Electric parking lock device

Abstract

To provide an electric parking lock device which can semi-automatically lock a parking gear even if power source failure occurs in the state that the parking gear is not locked.SOLUTION: An electric parking lock device 1 comprises a first electromagnetic solenoid 41 which locks one engagement part 331 against an energization force of a first energization component 31 so that one engagement part 331 does not oscillate during electric conduction, and permits that one engagement part 331 oscillates in a direction of engaging with the other engagement part 332 by the energization force of the first energization component 31 during power source failure. One engagement part 331 is connected to the first energization component 31 provided at a tip of a parking pole 11, and the other engagement part 332 is connected to a brake pedal 60. When depression of the brake pedal 60 is released during electric source failure, a pair of engagement parts 331, 332 engages with each other to oscillate the parking pole 11 in a direction of engaging with a parking gear 12.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an electric parking lock device.

Background Art

[0002] Conventionally, in an automatic transmission, when the P (parking) range is selected, a parking lock device is provided in which a parking gear fitted to the output shaft of the automatic transmission is locked. In recent years, an automatic transmission equipped with a shift-by-wire (SBW) mechanism that detects the shift range selected by the driver using a switch or the like and switches the shift range of the automatic transmission by driving an electric actuator such as an electric motor based on the detection result has been put into practical use.

[0003] In an electric shift-by-wire mechanism (a parking lock device using an electric actuator), for example, when the P range is selected, an electric actuator such as an electric motor is driven, the parking pole swings, and the parking gear is locked. On the other hand, when a shift range other than the P range is selected, an electric actuator such as an electric motor is driven, and the lock of the parking gear is released.

[0004] By the way, in an electric parking lock device, when a power failure occurs due to, for example, an abnormality of the battery, a disconnection or short circuit of the power line (harness), or a breakage of the main fuse while the parking gear is locked, the parking lock cannot be released. Therefore, for example, Patent Documents 1 and 2 disclose an electric parking lock device provided with manual lock release means that can manually release the parking lock during a power failure.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] On the other hand, when a power failure occurs while the parking gear is not locked (unlocked state), an electric actuator such as an electric motor cannot be driven, and the parking gear cannot be locked. However, Patent Documents 1 and 2 do not consider locking the parking gear when a power failure occurs in the unlocked state.

[0007] The present invention has been made to solve the above problems, and an object of the present invention is to provide an electric parking lock device that can semi-automatically lock the parking gear even when a power failure occurs while the parking gear is not locked (unlocked state) in the electric parking lock device. MEANS FOR SOLVING THE PROBLEMS

[0008] The electric parking lock device according to the present invention has a parking gear and a parking pole, and a parking mechanism that locks the parking gear by engaging the parking pole with the parking gear to put the vehicle in a parking state, and an electric actuator that swings the parking pole to lock the parking gear. In the electric parking lock device, an engaging member having a pair of engaging portions that can engage with each other, and a first biasing member that applies a biasing force to one of the engaging portions constituting the engaging member so that the one engaging portion swings in a direction in which it engages with the other engaging portion, and when energized, a first electromagnetic solenoid that locks one engaging portion against the biasing force of the first biasing member so that the one engaging portion does not swing. The base end portion of one engaging portion is connected to a first biasing member provided at the tip end portion of the parking pole, the base end portion of the other engaging portion is connected to the brake pedal, and when a power failure occurs, the first electromagnetic solenoid permits the one engaging portion to swing in a direction in which it engages with the other engaging portion by the biasing force of the first biasing member. When the depression of the brake pedal is released during a power failure, the pair of engaging portions engage with each other, and with the release of the depression of the brake pedal, the parking pole is swung in a direction in which it engages with the parking gear.

[0009] According to the electric parking lock device of the present invention, when a power failure occurs, the one engaging portion is permitted to swing in a direction in which it engages with the other engaging portion by the biasing force of the first biasing member. Here, since the base end portion of one engaging portion is connected to the first biasing member provided at the tip end portion of the parking pole and the base end portion of the other engaging portion is connected to the brake pedal, then when the depression of the brake pedal is released, with the release of the depression of the brake pedal (accompanying the return of the brake pedal position), the pair of engaging portions engage with each other, and the parking pole is swung in a direction in which it engages with the parking gear. As a result, even when a power failure occurs, the parking gear can be locked by releasing the depression of the brake pedal (that is, semi - automatically).

[0010] When the power supply is normal (when energized), one engaging portion is prevented from swinging (i.e., the one engaging portion and the other engaging portion are prevented from engaging), and the first electromagnetic solenoid locks one engaging portion against the biasing force of the first biasing member.

Advantages of the Invention

[0011] According to the present invention, in an electric parking lock device, even when a power failure occurs when the parking gear is not locked (unlocked state), it is possible to semi-automatically lock the parking gear.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0013] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts will be denoted by the same reference numerals. Also, in each figure, the same elements will be denoted by the same reference numerals and redundant explanations will be omitted.

[0014] First, with reference to FIGS. 1 to 3, the configuration of the electric parking lock device 1 according to the embodiment will be described. FIG. 1 is a diagram showing the configuration of a shift-by-wire mechanism 2 that constitutes the electric parking lock device 1. FIG. 2 is a schematic diagram (schematic view) showing the configuration of a power failure lock mechanism 3 that constitutes the electric parking lock device 1 (state when the power is normal (when energized)). FIG. 3 is a schematic diagram (schematic view) showing the configuration of a power failure lock mechanism 3 that constitutes the electric parking lock device 1 (state when the power fails (when not energized)).

[0015] The shift-by-wire mechanism (parking mechanism) 2 that constitutes the electric parking lock device 1 locks the rotation inside the automatic transmission so that the wheels do not rotate when the P (parking) range is selected. As shown in FIG. 1, a detent plate 14 is attached to the output shaft of an electric actuator 15 (for example, an electric motor) driven by a shift-by-wire control unit (hereinafter referred to as "SBW-CU") 20. A parking rod 13 is axially connected to the detent plate 14 so as to be able to advance and retreat. On the other hand, for example, a parking gear 12 is spline-fitted to the output shaft of the automatic transmission. Also, a parking pole 11 is provided so as to be swingable so that it can mesh with the parking gear 12.

[0016] When the P (parking) range is selected, the electric actuator 15 (electric motor) is rotated, so that the detent plate 14 swings and the parking rod 13 advances axially. Then, the parking pole 11 is pushed from the back by the tapered portion of the parking rod 13 and swings to mesh with the parking gear 12. Thereby, the rotation of the automatic transmission is locked. When the vehicle is traveling at a predetermined vehicle speed or higher, the parking pole 11 is repelled by the parking gear 12, and the parking pole 11 and the parking gear 12 are configured not to be able to mesh with each other.

[0017] Incidentally, when a power failure occurs due to, for example, an abnormality in the battery, a disconnection or short circuit in the power line (harness), or a break in the main fuse, the above-described SBW-CU20 or the electric actuator 15 cannot operate. That is, the parking gear 12 cannot be locked or unlocked (released). Here, the electric parking lock device 1 has a function of semi-automatically locking (parking lock) the parking gear 12 even when a power failure occurs while the parking gear 12 is in an unlocked state (non-locked state).

[0018] Therefore, the electric parking lock device 1 is provided with a power failure lock mechanism 3. As shown in FIGS. 2 and 3, the power failure lock mechanism 3 mainly includes a first biasing member 31, a second biasing member 32, an engaging member 33, an elastic member 34, a first electromagnetic solenoid 41, a second electromagnetic solenoid 42, and the like.

[0019] The engaging member 33 includes a pair of engaging portions 331 and 332 (one engaging portion 331 and the other engaging portion 332) that engage with each other. Each of the one engaging portion (engaging claw) 331 and the other engaging portion (engaging claw) 332 has a tip portion formed, for example, in a hook shape (or wedge shape). Further, when the outer surfaces of the tip portions of the one engaging portion 331 and the other engaging portion 332 are in contact with each other (for example, when a power failure occurs while the depression of the brake pedal 60 is released), they are configured to be displaceable (slidable) along the contact surface.

[0020] The base end portion of the one engaging portion 331 is connected to the first biasing member 31 provided at the tip end portion of the parking pole 11. The base end portion of the other engaging portion 332 is connected to the brake pedal 60 via a wire 51.

[0021] Here, an elastic member 34 (such as a coil spring or the like) that can expand and contract is interposed between the base end portion of one engaging portion 331 and the first biasing member 31 provided at the tip of the parking pole 11. The contraction force (spring force) of the elastic member 34 is set to be greater than the biasing force of the second biasing member 32. Further, the contraction force (spring force) of the elastic member 34 is set to a strength such that it extends and does not lock when the parking pole 11 is repelled by the parking gear 12.

[0022] The first biasing member 31 is composed of, for example, a coil spring or the like and is provided at the tip of the parking pole 11. The first biasing member 31 applies a biasing force to one engaging portion 331 constituting the engaging member 33 so that one engaging portion 331 swings in the direction in which it engages (approaches) the other engaging portion 332.

[0023] When the power supply is normal (when energized), the first electromagnetic solenoid 41, for example, locks one engaging portion 331 against the biasing force of the first biasing member 31 so that the plunger protrudes outward and one engaging portion 331 does not swing. Therefore, the engagement between one engaging portion 331 and the other engaging portion 332 is prohibited.

[0024] When the power supply fails (when not energized), the plunger of the first electromagnetic solenoid 41 returns inside (is housed), and one engaging portion 331 is permitted to swing in the direction in which it engages (approaches) the other engaging portion 332 by the biasing force of the first biasing member 31. That is, the engagement between one engaging portion 331 and the other engaging portion 332 is permitted. Therefore, when the depression of the brake pedal 60 is released when the power supply fails (when not energized), the pair of engaging portions 331, 332 engage with each other, and as the depression of the brake pedal 60 is released (as the position of the brake pedal returns), it is pulled by the wire 51 and the parking pole 11 is swung in the direction of meshing with the parking gear 12.

[0025] The second biasing member 32 is made of, for example, a coil spring or the like, and is provided at the base end portion (oscillation center axis) of the parking pole 11. The second biasing member 32 applies a biasing force to the parking pole 11 in a direction in which the parking pole 11 moves away from the parking gear 12 (unlock side).

[0026] When the power supply is normal (energized), for example, the plunger of the second electromagnetic solenoid 42 retracts inside (is housed), and the biasing force of the second biasing member 32 allows the parking pole 11 to move away from the parking gear 12 (the lock is released). When the power supply fails (de-energized), the plunger of the second electromagnetic solenoid 42 protrudes outside, and against the biasing force of the second biasing member 32, holds the parking pole 11 in a parking locked state (a state of being fitted to the parking gear 12).

[0027] The electric parking lock device 1 further has a release member (release lever) 43 that mechanically releases the holding of the parking state by the second electromagnetic solenoid 42 when the power supply fails (de-energized). More specifically, for example, the release member 43 is connected to the plunger of the second electromagnetic solenoid 42 by a wire or the like, and by pulling the release member 43, the plunger of the second electromagnetic solenoid 42 is pulled (retracted inside). As a result, due to the biasing force of the second biasing member 32, the parking pole 11 moves away from the parking gear 12 and the lock is released.

[0028] With the above-described configuration, when the power supply fails, as shown in FIG. 3, the plunger of the first electromagnetic solenoid 41 retracts (is retracted inside). Therefore, due to the biasing force of the first biasing member 31, one engaging portion 331 can swing in a direction to engage with the other engaging portion 332.

[0029] Here, the proximal end portion of one engaging portion 331 is connected to a first biasing member 31 provided at the distal end portion of the parking pole 11, and the proximal end portion of the other engaging portion 332 is connected to the brake pedal 60 via a wire 51. Therefore, thereafter, when the depression of the brake pedal 60 is released, as the depression of the brake pedal 60 is released, the pair of engaging portions 331 and 332 engage with each other, and the parking pole 11 is swung in a direction to engage with the parking gear 12. As a result, the parking gear 12 is locked (parking lock) by releasing the depression of the brake pedal 60 (i.e., semi-automatically).

[0030] Also, when there is a power failure, the plunger of the second electromagnetic solenoid 42 projects outward. Therefore, against the biasing force of the second biasing member 32, the parking pole 11 is held in the parking lock state. Note that even when there is a power failure, when the release member 43 is pulled, the plunger of the second electromagnetic solenoid 42 is pulled (returned inside), and by the biasing force of the second biasing member 32, the parking pole 11 is separated from the parking gear 12 and the lock is released.

[0031] On the other hand, when the power is normal (energized), as shown in FIG. 2, the plunger of the second electromagnetic solenoid 42 returns inside (is housed), and the plunger of the first electromagnetic solenoid 41 projects outward. Therefore, the parking pole 11 becomes swingable, and against the biasing force of the first biasing member 31, one engaging portion 331 is locked so that one engaging portion 331 does not swing (i.e., so that one engaging portion 331 and the other engaging portion 332 do not engage). Thus, as described above, by driving the electric actuator 15, the parking gear 12 is locked or unlocked.

[0032] As described above, according to the present embodiment, when a power failure occurs, one engaging portion 331 is permitted to swing in a direction in which it engages with the other engaging portion 332 by the biasing force of the first biasing member 31. Here, the base end portion of one engaging portion 331 is connected to the first biasing member 31 provided at the tip end portion of the parking pole 11, and the base end portion of the other engaging portion 332 is connected to the brake pedal 60 via the wire 51. Therefore, when the depression of the brake pedal 60 is released thereafter, as the depression of the brake pedal 60 is released, the pair of engaging portions 331 and 332 engage with each other, and the parking pole 11 is swung in a direction in which it meshes with the parking gear 12. As a result, even when a power failure occurs when the parking gear 12 is not locked (unlocked state), by releasing the depression of the brake pedal 60, it becomes possible to semi-automatically lock the parking gear 12.

[0033] When the power supply is normal (when energized), the plunger of the second electromagnetic solenoid 42 retracts (is housed) inside, and the plunger of the first electromagnetic solenoid 41 protrudes outside. Therefore, while the parking pole 11 can swing, one engaging portion 331 is locked against the biasing force of the first biasing member 31 so that one engaging portion 331 does not swing (that is, so that one engaging portion 331 and the other engaging portion 332 do not engage). Therefore, by driving the electric actuator 15, the parking gear 12 is locked or unlocked.

[0034] According to the present embodiment, the tip end portions of both the one engaging portion 331 and the other engaging portion 332 are formed in a hook shape (or wedge shape), and when the outer surfaces of the tip end portions of the one engaging portion 331 and the other engaging portion 332 come into contact with each other (for example, when a power failure occurs with the depression of the brake pedal 60 released), they are configured to be able to shift along the contact surface. Therefore, even when a power failure occurs with the depression of the brake pedal 60 released, by depressing the brake pedal 60 and then releasing the depression of the brake pedal 60 again, parking can be locked.

[0035] According to this embodiment, a second biasing member 32 that applies a biasing force to the parking pole 11 in a direction away from the parking gear 12, and when energized, allows the parking pole 11 to move away from the parking gear 12 by the biasing force of the second biasing member 32, and when a power failure occurs, a second electromagnetic solenoid 42 that holds the parking pole 11 in a parking lock state against the biasing force of the second biasing member 32 are provided. Therefore, even when a power failure occurs, the parking lock state can be maintained against the biasing force of the second biasing member 32.

[0036] According to this embodiment, a further provided is an elastic member 34 that is interposed between the base end portion of one engaging portion 331 and the first biasing member 31 provided at the tip of the parking pole 11 and is stretchable and contractible, and the contracting force of the elastic member 34 is set to be greater than the biasing force of the second biasing member 32. Therefore, for example, when a power failure occurs during running, when the parking pole 11 is bounced against the parking gear 12, it can stretch to prevent the parking gear 12 from being locked. On the other hand, when the parking pole 11 is not bounced against the parking gear 12, it can be set in a locked state and the locked state can be maintained.

[0037] According to this embodiment, since a release member 43 that mechanically releases the holding of the parking state by the second electromagnetic solenoid 42 is further provided when a power failure occurs, the lock can be released (unlocked) even when a power failure occurs.

[0038] As described above, the embodiments of the present invention have been described, but the present invention is not limited to the above embodiments and various modifications are possible. For example, the shapes of one engaging portion 331 and the other engaging portion 332 are not limited to the above embodiments. Also, the arrangements of the first electromagnetic solenoid 41 and the second electromagnetic solenoid 42 are not limited to the above embodiments.

[0039] Also, the system configuration of the above embodiment is an example, and the system configuration of the present invention is not limited to the above embodiment. For example, SBW-CU20 and the electric actuator 15 may be integrated.

[0040] Note that the present invention can also be applied to vehicles not equipped with an automatic transmission, such as EVs (electric vehicles) that directly drive the wheels with an electric motor or the like, FCVs (fuel cell vehicles), SHEVs (series hybrid vehicles), and the like.

Description of Reference Numerals

[0041] 1 Electric parking lock device 2 Shift-by-wire mechanism 3 Lock mechanism in case of power failure 11 Parking pole 12 Parking gear 13 Parking rod 14 Detent plate 15 Electric actuator (electric motor) 20 Shift-by-wire control unit (SBW-CU) 31 First biasing member 32 Second biasing member 33 Engaging member 331 One engaging portion 332 The other engaging portion 34 Elastic member (coil spring) 41 First electromagnetic solenoid 42 Second electromagnetic solenoid 43 Release member 51 Wire 60 Brake pedal

Claims

1. A parking mechanism having a parking gear and a parking pawl, the parking pawl engaging with the parking gear to lock the parking gear and put the vehicle in a parked state, and an electric actuator that swings the parking pawl to lock the parking gear. In the electric parking lock device comprising: An engaging member having a pair of engaging portions that can engage with each other; A first biasing member that applies a biasing force to one of the engaging portions constituting the engaging member so that the one engaging portion swings in a direction in which it engages with the other engaging portion; A first electromagnetic solenoid that locks the one engaging portion against the biasing force of the first biasing member so that the one engaging portion does not swing when energized; A proximal end portion of the one engaging portion is connected to the first biasing member provided at a tip portion of the parking pawl; A proximal end portion of the other engaging portion is connected to a brake pedal; When power fails, the first electromagnetic solenoid permits the one engaging portion to swing in a direction in which it engages with the other engaging portion by the biasing force of the first biasing member; When the depression of the brake pedal is released when power fails, the pair of engaging portions engage with each other, and as the depression of the brake pedal is released, the parking pawl is swung in a direction in which it engages with the parking gear. An electric parking lock device characterized by this.

2. Each of the one engaging portion and the other engaging portion has a tip portion formed in a hook shape, and when the outer surfaces of the tip portions of the one engaging portion and the other engaging portion are in contact with each other, they are configured to be able to shift along the contact surface. The electric parking lock device according to claim 1, characterized by this.

3. A second biasing member that applies a biasing force to the parking pawl in a direction in which the parking pawl moves away from the parking gear; When energized, the second biasing member permits the parking pawl to move away from the parking gear by the biasing force of the second biasing member, and when power fails, a second electromagnetic solenoid that holds the parking pawl in a parking locked state against the biasing force of the second biasing member. The electric parking lock device according to claim 1 or 2, further comprising this.

4. Further provided is a telescopic elastic member interposed between a base end portion of the one engaging portion and the first biasing member provided at a tip end portion of the parking pole. The electric parking lock device according to claim 3, wherein a contraction force of the elastic member is greater than a biasing force of the second biasing member.

5. The electric parking lock device according to claim 3 or 4, further comprising a release member that mechanically releases the holding of the parking state by the second electromagnetic solenoid in the event of a power failure.

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