Motor control device, motor system, and electric vehicle

Abstract

To provide a technique capable of miniaturizing a motor control device having a plurality of control boards.SOLUTION: A motor control device comprises: a first substrate and a second substrate to which a component for controlling an electric motor is mounted; a first case that houses the first substrate; and a second case that houses the second substrate. Each of the first and second cases, comprises: a main wall that is opposite to the first or second substrate in a first direction as a thickness direction of the first and second substrates; and a frame-shaped side wall that is projected to a first direction from an outer edge part of the main wall so as to surround an outer periphery of the first or second substrate. A surface opposite to the main surface is opened while nipping the side wall. Each of the first substrate and the second substrate is housed in the first or second case in a state where a mounting surface of a component is directed to a surface to be opened. The first case and the second case are coupled so that both of projection ends of the side wall is contacted.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a motor control device, a motor system, and an electric vehicle.

Background Art

[0002] In recent years, efforts have been made to promote the Sustainable Development Goals (2030 Agenda for Sustainable Development, adopted at the United Nations Summit on September 25, 2015, hereinafter referred to as "SDGs"). Along with this, technologies aiming at reducing waste and defective products have been known in order to ensure sustainable production and consumption patterns.

[0003] Conventionally, in a motor control device that controls the drive of an electric motor, when attempting to mount components for controlling a plurality of electric motors on a single control board, there have been problems that the size of the control board increases and the layout of the components becomes difficult. In addition, since it is necessary to separately design a motor control device for controlling one electric motor and a motor control device for controlling a plurality of electric motors, there has been a problem that the development man-hours and manufacturing costs increase.

[0004] Therefore, there is a technique of combining a plurality of control boards each controlling one electric motor to constitute one motor control device (see, for example, Patent Documents 1 and 2). More specifically, in Patent Document 1, a plurality of control boards are arranged on the same plane and housed in a housing. In Patent Document 2, a plurality of housings each housing a control board are stacked in the thickness direction.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the motor control device of Patent Document 1, it becomes larger in the arrangement direction of the control board. Further, in the motor control device of Patent Document 2, since the control boards are housed in independent cases and stacked, it becomes larger in the stacking direction.

[0007] Therefore, an object of the present invention is to provide a technique for miniaturizing a motor control device including a plurality of control boards.

Means for Solving the Problems

[0008] To achieve the above object, the present invention includes a first board and a second board on which components for controlling an electric motor are mounted, a first case for housing the first board, and a second case for housing the second board. The first case and the second case include a main wall facing the first board or the second board in a first direction which is the thickness direction of the first board and the second board, and a frame-shaped side wall protruding in the first direction from an outer edge portion of the main wall so as to surround an outer periphery of the first board or the second board. A surface on the opposite side of the main wall across the side wall is open, and the first board and the second board are housed in the first case or the second case with the mounting surface of the components being open, and the first case and the second case are characterized in that the protruding ends of the side walls are joined so as to abut against each other.

Effects of the Invention

[0009] According to the present invention, it is possible to miniaturize a motor control device including a plurality of control boards. Problems, configurations, and effects other than those described above will be clarified by the description of the following embodiments.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0011] [Configuration of Electric Assist Bicycle 1] FIG. 1 is a side view of an electric assist bicycle 1 according to this embodiment. FIG. 2 is a block diagram of a motor system 100 according to this embodiment. Hereinafter, on the premise that the electric assist bicycle 1 is placed on a horizontal plane, the direction perpendicular to the placement surface is referred to as the "vertical direction", the direction including the traveling direction of the electric assist bicycle 1 is referred to as the "front-rear direction", and the direction perpendicular to the vertical direction and the front-rear direction is referred to as the "left-right direction".

[0012] The electric assist bicycle 1 is an example of an electric vehicle that assists the force (hereinafter referred to as "pedaling force") of a user (hereinafter simply referred to as "user") stepping on pedals 23L and 23R of the electric assist bicycle 1 with an electric motor to rotate the front wheel 7F and the rear wheel 7B (that is, to run the electric assist bicycle 1). As shown in FIGS. 1 and 2, the electric assist bicycle 1 is composed of a main body 2 and a motor system 100.

[0013] The main body 2 is a bicycle whose driving force is assisted by the motor system 100. The main body 2 may be an existing bicycle diverted, or newly designed to mount the motor system 100. As shown in FIG. 1, the main body 2 mainly includes a frame 3, a front fork 4, a saddle 5, handlebars 6, a front wheel 7F and a rear wheel 7B (hereinafter, these may be collectively referred to as "wheel 7"), a steering column 8, a pedaling force transmission mechanism 20, and a braking mechanism 30.

