JPH0369018B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention aims to reduce shocks that occur when operating a control device for an automatic transmission mounted on an automobile, particularly a shift lever. (Prior art) In a vehicle equipped with an automatic transmission, when the shift lever of the transmission is operated from a neutral range to a driving range such as D range or 2 range while stopped, a so-called N-D shock occurs. There is a problem in that a so-called shock occurs, which causes discomfort to the occupants. In this shock, when the shift lever is operated as described above, the transmission gear mechanism of the automatic transmission is switched from the power cutoff state to the power transmission state by the engagement action of the friction engagement member, and accordingly, the engine output is changed to the power transmission state. This occurs when the driving force is transmitted to the wheels via the speed change gear mechanism. In that case, the transmission gear mechanism switches from the power cutoff state to the first speed state where the engine output is amplified and transmitted at the specified gear ratio, so a large driving force is suddenly transmitted to the wheels. In addition, in general, in 1st gear, the oil pressure for engaging the frictional engagement member is set higher than that at other gears, and the frictional engagement member is rapidly engaged, which causes the frictional engagement to occur particularly when shifting from the neutral range to the driving range. A big shock occurs. For this problem, for example, Japanese Patent Application Laid-Open No. 53-93527
As disclosed in the publication, during a shift operation from a neutral range to a driving range, the transmission gear mechanism is switched from a power cutoff state to a predetermined high speed gear among a plurality of gears provided in the driving range, It has been proposed to then switch to the first speed in the range. In this way, during a shift operation, a small driving force corresponding to the high gear of the transmission gear mechanism is first transmitted from the transmission to the wheels, and then a driving force corresponding to the first speed of the transmission gear mechanism is transmitted. In addition, since the hydraulic pressure to tighten the frictional fastening member is low when switching to high gear, the fastening member is loosely fastened, which causes the shock to shift from the neutral range to the drive range. will be reduced. However, as mentioned above, if the time for temporarily setting the gear gear to the high gear during the shift operation from the neutral range to the driving range is too short, the shift to the first gear may occur before the shift to the high gear is completed. If it becomes too long, the shock reduction effect of passing through the high-speed stage cannot be obtained sufficiently, and if it is too long,
When starting immediately after a shift operation, there may be cases where the vehicle has not yet switched to first gear when the accelerator pedal is depressed. Therefore, this time is set as the period until the transmission gear mechanism completes switching from the neutral state to the high speed gear by the fastening operation of the frictional fastening member. It is desirable to immediately switch to 1st speed after switching to . However, in the invention disclosed in the above-mentioned publication, since the time to set the high speed gear is set to a fixed time, this fixed time is assumed to be the time until the switching to the high speed gear is completed, that is, the fastening of the friction fastening member. Even if you try to match the time it takes for the operation to complete, the time to complete the engagement will not be constant due to mechanical variations in each part of the automatic transmission and changes over time, and the differential fluid changes depending on the temperature. It also changes depending on the viscosity of the fluid and the pressure of the differential fluid, which is adjusted according to the engine load (throttle opening). Therefore, if the time to set the high speed gear is set to a fixed time, the time may become shorter or longer relative to the time it actually takes to complete the switching operation to the high speed gear, and as a result, Because the shift to 1st gear is not performed reliably, the shock is not effectively reduced, or when starting immediately after a shift operation, the shift to 1st gear is delayed and the starting performance deteriorates. . (Object of the Invention) The present invention has the above-mentioned effect by switching the transmission gear mechanism from the neutral state to the first speed via the high speed gear provided in the driving range when shifting from the neutral range to the driving range. In an automatic transmission designed to reduce shock during shift operations, the time for setting the high speed gear is determined depending on the switching operation from the neutral state of the transmission gear mechanism to the high speed gear or the fastening operation of the friction fastening member. By setting this, even if the time required to complete the switching operation to the high gear changes due to mechanical variations in the transmission, changes over time, or the viscosity and pressure of the working fluid that connects the frictional fastening members, the The high speed gear should be set until the optimum point. As a result, when shifting from the neutral range to the driving range, the vehicle always goes through the high speed gear, thereby reliably reducing the shock during the shift operation, and also eliminates the delay in switching to 1st gear, so that it always goes through the high speed gear even during a rapid start. The purpose is to enable a smooth start from 1st gear. (Structure of the Invention) A control device for an automatic transmission according to the present invention is characterized by having the following structure in order to achieve the above object. That is, as shown in FIG. 1, a torque converter B is connected to the output shaft of the engine A, and a speed change gear mechanism C is connected to the output shaft of the torque converter B.
