JP2001343069A - Automatic transmission for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve an automatic transmission shift busy problem which may be caused at gear shift up while a vehicle climbs on the upgrade with acceleration. SOLUTION: The automatic transmission comprises a transmission gear set, a control unit controlling the gear shifting of the transmission gears, an actuator which carry out the gear shifting based upon a signal from the control unit and has an automatic shifting gear mode which can be automatically shifting gears in accordance with the predetermined map. During the automatic shifting gear mode, the gear shifting is suppressed if the controller judges that the gear shifting within the predetermined gear ratio is required from the map before the predetermined time t is elapsed after gear shifting. In this case, the gear shifting within the predetermined gear shifting ratio is preferably one step shift down. Furthermore, after gear shifting, the controller allows the gear shifting if the gear sifting beyond the above mentioned predetermined gear shifting ratio is required from the above mentioned map even if before the predetermined time t is elapsed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission for a vehicle particularly applied to a large vehicle such as a tractor.

[0002]

2. Description of the Related Art In recent years, in order to reduce the burden on a driver, an automatic transmission is often used in large vehicles such as tractors and trucks. In this case, the optimum gear position according to the vehicle speed is determined according to the map, and the upshift and downshift are automatically performed in accordance with the acceleration and deceleration of the vehicle.

[0003]

However, such an automatic transmission may have the following problems. That is, when the upshift is performed during the uphill acceleration traveling, the clutch is disengaged in the upshift process, and the vehicle stalls. Then, in spite of the shift up, a shift request is issued on the map to shift back to the previous gear by one gear lower, that is, a shift down to the original gear immediately after the shift up, a so-called shift busy. Problems occur. Thereafter, even if the gear is returned to the original gear and reaccelerated, there arises a problem that the next upshift causes a stall and the downshift is repeated again.

An object of the present invention is to eliminate such a shift busy problem.

[0005]

SUMMARY OF THE INVENTION The present invention comprises a transmission, a control unit for controlling a shift of the transmission, and an actuator for performing a shift based on a signal from the control unit, and performs an automatic shift according to a predetermined map. An automatic transmission having an automatic transmission mode to be executed, wherein during the automatic transmission mode, before a predetermined time elapses after shifting,
If it is determined from the map that a shift within a predetermined number of steps is necessary, the shift is prohibited.

Here, it is preferable that the shift within the predetermined number of steps is a one-step downshift.

[0007] In addition, it is preferable that the shift is permitted if it is determined from the map that a shift exceeding the predetermined number of steps is necessary even before the predetermined time has elapsed after the shift.

[0008]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 2 shows an automatic transmission for a vehicle according to this embodiment. Here, the vehicle is a tractor for towing a trailer, and the engine is a diesel engine. As shown in the figure, a transmission 3 is attached to an engine 1 via a clutch 2, and an output shaft 4 (see FIG. 3, also referred to as an output shaft) of the transmission 3 is connected to a propeller shaft (not shown) to be connected to a rear wheel (see FIG. 3). (Not shown). The engine 1 is electronically controlled by an engine control unit (ECU) 6. That is, the ECU 6
Reads the current engine speed and engine load from the outputs of the engine speed sensor 7 and the accelerator opening sensor 8, controls the fuel injection pump 1a based on these, and controls the fuel injection timing and fuel injection amount. I do.

As shown in FIG. 3, a flywheel 1b is attached to the crankshaft of the engine, and a ring gear 1c is formed on the outer periphery of the flywheel 1b.
Each time the tooth c passes, the engine rotation sensor 7 outputs a pulse, and the ECU 6 counts the number of pulses per unit time to calculate the engine speed.

As shown in FIG. 2, the clutch 2 and the transmission 3 are automatically controlled based on a control signal of a transmission control unit (TMCU) 9.
The ECU 6 and the TMCU 9 are connected to each other via a bus cable or the like, and can communicate with each other.

