Electric Propulsion Unit

Abstract

To provide an electrically-driven propulsion unit capable of switching between forward and backward movement of an electrically-driven movable body with easy operation and eventually aim to contribute to energy efficiency.SOLUTION: An electrically-driven propulsion unit 1 that makes an electrically-driven movable body 2 generate propulsion force has an electric motor 8, a propulsion generating member 12, a battery 9, an operation unit 30, and a control device 10. The operation unit is configured to be displaceable in the positive direction and the inverse direction, and accepts a changing operation for changing the output torque of the electric motor. The control device controls the electric motor so that a target output torque based on an operation amount θ of the operation unit is achieved. The control device sets the target output torque to a positive value when the operation unit is operated in the positive direction during the positive rotation of the electric motor, and sets the target output torque to a negative value when the operation unit is operated in the positive direction during the inverse rotation of the electric motor. The control device sets the target output torque to a negative value when the operation unit is operated in the inverse direction during the positive rotation of the electric motor.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an electric propulsion unit. [Background technology]

[0002] In recent years, research and development into secondary batteries that contribute to energy efficiency has been conducted to ensure that more people have access to affordable, reliable, sustainable, and advanced energy. An electric outboard motor powered by a secondary battery drives a boat forward or backward by applying driving force from the electric motor to a propeller. The electric motor rotates in a forward direction to move the boat forward and in a reverse direction to move the boat backward. The electric outboard motor described in Patent Document 1 includes a propeller, an electric motor that rotates the propeller, an electronic control unit that controls the electric motor, and a tiller handle that rotates relative to the boat body and the outboard motor body. The tiller handle has an accelerator grip that rotates relative to the tiller handle and a shift switch. The electronic control unit controls the output of the electric motor (the magnitude of the current supplied to the electric motor) in accordance with the rotation angle of the accelerator grip. The shift switch is operated to switch the rotation direction of the electric motor between forward and reverse. This allows the control device to switch the rotation direction of the electric motor, thereby switching the boat forward or backward. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-126954 Summary of the Invention [Problem to be solved by the invention]

[0004] In the electric outboard motor described in Patent Document 1, to switch the boat between forward and reverse, the user must operate both a shift switch and an accelerator grip. That is, to switch the boat between forward and reverse, the user must return the accelerator grip to its initial position and then press the shift switch with the accelerator grip returned to its initial position. This operation is therefore cumbersome, and there is room for improvement in the operation of switching between forward and reverse.

[0005] In view of the above background, the present invention aims to provide an electric propulsion unit that can switch between forward and reverse drive of an electric vehicle with a simple operation, thereby contributing to improved energy efficiency. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention provides an electric propulsion unit (1) that generates a propulsive force in an electric vehicle (2), the electric propulsion unit having an electric motor (8), a propulsive force generating member (12) that is driven by the electric motor to generate a propulsive force, a battery (9) that supplies power to the electric motor, an operation unit (30) that receives a change operation for changing the output torque of the electric motor, and a control device (10) that sets a target output torque for the electric motor based on an operation amount (θ) of the operation unit and controls the electric motor so that the target output torque is achieved, the operation unit being configured to be displaceable in forward and reverse directions from a neutral position, the control device setting the target output torque to a positive value when the operation unit is operated in the forward direction while the electric motor is rotating in the reverse direction, and setting the target output torque to a negative value when the operation unit is operated in the forward direction while the electric motor is rotating in the reverse direction, and the control device setting the target output torque to a negative value when the operation unit is operated in the forward direction while the electric motor is rotating in the forward direction. than the neutral position When the operation is performed in the reverse direction, the target output torque is set to a negative value.

[0007] According to this aspect, the user can switch the direction and value of the output torque of the electric motor by operating a single operating unit, and therefore can easily switch the direction of the output torque of the electric motor, i.e., the direction of the electric vehicle's forward and reverse motion.

[0008] In the above aspect, the operation unit is configured to be constantly biased to the neutral position, and the control device may set the target output torque to a negative value when the operation unit is returned to the neutral position while the electric motor is rotating in the forward direction.

[0009] According to this aspect, the electric motor generates a negative output torque, that is, a deceleration force, so that the electric vehicle can be stopped quickly.

[0010] In the above aspect, when the rotation speed (ω) of the electric motor during forward rotation is equal to or less than a predetermined first threshold (ω1), the control device may set the target output torque to 0 when the operating unit is in the neutral position.

[0011] According to this aspect, the electric motor switches from a state generating deceleration force to a state where output is stopped simply by returning the operating unit to the neutral position while the electric motor is rotating in the forward direction, making it easy to stop the electric vehicle while it is moving forward.

[0012] In the above aspect, when the operating unit is returned to the neutral position while the electric motor is rotating forward, the control device may execute regenerative charging control to cause the electric motor to function as a generator and perform regenerative charging of the battery in order to achieve the target output torque, which is set to a negative value.

[0013] According to this aspect, the control device converts deceleration energy into regenerative energy while the electric vehicle is moving forward, thereby reducing energy loss in the battery, thereby contributing to improved energy efficiency.

[0014] In the above aspect, when the operating unit is returned to the neutral position while the electric motor is rotating in reverse, the control device may set the target output torque to a positive value.

[0015] According to this aspect, the electric motor generates a positive output torque, i.e., a deceleration force (acceleration force) during reverse travel, so that the electric vehicle can be stopped quickly during reverse rotation of the electric motor, typically while the electric vehicle is traveling in reverse.

[0016] In the above aspect, if the absolute value of the rotational speed of the electric motor during reverse rotation is equal to or less than a predetermined second threshold value (ω2), the control device may set the target output torque to 0 when the operating unit is in the neutral position.

[0017] According to this aspect, the electric motor switches from a state in which it generates deceleration force while reversing to a state in which it stops outputting power simply by operating the operating unit to the neutral position while the electric motor is rotating in reverse, making it easy to stop the electric vehicle while reversing.

[0018] In the above aspect, when the operating unit is operated in the reverse direction while the electric motor is rotating in reverse at a rotational speed with an absolute value greater than a predetermined value, the control device may set the target output torque to 0.

[0019] According to this aspect, when the operating unit is operated in the reverse direction while the electric motor is rotating in the reverse direction, typically while the electric vehicle is moving backward, the electric motor stops outputting power, causing the electric vehicle to slowly stop.

[0020] In the above aspect, when the operating unit is returned to the neutral position while the electric motor is rotating in reverse, the control device may execute regenerative charging control to cause the electric motor to function as a generator and perform regenerative charging of the battery in order to achieve the target output torque that is set to a positive value.

[0021] According to this aspect, even when the electric vehicle is moving backward, the deceleration energy is converted into regenerative energy by the control device.

[0022] In the above aspect, the operating unit may be configured so that a maximum amount of operation in the reverse direction from the neutral position is smaller than the maximum amount of operation in the forward direction.

[0023] According to this aspect, the user can determine whether the operating unit is being operated in the forward direction or the reverse direction.

[0024] In the above aspect, the control device is configured to: than the neutral position When the operation unit is operated in the reverse direction, the target output torque may be set to a negative value that is set in accordance with the rotation speed of the electric motor, regardless of the amount of operation of the operation unit.

[0025] According to this aspect, the user can switch the operation of the operating unit from the reverse direction to the forward direction by controlling the speed of the electric vehicle.

[0026] In the above aspect, the maximum absolute value of the negative target output torque, which is set when the electric motor is rotating in reverse and the operating unit is operated in the reverse direction, may be smaller than the maximum absolute value of the positive target output torque, which is set when the electric motor is rotating in forward direction and the operating unit is operated in the forward direction.

[0027] According to this aspect, when the electric vehicle is moving backward, it is possible to prevent excessive output torque from being output and the electric vehicle from being subjected to excessive deceleration force, i.e., excessive acceleration of the reverse rotation of the electric motor is prevented.

[0028] In the above aspect, the electric propulsion unit may further include a notification section (36) that notifies that the electric motor has shifted from forward rotation to reverse rotation.

[0029] According to this aspect, when switching the electric vehicle from forward to reverse, the user can recognize the timing to operate the operating unit from the reverse direction to the forward direction in order to increase the absolute value of the negative output torque. [Effects of the Invention]

[0030] According to the above configuration, an electric propulsion unit can be provided that allows the electric vehicle to switch between forward and reverse motion with a simple operation, which in turn can contribute to improved energy efficiency. [Brief explanation of the drawings]

[0031] [Figure 1] 1 is a side view of an electric outboard motor to which an electric propulsion unit according to the present invention is applied; [Figure 2] An explanatory diagram showing a means for determining the neutral position of the accelerator grip. [Figure 3] Block diagram showing the electrical configuration of an electric outboard motor [Figure 4] Torque map diagram [Figure 5] 10 is a diagram illustrating the target output torque and the operation of the electric motor according to the operation. [Figure 6] 10 is a diagram illustrating the target output torque and the operation of the electric motor according to the operation. [Figure 7] 10 is a diagram illustrating the target output torque and the operation of the electric motor according to the operation. [Figure 8] 10 is a diagram illustrating the target output torque and the operation of the electric motor according to the operation. [Figure 9] 10 is a diagram illustrating the target output torque and the operation of the electric motor according to the operation. DETAILED DESCRIPTION OF THE INVENTION

[0032] An electric propulsion unit according to the present invention will be described below with reference to the drawings. In this embodiment, a boat to which the electric propulsion unit is applied will be described. The boat includes a hull 2 ​​and an electric outboard motor 1 that generates propulsive force for the hull 2. In the following embodiment, terms indicating directions such as front-to-rear and up-down will be used based on the operating state in which the electric outboard motor 1 is attached to the hull 2.

[0033] The electric outboard motor 1 includes an outboard motor main body and a mounting device 5 for mounting the outboard motor main body to a hull 2. The outboard motor main body includes a main body case 6, an electric motor 8, a thrust generating member, a battery 9, and a control device 10. In this embodiment, a propeller 12 is used as the thrust generating member. The outboard motor main body also includes a drive shaft 14, a gear device 15, a propeller shaft 16, and a tiller handle 18. The components of the electric outboard motor 1 will be described in order below.

[0034] The main body case 6 is made of a metal material or a hard resin material and has a predetermined rigidity. The main body case 6 includes an upper case 20 disposed on the top and a lower case 21 disposed below the upper case 20. The upper case 20 and the lower case 21 may be made of the same material or different materials. The upper case 20 has a hollow shape that is flat in the vertical direction and long in the front-to-rear direction. The upper case 20 houses the electric motor 8 and the control device 10. The lower case 21 has a hollow shape that is long in the vertical direction. The lower case 21 houses the gear device 15. A drive shaft 14 extending from the upper case 20 to the lower case 21 is disposed in the main body case 6.

[0035] The electric motor 8 serves both as an electric motor for rotating the propeller 12 and as a generator for regeneration. The electric motor 8 is powered by a battery 9, which is a secondary battery, and a control device 10 (described later) controls the power supply from the battery 9 and the power supply (charging) to the battery 9 via an inverter 24. The electric motor 8 is disposed above the upper case part 20 so that the output shaft extends vertically downward. The battery 9 may be disposed outside the main body case 6, i.e., in the hull 2, or may be disposed inside the main body case 6.

[0036] The drive shaft 14 extends in the vertical direction below the electric motor 8. The upper end of the drive shaft 14 is connected to the output shaft of the electric motor 8. A drive gear 25 consisting of a first bevel gear is integrally provided at the lower end of the drive shaft 14. The drive shaft 14 is rotatably supported by the lower case 21 via a pair of upper and lower bearings.

[0037] The propeller shaft 16 extends in the front-to-rear direction (horizontal direction) below the drive shaft 14. That is, the axial direction of the propeller shaft 16 is the front-to-rear direction. The propeller shaft 16 is rotatably supported by the case lower part 21 via a pair of front and rear bearings. A driven gear 26 consisting of a second bevel gear that meshes with the drive gear 25 is integrally provided at the front end of the propeller shaft 16. The propeller shaft 16 passes through a support hole in the case lower part 21, extends rearward from the case lower part 21, and is exposed to the outside of the main body case 6.

[0038] The gear device 15 includes a drive gear 25 provided at the lower end of the drive shaft 14 and a driven gear 26 provided at the front end of the propeller shaft 16. The rotation of the drive shaft 14 is transmitted to the propeller shaft 16 via the gear device 15.

[0039] The propeller 12 is driven by the electric motor 8 to generate propulsive force. The propeller 12 is fixed to the outer periphery of the rear part of the propeller shaft 16. The propeller 12 is located rearward of the rear end of the case lower part 21 and is exposed to the outside of the main body case 6. A plurality of fins 27 protrude from the outer periphery of the propeller 12.

[0040] The tiller handle 18 is rotatably mounted on the hull 2 ​​together with the outboard motor body. That is, the tiller handle 18 is rotatably mounted on the upper case 20 about an axis in the left-right direction. The tiller handle 18 has a rotatably mounted accelerator grip 30. The accelerator grip 30 is mounted so as to cover the outer periphery of the tiller handle 18. In this embodiment, the accelerator grip 30 is configured so that it can be displaced in the forward and reverse directions from a neutral position and is always biased to the neutral position. The accelerator grip 30 is also configured so that the maximum rotational operation amount (maximum opening θ) of the accelerator grip 30 in the reverse direction is smaller than the maximum opening θ of the accelerator grip 30 in the forward direction.

[0041] As shown in FIG. 2 , the tiller handle 18 is provided with a means for determining the neutral position of the accelerator grip 30. Specifically, a first spring 31 and a second spring 32 are provided between the tiller handle 18 and the accelerator grip 30. The first spring 31 generates a biasing force to return the accelerator grip 30 to the neutral position when the accelerator grip 30 is rotated in the forward direction from the neutral position. The second spring 32 generates a biasing force to return the accelerator grip 30 to the neutral position when the accelerator grip 30 is rotated in the reverse direction from the neutral position. For more detailed structure, please refer to the accelerator grip 30 described in Japanese Patent No. 5166192. As a result, when a user rotates the accelerator grip 30 and then releases their hand from the accelerator grip 30, the biasing force of the first spring 31 or the second spring 32 returns the accelerator grip 30 to the neutral position.

[0042] As shown in Fig. 3, an inverter 24 is electrically connected to the control device 10. The control device 10 is connected to the electric motor 8 via the inverter 24. The control device 10 also has an opening sensor 34 that detects the amount of rotation of the accelerator grip 30, i.e., the opening θ of the accelerator grip 30, a rotation speed sensor 35 that detects the rotation speed ω of the electric motor 8, and a notification unit 36. A battery 9 is connected to the control device 10 and is also connected to the electric motor 8 via the inverter 24.

[0043] The control device 10 comprises a processor 11 as an arithmetic processing device such as a CPU or MPU, and a storage device 13 (memory such as ROM and RAM), and is configured to execute various processes necessary for controlling the electric motor 8. The control device 10 being configured to execute various processes means that the processor 11 (arithmetic processing device) constituting the control device 10 is programmed to read necessary data and application software from the storage device 13 (memory) in accordance with an execution command from the opening sensor 34, and execute the predetermined arithmetic processing in accordance with the software. The control device 10 executes drive control or regenerative charging control by having the CPU execute the predetermined arithmetic processing in accordance with the program. The control device 10 may be configured as a single piece of hardware, or may be configured as a unit consisting of multiple pieces of hardware.

[0044] The accelerator grip 30 accepts rotation operations in the forward and reverse directions and an operation to return it to the neutral position as change operations for changing the output torque of the electric motor 8. The opening sensor 34 detects the opening θ of the accelerator grip 30 and outputs the detected opening signal to the control device 10.

[0045] In this embodiment, the opening sensor 34 outputs a rotational operation of the accelerator grip 30 in the forward direction as a positive value, an operation amount in the reverse direction as a negative value, and an operation amount in the neutral position as 0. Furthermore, the output torque is set as a positive output torque in the forward direction of the boat, and as a negative output torque in the reverse direction of the boat. With regard to the rotational direction of the electric motor 8, the rotational speed ω in the forward direction for moving the boat 2 forward may be set as positive, and the rotational speed ω in the reverse direction for moving the boat 2 backward may be set as negative. The output torque may be torque, or may be the product of the torque and the rotational speed ω of the electric motor 8.

[0046] The control device 10 is provided with a torque map 40 for controlling the electric motor 8. The torque map 40 sets a target output torque for the electric motor 8 corresponding to the opening degree θ of the accelerator grip 30. The control device 10 sets the target output torque by referring to the torque map 40 and controls the electric motor 8 so that the target output torque is achieved. Specifically, in drive control, the control device 10 supplies a current corresponding to the opening degree θ of the accelerator grip 30 from the battery 9 to the electric motor 8 via the inverter 24. This causes the electric motor 8 to rotate in a forward or reverse direction. The rotational force of the electric motor 8 rotates the propeller 12 via the drive shaft 14, gear device 15, and propeller shaft 16. The propulsive force generated by the rotation of the propeller 12 moves the hull 2 ​​forward or backward.

[0047] In regenerative charging control, the control device 10 causes the electric motor 8 to function as a generator and controls the power supply (regenerative charging) to the battery 9 via the inverter 24. The rotational force of the propeller 12 rotates the electric motor 8 via the propeller shaft 16, the gear device 15, and the drive shaft 14. In other words, the electric motor 8 serves as a regenerative braking means that converts deceleration energy into electric power during deceleration to generate regenerative braking force. The control device 10 executes regenerative charging control when the direction of the rotational speed ω of the electric motor 8 detected by the rotational speed sensor 35 does not match the direction of the target output torque output from the opening sensor 34.

[0048] The control device 10 sets the target output torque to a positive value when the accelerator grip 30 is rotated in the forward direction while the electric motor 8 is rotating in the forward direction, and sets the target output torque to a negative value when the accelerator grip 30 is rotated in the forward direction while the electric motor 8 is rotating in the reverse direction. than the neutral position When the accelerator grip 30 is rotated in the reverse direction, the target output torque is set to a negative value that is set in accordance with the rotation speed ω of the electric motor 8, regardless of the opening degree θ of the accelerator grip 30 in the reverse direction.

[0049] 4 is a diagram showing a torque map 40 in which a target output torque is set according to the rotational speed ω of the electric motor 8 and the opening degree θ of the accelerator grip 30. As shown in FIG. 4, the torque map 40 has a vertical axis V and a horizontal axis H that is perpendicular to the vertical axis V. In this embodiment, the vertical axis V represents the opening degree θ of the accelerator grip 30, and the horizontal axis H represents the rotational speed ω of the electric motor 8.

[0050] In the torque map 40, a plurality of vertical lines parallel to the vertical axis V and a plurality of horizontal lines parallel to the horizontal axis H intersect to form a plurality of squares. A target output torque corresponding to the opening degree θ of the accelerator grip 30 and the rotational speed ω of the electric motor 8 is set in each square. A white square indicates that the target output torque value is set to 0. A lightly hatched square indicates that the target output torque value is set to a positive value. A darkly hatched square indicates that the target output torque value is set to a negative value. In this embodiment, the vertical width of each square is set to the opening degree θ of the accelerator grip 30, and the horizontal width of each square is set to the rotational speed ω of the electric motor 8. The target output torque when the opening degree θ of the accelerator grip 30 is 0 is set to one horizontal row of squares. The vertical width is set to 0 only. The target output torque when the rotational speed ω of the electric motor 8 is 0 is set to one vertical row of squares. The horizontal width is set to 0 only. The squares where the opening degree θ of the accelerator grip 30 is not 0 have a range for the opening degree θ of the accelerator grip 30. In other words, the opening degree θ of the accelerator grip 30 set in a specific square has a range that is greater than the absolute value of the opening degree θ of the accelerator grip 30 set in an adjacent square on the side where the absolute value of the opening degree θ of the accelerator grip 30 is smaller, and is equal to or smaller than the absolute value of the opening degree θ. The squares where the rotational speed ω of the electric motor 8 is not 0 have a range for the rotational speed ω of the electric motor 8. In other words, the rotational speed ω of the electric motor 8 set in a specific square has a range that is greater than the absolute value of the rotational speed ω of the electric motor 8 set in an adjacent square on the side where the absolute value of the rotational speed ω of the electric motor 8 is smaller, and is equal to or smaller than the absolute value of the rotational speed ω of the electric motor 8.

[0051] The control device 10 refers to the torque map 40 and sets a target output torque according to the opening θ of the accelerator grip 30 and the rotation speed ω of the electric motor 8, and controls the electric motor 8 to achieve the set target output torque. In this embodiment, when the accelerator grip 30 is rotated in the forward direction, a target output torque according to the opening θ (the larger the opening θ, the larger the absolute value of the target output torque) is set. On the other hand, when the accelerator grip 30 is rotated in the reverse direction, a constant target output torque is set regardless of the opening θ.

[0052] The torque map 40 has four regions, first to fourth. The first region 41 is the region where the opening θ is equal to or greater than 0 (below the horizontal axis H) and the rotational speed ω is equal to or greater than 0 (to the right of the vertical axis V), indicating that the accelerator grip 30 is in a forward rotation position or a neutral position, and the electric motor 8 is rotating forward or stopped. The second region 42 is the region where the opening θ is less than 0 (above the horizontal axis H) and the rotational speed ω is equal to or greater than 0, indicating that the accelerator grip 30 is in a reverse rotation position and the electric motor 8 is stopped or rotating forward. The third region 43 is the region where the opening θ is less than 0 and the rotational speed ω is less than 0 (to the left of the vertical axis V), indicating that the accelerator grip 30 is in a reverse rotation position and the electric motor 8 is rotating reverse. The fourth region 44 is a region where the opening angle θ is equal to or greater than 0 and the rotation speed ω is less than 0, and indicates that the accelerator grip 30 is in a forward rotation position or a neutral position and the electric motor 8 is rotating in the reverse direction.

[0053] In the first region 41, a positive target output torque is set in the area where the opening θ of the accelerator grip 30 is greater than 0. A target output torque of 0 or a negative value is set in the area where the opening θ of the accelerator grip 30 is 0. In order to switch between a target output torque of 0 and a target output torque of a negative value, a predetermined first threshold value ω1 is set for the rotational speed ω of the electric motor 8. A target output torque of 0 is set in the area where the opening θ of the accelerator grip 30 is 0 and the rotational speed ω of the electric motor 8 is equal to or less than the first threshold value ω1. A negative target output torque is set in the area where the opening θ of the accelerator grip 30 is 0 and the rotational speed ω of the electric motor 8 is greater than the first threshold value ω1.

[0054] In the second region 42, a negative target output torque is set for the entire region where the opening θ of the accelerator grip 30 is less than 0. The absolute value of the negative target output torque is preferably set to be smaller than the absolute value of the positive target output torque corresponding to the maximum opening θ of the accelerator grip 30 in the positive direction.

[0055] A target output torque of 0 or a negative value is set in the squares of the third region 43. In order to switch between a target output torque of 0 and a target output torque of a negative value, a predetermined second threshold value ω2 is set for the rotational speed ω of the electric motor 8. A target output torque of 0 is set in the squares where the opening θ of the accelerator grip 30 is 0 and the absolute value of the rotational speed ω is greater than the absolute value of the second threshold value ω2. The absolute value of the second threshold value ω2 may be set to a value equal to the absolute value of the first threshold value ω1 or may be set to a value different from the absolute value of the first threshold value ω1.

[0056] In the fourth region 44, a negative target output torque is set for a square where the opening θ of the accelerator grip 30 in the positive direction is greater than 0. A positive value or a target output torque of 0 is set for a square where the opening θ of the accelerator grip 30 is 0. The second threshold value ω2 is set in order to switch between a target output torque of 0 and a positive target output torque. A target output torque of 0 is set for a square where the opening θ of the accelerator grip 30 is 0 and the absolute value of the rotation speed ω of the electric motor 8 is equal to or less than the absolute value of the second threshold value ω2. A positive target output torque is set for a square where the opening θ of the accelerator grip 30 is 0 and the absolute value of the rotation speed ω of the electric motor 8 is greater than the absolute value of the second threshold value ω2.

[0057] In another embodiment, in the fourth region 44, the second threshold ω2 for switching between a target output torque of 0 and a target output torque of a positive value may be set to a value different from the second threshold ω2 set in the third region 43. In this case, the absolute value of the second threshold ω2 in the third region 43 may be larger than the absolute value of the second threshold ω2 in the fourth region 44. Furthermore, the absolute value of the second threshold ω2 in the fourth region 44 may be set equal to the absolute value of the first threshold ω1.

[0058] 4 and 5, the target output torque set in response to the operation of the accelerator grip 30 and the operation of the electric motor 8 will be described below. The state of the electric motor 8 (the target output torque set by the control device 10 for the electric motor 8) is indicated by placing a black circle in the square. To simplify the description, as an example, the electric motor 8 will be described starting from a stopped state 45, and going through a steady state 46, a deceleration state, a reverse state 48, and a reverse steady state 49. During the transitions between each state, the opening degree θ of the accelerator grip 30 is maintained constant. Also, the opening degree θ of the accelerator grip 30 is assumed to be at its maximum.

[0059] The process by which the electric motor 8 changes from a stopped state 45 to a steady state 46 will now be described. This process takes place in the first region 41. In this embodiment, the stopped state 45 of the electric motor 8 refers to a state in which the accelerator grip 30 is in the neutral position, i.e., the opening θ is 0, and the rotational speed ω of the electric motor 8 is 0. The steady state 46 refers to a state in which the accelerator grip 30 is operated in the forward direction with the maximum opening θ, and the rotational speed ω of the electric motor 8 in the forward rotation is at its maximum value, i.e., the rotational speed ω of the electric motor 8 is constant. As shown in FIG. 5 , in the stopped state 45 of the electric motor 8, the opening θ is 0, the rotational speed ω of the electric motor 8 is 0, and the target output torque is set to 0 in the intersection cell between the vertical axis V and the horizontal axis H. In the steady state 46, the target output torque is set to a positive value in the steady state cell 51 at the lower right, where the opening θ of the accelerator grip 30 is at its maximum value in the forward direction and the rotational speed ω of the electric motor 8 is at its maximum value in the forward rotation.

[0060] When the accelerator grip 30 is rotated in the forward direction from the neutral position, the control device 10 changes the target output torque from 0 to the maximum positive value and executes drive control. That is, the control device 10 supplies a current corresponding to the maximum forward opening θ of the accelerator grip 30 from the battery 9 via the inverter 24 to the electric motor 8. This transition corresponds to the target output torque of the electric motor 8 set by the control device 10 moving from the mass in the stopped state 45 to the first end mass 52, which is parallel to the vertical axis V and located at the bottom.

[0061] The electric motor 8 starts rotating in the forward direction with maximum output torque due to the current supplied from the battery 9. Thereafter, the rotational speed ω of the electric motor 8 increases and reaches a steady state 46, where the rotational speed ω reaches its maximum value. This transition corresponds to the target output torque of the electric motor 8 being set from the first end mass 52 to the steady state mass 51.

[0062] The process by which the electric motor 8 goes from the steady state 46 to the deceleration state will be described. In this embodiment, the deceleration state includes a stop deceleration state 47A for bringing the electric motor 8 into the stop state 45, and a reverse deceleration state 47B for bringing the electric motor 8 into the reverse state 48, which will be described later.

[0063] The process by which the electric motor 8 changes from the steady state 46 to the deceleration-for-stop state 47A will be described. This process takes place in the first region 41. When the accelerator grip 30 is returned to the neutral position in the steady state 46 of the electric motor 8, the control device 10 sets a negative target output torque. Specifically, as shown in FIG. 6 , the target output torque of the electric motor 8 is set so as to move from the steady state mass 51 to a deceleration-for-stop state mass 53 that is parallel to the vertical axis V and where the opening θ of the accelerator grip 30 is 0. Because a negative target output torque is set in the deceleration-for-stop state mass 53, the control device 10 controls the electric motor 8 to achieve the negative target output torque.

[0064] At this time, the sign of the target output torque does not match the sign of the output torque of the electric motor 8, so the control device 10 stops drive control and executes regenerative charging control. Execution of regenerative charging control causes the rotational speed ω of the electric motor 8 to decrease. That is, the target output torque of the electric motor 8 is set so as to move from the stop reverse state mass to the left, parallel to the horizontal axis H. When the rotational speed ω of the electric motor 8 becomes equal to or less than the first threshold value ω1, the control device 10 sets the target output torque to 0, and puts the electric motor 8 into the stopped state 45.

[0065] Next, the process by which the electric motor 8 changes from the steady state 46 to the reverse deceleration state 47B will be described. This process occurs in the first region 41 and the second region 42. When the accelerator grip 30 is operated from the maximum forward opening θ to the maximum reverse opening θ in the steady state 46 of the electric motor 8, the control device 10 sets a negative target output torque. The target output torque of the electric motor 8 is set so that the electric motor 8 moves from the steady state mass 51 to the reverse deceleration state mass 54, which is parallel to the vertical axis V and where the reverse opening θ of the accelerator grip 30 is less than 0. Because a negative target output torque is set in the reverse deceleration state mass 54, the control device 10 controls the electric motor 8 to achieve the negative target output torque.

[0066] At this time, the sign of the target output torque does not match the sign of the output torque of the electric motor 8, so the control device 10 stops the drive control and executes the regenerative charging control. The execution of the regenerative charging control causes the rotation speed ω of the electric motor 8 to decrease.

[0067] Next, the process by which the electric motor 8 transitions from the reverse deceleration state 47B to the reverse state 48 will be described. This process occurs in the second region 42 and the third region 43. In this embodiment, the reverse state 48 is the state after the process executed by the control device 10 switches from regenerative charging control to drive control. That is, the reverse state 48 refers to a state in which the electric motor 8 is driven and controlled in the reverse rotation direction with a target output torque that is a negative value such that the rotational speed ω of the electric motor 8 in the reverse rotation does not exceed the second threshold value ω2.

[0068] When the rotational speed ω of the electric motor 8 becomes equal to or lower than a predetermined threshold, the control device 10 stops the regenerative charging control and executes drive control to achieve a negative target output torque. Specifically, as shown in FIG. 8 , the target output torque of the electric motor 8 is set so as to transition from a reverse deceleration state mass 54 to a reverse state mass 55 that is parallel to the horizontal axis H, has a reverse opening θ of the accelerator grip 30 less than 0, and has a reverse rotational speed ω less than 0. The predetermined threshold may be 0 or may be the same value as the first threshold ω1. Alternatively, the predetermined threshold may be set to a value smaller than the first threshold ω1 and greater than 0.

[0069] When the control of the electric motor 8 is switched from regenerative charging control to drive control, i.e., when the electric motor 8 starts to rotate in reverse, the control device 10 notifies the user of this via the notification unit 36. The notification unit 36 ​​may notify the user by, for example, sound, light, text, graphics, vibration, or the like.

[0070] The subsequent process by which the electric motor 8 transitions from the reverse state 48 to the reverse steady state 49 will be described. This process occurs in the third region 43 and the fourth region 44. When the accelerator grip 30 is rotated in the forward direction while the electric motor 8 is in the reverse state 48, the control device 10 controls the electric motor 8 to transition to the reverse steady state 49. In this embodiment, the reverse steady state 49 refers to a state in which the accelerator grip 30 is rotated in the forward direction to the maximum opening θ, and the rotational speed ω of the reverse rotation of the electric motor 8 is at its maximum value. Specifically, in response to the operation of the accelerator grip 30 to the maximum opening θ in the forward direction, the control device 10 supplies current to the electric motor 8 to achieve a maximum target output torque that is a negative value. This transition corresponds to the target output torque of the electric motor 8 being set from the reverse state mass 55 to the second end mass 56, which is parallel to the vertical axis V and at the lower end, as shown in FIG. 9 . Thereafter, the rotational speed ω of the reverse rotation of the electric motor 8 increases, and the electric motor 8 transitions to the reverse steady state 49. This transition corresponds to the target output torque of the electric motor 8 being set from the second end mass 56 to a reverse steady state mass 57 having a maximum rotational speed ω of the electric motor 8 in reverse rotation at the maximum forward opening θ of the accelerator grip 30. The absolute value of the maximum target output torque in the reverse steady state 49 may be less than or equal to the absolute value of the maximum target output torque in the steady state 46.

[0071] The electric motor 8 transitions from the reverse steady state 49 to the stopped state 45, i.e., switches from a negative target output torque to zero or a positive target output torque, by operating the accelerator grip 30 in the reverse direction or returning it to the neutral position. When the accelerator grip 30 is returned to the neutral position in the reverse steady state 49 of the electric motor 8, the control device 10 controls the electric motor 8 to achieve a positive target output torque. At this time, because the sign of the target output torque does not match the sign of the output torque of the electric motor 8, the control device 10 stops drive control and executes regenerative charging control. Execution of regenerative charging control reduces the rotational speed ω of the electric motor 8. When the rotational speed ω of the electric motor 8 becomes equal to or greater than the second threshold value ω2, i.e., when the absolute value of the rotational speed ω becomes equal to or less than the absolute value of the second threshold value ω2, the control device 10 sets the target output torque to zero and places the electric motor 8 in the stopped state 45.

