Inspection device, inspection method, and vehicle

Abstract

The invention provides an inspection device, an inspection method, and a vehicle. The consumption state of a gear of the vehicle is estimated with a simple structure. An inspection device for inspecting a vehicle in which a driving force generated by a motor is transmitted to a driving wheel via a plurality of gears includes: a generation unit that causes the motor to generate torques in two mutually different rotational directions in a state in which the vehicle is stopped; and an estimation unit that estimates the wear state of the plurality of gears on the basis of the amount of rotation of the motor in accordance with the torque in a state in which the vehicle is stopped.

Description

Technical Field

[0001] The present invention relates to an inspection device, an inspection method and a vehicle. Background Art

[0002] A vehicle includes gears for transmitting driving force generated by a driving source to driving wheels. The gears wear as the vehicle travels. Gears that have been greatly worn need to be replaced. It is cumbersome to disassemble the vehicle, remove the gears, and confirm the wear status of the gears. Patent document 1 proposes a technology that uses a laser to estimate the wear status of the gears without removing the gears.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2007-121151 Summary of the invention

[0006] Problems to be solved by the invention

[0007] In the technique described in Patent Document 1, since the wear state of the gear is estimated using laser, the structure may become complicated. One aspect of the present invention aims to estimate the wear state of the gear of a vehicle with a simple structure.

[0008] Means used to solve problems

[0009] According to some embodiments, there is provided an inspection device for inspecting a vehicle in which a driving force generated by a motor is transmitted to driving wheels via a plurality of gears, the inspection device comprising: a generating unit for causing the motor to generate torques in two different rotational directions when the vehicle is stopped; and an estimating unit for estimating the wear state of the plurality of gears based on the rotation amount of the motor corresponding to the torque when the vehicle is stopped. According to other embodiments, there is provided an inspection method for inspecting a vehicle in which a driving force generated by a motor is transmitted to driving wheels via a plurality of gears, the inspection method comprising: a generating step in which the motor is caused to generate torques in two different rotational directions when the vehicle is stopped; and an estimating step in which the wear state of the plurality of gears is estimated based on the rotation amount of the motor corresponding to the torque when the vehicle is stopped.

[0010] Effects of the Invention

[0011] According to some embodiments, the wear state of gears of a vehicle can be estimated with a simple configuration. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The schematic diagrams are for explaining a configuration example of a vehicle according to some embodiments.

[0013] Figure 2 It is a cross-sectional schematic diagram for explaining a configuration example of a power unit according to some embodiments.

[0014] Figure 3 It is a schematic diagram for explaining a configuration example of a gear according to some embodiments.

[0015] Figure 4 This is a flowchart for explaining an example of an inspection method according to some embodiments.

[0016] Figure 5 The diagrams are for explaining time changes of torque and rotation amount according to some embodiments.

[0017] Description of Reference Numerals

[0018] V: vehicle;

[0019] 1: Electronic control unit;

[0020] 2: Power unit;

[0021] 11: Motor. DETAILED DESCRIPTION

[0022] Hereinafter, the embodiments are described in detail with reference to the accompanying drawings. It should be noted that the following embodiments do not limit the invention involved in the technical solution. In addition, not all of the feature combinations described in the embodiments are necessary for the invention. Two or more of the multiple features described in the embodiments can be combined arbitrarily. In addition, the same symbols are marked for the same or identical structures, and repeated descriptions are omitted.

[0023] <Vehicle Configuration>

[0024] Reference Figure 1 A configuration example of a vehicle V according to some embodiments will be described. Figure 1 , a top view and a side view of a vehicle V are shown. The vehicle V may have Figure 1 The vehicle V may also have Figure 1 The components not shown may not have Figure 1The vehicle V may be a vehicle having a motor as a driving source. For example, the vehicle V may be an electric vehicle or a hybrid vehicle. The vehicle V may be a four-wheeled vehicle, a two-wheeled vehicle, or any other vehicle. The vehicle V may be an autonomous vehicle having a driving assistance function that allows the vehicle to travel automatically without requiring a driver to perform a driving operation, or a vehicle that does not have such a driving assistance function. Figure 1 In the following, a case where the vehicle V is a four-wheeled electric vehicle is described.