[0014] The frame 3 is a member that supports the components (4 to 8, 20, 30) of the main body 2. The frame 3 is composed of, for example, steel, aluminum alloy, chromolybdenum steel, carbon (carbon fiber reinforced plastic), or a combination thereof. The frame 3 mainly includes, for example, a top tube 11, a down tube 12, a seat tube 13, a head tube 14, seat stays 15, chain stays 16, and a bottom bracket shell 17.

[0015] The front end of the top tube 11 is connected to the head tube 14, and the rear end is connected to the upper end of the seat tube 13, extending generally in the front-rear direction. The front end of the down tube 12 is connected to the head tube 14, and the rear end is connected to the bottom bracket shell 17, extending obliquely rearward and downward. The upper end of the seat tube 13 is connected to the rear end of the top tube 11, and the lower end is connected to the bottom bracket shell 17, extending obliquely forward and downward. The seat tube 13 supports the saddle 5 so as to be able to move up and down at its upper end.

[0016] The head tube 14 is connected to the front ends of the top tube 11 and the down tube 12 and extends obliquely forward and downward. And a steering column 8 of the front fork 4 is rotatably inserted into the head tube 14. The steering column 8 supports the handlebar 6 at its upper end. The front fork 4 extends obliquely forward and downward from the head tube 14 and rotatably supports the front wheel 7F at its lower end. Thus, when the handlebar 6 is operated by the user, the direction of the front wheel 7F (i.e., the traveling direction of the electric assist bicycle 1) changes.

[0017] The seat stay 15 has its front end connected to the seat tube 13 and extends obliquely rearward and downward. The chain stay 16 has its front end connected to the bottom bracket shell 17 and extends generally rearward. And a rear wheel 7B is rotatably supported at the connecting portion (i.e., the rear end) of the seat stay 15 and the chain stay 16.

[0018] The pedaling force transmission mechanism 20 is a mechanism that transmits the pedaling force of a user sitting on the saddle 5 to the rear wheel 7B. The pedaling force transmission mechanism 20 mainly includes, for example, a crankshaft 21, a pair of crank arms 22L and 22R, a pair of pedals 23L and 23R, a drive gear 24, a driven gear 25, and a chain 26.

[0019] The crankshaft 21 extends in the left - right direction and is rotatably supported by the bottom bracket shell 17. The crank arms 22L and 22R have one end connected to both ends of the crankshaft 21 and extend in a direction orthogonal to the crankshaft 21. Also, pedals 23L and 23R are rotatably attached to the other ends of the crank arms 22L and 22R. The drive gear 24 is attached to the crankshaft 21 and rotates integrally with the crankshaft 21. The driven gear 25 is attached to the rear wheel 7B and rotates integrally with the rear wheel 7B. The chain 26 is looped around the drive gear 24 and the driven gear 25.

[0020] When a user sitting on the saddle 5 steps on the pedals 23L and 23R, the crankshaft 21 rotates together with the drive gear 24 by the stepping force transmitted by the crank arms 22L and 22R. The rotation of the drive gear 24 is transmitted to the driven gear 25 through the chain 26. The driven gear 25 shifts the rotation of the drive gear 24 transmitted through the chain 26 according to the gear ratio of the drive gear 24 and the driven gear 25, and rotates the rear wheel 7B. Note that the pedaling force transmission mechanism 20 may include a plurality of driven gears that rotate integrally with the rear wheel 7B, and a derailleur that switches the driven gear around which the chain 26 is looped from among the plurality of driven gears.

[0021] The brake mechanism 30 is a mechanism that brakes the electric assist bicycle 1 according to the operation of the user. The brake mechanism 30 mainly includes, for example, a pair of brake levers 31L and 31R, a front brake 32, and a rear brake 33.

[0022] The brake levers 31L and 31R are attached to the handlebar 6. The brake lever 31L is operated with the user's left hand, and the brake lever 31R is operated with the user's right hand. The front brake 32 clamps the rim of the front wheel 7F and brakes the front wheel 7F in response to the operation of the brake lever 31R. The rear brake 33 clamps the rim of the rear wheel 7B and brakes the rear wheel 7B in response to the operation of the brake lever 31L. Note that the front brake 32 and the rear brake 33 may clamp a disk that rotates integrally with the wheel 7 instead of clamping the rim of the wheel 7.

[0023] [Configuration of the motor system 100] As shown in FIGS. 1 and 2, the motor system 100 mainly includes, for example, a battery 101 (power source), a front wheel motor 102F and a rear wheel motor 102B (hereinafter, these may be collectively referred to as "wheel motors 102"), and a motor control device 103.

[0024] The battery 101 stores electric power for operating the wheel motor 102 and the motor control device 103. The battery 101 may store, for example, electric power supplied from a commercial power source with a cable (not shown) attached, or may store the regenerative electric power generated by the wheel motor 102. Further, as shown in FIG. 1 for example, the battery 101 is detachably attached to the upper surface of the down tube 12. However, the battery 101 is not limited to being installed at the position shown in FIG. 1 and can be installed at any position of the main body 2.