As shown in FIGS. 2, 3 and 4, the clutch 2 is a mechanical friction clutch. And a pressure plate 2b for causing frictional contact or separation from the pressure plate 2b. The clutch 2 operates the pressure plate 2b in the axial direction by the clutch booster 10, and is basically automatically connected and disconnected, so that the burden on the driver can be reduced. On the other hand, manual clutch connection / disconnection by the clutch pedal 11 is also possible here in order to enable a delicate clutch work at the time of a very low speed back and a sudden clutch disconnection in an emergency. This is a configuration of a so-called selective auto clutch. A clutch stroke sensor 14 for detecting a stroke of the clutch itself (that is, a position of the pressure plate 2b) and a clutch pedal stroke sensor 16 for detecting a depression stroke of the clutch pedal 11 are provided, and are respectively connected to the TMCU 9.

As shown in FIG. 4, the clutch booster 10 is connected to the air tank 5 through two systems of pneumatic passages a and b shown by solid lines, and operates with pneumatic pressure supplied from the air tank 5. One passage a is for automatic clutch connection / disconnection,
The other passage b is for clutch manual connection / disconnection. One passage a is branched into two branches, one of which is provided with solenoid valves MVC1 and MVC2 for automatic connection / disconnection in series, and the other is provided with an emergency solenoid valve MVCE. A double check valve DCV1 is provided at the junction. A hydraulically operated valve 12 attached to the clutch booster 10 is provided in the other passage b. A double check valve DCV2 is also provided at the junction of the two passages a and b. The double check valves DCV1 and DCV2 are differential pressure operated three-way valves.

The above solenoid valves MVC1, MVC2, MVCE
Is ON / OFF controlled by the TMCU 9, and when ON, the upstream side communicates with the downstream side, and when OFF, the upstream side is shut off and the downstream side is opened to the atmosphere. First, the automatic side will be described.
1 is ON / OFF simply according to ON / OFF of ignition key
It is just done. The ignition key is turned off, that is, turned off when the vehicle is stopped, and the air pressure from the air tank 5 is shut off. The solenoid valve MVC2 is a proportional control valve and can freely control the supply or discharge air amount. This is for controlling the connection / disconnection speed of the clutch. Solenoid valve MVC1, MVC2
Are ON, the air pressure of the air tank 5 switches between the double check valves DCV1 and DCV2 and is supplied to the clutch booster 10. Thereby, the clutch is disconnected. When connecting the clutch, only MVC2 is OFF
As a result, the air pressure of the clutch booster 10 becomes MVC
2 and the clutch is engaged.

If the solenoid valve MVC1 or MVC2 becomes abnormal during disconnection of the clutch and either of them is turned off, the clutch is suddenly engaged against the driver's intention. Therefore, when such an abnormality is detected by the abnormality diagnosis circuit of the TMCU 9, the solenoid valve MVCE is immediately turned on.
Then, the air pressure that has passed through the solenoid valve MVCE switches the double check valve DCV1 in the opposite direction, and the clutch booster 10
, And the clutch disconnection state is maintained, and sudden clutch engagement is prevented.

Next, the manual side will be described. The master cylinder 1 according to the depression / return operation of the clutch pedal 11
The hydraulic pressure is supplied / discharged from the hydraulic valve 3 and is supplied to the hydraulic valve 12 through a hydraulic passage 13a indicated by a broken line. As a result, the hydraulic valve 12 is opened and closed, and the clutch booster 10 is opened.
The air pressure is supplied to and discharged from the clutch 2, and the manual connection and disconnection of the clutch 2 is executed. When the hydraulic valve 12 is opened, the air pressure passing therethrough switches the double check valve DCV2 to reach the clutch booster 10. When the automatic connection / disconnection of the clutch and the manual connection / disconnection interfere, the manual connection / disconnection is prioritized.

As shown in detail in FIG. 3, the transmission 3 is basically a so-called multi-stage transmission of a constant-mesh type.
The speed can be changed to two-speed, reverse. The transmission 3 includes a splitter 17 and a range gear 19 as an auxiliary transmission on the input side and an output side, respectively, and a main gear 18 as a main transmission between them. Then, the engine power transmitted to the input shaft 15 is sequentially sent to the splitter 17, the main gear 18, and the range gear 19 and output to the output shaft 4.

To automatically shift the transmission 3, a gear shift unit GSU is provided. The gear shift unit GSU includes a splitter actuator 20, a main actuator 2, and a splitter actuator 17, which are in charge of shifting of a splitter 17, a main gear 18, and a range gear 19, respectively.
1 and a range actuator 22. These actuators are also pneumatically operated similarly to the clutch booster 10 and controlled by the TMCU 9. Each gear 17,1
The current position of 8, 19 is gear position switch 2.
3 (see FIG. 2). The rotation speed of the counter shaft 32 is detected by the counter shaft rotation sensor 26, and the rotation speed of the output shaft 4 is detected by the output shaft rotation sensor 28. These detection signals are sent to TMCU9.

