JP2013174263A - Control device and control method of transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the durability of a transmission by suppressing the drag of a clutch which is a friction engagement element having a cancel oil chamber when a vehicle travels in a cold state.SOLUTION: When a shift ECU determines that the traveling of a vehicle is performed in a cold state based on an outdoor air temperature Ta and an oil temperature Toil (step S120-S140), the formation of a fifth gear and a sixth gear in which a clutch C1 having an cancel oil chamber 1c is released is inhibited among a plurality of gear positions of an automatic transmission 25 (step S160), and the higher the hydraulic oil temperature Toil is, the determination time tref is set longer (step S200), and thereby the inhibition time of the formation of the fifth gear and the sixth gear in which the clutch C1 is released is made longer.

Description

  The present invention selects a plurality of friction engagement elements including at least one clutch mounted on a vehicle and each having an engagement side oil chamber to which hydraulic oil is supplied and a cancellation oil chamber for canceling centrifugal hydraulic pressure. The present invention relates to a transmission control device and a control method that can be engaged with each other to form a plurality of shift stages.

  Conventionally, as a transmission control device capable of selectively engaging a plurality of friction engagement elements to form a plurality of shift stages, when the actual hydraulic oil temperature of the transmission is lower than a predetermined value, In order to suppress the occurrence of seizure due to insufficient lubrication of gear parts rotating at high speed, there is known one that prohibits selection of at least the highest speed shift stage among a plurality of shift stages (for example, Patent Document 1). This control device controls the increase of the line pressure according to the actual hydraulic oil temperature and the prohibition area in which selection of the highest speed shift stage is prohibited according to the hydraulic oil temperature. The shift is controlled separately from the conditional permission region that permits the selection of the shift stage on the side, thereby expanding the temperature range in which the shift stage on the highest speed side can be selected.

JP-A-8-326906

  According to the above-described conventional control device, when the hydraulic oil temperature reaches the lower limit temperature of the conditional permission region, the selection of the speed stage on the highest speed side is permitted. However, in the transmission including the engagement side oil chamber and the clutch having the cancel oil chamber for canceling the centrifugal oil pressure generated in the engagement side oil chamber and acting on the piston, the hydraulic oil is not If the shift restriction is released when the temperature rises to some extent, the clutch may be dragged when any of the shift stages in which the clutch is released is formed.

  Therefore, the transmission control device and the control method according to the present invention improve the durability of the transmission by suppressing the dragging of the clutch having the cancel oil chamber when the vehicle travels in a cold state. The main purpose.

  The transmission control apparatus and control method according to the present invention employ the following means in order to achieve the main object.

A transmission control apparatus according to the present invention includes:
A plurality of frictional engagement elements including at least one clutch mounted on a vehicle and each having an engagement oil chamber to which hydraulic oil is supplied and a cancel oil chamber for canceling centrifugal hydraulic pressure are selectively engaged. In a transmission control device capable of forming a plurality of shift speeds,
Outside temperature acquisition means for acquiring outside temperature;
Oil temperature acquisition means for acquiring the oil temperature of the hydraulic oil;
Cold running determination means for determining whether or not the vehicle travels in a cold state based on at least the outside air temperature acquired by the outside air temperature acquisition means;
Shift limiting means for prohibiting formation of a predetermined shift speed at which the clutch is released among the plurality of shift speeds when the cold travel determination means determines that the vehicle travels in the cold state. And
The shift limiting means extends the formation prohibition time for prohibiting the formation of the predetermined gear stage as the oil temperature acquired by the oil temperature acquisition means is higher.

  When the transmission control device determines that the vehicle travels in a cold state based on at least the outside air temperature, the clutch having the cancel oil chamber is released among the plurality of shift stages of the transmission. The formation of gears is prohibited. That is, when the vehicle is traveling in the cold state and the clutch is released in a state where the hydraulic oil is not sufficiently supplied to the cancel oil chamber, the clutch is released in the engagement-side oil chamber as the constituent members of the clutch rotate. The generated centrifugal hydraulic pressure cannot be cancelled, and the centrifugal hydraulic pressure acts on the components of the clutch, which may cause the clutch to be dragged. For this reason, when it is determined that the vehicle travels in the cold state, this control device prohibits the formation of a predetermined gear stage in which the clutch having the cancel oil chamber is released. Here, if the oil temperature rises to some extent while the formation of the predetermined gear stage is prohibited, the viscosity of the hydraulic oil decreases, so that the hydraulic oil reaches a cancellation oil chamber of the clutch before the cancellation oil chamber. In some cases, a sufficient amount of hydraulic oil may not be supplied to the cancellation oil chamber of the clutch even though the oil temperature has risen to some extent. In view of this, this control device lengthens the formation prohibition time of the predetermined gear stage in which the clutch having the cancel oil chamber is released as the temperature of the hydraulic oil increases. Accordingly, it is possible to prevent the clutch from being released in a state where the hydraulic oil is not sufficiently supplied to the cancel oil chamber due to an increase in the oil temperature. As a result, according to this control device, it is possible to improve the durability of the transmission by satisfactorily suppressing the occurrence of dragging of the clutch having the cancel oil chamber when the vehicle travels in a cold state. Become.

  The cancellation oil chamber of the clutch that is released when the predetermined shift speed is formed may be connected to an operating oil supply source via an operating oil supply path, and the canceling oil is supplied from the operating oil supply path. Another oil passage may be branched on the hydraulic oil supply source side from the chamber. In such a configuration, when the vehicle travels in a cold state, if the oil temperature rises to some extent and the viscosity of the hydraulic oil decreases, the hydraulic oil supply path is closer to the hydraulic oil supply source side than the cancellation oil chamber of the clutch. As a result, the hydraulic oil easily flows into the other branched oil passages. As a result, a sufficient amount of the hydraulic oil may not be supplied to the cancellation oil chamber of the clutch. Therefore, in such a configuration, if the formation prohibition time of the predetermined gear stage in which the clutch having the cancel oil chamber is released is increased as the oil temperature is higher, the cancel oil chamber is provided when the vehicle travels in a cold state. It is possible to suppress the occurrence of clutch drag extremely well.

