JP2017166675A - Power transmission device, method for controlling power transmission device, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a torque control of a pulse-drive type power transmission device to be carried out.SOLUTION: A control part 19 controls a clutch member and a brake member in such a way that a first phase in which an operation of a vibrator 20 is released from any one of a clutch member 22 and a brake member 24 and vibrated; a second phase in which it is engaged with an input shaft 12 by a clutch member; a third phase in which it is released from any one of the clutch member and the brake member and vibrated; and a fourth phase in which it is engaged with a fixed part 17 by the brake member are repeated. The control part requests an output torque that is a transmission torque in reference to an elastic energy accumulated at the elastic member 18 and a difference of angular speed difference of the input shaft and the output shaft 14. The control part defines an engaging and releasing timing of the clutch member and the brake member on the basis of a first phase amplitude and a third phase amplitude corresponding to the output torque.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a so-called pulse drive type driving force transmission device that intermittently transmits a driving force of an input shaft to an output shaft, a control method thereof, and a program.

  2. Description of the Related Art Conventionally, a driving force transmission device that transmits driving of an input shaft intermittently to an output shaft by changing angular velocity or torque has been used. For example, Patent Document 1 discloses a so-called pulse drive type driving force transmission device.

  In the transmission device, an elastic member is arranged around the output shaft. One end of the elastic member is connected to the output shaft, and the other end is connected to a vibrator serving as a weight. The vibrator freely moves (vibrates) around the output shaft as the elastic member expands and contracts. At a predetermined timing, for example, when the angular velocity of the vibrator becomes equal to the rotational speed of the input shaft, the vibrator is engaged with the input shaft by the clutch. During this engagement period, the elastic member is stretched (or contracted) to accumulate elastic energy. Thereafter, the vibrator disengaged from the input shaft is further fixed by a brake at a predetermined timing, for example, at a timing when the angular velocity of the vibrator becomes zero. At this time, torque is transmitted to the output shaft by the elastic member biasing the output shaft. Thus, torque is transmitted from the input shaft to the output shaft via elastic energy.

Japanese Patent Application Laid-Open No. 2015-135179

  An object of the present invention is to provide a means that enables torque control of a pulse drive type driving force transmission device disclosed in Patent Document 1.

  The present invention relates to a driving force transmission device. The apparatus includes an input shaft that is rotationally driven by a drive source, an output shaft that is provided coaxially with the input shaft, and an elastic member that has one end connected to the output shaft and disposed in the circumferential direction of the output shaft. A vibrator coupled to the other end of the elastic member and vibrated in the axial circumferential direction of the output shaft as the elastic member expands and contracts, and an angular velocity of the vibrator and the input shaft is equal to or less than a predetermined value A clutch member that engages both of them, a brake member that engages the vibrator with a fixed portion when the angular velocity of the vibrator is zero, and the engagement and release timing of the clutch member and the brake member are controlled. And a control unit that controls transmission torque transmitted between the input shaft and the output shaft via the elastic member. The control unit includes a first phase in which the operation of the vibrator is released from both the clutch member and the brake member and vibrates, a second phase in which the clutch member is engaged with the input shaft, and the second phase. The clutch member is repeated such that the fourth phase, which is released from both the clutch member and the brake member after the phase and vibrates, and the fourth phase engaged with the fixed portion by the brake member, is repeated. And controlling the brake member. Further, the control unit obtains the elasticity in the second phase obtained from a first phase amplitude that is an amplitude of the vibrator in the first phase and a third phase amplitude that is an amplitude of the vibrator in the third phase. The transmission torque is obtained from the elastic energy accumulated in the member and the angular velocity difference between the input shaft and the output shaft. Furthermore, the control unit determines the engagement and disengagement timings of the clutch member and the brake member based on the first phase amplitude and the third phase amplitude corresponding to the obtained transmission torque.

  Preferably, in the above invention, the control unit obtains a plurality of the transmission torques corresponding to a plurality of candidate values of the first phase and the third phase, and among the obtained plurality of the transmission torques, a target The engagement and disengagement timings of the clutch member and the brake member are determined so that the difference from the transmission torque becomes the first phase amplitude and the third phase amplitude corresponding to the transmission torque that is the smallest.

  In the above invention, preferably, the control unit obtains a plurality of sets of candidate values of the first phase amplitude and the third phase amplitude corresponding to the transmission torque that minimizes a difference from the target transmission torque. Sometimes, based on a set of candidate values relatively separated from both the minimum amplitude obtained from the angular velocity difference between the input shaft and the output shaft and the maximum amplitude obtained from the strength of the elastic member, the clutch member and The engagement and release timing of the brake member is determined.

  Preferably, in the above invention, the control unit obtains a plurality of sets of candidate values of the first phase amplitude and the third phase amplitude corresponding to the transmission torque that minimizes a difference from the target transmission torque. The engagement and disengagement timings of the clutch member and the brake member are determined based on a set of candidate values in which the difference between the first phase amplitude and the third phase amplitude is relatively large.

  Preferably, in the above invention, one of the first phase amplitude and the third phase amplitude is set to a fixed value, and the controller is configured to set the fixed value and the other of the first phase amplitude and the third phase amplitude. The plurality of transmission torques corresponding to the plurality of candidate values are obtained, and the other of the first phase amplitude and the third phase amplitude is different from the target transmission torque among the obtained plurality of transmission torques. Engagement and disengagement timings of the clutch member and the brake member are determined so that the amplitude corresponds to the minimum transmission torque.

  The present invention also relates to a program. The program causes a computer to function as the control unit described in the above invention.

  The present invention also relates to a method for controlling a driving force transmission device. The driving force transmission device includes an input shaft that is rotationally driven by a driving source, an output shaft that is provided coaxially with the input shaft, and one end connected to the output shaft and disposed in the axial direction of the output shaft. An elastic member, a vibrator connected to the other end of the elastic member and reciprocated in the axial circumferential direction of the output shaft as the elastic member expands and contracts, and an angular velocity of the vibrator and the input shaft is a predetermined value A clutch member that engages both in the following cases, a brake member that engages the vibrator with a fixed portion when the angular velocity of the vibrator is zero, and engagement and release timings of the clutch member and the brake member By controlling the transmission torque transmitted between the input shaft and the output shaft via the elastic member. As a control method of such a driving force transmission device, the operation of the vibrator is engaged with the input shaft by the clutch member in a first phase that is released from both the clutch member and the brake member and vibrates. The second phase, the third phase that is released from both the clutch member and the brake member and vibrates after the second phase, and the fourth phase that is engaged with the fixed portion by the brake member are repeated. The clutch member and the brake member are controlled. Further, it is accumulated in the elastic member in the second phase obtained from the first phase amplitude that is the amplitude of the vibrator in the first phase and the third phase amplitude that is the amplitude of the vibrator in the third phase. The transmission torque is obtained from the elastic energy obtained and the angular velocity difference between the input shaft and the output shaft. Further, the engagement and disengagement timings of the clutch member and the brake member are determined based on the first phase amplitude and the third phase amplitude corresponding to the determined transmission torque.