In this automatic transmission, a manual mode is set in addition to the normal automatic transmission mode, so that a manual transmission based on a driver's shift change operation is possible.
In this case, as shown in FIG. 2, the connection / disconnection control of the clutch 2 and the shift control of the transmission 3 are performed by a shift instruction signal from a shift lever device 29 provided in the driver's seat as a signal. That is, when the driver performs a shift operation on the shift lever 29a of the shift lever device 29, the shift switch built in the shift lever device 29 is operated, and the shift instruction signal is set to TM.
The TMCU 9 operates the clutch booster 10, the splitter actuator 20, the main actuator 21, and the range actuator 22 as appropriate to execute a series of shift operations (clutch disengagement → gear disengagement → gear engagement → clutch engagement). I do. Then, the TMCU 9 displays the current shift stage on the monitor 31.

In the shift lever device 29, R means reverse, N means neutral, D means drive, UP means shift up, and DOWN means shift down.
The shift switch outputs a shift instruction signal corresponding to each of these positions. A mode switch 24 for switching the shift mode between automatic and manual is provided on the driver's seat.
And a skip switch 25 for switching between shifting one gear at a time (normal mode) and skipping a predetermined number of gears (skip mode). These switches are manual switches.

In the automatic shifting mode, the shift lever 29
If a is set in the D range, the shift is automatically performed according to the vehicle speed. Also in this automatic shifting mode, if the driver operates the shift lever 29a to UP or DOWN,
Upshifting or downshifting manually is possible. In this automatic shifting mode, if the skip switch 25 is OFF (normal mode), shifting is performed one step at a time. This is effective when the loaded load is relatively large, such as when towing a trailer. If the skip switch 25 is ON (skip mode), the shift is skipped by a predetermined number of steps.
It is performed by step skipping. This is effective when the trailer is not towed or the load is light.

On the other hand, in the manual shifting mode, shifting is completely in accordance with the driver's intention. Shift lever 29a
Is not in the D range, the shift is not performed, the current gear is held, and the shift lever 29a is moved to the U
Upshifting or downshifting is possible only when operating to P or DOWN. At this time, similarly to the above, if the skip switch 25 is OFF, the shift is performed one step at a time, and if the skip switch 25 is ON, the shift is skipped by one step. In this mode, the D range is H which holds the current gear.
(Hold) range.

An emergency shift switch 27 is provided in the driver's seat, and when the solenoid valve of the GSU or the like breaks down, the gear can be shifted by manual switching of the switch 27.

As shown in FIG. 3, in the transmission 3,
The input shaft 15, the main shaft 33 and the output shaft 4 are arranged coaxially, and the counter shaft 32 is arranged below them in parallel. The input shaft 15 is connected to the driven plate 2 a of the clutch 2, and the input shaft 15 and the main shaft 33
Are rotatably supported.

First, the structure of the splitter 17 and the main gear 18 will be described. The split high gear SH is rotatably attached to the input shaft 15. Gears M4, M3, M2, M1 and MR are also rotatably mounted on the main shaft 33 in order from the front. Gears SH, M4, except MR
M3, M2 and M1 are counter gears CH, C4, C3, C2 and C1, respectively, fixed to the counter shaft 32.
Is always engaged. Gear MR is idle reverse gear I
The idle reverse gear IR is always meshed with a counter gear CR fixed to the counter shaft 32.

Each of the gears SH, M4,... Attached to the input shaft 15 and the main shaft 33 is integrally provided with a spline 36 so that the gear can be selected. Shaft 3
3, first to fourth splines 37 to 40 are fixedly provided. First to fourth sleeves 42 to 45 are provided so as to be slidable back and forth by always engaging with the first to fourth splines 37 to 40. The gears can be engaged and disengaged by appropriately selecting and sliding the first to fourth sleeves 42 to 45 to engage and disengage with the gear-side splines 36. The movement of the first sleeve 42 is performed by the splitter actuator 20,
The movement of the second to fourth sleeves 43 to 45 is performed by the main actuator 21.

