Clutch engagement control system

Abstract

A clutch actuator (5) causes a first clutch member (11) and a second clutch member (12) of a dog clutch (10) to move relative to each other in the axial direction. A phase difference sensor (6) detects the phase difference between the first clutch member (11) and the second clutch member (12). A control device (7) performs a synchronization operation for gradually reducing the rotation speed difference between input and output shafts until the rotation speed difference reaches a target rotation speed difference (ωs), and detects the current engagement timing on the basis of the output of the phase difference sensor (6). After an adjustment reference time (t1) at which the rotation speed difference between the input and output shafts reaches a rotation speed difference (ω0) at which the phase difference can be detected by the phase difference sensor (6), the control device (7) adjusts the phase difference by changing the change characteristics of the rotation speed difference between the input and output shafts so that any future engagement timing matches a completion target time (tall), on the basis of information acquired at an arbitrary phase difference detection time (td).

Description

Cross-reference to Related Applications 【0001】 This application is based on Japanese Application No. 2023-185557 filed on October 30, 2023, the contents of which are incorporated herein by reference. 【Technical Field】 【0002】 The present disclosure relates to a meshing clutch engagement control system. 【Background Art】 【0003】 Conventionally, a meshing clutch engagement control system for engaging an input shaft and an output shaft that rotate at different rotational speeds in a disengaged state is known. For example, Patent Document 1 discloses a technique for predicting a future engagement timing based on a plurality of past engagement timings (meshing timings) detected from the output of a phase difference sensor. The control device performs a synchronization operation so that the rotational speed difference between the motor and the axle (i.e., the input / output shaft rotational speed difference) reaches a predetermined target rotational speed difference. Then, the clutch actuator is pre-driven so that the meshing clutch engages at the predicted engagement timing after the input / output shaft rotational speed difference reaches the target rotational speed difference. 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2021-025561 【Summary of the Invention】 【0005】 In the technique of Patent Document 1, the control device stores a plurality of past engagement timings, calculates an approximation line passing through each point, and predicts a future engagement timing. Since the future engagement timing is predicted approximately from the past engagement timings, the error from the actual operation increases. Then, the time for phase alignment from when the input / output shaft rotational speed difference reaches the target rotational speed difference until engagement is executed becomes longer, and the responsiveness to the engagement instruction decreases. 【0006】 The purpose of this disclosure is to provide a clutch engagement control system that achieves high-precision phase difference adjustment of input and output shafts and improves the responsiveness of clutch engagement. 【0007】 The meshing clutch engagement control system of this disclosure comprises a meshing clutch, a clutch actuator, a phase difference sensor, and a control device. 【0008】 The engaging clutch comprises a first clutch member and a second clutch member, and the engagement and disengagement states of the first clutch member and the second clutch member can be switched. The first clutch member is connected to the input shaft and has a plurality of first engaging teeth arranged circumferentially. The second clutch member is connected to the output shaft and has a plurality of second engaging teeth arranged circumferentially that can engage with the first engaging teeth directly or via an intermediate member. 【0009】 In a vehicle-mounted clutch engagement control system, the input shaft is connected to a motor or internal combustion engine, for example, via a reduction gear. The output shaft is connected to the drive wheels via an axle. 【0010】 The clutch actuator moves the first clutch member and the second clutch member relative to each other in the axial direction, or, if an intermediate member is used, moves the intermediate member relative to the first clutch member and the second clutch member in the axial direction. The phase difference sensor detects the phase difference between the first clutch member and the second clutch member. 【0011】 The control device controls the input / output shaft rotational speed difference, which is the difference between the rotational speed of the input shaft and the rotational speed of the output shaft. The control device performs a synchronization operation in which it gradually reduces the input / output shaft rotational speed difference until it reaches a target rotational speed difference that the meshing clutch can engage, by issuing an engagement command to engage the meshing clutch which is in the disengaged state. 【0012】 In synchronized operation, the control device determines the engagement timing for which the meshing clutch can engage based on the phase difference sensor output. hand Detecting the timing of engagement It is possible. The control device considers the time when the engagement timing is detected as the present time.A drive command is output to the clutch actuator to engage the meshing clutch at a future engagement time after the input / output shaft rotational speed difference reaches the target rotational speed difference. 【0013】 The control device adjusts the phase difference between the first clutch member and the second clutch member by changing the change characteristics of the input / output shaft rotational speed difference so that any future engagement timing coincides with the completion target time, based on information acquired at an arbitrary phase difference detection time when an arbitrary phase difference is detected based on the output of the phase difference sensor, after the adjustment reference time. The adjustment reference time is the time when the input / output shaft rotational speed difference reaches a rotational speed difference that can be detected by the phase difference sensor. The completion target time is the time after the completion target time from the adjustment reference time. The arbitrary phase difference detection time is, for example, the time when the first engagement timing is detected after the adjustment reference time. 【0014】 The "change characteristics of the input / output shaft rotation speed difference" that are changed in the phase difference adjustment of this disclosure are, for example, the "gradient," which is the rate of change of the input / output shaft rotation speed difference over time, or the "target rotation speed difference." In this disclosure, by changing the change characteristics of the input / output shaft rotation speed difference during synchronization, the control device can achieve high-precision phase difference adjustment and improve the responsiveness of clutch engagement. 【0015】 Here, we assume an alternative control method in which the timing at which the input / output shaft rotational speed difference reaches the target rotational speed difference during synchronization is defined as the arrival time, and after predicting the future engagement time, the engagement time is brought closer to the arrival time. In that case, if torque is applied to the input shaft in an attempt to bring the engagement time closer to the arrival time, the input shaft rotational speed changes, the arrival time shifts, and the accuracy of phase difference adjustment may decrease. In contrast, in this disclosure, the change in the change characteristics of the input / output shaft rotational speed difference and phase difference adjustment are performed simultaneously based on information acquired at an arbitrary phase difference detection time, thereby enabling highly accurate phase difference adjustment. Furthermore, in this disclosure, the future engagement time does not necessarily need to be predicted. [Brief explanation of the drawing] 【0016】 The above objects, other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. The drawings are [Figure 1] FIG. 1 is a diagram of a configuration example of a vehicle to which a meshing clutch engagement control system is applied, [Figure 2] FIG. 2 is a schematic diagram showing the switching between 2WD and 4WD, [Figure 3] FIG. 3 is a time chart showing the switching operation from 2WD to 4WD by the control of the comparative example and the present embodiment, [Figure 4] FIG. 4 is a schematic diagram showing the state transition of the meshing clutch, [Figure 5] FIG. 5 is a configuration diagram of the meshing clutch engagement control system of the present embodiment, [Figure 6] FIG. 6 is a block diagram of the control device, [Figure 7] FIG. 7 is a diagram for explaining the detection principle of the phase difference sensor, [Figure 8] FIG. 8 is a diagram showing the beat waveform of the phase difference sensor output, [Figure 9] FIG. 9 is a time chart of the synchronization operation according to the first embodiment, [Figure 10] FIG. 10 is a time chart of the phase difference adjustment (after the adjustment reference time t1 in FIG. 9) according to the first embodiment, [Figure 11] FIG. 11 is a flowchart of the clutch engagement control according to the first embodiment, [Figure 12] FIG. 12 is a time chart of the phase difference adjustment according to the second embodiment, [Figure 13] FIG. 13 is a time chart of the phase difference adjustment according to the third embodiment, [Figure 14] FIG. 14 is a time chart of the phase difference adjustment according to the fourth embodiment, [Figure 15] FIG. 15 is a time chart of the phase difference adjustment according to the fifth embodiment, [Figure 16] FIG. 16 is a time chart of the phase difference adjustment according to the sixth embodiment, [Figure 17] Figure 17 is a time chart of phase difference adjustment according to the seventh embodiment. [Figure 18] Figure 18 is a provisional time chart of phase difference adjustment at td1 during the first phase difference detection in the eighth embodiment. [Figure 19] Figure 19 is a provisional time chart of phase difference adjustment at td2 during the second phase difference detection in the eighth embodiment. [Figure 20] Figure 20 is the final time chart for phase difference adjustment at td3 during the third phase difference detection in the eighth embodiment. [Figure 21] Figure 21 is a flowchart of clutch engagement control according to the eighth embodiment. [Modes for carrying out the invention] 【0017】 Multiple embodiments of a meshing clutch engagement control system will be described based on the drawings. The basic system configuration of the first to eighth embodiments is the same, but the control configuration by the control device differs. The first to eighth embodiments are collectively referred to as "this embodiment." The meshing clutch engagement control system of this embodiment is a system that engages a meshing clutch by driving a clutch actuator according to the engagement timing when the meshing clutch provided in the vehicle's powertrain system is in the disengaged state. 