JP6219211B2 - Control device for transmission - Google Patents

Description

  In the present invention, a continuously variable transmission mechanism and a fixed-stage transmission mechanism provided in parallel with each other are selectively used as a transmission mechanism for transmitting power from a power source of the vehicle to a driving wheel of the vehicle in a shifted state. The present invention relates to a transmission control device.

  Conventionally, as a control device for this type of transmission, for example, the one disclosed in Patent Document 1 is known. This transmission includes a belt-type continuously variable transmission mechanism and a gear-type fixed-stage transmission mechanism having a fixed transmission ratio on the low speed side as a transmission mechanism for transmitting the power of the internal combustion engine to the drive wheels in a state of being changed. have. In the transmission, the first and second clutches are provided between the internal combustion engine and the drive wheels, and a power transmission path between the internal combustion engine and the drive wheels is established by controlling the first and second clutches by the control device. By switching, the continuously variable transmission mechanism and the fixed-stage transmission mechanism are selectively used. Specifically, a fixed speed change mechanism is used when the vehicle starts, and a continuously variable speed change mechanism is used when the start ends and the vehicle shifts to a running state.

Japanese Patent No. 4996123

  In recent years, in order to improve the fuel efficiency of a vehicle, there has been a technology for automatically stopping an internal combustion engine when a predetermined stop condition is satisfied and restarting the internal combustion engine when a predetermined restart condition is satisfied during the automatic stop. Are known. This stop condition includes conditions such as the ignition switch being ON, the vehicle speed of the vehicle being a predetermined speed or less, the accelerator pedal not being depressed, and the brake pedal being depressed. In this case, since the stop condition includes that the vehicle speed is equal to or lower than a predetermined speed, the internal combustion engine may be automatically stopped not only when the vehicle is stopped but also during traveling. Further, in a general belt-type continuously variable transmission mechanism, a hydraulic ratio is applied to the movable sheave of the pulley, the movable sheave is moved with respect to the fixed sheave, and the effective diameter of the pulley is changed to change the gear ratio. It is changed steplessly. The hydraulic pressure is supplied using an oil pump whose drive source is an internal combustion engine.

  In the case where the above-described conventional control device is applied to the transmission having the continuously variable transmission mechanism as described above, the following problems may occur when the internal combustion engine is automatically stopped. That is, in the conventional control device, the continuously variable transmission mechanism is selected while the vehicle is traveling as described above. (Referred to as “traveling I / S”). In this case, since the condition of the automatic stop includes that the accelerator pedal is not depressed, the gear ratio of the continuously variable transmission mechanism is controlled to the low speed side accordingly just before the start of the traveling I / S. There may be. Further, when the internal combustion engine is restarted from the running I / S, in order to obtain a good acceleration response of the vehicle, the transmission ratio of the continuously variable transmission mechanism is set to the low speed side in order to transmit a larger torque to the drive wheels. In order to quickly control the speed ratio to the low speed side, the speed ratio of the continuously variable transmission mechanism during the traveling I / S is held at the low speed value immediately before the start. Is preferred.

  However, as described above, since the oil pump is driven by the internal combustion engine, the oil pressure is not gradually supplied from the oil pump to the continuously variable transmission mechanism during traveling I / S. The thrust that maintains the effective diameter of the pulley is reduced. Further, although the internal combustion engine is automatically stopped during the traveling I / S, the driving wheel rotates with inertia, and therefore the driving wheel side pulley is driven by the driving wheel. As described above, during traveling I / S, the effective diameter of the pulley, that is, the gear ratio of the continuously variable transmission mechanism, may not be maintained on the low speed side but may vary on the high speed side. At the time of restart, it takes time to control the speed ratio of the continuously variable transmission mechanism to the low speed side, and as a result, good acceleration response of the vehicle cannot be obtained.

  The present invention has been made in order to solve the above-described problems, and can appropriately select a speed change mechanism during an automatic stop during traveling, thereby accelerating the vehicle when the power source is subsequently restarted. It is an object of the present invention to provide a control device for a transmission that can improve responsiveness.

  In order to achieve the above object, the invention according to claim 1 is directed to driving wheels of the vehicle V in a state where the power from the power source of the vehicle V (engine 3 in the embodiment (hereinafter, the same applies to this section)) is shifted. As a transmission mechanism for transmitting to DW and DW, a continuously variable transmission mechanism (CVT 70) and a meshing fixed-stage transmission mechanism (LOWT80) provided in parallel with each other are selectively used in the control device of the transmission 1. The power source is automatically stopped when a predetermined stop condition is satisfied, and is restarted when a predetermined restart condition is satisfied during the automatic stop. In some cases, the automatic transmission stop when the power source is automatically stopped is included, and the continuously variable transmission mechanism includes fixed sheaves 14a and 16a and movable sheaves 14b and 16b, respectively, and an oil chamber (drive pulley oil chamber 14c, driven pulley oil). 16c) each having a pair of pulleys (drive pulley 14 and driven pulley 16) and a belt 17 wound around the pair of pulleys, from the oil pump 7 using the power source as the drive source to the oil chamber The movable sheaves 14b, 16b are moved relative to the fixed sheaves 14a, 16a by the oil pressure of the supplied oil, and the gear ratio is changed steplessly by changing the effective diameters of the pair of pulleys. The fixed sheave 14a, 16a and the movable sheaves 14b, 16b are configured to be sandwiched between the fixed sheaves 14a, 16a, and the fixed speed transmission mechanism is configured to shift the power of the power source at a predetermined fixed speed ratio on the low speed side. And a selection means (ECU2) for selecting one of a continuously variable transmission mechanism and a fixed-stage transmission mechanism as a transmission mechanism, and a transmission ratio ratio indicating a transmission ratio of the continuously variable transmission mechanism Gear ratio parameter detecting means for detecting a meter (drive pulley angle sensor 112, driven pulley angle sensor 113, ECU 2, step 5 in FIG. 8), and the selecting means is a stepless speed change mechanism during automatic stop during traveling. In the case of selection, a predetermined continuously variable transmission including that the gear ratio of the continuously variable transmission mechanism represented by the detected gear ratio parameter (CVT gear ratio RATCVT) is greater than or equal to the predetermined gear ratio RATREF (step 9). When the continuation condition is satisfied, the continuously variable transmission mechanism is continuously selected (step 13). When the continuously variable transmission continuation condition is not satisfied, the transmission mechanism is switched from the continuously variable transmission mechanism to the fixed speed transmission mechanism. (Step 14).

  According to this configuration, the power source of the vehicle is automatically stopped when a predetermined stop condition is satisfied, and is restarted when a predetermined restart condition is satisfied during the automatic stop. This automatic stop includes an automatic stop during driving in which the power source is automatically stopped when the vehicle is driving. In addition, a continuously variable transmission mechanism and a meshing fixed-stage transmission mechanism provided in parallel with each other are selectively used as a transmission mechanism for transmitting power from the power source to the drive wheels in a state of being shifted.

  The continuously variable transmission mechanism is a belt-type continuously variable transmission mechanism having a pair of pulleys and belts, and the oil pressure supplied to the oil chamber of each pulley from an oil pump having a power source as a driving source is used for each pulley. The gear ratio is changed steplessly by changing the effective diameter, and the belt is sandwiched between the fixed sheave and the movable sheave of each pulley. The fixed stage speed change mechanism is configured to change the power of the power source at a predetermined fixed speed ratio on the low speed side. Thus, since the gear ratio of the fixed-stage transmission mechanism is fixed, unlike the belt-type continuously variable transmission mechanism described above, it does not fluctuate on the high speed side during automatic stop during traveling.

  Further, when the continuously variable transmission mechanism is selected as the transmission mechanism during the automatic stop during traveling, the transmission ratio of the continuously variable transmission mechanism represented by the detected transmission ratio parameter is greater than or equal to the predetermined transmission ratio (low speed side). When a predetermined continuously variable transmission continuation condition including a certain condition is satisfied, the continuously variable transmission mechanism is continuously selected. Further, when the continuously variable transmission continuation condition is not satisfied, that is, when the transmission ratio of the continuously variable transmission mechanism becomes smaller than the predetermined transmission ratio (high speed side), the transmission mechanism is moved from the continuously variable transmission mechanism to the low speed side. Is switched to a fixed-stage transmission mechanism having a transmission ratio of. As a result, when the power source is restarted from the automatic stop during traveling, the power from the power source can be quickly transmitted to the drive wheels while shifting at the low speed gear ratio, thereby improving the acceleration response of the vehicle. Can do. In addition, as long as the continuously variable transmission continuation condition is satisfied, the continuously variable transmission mechanism is continuously selected, so that the power of the power source can be finely shifted when the power source is subsequently restarted. Can be increased.

According to a second aspect of the present invention, in the control device for the transmission 1 according to the first aspect of the present invention, the control device further includes a hydraulic pressure detection means (hydraulic sensor 114) for detecting a hydraulic pressure in at least one oil chamber of the pair of pulleys. The shift continuation condition further includes that the detected oil pressure in the oil chamber (oil chamber oil pressure PPU) is larger than a predetermined oil pressure PREF (step 10 in FIG. 8).