, a gear speed switching means D that switches the power transmission path of the speed change gear mechanism C to set a plurality of gear speeds, and a shift lever E that manually switches between a plurality of ranges such as a travel range and a neutral range. The automatic transmission F includes: shift detection means G for detecting that the shift lever E has been shifted from the neutral range to the driving range; and turbine rotation speed detection means H for detecting the output shaft rotation speed of the torque converter B. In response to the output signals of these detection means G and H, the gear shift means changes from the time when the shift lever E is shifted from the neutral range to the travel range until the turbine rotational speed decreases below a predetermined value. A control means I is provided for controlling D to set the gear position to a high speed position. According to such a configuration, when the shift lever is shifted from the neutral range to the driving range while the vehicle is stopped, the transmission gear mechanism C is temporarily switched to the high gear in the driving range, and the turbine rotational speed of the torque converter B is changed to a predetermined speed. When the speed drops to this value, the gear is switched to the first speed, thereby reducing the shock caused by the sudden transmission of large driving force to the wheels. By the way, the above-mentioned turbine rotational speed is approximately equal to the engine rotational speed when the speed change gear mechanism C is in the neutral state, and when the speed change gear mechanism C is in a shift operation to the driving range, the speed change gear mechanism C transmits power as the frictional fastening member is engaged. However, the situation in which the rotation speed decreases corresponds to the situation in which the rotation speed is switched to the power transmission state, and when the turbine rotation speed reaches a very low predetermined value (for example, 200 RPM). When the speed decreases, the switching operation of the transmission gear mechanism is always substantially completed. Therefore, due to mechanical variations in the automatic transmission, changes over time, viscosity and pressure of the differential fluid that connects the frictional fastening members, etc., the time required for the speed change gear mechanism C to complete the shift from the neutral state to the high speed gear may be affected. Even if the time changes, by setting the high speed gear until the turbine rotational speed drops below a predetermined value, the gear can always be switched to the high gear reliably, and after switching to the high gear, the gear can be switched to the high gear quickly. It will be possible to switch quickly. (Example) Hereinafter, an example of the present invention will be described based on the drawings. FIG. 2 shows the mechanical structure and fluid control circuit of the automatic transmission 1. The automatic transmission 1 includes a torque converter 10 and a multi-speed gear mechanism 20.
and an overdrive speed change gear mechanism 40 disposed between the two. The torque converter 10 includes a drive plate 1
1 and the output shaft 3 of the engine 2 via the case 12
The turbine 14 includes a pump 13 directly connected to the turbine 13, a turbine 14 disposed opposite the pump 13 in the case 12, and a stator 15 disposed between the pump 13 and the turbine 14.
4 is coupled to an output shaft 16. Further, a lock-up clutch 17 is provided between the output shaft 16 and the case 12. This lock-up clutch 17 is constantly pressed in the tightening direction by the pressure of the working fluid circulating within the torque converter 10, and is released when release fluid pressure is supplied from the outside. The multi-speed gear mechanism 20 has a front planetary gear mechanism 21 and a rear planetary gear mechanism 22, and sun gears 23 and 24 in both mechanisms 21 and 22 are connected by a connecting shaft 25. The input shaft 26 to this multi-speed gear mechanism 20 is connected to the front clutch 2
7 to the connecting shaft 25 and to the ring gear 29 of the front planetary gear mechanism 21 through the rear clutch 28, and the connecting shaft 25, that is, both planetary gear mechanisms 21 and 22
Sun gears 23, 24 and transmission case 30 in
A second brake 31 is provided between the two. The pinion carrier 32 of the front planetary gear mechanism 21 and the ring gear 3 of the rear planetary gear mechanism 22
3 is connected to an output shaft 34, and a low reverse brake 36 and a one-way clutch 37 are interposed between the pinion carrier 35 of the rear planetary gear mechanism 22 and the transmission case 30, respectively. On the other hand, in the overdrive transmission gear mechanism 40, a pinion carrier 41 is connected to the output shaft 16 of the torque converter 10, and a sun gear 42 and a ring gear 43 are connected by a direct coupling clutch 44. . Further, an overdrive brake 45 is provided between the sun gear 42 and the transmission case 30, and the ring gear 43 is connected to the input shaft 26 to the multi-speed gear mechanism 20. The multi-speed gear mechanism 20 configured as described above is conventionally known, and includes the clutches 27, 28 and the brake 3.
