JP2003185005A - Automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic transmission capable of reducing the load of a driver at the time of starting. <P>SOLUTION: This automatic transmission comprises a normal start means set to a second stage or higher as the start stage of a vehicle and a selected start stage selectable instead of the normal start stage. When the gear shift is raised to a specified gear shift or higher after the vehicle is started with the selected start stage at a stage lower than the normal transmission stage, the start stage can be automatically reset to the normal one. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission that reduces the burden on the driver when starting.

[0002]

2. Description of the Related Art In a loaded vehicle such as a truck or a tractor, it is common to start at a preset second or higher speed during normal starting. Then, under special circumstances such as when starting a steep slope, the vehicle starts at a lower speed than the gear used during normal starting. Generally, a vehicle equipped with an automatic transmission is provided with a normal start stage (also referred to as a default stage) set and stored in advance at a second speed or higher,
During normal operation, the vehicle is started at the normal start stage, and when the vehicle is placed under special circumstances, the driver selects a lower speed stage as the start stage than the normal start stage and starts the vehicle.

For example, in the automatic transmission disclosed in Japanese Patent Publication No. 6-63559, only when the driver presses the switch for selecting the first speed, the vehicle starts at the first speed and the driver does not press the switch. It starts at the 2nd speed (normal start stage).

However, in such a conventional automatic transmission, when the vehicle is placed at a lower speed than the normal starting speed and then the situation in which the vehicle is placed changes and the vehicle needs to start at the normal starting speed, However, it is necessary for the driver to detect and judge the situation and perform an operation for changing to the normal start stage (release of the switch for selecting the first speed in the above example), which is a burden on the driver.

Further, the applicant of the present invention filed Japanese Patent Application No. 2000-7636.
In the automatic transmission described in 8, the driver selects a gear and learns that gear as the starting gear, so that the vehicle will start at the selected gear after the next time. In this automatic transmission, the driver selects and learns the most suitable gear stage according to the state of the vehicle (loading state, etc.) or the state where the vehicle is placed, so that the vehicle starts at the optimal gear stage at least under those circumstances. be able to.

[0006]

However, even with this automatic transmission, the situation in which the vehicle is placed after the vehicle has been started by learning the lower gear than the gear suitable for normal starting as the starting gear If there is a change and it becomes necessary to start at the normal start stage, the driver needs to sense and judge the need and perform the learning operation of the gear stage suitable for the normal start stage,
The driver's burden at the start was still present.

In short, starting at a speed lower than the normal starting speed is necessary only under special circumstances as described above, and if the special situation is exited, it becomes necessary to return the starting speed to the normal starting speed. However, in the conventional automatic transmission, it is necessary for the driver to judge that the vehicle has come out of a special situation and perform an operation of returning to the normal start stage.

Therefore, an object of the present invention is to provide an automatic transmission that can reduce the burden on the driver when starting.

[0009]

In order to achieve the above object, the present invention provides a normal starting stage set to a second speed or higher as a starting stage of a vehicle, and a selective starting that can be selected in place of the normal starting stage. An automatic transmission equipped with a gear, after the vehicle is started at a selected start gear lower than the normal start gear,
When the gear is shifted up to a predetermined gear or higher, the starting gear is automatically returned to the normal starting gear.

Here, the predetermined gear may be a normal starting gear.

Further, the present invention is an automatic transmission including a normal starting stage set to a second speed or higher as a starting stage of a vehicle and a selectable starting stage selectable in place of the normal starting stage. After the vehicle is started at the selected starting speed lower than the normal starting speed and the vehicle speed becomes equal to or higher than the predetermined speed, the starting speed is automatically returned to the normal starting speed.

[0012] Here, the vehicle is a tractor to which a trailer can be connected at a rear portion thereof, and is provided with detection means for detecting connection / disconnection of the tractor, and the normal start stage is connected to the tractor when the tractor is connected. A different value is set when connected.
The normal starting stage may be automatically selected according to the detection result of the detecting means.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

In this embodiment, the applicant of the present invention applies to Japanese Patent Application No. 2000-
The present invention is applied to the automatic transmission having the starting gear learning function described in 76368. First, the outline of the automatic transmission will be described.