[0025] The electronic control unit 1 functions as a control device for controlling multiple components of the vehicle V including the power unit 2, the hydraulic device 3, etc. The electronic control unit 1 may be composed of one ECU (Electronic Control Unit) or a plurality of ECUs. The plurality of ECUs may control different components (the power unit 2, the hydraulic device 3, etc.), respectively.

[0026] The electronic control unit 1 may include a processor 1a represented by a CPU (Central Processing Unit), a memory 1b such as a semiconductor memory, and an interface (not shown) with other devices. The memory 1b stores programs executed by the processor 1a, data used for processing by the processor 1a, etc. The interface may include an input / output interface and a communication interface.

[0027] The electronic control unit 1 controls the driving (acceleration) of the vehicle V by controlling the power unit 2. The power unit 2 is a travel drive unit that generates a driving force (torque) for rotating the driving wheels of the vehicle V. The electronic control unit 1 controls the output of the power unit 2 based on the driving operation of the driver detected by the operation detection sensor 2a provided on the accelerator pedal AP and the operation detection sensor 2b provided on the brake pedal BP. The electronic control unit 1 can measure the speed of the vehicle V based on the rotation speed of the wheel detected by the wheel speed sensor 2c.

[0028] The electronic control unit 1 controls the braking (deceleration) of the vehicle V by controlling the hydraulic device 3. The hydraulic device 3 is a driver that can control the hydraulic pressure of the working oil supplied to the brake devices 3a (e.g., disc brake devices) provided on the four wheels, based on the hydraulic pressure transmitted from the brake master cylinder BM. The electronic control unit 1 can control the braking of the vehicle V by driving and controlling the solenoid valves and the like provided in the hydraulic device 3.

[0029] The electronic control unit 1 controls the steering of the vehicle V by controlling the electric power steering device 4. The electric power steering device 4 includes a mechanism for steering the front wheels according to the driver's driving operation (steering operation) of the steering wheel ST. The electric power steering device 4 may include: a drive unit 4a including a motor that exerts a driving force for assisting the steering operation, a steering angle sensor 4b, a torque sensor 4c that detects the steering torque borne by the driver, and the like.

[0030] The electronic control unit 1 controls the information output device 5 that reports information to the vehicle. The information output device 5 may include, for example, a display device 5a that reports information to the driver through images, and a voice output device 5b that reports information to the driver through voice. The display device 5a may include, for example, a display device provided on the instrument panel, or a display device provided on the steering wheel ST. The display device 5a may also include a head-up display. The information output device 5 may report information to the occupant through vibration or light.

[0031] The electronic control unit 1 receives an instruction input from the driver via the input device 6. The input device 6 is arranged at a position where the driver can operate, and may include, for example, a switch group 6a for the driver to instruct the vehicle V, a direction indicator lever 6b for operating the direction indicator (turn indicator), and a shift lever 6c for indicating the gear position. The switch group 6a may include a switch for indicating the operation of the electric parking brake. The electronic control unit 1 controls the electric parking brake device 3c provided on the rear wheel according to the instruction from the driver to operate the electric parking brake, thereby maintaining the vehicle V in a stopped state. The vehicle V may have a parking brake mechanism that replaces the electric parking brake mechanism and operates according to the operation of the parking lever or the parking pedal performed by the driver.

[0032] The gears that can be set by the shift lever 6c may include a forward gear for moving the vehicle V forward, a reverse gear for moving the vehicle V backward, a parking gear for maintaining the vehicle V in a stopped state, and a neutral gear for maintaining a state in which the driving force of the power unit 2 is not transmitted to the drive wheels.

[0033] The electronic control unit 1 can communicate with a device outside the vehicle V using the communication device 7. The communication performed by the communication device 7 may be wireless communication or wired communication.

