Drive unit and cover for a drive unit

Abstract

The present application relates to a drive unit and a cover of the drive unit, which can effectively discharge water inside the cover of the drive unit. The drive unit (10) is provided with a motor (3), a housing (1) holding the motor (3) and capable of being mounted to a vehicle, and a cover (2). The cover (2) includes a bottom (2B) covering at least a portion of a lower surface of the housing (1) from below, and a left side wall (2L) extending from the bottom (2B) and covering at least a portion of a left side of the housing (1). The cover (2) has a first hole (2a) provided in at least one of a portion of the bottom (2B) on the left side of the center of the vehicle in the left-right direction and the left side wall (2L). In a case where the vehicle in which the housing (1) is mounted is inclined to the left by 5° from an upright state, at least a portion of an edge (2af) of the cover inside the first hole (2a) is in a position that is lowest on the cover inner surface (2n) in the direction of gravity.

Description

Technical Field

[0001] This invention relates to a drive unit and its cover that are mounted on a vehicle. Background Technology

[0002] For example, a drive unit with a motor is installed in vehicles such as electric-assisted bicycles. The drive unit has a housing configured to be mounted to the vehicle and a motor housed within the housing. Japanese Patent Application Publication No. 2021-035110 (Patent Document 1) describes a drive unit comprising a housing, a motor, and a cover. The cover is configured to cover at least a portion of the housing and the motor. A through hole is formed in the portion of the cover that covers at least a portion of the housing and the motor. The through hole is a slit with a width of 10 mm or less, or a maximum width of 10 mm or less.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent document 1: Japanese Patent Application Publication No. 2021-035110. Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] The inventors noticed that water sometimes accumulates inside the cover of the drive unit when the vehicle is parked. In conventional drive units, effective drainage of the water inside the cover was not considered.

[0008] This application discloses a drive unit and a cover capable of effectively draining water from the inside of a cover.

[0009] Methods for solving problems

[0010] In an embodiment of the present invention, a drive unit is mounted to a vehicle. The drive unit includes: a motor; a housing for holding the motor and for mounting to the vehicle; and a cover covering at least a portion of the housing. The cover includes: a bottom that covers at least a portion of the lower surface of the housing from below; and a left side wall that extends from the bottom and covers at least a portion of the housing on the left side in a vehicle-to-left direction. The cover has a first hole, which is disposed on at least one of the portion of the bottom that is to the left of the center in a vehicle-to-left direction and the left side wall. Here, "the first hole disposed on at least one of the portion of the bottom that is to the left of the center in a vehicle-to-left direction and the left side wall" can mean that the first hole is disposed only on the portion of the bottom, only on the left side wall, or on both the portion of the bottom and the left side wall. When the vehicle with the housing mounted tilts 5° to the left from an upright position, at least a portion of the inner edge of the cover with the first hole is at its lowest position in the direction of gravity on the inner surface of the cover.

[0011] Invention Effects

[0012] According to this disclosure, a drive unit capable of effectively draining water from the inside of a hood is provided. Attached Figure Description

[0013] Figure 1 This is a left view showing an example of a vehicle equipped with the drive unit of this embodiment.

[0014] Figure 2 yes Figure 1 A partially enlarged view of the drive unit shown.

[0015] Figure 3 yes Figure 2 The right view of the cover shown.

[0016] Figure 4 yes Figure 2 A cross-sectional view of line A.

[0017] Figure 5 It is shown to be with Figure 2 Left view of examples of drive units mounted to the vehicle frame at different angles.

[0018] Figure 6 It is shown to be with Figure 2 Left view of examples of drive units mounted to the vehicle frame at different angles.

[0019] Figure 7 yes Figure 2 A partial bottom view of the cover of the drive unit shown.

[0020] Figure 8 yes Figure 2 A partial top view of the cover of the drive unit shown.

[0021] Figure 9 It is shown Figure 4 Cross-sectional view of a modified example of the cover shown.

[0022] Figure 10 It is shown Figure 4 Cross-sectional views of other variations of the cover shown. Detailed Implementation

[0023] Unless otherwise specified, in this specification, with the housing installed in a vehicle, the forward / backward, left / right, and up / down directions of the drive unit and the cover are defined as those of the vehicle when it is in an upright position. The upright position of the vehicle is defined as the vertical axis of the vehicle body (body frame) aligning with the vertical direction (direction of gravity). The up / down and forward / backward directions of the drive unit and the cover when not installed in a vehicle may not be strictly unique. For example, in a drive unit and cover not installed in a vehicle, the up / down and forward / backward directions can be any direction within the range that would be possible when installed in a vehicle.

[0024] When a cover is installed on the drive unit of a vehicle, liquids such as water often seep into the space between the cover and the drive unit. To drain this water, the inventors provided drainage holes at the lowest point of the cover. However, it has been found that even with drainage holes, water sometimes remains on the inner surface of the cover. Further detailed research revealed that when the vehicle is parked, the tilt of the drive unit changes subtly compared to when it is moving, making it difficult for water to drain from the inside of the cover through the holes. For example, bicycles are mostly parked tilted to the left rather than upright. Therefore, water may remain inside the cover without draining through the holes. In contrast, when the vehicle is in motion, water entering the cover of the drive unit is easily drained through the holes due to the vehicle's movement. Based on these insights, a detailed study was conducted on the structure of the cover for effectively draining water, resulting in the following embodiment.