FIG. 1 shows an automatic transmission for a vehicle according to this embodiment. Here, the vehicle is a tractor capable of connecting a trailer to the rear part, and the engine 1 is a diesel engine equipped with an electronic governor 1d. 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. 2) of the transmission 3 is connected to drive wheels via a propeller shaft (not shown) and the like. . The engine 1 is electronically controlled by an engine control unit (ECU) 6. That is, the ECU 6 mainly controls the electronic governor 1d of the fuel injection pump 1a based on the values of the engine speed and the accelerator opening detected by the engine rotation sensor 7 and the accelerator opening sensor 8.

As shown in FIG. 2, the flywheel 1b is attached to the crankshaft of the engine, and the ring gear 1c is formed on the outer periphery of the flywheel 1b.
The engine rotation sensor 7 outputs a pulse each time the tooth c passes, and the ECU 6 counts the number of pulses per unit time to calculate the engine rotation speed.

As shown in FIG. 1, here, 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. 1, 2, and 3, the clutch 2 is a mechanical friction clutch, and the flywheel 1b that forms the input side, the driven plate 2a that forms the output side, and the driven plate 2a are the flywheel 1a. It is composed of a pressure plate 2b which is pressed against or separated from. The clutch 2 operates the pressure plate 2b in the axial direction by the clutch booster (clutch actuator) 10 and is basically automatically connected / disconnected to reduce the load on the driver. On the other hand, in order to enable delicate clutch work at the time of a slight low speed reverse and sudden clutch disconnection in an emergency, manual connection / disconnection by the clutch pedal 11 is also possible. This is a so-called selective auto clutch configuration. A clutch stroke sensor 14 that detects the stroke of the clutch itself (that is, the position of the pressure plate 2b) and a clutch pedal stroke sensor 1 that detects the depression stroke of the clutch pedal 11.
6 and 6 are respectively connected to the TMCU 9.

As shown in FIG. 3, the clutch booster 10
Is connected to the air tank 5 through two lines of pneumatic passages a and b indicated by the solid line, and operates with the air pressure supplied from the air tank 5. One passage a is for automatic clutch connection / disconnection, and the other passage b is for clutch manual connection / disconnection. One passage a is bifurcated, and one of them is a solenoid valve M for automatic connection / disconnection.
VC1 and MVC2 are provided in series, and an emergency solenoid valve MVCE is provided on the other side. A double check valve DCV1 is provided at the branch / merge portion. A hydraulically actuated 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 confluence of both passages a and b. Double check valve DCV
Reference numerals 1 and DCV2 are differential pressure operated three-way valves.

The solenoid valves MVC1, MVC2 and MVCE
ON / OFF is controlled by the TMCU 9. 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 explained. The solenoid valve MVC1 simply turns on / off the ignition key.
It is only turned on / off according to. The ignition key is turned off, that is, turned off while 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 amount of supplied or discharged air. This is for controlling the connecting / disconnecting speed of the clutch.
When both the solenoid valves MVC1 and MVC2 are ON, the air pressure in the air tank 5 is supplied to the clutch booster 10 by switching the double check valves DCV1 and DCV2. This disconnects the clutch. When connecting the clutch, only the MVC 2 is turned off, whereby the air pressure of the clutch booster 10 is discharged from the MVC 2 and the clutch is connected.

By the way, if the solenoid valve MVC1 or MVC2 becomes abnormal during clutch disengagement, either of them is turned off.
In that case, the clutch is suddenly contacted 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 is switched to the double check valve DCV1 in the opposite direction and supplied to the clutch booster 10, the clutch disengaged state is maintained, and the clutch abrupt contact is prevented.

Next, the manual side will be described. Clutch pedal 1
The hydraulic pressure is supplied to and discharged from the master cylinder 13 in response to the stepping-in / returning operation of 1, and this hydraulic pressure is shown in a hydraulic passage 13a indicated by a broken line.
Is supplied to the hydraulically actuated valve 12 via. As a result, the hydraulically actuated valve 12 is opened and closed, air pressure is supplied to and discharged from the clutch booster 10, and the clutch 2 is manually connected and disconnected. When the hydraulically actuated valve 12 opens, the air pressure passing therethrough switches the double check valve DCV2 and reaches the clutch booster 10. When the automatic connection / disconnection of the clutch interferes with the manual connection / disconnection, the manual connection / disconnection is prioritized.

As shown in detail in FIG. 2, the transmission 3 is basically a so-called multi-stage transmission of a constant mesh type, and can shift to 16 forward gears and 2 reverse gears. Further, the transmission 3 itself has the same structure as the manual transmission. The transmission 3 is provided with a splitter 17 and a range gear 19 as an auxiliary transmission on the input side and the output side, respectively, and a main gear stage 18 between them. Then, the engine power transmitted to the input shaft 15 is sequentially sent to the splitter 17, the main gear stage 18, and the range gear 19 and output to the output shaft 4.

A gear shift unit GSU is provided for automatically shifting the transmission 3, and comprises a splitter actuator 20, a main actuator 21, and a range actuator 22, which are in charge of shifting the splitter 17, the main gear stage 18, and the range gear 19, respectively. . Like the clutch booster 10, these actuators are pneumatically operated and controlled by the TMCU 9. The current gear stage of the transmission 3 is detected by the gear position switch 23 (see FIG. 1). 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, the manual mode is set, and the manual shift is also possible based on the driver's shift change operation. In this case, as shown in FIG. 1, the engagement / disengagement control of the clutch 2 and the gear shift control of the transmission 3 are performed in response to a signal from a shift lever device 29 provided in the driver's seat. That is, the shift lever device 29 has a built-in shift switch (not shown) that outputs a signal in response to a manual operation of the shift lever 29a. When the driver shifts the shift lever 29a, the signal is sent to the TMCU 9. Based on this, the TMCU 9 appropriately operates the clutch booster 10, the splitter actuator 20, the main actuator 21, and the range actuator 22 to execute a series of gear shift operations. TMC
U9 displays the current gear on the monitor 31. In this way, as far as the manual mode is limited, such an automatic transmission is a remote-operated type manual transmission in which the shift control is performed by the TMCU 9 based on the output signal of the shift switch. That is, the manual transmission is automatically shifted to the driver's instruction stage without using a mechanical connecting means such as a shift cable.

In the shift lever device 29 shown in FIG. 1, R is reverse, N is neutral, D is drive,
UP means upshift, and DOWN means downshift, and when the shift lever 29a is operated to each position, a signal corresponding to those positions is output.
In the driver's seat, there is a mode switch 24 for switching the shift mode between automatic and manual, and whether the shift is performed step by step.
A skip switch 25 is provided for switching between step skipping.

In the automatic shift mode, the shift lever 29
If a is set in the D range, the gear shift is automatically performed according to the vehicle speed and the like. Also in this automatic shift mode, manual upshifting or downshifting is possible if the driver operates the shift lever 29a to UP or DOWN. In this automatic speed change mode, if the skip switch 25 is OFF (normal mode), the speed change is performed step by step. This is effective when the load is relatively large, such as when the trailer is towed. Also, the skip switch 25 is O
If N (skip mode), the shift is skipped by one gear. This is effective when the trailer is not towed or when the load is light.

On the other hand, in the manual shift mode, shifting completely complies with the driver's intention. Shift lever 29a
When is in the D range, gear shifting is not performed, the gear is currently held, and the driver is positively willing to shift the shift lever 29a to U.
Only when operated to P or DOWN, shift up or down is performed. Also at this time, similarly to the above, if the skip switch 25 is OFF, the gear shift is performed step by step, and if the skip switch 25 is ON, the gear shift is skipped by one step.

An emergency speed change switch 27 is provided in the driver's seat so that when the solenoid valve of the GSU or the like fails, the switch 27 can be manually switched to change the speed.

As shown in FIG. 2, 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 connected.
And are supported for relative rotation.

First, the configurations of the splitter 17 and the main gear stage 18 will be described. Split high gear SH on input shaft 15
Is rotatably mounted. Also the main shaft 33
Also, from the front, main gears M4, M3, M2, M1,
The MR is rotatably mounted. Gear S excluding MR
H, M4, M3, M2 and M1 are counter gears CH, C4, C3 fixed to the counter shaft 32, respectively.
It is always meshed with C2 and C1. The gear MR is constantly meshed with the idle reverse gear IR, and the idle reverse gear I
R is a counter gear C fixed to the counter shaft 32
Always meshed with R.

Splines 36 are integrally provided on the gears SH, M4 ... Attached to the input shaft 15 and the main shaft 33 so as to select the gears. Shaft 3
The first to the fourth splines 37 to 40 are fixedly installed at the position 3. The first to fourth sleeves 42 to 45 are provided so as to be always engaged with the first to fourth splines 37 to 40 and slidable in the front-rear direction (shift direction). By appropriately selecting and slidingly moving the first to fourth sleeves 42 to 45, and engaging and disengaging with the gear side spline 36, gear insertion and gear removal can be performed. The splitter actuator 20 moves the first sleeve 42, and the main actuator 21 moves the second to fourth sleeves 43 to 45.

In this way, the splitter 17 and the main gear stage 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 synchronizing mechanism, but the spline portion of the main gear stage 18 does not have a synchronizing mechanism. For this reason, when the main gear stage 18 is shifted, synchro control is performed to adjust the engine rotation and the gear speed so that they can be synchronized without the synchro mechanism. Here, in addition to the main gear stage 18, the splitter 17 is also provided with a neutral position to prevent so-called rattling noise (see Japanese Patent Application No. 11-319915).

Next, the structure 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 position or a low position. The planetary gear mechanism 34 includes a sun gear 65 fixed to the rear end of the main shaft 33, a plurality of planetary gears 66 meshed with the outer periphery of the sun gear 65, and a ring gear 67 having inner 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 integrally has a pipe portion 69, and the pipe portion 69 is relatively rotatably fitted to the outer periphery of the output shaft 4 and constitutes a double shaft together with the output shaft 4.

The fifth spline 41 is provided integrally with the pipe portion 69. An output shaft spline 70 is integrally provided on the output shaft 4 adjacent to the rear side of the fifth spline 41. A fixed spline 71 fixed to the mission 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 slidable back and forth. Fifth sleeve 46
Is moved by the range actuator 22. A synchro mechanism exists in each 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 mission case side, and the output shaft 4 is rotationally driven at a reduction ratio greater 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, it is possible to shift to two stages of high and low by the splitter 17, four stages of the main gear stage 18, and two stages of high and low by the range gear 19. It is possible to shift to 2 × 4 × 2 = 16 steps. On the reverse side, the splitter 17 alone can switch between high and low to shift gears in two steps.

Next, each actuator 20, 21, 22
Will be described. These actuators are composed of a pneumatic cylinder that operates by the pneumatic pressure of the air tank 5, and a solenoid valve that switches between supplying and discharging pneumatic pressure to the pneumatic cylinder. Then, these electromagnetic valves are selectively switched by the TMCU 9 to selectively operate the pneumatic cylinders. The splitter actuator 20 includes a pneumatic cylinder 47 having a double piston and three solenoid valves MVH, MVF, M.
And VG. MVH / ON, MVF / OFF, MVG / O when the splitter 17 is set to neutral
N. MVH to turn splitter 17 high
/ OFF, MVF / OFF, MVG / ON. MVH / OFF, MV to turn 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 the operation on the select side.
8 and a pneumatic cylinder 49 having a single piston and in charge of the shift side operation. The pneumatic cylinder 48 is provided with three solenoid valves MVC, MVD and MVE, and the pneumatic cylinder 49 is provided with two solenoid valves MVB and MVA.