By selectively operating the gears 1 and 36, a gear ratio of three forward speeds and one reverse speed can be obtained between the input shaft 26 and the output shaft 34. Further, the overdrive speed change gear mechanism 40 operates when the clutch 44 is engaged and the brake 4
When the clutch 44 is released and the brake 45 is engaged, the output shaft 16 of the torque converter 10 and the input shaft 26 to the multi-speed gear mechanism 20 are directly connected. Combine drives. Next, the fluid control circuit of the automatic transmission will be explained. The working fluid discharged into the main line 51 from the oil pump 50 which is constantly driven by the engine output shaft 3 via the torque converter 10 is guided to the select valve 53 after its oil pressure is adjusted by the pressure regulating valve 52. . This select valve 53 has P,
It has a range of R, N, D, 2, 1, and D, 2, 1
In the range, the main line 51 is connected to port a.
communicate with. This port a is connected to the actuator 28a of the rear clutch 28 through a line 54.
Therefore, in each of the forward ranges D, 2, and 1, the rear clutch 28 is always held in the engaged state. Further, the port a communicates with first, second, third, and fourth control lines 56, 57, 58, and 59. These control lines 56-59 are 1-
2 shift valve 61, 2-3 shift valve 62, 3-4 shift valve 63, and one end of lock-up valve 64, and drain lines 66, 67, 68, 69 are connected from each control line 56 to 59, respectively. The drain lines 66 to 69 are branched, and first, second, third, and fourth solenoids 71, 72, 73, and 74 are provided to open and close these drain lines 66 to 69, respectively. When these solenoids 71 to 74 are OFF, the drain lines 66 to 69 are released and the pressure in the corresponding control lines 56 to 59 is zero, but when they are ON, the drain lines 66 to 69 are closed and the pressure in the control line 5 is set to zero.
By increasing the pressure within 6 to 59, the above 1-
The spools 61a, 62a, 63a, and 64a of the 2-shift valve 61, 2-3 shift valve 62, 3-4 shift valve 63, and lock-up valve 64 are moved from the illustrated positions in the directions of arrows A, B, C, and D, respectively. Port a in the select valve 53 also reaches the 1-2 shift valve 61 via a line 76 branched from the line 54, and connects to the spool 61a.
When the valve is moved in the direction A by the working fluid from the first control line 56, it communicates with the line 77, and also connects to the second lock valve 78 and the line 79.
It communicates with the engagement side port 31a' of the actuator 31a of the second brake 31 through the above. As a result, working fluid is supplied to the port 31a', and the second brake 31 is engaged. Here, in the D range, the second lock valve 78 is supplied with working fluid from both ports b and c of the select valve 53 via lines 80 and 81, and is connected to the lines 77 and 79 as shown. However, in the 2nd range where port c is closed, working fluid is supplied only from port b and the spool 78a moves downward, thereby bringing the lines 80 and 79 into communication.
Therefore, in the 2nd range, the second brake 3
1 is tightened regardless of the state of the 1-2 shift valve 61. Port c, which communicates with the main line 51 in the D range, is guided by the line 81 to the 2-3 shift valve 62 via a one-way throttle valve 82. When the spool 62a of the 2-3 shift valve 62 is moved in the direction B by the working fluid from the second control line 57, it is connected to the line 83, which is further branched into lines 84 and 85, one of which is Actuator 31 of the second brake 31
The other end leads to the actuator 27a of the front clutch 27.