  According to the present invention, it is possible to control the torque of the driving force transmission device.

It is a schematic diagram which shows the structure of the driving force transmission apparatus which concerns on this embodiment. It is a perspective sectional view which illustrates the concrete composition of the driving force transmission device concerning this embodiment. It is a figure explaining operation | movement (phase 1) of the driving force transmission apparatus which concerns on this embodiment. It is a figure explaining operation | movement (phase 2) of the driving force transmission apparatus which concerns on this embodiment. It is a figure explaining operation | movement (phase 4) of the driving force transmission apparatus which concerns on this embodiment. It is a figure explaining operation | movement for 1 period of the driving force transmission apparatus which concerns on this embodiment. It is a figure explaining operation | movement for 1 period of the driving force transmission apparatus which concerns on this embodiment with a torque fluctuation. It is a diagram explaining operation | movement of the driving force transmission apparatus which concerns on this embodiment. It is a diagram explaining operation | movement of the driving force transmission apparatus which concerns on this embodiment. It is a figure which illustrates the mesh graph for extracting an amplitude candidate value. It is a flowchart which illustrates the extraction flow of an amplitude candidate value, and the control flow of the driving force transmission apparatus which concerns on this embodiment. It is a diagram explaining operation | movement of the driving force transmission apparatus which concerns on this embodiment. It is a figure which illustrates the mesh graph for extracting an amplitude candidate value. It is a flowchart which shows another example of the control flow of extraction of an amplitude candidate value, and the driving force transmission apparatus which concerns on this embodiment. It is a flowchart which shows another example of the control flow of extraction of an amplitude candidate value, and the driving force transmission apparatus which concerns on this embodiment. It is a flowchart which shows another example of the control flow of extraction of an amplitude candidate value, and the driving force transmission apparatus which concerns on this embodiment. It is a figure which illustrates the mesh graph for extracting an amplitude candidate value.

<Overall configuration>
In FIG. 1, the schematic diagram of the driving force transmission apparatus 10 which concerns on this embodiment is shown. The driving force transmission device 10 includes an input shaft 12, an output shaft 14, a transmission member 16, a control unit 19, and speed sensors 21A, 21B, and 21C. The driving force transmission device 10 is used as a transmission means for transmitting driving force from a driving source such as an internal combustion engine of a vehicle to driving wheels, for example.

  The input shaft 12 and the vibrator 20 are engaged by the clutch member 22. At this time, the elastic member 18 connected to the vibrator 20 by the input shaft 12 is contracted or extended. That is, the kinetic energy of the input shaft 12 is converted into the elastic energy of the elastic member 18.

  After the clutch member 22 is released, the vibrator 20 is engaged with the fixed portion 17 such as a casing by the brake member 24. At this time, the output shaft 14 is biased according to the expansion and contraction of the elastic member 18. For example, if the output shaft 14 extends from the natural length, the output shaft 14 is rotated in the process of contraction. Further, if the output shaft 14 is contracted from its natural length, the output shaft 14 is pushed around in the process of extension. In this way, kinetic energy or torque is transmitted between the input shaft 12 and the output shaft 14 via the elastic energy of the elastic member 18.

<Details of each configuration>
The input shaft 12 is driven to rotate by a drive source (not shown). The output shaft 14 is provided so as to be separated from the input shaft 12 and is provided coaxially with the input shaft 12. The output shaft 14 may have a hollow shape as shown in FIG. 1, for example, and the input shaft 12 may be disposed inside the output shaft 14 or may be coaxial with the input shaft 12 as shown in FIG. It may be arranged side by side.

  The transmission member 16 transmits the driving force of the input shaft 12 to the output shaft 14 via the elastic member 18. In addition, in FIG. 1, although the two transmission members 16 are provided on the output shaft 14, it is not restricted to this form. For example, the number of transmission members 16 may be one. Further, in order to balance in the radial direction (as a counterweight), a plurality of transmission members 16 may be provided on the axial object. The transmission member 16 includes an elastic member 18, a vibrator 20, a clutch member 22, and a brake member 24.

  The elastic member 18 has one end connected to the output shaft 14 and the vibrator 20 connected to the other end. The elastic member 18 is arranged around the shaft circumference at a position deviated from the axis of the output shaft 14. For example, as shown in FIG. 2, an annular slot (ring slot) is formed on the axial end surface of the output shaft 14, and the elastic member 18 is disposed in the slot. The slot serves as a guide, and the elastic member 18 is expanded and contracted (elastically vibrated) along the circumference of the output shaft 14. The elastic member 18 may be composed of a coil spring, for example.

  The vibration period of the elastic member 18 is preferably formed so as to be shorter than the maximum rotation period of the drive source. For example, when the drive source is an internal combustion engine and the maximum rotation speed (maximum allowable rotation speed) is 6000 rpm (= 100 Hz), it is preferable to include the elastic member 18 having a natural frequency ω higher than 100 Hz. In this way, as will be described later, it is possible to transmit the driving force to the output shaft 14 a plurality of times during one rotation of the input shaft 12.

  The vibrator 20 is connected to the elastic member 18 and is vibrated (reciprocated) along the axial direction of the output shaft 14 as the elastic member 18 expands and contracts. The vibrator 20 may be made of, for example, a rigid material such as metal, and may be formed of a weight that reciprocates along the slot together with the elastic member 18. Further, as shown in FIG. 2, the transmission shaft 26 may be arranged coaxially with the output shaft 14 and rotated around the axis as the elastic member 18 expands and contracts.

  The clutch member 22 is an engaging means that engages the vibrator 20 and the input shaft 12. As will be described later, the clutch member 22 can be engaged when the angular velocity of the vibrator 20 and the input shaft 12 is equal to or less than a predetermined value, preferably equal. By adopting such an engagement timing, slip loss during engagement can be suppressed. Here, the equal angular velocities are not limited to the case where the angular velocities of the vibrator 20 and the input shaft 12 completely coincide with each other, but also include a substantially equal range. For example, a range in which the slip loss caused by the engagement between the vibrator 20 and the input shaft 12 is 10% or less of the kinetic energy transmitted by the engagement may be a range where the angular velocities are equal.