[0025] The wheel motor 102 is an electric motor driven by electric power supplied from the battery 101 through the motor control device 103. Also, the wheel motor 102 is driven according to the control of the motor control device 103. The front wheel motor 102F is attached to the hub of the front wheel 7F, for example, as shown in FIG. 1, to rotate the front wheel 7F. Similarly, the rear wheel motor 102B is attached to the hub of the rear wheel 7B, for example, to rotate the rear wheel 7B.

[0026] The motor control device 103 controls the drive of the wheel motor 102 with the electric power supplied from the battery 101. The motor control device 103 is attached to the back side of the saddle 5 (more specifically, the back of the seat post that supports the saddle 5), for example, as shown in FIG. 1. However, the motor control device 103 is not limited to being installed at the position shown in FIG. 1 and can be installed at any position of the main body 2. The motor control device 103 is composed of, for example, a first control unit 104F, a second control unit 104B, a third control unit 105, and a harness unit 106 (see FIGS. 3 and 4).

[0027] The first control unit 104F controls the drive of the front-wheel motor 102F (an example of the first motor). The second control unit 104B controls the drive of the rear-wheel motor 102B (an example of the second motor). However, the first control unit 104F may control the drive of the rear-wheel motor 102B (another example of the first motor), and the second control unit 104B may control the drive of the front-wheel motor 102F (another example of the second motor). That is, the first control unit 104F may control one of the front-wheel motor 102F and the rear-wheel motor 102B, and the second control unit 104B may control the other of the front-wheel motor 102F and the rear-wheel motor 102B.

[0028] The third control unit 105 distributes the electric power supplied from the battery 101 to the first control unit 104F and the second control unit 104B. The harness unit 106 electrically connects the motor control device 103 to the battery 101 and the wheel motors 102. The harness unit 106 is composed of, for example, a pair of power lines 107a, 107b, a pair of control lines 108F, 108B, and a packing 109, as shown in FIG. 3.

[0029] The power lines 107a, 107b electrically connect the battery 101 and the third control unit 105. The control line 108F electrically connects the first control unit 104F and the front-wheel motor 102F. The control line 108B electrically connects the second control unit 104B and the rear-wheel motor 102B. The packing 109 seals the openings formed by the cutouts 128F, 128B described later and allows the power lines 107a, 107b and the control lines 108F, 108B to pass through.

[0030] [Configuration of Motor Control Device 103] FIG. 3 is an external view of the motor control device 103. FIG. 4 is an exploded perspective view of the motor control device 103. FIG. 5 is an inner view (A) of the case 120F, a front view (B) of the substrate 110F housed in the case 120F, and a rear view (C) of the substrate 110F. FIG. 6 is an exploded view (A) and an assembled view (B) of the first control unit 104F and the second control unit 104B as seen from the third control unit 105 side.

[0031] As shown in FIGS. 3 to 6, the first control unit 104F mainly includes, for example, a substrate 110F (first substrate) and a case 120F (first case). The second control unit 104B mainly includes, for example, a substrate 110B (second substrate) and a case 120B (second case). The third control unit 105 mainly includes, for example, a substrate 140 (third substrate) and a case 150 (third case).

[0032] Since the configurations of the first control unit 104F and the second control unit 104B are common, the configuration of the first control unit 104F will be described in detail below. The same reference numerals will be added to the common components, and they will be distinguished by "F" and "B" at the end. The motor control device 103 is typically configured by combining the first control unit 104F and the second control unit 104B having the same configuration. However, the first control unit 104F and the second control unit 104B are not limited to having exactly the same shape and layout, and it is sufficient that the shapes and layouts of the main parts are the same. For example, even if there are marks or seals for distinguishing the two, or slight differences in shape (e.g., the presence or absence of notches), they may be included within the range of common configurations.

[0033] The substrate 110F is a so-called "mounting substrate (printed circuit board)" on which various components (111 to 114) for controlling the electric motor are mounted. The substrate 110F according to the present embodiment has a generally rectangular outer shape having a longitudinal direction and a lateral direction.

[0034] In the present embodiment, the thickness direction of the substrate 110F corresponds to the "first direction", the longitudinal direction of the substrate 110F corresponds to the "second direction", and the lateral direction of the substrate 110F corresponds to the "third direction". However, the second direction and the third direction are not limited to the above examples as long as they are orthogonal to the first direction and orthogonal to each other. Since the thickness directions, longitudinal directions, and lateral directions of the motor control device 103, the substrates 110F and 110B, and the cases 120F and 120B are the same, hereinafter, they may be simply referred to as the "thickness direction", "longitudinal direction", and "lateral direction".