  As described above, the continuously variable transmission mechanism is a belt type. For this reason, when the power source is restarted from the automatic stop during traveling, even if the gear ratio of the continuously variable transmission mechanism is low, the oil pressure in the oil chamber of the pulley is small, and the gap between the fixed sheave and the movable sheave is low. Since the belt clamping force (hereinafter referred to as “belt clamping force”) is small, the belt slips with respect to the pulley, and torque transmission loss may occur. As a result, the acceleration response of the vehicle may decrease. is there. On the other hand, unlike the continuously variable transmission mechanism, the fixed-stage transmission mechanism is a meshing type, so that torque transmission loss due to slippage of the belt with respect to the pulley does not occur.

  According to the configuration described above, the continuously variable speed continuation condition described in the description of the invention according to claim 1 further includes that the detected hydraulic pressure in the oil chamber is larger than a predetermined hydraulic pressure. As a result, when the continuously variable transmission mechanism is selected during the automatic stop during traveling, the oil pressure in the oil chamber is greater than the predetermined oil pressure in addition to the gear ratio of the continuously variable transmission mechanism being greater than or equal to the predetermined gear ratio. In other words, the continuously variable transmission mechanism is continuously selected on the condition that the belt clamping force is relatively large. Even if the gear ratio of the continuously variable transmission mechanism is greater than or equal to a predetermined gear ratio, the transmission mechanism is switched to the fixed-stage transmission mechanism when the hydraulic pressure in the oil chamber decreases below the predetermined hydraulic pressure, that is, when the belt clamping force decreases. . Therefore, when the power source is restarted thereafter, the belt can be prevented from slipping with respect to the pulley, and the acceleration response of the vehicle can be improved with certainty.

  According to a third aspect of the present invention, in the control device for the transmission 1 according to the first or second aspect, a travel distance acquisition means (ECU2, FIG. 2) for acquiring the travel distance of the vehicle V after the start of the automatic stop during travel is started. 8) and a travel time acquisition means (ECU2) for acquiring the travel time of the vehicle V after the start of the automatic stop during travel, and the continuously variable speed continuation condition is the acquired travel distance (I / S accumulated travel distance SDI / S) is smaller than the predetermined distance DREF, and the acquired travel time (timer value tI / S of the I / S timer) is smaller than the predetermined time TMREF (step 11) 12) is further included.

  When calculating (detecting) the gear ratio of the continuously variable transmission mechanism based on the detection result of a rotational speed sensor such as an electromagnetic pickup type, the pulley rotation speed becomes very low due to a decrease in the vehicle speed during automatic stop during traveling. In some cases, the gear ratio cannot be calculated properly because an appropriate detection result of the rotation speed sensor cannot be obtained. In that case, there is a possibility that selection of the transmission mechanism based on the transmission ratio described in the invention according to claim 1 cannot be performed appropriately.

  According to the above-described configuration, the vehicle travel distance and travel time (hereinafter referred to as “travel distance during I / S” and “travel time during I / S”, respectively) after the automatic stop during travel is started are acquired. Is done. Further, the above-described continuously variable speed continuation condition further includes that the acquired traveling distance during I / S and traveling time during I / S are smaller than the predetermined distance and the predetermined time, respectively.

  As a result, when the continuously variable transmission mechanism is selected during the automatic stop during traveling, the transmission ratio is equal to or greater than the predetermined transmission ratio, and the I / S traveling distance and the I / S traveling time are the predetermined distance. The continuously variable transmission mechanism is continuously selected on the condition that each is shorter than the predetermined time, that is, on the condition that the number of rotations of the pulley is not very low due to a decrease in the vehicle speed. Furthermore, even when the gear ratio of the continuously variable transmission mechanism is equal to or greater than a predetermined gear ratio, when the I / S traveling distance is equal to or greater than a predetermined distance, or when the I / S traveling time is equal to or greater than a predetermined time, When the number of rotations of the pulley becomes very low, the transmission mechanism is switched to the fixed stage transmission mechanism. Accordingly, when the speed change ratio of the continuously variable transmission mechanism cannot be properly detected (calculated) and thus it becomes impossible to select the speed change mechanism based on the speed ratio, the speed change mechanism can be switched to the fixed speed change mechanism. Therefore, the effect that the acceleration response of the vehicle can be improved can be obtained more reliably.

1 is a skeleton diagram schematically showing a transmission device to which a control device according to an embodiment is applied and a vehicle on which the transmission device is mounted. FIG. It is a block diagram which shows ECU etc. of a control apparatus. FIG. 3 is a hydraulic circuit diagram schematically showing a first clutch oil chamber, a second clutch oil chamber, a pressure accumulator, and the like. It is a figure which fractures | ruptures some components and shows the pressure accumulator etc. in the driving | operation of an internal combustion engine. It is a figure for demonstrating operation | movement of the transmission in CVT mode. It is a figure for demonstrating operation | movement of the transmission in LOW mode. It is a figure for demonstrating operation | movement of the transmission in OD mode. It is a flowchart which shows the mode selection process during driving | running | working I / S performed by ECU. It is a timing chart which shows the operation example of mode selection processing during driving | running | working I / S. FIG. 10 is a timing chart showing an operation example different from FIG. 9 in the traveling I / S mode selection process. FIG. It is a figure which shows the relationship between CVT required oil pressure and clutch required oil pressure with respect to the output torque of an internal combustion engine.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the transmission 1 transmits the power of an internal combustion engine (hereinafter referred to as “engine”) 3, which is a power source of the vehicle V, to the left and right drive wheels DW and DW while shifting the power. It is mounted on the vehicle V. The engine 3 is a gasoline engine, and includes a starter motor 11 for starting the engine 3 and a fuel injection valve 12 for supplying fuel to the engine 3 (see FIG. 2). The amount of fuel injected from the fuel injection valve 12 is controlled by the ECU 2 described later in accordance with detection signals from various sensors.

  The transmission 1 is a continuously variable transmission mechanism (hereinafter referred to as “CVT”) 70 provided in parallel with each other as a transmission mechanism for transmitting power from the engine 3 to the drive wheels DW and DW in a shifted state. Fixed-stage transmission mechanism (hereinafter referred to as “LOWT”) 80 and a high-speed fixed-stage transmission mechanism (hereinafter referred to as “ODT”) 90. Between the engine 3 and the drive wheels DW and DW, there are provided an input shaft 6, a counter shaft 8 and a first output shaft 18 for CVT 70, and a second output shaft 20 for LOW 80 and 90 for ODT. The input shaft 6, the sub shaft 8, the first output shaft 18, and the second output shaft 20 are rotatably supported by bearings (not shown) and are arranged in parallel to each other.

  The crankshaft 3a of the engine 3 is connected to the pump impeller 4a of the torque converter 4, the turbine runner 4b of the torque converter 4 is connected to the input shaft 6, and hydraulic oil is filled between the two 4a and 4b. Has been. The power of the engine 3 is transmitted to the input shaft 6 via the pump impeller 4a, hydraulic oil, and the turbine runner 4b. The crankshaft 3a is connected to an oil pump 7 for supplying hydraulic pressure for operation to the CVT 70 or the like. The oil pump 7 is a gear pump and is driven by the engine 3.

  The CVT 70 is a transmission mechanism for transmitting the power of the engine 3 to the drive wheels DW and DW in a state where the power of the engine 3 is continuously changed, and is a belt type that is operated by hydraulic pressure. The CVT 70 includes a drive pulley 14, a driven pulley 16, a metal belt 17 wound around the pulleys 14 and 16, and the drive pulley 14 includes a fixed sheave 14a and a movable sheave 14 facing each other. 14b. The fixed sheave 14a is fixed to the input shaft 6, and the movable sheave 14b is attached to the input shaft 6 so as to be movable in the axial direction and relatively non-rotatable. The movable sheave 14b is biased to the opposite side of the fixed sheave 14a by a return spring (not shown). A V-shaped belt groove is formed between the sheaves 14a and 14b.

  The driven pulley 16 is configured in the same manner as the drive pulley 14, the fixed sheave 16a is fixed to the auxiliary shaft 8, and the movable sheave 16b is movable to the auxiliary shaft 8 in the axial direction and cannot rotate. Is attached. The movable sheave 16b is biased to the opposite side of the fixed sheave 16a by a return spring (not shown), and a V-shaped belt groove is formed between the sheaves 16a and 16b. . The belt 17 is wound around the pulleys 14 and 16 in a state of being fitted in the belt grooves of the driving pulley 14 and the driven pulley 16.

  The movable sheave 14b of the drive pulley 14 and the movable sheave 16b of the driven pulley 16 are respectively connected to the oil pump 7 via an oil passage (not shown) and the driven pulley oil chamber 14c and the driven pulley oil chamber 16c. Is provided. When the oil pressure from the oil pump 7 is supplied to the drive pulley oil chamber 14c and the driven pulley oil chamber 16c, the movable sheaves 14b and 16b move in the axial direction by being pressed by the supplied oil pressure. As a result, the pulley widths of the driving pulley 14 and the driven pulley 16 are changed, their effective diameters are changed, and the fixed sheave 14a and the movable sheave 14b are prevented from slipping with respect to the pulleys. And between the fixed sheave 16a and the movable sheave 16b.

