Transmission control device, transmission control method, and program

Abstract

[Problem] To smoothly transition a release side engagement element from a one-way clutch state to a release state. [Solution] A transmission control device is used in a transmission that has a first engagement element, a second engagement element, and a third engagement element. The transmission control device drives the actuator of the first engagement element with the third engagement element in a slip state, thereby causing the first engagement element to transition from the one-way clutch state to the release state, and engaging the second engagement element.

Description

Technical Field

[0001] The present invention relates to a control device for a transmission, a control method for a transmission, and a program.

Background Art

[0002] Patent Document 1 discloses a vehicle drive device in which a rotating electric machine and a transmission are arranged on a first shaft, and a differential gear device is arranged on a second shaft. The transmission gear mechanism of the transmission includes a first planetary gear mechanism including a first one-way clutch and a second planetary gear mechanism including a second one-way clutch. Both the first one-way clutch and the second one-way clutch are selectable one-way clutches configured to be switchable between a one-way restriction state that restricts rotation in one direction, a two-way restriction state that restricts rotation in both directions, and a release state that allows rotation in both directions.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a transmission including an engaging element that engages in a one-way clutch state (one-way restriction state), when changing the engaging element during a gear shift, the engaging element that engages in the one-way clutch state can become a release-side engaging element. However, in this case, meshing fastening is performed by the release-side engaging element. Therefore, when torque acts on the release-side engaging element, the force required for release increases accordingly. As a result, there is a possibility that smooth release cannot be performed due to the torque acting on the release-side engaging element.

[0005] The present invention has been made in view of such problems, and an object thereof is to smoothly transition a release-side engaging element from a one-way clutch state to a release state. [Means for solving the problem]

[0006] A transmission control device according to one aspect of the present invention is used in a transmission having a first engaging element, a second engaging element, and a third engaging element. The transmission control device is used in a transmission having the third engaging element From the released state slip State transitions Let The torque is shared with the third engaging element, thereby reducing the torque shared with the first engaging element. By driving the actuator of the first engaging element in this state, the first engaging element is transitioned from a one-way clutch state to a released state, and then the second engaging element is engaged.

[0007] According to another aspect of the present invention, a method for controlling a transmission corresponding to the above-mentioned control device for the transmission is provided. Furthermore, according to yet another aspect of the present invention, a program corresponding to the above-mentioned control device for the transmission is provided. [Effects of the Invention]

[0008] According to these embodiments, when transitioning the first engaging element, which is the release-side engaging element, from a one-way clutch state to a release state, the torque share of the third engaging element is increased, thereby decreasing the torque share of the first engaging element. This reduces the reaction force acting on the engaging portion of the first engaging element, allowing the first engaging element to be released smoothly. However, if the torque share of the third engaging element is increased all at once to achieve full engagement, the shock will be large. For this reason, it is preferable to have a slip state in which the torque borne by the third engaging element is smaller than that of full engagement. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram of the unit's configuration. [Figure 2] Figure 2 is a skeleton diagram of the unit. [Figure 3] Figure 3 is a diagram showing the fastening table for the transmission mechanism. [Figure 4A] Figure 4A is the first diagram illustrating the switching mechanism. [Figure 4B]Figure 4B is the second diagram in the explanatory diagram of the switching mechanism. [Figure 4C] Figure 4C is the third diagram in the explanatory diagram of the switching mechanism. [Figure 5] Figure 5 is a flowchart illustrating an example of control in the embodiment. [Figure 6] Figure 6 shows an example of a timing chart for an embodiment. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the attached drawings.

[0011] Figure 1 is a schematic diagram of unit 100. Figure 2 is a skeleton diagram of unit 100. Regarding the term "unit," a unit can also be referred to as, for example, a motor unit (a unit having at least a motor) or a power transmission device (a device having at least a power transmission mechanism). A motor is a rotating electric machine having an electric motor function and / or a generator function (at least one of the electric motor function and / or a generator function). A power transmission mechanism is, for example, a gear mechanism and / or a differential gear mechanism. A device (unit) having a motor and a power transmission mechanism is included in both the concepts of a motor unit and a power transmission device.

[0012] As shown in Figure 1, unit 100 comprises a housing 10 and a transmission mechanism 20. Unit 100 is mounted on a vehicle, which is an electric vehicle. Power is input to unit 100 from MG40. MG40 is a rotating electric machine that functions as a motor generator, and unit 100 can also be understood as a configuration that further includes MG40.

