JPH056064B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a synchronized mesh automatic transmission that determines the optimum gear position based on the vehicle speed and the amount of depression of the accelerator pedal, and shifts the transmission to the optimum gear position. Regarding.

[Conventional technology]

Conventional synchronized mesh automatic transmissions set the optimum gear position based on the vehicle speed and the amount of depression of the accelerator pedal using a shift map stored in the memory of the electronic control unit. If you follow this shift map, after accelerating and shifting to 2nd gear, when driving from about 10km/h to 20km/h,
During normal driving, the vehicle remains in 2nd gear, but if the accelerator pedal is pressed too hard to accelerate suddenly, the vehicle will pass the shift point and shift down to 1st gear. On the other hand, the shift time at this time varies depending on the oil temperature of the transmission, as shown in FIG. 6, due to the characteristics of the synchronous mesh mechanism. In other words, when the oil temperature is lower than the set temperature, the viscosity of the oil is high;
The time required to synchronize gears and mesh with gears in other stages during gear changes increases. The oil temperature in the transmission will rise to about 30℃ to 80℃ after driving for a certain period of time, but it will rise to -20℃ to 15℃ immediately after starting in winter etc.
Therefore, as mentioned above, the shift time becomes extremely long.

Therefore, as mentioned above, when attempting to shift down to 1st gear when the oil temperature is low, the shift itself takes time, resulting in a significant delay in acceleration. In some cases, it may be preferable to accelerate while the

The purpose of the present invention is to detect the oil temperature of the transmission, and when the oil temperature is high, it is possible to shift down to 1st gear according to a shift map that matches the driving performance of the vehicle, while at low temperatures, the shift time becomes longer. In order to prevent delays in acceleration, downshifting to a lower gear is prohibited when the vehicle speed is higher than a set vehicle speed, thereby ensuring stable shift performance.

[Means for solving problems]

The present invention detects the oil temperature of the transmission, and when the oil temperature is high, it is possible to shift down to 1st gear according to the shift map that matches the vehicle's driving performance, while when the oil temperature is low, it is possible to shift down to 1st gear due to the longer shift time. In order to prevent delays, downshifting to lower gears is prohibited to ensure stable gear shifting performance.

By the way, when driving on a steep slope, 10
At Km/h to 20 Km/h, torque is insufficient and in such a case sufficient acceleration performance cannot be obtained, so acceleration by kickdown is required. If automatic downshifting to a low gear is prohibited, the driver will be required to operate the selector lever to first gear at this time. In order to cope with such a situation, the invention of claim 2 enables automatic downshifting when the vehicle speed falls below a set value.

[Effect]

In the present invention, when the optimum gear position, that is, the gear selection stage determined based on the vehicle speed and the amount of depression of the accelerator pedal, is lower than the current gear stage, when the accelerator pedal is depressed to accelerate, the oil temperature of the transmission increases. If it is below the set value, the electronic control unit controls the transmission actuator to continue to hold the gear in the current gear. Therefore, a shift delay due to gear shift is prevented, and acceleration is started from the current gear. In addition, in the invention of item 2, when climbing a steep slope where the vehicle speed decreases,
The gears are automatically downshifted, allowing for rapid acceleration and high torque performance.

