JP2016002950A - Power transmission control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission control device for a vehicle, which uses a double clutch transmission, the control device being designed to shorten a period required for a shift operation during shift down and to be capable of restricting vibration of a driving system caused after the shift operation during shift down.SOLUTION: "At a point when a selection gear change is altered from a change gear before alteration to a change gear after the alteration"(t1) during a shift operation for shift down, an engine torque Te is decreased by a predetermined amount a from a value Tem corresponding to the degree of opening of an acceleration and, thereafter, the engine torque Te is maintained at "Tem-a" (>torque Tx for half joint). Thereafter, "at a point when a predetermined period (bC) has passed from a point (t2) when an engine revolving speed Ne reaches a rotating speed Ni1 corresponding to the vehicle speed of the change gear after the alteration," the engine torque Te is returned from "Tem-a" to "Tem." The "predetermined period" is set to a time of 25 to 50% of the oscillation period C of the driving system of a vehicle.

Description

  The present invention relates to a vehicle power transmission control device.

  Conventionally, as described in Patent Literature 1 and the like, first and second input shafts to which power is input from a vehicle engine, an output shaft that outputs power to drive wheels of the vehicle, An established state in which any one of a part (for example, a plurality of odd-numbered stages including the first speed) is selectively established to form a power transmission system between the first input shaft and the output shaft, or any shift stage 1st mechanism part which selectively achieves the open state which does not form a power transmission system between the 1st input shaft and the output shaft without establishing, and the remainder (for example, including 2nd gear) Any one of a plurality of even-numbered stages) is selectively established to form a power transmission system between the second input shaft and the output shaft, or the second input shaft without establishing any shift stage. And a second mechanism that selectively achieves an open state in which a power transmission system is not formed between the output shaft and the output shaft. To have.

  This transmission is interposed between the engine output shaft and the first input shaft, and is capable of transmitting the maximum torque (first torque) between the engine output shaft and the first input shaft by adjusting the clutch stroke. (Clutch torque) can be adjusted between the engine output shaft and the second input shaft by adjusting the clutch stroke. And a second clutch capable of adjusting a maximum torque (second clutch torque). A mechanism obtained by such a combination is also called a “double clutch transmission” (hereinafter also referred to as “DCT”).

  Hereinafter, a system configured by the first clutch, the first input shaft, and the first mechanism unit is referred to as a “first system”, and a system configured by the second clutch, the second input shaft, and the second mechanism unit. This is called “second system”. A state where the clutch torque is greater than “0”, that is, a state where the clutch transmits power is referred to as a “engaged state”, and a state where the clutch torque is “0”, ie, the state where the clutch does not transmit power is divided. Called “state”.

  When controlling the DCT, one shift speed to be achieved (hereinafter referred to as “selected shift speed”) is selected based on the operation of the shift lever by the driver of the vehicle and / or the running state of the vehicle. . Hereinafter, among the first and second mechanism units, the first and second clutches, the first and second input shafts, and the first and second systems, the one corresponding to the selected gear stage is referred to as the “selection mechanism unit”. , “Selected clutch”, “Selected input shaft”, “Selected system”, and those that do not correspond to the selected gear stage are “Non-selected mechanism”, “Non-selected clutch”, “Non-selected input shaft”, “ It is called “non-selected line”.

  When the selected gear stage is selected, the selected clutch is controlled to be in an engaged state with the selected gear stage established in the selection mechanism (the clutch torque of the selected clutch is greater than the engine drive torque (engine torque)). The non-selected clutch is controlled to be in a disconnected state (the clutch torque of the non-selected clutch is controlled to zero). As a result, a power transmission system having a reduction gear ratio of the selected gear stage is formed between the output shaft of the engine and the output shaft of the transmission via the selected system. Engine torque is transmitted to the drive wheels via this power transmission system, and the vehicle can be accelerated. The engine torque is normally adjusted to a value (operation amount equivalent value) corresponding to the operation amount of the accelerator pedal.

  On the other hand, in the non-selected system, the non-selected clutch is in a disconnected state. Accordingly, the next selected gear stage (specifically, the adjacent gear stage on the high speed side or the low speed side with respect to the selected gear stage (typically, one speed stage on the high speed side or the low speed side). The non-selection mechanism unit can be kept in a standby state in which the speed is set to only 3 or 5 and may be the high speed or low speed. If this is utilized, a shift operation in which the selected system and the non-selected system are switched between the first and second systems (shift up to change the gear stage to the high speed side by one stage, or change to the low speed side by one stage) When the first and second clutches are made, “operation to change the clutch in the engaged state to the disconnected state” and “operation to change the clutch in the disconnected state to the engaged state” By executing it at the same time, the engine torque can be continuously transmitted to the output shaft of the transmission (and hence the drive wheels). As a result, the shift shock can be reduced.

JP 2010-48416 A

  In the DCT, the selected shift speed is changed from “the selected shift speed currently established in the selection mechanism section” (hereinafter also referred to as “the pre-change shift speed”) to “currently established in the non-selection mechanism section. Selected clutch between the first and second clutches when the speed is changed to the high speed side or the low speed side adjacent speed stage (hereinafter also referred to as “changed speed stage”). And the non-selected clutch is replaced. Here, the case where the post-change gear stage is a higher speed gear stage than the pre-change gear stage corresponds to “shift-up”, and the case where the post-change gear stage is a low-speed side gear stage corresponds to “shift down”.

  Hereinafter, among the shift operations (shift-up or shift-down), particularly, the operation at the time of shift-down will be considered. When shifting down, the following operations including the above-described clutch replacement are generally assumed (see FIG. 5 described later for details).

  First, when the selected shift speed is changed from “before-change shift speed” to “after-change shift speed”, the engine torque is maintained at a value corresponding to the operation amount, and the changeover shifts from the non-selected clutch to the selected clutch. The clutch torque of the clutch (junction side clutch) is maintained at zero, and the clutch torque of the clutch (open side clutch) that shifts from the selected clutch to the non-selection clutch by the replacement is reduced from the complete engagement torque (> engine torque). To be adjusted to half-joint torque (<engine torque). That is, the open side clutch is in a “half-joined state” with slip.

