JP2009058112A - Control device for automatic transmission for vehicle - Google Patents

Abstract

[PROBLEMS] To prevent the accelerator pedal from being depressed in a transient state while returning from the neutral control to the normal traveling control while ensuring the appropriate depression range of the accelerator pedal in which the target throttle opening should be zero during the normal traveling control. Provided is a control device for an automatic transmission for a vehicle that can reduce the frequency with which a driver feels slack when the amount is very small.
An ECU includes a map Ma in which a target throttle opening with respect to an actual accelerator opening is set to zero with a target throttle opening with respect to an actual accelerator opening equal to or less than a first threshold Sa, and a second threshold smaller than the first threshold Sa. A map Mb in which the target throttle opening with respect to the actual accelerator opening is set to zero with the target throttle opening with respect to the actual accelerator opening equal to or less than Sb being stored, and in the transient state, the map Mb and the actual accelerator opening are Based on this, idle determination is performed.
[Selection] Figure 6

Description

  The present invention relates to a control device for an automatic transmission for a vehicle. In particular, the present invention relates to a control device for an automatic transmission for a vehicle that performs neutral control for bringing an automatic transmission into a neutral state when a predetermined condition is satisfied.

  Examples of the automatic transmission for a vehicle include a planetary gear type transmission that uses a clutch and brake and a planetary gear device, and a belt type continuously variable transmission that adjusts a gear ratio steplessly.

  Generally, a vehicle equipped with an automatic transmission is provided with a shift lever operated by a driver. By operating the shift lever, the shift position of the automatic transmission is set to a P range (parking range), It is possible to switch to the R range (reverse travel range), N range (neutral range), D range (forward travel range), and the like.

  In a vehicle equipped with such an automatic transmission, for example, when the D range is set and the vehicle is stopped, the driving force from the engine during idle operation is transmitted to the automatic transmission via the torque converter. Since this is transmitted to the wheels, a so-called creep phenomenon occurs. The creep phenomenon is useful under predetermined conditions, such as being able to smoothly start from a stop on an uphill road, but is unnecessary when the driver desires a stop state of the vehicle. In this case, the driver suppresses the creep force by operating the brake of the vehicle, but there is a problem that the fuel consumption of the engine is reduced correspondingly.

  For this reason, a predetermined neutral control start condition during idle operation, for example, “the shift position of the automatic transmission is in the D range, the accelerator is OFF, the brake is operating, and the vehicle is stopped. When the condition “is present” is satisfied, neutral control is performed to improve fuel efficiency by setting the automatic transmission to a neutral state that is close to neutral while maintaining the D range. Neutral control is control in which the engagement force of a friction engagement element (for example, an input clutch) of an automatic transmission that is engaged when the vehicle is running is reduced or released to bring it into a neutral state. For example, Patent Literature 1 discloses a control device for an automatic transmission for a vehicle that performs neutral control.

  When the condition for returning to normal travel control during neutral control is executed, for example, when the condition "Release brake pedal depression or relaxation of brake pedal depression" is established, a transient state during the return from neutral control to normal travel control And the engagement operation is started by increasing the engagement pressure of the input clutch. When the engagement pressure is sufficiently increased and the input clutch is completely engaged, the transition state is removed and the return to the normal travel control is completed.

  When the driver depresses the accelerator pedal in the transition state and the idling-off determination is made, the input clutch engagement instruction hydraulic pressure is optimized according to the accelerator opening so as not to impair the responsiveness when starting the vehicle. The engagement operation speed is increased by setting a higher engagement instruction oil pressure, and the input clutch is engaged in a shorter time than when the accelerator pedal is not depressed (return to normal travel control). Is completed. Thereby, the responsiveness to the sudden start requested by the driver depressing the accelerator pedal is ensured (see, for example, Patent Document 2).