【0018】 [Vehicle, meshing clutch engagement control system] Referring to Figures 1 and 2, an example configuration of a vehicle 90 to which the meshing clutch engagement control system is applied will be described. This vehicle 90 is an electric vehicle powered by two MGs (motor generators), an MG81 for the front wheels and an MG82 for the rear wheels. The MG81 and 82 combine the functions of electric motors during acceleration and generators during regenerative braking. This vehicle 90 can switch between two-wheel drive (2WD) using only the front wheels 91 and four-wheel drive (4WD) using both the front wheels 91 and the rear wheels 92. 【0019】 The front wheel MG81 is always connected to the front wheel 91 via the differential 93 and connecting shaft 95. Therefore, the front wheel 91 is always a drive wheel. On the other hand, a meshing clutch 10 is provided in the power transmission path from the rear wheel MG82 to the rear wheel 92. In the example shown in Figure 1, the meshing clutch 10 is provided between the rear wheel MG82 and the differential 94, but the meshing clutch 10 may also be provided on the rear wheel 92 side of the differential 94. 【0020】 When the engagement clutch 10 is disengaged, the rear wheel MG82 is not connected to the rear wheel 92, and the rear wheel 92 rotates as a driven wheel of the front wheel 91. When the engagement clutch 10 is engaged, the rear wheel MG82 is connected to the rear wheel 92 via the differential 94 and the connecting shaft 96. In this case, the rear wheel 92 becomes a drive wheel in addition to the front wheel 91. Reducers 87 and 88 may be provided on the output shafts of the front wheel MG81 and the rear wheel MG82, respectively. 【0021】 In this way, the vehicle 90 switches between 2WD and 4WD by switching between the disengaged and engaged states of the engagement clutch 10. For example, on a flat road with low load, 2WD with 1MG is selected, while on an uphill slope where high driving force is required, 4WD with 2MG is selected. When switching from 4WD to 2WD, it is necessary to reduce drag losses by disengaging the clutch and improve energy efficiency. When switching from 2WD to 4WD, responsive acceleration performance is required due to high-response clutch engagement. If clutch engagement is delayed, the torque response of the disengaged rear wheel MG 82 is delayed, and the torque response of the entire vehicle is delayed. As a result, the torque response to the driver's accelerator input is delayed, affecting drivability. 【0022】 A higher-level vehicle control device (not shown) determines, based on the vehicle's driving state, external environment such as the road surface, or driver instructions, that a switch from 2WD to 4WD is necessary and transmits an engagement instruction to the engagement clutch control system 100. When the engagement clutch control system 100 receives an engagement instruction while the engagement clutch 10 is released, it engages the engagement clutch 10. The engagement clutch control system 100 comprises the engagement clutch 10, a clutch actuator 5, a phase difference sensor 6, and a control device 7. In the following specification and drawings, the clutch actuator 5 may be referred to as "ACT" as appropriate. 【0023】 The engaging clutch 10 has a first clutch member 11 connected to the input shaft 3 and a second clutch member 12 connected to the output shaft 4. The first clutch member 11 has a plurality of first engaging teeth 13 arranged in the circumferential direction and rotates around its axis. The second clutch member 12 has second engaging teeth 14 formed in the circumferential direction that can directly engage with the first engaging teeth 13 and rotates coaxially and in the same direction as the first clutch member 11. In the configuration example shown in Figure 1, a reduction gear 88 is provided between the rear wheel MG 82 and the first clutch member 11. The rotation of the motor shaft 83 of the rear wheel MG 82 is reduced by the reduction gear 88 and transmitted to the input shaft 3. 【0024】 The clutch actuator 5 moves the first clutch member 11 and the second clutch member 12 relative to each other in the axial direction. The clutch actuator 5 may be provided not only on the side of the first clutch member 11, but also on the side of the second clutch member 12. When the first clutch member 11 and the second clutch member 12 move toward each other, the first engaging teeth 13 and the second engaging teeth 14 engage. When the first clutch member 11 and the second clutch member 12 move toward each other, the engagement is released. In other words, the engagement and release states of the first clutch member 11 and the second clutch member 12 are switched by the relative axial movement of the first clutch member 11 and the second clutch member 12. Note that a sleeve-type clutch, which is different from this type of clutch, is described in the "Other Embodiments" section. 【0025】 When the engagement clutch 10 is disengaged and the input shaft 3 and output shaft 4 are rotating at different rotational speeds, the phase difference sensor 6 detects the phase difference between the first clutch member 11 and the second clutch member 12, i.e., the phase difference between the input shaft 3 and the output shaft 4, and outputs a phase difference sensor signal to the control device 7. The engagement clutch control system 100 of this embodiment is mounted on a vehicle 90 to which the output shaft 4 is connected to the rear wheel 92, which is a drive wheel. 【0026】 Hereinafter, the "time when the phase difference becomes such that the meshing clutch 10 can engage" is defined as the "engagement time." The "engagement time" includes not only the single time when the engagement operation is actually performed, but also multiple times when engagement is possible but does not occur. The control device 7 detects the current engagement time based on the phase difference sensor signal and outputs a drive command to the clutch actuator 5 according to the future engagement time. Specifically, the control device 7 starts the preliminary operation of the clutch actuator 5 a predetermined preliminary operation time before the future engagement time. The control device 7 also controls the input / output shaft rotation speed difference, which is the difference between the rotation speed of the input shaft 3 and the rotation speed of the output shaft 3, by controlling the rotation of the rear wheel MG 82. Hereinafter, the symbols for "input shaft 3" and "output shaft 4" related to rotation speed will be omitted as appropriate. 【0027】 Referring to Figures 3 and 4, the general engagement operation during switching from 2WD to 4WD will be explained. Figure 3 shows the changes in input / output shaft rotation speed and ACT stroke under the control of the comparative example and this embodiment. To distinguish it from the symbols such as time t1 used in Figure 9, etc., Figure 3 uses the symbols "τ0~τ5" for time. The control of the comparative example and this embodiment differs in the length of period IV from time τ3 to τ4. During period I from time τ0 to τ1, the control device 7 receives a switching instruction and determines the start of the switching operation. The switching instruction from 2WD to 4WD generates an "engagement instruction to engage the disengaged meshing clutch". 【0028】 Upon receiving the engagement instruction, the control device 7 drives the rear wheel MG82 during period II from time τ1 to τ2, increasing the input shaft rotation speed Nin toward the output shaft rotation speed Nout so that the rotation of the input shaft 3 is synchronized with the rotation of the output shaft 4. The output shaft rotation speed Nout corresponds to the rotation speed of the axle, which is proportional to the vehicle speed. The operation of matching the input shaft rotation speed Nin and the output shaft rotation speed Nout is called the "synchronization operation". During periods I and II, the engagement clutch 10 is in the disengaged state as shown in Figure 4, and the engagement teeth 13 and 14 are separated from each other. 【0029】 The target rotational speed N_tgt of the input shaft rotational speed Nin is set such that the difference ΔN between it and the output shaft rotational speed Nout is within the acceptable range for engagement shock. Engagement is performed when the input shaft rotational speed Nin reaches the target rotational speed N_tgt, the input / output shaft rotational speed difference ΔN becomes less than or equal to the target rotational speed difference ωs, the ACT stroke reaches the standby stroke Stsb, and there is a phase difference that allows engagement (i.e., the engagement timing). Hereafter, "input / output shaft rotational speed difference" will be abbreviated and referred to as "rotational speed difference". The rotational speed difference is defined as 0 or a positive value. The symbol "ωs" will be explained later in the descriptions of Figures 9 and 10. 