[0035] On the substrate 110F, for example, electronic components such as a capacitor 111F and an integrated circuit 112F, a heat sink 113F for dissipating the heat of the substrate 110F, and a connector 114F into which a connection terminal 141F described later is inserted are mounted. In the present embodiment, as shown in FIGS. 5(B) and 5(C), the connector 114F is mounted on the surface of the substrate 110F, and the capacitor 111F, the integrated circuit 112F, and the heat sink 113F are mounted on the back surface of the substrate 110F.

[0036] Note that although only some of the components have been described in this specification, the components mounted on the substrate 110F are not limited to these. Also, components (111F to 114F) may be mounted on both surfaces in the thickness direction of the substrate 110F, or components (111F to 114F) may be mounted on only one surface in the thickness direction. The surface of the substrate 110F on which the components (111F to 114F) are mounted is referred to as the "mounting surface".

[0037] As shown in FIG. 5(B), the connector 114F is mounted at an end in the longitudinal direction of the substrate 110F. Also, the connector 114F is mounted at a position deviated to one side in the short direction from a virtual line L extending in the longitudinal direction through the center of the substrate 110F. The center of the substrate 110F may refer to, for example, the intersection of two diagonal lines of a rectangular shape, or may refer to the center of gravity position of the substrate 110F. Further, the connector 114F is a so-called "right angle connector" into which the connection terminal 141F of a substrate 140 described later is inserted in the longitudinal direction (i.e., parallel to the mounting surface).

[0038] The case 120F is a member having an internal space for accommodating the substrate 110F. The case 120F is, for example, integrally formed by aluminum die casting for the overall shape, and fine parts (for example, a notch 127F described later) may be formed by cutting. The case 120F mainly includes, for example, a main wall 121F and side walls 122F.

[0039] The main wall 121F is the surface facing the substrate 110F in the thickness direction. The main wall 121F, similar to the substrate 110F, exhibits a generally rectangular outer shape having a longitudinal direction and a lateral direction. The side wall 122F is in a frame shape protruding in the thickness direction from the outer edge of the main wall 121F so as to surround the outer periphery of the substrate 110F. On the other hand, the surface on the side opposite to the main wall 121F across the side wall 122F of the case 120F (that is, the surface on the protruding end side of the side wall 122F) is open.

[0040] As shown in FIG. 5(A), a plurality of support protrusions 123F are formed on the inner surface of the main wall 121F. The support protrusions 123F each protrude in the thickness direction at different positions on the inner surface of the main wall 121F. Further, screw holes extending in the thickness direction are formed in the support protrusions 123F. When the back surface of the substrate 110F is placed on the support protrusions 123F with the main wall 121F facing, a simple hole 115F penetrating the substrate 110F in the thickness direction communicates with the screw holes of the support protrusions 123F. Then, as shown in FIG. 5(B), the substrate 110F is fixed to the case 120F by screwing a screw 116F inserted through the simple hole 115F into the screw holes.

[0041] Also, a housing recess 124F is formed in the main wall 121F. The housing recess 124F is a portion recessed from the inner surface of the main wall 121F toward the outer surface side and bulging on the outer surface side of the main wall 121F. The housing recess 124F houses a component (111 - 113) having a higher height in the thickness direction among the components mounted on the back surface of the substrate 110F (in this embodiment, the capacitor 111F).

[0042] On the other hand, as shown in FIG. 5(B), the surface of the substrate 110F on which the connector 114F is mounted faces the open surface of the case 120F. Further, as shown in FIG. 6(A), the connector 114F is a specific component protruding to a position away from the main wall 121F from the protruding end of the side wall 122F. However, the specific component is not limited to the connector 114F. Also, the number of specific components mounted on the substrate 110F is not limited to one.

[0043] Further, a contact portion 125F is formed on the inner surface of the main wall 121F. The contact portion 125F is a portion that protrudes in the thickness direction from the inner surface of the main wall 121F and contacts (surface contacts) the heat dissipation plate 113F of the substrate 110F. Further, a heat sink 126F is formed on the outer surface of the main wall 121F. The heat sink 126F is a fin-shaped portion that protrudes from the outer surface of the main wall 121F at a position corresponding to the contact portion 125F. The heat generated by the substrate 110F is radiated to the outside from the heat sink 126F through the heat dissipation plate 113F and the contact portion 125F. It is desirable that the protruding amount of the heat sink 126F is larger than that of the accommodation recess 124F.

[0044] Notches 127F and 128F are formed in the side wall 122F. The notches 127F and 128F are portions where the protruding height of the side wall 122F is reduced at both longitudinal ends of the case 120F. As shown in FIG. 6, the notch 127F is a portion that exposes the connector 114F in the longitudinal direction of the case 120F. The notch 128F is a portion where the packing 109 of the harness unit 106 is attached. The notch 127F may be formed, for example, by cutting a part of the side wall 122F after forming the overall shape of the case 120f by aluminum die casting. The notch 128F may be formed in the same manner as the notch 127F, or may be formed by devising the shape of the mold.