[0013] The housing 10 houses the transmission mechanism 20. The transmission mechanism 20 comprises a case 21, a rotating shaft 22, a first planetary gear mechanism PGM1, a second planetary gear mechanism PGM2, a first brake B1, a second brake B2, and a clutch CL. The case 21 has a cylindrical shape and is fixed to the inner circumference of the housing 10. The first planetary gear mechanism PGM1 is provided inside the case 21 via the first brake B1, and the second planetary gear mechanism PGM2 is provided via the second brake B2. The rotating shaft 22 is connected to the MG 40 and rotates due to power from the MG 40. The direction of extension of the rotating shaft 22 corresponds to the axial direction of the unit 100, and this axial direction means the axial direction of the rotating shafts of the components constituting the unit (e.g., motor, gear mechanism, differential gear mechanism).

[0014] The first planetary gear mechanism PGM1 comprises a first sun gear S1, a first carrier C1, a first ring gear R1, and a first pinion gear P1. The first sun gear S1 is coaxially fixed to the rotating shaft 22. The first carrier C1 rotatably supports the first pinion gear P1. The first pinion gear P1 meshes with both the first sun gear S1 and the first ring gear R1. These characteristics are also true for the second planetary gear mechanism PGM2, which comprises a second sun gear S2, a second carrier C2, a second ring gear R2, and a second pinion gear P2.

[0015] The second planetary gear mechanism PGM2 is arranged axially alongside the first planetary gear mechanism PGM1. Therefore, the first planetary gear mechanism PGM1 has a portion that overlaps with the second planetary gear mechanism PGM2 in an axial view. Overlapping in a predetermined direction, including radial and axial views, means overlapping in a predetermined direction, and it means that multiple elements are aligned in that predetermined direction. From this, if a drawing shows multiple elements aligned in a predetermined direction, it can be assumed that there is a sentence in the specification explaining that multiple elements overlap in a predetermined direction.

[0016] The second planetary gear mechanism PGM2 is provided on the side away from the MG40 with respect to the first planetary gear mechanism PGM1. The second carrier C2 is integrally formed with the first ring gear R1 and is connected to the first ring gear R1. The second carrier C2 constitutes an output element of the second planetary gear mechanism PGM2. On the other hand, the first carrier C1 constitutes an output element of the first planetary gear mechanism PGM1 and also constitutes an output element of the entire first planetary gear mechanism PGM1 and the second planetary gear mechanism PGM2, thereby constituting an output element of the entire transmission mechanism 20.

[0017] The first brake B1 is provided on the outer periphery of the first ring gear R1 and is connected to the first planetary gear mechanism PGM1. Also, the second brake B2 is provided on the outer periphery of the second ring gear R2 and is connected to the second planetary gear mechanism PGM2. Therefore, the first brake B1 has a portion that overlaps with the first planetary gear mechanism PGM1 in a radial view, and the second brake B2 has a portion that overlaps with the second planetary gear mechanism PGM2 in a radial view.

[0018] Both the first brake B1 and the second brake B2 are meshing engagement elements and have a meshing fastening structure. When the first brake B1 is fastened, the first ring gear R1 is fixed to the case 21 together with the second carrier C2. As a result, the first ring gear R1 is fixed to the housing 10 together with the second carrier C2. When the second brake B2 is fastened, the second ring gear R2 is fixed to the case 21. As a result, the second ring gear R2 is fixed to the housing 10. The first brake B1 corresponds to the first engagement element, and the second brake B2 corresponds to the second engagement element.

[0019] The clutch CL is arranged axially in parallel with the second planetary gear mechanism PGM2 from the side away from the MG40. The clutch CL is provided for the rotating shaft 22 and the second carrier C2 and connects and disconnects them. The clutch CL is a friction engagement element and is a multi-plate clutch. The clutch CL is, for example, an electric clutch and includes a hub 23, a drum 24, a plurality of drive plates 25, a plurality of driven plates 26, and a piston 27.

[0020] The hub 23 is fixed coaxially to the rotating shaft 22. The hub 23 has an inner cylindrical portion 23a, an outer cylindrical portion 23b, and a bottom wall portion 23c connecting them, and is fixed coaxially to the rotating shaft 22 at the inner cylindrical portion 23a. The drum 24 has a cylindrical portion 24a and a bottom wall portion 24b and is provided coaxially with respect to the rotating shaft 22. The drum 24 opens in a direction away from the MG 40. The hub 23 is housed inside the drum 24, and the outer circumference of the outer cylindrical portion 23b of the hub 23 faces the inner circumference of the cylindrical portion 24a of the drum 24. The drum 24 is fixedly connected to the second carrier C2 at the ring-plate shaped bottom wall portion 24b.