As described above, the splitter 17 and the main gear 18 are of a constant mesh type which can be automatically shifted by the actuators 20 and 21. In particular, the spline portion of the splitter 17 has a normal mechanical synchronization mechanism, but the spline portion of the main gear 18 has no synchronization mechanism. For this reason, synchronization can be achieved by performing what is called synchro control, and the gear can be shifted without a synchro mechanism. Here, in addition to the main gear 18, the splitter 17 is also provided with a neutral position to prevent so-called rattle noise (Japanese Patent Application No. 11-319915).
No.).

Next, the configuration of the range gear 19 will be described. The range gear 19 employs a planetary gear mechanism 34 and can be switched to either a high or low position. The planetary gear mechanism 34 includes a sun gear 65 fixed to the rearmost end of the main shaft 33, a plurality of planetary gears 66 meshed with the outer periphery thereof, and a ring gear 67 having internal teeth meshed with the outer periphery of the planetary gear 66. Become.
Each planetary gear 66 is rotatably supported by a common carrier 68, and the carrier 68 is connected to the output shaft 4. The ring gear 67 has a tube portion 69 integrally, and the tube portion 69 is rotatably fitted around the outer periphery of the output shaft 4 to form a double shaft together with the output shaft 4.

The fifth spline 41 is provided integrally with the pipe 69. An output shaft spline 70 is integrally provided on the output shaft 4 adjacent to the rear of the fifth spline 41. A fixed spline 71 fixed to the transmission case side is provided adjacent to the front of the fifth spline 41. The fifth sleeve 4 is always engaged with the fifth spline 41.
6 is provided so as to be able to slide back and forth. Fifth sleeve 46
Is performed by the range actuator 22. A mechanical synchro mechanism exists in the spline portion of the range gear 19.

When the fifth sleeve 46 moves forward, it engages with the fixed spline 71, and the fifth spline 41 and the fixed spline 71 are connected. As a result, the ring gear 67 is fixed to the transmission case side, and the output shaft 4 is driven to rotate at a reduction ratio (here, 4.5) larger than 1. This is the low position.

On the other hand, when the fifth sleeve 46 moves rearward, it engages with the output shaft spline 70, and the fifth spline 41 and the output shaft spline 70 are connected. As a result, the ring gear 67 and the carrier 68 are fixed to each other, and the output shaft 4 is directly driven at a reduction ratio of 1. This is the high position.

As described above, in the transmission 3, on the forward side, the gear can be shifted to two stages of high and low by the splitter 17, four stages of the main gear 18, and two stages of high and low by the range gear 19, for a total of two stages. × 4 × 2 = 16 gears can be changed.

On the reverse side, the Rev.
Is selected, and the range gear 19 is fixed at low. The splitter 17 switches between high and low, and the reverse stage can be switched between high and low two stages.

Next, each of the actuators 20, 21, 22
Will be described. These actuators are composed of a pneumatic cylinder that operates by pneumatic pressure of the air tank 5 and a solenoid valve that switches supply and discharge of pneumatic pressure to and from the pneumatic cylinder. These solenoid valves are selectively switched by the TMCU 9 to selectively operate the pneumatic cylinder. The splitter actuator 20 includes a pneumatic cylinder 47 having a double piston and three solenoid valves MVH, MVF, M
VG. To make the splitter 17 neutral, MVH / ON, MVF / OFF, MVG / O
N. MVH to set the splitter 17 high
/ OFF, MVF / OFF, MVG / ON. MVH / OFF, MV to make splitter 17 low
F / ON and MVG / OFF.

The main actuator 21 is a pneumatic cylinder 4 having a double piston and in charge of operation on the select side.
8 and a pneumatic cylinder 49 having a single piston and in charge of a shift-side operation. Three solenoid valves MVC, MVD, MVE and MVB, M for each pneumatic cylinder
VA is provided.

The select side pneumatic cylinder 48 is provided with an MVC /
At the time of OFF, MVD / ON, MVE / OFF, the main gear moves downward in the figure, and 3rd, 4th or N3 of the main gear can be selected, and MVC / ON, MVD / OFF, MVE / O
When it is N, it is neutral, and it is possible to select 1st, 2nd or N2 of the main gear, and MVC / ON, MVD / OFF,
At the time of MVE / OFF, it moves upward in the figure, and makes it possible to select Rev or N1 of the main gear.

