Automatic transmission control device

Abstract

To provide a driver with sound causing the same to have a comfortable sense of rhythm during acceleration operation of a vehicle.SOLUTION: A PCM 40 controls an automatic transmission 2 in a vehicle comprising an engine, an automatic transmission 2 connected to the engine, an acceleration opening sensor SN1 detecting an acceleration opening, and a vehicle speed sensor SN2 detecting a vehicle speed. The PCM 40 has: a shift map storage section 43 which stores a shift map with shift lines SU1 to SU6 for switching a shift stage on the basis of the acceleration opening and the vehicle speed set therein; and a shift control section 42 which performs shift control of the automatic transmission 2 on the basis of the shift map. In the shift map, shift lines are set so that, in an acceleration operation region A1, engine rotation speeds when vehicle speeds are shifted with identical acceleration openings in respective shift lines are almost identical with each other and acceleration time in a higher shift stage is longer than the same in a lower shift stage.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a control device for an automatic transmission incorporated in a power transmission system of an engine of a vehicle or the like. [Background technology]

[0002] In a vehicle equipped with a multi-speed automatic transmission (AT), unlike a continuously variable automatic transmission (CVT), for example, when accelerating from start, the driver can feel the sensation of acceleration accompanied by the sound of the gears gradually shifting up to higher gears. Patent Document 1 discloses a gear change control that shifts up so that the acceleration time at each gear is approximately the same during acceleration. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-185386 Summary of the Invention [Problem to be solved by the invention]

[0004] One factor that allows a driver to experience a comfortable driving experience is a pleasant acceleration feel. Research by the present inventors has revealed that the rhythmic feel of the automatic transmission's upshift sound during acceleration is crucial to providing a pleasant acceleration feel. However, with the above-described gear shift control that makes the acceleration time at each gear approximately the same, it is not always possible to produce a dynamic, rhythmic sound, making it difficult to provide the driver with an outstanding comfortable acceleration feel.

[0005] An object of the present invention is to provide a control device for an automatic transmission that can provide a driver with a pleasant rhythmic sound when the vehicle is accelerating. [Means for solving the problem]

[0006] An automatic transmission control device according to one aspect of the present invention is a control device for an automatic transmission in a vehicle that includes an engine and an automatic transmission connected to the engine, an accelerator opening sensor that detects an accelerator opening, and a vehicle speed sensor that detects vehicle speed, and the control device includes a memory unit that stores a shift map in which multiple shift lines are set to switch gears based on the accelerator opening and the vehicle speed, and a shift control unit that performs shift control of the automatic transmission based on the shift map, and the shift lines are set in the shift map so that, in an accelerator opening range corresponding to acceleration driving, the shift vehicle speed at each shift line at the same accelerator opening is approximately the same as the engine rotation speed at the time of shifting at each shift line, and the acceleration time at each gear is longer at the higher gear side than at the lower gear side.

[0007] With this control device, when acceleration is performed with the same accelerator pedal position, the engine speeds are synchronized when shifting up from one gear to another. As a result, when accelerating, for example, when shifting up sequentially from 1st to 2nd, 2nd to 3rd, and 3rd to 4th, the engine sounds generated are also synchronized. Therefore, the driver can be provided with a sound with a pleasant rhythm when accelerating. In addition, the acceleration time at each gear is longer at the higher gear than at the lower gear. This allows the driver to experience a sense of acceleration that responds to the accelerator pedal depression from the middle to the latter stages of acceleration. As a result, a gear change feeling that meets the driver's expectations can be provided.

[0008] In the above-described automatic transmission control device, the shift lines of the shift map may include a first shift line for shifting the gear from first gear to second gear, a second shift line for shifting the gear from second gear to third gear, and a third shift line for shifting the gear from third gear to fourth gear, and in the region of accelerator opening corresponding to the accelerating operation, the slope of the second shift line may be set to 1 / 2 of the slope of the first shift line, and the slope of the third shift line may be set to 1 / 3 of the slope of the first shift line.