[0025] (Structure 1)

[0026] The drive unit in an embodiment of the present invention is a drive unit mounted to a vehicle, comprising: a motor; a housing for holding the motor and for mounting to the vehicle; and a cover covering at least a portion of the housing. The cover includes: a bottom that covers at least a portion of the lower surface of the housing from below; and a left side wall that extends from the bottom and covers at least a portion of the housing on the left side in a vehicle-to-left direction. The cover has a first hole, which is located on at least one of the portion of the bottom that is to the left of the center in the vehicle-to-left direction and the left side wall. When the vehicle with the housing mounted tilts 5° to the left from an upright position, at least a portion of the inner edge of the cover with the first hole is at its lowest position in the direction of gravity on the inner surface of the cover.

[0027] According to structure 1 described above, when the vehicle, on which the housing is mounted, tilts 5° to the left from an upright position, at least a portion of the inner edge of the first hole does not exceed any position above the inner surface of the cover in the direction of gravity. That is, when the vehicle is parked and tilted to the left from an upright position, at least a portion of the inner edge of the first hole is at its lowest point in the direction of gravity on the inner surface of the cover. Therefore, water inside the cover is easily drained when the vehicle is parked. Furthermore, the first hole is positioned so that water can easily drain from it during vehicle movement. As a result, a drive unit capable of effectively draining water from inside the cover can be realized.

[0028] In the above structure 1, in a cross-section of a surface parallel to the left-right direction of the vehicle and passing through the first hole, at least a portion of the inner edge of the first hole is the lowest point on the inner surface of the cover, in a direction extending obliquely downward to the left at an angle of 5° relative to the vertical direction of the vehicle. The inner edge of the first hole is the edge of the first hole that contacts the inner surface of the cover.

[0029] Preferably, when the vehicle with the housing installed is tilted 5° to the left from an upright position, the inner surface of the cover does not include a portion that rises in the direction of gravity as it approaches the inner edge of the first hole. That is, preferably, when the housing is tilted 5° to the left, the entire inner surface of the cover either decreases in the direction of gravity or remains constant as it approaches the inner edge of the first hole. Therefore, when the vehicle is tilted 5° to the left, water on the inner surface of the cover easily flows towards the first hole due to gravity.

[0030] The bottom of the cover can also be a shape that bulges downward when viewed from the left side of the vehicle in a left-right direction, with the vehicle in an upright position. For example, it can also be a shape in which the middle portion between the front and rear portions of the bottom of the cover in a front-rear direction is located lower when viewed from the left side of the vehicle. In this case, the first hole can also be located on at least one of the portion of the left side wall above the middle portion of the bottom, between the front and rear portions (i.e., the middle portion).

[0031] The first hole can also be positioned to overlap with an imaginary line (line A) when viewed from the left side of the vehicle. This imaginary line passes through the lowest point on the inner surface of the cover when the vehicle with the housing is in an upright position and extends upwards in the vertical direction of the vehicle. As a result, water on the inner surface of the cover can easily flow to the first hole due to gravity.

[0032] The first hole can also reach the ridge line between the bottom of the cover and the left side wall. Thus, when the vehicle is tilted to the left, water can easily drain from the first hole. For example, the first hole can also be located at a position where it reaches the ridge line between the bottom and the left side wall, and at least one of the left side wall.

[0033] The first hole can also be positioned such that, when the vehicle with the housing installed is in an upright position, a portion of the inner edge of the first hole is at its lowest point on the inner surface of the cover. Thus, water can easily drain from the first hole regardless of whether the vehicle is upright or tilted to the left.

[0034] Alternatively, when the vehicle with the housing installed is in an upright position, the lowest part of the inner edge of the first hole is located below the housing. This ensures a space for water to pass through between the housing and the portion of the cover with the first hole. For example, a space can be provided at the lower part of the housing between the cover and the housing, and the first hole can be configured to connect to this space.

[0035] The distance between the housing and the inner edge of the cover of the first hole is preferably 5 mm or more, more preferably 10 mm or more. By providing a gap between the housing and the first hole, a channel for water to flow into the first hole can be ensured, allowing water to flow easily into the first hole.

[0036] The maximum width of the first hole is preferably 5 mm or more. This prevents water from easily becoming trapped and blocking the first hole due to surface tension. As a result, water can drain more easily from the first hole. Furthermore, the maximum width is the width along the direction of the largest opening size formed by the first hole.

[0037] The front-to-back dimension of the first hole can also be longer than at least one of the vertical dimension and the horizontal dimension. In this way, by forming the first hole into an elongated shape in the front-to-back direction, a water discharge channel can be ensured over a large range throughout the entire front-to-back direction.

[0038] The cover may also have a convex shape that protrudes downwards from the vehicle when viewed from the left or right side. In this case, when viewed from the side, the first hole may also be located at least one of the top of the convex shape at the bottom and the left side wall portion corresponding to the top.

[0039] The vehicle's left-right direction can also be the same as the direction of the motor shaft of the motor held by the housing. Alternatively, the housing can have a mounting portion (shaft sleeve portion) with bolt holes for mounting to the vehicle. The vehicle's left-right direction can also be the same as the axial direction of the bolt holes of the mounting portion (shaft sleeve portion) of the housing.