[0045] Further, recesses 129F and 130F are formed in the side wall 122F. The recesses 129F and 130F are portions that are recessed in the thickness direction from the side of the main wall 121F toward the side of the protruding end of the side wall 122F. As shown in FIG. 3, the recess 129F and the recess 130F are formed at positions that are rotationally symmetric with respect to an imaginary line L that extends in the longitudinal direction through the center of the main wall 121F. Note that the imaginary line L is common to the substrate 110F and the main wall 121F. Further, the recesses 129F and 130F are provided at two locations each (a total of four locations) on one side and the other side in the short direction with the imaginary line L interposed therebetween. Further, the recess 129F has a larger amount of recess in the thickness direction than the recess 130F.

[0046] In addition, a simple hole 131F is formed in the side wall 122F at the position (inside) of the recess 129F, and a threaded hole 132F is formed at the position (inside) of the recess 130F. The simple hole 131F penetrates the side wall 122F in the thickness direction, and no female thread is formed on the inner surface. The threaded hole 132F extends in the thickness direction from the side of the protruding end of the side wall 122F, and a female thread is formed on the inner surface. Also, the threaded hole 132F may not penetrate to the side of the main wall 121F. A screw 133F is inserted into the simple hole 131F, and a screw 133B is screwed into the threaded hole 132F.

[0047] When the protruding ends of the side walls 122F and 122B of the cases 120F and 120B rotated about the virtual line L are brought into contact with each other while sandwiching the power lines 107a, 107b and the control lines 108F, 108B inserted through the packing 109, the simple hole 131F of the case 120F communicates with the threaded hole 132B of the case 120B, and the threaded hole 132F of the case 120F communicates with the simple hole 131B of the case 120B. Then, by screwing the screw 133F inserted from the side of the simple hole 131F into the threaded hole 132B and screwing the screw 133B inserted from the side of the simple hole 131B into the threaded hole 132F, the cases 120F and 120B accommodating the substrates 110F and 110B in the internal space are joined. Also, the openings formed by the notches 128F and 128B are sealed by the packing 109.

[0048] Here, the substrates 110F and 110B are accommodated in the internal space surrounded by the cases 120F and 120B with the surfaces on which the connectors 114F and 114B are mounted facing each other. Also, the connectors 114F and 114B are mounted on the substrates 110F and 110B respectively at the same position deviated from one side in the short side direction from the virtual line L. Thereby, as shown in FIG. 6(B), when the cases 120F and 120B accommodating the substrates 110F and 110B are joined, the connectors 114F and 114B are displaced and arranged in the short side direction.

[0049] As a result, even if the connectors 114F and 114B are arranged so as to overlap when viewed from the short side direction, it is possible to prevent the connectors 114F and 114B from interfering with each other. That is, since the distance between the boards of the boards 110F and 110B can be made shorter than the total height of the connectors 114F and 114B, the motor control device 103 can be downsized in the thickness direction.

[0050] Furthermore, on the outer surface of the side wall 122F in the longitudinal direction of the case 120F (the surface facing the case 150), a screw hole 134F extending in the longitudinal direction is formed. More specifically, the screw holes 134F and 134B of the cases 120F and 120B are formed so as to surround the openings formed by the notches 127F and 127B (in this embodiment, a total of four locations). Furthermore, the connectors 114F and 114B are exposed from the openings formed by the notches 127F and 127B when viewed from the longitudinal direction.

[0051] Power lines 107a and 107b that have passed between the boards 110F and 110B are connected to the board 140. The board 140 also includes connection terminals 141F and 141B that are inserted and removed from the connectors 114F and 114B in the longitudinal direction. When the connection terminals 141F and 141B are inserted into the connectors 114F and 114B, the power supplied from the battery 101 through the power lines 107a and 107b is distributed to the boards 110F and 110B.

[0052] The case 150 is a box-shaped member that houses the board 140. The case 150 mainly includes, for example, a housing portion 151 and a flange portion 152. The housing portion 151 is a portion that houses the board 140. Also, one surface of the housing portion 151 (the surface facing the cases 120F and 120B) is open. The board 140 is fixed inside the housing portion 151 by screws (not shown) with the connection terminals 141F and 141B facing the open surface of the housing portion 151. The flange portion 152 is a wall surface that protrudes outward from the open surface of the housing portion 151 and is continuous in the circumferential direction. A plurality of simple holes 153 penetrating in the longitudinal direction (the thickness direction of the flange portion 152) are formed in the flange portion 152.