[0009] According to this control device, as described above, the gradients of the first to third shift lines in the shift map become gentler as the speed increases, making it easier to set each shift line so that the acceleration time at each gear is longer at the higher gears than at the lower gears.

[0010] In the above-mentioned automatic transmission control device, it is desirable that the low gear is second gear and the high gear is third gear, and that each gear shift line is set so that the acceleration time in third gear is longer than the acceleration time in second gear.

[0011] With a normal gear structure, the feeling of acceleration is most noticeable after shifting from second gear to third gear. With the control device described above, the engine speed remains substantially constant during gear changes in this range, and a sense of increased acceleration is provided after shifting to third gear, giving the driver a comfortable, rhythmic feeling of acceleration.

[0012] In the above-mentioned control device for an automatic transmission, it is desirable that the accelerator opening corresponding to the acceleration operation is in the range of 50% to 75%.

[0013] When the accelerator pedal is less than 50%, the driver has little intention of enjoying the feeling of acceleration, so it is desirable to perform gear shift control aimed solely at improving fuel efficiency. Also, when the accelerator pedal is over 75%, the rev limit is generally reached, so it is desirable to leave this range outside the scope of this gear shift control. Therefore, it is desirable to perform this gear shift control within the accelerator pedal opening range of 50% to 75%. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a control device for an automatic transmission that can provide a driver with a comfortable rhythmic sound when accelerating a vehicle. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram that schematically shows a power train and a control device of a vehicle to which an automatic transmission control device according to the present invention is applied. [Figure 2] FIG. 2 is a functional block diagram showing a control system for the engine and automatic transmission. [Figure 3] FIG. 3 is a graph showing a shift map for upshifting of an automatic transmission. [Figure 4] FIG. 4 is a graph showing the change in engine speed over time during acceleration, where chart (A) shows the case where the shift map of the embodiment is applied, and chart (B) shows the case where the shift map of the comparative example is applied. [Figure 5] FIG. 5 is a graph showing the relationship between engine speed and vehicle speed for each gear, and is a diagram in which the acceleration time for each gear when shifting up with the accelerator pedal position kept constant is added. [Figure 6] FIG. 6 is a graph showing the gradient of the shift line in the shift map. [Figure 7] 7(A) and (B) are graphs showing the relationship between acceleration time, engine speed, and vehicle speed for each gear when accelerating with an accelerator pedal opening of 45%, where (A) shows a comparative example, (B) shows an example, and FIG. 7(C) is a table showing these. [Figure 8] Figures 8(A) and (B) are graphs showing the relationship between acceleration time, engine speed, and vehicle speed for each gear when accelerating with an accelerator pedal opening of 50%, where (A) shows a comparative example, (B) shows an example, and Figure 8(C) is a table listing these. [Figure 9] Figures 9(A) and (B) are graphs showing the relationship between acceleration time, engine speed, and vehicle speed for each gear when accelerating with an accelerator pedal opening of 60%, where (A) shows a comparative example, (B) shows an example, and Figure 9(C) is a table listing these. [Figure 10] Figures 10(A) and (B) are graphs showing the relationship between acceleration time, engine speed, and vehicle speed for each gear when accelerating with an accelerator pedal opening of 70%, where (A) shows a comparative example, (B) shows an example, and Figure 10(C) is a table showing these. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, a control device for an automatic transmission according to an embodiment of the present invention will be described in detail with reference to the drawings. In this embodiment, an automatic transmission is incorporated into the power train of an engine mounted on a vehicle such as an automobile as a power source for driving the vehicle, and a control device for the automatic transmission is incorporated into a control device for the vehicle (PCM 40, which will be described later).

[0017] [Vehicle powertrain] Fig. 1 is a diagram showing a schematic view of a powertrain PT and a portion of a control system of a vehicle according to this embodiment. The powertrain PT includes an engine 1, an automatic transmission 2, a propeller shaft 31, a differential 32, a drive shaft 33, and drive wheels W. As the control system, Fig. 1 shows a PCM 40 (control device), an accelerator position sensor SN1, a vehicle speed sensor SN2, and a crank angle sensor SN3.