[0034] <Example of power unit configuration>

[0035] Reference Figure 2 as well as Figure 3 In (a) of the accompanying drawings, a configuration example of the power unit 2 of the vehicle V is described. Figure 2 It is a cross-sectional view of the power unit 2. Figure 3(a) is a schematic diagram focusing on the relationship between the motor 11, multiple gears, and multiple shafts among the components of the power unit 2. The power unit 2 may have Figure 2 The power unit 2 may also have Figure 2 The components not shown may not have Figure 2 A portion of the components shown.

[0036] like Figure 2 As shown, the power unit of the vehicle V has a motor 11, a speed reducer 12, and a differential gear 13 inside a housing 14. The motor 11 can be used as a driving source for accelerating the vehicle V, and can be used as a generator when decelerating. The housing 14 is divided into three parts in the vehicle width direction. The parts divided into three parts are represented as a left housing 15, a center housing 16, and a right housing 17 in order from the left side of the vehicle V. A storage portion 43 is divided between the left housing 15 and the center housing 16. A storage portion 44 is divided between the center housing 16 and the right housing 17.

[0037] The motor 11 is arranged in the storage portion 43. The motor 11 includes a motor shaft 20, a rotor 21, a stator 22, and a rotary transformer 40. The motor shaft 20 is supported by the left housing 15 via a ball bearing 18, and is supported by the center housing 16 via a ball bearing 19. The rotor 21 is fixed to the motor shaft 20. The stator 22 surrounds the outer circumference of the rotor 21 and is fixed to the center housing 16. Oil is retained at the bottom of the housing 14.

[0038] The resolver 40 is a rotation angle sensor for detecting the rotation angle of the rotor 21. Other rotation angle sensors such as an encoder may be used instead of the resolver 40. The rotation angle of the rotor 21 is expressed as the rotation angle of the motor 11. The rotation angle of the rotor 21 is equal to the rotation angle of the motor shaft 20 fixed to the rotor 21. Further, the rotation angle of the rotor 21 is equal to the rotation angle of the reduction gear 23 fixed to the motor shaft 20.

[0039] The speed reducer 12 is arranged in the storage portion 44. The speed reducer 12 has a speed reduction gear 23, a speed reduction shaft 26, a speed reduction gear 27, a final driving gear 28, and a final driven gear 29. The speed reduction gear 23 is fixed to the front end of the motor shaft 20 that protrudes to the right beyond the central housing 16. The speed reduction shaft 26 is supported by the central housing 16 via an angular contact roller bearing 24, and is supported by the right housing 17 via an angular contact roller bearing 25. The speed reduction gear 27 and the final driving gear 28 are respectively fixed to the speed reduction shaft 26. The final driven gear 29 is fixed to the outer periphery of the differential gear 13. The speed reduction gear 27 meshes with the speed reduction gear 23. The final driven gear 29 meshes with the final driving gear 28.

[0040] The differential gear 13 is arranged in the storage portion 44. The outer profile of the differential gear 13 is formed by the differential case 30. The differential case 30 is supported by the center case 16 via an angular contact roller bearing 31, and is supported by the right case 17 via an angular contact roller bearing 32. An inner joint 34 is provided at the front end of a long left output shaft 33 extending in the left direction from the differential case 30. The inner joint 34 protrudes outward from the left case 15. An inner joint 36 is provided at the front end of a short right output shaft 35 extending in the right direction from the differential case 30. The inner joint 36 protrudes outward from the right case 17. The inner joint 34 on the left side is connected to the left rear wheel 41 via a left half shaft (not shown). In addition, the inner joint 36 on the right side is connected to the right rear wheel 42 via a right half shaft (not shown). The right end of the left output shaft 33 is supported by the differential gear 13. The left end of the left output shaft 33 is supported by the left case 15 via a ball bearing 37 .

[0041] The power unit 2 further includes a parking gear 38 and a parking pawl 39. The parking gear 38 is fixed to the differential case 30. The parking pawl 39 is fixed to the case 14. Concave portions and convex portions are alternately formed on the outer peripheral surface of the parking gear 38 in the circumferential direction. The parking pawl 39 includes a pawl portion that can mesh with the concave portion of the parking gear 38. The parking pawl 39 selectively meshes with the parking gear 38. That is, the parking pawl 39 may have a state of meshing with the parking gear 38 and a state of not meshing with the parking gear 38. When the shift lever 6c is in the parking position, the electronic control unit 1 meshes the parking pawl 39 with the parking gear 38. Thus, the rotation of the differential case 30 is suppressed, and the stopped state of the vehicle V is maintained. Suppressing the rotation of a specific component means that the specific component can be relatively fixed to the body of the vehicle V. When the shift lever 6c is not in the parking position, the electronic control unit 1 does not mesh the parking pawl 39 with the parking gear 38. Thus, the differential case 30 can rotate so that the driving force generated by the motor 11 is transmitted to the drive wheels.

[0042] In the vehicle V, the driving force generated by the motor 11 is transmitted through a plurality of gears (in Figure 3 In the example of (a), the differential gear 13, the reduction gear 23, the reduction gear 27, the final driving gear 28, the final driven gear 29) are transmitted to the driving wheel (in Figure 3 In the example of (a), the left rear wheel 41 and the right rear wheel 42).

[0043] Figure 3 (b) in the figure describes a modification of the power unit 2. Figure 3 In the configuration shown in (b) of FIG. 1 , the power unit 2 does not include the reduction shaft 26, the reduction gear 27, and the final driving gear 28. The final driven gear 29 meshes with the reduction gear 23. Figure 3In the modified example (b) of FIG. 1 , the driving force generated by the motor 11 is also transmitted to the driving wheel (in Figure 3 In the example of (a), the left rear wheel 41 and the right rear wheel 42).

[0044] <How to inspect gears>

[0045] Reference Figure 4 , an inspection method for inspecting the vehicle V will be described. In this inspection method, the wear state of a plurality of gears included in the power unit 2 is inspected. Figure 4 The inspection method may be performed by the electronic control unit 1 of the vehicle V. In this case, the electronic control unit 1 functions as an inspection device. Alternatively, Figure 4 The inspection method may also be performed by an inspection device different from the electronic control unit 1. The inspection device may be mounted on the vehicle V or on the outside of the vehicle V. When the inspection device is located outside the vehicle V, the inspection device may be used to perform Figure 4 The data of the inspection method can be sent from the vehicle V to the inspection device. Next, the electronic control unit 1 of the vehicle V is executed Figure 4 The inspection method is described below. Figure 4 Each step of the inspection method can be performed, for example, by the processor 1a of the electronic control unit 1 executing a program stored in the memory 1b of the electronic control unit 1. Alternatively, Figure 4 Part or all of the steps of the inspection method may be performed by a dedicated integrated circuit such as an application specific integrated circuit (ASIC). Figure 4 The inspection method may be started based on the power supply of the vehicle V (eg, ignition power) being turned on.

[0046] In S401, the electronic control unit 1 determines whether the vehicle V has stopped. When the electronic control unit 1 determines that the vehicle V has stopped ("Yes" in S401), the processing is transferred to S402, and in other cases ("No" in S401), S401 is repeated. When the vehicle V stops, the speed of the vehicle V is zero. The speed of the vehicle V can be calculated based on the output of the wheel speed sensor 2c, for example.

[0047] In S401, the electronic control unit 1 may determine whether the parking mechanism of the vehicle V has been operated in addition to or instead of determining that the vehicle V has stopped. In this case, the electronic control unit 1 performs the steps below S402 according to the fact that the parking mechanism of the vehicle V has been operated. The parking mechanism of the vehicle V may include a parking gear 38 and a parking pawl 39. Alternatively or in addition thereto, the parking mechanism of the vehicle V may also include an electric parking brake device 3c. The electronic control unit 1 operates the parking mechanism according to the fact that the gear position of the vehicle V has been changed to the parking gear. Specifically, the electronic control unit 1 engages the parking pawl 39 with the parking gear 38 according to the fact that the gear position of the vehicle V has been changed to the parking gear. In addition, the electronic control unit 1 may operate the electric parking brake according to the fact that the gear position of the vehicle V has been changed to the parking gear.