As a result, working fluid is supplied to the port 31a'' and the actuator 27a, the second brake 31 is released, and the front clutch 27 is engaged. The working fluid is led to the 1-2 shift valve 61 through a line 86, and further to the actuator 36a of the low reverse brake 36 through a line 87 when the spool 61a of the valve 61 is in the position shown.
leading to. As a result, the low reverse brake 3
6 is concluded. Further, in the R range, the port e as well as the port d communicate with the main line 51, so that the working fluid is guided to the 2-3 shift valve 62 through the line 88, and the space 62a of the valve 62 is connected to the main line 51. above line 83 when in position
The second brake actuator 31a is connected to the release side port 31a'' of the second brake actuator 31a and the actuator 27a of the front clutch 27 via lines 84 and 85.Thereby, in the R range, the front clutch 27 is engaged together with the low reverse brake 36. In this case, the port a is closed and the rear clutch 28 is released.The main line 51 is selectively switched to its course by the select valve 53 as described above, and at the same time,
It is led to the 3-4 shift valve 63 and the engagement side port 45a' of the actuator 45a of the overdrive brake 45 via branch lines 89 and 90. The line 89 led to the 3-4 shift valve 63 is further connected to lines 91 and 92 when the spool 63a of the valve 63 is in the position shown, and one line 91 is connected to the actuator 44a of the direct coupling clutch 44. , the other line 92 leads to the release side port 45a'' of the overdrive brake actuator 45a. Therefore, when the 3-4 shift valve 63 is in the illustrated state, the overdrive brake actuator 45a is closed. Both side and release side ports 45a', 4
5a'', the overdrive brake 45 is released, and the direct coupling clutch 44 is
is in a state of being concluded. Then, the spool 63a of the 3-4 shift valve 63 is connected to the third control line 5.
By draining the lines 91 and 92 when moved in the C direction by the working fluid from 8,
Direct coupling clutch 44 is released and overdrive brake 45 is engaged. Further, from the main line 51, the pressure regulating valve 52 is connected to the main line 51.
Working fluid is led to the lock-up valve 64 via a branch line 93 that passes through the lock-up valve 64. When the spool 64a of the valve 64 is in the position shown, the torque converter 1 is connected to the torque converter 1 via the line 94.
0, causing the lock-up clutch 17 in the torque converter 10 to disengage. and,
The spool 64a of the lock take valve 64 is
When moved in both directions by the actuating fluid from control line 59, the lock-up clutch 17 is engaged by fluid pressure within torque converter 10 by draining line 94. In addition to the above configuration, this fluid control circuit has a working fluid introduced from the main line 51 via a branch line 95, and applies the line pressure adjusted by the pressure regulating valve 52 to the engine load (throttle opening). Throttle valve 9 changes the throttle pressure to a value corresponding to
7 and a throttle backup valve 97' that assists the throttle valve 97. Further, by moving the spool 98a in the E direction in response to the hydraulic pressure from the first control line 56 at a gear stage other than the first speed, a cutback is made that connects the throttle pressure line 96 to the pressure reducing line 99 leading to the pressure regulating valve 52. A valve 98 is provided. As a result, in gears other than 1st gear in the D range, throttle pressure is introduced into the pressure regulating valve 52 and the line pressure is reduced in accordance with the engine load, and in 1st gear, the line pressure is set to a relatively high pressure. It's becoming like that. Regarding the above configuration, the relationship between each of the shift solenoids 71 to 73 and the gear position in the D range, the relationship between the solenoid 74 and the lockup, and the relationship between the operating state of the clutch and brake in each range and the gear position are shown in the first diagram. , shown in Tables 2 and 3.

【table】

【table】

【table】

[Table] Next, the electric control circuit of the automatic transmission 1 will be explained using FIGS. 3 to 6. As shown in FIG. 3, this control circuit 100 is provided with a gear stage determination circuit 101 and a lock-up determination circuit 102, and these circuits 101, 1
02, a turbine rotation sensor 1 detects the rotation speed of the turbine 14 in the torque converter 10.
03, the throttle opening signal b from the throttle opening sensor 104 that detects the opening of the throttle valve in the engine 2, and the position of the shift lever provided in the automatic transmission 1. A D, 2, 1 range signal c from the shift position sensor 105 is input. Then, in response to these signals a, b, and c, the gear stage determination circuit 101 and the lock-up determination circuit 102 perform gear shift and lock-up determination circuits that are set in advance according to the turbine rotational speed and the throttle opening as shown in FIG. By looking at the lock-up map, determine whether the operating state is in the shift-up zone, shift-down zone, or hold zone, and also determine whether the lock-up is activated or released. 1 depending on the result
~4 speed signals _d1 ~ _d4 and lockup signal e are output. Among these signals, 1st to 4th speed signals d ₁ to _{d 4}
are AND circuits 106, 107, 108 and OR
Solenoid selection map 110 via circuit 109
, and from the map 110, the solenoid corresponding to the gear to be set according to the above-mentioned Table 1 is determined.