〔Example〕

FIG. 1 is a block diagram of an embodiment for realizing the present invention. In the figure, 1 includes a throttle valve for controlling the amount of intake gas (air or mixture) in the engine, and a flywheel 1a. Equipped with. Reference numeral 2 represents a clutch body, which is composed of a well-known friction clutch and has a release lever 2a, and 3 represents a clutch actuator, whose piston rod 3a is connected to the release lever 2a in order to control the amount of engagement of the clutch body 2. It is what drives the. 4 is a hydraulic mechanism, and 5 is a transmission actuator, which will be described later. Reference numeral 6 denotes a synchronous mesh type transmission, which is driven by a transmission actuator 5 to perform a gear change operation, and includes an input shaft 6a connected to the clutch 2, an output shaft (drive shaft) 6b, and a gear position (gear position). ) is provided with a gear position sensor 6c for detecting. 7 is a select lever, which is operated by the driver;
"N" range (neutral position), "D" range (automatic shift), "1" range (1st speed), "2" range (2nd speed),
"3" range (1st, 2nd, 3rd automatic transmission), "R"
Each range (reverse) can be selected by the lever position, and a selection signal SP indicating the selected range is outputted by the selection sensor 7a. 8a is a rotation sensor for detecting the rotation speed of the simple shaft 6a;
8b is a vehicle speed sensor for detecting the vehicle speed from the rotation speed of the drive shaft 6b, and 10 is an engine rotation sensor for detecting the rotation speed of the engine 1 by detecting the rotation speed of the flywheel 1a. It is something. Reference numeral 9 denotes an electronic control device composed of a microcomputer, which includes a processor 9a that performs arithmetic processing, a read-only memory (ROM) 9b that stores a control program for controlling the transmission 6 and the clutch 3, and an output port 9c. , an input port 9d, a random access memory (RAM) 9e that stores calculation results, etc., and an address/data bus (BUS) 9f that connects these. The output port 9c is connected to the clutch actuator 3, the hydraulic mechanism 4, and the transmission actuator 5, and receives a drive signal to drive these.
Output CDV, PDV, ADV.

On the other hand, the input port 9d has various sensors 6c,
It is connected to 7a, 8a, 8b, 10 and an accelerator pedal and a brake pedal, which will be described later, and receives detection signals from these pedals. 11 is an accelerator pedal, and a sensor 1 detects the amount of depression of the accelerator pedal 11.
1a (potentiometer), 12 is a brake pedal, and has a sensor 12a (potentiometer) for detecting the amount of depression of the brake pedal 12.

FIG. 2 is a block diagram of the aforementioned clutch, transmission actuators 3 and 5, and hydraulic mechanism 4. In the figure, T
is a tank, P is a hydraulic pump, V ₁ is an on-off valve,
These constitute the hydraulic mechanism 4.

The clutch actuator 3 is a cylinder 33
, a piston 31, and piston rods 31a, 3a, which have one end connected to the piston 31 and the other end connected to the release lever 2a of the clutch 2,
The chamber 33a is connected to the pump P (on-off valve _V1) via the on-off valve _V2 .
via the on-off valve V 3 and the tank T via the on-off valve V ₃ and the pulse-controlled on-off valve V ₄
communicate with. Note that the chamber 33b is piped so as to always communicate with the tank T side. Note that 34 is a position sensor that detects the position of the piston rod 31a and outputs the amount of engagement of the clutch 2.

Therefore, when the on-off valve _V2 is opened by the drive signal CDV1, hydraulic pressure is applied to the chamber 33a, and the piston 3
1 moves to the right and turns off the clutch,
When the on-off valves V ₃ and V ₄ are opened by the drive signals CDV2 and CDV3, the oil pressure in the chamber 33a is released, the piston 31 moves to the left, and the clutch 2 is turned on.
Since the on-off valve _V4 is pulse-driven by the drive signal CDV3, the clutch 2 is gradually turned on (closed).

The transmission actuator 5 includes a select actuator 50 and a shift actuator 55. The select and shift actuators 50 and 55 are configured to be able to stop at three positions, including stepped cylinders 53 and 58, first pistons 51 and 56,
the first pistons 51 and 56; a cylindrical second piston 52 that fits into the first piston 31;
and 57, and the rods 51a and 56a of the first piston are engaged with an internal lever of the transmission 6 (not shown). Both the actuators 50 and 55 have their stepped cylinders 5
3 and 58, respectively, both chambers 53a, 53b and 5.
When hydraulic pressure is applied to chambers 8a and 58b, they are in the neutral state shown in the figure, and when hydraulic pressure is applied to chambers 53a and 58a, the first pistons 51 and 56 move to the right in the figure together with the second pistons 52 and 57. Furthermore, when hydraulic pressure is applied to the chambers 53b and 58b, only the first pistons 51 and 56 move to the left in the figure.