[0018] The engine body 1 is a drive source that generates driving force to be applied to the drive wheels W, and is, for example, a four-stroke diesel engine. Of course, the engine body 1 may also be a gasoline engine. The engine body 1 has four cylinders 11 aligned in the longitudinal direction of the vehicle. The engine body 1 is disposed in an engine room at the front of the vehicle. An automatic transmission 2 is connected to a crankshaft 12, which is the output shaft of the engine body 1.

[0019] The automatic transmission 2 has the function of changing the speed of the rotation of the crankshaft 12 of the engine main body 1 and outputting it. The propeller shaft 31, the differential 32, and the drive shafts 33 form a power transmission system from the automatic transmission 2 to the drive wheels W. The propeller shaft 31 extends rearward from the automatic transmission 2. The differential 32 is connected to the rear end of the propeller shaft 31. The drive shafts 33 extend in the vehicle width direction from the differential 32. A drive wheel W is attached to each end of each drive shaft 33 in the vehicle width direction. The output rotation of the engine main body 1 is changed in speed by the automatic transmission 2 and then input to the differential 32 via the propeller shaft 31. The rotation input to the differential 32 is transmitted to each drive wheel W via both drive shafts 33.

[0020] The automatic transmission 2 includes a torque converter 21 and a transmission body 22. The torque converter 21 is a fluid clutch that transmits the rotation of the crankshaft 12 of the engine body 1 to the transmission body 22 via a working fluid. The transmission body 22 transmits the rotation input from the torque converter 21 to the drive wheels W while changing the speed.

[0021] The torque converter 21 incorporates a pump impeller 23 that rotates integrally with the crankshaft 12, a turbine runner 24 that is disposed opposite the pump impeller 23, and a stator 25 that is disposed between the pump impeller 23 and the turbine runner 24. The rotation of the pump impeller 23 is transmitted to the turbine runner 24 via the working fluid in the torque converter 21. The rotation of the turbine runner 24 is input to the transmission body 22 via a turbine shaft 26.

[0022] A lock-up clutch 27 is disposed inside the torque converter 21. The lock-up clutch 27 is a clutch that connects and disconnects the crankshaft 12 and the turbine runner 24. When the lock-up clutch 27 is engaged to connect the crankshaft 12 and the turbine runner 24, the crankshaft 12 and the turbine shaft 26, which is the input shaft of the transmission main body 22, are mechanically connected without the intervention of the working fluid. As a result, the rotational force of the crankshaft 12 is transmitted directly to the drive wheels W.

[0023] The transmission main body 22 incorporates a multi-stage transmission mechanism 28 capable of achieving multiple gear stages with different reduction ratios. The transmission mechanism 28 includes a gear mechanism 29 that combines multiple planetary gear sets, multiple frictional engagement elements (not shown) including clutches and brakes that are engaged or disengaged to switch the power transmission path of the gear mechanism 29, and a hydraulic control valve 20 ( FIG. 2 ) consisting of a solenoid valve or the like that controls the hydraulic pressure supplied to each frictional engagement element to switch between engagement and disengagement. The hydraulic control valve 20 engages or disengages the appropriate frictional engagement elements, thereby achieving a desired gear stage (speed change stage) in the transmission mechanism 28 according to the vehicle speed, etc. The rotation of the turbine shaft 26 of the torque converter 21 is changed in speed at a reduction ratio corresponding to the gear stage of the transmission mechanism 28 and then transmitted to the drive wheels W via a propeller shaft 31 and a drive shaft 33.

