sectional view showing a rib group.

FIG. 13 is a side view showing the vicinity of the lower part of the substrate.

FIG. 14 is a plan view showing an arrangement of lead wires of a main circuit.

[Explanation of symbols]

 38 electric motor 68 motor control unit 72A, 72B FET as a switching element 80 CPU 100 upper case half body 102 lower case half body 108, 110 rib group 120 circuit board 122 heat sink 130 preliminary assembly

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 2, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

[Figure 4]

[Procedure Amendment 2]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 5

[Correction method] Change

[Correction content]

[Figure 5]

[Procedure 3]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 6

[Correction method] Change

[Correction content]

[Figure 6]

[Procedure amendment 4]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 7

[Correction method] Change

[Correction content]

[Figure 7]

[Procedure Amendment 5]

[Document name to be corrected] Drawing

[Correction target item name] Figure 8

[Correction method] Change

[Correction content]

[Figure 8]

[Procedure correction 6]

[Document name to be corrected] Drawing

[Correction target item name] Figure 9

[Correction method] Change

[Correction content]

[Figure 9]

[Procedure Amendment 7]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 10

[Correction method] Change

[Correction content]

[Figure 10]

[Procedure Amendment 8]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 11

[Correction method] Change

[Correction content]

FIG. 11

[Procedure Amendment 9]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 12

[Correction method] Change

[Correction content]

[Fig. 12]

[Procedure Amendment 10]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 13

[Correction method] Change

[Correction content]

[Fig. 13]

[Procedure Amendment 11]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 14

[Correction method] Change

[Correction content]

FIG. 14

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Suetsugu Nagai 2500 Shinrai, Iwata, Shizuoka Prefecture, Yamaha Motor Co., Ltd. (72) Inventor, Yasuo Suganuma 2500, Shinkai, Iwata, Shizuoka Yamaha Motor Co.

Claims (1)

[Claims] 1. A motor control unit attached to a moving body driven by an electric motor, comprising: a resin upper case half body fixed to a vehicle body and having a lower surface opened; and a lower part of the upper case half body so as to close the lower surface opening. A lower case half made of metal, a plate-like heat sink fixed to the inner bottom surface of the lower case half and having at least a switching element of the main circuit of the electric motor mounted on the upper surface thereof, A circuit board which stands up from one side and enters into the upper case half body when the lower case half body is attached to the upper case half body from below and the upper edge of which is locked to the inner surface of the upper case half body. A motor control unit for a mobile body, comprising: