JP2021032567A - Wear estimation method, wear estimation device and vehicle - Google Patents

Abstract

To provide a wear estimation device capable of appropriately estimating a defect caused by wear in a portion between a drive unit and a wheel.SOLUTION: A wear estimation device 10 includes: an output torque detection unit 22 for detecting output torque of a motor 12 of a vehicle; an acceleration detection unit 23 for detecting acceleration when wheels are rotated by the output torque via a driving force transmission mechanism that transmits a driving force of the motor 12 to the wheels; a transmission efficiency calculation unit 264 that calculates transmission efficiency of the driving force in the driving force transmission mechanism based on the weight, output torque, and acceleration of the vehicle; and a wear estimation unit 265 that estimates a wear state of a connection portion between the motor 12 and the driving force transmission mechanism based on the transmission efficiency.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to wear estimation methods, wear estimation devices and vehicles.

Conventionally, as disclosed in Patent Document 1, for example, a technique for detecting a failure of a self-supporting vehicle is known. In the configuration of Patent Document 1, it is determined whether or not the speed difference between the rotation speed of the drive wheels and the rotation speed of the motor or engine that drives the drive wheels is larger than the threshold value. When the speed difference is larger than the threshold value, it is determined that the sensor that detects the rotational speed, the reduction gear that connects the motor and the wheel, and the belt have failed.

JP-A-2017-123758

However, in the configuration as in Patent Document 1, there is a possibility that a defect due to wear in the portion between the drive unit and the wheel cannot be estimated.

An object of the present disclosure is to provide a wear estimation method, a wear estimation device, and a vehicle capable of appropriately estimating a defect caused by wear in a portion between a drive unit and a wheel.

In the wear estimation method according to the present disclosure, when the wheel is rotated by the output torque via a driving force transmission mechanism that detects the output torque of the driving unit of the vehicle and transmits the driving force of the driving unit to the wheel. The acceleration of the vehicle is detected, the transmission efficiency of the driving force in the driving force transmission mechanism is calculated based on the weight of the vehicle, the output torque, and the acceleration, and the driving unit and the driving force are calculated based on the transmission efficiency. Estimate the wear state of the connection with the transmission mechanism.

The wear estimation device according to the present disclosure is the wheel with the output torque via an output torque detecting unit that detects the output torque of the driving unit of the vehicle and a driving force transmission mechanism that transmits the driving force of the driving unit to the wheels. An acceleration detection unit that detects the acceleration when the wheel is rotated, a transmission efficiency calculation unit that calculates the transmission efficiency of the driving force in the driving force transmission mechanism based on the weight of the vehicle, the output torque, and the acceleration. It is provided with a wear estimation unit that estimates the wear state of the connection portion between the drive unit and the drive force transmission mechanism based on the transmission efficiency.

The vehicle according to the present disclosure estimates the wear state of the drive unit, the wheels, the drive force transmission mechanism that transmits the drive force of the drive unit to the wheels, and the connection portion between the drive unit and the drive force transmission mechanism. The above-mentioned wear estimation device and the above-mentioned wear estimation device are provided.

According to the present disclosure, it is possible to provide a wear estimation method, a wear estimation device, and a vehicle capable of appropriately estimating a defect caused by wear in a portion between a drive unit and a wheel.

Schematic diagram schematically showing a part of the structure of the vehicle according to the embodiment of the present disclosure. A block diagram showing a vehicle control system according to an embodiment of the present disclosure. A flowchart showing a wear estimation process according to an embodiment of the present disclosure.

Hereinafter, the vehicle according to the embodiment of the present disclosure will be described. In the following, the description of the configuration not related to the wear estimation method and the wear estimation device of the present disclosure will be omitted.

[Vehicle structure]
First, the structure of the vehicle will be described. FIG. 1 is a schematic view schematically showing a part of the structure of the vehicle.

The vehicle 1 shown in FIG. 1 is an electric dust vehicle that travels by the driving force of the motor 12. The vehicle 1 includes a housing 11, a motor 12 which is an example of a drive unit, wheels 13, a driving force transmission mechanism 14 for transmitting the driving force of the motor 12 to the wheels 13, and a dust collecting device 15 (see FIG. 2). And have.

The motor 12 is driven by using electric energy charged in a storage battery (not shown). The motor 12 includes a rotor 121 that is rotated by electric energy. The rotor 121 is formed in a cylindrical shape. A plurality of internal teeth 121A extending in the axial direction are formed on the inner peripheral surface of the rotor 121 at equal intervals in the inner peripheral direction.

