JP6069521B2 - Power transmission device - Google Patents

Description

  The present invention relates to a power transmission device including a lever crank mechanism.

  Conventionally, an input unit to which a driving force from a traveling drive source such as an engine provided in a vehicle is transmitted, an output shaft connected to a drive wheel and arranged in parallel with a rotation center axis of the input unit, and a plurality of 2. Description of the Related Art There is known a power transmission device that includes a lever crank mechanism, and a four-link mechanism type continuously variable transmission that includes a drive source for travel and a control device that controls the operation of the lever crank mechanism (see, for example, Patent Document 1). ).

  The lever crank mechanism of Patent Document 1 includes a turning radius adjusting mechanism provided at an input portion, a swinging link pivotally supported on an output shaft, and a rotating radius adjusting mechanism at one end thereof. The connecting rod has an input-side annular portion that is externally fitted and the other end portion is connected to the swing end portion of the swing link.

  Between the swing link and the output shaft, an idling state (so-called disengaged state) in which the swing link idles with respect to the output shaft when attempting to rotate relative to the output shaft on one side, and the output shaft A one-way clutch is provided as a one-way rotation prevention mechanism that can be switched to a fixed state (so-called engagement state) in which the swing link is fixed to the output shaft when it is about to rotate relative to the other side. .

JP 2013-47492 A

  In the power transmission device described in Patent Document 1, when the vehicle drive wheels are not slipped (grip state) and transition to the slip state, the load acting on the driving source for driving and the drive wheels is greatly reduced. As a result, the output rotational speed of the driving source for driving and the rotational speed of the drive wheels increase rapidly. Then, when the slip state returns to the grip state, the rotational speed of the drive wheel rapidly decreases, and as a result, the rotational speed of the output shaft connected to the drive wheel also decreases rapidly. At this time, if the rotation speed of the output shaft is lower than the rotation speed of the swing link to which power from the driving source for traveling is transmitted, a large load acts on the one-way rotation prevention mechanism.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a power transmission device that can reduce the load acting on the one-way rotation prevention mechanism when the slip state returns to the grip state.

  The present invention includes an input portion to which a driving force of a driving source for driving a vehicle is transmitted, an output shaft disposed in parallel with a rotation center axis of the input portion, and a swing link pivotally supported by the output shaft. A lever crank mechanism for converting the rotation of the input portion into the swing of the swing link, and the swing link with respect to the output shaft when attempting to rotate relative to the output shaft to one side. A one-way rotation prevention mechanism capable of switching between an idle state in which the rotary shaft is idle, and a fixed state in which the swing link is fixed to the output shaft when attempting to rotate relative to the other side with respect to the output shaft, The lever crank mechanism includes an adjustment drive source, a rotation radius adjustment mechanism capable of adjusting a rotation radius when rotating about the rotation center axis by a driving force of the adjustment drive source, and the rotation radius adjustment mechanism and the rotation radius Coupling that connects the swing link A gear ratio can be changed by changing the turning radius of the turning radius adjusting mechanism, and the driving force of the driving source for driving is changed according to the turning radius to A power transmission device for transmitting to a drive wheel, wherein when the drive wheel is slipping, the one-way rotation preventing mechanism is A control device that performs a slip radius control process for controlling the turning radius so as to be in an idling state is provided.

  In the present invention, the control device controls the turning radius so that when the transition from the grip state to the slip state occurs, even if the grip state is returned to the current grip state, the one-way rotation prevention mechanism is in the idling state. Therefore, when the transition is made from the slip state to the grip state, the one-way rotation prevention mechanism is in the idling state, so that the load acting on the one-way rotation prevention mechanism can be reduced.

  In the present invention, when the control device is in a slip state, the control device executes a slip driving power source rotation lowering process for reducing the output rotational speed of the driving power source, and at the present time in the slip radius control process, Even if it returns to the grip state, within the range where the one-way rotation prevention mechanism is maintained in the idling state, the rotation radius is increased in accordance with the decrease in the output rotation speed of the driving source for driving, and the grip is removed from the slip state. When returning to the state, it is preferable to execute a slip end process for controlling the travel drive source or the rotation radius so that the one-way rotation prevention mechanism is in the fixed state.

  When the rotational speed of the output shaft is the same, if the output rotational speed of the drive source for traveling decreases, the rotational radius when the one-way rotation prevention mechanism changes from the idling state to the fixed state becomes larger than before the decrease. .

  Therefore, according to the above configuration, in the slip state, the control device sets the rotation radius of the travel drive source within the range in which the one-way rotation prevention mechanism is maintained in the idling state even if the control device returns to the grip state at the present time. Increasing as the output rotation speed decreases. As a result, when the control device returns to the grip state from the slip state and executes the processing at the end of the slip, the control device controls the traveling drive source or the turning radius, and the unidirectional rotation blocking mechanism is fixed in a relatively short time. Can be.

  In the present invention, in the radius control process at the time of the slip, the control device, when the amount of decrease in the rotational speed of the output shaft or the amount of time change of the amount of decrease is larger than a predetermined amount, is smaller than the predetermined amount It is preferable to make the rotation radius smaller than that.

  According to this configuration, the amount of decrease in the rotation speed of the output shaft or the amount of time change in the amount of decrease is greater than a predetermined amount (for example, when the vehicle is decelerated by operating the braking device of the vehicle) Therefore, it is possible to prevent in advance that the rotational speed of the output shaft is lower than the rotational speed of the swing link to which the power from the travel drive source is transmitted. Thereby, it is possible to prevent a large load from acting on the one-way rotation prevention mechanism.

  In the present invention, it is preferable that the control device controls the rotation radius based on an output rotation speed of the travel drive source and a moving speed of the vehicle in the slip radius control process.

  According to this configuration, the control device can accurately control the radius of rotation based on the output rotational speed of the driving source for travel and the moving speed of the vehicle.

Sectional drawing which shows the power transmission device of embodiment of this invention. The figure which looked at the turning radius adjustment mechanism, connecting rod, and rocking | fluctuation link of the power transmission device of this embodiment from the axial direction. The figure explaining the change of the rotation radius of the rotation radius adjustment mechanism of the power transmission device of this embodiment. 3A shows a state where the turning radius is maximum, FIG. 3B shows a case where the turning radius is medium, FIG. 3C shows a case where the turning radius is small, and FIG. 3D shows a state where the turning radius is zero. FIG. 4 is a diagram illustrating the relationship between the change in the rotation radius of the rotation radius adjusting mechanism of the power transmission device of the present embodiment and the rocking angle θ2 of the rocking motion of the rocking link; 4A is the maximum rotation radius, and 4B is the rotation radius. 4C and 4C respectively show the swing angles of the swing motion of the swing link when the rotation radius is small. The graph which shows the change of angular velocity (omega) of a rocking | fluctuation link with respect to the change of the rotation radius of the rotation radius adjustment mechanism of the power transmission device of this embodiment. The power transmission of this embodiment WHEREIN: The graph which shows the state in which an output shaft is rotated by the six lever crank mechanisms which respectively made the phase differ 60 degree | times. The figure which shows the relationship between the angular velocity of the rocking | fluctuation link and the angular velocity of an output shaft, the idle state, and a fixed state of the power transmission device of this embodiment. The figure which shows the relationship between a vehicle speed, the amount of eccentricity, the output rotational speed of the drive source for driving | running | working, and a boundary line. The functional block diagram which shows the structure of the control apparatus of the power transmission device of this embodiment. The flowchart which shows the process of the control apparatus of the power transmission device of this embodiment. The timing chart which shows the time change of each vehicle information when changing to a grip state after changing from a grip state to a slip state. 12A is the time before time t1, 12B is the time t2, 12C is the time t3, 12D is the time t5, and 12E is the time t7. The angular velocity of the oscillating link 18, the angular velocity of the output shaft 3, and the virtual boundary output shaft angular velocity. The figure which shows a relationship.

(1. Configuration of power transmission device)
Hereinafter, embodiments of the power transmission device of the present invention will be described. In the power transmission device 1A (see FIG. 9) of the present embodiment, the speed ratio i (i = rotational speed of the input shaft / rotational speed of the output shaft) is set to infinity (∞), and the rotational speed of the output shaft is “0”. A continuously variable transmission, so-called IVT (Infinity Variable Transmission).

  Referring to FIG. 1, a continuously variable transmission 1 is mounted on a vehicle C (see FIG. 9), and is driven to rotate from a driving source 50 (see FIG. 9) such as an internal combustion engine or an electric motor. A hollow input shaft 2 (corresponding to the “input unit” of the present invention) that rotates about the input center axis P1 by receiving a force is provided. Further, the continuously variable transmission 1 is arranged in parallel to the input shaft 2 and outputs an output shaft 3 that transmits rotational power to the drive wheels 60 (see FIG. 9) of the vehicle C via a differential gear, a propeller shaft, etc., not shown. And six turning radius adjusting mechanisms 4 provided on the input shaft 2.

  As shown in FIG. 2, each turning radius adjusting mechanism 4 includes a cam disk 5 and a rotating disk 6. The cam disks 5 have a disk shape, and are provided in pairs on the input shaft 2 so as to be eccentric from the input center axis P1 and rotate integrally with the input shaft 2. Each set of cam disks 5 is arranged so as to make a round in the circumferential direction of the input shaft 2 with six sets of cam disks 5 with a phase difference of 60 degrees. In addition, a disc-shaped rotating disk 6 having a receiving hole 6 a for receiving the cam disk 5 is fitted on each set of cam disks 5 so as to be rotatable in an eccentric manner with respect to the cam disk 5.

  In the rotating disk 6, the center point of the cam disk 5 is P2, the center point of the rotating disk 6 is P3, the distance Ra between the input center axis P1 and the center point P2, and the distance Rb between the center point P2 and the center point P3 are the same. So that it is eccentric with respect to the cam disk 5.

  The receiving hole 6 a of the rotating disk 6 is provided with internal teeth 6 b that are positioned between the pair of cam disks 5. The input shaft 2 (FIG. 1) is formed with a notch hole 2a that is positioned between a pair of cam disks 5 and that communicates the inner peripheral surface and the outer peripheral surface at a location facing the eccentric direction of the cam disk 5. ing.

  A pinion shaft 7 is disposed concentrically with the input shaft 2 in the hollow input shaft 2. The pinion shaft 7 includes external teeth 7 a at locations corresponding to the rotary disk 6. The pinion shaft 7 is disposed so as to be rotatable relative to the input shaft 2. The external teeth 7 a of the pinion shaft 7 mesh with the internal teeth 6 b of the rotating disk 6 through the cutout holes 2 a of the input shaft 2.

  A differential mechanism 8 is connected to the pinion shaft 7. The differential mechanism 8 is configured by a planetary gear mechanism, and includes a sun gear 9, a first ring gear 10 connected to the input shaft 2, a second ring gear 11 connected to the pinion shaft 7, a sun gear 9 and A carrier 13 is provided that supports a stepped pinion 12 including a large-diameter portion 12a that meshes with the first ring gear 10 and a small-diameter portion 12b that meshes with the second ring gear 11 so as to rotate and revolve freely.

  The sun gear 9 is connected to a rotating shaft 14a of an adjustment drive source 14 composed of an electric motor for the pinion shaft 7. If the rotational speed of the adjusting drive source 14 is the same as the rotational speed of the input shaft 2, the sun gear 9 and the first ring gear 10 rotate at the same speed. As a result, the four elements of the sun gear 9, the first ring gear 10, the second ring gear 11, and the carrier 13 are locked so that they cannot rotate relative to each other, and the pinion shaft 7 connected to the second ring gear 11 is connected to the input shaft 2. And rotate at the same speed.

  When the rotational speed of the adjusting drive source 14 is made slower than the rotational speed of the input shaft 2, the rotational speed of the sun gear 9 is Ns, the rotational speed of the first ring gear 10 is NR1, and the gear ratio between the sun gear 9 and the first ring gear 10 is. The number of rotations of the carrier 13 is (j · NR1 + Ns) / (j + 1) where j is the number of teeth of the first ring gear 10 / the number of teeth of the sun gear 9.

  The gear ratio between the sun gear 9 and the second ring gear 11 ((number of teeth of the second ring gear 11 / number of teeth of the sun gear 9) × (number of teeth of the large diameter portion 12a of the stepped pinion 12 / tooth of the small diameter portion 12b) If the number)) is k, the rotation speed of the second ring gear 11 is {j (k + 1) NR1 + (k−j) Ns} / {k (j + 1)}.

  When the rotational speed of the input shaft 2 to which the cam disk 5 is fixed and the rotational speed of the pinion shaft 7 are the same, the rotating disk 6 rotates together with the cam disk 5. When there is a difference between the rotational speed of the input shaft 2 and the rotational speed of the pinion shaft 7, the rotating disk 6 rotates the periphery of the cam disk 5 around the center point P <b> 2 of the cam disk 5.

  As shown in FIG. 2, the rotating disk 6 is eccentric with respect to the cam disk 5 so that the distance Ra and the distance Rb are the same. For this reason, the center point P3 of the rotary disk 6 is positioned on the same axis as the input center axis P1, and the distance between the input center axis P1 and the center point P3, that is, the eccentricity R1 is set to “0”. it can.

  A connecting rod 15 having a large-diameter large-diameter annular portion 15a at one end and a small-diameter annular portion 15b having a smaller diameter than the large-diameter annular portion 15a at the other end is provided at the periphery of the rotating disk 6. A large-diameter annular portion 15a is rotatably fitted via a connecting rod bearing 16 made of a ball bearing. The output shaft 3 is provided with six swing links 18 corresponding to the connecting rod 15 via a one-way clutch 17 as a one-way rotation prevention mechanism.

  A one-way clutch 17 as a one-way rotation prevention mechanism is provided between the swing link 18 and the output shaft 3. The one-way clutch 17 fixes the swing link 18 to the output shaft 3 when attempting to rotate relative to the output shaft 3 on the one side, and relative to the output shaft 3 when attempting to rotate relative to the other side. The swing link 18 is idled. The swing link 18 is swingable with respect to the output shaft 3 when the one-way clutch 17 is idle with respect to the output shaft 3.

  The swing link 18 is formed in an annular shape, and a swing end portion 18 a connected to the small diameter annular portion 15 b of the connecting rod 15 is provided above the swing link 18. The swing end portion 18a is provided with a pair of projecting pieces 18b projecting so as to sandwich the small-diameter annular portion 15b in the axial direction. The pair of projecting pieces 18b are formed with through holes 18c corresponding to the inner diameter of the small-diameter annular portion 15b. A connecting pin 19 is inserted into the through hole 18c and the small diameter annular portion 15b. Thereby, the connecting rod 15 and the swing link 18 are connected.

  FIG. 3 shows the positional relationship between the pinion shaft 7 and the rotating disk 6 in a state where the eccentric amount R1 (the distance between the input center axis P1 and the center point P3) of the turning radius adjusting mechanism 4 is changed. FIG. 3A shows a state in which the amount of eccentricity R1 is “maximum”. At this time, the positional relationship between the pinion shaft 7 and the rotating disk 6 is such that the input center axis P1, the center point P2 of the cam disk 5, and the center point P3 of the rotating disk 6 are aligned. At this time, the gear ratio i is minimized.

  FIG. 3B shows a state in which the eccentric amount R1 is set to “medium” which is smaller than that in FIG. 3A, and FIG. 3C shows a state in which the eccentric amount R1 is set to “small” which is further smaller than that in FIG. The gear ratio i is “medium” which is larger than the gear ratio i in FIG. 3A in FIG. 3B and “large” which is larger than the gear ratio i in FIG. 3B in FIG. 3C.

  FIG. 3D shows a state where the amount of eccentricity R1 is “0”, and the input center axis P1 and the center point P3 of the rotating disk 6 are located concentrically. The gear ratio i at this time is infinite (∞). The continuously variable transmission 1 according to the present embodiment can adjust the radius of the rotational motion of the rotational radius adjusting mechanism 4 by changing the eccentric amount R1 by the rotational radius adjusting mechanism 4. In the present embodiment, the eccentric amount R1 is substantially the same as the radius of the rotational motion of the rotational radius adjusting mechanism 4 (that is, the “rotational radius” of the present invention).

  As shown in FIG. 2, the turning radius adjusting mechanism 4, the connecting rod 15, and the swing link 18 of the present embodiment constitute a lever crank mechanism 20 (four-bar linkage mechanism). Then, the lever crank mechanism 20 converts the rotational motion of the input shaft 2 into the swing motion of the swing link 18. The continuously variable transmission 1 of this embodiment includes a total of six lever crank mechanisms 20.

  When the input shaft 2 is rotated and the pinion shaft 7 is rotated at the same speed as the input shaft 2 when the eccentric amount R1 is not “0”, each connecting rod 15 changes its phase by 60 degrees, and the eccentric amount R1. On the basis of this, it is repeatedly swung between the input shaft 2 and the output shaft 3 by alternately pushing to the output shaft 3 side or pulling to the input shaft 2 side.

  A small-diameter annular portion 15 b of the connecting rod 15 is connected to a swing link 18 provided on the output shaft 3 via a one-way clutch 17. Therefore, when the swing link 18 is pushed and pulled by the connecting rod 15 and swings, the output shaft 3 rotates only when the swing link 18 rotates in either the push direction side or the pull direction side.

  When the swing link 18 rotates in the other direction, the swinging movement force of the swing link 18 is not transmitted to the output shaft 3 and the swing link 18 rotates idle. Since each turning radius adjusting mechanism 4 is arranged with a phase changed every 60 degrees, the output shaft 3 is rotated in turn by each turning radius adjusting mechanism 4.

  4A shows the case where the eccentric amount R1 is “maximum” in FIG. 3A (when the gear ratio i is minimum), and FIG. 4B shows the case where the eccentric amount R1 is “medium” in FIG. 3B (the gear ratio i is medium). 4C shows the swing range θ2 of the swing link 18 with respect to the rotational movement of the turning radius adjusting mechanism 4 when the eccentric amount R1 is “small” in FIG. 3C (when the speed ratio i is large). Is shown.

  As is clear from FIG. 4, as the amount of eccentricity R1 decreases, the swing range θ2 of the swing link 18 decreases. When the eccentric amount R1 is “0”, the swing link 18 does not swing. In the present embodiment, the position closest to the input shaft 2 in the swing range θ2 of the swing end 18a of the swing link 18 is the internal dead center, and the position farthest from the input shaft 2 is the external dead center. .

  FIG. 5 shows the angular velocity ω_i of the swing link 18 accompanying the change in the eccentric amount R1 of the rotational radius adjusting mechanism 4 with the rotational angle θ of the rotational radius adjusting mechanism 4 of the continuously variable transmission 1 as the horizontal axis and the angular velocity ω as the vertical axis. The relationship of changes is shown. As can be seen from FIG. 5, the angular velocity ω_i of the swing link 18 increases as the eccentric amount R1 increases (the transmission ratio i decreases).

  FIG. 6 shows the rotation radius adjustment mechanism 4 when the six rotation radius adjustment mechanisms 4 having different phases by 60 degrees are rotated (when the input shaft 2 and the pinion shaft 7 are rotated at the same speed). The angular velocity ω_i of each swing link 18 with respect to the rotation angle θ1 is shown. As can be seen from FIG. 6, the output shaft 3 is smoothly rotated by the six lever crank mechanisms 20.

  As shown in FIG. 9, the continuously variable transmission 1 includes a control device 40. The control device 40 is an electronic unit that includes a CPU, a memory, and the like.

  The control device 40 controls the operation of the travel drive source 50 and the adjustment drive source 14 by causing the CPU to execute a travel drive source 50 and a control program for the continuously variable transmission 1 held in the memory. In addition, the control device 40 realizes a function of controlling the eccentric amount R1 of the turning radius adjusting mechanism 4 by controlling the operation of the adjusting drive source 14.

  In addition, the vehicle C on which the continuously variable transmission 1 is mounted has an input for detecting the rotational speed of the input shaft 2 of the continuously variable transmission 1 (same as the output rotational speed Ne of the travel drive source 50 in this embodiment). Of the side rotation speed detection unit 41 (for example, rotation speed sensor), the drive wheel rotation speed detection unit 42 (for example, rotation speed sensor) for detecting the rotation speed of the drive wheel 60 of the vehicle C, and the driven wheel 61 of the vehicle C. And a driven wheel rotation speed detector 43 (for example, a rotation speed sensor) that detects the rotation speed.

  The control device 40 receives output signals from the input side rotational speed detector 41, the drive wheel rotational speed detector 42, and the driven wheel rotational speed detector 43. The control device 40 detects the output rotation speed Ne (unit: [rpm], for example) of the travel drive source 50 from the output signal of the input side rotation speed detection unit 41.

  The control device 40 detects the rotational speed of the driving wheel 60 (hereinafter referred to as “driving wheel rotational speed”. The unit is, for example, [rpm]) Ndrive from the output signal of the driving wheel rotational speed detection unit 42. Based on the detected “drive wheel rotational speed Ndrive” and “transmission ratio between the output shaft 3 and the drive wheel 60”, the control device 40 determines the rotational speed No. (unit: [rpm], for example, of the output shaft 3). ) Is detected.

  Further, the control device 40 detects the rotational speed of the driven wheel 61 (hereinafter referred to as “driven wheel rotational speed”) Ndriven (unit: [rpm], for example) based on the output signal of the driven wheel rotational speed detection unit 43. To do. The control device 40 detects the traveling speed (hereinafter referred to as “vehicle speed”) V (unit: [km / h], for example) of the vehicle C based on the detected driven wheel rotation speed Ndriven.

(2. State of one-way clutch)
Referring to FIG. 7, when the one-way clutch 17 fixes the swing link 18 to the output shaft 3 (that is, when the driving force from the input shaft 2 can be transmitted to the output shaft 3), the output shaft 3. In contrast, the case where the swing link 18 is idled (that is, when the driving force from the input shaft 2 cannot be transmitted to the output shaft 3) will be described. 7, the horizontal axis indicates time, the vertical axis indicates angular velocity, and the relationship between the angular velocity ω of one swing link 18 (swing end 18a) and the angular velocity ω_o of the output shaft 3 is illustrated.

  As indicated by hatching in FIG. 7, one direction after the angular velocity ω_i of the swing link 18 exceeds the angular velocity ω_o of the output shaft 3 and after the angular velocity ω_i of the swing link 18 falls below the angular velocity ω_o of the output shaft 3. A driving force is transmitted from the input shaft 2 to the output shaft 3 through the lever crank mechanism 20 until the twist (a twist of several degrees) of the clutch 17 is released.

  Hereinafter, the state of the one-way clutch 17 that cannot transmit the driving force from the input shaft 2 to the output shaft 3 is referred to as an “idle state” (the idling state is a so-called “disengaged state”). The state of the one-way clutch 17 that can transmit the driving force from the input shaft 2 to the output shaft 3 is referred to as a “fixed state” (the fixed state is a so-called “engaged state”).

(2-1. Borderline at which the state changes)
FIG. 8 is a characteristic diagram according to the vehicle speed V of the boundary line L corresponding to the eccentric amount R1 of the turning radius adjusting mechanism 4 and the output rotational speed Ne of the traveling drive source 50. Here, in FIG. 8, the horizontal axis indicates the eccentricity R1, and the vertical axis indicates the output rotation speed Ne of the travel drive source 50.

  Whether the one-way clutch 17 is in an idle state or a fixed state varies depending on the vehicle speed V, the amount of eccentricity R1, and the output rotational speed Ne of the travel drive source 50.

  Lines La, Lb, and Lc shown in FIG. 8 are boundary lines when the one-way clutch 17 shifts from the idling state to the fixed state. Note that each of the boundary lines L (La, Lb, Lc) indicates a boundary line L having a different vehicle speed V, and the more the boundary line L is located on the upper right side of FIG. 8 (“La → Lb → Lc”). The vehicle speed V increases.

  That is, since the angular speed ω_o of the output shaft 3 increases as the vehicle speed V increases, the angular speed ω_i of the swing link 18 when the one-way clutch 17 shifts from the idling state to the fixed state increases as the vehicle speed V increases. Because it grows.

  Further, when the vehicle speed V is constant (that is, at each of the boundary lines La, Lb, and Lc), the greater the eccentric amount R1, the smaller the speed ratio i of the continuously variable transmission 1, and therefore the angular speed ω_i of the swing link 18. Becomes larger. Therefore, when the one-way clutch 17 shifts from the idling state to the fixed state, the output rotational speed Ne of the travel drive source 50 decreases as the eccentric amount R1 increases.

(3. Control)
(3-1. Overview of control)
FIG. 9 shows a functional block diagram of the control device 40 and the power transmission device 1A for controlling the power transmission device 1A of the present embodiment.

  First, an outline of the control device 40 will be described. The control device 40 includes, as main processing units, a slip determination processing unit 71, a slip radius control processing unit 72, a slip traveling drive source rotation reduction processing unit 73, and a slip end processing unit 74.

  The slip determination processing unit 71 is based on the driving wheel rotational speed Ndrive and the driven wheel rotational speed Ndriven detected by the control device 40, or the slip state where the driving wheel 60 of the vehicle C is slipping or the grip state where the driving wheel 60 is not slipping. A slip determination process is performed to determine whether or not. Specifically, the slip determination processing unit 71 determines a slip state when the difference between the drive wheel rotational speed Ndrive and the driven wheel rotational speed Ndriven is equal to or greater than a predetermined value ΔN_threshold, and determines that the grip state is less than the predetermined value ΔN_threshold. judge. Here, the predetermined value ΔN_threshold is set to such a value that it can be determined whether the driving wheel 60 is in the slip state or the grip state by an experiment conducted in advance.

  In the present embodiment, the control device 40 performs the slip determination by the slip determination processing unit 71. However, the control device 40 does not include the slip determination processing unit 71, and another control device or the like performs the slip determination processing. A function equivalent to that of the unit 71 may be provided. In this case, a signal indicating the result of determining whether another control device or the like is in the slip state or the grip state is output, and the control device 40 determines whether the slip state or the grip state is based on the output signal. You may be able to do it.

  Hereinafter, the state in which the slip determination processing unit 71 detects the grip state is referred to as “grip detection state”, and the state in which the slip state is detected is referred to as “slip detection state”.

  The slip radius control processing unit 72 controls the eccentricity R1 so that the one-way clutch 17 is idling even when the grip detection state is changed to the slip detection state when the slip detection state transitions to the slip detection state. Perform time radius control processing.

  As a result, when the transition from the slip state to the grip state occurs, the one-way clutch 17 enters the idling state, so that the load acting on the one-way clutch 17 can be reduced.

  The slip radius control processing unit 72 controls the eccentricity R1 based on the output rotational speed Ne of the travel drive source 50 and the vehicle speed V in the slip radius control processing. Thereby, the radius control processing part 72 at the time of slip can control the eccentric amount R1 with high precision.

  Further, the slip radius control processing unit 72 reduces the eccentric amount R1 when the decrease amount ΔNo of the rotational speed No of the output shaft 3 is larger than the predetermined amount α as compared with the case where it is smaller than the predetermined amount α. To do.

  As a result, the reduction amount ΔNo of the rotational speed No of the output shaft 3 becomes larger than the predetermined amount α (for example, when the vehicle C is decelerated by operating a braking device (not shown)). As a result, it is possible to prevent in advance that the rotational speed No of the output shaft 3 is lower than the rotational speed of the swing link 18 to which the power from the travel drive source 50 is transmitted. Thereby, it is possible to prevent a large load from acting on the one-way clutch 17.

  In addition, the slip travel drive source rotation reduction processing unit 73 executes slip travel drive source rotation decrease processing for reducing the output rotational speed Ne of the travel drive source 50 in the slip detection state. At the same time, the slip radius control processing unit 72 sets the eccentricity amount R1 as the driving for driving within the range in which the one-way clutch 17 is maintained in the idling state even when the grip is returned to the grip state as the slip radius control processing. The output is increased in accordance with a decrease in the output rotation speed Ne of the source 50.

  Then, the slip end processing unit 74 controls the travel drive source 50 or the eccentric amount R1 so that the one-way clutch 17 is fixed when the slip detection state returns to the grip detection state. Execute.

  When the rotational speed No of the output shaft 3 is the same, when the output rotational speed Ne of the traveling drive source 50 decreases, the eccentric amount when the one-way clutch 17 changes from the idling state to the fixed state compared to before the decrease. R1 increases.

  That is, when the slip radius control processing unit 72 is in the slip detection state, the one-way clutch 17 is in the idling state even if it returns to the grip state at the present time according to the decrease in the output rotational speed Ne of the travel drive source 50. By increasing the eccentric amount R1 within the range to be maintained, when the traveling drive source 50 or the eccentric amount R1 is controlled when actually returning to the grip state, the one-way clutch 17 is fixed in a relatively short time. Can be.

(3-2. Details of control)
The details of the control processing executed by the control device 40 will be described with reference to FIGS.

  FIG. 10 is a flowchart showing a control process executed by the control device 40.

  FIG. 11 shows a time change (horizontal axis is the horizontal axis) when the vehicle C returns to the grip state (after time t4) after transitioning from the grip state (before time t1) to the slip state (time t1 to t4). Represents time). In FIG. 11, since the illustration is given with emphasis on ease of understanding for easy understanding, the time change of each vehicle information at each time point is schematically shown. Further, there is a slight time difference from the grip state or the slip state to the grip detection state or the slip detection state (for example, time point t1 → time point t2 or time point t4 → time point t6 in FIG. 11).

  Here, the vehicle information includes the driving wheel rotation speed Ndrive (solid line of “wheel rotation speed”), the driven wheel rotation speed Ndriven (dotted line of “wheel rotation speed”), and the output rotation speed Ne of the travel drive source 50. , Eccentric amount R1, angular velocity ω_i of the oscillating link 18 (solid line of “angular velocity”, value obtained by multiplying the rotational speed of the oscillating link 18 by “2π [rad]”), angular velocity ω_o of the output shaft 3 (of “angular velocity”) Dotted line, the value obtained by multiplying the rotation speed No of the output shaft 3 by “2π [rad]”), the virtual boundary output shaft angular velocity ω_bound (the broken line of “angular velocity”. Details of the virtual boundary output shaft angular velocity will be described later), and the vehicle C driving force.

  12 (in FIGS. 12A to 12E, the horizontal axis represents time, and the vertical axis represents angular velocity), “the angular velocity ω_i of the swing link 18 (solid line) at a predetermined time point in the timing chart shown in FIG. ) ”,“ Angular velocity ω_o of output shaft 3 (dashed line) ”, and“ Virtual boundary output axis angular velocity ω_bound (broken line) ”.

  The predetermined time point is a time point before time point t1 in FIG. 12A, time point t2 in FIG. 12B, time point t3 in FIG. 12C, time point t5 in FIG. 12D, and time point t7 in FIG.

  Here, the virtual boundary output shaft angular velocity ω_bound is an angular velocity of the output shaft 3 when it is assumed that the grip state is returned to the grip state at the present time. Since the virtual boundary output shaft angular velocity ω_bound does not exist in the grip state, it is illustrated only in the slip state (in FIG. 11, only times t1 to t4, and in FIG. 12, only 12B and 12C).

  Here, the virtual boundary output shaft angular velocity ω_bound is “driven wheel rotational speed Ndriven (the rotational speed representing the actual moving speed V of the vehicle C. In other words, the driving wheel rotational speed Ndrive when returning to the grip state at the present time)” , “2π [rad]” in the “rotational speed No of the output shaft 3 when assuming that the gear ratio between the output shaft 3 and the driving wheel 60 is returned to the grip state” at the present time. Is the value multiplied by. That is, the virtual boundary output shaft angular velocity ω_bound represents the maximum angular velocity at which the one-way clutch 17 is in the idling state even when the slip detection state returns to the grip state at the present time.

  Accordingly, when the control device 40 controls the eccentric amount R1 so that the angular velocity ω_i of the swing link 18 is equal to or less than the virtual boundary output shaft angular velocity ω_bound in the slip detection state, the control device 40 has returned to the grip state at the present time. Even so, the one-way clutch 17 can be idled.

  Strictly speaking, the change in the driving wheel rotational speed Ndrive occurs in a very short time from the time point t4 to the time point t5, but “when returning to the grip state at the present time” means the time point t5 (that is, the end of the transient state). Time).

  Strictly speaking, after the angular velocity ω_i of the swing link 18 is lower than the angular velocity ω_o of the output shaft 3, the one-way clutch 17 is twisted in one direction until the twist (twist of several degrees) is released. The clutch 17 is in a fixed state. Therefore, when the one-way clutch 17 transitions from the fixed state to the idling state, the angular velocity ω_i of the swing link 18 is once set in a region lower than the virtual boundary output shaft angular velocity ω_bound by the angular velocity for releasing the torsion. The eccentric amount R1 is controlled, but “controlling the eccentric amount R1 so that the angular velocity ω_i of the swing link 18 is equal to or less than the virtual boundary output shaft angular velocity ω_bound” includes such control. It is. Note that when the one-way clutch 17 is already idling, the torsion does not occur. Therefore, the eccentric amount R1 may be controlled so that the angular velocity ω_i of the swing link 18 is equal to or less than the virtual boundary output shaft angular velocity ω_bound.

  When the control device 40 controls the amount of eccentricity R1 as described above, when the transition from the grip detection state in which the slip state is not detected to the slip detection state in the present invention has been made, This is equivalent to controlling the turning radius so that the one-way rotation prevention mechanism is in the idling state even when the driving wheel returns to the grip state where it does not slip.

  Hereinafter, the control process executed by the control device 40 will be described with reference to FIG. The control device 40 executes the flowchart shown in FIG. 10 at predetermined intervals. In the first step ST1, the control device 40 executes a slip determination process based on the driving wheel rotational speed Ndrive and the driven wheel rotational speed Ndriven to determine whether the slip state or the grip state. Here, the process executed in step ST1 corresponds to the slip determination process executed by the slip determination processing unit 71.

  When it is determined that the slip state is detected in step ST1 (for example, when the difference between the drive wheel rotational speed Ndrive and the driven wheel rotational speed Ndriven is large as at time t2 in FIG. 11), the control device 40 proceeds to step ST2. While performing fuel cut (slipping travel drive source rotation lowering process), an upshift (that is, a process of increasing the eccentricity R1) is prohibited. By performing the fuel cut in this way, the output rotational speed Ne of the travel drive source 50 can be reduced after the time point t2.

  In step ST3, the control device 40 calculates the actual ratio R_act by dividing the output rotational speed Ne of the traveling drive source 50 by the driven wheel rotational speed Ndriven. The actual ratio R_act is a ratio obtained by dividing the output rotational speed Ne of the driving source 50 for traveling in the slip state by “the driving wheel rotational speed Ndrive when assuming that the gripping state is returned to the current state” ( Gear ratio).

  In subsequent step ST4, the control device 40 determines the boundary ratio R_bound based on the output rotational speed Ne of the traveling drive source 50 and the driven wheel rotational speed Ndriven. Here, the boundary ratio R_bound is a ratio of a boundary where the fixed state and the idling state are switched when it is assumed that the slip state is returned to the grip state at the present time. That is, the boundary ratio R_bound is the eccentric amount R1 corresponding to the output rotational speed Ne of the travel drive source 50 on the boundary line L corresponding to the driven wheel rotational speed Ndriven (or the vehicle speed V) (see FIG. 8). The corresponding gear ratio.

  Here, when the actual ratio R_act and the boundary ratio R_bound are the same, the angular velocity ω_i of the swing link 18 and the virtual boundary output shaft angular velocity ω_bound are the same. That is, when in the slip state, the boundary ratio R_bound is larger than the actual ratio R_act means that the angular velocity ω_i of the swing link 18 exceeds the virtual boundary output shaft angular velocity ω_bound when returning to the grip state at the present time. The one-way clutch 17 is in a fixed state. Thereby, there is a possibility that a large load acts on the one-way rotation prevention mechanism abruptly.

  Therefore, in the slip state, by controlling the eccentric amount R1 so that the boundary ratio R_bound is equal to or less than the actual ratio R_act (and by controlling the boundary ratio R_bound), the grip state is returned to the current state. Even in such a case, the one-way clutch 17 can be idled.

  In step ST5, the control device 40 determines whether or not the actual ratio R_act is smaller than the boundary ratio R_bound.

  If the control device 40 determines in step ST5 that “actual ratio R_act <boundary ratio R_bound”, the control device 40 proceeds to step ST6 and sets the target eccentricity amount R1_cmd, which is the target value of the eccentricity amount R1, to the rule for slipping. Determine according to Specifically, the control device 40 determines the eccentric amount R1 that can maintain the idle rotation state of the one-way clutch 17 as the target eccentric amount R1_cmd even when the gripping state is returned to the current state. That is, the control device 40 determines the eccentric amount R1 at which the angular velocity ω_i of the swing link 18 is equal to or less than the virtual boundary output shaft angular velocity ω_bound as the target eccentric amount R1_cmd.

  In the present embodiment, basically, the angular velocity ω_i of the swing link 18 is set to be the same value as the virtual boundary output shaft angular velocity ω_bound. For this reason, when the output rotational speed Ne of the travel drive source 50 decreases, the control device 40 is within the range in which the one-way clutch 17 is maintained in the idling state even if it returns to the grip state at the present time. As the output rotational speed Ne decreases by 50, the eccentricity R1 is increased. In addition, although the upshift (that is, the increase in the eccentric amount R1) is prohibited in step ST2, the increase in the eccentric amount R1 due to the processing is not subject to the prohibition.

  In subsequent step ST7, the control device 40 determines whether or not the reduction amount ΔNo of the rotational speed No of the output shaft 3 exceeds a predetermined amount α. If it is determined in step ST7 that “decrease amount ΔNo> predetermined amount α”, the control device 40 proceeds to step ST8 and decreases the target eccentricity amount R1_cmd determined in step ST6 according to the decrease amount ΔNo. .

  If it is determined in step ST7 that “decrease amount ΔNo ≦ predetermined amount α”, or if the process of step ST8 is completed, the control device 40 proceeds to step ST9, and the eccentricity amount R1 is set to step ST6 or step ST6. The adjustment drive source 14 is controlled so as to be the target eccentricity R1_cmd determined in ST8.