  Next, in a state where the engine torque is maintained at the value corresponding to the operation amount, “the engine speed increasing due to the engine torque being larger than the half-joining torque” becomes “the reduction gear ratio of the post-change gear stage”. And the vehicle speed corresponding to the speed of the post-change gear determined by the vehicle speed is reached, the clutch torque of the engagement side clutch is increased from zero and adjusted to the complete engagement torque (> engine torque), and the release side The clutch torque of the clutch is reduced from the half-joint torque and adjusted to zero. With the above operation, the operation at the time of downshifting can be achieved.

  By the way, in general, as a case where a downshift is performed, the driver often demands that the driver wants to accelerate the vehicle, such as increasing the accelerator pedal. Therefore, it is preferable to complete the operation at the time of downshifting in as short a time as possible. For this purpose, it is necessary to shorten the period required for the above-described “increase in engine rotation speed” and the period required for “adjustment of clutch torque” as much as possible. For this purpose, it is necessary to increase the increase gradient of the engine rotation speed as much as possible and to increase the increase gradient of the engagement side clutch torque (the engagement speed of the engagement side clutch) as much as possible.

  However, when the increase gradient of the engine rotation speed is increased and / or the engagement speed of the engagement side clutch is increased, the operation completion time at the time of downshifting (specifically, when the engagement of the engagement side clutch is completed). Thereafter, vibrations are easily generated and continued in the drive system of the vehicle.

  This vibration is caused by the fact that the increase in engine rotation speed stops abruptly when the engagement of the engagement side clutch is completed, so that "the engine inertia torque in the vehicle acceleration direction" is generated in the output shaft of the engine, and This is based on the fact that the magnitude of the torque transmitted to the output shaft of the transmission increases suddenly immediately before and after the completion of the engagement of the connection side clutch.

  The greater the increase gradient of the engine rotation speed and the greater the engagement speed of the engagement side clutch (that is, the shorter the period required for operation during shift down), the greater the degree of vibration. It has been desired to suppress such vibration.

  An object of the present invention is a power transmission control device for a vehicle using a DCT, in which a period required for a shift operation at the time of downshifting is short, and vibration of a drive system that occurs after completion of the operation at the time of downshifting is suppressed. It is to provide what you get.

  The vehicle power transmission control device according to the present invention includes the same “first input shaft (Ai1)”, “second input shaft (Ai2)”, “output shaft (Ao)”, “first mechanism unit (M1) as described above. ) ”And“ second mechanism section (M2) ”, a first clutch (C1), and a second clutch (C2). Here, the plurality of shift stages of the first group are provided with a plurality of odd stages including the first speed, and the plurality of shift stages of the second group are provided with a plurality of even stages including the second speed. Is preferred.

  The power transmission control device is characterized in that the torque of the power source is changed from the “operation amount equivalent value” at the time “when the selected shift stage is changed from the pre-change shift stage to the post-change shift stage” during the shift down operation. After that, the torque of the power source is maintained at “a value smaller than the operation amount equivalent value by a predetermined amount” (> half-junction torque), and then “the rotational speed of the power source is The point is that the torque of the power source is returned (increased) to the “operation amount equivalent value” at a point in time when the predetermined period has elapsed from the time when the rotational speed corresponding to the vehicle speed is reached.

  The inventor has started to generate vibrations in the vehicle drive system after “when the rotational speed of the power source reaches the rotational speed corresponding to the vehicle speed of the post-change gear stage” (and therefore when the engagement of the engagement side clutch is completed). In this state, if the torque of the power source is increased by a predetermined amount at a certain appropriate timing, the “increased torque of the power source” can act in the direction of canceling the vibration, and as a result, the vibration can be suppressed. I found out.

  Thus, as a preparation for increasing the power source torque by a predetermined amount (to ensure an increase in the torque of the power source), in the present invention, “the selected shift speed is changed from the pre-change speed to the post-change speed. At the “changed time point”, the torque of the power source is reduced in advance by a predetermined amount from the operation amount equivalent value.

  Here, the predetermined amount is determined based on a reduction ratio of the pre-change gear stage, a reduction ratio of the post-change gear stage, the semi-junction torque, and the torque of the power source at the first time point. It is preferred that

  “The amount of increase in the torque of the power source” for effectively canceling the vibration is “the torque (output shaft torque) transmitted to the output shaft of the transmission immediately before and after the completion of the engagement of the engagement side clutch. It can be considered that it largely depends on the “increase amount”. On the other hand, immediately before the completion of the engagement of the connection side clutch, the output shaft torque can be determined based on the “speed reduction ratio of the pre-change gear stage” and the “half-connection torque”. Immediately after that, the output shaft torque can be determined based on “the gear ratio after change” and “the torque of the power source”. Therefore, from the above, the increase amount of the output shaft torque from immediately before to immediately after the completion of the engagement of the engagement side clutch is the reduction ratio of the pre-change gear stage, the reduction ratio of the post-change gear stage, the half-joining torque, And the torque of the power source (at the first time point). The above configuration is based on such knowledge.

  Further, it is preferable that the predetermined period is determined based on a vibration cycle of a power transmission system from the power source to the drive wheels, which is determined based on a reduction ratio of the post-change gear. More specifically, through various experiments and simulations, it has been found that the predetermined period is more preferably determined based on a time of 25 to 50% of the vibration period.

  In general, the vibration cycle of the power transmission system from the power source of the vehicle to the drive wheels of the vehicle greatly depends on the reduction gear ratio of the gear stage established in the transmission. Accordingly, the vibration cycle of the power transmission system after completion of the downshift operation can be determined based on the reduction gear ratio of the post-change gear.

