JPH02180360A - Automatic transmission control device - Google Patents

Abstract

PURPOSE:To select optimum engine brake condition certainly by determining optimum gear shift position from a pre-stored memory map for car speed vs brake pedal stamping amount when idling condition is sensed, and thereupon performing shift control. CONSTITUTION:When an accel. pedal stamping amount sensing means 11a has sensed idling condition, a control device 9 determines optimum gear shift position in accordance with the car speed give by a car speed sensing means 8 and the brake pedal 12 stamping amount given by a brake stamping amount sensing means 12a by reference to a memory map for cap speed vs brake stamping amount stored previously in a RAM 9e, and thereupon performs shift control of a transmission 6. This does not require any foot brake force, and when the driver wants to apply brakes, engine brake in accordance therewith can be obtained, which provides safe driving operation.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an automatic transmission control device, and particularly to a control device for an electronically controlled automatic transmission.

[Conventional technology]

In conventional automatic transmissions, when the accelerator pedal is released to activate the engine brake, there are generally two methods: (1) maintaining the current gear and applying the engine brake, and (2) applying the engine brake in response to a decrease in vehicle speed. The engine brake is activated while downshifting to a lower gear.

[Problems to be Solved by the Invention] In such conventional automatic transmissions, in the method (1) above, when the vehicle speed is high and the gear is held in a high speed gear, engine braking force is insufficient. For this reason, the foot brake is often used, which increases the load on the mat brake, causing early wear of the brake lining and band.Also, with method (2) above, when downshifting to a low gear, timing is difficult and Engine braking may be applied too strongly when downshifting than the driver expects, or downshifting late in the day may result in insufficient engine braking and put a strain on the brake pads, which will also accelerate the wear of brake linings and pads. There was a problem.

In light of the above, an object of the present invention is to provide an automatic transmission control device that can operate the engine brake in response to the vehicle situation or the driver's will, thereby reducing the load on the foot brake.

[Means to solve the problem]

In order to achieve the above object, an automatic transmission control device according to a first aspect of the present invention includes a brake pedal depression amount detection means, a vehicle speed detection means, an accelerator pedal depression amount detection means, and an accelerator pedal depression amount detection means. and a control device that determines an optimum gear from a pre-stored memory map of the vehicle speed versus brake pedal depression amount when the vehicle is in an idling state, and performs speed change control.

Further, in the second aspect of the present invention, the vehicle speed detection means, the accelerator pedal depression amount detection means, the multi-stage υ1 air brake switch, and the exhaust brake step-by-step when the accelerator pedal depression amount detection means indicates the idle state. It is also possible to include a control device that determines the optimum gear for the vehicle speed stored in advance and controls the speed change.

[For production]

In the first aspect of the present invention, when the control device indicates that the accelerator pedal depression amount detection means is in an idle state, the control device detects the vehicle speed and The optimum gear stage is determined according to the amount of brake pedal depression detected by the brake pedal depression amount detection means, and the gear shift is controlled to this optimum gear stage.

In addition, in the second invention, instead of detecting the amount of depression of the brake pedal, the exhaust brake stage is detected by a multi-stage exhaust brake switch, and the optimal gear stage stored in advance for each exhaust brake stage is set according to the vehicle speed. Decide and control the speed change.

In this way, in any of the present inventions, when the driver wants to apply braking, the engine brake can be obtained without requiring foot braking force.

〔Example〕

FIG. 1 shows an embodiment of an automatic transmission control device according to the first invention. 1 is the engine, and the intake air (
It includes a throttle lever that controls the flow rate of air (air or mixture), and is a 1a flywheel. Reference numeral 2 denotes a clutch body, which is composed of a well-known friction clutch and has a release lever 2a, and 3 is a clutch actuator, whose piston rod 3a moves the release lever 28 in order to control the engagement amount of the clutch body 2. It is something that is driven. 4 is a hydraulic mechanism, 5 is a transmission actuator, 6
is a transmission that is driven by a synchronous mesh transmission actuator 5 and performs a speed change operation, and includes an input shaft (input shaft) 6a connected to the clutch body 2, and an output shaft (drive shaft).
6b, gear position sensor 6 that detects the gear position (gear position)
It is equipped with C.