The ON and OFF states are read, and control signals f ₁ to f ₃ are output to the first to third solenoids 71 to 73 shown in FIG. 2 so as to attain the ON and OFF states. As a result, the ON and OFF states of the solenoids 71 to 73 are set, and the automatic transmission 1 is controlled to a required gear position according to the operating range. Further, the lockup signal e is sent to the fourth solenoid 74 shown in FIG. 2, and the solenoid 74 is turned on and off according to Table 2.
Turn it OFF to activate or release the lockup depending on the operating range. However, this control circuit 100 is equipped with an N-D shock reduction circuit 111 in addition to the above configuration. This N-D shock reduction circuit 111 includes an N range switch 112 that is turned on when the shift lever is shifted to the N range, as shown in FIG. 5, and a D range switch 112 that is turned on when the shift lever is shifted to the D range. N range signal g and D range signal h from the range switch 113 (these switches 112, 113 may also serve as the shift position sensor 105 in FIG. 3), and the turbine rotation signal a from the turbine rotation sensor 103. is input. The N range signal g and the D range signal h are input to the D and T terminals of the D-type flip-flop circuit 114, respectively, and the turbine rotation signal a is converted into a voltage by the F-V converter 115 from a pulse signal indicating the rotation speed. It is converted into a signal and compared with a predetermined voltage by the comparator 116, and the turbine rotation speed is determined to be a very small predetermined rotation speed no (e.g.
The comparator 116 outputs the low speed signal a' which becomes "1" when the speed decreases to 200 RPM or less. Then, this low-speed signal a' is inverted by the NOT circuit 117 and then transferred to the flip-flop circuit 114.
The flip-flop circuit 114 inputs the reset signal a'' from "1" to "0" when the D range signal h input to the T terminal changes from "0" to "1". The state of the N range signal g that was input to the D terminal when the D range signal g changed to "1" is output from the Q terminal as an output signal i. In that case, N
When shifting from range to D range, after the D range signal h changes to "1" as shown in Fig. 6 1 and 2, the N range signal g changes to "0" after a certain shift time t. ”, the output signal i of the flip-flop circuit 114, as shown in FIGS.
The state remains "1" until the low speed signal a' changes to "1" (until the reset signal a' changes to "0").Then, this output signal i and the above By inputting the N range signal g to the OR circuit 118, the sixth
As shown in FIG. 6, from the time the shift is made to the N range until the flip-flop circuit output signal i changes to "0" after the shift to the D range, in other words, until the turbine rotational speed drops to the predetermined rotational speed no. A 4th speed fixed signal j held at "1" is output.
Here, in order to prevent hunting, the output signal (low speed signal) a' of the comparator 116 becomes "1" when the rotation speed decreases to a predetermined rotation speed no (for example, 200 RPM), and When ascending, the rotation speed is higher than the specified rotation speed no. (e.g.
Hysteresis operation is performed so that the signal a' becomes "0" when the speed increases to 280 RPM. However, the above 4th speed fixed signal j is shown in Fig. 3.
It is input to the OR circuit 109 together with the 4-speed signal _d4 , and the three AND circuits 106, 107, 108
The signals are inverted and input together with the first to third speed signals _d1 to _d3 , respectively. Therefore, the fourth speed fixed signal j is “0”
At this time, the 1st to 4th speed signals d ₁ to d 4 corresponding to the determination result by the gear stage determination circuit 101 are input as they are to the solenoid selection map 110, and the first to fourth gear signals d 1 to d ₄ are inputted as they are to the solenoid selection map 110, and the first to fourth gear signals d 1 to d 4 are inputted as they are to the solenoid selection map 110 to obtain the gear stage according to the determination result. The third solenoids 71 to 73 operate, but when the 4th speed fixed signal j is "1", the 4th speed fixed signal j has the same function as the 4th speed signal _d4 , regardless of the judgment result of the gear stage judgment circuit 101. Solenoid selection map 110 as a signal to
In response to this, the first to third solenoids 71 to 73 operate so that the gear position becomes 4th speed. Here, as mentioned above, the 4th speed fixed signal j is "1" before the shift operation from the N range to the D range.
, and from when it is in the N range, the first to third
ON for solenoids 71 to 73 to obtain 4th speed,
Although it is in the OFF state, in the N range, each shift valve 6 from the select valve 53 shown in FIG.