The select side pneumatic cylinder 48 is MVC /
When it is OFF, MVD / ON, MVE / OFF, it moves to the lower part of the figure, and 3rd, 4th or N3 of the main gear can be selected, MVC / ON, MVD / OFF, MVE / O.
When it is N, it becomes neutral as shown in the figure and the 1st of the main gear,
2nd or N2 can be selected, MVC / ON, MVD
When / OFF or MVE / OFF, it moves to the upper part of the figure and Rev or N1 of the main gear can be selected.

The shift side pneumatic cylinder 49 is equipped with an MVA / O.
When N and MVB / ON, it becomes neutral and N of main gear
1, N2 or N3 can be selected, MVA / ON, MV
When B / OFF, move to the left side of the figure, 2n of the main gear
Selectable d, 4th or Rev, MVA / OF
When 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 22 includes a pneumatic cylinder 50 having a single piston and two solenoid valves MV.
I and MVJ. Pneumatic cylinder 50 is MV
When I / ON or MVJ / OFF, the range gear is moved to the right side, and the range gear is set to high. When MVI / OFF or MVJ / ON, the range gear is moved to the left side, and the range gear is set to low.

By the way, in order to brake the counter shaft 32 during the above-mentioned synchronizing control, the counter shaft 3
A counter shaft brake 27 is provided at 2. The counter shaft brake 27 is a wet multi-plate brake and operates by the air pressure of the air tank 5. A solenoid valve MV BRK is provided to switch between supply and discharge of this pneumatic pressure. When the solenoid valve MV BRK is ON, air pressure is supplied to the counter shaft brake 27, and the counter shaft brake 27
Is activated. When the solenoid valve MV BRK is off, air pressure is discharged from the counter shaft brake 27, and the counter shaft brake 27 is deactivated.

Next, the contents of the automatic shift control will be described. T
The MCU 9 stores the shift-up map shown in FIG. 4 and the shift-down map shown in FIG.
9 executes the automatic shift according to these maps in the automatic shift mode. For example, in the shift-up map of FIG. 4, the shift-up diagram from the gear stage n (n is an integer from 1 to 15) to n + 1 is the accelerator opening (%) and the output shaft (output shaft) rotation speed (rpm).
) Is determined by the function. Then, on the map, only one point is determined from the current accelerator opening (%) and output shaft speed (rpm). During vehicle acceleration, the rotation speed of the output shaft 4 connected to the drive wheels gradually increases. Therefore, in the normal automatic shift mode, every time one current point exceeds each diagram, the gear is shifted up one step. At this time, if the mode is the skip mode, the lines are alternately skipped one by one and upshifted by two steps.

Similarly, in the shift-down map of FIG. 5, gears n + 1 (n is an integer from 1 to 15) to n
The shift-down diagram for is determined by the function of accelerator opening (%) and output shaft speed (rpm). And on the map, the current accelerator opening (%) and output shaft speed (rpm)
) And only one point is decided. Since the rotation speed of the output shaft 4 gradually decreases during deceleration of the vehicle, in the normal automatic transmission mode, the gear is downshifted by one step each time one current point exceeds each diagram. In the skip mode, the charts are alternately skipped one by one and downshifted by two steps.

On the other hand, in the manual mode, the driver can freely shift up / down regardless of these maps. In the normal mode, one shift change operation allows one speed change, and in the skip mode, one shift change operation allows two speed change. 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. Especially TM
The CU 9 converts the current vehicle speed from the current output shaft speed value and displays this on the speedometer. That is, the vehicle speed is indirectly detected from the output shaft rotation speed, and the output shaft rotation speed and the vehicle speed correspond to each other.

As shown in FIG. 1, a trailer detector 80 for detecting whether a trailer is connected to the rear portion of the tractor is connected to the automatic transmission. The trailer detector 80 is provided in the rear part of the tractor, and is provided in the tractor side connecting mechanism 81 for fitting the trailer connecting mechanism (not shown) to connect the trailer, and the tractor side connecting mechanism 81. Contact type or optical type connection switch 82 for detecting the fitting of the connection mechanism of FIG. The connection switch 82 detects whether the trailer connecting mechanism is fitted, that is, whether the trailer is connected, and outputs the signal to the TMCU 9.

The outline of the automatic transmission according to the present embodiment has been described above. The starting stage in the automatic transmission mode, which is the gist of the present invention, will be described below.

First, in the TMCU 9, a gear stage suitable for normal starting, that is, a normal starting stage is set and stored in advance. In the present embodiment, since the vehicle is a tractor that can connect the trailer, the tractor is set depending on whether the trailer is connected or not. Here, the normal start stage is 4 speed when the trailer is connected, and the normal start stage when the trailer is not connected. The starting gear is set to 9th speed. The TMCU 9 automatically selects the normal start stage when the trailer is connected or the normal start stage when the trailer is not connected according to the detection result of the trailer detector 80.

Although the vehicle normally starts at this normal start stage, the automatic transmission of the present embodiment is further suitable for the driver's vehicle condition (loaded condition, etc.) and vehicle condition. It is equipped with a learning function for the starting gear so that it is possible to select a desired gear and start. When the driver performs the learning operation of the starting stage, regardless of the normal starting stage, the learning starting stage (the starting stage that the driver selects according to his or her will, hereinafter referred to as the selected starting stage) regardless of the normal starting stage.
It is to take off. For example, when starting a steep slope, a smoother start can be achieved by selecting and learning a lower speed stage than the normal start stage as the start stage.

The learning control of the selective starting stage will be described with reference to FIG.

First, in step S1, the vehicle speed = 0 km based on the value detected by the output shaft rotation sensor 28.
/ H, that is, whether the vehicle is stopped.
If the vehicle is not stopped, it is not necessary to learn the starting stage, and the process ends. When it is determined that the vehicle is stopped, the process proceeds to step S2, and it is determined whether or not the brake pedal is depressed by a signal from a brake switch (not shown) provided on the brake pedal. The depression of the brake pedal is set to determine the learning permission, and the depression of the brake pedal means that the driver wants to learn the starting stage.
Therefore, if the depression of the brake pedal is not detected, the process ends. The start stage learning permission can be determined by providing an independent learning switch and performing learning only when the driver presses the learning switch, but if the determination is made by depressing the brake pedal, the number of parts can be reduced. It has the advantage of not increasing.

When the depression of the brake pedal is detected, the routine proceeds to step S3, where it is judged if the accelerator opening is 0%. If the accelerator opening is not 0%, that is, if the accelerator pedal is depressed, it is possible that the driving situation is not normal, for example, when the vehicle is starting up a slope, and the learning is not performed. If the accelerator pedal is not depressed, the process proceeds to step S4, and it is determined whether or not the vehicle stop time has passed a predetermined time (for example, 1.5 seconds). This is to prevent unnecessary learning at the time of a temporary stop at a temporary stop line or railroad crossing. Therefore, learning is not performed unless the vehicle is stopped for a predetermined time or longer. If it is determined that the vehicle has stopped for a predetermined time or more, the process proceeds to step S5, and it is determined whether the current gear is neutral. When the gear is in neutral, learning is not performed because it is not in the control state for start preparation. If the current gear is not neutral, that is, if the gear is in one of the 1st to 16th gears, the process proceeds to step S6, and whether the trailer is currently connected by the signal output from the trailer detector 80. Determine whether When it is determined that the trailer is connected, the process proceeds to step S7, the current gear is stored as the selected start stage when the trailer is connected, and the process ends. On the other hand, if it is determined that the trailer is not connected, the process proceeds to step S8, the current gear is stored as the selected starting stage when the trailer is not connected, and the process ends. After the learning of the selected starting stage, basically, the selected starting stage corresponding to the connection / non-connection of the trailers is automatically selected and started.

Further, in this embodiment, in order to prevent the driver from intentionally or inadvertently selecting an extremely high speed gear stage and placing a heavy load on the clutch 2 etc. at the time of starting, the selected start stage is selected. An upper limit function is provided.

This will be described with reference to FIG. 7. First, in step S11, it is determined based on the value detected by the output shaft rotation sensor 28 whether vehicle speed = 0 km / h (vehicle stopped). If the vehicle is not stopped, the process ends. When it is determined that the vehicle is stopped, the process proceeds to step S12, and it is determined whether there is a shift request from a signal from the shift switch of the shift lever device 29. If there is no shift request, that is, if the driver is not operating the shift lever device 29, the process ends. If it is determined that there is a shift request, the process proceeds to step S13, where the trailer detector 80
The signal from determines if the trailer is currently connected. When it is determined that the trailer is connected, the process proceeds to step S14, and the upper limit value when the trailer is connected is set as the upper limit value (sixth speed in the present embodiment).
Select. On the other hand, if it is determined that the trailer is not connected, the process proceeds to step 15 and a preset upper limit value when the trailer is not connected (11th speed in this embodiment) is selected as the upper limit value. Next, the routine proceeds to step S16, where the target gear stage according to the driver's shift request is step 1
4 or it is determined whether the speed is higher than the upper limit selected in step 15. When the target gear speed is higher than the upper limit value, it means that an inappropriate gear speed is selected as the selected start speed, and therefore the gear shift is prohibited. In this case, the current gear may be maintained as the gear, or one of the gears lower than the upper limit may be selected. If it is determined that the target gear is equal to or less than the upper limit value, the gear shift is permitted because it is a gear that has no problem as the selected start gear.

As described above, by providing the upper limit function, it is possible to prevent the gear stage which is inappropriate as the selective starting stage from being selected and learned.

In the present invention, when a low speed stage is selected as the above-described selected start stage from the normal start stage, it can be considered that the start is under a special situation such as a steep slope start, and such a situation is possible. When a predetermined condition (a condition that can be regarded as having exited a special situation) is satisfied after the vehicle has started at the selected start stage, the driver's burden is reduced by automatically returning the start stage to the normal start stage. .

This will be described below with reference to FIG. FIG. 8 is a flow chart showing a starting stage automatic return control program by the TMCU 9.

First, in step 101, it is determined from the signal from the trailer detector 80 whether the trailer is currently connected. When it is determined that the trailers are connected, the process proceeds to step S102, and the value when the trailers are connected is selected as the normal start stage. That is, in the present embodiment, it is the fourth speed. On the other hand, when it is determined that the trailer is not connected, the routine proceeds to step 103, where the value when the trailer is not connected is selected as the normal start stage. That is, in the present embodiment, the speed is 9th.

Next, the routine proceeds to step 104, where it is determined whether the present starting gear is a lower speed than the normal starting gear.
In the present embodiment, it is determined whether or not the current start gear stage ≦ normal start stage-2nd speed. If the current start stage is the normal start stage, this condition is not satisfied and the process ends. Further, the current start stage is the selected start stage by the learning operation of the driver, and the selected start stage> normal start stage-
If it is in the 2nd speed, it ends. On the other hand, if the current start stage is the selected start stage and it is determined that the selected start stage ≦ normal start stage-the second speed, that is, in the present embodiment, the second speed or less when the trailer is connected, When it is determined that the vehicle is in the 7th speed or lower when the trailer is not connected, the process proceeds to step S105, and it is determined whether the vehicle speed is not 0 km / h based on the value detected by the output shaft rotation sensor 28. Vehicle speed =
When it is 0 km / h, it means that the vehicle has not started yet, so the process ends. If it is determined that the vehicle speed is not 0 km / h, the process proceeds to step S106, where the current gear is a preset gear (in the present embodiment, 4th and 9th, which are normal start stages both when the trailer is connected and when the trailer is not connected). ) Determine if it is a higher speed. That is, this step S106 is a step of determining whether or not the vehicle has exited the special state. If the current gear is lower than the set value, it can be considered that the vehicle has exited the special state. It ends because there is no. Therefore, when the vehicle tries to stop in this state, the vehicle is automatically downshifted to the selected starting stage, and the vehicle will start at the selected starting stage even when the vehicle is next started.

On the other hand, when it is determined that the current gear is higher than the set value, that is, in the present embodiment, it is determined that the gear has been shifted up beyond the normal starting gear, the vehicle is out of the special situation. Since it can be regarded, the process proceeds to step S107, and the starting stage is automatically returned to the normal starting stage. Therefore, if the vehicle tries to stop in this state, the gear is automatically changed to the normal start stage, and at the next start, the vehicle starts at the normal start stage according to the trailer connection / non-connection.