  As described above, the cause of the vibration is that the "inertia torque of the engine in the vehicle acceleration direction" is generated on the output shaft of the engine at the time when the engagement of the connection side clutch is completed, and that the connection side clutch is engaged. That is, the magnitude of the output shaft torque increases abruptly immediately before and after completion. Therefore, the vibration of the torque of the input shaft and the output shaft of the transmission starts from a state in which the transition of the torque becomes “upwardly convex” immediately after the completion of the engagement of the engagement side clutch.

  In such a mode of vibration, the inventor has determined that the timing at which the torque of the power source is increased by a predetermined amount is “when the time of 25 to 50% of the vibration period has elapsed since the completion of the engagement of the engagement side clutch. It was found that the vibration can be effectively canceled out. This is because “the time when 25 to 50% of the vibration period has elapsed since the completion of the engagement of the clutch on the engagement side” easily matches the “timing at which the rotational speed of the vibrating power source decreases”. , Based on.

It is the schematic diagram which showed the power transmission control apparatus which concerns on embodiment of this invention. 2 is a graph showing a map defining “stroke-torque characteristics” for the first and second clutches shown in FIG. 1. 2 is a graph showing a map in which a relationship between “accelerator opening” and “engine torque” is referred to by the ECU shown in FIG. 1 in advance. 2 is a graph showing a shift map in which a relationship between “a combination of vehicle speed and accelerator opening” and “selected shift speed” is referred to by the ECU shown in FIG. 1 in advance. It is the time chart which showed an example of the action | operation in the case of a downshift by the power transmission control apparatus which concerns on a comparative example. FIG. 6 is a time chart corresponding to FIG. 5 showing an example of an operation during downshifting by the power transmission control device according to the embodiment of the present invention.

  Hereinafter, a vehicle power transmission control device (this device) according to an embodiment of the present invention will be described with reference to the drawings. This device includes a transmission T / M, a first clutch C1, a second clutch C2, and an ECU. The transmission T / M includes six shift speeds (1st to 6th speed) for forward travel of the vehicle and one shift speed (reverse) for reverse travel of the vehicle.

  The transmission T / M includes a first input shaft Ai1, a second input shaft Ai2, an output shaft Ao, a first mechanism unit M1, and a second mechanism unit M2. The first and second input shafts Ai1 and Ai2 are supported by a case (not shown) so as to be coaxial and relatively rotatable. The output shaft Ao is supported by the case in parallel with the first and second input shafts Ai1 and Ai2 at a position shifted from the first and second input shafts Ai1 and Ai2.

  The first input shaft Ai1 is connected to the output shaft AE of the engine E / G that is a drive source of the vehicle via the first clutch C1. Similarly, the second input shaft Ai1 is connected to the output shaft AE of the engine E / G via the second clutch C2. The output shaft Ao is connected to drive wheels of the vehicle so that power can be transmitted.

  The first mechanism M1 is always meshed with a first-speed drive gear G1i and a first-speed driven gear G1o that are always meshed with each other, and a third-speed drive gear G3i and a third-speed driven gear G3o that are always meshed with each other. High-speed drive gear G5i and 5-speed driven gear G5o, reverse drive gear GRi and reverse driven gear GRo that do not always mesh with each other, reverse idle gear GRd that always meshes with drive gear GRi and driven gear GRo, respectively, and sleeve S1 and S2. The sleeves S1 and S2 are driven by sleeve actuators AS1 and AS2, respectively.

  Of the drive gears G1i, G3i, G5i, GRi, G1i, GRi are fixed so as to rotate integrally with the first input shaft Ai1, and G3i, G5i are supported by the first input shaft Ai1 so as to be relatively rotatable. Of the driven gears G1o, G3o, G5o, and GRo, G1o and GRo are supported so as to be relatively rotatable on the output shaft Ao, and G3o and G5o are fixed so as to rotate integrally with the output shaft Ao.

  The sleeve S1 is always spline-fitted to the hub that rotates integrally with the output shaft Ao so as to be movable in the axial direction. When the sleeve S1 is in the position shown in FIG. 1 (disconnected position), the sleeve S1 is spline-fitted to both the first speed piece that rotates integrally with the driven gear G1o and the reverse piece that rotates integrally with the driven gear GRo. do not do. When the sleeve S1 moves to the left position (first speed position) from the non-connection position, the sleeve S1 is spline-fitted to the first speed piece, and when the sleeve S1 moves to the right position (reverse position), the sleeve S1 becomes the reverse piece. The spline is mated to it.

  The sleeve S2 is always spline-fitted so as to be movable in the axial direction with respect to the hub that rotates integrally with the first input shaft Ai1. When the sleeve S2 is in the position shown in FIG. 1 (disconnected position), the sleeve S2 is spline-fitted to both the third speed piece that rotates integrally with the drive gear G3i and the fifth speed piece that rotates integrally with the drive gear G5i. Do not match. When the sleeve S2 moves to the left position (third speed position) from the non-connection position, the sleeve S2 is spline-fitted to the third speed piece, and when the sleeve S2 moves to the right position (fifth speed position), the sleeve S2 moves to the fifth speed. Spline fit to the piece.

  As described above, in the first mechanism unit M1, when the sleeves S1 and S2 are both adjusted to the non-connection position, a neutral state in which no power transmission system is formed between the first input shaft Ai1 and the output shaft Ao is obtained. When the sleeve S1 moves to the 1st speed position in the neutral state, a power transmission system having a 1st speed reduction ratio is formed (1st speed is established), and when the sleeve S1 moves to the reverse position in the neutral state, the reverse reduction ratio Is formed (reverse is established). When the sleeve S2 moves to the 3rd speed position in the neutral state, a power transmission system having a reduction ratio of 3rd speed is formed (3rd speed is established), and when the sleeve S2 moves to the 5th speed position in the neutral state, A power transmission system having a reduction ratio is formed (5th speed is established).

  The second mechanism portion M2 is always meshed with a second-speed drive gear G2i and a second-speed driven gear G2o that are always meshed with each other, and a fourth-speed drive gear G4i and a fourth-speed driven gear G4o that are always meshed with each other. A high-speed driving gear G6i, a sixth-speed driven gear G6o, and sleeves S3 and S4 are provided. The sleeves S3 and S4 are driven by sleeve actuators AS3 and AS4, respectively.