Since the working fluid is not supplied to gears 1, 62, and 63, each frictional engagement member or speed change gear mechanism will not be in the 4th speed state. In other words, setting the 4th speed fixed signal j to "1" before shifting to the D range is as follows:
The first to third solenoids 71 to 7 are used to quickly switch to 4th gear when shifting to D range.
This is to set the gear 3 to the 4th speed state in advance. As described above, when the shift lever is operated from the N range to the D range, the automatic transmission 1 or the transmission gear mechanism is temporarily switched to the 4th speed state by the 4th speed fixed signal j, and the 4th speed fixed signal j is When the signal changes to “0”, the gear position determination circuit 10 in FIG.
According to the normal control by No. 1, the speed is changed to the first speed. As a result, during the shift operation,
The engine output is first transmitted from the automatic transmission 1 to the wheels as a relatively small driving force, and then as a relatively large driving force amplified by the first gear ratio. The shock is significantly reduced compared to the case where a large driving force corresponding to the first gear is suddenly transmitted to the wheels.
Furthermore, when switching to 4th speed, the pressure of the working fluid (line pressure) acting on the frictional fastening member is lower than when switching to 1st speed, so the fastening action of the frictional fastening member is performed slowly. Therefore, shock can be further reduced by passing through the fourth gear. The time during which the 4th speed fixed signal j is held at "1" and the gear stage is set to 4th speed is the time until the turbine rotational speed drops to the predetermined rotational speed no. The situation in which the turbine rotation speed decreases corresponds to the engagement condition of the friction fastening member or the switching condition of the speed change gear mechanism, so when the rotation speed drops to the predetermined rotation speed no., regardless of the time required up to that point, the shift is always to 4th gear. The switching operation has almost been completed. In other words, as shown in FIG. 7, when the turbine rotation speed, which was approximately equal to the engine rotation speed in the N range, decreases with the shift operation to the D range, the engine load increases, for example, as shown by the symbol F. Therefore, the pressure (line pressure) of the working fluid used to fasten the friction fastening member is low, or the viscosity of the working fluid is high when it is cold, so the fastening operation is performed slowly, and the turbine rotational speed is therefore slow. In both cases, as shown by symbol G, the turbine speed decreases quickly due to a large engine load and high line pressure. Predetermined rotation speed
The 4th speed state is set until the speed decreases to no, that is, until the switching to 4th speed is completed. As a result, when operating from N range to D range, the vehicle always goes through 4th gear regardless of the state of the engine or transmission, reliably reducing shock, and immediately switching to 1st gear after completing the shift to 4th gear. Even if the vehicle is shifted and the vehicle is started immediately after the shift operation, the vehicle will always start from the first gear state. Note that the control circuit 100 that performs the above control is as follows:
For example, it can be configured by a microcomputer, in which case the control circuit 100 operates according to the flowchart shown in FIG. 8 and subsequent figures. Next, this operation will be explained. Main Control First, to explain the main control flowchart shown in Fig. 8, the control circuit first performs the following steps.
In accordance with _A1 to _A3 , various states are initialized, the range set by the shift lever or selector valve 53 is read, and it is determined whether the range has been switched from the N range to the D range. . Then, if the range has not been changed and is set to 1 range, execute steps A ₄ to A ₅ to A ₉ ,
First, release the lock-up and check by calculation whether the engine speed will overrun when downshifting to 1st gear. If it does, shift to 2nd gear; if not, shift to 1st gear.
Shift to different speeds. If the gear is set to the 2nd gear range, steps _A4 to _A10 are executed, steps _A11 to _A12 are executed, the lockup is released, and the gear is shifted to the second gear. If the setting is other than range 1 and range 2, that is, range D, follow step A ₁₀ above.
Steps _A13 to _A15 are then executed to perform shift-up control, shift-down control, and lock-up control, which will be described later. However, if it is determined in step _A3 that the range has been switched from N range to D range, then in step _A16 it is determined whether the vehicle is running or stopped, and if it is running, it is determined that the range has been switched from N range to D range. , the above steps
Normal shift control and lock-up control are performed according to _A4 to _A15 . On the other hand, if the vehicle is stopped, the turbine rotation speed T of the torque converter is further determined in step _A17 .