[0040] The bottom of the cover may also be formed by a plate-shaped lower cover (bottom cover) integrally formed from left to right below the housing. Alternatively, the cover may be composed of a left cover covering the left side of the housing and a right cover covering the right side of the housing and connected to the left cover below the housing. In this case, the bottom of the cover may also be formed at the lower part of the left cover and the lower part of the right cover.

[0041] (Structure 2)

[0042] In structure 1 described above, ribs extending upward from the inner surface can also be provided at the bottom of the cover. This allows the ribs to suppress deformation of the cover when a lifting force is applied from below. As a result, the impact resistance of the cover is improved.

[0043] (Structure 3)

[0044] In structure 1 or 2 described above, the first hole may also be located on the left side wall. In this case, viewed from the left in the left-right direction of the vehicle, at least a portion of the first hole may be configured to be located below the housing and not overlap with the housing. This allows for drainage while ensuring a space is temporarily maintained between the housing and the cover.

[0045] (Structure 4)

[0046] In any of the structures 1 to 3 described above, the cover may also have a right side wall extending from the bottom and covering at least a portion of the right side of the housing in the vehicle's left-right direction. The cover may also have a second hole located on at least one of the portion of the bottom further to the right of the center in the vehicle's left-right direction and the right side wall. The second hole may also be provided such that, when the vehicle with the housing mounted tilts 5° to the right from an upright position, at least a portion of the inner edge of the cover with the second hole becomes the lowest point in the direction of gravity on the inner surface of the cover. Thus, water can be effectively drained from the inside of the cover regardless of whether the vehicle is tilted to the left or right when parked.

[0047] (Structure 5)

[0048] In structure 4 described above, the first hole can also be a hole located on the left side wall. The second hole can also be a hole located on the right side wall. When viewed from the left-right direction of the vehicle, at least a portion of the first hole can overlap with at least a portion of the second hole. This allows air to easily flow into the cover in the left-right direction. Consequently, water can easily drain from the inside of the cover.

[0049] (Structure 6)

[0050] In any of the structures 1 to 5 described above, the edge of the first hole, as viewed from the left-right direction of the vehicle, may also include a line extending diagonally downwards from front to back. By tilting the edge of the first hole in this way, water inside the cover can be efficiently discharged using the airflow during vehicle operation. From the same perspective, the edge of the second hole, as viewed from the left-right direction of the vehicle, may also include a line extending diagonally downwards from front to back.

[0051] (Structure 7)

[0052] In any of the structures 1 to 6 described above, when the vehicle with the housing installed is in an upright position, the inner edge of the cover of the first hole can also be tilted to the left in the left-right direction of the vehicle. That is, the left end of the edge of the first hole can be located above the right end. As a result, water flowing from above the first hole along the inner surface of the cover can easily drain out through the first hole.

[0053] Furthermore, when the vehicle with the housing installed is in an upright position, the inner edge of the cover of the first hole can also be tilted to the right in the left-right direction of the vehicle. In this case, its lower end is located on the left (outer side) compared to the upper end of the edge of the first hole. Therefore, water droplets and mud kicked up from below during driving are less likely to enter the inside of the cover through the first hole.

[0054] When the vehicle with the housing installed is in an upright position, the inner edge of the second hole can also be tilted to the right in the left-right direction of the vehicle. That is, the right end of the edge of the second hole can also be located above the left end. This allows water flowing from above the second hole along the inner surface of the cover to easily drain out through the second hole. Furthermore, when the vehicle with the housing installed is in an upright position, the inner edge of the cover with the second hole can also be tilted to the left in the left-right direction of the vehicle.

[0055] (Structure 8)

[0056] In any of the structures 1 to 7 described above, the left side wall may also be formed by extending upwards from the inner edge of the cover of the first hole and outwards in the left-right direction of the vehicle. This allows the left side wall above the first hole to be shaped to easily follow the shape of the housing.

[0057] (Structure 9)

[0058] In any of the structures 1 to 7 described above, the left side wall may also be formed by extending upwards from the inner edge of the cover of the first hole and inwards in the left-right direction of the vehicle. Therefore, the first hole is difficult to see from a slightly upward side. Furthermore, since the portion of the left side wall above the first hole extends downwards and outwards, air inside the cover can easily escape through the first hole.

[0059] The cover in the aforementioned drive unit is also included in embodiments of the present invention. The cover in embodiments of the present invention is a cover for a drive unit having a housing mounted to a vehicle and holding a motor. The cover includes: a bottom that covers at least a portion of the lower surface of the housing from below; a left side wall that extends from the bottom and covers at least a portion of the left side of the housing in the vehicle's left-right direction; and a first hole disposed at least one of the portion of the bottom that is to the left of the center in the vehicle's left-right direction and the left side wall. In a cross-section of a plane parallel to the vehicle's left-right direction and passing through the first hole, in a direction extending obliquely downwards and to the left at an angle of 5° relative to the vehicle's vertical direction, the inner edge of the cover of the first hole is lower than any position on the inner surface of the cover.

[0060] Hereinafter, a bicycle according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the drawings, the same or equivalent parts are labeled with the same reference numerals, and the description of these parts will not be repeated. Furthermore, the dimensions of the structural components in the drawings do not faithfully represent the actual dimensions of the structural components or the dimensional ratios of each structural component. In the following description, the front-back, left-right, and up-down directions of the vehicle refer to the front-back, left-right, and up-down directions relative to the occupant of the vehicle. The front-back, left-right, and up-down directions of the vehicle are the same as the front-back, left-right, and up-down directions of the vehicle frame and the drive unit mounted to the vehicle. Additionally, the direction of travel of the vehicle is the same as the front-back direction of the vehicle. In the accompanying drawings, F, B, U, D, R, and L represent front, back, up, down, right, and left, respectively.

[0061] <Example of vehicle overall structure>

[0062] Figure 1 This is a left view showing an example of a vehicle equipped with the drive unit of this embodiment. Figure 1 The vehicle 100 is shown in an upright position. Figure 1 The vehicle 100 shown is an electric-assisted bicycle.

[0063] exist Figure 1 In this vehicle 100, there is a frame 11. The frame 11 extends in the longitudinal direction. A head tube 12 is provided at the front of the frame 11. The head tube 12 supports a steering shaft 13 for rotation. A handlebar 23 is mounted on the upper part of the steering shaft 13, and a front fork 26 is mounted on the lower part. The front fork 26 supports a front wheel 21 for rotation at its lower end. The rear of the frame 11 supports a rear wheel 22 for rotation. A seat 24 is mounted on the upper part of the frame 11. The crankshaft 41 is supported on the lower part of the frame 11 for rotation. Brake levers 74 are mounted on the left and right sides of the handlebar 23. The left brake lever 74 is a lever for operating the brake 76 of the rear wheel 22. The right brake lever 74 is a lever for operating the brake 75 of the front wheel 21.

[0064] exist Figure 1 In the example shown, a drive unit 10 is mounted on the lower part of the body frame 11. A crankshaft 41 is rotatably mounted to the drive unit 10. In this example, the crankshaft 41 is rotatably supported on the body frame 11 via the drive unit 10. The drive unit 10 is mounted, for example, to a bracket 15 on the body frame 11. The bracket 15 is located at the lower end of the body frame 11 (in this example, the seat frame and lowering frame). The drive unit 10 is mounted suspended from the body frame 11.

[0065] The drive unit 40 includes a motor 3, a housing 1 for holding the motor 3, and a cover 2. The housing 1 is configured to be mounted to the vehicle 100. The housing 1 has a mounting portion (shoulder sleeve portion) with bolt holes extending through in the left-right direction of the vehicle. Bolts extending through the mounting portion of the housing 1 are fastened to brackets 15 of the vehicle body frame 11. Thus, the housing 1 is mounted to the vehicle body frame 11.

[0066] The crankshaft 41 extends along the left-right direction of the bicycle. Crank arms 31 are mounted at both ends of the crankshaft 41. Pedals 33 are mounted at the front ends of the crank arms 31. Although not shown, the bicycle 100 has a drive sprocket that rotates with the crankshaft 41 and a driven sprocket that rotates with the rear wheel 22. A chain 46 is wound between the drive sprocket and the driven sprocket. Alternatively, a belt may be used instead of a chain 46. The drive sprocket, chain 46, and driven sprocket are examples of transmission components that transmit the rotation of the pedals to the rear wheel. The transmission components are not limited to these. For example, gears and shafts may be provided instead of sprockets and chains. In addition, the transmission components may also include a one-way clutch. The one-way clutch transmits rotation in the forward direction but not rotation in the backward direction.

[0067] The vehicle (bicycle) 100 has a bracket 25 mounted to the frame 11. The bracket 25 supports the vehicle 100 in a manner that prevents it from tipping over when parked. Figure 1 In the example, when parked, the vehicle 100 is supported by bracket 25 while tilted to the left. When the vehicle 100 is upright, bracket 25 is not in contact with the ground. Figure 1 In this example, bracket 25 is mounted to the chain link, which is part of the vehicle frame 11. Alternatively, bracket 25 is not limited to the chain link and can also be mounted to other parts of the vehicle frame 11.

[0068] Figure 2 yes Figure 1 A partially enlarged view of the drive unit 10 shown. Figure 3 yes Figure 2 The right view of the cover shown. Figure 4 yes Figure 2 A cross-sectional view of line A. In Figures 2 to 4The image shows the drive unit 10, housing 1, and cover 2 of a vehicle 100 mounted in an upright position. Figure 2 In order to make it easier to understand, dotted lines were implemented in part 2 of the cover.

[0069] like Figure 2 As shown, the cover 2 has a bottom 2B and a left side wall 2L. The bottom 2B covers at least a portion of the lower surface of the housing 1 from below. The left side wall 2L extends upward from the bottom 2B and covers at least a portion of the left side of the housing 1.

[0070] A first hole 2a is provided on the left side wall 2L of the cover 2. When the vehicle is upright, the first hole 2a is positioned when viewed from the left in the left-right direction of the vehicle, and overlaps with the lowest point 2nU of the inner surface 2n of the cover 2 in the vertical direction. That is, when viewed from the left, the first hole 2a is positioned to overlap with an imaginary line (line A) that passes through the lowest point 2nU of the inner surface 2n of the cover 2 and extends upward.

[0071] exist Figure 2 In the example shown, the bottom 2B of the cover 2 has a shape that protrudes downwards when viewed from the left. The middle portion between the front and rear portions of the bottom 2B in the vehicle's longitudinal direction is located further downwards. That is, a protrusion protruding downwards from the front and rear ends is provided between the front and rear ends of the bottom 2B of the cover 2. When viewed from the left, the first hole 2a is located on the left side wall portion above the top of the protrusion of the bottom 2B.

[0072] like Figure 3 As shown, the cover 2 has a right side wall 2R. Figure 3 For ease of understanding, a dotted line is applied to a portion of the right side wall 2R. The right side wall 2R extends upward from the bottom 2B, covering at least a portion of the right side of the housing 1. A second hole 2b is provided on the right side wall 2R. When the vehicle is upright, the second hole 2b is positioned, when viewed from the right in the left-right direction, to overlap with the lowest point 2nU of the inner surface 2n of the cover 2 in the vertical direction. That is, when viewed from the right, the second hole 2b is positioned to overlap with an imaginary line (line A) extending upward through the lowest point 2nU of the inner surface 2n of the cover 2. Figure 3 In this example, the right side wall 2R has an opening through which the crankshaft 41 passes. The portion 2Ra above this opening is inserted and becomes part of the right side wall 2R after the cover 2 is installed into the housing 1.

[0073] Figure 4 It is a cross-section of the surface passing through the lowest point 2nU of the inner surface 2n of the cover 2 in its upright state, and parallel to the left-right direction. Figure 4 In the diagram, line AL represents the direction of gravity when the vehicle 100, equipped with drive unit 10 (i.e., housing 1), tilts 5° to the left from an upright position. For example... Figure 4As shown, when the vehicle 100 with housing 1 installed tilts 5° to the left from an upright position, at least a portion of the inner edge 2af of the first hole 2a is at its lowest position in the direction of gravity on the inner surface 2n of the housing. In other words, in a cross-section of a surface parallel to the left-right direction of the vehicle and passing through the first hole 2a, in the direction of the reference axis (line AL) extending obliquely downward to the left at an angle of 5° relative to the vertical direction of the vehicle, at least a portion of the inner edge 2af of the first hole 2a is not higher than any position on the inner surface 2n of the housing 2.

[0074] exist Figure 4 In the diagram, line AR represents the direction of gravity when the vehicle 100, equipped with drive unit 10 (i.e., housing 1), is tilted 5° to the right from its upright position. For example... Figure 4 As shown, when the vehicle 100 with housing 1 installed tilts 5° to the right from its upright position, at least a portion of the inner edge 2bf of the second hole 2b is at its lowest position in the direction of gravity on the inner surface 2n of the housing. In other words, in a cross-section of a surface parallel to the left-right direction of the vehicle and passing through the second hole 2b, in the direction of a reference axis (line AR) extending obliquely downward to the right at an angle of 5° relative to the vertical direction of the vehicle (line A), at least a portion of the inner edge 2bf of the second hole 2b is not higher than any position on the inner surface 2n of the housing 2.

[0075] exist Figure 4 In the example shown, the left end of the bottom 2B of the cover 2 becomes the edge of the first hole 2a. The inner surface 2n of the bottom 2B of the cover 2 slopes downwards as it enters from the left end in the left-right direction of the vehicle. In this case, the left-right slope of the inner surface 2n from the left end of the bottom 2B toward the inside can be less than 5°. Thus, when the vehicle is tilted 5° to the left from an upright position, the edge of the first hole 2a at the left end of the bottom 2B is lowest on the inner surface of the bottom 2B.

[0076] In addition, Figure 4 In the example shown, the right end of the bottom 2B of the cover 2 becomes the edge of the second hole 2b. The inner surface 2n of the bottom 2B of the cover 2 slopes downwards as it enters from the right end in the left-right direction of the vehicle. In this case, the left-right slope of the inner surface 2n from the right end of the bottom 2B toward the inside can be less than 5°. Thus, when the vehicle is tilted 5° to the right from an upright position, the edge of the second hole 2b at the right end of the bottom 2B is lowest on the inner surface of the bottom 2B.

[0077] exist Figure 4In the example shown, when the vehicle 100 is tilted 5° to the left from an upright position, the inner surface 2n of the cover does not include the portion that rises in the direction of gravity (the direction of line AL) as it approaches the inner edge of the first hole 2a. Therefore, when the vehicle 100 is tilted 5° to the left, water on the inner surface 2n of the cover easily flows towards the first hole 2a.

[0078] In addition, Figure 4 In the example shown, when the vehicle 100 is tilted 5° to the right from an upright position, the inner surface 2n of the cover does not include the portion that rises in the direction of gravity (the direction of line AR) as it approaches the inner edge of the second hole 2b. Therefore, when the vehicle 100 is tilted 5° to the right, water on the inner surface 2n of the cover easily flows towards the second hole 2b.

[0079] exist Figure 4 In the example shown, when viewed from the left-right direction of the vehicle, at least a portion of the first hole 2a overlaps with at least a portion of the second hole 2b. A space is provided between the first hole 2a and the second hole 2b, extending in the left-right direction of the vehicle. This allows air to easily flow in the left-right direction within the cover 2.

[0080] Figure 4 This is a cross-sectional view of the lowest point 2nU (hereinafter referred to as the lowermost point 2nU) of the inner surface 2n of the cover 2 in its upright state, parallel to the left-right direction of the vehicle. The lowermost point 2nU of the inner surface 2n of the cover 2 depends on the angle of the housing 1 relative to the vehicle frame 11. That is, if the angle (installation angle) of the housing 1 relative to the vehicle frame 11 is different, the lowermost point 2nU of the inner surface 2n of the cover 2 will also be different.

