JP2024043131A - parking lock control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle drive system capable of enhancing safety of operating a vehicle by confirming that a parking lock mechanism experiences no abnormality when a power source of the vehicle is switched from OFF to ON.

SOLUTION: When a parking lock mechanism 50 is detected to be in a locked state through an actuator sensor 14a and a parking gear sensor 14b while starting up a vehicle, a VCU 17 issues an operation instruction to actuate an actuator 51 in a direction to release the locked state within a level that maintains the locked state. When the parking lock mechanism 50 is detected to be in a released state after checking whether or not actual operation of the actuator 51 corresponds to the operation instruction, the VCU 17 actuates the actuator 51 to shift the parking lock mechanism 50 from the released state to the locked state.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a parking lock control device that controls an electric parking lock.

In the parking lock mechanism of a vehicle drive system, when the parking switch or shift lever installed near the driver's seat of the vehicle is switched to the parking range (P), the actuator is activated by an instruction (control signal) from a control device (so-called VCU). The engaging portion provided on the actuator and the parking gear in the transmission mesh with each other. This makes the parking gear non-rotatable (that is, the parking lock is activated), so the vehicle can be stopped stably.

The following Patent Document 1 discloses a control device that, in order to properly terminate the unlocking control if some abnormality occurs between the start of unlocking control of the parking lock mechanism and the switching of the parking lock mechanism to an unlocked state, terminates the unlocking control when a forced termination condition is met during the execution of the unlocking control, and returns the transmission mechanism to a neutral state and the parking lock mechanism to a locked state.

JP 2017-180632 Publication

By the way, when the power of the vehicle is off, the parking switch or shift lever is normally set to the parking range (P), and the parking lock mechanism of this vehicle functions normally, so that the parking lock by the parking lock mechanism is disabled. kept in normal working condition. However, in order to further improve vehicle driving safety, it is preferable to reconfirm that there is no abnormality in the parking lock mechanism when the power of the vehicle is switched from off to on (key on).

SUMMARY OF THE INVENTION An object of the present invention is to provide a vehicle drive system that can confirm that there is no abnormality in the parking lock mechanism when the power of the vehicle is turned on, and that can maintain the vehicle in a safer state.

The present invention has been made to solve at least part of the above-mentioned problems, and can be realized as the following aspects or application examples.

The vehicle drive system according to this application example includes a parking lock mechanism that switches a parking gear of a transmission to a locked state or a released state by driving an actuator, and a detection unit that detects whether the parking lock mechanism is in a locked state or a released state. a parking lock control device comprising: when the detection section detects a locked state of the parking lock mechanism when the vehicle is started, the actuator is actuated in the release direction within a range where the locked state can be maintained; and checks whether the actual operation of the actuator matches the operation instruction, and if the release state of the parking lock mechanism is detected by the detection unit at the time of starting the vehicle, the parking lock mechanism is activated. The actuator is actuated to change from the released state to the locked state.

In this way, when the vehicle is started (when the key is on), it is detected whether the parking lock mechanism is in the locked or released state, and if it is in the locked state, the actuator is operated within the range that can maintain the locked state. By checking whether the actuator operation complies with the operation instruction, it is possible to confirm whether there is any abnormality in the parking lock mechanism. On the other hand, when the parking lock mechanism is in the released state, the actuator is operated to change from the released state to the locked state.

In this way, it is possible to confirm that there are no abnormalities in the parking lock mechanism when the vehicle is turned on, and to keep the vehicle in a safer state.

1 is an overall configuration diagram showing an embodiment of a vehicle drive system including a parking lock control device according to the present invention. 2 is a cross-sectional view of the vehicle drive system shown in FIG. 1. FIG. 2 is a schematic perspective view showing a parking lock mechanism included in the vehicle drive system shown in FIG. 1. FIG. FIG. 4 is a schematic perspective view showing the parking lock mechanism shown in FIG. 3 from a different angle. It is a flow chart for explaining operation of one embodiment of a parking lock control device concerning the present invention. It is a graph showing the relationship between the stroke amount of the output shaft of the actuator (horizontal axis) and the detected voltage of the actuator sensor (vertical axis).

(Configuration of Vehicle Drive System)
Next, a configuration of an embodiment of a vehicle drive system including a parking lock control device according to the present invention will be described. As shown in Figures 1 and 2, the vehicle drive system 100 includes a motor 11, an inverter 12, a driving battery 13, a gear box 14, drive shafts 15 (15A, 15B), drive wheels 16 (16A, 16B), a VCU 17 (control unit), a parking switch sensor 18, an auxiliary battery 19, and a relay 20. The gear box 14 includes a drive mechanism 30, a differential mechanism 40, a parking lock mechanism 50, an actuator sensor 14a (detection unit), and a parking gear sensor 14b (detection unit).

The motor 11 generates the driving force (torque) necessary for running the vehicle including the vehicle drive system 100 by being supplied with AC power from the running battery 13 via the inverter 12 .

A description of each component of the gear box 14 is as follows. The drive mechanism 30 is a reduction gear, is connected to the motor 11, and transmits the driving force generated by the motor 11 to the differential mechanism 40. The differential mechanism 40 transmits the driving force transmitted from the drive mechanism 30 to the respective drive shafts 15A and 15B. The parking lock mechanism 50 is for maintaining the vehicle stopped. The respective drive shafts 15A, 15B transmit the driving force transmitted from the differential mechanism 40 to the respective drive wheels 16A, 16B.

The actuator sensor 14a is capable of detecting the state of the actuator 51 shown in FIG. 3 and transmitting the detected actuator information to the VCU 17. Specifically, the actuator sensor 14a detects the voltage value of the power supplied to the actuator 51. The voltage value corresponds to the stroke amount (rotation angle) of the output shaft 51b of the actuator 51 shown in FIGS. 3 and 4.

The parking gear sensor 14b determines the engagement state (locked state or released state) of the parking gear 55 shown in FIGS. 3 and 4.

The vehicle also includes an auxiliary battery 19 for supplying power to various electrical components inside the vehicle. The auxiliary battery 19 is, for example, a lead-acid battery or a lithium ion battery, and is a secondary battery with a lower voltage and smaller capacity than the driving battery 13. In this embodiment, the auxiliary battery 19 is connected to the actuator 51 of the parking lock mechanism 50 via the relay 20, and supplies power to the actuator 51 when the relay 20 is turned on.

The VCU (Vehicle Control Unit) 17 is a computer that controls the entire vehicle drive system 100 and can send and receive signals to and from each element that constitutes the vehicle drive system 100. Specifically, the VCU 17 includes a motor 11, an inverter 12, a driving battery 13, a drive mechanism 30 for the gear box 14, a differential mechanism 40, a parking lock mechanism 50, an actuator sensor 14a, and a parking gear sensor 14b. Signals can be transmitted and received between the parking switch sensor 18 and the relay 20. Furthermore, the VCU 17 can also send and receive signals to and from the base 51a of the actuator 51 shown in FIG.

When a parking range is selected (shift changed) from a range other than the parking range (for example, drive range and reverse range) by the parking switch or shift lever of the vehicle, the VCU 17 sends a signal to the parking switch sensor 18 to transmit a signal to that effect. , the relay 20 is turned ON, and the output shaft 51b of the actuator 51 shown in FIG. 3 is driven, thereby switching the parking gear 55 shown in FIGS. (The method will be described later). In addition, when a range other than the parking range (for example, a drive range and a reverse range) is selected (shift change) from the parking range by the parking switch or shift lever of the vehicle, the VCU 17 sends a signal to the parking switch to transmit that effect. The parking gear 55 shown in FIGS. 3 and 4 is switched from the locked state to the released state by receiving the signal from the sensor 18, turning on the relay 20, and driving the output shaft 51b of the actuator 51 shown in FIG. The switching method will be described later).

Note that the drive range is a range selected when moving the vehicle forward. The reverse range is a range selected when moving the vehicle backwards. The parking range is a range selected when stopping (parking) the vehicle.

As shown in FIG. 2, the drive mechanism 30 includes a housing 31, an input shaft 32, an intermediate shaft 33, an output shaft 34, a first gear 35a, a second gear 35b, a third gear 35c, It includes a fourth gear 35d and a fifth gear 35e. The input shaft 32, the intermediate shaft 33, and the output shaft 34 each extend parallel to the vehicle width direction. One end of an input shaft 32 is connected to the motor output shaft 11a of the motor 11. The input shaft 32 is provided with a first gear 35a. The first gear 35a meshes with the second gear 35b. The second gear 35b is provided on the intermediate shaft 33. The intermediate shaft 33 is provided with a third gear 35c. The third gear 35c meshes with the fourth gear 35d. The fourth gear 35d is provided on the output shaft 34. The output shaft 34 is provided with a fifth gear 35e. The diameter of each gear is set so that the reduction ratio required for the drive mechanism 30 can be achieved. The drive mechanism 30 is configured to be able to convert high rotation, low torque rotational driving force input from the motor output shaft 11a of the motor 11 into low rotation, high torque and output the same.

As shown in FIG. 2, the differential mechanism 40 includes a sixth gear 41 (ring gear), a seventh gear 42, an eighth gear 43 (side gear), a power transmission member 44 (for example, a pinion gear), and a ninth gear. A gear 45 (side gear) is provided. The fifth gear 35e of the drive mechanism 30 meshes with the sixth gear 41. The sixth gear 41 meshes with the seventh gear 42. The seventh gear 42 meshes with the eighth gear 43. The eighth gear 43 is provided on the drive shaft 15A. Drive wheels 16A and 16C are provided on the drive shaft 15A. On the other hand, the aforementioned seventh gear 42 is provided with a power transmission member 44 . The power transmission member 44 is provided with a ninth gear 45 . The ninth gear 45 is provided on the drive shaft 15B. Drive wheels 16B and 16D are provided on the drive shaft 15B.

A parking lock mechanism 50 is provided in the area surrounded by the dashed line in FIG. 2 . As shown in FIG. 3, the parking lock mechanism 50 includes an actuator 51, a parking lock link 52, a parking lock shaft 53, a parking lock pin 54, a parking gear 55, and a parking lock lever 56.

As shown in FIG. 3, the actuator 51 includes a base 51a that transmits and receives signals to and from the VCU 17, and an output shaft 51b that protrudes from the base 51a and is rotatable in the direction of C shown in FIG. 3 (lock direction) and the opposite direction (release direction). The parking lock link 52 is provided on the output shaft 51b and rotates with the rotation of the output shaft 51b. The parking lock shaft 53 is provided on the parking lock link 52 and operates with the rotation of the parking lock link 52. The parking lock pin 54 is provided on the outer periphery of the tip of the parking lock shaft 53. The parking lock pin 54 is formed in a truncated cone shape that tapers toward the tip of the parking lock shaft 53.

As shown in FIGS. 3 and 4, the parking gear 55 has a plurality of engagement teeth 55b provided at equal intervals on the outer peripheral side of a disc-shaped base 55a, and two teeth 55b in the circumferential direction of the base 55a. A recess 55c is formed in between. A key portion 55d, which is a concave portion, is provided in the inner peripheral portion of the base portion 55a. The parking gear 55 has a key portion 55d fitted into the input shaft 32 of the drive mechanism 30 shown in FIG. 2, and is fixed to the input shaft 32 so as not to rotate relative to the input shaft 32.

The parking lock lever 56 is a so-called cantilever, and as shown in Figs. 3 and 4, one end of the lever base 56a extending in the longitudinal direction is supported by a support shaft 60 so as to be freely rotatable. An engagement portion 56b protruding from the lever base 56a is formed on the other end of the lever base 56a, and the engagement portion 56b is capable of engaging with a recess 55c of the parking gear 55. The parking lock lever 56 is biased at the other end in a direction away from the recess 55c of the parking gear 55 (in a direction to release the engagement). The pin receiving portion 56c is a notch formed in a truncated cone shape. As shown in Fig. 3, the parking lock pin 54 is slidably supported by the pin receiving portion 56c.

When the output shaft 51b rotates in the direction C shown in FIG. 3, the parking lock link 52 rotates, and the parking lock shaft 53 and the parking lock pin 54 are pushed in the direction A shown in FIG. 3. Then, the parking lock lever 56 is pushed in the direction B shown in FIG. 3 by the parking lock pin 54, and the engaging portion 56b of the parking lock lever 56 engages with the recess 55c of the parking gear 55. Then, the parking gear sensor 14b detects that the rotation of the parking gear 55 is locked and that the engaging portion 56b has come into contact with the surface of the recess 55c. Furthermore, the parking gear sensor 14b transmits a signal to the VCU 17 indicating the detection result that the rotation of the parking gear 55 has been locked, i.e., that the vehicle has been placed in a parking lock state.

On the other hand, when the output shaft 51b rotates in the opposite direction to the direction C shown in FIG. 3, the parking lock mechanism 50 performs the opposite operation to the above. As a result, the parking gear sensor 14b transmits a signal to the VCU 17 indicating that the rotation of the parking gear 55 has been released, i.e., that the vehicle has been released.

(Operation of vehicle drive system)
Next, the operation of one embodiment of the parking lock control device according to the present invention will be described. FIG. 5 shows a flowchart for explaining the operation of the parking lock control device, and the following description will be made along the same flowchart. Note that the flowchart in FIG. 5 is control at the time of starting the vehicle, so it starts from the vehicle stopped state (key-off state).

1. Detecting the state of the parking lock mechanism when starting the vehicle As shown in FIG. 5, in step S1, the VCU 17 determines whether the vehicle is starting (so-called key-on) based on a signal received from an ignition switch (not shown). That is, the VCU 17 determines whether it is time to start the vehicle. When step S1 is Yes, that is, when the vehicle is started, the VCU 17 advances the process to step S2. On the other hand, if step S1 is No, that is, if the vehicle is maintained in a stopped state, the VCU 17 ends the flow.

In step S2, the VCU 17 determines, based on the signal received from the parking switch sensor 18, whether a parking range is selected by a parking switch or a parking lever (not shown) mounted on the vehicle. If Step S2 is Yes, that is, if the parking range is selected, the VCU 17 advances the process to Step S3. On the other hand, if step S2 is No, that is, if the parking range is not selected, the VCU 17 ends the flow.

In step S3, the VCU 17 determines whether the parking gear 55 is in the locked state based on the signal received from the parking gear sensor 14b. If step S3 is Yes, that is, if parking gear 55 is in the locked state, the VCU 17 advances the process to step S4. On the other hand, if step S3 is No, that is, if parking gear 55 is in the released state, VCU 17 advances the process to step S12.

2. Checking the operation of the parking gear from the locked state In step S4, the VCU 17 determines that the voltage value V detected by the actuator sensor 14a (hereinafter referred to as detected voltage V) is a first predetermined voltage V1 based on the signal from the actuator sensor 14a. It is determined whether or not V≧V1 is satisfied. The first predetermined voltage V1 is set to a voltage value corresponding to a position where the engagement of the parking gear is not released even if the actuator 51 is operated in the release direction. If Step S4 is Yes, that is, if the detected voltage V is equal to or higher than the first predetermined voltage V1, the VCU 17 advances the process to Step S5. On the other hand, if the detected voltage V is less than the first predetermined voltage V1, the VCU 17 does not proceed with the operation check any further, and the VCU 17 ends the flow.

In step S5, the VCU 17 records the detected voltage V detected by the actuator sensor 14a at this point in time (before the operation instruction) as the first pre-operation voltage Va, based on the signal from the actuator sensor 14a.

After step S5 ends, in step S6, the VCU 17 turns on the relay 20 to operate the actuator 51.

After step S6 is completed, in step S7, the VCU 17 controls the actuator 51 (specifically, PWM control) to rotate the output shaft 51b in the release direction for a first predetermined time T1. This first predetermined time T1 is set within a range in which the rotation of the output shaft 51b can maintain the parking gear 55 in a locked state.

After step S7 ends, in step S8, the VCU 17 records the detected voltage V detected by the actuator sensor 14a at this point (after the operation instruction) as the first post-operation voltage Vb, based on the signal from the actuator sensor 14a. .

Then, in step S9, the VCU 17 calculates the difference (Va-Vb) between the first pre-operation voltage Va and the first post-operation voltage Vb, and checks whether the calculated difference is equal to or greater than the first difference threshold ΔD1, i.e., whether the actual operation of the output shaft 51b of the actuator 51 matches the operation command in step S6. If step S9 is Yes, i.e., if the difference in the detected voltage before and after the operation command is equal to or greater than the first difference threshold ΔD1, the VCU 17 proceeds to step S10. On the other hand, if the difference in the detected voltage before and after the operation check is less than the first difference threshold ΔD1, the VCU 17 proceeds to step S11.

In step S10, the VCU 17 determines that the parking lock mechanism 50 is functioning normally, opens (turns off) the relay that was turned on in step S6, and ends the flow.

In step S11, the VCU 17 opens the relay (OFF), determines that the parking lock mechanism 50 may not be functioning properly (an abnormality exists), issues a warning, and ends the flow. Examples of the warning include lighting up the multiple display monitor in red or emitting a warning sound.

3. Checking the operation of the parking gear from the released state If the above step S3 is No, that is, if the parking gear 55 is in the released state, in step S12, the VCU 17 performs the following based on the signal from the actuator sensor 14a. It is determined whether the detected voltage V detected by the actuator sensor 14a is less than a second predetermined voltage V2 (V<V2). The second predetermined voltage V2 is a voltage value lower than the first predetermined voltage V1, and is set to a voltage value corresponding to a position where the parking gear 55 is in a released state. If Step S12 is Yes, that is, if the detected voltage V is less than the second predetermined voltage V2, the VCU 17 advances the process to Step S13. On the other hand, if the detected voltage V is equal to or higher than the second predetermined voltage V2, the VCU 17 does not proceed with the operation check any further, and the VCU 17 ends the flow.

In step S13, the VCU 17 records the detected voltage V detected by the actuator sensor 14a at this point in time (before the operation instruction) as the second pre-operation voltage Vc, based on the signal from the actuator sensor 14a. Although not shown, the VCU 17 turns on the relay 20 to operate the actuator.

In step S14, the VCU 17 controls the actuator 51 (specifically, PWM control) to rotate the output shaft 51b in the locking direction for a second predetermined time T2. The second predetermined time T2 is set to be longer than the first predetermined time T1 in step S6 so as to bring the parking gear 55 in the released state into the locked state.

In step S15, the VCU 17 records the detected voltage V detected by the actuator sensor 14a at this point (after the operation instruction) as the second post-operation voltage Vd, based on the signal from the actuator sensor 14a.

After step S15, in step S16, the VCU 17 calculates the difference (Vc-Vd) between the second pre-operation voltage Vc and the second post-operation voltage Vd, and the calculated difference is equal to or greater than the second difference threshold ΔD2. In other words, it is checked whether the actual operation of the output shaft 51b of the actuator 51 matches the operation instruction in step S14. If Step S16 is Yes, that is, if the difference between the detected voltages before and after the operation instruction is greater than or equal to the second difference threshold ΔD2, the VCU 17 advances the process to Step S10. On the other hand, if the difference between the detected voltages before and after the operation instruction is less than the second difference threshold ΔD2, the VCU 17 advances the process to step S11. The processing in step S10 and step S11 is as described above.

4. Others FIG. 6 shows a graph showing the relationship between the stroke amount of the output shaft of the actuator (horizontal axis) and the detected voltage of the actuator sensor (vertical axis).

As shown in Figure 6, the detection voltage V of the actuator sensor 14a correlates with the stroke amount (specifically, the rotation angle) of the output shaft 51b of the actuator 51. The detection range of the actuator sensor 14a is from Vmin to Vmax, but the range used as the stroke amount of the output shaft 51b of the actuator 51 is from S2min to S1max (detection voltage V2min to V1max), with the stroke amount S2min being the completely released position and the stroke amount S1max being the completely locked position.

The above-mentioned first predetermined voltage V1 is set to a voltage value that is lower than the detection voltage V1max corresponding to a completely locked position and higher than the detection voltage Vborder corresponding to the boundary stroke amount Sborder that is the boundary between the locked state and the released state. has been done. That is, when the stroke amount S of the output shaft 51b at the time of key-on is within the first range A1 shown in FIG. 6, the operation check in the release direction is executed. To check the operation in the release direction, the parking gear 55 is operated by a first operation stroke amount St1 within a range in which the locked state of the parking gear 55 is not released, that is, a range that does not exceed the boundary stroke amount Sborder from the first range A1. This first operation stroke amount St1 corresponds to the first predetermined time T1 of the operation instruction in step S7.

On the other hand, the above-mentioned second predetermined voltage V2 is a voltage value that is larger than the detection voltage V2min corresponding to the complete release position and lower than the detection voltage Vborder corresponding to the boundary stroke amount Sborder that is the boundary between the locked state and the released state. is set to . That is, when the stroke amount S of the output shaft 51b at the time of key-on is within the second range A2 shown in FIG. 6, the operation check in the locking direction is executed. In the operation check in the locking direction, the parking gear 55 is operated by a second operation stroke amount St2 exceeding the boundary stroke amount Sborder so as to bring the parking gear 55 from the released state to the locked state. This second operation stroke amount St2 corresponds to the second predetermined time T2 of the operation instruction in step S14.

(Effects of the parking lock control device)
According to the parking lock control device of this embodiment, when the power supply of the vehicle is turned on (key on), it is determined whether the parking lock mechanism 50 is in a locked state or a released state, and if it is in a locked state, it operates the actuator within a range in which the locked state can be maintained, and checks whether the operation of the actuator matches the operation command to check whether there is an abnormality in the parking lock mechanism. On the other hand, if the determination unit determines that it is in a released state, it operates the actuator to change from the released state to the locked state, and also checks whether there is an abnormality in the parking lock mechanism.

In this way, by confirming that there is no abnormality in the parking lock mechanism when powering up the vehicle, the vehicle can be kept in a safer state.

This concludes the explanation of the embodiment of the vehicle drive system according to the present invention, but the aspects of the present invention are not limited to this embodiment.

In the above embodiment, there are three ranges that can be selected: the parking range, the drive range, and the reverse range, but a configuration may also be adopted in which other ranges such as the neutral range, first range, and second range can also be selected.

11: Motor 11a: Motor output shaft 12: Inverter 13: Running battery 14: Gear box 14a: Actuator sensor 14b: Parking gear sensor 18: Parking switch sensor 19: Auxiliary battery 20: Relay 30: Drive mechanism 40: Differential Mechanism 50: Parking lock mechanism 51: Actuator 51a: Base 51b: Output shaft 52: Parking lock link 53: Parking lock shaft 54: Parking lock pin 55: Parking gear 55a: Base 55b: Teeth 55c: Recess 55d: Key portion 56 : Parking lock lever 56a : Lever base 56b : Engagement part 56c : Pin receiving part 60 : Support shaft 100 : Vehicle drive system

Claims (1)

A parking lock control device comprising: a parking lock mechanism that switches a parking gear of a transmission to a locked state or a released state by driving an actuator; and a detection section that detects whether the parking lock mechanism is in a locked state or a released state. hand,
When the detection unit detects the locked state of the parking lock mechanism when the vehicle is started, an operation instruction is given to operate the actuator in the release direction within a range in which the locked state can be maintained, and the actual operation of the actuator is performed. Check whether or not it matches the operation instruction,
A parking lock control device that operates the actuator to change from the released state to a locked state when the detection unit detects a released state of the parking lock mechanism when the vehicle is started.

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