The shift-side pneumatic cylinder 49 is an MVA / O
N, neutral at MVB / ON, N
1, N2 or N3 can be selected, MVA / ON, MV
When it is B / OFF, it moves to the left side of the figure,
d, 4th or Rev can be selected, and MVA / OF
In the case of F, MVB / ON, it moves to the right side of the figure, and 1st or 3rd of the main gear can be selected.

The range actuator 21 includes a pneumatic cylinder 50 having a single piston and two solenoid valves MV.
I, MVJ. The pneumatic cylinder 50 is an MV
In the case of I / ON, MVJ / OFF, it moves to the right side of the figure, and the range gear is set to high. In the case of MVI / OFF, MVJ / ON, it moves to the left side of the figure, and the range gear is set to low.

By the way, in order to brake the counter shaft 32 during the above-mentioned synchro control, the counter shaft 3
2 is provided with a counter shaft brake 27. The countershaft brake 27 is a wet-type multi-plate brake, and operates by the air pressure of the air tank 5. An electromagnetic valve MV BRK is provided to switch between supply and discharge of the air pressure. When the solenoid valve MV BRK is ON, air pressure is supplied to the counter shaft brake 27,
Is activated. When the solenoid valve MV BRK is OFF, air pressure is discharged from the countershaft brake 27 and the countershaft brake 27 is deactivated.

Next, the contents of the automatic shift control will be described. T
The MCU 9 stores a shift-up map shown in FIG. 5 and a shift-down map shown in FIG.
9 executes an automatic shift according to these maps when in the automatic shift mode. For example, in the shift-up map of FIG. 5, gears n (n is an integer from 1 to 15) to n
The shift-up diagram to +1 is determined by a function of the accelerator opening (%) and the output shaft speed (rpm). Then, on the map, only one point is determined from the current accelerator opening (%) and the output shaft rotation speed (rpm). While the vehicle is accelerating, the rotation speed of the output shaft 4 connected to the wheels gradually increases.
Therefore, in the normal automatic shift mode, the gear is shifted up by one step each time the current point exceeds each diagram.
Specifically, every time a current point crosses each diagram, TMCU
9, a speed change request is issued, and the TMCU 9 executes a predetermined speed change control in accordance with the request. In this case, if the skip mode is set, the diagram is alternately skipped one by one to shift up by two stages.

Similarly, in the shift-down map of FIG. 6, gear positions n + 1 (n is an integer from 1 to 15) to n
The shift-down diagram is determined by a function of the accelerator opening (%) and the output shaft speed (rpm). And on the map, the current accelerator opening (%) and the output shaft speed (rpm)
) And only one point is determined. Since the rotation speed of the output shaft 4 gradually decreases while the vehicle is decelerating, in the normal automatic shift mode, the shift down is performed one step at a time when the current point crosses each diagram. In the skip mode, the diagram is alternately skipped one by one to shift down by two stages.

On the other hand, in the manual mode, the driver can freely shift up and down regardless of these maps. In the normal mode, one shift can be performed by one shift change operation, and in the skip mode, two shifts can be performed by one shift change operation. The current accelerator opening is detected by the accelerator opening sensor 8, and the current output shaft rotation speed is detected by the output shaft rotation sensor 28. In particular, TM
The CU 9 converts the current vehicle speed from the current value of the output shaft rotation speed, and displays this on a speedometer. That is, the vehicle speed is indirectly detected from the output shaft rotation speed, and the output shaft rotation speed is proportional to the vehicle speed.

Incidentally, the following problems may occur in such an automatic transmission. That is, when the upshift is performed during the uphill acceleration traveling, the clutch is disengaged in the upshift process, and the vehicle stalls. Then, in spite of the shift up, a shift request is issued on the map to shift back to the previous gear by one gear lower, that is, a shift down to the original gear immediately after the shift up, a so-called shift busy. Problems occur. Thereafter, even if the gear is returned to the original gear and reaccelerated, there is a problem that the next gearshift is performed again, the motor is stalled, and the gearshift is repeated again.

Therefore, in order to solve such a shift busy problem, the present apparatus executes the following control.