  The clutch member 22 is composed of a member that can engage / release the vibrator 20 and the input shaft 12 at high speed. For example, it is preferable that the engagement / release can be performed in a cycle shorter than the frequency of the elastic member 18 (and the vibrator 20). In addition, it is preferable that engagement / release can be quickly performed in accordance with a control signal from the control unit 19. From this, the clutch member 22 may be an electromagnetic clutch that performs engagement / release operation with intermittent power to the electromagnet, for example.

  The brake member 24 engages the vibrator 20 with a fixed portion 17 (non-rotating member) such as a casing. As will be described later, the brake member 24 can engage the vibrator 20 with the fixed portion 17 when the angular velocity of the vibrator 20 is zero. By adopting such an engagement timing, slip loss during engagement can be suppressed.

  It should be noted that the range in which the angular velocity is zero includes a range where the angular velocity is substantially zero. For example, the angular velocity is zero in a range where the slip loss caused by the engagement between the vibrator 20 and the fixed portion 17 is 10% or less of the kinetic energy transmitted from the elastic member 18 to the output shaft 14 by the engagement. It is good also as a range which can be recognized.

  Similar to the clutch member 22, the brake member 24 is preferably composed of a member that can fasten / release the vibrator 20 at high speed. In addition, it is preferable that engagement / release can be quickly performed in accordance with a control signal from the control unit 19. From this, the brake member 24 is comprised from the electromagnetic brake which performs the operation | movement of engagement / release with the interruption of the electric power to an electromagnet, for example.

  The speed sensor 21 </ b> A measures the angular speed (rotational speed) of the input shaft 12. The speed sensor 21B measures the angular speed of the vibrator 20. The speed sensor 21 </ b> C measures the angular speed of the output shaft 14. These speed sensors 21 </ b> A to 21 </ b> C transmit respective measured values to the control unit 19.

  The control unit 19 controls the operations of the clutch member 22 and the brake member 24 according to the angular velocities of the input shaft 12, the vibrator 20, and the output shaft 14. The control unit 19 may be a computer including an arithmetic circuit such as a CPU and storage means such as a hard disk. The computer may be a computer in which a control program for controlling the engagement / release timing of the clutch member 22 and the brake member 24 is stored, or an embedded computer. By executing the control program, the computer functions as the control unit 19 of the drive transmission device. In addition, the control unit 19 receives an angular velocity of the input shaft 12 from the speed sensor 21A, receives an angular velocity of the vibrator 20 from the speed sensor 21B, and receives an angular velocity of the output shaft 14 from the speed sensor 21C. Is provided.

  The controller 19 controls the engagement and release timing of the clutch member 22 and the brake member 24 by outputting an engagement and release signal. For example, conduction and disconnection of the electromagnets of the electromagnetic clutch and the electromagnetic brake are controlled by the engagement signal and the release signal. As will be described later, by controlling the engagement and release timing of the clutch member 22 and the brake member 24, the transmission torque transmitted between the input shaft 12 and the output shaft 14 via the elastic member 18 is controlled. .

<Specific configuration example of driving force transmission device>
FIG. 2 illustrates a specific configuration of the driving force transmission device 10. The input shaft 12, the transmission shaft 26, and the output shaft 14 are arranged side by side on the same axis. The input shaft 12 and the transmission shaft 26 are rotatably supported by the base 30 via bearings 28.

  A flange 32 is formed on the input shaft 12 so as to project in the radial direction. The clutch member 22 is provided so as to sandwich the flange 32. The clutch member 22 includes a movable part 22A and an excitation part 22B.

  The excitation unit 22B receives an excitation current from a power source (not shown), thereby generating a magnetic flux. The exciting portion 22B is an annular member, and is fixed to the base 30 so as to be separated from the input shaft 12 and the transmission shaft 26.

  The movable portion 22A is an annular member made of a magnetic material such as metal, and is movable according to the magnetic flux generated from the exciting portion 22B. The movable portion 22A is coupled to the transmission shaft 26 via a fastening portion 34 that is screwed into the movable portion 22A in the axial direction. The length of the shaft portion 36 of the fastening portion 34 is formed longer than the axial thickness of the input side flange 38 of the transmission shaft 26. With such a structure, the movable portion 22A is fixed in the axial circumferential direction with respect to the transmission shaft 26 and is movable in the axial direction. When a magnetic flux is generated in the exciting portion 22B, the movable portion 22A is attracted in the axial direction and engaged with the flange 32 of the input shaft 12.

  The transmission shaft 26 includes an input side flange 38, an intermediate flange 40, and an output side flange 42. These flanges are respectively formed on the transmission shaft 26 along the axial direction from the input shaft 12 toward the output shaft 14. When the movable portion 22 </ b> A of the clutch member 22 provided on the input side flange 38 is engaged with the input shaft 12, the transmission shaft 26 rotates in synchronization with the input shaft 12.

  The elastic member 18 is connected to the output flange 42. The elastic member 18 is disposed in an annular slot 44 provided around the axis of the output shaft 14, one end along the extending direction of the slot 44 is connected to the output flange 42, and the other end is output shaft. 14. When the transmission shaft 26 is engaged with the input shaft 12, the transmission shaft 26 urges the elastic member 18 to contract.

  A brake member 24 is provided on the intermediate flange 40. Similarly to the clutch member 22, the brake member 24 includes a movable portion 24A and an exciting portion 24B so as to sandwich the intermediate flange 40. The movable portion 24 </ b> A is movable only in the axial direction with respect to the base 30. When a magnetic flux is generated in the exciting portion 24B, the movable portion 24A is attracted in the axial direction and engaged with the transmission shaft 26. Thereby, the rotation of the transmission shaft 26 is stopped.

  Transmission of driving force from the input shaft 12 to the output shaft 14 is performed as follows. First, when the input shaft 12 and the transmission shaft 26 are engaged by the clutch member 22, both of them rotate synchronously. By this synchronous rotation, the elastic member 18 connected to the transmission shaft 26 is contracted. Further, the elastic member 18 transmits elastic energy to the output shaft 14 by releasing the clutch member 22 and fixing the transmission shaft 26 by the brake member 24. As a result, driving force is transmitted from the input shaft 12 to the output shaft 14.

