JP5932372B2 - Control device for automatic transmission for vehicle - Google Patents

Description

  The present invention relates to a control device for an automatic transmission for a vehicle that includes a fixed range that can be fixed to a relatively low speed gear stage in addition to an automatic shift range that automatically shifts based on a shift map.

  In general, an automatic transmission for a vehicle has an automatic shift range that travels while automatically shifting between a low speed stage and a high speed stage, and a relatively low speed stage such as a first speed stage or a second speed stage. It has a fixed range. For example, based on the speed change characteristics described in Patent Documents 1 and 2, the speed is changed according to the vehicle speed and the engine load. That is, in the automatic shift range, based on the shift map having a predetermined shift characteristic from the vehicle speed detected by the vehicle speed detecting means such as a vehicle speed sensor and the engine load detected by the engine load detecting means such as the throttle opening sensor. The automatic shift is performed by sequentially determining the optimum shift stage from all the shift stages. Also, unlike the automatic shift range, a fixed range that is substantially held at the second or first gear on the low speed side is provided with a third or second gear to prevent engine overrevs. It has been.

Japanese Patent Laid-Open No. 2-159467 Japanese Patent No. 3426380

  The control device for an automatic transmission for a vehicle described in Patent Document 2 can select an automatic shift range and a fixed range, and when the gradient determination means determines a flat road or an uphill road, In FIG. 2, the gear ratio on the higher speed side than the gear ratio for relatively low speed is selected.

  However, in the automatic transmission shift control device having the automatic shift range and the fixed range as described above, when the fixed range is switched by the operation of the select lever (immediately after being switched to the fixed range), The shift stage is switched at the same vehicle speed when the vehicle is traveling in the selected state. Therefore, the vehicle speed at which a downshift is caused by the operation of the select lever is the same as the vehicle speed at which a downshift is caused by automatic shift during traveling in a fixed range. In other words, when the vehicle is switched to the fixed range by operating the select lever by the driver in a situation where engine braking is required, and the vehicle speed that is automatically shifted down while traveling in the fixed range. Are the same vehicle speed.

  However, as described above, the vehicle speed at which a downshift occurs due to manual operation (select lever operation to the fixed range by the driver) is the same as the vehicle speed at which the downshift occurs due to an automatic shift while the fixed range is selected. It is difficult to achieve both of ensuring engine braking performance required during downshifts by manual operation and ensuring stability (travel stability of the vehicle) by suppressing shift shocks during downshifts by automatic shifting was there.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and its purpose is to ensure engine braking performance necessary for downshifting by manual operation and to ensure stability by suppressing shift shock during downshifting by automatic shifting. An object of the present invention is to provide a control device for an automatic transmission for a vehicle capable of achieving both of these.

  In order to solve the above problems, the present invention provides a control means (5) for controlling switching of the gear position of the automatic transmission (2), a vehicle speed detection means (203) for detecting the vehicle speed, and an engine for detecting the engine load. A control device for an automatic transmission for a vehicle, comprising: a load detection means (207); and a select lever operation detection means (211) for detecting an operation of the select lever (10) by a driver. As a shift range of the automatic transmission (2), a predetermined speed is determined from a vehicle speed (V) detected by the vehicle speed detection means (203) and an engine load (AP) detected by the engine load detection means (207). An automatic shift range for performing automatic shift by determining a shift stage based on a shift map having shift characteristics, and a fixed range that can be fixed to a predetermined range of shift stages that are relatively low speed shift stages. And said The automatic shift range and the fixed range can be selectively set according to the operation of the collect lever (10), and the shift stage can be changed based on the shift map as a shift control mode in the fixed range. A first shift mode for a range, and a second shift mode for a fixed range in which a gear position can be set using a vehicle speed preset for the fixed range as a determination condition, and the select lever (10) According to an operation method, the first shift mode or the second shift mode is selected and set as the shift control mode in the fixed range.