  As described above, even when the grip state is returned to the current state, the eccentric amount R1 is set in step ST9 so that the target eccentric amount R1_cmd set in step ST6 is set so that the one-way clutch 17 can maintain the idling state. Therefore, when the transition from the slip state to the grip state occurs, the one-way clutch 17 enters the idling state. Therefore, the load acting on the one-way clutch 17 can be reduced.

  Here, in step ST6, the determined target eccentricity R1_cmd (that is, the eccentricity R1 that allows the one-way clutch 17 to maintain the idling state even when the gripping state is returned to the current state) is set. Controlling the eccentric amount R1 in step ST9 corresponds to the slip radius control process executed by the slip radius control processing section 72.

  If it is determined in step ST7 that “decrease amount ΔNo> predetermined amount α”, in step ST8, the target eccentricity amount R1_cmd determined in step ST6 is decreased according to the decrease amount ΔNo. Thereby, the eccentric amount R1 is controlled in step ST9 so that the decreased target eccentric amount R1_cmd is obtained in step ST9.

  Therefore, for example, even when the vehicle C is decelerated by operating a braking device (not shown), the rotational speed No of the output shaft 3 is a fluctuation to which the power from the driving source 50 is transmitted. It can prevent beforehand that the rotational speed of the dynamic link 18 is less than. Thereby, it is possible to prevent a large load from acting on the one-way clutch 17.

  Here, the process in which step ST8 is executed after the determination in step ST7 and step ST9 is executed is performed by the above-mentioned slip radius control processing unit 72, “a decrease amount ΔNo of the rotational speed No of the output shaft 3 is a predetermined amount α. Is larger than the predetermined amount α, it corresponds to the process of “decreasing the eccentricity R1 smaller than the case where it is smaller than the predetermined amount α”.

  When it is determined in step ST5 that “actual ratio R_act ≧ boundary ratio R_bound”, or when the process of step ST9 ends, the control device 40 proceeds to step ST10. In step ST10, the control device 40 determines whether or not it is in the slip state as in step ST1. Here, the process executed in step ST10 corresponds to the slip determination process executed by the slip determination processing unit 71.

  If the control device 40 determines in step ST10 that the vehicle is in the slip state, the control device 40 returns to step ST3.

  When the control device 40 determines in step ST10 that the vehicle is in the grip state (for example, when the difference between the driving wheel rotational speed Ndrive and the driven wheel rotational speed Ndriven is small as at time t6 in FIG. 11), the control unit 40 performs step ST11. Proceed to, cancel the fuel cut and cancel the prohibition of upshifting.

  In subsequent step ST12, the control device 40 determines the target eccentric amount R1_cmd so that the one-way clutch 17 is in a fixed state. Specifically, the control device 40 determines the target eccentric amount R1_cmd so as to be larger than the current eccentric amount R1 at least while the one-way clutch 17 is idling.

  In subsequent step ST13, the control device 40 controls the adjustment drive source 14 so that the eccentric amount R1 becomes the target eccentric amount R1_cmd determined in step ST12.

  When the output rotational speed Ne of the travel drive source 50 decreases in step ST6, the control device 40 is within the range in which the one-way clutch 17 is maintained in the idling state even if it returns to the grip state at the present time. As the output rotational speed Ne of the drive source 50 decreases, the eccentric amount R1 is increased. Thus, when the adjustment drive source 14 is controlled to increase the eccentricity R1 in step ST13, the one-way clutch 17 is fixed in a relatively short time (for example, immediately after time t6 in FIG. 11). Can be.

  Here, the processing in steps ST12 to ST13 from “when the transition from the slip detection state to the grip detection state” to “when the one-way clutch 17 transitions from the idling state to the fixed state” is the slip end processing. It corresponds to.

  In step ST12 and ST13, the eccentric amount R1 is controlled as the slip end process, but in the slip end process, the one-way clutch 17 is idling by controlling the output rotational speed Ne of the travel drive source 50. Processing to change from a state to a fixed state may be used.

  When it is determined in step ST1 that the control device 40 is in the grip state, or when the processing of step ST13 is completed, the control device 40 ends this flowchart.

  Next, with reference to FIG. 11, the time change of each vehicle information by the control apparatus 40 as mentioned above performing the control processing shown by FIG. 10 is demonstrated.

  When the slip state is reached at the time t1, the output rotational speed Ne and the drive wheel rotational speed Ndrive of the travel drive source 50 increase due to reasons such as a decrease in load. At this time, the slippage causes the driving force of the vehicle C to become zero.

  At time t2, the control device 40 enters the slip detection state and step ST2 is executed, so that the output rotational speed Ne of the travel drive source 50 gradually decreases after time t2. At this time, the driving wheel rotational speed Ndrive is transmitted from the driving source 50 for traveling by controlling the eccentric amount R1 so that the one-way clutch 17 is idling in steps ST6 to ST9. It will be in a state of rotating with inertia. Accordingly, the drive wheel rotational speed Ndrive gradually decreases after time t2.

  Since the output rotational speed Ne of the travel drive source 50 is decreased at the time point t3, the one-way clutch 17 is maintained in the idling state even if the grip state is returned to the current state due to the decrease. The eccentric amount R1 increases as the output rotational speed Ne of the traveling drive source 50 decreases.

  When the grip state is reached at time t4, the driving wheel rotational speed Ndrive decreases rapidly to the driven wheel rotational speed Ndriven for a short time until time t5.

  Thereafter, at time t6, the grip detection state is established, and the eccentric amount R1 increases so that the one-way clutch 17 is in the fixed state. In addition, even if it returns to the grip state at the present time, the eccentric amount R1 is increased in accordance with the decrease in the output rotational speed Ne of the travel drive source 50 within the range where the one-way clutch 17 is maintained in the idling state. Immediately after time t6, the one-way clutch 17 is in a fixed state, the driving force of the vehicle C gradually increases from 0, and can return to the running state before the slip state smoothly until time t7.

(4. Modifications)
In the present embodiment, the slip radius control processing unit 72 of the control device 40 (steps ST7 and ST8) determines that the amount of decrease ΔNo of the rotational speed No of the output shaft 3 is larger than the predetermined amount α. The amount of eccentricity R1 is made smaller than in the case where it is smaller than this, but is not limited thereto. For example, when the time variation dΔNo / dt of the decrease amount ΔNo of the rotation speed No of the output shaft 3 is larger than the predetermined amount α2, the control device sets the eccentricity amount R1 as compared with the case where it is smaller than the predetermined amount α2. You may comprise so that it may become smaller. At this time, instead of the rotation speed No of the output shaft 3, the driven wheel rotation speed Ndriven (that is, the decrease amount or the time change amount of the decrease amount) may be used.