【0030】 When the input shaft rotation speed Nin reaches the target rotation speed N_tgt at time τ2, a drive command is output to the clutch actuator 5. During the period III from time τ2 to τ3, the ACT stroke changes from 0 to the standby stroke Stsb, and the engaging clutch 10 transitions from the released state in Figure 4 to the standby position. In the standby position, for example, the tooth top surfaces of the engaging teeth 13 and 14 are in contact with each other, and there is no gap. 【0031】 During period IV from time τ3 to τ4, the phase alignment of the first clutch member 11 and the second clutch member 12 is performed. Once the phase alignment is complete and engagement is possible, during period V from time τ4 to τ5, the ACT stroke changes from the standby stroke Stsb to the full stroke Stfl, and the meshing clutch 10 transitions from the standby position in Figure 4 to the fully engaged state. The sum of periods III, IV, and V constitutes the clutch operation period. 【0032】 Conventional techniques that predict future engagement times by approximation from past engagement times result in increased errors with actual operation and longer phase alignment times. Phase alignment time becomes dominant in clutch operation time, reducing responsiveness to engagement commands. Therefore, this embodiment aims to shorten the phase alignment time by controlling the phase difference adjustment. This enables highly responsive switching from 2WD to 4WD via clutch engagement. 【0033】 Referring to Figures 5 to 8, the configuration of the meshing clutch engagement control system of this embodiment will be described. In Figure 5 and subsequent figures, we will focus only on the clutch engagement on the rear wheel 92 side of the vehicle 90, and the rear wheel MG82 will be simply referred to as "MG82". The rotational speed of the MG82 is detected by a rotational speed sensor 23 such as a resolver, and is converted to the rotational speed of the input shaft 3 by multiplying it by the reduction ratio of the reduction gear 88. In Figure 5, the converted input shaft rotational speed Nin is assumed to be input to the control device 7. On the other hand, the rotational speed of the output shaft 4 is detected by a rotational speed sensor 24 such as a wheel speed sensor, and the converted output shaft rotational speed Nout is input. 【0034】 The phase difference sensor 6 is composed of a magnetic detection element, such as a Hall element, and a magnet. The phase difference sensor 6 has an axial position spanning the first engaging tooth 13 and the second engaging tooth 14 as its detection range SA (see Figure 7), and is positioned so as to face the clutch axis Z from the radially outer side without interfering with the meshing clutch 10. The phase difference sensor 6 detects the total area of ​​the first engaging tooth 13 and the second engaging tooth 14 as they pass through the detection range SA as they rotate, based on the change in magnetic flux strength. 【0035】 The pitch angle P is the angle obtained by dividing the angle of one rotation (i.e., 360 degrees) of the first clutch member 11 and the second clutch member 12 by the number of teeth. For example, the number of teeth of the first engaging tooth 13 and the second engaging tooth 14 is 36, and the pitch angle P is 10 degrees. Figure 7 assumes a configuration with 36 teeth and shows the phase difference range as ±5 degrees. Note that a different definition of phase difference is described in the "Other Embodiments" section. 【0036】 The upper part of Figure 7 shows the general phase difference Δθ during rotation. The middle part shows the state where the rotational phases of the first engaging tooth 13 and the second engaging tooth 14 coincide, resulting in a "phase difference Δθ = 0". In this state, the first clutch member 11 and the second clutch member 12 cannot engage. The sensor output is maximized when the teeth of both the first engaging tooth 13 and the second engaging tooth 14 are included in the detection range SA and the total area is maximized. The sensor output is minimized when the gaps between the first engaging tooth 13 and the second engaging tooth 14 are included in the detection range SA and the total area is minimized. 【0037】 The lower part of Figure 7 shows a state where the rotational phase of the first engaging tooth 13 and the second engaging tooth 14 is shifted by half the pitch angle P, resulting in a "phase difference Δθ = ±(1 / 2)P (= ±5 degrees)". In this state, the first clutch member 11 and the second clutch member 12 can engage. When the detection range SA includes the tooth portion of one of the first engaging tooth 13 and the gap portion of the other, and the total area is at an intermediate value between the maximum and minimum values, the sensor output becomes an intermediate value. 【0038】 Returning to Figure 5, the control device 7 switches the engagement or disengagement of the meshing clutch 10 based on an engagement or disengagement instruction from an external source. The control device 7 acquires the phase difference sensor signal, the input shaft rotation speed Nin, and the output shaft rotation speed Nout, and controls the rotation of the MG82 based on this information, and also outputs a drive instruction to the clutch actuator 5. When the control device 7 receives an engagement instruction to engage the meshing clutch 10 from the disengaged state, it rotates the MG82 and starts a synchronization operation to increase the input shaft rotation speed Nin so that it approaches the output shaft rotation speed Nout. 【0039】 As shown in Figure 6, the control device 7 includes a phase difference detection unit 71, a rotation speed difference / gradient calculation unit 72, a current phase difference estimation unit 73, a rotation speed difference change characteristic calculation unit, an MG rotation speed calculation unit 75, an MG rotation speed control unit 76, an ACT drive determination unit 77, an operation delay time estimation unit 78, and a completion target time correction unit 79. The symbols Δθd, td, ac, ωsc, Tall, and Tpre in the figure will be explained later in the descriptions of Figures 9 and 10. 【0040】 The phase difference detection unit 71 filters the output of the phase difference sensor 6 to remove fluctuation components in a predetermined frequency range. As shown in Figure 8, the phase difference sensor output after filtering exhibits a beat waveform. The nodes of the beat waveform correspond to the phase difference (Δθ = ±(1 / 2)P) at which the meshing clutch 10 can engage. The phase difference detection unit 71 outputs the phase difference Δθd detected from the phase difference sensor output, and the time td at which the phase difference Δθd was detected, to the rotational speed difference change characteristic calculation unit 74. 【0041】 The rotational speed difference / gradient calculation unit 72 calculates the rotational speed difference between the input shaft rotational speed Nin and the output shaft rotational speed Nout, and the gradient, which is the rate of change of the rotational speed difference over time. The gradient is the rate of change of the rotational speed difference over time and is calculated by dividing the rotational speed difference by the elapsed time. The target value of the gradient in rotational speed difference control is called the "target gradient". The current phase difference estimation unit 73 estimates the current phase difference from the cumulative value of the rotational speed difference from a predetermined reference time to the present. When the estimated phase difference at each time is plotted, a sawtooth-like change is shown, as shown in Figures 9 and later. This makes it possible to predict the phase difference at any future time. 【0042】 The rotational speed difference change characteristic calculation unit 74 calculates the target gradient ac or target rotational speed difference ωsc as the rotational speed difference change characteristic to be changed by phase difference adjustment control, based on information including the phase difference Δθd and time td obtained from the phase difference detection unit 71. In the first to fourth embodiments, the gradient is changed as the rotational speed difference change characteristic, and in the seventh embodiment, the target rotational speed difference is changed. In the fifth and sixth embodiments, both the gradient and the target rotational speed difference are changed. Further details will be described later in the description of each embodiment. 【0043】 The MG rotation speed calculation unit 75 calculates the current MG rotation speed based on the output of the rotation speed sensor 23 and notifies the MG rotation speed control unit 76. The MG rotation speed control unit 76 controls the rotation of the MG 82 so that the target gradient ac or target rotation speed difference ωsc calculated by the rotation speed difference change characteristic calculation unit 74 is achieved. 【0044】 In Figure 6, for convenience, the MG rotation speed control unit 76 is shown as part of the control device 7. However, in reality, the control device of the meshing clutch engagement control system 100 and another MG control device function in conjunction to constitute the control device 7. The MG control device primarily controls the power supply from the power source to the MG 82 by operating an inverter, with the aim of controlling the drive during the regenerative power operation of the rear wheels 92 after clutch engagement. In contrast, the MG rotation speed control unit 76 in Figure 6 exclusively controls the input shaft rotation speed Nin during the synchronization operation before clutch engagement. In other words, at least a portion of the MG control device's functions that perform the synchronization operation corresponds to the MG rotation speed control unit 76. 