  The drive gears G2i, G4i, and G6i are all fixed to the second input shaft Ai2 so as to rotate integrally. The driven gears G2o, G4o, G6o are all supported on the output shaft Ao so as to be relatively rotatable.

  The sleeve S3 is always spline-fitted to the hub rotating integrally with the output shaft Ao so as to be movable in the axial direction. When the sleeve S3 is in the position shown in FIG. 1 (non-connection position), the sleeve S3 is splined to both the second speed piece that rotates integrally with the driven gear G2o and the fourth speed piece that rotates integrally with the driven gear G4o. Do not match. When the sleeve S3 is moved to the right position (second speed position) from the non-connection position, the sleeve S3 is spline-fitted to the second speed piece, and when the sleeve S3 is moved to the left position (fourth speed position), the sleeve S3 is fourth speed. Spline fit to the piece.

  The sleeve S4 is always spline-fitted to the hub rotating integrally with the output shaft Ao so as to be movable in the axial direction. When the sleeve S4 is in the position shown in FIG. 1 (disconnected position), the sleeve S4 is not spline-fitted to the sixth speed piece that rotates integrally with the driven gear G6o. When the sleeve S4 moves to the right side position (sixth speed position) from the non-connection position, the sleeve S4 is spline-fitted to the sixth speed piece.

  As described above, in the second mechanism unit M2, when the sleeves S3 and S4 are both adjusted to the non-connection position, a neutral state in which a power transmission system is not formed between the second input shaft Ai2 and the output shaft Ao is obtained. When the sleeve S3 moves to the 2nd speed position in the neutral state, a power transmission system having a reduction ratio of 2nd speed is formed (2nd speed is established). When the sleeve S3 moves to the 4th speed position in the neutral state, the 4th speed A power transmission system having a reduction ratio is formed (fourth speed is established). When the sleeve S4 moves to the 6th speed position in the neutral state, a power transmission system having a 6th speed reduction ratio is formed (6th speed is established). In this specification, “N-speed reduction ratio” (N: a natural number of 1 to 6) means “an input corresponding to the N-speed with respect to the rotational speed of the output shaft Ao when the N-speed is established. "Ratio of the rotational speed of the shaft (Ai1, or, Ai2)".

  The first and second clutches C1 and C2 are coaxially arranged in series in the axial direction. The clutch stroke St1 of the first clutch C1 is adjusted by the clutch actuator AC1. As shown in FIG. 2, the maximum torque (first clutch torque Tc1) that can be transmitted by the first clutch C1 can be adjusted by adjusting the clutch stroke St1. In the state of “Tc1 = 0”, a power transmission system is not formed between the output shaft AE of the engine E / G and the first input shaft Ai1. This state is referred to as “divided state”. In the state of “Tc1> 0”, a power transmission system is formed between the output shaft AE of the engine E / G and the first input shaft Ai1. This state is called a “joined state”. The clutch stroke means the amount of movement of the friction member (not shown) driven by the clutch actuator from the original position (clutch stroke = 0) in the pressure-bonding direction (increase direction of the clutch torque).

  Similarly, the clutch stroke St2 of the second clutch C2 is adjusted by the clutch actuator AC2. As shown in FIG. 2, the maximum torque (second clutch torque Tc2) that can be transmitted by the second clutch C2 can be adjusted by adjusting the clutch stroke St2. Similarly to the first clutch C1, the “separated state” and the “engaged state” are defined for the second clutch C2.

  This device also detects the wheel speed sensor V1 that detects the wheel speed of the vehicle wheel, the accelerator opening sensor V2 that detects the operation amount (accelerator opening) Accp of the accelerator pedal AP, and the position of the shift lever SF. And a brake fluid pressure sensor V4 for detecting the depression force (corresponding to the brake fluid pressure) of the brake pedal BP. Note that the magnitude of the brake fluid pressure (accordingly, the pressing force of the brake pad against the brake disc, the friction braking force) is adjusted according to the depression force of the brake pedal BP.

  Furthermore, this apparatus includes an electronic control unit ECU. The ECU controls the clutch actuators AC1 and AC2 and the sleeve actuators AS1 to AS4 based on the information from the sensors V1 to V4, and the first and second gears of the transmission T / M. The state of the clutches C1 and C2 is controlled. Thus, this device is a power transmission device using a double clutch transmission (DCT).

  In this device, the torque (engine torque) Te of the output shaft AE of the engine E / G is normally controlled to a value (opening equivalent value) Tem corresponding to the accelerator opening degree Accp. The opening degree equivalent value Tem is set to increase as the accelerator opening degree Accp increases, for example, as shown in FIG. The engine torque Te can be adjusted by adjusting the fuel injection amount, the ignition timing, and the like in the engine E / G.

  In this apparatus, when the position of the shift lever SF is at the position corresponding to the “automatic mode”, the transmission T / M is controlled based on the shift map shown in FIG. 4 stored in the ROM (not shown) in the ECU. A gear position is determined. More specifically, the region of which gear stage on the shift map is a combination of the vehicle speed calculated based on the wheel speed obtained from the wheel speed sensor V1 and the accelerator opening degree Accp obtained from the accelerator opening degree sensor V2. Depending on whether or not it corresponds to, one shift speed to be achieved (hereinafter referred to as “selected shift speed”) is selected. For example, when the current vehicle speed is α and the current accelerator opening is β (see the black dots shown in FIG. 4), “3rd speed” is selected as the selected shift speed.

  The shift map shown in FIG. 4 can be obtained by repeatedly performing an experiment that matches the optimum shift speed with respect to the combination of the vehicle speed and the accelerator opening while changing the combination in various ways. The shift map is stored in a ROM in the ECU. When the shift lever SF is in a position corresponding to the “manual mode”, the selected shift speed is selected based on the operation of the shift lever SF by the driver.