By the way, the idle-off determination is performed by referring to a map in which parameters of the accelerator opening and the target opening of the electronic throttle are set by an ECU (electronic control unit) as shown in FIG. In this map, the target throttle opening with respect to the actual accelerator opening is set with the throttle opening with respect to the actual accelerator opening equal to or less than a certain value Sa being set to zero. Therefore, when the actual accelerator opening is equal to or less than the predetermined value Sa, the target throttle opening is zero, so that the idling-off determination is not made. When the actual accelerator opening exceeds the predetermined value and the target throttle opening rises from zero, an idle-off determination is made. Note that the region where the target throttle opening is zero when the actual accelerator opening is equal to or less than the predetermined value Sa is provided to ensure safety and the like. For example, by providing a region in which the target throttle opening is zero, it is possible to prevent the vehicle from suddenly popping out due to a small depression of the accelerator pedal that is not intended by the driver.
JP 2001-315551 A JP-A-11-230327

  However, when the driver depresses the accelerator pedal in a minute amount and the accelerator opening is equal to or less than the predetermined value, the idling-off determination is not made, and therefore the engagement operation speed of the input clutch cannot be increased. That is, as in the case where the accelerator pedal is not depressed in the transitional state during the return from the neutral control to the normal traveling control, the engaging operation of the input clutch is performed with a relatively long time.

  When a driver intentionally depresses a small amount of an accelerator pedal while the vehicle is stopped, the driver often expects a quick start response while expecting a gentle start. For this reason, there has been a problem that if the engagement operation of the input clutch is not completed (returning to the normal travel control) quickly, the user feels slack.

  In addition, when the vehicle is stopped under certain neutral control non-operating conditions and the brake pedal is released, the vehicle immediately moves forward due to the creep phenomenon under normal travel control, but the driver starts from this state. From the comparison with responsiveness, the above-mentioned slack is felt.

  The present invention was devised in view of the above problems, and during normal travel control, normal travel control from neutral control while ensuring the appropriate depression range of the accelerator pedal where the target throttle opening should be zero. It is an object of the present invention to provide a control device for an automatic transmission for a vehicle that can reduce the frequency with which the driver feels loose when the accelerator pedal is depressed in a transitional state in the middle of returning to the vehicle.

  As means for solving the above-described problems, the control device for a vehicle automatic transmission according to the present invention is configured as follows. That is, the control device for an automatic transmission for a vehicle according to the present invention provides friction of the automatic transmission that is engaged when the vehicle travels when a neutral control start condition including selection of a forward travel position and an accelerator off state is satisfied. Neutral control means for reducing or releasing the engagement force of the engagement element to bring it into a neutral state, and neutral control for starting the engagement operation of the friction engagement element when a neutral control return condition is satisfied in the neutral state A return means; a storage means for storing a first throttle opening setting in which the target throttle opening for the actual accelerator opening is set to zero with the target throttle opening for the actual accelerator opening equal to or less than the first threshold; and the storage means Idle for performing idle determination based on the stored first throttle opening setting and actual accelerator opening And the engagement operation of the friction engagement element when the idle determination is made by the idle determination means in a transitional state in the middle of returning from the neutral control to the normal travel control after the neutral control return condition is established. And an engagement operation speed increasing means for increasing the speed, wherein the storage means is a target throttle opening degree relative to an actual accelerator opening degree that is less than a first threshold value and less than or equal to a second threshold value. The second throttle opening setting in which the target throttle opening with respect to the actual accelerator opening is set as zero is further stored, and the idle determination means is configured to set the second throttle opening and the actual accelerator opening in the transient state. Idle determination is performed based on the degree, and during normal travel control, based on the first throttle opening setting and the actual accelerator opening Performing idle judgment, those.

  According to such a configuration, in the transient state, the idle determination means has a threshold value in a range where the target throttle opening is zero, which is smaller than the first slot opening setting (slot opening setting used during normal travel control). Since the idling determination is performed based on the second throttle opening setting, even when the accelerator pedal depression amount is very small, it is easy to determine the idling off, and the engagement operation speed of the friction engagement element is easily increased. As a result, the driver is less likely to feel slack when the accelerator pedal is depressed in the transient state.

  Further, during normal travel control, it is possible to ensure an accelerator pedal depression range within a suitable range where the target throttle opening should be zero.