FIG. 1 is a flowchart showing the contents of the shift busy prevention control. This flow is based on TMC
The process is repeatedly executed by U9 every predetermined control time (ex. 32 ms).

The TMCU 9 first determines at step 101 whether or not the automatic shift mode is currently selected instead of the manual mode based on the output of the mode switch 24.
If NO, the process proceeds to step 110 to clear the timer, and then, in step 111, the shift is permitted. That is, this control is substantially effective only in the automatic shift mode. If YES, proceed to step 102.

In step 102, it is determined whether or not the shift lever 29a is currently in the D (drive) range based on the output of the shift switch. If it is outside the D range, the process proceeds to steps 110 and 111. If it is the D range, the process proceeds to step 103. Since the range is the D range, at this time, the shift up and down are automatically performed according to the vehicle speed without operating the shift lever by the driver. In step 103, it is determined whether the current vehicle speed is other than 0, that is, whether the vehicle is running. If the vehicle speed is 0, the process proceeds to steps 110 and 111. If the vehicle speed is not 0, the process proceeds to step 104.

In step 104, it is determined whether or not the target gear and the current gear correspond. The target gear here is a gear determined according to the maps of FIGS. 5 and 6 from the current accelerator opening and the output shaft speed, and the current gear is detected by the gear position switch 23. This is an actual transmission gear stage. Therefore, the fact that the target gear is in agreement with the current gear means that there is no gear shift request and the gear shift is complete, and conversely, if they do not match, there is a gear shift request according to the map and This means that the gear is being shifted. When the shift is in progress, the process proceeds to step 109, and when the shift is completed, the process proceeds to step 105.

In step 109, it is determined whether or not shifting is currently prohibited. That is, it is determined whether or not gear shifting is prohibited by passing through step 108 in the execution of the flow before the previous time. If YES, proceed to step 105, and if NO, proceed to steps 110 and 111.

In step 105, the timer is incremented (added). In the next step 106, the timer value is compared with a predetermined time t to determine whether the timer value is less than t. Here, t is 5 (s).
If it is greater than or equal to t, the process proceeds to step 111;

In step 107, it is determined whether the target gear and the current gear are different by two or more. When a shift request is made, if this is a one-step upshift or downshift, this step is NO, and if there is more than one step upshift or downshift, this step is YES. In this case, however, the problem is the shift-down immediately after the shift-up at the time of the uphill acceleration. Therefore, it is substantially determined whether or not a one-stage shift-down request has been issued, as described later. If YES, step 111
The program proceeds to step 108 to permit the shifting, and if NO, the program proceeds to step 108 to inhibit the shifting. This ends the flow.

This flow is applied to an actual vehicle driving situation. If the vehicle has been traveling uphill with sufficient speed (at least t or more) with the automatic transmission mode and the D range fixed, the process proceeds to steps 101 to 104.
It becomes YES and reaches step 105. Then, the timer is incremented, and in step 106, the timer ≧ t
Therefore, the process proceeds to NO, and the gear change is permitted in step 111.

When a shift-up request is received in this state, the process proceeds to steps 109 through steps 101 to 104 for the first time. At this time, since the shift is permitted, proceed to NO and go to step 11
After the timer is cleared at 0, the shift permission is maintained at step 111. The shift up is completed as the route is repeated. The time required for upshifting is extremely short compared to t.

The first flow after the completion of the upshift is as follows. Steps 101 to 104 are reached, and step 1
04 is YES, and the routine proceeds to step 105. Step 1
In step 05, the timer is counted by one unit. However, since the timer has been cleared by the previous flow during upshifting, the timer <t is established in step 106. Then YE
S is reached, and the routine proceeds to step 107. Since no shift request has been issued at present, step 107 becomes NO and step 10
At 8, the gear change is prohibited. In this state, a shift request is issued (NO in step 104), or a timer ≧ t (step 10
6 until NO).

Here, it is assumed that the vehicle stalls due to an upshift and a one-stage downshift request is issued before the timer ≥ t. Then, when the process proceeds from step 101 to step 104 to step 109, since the shift is already prohibited, the process proceeds to YES. Thereafter, the process proceeds to step 107 via steps 105 and 106. Since the answer is NO in step 107, the shift prohibition is maintained in step 108.