  Even in this case, for example, even when the vehicle C is decelerated by operating a braking device (not shown) of the vehicle C, the rotational speed No of the output shaft 3 is obtained from the driving source 50 for traveling. It is possible to prevent in advance that the rotational speed of the swing link 18 to which the motive power is transmitted is lower, and thus it is possible to prevent a large load from acting on the one-way clutch 17.

  In the present embodiment, the angular velocity ω_i of the swing link 18 is set to be the same value as the virtual boundary output shaft angular velocity ω_bound. A value lower than the boundary output shaft angular velocity ω_bound may be set. In this case, in FIGS. 11 and 12, the angular velocity ω_i of the swing link 18 is positioned below the virtual boundary output shaft angular velocity ω_bound.

  Further, the controller may be configured not to control the eccentric amount R1 according to the relationship between the decrease amount ΔNo of the rotation speed No of the output shaft 3 or the time change amount dΔNo / dt of the decrease amount ΔNo and the predetermined amount α. Good. In this case, steps ST7 and ST8 in FIG. 10 are omitted.

  Further, in the present embodiment, the control device 40 executes the slip driving power source rotation reduction process in the slip detection state, and the one-way clutch even if the slip radius control process returns to the grip state at the present time. The eccentric amount R1 is increased in accordance with a decrease in the output rotational speed Ne of the travel drive source 50 within a range where 17 is maintained in the idling state (step ST6). In the configuration, the control of the eccentric amount R1 (the control for increasing the eccentric amount R1) according to the decrease in the output rotation speed Ne of the traveling drive source 50 may not be performed.

  In the present embodiment, the control device 40 controls the eccentric amount R1 based on the output rotational speed Ne of the travel drive source 50 and the vehicle speed V in the slip radius control process. However, the vehicle speed V at this time is not obtained based on the driven wheel rotation speed Ndriven, but may be obtained by estimating the actual moving speed of the vehicle. For example, the vehicle speed V is estimated based on vehicle movement information obtained by a GPS (Global Positioning System) receiver mounted on the vehicle and vehicle acceleration obtained by an acceleration sensor mounted on the vehicle. It may be obtained.

  In the present embodiment, the one-way clutch 17 is used as the one-way rotation prevention mechanism. However, the one-way rotation prevention mechanism of the present invention is not limited to this, and torque is applied from the swing link 18 to the output shaft 3. May be configured by a two-way clutch (two-way clutch) configured to be able to switch the rotation direction of the swing link 18 capable of transmitting the rotation relative to the output shaft 3.

  Moreover, in this embodiment, although the thing provided with the cam disk 5 and the rotation disk 6 which rotate integrally with the input shaft 2 as the rotation radius adjustment mechanism 4 was demonstrated, the rotation radius adjustment mechanism 4 of this invention is the following. Not limited to this. For example, the turning radius adjustment mechanism is a disc-shaped rotating disk having a through hole formed eccentrically from the center, a ring gear provided on the inner peripheral surface of the through hole, and fixed to the input shaft and meshed with the ring gear. And a carrier to which the driving force from the adjusting drive source is transmitted, and two second pinions that are pivotally supported by the carrier so as to rotate and revolve, and mesh with the ring gear, respectively. Also good.

  DESCRIPTION OF SYMBOLS 1A ... Power transmission device, C ... Vehicle, 2 ... Input shaft (input part), 3 ... Output shaft, 4 ... Turning radius adjustment mechanism, 14 ... Adjustment drive source, 15 ... Connecting rod, 17 ... One-way clutch (one Direction rotation prevention mechanism), 18 ... swing link, 20 ... lever crank mechanism, 40 ... control device, 50 ... driving source for driving, 60 ... driving wheel, 61 ... driven wheel, i ... gear ratio, No ... output shaft 3 , Ne: output rotational speed of the driving source 50 for travel, V: vehicle speed (vehicle moving speed), ΔNo: reduction amount, dΔNo / dt: time change amount of reduction amount ΔNo, α: predetermined amount.

Claims (4)

An input unit to which a driving force of a driving source for driving the vehicle is transmitted;
An output shaft disposed parallel to the rotation center axis of the input unit;
A lever crank mechanism pivotally supported by the output shaft, and a lever crank mechanism for converting the rotation of the input portion into the swing of the swing link;
The idling state in which the rocking link idles with respect to the output shaft when attempting to rotate relative to the output shaft, and the relative rotation toward the other side with respect to the output shaft. A one-way rotation prevention mechanism capable of switching a fixed state in which the swing link is fixed to the output shaft,
The lever crank mechanism includes an adjustment drive source, a rotation radius adjustment mechanism capable of adjusting a rotation radius when rotating about the rotation center axis by a driving force of the adjustment drive source, and the rotation radius adjustment mechanism and the rotation radius Having a connecting rod connecting the swing link,
The transmission ratio can be changed by changing the turning radius of the turning radius adjusting mechanism, and the driving force of the driving source for traveling is changed according to the turning radius and transmitted to the driving wheels of the vehicle. A device,
When the driving wheel is slipping, the turning radius is controlled so that the one-way rotation prevention mechanism is in the idling state even if the driving wheel is returned to the gripping state at present. A power transmission device comprising a control device that performs a slip radius control process. The power transmission device according to claim 1,
The controller is
In the slip state, a slip travel drive source rotation lowering process for reducing the output rotational speed of the travel drive source is executed, and even if the slip radius control process returns to the grip state at the present time, In the range in which the direction rotation prevention mechanism is maintained in the idling state, the rotation radius is increased in accordance with a decrease in the output rotation speed of the traveling drive source,
When the slip state returns to the grip state, a slip end process for controlling the driving source for driving or the rotation radius is executed so that the one-way rotation prevention mechanism is in the fixed state. Transmission device. The power transmission device according to claim 1,
In the slip radius control process, the control device is configured such that when the amount of decrease in the rotational speed of the output shaft or the time change amount of the decrease amount is greater than a predetermined amount, compared to a case where the amount is smaller than the predetermined amount. A power transmission device characterized in that the turning radius is further reduced. The power transmission device according to claim 1,
In the slip radius control process, the control device controls the rotation radius based on an output rotation speed of the driving source for travel and a moving speed of the vehicle.