[0053] When the connection terminals 141F and 141B of the substrate 140 fixed to the case 150 are inserted into the connectors 114F and 114B in the longitudinal direction, the simple hole 153 of the flange portion 152 communicates with the screw holes 134F and 134B of the cases 120F and 120B. Then, by screwing the screw 154 inserted into the simple hole 153 into the screw holes 134F and 134B, the case 150 is coupled to the outer surfaces of the cases 120F and 120B.

[0054] [Configuration of the motor control device 103' including only one substrate 110F'] FIG. 7 is an exploded view (A) and an assembled view (B) of the motor control device 103' including only one substrate 110F'. The motor control device 103' including only one substrate 110F' mainly includes a substrate 110F', a case 120F', and a cover 160, with the substrates 110B, 140 and the cases 120B, 150 omitted.

[0055] As shown in FIG. 7(A), the case 120F' is different from the case 120F in that the notch 127F (i.e., the process of cutting the notch 127F) is omitted, and the other points are common to the case 120F. Further, the substrate 110F' is different from the substrate 110F in that the connector 114F is omitted and the power lines 107a and 107b are directly connected (e.g., soldered), and the other points are common to the substrate 110F.

[0056] In the cover 160, for example, a simple hole (not shown) penetrating in the thickness direction is formed at a position where it can communicate with the screw hole 132F of the case 120F'. Then, the cover 160 is attached to the protruding end of the side wall 122F so as to close the open surface of the case 120F' in which the substrate 110F' is accommodated. Then, by screwing the screw 133B inserted into the simple hole into the screw hole 132F, the cover 160 is fixed to the case 120F'. Here, since no component protruding from the protruding end of the side wall 122F is mounted on the substrate 110F' from which the connector 114F is omitted, the cover 160 can have a simple flat plate shape.

[0057] [Operational effects of the embodiment] According to the above-described embodiment, by joining the case 120F containing the substrate 110F and the case 120B containing the substrate 110B with their open surfaces facing each other, the motor control device 103 can be miniaturized in the thickness direction as compared with the case of stacking a housing that surrounds the entire surface of the substrate as in Patent Document 2, for example.

[0058] Further, according to the above-described embodiment, by arranging the connectors 114F and 114B protruding from the protruding ends of the side walls 122F and 122B at positions deviated in the short direction from the virtual line L, when the surfaces of the substrates 110F and 110B on which the connectors 114F and 114B are mounted face each other, the connectors 114F and 114B are arranged with a shift in the short direction. Thereby, the motor control device 103 can be further miniaturized in the thickness direction. Also, by arranging the connectors 114F and 114B inside, it contributes to the miniaturization of the substrate 140. Furthermore, by adopting right-angle connectors for the connectors 114F and 114B, the attachment and detachment of the connection terminals 141F and 141B to and from the connectors 114F and 114B arranged inside become easy.

[0059] Further, according to the above-described embodiment, by forming the simple holes 131F and 131B and the screw holes 132F and 132B at positions that are rotationally symmetric about the virtual line L, the cases 120F and 120B can be joined without using nuts. Thereby, reduction in the number of parts and weight reduction of the motor control device 103 can be achieved.

[0060] Further, according to the above-described embodiment, by forming the simple holes 131F and 131B and the screw holes 132F and 132B in the recesses 129F, 129B, 130F, and 130B, the lengths of the screws 133F and 133B can be shortened. Furthermore, by making the recess amounts of the recesses 129F and 129B provided with the simple holes 131F and 131B larger than those of the recesses 130F and 130B provided with the screw holes 132F and 132B, the length of the screw engagement between the screws 133F and 133B and the screw holes 132F and 132B can be ensured. As a result, while maintaining the joining strength of the cases 120F and 120B, weight reduction of the motor control device 103 can be achieved.

[0061] Further, according to the above embodiment, instead of the substrates 110B and 140 and the cases 120B and 150, by closing the open surface of the case 120F' that houses the substrate 110F' with the cover 160, a motor control device 103' including only one substrate 110F' can be realized. Further, since the motor control device 103' only omits a part of the manufacturing process (cutting of the notch 127F and attachment of the connector 114F) compared to the motor control device 103 including two substrates 110F and 110B, the basic designs of the substrates 110F and 120F can be shared. As a result, the development man-hours and manufacturing costs of the motor control devices 103 and 103' can be reduced.

[0062] [Modification Example 1] Referring to FIG. 8, the motor control device 103'' according to Modification Example 1 will be described. FIG. 8 is an exploded perspective view of the substrates 110F'' and 110B'' according to Modification Example 1. Note that a detailed description of the common points with the above embodiment will be omitted, and the description will focus on the differences.

[0063] The substrates 110F'' and 110B'' according to Modification Example 1 differ from the substrates 110F and 110B in that they further include contacts 117F and 117B (117F is not shown), and other points are common to the substrates 110F and 110B. Further, the motor control device 103'' according to Modification Example 1 differs from the motor control device 103 in that it further includes header pins 161, and other points are common to the motor control device 103.