[0048] The determination of S401 may be further performed based on other conditions. For example, a predetermined time (e.g., 24 hours) may have passed since the condition of S401 was last met, or the vehicle V has only traveled a predetermined distance (e.g., 10 km) may be added as an additional condition. By further determining such conditions, the situation where the steps after S402 are performed too frequently is suppressed.

[0049] In S402, the electronic control unit 1 causes the motor 11 to generate torques in two different rotation directions when the vehicle V is stopped. The two different rotation directions may be clockwise and counterclockwise with the motor shaft 20 of the motor 11 as the center. Figure 5 In (a) of FIG. 1 , an example of the torque generated by the motor 11 is described. Figure 5 The horizontal axis of the graph 501 in (a) represents the elapsed time from when the motor 11 starts generating torque. Figure 5 The vertical axis of the graph 501 in (a) represents the torque generated by the motor 11. One of the two different rotation directions is regarded as a positive direction, and the value of the torque rotating in this direction is regarded as positive. The other of the two different rotation directions is regarded as a negative direction, and the value of the torque rotating in this direction is regarded as negative.

[0050] exist Figure 5 In the example (a) in FIG. 1 , the electronic control unit 1 causes the motor 11 to generate a torque of a sine wave having a preset period and amplitude. Alternatively, the electronic control unit 1 can cause the motor 11 to generate torque of other waveforms. The electronic control unit 1 causes the motor 11 to continue generating torque only for a preset time (e.g., 10 seconds) or a preset number of waves (e.g., 10). The electronic control unit 1 causes the motor 11 to generate a torque of an amplitude that maintains the vehicle V in a stopped state.

[0051] In S403, the electronic control unit 1 measures the rotation amount of the motor 11 corresponding to the torque generated in S402 when the vehicle V is stopped. The rotation amount of the motor 11 may refer to the range of the rotation angle of the motor 11. The rotation angle of the motor 11 is measured by, for example, the resolver 40. Figure 5 (b) in FIG. 1 illustrates an example of the rotation amount of the motor 11. Figure 5 The horizontal axis of the graph 502 in (b) represents the elapsed time from when the motor 11 starts generating torque. Figure 5 The vertical axis of the graph 502 in (b) represents the rotation angle of the motor 11. In the graph 502, the rotation angle at the time when the motor 11 starts to generate torque is set to zero.

[0052] like Figure 4 As shown in (a), when the parking pawl 39 is engaged with the parking gear 38, the rotation of the differential case 30 of the differential gear 13 is suppressed. Therefore, the rotation of the final driven gear 29 relatively fixed in the differential case 30 is also suppressed. On the other hand, there is a backlash in the meshing between the final driving gear 28 and the final driven gear 29, so the final driving gear 28 can rotate within the range of the backlash. The backlash refers to a gap intentionally provided in the rotation direction. Since the final driving gear 28 can rotate, it can also rotate in the same way as the reduction gear 27 relatively fixed in the final driving gear 28.

[0053] There is also a backlash in the meshing between the reduction gear 23 and the reduction gear 27. Therefore, the reduction gear 23 can rotate within the total range of the range in which the reduction gear 27 can rotate and the range of the backlash. Therefore, the motor shaft 20 fixed to the reduction gear 23 can also rotate. Figure 5 In the example of (b), as shown in the graph 502, the motor 11 can rotate until the rotation angle becomes v1 according to the torque generated in the positive direction by the motor 11. The motor 11 can rotate until the rotation angle becomes v2 according to the torque generated in the negative direction by the motor 11. The absolute value of v1 and the absolute value of v2 may refer to values ​​that differ depending on the positional relationship of the gears at the start point of the torque generation. The electronic control unit 1 measures the range (v1-v2) in which the motor 11 can rotate while the vehicle V is in a stopped state as the rotation amount of the motor 11.

[0054] Reference Figure 5 (c) of FIG. 1 describes the rotation amount of the motor 11 when the backlash increases due to gear wear. Figure 5 The horizontal axis of the graph 503 in (c) represents the elapsed time from when the motor 11 starts generating torque. Figure 5The vertical axis of the graph 503 in (c) represents the rotation angle of the motor 11. In the graph 503, the rotation angle at the time when the motor 11 starts to generate torque is set to zero.

[0055] exist Figure 5 In the example (c) in FIG. 5 , as shown in the graph 502, the motor 11 can rotate until the rotation angle reaches v3 due to the torque generated in the positive direction by the motor 11. The motor 11 can rotate until the rotation angle reaches v4 due to the torque generated in the negative direction by the motor 11. Due to the increase in the backlash, the rotation amount (v3-v4) of the motor 11 in the case shown in the graph 503 becomes larger than the rotation amount (v1-v2) of the motor 11 in the case shown in the graph 502.

[0056] In S404, the electronic control unit 1 estimates the wear state of the plurality of gears included in the power unit 2 based on the rotation amount of the motor 11 measured in S403. For example, the electronic control unit 1 may calculate an index representing the wear state of the plurality of gears based on the rotation amount of the motor 11 measured in S403. In the following description, the index representing the wear state of the plurality of gears is represented as a wear index. The electronic control unit 1 may use the rotation amount of the motor 11 measured by S403 as the wear index. Alternatively, the value obtained by subtracting the rotation amount of the motor 11 measured in the pre-shipment inspection of the vehicle V from the rotation amount of the motor 11 measured by S403 may be used as the wear index. Alternatively, the value obtained by dividing the rotation amount of the motor 11 measured by S403 by the rotation amount of the motor 11 measured in the pre-shipment inspection of the vehicle V may be used as the wear index. The rotation amount of the motor 11 measured in the pre-shipment inspection of the vehicle V may be stored in the memory 1b of the electronic control unit 1, for example, or may be received from a server outside the vehicle V. The rotation amount of the motor 11 measured in the pre-shipment inspection of the vehicle V is an example of the rotation amount of the motor 11 in a state where the wear of the plurality of gears is small, and the rotation amount of the motor 11 measured at other time points may also be used.

[0057] The wear state represented by the wear index based on the rotation amount of the motor 11 measured in S403 represents the wear state of the gears located on the torque transmission path from the motor 11 to the parking gear 38 among the plurality of gears included in the power unit 2. Specifically, Figure 4 In the configuration example (a) in FIG. 1 , the torque transmission path from the motor 11 to the parking gear 38 includes the reduction gear 23, the reduction gear 27, the final driving gear 28, and the final driven gear 29. Figure 4 In the configuration example (b) in FIG. 1 , the torque transmission path from the motor 11 to the parking gear 38 includes the reduction gear 23 and the final driven gear 29. Figure 4 (a) or Figure 4 In the configuration example (b), when the parking gear 38 is fixed to the left output shaft 33 or the right output shaft 35 , the differential gear 13 is also included in the torque transmission path from the motor 11 to the parking gear 38 .

[0058] like Figure 4 As shown in (a) in FIG. 1 , when the torque transmission path from the motor 11 to the parking gear 38 includes multiple meshings (for example, the meshing between the reduction gear 23 and the reduction gear 27, and the meshing between the final driving gear 28 and the final driven gear 29), the electronic control unit 1 can calculate the wear index for each of the multiple meshings. The calculation method is described in detail below.

[0059] The ratio of the reduction gear 27 to the reduction gear 23 is i1. The rotation amount of the reduction gear 27 relative to the reduction gear 23 is R1. The rotation amount of the final driven gear 29 relative to the final driving gear 28 is R2. R1 and R2 can change according to the wear state of these gears. According to the results of the previous test, as these gears wear, R1 and R2 satisfy

[0060] R2=a×R1…(Formula 1)

[0061] A can be a constant or a function corresponding to the total rotation amount of the motor 11. In this case, when the rotation amount of the motor 11 is set to R,

[0062] R=R1+R2×i1…(Formula 2)

[0063] Established. i1 is determined according to the number of teeth of the reduction gear 23 and the number of teeth of the reduction gear 27, a is provided by a previous test (and the current total rotation amount of the motor 11 according to the situation), and R is measured in S404. Therefore, the electronic control unit 1 is able to calculate R1 and R2 by solving equations 1 and 2 simultaneously. Thereafter, the electronic control unit 1 calculates the wear index relative to the meshing of the reduction gear 23 and the reduction gear 27 based on R1, and calculates the wear index relative to the meshing of the final driving gear 28 and the final driven gear 29 based on R2. These wear indices represent the wear states for multiple meshings respectively.

[0064] The electronic control unit 1 may store the estimated wear state (for example, expressed as a wear index) in the memory 1 b in association with the current time, or may transmit the estimated wear state to a server outside the vehicle V.

[0065] In S405, the electronic control unit 1 determines whether the wear state estimated in S404 satisfies a predetermined condition. The electronic control unit 1 transfers the processing to S406 when it is determined that the wear state satisfies the predetermined condition ("Yes" in S405), and transfers the processing to S401 in other cases ("No" in S405). The predetermined condition may refer to a condition indicating the exchange of gears included in the recommended power unit 2. For example, the predetermined condition may be a case where the wear index calculated in S404 exceeds a predetermined threshold. The threshold may be pre-set and stored in the memory 1b. In the case of calculating the wear index for multiple meshings separately, the predetermined condition may be a case where at least any one of the multiple wear indexes exceeds a predetermined threshold. Thresholds of different values ​​may be set for the multiple wear indexes respectively.

[0066] In S406, the electronic control unit 1 notifies the wear status of the plurality of gears included in the power unit 2. The notification of S406 can be made to the driver of the vehicle V using the information output device 5, for example. Alternatively or in addition, the notification of S406 can also be made to the owner or manager of the vehicle V. S406 can also be omitted. If it is not determined in S405 that the predetermined condition is satisfied, the electronic control unit 1 checks the wear status of the gears again when the vehicle V stops next time.

[0067] According to the above-mentioned embodiment, the wear state of the gear is estimated using the motor 11 which is the driving source of the vehicle V, so the wear state of the gear can be estimated with a simple structure. In addition, the motor 11 generates torque when the vehicle V is stopped, so the wear state of the gear can be estimated with high accuracy. In this way, since the wear state of the gear can be estimated with high accuracy, the product life of the gear can be extended. Furthermore, according to some embodiments, the wear state is estimated for multiple meshings separately, so the wear state of the gear can be estimated with higher accuracy.

[0068] <Summary of implementation methods>

[0069] [Project 1]

[0070] An inspection device (1) is used to inspect a vehicle (V) in which a driving force generated by a motor (11) is transmitted to driving wheels (41, 42) via a plurality of gears (23, 27, 28, 29), wherein:

[0071] The inspection device (1) comprises:

[0072] a generating unit (S402) for causing the motor to generate torques in two different rotation directions when the vehicle is stopped; and

[0073] An estimating unit (S404) estimates the wear state of the plurality of gears based on the rotation amount of the motor corresponding to the torque in a state where the vehicle is stopped.

[0074] According to this item, the wear state of the gear can be estimated with a simple configuration.

[0075] [Project 2]

[0076] The inspection device according to item 1, wherein:

[0077] The generating unit causes the motor to generate the torque in response to a condition in which a parking mechanism (38, 39, 3c) of the vehicle has been operated.

[0078] According to this item, unintentional movement of the vehicle can be suppressed.

[0079] [Item 3]

[0080] The inspection device according to item 2, wherein:

[0081] The parking mechanism is operated in response to a situation in which the gear position of the vehicle is changed to a parking position.

[0082] According to this item, it can be determined that the parking mechanism is operating.

[0083] [Item 4]

[0084] The inspection device according to item 2 or 3, wherein:

[0085] The parking mechanism includes a parking gear (38) and a parking pawl (39) selectively meshing with the parking gear.

[0086] According to this item, the stopped state of the vehicle can be reliably maintained.