  The effective diameters of the drive pulley 14 and the driven pulley 16 are the hydraulic pressures supplied to the drive pulley oil chamber 14c and the driven pulley oil chamber 16c (hereinafter referred to as “drive pulley supply hydraulic pressure” and “driven pulley supply hydraulic pressure”, respectively). The higher the value, the larger the size, and the size is controlled according to the drive pulley supply hydraulic pressure and the driven pulley supply hydraulic pressure. The driving pulley supply hydraulic pressure and the driven pulley supply hydraulic pressure are adjusted by controlling the opening degree of the first and second electromagnetic valves SO1 and SO2 shown in FIG.

  As described above, in the CVT 70, the opening degrees of the first and second electromagnetic valves SO1 and SO2 are controlled by the ECU 2 to change the drive pulley supply hydraulic pressure and the driven pulley supply hydraulic pressure, respectively. By changing the effective diameter of the driven pulley 16, the gear ratio (ratio between the rotational speed of the driving pulley 14 and the rotational speed of the driven pulley 16) is changed steplessly. Hereinafter, the transmission ratio of the CVT 70 is referred to as “CVT transmission ratio”.

  The countershaft 8 is provided with a first clutch 30 and a drive gear 32 for the CVT 70. The first clutch 30 is for connecting / disconnecting between the countershaft 8 and the drive gear 32, and is constituted by a hydraulic multi-plate clutch, and includes an outer 30a, an inner 30b, and a first clutch oil chamber 30c. (See FIG. 3).

  The outer 30a of the first clutch 30 is provided integrally with the auxiliary shaft 8, and the inner 30b is provided rotatably on the auxiliary shaft 8 and has a drive gear 32 integrally therewith. As shown in FIG. 3, the first clutch oil chamber 30c is connected to the oil pump 7 via the oil passage OL and the third electromagnetic valve SO3. The first clutch 30 side of the oil passage OL is bifurcated, and a first clutch oil chamber 30c is connected to one of the branched ends. A valve SO3 is provided. The hydraulic pressure supplied from the oil pump 7 to the first clutch oil chamber 30c is adjusted by controlling the opening degree of the third electromagnetic valve SO3 by the ECU 2 (see FIG. 2). Specifically, the first clutch target hydraulic pressure POBJ1 (see FIGS. 9 and 10) is set according to the operating state of the engine 3, and the hydraulic pressure supplied to the first clutch oil chamber 30c is set. The opening degree of the third electromagnetic valve SO3 is controlled so as to be the first clutch target hydraulic pressure POBJ1.

  Further, in the first clutch 30, when the hydraulic pressure is supplied to the first clutch oil chamber 30c, the outer 30a and the inner 30b are engaged with each other, thereby connecting the countershaft 8 and the drive gear 32 to each other. . In this case, the degree of engagement between the outer 30a and the inner 30b increases as the hydraulic pressure supplied to the first clutch oil chamber 30c increases. Further, the supply of hydraulic pressure to the first clutch oil chamber 30c is stopped, so that the engagement between the outer 30a and the inner 30b is released, and thereby the gap between the auxiliary shaft 8 and the drive gear 32 is cut off. . Note that an electromagnetic clutch may be used as the first clutch 30.

  The first output shaft 18 is provided with a driven gear 54 and an output gear 56 for CVT 70. The driven gear 54 is provided integrally with the first output shaft 18 and meshes with the drive gear 32 described above. The output gear 56 is provided integrally with the first output shaft 18 and meshes with the ring gear 48 of the differential gear mechanism 46. The differential gear mechanism 46 is connected to the left and right drive wheels DW and DW via left and right drive shafts 50 and 50, respectively.

  The first output shaft 18 is further provided with a reverse RVS driven gear 58 and a second synchro clutch 60, and the RVS driven gear 58 is rotatably provided on the first output shaft 18. The second synchro clutch 60 is for connecting the RVS driven gear 58 to the first output shaft 18, and has a sleeve 60a, first and second oil chambers (both not shown). These first and second oil chambers are connected to the oil pump 7 via a plurality of oil passages (both not shown) and the first switching valve SE1 shown in FIG.

  The first switching valve SE1 is configured by a solenoid-equipped spool valve. When a control signal is input from the ECU 2, the first oil chamber communicates with the oil pump 7 and the second oil chamber is drained (see FIG. (Not shown). As a result, the hydraulic pressure from the oil pump 7 is supplied to the first oil chamber and the oil in the second oil chamber is discharged, so that the sleeve 60a extends along the first output shaft 18 on the right side of FIG. The RVS driven gear 58 is connected to the first output shaft 18 by moving to the engagement position. Further, the first switching valve SE1 causes the second oil chamber to communicate with the oil pump 7 and the first oil chamber to communicate with the drain when no control signal is input from the ECU 2. As a result, the oil pressure from the oil pump 7 is supplied to the second oil chamber, and the oil in the first oil chamber is discharged, so that the sleeve 60a extends along the first output shaft 18 on the left side of FIG. Moving to the disengaged position, the connection of the RVS driven gear 58 to the first output shaft 18 is thereby released.

  The LOW 80 is a transmission mechanism for transmitting to the drive wheels DW and DW while being shifted at a low speed side fixed gear ratio, and the ODT 90 is a drive wheel while being shifted at a high speed side fixed gear ratio. A transmission mechanism for transmitting to DW and DW. The input shaft 6 is provided with the LOW driving gear 26 for the LOW 80, the OD driving gear 28 for the ODT 90, and the second clutch 34 for the LOW 80 and the ODT 90.

  The second clutch 34 is for connecting / disconnecting the input shaft 6 and the LOW drive gear 26 and the OD drive gear 28, and is configured by a hydraulic multi-plate clutch similar to the first clutch 30. Yes. An outer 34 a of the second clutch 34 is integrally provided on the input shaft 6, and an inner 34 b is rotatably provided on the input shaft 6. The drive gears 26 and 28 are integrally formed with each other, and are integrally connected to the inner 34b of the second clutch 34, and are rotatably provided on the input shaft 6 together with the inner 34b.

  As shown in FIG. 3, the second clutch oil chamber 34c of the second clutch 34 is connected to the oil pump 7 through the oil passage OL and the fourth electromagnetic valve SO4. The second clutch oil chamber 34c is connected to the other end of the oil passage OL that is branched into two branches, and a fourth electromagnetic valve SO4 is provided in the middle of the other branched portion. The hydraulic pressure supplied from the oil pump 7 to the second clutch oil chamber 34c is adjusted by controlling the opening degree of the fourth electromagnetic valve SO4 by the ECU 2 (see FIG. 2). Specifically, the second clutch target hydraulic pressure POBJ2 (see FIGS. 9 and 10) is set according to the operating state of the engine 3, and the hydraulic pressure supplied to the second clutch oil chamber 34c is set. The opening degree of the fourth solenoid valve SO4 is controlled so that the two-clutch target oil pressure POBJ2 is obtained. Further, the second clutch 34 connects / disconnects between the input shaft 6 and the LOW drive gear 26 and the OD drive gear 28 by supplying / stopping the hydraulic pressure to the second clutch oil chamber 34c, and the engagement. The degree increases as the supplied hydraulic pressure increases. Note that an electromagnetic clutch may be used as the second clutch 34.

  Furthermore, the pressure accumulator 100 is connected to a portion closer to the oil pump 7 than a portion branched into two branches of the oil passage OL. Since the configuration and function of the pressure accumulator 100 are the same as those disclosed in Japanese Patent Application Laid-Open No. 2014-43876 by the present applicant, these will be briefly described below.

  As shown in FIG. 4, the pressure accumulator 100 includes a sub oil passage 101, piston-type first and second accumulators 102 and 103, and a shut-off valve 104 composed of ON / OFF-type solenoid valves. Yes. One end of the sub oil passage 101 is connected to a portion closer to the oil pump 7 than the bifurcated branch portion of the oil passage OL, and the other end is connected to the first accumulator 102. The shut-off valve 104 is provided in the middle of the sub oil passage 101. When the shut-off valve 104 is opened and closed by the ECU 2 (see FIG. 2), the sub oil passage 101 is opened / closed. The second accumulator 103 is connected to the sub oil passage 101 so as to bypass the shutoff valve 104 via the first oil passage 105 and the second oil passage 106.

  In the pressure accumulator 100 having the above configuration, when the engine 3 is in operation and the oil pump 7 using the engine 3 as a drive source is in operation, the shut-off valve 104 is held in the open state. As a result, when the sub oil passage 101 is opened, the hydraulic pressure supplied from the oil pump 7 to the sub oil passage 101 via the oil passage OL is further supplied to the first accumulator 102 as shown in FIG. Accumulated. In this case, the oil pressure from the oil passage OL acts as a back pressure on the piston of the second accumulator 103 via the sub oil passage 101 and the first oil passage 105, so that the second accumulator 103 has almost no oil pressure. Not accumulated. In FIG. 4, the oil is indicated by a dotted line, and the oil flow is indicated by an arrow drawn in the vicinity of each oil passage.

  Further, the shut-off valve 104 is held in a closed state during the automatic stop of the engine 3 which will be described later. Thereby, by closing the sub oil passage 101, a closed circuit including the sub oil passage 101, the first accumulator 102, the second oil passage 106, and the second accumulator 103 is formed, so that the first accumulator 102 has The hydraulic pressure accumulated so far is maintained. At that time, the second accumulator 103 functions as a pressure reducing accumulator for reducing the hydraulic pressure in the closed circuit.

  Then, at the start of the restart operation from the automatic stop of the engine 3, the shut-off valve 104 is opened. As a result, the hydraulic pressure in the closed circuit including the first accumulator 102 held during the automatic stop of the engine 3 is transferred to the first clutch oil chamber 30c and the second clutch oil via the sub oil path 101 and the oil path OL. It is supplied to the chamber 34c. The second accumulator 103, the first oil passage 105, and the second oil passage 106 may be omitted. Further, the number of first accumulators 102 is not limited to one and is arbitrary.

  The second output shaft 20 is provided with a LOW driven gear 36 for LOW80, an OD driven gear 38 for ODT90, and output gears 44 for LOW80 and ODT90. The LOW driven gear 36 is rotatably provided on the second output shaft 20 via the one-way clutch 42 and meshes with both the LOW driving gear 26 and the RVS driven gear 58. In FIG. 1, for the sake of convenience, the LOW driven gear 36 drawn with a solid line is shown at a position away from the RVS driven gear 58, and the fact that the LOW driven gear 36 meshes with the RVS driven gear 58 is drawn with a broken line. The LOW driven gear 36 is represented by the vicinity of the RVS driven gear 58. The gear ratio between the LOW driven gear 36 and the LOW driving gear 26 (the number of teeth of the LOW driven gear 36 / the number of teeth of the LOW driving gear 26) is the lowest speed ratio (hereinafter referred to as "CVT minimum") that can be set as the CVT speed ratio in the CVT 70. It is set to the same value as “speed gear ratio RLOCVT”.

  The OD driven gear 38 is rotatably provided on the second output shaft 20 and meshes with the OD drive gear 28. The gear ratio between the OD driven gear 38 and the OD drive gear 28 (the number of teeth of the OD driven gear 38 / the number of teeth of the OD drive gear 28) is set to the same value as the highest speed gear ratio that can be set as the CVT gear ratio. Yes. The output gear 44 is provided integrally with the second output shaft 20 and meshes with the ring gear 48 of the differential gear mechanism 46. In FIG. 1, for convenience, the output gear 44 drawn with a solid line is shown at a position away from the ring gear 48, and the fact that the output gear 44 meshes with the ring gear 48 is indicated by the ring gear 48. It is expressed by showing in the vicinity.

  A first sync clutch 40 for LOW 80 and ODT 90 is provided between the LOW driven gear 36 and the OD driven gear 38. The first sync clutch 40 is for selectively connecting the LOW driven gear 36 and the OD driven gear 38 to the second output shaft 20, and includes a sleeve 40a, first and second oil chambers (both not shown). )have. These first and second oil chambers are connected to the oil pump 7 via a plurality of oil passages (both not shown) and the second and third switching valves SE2 and SE3 shown in FIG. Yes.

  The second switching valve SE2 is constituted by a solenoid-equipped spool valve. When a control signal is input from the ECU 2, the first oil chamber is communicated with the oil pump 7, and when it is not input, the first oil valve Make the room communicate with the drain. The third switching valve SE3 is composed of a solenoid-equipped spool valve similar to the second switching valve SE2, and when a control signal is input from the ECU 2, the second oil chamber is communicated with the oil pump 7 to input the third switching valve SE3. If not, the second oil chamber is connected to the drain.

  In the first synchro clutch 40 configured as described above, the hydraulic pressure from the oil pump 7 is supplied to the first oil chamber and the oil in the second oil chamber is controlled by the control of the second and third switching valves SE2 and SE3 by the ECU 2. As a result, the sleeve 40a moves along the second output shaft 20 to the engagement position (LOW position) on the right side of FIG. Thereby, the LOW driven gear 36 is connected to the second output shaft 20 and the connection of the OD driven gear 38 to the second output shaft 20 is released. Further, when the oil pressure from the oil pump 7 is supplied to the second oil chamber and the oil in the first oil chamber is discharged, the sleeve 40a extends along the second output shaft 20 on the left side of FIG. Move to the engagement position (OD position). As a result, the OD driven gear 38 is connected to the second output shaft 20 and the connection of the LOW driven gear 36 to the second output shaft 20 is released. Further, when the hydraulic pressure from the oil pump 7 is supplied to both the first and second oil chambers, the sleeve 40a is positioned at the center non-engagement position (N position), whereby the second output shaft The connection of the LOW driven gear 36 and the OD driven gear 38 to 20 is released.

  The transmission 1 having the above configuration has a CVT mode, a LOW mode, an OD mode, and an N mode as power transmission modes. As the speed change mechanism, CVT 70 is used in the CVT mode, LOW 80 is used in the LOW mode, and ODT 90 is used in the OD mode. The power transmission mode of the transmission 1 is selectively set to one of these modes by the control of the first and second clutches 30 and 34 and the first and second synchro clutches 40 and 60 by the ECU 2. Hereinafter, these power transmission modes will be described in order with reference to FIGS.

[CVT mode]
As shown in FIG. 5, during the CVT mode, the first clutch 30 is engaged (ON) to connect the countershaft 8 and the drive gear 32 and to disengage the second clutch 34 ( By turning off, the input shaft 6 is disconnected from the LOW drive gear 26 and the OD drive gear 28. Further, the first sync clutch 40 is controlled to any one of the LOW position, the N position and the OD position, and the second sync clutch 60 is controlled to the left non-engagement position (N position). The connection of the RVS driven gear 58 to 18 is released.

  As described above, as shown by the hatched thick line in FIG. 5, during the CVT mode, the power transmitted from the engine 3 to the input shaft 6 through the torque converter 4 is transmitted to the drive pulley 14 and the belt of the CVT 70. 17, the driven pulley 16, the countershaft 8, the first clutch 30, the drive gear 32, the driven gear 54, the first output shaft 18, and the output gear 56 are transmitted to the ring gear 48, and the differential gear mechanism 46 and It is transmitted to the left and right drive wheels DW and DW via the drive shafts 50 and 50. Further, during the CVT mode, the power of the engine 3 is transmitted to the drive wheels DW and DW in a state where the speed is steplessly changed at a predetermined speed ratio based on the CVT speed ratio.

  Since the output gear 44 on the second output shaft 20 meshes with the ring gear 48 of the differential gear mechanism 46, the power transmitted from the first output shaft 18 to the differential gear mechanism 46 during the CVT mode is Are transmitted to the second output shaft 20 through the gears 48 and 44 and rotated. However, since the one-way clutch 42 is interposed between the second output shaft 20 and the driven gear 36, the power of the second output shaft 20 is not transmitted to the driven gear 36.

[LOW mode]
As shown in FIG. 6, during the LOW mode, the engagement of the first clutch 30 is released (OFF), thereby disconnecting the sub shaft 8 from the drive gear 32 and engaging the second clutch 34 ( ON) to connect between the input shaft 6 and the LOW drive gear 26 and the OD drive gear 28. Further, by controlling the first synchro clutch 40 to the right LOW position, the LOW driven gear 36 is connected to the second output shaft 20 and the second synchro clutch 60 is controlled to the non-engagement position. 1 The RVS driven gear 58 is disconnected from the output shaft 18.

  As described above, as shown by the thick line with the hatched arrow in FIG. 6, the power of the engine 3 transmitted to the input shaft 6 is transmitted to the second clutch 34 of the LOW 80, the LOW drive gear 26, the LOW driven gear 36, It is transmitted to the ring gear 48 via the first sync clutch 40, the second output shaft 20 and the output gear 44, and further transmitted to the left and right drive wheels DW, DW via the differential gear mechanism 46 and the drive shafts 50, 50. Is done. As a result, during the LOW mode, the power of the engine 3 is determined by a gear ratio of a gear train including the LOW drive gear 26 and the LOW driven gear 36 of the LOW 80 that exists between the input shaft 6 and the second output shaft 20. The speed is changed at a low speed fixed gear ratio.

  As described above, the gear ratio between the LOW driven gear 36 and the LOW drive gear 26, that is, the transmission ratio of the LOW 80 is set to the same value as the CVT minimum speed transmission ratio RLOCVT (the minimum transmission ratio that can be set as the CVT transmission ratio). Has been. The gear ratio between the ring gear 48 and the output gear 44 is set to be equal to a value obtained by multiplying the gear ratio between the ring gear 48 and the output gear 56 and the gear ratio between the driven gear 54 and the drive gear 32. From the above, the transmission ratio of the entire transmission 1 during the LOW mode is the same as the overall transmission ratio of the transmission 1 when the CVT transmission ratio is controlled to the CVT minimum speed transmission ratio RLOCVT during the CVT mode.