In the above control device, as a method of operating the select lever (10), when the automatic shift range is switched to the fixed range by operating the select lever, the shift control mode in the fixed range is performed. The second speed change mode may be selected as follows. Further, in this case, the second speed change mode may be set to a vehicle speed at which a vehicle speed permitting a downshift to a predetermined gear position in the fixed range is higher than that of the first speed change mode. Further, the predetermined shift speed may be the lowest shift speed (first speed of the embodiment) that can be set by the automatic transmission. Further, in the second speed change mode, the vehicle speed permitting a downshift to a speed other than the lowest speed may be changed in accordance with the engine load detected by the engine load detecting means.

In the control apparatus for an automatic transmission for a vehicle according to the present invention, as a shift control mode in a fixed range, a first shift mode for a fixed range in which a shift stage can be changed based on a shift map and a preset for the fixed range are set. And a second shift mode for a fixed range in which the gear position can be set using the determined vehicle speed as a determination condition, and these can be selectively set according to the operation method of the select lever. In addition, when the automatic shift range is switched to the fixed range by the operation of the select lever, the second shift mode is selected as the shift control mode in the fixed range. That is, a downshift is generated with the vehicle speed set separately only when the automatic shift range is switched to the fixed range by the driver's operation of the select lever. Thus, the vehicle speed at which a downshift occurs due to an automatic shift while traveling in a fixed range is different from the vehicle speed at which a downshift occurs due to a manual shift to a fixed range by operating a select lever. When a manual shift to the fixed range is performed by operating the select lever, if a downshift occurs at a higher vehicle speed than the automatic shift during traveling in the fixed range, By downshifting at high vehicle speeds, the engine brake can be utilized to the maximum. On the other hand, at the time of automatic shift in the fixed range, a downshift occurs at a lower vehicle speed, so that the shift shock can be effectively reduced. As a result, it is possible to achieve both of ensuring the engine brake performance necessary for the downshift by manual operation and ensuring the running stability by suppressing the shift shock at the downshift by the automatic shift.
In addition, the code | symbol in said parenthesis shows the code | symbol of the component in embodiment mentioned later as an example of this invention.

  According to the control device for an automatic transmission for a vehicle according to the present invention, both of ensuring the engine brake performance necessary for the downshift by manual operation and ensuring the stability by suppressing the shift shock at the downshift by the automatic shift are achieved. Can be achieved.

1 is a schematic diagram of a vehicle drive system to which a control device for an automatic transmission for a vehicle according to an embodiment of the present invention is applied. It is a figure which shows an example of the shift map for L ranges used for the shift control concerning this invention. It is a flowchart for demonstrating the procedure of the shift control concerning this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic diagram of a vehicle drive system to which an automatic transmission control apparatus according to an embodiment of the present invention is applied. As shown in FIG. 1, the vehicle drive system of the present embodiment electronically controls the engine 1, an automatic transmission 2 connected to the engine 1 via a fluid type torque converter 3, and the engine 1. FI-ECU (fuel injection control device) 4, AT-ECU (automatic transmission control device) 5 that electronically controls automatic transmission 2 including torque converter 3, and rotation of torque converter 3 according to the control of AT-ECU 5 And a hydraulic control device 6 that hydraulically controls driving, lockup control, and engagement (engagement) / release of a plurality of friction engagement elements of the automatic transmission 2.

  The rotational output of the engine 1 is output to a crankshaft (output shaft of the engine 1) 21 and transmitted to the main shaft 22 of the automatic transmission 2 via the torque converter 3. The torque converter 3 is provided with a lockup clutch 30. The lockup clutch 30 is set to either the lockup ON or OFF state according to the lockup control by the AT-ECU 5.

  In the vicinity of the crankshaft 21, a crankshaft rotation speed sensor 201 for detecting the rotation speed Ne of the crankshaft 21 (engine 1) is provided. In the vicinity of the main shaft 22, a main shaft rotation number sensor 202 that detects the rotation number (input shaft rotation number of the automatic transmission 2) Ni of the main shaft 22 is provided. In the vicinity of the countershaft 23, a countershaft rotational speed sensor 203 for detecting the rotational speed of the countershaft 23 (the output shaft rotational speed of the automatic transmission 2) No is provided. Vehicle speed data V calculated from the rotational speed data Ne, Ni, No and No detected by the sensors 201 to 203 is given to the AT-ECU 5. The engine speed data Ne is given to a FI-ECU (fuel injection control device) 4.