[0081] Figure 5 and Figure 6 It is shown to be with Figure 2 Left view of an example of a drive unit 10 mounted to a vehicle frame 11 at different angles. Figure 5 The housing 1 of the drive unit 10 shown is viewed from the left with the vehicle's left-right direction as the axis. Figure 2 The housing 1 shown is mounted to the vehicle frame 11 by rotating it 20° clockwise. Figure 5 and Figure 6 The diagram shows the state in which the drive unit 10 is installed on the vehicle in an upright position.

[0082] exist Figure 5 In the example, the lowest position 2nU on the inner surface 2n of the cover 2 is greater than... Figure 2 The situation is further back. Additionally, in Figure 5 In the example, the vertical direction of the drive unit 10 (cover 2) is relative to... Figure 2 The drive unit rotates 20° up and down about the left and right axis. Figure 5In the case where the vehicle is upright, the first hole 2a is positioned at a location that overlaps with an imaginary line extending in the vertical direction from the left side of the vehicle, when viewed from the left side of the vehicle. This position overlaps with the lowermost position 2nU of the inner surface 2n of the cover 2.

[0083] exist Figure 6 In the example, the lowest position 2nU on the inner surface 2n of the cover 2 is greater than... Figure 2 The situation is closer to the front. Also, in Figure 6 In the example, the vertical direction of the drive unit 10 (cover 2) becomes relative to Figure 2 The drive unit 10 rotates 20° in the vertical direction about the left-right direction. Figure 6 In the case where the vehicle is upright, the first hole 2a is positioned at a location that overlaps with an imaginary line extending in the vertical direction from the left side of the vehicle, when viewed from the left side of the vehicle. This position overlaps with the lowermost position 2nU of the inner surface 2n of the cover 2.

[0084] like Figure 2 , Figure 5 and Figure 6 As shown, the mounting angle of the drive unit 10 (housing 1) relative to the vehicle frame 11 can sometimes be arbitrarily determined within a certain range. In such cases, it is preferable to provide a first hole 2a at a position that overlaps with an imaginary line extending upwards in the vertical direction of the vehicle, within the range of the envisioned mounting angle, in the area that can be the lowest position 2nU through the inner surface 2n of the cover 2. Thus, at any mounting angle within the envisioned range, the first hole 2a is located above the lowest position 2nU. For example, as... Figure 6 As shown, if the range of the installation angle is assumed to be 40°, the first hole 2a can be set in a way that crosses the area L1 between line A1 and line A2.

[0085] Furthermore, even with changes in the mounting angle in the direction of rotation about the vehicle's left-right axis, Figure 4 The left-right and up-down directions in the cross-section shown do not change. (Use) Figure 4 The structure described is a structure that is valid at any installation angle within the assumed range.

[0086] When viewed from the right side in the left-right direction of the vehicle, the second hole 2b can be positioned at a location that overlaps with an imaginary line extending upward in the vertical direction of the vehicle, passing through the inner surface 2n of the cover 2 when the vehicle with the housing 1 installed is in an upright state. This line would be the area that is the lowest position 2nU.

[0087] exist Figure 2 , Figure 5 and Figure 6In either case, when viewed from the left in the left-right direction of the vehicle, at least a portion of the first hole 2a is located below the housing 1 and does not overlap with the housing 1. The edge of the first hole 2a is configured to maintain an appropriate distance from the housing 1 below it. Thus, the space between the housing 1 and the cover 2 is properly maintained, allowing water to drain easily. Similarly, at least a portion of the second hole 2b, when viewed from the right in the left-right direction of the vehicle, can also be located below the housing 1 and does not overlap with the housing 1.

[0088] Reference Figure 4 The shortest distance D1 between the housing 1 and the inner edge 2af of the first hole 2a is not particularly limited, but is preferably 5 mm or more, and more preferably 10 mm or more.

[0089] exist Figure 2 , Figure 5 and Figure 6 In any case, the longitudinal dimension of the first hole 2a is longer than its vertical dimension. By making the first hole 2a elongated in the longitudinal direction, a water discharge channel can be ensured over a large range in the longitudinal direction. Therefore, for example, the first hole 2a can be made to correspond to a wider range of installation angles. From the same point of view, the longitudinal dimension of the second hole 2b can be made longer than its vertical dimension.

[0090] exist Figure 2 , Figure 5 and Figure 6 In either case, the edge of the first hole 2a, viewed from the left, includes a line extending diagonally downwards from front to back. Thus, water within the hood, flowing with the airflow, can easily drain along this line of the first hole 2a. In this example, the first hole 2a is separated by a pillar extending diagonally downwards from front to back. The edge of this pillar forms the diagonally downward-extending line of the edge of the first hole 2a. Figure 3 As shown, the edge of the second hole 2b, as seen from the right, also includes a line extending diagonally downwards from front to back.

[0091] Figure 7 yes Figure 2 A bottom view of the cover 2 of the drive unit 10 shown. Figure 7 As shown, the first hole 2a is positioned such that it reaches the ridge line (corner) between the bottom 2B and the left side wall 2L. The second hole 2b is positioned such that it reaches the ridge line (corner) between the bottom 2B and the right side wall 2R. Therefore, when the vehicle is tilted to the left or right, water can easily drain from the bottom 2B. Additionally, for example, as... Figure 7As shown by the dotted line, the first hole 2a can also be located on the bottom 2B, slightly to the left of the center in the left-right direction of the vehicle. In this case, for example, the first hole 2a on the bottom 2B can also reach the edge between the bottom 2B and the left side wall 2L. Alternatively, the first hole 2a can be formed covering both the left side wall 2L and the bottom 2B. For example, as... Figure 7 As shown by the dotted line, the second hole 2b can also be located to the right of the center of the bottom 2B in the left-right direction of the vehicle. In this case, for example, the second hole 2b can also reach the edge between the bottom 2B and the right side wall 2R. Alternatively, the second hole 2b can be formed across both the right side wall 2R and the bottom 2B.