[OD mode]
As shown in FIG. 7, during this OD mode, as in the case of the LOW mode, the first clutch 30 is disengaged, the second clutch 34 is engaged, and the second synchro clutch 60 is disengaged. On the other hand, unlike the case of the LOW mode, the OD driven gear 38 is connected to the second output shaft 20 by controlling the first synchro clutch 40 to the left OD position. As described above, as shown by the thick line with the hatched arrow in FIG. 7, the power of the engine 3 transmitted to the input shaft 6 is the second clutch 34 of the ODT 90, the OD drive gear 28, the OD driven gear 38, It is transmitted to the ring gear 48 via the first sync clutch 40, the second output shaft 20 and the output gear 44, and further transmitted to the left and right drive wheels DW, DW via the differential gear mechanism 46 and the drive shafts 50, 50. Is done. As a result, during the OD mode, the power of the engine 3 is determined by a gear ratio of the gear train including the OD drive gear 28 and the OD driven gear 38 of the ODT 90 that exists between the input shaft 6 and the second output shaft 20. The speed is changed at a high speed fixed gear ratio.

  As described above, the gear ratio between the OD driven gear 38 and the OD drive gear 28, that is, the gear ratio of the ODT 90 is set to the same value as the highest speed gear ratio that can be set as the CVT gear ratio. As described above, the gear ratio between the ring gear 48 and the output gear 44 is equal to the value obtained by multiplying the gear ratio between the ring gear 48 and the output gear 56 and the gear ratio between the driven gear 54 and the drive gear 32. Is set. From the above, the speed ratio of the entire transmission 1 during the OD mode is the same as the speed ratio of the entire transmission 1 when the CVT speed ratio is controlled to the highest speed ratio during the CVT mode.

[N mode]
The N mode is a power transmission mode in which the transmission of power from the engine 3 to the drive wheels DW and DW is cut off. As shown in FIG. 1, during the N mode, the first and second clutches 30 and 34 are both disengaged so that the auxiliary shaft 8 and the drive gear 32 and the input shaft 6 and the LOW drive gear are engaged. The first synchro clutch 40 is controlled to the LOW position, and the second synchro clutch 60 is controlled to the non-engagement position. As described above, the power of the engine 3 transmitted to the input shaft 6 is transmitted to the drive pulley 14, the driven pulley 16, and the auxiliary shaft 8, but the first and second clutches 30 and 34 described above block the first power. And the vehicle V is kept in the neutral state without being transmitted to any of the second output shafts 18 and 20. While the vehicle V is stopped, basically, the power transmission mode is set to the N mode.

  FIG. 11 shows the CVT required hydraulic pressure PCVT, which is the hydraulic pressure required for the drive pulley 14 and the driven pulley 16, with respect to the output torque (hereinafter referred to as “engine output torque”) Te of the engine 3, and the second clutch 34. The relationship with the required clutch hydraulic pressure PCL, which is the hydraulic pressure to be used, is shown. As shown in FIG. 11, the CVT required hydraulic pressure PCVT is higher than the clutch required hydraulic pressure PCL for the same engine output torque Te. The reason is that in CVT 70, the drive pulley supply hydraulic pressure and the driven pulley This is because the belt 17 must be clamped between the driving pulley 14 and the driven pulley 16 by the supply hydraulic pressure so as not to slide.

  As shown in FIG. 2, the CRK signal representing the rotational speed of the crankshaft 3 a is input to the ECU 2 from the crank angle sensor 111. The ECU 2 calculates the engine speed (hereinafter referred to as “engine speed”) NE of the engine 3 based on the CRK signal. Further, the ECU 2 receives detection signals representing the rotational speed of the driving pulley 14 and the rotational speed of the driven pulley 16 from the electromagnetic pickup type driving pulley angle sensor 112 and the driven pulley angle sensor 113 from the diaphragm type hydraulic sensor 114. Detection signals representing the hydraulic pressure in the driven pulley oil chamber 16c (hereinafter referred to as “oil chamber hydraulic pressure”) PPU are input. Based on the detection signals from the drive pulley angle sensor 112 and the driven pulley angle sensor 113, the ECU 2 rotates the rotational speed of the driving pulley 14 (hereinafter referred to as “driving pulley rotational speed”) NP1 and the rotational speed of the driven pulley 16 (hereinafter referred to as “driven”). NP2 (referred to as “pulley speed”) is calculated.

  Further, the ECU 2 receives a detection signal indicating an operation amount (hereinafter referred to as “accelerator opening”) AP of an accelerator pedal (not shown) of the vehicle V from the accelerator opening sensor 115 from the vehicle speed sensor 116. A detection signal representing a speed (vehicle speed) VP (km / h) and a detection signal representing a shift position SP of a shift lever (not shown) of the vehicle V are input from the shift position sensor 117, respectively. Further, the ECU 2 receives a detection signal indicating the on / off state of the ignition switch 118 and a detection signal indicating the on / off state of a brake pedal (not shown) of the vehicle V from the brake switch 119, respectively. Is done.

  The ECU 2 is composed of a microcomputer including a CPU, a RAM, a ROM, an input interface (all not shown), and the like. The ECU 2 controls the operation of the engine 3 and the transmission 1 according to the control program stored in the ROM in accordance with the detection signals from the various sensors 111 to 117 and the switches 118 and 119 described above.

  Specifically, the ECU 2 performs idle stop control in order to control the operation of the engine 3. In this idle stop control, in order to improve the fuel consumption of the vehicle V, when a predetermined stop condition is satisfied, the engine 3 is automatically stopped (automatic stop), and then a predetermined restart condition is satisfied. Sometimes, the engine 3 is automatically restarted.

The above stop conditions are, for example, the following conditions (a) to (e). When all of these conditions are satisfied, it is determined that the stop condition is satisfied.
(A) The ignition switch 118 is in an ON state (b) The vehicle speed VP is equal to or less than a predetermined speed VPREF (for example, 10 km / h) (c) The accelerator opening AP is substantially 0 (d) Shift position SP Is other than “P”, “R” and “N” (e) The brake switch 119 is in an ON state.

Further, the predetermined restart condition is, for example, the following conditions (f) and (g), and when either of the conditions (f) and (g) is satisfied, the restart condition is satisfied. It is determined that
(F) The accelerator opening AP is greater than or equal to a predetermined value APREF. (G) The brake switch 119 is in an off state.

  The automatic stop of the engine 3 is performed by stopping the fuel injection from the fuel injection valve 12. Further, during the automatic stop, the automatic stop flag F_I / S (see FIG. 9 and FIG. 10) is set to “1” to indicate that, and is set to “0” otherwise. Furthermore, the restart from the automatic stop of the engine 3 drives the starter motor 11 with electric power supplied from a battery (not shown) while injecting fuel from the fuel injection valve 12, and rotates the crankshaft 3a ( (Cranking).

  As described above, since the stop condition includes the condition (b) that the vehicle speed VP is equal to or lower than the predetermined speed VPREF, the automatic stop of the engine 3 may be performed while the vehicle V is traveling. Hereinafter, the automatic stop of the engine 3 while the vehicle V is traveling is referred to as “traveling I / S”.

  The ECU 2 basically selects the LOW mode when the vehicle V starts as the power transmission mode of the transmission 1 and selects the CVT mode while the vehicle V is traveling. Further, FIG. 8 shows a mode selection process during traveling I / S executed by the ECU 2. This process is to continue the selection of the CVT mode or switch the power transmission mode to the LOW mode when the CVT mode is selected during the driving I / S, and is repeated at a predetermined control cycle. Executed.

  First, in step 1 of FIG. 8 (illustrated as “S1”, the same applies hereinafter), it is determined whether or not the vehicle is traveling I / S. If the answer is NO and the vehicle is not traveling I / S, the I / S traveling distance DI / S and the I / S integrated traveling distance SDI / S, which will be described later, are reset to 0 (steps 2 and 3). Then, the timer value tI / S of the upcount I / S timer is reset to 0 (step 4), and this process is terminated.

  On the other hand, if the answer to step 1 is YES and the vehicle is traveling I / S, the ratio (NP1 / NP2) of the calculated drive pulley rotational speed NP1 and driven pulley rotational speed NP2 is set as the CVT gear ratio RATCVT. Calculate (step 5). Next, the I / S running distance DI / S is calculated based on the detected vehicle speed VP (step 6). Specifically, immediately after the answer to step 1 is switched from NO to YES, the I / S running distance DI / S is set to the value 0, and thereafter, the control cycle of this process is set to time (hour). The I / S running distance DI / S is calculated by multiplying the converted value by the vehicle speed VP. As is apparent from this calculation method, the I / S traveling distance DI / S represents the traveling distance of the vehicle V from the previous execution of this process during the traveling I / S to the current time.

  In step 7 following the above step 6, the calculated I / S traveling distance DI / S is added to the previous value SDI / SZ of the I / S accumulated traveling distance to thereby calculate the I / S accumulated traveling distance. The current value SDI / S is calculated. As is apparent from the above calculation method, the I / S integrated travel distance SDI / S represents the travel distance of the vehicle V from the start of the travel I / S to the current execution of this process.

  Next, it is determined whether or not the CVT mode flag F_CVTM is “1” (step 8). The CVT mode flag F_CVTM indicates that the CVT mode is selected by “1”. When the answer to step 8 is NO, the present process is terminated as it is. On the other hand, when YES and F_CVTM = 1, that is, when the CVT mode is selected, the CVT mode is selected in the subsequent steps 9 to 12. It is determined whether or not a continuously variable transmission continuation condition consisting of four predetermined conditions to be described later is satisfied.

  Specifically, first, in step 9, it is determined whether or not the CVT speed ratio RATCVT calculated in step 5 is greater than or equal to a predetermined speed ratio RATREF. The predetermined speed ratio RATREF is set to a value on the low speed side, and is set to a value slightly smaller than the CVT minimum speed speed ratio RLOCVT (value on the high speed side).

  If the answer to step 9 is YES and RATCVT ≧ RATREF, it is determined whether or not the detected oil chamber hydraulic pressure PPU (hydraulic pressure in the driven pulley oil chamber 16c) is greater than a predetermined oil pressure PREF (step 10). The predetermined hydraulic pressure PREF is set by experiment or the like so that the belt 17 does not slip with respect to the driven pulley 16 when the CVT speed ratio RATCVT is equal to or greater than the predetermined speed ratio RATREF. When the answer to step 10 is YES, it is determined whether or not the integrated traveling distance SDI / S during I / S calculated in step 7 is smaller than a predetermined distance DREF (step 11).

  If the answer to step 11 is YES, it is determined whether or not the timer value tI / S of the I / S timer reset in the step 4 is smaller than a predetermined time TMREF (step 12). The timer value tI / S of the I / S timer indicates the travel time of the vehicle V from the start of the travel I / S to the current execution of this process, as is apparent from the execution contents of the steps 1 and 4. Represent. In addition, the predetermined distance DREF and the predetermined time TMREF are not very low in the driving pulley rotational speed NP1 and the driven pulley rotational speed NP2 due to the decrease in the vehicle speed VP according to the predetermined speed VPREF used in the automatic stop condition described above. Such a value is set by experiment.

  When the answer to step 12 is YES, that is, all four conditions of RATCVT ≧ RATREF, PPU> PREF, SDI / S <DREF, and tI / S <TMREF are satisfied, and the continuously variable transmission continuation condition is When established, in order to continue the selection of the CVT mode, the CVT mode flag F_CVTM is set to “1”, and the LOW mode flag F_LOWM and the OD mode flag F_ODTM are both set to “0” (step 13). ), This process is terminated.

  On the other hand, if any of the answers to steps 9 to 12 is NO, RATCVT is less than RATREF, PPU is less than PREF, SDI / S is greater than DREF, or tI / S is greater than TMREF, and continuously variable transmission When the continuation condition is not satisfied, the LOW mode flag F_LOWM is set to “1” in order to switch the power transmission mode from the CVT mode to the LOW mode, and both the CVT mode flag F_CVTM and the OD mode flag F_ODTM are set to “0”. "(Step 14), and the process is terminated. With the execution of step 14, the control of the first and second clutches 30 and 34 and the first and second synchro clutches 40 and 60 is switched to the LOW mode.

  It should be noted that the first and second electromagnetic waves are controlled so that the CVT speed ratio RATCVT is maintained at the CVT minimum speed speed ratio RLOCVT regardless of whether the CVT mode or the LOW mode is selected during the traveling I / S. The opening degree of the valves SO1 and SO2 is controlled.

  Next, an operation example of the above-described traveling I / S mode selection process described above will be described with reference to FIGS. 9 and 10. 9 and 10, PACT1 and PACT2 are actual hydraulic pressures in the first and second clutch oil chambers 30c and 34c (hereinafter referred to as "first clutch actual hydraulic pressure" and "second clutch actual hydraulic pressure", respectively). The other parameters are as described above. FIG. 9 shows an operation example when the selection of the CVT mode is continued from the traveling I / S to the restart of the engine 3.

  As shown in FIG. 9, during driving I / S (VP> 0 and F_I / S = 1, step 1: YES in FIG. 8), the I / S integrated value representing the driving distance of the vehicle V from the start time The travel distance SDI / S is calculated (step 7), and the timer value tI / S of the I / S timer indicating the travel time of the vehicle V from the start of the travel I / S is counted up. In this case, since the CVT mode is selected as the power transmission mode (F_CVTM = 1, F_LOWM = 0), the second clutch target hydraulic pressure POBJ2 and the second clutch actual hydraulic pressure PACT2 are both 0, and the second clutch 34 The first clutch target hydraulic pressure POBJ1 and the first clutch actual hydraulic pressure PACT1 are both greater than the value 0, and the first clutch 30 is in the engaged state. In FIG. 9, for the sake of convenience, an alternate long and short dash line representing the second clutch target hydraulic pressure POBJ2 is slightly drawn on the upper side.

  In addition, during driving I / S, the power of the engine 3 is not output (NE = 0), so that the vehicle speed VP gradually decreases. Further, when the oil pump 7 using the engine 3 as a drive source is stopped, the oil pressure is not supplied from the oil pump 7 to the first clutch oil chamber 30c, the drive pulley oil chamber 14c, and the driven pulley oil chamber 16c. For this reason, the first clutch actual hydraulic pressure PACT1 gradually decreases due to the gradual removal of oil from the first clutch oil chamber 30c. For the same reason, when the oil gradually drains from the drive pulley oil chamber 14c and the driven pulley oil chamber 16c, the hydraulic pressure in the drive pulley oil chamber 14c and the oil chamber hydraulic pressure PPU gradually decrease, and the drive pulley 14 and the driven pulley 16 The thrust that maintains the effective diameter of the is reduced. In addition, during driving I / S, power is not output from the engine 3, but the drive wheels DW and DW rotate with inertia, so the driven pulley 16 is driven by the drive wheels DW and DW.

  As described above, the thrust for maintaining the effective diameters of the drive pulley 14 and the driven pulley 16 is reduced, the power from the engine 3 is not transmitted to the drive pulley 14, and the driven pulley 16 is driven by the drive wheels DW and DW. By being driven, the CVT speed ratio RATCVT is gradually reduced without being maintained at the CVT minimum speed speed ratio RLOCVT during the traveling I / S, and changes to the high speed side.

  In the operation example shown in FIG. 9, the CVT gear ratio RATCVT is greater than or equal to the predetermined gear ratio RATREF during the traveling I / S (step 9: YES), and the oil chamber hydraulic pressure PPU is greater than the predetermined hydraulic pressure PREF (step 10: YES), the integrated travel distance SDI / S during I / S is smaller than the predetermined distance DREF (step 11: YES), and the timer value tI / S is smaller than the predetermined time TMREF (step 12: YES). . That is, the continuously variable speed continuation condition is satisfied. As described above, during the traveling I / S, the CVT mode flag F_CVTM is held at “1” and the LOW mode flag F_LOWM is held at “0” (step 13), and the selection of the CVT mode is continued.

  When the brake switch 119 is turned off and the accelerator opening AP is equal to or greater than the predetermined value APREF, the aforementioned restart condition is satisfied (time t1, F_I / S = 0). A starting operation (such as cranking of the starter motor 11) is started. As a result, the engine speed NE increases with a delay, and increases rapidly with the complete explosion of the engine 3. In addition, with the establishment of the restart condition, the hydraulic pressure is supplied from the pressure accumulating device 100 to the first and second clutches 30 and 34 described above. Unlike the starting operation of the engine 3, the supply of the hydraulic pressure is performed quickly with almost no time delay, so that the first clutch actual hydraulic pressure PACT1 becomes a point before the engine speed NE rises from the value 0. Then it begins to increase. Further, as the engine speed NE increases, the supply of hydraulic pressure from the oil pump 7 is resumed, whereby the first clutch actual hydraulic pressure PACT1 further increases. As described above, the first clutch actual hydraulic pressure PACT1 converges to the first clutch target hydraulic pressure POBJ1 at a time before the time t2 when the engine 3 is completely exploded, whereby the first clutch 30 is completely engaged.

  On the other hand, the second clutch target hydraulic pressure POBJ2 and the second clutch actual hydraulic pressure PACT2 are both maintained at a value of zero. As described above, the first clutch 30 is held in the engaged state and the engagement of the second clutch 34 is held in the released state, so that the power of the engine 3 is driven through the CVT 70 to the driving wheel. As a result of being transmitted to DW and DW, vehicle speed VP increases. Further, when the supply of hydraulic pressure from the oil pump 7 is resumed, the CVT speed ratio RATCVT increases toward the lower speed CVT minimum speed speed ratio RLOCVT, and at the time t2 when the engine 3 is completely exploded, the CVT speed ratio RATCVT is increased. It almost converges to the lowest speed gear ratio RLOCVT.

  FIG. 10 shows an operation example when the power transmission mode is switched to the CVT mode during the traveling I / S. As shown in FIG. 10, during the traveling I / S, for the reason described above, the CVT gear ratio RATCVT fluctuates to the high speed side and falls below the predetermined gear ratio RATREF (time point t3, step 9 in FIG. 8: NO). Accordingly, in order to switch the power transmission mode to the LOW mode, the CVT mode flag F_CVTM is reset to “0” and the LOW mode flag F_LOWM is set to “1” (step 14). Accordingly, the first clutch target oil pressure POBJ1 is set to the value 0, so that the first clutch actual oil pressure PACT1 is reduced to the value 0. Further, although the second clutch target oil pressure POBJ2 is set to a value larger than the value 0, the oil pump 7 is stopped during the traveling I / S (VP> 0 and F_I / S = 1). The second clutch actual hydraulic pressure PACT2 changes with a value of zero.