[0021] Multiple drive plates 25 are provided on the hub 23. The multiple drive plates 25 have a ring shape and are provided so as to be axially slidable on the outer circumference of the outer cylindrical portion 23b. Multiple driven plates 26 are provided on the drum 24. The multiple driven plates 26 have a ring shape and are provided so as to be axially slidable on the inner circumference of the cylindrical portion 24a. The multiple drive plates 25 and the multiple driven plates 26 are provided one by one alternately in the axial direction.

[0022] The piston 27 is located inside the drum 24. The piston 27 is slidably mounted on the inner circumference of the open end of the drum 24. The piston 27 is an electric piston driven, for example, by an electric actuator of the clutch CL, and moves in the engagement direction (right in Figure 1) and disengagement direction (left in Figure 1) of the clutch CL to engage and disengage the multiple drive plates 25 and the multiple driven plates 26.

[0023] When the multiple drive plates 25 and multiple driven plates 26 are pushed in the engagement direction by the piston 27 and engage, the clutch CL becomes engaged. As a result, the rotating shaft 22 and the second carrier C2 are connected via the clutch CL. When the piston 27 moves in the disengagement direction from this state and the multiple drive plates 25 and multiple driven plates 26 are no longer engaged, the clutch CL becomes disengaged. As a result, the connection between the rotating shaft 22 and the second carrier C2 via the clutch CL is broken. In the transmission mechanism 20, the gear stages are formed as follows according to the engagement and disengagement states of the clutch CL, the first brake B1 and the second brake B2.

[0024] Figure 3 is a diagram showing the engagement table of the transmission mechanism 20. As shown in Figure 3, the transmission mechanism 20 is configured as a three-speed transmission mechanism having three gears: 1st, 2nd, and 3rd. 1st gear is achieved by engaging the first brake B1 and releasing the second brake B2 and clutch CL. 2nd gear is achieved by engaging the second brake B2 and releasing the first brake B1 and clutch CL. 3rd gear is achieved by engaging the clutch CL and releasing the first brake B1 and the second brake B2.

[0025] Returning to Figure 1, unit 100 further comprises a drive unit 30. The drive unit 30 is a drive unit for the first brake B1 and the second brake B2, and has an actuator 31 and a worm wheel 32. In Figure 1, the actuator 31 is schematically shown by a dashed line.

[0026] The actuator 31 is an electric motor and has a worm gear 311. The worm gear 311 forms the rotation axis of the actuator 31 and meshes with the worm wheel 32. The worm axis of the worm gear 311 and the central axis of the worm wheel 32 are perpendicular to each other, and the worm wheel 32 is mounted so as to be rotatable around the axis of the unit 100 by power from the actuator 31. Therefore, the longitudinal direction of the worm gear 311, which is the worm axis direction, intersects with the axial direction of the unit 100.

[0027] The worm gear 311 is located between the first brake B1 and the second brake B2 in the axial direction of the unit 100. Therefore, the actuator 31 has a portion sandwiched between the first brake B1 and the second brake B2. In the actuator 31, the worm gear 311 has such a portion. The worm wheel 32 is located between the first planetary gear mechanism PGM1 and the second planetary gear mechanism PGM2 in the axial direction of the unit 100.

[0028] The first brake B1 has a first switching mechanism SWM1, and the second brake B2 has a second switching mechanism SWM2. The first switching mechanism SWM1 switches the engagement state of the first brake B1, and the second switching mechanism SWM2 switches the engagement state of the second brake B2.

[0029] Figures 4A to 4C are explanatory diagrams of the switching mechanism SWM. Figure 4A shows the first switching mechanism SWM1 in the bidirectional restriction state. Figure 4B shows the first switching mechanism SWM1 in the unidirectional restriction state. Figure 4C shows the first switching mechanism SWM1 in the open state. In Figures 4A to 4C, the first switching mechanism SWM1 is used as an example to explain the switching mechanism SWM, but the same applies to the second switching mechanism SWM2.