[0092] exist Figure 7 In the example, the post 2a1 that separates the interior of the first hole 2a extends from front to back in a manner close to the inside of the vehicle's left-right direction. The post 2b1 that separates the interior of the second hole 2b extends from front to back in a manner close to the inside of the vehicle's left-right direction.

[0093] The front-to-back dimension of the first hole 2a is longer than its left-to-right dimension. The front-to-back dimension of the second hole 2b is longer than its left-to-right dimension. The first hole 2a and the second hole 2b are positioned opposite each other in the left-to-right direction of the vehicle. The bottom 2B of the cover 2 is positioned between the first hole 2a and the second hole 2b.

[0094] Figure 8 yes Figure 2 The diagram shows a partial top view of the cover 2 of the drive unit 10. Ribs 2p1, 2p2, and 2p3 extending upwards from the inner surface 2n are provided at the bottom 2B of the cover 2. Ribs 2p1, 2p2, and 2p3 are formed extending in the left-right direction of the vehicle. Ribs 2p1, 2p2, and 2p3 are not formed entirely in the left-right direction of the bottom 2B, but only partially. This prevents the ribs from obstructing the flow of water in the bottom 2B. Rib 2p1 is positioned forward of the first hole 2a. Rib 2p2 is positioned between the front and rear ends of the first hole 2a. Rib 2p3 is positioned rearward of the first hole 2a.

[0095] exist Figure 4 In the cover 2 of the drive unit 10 shown, in the upright state, the inner edge 2af of the first hole 2a is inclined to the left in the left-right direction of the vehicle. That is, the left end of the edge 2af of the first hole 2a is located above the right end. In this way, by setting the first hole 2a to a shape that is inclined to the left, water flowing from above the first hole 2a onto the inner surface 2n of the cover 2 can easily fall downwards from the edge of the first hole 2a and be discharged to the outside of the cover 2. In addition, in Figure 4In the example, the inner edge 2bf of the second hole 2b is inclined to the right in the left-right direction of the vehicle. By making the second hole 2b into a shape that is inclined to the right, water flowing from above can easily be discharged from the second hole 2b.

[0096] exist Figure 4 In this example, the left side wall 2L extends upward from the edge of the first hole 2a and outward (left side) in the left-right direction of the vehicle. In other words, the left side wall 2L extends upward from the first hole 2a and tilts to the left. Similarly, the right side wall 2R extends upward from the edge of the second hole 2b and outward (right side). In other words, the right side wall 2R extends upward from the second hole 2b and tilts to the right. This allows the cover above the first hole 2a and the second hole 2b to be formed in a shape that follows the shape of the housing 1.

[0097] Figure 9 It is shown Figure 4 A cross-sectional view of a modified example of cover 2 shown. Figure 9 In the illustrated cover 2, in the upright position, the inner edge 2af of the first hole 2a is inclined to the right in the left-right direction of the vehicle. That is, the lower end of the edge 2af of the first hole 2a is located to the left (outer) than the upper end. In this structure, water droplets and mud kicked up from below during driving are less likely to enter the first hole 2a. Furthermore, the inner edge 2bf of the second hole 2b is inclined to the left in the left-right direction of the vehicle. That is, the lower end of the edge 2bf of the second hole 2b is located to the right (outer) than the upper end.

[0098] exist Figure 9 In the example shown, in the upright position, the left end of the bottom 2B, including the left end that contacts the first hole 2a, bends diagonally downwards to the left. That is, the bottom 2B bends in a manner that extends upwards from the edge of the first hole 2a in the right (inner) direction of the vehicle's left and right, and then downwards. By bending the left end of the bottom 2B, including the left end that contacts the first hole 2a, downwards to the left, it is possible to further suppress water droplets and mud from entering the first hole 2a from below. Similarly, on the right side, in the upright position, the right end of the bottom 2B, including the right end that contacts the second hole 2b, bends diagonally downwards to the right. This, in turn, suppresses water droplets and mud from entering the second hole 2b from below.

[0099] Figure 10 It is shown Figure 4 A cross-sectional view of another modified example of the cover 2 shown. Figure 10In the shown cover 2, the left side wall 2L extends upward from the inner edge 2af of the first hole 2a and to the right (inner side) in the left-right direction of the vehicle. In this case, the first hole 2a is difficult to see from the upper left side. Furthermore, since the portion of the left side wall 2L above the first hole 2a extends downward and outward (left side), air inside the cover 2 can easily escape from the first hole 2a. Therefore, water is facilitated from escaping through the first hole 2a. From the same viewpoint, the right side wall 2R extends upward from the inner edge 2bf of the second hole 2b and to the right (inner side) in the left-right direction of the vehicle. That is, the portion of the right side wall 2R above the second hole 2b extends downward and outward (right side).

[0100] Vehicles equipped with a drive unit are not particularly limited; for example, they can also be vehicles that are parked tilted to the left. For instance, a vehicle equipped with a drive unit can be a tilting vehicle. A tilting vehicle is a vehicle that turns by tilting its body in the direction of the turn. Tilting vehicles are often parked with their bodies tilted to the left.

[0101] Vehicles equipped with drive units include, for example, bicycles. Bicycles included in this category include electric-assist bicycles, electric bicycles, etc. The type of bicycle included is not particularly limited; for example, mountain bikes, road bikes, city bikes, freight bikes, recumbent bikes, and other types of bicycles are included in the category of vehicles equipped with drive units. Furthermore, vehicles equipped with drive units are not limited to two-wheeled vehicles; they can also be three-wheeled or more. For example, vehicles equipped with drive units also include LMWs, electric quad bikes, etc.

[0102] In the above example, it is illustrated that when the vehicle is tilted 5° to the left from an upright position, at least a portion of the inner edge of the first hole 2a is lowest at the inner surface 2n of the cover 2. This structure is not limited to the case where the vehicle is tilted 5° to the left. In the above example, at least a portion of the inner edge of the first hole 2a is also lowest at the inner surface 2n of the cover 2 when the vehicle is tilted 5 to 10° from an upright position. Alternatively, for example, it may be configured such that at least a portion of the inner edge of the first hole 2a is lowest at the inner surface of the cover when the vehicle is tilted 3 to 10° from an upright position.

[0103] The embodiments of the present invention have been described above, but these embodiments are merely illustrative examples for implementing the present invention. Therefore, the present invention is not limited to the above embodiments, and can be implemented by appropriate modifications without departing from its spirit.

[0104] Symbol Explanation

[0105] 1: Shell

[0106] 2: Cover

[0107] 2a: First hole

[0108] 2b: Second hole

[0109] 2L: Left side wall

[0110] 2R: Right side wall

[0111] 2B: Bottom

[0112] 3: Motor

[0113] 10: Drive Unit

[0114] 100: Bicycle (vehicle)

Claims

1. A drive unit mounted to a vehicle, the drive unit comprising: a motor; a housing that holds the motor and is mountable to the vehicle; and a cover that covers at least a portion of the housing, the cover including: a bottom portion that covers at least a portion of a lower surface of the housing from below; and a left side wall that extends from the bottom portion and covers at least a portion of a left side of the housing in a vehicle left-right direction, the cover having a first hole provided in at least one of a portion of the bottom portion on a left side of a center in the vehicle left-right direction and the left side wall, at least a portion of an edge of the cover on an inner side of the first hole being located at a lowest position on an inner surface of the cover in a direction of gravity when the vehicle in which the housing is mounted is tilted 5° to the left from an upright state.

2. The drive unit according to claim 1, wherein a rib is provided on the bottom portion of the cover, the rib extending upward from the inner surface.

3. The drive unit according to claim 1, wherein the first hole is provided in the left side wall, at least a portion of the first hole being located at a position lower than the housing and not overlapping the housing as viewed from a left side in the vehicle left-right direction.

4. The drive unit according to claim 1, wherein the cover has a right side wall that extends from the bottom portion and covers at least a portion of a right side of the housing in the vehicle left-right direction, the cover having a second hole provided in at least one of a portion of the bottom portion on a right side of the center in the vehicle left-right direction and the right side wall, at least a portion of an edge of the cover on an inner side of the second hole being located at a lowest position on an inner surface of the cover in a direction of gravity when the vehicle in which the housing is mounted is tilted 5° to the right from an upright state.

5. The drive unit according to claim 4, wherein the first hole is provided in the left side wall, the second hole is provided in the right side wall, and at least a portion of the first hole overlaps at least a portion of the second hole as viewed in the vehicle left-right direction.

6. The drive unit according to any one of claims 1 to 5, wherein an edge of the first hole as viewed in the vehicle left-right direction includes a line extending obliquely downward from front to back.

7. The drive unit according to any one of claims 1 to 5, wherein an edge of the first hole on an inner side of the cover is inclined to a left side in the vehicle left-right direction when the vehicle in which the housing is mounted is in an upright state.

8. The drive unit according to any one of claims 1 to 5, wherein the left side wall is formed so as to extend upward and outward in the vehicle left-right direction from the edge of the first hole on the inner side of the cover.

9. The drive unit according to any one of claims 1 to 5, wherein the left side wall is formed so as to extend upward and inward in the vehicle left-right direction from the edge of the first hole on the inner side of the cover.

10. The drive unit according to claim 1, wherein a lowermost portion of an inner edge of the first hole is located at a position lower than the housing when the vehicle in which the housing is mounted is in an upright state. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 11. A cover of a drive unit that is mounted to a vehicle and has a housing that holds a motor, the cover comprising: a bottom that covers at least a portion of a lower surface of the housing from below; a left side wall that extends from the bottom and covers at least a portion of a left side of the housing in a vehicle left-right direction; and a first hole provided in at least one of a portion of the bottom that is on a left side of a center in the vehicle left-right direction and the left side wall, in a cross section of a plane that is parallel to the vehicle left-right direction and passes through the first hole, at least a portion of an edge of an inside of the cover in the first hole becomes lowest on an inside surface of the cover in a direction of a reference axis that extends obliquely downward to the left at an angle of 5° with respect to a vehicle up-down direction. ​

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