  Hereinafter, for convenience of explanation, a system including the first clutch C1, the first input shaft Ai1, and the first mechanism unit M1 is referred to as a “first system”, and the second clutch C2, the second input shaft Ai2, The system composed of the two mechanism units M2 is referred to as a “second system”. Further, the first and second mechanism portions M1 and M2, the first and second clutches C1 and C2, the first and second input shafts Ai1 and Ai2, and the first and second systems correspond to the selected shift speed. These are called “selection mechanism”, “selection clutch”, “selection input shaft”, and “selection system”, respectively, and the ones that do not correspond to the selected shift stage are “nonselection mechanism” and “nonselection clutch”, respectively. These are called “non-selected input shaft” and “non-selected system”.

  As described above, in the transmission T / M, an odd-numbered stage including the first speed (first speed, third speed, and fifth speed) can be selectively established in the first mechanism unit M1, and the second mechanism unit M2 Even-numbered stages including 2nd speed (2nd speed, 4th speed, 6th speed) can be selectively established. Therefore, every time the selected shift stage is changed (shifted up) from the current shift stage to a shift stage that is one speed higher than the current shift stage, or the selected shift stage changes from the current shift stage to the current shift stage. Each time the gear is changed (shifted down) to the lower speed side by one stage, the selected system and the non-selected system are switched between the first and second systems.

  In this device, the selected gear stage is established in the selection mechanism, and the clutch torque of the selected clutch is adjusted to a torque larger than the engine torque Te (hereinafter referred to as “completely-engaged torque”), and the selected clutch slips. It is controlled to a completely joined state without accompanying. On the other hand, the “adjacent shift speed” is established in the non-selection mechanism, and the clutch torque of the non-selection clutch is adjusted to zero, and the non-selection clutch is controlled to be disconnected.

  The adjacent shift speed is a shift speed that will be (and will) be selected next to the currently selected shift speed. Specifically, the shift speed on the high speed side or the low speed side is only one speed with respect to the currently selected shift speed. It is a step. In this device, one of the well-known methods is used to shift up and down based on the transition of the driving state of the vehicle up to now (for example, transition of vehicle speed, transition of engine torque, transition of accelerator opening, etc.). Which is to be done next is predicted. If it is predicted that an upshift will be made, the adjacent shift speed is set to “a shift speed that is one speed higher than the currently selected shift speed”, and if it is predicted that a downshift will be performed, The gear position is set to “a gear position that is one speed lower than the currently selected gear position”.

  The “completely connecting torque” can be set to an arbitrary value within a range larger than the engine torque Te (that is, within a range in which the selected clutch does not slip). For example, the complete joining torque may be set to a maximum value Tmax (constant) (see FIG. 2) or may be adjusted to a value that is larger than the engine torque by a constant value.

  As described above, when the selected shift speed is maintained at a certain shift speed, the selected shift speed is reduced between the output shaft AE of the engine E / G and the output shaft Ao of the transmission T / M via the selected system. A power transmission system having a ratio is formed. As a result, engine torque can be transmitted to the drive wheels via the selected system.

(Control during shifting)
Next, only one speed is selected from the speed stage where the selected speed stage is currently established (hereinafter also referred to as “prior speed speed stage”) due to changes in the vehicle state (combination of vehicle speed and accelerator opening). A description will be given of an operation (shift operation) when the speed is changed to the first gear (hereinafter also referred to as “changed gear”). Here, the case where the post-change gear stage is a gear stage on the high speed side by one stage relative to the pre-change gear stage corresponds to “shift up”, and the post-change gear stage is only one stage relative to the pre-change gear stage. The case of the low speed side shift stage corresponds to “shift down”.

  In this device, during the shift operation, the operation of exchanging the selected clutch and the non-selected clutch between the first and second clutches is executed at the same time. More specifically, “operation to change a clutch that shifts from a non-selection clutch to a selection clutch (hereinafter also referred to as“ joining clutch ”) from a split state to a joint state” and “transition from a selection clutch to a non-selection clutch” The operation of changing the clutch (hereinafter also referred to as “disengagement side clutch”) from the engaged state to the disconnected state is executed at the same time. Thereby, when the up-shift or the down-shift is performed while the vehicle is running, the engine torque can be transmitted to the output shaft AE (and hence the drive wheels) of the transmission T / M without interruption.

(Control when shifting up)
Hereinafter, the control at the time of upshifting by the present apparatus will be described more specifically. At the time of shift up, the clutch torque of the engagement side clutch is increased from zero and adjusted to “selection side torque”, and the clutch torque of the release side clutch is reduced from the complete engagement torque to become “non-selection side torque”. Adjusted. The “selection side torque” is a torque larger than zero and smaller than the complete joining torque, and the “non-selection side torque” is a torque larger than zero and smaller than the selection side torque. In addition, at the same time, the engine torque Te that has been adjusted to the opening equivalent value Tem is decreased from the opening equivalent value Tem (see FIG. 3).

  Thereafter, the engine torque Te is increased to the opening equivalent value Tem. In addition, at the same time, the clutch torque of the engagement side clutch is increased from the “selection side torque” to be adjusted to the “complete engagement torque”, and the clutch torque of the release side clutch is decreased from the “non-selection side torque”. And adjusted to zero. With the above operation, the shift operation at the time of upshifting is achieved.

(Control during shift down)
Next, the control at the time of downshifting by this apparatus will be described more specifically. First, as a preparation for this, a shift operation at the time of downshifting according to a comparative example will be described with reference to FIG.

  FIG. 5 is due to the fact that the driver increased the accelerator opening degree Accp to accelerate the vehicle while the vehicle was traveling at the fourth speed (the selected gear stage was at the fourth speed) before time t1. An example of the operation according to the comparative example when the selected shift speed is changed from the fourth speed to the third speed at time t1 will be described. In this example, the 4th speed and the 3rd speed correspond to the “speed stage before change” and the “speed stage after change”, respectively, and the first and second clutches C1 and C2 respectively It corresponds to “clutch” and “release side clutch”. The first and second input shafts Ai1 and Ai2 are also referred to as “joining side input shaft” and “release side input shaft”, respectively. Further, “N speed reduction ratio” (N: natural number of 1 to 6) is represented as “GN”. For example, the reduction ratio of the fourth speed is represented as “G4”.