Determine whether or not the speed is 200 RPM or less. If the rotational speed T is 200 RPM or more, the transmission gear mechanism is set to 4th speed in step _A18 , and if it is 200 RPM or less, normal control is performed according to steps _A4 to _A15 . In this case, since the vehicle is stopped, the first speed is set. Therefore, when the shift lever is shifted from N range to D range while the vehicle is stopped,
The gear stage is once set to 4th gear, and is set to 1st gear when the turbine rotational speed decreases to 200 PRM or less as a result of the shift operation to the D range. As a result, when shifting from N range to D range, the gear stage is set to 1st gear via 4th gear, reducing the shock during the shift operation, and especially reducing the turbine rotation speed. Since the gear is set to 4th gear until it drops below 200 PRM, which almost completes the switching operation to 4th gear, the gear must go through the 4th gear state and immediately switch to 1st gear when the switching to 4th gear is completed. Even if the vehicle is to start immediately after the shift operation, the vehicle will always start from 1st gear. Shift-up Control Next, normal control during driving will be explained. First, step A ₁₃ in the main control above.
To explain the shift up control, as shown in FIG. 9, in this control, first, in step _B1 , it is checked whether the transmission gear mechanisms 20, 40 shown in FIG. 2 are in the 4th speed state. When the gear is in 4th gear, it is not possible to shift up, so the control is terminated.
If the speed is other than 4th, follow steps _B2 to _B5 .
At the same time as reading the current throttle opening, reading out the set turbine rotation speed Tmap corresponding to the read throttle opening from the shift-up map that has been set and stored in advance, and reading the actual turbine rotation speed T, Number Tmap
Compare with. Here, as shown in Fig. 10, the shift-up map is defined as the set turbine rotation speed Tmap corresponding to each throttle opening.
This shift up line Mu
corresponds to the boundary line X between the shift up zone and the hold zone shown in FIG. Then, the actual turbine rotation speed T is the set turbine rotation speed Tmap
When it is larger, that is, the operating area is as shown in Fig. 4 or 10.
If the shift-up flag _F1 is “0” in the shift-up zone shown in the figure, the step
Following steps _B6 to _B8 from _B5 , the flag _F1 is set to "1" and the gear is shifted up by one gear. The shift-up flag _F1 indicates that shift-up control has been performed when it is "1", and therefore, in step _B6 , the shift-up flag F1 is set to "_1" .
If it has already been set to "1", the control is terminated without shifting up again. Also,
When it is determined in step _B5 above that the actual turbine rotation speed T is smaller than the set turbine rotation speed Tmap, the set turbine rotation speed Tmap is multiplied by 0.8 according to steps _B9 to _B11 and the result shown in FIG. A new shift-up line Mu' indicated by a broken line is set. Then, only when the actual turbine rotation speed T is smaller than the new set turbine rotation speed Tmap corresponding to this line Mu', the shift-up flag _F1 is reset to "0" in preparation for the next shift-up control. Turbine rotation speed T is the new set turbine rotation speed
When it is larger than Tmap, the control ends and shifts to downshift control. This step B ₉
The control by _B11 is to prevent so-called chattering, which is caused by forming a hysteresis zone and causing complicated gear changes when the turbine rotational speed T is on the shift up line Mu. Shift Down Control The shift down control at step _A14 in FIG. 8 is executed as follows according to the flowchart in FIG. First, in step _C1 , the speed change gear mechanism 20, 40
After confirming that the gear is in a position other than 1st gear, that is, in a gear position where downshifting is possible, follow steps _C2 to _C5 to read the actual throttle opening and create a downshift map as shown in Figure 12. The set turbine rotation speed Tmap corresponding to the throttle opening at that time is read from the shift down line Md set in , and this is compared with the actual turbine rotation speed T. Here, the shift down line Md corresponds to the boundary line Y between the hold zone and the shift down zone shown in FIG. When the actual turbine rotation speed is smaller than the set turbine rotation speed Tmap, that is, when the operating region is in the downshift zone of FIG. 4 or FIG. 12, according to steps _C6 to _C8 ,
After confirming that the downshift flag _F2 has been reset to "0" and setting the flag _F2 to "1", the gear stage is shifted down by one gear.