As described above, according to the present invention, after the vehicle is started at the selected starting stage which is used only under special circumstances, it is automatically judged whether or not the vehicle has exited the special situation, and the special situation is exited. If it is determined that the start stage is automatically returned to the normal start stage, it is not necessary for the driver to determine the situation in which the vehicle is placed, and it is not necessary to perform the operation of returning to the normal start stage. Therefore, the load on the driver at the time of starting can be significantly reduced.

Here, the determination condition of step S104 is
Although it has been described that the starting gear stage ≦ the normal starting stage-the second gear, the present invention is not limited in this respect. In other words, if the starting gear is lower than the normal starting stage, it can be considered as starting under special circumstances, so various conditions such as starting stage ≤ normal starting stage and starting stage ≤ normal starting stage-3 speed can be set. Is.

Further, the determination condition of step S106 for automatically returning to the normal starting stage is not limited to that of this embodiment. In other words, it can be considered that the special situation is exited if the gear is shifted up to at least the normal start stage, so various conditions are set such as the current gear ≧ normal start stage + 1 speed, or upshifting a predetermined number of stages after starting. It is possible.

Further, the condition for automatically returning to the normal starting stage may be determined by the vehicle speed. For example,
After the vehicle has started, the vehicle speed is somewhat high (for example, 50 km /
If it rises to h), it can be considered that the special situation is exited, and this may be set as the condition of step S106. Further, the vehicle speed setting in this case is set in the shift-up map of FIG. 4 when the gear stage is set as a condition (for example, the set value in step S106 = 4).
If the vehicle speed is set to a range covered by the fifth speed and the ninth speed, the conditions can be substantially the same as the case where the gear stage is used as the condition.

Further, the normal starting stage may be set and changed appropriately.

Further, the present invention is not limited to the automatic transmission having the starting gear learning function, and it is needless to say that the present invention can be applied to the type having no learning function.

Further, the vehicle to which the present invention is applied is not limited to the tractor to which the trailer can be connected.

[0070]

According to the present invention, the excellent effect that the load on the driver at the time of starting can be reduced is exhibited.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an automatic transmission for a vehicle according to an embodiment.

FIG. 2 is a configuration diagram showing an automatic transmission.

FIG. 3 is a configuration diagram showing an automatic clutch device.

FIG. 4 is a shift-up map.

FIG. 5 is a shift-down map.

FIG. 6 is a flow chart of start stage learning control.

FIG. 7 is a flowchart illustrating an upper limit function of start stage selection.

FIG. 8 is a flow chart of start stage automatic return control.

[Explanation of symbols]

2 clutch 3 transmission 6 ECU 9 TMCU 80 Trailer detector 81 Tractor side connection mechanism 82 Connection switch

Claims (4)

[Claims] 1. An automatic transmission including a normal start stage set to a second speed or higher as a start stage of a vehicle, and a selectable start stage selectable in place of the normal start stage. An automatic transmission, characterized in that, when a vehicle is started at a selected starting speed lower than a speed, and the vehicle is shifted up to a predetermined gear or higher, the starting speed is automatically returned to the normal starting speed. 2. The automatic transmission according to claim 1, wherein the predetermined gear stage is a normal start stage. 3. An automatic transmission including a normal starting stage set to a second speed or higher and a selectable starting stage selectable in place of the normal starting stage as a starting stage of a vehicle. An automatic transmission, characterized in that, when a vehicle starts at a selected starting speed lower than a speed, and the vehicle speed exceeds a predetermined speed, the starting speed is automatically returned to the normal starting speed. 4. The vehicle is a tractor capable of connecting a trailer to a rear portion thereof, and is provided with detection means for detecting connection / disconnection of the tractor, and the normal start stage is not connected when the tractor is connected. The automatic transmission according to any one of claims 1 to 3, wherein different values are set depending on time, and the normal start gear is automatically selected according to the detection result of the detection means.