[0030] The first switching mechanism SWM1 comprises a first fixed-side member CB1, a first rotating-side member RB1, a first claw CW1, and a first switching unit SW1. The first fixed-side member CB1 has a ring shape and is fixed to the inner circumference of the case 21. The first claw CW1 is an engaging portion and is installed on the portion of the first fixed-side member CB1 that protrudes radially inward. Multiple such portions are provided along the circumferential direction, and two first claws CW1 are provided as a set of claws for each such portion. In a set of claws, each first claw CW1 is provided facing opposite directions to correspond to the bidirectional rotation direction.

[0031] The first claw CW1 has a structure in which its radially inner tip rotates around its radially outer base. The first claw CW1 can be switched between a locked position that locks the rotation of the first ring gear R1 and a free position that allows it to rotate freely, and is biased to the locked position by a spring, which is a biasing member. Therefore, in the state shown in Figure 4A, each of the first claws CW1 is pushed to the locked position by the spring.

[0032] The first rotating side member RB1 is fixed to the outer circumference of the first ring gear R1. The first rotating side member RB1 has a ring shape and an engaging portion on its outer circumference, which is composed of a plurality of protrusions evenly distributed in the circumferential direction. The first claw CW1 engages with this engaging portion and together with the engaging portion, forms a meshing fastening structure. The first claw CW1 prevents the rotation of the first ring gear R1 in one rotational direction and allows the rotation of the first ring gear R1 in the other rotational direction.

[0033] For example, in the left-right set of pawls shown in the figure, the left-side first pawl CW1 prevents the rotation of the first ring gear R1 when rotating to the right in the figure by preventing its tip from moving radially outward, while allowing the rotation of the first ring gear R1 when rotating to the left by allowing its tip to move radially outward. The right-side first pawl CW1 prevents the rotation of the first ring gear R1 when rotating to the left, while allowing the rotation of the first ring gear R1 when rotating to the right. As a result, in the bidirectional restriction state shown in Figure 4A, the rotation of the first ring gear R1 is restricted in both the left-right and right directions. Therefore, the first brake B1 is engaged in response to bidirectional rotation of the first ring gear R1.

[0034] The first switching unit SW1 has a first switching plate PL1 and switches the position of the first claw CW1. In Figures 4A to 4C, the first switching plate PL1 of the first switching unit SW1 is shown by a dashed line. The first switching plate PL1 has a ring shape and is movable in the circumferential direction.

[0035] The first switching plate PL1 has a position corresponding to the bidirectional restricting state shown in Figure 4A, a position corresponding to the unidirectional restricting state shown in Figure 4B, and a position corresponding to the open state shown in Figure 4C. The first switching plate PL1 is mounted on the worm wheel 32 and rotates together with the worm wheel 32. Therefore, the first switching plate PL1 is driven circumferentially by the actuator 31, thereby switching the position of the first switching plate PL1.

[0036] For example, if the first switching plate PL1 is rotated to a fixed position to the right of the state shown in Figure 4A, the position of the first switching plate PL1 is switched to a position corresponding to the unidirectional restricting state shown in Figure 4B. At this time, the first switching unit SW1 pushes the tip of the left first claw CW1 radially outward against the biasing force of the spring, thereby switching the position of the left first claw CW1 to the free position. As a result, the left first claw CW1 disengages from the engagement portion of the first rotating side member RB1, so the rotation of the first ring gear R1 to the right becomes free. On the other hand, in this case, the right first claw CW1 remains engaged with the engagement portion, so the rotation of the first ring gear R1 to the left is locked. Therefore, in this case, the first brake B1 is released for the rotation of the first ring gear R1 to the right and engaged for the rotation of the first ring gear R1 to the left.

[0037] When the first switching plate PL1 is rotated to a fixed position to the left of the state shown in Figure 4A, the position of the first switching plate PL1 is switched to the position corresponding to the released state shown in Figure 4C. At this time, the first switching unit SW1 pushes the tips of both the left and right first claws CW1 radially outward against the biasing force of the spring, thereby switching the position of both the left and right first claws CW1 to the free position. As a result, the rotation of the first ring gear R1 in both the left and right directions becomes free.

[0038] Thus, the actuator 31 drives the first brake B1 by driving the first switching plate PL1. The actuator 31 can also drive the second brake B2 in the same manner as the first brake B1. The first switching unit SW1 and the second switching unit SW2 of the second brake B2 are configured so that the first brake B1 and the second brake B2 can transition states as shown in Figure 6, which will be described later, when the actuator 31 is driven. Both the first brake B1 and the second brake B2 constitute a selectable one-way clutch.