  Further, the throttle opening TH detected by the throttle opening sensor 209 provided in the engine 1, the accelerator pedal opening AP detected by the accelerator pedal opening sensor 207 provided in the accelerator pedal 8, and a selection operated by the driver. The select lever position P detected by the position sensor 211 provided on the lever 10 is given to the AT-ECU 5 or the FI-ECU 4.

  The automatic transmission according to the present embodiment has, for example, a P range (parking range), an R range (reverse range), an N range (neutral range), and a D range (1st to 6th automatic shift ranges) as shift ranges of a plurality of positions. ), D3 range (1st to 3rd automatic shift range) and L range (low speed fixed range), and the driver selects one of these multiple shift ranges by operating the select lever 10 Is possible. The shift control in the L range, which is a fixed range, includes control for fixing the shift speed to the second speed stage or the first speed stage, as well as a shift speed higher than the second speed stage or the first speed stage as necessary. And shifting up from 2nd gear or from 1st gear to higher gear is included.

  In addition to the above, the shift range by the automatic transmission of the present embodiment is not limited to the above, and a manual shift range in which a shift stage can be set by a manual shift operation by the driver, or automatic shift is performed only in a predetermined shift range. It may further have another automatic shift range.

  When the D range which is the automatic shift range is selected by the select lever 10, a shift map for automatic shift using the vehicle speed data V and the accelerator pedal opening AP (or the throttle opening TH) as parameters (FIG. (Not shown), for example, upshift and downshift between the first gear to the sixth gear are automatically executed. When the L range, which is a fixed range, is selected, the first gear or the second gear is established. However, when the L range is selected, the vehicle speed is high, and the engine 1 is overrev (overspeed) at the second gear. ) Occurs, first, the third gear is established, and after the vehicle speed decreases, the gear is shifted down to the second gear and fixed to the second gear. Further, when the vehicle speed exceeds the upshift limit vehicle speed during traveling in the L range, the first speed hold gear stage is shifted to the second speed gear stage, or the second speed gear stage is shifted to the third speed gear stage.

  Next, specific contents of the shift control in the L range will be described. FIG. 2 is a graph showing an example of a shift map used for shift control in the L range. FIG. 2A is a shift map used for automatic shifting during traveling in the L range (hereinafter, “normal shift map”). (B) is a graph showing a state in which the vehicle speed (specifically, the 2-1 downshift line L2-1) of the normal shift map M1 is changed. FIG. 7C shows the normal shift map M1 in FIG. 6A along with the downshift line L2-1 ′ changed in FIG. In the present embodiment, as the shift mode used for the shift control of the L range, a shift control mode (hereinafter referred to as “first shift mode”) based on the normal shift map M1 shown in FIG. 2A and FIG. ), The shift control mode (hereinafter referred to as “second shift mode”) based on a shift map in which the downshift line on the normal shift map M1 is changed. In accordance with the operation method of the select lever 10, either the first shift mode or the second shift mode is selected and set.

  Comparing the shift maps shown in FIGS. 2A and 2B, the upshift lines (1-2 upshift line L1-2, 2-3 upshift line L2-3) are the engine 1 in any shift map. Is set to shift up at a vehicle speed at which the maximum rotational speed reaches the maximum allowable rotational speed. On the other hand, for the downshift line, the 2-1 downshift line L2-1 ′ in the shift map after changeover used when the select lever 10 is operated (FIG. 2B) is used for automatic shifting in the L range. It is set on the higher vehicle speed side than the 2-1 downshift line L2-1 on the normal shift map M1 (FIG. 2A). That is, in the shift map after changeover used when operating to the L range, the 2-1 downshift line L2-1 is on the higher vehicle speed side than the normal shift map M1 used for automatic shifting during traveling in the L range. It is changing (V1 → V2). That is, a 2-1 downshift is generated with the vehicle speed (V2) set separately as a judgment condition only when the automatic shift range D range is switched to the fixed range L range by the operation of the select lever 10 by the driver. I am doing so.