<Details of operation of driving force transmission device>
Next, transmission of driving force by the driving force transmission device 10 will be described with reference to FIGS. In the following, it is assumed that the rotational speed of the input shaft 12 is faster than the rotational speed of the output shaft 14. As shown in FIG. 3, the elastic member 18 is biased around the axis in advance, and is elastically expanded and contracted along the axial direction of the output shaft 14. Along with this, the vibrator 20 is also vibrated (reciprocated) along the axial circumferential direction of the output shaft 14.

  In order to place the elastic member 18 in a vibrating state when the driving force is transmitted, it is preferable that the elastic member 18 is in an urging state at a stage before transmission (standby stage). For example, as shown by a broken line in FIG. 5 described later, the vibrator 20 and the output shaft 14 are fixed in a state where the elastic member 18 is contracted.

  As shown in FIG. 4, the clutch member 22 engages the input shaft 12 and the vibrator 20 in synchronization with the reciprocating period (vibration period) of the vibrator 20. In other words, the driving force of the input shaft 12 is transmitted to the output shaft 14 in synchronization with the vibration cycle of the elastic member 18.

  By transmitting the driving force in synchronization with the vibration cycle of the elastic member 18, it is possible to transmit the driving force independent of the rotation cycle of the input shaft 12. Further, by using the elastic member 18 whose vibration cycle (for example, the natural frequency of the elastic member 18) is shorter than the maximum rotation cycle of the drive source, the driving force can be transmitted multiple times during one rotation of the input shaft 12. Can be done. In addition, transmission of driving force is intermittently performed, but smooth transmission of driving force, such as PWM control, can be performed by performing this intermittent transmission at high speed (high frequency).

  As described above, the engagement is performed when the angular velocity of the vibrator 20 and the angular velocity of the input shaft 12 are equal to or less than a predetermined value. The angular velocity of the vibrator 20 changes according to the elastic energy of the elastic member 18, and the angular velocity of the input shaft 12 and the vibrator 20 is twice in one cycle in which the vibrator 20 vibrates except for the extreme value of the angular velocity. Will be equal. The clutch member 22 engages the input shaft 12 and the vibrator 20 at any one of the two times. By performing engagement when the angular velocities are equal, it is possible to prevent loss due to slipping.

  When the input shaft 12 and the vibrator 20 are engaged with each other by the clutch member 22, as shown from the upper stage to the lower stage in FIG. 4, the speed difference between the input shaft 12 and the output shaft 14 (input shaft angular speed> output shaft angular speed) is determined. Thus, the elastic member 18 is contracted and the elastic energy of the elastic member 18 is accumulated. That is, the kinetic energy of the input shaft 12 is converted into the elastic energy of the elastic member 18.

  Further, as shown in FIG. 5, the clutch member 22 is released and the vibrator 20 is fixed by the brake member 24. At this time, the elastic member 18 transmits the accumulated elastic energy to the output shaft 14. In other words, as the vibrator 20 is fixed, the contracted elastic member 18 rotates (pushes) the output shaft 14 so as to expand to the natural length. As described above, the driving force is transmitted from the input shaft 12 to the output shaft 14.

  Further, the engagement by the brake member 24 is performed when the angular velocity of the vibrator 20 is zero. By doing in this way, generation | occurrence | production of the slip loss at the time of engagement with the vibrator | oscillator 20 and the fixing | fixed part 17 via the brake member 24 can be suppressed.

  Transmission of the driving force from the input shaft 12 to the output shaft 14 via the elastic member 18 can be expressed numerically as follows. For example, when the ratio of the angular velocity of the input shaft 12 to the angular velocity of the output shaft 14 is 5: 3, the input energy of 2/5, which is a differential component during engagement of the clutch member 22, is elastic member. 18 and the remaining 3/5 of the energy is transmitted to the output shaft 14.

  FIG. 6 illustrates speed changes of the input shaft 12, the vibrator 20, and the output shaft 14 due to the drive transmission described above. In addition to the time chart of FIG. 6, FIG. 7 shows, in synchronization with this, the displacement of the elastic member 18, the torque due to the engagement of the clutch member 22 (LU1 torque), the torque due to the engagement of the brake member 24 (LU2 Torque) and a time chart of spring transmission torque by the elastic member 18 are shown.

  6 and 7, the vibrator 20 is released from the clutch member 22 and the brake member 24 and reciprocates (single vibration) along the axial direction of the output shaft 14. At this time, the maximum angular velocity of the vibrator 20 is larger than the angular velocity of the input shaft 12.

  As shown in the second phase (phase 2) of FIGS. 6 and 7, when the angular velocity of the vibrator 20 and the angular velocity of the input shaft 12 are equal to or less than a predetermined value, preferably equal to each other, the clutch member 22 causes the input shaft 12 and the vibrator 20 to Are engaged. During the engagement, the vibrator 20 and the input shaft 12 are at the same speed.

  As shown in the third phase (phase 3) of FIGS. 6 and 7, after the elastic energy is accumulated (shrinked) in the elastic member 18, the engagement by the clutch member 22 is released. When the angular velocity of the vibrator 20 becomes zero in the third phase that is released and vibrated by the clutch member 22 and the brake member 24, the brake member 24 causes the brake member 24, as shown in the fourth phase (phase 4) of FIGS. The vibrator 20 is engaged with the fixed portion 17. After the elastic energy of the elastic member 18 is transmitted to the output shaft 14, the brake member 24 is released and the vibrator 20 reciprocates again (first phase). Thereafter, the first to fourth phases are sequentially repeated.

FIG. 8 is a diagram illustrating changes in angular velocity and amplitude in the first to fourth phases. In this diagram, the horizontal axis represents the angular velocity, and the vertical axis represents the displacement of the elastic member 18. The angular velocity on the horizontal axis is standardized. That is, the value of the horizontal axis is divided by the natural frequency ω of the elastic member 18 after subtracting the angular velocity dθ _O / dt of the output shaft 14 (to which the transducer 20 is connected) from the angular velocity of the transducer 20. Values are shown. Therefore, in FIG. 8, the angular velocity dθ _O / dt of the output shaft 14 is converted to 0, and the fixed portion 17 (velocity = 0) is plotted on the coordinates of −dθ _O / dt × 1 / ω.

  In the following description, the notation of symbols is written as follows in the mathematical formulas and diagrams and the description in the specification in consideration of JIS standard X0208-1983, which is the specification standard of the specification. These shall refer to the same thing.

In the diagram of FIG. 8, the radius represents the amplitude of the vibrator 20. The minimum amplitude A _min is a limit condition for the angular velocity dθ / dt of the vibrator 20 to be equal to the larger angular velocity of the input shaft 12 and the output shaft 14, and in the diagram shown in FIG. It is set to be equal to dθ _i / dt. As described above, since the unit of the horizontal axis is standardized in the diagram of FIG. 8, considering this, the minimum amplitude A _min is the difference between the angular velocities of the input shaft 12 and the output shaft 14 as shown in the following formula (A). And the natural frequency ω of the elastic member 18.