The driving force transmission mechanism 14 includes a gearbox 141, a gear shaft 142, and an axle 143.

Inside the gearbox 141, a gear portion 144 including at least one gear (not shown) is housed.

One end side of the gear shaft 142 is inserted inside the gear box 141. On the outer peripheral surface of the gear shaft 142 on one end side, a plurality of external teeth (not shown) extending in the axial direction are formed at equal intervals in the outer peripheral direction. The external teeth mesh with one gear constituting the gear portion. Further, the other end side of the gear shaft 142 is inserted inside the rotor 121 of the motor 12. On the outer peripheral surface of the gear shaft 142 on the other end side, a plurality of external teeth 142A extending in the axial direction are formed at equal intervals in the outer peripheral direction. The external teeth 142A mesh with the internal teeth 121A of the rotor 121. That is, the meshing portion between the internal teeth 121A of the rotor 121 and the external teeth 142A of the gear shaft 142 becomes the connecting portion 16 between the motor 12 and the driving force transmission mechanism 14.

One end of the axle 143 is connected to the center of the wheel 13. The other end side of the axle 143 is inserted into the gearbox 141 from the side opposite to the gear shaft 142. On the outer peripheral surface of the axle 143 on the other end side, a plurality of external teeth (not shown) extending in the axial direction are formed at equal intervals in the outer peripheral direction. The external teeth mesh with one gear constituting the gear portion.

With the above configuration, when the motor 12 is driven to rotate the rotor 121, this rotational force is transmitted to the axle 143 via the gear shaft 142 and the gear portion 144, and the wheels 13 rotate.

The dust collecting device 15 accommodates the dust and discharges the contained dust to the dust collecting place. The dust collecting device 15 may be of any type of rotary plate type, compression plate type, and packing box rotary type.

[Vehicle control system]
Next, the control system of the vehicle will be described. FIG. 2 is a block diagram showing a vehicle control system.

As shown in FIG. 2, the vehicle 1 includes an accelerator 21, an output torque detection unit 22, an acceleration detection unit 23, a notification unit 24, a storage unit 25, and a control unit 26.

As shown in FIG. 1, the output torque detection unit 22 is arranged inside the motor 12. The output torque detection unit 22 detects the torque of the rotor 121 as the output torque of the motor 12, and outputs a detection signal corresponding to the detected output torque to the control unit 26.

The acceleration detection unit 23 detects the acceleration of the vehicle 1 and outputs a detection signal corresponding to the detected acceleration to the control unit 26. A well-known configuration can be applied to the acceleration detection unit 23.

The notification unit 24 notifies that the connection unit 16 between the motor 12 and the driving force transmission mechanism 14 needs to be inspected. When this notification is performed by displaying characters, figures, or the like, the notification unit 24 may be provided on an instrument panel on which a speedometer or the like is arranged, or may be provided on a portion other than the instrument panel. Further, the notification unit 24 may perform notification by sound.

The storage unit 25 stores various data necessary for controlling the vehicle 1.

The control unit 26 includes a motor control unit 261, a dust collection control unit 262, a weight estimation unit 263, a transmission efficiency calculation unit 264, and a wear estimation unit 265. The output torque detection unit 22, the acceleration detection unit 23, the weight estimation unit 263, the transmission efficiency calculation unit 264, and the wear estimation unit 265 constitute the wear estimation device 10 of the present disclosure.

The motor control unit 261 detects the operation amount of the accelerator 21 and controls the motor 12 so that the rotor 121 rotates at a rotation speed corresponding to the operation amount.

The dust collection control unit 262 controls the dust collection device 15 so as to accommodate and discharge dust based on an operation state of an operation unit (not shown).

The weight estimation unit 263 estimates the weight of the vehicle 1 while the vehicle 1 is running, and stores the estimation result in the storage unit 25. As a method for estimating the weight of the vehicle 1, a well-known method can be applied. As a well-known weight estimation method, for example, the method disclosed in JP-A-2018-91756 can be exemplified.