In this case as well, if the flag _F2 has already been set to "1" in step _C6 , the control is terminated. Further, when the actual turbine rotation speed T is larger than the set turbine rotation speed Tmap in step _C5 , the set turbine rotation speed Tmap is multiplied by 1/0.8 according to steps _C9 to _C11 as shown by the broken line in FIG. A new shift down line Md' is formed, and the actual turbine rotation speed T and a new set rotation speed corresponding to this line Md' are compared. And on top of that
>Tmap, the downshift flag _F2 is reset to "0" to prepare for the next downshift control. Lock-up control Furthermore, the steps in the main control shown in Fig.
The lockup control indicated by _A15 is executed according to the flowchart shown in FIG. In this control, the throttle opening degree is read according to steps _D1 to _D4 , and the lockup release line Moff set in the lockup map as shown in FIG. Read the turbine rotation speed Tmap and compare it with the actual turbine rotation speed T. When the actual turbine rotation speed T is smaller than the set turbine rotation speed Tmap, that is, when it is in the lockup release zone shown in FIG. 14, the lockup is released in step _D5 . Set turbine rotation speed Tmap at which the actual turbine rotation speed T corresponds to the lock-up release line Moff.
If the size is larger, step D ₆ and D ₇ are performed, and the first
The lockup release line is shown by the broken line in Figure 4.
Read the set turbine speed Tmap corresponding to the lockup operating line Mon, which is set by providing a hysteresis zone of a predetermined width on the high turbine speed side of Moff, and compare this set turbine speed Tmap with the actual turbine speed T. do. And T＞
Lockup operation is controlled by step _D8 during Tmap. In the above embodiment, from the N range to the D range
1 via 4th gear when shifted to range
For example, if there are multiple gears in the 2nd range or 1st range, the shift operation from the N range to these ranges may be necessary. When it was done,
The first gear may be set via a high gear of a plurality of gears. (Effects of the Invention) As described above, according to the present invention, in an automobile equipped with an automatic transmission, when the shift lever is shifted from the neutral range to the driving range while the vehicle is stopped, the gear position provided in the driving range is changed. In addition to setting the gear to 1st speed via the high speed gear, the time to set the high gear in that case was until the turbine rotational speed decreased to a predetermined value.
Even if the time required for the transmission gear mechanism to switch from the neutral state to the high gear changes due to mechanical variations in the automatic transmission, changes over time, or the pressure and viscosity of the working fluid that engages the frictional engagement members, The vehicle always passes through the high speed gear, thereby reliably reducing the shock during the shift operation from the neutral range to the driving range. Furthermore, since the first speed is immediately set when the high speed gear is switched, even when starting immediately after the shift operation, the vehicle always starts smoothly from the first speed.

[Brief explanation of drawings]

Fig. 1 is an overall configuration diagram of the present invention, Figs. 2 to 14 show embodiments of the invention, and Fig. 2 is a configuration diagram showing the mechanical structure and fluid control circuit of an automatic transmission.
Figures 3 and 5 are circuit diagrams showing the electric control circuit, Figure 4 is a characteristic diagram showing the control characteristics, Figures 6 and 7 are time charts showing the action, and Figures 8, 9, 11, and 13 are the operation diagrams. Flowchart diagram shown, No. 10, 12, 1
Figure 4 shows a shift-up map, a shift-down map, and a lock-up map used for control, respectively. 1... Automatic transmission, 2... Engine, 3... Engine output shaft, 10... Torque converter, 2
0, 40... Speed gear mechanism, 100... Gear stage switching means (control circuit), 103... Turbine rotation speed detection means (turbine rotation sensor), 111...
control means (ND shock reduction circuit), 112;
113...Shift detection means (N range switch,
D range switch).

Claims (1)

[Claims] 1. A torque converter connected to the output shaft of the engine, a speed change gear mechanism connected to the output shaft of the torque converter, and a speed change gear mechanism that switches the power transmission path of the speed change gear mechanism to set a plurality of speeds. and a shift lever that manually switches between a plurality of ranges such as a travel range and a neutral range, and a shift detection means for detecting that the shift lever is shifted from the neutral range to the travel range. , a turbine rotational speed detection means for detecting the output shaft rotational speed of the torque converter, and receiving the output signals of these detection means,
control means for controlling the gear changeover means to set the gear to a predetermined high speed until the turbine rotational speed falls below a predetermined value when the shift lever is shifted from the neutral range to the travel range; A control device for an automatic transmission characterized by comprising: