JP5041008B2 - Control device for automatic transmission, control method, program for realizing the method, and recording medium recording the program - Google Patents

Description

  The present invention relates to control of an automatic transmission for a vehicle, and more particularly to control of an automatic transmission capable of manual shift based on a driver's operation.

  A vehicle including an automatic transmission that is controlled in accordance with a plurality of shift positions such as a forward position, a parking position, a reverse position, and a neutral position is known. When such a vehicle travels in the D position, regardless of the driver's intention, a shift based on the state of the vehicle (vehicle speed, accelerator opening, etc.) (hereinafter also referred to as an automatic shift) according to a previously stored shift map. Is performed). In recent years, in addition to such automatic shifts, automatic transmissions that enable shifts (hereinafter also referred to as manual shifts) that allow a driver to select an arbitrary shift stage by operating switches and levers have been developed. Are known. In a vehicle equipped with such an automatic transmission capable of manual shifting, a technique for executing a driver's shift command while preventing over-rotation or stalling of the engine is disclosed in, for example, Japanese Patent Laid-Open No. 8-210495 ( Patent Document 1) discloses this.

  The control device disclosed in this publication controls the shift of an automatic transmission based on the output of a vehicle speed detector that detects a value corresponding to the vehicle speed and the output of an engine load detector that detects a value corresponding to the engine load. A shift command unit that outputs a predetermined shift command by manual operation, and a shift command output by the shift command unit based on an output of the vehicle speed detection unit or an output of the engine load detection unit. An area setting unit for setting a permission area for permitting the execution of the shift and a shift prohibition area for prohibiting the execution of the shift command; and a shift permission area within the predetermined period after the shift command means outputs the shift command in the shift prohibition area. And a delay unit that executes a shift command when it becomes. In this control apparatus, when the shift switch is operated continuously three times or more, the operations up to the second time are stored, but the operations after the third time are ignored.

  According to the control device disclosed in this publication, when a shift command is output in the shift prohibition region, execution of the shift command is delayed, and the shift is performed when the shift permission region is reached within a predetermined period after the shift command is output. Since the command is executed, it is possible not only to prevent overrev or stall in the engine even if an inappropriate gear shift command is given, but also to execute the gear shift command of the driver as much as possible and to re-operate Can be eliminated.

JP-A-8-210495

  However, the control device described in Patent Document 1 has the following problems when a plurality of downshift operations are performed in a short time. That is, when the speed change switch is operated three or more times continuously, the third and subsequent operations are uniformly ignored even in a vehicle state in which the engine does not over-rotate, which makes the driver feel uncomfortable. Further, since whether or not to allow all shifts is determined at the shift operation timing, even if the second shift is permitted, for example, the accelerator is turned on during execution of the first shift after the shift operation timing and the vehicle speed is increased. If the engine speed increases, the engine may overspeed when the second speed change is executed. Further, if the second shift output is prohibited, the second shift determination has already been made, so that the shift output is delayed until the shift is permitted until the accelerator is returned or the vehicle speed is reduced to enter the shift permission region. Since the second shift is executed, a further time lag occurs between the shift operation timing and the second shift execution timing, which gives the driver an uncomfortable feeling.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to appropriately suppress engine overspeed in an automatic transmission capable of manual shift based on a driver's operation, To provide a control device, a control method, a program for realizing the method, and a recording medium on which the program is recorded, which can execute a manual shift based on the operation of the driver without causing the driver to feel uncomfortable.