The transmission efficiency calculation unit 264 calculates the transmission efficiency η of the driving force of the motor 12 in the driving force transmission mechanism 14. For example, the transmission efficiency calculation unit 264 has M for the weight of the vehicle 1 estimated by the weight estimation unit 263, T for the output torque detected by the output torque detection unit 22, and A for the acceleration detected by the acceleration detection unit 23. When the radius of the wheel 13 is R, the transmission efficiency η is calculated based on the following equation (1). Then, the transmission efficiency calculation unit 264 stores the calculation result in the storage unit 25.
η = (M × A × R) / T… (1)

The transmission efficiency η is 1 when the vehicle 1 is a new vehicle and the connecting portion 16 is not worn, that is, when both the internal teeth 121A of the rotor 121 and the external teeth 142A of the gear shaft 142 are not worn. become. On the other hand, when the connecting portion 16 is worn from the state of the new vehicle, that is, when at least one of the internal teeth 121A of the rotor 121 and the external teeth 142A of the gear shaft 142 is worn, the value becomes less than 1.

The wear estimation unit 265 estimates the wear state of the connecting unit 16 based on the transmission efficiency η calculated by the transmission efficiency calculation unit 264. For example, when the transmission efficiency η is equal to or less than a preset threshold value, the wear estimation unit 265 estimates that the wear of the connecting unit 16 has progressed to the extent that inspection or replacement is necessary. The threshold value may be set to a value less than 1 according to the wear state that needs to be inspected or replaced by the manufacturer of the vehicle 1. For example, as the threshold value, a value of 0.7 or more can be exemplified. Then, when the wear estimation unit 265 determines that the transmission efficiency η is equal to or less than the threshold value, the wear estimation unit 24 notifies the notification unit 24 that the connection unit 16 needs to be inspected. On the other hand, when the wear estimation unit 265 determines that the transmission efficiency η exceeds the threshold value, the wear estimation unit 265 does not notify the notification unit 24.

[Abrasion estimation process]
Next, the wear estimation process at the connection portion between the vehicle motor and the driving force transmission mechanism will be described. This friction estimation process is performed based on the friction estimation method of the present disclosure. The friction estimation process may be performed at preset intervals while the vehicle 1 is traveling. The friction estimation process can be performed at any time while the vehicle 1 is running, such as every time an acceleration operation is performed by the accelerator 21, every time dust is stored in the dust collecting device 15, or every time dust is discharged from the dust collecting device 15. It may be done at the timing. FIG. 3 is a flowchart showing the wear estimation process.

First, as shown in FIG. 3, the weight estimation unit 263 estimates the weight of the vehicle 1 while the vehicle 1 is running (S1). Next, the output torque detection unit 22 detects the output torque of the motor 12 (S2). After that, the acceleration detection unit 23 detects the acceleration of the vehicle 1 (S3). After that, the transmission efficiency calculation unit 264 calculates the transmission efficiency η based on the above equation (1) (S4). Then, the wear estimation unit 265 determines whether or not the transmission efficiency η is equal to or less than the threshold value (S5).

When the wear estimation unit 265 determines that the transmission efficiency η is equal to or less than the threshold value (S5: YES), the wear estimation unit 265 uses the notification unit 24 to notify that the connection unit 16 needs to be inspected (S6). This completes the friction estimation process. On the other hand, when the wear estimation unit 265 determines that the transmission efficiency η exceeds the threshold value (S5: NO), the friction estimation process ends.

[Action and effect of the embodiment]
The wear estimation device 10 calculates the transmission efficiency η of the driving force in the driving force transmission mechanism 14 based on the weight of the running vehicle 1, the output torque of the motor 12, and the acceleration of the vehicle 1. Then, the wear estimation device 10 estimates the wear state of the connecting portion 16 between the motor 12 and the driving force transmission mechanism 14 based on the transmission efficiency η. When the wear state of the connecting portion 16 is estimated based on the speed difference between the rotating speed of the rotor 121 of the motor 12 and the rotating speed of the wheels 13 as in the technique described in Patent Document 1, the wear of the connecting portion 16 is estimated. Since it is not possible to distinguish between the speed difference when the wear is progressing and the speed difference when the wear is not progressing, there is a possibility that the wear state cannot be estimated appropriately. On the other hand, in the present embodiment, the transmission efficiency η whose value changes according to the wear state is used for estimating the wear state. Therefore, the wear estimation device 10 can appropriately estimate defects caused by wear in the portion between the motor 12 and the wheels 13.

The wear estimation device 10 estimates the weight of the moving vehicle 1 and calculates the transmission efficiency η based on the estimated weight. When the vehicle 1 is an electric dust vehicle as in the present embodiment, its weight varies greatly depending on the amount of dust stored in the dust collecting device 15. For example, the weight of the vehicle 1 varies in tons (1000 kg) units. As described above, even when the weight of the vehicle 1 changes significantly, the wear estimation device 10 calculates the transmission efficiency η in consideration of the weight after the change, so that the wear state can be appropriately estimated.