  In this example, before the time t1, the fourth speed is established in the second mechanism part M2, the third speed is established in the first mechanism part M1, and the clutch torque Tc2 of the release side clutch C2 is the torque T1 for complete joining. (> Engine torque Te) is adjusted (disengagement side clutch C2 is in the engaged state), clutch torque Tc1 of engagement side clutch C1 is adjusted to zero (the engagement side clutch C1 is in the disconnected state), and engine torque Te is It changes at the opening equivalent value Tem, and the rotational speed (engine rotational speed) Ne of the output shaft AE of the engine E / G is determined from the “fourth speed reduction ratio G4” and the “vehicle speed”. "Corresponding rotational speed" (= rotational speed Ni2 of the release side input shaft Ai2). The torque Ti1 of the joining side input shaft Ai1 is maintained at zero, and the torque Ti2 of the opening side input shaft Ai2 changes at the same value (= opening equivalent value Tem) as the engine torque Te. The torque To of the output shaft Ao changes with the value “G4 · Tem”.

  When the selected shift speed is changed from the 4th speed to the 3rd speed at time t1, on the basis of this, the engagement side clutch torque is maintained with the engine torque Te maintained at the opening equivalent value Tem after time t1. Tc1 is still maintained at zero, and the release side clutch torque Tc2 is reduced from the full joining torque T1 (> engine torque Te) to be adjusted to the half joining torque Tx (0 <Tx <engine torque Te). In other words, the connection side clutch C1 is still maintained in the disconnected state, while the release side clutch C2 is shifted from the “completely connected state” without slipping to the “half-joined state” with slipping. The magnitude of the half-joining torque Tx can be determined in advance through various experiments.

  As a result, after the time t1, in a state where the engine torque Te is maintained at the opening-equivalent value Tem, the engine rotational speed Ne is “when the engine torque Te is greater than the half-joining torque Tx”. It increases from the “fourth speed corresponding to the vehicle speed” (= Ni2). The joint-side input shaft torque Ti1 is still maintained at zero, and the open-side input shaft torque Ti2 changes with the semi-joint torque Tx. The output shaft torque To changes with the value “G4 · Tx” (> 0). Since “Tem> Tx> 0”, the relationship “G4 · Tem”> “G4 · Tx”> 0 is established. Therefore, before and after time t1, the output shaft torque To (and hence the vehicle drive torque) decreases, but the vehicle drive torque is not interrupted (becomes zero).

  At time t2, the increasing engine rotational speed Ne is determined from the “third speed reduction ratio G3” and the “vehicle speed”, and “the third speed corresponding to the vehicle speed” (= the rotational speed of the joint-side input shaft Ai1). When reaching Ni1), based on this fact, the engagement-side clutch torque Tc1 is increased from zero in a state where the engine torque Te is maintained at the opening equivalent value Tem after the time t2, and the complete engagement torque T1 (> The engine torque Te) is adjusted, and the release side clutch torque Tc2 is reduced from the half-joining torque Tx to zero. That is, the engagement side clutch C1 is shifted from the disconnected state to the fully engaged state, and the open side clutch C2 is shifted from the semi-connected state to the disconnected state. Thereby, the shift operation at the time of downshifting according to the comparative example is completed.

  As a result, after the time t2, the open-side input shaft torque Ti2 is maintained at zero while the engine torque Te is maintained at the opening degree equivalent value Tem. Further, the engine rotation speed Ne is maintained at the “third-speed rotation speed corresponding to the vehicle speed” (= Ni1), the joint-side input shaft torque Ti1 changes at the same value (= Tem) as the engine torque Te, and the output shaft torque To It changes (should be) at the value “G3 · Tem”. Since “G3> G4” and “Tem> Tx”, the relationship “G3 · Tem”> “G4 · Tx”> 0 is established. Therefore, before and after time t2, the output shaft torque To (accordingly, the driving torque of the vehicle) increases rapidly.

  However, as shown after time t2 in FIG. 5, after the completion of the shift operation at the time of downshifting (specifically, when the engagement of the engagement side clutch C1 is completed), vibration is generated in the drive system of the vehicle. To do. In FIG. 5, after time t2, vibrations are generated in the engine rotational speed Ne, the joining side input shaft torque Ti1, and the output shaft torque To.

  This vibration is caused when the increase in the engine rotational speed Ne is suddenly stopped at the time when the engagement of the engagement side clutch C1 is completed, so that “the inertia torque of the engine E / G in the vehicle acceleration direction” is applied to the engine output shaft AE. This is considered to be based on the fact that the output shaft torque To suddenly increases immediately before and after the completion of the engagement of the engagement side clutch C1, as described above.

  In general, as a case where a downshift is performed, the driver often requests “accelerate the vehicle”, for example, the driver increases the accelerator pedal as in the example shown in FIG. Therefore, it is preferable that the shift operation at the time of downshifting is completed in a short period as much as possible. For this purpose, it is necessary to shorten the period required for the above-described “increase in engine rotation speed” and the period required for “adjustment of clutch torque” as much as possible. For this purpose, it is necessary to increase the increase gradient of the engine rotation speed as much as possible and to increase the increase gradient of the engagement side clutch torque (the engagement speed of the engagement side clutch) as much as possible.

  However, the greater the gradient of increase in engine rotation speed and the greater the engagement speed of the engagement-side clutch (that is, the shorter the period required for shifting operation during downshifting), the greater the degree of vibration. From the above, it is desired that the period required for the shift operation at the time of downshifting is short and that the above vibration is suppressed.

  Therefore, in the present apparatus, in order to cope with such a request, as shown in FIG. 6 corresponding to FIG. 5, during the shift operation at the time of downshifting, an operation different from the comparative example is performed in the following points. In FIG. 6, a thin broken line indicates the operation shown in FIG. 5 according to the comparative example.