7 is a select lever operated by the driver;
"N" range (neutral position), "D" range (automatic shift), "L" range (1st speed), "2" range (2nd speed), "
3" range (3rd speed), "4" range (4th speed), "5" range (5th speed), "R"range'; each range of <reverse> can be selected by the lever position, and the selected range 8 is a vehicle speed sensor that detects the vehicle speed from the rotation speed of the drive shaft 6b, and both sensors 7a and 8 are connected to the control device 9. ing.

The above control device 9 is composed of a microcomputer,
A processor 9a that performs arithmetic processing, a read-on memory (ROM) 9b that stores a control program for controlling the transmission 6 and the clutch 2, an output boat 9c, an input port 9d, and a random access memory that stores arithmetic results. Memory (RAM) 9e and a data bus (
BUS) 9f and Kapo) 9c are composed of
A drive signal CDV connected to the clutch actuator 3, the hydraulic mechanism 4, and the transmission actuator 5 to drive them;
Outputs PDV and ADV.

On the other hand, the input boat 9a includes the clutch actuator 3, various sensors 6c, 7a, 8.10, a sensor 11a (potentiometer or pressure sensor) that detects the amount of depression of the accelerator pedal 11 (described later), and the amount of depression of the brake pedal 12. It is connected to a sensor 12a (potentiometer or pressure sensor) that detects the amount, and receives and receives these detection signals.

Next, the operation of the embodiment shown in FIG. 1 will be explained with reference to the flowchart shown in FIG.

First, select lever position from lever position sensor 7a, vehicle speed from vehicle speed sensor 8, accelerator pedal sensor I
Accelerator pedal depression amount from la, gear position sensor 6c
Each signal regarding the current gear position from the brake pedal sensor 12a and the amount of brake depression from the brake pedal sensor 12a is read (step St).

Next, the select lever position is determined (step S2),
If the select lever 7 is in the D range, the previous optimum gear is determined (step S6), and if it is determined that the previous optimum gear is not in the "N" range, the amount of depression of the accelerator pedal 11 is established. (step S7), and if there is no accelerator pedal depression and the vehicle is in an idling state, control is performed according to the brake depression amount and vehicle speed (step 310).
.

In this step SIO, ■brake pedal 12
When the amount of brake depression is very small, the engine brake force is judged to be small and the previous optimum gear is maintained, and the gear is selected to downshift earlier as the amount of brake depression gradually increases In order to ensure proper engine braking, ■Furthermore, when the amount of brake depression is extremely large (Sakae, when braking), the setting is made so that the previous gear is maintained to prevent empty running during downshifts. .

The gear position thus obtained in step SIO is stored in the RAM 9C as the optimum gear position (step 511).

Then, compare the optimum gear determined in step Sll with the current gear from the gear sensor 6c (step 512).
, if different, the gear shift operation to the optimum gear is carried out (step 513), and the optimum gear=current gear ends as it is (step 513).
Step 512).

On the other hand, when the previous optimum gear position is in the "N" range in step S6, or when the accelerator 11 is depressed and is not in an idling state in step S7, the normal optimum gear position determination process for the D range is performed (step S8); The determined optimum gear stage is stored in the RAM 9e (step 39).

Furthermore, if it is determined in step S2 that the select lever position is in the "Nj range", the "N" range is assumed to be the optimum gear stage (step S3), and the process proceeds to step 312. In addition, if it is determined in step S2 that the select lever position is neither the "N" range nor the "DJ range", processing for the fixed range is performed (step S4), and the optimum gear is determined based on the processing result (step S5), step S
Proceed to step 12. This is to determine the optimum gear stage to prevent the engine from overrunning even in the case of a fixed range.

The flowchart shown in Figure 3 is the step 3 shown in Figure 2.
This is a detailed explanation of the state of the downshift control in No. 10, and in the figure, the setting value l is a dark value for determining whether the amount of brake pedal depression is extremely large, and the setting value 2 (setting value 2
<Set value 1) is a dark value for determining whether or not the amount of depression of the brake pedal is extremely small, and is set as follows.

2ND3RD, 4TH, and 5TH indicate select lever positions, respectively.

First, compare the brake pedal depression and set value 1 in step 5.
101), when the amount of brake depression is greater than or equal to the set value 1, that is, when the amount of brake depression is extremely large as explained in step SIO in FIG. 2, or when the amount of brake depression is set to 2
In step 5102), if the amount of brake depression is less than the set value 2, that is, if the amount of brake depression is small, the previous gear is set as the optimum gear and the process ends (proceed to step 311 in FIG. 2). .