[0024] The vehicle is equipped with an accelerator pedal position sensor SN1, a vehicle speed sensor SN2, and a crank angle sensor SN3. The accelerator pedal position sensor SN1 detects the depression amount of the accelerator pedal 13 operated by the vehicle driver, i.e., the accelerator position. The vehicle speed sensor SN2 detects the traveling speed of the vehicle, i.e., the vehicle speed. The crank angle sensor SN3 detects the crank angle, which is the rotation angle of the crankshaft 12, and the engine speed, which is the rotation speed of the crankshaft 12.

[0025] [Control system] 2 is a functional block diagram showing a control system for the engine, including the engine main body 1, and the automatic transmission 2. The vehicle is equipped with a PCM 40 that performs overall control of the operations of the engine and the automatic transmission 2. The PCM 40 is a microprocessor, and is composed of a well-known CPU, ROM, RAM, etc.

[0026] Information detected by various sensors is input to the PCM 40. For example, information detected by an accelerator position sensor SN1, a vehicle speed sensor SN2, and a crank angle sensor SN3, i.e., information on the accelerator position, vehicle speed, crank angle, and engine speed, is sequentially input to the PCM 40. In addition, information necessary for controlling the engine and automatic transmission 2, such as engine water temperature, intake air volume, intake pressure, and intake air temperature, obtained by sensors not shown, is also sequentially input to the PCM 40.

[0027] The PCM 40 controls each part of the engine and automatic transmission 2 based on input information from each of the sensors SN1 to SN3. The PCM 40 is electrically connected to the fuel injection valve 14 that injects fuel into the cylinder 11 of the engine main body 1, as well as control valves of each part of the engine (not shown), and the lock-up clutch 27 and hydraulic control valve 20 of the automatic transmission 2 described above. The PCM 40 outputs control signals generated based on input information from each of the sensors SN1 to SN3 to these devices.

[0028] By executing a predetermined program, the PCM 40 operates so as to functionally comprise an engine control unit 41, a gear change control unit 42, and a gear change map storage unit 43 (storage unit). The engine control unit 41 controls the fuel injection amount and injection timing of the fuel injection valve 14 and the operation of various valves so that the engine main body 1 generates the required engine torque, based on the accelerator opening detected by the accelerator opening sensor SN1. The gear change control unit 42 controls the gear change of the automatic transmission 2, i.e., controls the operation of the lock-up clutch 27 and the hydraulic control valve 20, based on a preset gear change map.

[0029] The shift map storage unit 43 stores a shift map. The shift map has multiple shift lines set therein for shifting gears based on the accelerator opening degree and the vehicle speed. The shift control unit 42 applies the accelerator opening degree detected by the accelerator opening degree sensor SN1 and the vehicle speed detected by the vehicle speed sensor SN2 to the shift map stored in the shift map storage unit 43 to identify the gear that should be selected in the current driving state, and shifts the gear of the automatic transmission 2 as necessary.

[0030] FIG. 3 is a graph showing a shift map for upshifting of an automatic transmission. The vertical axis of FIG. 3 represents accelerator opening (%), and the horizontal axis represents the vehicle speed (km / h) of the vehicle equipped with engine body 1. FIG. 3 shows upshift lines SU1, SU2, SU3, SU4, and SU5, which are the vehicle speed changeover points when shifting from a lower gear to a higher gear. Note that FIG. 3 does not show the downshift lines, which are the vehicle speed changeover points when shifting from a lower gear to a higher gear. In accordance with this shift map, gear shift control unit 42 controls hydraulic control valve 20 of automatic transmission 2 to perform the required gear shifting operation.

[0031] FIG. 3 shows the gear stages when shifting up from 1st to 5th gear. SU1 on the far left is the gear line from 1st to 2nd gear, SU2 from 2nd to 3rd gear, SU3 from 3rd to 4th gear, SU4 from 4th to 5th gear, and SU5 on the far right is the gear line from 5th to 6th gear. The region of the accelerator opening indicated by arrow A1 in FIG. 3, which is 45% to 70%, corresponds to the region corresponding to acceleration driving (hereinafter referred to as acceleration driving region A1). In other words, this is the region where the driver depresses the accelerator pedal 13 considerably and the vehicle enters an acceleration driving state with relatively large acceleration.