[0064] The contacts 117F and 117B are formed on the surfaces of the substrates 110F'' and 110B'' that face each other (the surfaces on which the connectors 114F and 114B are mounted). Further, the contacts 117F and 117B are arranged on a virtual line L that extends in the longitudinal direction through the centers of the substrates 110F'' and 110B''. Although five contacts 117B are shown in FIG. 8, the number of the contacts 117F and 117B is not limited to this, and may be one or a plurality.

[0065] The header pin 161 is composed of a plurality of pins 162 that electrically connect the contacts 117F and 117B, and a holder 163 that holds the plurality of pins 162 arranged linearly. The header pin 161 is disposed between the substrates 110F’’ and 110B’’. More specifically, the header pin 161 is fixed inside the cases 120F and 120B such that one end of the pin 162 abuts against the contact 117F and the other end of the pin 162 abuts against the contact 117B. Then, the header pin 161 relays the communication between the substrates 110F’’ and 110B’’ through the contacts 117F and 117B.

[0066] According to Modification 1, by arranging the contacts 117F and 117B on the virtual line L, when the cases 120F and 120B accommodating the substrates 110F’’ and 110B’’ are combined, the contacts 117F and 117B face each other in the thickness direction. As a result, the contacts 117F and 117B can be electrically connected by the simple header pin 161 including the linearly extending pins 162. Consequently, the motor control device 103’’ that can control the front-wheel motor 102F and the rear-wheel motor 102B in conjunction can be realized with a simple configuration.

[0067] [Modification 2] Referring to FIG. 9, the motor system 100’ according to Modification 2 will be described. FIG. 9 is a block diagram of the motor system 100’ according to Modification 2. Note that a detailed description of the common points with the above-described embodiment will be omitted, and the description will focus on the differences. The motor system 100’ according to Modification 1 is different from the above-described embodiment in that the motor control device 103 controls the drive of one wheel motor 102, and the other points are common to the above-described embodiment.

[0068] The first control unit 104F and the second control unit 104B according to Modification 2 are connected to the same wheel motor 102 through control lines 108F and 108B. Also, the first control unit 104F and the second control unit 104B according to Modification 2 are configured to be able to communicate with each other. As an example, the substrates 110F and 110B may be electrically connected by a harness. As another example, the motor system 100' according to Modification 2 may include the motor control device 103' according to Modification 1 instead of the motor control device 103 according to the above-described embodiment.

[0069] The first control unit 104F controls the drive of the wheel motor 102. On the other hand, the second control unit 104B does not control the wheel motor 102 while the first control unit 104F is operating normally. Then, when the first control unit 104F (more specifically, the substrate 110F) fails, the second control unit 104B controls the drive of the wheel motor 102 in place of the first control unit 104F.

[0070] For example, while the first control unit 104F is controlling the wheel motor 102, the first control unit 104F repeatedly transmits a normal signal indicating that it is operating normally to the second control unit 104B at a predetermined time interval. The second control unit 104B does not control the wheel motor 102 while receiving the normal signal from the first control unit 104F. Then, when the second control unit 104B does not receive the normal signal from the first control unit 104F for a predetermined period (a period longer than the transmission interval of the normal signal), the second control unit 104B starts controlling the wheel motor 102.

[0071] According to Modification 2, since the control of the wheel motor 102 is duplicated by the first control unit 104F and the second control unit 104B, the reliability of the motor system 100' is improved. When the motor system 100' according to Modification 2 is applied to the electric assist bicycle 1, the wheel motor 102 may be attached to either the front wheel 7F or the rear wheel 7B.

[0072] [Other Modifications] The electric vehicles to which the motor systems 100 and 100' can be applied are not limited to electric assist bicycles 1. As other examples, the electric vehicles to which the motor systems 100 and 100' can be applied may have a plurality of front wheels 7F and / or rear wheels 7B, or may be equipped with a pair of left and right wheels instead of the front wheels 7F and the rear wheels 7B. As still other examples, the electric vehicles to which the motor systems 100 and 100' can be applied are not limited to those that assist the user's pedaling force with the wheel motor 102 to rotate the wheel 7, and may be those that run only with the driving force of the wheel motor 102 (for example, kick scooters, specific small motorcycles). Further, the motor systems 100 and 100' are applicable not only to electric vehicles but also to any device driven by an electric motor.

[0073] The embodiments of the present invention have been described above. It should be noted that the present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Also, a part of the configuration of this embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can also be added to the configuration of this embodiment. Furthermore, for a part of the configuration of this embodiment, addition, deletion, or replacement with other configurations is possible.