  As a result, as shown in FIG. 2 (c), the area near the 2-1 downshift lines L2-1 and L2-1 ′ on the L range shift map is displayed at the time when the select lever 10 is operated. Region A, which is the first gear in any automatic shift in the range, Region B, which is in the first gear when the select lever 10 is operated, and the second gear in the automatic gear shift in the L range, and operation of the select lever 10 There is a region C which is the second speed stage both in the hour and in the automatic shift in the L range.

  Note that the vehicle speed (the position of the 2-1 downshift line L2-1) V1 at which the 2-1 downshift occurs on the normal shift map M1 is an automatic shift shift used in the automatic shift range (D range). This is the same vehicle speed (same position) as the vehicle speed (2-1 downshift line position) at which a 2-1 downshift occurs on the map.

  In FIG. 2, the 3-2 downshift line L3-2 is set to generate a 3-2 downshift at a constant vehicle speed regardless of the accelerator pedal opening AP. Alternatively, the 3-2 downshift line L3-2 may be set so that the vehicle speed V at which the 3-2 downshift occurs is changed according to the accelerator pedal opening AP. Specifically, the vehicle speed at which a 3-2 downshift occurs may be changed between when the accelerator is on and when the accelerator is off, as in a procedure according to a flowchart described below.

  In the control device of the present embodiment, when the automatic shift range D range is switched to the fixed range L range by operating the select lever 10 (immediately after the switch), the shift in the L range is performed. As the control mode, the second shift mode based on the shift map after the change (FIG. 2B) is selected.

  FIG. 3 is a flowchart for explaining the procedure of the shift control in the L range. Hereinafter, the shift control in the L range will be described in detail with reference to the flowchart of FIG. In this shift control, first, it is determined whether or not it is immediately after the operation of the select lever 10 from the D range that is the automatic shift range to the L range that is the fixed range (step ST1). As a result, if it is not immediately after the operation of the select lever 10 to the L range (NO), shift control along the normal shift map is performed (step ST2). On the other hand, if it is immediately after the select lever is operated to the L range (YES), whether or not the gear position on the shift map (normal shift map) is the first speed (Low). Is determined (step ST3). As a result, if the shift speed on the shift map is the first speed (Low) (YES), the shift control is performed along the normal shift map (step ST2). On the other hand, if the gear position on the shift map is not the first gear (NO), that is, if it is the second gear (2nd) or the third gear (3rd) or higher, then the gear on the shift map is the third gear. It is determined whether or not (3rd) or more (step ST4). As a result, if the shift speed on the shift map is less than the third speed (NO), it is further determined whether or not the current vehicle speed is higher than the 2-1 downshift vehicle speed (step ST5). If the vehicle speed is equal to or lower than the downshift vehicle speed (NO), 2-1 downshift is performed (step ST6), and if the vehicle speed is higher than the 2-1 downshift vehicle speed (YES), the second gear is maintained (step ST7). . The 2-1 downshift vehicle speed here is a vehicle speed V2 on the 2-1 downshift line L2-1 ′ shown in FIG.

  On the other hand, if the shift speed on the shift map is 3rd speed or higher in the previous step ST4 (YES), it is subsequently determined whether or not the current shift speed is 3rd speed (3rd) or higher (step ST8). If the speed is lower than the third speed (NO), the processes of steps ST5 to ST7 are performed. On the other hand, if the speed is 3 or higher in step ST8 (YES), it is determined whether or not the accelerator is on (accelerator pedal opening AP ≧ 0) (step ST9), and the accelerator is on. If not (NO), it is determined whether or not the current vehicle speed V is higher than the 3-2 downshift vehicle speed in the accelerator-off state (step ST10). As a result, if the vehicle speed is higher than the 3-2 downshift vehicle speed in the accelerator off state (YES), 4-3 downshift is performed or the third speed is maintained (step ST11), and the 3-speed down in the accelerator off state is maintained. If the vehicle speed is lower than 2 downshift vehicle speed (NO), 3-2 downshift is performed (step ST12). On the other hand, if the accelerator is on in step ST9 (YES), it is determined whether or not the current vehicle speed is higher than the 3-2 downshift vehicle speed in the accelerator on state (step ST13). As a result, if the vehicle speed is higher than the 3-2 downshift vehicle speed in the accelerator-on state (YES), 4-3 downshift is performed or the third gear is maintained (step ST11). If the vehicle speed is lower than 2 down vehicle speed (NO), 3-2 downshift is performed (step ST12).