  Furthermore, the hydraulic oil supply path may include a cooling means for cooling the hydraulic oil on the hydraulic oil supply source side of the cancellation oil chamber of the clutch. That is, when such a cooling means is arranged in the middle of the hydraulic oil supply path, even if the oil temperature rises to some extent, the hydraulic oil tends to stay in the cooling means by being cooled by the cooling means. As a result, it becomes difficult to flow downstream, and as a result, a sufficient amount of hydraulic oil may not be supplied to the cancellation oil chamber of the clutch. Therefore, in such a configuration, the longer the prohibition time for forming the predetermined gear stage in which the clutch having the cancel oil chamber is released, the higher the oil temperature, the longer the clutch is dragged when the vehicle travels in the cold state. It is possible to suppress the occurrence very well.

  In addition, when the predetermined shift speed is formed, any component of the released clutch may rotate at a predetermined rotation speed or higher. In such a configuration, if the formation prohibition time of the predetermined gear stage is increased as the oil temperature is higher, the centrifugal hydraulic pressure generated in the engagement-side oil chamber with the rotation of the released clutch component can be canceled. It is possible to very well suppress the occurrence of dragging of the clutch.

  Further, the cold state may be a state in which at least the oil temperature is equal to or lower than the first oil temperature, and the shift limiting means is configured so that the oil temperature is equal to or higher than the second oil temperature higher than the first oil temperature. Then, the predetermined gear position may be allowed to be formed. In such a configuration, if the prohibition time for the predetermined shift stage is increased as the oil temperature is higher, the oil temperature becomes higher than or equal to the second oil temperature, that is, until the predetermined shift stage is allowed to be formed. The higher the oil temperature, the longer the time for prohibiting the formation of the predetermined gear stage, and it is possible to very well suppress the occurrence of dragging of the clutch having the cancel oil chamber.

A transmission control method according to the present invention includes:
A plurality of frictional engagement elements including at least one clutch mounted on a vehicle and each having an engagement oil chamber to which hydraulic oil is supplied and a cancel oil chamber for canceling centrifugal hydraulic pressure are selectively engaged. In a transmission control method capable of forming a plurality of shift speeds,
(A) determining whether or not the vehicle travels in a cold state based on at least the outside air temperature;
(B) When it is determined in step (a) that the vehicle travels in the cold state, a step of prohibiting the formation of a predetermined shift stage in which the clutch is released among the plurality of shift stages. Including
The step (b) is characterized in that the higher the oil temperature of the hydraulic oil, the longer the formation prohibition time of the predetermined gear stage.

  According to this method, the clutch is prevented from being released when hydraulic oil is not sufficiently supplied to the cancel oil chamber due to the rise in the oil temperature, and the clutch is dragged when the vehicle travels in a cold state. It is possible to improve the durability of the transmission by satisfactorily suppressing the occurrence of the transmission.

It is a schematic block diagram of the motor vehicle 10 carrying the power transmission device 20 containing the automatic transmission 25 controlled by the control apparatus by this invention. FIG. 2 is a schematic configuration diagram showing a power transmission device 20. 3 is an operation table showing a relationship between each gear position of the automatic transmission 25 and operation states of clutches and brakes. 3 is a speed diagram illustrating the relationship of rotational speeds between rotating elements constituting the automatic transmission 25. FIG. 2 is a system diagram showing a hydraulic control device 50. FIG. 3 is a schematic diagram for explaining a hydraulic system for supplying hydraulic oil to clutches C1 to C3 of the automatic transmission 25. FIG. It is a flowchart which shows an example of the shift limitation routine performed by shift ECU21 which is a control apparatus by this invention. It is explanatory drawing which shows an example of the determination time setting map.

  Next, embodiments of the present invention will be described using examples.

  FIG. 1 is a schematic configuration diagram of an automobile 10 equipped with a power transmission device 20 including an automatic transmission 25 controlled by a control device according to the present invention. An automobile 10 shown in the figure includes an engine (internal combustion engine) 12 as a prime mover that outputs power by explosion combustion of a mixture of hydrocarbon fuel such as gasoline and light oil and air, and an engine electronic for controlling the engine 12. A control unit (hereinafter referred to as “engine ECU”) 14, a brake electronic control unit (hereinafter referred to as “brake ECU”) 16 for controlling an electronically controlled hydraulic brake unit (not shown) 16, and an engine 12 are connected to the engine 12. Including a power transmission device 20 that transmits power from the left and right drive wheels DW. The power transmission device 20 includes a transmission case 22, a fluid transmission device (torque converter) 23, an automatic transmission 25, a hydraulic control device 50, and a shift electronic control unit (hereinafter, “ 21) and the like.

  The engine ECU 14 is configured as a microcomputer centering on a CPU (not shown). In addition to the CPU, a ROM that stores various programs, a RAM that temporarily stores data, an input / output port, and a communication port (all not shown). Etc.). As shown in FIG. 1, the engine ECU 14 detects the accelerator opening Acc from the accelerator pedal position sensor 92 that detects the depression amount (operation amount) of the accelerator pedal 91, the vehicle speed V from the vehicle speed sensor 97, and the outside air temperature. The outside air temperature Ta from the outside air temperature sensor 100, signals from various sensors such as a crankshaft position sensor (not shown) for detecting the rotational position of the crankshaft, signals from the brake ECU 16 and the shift ECU 21 and the like are input. Based on these signals, an electronically controlled throttle valve, fuel injection valve, spark plug, etc. (not shown) are all controlled.

  The brake ECU 16 is also configured as a microcomputer centering on a CPU (not shown). In addition to the CPU, a ROM for storing various programs, a RAM for temporarily storing data, an input / output port and a communication port (none of which are shown). ) Etc. As shown in FIG. 1, the brake ECU 16 receives the master cylinder pressure Pmc detected by the master cylinder pressure sensor 94 when the brake pedal 93 is depressed, the vehicle speed V from the vehicle speed sensor 97, various sensors (not shown), and the like. Signals, signals from the engine ECU 14 and the shift ECU 21 and the like are input, and the brake ECU 16 controls a brake actuator (hydraulic actuator) (not shown) based on these signals.