  Then, when the restart condition described above is satisfied (time t4, F_I / S = 0), the hydraulic pressure is supplied from the pressure accumulator 100 as in the case of FIG. The actual clutch hydraulic pressure PACT2 starts to increase at a point before the engine speed NE increases. Further, the second clutch actual hydraulic pressure PACT2 further increases by restarting the supply of the hydraulic pressure from the oil pump 7 with the subsequent increase in the engine speed NE. Here, the clutch required hydraulic pressure PCL required for the second clutch 34 is relatively small as described with reference to FIG. As described above, the second clutch actual hydraulic pressure PACT2 converges to the second clutch target hydraulic pressure POBJ2 at a time before the time t5 when the engine 3 is completely exploded, whereby the second clutch 34 is completely engaged. On the other hand, the first clutch target hydraulic pressure POBJ1 and the first clutch actual hydraulic pressure PACT1 are both zero. In FIG. 10, for the sake of convenience, a one-dot chain line representing the first clutch target hydraulic pressure POBJ1 is slightly drawn on the upper side. As described above, when the second clutch 34 is engaged and the engagement of the first clutch 30 is released, the power of the engine 3 is transmitted to the drive wheels DW and DW via the LOWT 80. The vehicle speed VP increases.

  Further, the CVT gear ratio RATCVT increases toward the CVT minimum speed gear ratio RLOCVT by resuming the supply of hydraulic pressure from the oil pump 7. As described with reference to FIG. 11, the CVT required hydraulic pressure PCVT is relatively large, and the CVT speed ratio RATCVT greatly fluctuates on the high speed side as compared with the operation example shown in FIG. 9 during the traveling I / S. ing. From the above, the CVT gear ratio RATCVT is on the higher speed side than the CVT lowest speed gear ratio RLOCVT at the time t5 when the engine 3 is completely exploded, and the difference is relatively large.

  The correspondence between various elements in the present embodiment and various elements in the present invention is as follows. That is, the engine 3 in the present embodiment corresponds to the power source in the present invention, the CVT 70 in the present embodiment corresponds to the continuously variable transmission mechanism in the present invention, and the LOW80 in the present embodiment corresponds to the fixed stage in the present invention. It corresponds to a transmission mechanism. The driving pulley 14 and the driven pulley 16 in the present embodiment correspond to a pair of pulleys in the present invention, and the driving pulley oil chamber 14c and the driven pulley oil chamber 16c in the present embodiment correspond to an oil chamber in the present invention. To do.

  Further, the ECU 2 in the present embodiment corresponds to selection means, speed ratio parameter detection means, travel distance acquisition means, and travel time acquisition means in the present invention. The driving pulley angle sensor 112 and the driven pulley angle sensor 113 in the present embodiment correspond to the gear ratio parameter detection means in the present invention, and the hydraulic sensor 114 in the present embodiment corresponds to the hydraulic pressure detection means in the present invention. .

  As described above, according to the present embodiment, the engine 3 is automatically stopped when the predetermined stop condition is satisfied, and is restarted when the predetermined restart condition is satisfied during the automatic stop. This automatic stop includes a traveling I / S in which the engine 3 is automatically stopped when the vehicle V is traveling. Further, a CVT 70 and a meshing type LOW 80 provided in parallel with each other are selectively used as a speed change mechanism for transmitting the power from the engine 3 to the drive wheels DW and DW in a state where the power is changed.

  The CVT 70 is a belt-type continuously variable transmission mechanism, and the drive pulley 14 and the driven pulley are driven by the oil pressure of oil supplied from the oil pump 7 having the engine 3 as a drive source to the drive pulley oil chamber 14c and the driven pulley oil chamber 16c. The CVT speed change ratio RATCVT is changed steplessly by changing the effective diameter of each of the belts 16, and the belt 17 is sandwiched between the fixed sheave 14a and the movable sheave 14b and between the fixed sheave 16a and the movable sheave 16b. Has been. The LOWT 80 is configured to shift the power of the engine 3 at a predetermined fixed speed ratio on the low speed side. Thus, since the gear ratio of the LOWT 80 is fixed, unlike the belt-type continuously variable transmission mechanism, it does not fluctuate to the high speed side during traveling I / S.

  Further, during traveling I / S (step 1: YES in FIG. 8), when CVT 70 is selected as the speed change mechanism (step 8: YES), CVT speed ratio RATCVT is greater than or equal to a predetermined speed ratio RATREF (low speed side). When the predetermined continuously variable speed continuation condition including that (step 9) is satisfied, the CVT 70 is continuously selected (step 13). When the continuously variable speed continuation condition is not satisfied, that is, when the CVT speed ratio RATCVT is smaller than the predetermined speed ratio RATREF (high speed side) (step 9: NO), the speed change mechanism is Then, the mode is switched to LOW 80 having a low speed side gear ratio (step 14).

  As a result, when the engine 3 is restarted from the traveling I / S, the power from the engine 3 can be quickly transmitted to the drive wheels DW and DW while being shifted at the low speed gear ratio. Can be improved. Further, as long as the continuously variable speed continuation condition is satisfied, the CVT 70 is continuously selected. Therefore, when the engine 3 is subsequently restarted, the power of the engine 3 can be finely shifted, and thus the efficiency of the vehicle V is improved. be able to.

  Further, since the CVT 70 is of the belt type, when the engine 3 is restarted from the traveling I / S and the hydraulic pressure in the drive pulley oil chamber 14c and the oil chamber hydraulic pressure PPU are small, the fixed sheave 14a and the movable sheave 14b Between the fixed sheave 16a and the movable sheave 16b (hereinafter referred to as "belt clamping force") is reduced, so that the belt 17 slides against both pulleys 14 and 16 and torque As a result, the acceleration responsiveness of the vehicle V may be reduced. In particular, the effective diameter of the drive pulley 14 is set to its minimum value in order to control the CVT speed ratio RATCVT to the CVT minimum speed speed ratio RLOCVT during acceleration of the vehicle V accompanying the restart of the engine 3 from the running I / S. In order to control the effective diameter of the driven pulley 16 to its maximum value, the hydraulic pressure required for the driven pulley 16 is larger than the hydraulic pressure required for the drive pulley 14. Becomes slippery. On the other hand, unlike the CVT 70, the LOW 80 is a meshing type, so that the torque transmission loss described above does not occur.

  According to the present embodiment, when the CVT 70 is selected during the traveling I / S, the oil chamber hydraulic pressure PPU is greater than the predetermined hydraulic pressure PREF in addition to the above-described conditions regarding the CVT gear ratio RATCVT (step 10). CVT 70 is continuously selected on the condition that the belt holding force in the driven pulley 16 is relatively large (step 13). Even if the condition regarding the CVT gear ratio RATCVT is satisfied, when the oil chamber hydraulic pressure PPU drops below the predetermined hydraulic pressure PREF (step 10: NO), that is, when the belt clamping force becomes small, the transmission mechanism is LOWT80. (Step 14). Therefore, when the engine 3 is subsequently restarted, the belt 17 can be prevented from slipping with respect to the drive pulley 14 and the driven pulley 16 and, consequently, the acceleration response of the vehicle V can be improved. Can do.

  Further, the CVT gear ratio RATCVT is calculated based on the detection results of the electromagnetic pickup type drive pulley angle sensor 112 and the driven pulley angle sensor 113 (step 5 in FIG. 8). In this case, during driving I / S, when the driving pulley rotational speed NP1 and the driven pulley rotational speed NP2 become very low due to a decrease in the vehicle speed VP, an appropriate detection result of both the sensors 112 and 113 cannot be obtained. In some cases, the CVT gear ratio RATCVT cannot be calculated appropriately. In that case, there is a possibility that the selection of the transmission mechanism based on the CVT transmission ratio RATCVT described above cannot be performed appropriately.

  According to the present embodiment, the integrated travel distance SDI / S during I / S that represents the travel distance of the vehicle V since the start of the travel I / S is calculated (step 7 in FIG. 8), and at the time of travel The timer value tI / S of the I / S timer that represents the travel time of the vehicle V since the start of I / S is counted up. Further, when CVT 70 is selected during traveling I / S, in addition to the above-described conditions relating to CVT gear ratio RATCVT and oil chamber hydraulic pressure PPU, accumulated traveling distance SDI / S during I / S and timer value tI / S Is smaller than the predetermined distance DREF and the predetermined time TMREF (steps 11 and 12), that is, the drive pulley rotational speed NP1 and the driven pulley rotational speed NP2 are not very low due to the decrease in the vehicle speed VP. As a condition, CVT 70 is continuously selected (step 13).

  Even if the conditions regarding the CVT gear ratio RATCVT and the oil chamber hydraulic pressure PPU are satisfied, the accumulated travel distance SDI / S during I / S becomes equal to or greater than the predetermined distance DREF (step 11: NO), or the timer value tI. When / S exceeds the predetermined time TMREF (step 12: NO), that is, when the driving pulley rotational speed NP1 and the driven pulley rotational speed NP2 become very low, the speed change mechanism is switched to LOW80 (step 14). . As a result, when the CVT transmission ratio RATCVT cannot be calculated appropriately, and the transmission mechanism cannot be properly selected based on the CVT transmission ratio RATCVT, the transmission mechanism can be switched to LOW80. The effect that the acceleration response can be improved can be obtained more reliably.

  In addition, this invention can be implemented in various aspects, without being limited to the described embodiment. For example, in the embodiment, the CVT transmission ratio RATCVT, that is, the transmission ratio of the CVT 70 itself is used as the transmission ratio parameter in the present invention, but other appropriate parameters representing the transmission ratio of the continuously variable transmission mechanism may be used. . For example, the effective diameter of the driving pulley 14 and the effective diameter of the driven pulley 16 are detected by a plurality of proximity sensors, and the ratio between the detected effective diameter of the driven pulley 16 and the effective diameter of the driving pulley 14 (the driven pulley 16 Effective diameter / effective diameter of drive pulley 14) or the reciprocal thereof may be used as the transmission ratio parameter. Alternatively, the oil pressure in the drive pulley oil chamber 14c is detected by a sensor, and the ratio between the oil chamber oil pressure PPU (the oil pressure in the driven pulley oil chamber 16c) and the detected oil pressure in the drive pulley oil chamber 14c (oil chamber oil pressure). PPU / hydraulic pressure in the drive pulley oil chamber 14c) or the reciprocal thereof may be used as the transmission ratio parameter.

  In the embodiment, the hydraulic sensor 114 is a diaphragm type, but may be a piezo type or a semiconductor type. Furthermore, in the embodiment, when the vehicle V is accelerated due to the restart of the engine 3 from the traveling I / S, particularly in view of the fact that the belt 17 becomes slippery in the driven pulley 16, the oil pressure in the oil pulley of the driven pulley 16 is increased. Although the condition regarding the PPU is used as the continuously variable transmission continuation condition, instead of or together with this, the fact that the hydraulic pressure in the drive pulley oil chamber 14c is larger than the predetermined hydraulic pressure may be used as the continuously variable transmission continuation condition. Good. In this case, the hydraulic pressure in the drive pulley oil chamber 14c is detected by a sensor or the like, and the predetermined hydraulic pressure is implemented as a threshold value for comparison with the hydraulic pressure in the drive pulley oil chamber 14c by experiments or the like. It is set separately from the predetermined hydraulic pressure PREF in the embodiment.

  In the embodiment, the condition relating to the CVT gear ratio RATCVT (step 9 in FIG. 8), the condition relating to the oil pressure in the oil chamber PPU (step 10), the condition relating to the accumulated travel distance SDI / S during I / S and the timer value tI / S ( The success or failure of steps 11 and 12) is determined in this order, but the order is not limited to this and is arbitrary. Furthermore, in the embodiment, in addition to the condition relating to the CVT gear ratio RATCVT, the condition relating to the oil chamber hydraulic pressure PPU, the I / S accumulated travel distance SDI / S, and the condition relating to the timer value tI / S are used as the continuously variable transmission continuation condition. However, the conditions relating to the accumulated travel distance SDI / S during I / S and the timer value tI / S may be omitted. Alternatively, the conditions related to the oil chamber hydraulic pressure PPU may be omitted, and the conditions related to the oil chamber hydraulic pressure PPU, the I / S integrated travel distance SDI / S, and the timer value tI / S may be omitted. Alternatively, other appropriate conditions may be included in the continuously variable transmission continuation condition.

  In the embodiment, the first clutch 30 is provided so as to connect / disconnect between the input shaft 6 and the LOW drive gear 26 and the OD drive gear 28, but the second output shaft 20 and the output gear 44 You may provide so that it may connect / cut off. In this case, the LOW drive gear 26 and the OD drive gear 28 are provided integrally with the input shaft 6. Further, in the embodiment, the second clutch 34 is provided so as to connect / disconnect between the auxiliary shaft 8 and the drive gear 32, but is provided so as to connect / disconnect between the input shaft 6 and the drive pulley 14. May be. In this case, the drive gear 32 is provided integrally with the auxiliary shaft 8. In the embodiment, the gear ratio of the LOW 80 (the gear ratio of the LOW driven gear 36 and the LOW driving gear 26) is set to the same value as the CVT minimum speed gear ratio RLOCVT, but a larger value (a lower speed side). Value).

  Further, in the embodiment, a gear type LOWT 80 including a plurality of gears including the LOW drive gear 26 is used as the fixed stage transmission mechanism in the present invention. For example, a fixed-stage transmission mechanism having a chain and a sprocket may be used instead of the gear. In the embodiment, the oil pump 7 is a gear pump, but may be another appropriate pump using an engine as a drive source, such as a vane pump or a trochoid pump. Furthermore, in the embodiment, the engine 3 that is a gasoline engine is used as a power source of the vehicle V, but a diesel engine, an LPG engine, or an electric motor may be used.

  In the embodiment, the transmission 1 according to the present invention is applied to a vehicle drive system. However, the transmission 1 may be applied to another appropriate mechanism, for example, a ship drive system. Variations regarding the above embodiments can be applied in combination as appropriate. In addition, it is possible to appropriately change the detailed configuration within the scope of the gist of the present invention.

V vehicle DW drive wheel
1 Transmission
2 ECU (selection means, gear ratio parameter detection means, travel distance acquisition means, travel
Time acquisition means)
3 Engine (Power source)
7 Oil pump 14 Drive pulley (a pair of pulleys)
14a Fixed sheave 14b Movable sheave 14c Drive pulley oil chamber (oil chamber)
16 Driven pulley (a pair of pulleys)
16a fixed sheave 16b movable sheave 16c driven pulley oil chamber (oil chamber)
17 belt 70 CVT (continuously variable transmission mechanism)
80 LOWT (fixed stage speed change mechanism)
112 Drive pulley angle sensor (speed ratio parameter detecting means)
113 Driven pulley angle sensor (speed ratio parameter detecting means)
114 Hydraulic sensor (hydraulic detection means)
RATCVT CVT gear ratio (speed ratio parameter)
RATREF Predetermined gear ratio PPU Oil chamber oil pressure (oil chamber oil pressure)
PREF Predetermined hydraulic pressure SDI / SI I / S accumulated travel distance (travel distance of the vehicle after the start of automatic stop during travel)
Separated)
tI / S Timer value of the I / S timer (the vehicle travels after the start of automatic stop during travel)
time)
DREF predetermined distance TMREF predetermined time

Claims (3)

A continuously variable transmission mechanism and a meshing fixed-stage transmission mechanism provided in parallel with each other are selectively used as a transmission mechanism for transmitting the power from the power source of the vehicle to the drive wheels of the vehicle in a shifted state. A transmission control device, comprising:
The power source is automatically stopped when a predetermined stop condition is satisfied, is restarted when a predetermined restart condition is satisfied during the automatic stop, and the automatic stop is performed when the vehicle travels. Includes automatic stop when traveling to automatically stop the power source,
The continuously variable transmission mechanism includes a fixed sheave and a movable sheave, each of which has a pair of pulleys each provided with an oil chamber, a belt wound around the pair of pulleys, and the power source as a drive source With the oil pressure supplied from the oil pump to the oil chamber, the movable sheave is moved relative to the fixed sheave, and the effective diameter of each of the pair of pulleys is changed to change the gear ratio steplessly. The belt is configured to be sandwiched between the fixed sheave and the movable sheave.
The fixed stage speed change mechanism is configured to change the power of the power source at a predetermined fixed speed ratio on the low speed side,
Selection means for selecting one of the continuously variable transmission mechanism and the fixed-stage transmission mechanism as the transmission mechanism;
Gear ratio parameter detecting means for detecting a gear ratio parameter representing a gear ratio of the continuously variable transmission mechanism,
In the case where the continuously variable transmission mechanism is selected during the automatic stop during traveling, the selection means has a speed ratio of the continuously variable transmission mechanism represented by the detected speed ratio parameter equal to or greater than a predetermined speed ratio. When a predetermined continuously variable transmission continuation condition including a certain condition is satisfied, the continuously variable transmission mechanism is continuously selected. When the continuously variable transmission continuation condition is not satisfied, the continuously variable transmission mechanism A transmission control apparatus, wherein the transmission mechanism is switched to a fixed-stage transmission mechanism. An oil pressure detecting means for detecting an oil pressure in the oil chamber of at least one of the pair of pulleys ;
2. The transmission control device according to claim 1, wherein the continuously variable transmission continuation condition further includes that the detected hydraulic pressure in the oil chamber is larger than a predetermined hydraulic pressure. A travel distance acquisition means for acquiring a travel distance of the vehicle from when the automatic stop at the time of travel is started;
A travel time acquisition means for acquiring a travel time of the vehicle since the automatic stop at the time of the travel is started,
3. The continuously variable speed continuation condition further includes that the acquired travel distance is smaller than a predetermined distance, and that the acquired travel time is smaller than a predetermined time. The control apparatus of the transmission described in 1.

Images