[0039] Returning to Figure 1, unit 100 further includes a transmission controller 60 and an MG controller 70. The transmission controller 60, together with the transmission mechanism 20, constitutes the transmission TM. The transmission controller 60 is a controller for controlling the transmission TM and constitutes the control device for the transmission TM. The transmission controller 60 is connected to the MG controller 70 for controlling the MG 40 in a manner that enables mutual communication. Unit 100 may also be configured to further include an integrated controller that manages the integrated control of the transmission controller 60, the MG controller 70, etc., or the transmission controller 60 and the MG controller 70 may be configured by a single controller.

[0040] Each of the transmission controllers, 60 and 70, consists of one or more computers (microcomputers) equipped with a central processing unit (CPU), read-only memory (ROM), random access memory (RAM), and input / output interface (I / O interface). These controllers, 60 and 70, perform control by executing a program stored in ROM or RAM via the CPU. The program may be stored on a non-transient storage medium such as a CD-ROM.

[0041] The transmission controller 60 receives signals from a sensor / switch group 80 that indicate various sensors and switches. The sensor / switch group 80 includes, for example, a vehicle speed sensor for detecting the vehicle speed VSP, an accelerator opening sensor for detecting the accelerator opening APO, a position sensor for detecting the rotational position of the actuator 31, an input rotational speed sensor for detecting the input rotational speed Nin of the transmission TM, and an output rotational speed sensor for detecting the output rotational speed Nout of the transmission mechanism 20. The input rotational speed Nin is, for example, the rotational speed of the rotating shaft 22, and the output rotational speed Nout is, for example, the rotational speed of the first carrier C1. Other appropriate signals may be input to the transmission controller 60.

[0042] The transmission controller 60 controls the transmission TM based on the input signals. The transmission TM is controlled by controlling the actuator 31 and the clutch CL based on the input signals.

[0043] In the transmission TM, as the vehicle speed VSP increases, the gear changes from 1st to 2nd gear, and then from 2nd to 3rd gear. When a 1-2 shift occurs, which is a shift from 1st to 2nd gear, the engagement and disengagement states of the three engagement elements—the first brake B1, the second brake B2, and the clutch CL—transition from a state where only the first brake B1 is engaged to a state where only the second brake B2 is engaged, as shown in Figure 3. Therefore, the first brake B1 becomes the disengaged engagement element, and the gear change occurs.

[0044] In this case, using Figure 4A, by setting the pawl on the side of the left and right set of first pawls CW1 that is not responsible for torque transmission to the free position, the first brake B1 can first be transitioned from a bidirectional restricting state to a one-way clutch state. Then, by transitioning the first brake B1 from the one-way clutch state to the release state, the first brake B1 can be released.

[0045] However, in this case, engagement is performed at the first brake B1. Therefore, when torque is applied to the first brake B1, the force required for release increases accordingly. As a result, there is a concern that smooth release may not be possible due to the torque applied to the first brake B1.

[0046] In light of these circumstances, in this embodiment, the transmission controller 60 performs the control described below.

[0047] Figure 5 is a flowchart illustrating an example of the control performed by the transmission controller 60. In step S11, it is determined whether or not a 1-2 gear shift instruction has been given. Whether or not a 1-2 gear shift instruction has been given can be determined by whether or not the execution conditions for 1-2 gear shifting have been met. The execution conditions for 1-2 gear shifting may be any appropriate conditions, such as the vehicle speed VSP condition. If the determination in step S11 is negative, the process ends. If the determination in step S11 is positive, 1-2 gear shifting is started, and the process proceeds to step S12 and then to step S13.

[0048] In step S12, the actuator 31 is driven. This drive transitions the first brake B1 from a locked / locked state to a locked / free state. The locked / locked state is, in other words, a bidirectional restricted state, and the locked / free state is, in other words, a one-way clutch state.

[0049] In step S13, control is performed to transition the clutch CL from the released state to the slipped state. Here, with respect to the clutch CL, which is a friction engagement element, "release" refers to a state in which the clutch CL has no torque capacity. "Slip" refers to a state in which the clutch CL has torque capacity, but there is a difference in input and output rotation of the clutch CL. "Engaged" or "fully engaged" refers to a state in which the clutch CL has torque capacity, but there is no difference in input and output rotation of the clutch CL.

[0050] A state in which the clutch CL has no torque capacity means, in other words, that the clutch CL does not transmit power, and a state in which the clutch CL has torque capacity means, in other words, that the clutch CL transmits power. With respect to the clutch CL, slip means, in other words, that the torque capacity of the clutch CL is less than the input torque, and engagement or full engagement means, in other words, that the torque capacity of the clutch CL is greater than the input torque, resulting in a fully engaged state.