The chambers 53a and 53b of the select actuator 50 communicate with the pump P (via the on-off valve _V1 ) or the tank T via flow path switching valves _V5 and _V6 , respectively. Further, the shift actuator 5
The chambers 58a and 58b communicate with the pump P (via the on-off valve _V1 ) or the tank T via flow path switching valves _V7 and _V8 , respectively.

Therefore, in the state shown in the figure, the transmission 6 is in a neutral state, and the flow path switching valve is activated by the drive signal ADV4.
When _V7 is connected to the pump P side and the flow path switching valve _V8 is connected to the tank T side by the drive signal ADV3, the transmission becomes 4th speed. When a shift signal from the fourth speed to the fifth speed is received, first, the drive signals ADV3 and ADV4 connect the flow path switching valves _V8 and ₇ to the pump P side, so that the shift actuator 55
Return to the neutral state shown. Next, drive signal ADV1
, the flow path switching valve V ₆ is moved to the pump P side, and the drive signal is
ADV2 connects the flow path switching valve _V5 to the tank T side, and operates the select actuator 50 to the 5th speed-reverse select position. Then the drive signal
ADV3 connects the flow path switching valve _V8 to the pump P side, drive signal ADV4 connects the flow path switching valve _V7 to the tank T side, operates the shift actuator 55 to the 5th gear position, and shifts the transmission to the 5th gear position. Shift to 5th gear.

In this way, the drive signals ADV1, ADV2 and
Shift operation to each gear stage is performed by operating flow path switching valves V ₆ , V ₅ and V ₈ , V ₇ by ADV 3 and ADV 4, and alternately operating select actuator 50 and shift actuator 55. It can be performed.

Next, the operation of the configuration shown in FIG. 1 will be explained.

First, the select lever 7 is operated to the "D" range, and when the selection signal SP for the "D" range is input from the position sensor 7a to the input port 9d, the processor 9a reads it via the BUS 9f.
Store in RAM9e. Next, the processor 9a outputs a drive signal ADV to the transmission actuator 5 from the output port 9c to drive the transmission actuator 5 and shift the transmission 6 to the first speed.

The processor 9a receives the selected gear signal GP from the gear position sensor 6c via the input port 9d,
Detecting that the transmission 6 has been shifted to 1st speed,
This is stored in RAM9e.

Next, the processor 9a outputs the clutch drive signal.
CDV is sent to the clutch actuator 3 through the output port 9c, and the clutch actuator 3
, the piston rod 3a is gradually moved to the left, and the release lever 2a is gradually driven to the left. This causes clutch 2 to move to a
As shown, the amount of engagement of the clutch 2 changes, and the clutch 2 changes from a disengaged state to a half-clutch state to an engaged state. This causes the vehicle to start.

From then on, set the vehicle speed V, accelerator pedal depression amount AP, and selector lever 7 selection signal SP as follows.
The optimum gear position is determined according to the following, and the disguise operation is executed.

This will be explained using the processing flow diagram of an embodiment according to the present invention shown in FIG.

This processing flow is described as corresponding to the invention in Section 2. The flow of the invention described in item 1 corresponds to one in which the vehicle speed determination in 1), m), and n) described below is omitted.

a First, a selection signal SP indicating the selection range of the selector lever 7 is received from the input port 9d, and the processor 9a discriminates this. If the selection signal SP is in the neutral (N) range, the gear command
GEAR: Set OPT to “N”.

b When the processor 9a determines that the selection signal SP is in the reverse (R) range, it then determines the vehicle speed V. This vehicle speed V periodically receives a detection pulse WP from the vehicle speed sensor 8b from the input port 9d, and the processor 9a periodically calculates the vehicle speed V and stores it in the RAM 9e, so the vehicle speed V is read out and determined whether it is zero or not. do. If the vehicle speed V is zero, the vehicle is stopped, so the gear command
GEAR: Set OPT to “R”. Conversely, if the vehicle speed V is not zero, the vehicle is moving, so the process ends without performing any processing.