When the transmission efficiency η is equal to or less than the threshold value, the wear estimation device 10 notifies the driver that the connecting portion 16 is being worn and needs to be inspected. Therefore, the driver can inspect the connecting portion 16 and replace parts, etc., and can prevent a situation in which the vehicle 1 cannot travel due to excessive wear.

[Modified example of the embodiment]
Needless to say, the present disclosure is not limited to that shown in the embodiments described above, and various modifications can be made without departing from the spirit of the present disclosure.

For example, as the vehicle of the present disclosure, the weight of a towing vehicle, a dump truck, a mixer truck, a bus, or the like that connects and pulls a trailer may change significantly. In this case, it is preferable that the wear estimation device 10 has a function of estimating the weight of the vehicle during traveling. Further, the vehicle of the present disclosure may be a vehicle such as a passenger car or a taxi whose weight does not change significantly. In this case, the wear estimation device 10 may or may not have a function of estimating the weight of the vehicle during traveling. When the function of estimating the weight is not provided, one value may be stored in the storage unit 25 as the weight of the vehicle, and this value may be used for the calculation of the transmission efficiency η.

The drive unit of the present disclosure may be an internal combustion engine. Further, when a motor is applied as the driving unit of the present disclosure, the driving source of the motor may be the electric energy of the fuel cell.

The wear estimation unit 265 may notify the determination result of whether or not the transmission efficiency η is equal to or less than the threshold value only when there is a request from the driver. The wear estimation result notified by the notification unit 24 may simply indicate the progress state of wear stepwise or continuously.

The configurations of the present disclosure can be applied to wear estimation methods, wear estimation devices and vehicles.

1 Vehicle 10 Wear estimation device 11 Housing 12 Motor (drive unit)
13 Wheels 14 Driving force transmission mechanism 15 Dust collection device 16 Connection part 21 Accelerator 22 Output torque detection part 23 Acceleration detection part 24 Notification part 25 Storage part 26 Control part 121 Rotor 121A Internal tooth 141 Gearbox 142 Gear shaft 142A External tooth 143 Axle 144 Gear unit 261 Motor control unit 262 Dust collection control unit 263 Weight estimation unit 264 Transmission efficiency calculation unit 265 Wear estimation unit

Claims (8)

Detects the output torque of the drive unit of the vehicle and
The acceleration when the wheel is rotated by the output torque is detected via the driving force transmission mechanism that transmits the driving force of the driving unit to the wheel.
Based on the weight of the vehicle, the output torque, and the acceleration, the transmission efficiency of the driving force in the driving force transmission mechanism is calculated.
Based on the transmission efficiency, the wear state of the connecting portion between the driving unit and the driving force transmission mechanism is estimated.
Wear estimation method. The weight of the vehicle is estimated while the vehicle is running, and the weight of the vehicle is estimated.
Based on this estimated weight, the transmission efficiency is calculated.
The wear estimation method according to claim 1. When the transmission efficiency is equal to or less than the threshold value, the driver of the vehicle is notified that the connection portion needs to be inspected.
The wear estimation method according to claim 1 or 2. An output torque detector that detects the output torque of the drive unit of the vehicle,
An acceleration detection unit that detects the acceleration when the wheel is rotated by the output torque via a driving force transmission mechanism that transmits the driving force of the driving unit to the wheels.
A transmission efficiency calculation unit that calculates the transmission efficiency of the driving force in the driving force transmission mechanism based on the weight of the vehicle, the output torque, and the acceleration.
A wear estimation unit for estimating a wear state of a connection portion between the drive unit and the driving force transmission mechanism based on the transmission efficiency is provided.
Wear estimation device. A weight estimation unit that estimates the weight of the vehicle while the vehicle is running is further provided.
The wear estimation device according to claim 4. When the transmission efficiency is equal to or less than the threshold value, the wear estimation unit notifies the notification unit that the connection portion needs to be inspected.
The wear estimation device according to claim 4 or 5. Drive unit and
With wheels
A driving force transmission mechanism that transmits the driving force of the driving unit to the wheels,
The wear estimation device according to any one of claims 4 to 6, which estimates the wear state of the connecting portion between the driving unit and the driving force transmission mechanism.
vehicle. The drive unit is a motor.
The vehicle according to claim 7.

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