[0032] The upshifting gear lines SU1 to SU4 are drawn so that they branch into two parts, a solid line and a dotted line, at a portion that roughly overlaps with the acceleration driving region A1. The dotted line shifting lines SU11, SU21, SU31, and SU41 are upshifting gear lines according to a comparative example of this embodiment, and are set with a focus solely on fuel economy. In contrast, the solid line shifting lines SU12, SU22, SU32, and SU42 are upshifting gear lines according to this embodiment. The shifting lines SU12 to SU42 of this embodiment are set with an emphasis on the acoustic effect provided to the driver when upshifting, while also taking fuel economy into consideration. In other words, these shifting lines SU12 to SU42 can provide the driver with a comfortable rhythmic sound when accelerating the vehicle.

[0033] [Shift-up control based on a shift map that takes sound into account] 4 is a graph showing the change in engine speed over time during acceleration in the acceleration operation region A1, where chart (A) shows the case where the upshifting shift map (shift lines SU12 to SU42) of the embodiment is applied, and chart (B) shows the case where the upshifting shift map (shift lines SU11 to SU41) of the comparative example is applied. In charts (A) and (B), the upper row shows the accelerator opening, the middle row shows the engine speed, and the lower row shows the acceleration G.

[0034] The shift lines SU1 to SU4 (SU12 to SU42) in the shift map of the embodiment are set so as to satisfy both of the following requirements 1 and 2 in the acceleration operation region A1. (Requirement 1) The vehicle speed at each shift line when the accelerator pedal is opened is approximately the same as the engine speed at the time of shifting at each shift line. (Requirement 2) The acceleration time at each gear position with the same throttle opening is longer at the higher gear position than at the lower gear position.

[0035] Charts (A) and (B) in FIG. 4 show the time change in engine speed and the timing of upshifting gears when accelerating at a constant accelerator opening of 50%, as indicated by arrow A2 in FIG. 3. Regarding requirement 1 above, in the example, the engine speeds are roughly consistent when shifting from first to second, second to third, and third to fourth. In particular, the engine speeds are roughly the same when upshifting from second to third and third to fourth. In contrast, in the comparative example, there is a relatively large variation in engine speed when shifting gears. In particular, the engine speed is significantly lower when upshifting from third to fourth than when upshifting from second to third.

[0036] Next, regarding Requirement 2, in the embodiment as shown in Chart (A), the acceleration times at the second and third speeds are longer than the acceleration time at the first speed. The difference in acceleration time between the first and second speeds is small, but the acceleration time at the third speed is about 1.5 times longer than that at the second speed. In contrast, in the comparative example as shown in Chart (B), the acceleration times at the first, second, and third speeds are substantially the same.

[0037] The above-described comparative example and embodiment will be described more specifically with reference to FIG. 5. FIG. 5 is a graph showing the relationship between the engine speed and the vehicle speed for each gear stage. In the figure, G1, G2, G3, G4, G5, and G6 are lines showing the relationship between the engine speed and the vehicle speed when driving at the gear ratios of the first, second, third, fourth, fifth, and sixth speeds of the automatic transmission 2, respectively. In FIG. 5, in accordance with the respective shift maps of the embodiment and the comparative example, the acceleration times T11, T12, T13 (embodiment) and T21, T22, T23 at each gear stage when the accelerator opening is kept at 50% and upshifting are noted.

[0038] In the embodiment, the shift vehicle speeds at the first-speed to second-speed upshift, second-speed to third-speed upshift, and third-speed to fourth-speed upshift are 36 km / h, 67 km / h, and 98 km / h, respectively, and the engine speeds are 4700 rpm, 4900 rpm, and 4800 rpm, respectively. In other words, as per the above Requirement 1, in the embodiment, the shift vehicle speed is set such that the engine speed at the time of shifting is substantially the same. Also, as per Requirement 2 in the embodiment, among the acceleration times T11, T12, and T13 at the first, second, and third speeds, the relationship is T11 < T12 < T13, and the acceleration time is longer on the higher-speed side than on the lower-speed side.

[0039] In contrast, in the comparative example, the vehicle speeds during the shifts from 1st gear to 2nd gear, 2nd gear to 3rd gear, and 3rd gear to 4th gear are 30 km / h, 57 km / h, and 76 km / h, respectively, and the engine speeds are 3900 rpm, 4200 rpm, and 3800 rpm, respectively.<T12、T12> This is in the relationship T13, and does not satisfy the above requirement 2. With such a transition in acceleration time, it is difficult to provide the driver with a comfortable sense of rhythm in acceleration or a sufficient sense of acceleration.

[0040] By adopting the shift control using the shift map of the embodiment, when acceleration is performed with the same accelerator pedal position, the engine speeds are synchronized during upshifts. As a result, the engine sounds generated during sequential upshifts from 1st to 2nd, 2nd to 3rd, and 3rd to 4th during acceleration are also synchronized. Therefore, the driver can experience a pleasant rhythmic sound during acceleration. In addition, the acceleration times T11, T12, and T13 at each gear are longer at the higher gears than at the lower gears. This allows the driver to experience a sense of acceleration corresponding to the depression of the accelerator pedal 13 from the middle to the latter stages of acceleration.

[0041] The gear shift control of the embodiment produces a consistent engine sound during gear shifting, and also produces a sense of rhythm with the acceleration increasing, providing a sense of acceleration accompanied by a pleasant sound. This allows for a gear shift feeling that meets the driver's expectations. In contrast, in the comparative example, the engine speed when shifting to fourth gear is significantly lower than when shifting to third gear. Combined with the fact that the acceleration time in third gear is also short, the gear shift control of the comparative example is inferior to the embodiment in terms of gear shift feeling.

[0042] Next, the characteristics of the gradients of the shift lines in the shift map of the embodiment will be explained with reference to Fig. 6. Fig. 6 shows the shift lines SU1 to SU5 shown in the shift map of Fig. 3. Here, attention will be paid to the first shift line SU1 for shifting the gear from first to second, the second shift line SU2 for shifting the gear from second to third, and the third shift line SU3 for shifting the gear from third to fourth. The vehicle speed gradients C1, C2, and C3 of the shift lines SU1, SU2, and SU3 in the portion including the acceleration driving region A1 will be compared.

[0043] The shift lines SU1 to SU3 have slopes roughly within the range of accelerator opening = 20 to 60%. The vehicle speed slope C1, which approximates the slope of the first shift line SU1 within this range, is 1.382. Furthermore, the vehicle speed slopes C2 and C3, which approximate the slopes of the second and third shift lines SU2 and SU3, are 0.689 and 0.457, respectively. Looking at the relationship between these vehicle speed slopes C1 to C3, it can be seen that the vehicle speed slope C2 of the second shift line SU2 is set to 1 / 2 of the vehicle speed slope C1 of the first shift line SU1, and the slope of the third shift line SU3 is set to 1 / 3 of the vehicle speed slope C1 of the first shift line SU1. Strictly speaking, C2 and C3 are not 1 / 2 and 1 / 3 of C1, but they are within a range of difference that can be treated as essentially 1 / 2 and 1 / 3. On this scale, if the gradients C1 to C3 of the first to third shift lines SU1 to SU3 in the shift map are made gentler toward the higher speed side, there is an advantage that it is easier to set the acceleration time at each gear so that it is longer on the higher gear side than on the lower gear side.