[0051] By putting the clutch CL into a slipping state, torque can be shared with the clutch CL, thereby reducing the torque shared by the first brake B1. In step S13, the torque transmitted by the clutch CL is gradually increased by controlling the clutch CL.

[0052] In step S14, a determination is made as to whether the first brake B1 can be released. This determination can be made, for example, by checking whether a predetermined estimated elapsed time has passed since the actuator 31 was driven in step S12, which is the time it takes for the torque capacity of the first brake B1 to become zero. If the determination in step S14 is negative, the process returns to step S14. If the determination in step S14 is positive, the process proceeds to step S15.

[0053] In step S15, the actuator 31 is driven. This drive transitions the first brake B1 from a locked / free state to a free / free state. The free / free state is, in other words, a released state. In step S15, with the clutch CL slipping in step S13, the actuator 31 of the first brake B1 is driven, causing the first brake B1 to transition from a one-way clutch state to a released state. In this way, the torque share of the clutch CL is increased, which reduces the torque share of the first brake B1, allowing the first brake B1 to be released smoothly.

[0054] In step S16, rotational synchronization is initiated to engage the second brake B2. Rotational synchronization is initiated in response to the affirmative judgment in step S14. Rotational synchronization is performed by controlling the clutch CL to further advance the state transition of the clutch CL to the engaged side, thereby further increasing the transmitted torque of the clutch CL. As a result, the input rotational speed Nin begins to decrease, and the speed ratio (input rotational speed Nin / output rotational speed Nout) also begins to decrease.

[0055] In step S17, a determination is made as to whether the rotations are synchronized. This determination can be made by checking whether the magnitude of the difference between the input rotation speed Nin and the input rotation speed Nin_2nd, which is the input rotation speed Nin corresponding to the second speed, has become smaller than a predetermined value α. The predetermined value α can be set in advance as a determination value to determine whether the input rotation speed Nin has approached the input rotation speed Nin_2nd to the extent that the second brake B2, which engages and engages, can engage. If the determination in step S17 is negative, the process returns to step S17. If the determination in step S17 is positive, the process proceeds to step S18.

[0056] In step S18, the rotational synchronization process begins to end. Rotational synchronization is terminated by reducing the transmission torque of clutch CL, which was increased for rotational synchronization.

[0057] In step S19, a determination is made as to whether rotational synchronization has ended. This determination can be made, for example, by determining whether the piston 27 has returned to the rotational synchronization start position based on the amount of operation of the electric actuator of the clutch CL. If the determination in step S19 is negative, the process returns to step S19. If the determination in step S19 is positive, the process proceeds to step S20.

[0058] In step S20, the actuator 31 is driven. This drive transitions the second brake B2 from a free / free state to a locked / free state. Consequently, the second brake B2 is engaged in a one-way clutch state.

[0059] When engaging the second brake B2, there is a requirement to transition the state in a direction that reduces the input-output rotational difference of the transmission TM in order to reduce shift shock. In response to this, the clutch CL slips in step S13 and remains in a slipped state until step S21, which will be described later.

[0060] Therefore, the second brake B2 is engaged in step S20 with the clutch CL slipping, and thus the clutch CL is kept slipping when the second brake B2 is engaged. As a result, when the second brake B2 is engaged, the transmission TM transitions to a state in a direction that reduces the input-output rotation difference.

[0061] The clutch CL slips with the first brake B1 and the second brake B2 released after the first brake B1 is transitioned from a one-way clutch state to a released state in step S15 and before the second brake B2 is engaged in step S20.

[0062] This provides a release period for both the first brake B1 and the second brake B2, preventing interlock (double engagement) between the two brakes. Furthermore, since the clutch CL has torque capacity during this time, the feeling of the vehicle coasting is also suppressed.

[0063] In step S21, it is determined whether the speed ratio has reached the speed ratio for 2nd gear. The speed ratio for 2nd gear can be known in advance. If the speed ratio for 2nd gear is achieved, the torque that the clutch CL is responsible for is transferred to the second brake B2, thereby completing the transfer of torque from the first brake B1 to the second brake B2 via the clutch CL, and thus completing the 1st-2nd gear shift. If the result in step S21 is negative, the process returns to step S21. If the result in step S21 is positive, the process proceeds to step S22.