【0045】 The ACT drive determination unit 77 drives the clutch actuator 5 in the forward direction in two stages in response to an engagement instruction. First, the ACT drive determination unit 77 moves the clutch actuator 5 to the standby position before the engagement time. Next, when engagement is performed, the ACT drive determination unit 77 moves the clutch actuator 5 to the full stroke position and engages the meshing clutch 10. The ACT drive determination unit 77 also drives the clutch actuator 5 in the reverse direction in response to a release instruction and disengages the meshing clutch 10. 【0046】 The operation delay time estimation unit 78 estimates the operation delay time when a delay factor occurs in the operation of the clutch actuator 5. For example, the larger the time constant of the filtering process in the phase difference detection unit 71, the more delayed the detection of the phase difference. Also, the greater the computational load on the CPU constituting the control device 7, the more processing delays and communication delays between CPUs via CAN, etc. may occur. In addition, the operating speed may change depending on the temperature of the clutch actuator 5. The operation delay time estimation unit 78 estimates the operation delay time of the clutch actuator 5 from this information and adjusts the ACT preceding operation time Tpre according to the operation delay time. The adjusted ACT preceding operation time Tpre is fed back to the ACT drive determination unit 77. 【0047】 As shown in Figures 9 and 10, the target completion time Tall is the time from the adjustment reference time t1 to the target completion time tall at which engagement is performed. The control device 7 starts the preliminary operation of the clutch actuator 5 a predetermined preliminary operation time Tpre before the target completion time tall. The target completion time Tall is, in principle, a default value, but if a delay in the operation of the clutch actuator 5 occurs, the target completion time correction unit 79 corrects the target completion time Tall according to the operation delay time and outputs it to the rotational speed difference change characteristic calculation unit 74. 【0048】 The above is a description of the configuration example of the control device 7 according to this embodiment. The control device 7 of this embodiment adjusts the phase difference by coordinating the change in rotational speed difference in the synchronization operation with the change in phase difference, thereby shortening the time for phase alignment (see Figure 3) and improving the responsiveness of clutch engagement. Next, the specific configuration of phase difference adjustment according to each embodiment will be described in order. 【0049】 (First Embodiment) The phase difference adjustment according to the first embodiment will be explained with reference to Figures 9 to 11. Figure 9 shows, from top to bottom, the input / output shaft rotation speed, rotation speed difference, phase difference, and integrated phase difference for the entire period of synchronization operation in which the input shaft rotation speed Nin increases from 0. Figure 10 shows, from top to bottom, the rotation speed difference, phase difference, ACT drive instruction, and ACT stroke for the period after the adjustment reference time t1. The time charts for rotation speed difference and phase difference shown in the second and third rows of Figure 9 and the first and second rows of Figure 10 overlap in some respects, but the range of the time axis is different. In Figure 10, the changes during phase difference adjustment are shown in more detail than in Figure 9, and supplementary information is also included. 【0050】 In Figures 9 and 10, the solid line represents the control of the first embodiment, and the dashed line represents the control of the comparative example without phase difference adjustment. Furthermore, the hatched triangles indicate the engagement timing in the control of the first embodiment, and the dashed triangles indicate the engagement timing in the control of the comparative example. In the first embodiment, engagement is performed at the completion target time tall, while in the comparative example, engagement is performed at time tz. 【0051】 In the diagram of input / output shaft rotational speed, the rotational speed is represented by the symbol N [rpm]. In the diagram of rotational speed difference, for consistency with the mathematical formula, the rotational speed difference is represented by ω [deg / sec] instead of ΔN. The rotational speed difference ΔN [rpm] is converted to ω [deg / sec] using equation (1). Therefore, the rotational speed difference is treated as a quantity synonymous with the phase difference change rate (or angular velocity difference). 【0052】 ω[deg / sec] =ΔN[rpm]×360[deg]÷60[sec] ···(1) 【0053】 The symbols in Figure 3 are used in the diagram of input and output shaft rotation speeds. The output shaft rotation speed Nout is constant, and the input shaft rotation speed Nin increases from an initial value of 0 towards the output shaft rotation speed Nout. When the input shaft rotation speed Nin reaches the detectable rotation speed N_sen at time t1, phase difference detection by the phase difference sensor 6 becomes possible. This time is defined as the "adjustment reference time t1". 【0054】 Furthermore, the target rotational speed N_tgt is set such that the rotational speed difference between it and the output shaft rotational speed Nout is within the acceptable range for engagement shock. Engagement is performed at the engagement time after the input shaft rotational speed Nin reaches the target rotational speed N_tgt and the ACT stroke reaches the standby stroke Stsb (see Figure 10). The time at which the input shaft rotational speed Nin reaches the target rotational speed N_tgt is time tt in the comparative example and time ts in the first embodiment. 【0055】 When the output shaft rotational speed Nout is constant, the rotational speed difference diagram is equivalent to an inverted version of the rotational speed diagram. The difference between the detectable rotational speed N_sen and the output shaft rotational speed Nout corresponds to the "phase difference detectable rotational speed difference ω0". The difference between the target rotational speed N_tgt and the output shaft rotational speed Nout corresponds to the "target rotational speed difference ωs that the meshing clutch 10 can engage". The control device 7 controls the rotational speed difference and performs a synchronization operation to gradually reduce the rotational speed difference until it reaches the target rotational speed difference ωs by issuing an engagement instruction to engage the meshing clutch 10 in the disengaged state. 【0056】 Regarding the phase difference diagram, when the number of teeth is 36, the phase difference Δθ changes within a range of ±5 degrees centered at 0 degrees. Although the hypotenuse of the sawtooth wave is strictly curved, it is illustrated as a straight line for convenience. In the phase difference diagram, the dashed line for the period before the adjustment reference time t1 means that the phase difference cannot be detected. 【0057】 After the adjustment reference time t1, the time at which an arbitrary phase difference is detected based on the output of the phase difference sensor 6 is defined as the "arbitrary phase difference detection time td". In the synchronization operation, the control device 7 detects the current engagement timing based on the output of the phase difference sensor 6. The phase difference detected at the arbitrary phase difference detection time td is represented as Δθd, and the rotational speed difference at the phase difference detection time td is represented as ωd. If the arbitrary phase difference detection time td is the present, the engagement timings shown after time td indicate future engagement timings. The diagram of the phase difference change after time td is interpreted as being drawn as a result. At time td, it is not always necessary for the control device 7 to predict future phase difference changes. An example in which it is preferable to predict future phase differences will be described later in the 8th embodiment. 【0058】 In this example, the phase difference Δθd detected at the arbitrary phase difference detection time td is +5deg, which corresponds to the "phase difference that the meshing clutch 10 can engage with". In Figure 7, the engageable phase difference is expressed as "Δθd = ±5deg", but in equation (4) described later, if Δθd takes two values, the solution is not uniquely determined. Therefore, the domain of Δθd is defined as "-5deg < Δθd ≤ +5deg", and -5deg is excluded. Also, the target phase difference Δθt at the time of engagement is basically +5deg. Therefore, in this example, "Δθt - Δθd = 0". The slope of the line in the integrated phase difference diagram represents the phase difference change rate ω [deg / sec]. 【0059】 The control device 7 outputs a drive command to the clutch actuator 5 to engage the meshing clutch 10 at a future engagement time after the rotational speed difference reaches the target rotational speed difference ωs. In this embodiment, the control device 7 adjusts the phase difference so that any future engagement time coincides with the completion target time tall, which is a time after the completion target time Tall from the adjustment reference time t1. In other words, the completion target time tall becomes the target timing for engagement execution. 【0060】 The third panel of Figure 10 shows the ON / OFF state of the drive command for the clutch actuator 5. The bottom panel of Figure 10 shows the stroke of the clutch actuator 5. The control device 7 starts the preliminary operation of the clutch actuator 5 at time tpre, which is a predetermined preliminary operation time Tpre before the target completion time tall. The clutch actuator 5 reaches the standby position with a standby stroke Stsb at time tsb. Then, when the target completion time tall arrives, the control device 7 moves the clutch actuator 5 to its full stroke Stfl, bringing the engaging clutch 10 into a fully engaged state. 