[0044] [Example of evaluation with different accelerator openings] Next, Figs. 7 to 10 show evaluation results of acceleration time for each gear and engine speed during gear shifting when the accelerator pedal position during acceleration is varied. Fig. 7 shows the evaluation results when the accelerator pedal position is constant at 45%, Fig. 8 shows the evaluation results when the accelerator pedal position is constant at 50%, Fig. 9 shows the evaluation results when the accelerator pedal position is constant at 60%, and Fig. 10 shows the evaluation results when the accelerator pedal position is constant at 70%. In Figs. 7 to 10, each (A) is a graph showing the relationship between acceleration time for each gear, engine speed during gear shifting, and vehicle speed when the gear shift map of the comparative example is applied, and each (B) is a graph showing the relationship between acceleration time for each gear, engine speed during gear shifting, and vehicle speed when the gear shift map of the embodiment is applied. Each (C) is a table listing the acceleration time and engine speed.

[0045] 7(A) to 7(C) for the case of 45% throttle opening, in the comparative example, the acceleration time to third gear (2.7 seconds) is 0.5 seconds shorter than the acceleration time to second gear (3.2 seconds). Furthermore, the engine speed when upshifting from third to fourth gear (3100 rpm) drops significantly compared to the engine speed when upshifting from second to third gear (3600 rpm). With this type of acceleration, the driver will find it difficult to experience a pleasant upshift sound or increased acceleration.

[0046] In contrast, in the Example, the acceleration time is longer for the first gear (2.4 seconds), second gear (3.0 seconds), and third gear (3.2 seconds), with the higher gears becoming longer. Furthermore, although there is some variation in engine speed during gear changes, it is improved compared to the Comparative Example. That is, in the Example, the drop in engine speed (3900 rpm) when shifting from third gear to fourth gear compared to the engine speed (4200 rpm) when shifting from second gear to third gear is suppressed compared to the Comparative Example. Therefore, the Example can provide a gear change feeling that is better than that of the Comparative Example.

[0047] 8(A) to 8(C) for the case where the accelerator opening is 50%, in the comparative example, the acceleration time to third gear (2.7 seconds) is shorter than the acceleration time to the preceding second gear (3.1 seconds). Also, compared to the engine speed (4200 rpm) when upshifting from second gear to third gear, there is a large drop in engine speed (3800 rpm) when upshifting from third gear to fourth gear.

[0048] In contrast, in the Example, the acceleration time increases with increasing speed: 1st gear = 2.6 seconds, 2nd gear = 3.2 seconds, and 3rd gear = 4.5 seconds. In particular, the acceleration time in 3rd gear is approximately 1.4 times longer than in 2nd gear, making it easier to feel the acceleration. Furthermore, the variation in engine speed during gear changes is kept within a range of 200 rpm. With this level of variation, there is not much difference in engine sound, so it can be evaluated that the engine speed during gear changes is approximately the same. In particular, the drop in engine speed (4800 rpm) when shifting from 3rd gear to 4th gear compared to the engine speed (4900 rpm) when shifting from 2nd gear to 3rd gear is significantly improved compared to the Comparative Example.

[0049] 9(A) to 9(C) for the accelerator opening = 60%, in the comparative example, the acceleration time becomes longer as the gear becomes higher, and there is no problem with the acceleration time. However, there is a large variation in engine speed when upshifting. That is, compared to the engine speed (5000 rpm) when upshifting from 1st to 2nd, there is a significant increase in engine speed (5700 rpm) when upshifting from 2nd to 3rd. Also, compared to the engine speed (5700 rpm) when upshifting from 2nd to 3rd, there is a drop in engine speed (5500 rpm) when upshifting from 3rd to 4th.

[0050] In the example, the acceleration time increases as the gear becomes higher. In particular, the acceleration time in third gear is more than 1.5 times longer than in second gear. In addition, the variation in engine speed during upshifting is small. That is, although the engine speed (6000 rpm) when shifting up from second gear to third gear is higher than the engine speed (5600 rpm) when shifting up from first gear to second gear, this is an improvement over the comparative example. Furthermore, the engine speed (6000 rpm) when shifting up from second gear to third gear is the same as the engine speed (6000 rpm) when shifting up from third gear to fourth gear.