c When the aforementioned selection signal SP is not in the "N" or "R" range, and furthermore not in the 3rd speed "3" or "D" range, it is in the "1" or "2" range, so the selection signal SP Gear selection signal GOPT to RAM9e
Store as . Next, the downshift limit vehicle speed RT set for each gear is retrieved from the table provided in ROM9b, and this and the above-mentioned
Compare with vehicle speed V of RAM9e. Processor 9
a is RT<V, that is, if the vehicle speed V is above the downshift limit vehicle speed, the engine speed will overrun, so in order to specify one or more gears, add "1" to GOPT to select the gear. Let the signal be GOPT. RT≧V to processor 9
If a is determined, the gear selection signal GOPT is set to the gear command GEAR:OPT.

d When the processor 9a determines that the selection signal SP is in the "3" or "D" range, it then performs cold time correction.

That is, the processor 9a detects whether the water temperature is at room temperature or not at room temperature (cold) based on a water temperature signal from a sensor (not shown) that detects the water temperature during engine cooling, and if it is cold, the processor 9a detects the detected accelerator pedal depression amount.
A predetermined value α is added to AP and stored as the accelerator amount APP in RAM9e. Conversely, if the temperature is normal, the detected accelerator pedal depression amount AP is directly stored in the RAM
Store it in 9e as the accelerator amount APP.

e Next, the processor 9e detects the current gear position GP of the transmission 6 from the gear position sensor 6c via the input port 9d, and determines whether the gear position GP is neutral. If the gear position GP is neutral, control is in progress in a deceleration state, so the process proceeds to step i, which will be described later.

f On the other hand, if the gear position GP is not neutral,
The processor 9a determines whether the accelerator pedal depression amount AP is greater than or equal to the set value APS. If AP is less than APS, the previous accelerator pedal depression amount AP (t-1)
and the current accelerator pedal depression amount AP(t)
Ask for APD. If this difference APD is not zero, it is assumed that the output of the sensor 11a is not stable, and the process ends without performing any processing.

Conversely, if the difference APD is zero (i.e., sensor 11
If the output of a is stable) and AP>APS
In this case, proceed to the next shift map search step.

g The processor 9a searches the shift map from the speed V of the RAM 9e and the accelerator amount AP, and determines the optimum gear position.

That is, as shown in FIG. 3, the ROM 9b stores a shift map corresponding to the vehicle speed and the accelerator amount APP as a table. In the figure,
.

First, use the upshift map to find the highest gear that can be shifted up from the vehicle speed V and the accelerator amount APP, and send a gear selection signal to RAM9e.
Store as GOPT.

h Next, the processor 9a compares the gear position GP of the RAM 9e detected via the input port 9d with the gear selection signal GOPT. Processor 9
a is GOPT>GP, that is, when shifting up,
Gear selection signal GOPT to gear command GEAR:OPT
shall be.

i On the other hand, when GP≧GOPT, upshifting is not possible, so use the downshift map of the shift maps in ROM9b to adjust the vehicle speed V and accelerator amount.
The lowest gear position that can be downshifted is determined from the APP and stored as the gear selection signal GOPT in RAM9e.

j Next, the processor 9a compares the gear position GP in the RAM 9e with the gear selection signal GOPT. GP
If ≦GOPT, downshifting is not possible, so the process ends without doing anything.

On the other hand, when GP>GOPT, that is, when downshifting is possible, the processor 9a detects whether the gear selection signal GOPT is in 1st gear, and if it is in 2nd gear or higher, the processor 9a detects whether the gear selection signal GOPT is in 1st gear or higher.
Set the gear command GEAR:OPT to drive in the second or higher gear.

l On the other hand, when the gear selection signal GOPT is 1st gear (GOPT=1), the processor 9a determines whether or not the current vehicle speed V is lower than the set vehicle speed (V≦V ₀ ), and if it is low or If they are equal, GEAR:OPT is set as the first gear selection signal GOPT.

m Also, if the vehicle speed V exceeds the set vehicle speed _V0 , V>
When _V0 , the processor 9a checks whether the oil temperature of the transmission has cooled down to below the set temperature. If the oil temperature is warmer than the set temperature, that is, if the oil has a viscosity that does not require time to shift, the gear command GEAR:OPT is held at first gear.