【0061】 Next, regarding the control of the rotational speed difference, specifically, we will describe a control method that changes the gradient, which is the rate of change of the rotational speed difference over time, as the "characteristic of change in the input / output shaft rotational speed difference." In both the comparative example and the first embodiment, the initial gradient from the adjustment reference time t1 to the arbitrary phase difference detection time td is set to a0. Here, the initial gradient a0 at the time of phase difference detection has a smaller absolute value than the gradient a00 during the period when no phase difference is detected, from the start of the synchronization operation to the adjustment reference time t1, i.e., the slope is set to be gentler. This setting is effective in shortening the phase difference detection time. 【0062】 In the comparative example, the initial gradient a0 is maintained constant from the adjustment reference time t1 until the arrival time tt when the rotational speed difference reaches the target rotational speed difference ωs. In contrast, in the first embodiment, the control device 7 calculates the target gradient ac, which is the target value of the gradient, based on the information acquired at the arbitrary phase difference detection time td, and changes the initial gradient a0 to the target gradient ac. In the first embodiment, the initial engagement time after the adjustment reference time t1 is set to the arbitrary phase difference detection time td. 【0063】 The control device 7 adjusts the phase difference by changing the gradient at an arbitrary phase difference detection time td, so that one of the future engagement times matches the completion target time tall. If the arbitrary phase difference detection time td is the present, in the first embodiment, the system is controlled so that the next engagement time from the present, i.e., the first future engagement time, matches the completion target time tall. When the system is controlled so that the nth future engagement time matches the completion target time tall, n is called the "adjustment cycle number". In the first embodiment, "n=1". 【0064】 The target gradient ac has a larger absolute value than the initial gradient a0, meaning the slope is set steeper. Therefore, the time ts at which the rotational speed difference reaches the target rotational speed difference ωs is earlier than the time tt in the comparative example. As a result, engagement is performed at the target completion time tall, which is earlier than the engagement execution time tz in the comparative example, enabling power transmission. This results in clutch engagement with higher precision and responsiveness compared to the comparative example. 【0065】 The time symbols in the diagram are explained below. Td represents the initial gradient duration from the adjustment reference time t1 to the arbitrary phase difference detection time td. Ts represents the target gradient duration from the arbitrary phase difference detection time td to the arrival time ts. Tc represents the target rotational speed difference duration from the arrival time ts to the completion target time tall. The sum of Td, Ts, and Tc is equal to the completion target time Tall (Td + Ts + Tc = Tall). 【0066】 Next, we will explain the theoretical formula for calculating the target gradient ac. The target gradient ac is defined by equation (2). Also, in the rotational speed difference diagram in Figure 10, when the sum of the area of ​​right triangle A and the area of ​​rectangle B is equal to the accumulated phase difference from the arbitrary phase difference detection time td to the completion target time tall, equation (3) holds. The "10" on the right side of equation (3) represents the pitch angle P (=10deg) of the gear with 36 teeth. The units of each parameter are as follows. 【0067】 Rotational speed difference: ωd, ωs [deg / sec] Time: Ts, Td, Tall [sec] Gradient: ac[deg / sec] 2 ] Phase difference: Δθt, Δθd[deg] 【0068】 【number】 【0069】 Eliminating Ts from equations (2) and (3) yields equation (4) for finding ac. 【0070】 【number】 【0071】 According to equation (4), the control device 7 calculates the target gradient ac based on the following six parameters. The number of adjustment cycles n is set as appropriate. If these parameters can be obtained, the control device 7 does not need to predict the future engagement timing at the arbitrary phase difference detection time td. ·Completion target time Tall • Time Td from adjustment reference time t1 to arbitrary phase difference detection time td • Phase difference Δθd detected at arbitrary phase difference detection time td • Target phase difference Δθt at the time of engagement • Rotational speed difference ωd at arbitrary phase difference detection time td • Target rotational speed difference ωs 【0072】 Of these, the target completion time Tall, the target phase difference Δθt at the time of engagement, and the target rotational speed difference ωs are stored as default values. However, as described above with reference to Figure 6, if a delay factor occurs in the operation of the clutch actuator 5, the target completion time correction unit 79 corrects the target completion time Tall according to the operation delay time estimated by the operation delay time estimation unit 78. 【0073】 The control device 7 acquires information on the following three parameters at an arbitrary phase difference detection time td. • Time Td from adjustment reference time t1 to arbitrary phase difference detection time td • Phase difference Δθd detected at arbitrary phase difference detection time td • Rotational speed difference ωd at arbitrary phase difference detection time td 【0074】 The reasoning behind equation (3) is as follows: The control device 7 calculates the target gradient ac such that the time integral of the value obtained by converting the rotational speed difference during the period from the arbitrary phase difference detection time td to the target completion time tall into a phase difference change rate matches the phase difference obtained by adding the target phase difference Δθt at the time of engagement and the phase difference Δθd detected at the arbitrary phase difference detection time td to an integer multiple of the pitch angles of the first engaging tooth 13 and the second engaging tooth 14. 【0075】 The clutch engagement control according to the first embodiment will be explained with reference to the flowchart in Figure 11. In the flowchart, the symbol "S" represents a step. Steps S15 to S17 are omitted in Figure 11 in order to use the same step numbers as in Figure 21 of the eighth embodiment. 【0076】 After the synchronization operation is started, the rotational speed difference gradually decreases. In S11, at the adjustment reference time t1, the rotational speed difference ω0, which can be detected by the phase difference sensor 6, is reached. Subsequently, S12 to S18 are executed with respect to the MG rotation. In S12, the control device 7 detects the phase difference Δθd at the arbitrary phase difference detection time td. In the first embodiment, the initial engagement time after the adjustment reference time t1 is detected at the arbitrary phase difference detection time td. 【0077】 The control device 7 acquires information on the time Td from the adjustment reference time t1 to the arbitrary phase difference detection time td, the phase difference Δθd detected at the arbitrary phase difference detection time td, and the rotational speed difference ωd at the arbitrary phase difference detection time td. The control device 7 also stores information on the completion target time Tall, the engagement target phase difference Δθt, and the target rotational speed difference ωs. In S13, the control device 7 starts phase difference adjustment based on this information. 【0078】 In S14, the control device 7 calculates the target gradient ac and changes the initial gradient a0 to the target gradient ac. In S18, at the arrival time ts, which is after the target gradient duration Ts has elapsed from the arbitrary phase difference detection time td, the rotational speed difference reaches the target rotational speed difference ωs. 【0079】 Following S11, S21 to S23 are executed in parallel with S12 to S18 regarding the operation of the clutch actuator 5. In S21, the control device 7 calculates the time tpre which is before the preceding operation time Tpre from the target completion time tall. In S22, the control device 7 starts the preceding operation of the clutch actuator 5 at time tpre. In S23, the clutch actuator 5 reaches the standby position at time tsb. 【0080】 Following S18 regarding MG rotation and S23 regarding ACT operation, in S31, the completion target time Tall has elapsed from the adjustment reference time t1. In S32, the engagement of the meshing clutch 10 is performed. 【0081】 As described above, in the first embodiment, the control device 7 calculates the target gradient ac based on the information acquired at the arbitrary phase difference detection time td, and changes the initial gradient a0 to the target gradient ac, thereby aligning the timing of the first engagement in the future with the completion target time tall. This enables highly accurate phase difference adjustment and improves the responsiveness of clutch engagement. 【0082】 Here, for comparison, let's assume an alternative control method. In this assumed control method, after predicting the future engagement time, the system adjusts that engagement time to bring it closer to the target time. In that case, if torque is applied to the input shaft to bring the engagement time closer to the target time, the input shaft rotation speed changes, causing the target time to shift and potentially reducing the accuracy of the phase difference adjustment. In contrast, in this embodiment, the rotation speed difference gradient is changed and the phase difference adjustment is performed simultaneously based on information acquired at an arbitrary phase difference detection time td, thus enabling highly accurate phase difference adjustment. Furthermore, in this embodiment, the future engagement time does not necessarily need to be predicted. 