[0051] 10(A) to 10(C) for the accelerator opening = 70%, in the comparative example, the acceleration time becomes longer as the gear becomes higher, and there is no problem with the acceleration time. However, compared to the engine speed (5200 rpm) when upshifting from 1st to 2nd, there is a significant increase in engine speed (6100 rpm) when upshifting from 2nd to 3rd. Although the engine speed (6100 rpm) is the same when upshifting from 2nd to 3rd and from 3rd to 4th, the fluctuation in engine speed in the previous stages is too large, resulting in a poor sense of rhythm.

[0052] In the example, the acceleration time increases as the gear becomes higher. Additionally, the variation in engine speed during upshifts is small. That is, the difference between the engine speed (5800 rpm) during upshifts from 1st to 2nd gear and the engine speed (6100 rpm) during upshifts from 2nd to 3rd gear is significantly improved compared to the comparative example. Furthermore, the engine speed (6100 rpm) during upshifts from 2nd to 3rd gear is the same as the engine speed (6100 rpm) during upshifts from 3rd to 4th gear.

[0053] 7 to 10, it was confirmed that by performing gear shift control using the gear shift map of the embodiment in the accelerator opening range of 45% to 70%, it is possible to make the engine speeds during gear shifts as consistent as possible and to make the acceleration time for each gear longer for the higher gears than for the lower gears. In particular, it was confirmed that when the accelerator opening range is 50% to 75%, it is possible to improve the drop in engine speed when shifting from third to fourth gear compared to the engine speed when shifting from second to third gear.

[0054] Generally speaking, when a driver intends to enjoy the feeling of acceleration, he or she depresses accelerator pedal 13 so that the accelerator opening is 50% or more. Therefore, when the accelerator opening is less than 50%, it is desirable to perform gear shift control aimed solely at improving fuel efficiency. Also, when the accelerator opening exceeds 75%, the rev limit is generally reached, so it is desirable to leave this range outside the scope of this gear shift control. Therefore, it is desirable to have gear shift control unit 42 perform gear shift control by applying the gear shift map according to the above-mentioned embodiment at least within the range of accelerator opening = 50% to 75%. [Explanation of symbols]

[0055] 1 Engine body (engine) 2. Automatic transmission 40 PCM (controller) 41 Engine control unit 42 Transmission control section 43 Shift map memory unit (memory unit) SN1 Accelerator opening sensor SN2 Vehicle speed sensor SU1~SU5 gear shift line

Claims

1. A control device for an automatic transmission in a vehicle including an engine, an automatic transmission connected to the engine, an accelerator opening sensor that detects an accelerator opening, and a vehicle speed sensor that detects a vehicle speed, The control device a storage unit that stores a shift map in which a plurality of shift lines for switching gear positions based on the accelerator opening and the vehicle speed are set; a shift control unit that controls the shift of the automatic transmission based on the shift map, The shift map is configured such that, in an accelerator opening range corresponding to acceleration driving, The vehicle speed at each shift line at the same accelerator opening is set so that the variation in engine speed at the time of shifting at each shift line is 400 rpm or less, and A control device for an automatic transmission in which each gear line is set so that the acceleration time at each gear is longer at the higher gear side than at the lower gear side.

2. 2. The automatic transmission control device according to claim 1, The shift lines of the shift map are: a first shift line for shifting the gear stage from first speed to second speed, a second shift line for shifting the gear stage from second speed to third speed, and a third shift line for shifting the gear stage from third speed to fourth speed, A control device for an automatic transmission, wherein in a region of accelerator opening corresponding to the accelerating operation, the slope of the second shift line is set to 1 / 2 of the first shift line, and the slope of the third shift line is set to 1 / 3 of the first shift line.

3. 2. The automatic transmission control device according to claim 1, The control device for an automatic transmission, wherein the low speed stage is second speed and the high speed stage is third speed, and each shift line is set so that the acceleration time at third speed is longer than the acceleration time at second speed.

4. The automatic transmission control device according to any one of claims 1 to 3, The accelerator opening corresponding to the acceleration operation is in the range of 50% to 75%.

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