JP7353719B2 - Automatic transmission control device - Google Patents

Description

The present invention relates to a control device for an automatic transmission mounted on a vehicle.

A first friction element that is engaged in the first gear, released in the second gear after the first gear, and engaged in the third gear after the second gear, and released in the first gear and engaged in the second gear. It includes a second friction element that is engaged at the third gear, and a third friction element that is engaged at the first gear, engaged at the second gear, and released at the third gear. If the target gear changes from the second gear to the third gear after the start of the inertia phase of the first gear is detected, the second gear is started while the first gear is being executed, and the hydraulic pressure applied to the first friction element is A control device for an automatic transmission is known that is configured to compare a hydraulic pressure command value for a first shift and a hydraulic pressure command value for a second shift and select the larger one as a command value (Patent Document 1). ). Note that the second speed change control means once outputs a high-pressure hydraulic command value when the first friction element is engaged, and then executes precharge control in which the pressure is held at a low pressure to accelerate the piston stroke, and the third friction element control It is disclosed that the precharge control by the second shift control means is prohibited.

Japanese Patent Application Publication No. 2007-170638

However, in the prior art described in Patent Document 1, for the purpose of executing speed change control, the second speed change is started before the first speed change ends, so that the first speed change and the second speed change are performed. The control is made to overlap. For this reason, the increase in the engagement oil pressure to the friction elements engaged in the first shift and the supply of precharge pressure to the friction elements engaged in the second shift overlap, and the increase in the amount of oil required increases. There was a problem in that the amount was insufficient and the line pressure fluctuated, which could lead to unstable vehicle behavior.

The present invention has been made with attention to the above-mentioned problem, and when a multiple shift is performed in which a second shift is started during a first shift, the vehicle behavior is improved by suppressing line pressure fluctuations. The purpose is to prevent stability.

In order to achieve the above object, the present invention includes a transmission control unit that performs speed change control that switches a plurality of gears by changing the engagement state of a plurality of friction elements that are engaged using line pressure as a source pressure. In this automatic transmission control device, when a transmission control unit determines a multiple shift request to start a second shift during a first shift, the transmission control unit mediates the shift progress status of the first shift and the second shift. It has a speed change control section. The shift control unit increases the engagement hydraulic pressure supplied to the first friction element that transitions from a released state to an engaged state in a first shift, and increases the pressure applied to a second friction element that shifts from a released state to an engaged state in a second shift. Arbitration control is performed so that the supply of charge pressure does not overlap. After outputting a command to increase the engagement pressure to the first friction element, when a second shift is requested, the mediation control increases the pressure to the second friction element while the hydraulic pressure supplied to the first friction element is increasing. The supply of charge pressure is prohibited, and when the increase in the oil pressure supplied to the first friction element converges, the supply of precharge pressure to the second friction element is permitted.

By adopting the above solution, when a multiple shift is executed in which the second shift is started during the first shift, fluctuations in line pressure are suppressed, thereby preventing vehicle behavior from becoming unstable. I can do it. In addition, during multiple gear shifting in which a second gear shift is started during a first gear shift, supply of precharge pressure to the second friction element is permitted by monitoring the oil pressure supplied to the first friction element. As for timing, it is possible to obtain appropriate timing early.

1 is an overall system diagram showing an engine vehicle equipped with an automatic transmission to which the control device of Example 1 is applied; FIG. FIG. 2 is a skeleton diagram showing an example of a gear train of an automatic transmission. FIG. 3 is an engagement table showing the engagement state of a gear shift friction element at each gear stage in an automatic transmission. FIG. 3 is a shift map diagram showing an example of a shift map in an automatic transmission. FIG. 2 is a hydraulic control system configuration diagram showing a control valve unit of an automatic transmission. It is a characteristic diagram which shows an example of the target line pressure characteristic with respect to the input torque to a gear train. FIG. 6 is a characteristic diagram showing an example of the engagement pressure command characteristics to the friction element when transitioning from the release state to the engagement state. 3 is a flowchart showing the flow of a shift control process executed by a shift control section of a transmission control unit. In a multiple gear shift scene from 4th gear → 3rd gear → 2nd gear, the first friction element engaged in the first gear (4th gear → 3rd gear) and the second gear (3rd gear → 2nd gear) ) is a time chart showing a fastening pressure command characteristic 1 for the second friction element fastened. In a multiple gear shift scene from 4th gear → 3rd gear → 2nd gear, the first friction element engaged in the first gear (4th gear → 3rd gear) and the second gear (3rd gear → 2nd gear) ) is a time chart showing the fastening pressure command characteristic 2 for the second friction element fastened.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments for implementing the automatic transmission control device of the present invention will be described based on a first embodiment shown in the drawings.

The control device of Example 1 is applied to an engine vehicle (an example of a vehicle) equipped with a shift-by-wire and park-by-wire automatic transmission having nine forward speeds and one reverse gear. be. The configuration of the first embodiment will be explained below by dividing it into "overall system configuration," "detailed configuration of automatic transmission," "detailed configuration of hydraulic control system," and "shift control processing configuration."

[Overall system configuration (Figure 1)]
As shown in FIG. 1, the drive system of the engine vehicle includes an engine 1, a torque converter 2, an automatic transmission 3, a propeller shaft 4, and drive wheels 5. The torque converter 2 has a built-in lock-up clutch 2a that directly connects the crankshaft of the engine 1 and the input shaft IN of the automatic transmission 3 when engaged. The automatic transmission 3 includes a gear train 3a and a park gear 3b. The automatic transmission 3 is equipped with a control valve unit 6 that includes a spool valve, a hydraulic control circuit, a solenoid valve, and the like for changing gears.

The control valve unit 6 includes, as solenoid valves, six clutch solenoids 20 provided for each friction element, and one line pressure solenoid 21, one lubricating solenoid 22, and one lock-up solenoid 23 provided for each. That is, it has a total of nine solenoid valves. Each of these solenoid valves has a three-way linear solenoid structure, and operates to regulate pressure upon receiving a control command from the transmission control unit 10.

As shown in FIG. 1, the electronic control system of an engine vehicle includes a transmission control unit 10 (abbreviated as "ATCU"), an engine control module 11 (abbreviated as "ECM"), and a CAN communication line. 70. Here, the transmission control unit 10 is started/stopped by an ignition signal from a sensor module unit 71 (abbreviation: "USM"). In other words, the starting/stopping of the transmission control unit 10 is performed as "wake-up/sleep control" which allows for more variation in starting than when starting/stopping using an ignition switch.

The transmission control unit 10 is mechanically and electrically integrated on the upper surface of the control valve unit 6, and includes a main board temperature sensor 31 and a sub board temperature sensor 32 on the unit board in a redundant system while ensuring independence from each other. . That is, the main board temperature sensor 31 and the sub board temperature sensor 32 transmit sensor value information to the transmission control unit 10, but unlike a known automatic transmission unit, the main board temperature sensor 31 and the sub board temperature sensor 32 transmit the sensor value information to the transmission control unit 10. transmitting temperature information without direct contact with the This transmission control unit 10 also receives signals from a turbine rotation sensor 13, an output shaft rotation sensor 14, and a third clutch oil pressure sensor 15. Furthermore, signals from the shifter control unit 18, intermediate shaft rotation sensor 19, etc. are input.

Turbine rotation sensor 13 detects the turbine rotation speed (=transmission input shaft rotation speed) of torque converter 2 and transmits a signal indicating turbine rotation speed Nt to transmission control unit 10. The output shaft rotation sensor 14 detects the output shaft rotation speed of the automatic transmission 3 and transmits a signal indicating the output shaft rotation speed No. (=vehicle speed VSP) to the transmission control unit 10. The third clutch oil pressure sensor 15 detects the clutch oil pressure of the third clutch K3, and transmits a signal indicating the third clutch oil pressure PK3 to the transmission control unit 10.

The shifter control unit 18 determines the range position selected by the driver's selection operation on the shifter 181, and transmits a range position signal to the transmission control unit 10. Note that the shifter 181 has a momentary structure, and has a P range button 181b on the top of the operating section 181a, and a lock release button 181c (only when N→R) on the side of the operating section 181a. The range positions include H range (home range), R range (reverse range), D range (drive range), and N(d), N(r) (neutral range). The intermediate shaft rotation sensor 19 detects the rotation speed of an intermediate shaft (intermediate shaft = rotating member connected to the first carrier C1), and transmits a signal indicating the intermediate shaft rotation speed Nint to the transmission control unit 10.

The transmission control unit 10 monitors changes in operating points (VSP, APO) due to vehicle speed VSP and accelerator opening APO on the shift map (see Figure 4).
1.Auto upshift (by increasing vehicle speed while keeping the accelerator opening)
2. Foot-off upshift (by foot-off operation on the accelerator)
3. Foot release upshift (by accelerator release operation)
4. Power-on downshift (by reducing vehicle speed while keeping the accelerator open)
5.Small opening sudden downshift (due to small accelerator operation amount)
6. Wide opening sudden downshift (depending on large accelerator operation: "kick down")
7. Gentle downshift (due to gentle accelerator pedal operation and increase in vehicle speed)
8. Coast downshift (due to a decrease in vehicle speed when the accelerator is released)
Shift control is performed using a basic shift pattern called .

The engine control module 11 receives signals from an accelerator opening sensor 16, an engine rotation sensor 17, and the like.

The accelerator opening sensor 16 detects the accelerator opening due to the driver's accelerator operation, and sends a signal indicating the accelerator opening APO to the engine control module 11. The engine rotation sensor 17 detects the rotation speed of the engine 1 and transmits a signal indicating the engine rotation speed Ne to the engine control module 11.

In addition to various controls for the engine itself, the engine control module 11 performs engine torque limit control and the like through cooperative control with the transmission control unit 10. The transmission control unit 10 is connected to the transmission control unit 10 via a CAN communication line 70 that can exchange information in both directions, so when an information request is input from the transmission control unit 10, the accelerator opening APO and engine speed are Ne information is output to the transmission control unit 10. Further, information on the estimated calculated engine torque Te and turbine torque Tt is output to the transmission control unit 10. Further, when an engine torque limitation request using an upper limit torque is input from the transmission control unit 10, engine torque limitation control is executed to limit the engine torque to a torque limited by a predetermined upper limit torque.

[Detailed configuration of automatic transmission (Figure 2, Figure 3, Figure 4)]
The automatic transmission 3 has a gear train 3a (stepped transmission mechanism) capable of setting a plurality of gears and a plurality of friction elements, and is characterized by the following points.
(a) A one-way clutch that mechanically engages/slips is not used as a transmission element.
(b) The first brake B1, second brake B2, third brake B3, first clutch K1, second clutch K2, and third clutch K3, which are friction elements, are independently engaged/released by the clutch solenoid 20 during gear shifting. The state is controlled.
(c) During in-gear to maintain the engaged state in the engagement pressure control of the friction element, instead of outputting the maximum pressure command to the clutch solenoid, the clutch solenoid 20 outputs an intermediate pressure command equivalent to the element input torque that can suppress clutch slippage. Output to.
(d) The second clutch K2 and the third clutch K3 have a centrifugal cancel chamber that cancels centrifugal pressure due to centrifugal force acting on the clutch piston oil chamber.

As shown in FIG. 2, the automatic transmission 3 includes a first planetary gear PG1, a second planetary gear PG2, and a third planetary gear from the input shaft IN to the output shaft OUT as planetary gears constituting the gear train 3a. It includes a planetary gear PG3 and a fourth planetary gear PG4.

The first planetary gear PG1 is a single pinion type planetary gear, and includes a first sun gear S1, a first carrier C1 that supports a pinion that meshes with the first sun gear S1, and a first ring gear R1 that meshes with the pinion.

The second planetary gear PG2 is a single pinion type planetary gear, and includes a second sun gear S2, a second carrier C2 that supports a pinion that meshes with the second sun gear S2, and a second ring gear R2 that meshes with the pinion.

The third planetary gear PG3 is a single pinion type planetary gear, and includes a third sun gear S3, a third carrier C3 that supports a pinion that meshes with the third sun gear S3, and a third ring gear R3 that meshes with the pinion.

The fourth planetary gear PG4 is a single pinion type planetary gear, and includes a fourth sun gear S4, a fourth carrier C4 that supports a pinion that meshes with the fourth sun gear S4, and a fourth ring gear R4 that meshes with the pinion.

As shown in FIG. 2, the automatic transmission 3 includes an input shaft IN, an output shaft OUT, a first connection member M1, a second connection member M2, and a transmission case TC. A first brake B1, a second brake B2, a third brake B3, a first clutch K1, a second clutch K2, and a third clutch K3 are provided as friction elements that are engaged/released by shifting. There is.

The input shaft IN is a shaft to which driving force from the engine 1 is input via the torque converter 2, and is constantly connected to the first sun gear S1 and the fourth carrier C4. The input shaft IN is connectably and disconnectably connected to the first carrier C1 via the second clutch K2.

The output shaft OUT is a shaft that outputs the shifted drive torque to the drive wheels 5 via the propeller shaft 4 and a final gear (not shown), etc., and is constantly connected to the third carrier C3. The output shaft OUT is connectably and disconnectably connected to the fourth ring gear R4 via the first clutch K1.

The first connecting member M1 is a member that constantly connects the first ring gear R1 of the first planetary gear PG1 and the second carrier C2 of the second planetary gear PG2 without intervening a friction element. The second connection member M2 constantly connects the second ring gear R2 of the second planetary gear PG2, the third sun gear S3 of the third planetary gear PG3, and the fourth sun gear S4 of the fourth planetary gear PG4 without intervening a friction element. is a member who

The first brake B1 is a friction element that can lock the rotation of the first carrier C1 with respect to the transmission case TC. The second brake B2 is a friction element that can lock the rotation of the third ring gear R3 relative to the transmission case TC. The third brake B3 is a friction element that can lock the rotation of the second sun gear S2 with respect to the transmission case TC.

The first clutch K1 is a friction element that selectively connects the fourth ring gear R4 and the output shaft OUT. The second clutch K2 is a friction element that selectively connects the input shaft IN and the first carrier C1. The third clutch K3 is a friction element that selectively connects the first carrier C1 and the second connection member M2.

Based on FIG. 3, a transmission configuration for establishing each gear stage will be explained. The first gear (1st) is achieved by simultaneously engaging the second brake B2, third brake B3, and third clutch K3. The second gear (2nd) is achieved by simultaneously engaging the second brake B2, second clutch K2, and third clutch K3. The third gear (3rd) is achieved by simultaneously engaging the second brake B2, third brake B3, and second clutch K2. The fourth gear (4th) is achieved by simultaneously engaging the second brake B2, the third brake B3, and the first clutch K1. The fifth gear (5th) is achieved by simultaneously engaging the third brake B3, the first clutch K1, and the second clutch K2. The above-mentioned 1st to 5th speeds are underdrive gears with a reduction gear ratio exceeding 1.

The sixth gear (6th) is achieved by simultaneously engaging the first clutch K1, the second clutch K2, and the third clutch K3. This sixth gear is a direct gear with a gear ratio of 1.

The seventh gear (7th) is achieved by simultaneously engaging the third brake B3, the first clutch K1, and the third clutch K3. Eighth gear (8th) is achieved by simultaneously engaging the first brake B1, first clutch K1, and third clutch K3. The ninth gear (9th) is achieved by simultaneously engaging the first brake B1, the third brake B3, and the first clutch K1. The 7th to 9th speeds described above are overdrive gears with increasing gear ratios having a gear ratio of less than 1.

Furthermore, when performing an upshift to an adjacent gear among the first to ninth gears, or a downshift, as shown in FIG. . In other words, shifting to an adjacent gear is achieved by releasing one friction element and engaging one friction element while keeping two of the three friction elements engaged. .

The reverse gear (Rev) by selecting the R range position is achieved by simultaneously applying the first brake B1, the second brake B2, and the third brake B3. Note that when the N range position and the P range position are selected, all six friction elements B1, B2, B3, K1, K2, and K3 are basically released.

The transmission control unit 10 stores and sets a gear shift map as shown in FIG. Shifting is performed according to this shift map. That is, when the operating point (VSP, APO) at that time crosses the upshift line shown by the solid line in FIG. 4, an upshift speed change request is issued. Further, when the operating point (VSP, APO) crosses the downshift line shown by the broken line in FIG. 4, a downshift shift request is issued.

[Detailed configuration of hydraulic control system (Figures 5 to 7)]
The control valve unit 6, which is hydraulically controlled by the transmission control unit 10, includes a mechanical oil pump 61 and an electric oil pump 62 as hydraulic power sources, as shown in FIG. The mechanical oil pump 61 is pump-driven by the engine 1, and the electric oil pump 62 is pump-driven by an electric motor 63.

The control valve unit 6 includes a line pressure solenoid 21, a line pressure regulating valve 64, a clutch solenoid 20, and a lock-up solenoid 23 as valves provided in the hydraulic control circuit. It also includes a lubrication solenoid 22, a lubrication pressure regulating valve 65, and a boost switching valve 66. Furthermore, a P-nP switching valve 67 and a park hydraulic actuator 68 are provided.

The line pressure regulating valve 64 regulates the oil discharged from at least one of the mechanical oil pump 61 and the electric oil pump 62 to a line pressure PL based on the valve actuation signal pressure from the line pressure solenoid 21.

Here, the line pressure solenoid 21 is driven to adjust its pressure by a control command from a line pressure control section 100 included in the transmission control unit 10. As will be described later, the line pressure control unit 100 outputs an intermediate pressure command to the clutch solenoid 20 while in gear, and adjusts the target line pressure characteristic PLc with respect to the magnitude of the input torque to the gear train 3a to the maximum value while in gear. The pressure is set to be lower than the target line pressure characteristic PLc' when outputting the pressure command to the clutch solenoid (see FIG. 6).

The clutch solenoid 20 is a transmission solenoid that uses line pressure PL as a source pressure and controls engagement pressure and release pressure for each friction element (B1, B2, B3, K1, K2, K3). Although FIG. 5 shows one clutch solenoid 20, there are six solenoids for each friction element (B1, B2, B3, K1, K2, K3).

Here, the clutch solenoid 20 is driven to adjust its pressure by a control command from a shift control section 101 included in the transmission control unit 10. The shift control section 101 has an individual shift control function, a multiple shift control function, and an engagement pressure control function. The independent shift control function is a function that, upon determining an upshift request or a downshift request to shift to an adjacent gear, executes a shift by switching engagement/disengagement control. The multiple shift control function is a function that arbitrates the shift progress status of the first shift and the second shift when a multiple shift request to start the second shift (rear shift) is determined during the first shift (previous shift). means. The engagement pressure control function does not output the maximum pressure command Pmax to the clutch solenoid during in-gear to maintain the engagement state in the engagement pressure control of the friction element, but outputs an intermediate pressure command equivalent to the element input torque that can suppress clutch slippage. This refers to the function of outputting Plimit to the clutch solenoid 20 (see FIG. 7).

The lockup solenoid 23 controls the clutch differential pressure of the lockup clutch 2a using the line pressure PL generated by the line pressure regulation valve 64 and the pressure regulation surplus oil when the lockup clutch 2a is engaged in slip.

Here, the lockup solenoid 23 is driven to adjust its pressure by a control command from the lockup control section 102 included in the transmission control unit 10. During driving in the slip lockup region, the lockup control unit 102 controls the clutch differential pressure control that maintains the slip engagement state of the lockup clutch 2a to the gear stage of the gear train 3a, rather than the clutch differential pressure control that maintains the fully engaged state of the lockup clutch 2a. Execute regardless of speed change. Note that the "slip lockup area" refers to a driving area where the vehicle speed is higher than a predetermined vehicle speed set in a low vehicle speed area, for example. "Clutch differential pressure control that maintains the slip engagement state" refers to slip engagement control of the lock-up clutch 2a, in which a minute slip value is set as the target value, and the slip deviation is adjusted so that the actual slip value converges to the target value. This refers to feedback control that is executed accordingly.

The lubrication solenoid 22 has the function of creating a valve actuation signal pressure to the lubrication pressure regulating valve 65 and a switching pressure to the boost switching valve 66, and regulating the lubrication flow rate supplied to the friction element to an appropriate flow rate to suppress heat generation. . It is a solenoid that mechanically guarantees the minimum lubrication flow rate to suppress heat generation of the friction elements when not in continuous gear protection, and adjusts the lubrication flow rate that is added to the minimum lubrication flow rate.

The lubrication pressure regulating valve 65 can control the flow rate of lubrication supplied to the power train (PT) including the friction element and the gear train 3a via the cooler 69 based on the valve actuation signal pressure from the lubrication solenoid 22. Friction is reduced by optimizing the PT supply lubricant flow rate using the lubricant pressure regulating valve 65.

The boost switching valve 66 increases the amount of oil supplied to the centrifugal cancel chambers of the second clutch K2 and the third clutch K3 using switching pressure from the lubrication solenoid 22. This boost switching valve 66 is used to temporarily increase the amount of oil supplied in a situation where the amount of oil in the centrifugal cancel chamber is insufficient.

The P-nP switching valve 67 switches the line pressure path to the park hydraulic actuator 68 using switching pressure from the lubrication solenoid 22 (or park solenoid). A park lock is performed to engage the park gear 3b when selecting the P range, and a park lock release is performed to disengage the park gear 3b when selecting from the P range to a range other than the P range.

In this way, the configuration of the control valve unit 6 eliminates the manual valve that is mechanically connected to the shift lever operated by the driver and switches the D range pressure oil path, R range pressure oil path, P range pressure oil path, etc. There is. When the D, R, N range is selected by the shifter 181, control is adopted to independently engage/disengage six friction elements based on the range position signal from the shifter control unit 18. "Buy Wire" has been achieved. Furthermore, when the P range is selected by the shifter 181, the P-nP switching valve 67 and the park hydraulic actuator 68, which constitute the park module, are operated based on the range position signal from the shifter control unit 18.・Achieved "Wire".

[Shift control processing configuration (Figure 8)]
FIG. 8 shows the flow of the speed change control process executed by the speed change control section 101 of the transmission control unit 10. Each step in FIG. 8 will be explained below.

In step S1, following the start of the process, it is determined whether there is a request for a first shift (previous shift). If YES (a first shift is requested), the process proceeds to step S2; if NO (a first shift is not requested), the process proceeds to return.

In step S2, following the determination that there is a request for the first shift in S1 or the determination that the predetermined time has not elapsed in S3, the first shift is shifted from the released state to the engaged state in the first shift. A precharge pressure command is output to the friction element, and the process advances to step S3. Here, the "precharge pressure" refers to the hydraulic pressure for quickly filling the oil passage or oil chamber to the first friction element from which the hydraulic oil is drained with the hydraulic oil. The "first friction element" means, for example, when the first shift is a downshift from 4th gear to 3rd gear, the second clutch K2 is released in 4th gear and is engaged in 3rd gear. Say something.

In step S3, following the output of the precharge pressure command in S2, it is determined whether a predetermined time has elapsed since the start of outputting the precharge pressure command. If YES (the predetermined time has elapsed), the process advances to step S4; if NO (the predetermined time has not elapsed), the process returns to step S2. Here, the "predetermined time" refers to the output duration Tp of the precharge pressure command for filling the oil path and oil chamber to the first friction element with hydraulic oil, as shown in FIG.

In step S4, following the determination in S3 that the predetermined time has elapsed or the determination in S6 that the first shift target gear ratio has not been reached, a precharge pressure command is output to the first friction element. Subsequently, a tightening pressure increase command is output, and the process proceeds to step S8. Here, the "engagement pressure increase command" refers to a command to force and supply hydraulic oil into the oil path to the first friction element to increase the engagement oil pressure of the first friction element. For example, as shown in FIG. , given by the characteristic of increasing the rising slope of the command value in stages.

In step S5, following the output of the engagement pressure increase command in S4, it is determined whether or not there is a request for a second shift (rear shift). If YES (second shift is requested), the process advances to step S8; if NO (second shift is not requested), the process advances to step S6.

In step S6, following the determination in S5 that there is no request for the second shift, it is determined whether the actual gear ratio has reached the first shift target gear ratio. If YES (the first shift target gear ratio has been reached), the process proceeds to step S7, and if NO (the first shift target gear ratio has not been reached), the process returns to step S4. Here, the "actual gear ratio" is determined by dividing the turbine rotation speed Nt (=transmission input rotation speed) from the turbine rotation sensor 13 and the transmission output shaft rotation speed No from the output shaft rotation sensor 14 as needed. Find by.

In step S7, following the determination in S6 that the first gear shift target gear ratio has been reached, an intermediate pressure command is output to the first friction element that transitions to the engaged state in the first gear shift, and the process proceeds to return.

In step S8, it is determined that there is a request for the second shift in S5, or that the intermediate pressure command is not output in S9, or that a predetermined time has elapsed since the intermediate pressure command was output in S10. Subsequently, the output of the precharge pressure command to the second friction element that changes from the released state to the engaged state in the second gear shift is prohibited, and the process proceeds to step S9. Here, the "second friction element" refers to, for example, when the second gear is downshifting from 3rd gear to 2nd gear, the 3rd friction element is released in 3rd gear and engaged in 2nd gear. It refers to clutch K3.

In step S9, following the prohibition of output of the precharge pressure command to the second friction element in S8, it is determined whether or not an intermediate pressure command has been output to the first friction element that transitions to the engaged state in the first shift. If YES (the intermediate pressure command was output), the process proceeds to step S10, and if NO (the intermediate pressure command was not output), the process returns to step S8. Note that the intermediate pressure command is output to the first friction element at the timing when the actual gear ratio reaches the first shift target gear ratio.

In step S10, following the determination that the intermediate pressure command has been output in S9, it is determined whether a predetermined time Tw or a predetermined time Tw' has elapsed since the output of the intermediate pressure command to the first friction element was started. do. If YES (the predetermined time Tw, Tw' has elapsed), the process advances to step S11; if NO (the predetermined time Tw, Tw' has not elapsed), the process returns to step S8. Here, the "predetermined time Tw" refers to the waiting time required for the pressure of the release element to shift to the release state in the first shift to be released, and the "predetermined time Tw'" refers to the waiting time required for the pressure of the release element to be released when it shifts to the release state during the first shift, and the "predetermined time Tw'" refers to the waiting time required for the pressure of the release element to shift to the release state in the first shift. This refers to the waiting time required after the start of output until the oil pressure increase in the first friction element converges and a stable oil pressure state is reached. Note that the predetermined time may be either the predetermined time Tw or the predetermined time Tw', but in the first embodiment, the predetermined time Tw is used so that the second shift can be started earlier than the predetermined time Tw. ' is adopted.

In step S11, following the determination that the predetermined time Tw, Tw' has elapsed since the start of output of the intermediate pressure command to the first friction element in S10, the state shifts from the released state to the engaged state in the second shift. The output of the precharge pressure command to the second friction element is permitted, and the process proceeds to step S12.

In step S12, following the permission to output the precharge pressure command to the second friction element in S11 or the determination that the intermediate pressure command is not output in S13, the precharge pressure command to the second friction element is output. A second shift control is executed to shift to the output, the output of the engagement pressure increase command, and the output of the intermediate pressure command, and the process proceeds to step S13.

In step S13, following the execution of the second shift control in S12, it is determined whether an intermediate pressure command has been output to the second friction element. If YES (the intermediate pressure command was output), the process proceeds to return; if NO (the intermediate pressure command was not output), the process returns to step S12.

In addition, in the flowchart of FIG. 8, an example of a first shift and a second shift is shown as a multiple shift, but a case where the shifts are further overlapped from the first shift to the second shift to the third shift, etc. is also considered as a multiple shift. handle. In this case, after the transition from the first gear to the second gear, while the engagement pressure increase command is being output in the second gear (previous gear), the output of the precharge pressure command in the third gear (rear gear) is prohibited. .

Next, "background technology and problem-solving strategies" will be explained. The operation of the first embodiment will be explained separately into "shift control processing operation" and "shift control operation".

[Background technology and problem solving strategies]
As a shift control technique for mediating the progress of the first shift and the second shift in multiple shifts, a technique disclosed in Japanese Patent Application Laid-Open No. 2007-170638 is known. In this background art, for the purpose of executing speed change control, the second speed change is started before the first speed change ends, so that the first speed change and the second speed change are overlapped.

Therefore, in the background art, an increase in the engagement oil pressure to the first friction element engaged in the first shift and a supply of precharge pressure to the second friction element engaged in the second shift overlap and overlap. A large amount of oil will be consumed in these areas. Therefore, while the required amount of oil increases, the actual amount of oil becomes insufficient, resulting in a decrease in line pressure. When line pressure decreases, the lock-up clutch and friction elements, which are hydraulically controlled using line pressure as source pressure, may deviate from the desired engagement state, resulting in unstable vehicle behavior. .

For example, when performing lock-up control that executes clutch differential pressure control to maintain the lock-up clutch in a slipping and engaged state while driving, if a drop in line pressure occurs, the lock-up clutch cannot maintain its slipping state and is engaged. As a result, the vehicle behavior changes and becomes unstable. That is, when the line pressure decreases and the slip engagement state exceeds the target micro-slip value and the slip deviation increases, clutch differential pressure control is performed to converge the expansion of the slip deviation. As a result, the lock-up clutch momentarily enters the lock-up fully engaged state, causing fluctuations in the longitudinal G of the vehicle.

For example, with the aim of improving fuel efficiency, an intermediate pressure command equivalent to the element input torque that can suppress clutch slippage is output to the clutch solenoid during in-gear to maintain the engaged state of the friction element. Then, the target line pressure characteristic in line pressure control is set to a lower pressure side than the target line pressure characteristic when outputting the maximum pressure command to the clutch solenoid during in-gear. When the line pressure and the friction element engagement pressure in the in-gear are limited in this way, if the line pressure decreases due to a lack of oil, the friction element engagement pressure will decrease in response, causing slippage on the engaged friction element. may occur. If slippage occurs in the engaged friction element, the quality of the gear shift will deteriorate, giving the driver a sense of discomfort in shifting as the gear ratio of the gear train may suddenly fluctuate or the progress of the gear shift may be delayed.

As a result of verifying solutions to the above problems, the inventor has found that
(A) The cause of the oil shortage is due to the overlap between the increase in the engagement oil pressure to the first friction element engaged in the first shift and the supply of precharge pressure to the second friction element engaged in the second shift. be.
(B) Even if the line pressure and friction element engagement pressure in the in-gear are set low to improve fuel efficiency, the engagement oil pressure to the first friction element increases and the precharge pressure is supplied to the second friction element. It was confirmed that by separating the overlap between the two, it is possible to suppress the drop in oil pressure due to insufficient oil volume.
We focused on this point.

Based on the above points of interest, the present disclosure provides speed change control that switches multiple gears by changing the engagement state of multiple friction elements B1, B2, B3, K1, K2, and K3 that are engaged using line pressure PL as source pressure. A transmission control unit 10 is provided. In the control device for the automatic transmission 3, when the transmission control unit 10 determines a multiple shift request to start the second shift during the first shift, the transmission control unit 10 determines the shift progress status of the first shift and the second shift. It has a shift control section 101 that arbitrates. The shift control unit 101 increases the engagement oil pressure supplied to the first friction element that transitions from the released state to the engaged state in the first shift, and increases the engagement oil pressure supplied to the second friction element that shifts from the released state to the engaged state in the second shift. A solution was adopted in which arbitration control was performed so that the supply of precharge pressure and the supply of precharge pressure did not overlap.

That is, when a multiple shift request to start the second shift during the first shift is determined, the progress of the first shift and the second shift is arbitrated. This arbitration control increases the engagement oil pressure supplied to the first friction element that transitions from the released state to the engaged state in the first shift, and increases the pressure applied to the second friction element that shifts from the released state to the engaged state in the second shift. Control is performed so that the supply of charge pressure does not overlap. In other words, during multiple gear shifting where the second gear shift is started during the first gear shift, the amount of oil required due to the increase in the engagement oil pressure supplied to the first friction element and the amount of oil required due to the supply of precharge pressure to the second friction element are increased. There is no need to secure the amount of oil added to the amount of oil, and the problem of insufficient amount of oil is eliminated.

As a result, when a multiple shift is executed in which the second shift is started during the first shift, it is possible to prevent the vehicle behavior from becoming unstable by suppressing the occurrence of fluctuations in the line pressure PL. Become. In particular, when performing lock-up control that executes clutch differential pressure control to maintain the slip-engaged state of the lock-up clutch 2a while driving, engagement of the lock-up clutch 2a may make the vehicle behavior unstable and drive This prevents people from feeling uncomfortable.

Furthermore, if the target line pressure characteristic PLc is set to a lower pressure side than the target line pressure characteristic PLc' and the intermediate pressure command Plimit is output to the clutch solenoid 20 during in-gear (Figs. 6 and 7), the fuel efficiency can be improved. While improving the line pressure PL, the decrease in line pressure PL due to insufficient oil amount is suppressed. As the line pressure PL decreases, the friction element engagement pressure that maintains the engagement state of the friction elements is also suppressed from decreasing, and the shifting quality deteriorates due to slippage of the friction elements in the engaged state, which makes it difficult for the driver to shift gears. This prevents the user from feeling uncomfortable.

[Shift control processing action (Figure 8)]
First, the operation of the speed change control process will be explained based on the flowchart of FIG. If there is a request for the first shift (previous shift), the process proceeds to S1 → S2 → S3, and in S3 it is determined that a predetermined time has not elapsed since the start of outputting the precharge pressure command to the first friction element. During this period, the flow from S2 to S3 is repeated. In S2, a precharge pressure command is output to the first friction element that transitions from the released state to the engaged state during the first shift.

When it is determined that a predetermined time has elapsed since the start of output of the precharge pressure command to the first friction element, the process proceeds from S3 to S4 and then to S5. In S4, the engagement pressure increase command is output to the first friction element following the output of the precharge pressure command. In S5, it is determined whether or not there is a request for a second shift (rear shift). If it is determined that there is no request for the second shift, the process proceeds from S5 to S6, and in S6, it is determined whether the actual gear ratio has reached the first shift target gear ratio. While the actual gear ratio has not reached the first shift target gear ratio, the flow from S4 to S5 to S6 is repeated.

In S5, the determination that there is no request for the second shift (rear shift) is maintained, and if it is determined in S6 that the actual gear ratio has reached the first shift target gear ratio, the process proceeds from S6 to S7→Return. . In S7, an intermediate pressure command is output to the first friction element that transitions to the engaged state during the first shift. In other words, in independent shift control for only the first shift, when a first shift request (upshift request or downshift request to an adjacent gear) is determined, the engagement control side of the engagement/disengagement switching control , a speed change control is executed in which the output of the precharge pressure command → the output of the engagement pressure increase command → the output of the intermediate pressure command is executed (see FIG. 7).

On the other hand, when it is determined in S5 that there is a request for a second shift (rear shift) while the flow of proceeding from S4 to S5 to S6 is repeated, the process proceeds from S5 to S8 to S9. Then, while it is determined in S9 that the intermediate pressure command is not being output to the first friction element that transitions to the engaged state in the first gear shift, the flow from S8 to S9 is repeated. In S8, the output of the precharge pressure command to the second friction element that transitions from the released state to the engaged state during the second shift is prohibited.

Subsequently, when it is determined in S9 that an intermediate pressure command has been output to the first friction element that transitions to the engaged state in the first gear shift, the process proceeds from S9 to S10, and in S10, an intermediate pressure command is output to the first friction element. It is determined whether a predetermined time Tw has elapsed since the start of the process. While it is determined in S10 that the predetermined time Tw has not elapsed, the flow of proceeding from S8 to S9 to S10 is repeated, and in S8, the second friction element that changes from the released state to the engaged state in the second gear shift is Output of precharge pressure command is prohibited.

Then, when it is determined in S10 that the predetermined time Tw has elapsed since the start of outputting the intermediate pressure command to the first friction element, the process proceeds from S10 to S11→S12→S13. In S11, output of a precharge pressure command to the second friction element that transitions from the released state to the engaged state during the second shift is permitted. In S12, second shift control (engagement control of the second friction element) is executed in which the precharge pressure command output to the second friction element → the engagement pressure increase command output → the intermediate pressure command output. In S13, it is determined whether the intermediate pressure command has been output to the second friction element. While it is determined in S13 that the intermediate pressure command is not being output, the flow from S12 to S13 is repeated. Thereafter, when it is determined in S13 that the intermediate pressure command has been output, the process proceeds from S13 to return, and the current multiple speed change control is ended.

[Shift control action (Fig. 9, Fig. 10)]
FIG. 9 shows the first friction element engaged in the first gear (4th gear → 3rd gear) and the second gear (3rd gear) in a multiple gear shift scene from 4th gear → 3rd gear → 2nd gear. → 2nd gear) shows the engagement pressure command characteristic 1 to the second friction element engaged. Hereinafter, based on FIG. 9, the multiple speed change control action from 4th gear to 3rd gear to 2nd gear will be explained.

For example, when the operating point (VSP, APO) crosses the 4-3 downshift line on the shift map due to a slow accelerator depression operation, the first shift request (4th gear → 3rd gear request) is output at time t1. be done. When the first shift request is made at time t1, output of the precharge pressure command is immediately started to the second clutch K2, and the output of the precharge pressure command is continued until time t2. At time t2, output of the engagement pressure increase command is started following the precharge pressure command, and output of the engagement pressure increase command is continued until time t5.

Here, a 4-3 inertia phase in which the gear ratio changes from the 4th gear ratio toward the 3rd gear ratio is started at time t3 after the start time t2 of the output of the engagement pressure increase command. Furthermore, assume that at time t4, which is after time t3, the operating point (VSP, APO) crosses the 3-2 downshift line on the shift map, causing a second shift request (3rd gear → 2nd gear). . In this case, according to normal speed change control, output of the precharge pressure command to the third clutch K3 is started at time t4. However, while the engagement pressure increase command is being output during the first shift, the output of the precharge pressure command to the third clutch K3 is prohibited.

At time t5, when the actual gear ratio reaches the third gear ratio, which is the first shift target gear ratio, an intermediate pressure command is output to the second clutch K2. Then, at time t6, a predetermined time Tw has elapsed from output time t5 of the intermediate pressure command until completion of the decrease in the K1 release pressure command of the first clutch K1, which is released in the downshift from 4th gear to 3rd gear. , the output of the precharge pressure command to the third clutch K3 is permitted. That is, the output of the precharge pressure command to the third clutch K3 is delayed from time t4 to time t6 (=delay time Td), and the output period of the engagement pressure increase command in the first shift and the precharge pressure command in the second shift are Arbitration is performed so that the output sections do not overlap.

After the output of the precharge pressure command to the third clutch K3 is started at time t6, the output of the engagement pressure increase command is started at time t7 following the precharge pressure command. Then, at time t8, which is after the start time t7 of the engagement pressure increase command output, the 3-2 inertia phase in which the gear ratio changes from the 3rd gear ratio toward the 2nd gear ratio starts, and furthermore, at time t9. When the actual gear ratio reaches the second speed gear ratio, which is the second speed change target gear ratio, an intermediate pressure command is output to the third clutch K3. The above-described shift control action completes the multiple shift from 4th gear to 3rd gear to 2nd gear.

FIG. 10 shows the first friction element engaged in the first gear (4th gear → 3rd gear) and the second gear (3rd gear) in a multi-shift scene from 4th gear → 3rd gear → 2nd gear. → 2nd gear) shows the engagement pressure command characteristic 2 to the second friction element engaged. Hereinafter, based on FIG. 10, the multiple speed change control action from 4th gear to 3rd gear to 2nd gear will be explained.

Engagement pressure command characteristic 1 in FIG. 9 and engagement pressure command characteristic 2 in FIG. 10 permit the output of the precharge pressure command to the third clutch K3 after a predetermined time delayed by a delay time from time t4 in normal shift control. The idea is the same. However, in the case of engagement pressure command characteristic 2 in Fig. 10, from output time t5 of the intermediate pressure command until the actual pressure of the second clutch K2, which is engaged during the downshift from 4th gear to 3rd gear, has sufficient engagement capacity. At time t6' when the predetermined time Tw' has elapsed, output of the precharge pressure command to the third clutch K3 is permitted. Therefore, the delay time Td' that delays the output of the precharge pressure command to the third clutch K3 is from time t4 to time t6', which is shorter than the delay time Td in the engagement pressure command characteristic 1 in FIG. '＜Td).

That is, in the case of the engagement pressure command characteristic 1 shown in FIG. 9, the timing at which the output of the precharge pressure command to the third clutch K3 is permitted is set to the timing after the pressure on the release side is released. On the other hand, in the case of engagement pressure command characteristic 2 in FIG. You are giving permission at the right time. Therefore, the engagement pressure command characteristic 2 shown in FIG. 10 allows output of the precharge pressure command to the third clutch K3 at an earlier timing, and the problem of oil pressure fluctuation does not occur.

As described above, in the shift control process, while the oil pressure supplied to the first friction element (second clutch K2) is increasing, the precharge pressure is not supplied to the second friction element (third clutch K3). When the increase in the oil pressure supplied to the first friction element converges, the supply of precharge pressure to the second friction element is permitted (S5 to S11 in FIG. 8).

In other words, while the oil pressure supplied to the first friction element is increasing, the amount of oil used by the first friction element increases, but when the oil pressure stops increasing, the amount of oil used by the first friction element decreases. There is no rise. Therefore, during multiple gear shifting in which a second gear shift is started during a first gear shift, by monitoring the oil pressure supplied to the first friction element, the timing at which precharge pressure is allowed to be supplied to the second friction element can be determined. As such, it is possible to obtain early and appropriate timing.

In the shift control process, when a multiple shift request is determined, the actual gear ratio of the gear train 3a is monitored, and the actual gear ratio of the gear train 3a is monitored during the first shift until the actual gear ratio reaches the first shift target gear ratio. The output of the precharge pressure command to the second friction element is prohibited, and when the actual gear ratio reaches the first shift target gear ratio, the output of the precharge pressure command to the second friction element is permitted.

That is, the change in the actual gear ratio represents the degree of progress of the shift, and when the actual gear ratio reaches the first shift target gear ratio during the first shift, it can be considered that the increase in oil pressure has entered the convergence region. Therefore, during multiple gear shifting in which the second gear shift is started during the first gear shift, by monitoring the actual gear ratio of the gear train 3a, precharge pressure can be supplied to the second friction element without requiring a hydraulic sensor. Allow the right timing to be obtained.

As described above, the control device for the automatic transmission 3 of the first embodiment has the following effects.

(1) Equipped with a transmission control unit 10 that performs speed change control that switches multiple gears by changing the engagement state of multiple friction elements B1, B2, B3, K1, K2, and K3 that are engaged using line pressure PL as source pressure. A control device for an automatic transmission 3,
The transmission control unit 10 includes a shift control section 101 that mediates the shift progress status of the first shift and the second shift when determining a multiple shift request to start the second shift during the first shift,
The shift control unit 101 increases the engagement oil pressure supplied to the first friction element that transitions from the released state to the engaged state in the first shift, and increases the engagement oil pressure supplied to the second friction element that shifts from the released state to the engaged state in the second shift. Arbitration control is performed so that the supply of precharge pressure does not overlap.
Therefore, when a multiple shift in which the second shift is started during the first shift is executed, by suppressing the occurrence of fluctuations in the line pressure PL, it is possible to prevent the vehicle behavior from becoming unstable.

(2) A torque converter 2 having a lock-up clutch 2a is provided between the driving drive source (engine 1) and the stepped transmission mechanism (gear train 4a),
The transmission control unit 10 includes a lock-up control section 102 that performs clutch differential pressure control to maintain the slip engagement state of the lock-up clutch 2a during driving, regardless of the gear stage or speed change of the stepped transmission mechanism (gear train 4a). has.
Therefore, when performing lock-up control that executes clutch differential pressure control to maintain the slip-engaged state of lock-up clutch 2a while driving, the vehicle behavior becomes unstable due to engagement of lock-up clutch 2a, and the driver It is possible to prevent the person from feeling uncomfortable.

(3) While the oil pressure supplied to the first friction element is rising, the shift control unit 101 prohibits the supply of precharge pressure to the second friction element, and reduces the oil pressure supplied to the first friction element. When the rise converges, supply of precharge pressure to the second friction element is allowed.
For this reason, during multiple gear shifting in which the second gear shift is started during the first gear shift, supply of precharge pressure to the second friction element is permitted by monitoring the oil pressure supplied to the first friction element. As for timing, it is possible to obtain appropriate timing early.

(4) When the multiple shift request is determined, the shift control unit 101 monitors the actual gear ratio of the stepped transmission mechanism (gear train 3a),
Prohibits output of the precharge pressure command to the second friction element until the actual gear ratio reaches the first gear target gear ratio during the first gear shift;
When the actual gear ratio reaches the first shift target gear ratio, output of the precharge pressure command to the second friction element is permitted.
Therefore, during multiple gear shifting where the second gear shift is started during the first gear shift, by monitoring the actual gear ratio of the gear train 3a, the precharge pressure to the second friction element can be adjusted without requiring an oil pressure sensor. Appropriate timing to allow supply can be obtained.

(5) The shift control unit 101 outputs an intermediate pressure command Plimit equivalent to the element input torque capable of suppressing clutch slippage to the clutch solenoid 20 during in-gear to maintain the engaged state of the friction element,
The transmission control unit 10 defines a target line pressure characteristic PLc for the magnitude of input torque to the stepped transmission mechanism (gear train 3a) as a target line pressure characteristic PLc' when outputting a maximum pressure command to the clutch solenoid while in gear. It has a line pressure control section 100 that sets the pressure to a lower pressure side.
Therefore, while improving fuel efficiency by limiting the line pressure and the engagement pressure in in-gear, it is possible to prevent the shifting quality from deteriorating due to slippage of the friction element in the engaged state, which would cause the driver to feel uncomfortable about shifting. can. In other words, during multiple gear shifts where the second gear shift is started during the first gear shift, even if the line pressure PL and the friction element engagement pressure are set aiming at the lower limit range, the oil pressure may drop due to a temporary increase in the oil amount. is suppressed.

The automatic transmission control device of the present invention has been described above based on the first embodiment. However, the specific configuration is not limited to this first embodiment, and changes and additions to the design are permitted as long as they do not depart from the gist of the invention according to each claim.

In the first embodiment, the shift control unit 101 prohibits the supply of precharge pressure to the second friction element while the oil pressure supplied to the first friction element is rising, and the precharge pressure is supplied to the first friction element. An example has been shown in which the supply of precharge pressure to the second friction element is permitted when the increase in oil pressure converges. However, if a command to supply precharge pressure to the second friction element is received while the oil pressure supplied to the first friction element is rising, the speed change control unit outputs the command to supply precharge pressure. During this period, arbitration control may be performed to prohibit an increase in the oil pressure supplied to the first friction element. In this case, compared to the case where the precharge pressure is not supplied until the increase in the oil pressure supplied to the first friction element has converged, it is possible to improve the shift response in multiple shifts.

In the first embodiment, the transmission control unit 10 outputs an intermediate pressure command equivalent to the element input torque that can suppress clutch slippage to the clutch solenoid 20 during in-gear to maintain the engaged state in the engagement pressure control of the friction element. An example including a control unit 101 is shown. However, the transmission control unit can also be applied to an example having a speed change control section that outputs a maximum pressure command to the clutch solenoid during in-gear to maintain the engaged state in the engagement pressure control of the friction element.

In the first embodiment, an example of the automatic transmission 3 was shown as an automatic transmission that achieves nine forward speeds and one reverse speed by engaging three friction elements. However, as an automatic transmission, it may be possible to achieve multiple forward gears or reverse gears by engaging two friction elements, or it may be an example in which multiple forward gears or reverse gears are achieved by engaging four friction elements. Also good. The automatic transmission may also be an automatic transmission with stepped gears other than 9 forward speeds and 1 reverse speed, or an auxiliary transmission that combines a belt-type continuously variable transmission and a multi-speed transmission. It may also be used as a continuously variable transmission.

In the first embodiment, an example of a control device for an automatic transmission 3 installed in an engine vehicle was shown. However, it can be applied not only to engine vehicles but also as a control device for automatic transmissions of hybrid vehicles, electric vehicles, and the like.

1 Engine (drive source for driving)
2 Torque converter 2a Lock-up clutch 3 Automatic transmission 3a Gear train (stepped transmission mechanism)
4 Propeller shaft 5 Drive wheel 6 Control valve unit 10 Transmission control unit 20 Clutch solenoid 21 Line pressure solenoid 23 Lock-up solenoid 64 Line pressure regulating valve 100 Line pressure control section 101 Shift control section 102 Lock-up control section
B1,B2,B3,K1,K2,K3 Friction element

Claims (4)

A control device for an automatic transmission comprising a transmission control unit that performs speed change control for switching a plurality of gears by changing the engagement state of a plurality of friction elements that are engaged using line pressure as source pressure, the control device comprising:
The transmission control unit includes a shift control section that mediates the shift progress status of the first shift and the second shift when determining a multiple shift request to start a second shift during the first shift,
The shift control unit is configured to increase the engagement oil pressure supplied to the first friction element that transitions from a released state to an engaged state in the first shift, and to increase the engagement hydraulic pressure supplied to the first friction element that shifts from a released state to an engaged state in the second shift. Arbitration control is performed so that the supply of precharge pressure to
The mediation control may include, when a request for the second shift is made after outputting a command to increase the engagement pressure to the first friction element, while the hydraulic pressure supplied to the first friction element is increasing. An automatic system characterized by prohibiting the supply of precharge pressure to the friction element, and permitting the supply of the precharge pressure to the second friction element when the increase in the oil pressure supplied to the first friction element converges. Transmission control device. The automatic transmission control device according to claim 1,
Equipped with a torque converter with a lock-up clutch between the driving drive source and the stepped transmission mechanism,
The transmission control unit includes a lock-up control section that performs clutch differential pressure control to maintain the slip-engaged state of the lock-up clutch during driving, regardless of the gear position or speed change of the stepped transmission mechanism. Characteristic automatic transmission control device. The automatic transmission control device according to claim 2 ,
The shift control unit monitors an actual gear ratio of the stepped transmission mechanism when the multiple shift request is determined;
Prohibiting the output of the precharge pressure command to the second friction element until the actual gear ratio reaches the first shift target gear ratio during the first shift;
A control device for an automatic transmission, characterized in that when the actual gear ratio reaches a first shift target gear ratio, output of a precharge pressure command to the second friction element is permitted. The automatic transmission control device according to any one of claims 1 to 3,
The shift control unit outputs an intermediate pressure command equivalent to element input torque capable of suppressing clutch slippage to a clutch solenoid during in-gear to maintain the engaged state of the friction element;
The transmission control unit sets a target line pressure characteristic with respect to the magnitude of input torque to the stepped transmission mechanism to a lower pressure side than a target line pressure characteristic when outputting a maximum pressure command to a clutch solenoid during the in-gear. What is claimed is: 1. A control device for an automatic transmission, comprising a line pressure control section that controls the line pressure.