  As described above, in the control device for an automatic transmission for a vehicle according to the present embodiment, the shift stage can be changed based on the shift map (normal shift map M1) as the shift control mode for the L range which is a fixed range. 1 shift mode, and 2nd shift mode which can set a gear stage (specifically 2-1 downshift) using the vehicle speed (V2) preset for L range as discrimination conditions . In addition, when the automatic shift range is switched to the fixed L range by operating the select lever 10, the second shift mode is selected as the shift control mode in the L range. That is, a downshift (2-1 downshift) is generated using the vehicle speed (V2) set separately only when the selection lever 10 is switched to the fixed range by the operation of the select lever 10.

  As a result, the vehicle speed (V1) at which a downshift occurs due to an automatic shift while traveling in the L range is different from the vehicle speed (V2) at which a downshift occurs due to a manual shift to the L range by operating the select lever 10. It is When a manual shift to the L range is performed by operating the select lever 10, a downshift occurs at a higher vehicle speed than in the automatic shift during traveling in the L range (V2 ≧ V1). As a result, the engine brake can be utilized to the maximum by downshifting at a high vehicle speed during manual shifting. On the other hand, at the time of automatic shift in the L range, a downshift occurs at a lower vehicle speed, so that the shift shock can be effectively reduced. Therefore, it is possible to achieve both of ensuring the necessary engine braking performance in the downshift by manual operation and ensuring the running stability by suppressing the shift shock in the downshift by the automatic shift.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Deformation is possible. For example, the vehicle speeds shown in the above shift maps are merely examples, and the downshift and the upshift may be set to occur at vehicle speeds other than those shown in the above embodiment.

  Moreover, although the case of L range was demonstrated as an example of the fixed range concerning this invention in the said embodiment, the fixed range which implements the shift control concerning this invention is 2 ranges other than said L range, etc. Other fixed ranges may be used.

1 Engine 2 Automatic transmission 3 Torque converter 4 FI-ECU
5 AT-ECU (control means)
6 Hydraulic control device 8 Accelerator pedal 10 Select lever 21 Crankshaft 22 Main shaft 23 Countershaft 30 Lockup clutch 201 Crankshaft rotational speed sensor 201 Engine rotational speed sensor 202 Main shaft rotational speed sensor 203 Countershaft rotational speed sensor (vehicle speed detection means) )
207 Accelerator pedal opening sensor (engine load detection means)
209 Throttle opening sensor (engine load detection means)
211 Position sensor (select lever operation detection means)

Claims (1)

Control means for controlling the shift stage of the automatic transmission, vehicle speed detecting means for detecting vehicle speed, engine load detecting means for detecting engine load, and select lever operation detecting means for detecting operation of the select lever by the driver And comprising
The control means is a shift stage based on a shift map having a predetermined shift characteristic from the vehicle speed detected by the vehicle speed detection means and the engine load detected by the engine load detection means as a shift range of the automatic transmission. And an automatic shift range in which automatic shift is performed and a fixed range that can be fixed to a predetermined range of shift speeds that are relatively low speed shift stages, and according to the operation of the select lever, The automatic shift range and the fixed range can be selectively set,
As the shift control mode in the fixed range, the first shift mode for the fixed range in which the shift stage can be changed based on the shift map, and the shift stage can be set using the vehicle speed set in advance for the fixed range as a determination condition. A second shift mode for a fixed range,
The second speed change mode is set to a vehicle speed at which a vehicle speed permitting a downshift to the lowest gear settable by the automatic transmission in the fixed range is higher than the first speed change mode, and The vehicle speed that permits downshifting to a gear other than the lowest gear is changed according to the engine load detected by the engine load detecting means,
According to the operation method of the select lever, configured to select and set one of the first shift mode and the second shift mode as the shift control mode in the fixed range ,
The operation method of the select lever is such that the second shift mode is selected when the automatic shift range is switched to the fixed range by operating the select lever. A control device for an automatic transmission for a vehicle.

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