Explanation of Reference Numerals

[0074] 1... Electric assist bicycle, 2... Body, 3... Frame, 4... Front fork, 5... Saddle, 6... Handlebar, 7... Wheel, 8... Steering column, 11... Top tube, 12... Down tube, 13... Seat tube, 14... Head tube, 15... Seat stay, 16... Chain stay, 17... Bottom bracket shell, 20... Pedal force transmission mechanism, 21... Crankshaft, 22... Crank arm, 23... Pedal, 24... Driving gear, 25... Driven gear, 26... Chain, 30... Brake mechanism, 31... Brake lever, 32... Front brake, 33... Rear brake, 100... Motor system, 101... Battery, 102... Wheel motor, 103... Motor control device, 104B... Second control unit, 104F... First control unit, 105... Third control unit, 106... Harness unit, 107... Power line, 108... Control line, 109... Packing, 110, 140... Substrate, 111... Capacitor, 112... Integrated circuit, 113... Heat sink, 114... Connector, 115, 131, 153... Simple hole, 116, 133, 154... Screw, 117... Contact, 120, 150... Case, 121... Main wall, 122... Side wall, 123... Support protrusion, 124... Accommodating recess, 125... Contact portion, 126... Heat sink, 127, 128... Notch, 129, 130... Recess, 132, 134... Screw hole, 141... Connection terminal, 151... Accommodating portion, 152... Flange portion, 160... Cover, 161... Header pin, 162... Pin, 163... Holder

Claims

1. A first substrate and a second substrate on which components for controlling an electric motor are mounted, a first case for housing the first substrate, and a second case for housing the second substrate, wherein the first case and the second case in a first direction which is the thickness direction of the first substrate and the second substrate, have a main wall facing the first substrate or the second substrate, and a frame-shaped side wall protruding in the first direction from an outer edge portion of the main wall so as to surround an outer periphery of the first substrate or the second substrate, a surface on the opposite side of the main wall across the side wall is open, the first substrate and the second substrate are housed in the first case or the second case with the mounting surfaces of the components facing the open surfaces, and the first case and the second case are coupled such that protruding ends of the side walls abut against each other. A motor control device characterized by this.

2. In the motor control device according to Claim 1, among the components, a specific component protruding from a protruding end of the side wall is mounted on each of the first substrate and the second substrate at a position deviated to one side from a virtual line extending in a second direction orthogonal to the first direction and passing through the centers of the first substrate and the second substrate, and the first substrate and the second substrate are housed in the first case or the second case in a state rotated about the virtual line such that the mounting surfaces face each other. A motor control device characterized by this.

3. In the motor control device according to Claim 2, further comprising a third substrate for distributing power supplied from a power source to the first substrate and the second substrate, wherein the specific component is a connector into which a connection terminal of the third substrate is inserted and removed in the second direction. A motor control device characterized by this.

4. In the motor control device according to Claim 3, an opening for exposing the specific component in the second direction is formed in the side wall, and further comprising a third case for housing the third substrate and coupled to an outer surface of the first case and the second case at a position facing the opening. A motor control device characterized by this.

5. In the motor control device according to Claim 1, the side wall has a simple hole penetrating in the first direction, and a screw hole extending in the first direction from a protruding end side is formed at a position rotationally symmetric with the simple hole with respect to a virtual line extending in a second direction orthogonal to the first direction and passing through the center of the main wall. The first case and the second case are joined by a screw inserted from the side of the simple hole being screwed into the threaded hole in a state rotated about the virtual line such that the simple hole and the threaded hole communicate with each other. A motor control device characterized by this.

6. In the motor control device according to claim 5, A plurality of recesses recessed in the first direction are formed on the side wall from the side of the main wall toward the side of the protruding end. The simple hole and the threaded hole are formed at the positions of the recesses. A motor control device characterized in that the recess in which the simple hole is formed has a larger amount of recess in the first direction than the recess in which the threaded hole is formed.

7. In the motor control device according to claim 1, Contacts are arranged on the mounting surfaces of the first substrate and the second substrate respectively on a virtual line extending in a second direction orthogonal to the first direction passing through the center. A motor control device further comprising pins for electrically connecting the contacts of the first substrate and the second substrate.

8. In the motor control device according to claim 1, Instead of the second substrate and the second case, a cover is further provided which is attached to the protruding end of the side wall of the first case and closes the open surface of the first case in which the first substrate is accommodated. A motor control device characterized by this.

9. A motor control device according to claim 1, A first motor driven according to the control of the first substrate, A motor system comprising a second motor driven according to the control of the second substrate.

10. A motor control device according to claim 1, Comprising an electric motor driven according to the control of the first substrate, A motor system characterized in that the second substrate controls the driving of the electric motor in place of the first substrate when the first substrate fails.

11. A wheel, An electric motor for rotating the wheel, An electric vehicle comprising the motor control device according to claim 1 for controlling the driving of the electric motor.

Images