  According to the present invention, the accelerator pedal in a transient state during the return from the neutral control to the normal travel control while ensuring the appropriate depression range of the accelerator pedal at which the target throttle opening should be zero during the normal travel control. The frequency at which the driver feels slack when the amount of depression of the vehicle is very small can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a basic configuration of a vehicle equipped with a control device for an automatic transmission for a vehicle according to an embodiment of the present invention. Reference numeral 1 denotes an engine, reference numeral 2 denotes a torque converter, reference numeral 3 denotes an automatic transmission, and reference numeral 4 denotes an ECU (electronic control unit).

  The engine 1 is, for example, a multi-cylinder gasoline engine, and a crankshaft (not shown) that is an output shaft of the engine 1 is connected to an automatic transmission 3 via a torque converter 2. The engine 1 is provided with a water temperature sensor 11 that detects an engine water temperature, an air flow meter 12 that detects an intake air amount, a throttle position sensor 14, a crank position sensor 15, and the like.

  The torque converter 2 is a fluid power transmission device, and as shown in FIG. 2, a lock-up clutch 201 that directly connects an input shaft and an output shaft, a pump impeller 202 on the input shaft side, and an output shaft side A turbine impeller 203, a one-way clutch 204, a stator 205 that exhibits a torque amplification function, and the like are provided.

As shown in FIG. 2, the automatic transmission 3 is a planetary gear type transmission. As shown in FIG. It has. The rear gear unit 302 includes a third rotating element 350 including two sun gears S2 and S3 connected via an intermediate shaft 303, and a second rotating element including a carrier CR2 and a ring gear R3 connected via a connecting member 304. 340, a first rotating element 330 including a ring gear R1 and a ring gear R2 connected to each other, and an output rotating element including a carrier CR3 connected to the output shaft 305. Although not shown, the output shaft 305 of the automatic transmission 3 is connected to the left and right wheels via a differential gear device or the like. The automatic transmission 3 is provided with a rotation sensor 21 that detects the rotation speed of the output shaft 305. The output signal of the rotation sensor 21 is taken into the ECU 4.

  The above automatic transmission 3 can set five forward speeds and one reverse speed. The operation table of FIG. 3 shows engagement / release states of the clutches C1 to C3, the brakes B1 to B4, and the one-way clutches F1 to F3 for setting the respective gear positions. As shown in FIG. 3, for example, at the first speed used when the vehicle starts, the clutch C1 is engaged and the one-way clutch F3 is operated. When the engine brake is applied at the first speed, the brake B4 is engaged.

  In the automatic transmission 3 described above, when a predetermined neutral control start condition is satisfied, an engagement force of a clutch (input clutch) C1 that is a friction engagement element of the automatic transmission 3 that is engaged when the vehicle travels. Neutral control is performed to lower or cancel the value to bring it to the neutral state. The neutral control of the automatic transmission 3 is a control executed by the ECU 4 and will be described in detail later.

<ECU>
The ECU 4 includes a CPU, ROM, RAM, backup RAM, and the like (not shown). The ROM is a storage unit that stores various control programs, maps that are referred to when the various control programs are executed, and the like. The CPU executes arithmetic processing based on various control programs and maps stored in the ROM. The RAM is a memory that temporarily stores calculation results in the CPU, data input from each sensor, and the like. The backup RAM is a nonvolatile memory that stores data to be saved when the engine 1 is stopped. It is memory.

  As shown in FIG. 1, a water temperature sensor 11, an air flow meter 12, an accelerator position sensor 13, a throttle position sensor 14, and a crank position sensor 15 are connected to the ECU 4. Further, a shift position sensor 16 that detects the operation position of the shift lever 30, a brake pedal sensor 17, a vehicle speed sensor 18, an acceleration sensor 19, a gradient sensor 20 that detects a vehicle gradient relative to a horizontal plane, and an output shaft 305 of the automatic transmission 3. A rotation sensor 21 for detecting the rotation speed is connected.

  The ECU 4 includes a water temperature sensor 11, an air flow meter 12, an accelerator position sensor 13, a throttle position sensor 14, a crank position sensor 15, a shift position sensor 16, a brake pedal sensor 17, a vehicle speed sensor 18, an acceleration sensor 19, a gradient sensor 20, Based on the output signals of various sensors such as the rotation sensor 21, various controls of the engine 1 and various controls described later are executed.

<Neutral control>
The ECU 4 controls the hydraulic control circuit (not shown) of the automatic transmission 3 to reduce or release the engagement force of the clutch C1 when a predetermined neutral control start condition is satisfied during the idling operation of the engine 1. Thus, neutral control is performed to bring the automatic transmission 3 into the neutral state.

  The neutral control start condition is, for example, that the vehicle speed based on the vehicle speed detection signal from the vehicle speed sensor 18 is zero, and that the shift lever position based on the shift position sensor 16 is “D range” (the forward travel position is selected). The brake pedal is being depressed (the brake pedal sensor 17 is ON), and the amount of operation of the accelerator pedal based on the output of the accelerator position sensor 13 is zero (the accelerator is off). And so on.

  On the other hand, the neutral control return condition, which is a return condition from the neutral control to the normal travel control, is, for example, “release of brake pedal depression (brake pedal sensor 17 is OFF)”. In addition, it is good also as said neutral control return conditions that the depression force of a brake pedal is loosened during neutral control. In this case, the ECU 4 can detect that the brake pedal depression force has been loosened by monitoring the master cylinder pressure, and can start processing after the neutral control return condition is satisfied.

  When the neutral control return condition is satisfied, the ECU 4 starts the engagement operation of the clutch C1 in which the engagement force is reduced or released. Specifically, by controlling the engagement command pressure of the clutch C1, the engagement hydraulic pressure of the clutch C1 is gradually increased so that the engagement shock does not occur.

  After the engagement operation of the clutch C1 is started and before the engagement operation is completed (that is, in a transient state before returning from the neutral control to the normal travel control), the accelerator pedal is depressed and the ECU 4 is idled. When the OFF determination is made, the ECU 4 optimizes the engagement instruction oil pressure of the clutch C1 according to the accelerator opening obtained from the output of the accelerator position sensor 13, sets a higher engagement instruction oil pressure, and sets the engagement instruction oil pressure of the clutch C1. Increase the joint operation speed.

  Note that the ECU 4 sets a neutral control state flag in, for example, the RAM. This neutral control state flag sets a flag indicating that the neutral control is being executed when the neutral control start condition is satisfied and the neutral control is started, and then the neutral control return condition is satisfied and the normal control is started from the neutral control. In a transitional state in the middle of returning to traveling control (hereinafter also simply referred to as “transient state”), a flag indicating the transitional state is set, and then the transitional state is exited to return to normal traveling control. Sometimes a flag indicating that the normal running control is being executed is set. The determination that the transition state has been removed and the vehicle has returned to the normal travel control is performed, for example, when the ECU 4 detects that the clutch C1 has been released and the engagement has been completed. Such detection is performed, for example, from the rotational speed of the turbine impeller 203, the rotational speed of the output shaft 305 (the rotation sensor 21), and the like.

<Map>
5 and 6 are examples of maps Ma and Mb that are referred to when the ECU 4 performs idle determination described later. These maps Ma and Mb are obtained by nonlinearly setting the target throttle opening with respect to the actual accelerator opening, and are stored in advance in the ROM of the ECU 4.

  A map Ma shown in FIG. 5 is a map (first throttle opening setting) referred to by the ECU 4 during normal travel control. This map Ma has a predetermined accelerator opening as a first threshold Sa, a target throttle opening for an actual accelerator opening equal to or lower than the first threshold Sa is set to zero, and for an actual accelerator opening greater than the first threshold Sa. In general, the target throttle opening is set to increase as the accelerator opening increases.

  In the present specification and claims, the throttle opening being zero (fully closed state) is realized when a throttle actuator (not shown) is driven to the maximum on the valve closing side by a drive signal from the ECU 4. It means the most closed state of the throttle valve, and a small amount of air can flow from the upstream side to the downstream side of the throttle valve. Note that the throttle opening when the throttle valve is in the fully closed state only needs to be smaller than the opening when the engine 1 is in the fast idle state, and may be the opening in the normal idle state.

  A map Mb indicated by a solid line in FIG. 6 is a map (second throttle opening setting) referred to by the ECU 4 in a transient state in the middle of returning from the neutral control to the normal travel control. This map Mb sets the target throttle opening with respect to the actual accelerator opening between the first threshold Sa and the second threshold Sb to zero with the target throttle opening with respect to the actual accelerator opening equal to or smaller than the second threshold Sb being smaller than the first threshold Sa. The degree is set to a substantially constant value, and for the actual accelerator opening greater than the first threshold value Sa, the target throttle opening is set to increase with an increase in the accelerator opening.

  A one-dot chain line in FIG. 6 shows a map Ma for comparison. In the present embodiment, the map Ma and the map Mb overlap in an area that is greater than or equal to the actual accelerator opening Sc, but the magnitude relationship between the first threshold value Sa and the second threshold value Sb satisfies the above relationship. The map Ma and the map Mb may not overlap each other.

<Control procedure>
Next, the contents of the process executed by the ECU 4 will be described based on the flowchart shown in FIG. A series of processing described based on this flowchart is repeatedly executed at a predetermined time period. Further, the ECU 4 performs processing such as idle determination with reference to the map Ma until the map to be referred to for idle determination is changed in step ST3 described later.

  In step ST1, the ECU 4 determines whether or not neutral control is being executed. When the determination result is affirmative determination (YES), the process proceeds to step ST2, and when the determination result is negative determination (NO), the determination of step ST1 is repeatedly performed.

  The determination as to whether or not the neutral control is being executed is performed based on the neutral control state flag described above, for example. For example, when the D range is selected by the shift lever 30, the output of the shift position sensor 16 indicates the selected position, and the accelerator operation amount is zero without performing the accelerator operation. The output of the position sensor 13 indicates that the brake operation is being performed, and the output of the brake pedal sensor 18 indicates that the vehicle is stopped. When indicated by the output, the ECU 4 determines that the neutral control start condition is satisfied, sets the automatic transmission 3 to the neutral state, and sets a neutral control state flag indicating that the neutral control is being executed. To do. Then, the ECU 4 performs the determination process of ST1 based on the neutral control state flag.

  In step ST2, the ECU 4 is in the middle of returning to normal travel control from neutral control when neutral control return conditions such as release of brake pedal depression (OFF output of the brake pedal sensor 17) are satisfied during execution of neutral control. Whether or not it is in a state is determined based on, for example, a neutral control state flag. When the determination result is affirmative determination (YES), the process proceeds to step ST3, and when the determination result is negative (NO), the determination of step ST2 is repeatedly performed.

  In step ST3, the ECU 4 changes the map referred to for idle determination from the map Ma to the map Mb.

  In parallel with this control procedure, the ECU 4 repeatedly executes idle determination at a predetermined time period in the transient state. When the ECU 4 makes an idle-off determination by detecting that the actual accelerator opening obtained from the output of the accelerator position sensor 13 is greater than or equal to the second threshold value Sb, The engagement operation speed of the clutch C1 is increased according to the target throttle opening calculated from the actual accelerator opening and the map Mb.

  In step ST4, the ECU 4 determines whether or not the return from the transient state to the normal travel control has been completed based on, for example, a neutral control state flag. If the determination result is affirmative (YES), the process proceeds to step ST5. If the determination result is negative (NO), the determination in step ST4 is repeated.

  In step ST5, the ECU 4 returns the map referred to for the idle determination from the map Mb to the map Ma.

<Other embodiment 1>
1 to 3, the automatic transmission 3 capable of setting five forward speeds and one reverse speed is shown mounted on the FR vehicle. Of course, the number of gear speeds, the vehicle drive system, etc. Is not limited to this. For example, as shown in FIGS. 7 to 9, the present invention is also applied to an automatic transmission 3 ′ in which an automatic transmission 3 ′ capable of setting six forward speeds and one reverse speed is mounted on an FF (front engine / front drive) vehicle. Is applicable.

  7 to 9, the automatic transmission 3 'mounted on an FF vehicle will be briefly described below. In addition, about the structure similar to the structure demonstrated based on FIGS. 1-3, the same code | symbol is attached | subjected and the description is abbreviate | omitted. Further, the control procedure is the same as that of the above-described embodiment, and the description thereof is omitted.

  FIG. 7 shows a basic configuration of an FF vehicle equipped with a control device for an automatic transmission for a vehicle. Reference numeral 3 'denotes the automatic transmission capable of setting six forward speeds and one reverse speed.

  The automatic transmission 3 ′ includes a first transmission unit 41 mainly composed of a single pinion type first planetary gear unit 401, a single pinion type second planetary gear unit 402, and a double pinion type third planetary gear unit. A planetary gear type 6-speed transmission that has a second transmission portion 42 mainly composed of 403 on a coaxial line, shifts the rotation of the input shaft 43, transmits it to the output shaft 44, and outputs it from the output gear 45. It is. The output gear 45 is connected directly or via a counter shaft to a differential gear device mounted on the vehicle.

  The first planetary gear device 401 constituting the first transmission unit 41 includes three rotating elements, a sun gear S1 ', a carrier CA1 and a ring gear R1', and the sun gear S1 'is connected to the input shaft 43. Further, the sun gear S1 'is rotated at a reduced speed with respect to the input shaft 43 using the carrier CA1 as an intermediate output member when the ring gear R1' is fixed to the housing 46 via the third brake B3 '. In the second planetary gear device 402 and the third planetary gear device 403 constituting the second transmission unit 42, four rotating elements RM1 to RM4 are configured by being partially connected to each other. Specifically, the first rotating element RM1 is constituted by the sun gear S3 ′ of the third planetary gear unit 403, and the ring gear R2 ′ of the second planetary gear unit 402 and the ring gear R3 ′ of the third planetary gear unit 403 are mutually connected. The second rotation element RM2 is configured by being connected. Further, the carrier CA2 of the second planetary gear device 402 and the carrier CA3 of the third planetary gear device 403 are connected to each other to constitute a third rotating element RM3. The fourth rotating element RM4 is configured by the sun gear S2 'of the second planetary gear unit 402.

  In the second planetary gear device 402 and the third planetary gear device 403, the carriers CA2 and CA3 are constituted by a common member, and the ring gears R2 'and R3' are constituted by a common member. Further, the pinion gear of the second planetary gear device 402 also serves as the second pinion gear of the third planetary gear device 403.

  The first rotation element RM1 (sun gear S3 ′) is integrally connected to the carrier CA1 of the first planetary gear device 401 as an intermediate output member, and is selectively connected to the housing 46 by the first brake B1 ′. The rotation is stopped. The second rotating element RM2 (ring gears R2 ′ and R3 ′) is selectively coupled to the input shaft 43 via the second clutch C2 ′, while the housing 46 via the one-way clutch F1 ′ and the second brake B2 ′. The rotation is stopped by being selectively connected to. The third rotation element RM3 (carriers CA2 and CA3) is integrally connected to the output shaft 44. The fourth rotation element RM4 (sun gear S2 ') is selectively coupled to the input shaft 43 via the first clutch C1'.

  FIG. 9 is an operation table showing engagement / release states of the clutches C1 ′ to C2 ′, the brakes B1 ′ to B3 ′, and the one-way clutch F1 ′ for setting the above-described shift stages of the automatic transmission 3 ′. . For example, at the first speed used when the vehicle starts, the clutch C1 'is engaged and the one-way clutch F1' is operated. When the engine brake is applied at the first speed, the brake B2 'is engaged. When a predetermined neutral control start condition is satisfied, neutral control is performed in which the engagement force of the clutch C1 ′, which is a friction engagement element of the automatic transmission 3 ′ that is engaged when the vehicle is traveling, is reduced or released to bring it into a neutral state. Executed. The automatic transmission 3 ′ is provided with a rotation sensor 21 ′ that detects the rotation speed of the output shaft 44. The output signal of the rotation sensor 21 'is taken into the ECU 4.

<Other embodiment 2>
In the embodiment described above, the process of step ST3 is executed immediately after the determination process of step ST2. However, immediately after the determination process of step ST2 is omitted and an affirmative determination is made in step ST1, the ECU 4 performs the idle determination. The map to be referred to may be changed from the map Ma to the map Mb. That is, at least in a transient state, if the idle determination is performed based on the map Mb and the actual accelerator opening, the change from the map Ma to the map Mb may be performed during the neutral control.

<Other embodiment 3>
In the above-described embodiment, an example in which the present invention is applied to a vehicle equipped with a planetary gear type automatic transmission as an automatic transmission is shown. The present invention is not limited to this, and the CVT (belt type continuously variable) is used. It can also be applied to a vehicle equipped with a transmission.

<Other embodiment 4>
In the above-described embodiment, an example in which the present invention is applied to a vehicle in which only an engine is mounted as a drive source has been described. However, the present invention is not limited to this, and for example, an engine and an electric motor ( In a hybrid vehicle equipped with a traveling motor or a generator motor, for example, such a hybrid vehicle is used when limiting control for limiting the power supplied to the traveling motor or the like when a predetermined condition is satisfied. The present invention can also be applied to.

  The present invention can be applied to a control device for an automatic transmission for a vehicle that performs neutral control for setting the automatic transmission to a neutral state when a predetermined condition is satisfied.

It is a schematic structure figure showing an example of a vehicle to which the present invention is applied. It is a skeleton figure which shows the structure of the torque converter and automatic transmission mounted in the vehicle of FIG. Note that the lower half of the center line is not shown. FIG. 3 is a chart showing clutch / brake engagement / release states for setting each gear position in the automatic transmission of FIG. 2. It is a flowchart which shows the content of the map change process which ECU performs. It is a figure which shows the map which set the target throttle opening with respect to the actual accelerator opening, Comprising: It is a map used at the time of normal driving control. It is a figure which shows the map which set the target throttle opening with respect to an actual accelerator opening, Comprising: It is a map used for idle-off determination in the transient state in the middle of returning from neutral control to normal driving control. It is a schematic block diagram which shows an example of the other vehicle to which this invention is applied. It is a skeleton figure which shows the structure of the torque converter and automatic transmission mounted in the vehicle of FIG. Note that the lower half of the center line is not shown. FIG. 9 is a chart showing engagement / release states of clutches and brakes for setting each gear position in the automatic transmission of FIG. 8.

Explanation of symbols

C1, C1 'clutch (friction engagement element)
Ma map (1st throttle opening setting)
Mb map (second throttle opening setting)
Sa 1st threshold value Sb 2nd threshold value 3, 3 'Automatic transmission 4 ECU
16 Shift position sensor 17 Brake pedal sensor

Claims (1)

When the neutral control start condition including selection of the forward travel position and the accelerator off state is satisfied, the engagement force of the friction engagement element of the automatic transmission that is engaged when the vehicle is traveling is reduced or released to the neutral state. Neutral control means to
Neutral control return means for starting the engagement operation of the friction engagement element when a neutral control return condition is satisfied in the neutral state;
Storage means for storing a first throttle opening setting in which the target throttle opening with respect to the actual accelerator opening is set with zero as the target throttle opening with respect to the actual accelerator opening equal to or less than the first threshold;
Idle determination means for performing idle determination based on the first throttle opening setting and the actual accelerator opening stored in the storage means;
After the neutral control return condition is satisfied, the engagement operation speed of the friction engagement element is increased when an idle-off determination is made by the idle determination means in a transitional state in the middle of returning from neutral control to normal travel control. Engaging operation speed increasing means for
In a vehicle automatic transmission control device comprising:
The storage means further stores a second throttle opening setting in which the target throttle opening with respect to the actual accelerator opening is set to zero with the target throttle opening with respect to the actual accelerator opening equal to or less than the second threshold being smaller than the first threshold. And
The idle determination means performs an idle determination based on the second throttle opening setting and the actual accelerator opening in the transient state, and based on the first throttle opening setting and the actual accelerator opening during normal travel control. A control device for an automatic transmission for a vehicle, characterized by performing idle determination.

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