【0083】 Next, referring to Figures 12 to 17, the phase difference adjustment according to the second to seventh embodiments will be described in order as variations different from the first embodiment. Figures 12 to 17 correspond to Figure 10 of the first embodiment, and the symbols for time, duration, rotational speed difference, gradient, phase difference, etc., are the same as those in Figure 10. The dashed line shows the control of a comparative example in which phase difference adjustment is not performed. The diagrams for ACT drive request and ACT stroke are the same as in Figure 10 and are therefore omitted. 【0084】 In all embodiments, the target phase difference Δθt at the time of engagement is "Δθt = +5deg". Also, except for the fourth embodiment, the phase difference Δθd detected at the arbitrary phase difference detection time td is the phase difference at which the meshing clutch 10 can engage, i.e., "Δθd = +5deg". At this time, "Δθt - Δθd = 0". In other words, except for the fourth embodiment, the engagement time is detected at the arbitrary phase difference detection time td. Also, except for the third and fourth embodiments, the first engagement time after the adjustment reference time t1 is detected at the arbitrary phase difference detection time td. 【0085】 (Second Embodiment) In the second embodiment shown in Figure 12, the target gradient ac is calculated by setting the number of adjustment periods n to "n=2" so that the second future engagement timing after an arbitrary phase difference detection time td coincides with the target completion time tall. In this way, the target gradient ac is calculated so that the second and subsequent future engagement timings coincide with the target completion time tall, and the initial gradient a0 may be changed to the target gradient ac. 【0086】 (Third embodiment) In the third embodiment shown in Figure 13, the second engagement time after the adjustment reference time t1 is set to the arbitrary phase difference detection time td. Thus, the second and subsequent engagement times after the adjustment reference time t1 may be set to the arbitrary phase difference detection time td. 【0087】 (Fourth Embodiment) In the fourth embodiment shown in Figure 14, the phase difference Δθd detected at the arbitrary phase difference detection time td is a phase difference corresponding to the antinode of a beat wave (see Figure 8) where "Δθd = 0". At this time, "n = 1" and "Δθt - Δθd = +5 degrees". Thus, the phase difference Δθd detected at the arbitrary phase difference detection time td may be any phase difference other than the phase difference that the meshing clutch 10 can engage. 【0088】 (Fifth and sixth embodiments) In the fifth and sixth embodiments shown in Figures 15 and 16, the control device 7, based on the information acquired at the arbitrary phase difference detection time td, changes the target rotational speed difference from the reference value ωs to the modified value ωsc as the "characteristic of change in input / output shaft rotational speed difference," in addition to changing the gradient. The "information acquired by the control device at the arbitrary phase difference detection time td" includes time Td, phase difference Δθd, and rotational speed difference ωd, similar to the calculation parameters for the target gradient ac. 【0089】 In the examples shown in Figures 15 and 16, the modified target rotational speed difference ωsc is set to a value smaller than the reference value ωs (ωsc < ωs). As the rotational speed difference decreases along the target gradient ac to the modified target rotational speed difference ωsc, the arrival time ts is shifted slightly later. 【0090】 In the fifth embodiment, the target rotational speed difference is returned to the baseline value ωs before the target completion time tall, and the engagement shock during engagement is controlled at a standard level. In the sixth embodiment, the modified target rotational speed difference ωsc is maintained until the target completion time tall. Therefore, the engagement shock during engagement can be reduced below the standard level. 【0091】 (Seventh Embodiment) In the seventh embodiment shown in Figure 17, the control device 7, based on the information acquired at the arbitrary phase difference detection time td, changes the target rotational speed difference from the reference value ωs to the modified value ωsc as the "change characteristic of input / output shaft rotational speed difference," without changing the gradient. The modified target rotational speed difference ωsc is set to a value greater than the reference value ωs (ωsc > ωs). 【0092】 Here, the reference value ωs for the target rotational speed difference is set to a relatively small value, obtained by subtracting a margin from the allowable limit value ωs0 for engagement shock. Therefore, changing the target rotational speed difference to a larger value ωsc within the margin range from the reference value ωs is possible from the standpoint of avoiding the effects of engagement shock. By changing to a larger target rotational speed difference, that is, by changing to a lower input shaft rotational speed Nin, the phase difference period becomes shorter, and the target completion time tall becomes earlier compared to the comparative example. Thus, the responsiveness of clutch engagement can be improved. 【0093】 (Eighth embodiment) Next, referring to Figures 18 to 21, the phase difference adjustment according to the eighth embodiment will be described. The means for phase difference adjustment include changing the target gradient ac. In the first to sixth embodiments described above, between the adjustment reference time t1 and the arrival time ts, a phase difference Δθd for the purpose of phase difference adjustment is detected once at one arbitrary phase difference detection time td. During this period, for example, phase difference detection for monitoring the phase difference may be performed any number of times, but at least one phase difference Δθd that is reflected in the phase difference adjustment is detected. 【0094】 In contrast, the eighth embodiment assumes that multiple phase difference detections for the purpose of phase difference adjustment are performed at multiple arbitrary phase difference detection times between the adjustment reference time t1 and the arrival time ts. Here, we will describe the case in which the detection of phase differences Δθd1 to Δθd3 is performed three times at three arbitrary phase difference detection times td1 to td3. In particular, in the eighth embodiment, it is preferable for the control device 7 to predict future phase differences. In that case, the rotational speed difference change characteristic calculation unit 74 in Figure 6 acquires the phase difference estimated by the current phase difference estimation unit 73. 【0095】 Figures 18, 19, and 20 are time charts of phase difference adjustment at arbitrary phase difference detection times td1, td2, and td3, respectively, where the first, second, and third engagement times are detected after the adjustment reference time t1. The time charts for the first and second times show provisional operation, and the time chart for the third time shows the final operation. Similar to the figures of the above embodiment, the dashed line shows the control of a comparative example in which no phase difference adjustment is performed. 【0096】 As shown in Figure 18, at the first arbitrary phase difference detection time td1, the first target gradient ac1 is calculated based on time Td1, phase difference Δθd1, and rotational speed difference ωd1, and the initial gradient a0 is changed to the first target gradient ac1. At this point, assuming that the first target gradient ac1 is maintained until arrival time ts, future operation is tentatively predicted. 【0097】 However, during control after the arbitrary phase difference detection time td1, the actual phase difference may deviate from the target phase difference depending on the control cycle, rotation speed reading accuracy, and phase difference sensor reading accuracy. Alternatively, as shown by the dashed line, the actual rotation speed difference may change without following the target gradient ac. 【0098】 Therefore, the control device 7 recalculates the target gradients ac2 and ac3 at the arbitrary phase difference detection times td2 and td3, which are the second and third engagement timing detection opportunities, and updates the target gradient calculated previously. In Figures 19 and 20, the dashed lines show the operation calculated at the first arbitrary phase difference detection time td1. 【0099】 As shown in Figure 19, at the second arbitrary phase difference detection time td2, the second target gradient ac2 is calculated based on time Td2, phase difference Δθd2, and rotational speed difference ωd2, and the previous value, the first target gradient ac1, is updated to the current value, the second target gradient ac2. At this time, the phase difference Δθd2 detected this time is referenced to the phase difference predicted at the previous arbitrary phase difference detection time td1, thereby improving accuracy. In the example in Figure 19, there is a discrepancy between the target operation based on the first target gradient ac1 and the actual operation, and the second target gradient ac2 calculated at the second arbitrary phase difference detection time td2 is a different value from the first target gradient ac1. 【0100】 As shown in Figure 20, at the third arbitrary phase difference detection time td3, the third target gradient ac3 is calculated based on time Td3, phase difference Δθd3, and rotational speed difference ωd3, and the previous value, the second target gradient ac2, is updated to the current value, the third target gradient ac3. Similarly, the phase difference Δθd3 detected this time is referenced to the phase difference predicted at the previous arbitrary phase difference detection time td2, thereby improving accuracy. In the example in Figure 20, there is almost no discrepancy between the target operation based on the second target gradient ac2 and the actual operation. Therefore, the third target gradient ac3 calculated at the third arbitrary phase difference detection time td3 is almost the same value as the second target gradient ac2. 