  The speed change ECU 21 is also configured as a microcomputer centered on a CPU (not shown). In addition to the CPU, a ROM that stores various programs, a RAM that temporarily stores data, an input / output port, and a communication port (all not shown). ) Etc. As shown in FIG. 1, the shift ECU 21 includes an accelerator opening Acc from the accelerator pedal position sensor 92, a shift position SP from the shift position sensor 96 that detects the operation position of the shift lever 95, and a vehicle speed from the vehicle speed sensor 97. V, the rotational speed sensor 98 for detecting the input rotational speed of the automatic transmission 25 (the rotational speed of the turbine runner 23b or the input shaft 26 of the automatic transmission 25) Nin, and the hydraulic control device 50 (for example, in a bubble body (not shown)). Signals from various sensors such as an oil temperature sensor 99 that detects the oil temperature Toil of the hydraulic oil, signals from the engine ECU 14 and the brake ECU 16, and the like are input, and the transmission ECU 21 performs automatic transmission and automatic transmission based on these signals. The transmission 25, that is, the hydraulic control device 50 is controlled. The shift position SP that can be set by the shift lever 95 includes a parking position (P position), a reverse position (R position), a neutral position (N position), a forward drive position (D position), and a sports position ( S position) and the like.

  As shown in FIG. 2, the fluid transmission device 23 of the power transmission device 20 is connected to an input-side pump impeller 23 a connected to the crankshaft of the engine 12 and an input shaft (input member) 26 of the automatic transmission 25. The output side turbine runner 23b and the lockup clutch 23c are included. The oil pump 24 is configured as a gear pump including a pump assembly including a pump body and a pump cover, and an external gear connected to the pump impeller 23a of the fluid transmission device 23 via a hub. When the external gear is rotated by the power from the engine 12, the hydraulic oil (ATF) stored in the oil pan (not shown) is sucked by the oil pump 24 and is pumped to the hydraulic control device 50.

  The automatic transmission 25 is configured as a six-speed transmission, and as shown in FIG. 2, a single pinion planetary gear mechanism 30, a Ravigneaux planetary gear mechanism 35, and an input side to an output side. It includes three clutches C1, C2 and C3, two brakes B1 and B2 and a one-way clutch F1 for changing the power transmission path. The single pinion planetary gear mechanism 30 includes a sun gear 31 that is an external gear fixed to the transmission case 22, and an internal gear that is disposed concentrically with the sun gear 31 and connected to an input shaft (input member) 26. A ring gear 32, a plurality of pinion gears 33 that mesh with the sun gear 31 and mesh with the ring gear 32, and a carrier 34 that holds the plurality of pinion gears 33 so as to rotate and revolve.

  The Ravigneaux planetary gear mechanism 35 meshes with two sun gears 36a and 36b that are external gears, a ring gear 37 that is an internal gear fixed to the output shaft (output member) 27 of the automatic transmission 25, and the sun gear 36a. A plurality of short pinion gears 38a, a plurality of long pinion gears 38b meshed with the sun gear 36b and the plurality of short pinion gears 38a and meshed with the ring gear 37, and a plurality of short pinion gears 38a and a plurality of long pinion gears 38b coupled to each other. And a carrier 39 supported by the transmission case 22 via a one-way clutch F1. The output shaft 27 of the automatic transmission 25 is connected to the drive wheels DW via a gear mechanism 28 and a differential mechanism 29.

  The clutch C1 includes a piston, a plurality of friction plates and mating plates, an engagement side oil chamber 1e to which hydraulic oil is supplied, and a cancel oil chamber 1c for canceling centrifugal hydraulic pressure generated in the engagement side oil chamber 1e. (See FIG. 6) and the like, and the carrier 34 of the single pinion planetary gear mechanism 30 and the sun gear 36a of the Ravigneaux planetary gear mechanism 35 can be fastened and the fastening of both can be released. It is a multi-plate friction type hydraulic clutch (friction engagement element). The clutch C2 includes a piston, a plurality of friction plates and a mating plate, an engagement side oil chamber 2e to which hydraulic oil is supplied, and a cancel oil chamber 2c for canceling centrifugal hydraulic pressure generated in the engagement side oil chamber 2e. (See FIG. 6) A multi-plate friction type hydraulic clutch having a hydraulic servo constituted by, etc., capable of fastening the input shaft 26 and the carrier 39 of the Ravigneaux type planetary gear mechanism 35 and releasing the fastening of both. is there. The clutch C3 includes a piston, a plurality of friction plates and mating plates, an engagement side oil chamber 3e to which hydraulic oil is supplied, and a cancel oil chamber 3c for canceling centrifugal hydraulic pressure generated in the engagement side oil chamber 3e. (See FIG. 6) and the like, and the carrier 34 of the single pinion planetary gear mechanism 30 and the sun gear 36b of the Ravigneaux planetary gear mechanism 35 can be fastened and the fastening of both can be released. This is a multi-plate friction hydraulic clutch.

  The brake B1 is configured as a band brake or a multi-plate friction brake including a hydraulic servo, and fixes the sun gear 36b of the Ravigneaux type planetary gear mechanism 35 to the transmission case 22 and releases the fixation of the sun gear 36b to the transmission case 22. It is a hydraulic brake that can. The brake B2 is configured as a band brake or a multi-plate friction brake including a hydraulic servo, and fixes the carrier 39 of the Ravigneaux type planetary gear mechanism 35 to the transmission case 22 and releases the fixing of the carrier 39 to the transmission case 22. It is a hydraulic brake that can.

  These clutches C <b> 1 to C <b> 3 and brakes B <b> 1 and B <b> 2 operate by receiving and supplying hydraulic oil from the hydraulic control device 50. FIG. 3 shows an operation table showing the relationship between the respective speeds of the automatic transmission 25 and the operating states of the clutches C1 to C3 and the brakes B1 and B2. FIG. The speed diagram which illustrates the relationship of the rotational speed in is shown. The automatic transmission 25 sets the clutches C1 to C3 and the brakes B1 and B2 to the states shown in the operation table of FIG. 3 so that the forward 1st to 6th gears and the reverse gear 1 as shown in FIG. And provide.

  FIG. 5 is a system diagram showing the hydraulic control device 50. The hydraulic control device 50 is connected to the above-described oil pump 24 that is driven by the power from the engine 12 and sucks and discharges hydraulic oil from the oil pan, and is requested by the fluid transmission device 23 and the automatic transmission 25. The hydraulic oil is generated and hydraulic oil is supplied to lubricated parts such as various bearings. In addition to the valve body (not shown), the hydraulic control device 50 adjusts the hydraulic oil from the oil pump 24 to generate the line pressure PL and the operation position of the shift lever 95 as shown in FIG. Accordingly, the manual valve 52 for switching the supply destination of the line pressure PL from the primary regulator valve 51, the apply control valve 53, and the line pressure PL as the original pressure supplied from the manual valve 52 (primary regulator valve 51) are regulated. Including a first linear solenoid valve SL1, a second linear solenoid valve SL2, a third linear solenoid valve SL3, a fourth linear solenoid valve SL4, and the like as pressure regulating valves that generate hydraulic pressure to the corresponding clutch and the like.