  That is, in this device, at the time point t1 when the selected shift speed is changed from the pre-change speed (fourth speed) to the post-change speed (third speed), the engine torque Te is changed from the opening equivalent value Tem to a predetermined amount a (> 0) is decreased. After time t1, the engine torque Te is maintained at “Tem-a” (> half-joining torque Tx). Thereafter, “when a predetermined period“ b · C ”has elapsed from time t2 when the increasing engine rotational speed Ne has reached“ the rotational speed Ni1 corresponding to the third vehicle speed ”(= the rotational speed Ni1 of the joint-side input shaft Ai1). The engine torque Te is returned (increased) to the opening equivalent value Tem.

  The present inventor stated that, in a state where vibration has started in the vehicle drive system after “the time when the engine rotational speed reaches the rotational speed corresponding to the vehicle speed of the post-change gear stage” (time t2 in FIG. 6), It was found that when the engine torque is increased by a predetermined amount a at a proper timing, the “increase in engine torque” can act in the direction of canceling the vibration, and as a result, the vibration can be suppressed (in FIG. (See transitions (solid line) of the engine rotational speed Ne, the joint-side input shaft torque Ti1, and the output shaft torque To after t2.)

  In this device, as a preparation for increasing the engine torque Te by the predetermined amount a in this way (to ensure an increase in the engine torque Te), “the selected shift speed is changed from the shift speed before the change to the shift speed after the change. The engine torque Te is reduced in advance by a predetermined amount a from the opening-equivalent value Tem at the “time when it is performed” (time t1 in FIG. 6). That is, in the example shown in FIG. 6, the release side clutch torque Tc2 and the engine torque Te are started to decrease simultaneously. It should be noted that the engine torque Te may be decreased from the opening equivalent value Tem by a predetermined amount a between time t1 and time t2. Hereinafter, “the magnitude of the predetermined amount a” and “a timing when the engine torque Te is increased by the predetermined amount a and returned to the opening equivalent value Tem” will be described.

<Size of the predetermined amount a>
The magnitude of the predetermined amount a can be determined based on the speed reduction ratio of the pre-change gear stage, the speed reduction ratio of the post-change gear stage, the semi-junction torque, and the engine torque. In the example shown in FIG. 6, the predetermined amount a can be determined based on the reduction ratio G4 for the fourth speed, the reduction ratio G3 for the third speed, the torque Tx for half joining, and the engine torque Te (= Tem). The reason for this is as follows.

  That is, the “increase amount of the engine torque” (= predetermined amount a) for effectively canceling the vibration is “an increase amount of the output shaft torque To immediately before and after the completion of the engagement of the engagement side clutch C1”. It can be thought that it depends heavily. Here, as described above, immediately before the completion of the engagement of the engagement side clutch C1 (immediately before the time t2), the output shaft torque To is represented by “G4 · Tx”, and immediately after the completion of the engagement of the engagement side clutch C1. At (immediately after time t2), the output shaft torque To is represented by “G3 · Tem”. Accordingly, “the increase amount of the output shaft torque To from immediately before to after the completion of the engagement of the engagement side clutch C1” is expressed by “G3 · Te−G4 · Tx”. From the above, the magnitude of the predetermined amount a can be determined based on the reduction ratio of the pre-change gear stage, the reduction ratio of the post-change gear stage, the semi-joining torque, and the engine torque. As the “engine torque”, the value Tem at “the time point when the selected shift speed is changed from the shift speed before change to the shift speed after change” (time t1 in FIG. 6) can be used. Further, the predetermined amount a can be determined based on an attenuation coefficient when the vibration is attenuated as time elapses. This attenuation coefficient can be obtained in advance through various experiments.

<Time when engine torque Te is returned to Tem>
The time when the engine torque Te starts to return toward Tem is considered as “a time when a predetermined period has elapsed from the time when the engine speed reaches the speed corresponding to the vehicle speed of the post-change gear stage (time t2 in FIG. 6)”. The “predetermined period” is determined based on the “vibration cycle” of the power transmission system from the engine to the drive wheels after the shift operation. In general, the vibration period of the power transmission system from the vehicle engine to the drive wheels greatly depends on the reduction gear ratio of the gear stage established in the transmission. Therefore, the “vibration cycle” (period C in FIG. 6) of the power transmission system after the completion of the shift-down shift operation is based on the reduction gear ratio of the post-change gear stage (the third gear reduction ratio G3 in FIG. 6). Determined. Each “vibration cycle” for each gear position can be acquired in advance through various experiments.

  As described above, the cause of the vibration is that the "inertia torque of the engine in the vehicle acceleration direction" is generated on the output shaft of the engine at the time when the engagement of the connection side clutch is completed, and that the connection side clutch is engaged. That is, the magnitude of the output shaft torque increases abruptly immediately before and after completion. Therefore, the vibration of the torque of the input shaft and the output shaft of the transmission starts from a state in which the transition of the torque becomes “upwardly convex” immediately after the completion of the engagement of the engagement side clutch.

  In this way, the present inventor, in the mode of vibration that always starts from “convex upward”, the “predetermined period” is 25 to 50% of the “vibration period” (period C in FIG. 6). It has been found that the vibration can be effectively canceled out when it is determined (see period “b · C” in FIG. 6, where coefficient b = 0.25 to 0.50). This is because “at the time when 25 to 50% of the vibration period has elapsed since the completion of the engagement of the clutch on the engagement side” easily matches the “timing at which the vibrating engine rotation speed decreases”. It is considered to be based. A response delay inevitably occurs in adjusting the engine torque Te. Therefore, it is preferable that the command to the engine to return the engine torque Te to Tem is made earlier by the response delay than the target timing at which the engine torque Te actually starts to return to Tem.

  As shown in FIG. 6, when the engine torque Te is returned toward Tem, it is preferable to increase the engine torque Te so that the increasing speed of the engine torque Te gradually decreases. According to this, compared with the case where the engine torque Te is increased stepwise toward Tem, the vibration can be canceled more effectively.