【0101】 The formulas for calculating the target gradients ac1 to ac3 at each arbitrary phase difference detection time td1 to td3 are shown in equations (5.1) to (5.3). Assuming that one arbitrary phase difference detection time is set for each phase cycle after the adjustment reference time t1, the number of adjustment cycles n decreases by 1 each time a phase difference is detected. In the example in Figures 18 to 20, the first detection is "n=4", the second is "n=3", and the third is "n=2". Also, in this example, the detected phase differences Δθd1, Δθd2, Δθd3 and the engagement target phase difference Δθt are "Δθd1=Δθd2=Δθd3=Δθt=+5deg". 【0102】 【number】 【0103】 Figure 21 shows a flowchart of clutch engagement control according to the eighth embodiment. Compared to Figure 11, Figure 21 adds loop steps S15 to S17. S18 also serves as the loop termination determination step. The other steps are substantially the same as in Figure 11, and the same step numbers are used, so their explanations are omitted. Note that in S12, td is changed to td1, Δθd is changed to Δθd1, and in S14, ac is changed to ac1. 【0104】 In S15, the kth (k≧2) phase difference Δθk is detected at the arbitrary phase difference detection time tdk. In S16, the control device 7 updates the target gradient ac(k-1) calculated at the previous arbitrary phase difference detection time td(k-1) to the target gradient ack calculated at the current arbitrary phase difference detection time tdk. Accordingly, in S17, the future engagement timing is updated. 【0105】 In S18, it is determined whether the rotational speed difference has reached the target rotational speed difference ωs. If the answer in S18 is NO, steps S15 to S17 are repeated. If the answer in S18 is YES, the target gradient update is completed and the process moves to S31. In S31, once the completion target time Tall has elapsed from the adjustment reference time t1, the engagement of the meshing clutch 10 is performed in S32. 【0106】 As described above, in the eighth embodiment, by repeatedly updating the target gradient ac1~ack through feedback control based on multiple phase difference detections between the adjustment reference time t1 and the arrival time ts, clutch engagement with higher precision and responsiveness can be achieved. 【0107】 (Other embodiments) (a) The meshing clutch illustrated in Figures 1 and 5 is a face-type gear configuration in which the clutch members 11 and 12 themselves move relative to each other in the axial direction, and the first engaging teeth 13 of the first clutch member 11 and the second engaging teeth 14 of the second clutch member 12 can directly mesh. In addition to this configuration, a sleeve-type clutch may be used in which the clutch members are immovable and a movable sleeve is provided as a separate component as an intermediate member. 【0108】 A sleeve-type clutch is disclosed, for example, in Japanese Patent Publication No. 2010-96190. In a sleeve-type clutch, the first engaging teeth of the first clutch member and the second engaging teeth of the second clutch member can engage with each other via a sleeve acting as an intermediate member. The clutch actuator moves the sleeve axially relative to the first and second clutch members, thereby switching between the engaged and disengaged states of the engaging clutch. The detection portion of the phase difference sensor is adjusted so that different sensor signals are output for the engaged and disengaged states. 【0109】 (b) The engagement clutch 10 is not limited to being provided between the rear wheel MG 82 and the rear wheel 92 in the 2WD / 4WD switchable vehicle 90 illustrated in Figure 1, but may also be provided between the front wheel MG and the front wheel in a front-wheel drive (FF) vehicle, for example. 【0110】 (c) The phase difference sensor 6 is not limited to detecting the total area of ​​the engaging teeth 13 and 14 within the detection range SA, as illustrated in Figures 5 and 7, but is not limited to detecting information correlated with the difference in rotational position between the input shaft 3 and the output shaft 4 and converting it into a phase difference. Alternatively, the phase difference may be defined as 0 when the first clutch member 11 and the second clutch member 12 are engaged. In that case, the phase difference of the meshing clutch 10 with 36 teeth will vary in the range of 0 to +10 degrees. Regardless of the definition of the phase difference, the relative value of "Δθt-Δθd" in equation (4) will be the same. 【0111】 (d) The rotary drive source connected to the input shaft 3 is not limited to the MG82, but may be an internal combustion engine or the like. Furthermore, the meshing clutch engagement control system may be applied not only to the vehicle's powertrain but also to the power transmission mechanism of general machinery, etc. 【0112】 (e) The synchronization operation is not limited to an operation in which the output shaft rotation speed Nout (i.e., vehicle speed) is constant and only the input shaft rotation speed Nin gradually increases, but may also change so that both the output shaft rotation speed Nout and the input shaft rotation speed Nin approach each other. 【0113】 (f) In the synchronization operation shown in Figure 9, the input shaft 3 is stopped in the released state, and after the control device 7 receives an engagement instruction, the input shaft rotation speed Nin increases from 0 rpm toward the target rotation speed N_tgt. Alternatively, the input shaft rotation speed Nin may be held at a predetermined target idle speed in the released state. For example, by setting a higher target idle speed as the vehicle speed increases, the synchronization operation time at high speeds can be shortened. 【0114】 Furthermore, in the vehicle shown in Figure 2, it is necessary to quickly switch from 2WD to 4WD in situations such as [1] rain, snow, or icy roads, [2] sharp turns, and [3] braking at a red light or at the end of a traffic jam. Therefore, by setting a higher target idle speed in these situations, the synchronization operation time can be shortened. However, this comes at the cost of reduced fuel efficiency, so it is preferable to set an appropriate target idle speed according to the vehicle's driving conditions rather than setting it unnecessarily high. 【0115】 The present disclosure is not limited to these embodiments and can be implemented in various forms without departing from its spirit. 【0116】 (Disclosure of technical ideas) This specification discloses several technical concepts, as listed in the following paragraphs. Some paragraphs are written in a multiple dependent form, where subsequent paragraphs optionally refer to preceding paragraphs. Furthermore, some paragraphs are written in a multiple dependent form, referring to other multiple dependent forms. These paragraphs written in multiple dependent forms define several technical concepts. 【0117】 (Technical thought 1) A meshing clutch (10) having a first clutch member (11) connected to an input shaft (3) and having a plurality of first engaging teeth (13) arranged in the circumferential direction, and a second clutch member (12) connected to an output shaft (4) and having a plurality of second engaging teeth (14) arranged in the circumferential direction that can engage directly with the first engaging teeth or via an intermediate member, wherein the engaged state and disengaged state of the first clutch member and the second clutch member are switched, A clutch actuator (5) moves the first clutch member and the second clutch member relative to each other in the axial direction, or, when the intermediate member is used, moves the intermediate member relative to the first clutch member and the second clutch member in the axial direction; A phase difference sensor (6) for detecting the phase difference between the first clutch member and the second clutch member, A control device (7) controls the input / output shaft rotation speed difference, which is the difference between the rotation speed of the input shaft and the rotation speed of the output shaft, and performs a synchronization operation to gradually reduce the input / output shaft rotation speed difference until it reaches a target rotation speed difference (ωs) at which the meshing clutch can engage, by issuing an engagement command to engage the meshing clutch in the disengaged state, and in the synchronization operation, detects the current engagement timing based on the output of the phase difference sensor for the engagement timing at which the phase difference becomes such that the meshing clutch can engage, and outputs a drive command to the clutch actuator to engage the meshing clutch at a future engagement timing after the input / output shaft rotation speed difference has reached the target rotation speed difference, Equipped with, The control device is After the adjustment reference time (t1) when the input / output shaft rotation speed difference reaches a rotation speed difference (ω0) detectable by the phase difference sensor, based on the information acquired at the arbitrary phase difference detection time (td) when an arbitrary phase difference is detected based on the output of the phase difference sensor, A clutch engagement control system that adjusts the phase difference between the first clutch member and the second clutch member by changing the change characteristics of the input / output shaft rotation speed difference so that any future engagement timing coincides with a completion target time (tall) which is a time after the adjustment reference time by the completion target time (tall). (Technical thought 2) If we define the time rate of change of the input / output axis rotation speed difference as the gradient, and define the gradient during the period from the adjustment reference time to the arbitrary phase difference detection time as the initial gradient (a0), then The control device calculates a target gradient (ac), which is a target value of the gradient, based on the information acquired at the arbitrary phase difference detection time, and changes the initial gradient to the target gradient, as described in Technical Concept 1, for the meshing clutch engagement control system. (Technical Thought 3) A meshing clutch engagement control system according to Technical Concept 2, wherein the control device calculates the target gradient based on the target completion time (Tall), the time from the adjustment reference time to the arbitrary phase difference detection time (Td), the phase difference detected at the arbitrary phase difference detection time (Δθd), the target phase difference at engagement (Δθt), the input / output shaft rotation speed difference at the arbitrary phase difference detection time (ωd), and the target rotation speed difference (ωs). (Technical Thought 4) The control device calculates the target gradient such that the time integral of the value obtained by converting the input / output shaft rotation speed difference during the period from the arbitrary phase difference detection time to the target completion time into a phase difference change rate matches the phase difference obtained by adding the difference between the target phase difference at the time of engagement (Δθt) and the phase difference detected at the arbitrary phase difference detection time (Δθd) to an integer multiple of the pitch angles of the first and second engaging teeth. This is the meshing clutch engagement control system according to technical concept 3. (Technical Thought 5) The meshing clutch engagement control system according to any one of the technical concepts 1 to 4, wherein the phase difference detected at the arbitrary phase difference detection time is a phase difference that allows the meshing clutch to engage. (Technical Thought 6) The control device modifies the target rotational speed difference based on the information acquired at the arbitrary phase difference detection time. This is a clutch engagement control system according to any one of the technical concepts 1 to 5. (Technical Thought 7) The control device starts the preliminary operation of the clutch actuator at a time (tpre) that is a predetermined preliminary operation time (Tpre) before the target completion time. A clutch engagement control system according to any one of the technical concepts 1 to 6, wherein if a delay factor occurs in the operation of the clutch actuator, the target completion time is corrected according to the operation delay time. (Technical Thought 8) Assuming that phase difference detection is performed multiple times at multiple arbitrary phase difference detection times (td1~td3) between the adjustment reference time and the time (ts) when the input / output axis rotation speed difference reaches the target rotation speed difference, The control device updates the target gradient calculated at the previous arbitrary phase difference detection time to the target gradient calculated at the current arbitrary phase difference detection time, according to any one of technical concepts 2 to 4, in a meshing clutch engagement control system. 【0118】 The control devices and methods described herein may be implemented by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. Alternatively, the control devices and methods described herein may be implemented by a dedicated computer provided by configuring a processor by one or more dedicated hardware logic circuits. Alternatively, the control devices and methods described herein may be implemented by one or more dedicated computers configured by a combination of a processor and memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by the computer on a computer-readable non-transitional tangible recording medium. 【0119】 This disclosure is described in accordance with embodiments. However, this disclosure is not limited to such embodiments and structures. This disclosure also includes various modifications and variations within the scope of equivalents. Furthermore, various combinations and forms, as well as other combinations and forms that include only one, more, or fewer elements, fall within the scope and idea of ​​this disclosure.

Claims

[Claim 1] A clutch (10) comprising a first clutch member (11) connected to an input shaft (3) and having a plurality of first engaging teeth (13) arranged circumferentially, and a second clutch member (12) connected to an output shaft (4) and having a plurality of second engaging teeth (14) arranged circumferentially that can engage directly with the first engaging teeth or via an intermediate member, wherein the engagement state and disengagement state of the first clutch member and the second clutch member are switched, A clutch actuator (5) moves the first clutch member and the second clutch member relative to each other in the axial direction, or, when the intermediate member is used, moves the intermediate member relative to the first clutch member and the second clutch member in the axial direction; A phase difference sensor (6) for detecting the phase difference between the first clutch member and the second clutch member, A control device (7) controls the input / output shaft rotation speed difference, which is the difference between the rotation speed of the input shaft and the rotation speed of the output shaft, and performs a synchronization operation to gradually reduce the input / output shaft rotation speed difference until it reaches a target rotation speed difference (ωs) at which the meshing clutch can engage, by issuing an engagement command to engage the meshing clutch in the disengaged state, and in this synchronization operation, the engagement timing at which the phase difference becomes such that the meshing clutch can engage can be detected based on the output of the phase difference sensor, and with the time at which the engagement timing is detected as the present, outputs a drive command to the clutch actuator to engage the meshing clutch at a future engagement timing after the input / output shaft rotation speed difference has reached the target rotation speed difference, Equipped with, The control device is After the adjustment reference time (t1) when the input / output shaft rotation speed difference reaches a rotation speed difference (ω0) detectable by the phase difference sensor, based on the information acquired at the arbitrary phase difference detection time (td) when an arbitrary phase difference is detected based on the output of the phase difference sensor, A clutch engagement control system that adjusts the phase difference between the first clutch member and the second clutch member by changing the change characteristics of the input / output shaft rotation speed difference so that any future engagement timing coincides with a completion target time (tall), which is a time after the adjustment reference time by the completion target time (tall). [Claim 2] If we define the time rate of change of the input / output axis rotation speed difference as the gradient, and define the gradient during the period from the adjustment reference time to the arbitrary phase difference detection time as the initial gradient (a0), The control device calculates a target gradient (ac), which is a target value of the gradient, based on the information acquired at the arbitrary phase difference detection time, and changes the initial gradient to the target gradient, as described in claim 1 of the meshing clutch engagement control system. [Claim 3] The meshing clutch engagement control system according to claim 2, wherein the control device calculates the target gradient based on the target completion time (Tall), the time from the adjustment reference time to the arbitrary phase difference detection time (Td), the phase difference detected at the arbitrary phase difference detection time (Δθd), the target phase difference at engagement (Δθt), the input / output shaft rotation speed difference at the arbitrary phase difference detection time (ωd), and the target rotation speed difference (ωs). [Claim 4] The meshing clutch engagement control system according to claim 3, wherein the control device calculates the target gradient such that the time integral of the value obtained by converting the input / output shaft rotation speed difference during the period from the arbitrary phase difference detection time to the target completion time into a phase difference change speed matches a phase difference obtained by adding the difference between the target phase difference at the time of engagement (Δθt) and the phase difference detected at the arbitrary phase difference detection time (Δθd) to an integer multiple of the pitch angle of the first engagement tooth and the second engagement tooth. [Claim 5] The meshing clutch engagement control system according to claim 1 or 2, wherein the phase difference detected at the arbitrary phase difference detection time is a phase difference that allows the meshing clutch to engage. [Claim 6] The control device modifies the target rotational speed difference based on the information acquired at the arbitrary phase difference detection time, according to the meshing clutch engagement control system according to claim 1 or 2. [Claim 7] The control device starts the preliminary operation of the clutch actuator at a time (tpre) that is a predetermined preliminary operation time (Tpre) before the target completion time. The clutch engagement control system according to claim 1, wherein if a delay factor occurs in the operation of the clutch actuator, the target completion time is corrected by changing the target completion time from the initially assumed future engagement time to the next or later engagement time according to the operation delay time. [Claim 8] Assuming that phase difference detection is performed multiple times at multiple arbitrary phase difference detection times (td1 to td3) between the adjustment reference time and the time (ts) when the input / output axis rotation speed difference reaches the target rotation speed difference, The meshing clutch engagement control system according to claim 2, wherein the control device updates the target gradient calculated at the previous arbitrary phase difference detection time to the target gradient calculated at the current arbitrary phase difference detection time.

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