[0072] When the accelerator grip 30 is rotated in the reverse direction in the reverse steady state 49 of the electric motor 8, the control device 10 sets the target output torque to 0. This transition corresponds to the target output torque of the electric motor 8 being set from the reverse steady state mass 57 to the third end mass 58, which is parallel to the vertical axis V and disposed at the upper end.

[0073] When the control device 10 ends the regenerative charging control that outputs a negative output torque and the electric motor 8 enters a stopped state 45, the control device 10 may notify the user of this via the notification unit 36. The method of notifying that the regenerative charging control that outputs a negative output torque has ended and the electric motor 8 has entered a stopped state 45 may be different from the method of notifying that a switch from regenerative charging control to drive control has occurred during forward deceleration. For example, if the notification unit 36 ​​notifies the user by sound, the type of sound used to notify that the regenerative charging control that outputs a positive output torque has ended and the electric motor 8 has stopped may be different from the type of sound used to notify that a switch from regenerative charging control to drive control has occurred.

[0074] In the electric propulsion unit configured as described above, the accelerator grip 30 is configured to be displaceable in the forward and reverse directions from a neutral position. As shown in FIG. 4, when the accelerator grip 30 is operated in the forward direction while the electric motor 8 is rotating in the forward direction, the control device 10 sets the target output torque to a positive value. When the accelerator grip 30 is operated in the forward direction while the electric motor 8 is rotating in the reverse direction, the control device 10 sets the target output torque to a negative value. Furthermore, when the accelerator grip 30 is operated in the forward direction while the electric motor 8 is rotating in the reverse direction, the control device 10 sets the target output torque to a negative value. than the neutral position When operated in the reverse direction, the target output torque is set to a negative value. This allows the user to switch the direction and value of the output torque of the electric motor 8 by operating the accelerator grip 30. Therefore, the direction of the output torque of the electric motor 8, i.e., the direction between forward and reverse movement of the electric vehicle, can be switched with a simple operation.

[0075] When the accelerator grip 30 is returned to the neutral position while the electric motor 8 is rotating in the forward direction, the control device 10 controls the electric motor 8 to achieve a negative target output torque. As a result, the electric motor 8 generates a negative output torque, i.e., a deceleration force, while rotating in the forward direction, which quickly stops the boat. In other words, the deceleration of the boat increases. Furthermore, when the accelerator grip 30 is returned to the neutral position while the electric motor 8 is rotating in the reverse direction, the control device 10 controls the electric motor 8 to achieve a positive target output torque. As a result, the electric motor 8 generates a positive output torque while rotating in the reverse direction, i.e., a deceleration force (acceleration force) while the boat is moving in reverse. As a result, the electric vehicle quickly stops while the electric motor 8 is rotating in the reverse direction, typically while the electric vehicle is moving in reverse.

[0076] When the rotation speed ω of the electric motor 8 during forward rotation is equal to or less than a predetermined first threshold value ω1, the control device 10 sets the target output torque to 0 when the accelerator grip 30 is in the neutral position. As a result, by simply returning the accelerator grip 30 to the neutral position while the electric motor 8 is rotating forward, the electric motor 8 switches from a state in which it generates a deceleration force to a state in which it stops outputting. This makes it easy to stop the boat while it is traveling forward. Furthermore, when the absolute value of the rotation speed ω of the electric motor 8 during reverse rotation is equal to or less than the absolute value of the second threshold value ω2, the control device 10 sets the target output torque to 0 when the accelerator grip 30 is in the neutral position. As a result, by simply returning the accelerator grip 30 to the neutral position while the electric motor 8 is rotating reverse, the electric motor 8 switches from a state in which it generates a deceleration force while it is traveling backward to a state in which it stops outputting. This makes it easy to stop the boat while it is traveling backward.

[0077] When the accelerator grip 30 is returned to the neutral position while the electric motor 8 is rotating in the forward direction, the control device 10 executes regenerative charging control, which causes the electric motor 8 to function as a generator and regeneratively charges the battery 9, in order to achieve a target output torque that is set to a negative value. As a result, the control device 10 converts deceleration energy into regenerative energy while the boat is moving forward, and energy loss in the battery 9 is suppressed. Furthermore, when the accelerator grip 30 is returned to the neutral position while the electric motor 8 is rotating in the reverse direction, the control device 10 executes regenerative charging control in order to achieve a target output torque that is set to a positive value. As a result, deceleration energy is converted into regenerative energy even while the boat is moving backward, and energy loss in the battery 9 is suppressed. This can contribute to energy efficiency.

[0078] If the accelerator grip 30 is operated in the reverse direction when the absolute value of the rotation speed ω of the reverse rotation of the electric motor 8 is equal to or greater than the absolute value of the second threshold value ω2, the control device 10 sets the target output torque to 0. The electric motor 8 stops outputting power, causing the boat to slowly come to a stop.

[0079] The accelerator grip 30 is configured so that the maximum rotational operation amount (maximum opening θ) of the accelerator grip 30 in the reverse direction is smaller than the maximum opening θ of the accelerator grip 30 in the forward direction. This allows the user to determine whether the accelerator grip 30 is being rotated in the forward direction or the reverse direction by the feeling in the hand gripping the accelerator grip 30.

[0080] The control device 10 detects that the accelerator grip 30 is than the neutral position When the accelerator grip 30 is rotated in the reverse direction, the target output torque is set to a negative value that is set according to the rotational speed ω of the electric motor 8, regardless of the reverse opening θ of the accelerator grip 30. Typically, the hull 2 ​​propels at a speed that corresponds to the target output torque. Therefore, the user can determine that the target output torque corresponding to the reverse opening θ has been achieved when the speed of the hull 2 ​​becomes constant. This allows the user to smoothly switch from rotating the accelerator grip 30 in the reverse direction to rotating it in the forward direction.