  The primary regulator valve 51 generates a line pressure using the hydraulic pressure from the linear solenoid valve SLT as a signal pressure. The linear solenoid valve SLT adjusts hydraulic oil from the oil pump 24 side (for example, a modulator valve that regulates the line pressure PL and outputs a constant hydraulic pressure) to respond to an accelerator opening Acc or a throttle valve opening (not shown). The transmission ECU 21 is controlled to output the hydraulic pressure.

  The manual valve 52 is connected to the shift lever 95 in the axially slidable spool, the input port to which the line pressure PL is supplied, the input port of the first to fourth linear solenoid valves SL1 to SL4 and the oil passage. A drive range output port, a reverse range output port, and the like communicating with each other (both not shown). When the forward driving shift position such as the D position or the S position is selected by the driver, the input port is communicated only with the drive range output port by the spool of the manual valve 52, whereby the first to fourth linear solenoids are connected. A line pressure PL as a drive range pressure is supplied to the valves SL1 to SL4. Further, when the R range is selected by the driver, the input port is communicated only with the reverse range output port by the spool of the manual valve 52. Further, when the driver selects the P position or N position, the spool of the manual valve 52 blocks communication between the input port, the drive range output port, and the reverse range output port.

  The apply control valve 53 supplies the hydraulic pressure from the third linear solenoid valve SL3 to the clutch C3, the line pressure PL from the primary regulator valve 51 to the clutch C3, and the reverse range output port of the manual valve 52. The second state in which the line pressure PL (reverse range pressure) is supplied to the brake B2, and the line pressure PL (reverse range pressure) from the reverse range output port of the manual valve 52 is supplied to the clutch C3 and the brake B2. The spool valve can selectively form a third state and a fourth state in which the hydraulic pressure from the third linear solenoid valve SL3 is supplied to the brake B2.

  The first linear solenoid valve SL1 is a normally closed linear solenoid valve that adjusts the line pressure PL from the manual valve 52 according to the applied current to generate the hydraulic pressure Psl1 to the clutch C1. The second linear solenoid valve SL2 is a normally closed linear solenoid valve that adjusts the line pressure PL from the manual valve 52 according to the applied current to generate the hydraulic pressure Psl2 to the clutch C2. The third linear solenoid valve SL3 is a normally closed linear solenoid valve that adjusts the line pressure PL from the manual valve 52 according to the applied current to generate the hydraulic pressure Psl3 to the clutch C3 or the brake B2. The fourth linear solenoid valve SL4 is a normally closed linear solenoid valve that adjusts the line pressure PL from the manual valve 52 according to the applied current to generate the hydraulic pressure Psl4 to the brake B1. That is, the hydraulic pressures to the clutches C1 to C3 and the brakes B1 and B2 that are the friction engagement elements of the automatic transmission 25 are respectively corresponding to the first, second, third, or fourth linear solenoid valves SL1, SL2, and SL3. Or it is directly controlled (set) by SL4.

  Further, among the frictional engagement elements constituting the automatic transmission 25, the canceling oil chambers 1c, 2c and 3c of the clutches C1 to C3 are supplied with the operating oil via the operating oil supply path 70 as shown in FIG. Supplied. The hydraulic oil supply path 70 is formed in the components of the clutches C1 to C3 such as a clutch drum inside the input shaft 26, and the hydraulic oil from the hydraulic control device 50 as a hydraulic oil supply source is supplied to the hydraulic oil supply path 70. Inflow. In the embodiment, the hydraulic control device 50 includes a secondary regulator valve (not shown) that adjusts hydraulic fluid drained from the primary regulator valve 51 to generate a secondary pressure as the line pressure PL is generated. The supply passage 70 is supplied with hydraulic oil drained from the secondary regulator valve as the secondary pressure is generated and from the fluid transmission chamber after being supplied from the secondary regulator valve to the fluid transmission chamber (torus) of the fluid transmission device 23. The discharged hydraulic oil is selectively supplied.

  Further, an oil cooler (cooling means) 71 for cooling the hydraulic oil from the hydraulic control device 50 (fluid transmission device 23) is disposed in the middle of the hydraulic oil supply path 70, and a cancel oil chamber for the clutches C1 to C3. The hydraulic oil cooled by the oil cooler 71 is supplied to 1c, 2c and 3c. Then, as shown in FIG. 6, the hydraulic oil is supplied to the cancel oil chamber 3 c of the clutch C <b> 3 on the upstream side (hydraulic control device 50 side) of the cancel oil chamber 1 c of the clutch C <b> 1. An oil path 73 for supplying oil and an oil path 72 for supplying hydraulic oil to the cancel oil chamber 2c of the clutch C2 are branched. Accordingly, among the cancel oil chambers 1c to 3c, the cancel oil chamber 1c of the clutch C1 is farthest from the hydraulic control device 50 or the oil cooler 71 as a hydraulic oil supply source. Furthermore, in addition to the oil passages 72 and 73, an oil passage (not shown) for supplying the working oil as a lubricating medium to a bearing (not shown) of the automatic transmission 25 is branched from the hydraulic oil supply passage 70. From the viewpoint of cost reduction and the like, in the embodiment, a bypass oil passage, a thermostat, and the like for enabling the oil cooler to be bypassed according to the oil temperature Toil are omitted from the hydraulic oil supply passage 70.

  The above-described first to fourth linear solenoid valves SL1 to SL4 (currents applied thereto) are controlled by the transmission ECU 21. That is, the speed change ECU 21 changes the speed stage so that a target speed stage Gtag corresponding to the accelerator opening degree Acc (or the opening degree of the throttle valve) and the vehicle speed V acquired from a predetermined speed change diagram (not shown) is formed. A hydraulic pressure command value (engagement pressure command value) to any one of the first to fourth linear solenoid valves SL1 to SL4 corresponding to the clutch or brake (engagement element) engaged with the change of Sets a hydraulic pressure command value (release pressure command value) to any one of the first to fourth linear solenoid valves SL1 to SL4 corresponding to the clutch or brake (release element) released in accordance with the change of the gear position. To do. Further, the shift ECU 21 changes any one or two of the first to fourth linear solenoid valves SL1 to SL4 corresponding to the engaged clutch or brake (engagement element) during the shift stage change or after the shift is completed. Set the hydraulic pressure command value (holding pressure command value) to For this reason, the shift ECU 21 has the above-described hydraulic pressure command value, that is, the engagement pressure command value, the release pressure command value, in cooperation with hardware such as CPU, ROM, and RAM and software such as a control program installed in the ROM. And a shift control module (not shown) for setting the holding pressure command value is constructed as a functional block.

  Here, when the vehicle 10 travels in a cold state in which the outside air temperature Ta and the oil temperature Toil are very low, particularly when the ignition switch (start switch) is turned on in the cold state and the vehicle 10 starts traveling. If the viscosity of the hydraulic oil increases, the hydraulic oil may not be sufficiently supplied to the cancel oil chambers 1c to 3c of the clutches C1 to C3. When the clutch is released in a state where the hydraulic oil is not sufficiently supplied to the cancel oil chamber or the like, the interior of the engagement side oil chamber is increased as the constituent member (for example, clutch drum) of the clutch rotates at high speed. It is impossible to cancel the centrifugal hydraulic pressure generated in the step 1, and the centrifugal hydraulic pressure acts on the piston, so that the piston presses the friction material or the like, and the clutch may be dragged.

  However, as can be seen from FIG. 3 and FIG. 4, among the clutches C1 to C3, the clutches C2 and C3 are engaged when the high speed stage in which the vehicle speed V is relatively increased is formed. Therefore, even when the clutch C2 and C3 are released when the hydraulic oil is not sufficiently supplied to the cancel oil chambers 2c and 3c when the automobile 10 is traveling in the cold state, the constituent members of the clutches C2 and C3 are used. Is very unlikely to rotate at high speed. On the other hand, the clutch C1, which is a starting clutch that is engaged when the vehicle 10 starts, is engaged when the first to fourth speeds are formed, while the fifth speed and the sixth speed that are high speed stages. When the fifth speed and the sixth speed are formed, one of the constituent members (for example, the clutch drum) of the clutch C1 rotates at a predetermined rotational speed or more. Therefore, when the vehicle 10 travels in the cold state, the clutch C1 is released with the formation of the fifth speed and the sixth speed, and the clutch C1 is in a state where the hydraulic oil is not sufficiently supplied to the cancel oil chamber 1c. If a component member (for example, a clutch drum) rotates at the predetermined number of rotations or more, there is a possibility that the clutch C1 may be dragged. Therefore, in the automatic transmission 25 according to the embodiment, when the vehicle 10 starts running in the cold state (when the vehicle 10 runs in the cold state), the fifth speed and the sixth speed at which the clutch C1 is released. The formation of speed is prohibited.

  Next, a procedure for restricting the shift of the automatic transmission 25 when the vehicle 10 travels in a cold state, that is, a procedure for prohibiting the fifth speed and the sixth speed of the automatic transmission 25 will be described. FIG. 7 is a flowchart illustrating an example of a shift limiting routine that is executed by the shift ECU 21 when the ignition switch of the automobile 10 is turned on.

  At the start of the shift restriction routine of FIG. 7, the shift ECU 21 (CPU not shown) performs input processing of necessary data such as the shift position SP from the shift position sensor 96, the outside air temperature Ta, and the oil temperature Toil from the oil temperature sensor 99. Execute (Step S100). In the embodiment, the outside air temperature Ta detected by the outside air temperature sensor 100 is input from the engine ECU 14 by communication. After the input process of step S100, the shift ECU 21 determines whether or not the flag F set to the value 0 is 0 before the start of this routine (step S110).

  When it is determined that the flag F is 0, the speed change ECU 21 determines whether or not the outside air temperature Ta input in step S100 is less than a predetermined first outside air temperature Ta1 (for example, about −20 ° C.). (Step S120). When it is determined in step S120 that the outside air temperature Ta is equal to or higher than the first outside air temperature Ta1, the shift ECU 21 is not so low that the outside air temperature Ta prohibits the fifth speed and the sixth speed of the automatic transmission 25 from being formed. This routine is terminated. If it is determined in step S120 that the outside air temperature Ta is lower than the first outside air temperature Ta1, the transmission ECU 21 sets the oil temperature Toil input in step S100 to a first oil temperature To1 (for example, 70 ° C.) that is set in advance. It is judged whether it is less than (about) (step S130). When it is determined in step S130 that the oil temperature Toil is equal to or higher than the first oil temperature To1, the transmission ECU 21 is not so low that the oil temperature Toil prohibits the fifth speed and the sixth speed of the automatic transmission 25 from being formed. This routine is terminated.

  On the other hand, when it is determined in step S130 that the oil temperature Toil is lower than the first oil temperature To1, the shift ECU 21 is in the forward travel position such as the D position or the S position where the shift position SP input in step S100 is. It is determined whether or not there is (step S140). If it is determined in step S140 that the shift position SP is a forward travel position such as the D position, it is considered that the forward travel of the automobile 10 may be started and the automatic transmission 25 may be shifted, and the speed change ECU 21 Turns on a timer (not shown) and sets the flag F to 1 (step S150), and then sets the fifth and sixth speed prohibition flag Fhg to prohibit the fifth and sixth speeds of the automatic transmission 25. Is set to 1 (step S160). Thus, when the 5-6 speed formation prohibition flag Fhg is set to the value 1 in step S160, the fifth speed of the automatic transmission 25 and the automatic transmission 25 are set until the 5-6 speed formation prohibition flag Fhg is set to the value 0. Formation of the sixth speed is prohibited, and the transmission ECU 21 controls the hydraulic control device 50 so that only the fourth speed is formed from the first speed other than the fifth speed and the sixth speed. When the processes of steps S150 and S160 are executed, the shift ECU 21 thereafter executes this routine every predetermined time.

  If it is determined in step S140 that the shift position SP is a P position, R position, or N position other than the forward travel position, the transmission ECU 21 regards that the forward travel of the automobile 10 is not started, and in steps S150 and S160. Thereafter, this routine is executed every predetermined time without executing the processing. When the driver selects the R position, the clutch C3 is engaged. However, in the automatic transmission 25 according to the embodiment, when the R position is selected, the constituent members of the clutch C3 drag the clutch C3. The R position is excluded from the determination target in step S140 because the possibility of high-speed rotation is low enough to be generated.

  As described above, when an affirmative determination is made in all of steps S110, S120, and S130, flag F is set to a value of 1 in step S150, and thereafter, the processing after step S100 is executed every predetermined time. When the determination is made, a negative determination is made in step S110. When it is determined in step S110 that the flag F has a value of 1, the transmission ECU 21 sets a second predetermined temperature as the outside air temperature Ta input in step S100 is higher than the first outside air temperature Ta1. It is determined whether or not the ambient temperature is less than Ta2 (for example, about −15 ° C.) (step S170). When it is determined in step S170 that the outside air temperature Ta is equal to or higher than the second outside air temperature Ta2, the shift ECU 21 increases to a level that allows the outside air temperature Ta to allow the fifth speed and the sixth speed of the automatic transmission 25 to be formed. Therefore, the 5-6 speed formation prohibition flag Fhg is set to 0 (step S220), the timer is turned off and the flag F is set to 0 (step S230), and this routine is terminated. .

  When it is determined in step S170 that the outside air temperature Ta is lower than the second outside air temperature Ta2, the shift ECU 21 sets the oil temperature Toil input in step S100 as a value higher than the first oil temperature To1. It is determined whether or not the temperature is lower than a predetermined second oil temperature To2 (for example, about 75 ° C.) (step S180). If it is determined in step S180 that the oil temperature Toil is equal to or higher than the second oil temperature To2, the transmission ECU 21 increases to such an extent that the oil temperature Toil can allow the fifth speed and the sixth speed of the automatic transmission 25 to be formed. Therefore, the 5-6 speed formation prohibition flag Fhg is set to 0 (step S220), the timer is turned off and the flag F is set to 0 (step S230), and this routine is terminated. .

  Further, when it is determined in step S180 that the oil temperature Toil is lower than the second oil temperature To2, the shift ECU 21 determines whether the shift position SP input in step S100 is a forward travel position such as the D position or the S position. Is determined (step S190). When it is determined in step S190 that the shift position SP is a P position, R position, or N position other than the forward travel position, the shift ECU 21 regards the forward travel of the automobile 10 as having been completed, and forms the 5-6 speed described above. The prohibition flag Fhg is set to 0 (step S220), the timer is turned off and the flag F is set to 0 (step S230), and this routine is terminated.

  On the other hand, when it is determined in step S190 that the shift position SP is the forward travel position, the transmission ECU 21 sets the outside air temperature Ta and the oil temperature Toil input in step S100 from the determination time setting map created in advance. A corresponding value is derived, and the derived value is set as a determination time tref as a threshold (step S200), and it is then determined whether or not the time measured by the timer is equal to or greater than the determination time tref (step S210). . If it is determined in step S210 that the time count t is less than the determination time tref, the shift ECU 21 executes the processes in and after step S100 again. When the shift ECU 21 determines in step S210 that the time t is greater than or equal to the determination time tref, the shift ECU 21 sets the 5-6 speed formation prohibition flag Fhg to 0 (step S220), turns off the timer, and sets the flag. F is set to 0 (step S230), and this routine is terminated.

  FIG. 8 illustrates the determination time setting map used in step S200. As shown in the figure, the determination time setting map of the embodiment sets the second oil temperature To2 as an upper limit, increases the determination time tref as the oil temperature Toil of the hydraulic oil is higher, and sets the second outside air temperature Ta2. As an upper limit, it is created in advance through experiments and analysis so as to make the determination time tref longer as the outside air temperature Ta is lower, and is stored in the ROM of the transmission ECU 21. Thus, in the automatic transmission 25 according to the embodiment, the higher the oil temperature Toil of the hydraulic oil is, the higher the hydraulic oil temperature Toil is determined to be acceptable in any one of steps S170, S180, and S190. In addition, as the outside air temperature Ta is lower, the formation prohibition time for the fifth speed and the sixth speed is set longer. That is, the determination time tref set in step S200 corresponds to the formation prohibition time for the fifth speed and the sixth speed.

  That is, in the automatic transmission 25 according to the embodiment, the cancel oil chamber 1c of the clutch C1 that is released when the fifth speed and the sixth speed are formed is a hydraulic control device as a hydraulic oil supply source via the hydraulic oil supply path 70. As described above, the hydraulic oil is supplied to the cancel oil chamber 3c of the clutch C3 on the upstream side (hydraulic control device 50 side) from the cancel oil chamber 1c. An oil passage 73 for supplying hydraulic oil to the cancel oil chamber 2c of the clutch C2 and an oil passage 73 for branching are branched. Therefore, after the vehicle 10 starts running in the cold state, when the oil temperature Toil increases to some extent and the viscosity of the hydraulic oil decreases, the hydraulic oil branches from the hydraulic oil supply path 70 upstream of the cancel oil chamber 1c of the clutch C1. As a result, the hydraulic oil easily flows into the canceled oil passages 72 and 73, that is, the cancel oil chambers 2c and 3c of the clutches C2 and C2, and other bearings. As a result, a sufficient amount of the hydraulic oil enters the cancel oil chamber 1c of the clutch C1. It may not be supplied.

  In the automatic transmission 25 of the embodiment, the hydraulic oil supply path 70 includes an oil cooler 71 that cools the hydraulic oil upstream of the cancel oil chamber 1c of the clutch C1. Therefore, even if the oil temperature Toil increases to some extent, the oil is apt to stay in the oil cooler 71 due to being cooled by the oil cooler 71, so that it is difficult for the hydraulic oil to flow downstream. As a result, the cancel oil chamber of the clutch C1 The amount of 1c oil may be further insufficient. And when the bypass circuit which bypasses the oil cooler 71 is not provided in the hydraulic oil supply path 70, especially such a tendency becomes strong.

  In consideration of these, in the automatic transmission 25 according to the embodiment, the determination time tref is set longer as the oil temperature Toil of the hydraulic oil is higher, and thereby the fifth speed and the sixth speed at which the clutch C1 is released are prohibited. The time will be longer. Accordingly, it is possible to prevent the clutch C1 from being released in a state where the hydraulic oil is not sufficiently supplied to the cancel oil chamber 1c due to the increase in the oil temperature Toil. As a result, it is possible to improve the durability of the automatic transmission 25 by satisfactorily suppressing the occurrence of dragging of the clutch C1 having the cancel oil chamber 1c when the automobile 10 travels in a cold state.

  As described above, when the shift ECU 21, which is the control device of the automatic transmission 25 (power transmission device 20), determines that the vehicle 10 is traveling in the cold state based on the outside air temperature Ta and the oil temperature Toil. (Steps S120 to S140), among the plurality of shift stages of the automatic transmission 25, the formation of the fifth speed and the sixth speed at which the clutch C1 is released is prohibited (Step S160). Then, the transmission ECU 21 sets the determination time tref to be longer as the hydraulic oil temperature Toil is higher (step S200), thereby lengthening the formation prohibition time of the fifth speed and the sixth speed at which the clutch C1 is released. As a result, when the vehicle 10 is traveling in a cold state, it is possible to prevent the clutch C1 from being released when hydraulic oil is not sufficiently supplied to the cancel oil chamber 1c due to an increase in the oil temperature Toil. Thus, it is possible to improve the durability of the automatic transmission 25 by satisfactorily suppressing the occurrence of dragging of the clutch C1 having the cancel oil chamber 1c.

  In other words, in the above-described embodiment, the cancel oil chamber 1c of the clutch C1 is connected to the hydraulic control device 50 as a hydraulic oil supply source via the hydraulic oil supply path 70. An oil passage 73 for supplying hydraulic oil to the cancel oil chamber 3c of the clutch C3 and an oil passage 72 for supplying hydraulic oil to the cancel oil chamber 2c of the clutch C2 are branched upstream of the chamber 1c. . For this reason, in the automatic transmission 25, after the vehicle 10 starts running in the cold state (when the vehicle 10 runs in the cold state), the oil temperature Toil increases to some extent and the viscosity of the hydraulic oil decreases. The oil passages 72 and 73 branched from the hydraulic oil supply passage 70 on the upstream side of the cancel oil chamber 1c of the clutch C1 are easy to flow in the hydraulic oil, and the oil temperature Toil is increased, but the clutch C1 A sufficient amount of hydraulic oil may not be supplied to the cancel oil chamber 1c. Therefore, in the automatic transmission 25 having such a configuration, if the formation prohibition time of the fifth speed and the sixth speed at which the clutch C1 is released is increased as the oil temperature Toil is higher, the automobile 10 travels in a cold state. In this case, it is possible to suppress the occurrence of dragging of the clutch C1 having the cancel oil chamber 1c very well.

  Further, in the above embodiment, the oil cooler 71 for cooling the hydraulic oil is arranged in the middle of the hydraulic oil supply passage 70 upstream of the cancel oil chamber 1c of the clutch C1, so that the oil temperature Toil increases to some extent. However, since the oil is cooled by the oil cooler 71, the hydraulic oil tends to stay in the oil cooler 71 and hardly flows downstream. As a result, the amount of oil in the cancel oil chamber 1c of the clutch C1 is further insufficient. May end up. Therefore, in such a configuration including the oil cooler 71, the higher the oil temperature Toil, the longer the formation prohibition time of the fifth speed and the sixth speed at which the clutch C1 is disengaged, the vehicle 10 travels in the cold state. At this time, it is possible to very well prevent the dragging of the clutch C1 having the cancel oil chamber 1c.

  Furthermore, in the automatic transmission 25, when the fifth speed and the sixth speed on the high speed side are formed, the component (clutch drum) of the clutch C1 to be released rotates at a predetermined rotational speed or higher. Accordingly, in such an automatic transmission 25, if the formation prohibition time of the fifth speed and the sixth speed is increased as the oil temperature Toil is higher, the engagement-side oil is accompanied with the rotation of the released component of the clutch C1. Since it becomes impossible to cancel the centrifugal hydraulic pressure generated in the chamber 1e, it is possible to very well prevent the dragging of the clutch C1. However, in the gear stage that is prohibited to be formed as described above, the clutch constituent member released in a state where the hydraulic oil is not sufficiently supplied to the cancel oil chamber may cause the clutch to be dragged. As long as the gear is rotated by a number, the gear is not necessarily limited to the gear on the high speed side.

  Further, in the above embodiment, when it is determined that the vehicle 10 is traveling in a cold state in which the outside air temperature Ta is not less than the first outside air temperature Ta1 and the oil temperature Toil is not more than the first oil temperature Toil, Formation of the fifth speed and the sixth speed of the transmission 25 is prohibited, and the outside air temperature Ta becomes the second outside air temperature Ta2 higher than the first outside air temperature Ta1, or the oil temperature Toil is higher than the first oil temperature Toil. If the temperature is higher than the second oil temperature Toil, the fifth speed and the sixth speed are allowed to be formed. In the above embodiment, when the outside air temperature Ta is less than the second outside air temperature Ta2, the oil temperature Toil is less than the second oil temperature Toil, and the forward travel position is selected, the oil temperature Toil of the hydraulic oil is selected. The higher the is, the longer the determination time tref is set. In such a configuration, the higher the oil temperature Toil, the longer the formation prohibition time of the fifth speed and the sixth speed at which the clutch C1 is disengaged, the outside temperature Ta and the oil temperature Toil are increased sufficiently. Until the formation of the fifth speed and the sixth speed is permitted, the higher the oil temperature Toil, the longer the formation prohibition time of the fifth speed and the sixth speed is increased, and it is extremely favorable that the dragging of the clutch C1 occurs. It becomes possible to suppress.

  It should be noted that whether the automatic transmission 25 is in a cold state in which the formation of the fifth speed and the sixth speed should be prohibited when the automobile 10 travels (starts traveling) is either the outside air temperature Ta or the oil temperature Toil. May be determined based on Further, depending on a typical traveling mode of the automobile 10, even if the clutch C1 is released in association with the formation of the fifth speed or the sixth speed, the constituent member (for example, clutch drum) of the clutch C1 is equal to or higher than the predetermined rotational speed. In many cases, it does not rotate. Therefore, when the vehicle 10 travels in the cold state, it is not necessary to prohibit all of the gear positions where the clutch C1 is released. For example, when the vehicle 10 travels in the cold state, the sixth speed of the automatic transmission 25, for example. Only the formation of may be prohibited. Further, as the outside air temperature sensor 100, a sensor that detects the intake air temperature of the engine 12 may be used. In this case, all the steps S120 to S140 are affirmed so that the difference between the intake air temperature and the outside air temperature is eliminated. When the determination is made and the vehicle speed V is equal to or higher than the predetermined vehicle speed, it is preferable to determine that the automatic transmission 25 is in a cold state in which the formation of the fifth speed and the sixth speed should be prohibited. Moreover, in the said Example, what was detected by the outside temperature sensor 100 is used as the outside temperature Ta, However, It is not restricted to this, For example, the outside temperature Ta is detected by the cooling water temperature sensor which is not illustrated, for example. It may be estimated from the cooling water temperature of the engine 12, and the outside air temperature Ta thus estimated may be input (acquired) in step S100.

  Here, the correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In other words, in the above-described embodiment, a plurality of clutches C1 including the clutch C1 that is mounted on the automobile 10 and has the engagement side oil chamber 1e to which the hydraulic oil is supplied and the cancel oil chamber 1c for canceling the centrifugal hydraulic pressure. ˜C3 and the brakes B1 and B2 are selectively engaged, and the shift ECU 21 of the automatic transmission 25 that can form a plurality of shift speeds corresponds to the “control device” and executes the input process in step S100 of FIG. The speed change ECU corresponds to “outside air temperature acquisition means” and “oil temperature acquisition means”, and the speed change ECU 21 that executes the processing of steps S120 to S140 in FIG. 7 corresponds to “cold running determination means”. The shift ECU 21 that executes the processes of S150 to S230 corresponds to “shift limiter”.

  However, the correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the invention described in the column of means for solving the problem by the embodiment. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. In other words, the examples are merely specific examples of the invention described in the column of means for solving the problem, and the interpretation of the invention described in the column of means for solving the problem is It should be done based on the description.

  As mentioned above, although the embodiment of the present invention has been described using examples, the present invention is not limited to the above-described examples, and various modifications can be made without departing from the scope of the present invention. Needless to say.

  The present invention can be used in the transmission manufacturing industry.

  DESCRIPTION OF SYMBOLS 10 Automotive, 12 Engine, 14 Engine electronic control unit (engine ECU), 16 Brake electronic control unit (brake ECU), 20 Power transmission device, 21 Transmission electronic control unit (transmission ECU), 22 Transmission case, 23 Fluid Transmission device, 23a pump impeller, 23b turbine runner, 23c lock-up clutch, 24 oil pump, 25 automatic transmission, 26 input shaft, 27 output shaft, 28 gear mechanism, 29 differential mechanism, 30 single pinion planetary gear mechanism, 31, 36a, 36b Sun gear, 32, 37 ring gear, 33 pinion gear, 34, 39 carrier, 35 Ravigneaux planetary gear mechanism, 38a short pinion gear, 38b long pinion gear, 50 hydraulic control device, 51 primer Regulator valve, 52 Manual valve, 53 Apply control valve, 70 Hydraulic oil supply path, 71 Oil cooler, 72, 73 Oil path, 91 Accel pedal, 92 Accel pedal position sensor, 93 Brake pedal, 94 Master cylinder pressure sensor, 95 Shift Lever, 96 shift position sensor, 97 vehicle speed sensor, 98 rotational speed sensor, 99 oil temperature sensor, 100 outside air temperature sensor, B1, B2 brake, C1, C2, C3 clutch, 1c, 2c, 3c cancel oil chamber, 1e, 2e 3e Engagement side oil chamber, F1 one-way clutch, SL1 first linear solenoid valve, SL2 second linear solenoid valve, SL3 third linear solenoid valve, SL4 fourth linear solenoid valve, SLT linear solenoid Id valve.

Claims (6)

A plurality of frictional engagement elements including at least one clutch mounted on a vehicle and each having an engagement oil chamber to which hydraulic oil is supplied and a cancel oil chamber for canceling centrifugal hydraulic pressure are selectively engaged. In a transmission control device capable of forming a plurality of shift speeds,
Outside temperature acquisition means for acquiring outside temperature;
Oil temperature acquisition means for acquiring the oil temperature of the hydraulic oil;
Cold running determination means for determining whether or not the vehicle travels in a cold state based on at least the outside air temperature acquired by the outside air temperature acquisition means;
Shift limiting means for prohibiting formation of a predetermined shift speed at which the clutch is released among the plurality of shift speeds when the cold travel determination means determines that the vehicle travels in the cold state. And
The transmission control apparatus according to claim 1, wherein the shift restriction unit extends a formation prohibition time for prohibiting the formation of the predetermined shift stage as the oil temperature acquired by the oil temperature acquisition unit increases. The transmission control device according to claim 1,
The cancellation oil chamber of the clutch that is released when the predetermined shift speed is formed is connected to a hydraulic oil supply source via a hydraulic oil supply path.
2. A transmission control apparatus according to claim 1, wherein another hydraulic path is branched from the hydraulic oil supply path closer to the hydraulic oil supply source than the cancel oil chamber. The transmission control device according to claim 2,
The transmission control device according to claim 1, wherein the hydraulic oil supply path includes a cooling unit that cools the hydraulic oil on a side closer to the hydraulic oil supply source than the cancel oil chamber of the clutch. The transmission control device according to any one of claims 1 to 3,
The transmission control apparatus according to claim 1, wherein when the predetermined shift speed is formed, any one of the components of the clutch to be released rotates at a predetermined rotation speed or higher. In the transmission control device according to any one of claims 1 to 4,
The cold state is a state where at least the oil temperature is equal to or lower than the first oil temperature,
The transmission control device according to claim 1, wherein the shift limiting unit allows the formation of the predetermined shift stage when the oil temperature is equal to or higher than a second oil temperature higher than the first oil temperature. A plurality of frictional engagement elements including at least one clutch mounted on a vehicle and each having an engagement oil chamber to which hydraulic oil is supplied and a cancel oil chamber for canceling centrifugal hydraulic pressure are selectively engaged. In a transmission control method capable of forming a plurality of shift speeds,
(A) determining whether or not the vehicle travels in a cold state based on at least the outside air temperature;
(B) When it is determined in step (a) that the vehicle travels in the cold state, a step of prohibiting the formation of a predetermined shift stage in which the clutch is released among the plurality of shift stages. Including
Step (b) is a transmission control method characterized in that the higher the oil temperature of the hydraulic oil, the longer the formation prohibition time of the predetermined gear stage.

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