  As described above, according to the above embodiment, the period required for the shift operation at the time of downshifting is short, and vibration of the drive system that occurs after completion of the operation at the time of downshifting can be suppressed.

  T / M: manual transmission, E / G: engine, C1, C2: first, second clutch, Ai1, Ai2: first, second input shaft, Ao: output shaft, M1, M2: first, first 2 mechanical parts, AC1, AC2 ... clutch actuator, AS1 to AS4 ... sleeve actuator, V1 ... wheel speed sensor, V2 ... accelerator opening sensor, V3 ... shift position sensor, V4 ... brake fluid pressure sensor, ECU ... electronic control unit

Claims (5)

A first input shaft to which power is input from a power source of the vehicle; a second input shaft to which power is input from the power source; an output shaft that outputs power to the drive wheels of the vehicle; and a plurality of all speed stages And establishes a power transmission system between the first input shaft and the output shaft by selectively establishing any one of one or a plurality of shift speeds of a first group that is a part of the first group. A first mechanism part that selectively achieves an open state in which no power transmission system is formed between the first input shaft and the output shaft without establishing any of the state or the first group of gears; and A power transmission system is formed between the second input shaft and the output shaft by selectively establishing one or a plurality of gears of the second group, which is the remaining of all gears. The second input shaft and the output shaft without establishing either the established state or the second group of gears A transmission having a second mechanism for selectively achieving an open state of not forming a power transmission system, the between,
A first clutch that is interposed between an output shaft of the drive source and the first input shaft, and is capable of adjusting a first clutch torque that is a maximum value of torque that can be transmitted by the first clutch. When,
A second clutch that is interposed between an output shaft of the drive source and the second input shaft, and is capable of adjusting a second clutch torque that is a maximum value of torque that can be transmitted by the second clutch. When,
Based on the running state of the vehicle, the first and second mechanism units, the first and second clutch torques are controlled, and the torque of the power source is controlled by the driver of the vehicle. Control means for controlling to an operation amount equivalent value that is a value according to the operation amount;
A vehicle power transmission control device comprising:
The control means includes
Based on the running state of the vehicle, a selected shift stage that is a shift stage to be selected from among the plurality of shift stages is determined,
The control means includes
Of the first and second mechanisms, the selection mechanism corresponding to the selected gear is controlled to establish the selected gear, and the first and second clutches correspond to the selection mechanism. The clutch torque of the selected clutch is adjusted to a fully engaged torque that is larger than the torque of the power source, and the selected clutch is adjusted to a fully engaged state without slipping, and the selected one of the first and second mechanism portions is selected. The non-selection mechanism portion that does not correspond to the shift speed is controlled to establish a high-speed or low-speed adjacent shift speed with respect to the selected shift speed, and does not correspond to the selection mechanism section among the first and second clutches. It is configured to adjust the clutch torque of the non-selected clutch to zero and adjust the non-selected clutch to the disconnected state,
The control means includes
The selected gear stage is established in the selection mechanism unit, the adjacent gear stage on the low speed side is established with respect to the selected gear stage in the non-selection mechanism unit, and the clutch torque of the selected clutch is the torque for complete engagement. The clutch torque of the non-selected clutch is adjusted to zero, the torque of the power source is adjusted to the operation amount equivalent value, and the rotational speed of the power source is currently established in the selection mechanism unit In a state where the rotational speed corresponding to the vehicle speed of the pre-change gear determined by the reduction ratio of the pre-change gear that is the selected gear and the speed of the vehicle is maintained, the selected gear is the pre-change gear. The first and second clutches are based on the fact that the first time point from which the gear is changed to the post-change gear which is the adjacent gear on the low speed side currently established in the non-selection mechanism unit has arrived. Before When replacement of selected clutches and the non-selected clutch is performed,
The clutch torque of the engagement side clutch that shifts from the non-selection clutch to the selection clutch is maintained at zero by the replacement, and the clutch torque of the release side clutch that shifts from the selection clutch to the non-selection clutch by the replacement is completely engaged. The torque of the power source is reduced to a half-joint torque that is smaller than the full-joint torque and greater than zero, and is decreased from the operation amount equivalent value to be larger than the half-joint torque and the operation. Adjust to a value that is smaller than the amount equivalent by a predetermined amount,
In this state, the rotational speed of the power source that increases due to the torque of the power source being greater than the half-joining torque is determined from the reduction gear ratio of the post-change gear stage and the speed of the vehicle. Based on the arrival of a second time point at which the vehicle speed corresponding to the speed of the post-change gear is reached, the clutch torque of the engagement side clutch is increased from zero to adjust to the complete engagement torque, and the release The clutch torque of the side clutch is reduced from the half-joining torque and adjusted to zero, and the torque of the power source is maintained at a value smaller than the operation amount equivalent value by the predetermined amount,
In this state, based on the elapse of a predetermined period from the second time point, the torque of the power source is increased from a value smaller than the operation amount equivalent value by the predetermined amount and returned to the operation amount equivalent value. A vehicle power transmission control device configured as described above. The power transmission control device for a vehicle according to claim 1,
The predetermined amount is
Vehicle power transmission control determined based on the reduction ratio of the pre-change gear, the reduction ratio of the post-change gear, the semi-junction torque, and the torque of the power source at the first time point. apparatus. In the vehicle power transmission control device according to claim 1 or 2,
The predetermined period is
A power transmission control device for a vehicle, which is determined based on a vibration cycle of a power transmission system from the power source to the drive wheels, which is determined based on a reduction gear ratio of the post-change gear. The vehicle power transmission control device according to claim 3,
The predetermined period is
A power transmission control device for a vehicle, which is determined based on a time of 25 to 50% of a vibration cycle of the power transmission system, which is determined based on a reduction gear ratio of the post-change gear. The power transmission control device for a vehicle according to any one of claims 1 to 4,
The control means includes
The power transmission of the vehicle is configured to increase the torque of the power source so that the increasing speed of the torque of the power source gradually decreases when returning to the operation amount equivalent value while increasing the torque of the power source. Control device.

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