[0081] The absolute value of the negative target output torque set in the reverse state 48 is smaller than the maximum absolute value of the positive target output torque set in the steady state 46. This prevents the vessel from being subjected to excessive deceleration force due to excessive output torque being output when the vessel is moving in reverse.

[0082] The notification unit 36 ​​notifies the user that the control device 10 has shifted control from regenerative charging control to drive control, i.e., that the electric motor 8 has shifted from forward rotation to reverse rotation. This allows the user to recognize the timing to operate the accelerator grip 30 from reverse to forward in order to increase the absolute value of the negative output torque when switching the boat from forward to reverse.

[0083] Although the description of the specific embodiment has been completed, the present invention is not limited to the above embodiment and can be widely modified and implemented. For example, in the above embodiment, the present invention is applied to an electric outboard motor 1 as an example. However, the present invention may also be applied to electric vehicles such as vehicles, electric work machines, and electric snowmobiles. In this case, the propulsion generating member may be a wheel or a caterpillar. Note that the electric vehicle to which the present invention is applied does not have to be a ride-on type in which an operator rides. Furthermore, while the above embodiment uses the accelerator grip 30 as the operating unit, a lever with a grip or an operating button on a touch panel may also be used as the operating unit. In the above embodiment, the accelerator grip 30 is biased to the neutral position by a biasing member consisting of two springs. However, it may be biased to the neutral position by a single spring or not at all. For example, the neutral position of the accelerator grip 30 may be determined by a detent mechanism holding the accelerator grip 30 with a predetermined holding force. In addition, the specific configuration, arrangement, quantity, numerical values, and specific control mode of each component and part may be changed as appropriate within the scope of the present invention. Furthermore, not all of the components shown in the above embodiment are essential, and they can be selected. [Explanation of symbols]

[0084] 1: Electric outboard motor (electric propulsion unit) 2: Hull (electric vehicle) 8: Electric motor 9: Battery 10: Control device 12: Propeller (thrust generating component) 30: Accelerator grip (operating part) 36:Notification section θ: Opening degree (operated amount) ω: Rotation speed ω2: Second threshold ω1: First threshold

Claims

1. An electric propulsion unit that generates a propulsive force for an electric vehicle, An electric motor; a thrust generating member driven by the electric motor to generate thrust; a battery for supplying power to the electric motor; an operation unit that accepts a change operation for changing the output torque of the electric motor; a control device that sets a target output torque for the electric motor based on an operation amount of the operation unit and controls the electric motor so that the target output torque is achieved, The operating unit is configured to be displaceable in a forward direction and a reverse direction from a neutral position, the control device sets the target output torque to a positive value when the operating unit is operated in the forward direction while the electric motor is rotating in the forward direction, and sets the target output torque to a negative value when the operating unit is operated in the forward direction while the electric motor is rotating in the reverse direction; The control device sets the target output torque to a negative value when the operating unit is operated in the reverse direction from the neutral position while the electric motor is rotating in the forward direction.

2. The operating portion is configured to be constantly biased to the neutral position, The electric propulsion unit according to claim 1 , wherein the control device sets the target output torque to a negative value when the operating unit is returned to the neutral position while the electric motor is rotating in the forward direction.

3. 3. The electric propulsion unit according to claim 2, wherein the control device sets the target output torque, which is set when the operation unit is in the neutral position, to 0 when the rotational speed of the electric motor during forward rotation is equal to or less than a predetermined first threshold value.

4. 4. The electric propulsion unit according to claim 2 or 3, wherein, when the operating unit is returned to the neutral position while the electric motor is rotating in the forward direction, the control device executes regenerative charging control to cause the electric motor to function as a generator and to regeneratively charge the battery in order to achieve the target output torque that is set to a negative value.

5. The electric propulsion unit according to claim 2 , wherein the control device sets the target output torque to a positive value when the operating unit is returned to the neutral position while the electric motor is rotating in reverse.

6. 6. The electric propulsion unit according to claim 5, wherein the control device sets the target output torque to 0 when the operation unit is in the neutral position if the absolute value of the rotational speed of the electric motor during reverse rotation is equal to or less than a predetermined second threshold value.

7. 7. The electric propulsion unit according to claim 5, wherein the control device sets the target output torque to 0 when the operating unit is operated in the reverse direction while the electric motor is rotating in reverse at a rotational speed with an absolute value greater than a predetermined value.

8. 7. The electric propulsion unit according to claim 5, wherein, when the operating unit is returned to the neutral position while the electric motor is rotating in reverse, the control device executes regenerative charging control to cause the electric motor to function as a generator and to regeneratively charge the battery in order to achieve the target output torque that is set to a positive value.

9. The electric propulsion unit according to claim 1 , wherein the operating section is configured so that a maximum amount of operation in the reverse direction from the neutral position is smaller than the maximum amount of operation in the forward direction.

10. 10. The electric propulsion unit according to claim 9, wherein, when the operating unit is operated in the reverse direction from the neutral position while the electric motor is rotating in the forward direction, the control device sets the target output torque to a negative value that is set in accordance with the rotational speed of the electric motor, regardless of the amount of operation of the operating unit.

11. 3. The electric propulsion unit according to claim 1, wherein a maximum absolute value of the negative target output torque that is set when the electric motor is rotating in reverse and the operating unit is operated in the reverse direction is smaller than a maximum absolute value of the positive target output torque that is set when the electric motor is rotating in forward direction and the operating unit is operated in the forward direction.

12. The electric propulsion unit according to claim 1 or 2, further comprising a notification section that notifies that the electric motor has shifted from forward rotation to reverse rotation.

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