The maximum amplitude A _max indicates the strength limit of the elastic member 18, and represents a boundary value that causes damage when the elastic member 18 is further expanded. The maximum amplitude A _max can be obtained in advance according to the specifications relating to the strength of the elastic member 18.

For Figure 8, the transducer 20 in phase 1 vibrates at an amplitude _{A 1.} When the angular velocity dθ / dt of the vibrator 20 becomes equal to the angular velocity dθ _i / dt of the input shaft 12 ((dθ _i / dt−dθ _O / dt) under standardization) × 1 / ω, the clutch member 22 causes the vibrator 20 to vibrate. Is engaged with the input shaft 12. This engagement period (= phase 2 time) is represented by t _CL . With this engagement, the amplitude of the vibrator 20 increases to A ₂ while maintaining the angular velocity dθ _i / dt ((dθ _i / dt−dθ _O / dt) × 1 / ω under standardization). Further, when the engagement is released in phase 3 and the vibrator 20 vibrates and its angular velocity dθ / dt becomes zero (−dθ _O / dt × 1 / ω under standardization) (vertical portion 17 indicating the fixed portion 17). The vibrator 20 is engaged with the fixed portion 17 by the brake member 24 (when it matches the line). This engagement period (= phase 4 time) is represented by t _BR . The amplitude of the vibrator 20 by the engagement is returned to A _1.

<Model expression representing the operation of the driving force transmission device>
The storage unit of the control unit 19 stores the above-described first to fourth model equations. In this model formula, the loss due to friction during the operation of the driving force transmission device is ignored, and the motion of the vibrator 20 and the elastic member 18 is regarded as the motion of the spring / mass system. First, for the first phase (time t ₀ to t ₁ ), the displacement θ (t) and the angular velocity dθ (t) / dt of the vibrator 20 can be expressed as the following formulas (1) and (2). .

Here, dθ _O / dt is the angular velocity of the output shaft 14, t is the time, A ₁ is the amplitude (first phase amplitude) of the elastic member 18 (and the vibrator 20) in the first phase, and α ₁ is the initial phase. ing.

Here, regarding the first phase amplitude A ₁ , strictly speaking, the amplitude A ₁ attenuates within the first phase period due to the movement of the vibrator 20. Considering this decay, the first phase amplitude A ₁ may be said that the amplitude of the first phase start time point. However, if the period of the first phase is sufficiently short, the attenuation within that period can be substantially ignored. Therefore, in the following denote the amplitude during the first phase period A _1.

Subsequently, Equation (1), per the parameters of (2), omega is the natural angular frequency obtained by the following equation using the torsional stiffness k of inertia I _m and the elastic member 18 of the vibrator 20 (B).

Next, in the second phase (from time t ₁ to time t ₂ ), the input shaft 12 and the vibrator 20 rotate in synchronization because of the engagement by the clutch member 22. From this, the following mathematical formulas (3) and (4) are derived.

In the third phase (from time t ₂ to t ₃ ), the vibrator 20 is released from the clutch member 22 and the brake member 24, and thus vibrates simply as in the first phase. From this, the following mathematical formulas (5) and (6) are derived.

Here, A ₂ represents the amplitude (third phase amplitude) of the vibrator 20 (and the elastic member 18) in the third phase, and α ₂ represents the initial phase in the third phase.

In the fourth phase (from time t ₃ to time t ₄ ), the vibrator 20 is fixed by the brake member 24, and thus the following mathematical expressions (7) and (8) are derived.

Next, regarding the displacement ε _i (i = 1,..., 4) of the elastic member 18 (and the vibrator 20) at the end of each phase (immediately before shifting to the next phase) (see FIG. 8), the mathematical formula (1) ), (2), (4), the following formula (9) is derived for ε ₁ .

  Next, the following formula (10) is derived from the formulas (4), (5), and (6).

  Next, the following formula (11) is derived from the formulas (4), (5), and (8).

  Finally, from the equations (1), (2) and (7), the following equation (12) is derived assuming that the phase 4 is returned to the phase 1.

Among the above, when the change amount of the displacement of the elastic member 18 (and the vibrator 20) in the phases 1 and 3 is β _i (i = 1, 3), the following mathematical formulas (13) and (14) are obtained. It is done.

  From the above, the time of each phase is represented by the following mathematical formulas (15) to (18).

Next, energy E and torque transmitted between the input shaft 12 and the output shaft 14 in one cycle (period from the first phase to the fourth phase) of the driving force transmission device 10 according to the present embodiment will be described. . When the average values of torque applied to the input shaft 12 and the output shaft 14 are respectively T _i and T _O , the relationship with the energy E is expressed by the following formula (19).

  From the formula (19), the following formulas (20) and (21) are derived.

Further, the energy ΔE _c accumulated in the elastic member 18 during the engagement of the phase 2, that is, the clutch member 22, is expressed by the following equation (22) using the equations (9) and (10) and the spring constant k. It is expressed in

From Equation (22), the energy ΔE _c accumulated in the elastic member 18 during engagement of the clutch member 22 is surrounded by the first phase amplitude A ₁ and the third phase amplitude A ₂ as shown by hatching in FIG. It can be expressed by the area.

  The energy input from the driving source to the driving force transmission device 10 during the phase 2, that is, during the engagement of the clutch member 22 can be expressed as the following mathematical formula (23).

  Since the above formulas (22) and (23) represent the same energy, the following formula (24) is derived from the formulas (19), (22), and (23).

In Expression (24), a part of transmission of driving force (energy) from the input shaft 12 to the output shaft 14 is stored in the elastic member 18 as elastic energy ΔE _c , and the rest is transmitted between the input shaft 12 and the output shaft 14. It is shown that it is directly transmitted to the output shaft 14 in accordance with the angular velocity difference (dθ _i / dt−dθ _O / dt). As described above, in the present embodiment, the transmission torque transmitted between the input shaft 12 and the output shaft 14 is obtained from the elastic energy and the angular velocity difference between the input shaft 12 and the output shaft 14.

Of the mathematical formulas described above, when the arbitrary first phase amplitude A ₁ and the first phase amplitude A ₂ are substituted from the mathematical formula (22), the energy ΔE _c stored in the elastic member 18 corresponding to this is obtained. . Furthermore, since the speeds dθ _i / dt and dθ _O / dt of the input shaft 12 and the output shaft 14 are known from the speed sensors 21A and 21C, respectively, dθ _i / dt, dθ _O / dt, and ΔE _c are expressed by the formula (24 ), The corresponding transmission energy E (energy transmitted from the input shaft 12 to the output shaft 14) is obtained.

Further, by substituting the first phase amplitude A ₁ , the angular velocity dθ _i / dt of the input shaft 12, the angular velocity dθ _O / dt of the output shaft 14, and the known natural frequency ω of the elastic member 18 into Equation (9). displacement epsilon ₁ of the elastic member 18 in the phase 1 is determined. Further, from the equation (12), the displacement ε ₄ of the elastic member 18 in the phase ₄ is obtained. Further, the amount of change β ₁ of the displacement of the elastic member 18 in the phase ₁ is obtained from Expression (13).

Further, by substituting the third phase amplitude A ₂ , the angular velocity dθ _i / dt of the input shaft 12, the angular velocity dθ _O / dt of the output shaft 14, and the natural frequency ω of the elastic member 18 into the equation (10), The displacement ε 2 of the elastic member 18 at ₂ is obtained. Further, the displacement ε ₃ of the elastic member 18 in the phase ₃ is obtained from the equation (11). Further, the amount of change β ₃ of the displacement of the elastic member 18 in the phase ₃ is obtained from the mathematical formula (14).

By obtaining the displacements ε _{1 to} ε ₄ of the elastic member 18 of each phase and the displacement amounts β ₁ and β ₃ of the displacement of the elastic member 18 of the phases 1 and 3, respectively, Equations (15) to (18) are obtained, respectively. Time (period) of each phase t ₁ -t ₀ (time of the first phase), t ₂ -t ₁ (time of the second phase), t ₃ -t ₂ (time of the third phase), t ₄ -t ₃ (time of the fourth phase) is obtained. Furthermore, by tapping them together, the times t ₁ , t ₂ , t ₃ and t ₄ are obtained.

Substituting into the equation (21) the transmission energy E obtained by the equation (24), the times t ₄ and t ₀ obtained above, and the angular velocity dθ _O / dt of the output shaft 14 known from the velocity sensor 21C. in the output torque T _O is a transfer torque transmitted between the input shaft 12 and output shaft 14 are determined.

<Control of driving force transmission device>
As described above, in the present embodiment, the first phase amplitude A ₁ and the third phase amplitude A ₂ , the angular velocity dθ _i / dt of the input shaft 12 and the output shaft 14 that are known from the velocity sensors 21A and 21C, respectively. The output torque T _O that is the transmission torque can be obtained from the angular velocity dθ _O / dt. Control unit 19, based on the first phase corresponding to the output torque T _O obtained amplitude A ₁ and the third phase amplitude A _2, define the engagement and disengagement timing of the clutch member 22 and the brake member 24. Specifically, the clutch member 22 at time t ₁ corresponding to the first phase amplitude A ₁ and the third phase amplitude A ₂ to the engaged state is switched to the released state at time t _2. Also the brake member 24 in the engaged state at time t _3, switch to the released state at time t _4.

The control unit 19 substitutes a plurality of candidate values for the first phase amplitude A ₁ and the third phase amplitude A ₂ in the above equation to obtain an output torque T _O (transfer torque) for each set of candidate values. . Further, the control unit 19 _obtains an output torque T _{O —} a that minimizes a difference from the target transmission torque T _ref given in advance among these output torques T _O , and the first phase amplitude A ₁ and the first 3-phase based on the amplitude a ₂ defining the engagement and disengagement timing of the clutch member 22 and the brake member 24. By doing in this way, torque control of driving force transmission device 10 becomes possible.

Figure 10 is a mesh graph for obtaining the first phase candidate value of the amplitude A ₁ and the third phase amplitude A ₂ are illustrated. The horizontal axis represents the possible values of the third phase amplitude A _2, the horizontal axis represents the possible values of the first phase amplitude A ₁ is shown. Further, the roughness of the mesh is appropriately determined according to the response speed of the clutch member 22 and the brake member 24, the spring characteristics of the elastic member 18, and the like.

In the present embodiment, since the deceleration transmission in which the angular velocity dθ _O / dt of the output shaft is slower than the angular velocity dθ _i / dt of the input shaft 12 is taken as an example, the amplitude A ₁ = A _{2 in} the mesh graph of FIG. The area on the lower right side of the drawing with respect to the line becomes the candidate value area. Further, when the maximum amplitude A _max and the minimum amplitude A _min are provided in this region, finally, the candidate values of the first phase amplitude A ₁ and the third phase amplitude A ₂ are determined from within the hatched region (candidate region) in FIG. Extracted.

Specifically in accordance with the flowchart shown in FIG. 11, the control of the first phase amplitude A ₁ and the third phase amplitude A ₂ of the extraction and the driving force transmission apparatus 10 by the control unit 19 is performed. Control unit 19 extracts an arbitrary first phase candidate value of the amplitude _{A 1} and the third phase amplitude _{A 2} from the candidate region in FIG. 10 (S10). Further, based on the above formula, an output torque T _O corresponding to the extracted amplitude candidate values A ₁ and A ₂ is obtained (S12). Furthermore, the control unit 19 determines whether or not all sets of amplitude candidate values A ₁ and A ₂ have been extracted from the candidate area (S14). If there is a set of unextracted amplitude candidate values A ₁ and A _{2 in} the candidate area, new amplitude candidate values A ₁ and A ₂ are extracted (S16), and the process returns to step S12 again.

If all of the amplitude candidate values A _1, A ₂ set from the candidate region is extracted in step S14, the control unit 19, the difference between the output torque T _O and the target transmission torque T _ref that is calculated A minimum output torque _{TO_a} is obtained (S18). Further, the control unit 19 _engages and disengages the clutch member 22 and the brake member 24 based on the amplitudes A ₁ and A ₂ and the times t ₁ , t ₂ , t ₃ , and t ₄ corresponding to the obtained output torque T _{O — a.} Is controlled (S20). Furthermore, it waits until the next control cycle (S22), and then returns to step S10.

Incidentally, as shown in FIG. 9, the area surrounded by the first phase amplitude A ₁ and the third phase amplitude A ₂ represents the elastic energy Delta] E _c. At this time, the predetermined elastic energy ΔE _c is satisfied as in the set of the first phase amplitude A _{1_1} and the third phase amplitude A _{2_1 and} the set of the first phase amplitude A _{1_2} and the third phase amplitude A _{2_2} in FIG. the combination of the first phase amplitude a ₁ and the third phase amplitude a ₂ is likely to more satisfied. That is, there is a possibility that a plurality of output torques _{TO_a} that minimize the difference from the target transmission torque T _ref are established. That is, when described using the mesh graph of FIG. 10, for example as in the target transmission torque on line S1~S4 in FIG 13, the first phase amplitude A ₁ and the meet the target transmission torque to mesh graph of amplitude candidate value 3 phase amplitude a ₂ set is likely to more satisfied.

The control unit 19 extracts an appropriate one from the set of amplitude candidate values. For example, to extract what the least amount of change from the first phase amplitude A ₁ and the third phase amplitude A ₂ is currently set.

Further, the control unit 19 may extract a set of amplitude candidate values that are relatively separated from the minimum amplitude A _min and the maximum amplitude A _max . As described above, the amplitude is attenuated during the vibration process of the vibrator 20. Therefore, when the amplitude of the vibrator 20 is set to the minimum amplitude A _min, there is a synchronization can not take a risk of the input shaft 12 by the attenuation.

Further, as described above, the maximum amplitude A _max is a limit value obtained from the strength of the elastic member 18, and if a response delay or the like occurs in the clutch member 22, the amplitude of the elastic member 18 exceeds the maximum amplitude A _max. There is a risk of damage.

Therefore, the control unit 19 extracts a set of amplitude candidate values that are relatively separated from the minimum amplitude A _min and the maximum amplitude A _max . In the mesh graph shown in FIG. 13, the set indicated by S3 is the one most suitable for this requirement.

  Specifically, according to the flowchart shown in FIG. 14, the control unit 19 performs extraction of a set of amplitude candidate values and control of the driving force transmission device 10. The flowchart of FIG. 14 is obtained by inserting steps S24 and S26 between step S18 and step S20 with respect to the flowchart of FIG. In the following description, description of the steps already described in FIG. 11 will be omitted as appropriate.

When the output torque T _{O_a} that minimizes the difference from the target transmission torque T _ref is obtained in step S18, the control unit 19 has extracted a plurality of sets of amplitude candidate values A ₁ and A ₂ that become the output torque T _{O_a} . It is determined whether or not (S24). If only a single set of amplitude candidate values A ₁ and A ₂ has been extracted, the process proceeds to step S20.

When a plurality of sets of amplitude candidate values A ₁ and A ₂ that become the output torque T _{O — a} are extracted, the control unit 19 makes a relative from the minimum amplitude A _min and the maximum amplitude A _max based on the following formula (25). A set of amplitude candidate values A ₁ and A ₂ that are spaced apart from each other is extracted (S26). After extraction, the process proceeds to step S20.

In addition, when a plurality of sets of amplitude candidate values A ₁ and A ₂ that become the output torque T _{O — a} are extracted, the control unit 19 has a relatively large difference between the first phase amplitude A ₁ and the third phase amplitude A _2. A set of values may be extracted.

As the first phase amplitude A ₁ and the third phase amplitude A ₂ are close to the transition period from the first phase amplitude A ₁ to the third phase amplitude A ₂ is shortened. During the transition period, the clutch member 22 performs the engaging operation and the releasing operation. If the transition period becomes shorter than the time related to the engaging operation and the releasing operation, the clutch member 22 may be unresponsive.

Where the control unit 19, a first phase difference of the amplitude A ₁ and the third phase amplitude A ₂ extracts a set of relatively large amplitude candidate value. In the mesh graph shown in FIG. 13, the set indicated by S4 is the one most suitable for this requirement.

  Specifically, according to the flowchart shown in FIG. 15, the control unit 19 extracts a set of amplitude candidate values and controls the driving force transmission device 10. The flowchart of FIG. 15 is obtained by replacing step S26 with step S28 in the flowchart of FIG. In the following description, the description of the steps already described with reference to FIGS.

When a plurality of sets of amplitude candidate values A ₁ and A ₂ corresponding to the output torque T _{0 — a} that minimizes the difference from the target transmission torque T _ref are extracted in step S18, the control unit 19 calculates the following formula ( based on 26), a first phase amplitude _{a 1} and the third phase difference amplitude _{a 2} extracts a set of relatively large amplitude candidate value (S28). After extraction, the process proceeds to step S20.

In addition, the two extraction criteria, ie, those that are relatively separated from the minimum amplitude A _min and the maximum amplitude A _max, and those that have a relatively large difference between the first phase amplitude A ₁ and the third phase amplitude A ₂ are combined. The set of amplitude candidate values may be extracted. For example, instead of the mathematical formulas (25) and (26), a set of amplitude candidate values may be extracted based on the following mathematical formula (27).

ここで、数式（２７）中、ｗは重み係数であり、最小振幅Ａ_ｍｉｎ及び最大振幅Ａ_ｍａｘから離間させるとの条件と、第１フェーズ振幅Ａ_１と第３フェーズ振幅Ａ_２の差異を広げるとの条件のどちらを優先させるかを適宜変更することができる。

Here, in Equation (27), w is a weighting coefficient, and widens the difference between the first phase amplitude A ₁ and the third phase amplitude A ₂ , and the condition of separating from the minimum amplitude A _min and the maximum amplitude A _max. It is possible to appropriately change which of the above conditions is prioritized.

Also, if one of the first phase amplitude A ₁ and the third phase amplitude A ₂ is set as a fixed value, based on the fixed value and the target transmission torque T _ref, the first phase amplitude A ₁ and the third the other values of the phase amplitude a ₂ may be obtained. For example for stability control, the amplitude A ₁ of the first phase in the case that is set to a fixed value, such extraction is effective.

Specifically in accordance with the flowchart shown in FIG. 16, the control of the first phase amplitude A ₁ and the third phase amplitude A ₂ of the extraction and the driving force transmission apparatus 10 by the control unit 19 is performed. Note that, in the flowchart shown in FIG. 16, the steps denoted by the same reference numerals as those in the flowchart of FIG.

Control unit 19, among the first phase candidate value of the amplitude A ₁ and the third phase amplitude A _2, the candidate of the amplitude A _n that is not set to a fixed value, is extracted from the candidate regions of FIG. 17 (S30).

In FIG 17, the amplitude candidate values A _m, which is set to a fixed value as a first phase amplitude A _{1_k,} and the amplitude candidate value A _n as a third phase amplitude A ₂ is not set to a fixed value. Further, as shown in Figure 17, when fixing the one of the first phase candidate value of the amplitude A ₁ and the third phase amplitude A _2, the intersection between the target transmission torque line is only one point (S4) . Accordingly, in the flowchart of FIG. 16, it does not theoretically occur that a plurality of sets of amplitude candidate values A ₁ and A ₂ satisfying the output torque T _{O — a} are _generated as shown in FIGS.

After step S30, the control unit 19, based on the equations described above, obtaining the fixed value _A m _{(= A 1_k)} and the output torque _{T O} corresponding to the amplitude candidate value _{A n} extracted (S32). Further, the control unit 19 determines whether or not all amplitude candidate values _An are extracted from the candidate area (S34). If there is a set of amplitude candidate values A _n of the unextracted the candidate region by extracting a new amplitude candidate value A _n (S16), returns to step S32.

When all the amplitude candidate values _An are extracted from the candidate area in step S34, the control unit 19 outputs the output torque that minimizes the difference between the calculated output torque _TO and the target transmission torque _Tref. T _{O — a} is obtained (S18). Further, the control unit 19 _engages and disengages the clutch member 22 and the brake member 24 based on the amplitudes A ₁ and A ₂ and the times t ₁ , t ₂ , t ₃ , and t ₄ corresponding to the obtained output torque T _{O — a.} Is controlled (S20). Furthermore, it waits until the next control cycle (S22), and then returns to step S30.

DESCRIPTION OF SYMBOLS 10 Driving force transmission device, 12 Input shaft, 14 Output shaft, 16 Transmission member, 17 Fixed part, 18 Elastic member, 19 Control part, 20 Vibrator, 21A, 21B, 21C Speed sensor, 22 Clutch member, 24 Brake member.

Claims (7)

An input shaft that is driven to rotate by a drive source;
An output shaft provided coaxially with the input shaft;
An elastic member having one end connected to the output shaft and arranged in the axial circumferential direction of the output shaft;
A vibrator connected to the other end of the elastic member and vibrated in the axial direction of the output shaft as the elastic member expands and contracts;
A clutch member that engages the vibrator and the input shaft when the angular velocity is a predetermined value or less;
A brake member for engaging the vibrator with a fixed portion when the angular velocity of the vibrator is zero;
A control unit that controls transmission torque transmitted between the input shaft and the output shaft via the elastic member by controlling the engagement and release timing of the clutch member and the brake member;
A driving force transmission device comprising:
The controller is
The operation of the vibrator is released from both the clutch member and the brake member and vibrates in a first phase, the second phase engaged with the input shaft by the clutch member, and the clutch member after the second phase. The clutch member and the brake member are controlled such that the third phase that is released from both of the brake members and vibrates and the fourth phase that is engaged with the fixed portion by the brake members are repeated. And
Elasticity accumulated in the elastic member in the second phase, obtained from the first phase amplitude that is the amplitude of the vibrator in the first phase and the third phase amplitude that is the amplitude of the vibrator in the third phase. From the energy and the angular velocity difference between the input shaft and the output shaft, the transmission torque is obtained.
The engagement and disengagement timings of the clutch member and the brake member are determined based on the first phase amplitude and the third phase amplitude corresponding to the determined transmission torque.
A driving force transmission device characterized by that. The driving force transmission device according to claim 1,
The controller is
Obtaining a plurality of transmission torques corresponding to a plurality of candidate values of the first phase and the third phase;
Of the plurality of obtained transmission torques, the clutch member and the brake member are engaged such that the first phase amplitude and the third phase amplitude corresponding to the transmission torque with the smallest difference from the target transmission torque are obtained. And determine the release timing,
A driving force transmission device characterized by that. The driving force transmission device according to claim 2,
The controller is
When a plurality of sets of candidate values of the first phase amplitude and the third phase amplitude corresponding to the transmission torque that minimizes the difference from the target transmission torque are obtained, it is obtained from the angular velocity difference between the input shaft and the output shaft. The engagement and disengagement timings of the clutch member and the brake member are determined based on a set of candidate values relatively separated from both the minimum amplitude obtained and the maximum amplitude obtained from the strength of the elastic member.
A driving force transmission device characterized by that. The driving force transmission device according to claim 2 or 3,
When the control unit obtains a plurality of sets of candidate values of the first phase amplitude and the third phase amplitude corresponding to the transmission torque that minimizes the difference from the target transmission torque, the first phase amplitude And the engagement and disengagement timings of the clutch member and the brake member are determined based on a set of candidate values having a relatively large difference in the third phase amplitude.
A driving force transmission device characterized by that. The driving force transmission device according to claim 2,
One of the first phase amplitude and the third phase amplitude is set to a fixed value,
The controller is
Obtaining a plurality of transmission torques corresponding to the fixed value and a plurality of other candidate values of the first phase amplitude and the third phase amplitude;
The clutch member and the clutch member, so that the other of the first phase amplitude and the third phase amplitude is an amplitude corresponding to the transmission torque having a minimum difference from the target transmission torque among the determined plurality of transmission torques. Determine the engagement and release timing of the brake member,
A driving force transmission device characterized by that.   A program for causing a computer to function as the control unit according to any one of claims 1 to 5. An input shaft that is driven to rotate by a drive source;
An output shaft provided coaxially with the input shaft;
An elastic member having one end connected to the output shaft and arranged in the axial circumferential direction of the output shaft;
A vibrator connected to the other end of the elastic member and reciprocated in the axial direction of the output shaft as the elastic member expands and contracts;
A clutch member that engages the vibrator and the input shaft when the angular velocity is a predetermined value or less;
A brake member for engaging the vibrator with a fixed portion when the angular velocity of the vibrator is zero;
A control unit that controls transmission torque transmitted between the input shaft and the output shaft via the elastic member by controlling the engagement and release timing of the clutch member and the brake member;
A control method for a driving force transmission device comprising:
The operation of the vibrator is released from both the clutch member and the brake member and vibrates in a first phase, the second phase engaged with the input shaft by the clutch member, and the clutch member after the second phase. The clutch member and the brake member are controlled such that the third phase that is released from both of the brake members and vibrates and the fourth phase that is engaged with the fixed portion by the brake members are repeated. And
Elasticity accumulated in the elastic member in the second phase, obtained from the first phase amplitude that is the amplitude of the vibrator in the first phase and the third phase amplitude that is the amplitude of the vibrator in the third phase. From the energy and the angular velocity difference between the input shaft and the output shaft, the transmission torque is obtained.
The engagement and disengagement timings of the clutch member and the brake member are determined based on the first phase amplitude and the third phase amplitude corresponding to the determined transmission torque.
A control method for a driving force transmission device.

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