As described above, before the predetermined time t elapses after the upshift, the downshift of one stage to return to the original gear is prohibited, and the gear after the upshift is maintained. The gear is made sticky for a certain period of time after the upshift. During this time, since the vehicle is accelerating, usually the timer ≧
Prior to t, the previous downshift request disappears. In this case, the lapse of the time t ends without performing the downshift.

In this case, step 104 becomes YES before step 106 becomes NO. Then, the route from step 104 to steps 105, 106, 107 and 108 is repeated. Next, if step 106 becomes NO, step 111 allows gear shifting and returns to the initial state.

However, there is a case where a downshift request remains even after the time t has elapsed, and in this case, the shift down of one stage is immediately executed immediately after the elapse of the time t. In this case, the process proceeds from step 106 to step 111, and the shift is permitted, and the downshift is executed immediately.

Here, it is assumed that the degree of stall during the upshift is large, and a shift request lower by two or more steps is issued at the time of completion of the upshift. At this time, downshifting is immediately permitted even before the time t has elapsed. Otherwise, the vehicle will eventually stop. In this case, the process proceeds from step 107 to step 111, and the shift is permitted.

In this way, the problem of shift busy as described above is solved. And when the degree of stall during upshift is large, downshift is executed immediately,
The vehicle does not stop. This control is not performed in the skip mode, and is executed in the skip mode.
Since it is possible to shift down by one step, and downshifting by one step is not possible, YES is always obtained in step 107, which has substantially no meaning. This control has a substantial meaning only in the normal mode other than the skip mode.

Incidentally, in this embodiment, the shift is prohibited only in one downshift. In the "shift within a predetermined number of steps" in the present invention, the "predetermined number of steps" means one step in the present embodiment, and the shift means downshift. However, since there is no lower stage than one stage, “within one stage” means one stage. As an application example, the "predetermined number of steps" is set to two steps, three steps ...
It is also possible to change to "etc." or to shift up "shift". For example, if the "predetermined number of steps" is two steps, shifting within two steps, that is, one step or two steps, is prohibited, and shifting of three steps, four steps... Exceeding two steps is allowed.

As described above, the embodiments of the present invention are not limited to those described above. The value of the time t is not limited to 5 (s) but can be changed as appropriate according to the actual vehicle operation mode.

[0063]

The present invention exhibits the following excellent effects.

(1) The problem of shift busy during upshifting during uphill acceleration can be solved.

(2) If the degree of vehicle stall at the time of upshifting is large, downshifting can be allowed immediately.

[Brief description of the drawings]

FIG. 1 is a flowchart showing the contents of shift busy prevention control according to the present invention.

FIG. 2 is a configuration diagram illustrating an automatic transmission for a vehicle according to an embodiment.

FIG. 3 is a configuration diagram showing an automatic transmission.

FIG. 4 is a configuration diagram showing an automatic clutch device.

FIG. 5 is a shift-up map.

FIG. 6 is a downshift map.

[Explanation of symbols]

3 Transmission 9 Transmission control unit (TMC
U) 17 splitter 18 main gear 19 range gear 20 splitter actuator 21 main actuator 22 range actuator 23 gear position switch 25 skip switch 29 shift lever device GSU gear shift unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16H 63:12 F16H 63:12 F term (Reference) 3J552 MA02 MA04 MA13 MA17 MA25 MA26 NA04 NB01 PA19 PA32 PA35 RA03 RB15 RB22 SA03 SA26 SA29 SB20 SB31 TB13 UA03 VA03Z VA37Z VA62Z VA74W VA76Z VA77W VC01Z VC03Z

Claims (3)

[Claims] 1. An automatic transmission mode comprising: a transmission; a control unit for controlling a transmission of the transmission; and an actuator for performing a transmission based on a signal from the control unit, and performing an automatic transmission mode according to a predetermined map. An automatic transmission having: during the automatic transmission mode,
An automatic transmission for a vehicle, characterized in that if it is determined from the map that a shift within a predetermined number of steps is necessary before a predetermined time has elapsed after the shift, the shift is prohibited. 2. The automatic transmission according to claim 1, wherein the shift within the predetermined number of steps is a one-step downshift. 3. The vehicle according to claim 1, wherein the shift is permitted if it is determined from the map that a shift exceeding the predetermined number of steps is necessary even before the predetermined time has elapsed after the shift. Automatic transmission.