  A control device according to the present invention is a control device for an automatic transmission capable of manual shift based on a driver's operation, and means for detecting the driver's downshift operation and the downshift operation are continuously provided. If detected, limit the number of downshifts accepted based on at least one of the accelerator opening during the downshift operation, the vehicle speed during the downshift operation, and the gear stage formed by the automatic transmission during the downshift operation. Limiting means. The limiting means includes means for increasing the number of received downshifts when the accelerator opening during the downshift operation is small as compared to when the accelerator opening is large. The limiting means includes means for increasing the number of downshifts accepted when the vehicle speed during the downshift operation is low compared to when the vehicle speed is high.
  Preferably, the limiting means includes means for increasing the number of received downshifts when the shift stage formed by the automatic transmission at the time of the downshift operation is on the low speed side as compared with the case of the high speed side.
  A control method according to another aspect of the present invention is a control method of an automatic transmission capable of manual shift based on a driver's operation, and the step of detecting the driver's downshift operation and the downshift operation are continuous. The number of downshifts received based on at least one of the accelerator opening at the time of downshift operation, the vehicle speed at the time of downshift operation, and the gear stage formed by the automatic transmission at the time of downshift operation. And a restricting step for restricting. The limiting step includes a step of increasing the number of downshifts to be accepted when the accelerator opening during the downshift operation is small compared to when the accelerator opening is large. The limiting step includes a step of increasing the number of downshifts accepted when the vehicle speed during the downshift operation is low compared to when the vehicle speed is high.
  Preferably, the limiting step includes a step of increasing the number of received downshifts when the shift stage formed by the automatic transmission at the time of the downshift operation is on the low speed side compared to the case of the high speed side.
  A program according to another aspect of the present invention is a program for causing a computer to execute the control method of the present invention.
  A recording medium according to another aspect of the present invention is a recording medium in which a program for causing a computer to execute the control method of the present invention is recorded in a computer-readable manner.

It is a figure which shows the structure of the vehicle by which the control apparatus which concerns on embodiment of this invention is mounted. It is a figure which shows the shape of the shift gate in embodiment of this invention. It is a functional block diagram of a control device concerning an embodiment of the invention. It is a flowchart (the 1) which shows the control structure of ECU which comprises the control apparatus which concerns on embodiment of this invention. It is a figure which shows the relationship between the overspeed area of an engine speed, an accelerator opening, and a vehicle speed. It is a flowchart (the 2) which shows the control structure of ECU which comprises the control apparatus which concerns on embodiment of this invention. It is a flowchart which shows the control structure of ECU which comprises the control apparatus which concerns on the modification of embodiment of this invention. It is a figure which shows the relationship between a vehicle speed and the frequency | count of a continuous down limit. It is a figure which shows the relationship between the gear stage before operation, and the frequency | count of continuous down limitation. It is a figure which shows the relationship between an accelerator opening degree and the frequency | count of a continuous down limit.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<Embodiment>
A vehicle 10 equipped with a control device according to an embodiment of the present invention will be described with reference to FIG. The vehicle 10 is a front engine front drive (FF) vehicle. A vehicle other than FF may be used.

  Vehicle 10 includes an engine 100, a torque converter 210, an automatic transmission 200, drive wheels 12, a differential gear 14, a drive shaft 16, and an ECU (Electronic Control Unit) 400.

  Engine 100 is an internal combustion engine that burns a mixture of fuel and air injected from an injector (not shown) in a combustion chamber of a cylinder. The piston in the cylinder is pushed down by the combustion, and the crankshaft is rotated.

  Automatic transmission 200 includes a planetary gear unit 300 and a hydraulic circuit 220. Automatic transmission 200 is connected to engine 100 via torque converter 210. Hydraulic circuit 220 controls the operating states of the clutch elements and brake elements inside planetary gear unit 300 in accordance with a shift command from ECU 400. Thereby, automatic transmission 200 forms a desired gear stage, and changes the rotational speed of the crankshaft to a desired rotational speed.

  The output gear of the automatic transmission 200 meshes with the differential gear 14. A drive shaft 16 is connected to the differential gear 14 by spline fitting or the like. Power is transmitted to the left and right drive wheels 12 via the drive shaft 16.

  The ECU 400 includes a vehicle speed sensor 50, a position switch 54 of a shift lever 52 movably provided along a shift passage formed in the shift gate 80, an accelerator opening sensor 58 of an accelerator pedal 56, and brake pedal 60. The stroke sensor 62, the throttle opening sensor 64 of the electronic throttle valve 114, the engine speed sensor 66, the input shaft speed sensor 70, and the output shaft speed sensor 72 are connected via a harness or the like. Yes.

  The vehicle speed sensor 50 detects the vehicle speed V of the vehicle 10 from the rotational speed of the drive shaft 16 and transmits a signal representing the detection result to the ECU 400.

  The position switch 54 detects the position (shift position) SP of the shift lever 52 and transmits a signal representing the detection result to the ECU 400. Corresponding to the shift position SP, the gear stage of the automatic transmission 200 is automatically formed.

  The accelerator opening sensor 58 detects the opening (accelerator opening) ACC of the accelerator pedal 56 and transmits a signal representing the detection result to the ECU 400.

  Stroke sensor 62 detects a stroke amount (brake stroke amount) BS of brake pedal 60 and transmits a signal representing the detection result to ECU 400.

  The throttle opening sensor 64 detects the opening (throttle opening) of the electronic throttle valve 114 whose opening is adjusted by the actuator, and sends a signal representing the detection result to the ECU 400. The electronic throttle valve 114 adjusts the amount of air taken into the engine 100 (engine 100 output).

  Engine rotation speed sensor 66 detects the rotation speed (engine rotation speed) NE of the output shaft (crankshaft) of engine 100 and transmits a signal representing the detection result to ECU 400.

  Input shaft rotational speed sensor 70 detects input shaft rotational speed NIN of automatic transmission 200 and transmits a signal representing the detection result to ECU 400. Output shaft rotational speed sensor 72 detects output shaft rotational speed NOUT of automatic transmission 200 and transmits a signal representing the detection result to ECU 400.

  ECU 400 is sent from vehicle speed sensor 50, position switch 54, accelerator opening sensor 58, stroke sensor 62, throttle opening sensor 64, engine speed sensor 66, input shaft speed sensor 70, output shaft speed sensor 72, and the like. Based on the received signal, a map and a program stored in a ROM (Read Only Memory), the devices are controlled so that the vehicle 10 is in a desired running state.

  In the present embodiment, ECU 400 selects the 1st to 6th gears when D (drive) range is selected as the shift range of automatic transmission 200 when shift lever 52 is positioned at the D (drive) position. The automatic transmission 200 is controlled so that one of the gear positions is formed. The automatic transmission 200 can transmit the driving force to the drive wheels 12 by forming any one of the first to sixth gears. Note that the gear stage formed by the automatic transmission 200 is not limited to the first to sixth gears.

  The shift gate 80 will be described with reference to FIG. As shown in FIG. 2, a shift passage 82 is formed in the shift gate 80. The shift lever 52 is provided so as to be movable along the shift passage 82. A plurality of shift positions corresponding to each shift position in the automatic transmission 200 are set in the shift passage 82 in the shift gate 80. The plurality of shift positions are described as, for example, a forward position (hereinafter referred to as (D) position), a neutral position (hereinafter referred to as (N) position), and a parking position (hereinafter referred to as (P) position). ) And a reverse position (hereinafter referred to as (R) position). The shift gate 80 is formed so that the shift lever 52 can move from the position corresponding to the (P) position to the (R) position, (N) position, and (D) position on the lower side of the drawing in FIG.

  A sub gate 84 is connected to the shift passage 82. The shift passage 82 is connected to the central portion of the sub-gate 84 in the vertical direction of the drawing in FIG. A shift position (hereinafter referred to as “(M) position”) corresponding to a manual shift mode in which the driver can select an arbitrary gear according to the operation of the shift lever 52 by the driver is set at the center of the sub-gate 84. When the shift lever 52 is moved from the (D) position to the right in FIG. 2, the (M) position is reached.

  In the sub-gate 84, when the shift lever 52 is moved from the (M) position in the upward direction on the paper surface of FIG. 2, the shift lever 52 reaches the (+) position, and when the shift lever 52 is moved downward in the paper surface of FIG. The shape of the shift gate 80 is not particularly limited to this. Further, the shift gate 80 may be provided at the driver's seat so that the upward direction in the drawing of FIG. 2 is the front direction of the vehicle, or the upward direction of the drawing in FIG. Thus, it may be provided in the driver's seat.

  The driver operates the shift lever 52 along the shift passage 82 formed in the shift gate 80 to move the shift lever 52 to a desired position (shift position). The driver can select the power transmission state of the automatic transmission 200 by changing the position of the shift lever 52.

  When the driver moves the shift lever 52 to the (D) position, a signal indicating that the (D) position has been selected is transmitted from the position switch 54. When the ECU 400 receives a signal indicating that the position (D) is selected from the position switch 54, the ECU 400 controls the automatic transmission 200 to travel forward in the automatic transmission mode.

  When the automatic shift mode is selected, ECU 400 performs automatic shift of automatic transmission 200 based on a shift map using vehicle speed V and accelerator opening ACC as parameters.

  When the driver moves the shift lever 52 to the (M) position, a signal indicating that the (M) position has been selected is transmitted from the position switch 54. When ECU 400 receives a signal indicating that the (M) position has been selected from position switch 54, ECU 400 controls automatic transmission 200 to travel forward in the manual shift mode.

  When the signal indicating that the driver has moved shift lever 52 from (M) position to (+) position (hereinafter also referred to as (+) operation) is received from position switch 54, ECU 400 is currently formed. The automatic transmission 200 is controlled so as to form a gear corresponding to the gear ratio one speed higher than the gear. That is, in the manual shift mode, the upshift is manually performed by the driver's (+) operation.

  When the signal indicating that the driver has moved shift lever 52 from (M) position to (−) position (hereinafter also referred to as (−) operation) is received from position switch 54, ECU 400 is currently formed. The automatic transmission 200 is controlled so as to form a gear stage corresponding to the gear ratio one speed lower than the gear stage. That is, in the manual shift mode, the downshift is manually performed by the driver's (−) operation.

  With reference to FIG. 3, a functional block diagram of the control device according to the present embodiment will be described. As shown in FIG. 3, the control device includes a downshift receiving unit 410, a permitted shift speed storage unit 420, a permitted shift speed reception canceling unit 430, and a manual shift control unit 440.

  The downshift receiving unit 410 makes a shift determination corresponding to the downshift operation by the driver based on the shift position SP, the accelerator opening ACC, the vehicle speed V (or the output shaft rotational speed NOUT), and the input shaft rotational speed NIN. A required shift speed corresponding to the shift determination is calculated, and a required shift speed where the engine speed NE is not included in a predetermined overspeed range after downshifting is accepted as an allowed shift speed. The required shift speed is a shift speed after downshift based on shift determination.

  Permitted shift speed storage section 420 temporarily stores the permitted shift speed received by downshift accepting section 410.

  Permitted gear position acceptance cancel unit 430 cancels the permitted gear stage stored in permitted gear stage storage unit 420 based on accelerator opening ACC, vehicle speed V (or output shaft speed NOUT), and input shaft speed NIN. To do. That is, permission gear stage acceptance canceling section 430 cancels the shift determination corresponding to the downshift operation by the driver. The downshift to the permitted gear stage canceled by the permitted gear position reception cancel unit 430 is not executed even if it is a downshift accepted during the downshift operation.

  The manual shift control unit 440 outputs a shift command (hereinafter also referred to as a shift output) for executing a shift to the permitted shift stage stored in the permitted shift stage storage unit 420 to the hydraulic circuit 220. When there are a plurality of permitted shift speeds stored in the permitted shift speed storage section 420, the manual shift control section 440 completes downshifting to the permitted shift speed being output (input at the gear ratio of the permitted shift speed being output). After waiting for the shaft rotation speed NIN and the output shaft rotation speed NOUT (synchronization), a shift command to the subsequent permitted shift speed is output.

  The control device according to the present embodiment having such a functional block is read out from a CPU (Central Processing Unit) and a memory and a memory included in the ECU 400 even with hardware mainly composed of a digital circuit or an analog circuit. It can also be realized by software mainly composed of programs executed by the CPU. In general, it is said that it is advantageous in terms of operation speed when realized by hardware, and advantageous in terms of design change when realized by software. Below, the case where a control apparatus is implement | achieved as software is demonstrated. Note that a recording medium on which such a program is recorded is also an embodiment of the present invention.

  With reference to FIG. 4, a control structure of a program executed when ECU 400 that is the control device according to the present embodiment is downshifted by the driver will be described. Note that this program is repeatedly executed at a predetermined cycle time.

  In step (hereinafter, step is abbreviated as S) 100, ECU 400 determines whether or not there has been a downshift operation (ie, (−) operation) by the driver, based on shift position SP transmitted from position switch 54. To do. If it is determined that a downshift operation has been performed (YES in S100), the process proceeds to S102. Otherwise (NO in S100), the process proceeds to S112.

  In S102, ECU 400 calculates a required shift speed. As described above, the required shift speed is a shift speed after downshift based on the shift determination. For example, when it is determined that there have been three consecutive downshift operations during traveling at the sixth speed, ECU 400 calculates the required shift speed as 5th speed, 4th speed, and 3rd speed.

  In S104, ECU 400 determines, for each required shift speed, whether or not engine speed NE after the downshift is in a predetermined overspeed range. For example, ECU 400 determines whether or not the engine is in the overspeed range based on a map having accelerator opening ACC and vehicle speed V (or output shaft speed NOUT) as parameters as shown in FIG. In the map shown in FIG. 5, a threshold line is provided for each shift stage (first to sixth speeds) after downshift. These threshold lines become higher as the gear position after downshifting becomes higher, and become higher as the accelerator opening degree ACC is lower. ECU 400 determines that engine speed NE after the downshift is an overspeed area when the area including the intersection of accelerator opening ACC and vehicle speed V exceeds the threshold line. Therefore, if the vehicle speed V is the same, the lower the accelerator opening degree ACC, the more difficult it is to be determined as the overspeed range, and if the accelerator opening degree ACC is the same, the lower the vehicle speed V is, the more difficult it is to determine the overspeed range. Become. Further, if the accelerator opening degree ACC and the vehicle speed V are the same, the higher the shift speed after the downshift is, the more difficult it is to be determined as the overspeed range. Note that the method for determining whether or not the engine speed NE after the downshift is in the overspeed range is not limited to this.

  In S106, ECU 400 determines whether or not there is a required shift speed that becomes an overspeed range. If there is a required shift speed that is in the overspeed range (YES in S106), the process proceeds to S108. Otherwise (NO in S106), the process proceeds to S110.

  In S108, ECU 400 cancels reception of the requested shift speed that becomes the overspeed range.

  In S110, ECU 400 accepts and stores the requested shift speed that does not become the overspeed range as the permitted shift speed.

  In S112, ECU 400 executes manual shift control. Specifically, ECU 400 outputs a shift command for causing automatic transmission 200 to form the accepted permitted shift speed to hydraulic circuit 220. When there are a plurality of permitted shift speeds, ECU 400 waits for completion of downshifting to the permitted shift speed being output, and then outputs a shift command to the subsequent permitted shift speed. For example, when there are three permitted shift speeds of 5th speed, 4th speed, and 3rd speed, ECU 400 first outputs a command to execute a downshift to 5th speed. After completion of the downshift to the fifth gear (that is, after the fifth gear is formed), a shift command to the fourth gear is output. After completing the downshift to the fourth gear, a shift command to the third gear is output. In the following description, the shift speed instructed from the ECU 400 to the hydraulic circuit 220 by the shift command is also referred to as an output shift speed.

  With reference to FIG. 6, a control structure of a program executed by ECU 400, which is a control device according to the present embodiment, during execution of manual shift will be described. This program is repeatedly executed at a predetermined cycle time during execution of manual shift.

  In S150, ECU 400 determines whether there are a plurality of permitted shift speeds. If there are a plurality of permitted gear positions (YES in S150), the process proceeds to S152. Otherwise (NO in S150), this process ends.

  In S152, ECU 400 determines whether or not the permitted shift speed after the second shift speed is lower than the output speed. The permitted shift speed after the second shift speed is obtained by excluding the permitted shift speed on the highest speed side from among a plurality of permitted shift speeds (that is, a shift speed corresponding to the shift determination). For example, when there are three permitted shift speeds, ie, 5th speed, 4th speed, and 3rd speed, the permitted speeds after the 2nd speed are 4th speed and 3rd speed except for the 5th speed on the fastest side. It is a step. Further, as described above, the output shift speed is a shift speed that is instructed from the ECU 400 to the hydraulic circuit 220 by the shift command (that is, a shift speed corresponding to the shift output). If the permitted shift speed after the second shift speed is lower than the output shift speed (YES in S152), the process proceeds to S154. Otherwise (NO in S152), this process ends.

  In S154, ECU 400 determines whether or not engine speed NE after the downshift is in a predetermined overspeed range for each permitted shift speed determined to be lower than the output speed. To do. For example, ECU 400 determines whether or not the engine is in the overspeed range based on a map having accelerator opening degree ACC and vehicle speed V (or output shaft speed NOUT) as parameters as shown in FIG. ECU 400 may determine whether or not the engine speed NE after the downshift is in the overspeed range based on a map different from the map shown in FIG.

  In S156, ECU 400 determines whether or not there is an allowable shift speed that becomes an overspeed range. If there is an allowable shift speed that becomes an overspeed range (YES in S156), the process proceeds to S158. Otherwise (NO in S156), this process ends.

  In S158, ECU 400 cancels the permitted shift speed that is in the overspeed range so that the downshift to the permitted speed range that is in the overspeed range is not executed. That is, ECU 400 cancels the shift determination that is in the overspeed range.

  The operation of automatic transmission 200 controlled by ECU 400 that is the control apparatus according to the present embodiment based on the above-described structure and flowchart will be described.

  Assume that there are three consecutive downshifts during traveling at the sixth gear. In this case, at the time of the downshift operation, the fifth speed stage, the fourth speed stage and the third speed stage are calculated as the required shift speeds (S102), and whether or not the engine speed NE after the downshift is in the overspeed range is determined. The determination is made for each required shift speed (S104).

  If it is determined that all the required shift speeds (5th speed, 4th speed and 3rd speed) are not in the overspeed range during the downshift operation (NO in S106), these required shift speeds are permitted. It is received and stored as a gear position (S110).

  When the permitted shift speed is accepted, manual shift control is executed (S112). First, a downshift to the fifth speed closest to the gear ratio of the sixth speed is executed. The downshift to the fourth speed stage is executed after the downshift to the fifth speed stage is completed. Therefore, the downshift execution to the fourth speed is delayed with respect to the driver's downshift operation. Further, the downshift to the third gear is executed after the downshift to the fourth gear is completed. Therefore, the execution of the downshift to the third gear is further delayed with respect to the driver's downshift operation.

  Therefore, while the output gear stage is at the fifth speed stage (during the downshift to the fifth speed stage), it continues down to the fourth and third speed stages on the lower speed side than the output gear stage (fifth gear stage). It is determined for each gear position whether the engine speed NE after the shift is in a predetermined overspeed range (YES in S152, S154).

  If it is determined at this point that the downshift to the fourth speed or third speed is in the overspeed range (YES in S156), the downshift to the speed determined to be in the overspeed range is cancelled. (S158). Therefore, the downshift to the fourth gear or the third gear allowed during the downshift operation may cause the engine to over-rotate due to changes in the accelerator opening degree ACC or the vehicle speed V during the downshift to the fifth gear. You can cancel at any time. Furthermore, since the downshift to the fourth gear or the third gear is canceled when there is a possibility of overspeeding, there is no sudden downshift when the non-overspeed range is reached after a predetermined time has elapsed. , Does not give the driver a sense of incongruity.

  On the other hand, unless it is determined that the downshift to the fourth speed and third speed is in the overspeed range (NO in S156), the downshift to the fourth speed and third speed is executed without cancellation. (S112). Therefore, three downshifts based on the driver's operation can be executed without limiting the number of times.

  Further, the overspeed region determination at the time of downshift operation (S104) and the overspeed region determination after the downshift operation (S154) are performed based on the map as shown in FIG. That is, as described above, even if the vehicle speed V is the same, the lower the accelerator opening ACC, the less likely it is to be determined as an overspeed range. Therefore, compared with the case where engine overspeed is determined based only on vehicle speed V, it is possible to expand the region where the downshift required by the driver is allowed.

  As described above, according to the control device according to the present embodiment, when a downshift operation is continuously detected a plurality of times, the required shift speed corresponding to the shift determination is lower than the output shift speed corresponding to the shift output. If it is on the side, it is determined whether or not the engine is over-rotated due to a downshift to the required shift speed on the low speed side, and the shift determination corresponding to the requested shift speed determined to be over-rotated is cancelled. Therefore, even if the requested shift stage is once permitted at the time of the downshift operation, the downshift to the requested shift stage that may cause the engine to overspeed due to an increase in the vehicle speed after the downshift operation or the like is cancelled. As a result, it is possible to prevent the engine from over-rotating and to make a sudden downshift as compared with the case where the shift output is delayed until the non-over-speed range is reached without canceling the shift determination. Can be suppressed. Further, unless it is determined that the engine is over-rotated, the downshift based on the driver's operation can be executed without limiting the number of times.

  In the present embodiment, the case where an arbitrary gear stage is selected based on the operation of the shift lever 52 has been described. However, instead of the operation of the shift lever 52, for example, an arbitrary gear is selected based on the operation of a paddle switch. A stage may be selected.

  Further, for example, when the highest speed shift stage (that is, the range of the gear ratio to be automatically changed) is selected based on the operation of the paddle switch described above in the automatic transmission mode, the highest speed in the automatic transmission mode is selected. You may make it apply this invention at the time of selection of the side gear stage. In this case, the threshold line values shown in FIG. 5 (values for determining engine overspeed) when the gear stage is selected in the manual shift mode and when the highest speed stage is selected in the automatic shift mode. May be changed.

  Further, in a vehicle provided with a plurality of modes having different driving characteristics required by the driver, such as a sports mode and a normal mode, the threshold value shown in FIG. 5 may be changed for each mode.

<Modification of Embodiment>
The control structure of the program executed when the ECU 400 according to the above-described embodiment is downshifted by the driver is changed to the structure shown in the flowchart of FIG. 7 instead of the structure shown in the flowchart of FIG. May be.

  With reference to FIG. 7, a control structure of a program executed by ECU 400 which is a control device according to the present modification will be described. In the flowchart shown in FIG. 7, the same steps as those in the flowchart shown in FIG. 4 are given the same step numbers. The processing for them is the same. Therefore, detailed description thereof will not be repeated here.

  In S200, ECU 400 counts the number of continuous down operations. ECU 400 counts, for example, the number of times that a plurality of downshift operations have been performed within a time shorter than a predetermined time as the number of consecutive down operations.

  In S202, ECU 400 calculates the number of times of continuous down limit based on at least one of vehicle speed V, the gear stage formed in automatic transmission 200 before the downshift operation, and accelerator opening ACC. The continuous down limit number is the maximum value of the number of downshifts that is predicted that the engine speed NE will not be in the overspeed range even if executed continuously. For example, as shown in FIG. 8, ECU 400 calculates the continuous down limit number of times to a larger value as vehicle speed V is included in the low speed region. Further, for example, as shown in FIG. 9, ECU 400 calculates the number of continuous down-limits as a larger value as the shift stage formed by automatic transmission 200 before the downshift operation is included in the low speed stage region. Further, for example, as shown in FIG. 10, ECU 400 calculates the continuous down limit number of times as a larger value as it is included in a region where accelerator opening ACC is lower. It should be noted that the continuous down limit number is calculated based on two or more parameters of the vehicle speed V, the gear position before the downshift operation, and the accelerator opening ACC, and the smallest number of the calculated continuous down limit times is calculated. The continuous down limit number of times may be selected.

  In S204, ECU 400 determines whether or not the number of continuous down operations exceeds the number of continuous down limits. If the number of consecutive down operations exceeds the number of consecutive down operations (YES in S204), the process proceeds to S206. Otherwise (NO in S204), the process proceeds to S208.

  In S206, ECU 400 cancels reception of the requested shift stage for the number of times that the continuous down limit has been exceeded.

  In S208, ECU 400 accepts and stores the requested shift speeds for which the number of continuous down limits has not been exceeded as permitted shift speeds.

  As described above, when the downshift operation is continuously detected a plurality of times, the engine speed NE is not in the overspeed range even if the number of continuous downshifts is continuously executed during the downshift operation. (S206). Therefore, during the downshift operation, the number of received downshifts can be reduced to suppress engine overspeed.

  Further, as shown in FIGS. 8, 9 and 10 described above, when the accelerator opening is small, the speed before the downshift operation is on the low speed side, or when the vehicle speed is low, the engine overspeeds. If it is difficult to occur, the continuous down limit number is calculated to a large value (S202). Therefore, it is possible to prevent the downshift required by the driver from being unnecessarily limited. Therefore, the manual shift based on the operation of the driver can be executed without causing the driver to feel uncomfortable while appropriately suppressing the engine overspeed.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  10 vehicles, 12 drive wheels, 14 differential gears, 16 drive shafts, 50 vehicle speed sensors, 52 shift levers, 54 position switches, 56 accelerator pedals, 58 accelerator opening sensors, 60 brake pedals, 62 stroke sensors, 64 throttle opening sensors , 66 Engine speed sensor, 70 Input shaft speed sensor, 72 Output shaft speed sensor, 80 Shift gate, 82 Shift passage, 84 Sub gate, 100 Engine, 114 Electronic throttle valve, 200 Automatic transmission, 210 Torque converter, 220 Hydraulic pressure Circuit, 300 planetary gear unit, 400 ECU, 410 downshift accepting unit, 420 allowed gear stage storage unit, 430 allowed gear stage acceptance canceling unit, 440 manual Shift control unit.

Claims (6)

A control device for an automatic transmission capable of manual shifting based on a driver's operation,
Means for detecting a downshift operation of the driver;
When the downshift operation is continuously detected, at least one of the accelerator opening at the time of the downshift operation, the vehicle speed at the time of the downshift operation, and the gear stage formed by the automatic transmission at the time of the downshift operation on the basis of either, only including a limiting means for limiting the down-shift times to accept,
The limiting means includes means for increasing the number of downshifts received when the accelerator opening at the time of the downshift operation is small, compared to a case where the accelerator opening is large,
The control means includes a means for increasing the number of received downshifts when the vehicle speed during the downshift operation is low, compared to when the vehicle speed is high . The limiting means includes means for increasing the number of received downshifts when the shift stage formed by the automatic transmission at the time of the downshift operation is on the low speed side as compared to the case on the high speed side. The control device according to claim 1 . A control method for an automatic transmission capable of manual shifting based on a driver's operation,
Detecting a downshift operation of the driver;
When the downshift operation is continuously detected, at least one of the accelerator opening at the time of the downshift operation, the vehicle speed at the time of the downshift operation, and the gear stage formed by the automatic transmission at the time of the downshift operation on the basis of either, only it contains a limitation step of limiting the down-shift times to accept,
Said limiting step is the compared to the case when the accelerator opening at the time of a downshift operation is small is large, it viewed including the step of increasing the down-shift times for accepting said,
The limiting step includes a step of increasing the number of downshifts received when the vehicle speed during the downshift operation is low compared to when the vehicle speed is high . The limiting step includes a step of increasing the number of received downshifts when the shift stage formed by the automatic transmission at the time of the downshift operation is on the low speed side compared to the case of the high speed side. Item 4. The control method according to Item 3 . A program for causing a computer to execute the control method according to claim 3 or 4 . The recording medium which recorded the program for making a computer perform the control method of Claim 3 or 4 so that computer reading was possible.

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