However, if V>V ₀ and the oil temperature of the transmission is below the set temperature, and there is a high possibility that the shift operation will be delayed, the processor 9a sets the gear selection signal GOPT to 2nd speed. The gear selection signal GOPT at this time is set as the gear command GEAR:OPT.

In this way, when the vehicle speed is below the set value and the oil temperature is below the set value, the 2nd gear is not shifted from 2nd gear to 1st gear.
It will enter acceleration mode while maintaining speed.

o When the gear command GEAR:OPT is determined in this way, the processor 9a outputs the clutch drive signal.
By sending CDV to the clutch actuator 3 through the output port 9c, hydraulic pressure is applied to the chamber 33a of the cylinder 33 of the clutch actuator 3, thereby causing the piston rods 3a, 3
1a to the right, and release lever 2.
Return the clutch a to the right and gradually release the clutch as shown in b of Fig. 4. Next, the processor 9a sends a drive signal ADV for selecting the determined gear command to the transmission actuator 5 via the BUS 9f and the output port 9c.

As a result, the transmission actuator 5 is connected to the above-mentioned hydraulic mechanism 4, and the built-in select and shift actuators 50, 55 are hydraulically controlled to operate the transmission 6 and synchronously engage the desired shift/disengagement.

p Next, at the end of the gear shifting operation, the processor 9a sends the clutch drive signal CDV to the clutch actuator 3 as at the time of starting described above to close the clutch.

The above operations are performed periodically, and automatic gear change operations and gear changes depending on whether kickdown is possible or not are performed appropriately.

〔Effect of the invention〕

As explained above, according to the present invention, the processor of the electronic control unit determines and outputs the optimum gear stage based on the vehicle speed signal from the vehicle speed sensor and the accelerator depression amount signal from the accelerator pedal sensor. When controlling the transmission to its optimum gear, the system detects the oil temperature in the transmission, and when the oil temperature is high, it can shift down to a lower gear, such as 1st gear, according to a shift map that matches the vehicle's driving performance. On the other hand, when the temperature is low, downshifting to first gear is prohibited, allowing stable acceleration. Also,
The same effect can be obtained by performing the same process for kicking down from 3rd gear to 2nd gear. Furthermore, according to the invention of item 2,
When driving up a steep slope, the vehicle automatically kicks down, eliminating the need to operate the selector lever.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment for realizing the present invention, FIG. 2 is a block diagram of main parts in the configuration shown in FIG. 1,
FIG. 3 is an explanatory diagram of the shift map in the configuration shown in FIG. 1, FIG. 4 is an explanatory diagram of clutch operation in the configuration shown in FIG. 3 is a shift time graph showing the difference in shift time with respect to vehicle speed. In the diagram, 1...engine, 2...clutch, 6...
...Transmission, 7...Selector lever, 8b...Vehicle speed sensor, 9...Electronic control unit, 11...Accelerator pedal, 11a...Accelerator pedal sensor.

Claims (1)

[Scope of Claims] 1. An automatic transmission having a synchronous meshing mechanism, comprising means for determining an optimum gear position based on the vehicle speed and the amount of depression of the accelerator pedal, and means for shifting the transmission to the optimum gear position, When the means for detecting the oil temperature of the transmission and the means for determining the optimum gear when the oil temperature of the transmission is below a set value determine that the optimum gear is equal to or lower than the current gear. An automatic transmission device characterized in that it has control means for inhibiting downshifting and maintaining the current gear. 2. In the automatic transmission device according to claim 1, when the vehicle speed is below a set value, the optimum gear is determined to be below the current gear even though the oil temperature is below the set value. automatic transmission configured to downshift to that gear if the