[0064] In step S22, control is performed to transition the clutch CL from a slipped state to a released state. By controlling the clutch CL in this control, the torque transmitted by the clutch CL is gradually reduced. As a result, the torque that was previously handled by the clutch CL can be transferred to the second brake B2, and the 1st to 2nd gear shift can be completed.

[0065] Clutch CL is engaged with the second brake B2 in a one-way clutch state while clutch CL is slipped in step S20, and then released in step S22. This transitions the second brake B2 to a one-way clutch state, resulting in a smoother transfer of torque from clutch CL to the second brake B2 compared to, for example, transitioning to a lock / lock state. The process ends after step S22.

[0066] Figure 6 shows an example of a timing chart corresponding to the processing in the flowchart shown in Figure 5. At timing T1, 1-2 gear shifting begins. When 1-2 gear shifting begins, the actuator 31 first controls the first brake B1 to a one-way clutch state. As a result, the switching instruction for the first brake B1 transitions from a locked / locked state to a locked / free state, and the first brake B1 is controlled according to this switching instruction. When 1-2 gear shifting begins, the clutch CL is further controlled to a slip state. As a result, the torque transmitted by the clutch CL gradually increases.

[0067] An increase in the torque transmitted by clutch CL means an increase in the torque shared by clutch CL. Therefore, when the torque transmitted by clutch CL increases, the torque transmitted by the brake decreases accordingly. The torque transmitted by the brake in this case is the torque transmitted by the first brake B1, which is engaged by meshing. Therefore, the torque capacity of the first brake B1 does not change significantly in this case.

[0068] The output torque of the transmission TM remains constant. Therefore, as the transmission torque of the clutch CL increases, the input shaft torque of the transmission TM, i.e., the torque of the rotating shaft 22, increases accordingly. As a result, the torque ratio (output torque / input torque) of the transmission TM decreases in proportion to the increase in the transmission torque of the clutch CL. As the transmission torque of the brakes gradually decreases to zero, only the clutch CL among the first brake B1, second brake B2, and clutch CL is responsible for the torque. Therefore, the torque ratio gradually decreases toward the torque ratio of third gear.

[0069] At timing T2, the brake transmission torque becomes zero and the torque ratio becomes the torque ratio for 3rd gear. As a result, no torque is applied to the first brake B1, and the engagement of the first claw CW1 of the first brake B1, which was engaged in a one-way clutch state, can be easily released by the actuator 31.

[0070] Therefore, at timing T2, the switching instruction for the first brake B1 transitions from the locked / free state to the free / free state, and the actuator 31 controls the first brake B1 to the free / free state. As a result, the gear position is no longer 1st gear. However, since the second brake B2 is released at this point, the gear position is not 2nd gear, as can be seen from the engagement table mentioned above using Figure 3. At timing T2, the transmission torque of the clutch CL also starts to increase further. This initiates rotational synchronization for engaging the second brake B2. As a result, the input rotational speed Nin begins to decrease, and the speed ratio also begins to decrease.

[0071] From timing T3 onwards, the torque transmitted by clutch CL is assumed to be constant. At timing T4, the input rotational speed Nin approaches the input rotational speed Nin_2nd, and the rotations synchronize. As a result, at timing T4, the torque transmitted by clutch CL begins to decrease, and rotational synchronization begins to end. During rotational synchronization, the input shaft torque decreases when the torque transmitted by clutch CL increases, and increases when the torque transmitted by clutch CL decreases.

[0072] At timing T5, the torque transmitted by clutch CL returns to the magnitude it was at timing T2, and rotational synchronization ends. As a result, in order to shift to 2nd gear, the switching instruction for the second brake B2 transitions from the free / free state to the locked / free state, and the actuator 31 controls the second brake B2 to the one-way clutch state. The input rotational speed Nin becomes the input rotational speed Nin_2nd at timing T5. The torque capacity of the second brake B2 increases stepwise when the second brake B2 is actually in the locked / free state.

[0073] At timing T6, the speed ratio becomes that of second gear. As a result, the torque transmitted by clutch CL begins to decrease, and the torque transmitted by the brake begins to increase accordingly. Consequently, the torque shared by clutch CL decreases while the torque shared by the second brake B2 increases, and the torque ratio changes toward that of second gear. The input shaft torque decreases in accordance with the decrease in the torque transmitted by clutch CL.

[0074] At timing T7, the torque transmitted by clutch CL becomes zero. As a result, the torque previously handled by clutch CL is eliminated, and the transfer of torque from the first brake B1 to the second brake B2 via clutch CL is completed. Therefore, the torque ratio becomes the torque ratio for second gear, and the 1st to 2nd gear shift is completed.

[0075] Next, the main effects and advantages of this embodiment will be described.

[0076] (1) The transmission TM includes a first brake B1, a second brake B2, and a clutch CL. The transmission controller 60 drives the actuator 31 of the first brake B1 while the clutch CL is slipping, thereby transitioning the first brake B1 from a one-way clutch state to a released state, and then engages the second brake B2.

[0077] With this configuration, when transitioning the first brake B1, which is the release-side engaging element, from a one-way clutch state to a release state, the torque share of the clutch CL is increased, thereby decreasing the torque share of the first brake B1. This reduces the reaction force on the first claw CW1, which is the engaging part of the first brake B1, allowing the first brake B1 to be released smoothly. However, if the torque share of the clutch CL is increased all at once to fully engage, the shock will be large. For this reason, it is preferable to have a slip state in which the torque shared is smaller than that of fully engaged.

[0078] (2) The transmission controller 60 transitions the first brake B1 from the one-way clutch state to the released state, and then engages the second brake B2 with the clutch CL slipping. With this configuration, by keeping the clutch CL slipping when engaging the second brake B2, the transmission TM can be transitioned in a direction that reduces the input-output rotation difference.

[0079] (3) After the transmission controller 60 transitions the first brake B1 from the one-way clutch state to the released state and before engaging the second brake B2, it causes the clutch CL to slip with the first brake B1 and the second brake B2 released. With this configuration, by providing a release period for both the first brake B1 and the second brake B2, interlocking of the first brake B1 and the second brake B2 can be prevented. Also, since the clutch CL has torque capacity at this time, the feeling of the vehicle coasting can be suppressed.

[0080] (4) The transmission controller 60 engages the second brake B2 in a one-way clutch state with the clutch CL slipping, and then releases the clutch CL. With this configuration, the second brake B2 is switched to a one-way clutch state, so that torque can be smoothly transferred from the clutch CL to the second brake B2.

[0081] Although embodiments of the present invention have been described above, these embodiments only represent a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments.

[0082] For example, in the embodiment described above, a case was described in which an actuator 31 shared by the first brake B1 and the second brake B2 is provided. However, the first brake B1 and the second brake B2 may each be provided with different actuators. [Explanation of Symbols]

[0083] 10 Housing 20 Gear shift mechanism 30 Drive unit 31 Actuator 60. Transmission controller (control device, computer) 100 units B1 First brake (first engagement element) B2 Second brake (second engagement element) CL clutch (third engagement element) TM transmission

Claims

1. A control device for a transmission having a first engaging element, a second engaging element, and a third engaging element, By transitioning the third engaging element from a released state to a slip state, thereby distributing torque to the third engaging element and reducing the torque distributed to the first engaging element, the actuator of the first engaging element is driven, thereby transitioning the first engaging element from a one-way clutch state to a released state, and then engaging the second engaging element. A control device for the transmission.

2. A control device for a transmission according to claim 1, After transitioning the first engaging element from a one-way clutch state to a released state, the second engaging element is engaged while the third engaging element is in a slipped state. A control device for the transmission.

3. A transmission control device according to claim 2, After transitioning the first engaging element from a one-way clutch state to a released state and before engaging the second engaging element, the third engaging element is made to slip while the first and second engaging elements are released. A control device for the transmission.

4. A transmission control device according to claim 2, After engaging the second engaging element in a one-way clutch state with the third engaging element in a slip state, the third engaging element is released. A control device for the transmission.

5. A control method for a transmission having a first engaging element, a second engaging element, and a third engaging element, By transitioning the third engaging element from a released state to a slip state, thereby distributing torque to the third engaging element and reducing the torque distributed to the first engaging element, the actuator of the first engaging element is driven, thereby transitioning the first engaging element from a one-way clutch state to a released state, and then engaging the second engaging element. A method for controlling a transmission, including the control of a transmission.

6. A computer program executable by a transmission having a first engaging element, a second engaging element, and a third engaging element, By transitioning the third engaging element from a released state to a slip state, thereby distributing torque to the third engaging element and reducing the torque distributed to the first engaging element, the actuator of the first engaging element is driven, thereby transitioning the first engaging element from a one-way clutch state to a released state, and then engaging the second engaging element. program.

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