[0087] [Item 5]

[0088] The inspection device according to item 4, wherein:

[0089] The estimating unit estimates the wear state of a gear located on a torque transmission path from the motor to the parking gear among the plurality of gears.

[0090] Based on this item, the gear whose wear state can be estimated is identified.

[0091] [Item 6]

[0092] The inspection device according to item 5, wherein:

[0093] The plurality of gears on the transmission path include:

[0094] A first gear (23);

[0095] a second gear (27) meshing with the first gear;

[0096] a third gear (28); and

[0097] a fourth gear (29) meshing with the third gear,

[0098] The estimating unit estimates the wear state for meshing between the first gear and the second gear, and meshing between the third gear and the fourth gear.

[0099] According to this item, the wear state of the gear can be estimated with high accuracy.

[0100] [Item 7]

[0101] An inspection device according to any one of items 1 to 6, wherein:

[0102] The inspection device further includes a notification unit (S406) for notifying the wear status of the plurality of gears based on whether the estimated wear status satisfies a predetermined condition.

[0103] According to this item, the user can understand the wear status of the gear.

[0104] [Item 8]

[0105] A vehicle (V) comprising the inspection device according to any one of items 1 to 7.

[0106] According to this project, the above-mentioned effects are provided in the form of a vehicle.

[0107] [Item 9]

[0108] An inspection method is provided for inspecting a vehicle (V) in which a driving force generated by a motor (11) is transmitted to driving wheels (41, 42) via a plurality of gears (23, 27, 28, 29), wherein:

[0109] The inspection method comprises:

[0110] a generating step (S402), in which, when the vehicle is stopped, the motor is caused to generate torques in two different rotation directions; and

[0111] an estimating step ( S404 ), in which the wear state of the plurality of gears is estimated based on the rotation amount of the motor corresponding to the torque in a state where the vehicle is stopped.

[0112] According to this item, the wear state of the gear can be estimated with a simple configuration.

[0113] The present invention is not limited to the above-described embodiment, and various modifications and changes can be made within the scope of the gist of the invention.

Claims

1. An inspection device for inspecting a vehicle in which a driving force generated by a motor is transmitted to a driving wheel via a plurality of gears, wherein: The inspection device comprises: a generating unit configured to cause the motor to generate torques in two rotational directions different from each other when the vehicle is stopped; and The estimating unit estimates the wear state of the plurality of gears based on the rotation amount of the motor corresponding to the torque in a state where the vehicle is stopped.

2. The inspection device according to claim 1, wherein: The generating unit causes the motor to generate the torque in response to a condition in which a parking mechanism of the vehicle is operated.

3. The inspection device according to claim 2, wherein: The parking mechanism is operated in response to a situation in which the gear position of the vehicle is changed to a parking position.

4. The inspection device according to claim 2, wherein: The parking mechanism includes a parking gear and a parking pawl selectively engaged with the parking gear.

5. The inspection device according to claim 4, wherein: The estimating unit estimates the wear state of a gear located on a torque transmission path from the motor to the parking gear among the plurality of gears.

6. The inspection device according to claim 5, wherein: The plurality of gears on the transmission path include: First gear; a second gear meshing with the first gear; a third gear; and a fourth gear meshing with the third gear, The estimating unit estimates a wear state for each of meshing between the first gear and the second gear and meshing between the third gear and the fourth gear.

7. The inspection device according to claim 1, wherein: The inspection device further includes a notification unit configured to notify a state of wear of the plurality of gears based on a state that the estimated wear state satisfies a predetermined condition.

8. A vehicle comprising the inspection device according to any one of claims 1 to 7.

9. An inspection method for inspecting a vehicle in which a driving force generated by a motor is transmitted to a driving wheel via a plurality of gears, wherein: The inspection method comprises: a generating step of causing the motor to generate torques in two rotational directions different from each other while the vehicle is stopped; and and an estimating step of estimating the wear state of the plurality of gears based on the rotation amount of the motor corresponding to the torque in a state where the vehicle is stopped.

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