When the brake depression amount is set to 1 in step 5101 and the brake depression amount is set to 2 in step 5102, the vehicle speed is determined by the memory map shown in step 5103 (previously stored in the ROM 9b of the control device 9). A corresponding gear is determined and determined as the optimum gear (step 5204).

In this way, when the optimal gear is determined based on the vehicle speed and the amount of brake pedal depression, as shown in the map in step 3103, when the engine is braking in an idling state with neither the accelerator nor the brake pedal being depressed (the intersection of the dotted line and the horizontal axis ), it can be seen that the downshift is performed earlier.

Note that the amount of brake depression in the above embodiment can be considered to be completely equivalent when processed as brake pressure.

Next, an embodiment of an automatic transmission control device according to the second invention will be described with reference to FIGS. 4 to 6.

The automatic transmission control device shown in FIG. 4 is the same as the device shown in FIG. 1, but does not use the amount of depression of the brake pedal as a control parameter, but adds exhaust brake control. In other words, 13 in the figure is a two-stage exhaust system. The brake lever 13a is an exhaust brake switch that operates in response to the operation of the exhaust brake lever 13, and 14 is an exhaust brake that applies a load in response to the engine l; the rest is the same as that shown in FIG. .

FIG. 5 is an operational flowchart of the second embodiment of the present invention, and this flowchart is different from the flowchart of FIG. 2 only in steps 320 to S25 for controlling the exhaust brake system.

Therefore, to explain only the part to which this exhaust brake control is added, first read the select lever position signal, vehicle speed, accelerator pedal depression amount, current gear, and exhaust brake switch signal (step S1), and then read the select lever position signal. Confirm step S2), and if it is determined that it is in the D range, step S6 as described above.
Then, the amount of depression of the accelerator pedal is confirmed by processing in step S7, and if it is determined that the accelerator pedal is in the idle position, VA verification of the exhaust brake switch position is performed (step 520).

When the exhaust brake switch 13a is in the OFF' position, the previous optimum gear is stored in the optimum gear and the gear is held (step 521).

Exhaust brake switch 1 with exhaust brake lever 13
3a generates a light engine brake, so it is in the ON■ position (when it is determined that it is in the ONN13 of the first stage, a shift down process is performed on a late day (step 522) to ensure a somewhat strong engine braking force. The gear at this time is stored in the ROM 9b as the optimum gear (step 513).

In addition, the exhaust brake switch 13a is set to the ON position (second stage ON) to generate strong engine braking force.
When it is determined that the engine is in the position (step 514), a shift down process is performed earlier than in step S22 to ensure strong engine braking, and the gear at this time is stored as the optimum gear (step 515). ).

Then, compare the optimum gear and the current gear in step 51.
2) The gear shift operation to the optimum gear is performed only when the gears are different (step 513), and the rest is the same as that described with reference to FIG.

FIG. 6 shows a memory map diagram for determining the gear position in the downshift process of step 322 and step S24, and shows the delay when the exhaust brake lever 13 is operated to the first stage and the switch 13a is turned ON1. In the case of early shift down processing, find the gear corresponding to the vehicle speed from the map in Figure (a), and in the case of early shift down processing, find the gear corresponding to the vehicle speed from the map in Figure (B). ,
demand.

Therefore, each gear is downshifted at a higher vehicle speed than in the case of downshift processing on a late day, and a greater engine braking force is generated.

In addition, if the exhaust brake lever switch 13a is ON or O
Needless to say, when the engine brake reaches N■, the engine brake operates as appropriate as described above, and the exhaust brake 14 also operates at the same time to assist the engine brake.

In addition, although the explanation has been made using a two-stage exhaust brake lever, this is not limited to this; if a downshift lap is prepared for each of various multiple-stage exhaust brakes, it is not limited to a two-stage exhaust brake lever. .

〔Effect of the invention〕

As described above, according to the present invention, the optimum gear stage is determined from the vehicle speed based on the amount of depression of the brake pedal and the vehicle speed, or depending on the strength of the exhaust brake, and the shift control is performed. The driver can reliably select the desired deceleration and drive safely.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an automatic transmission control device according to the first invention, and FIG. 2 is a ttd diagram executed by the control means of the first invention.
l? II+ program flowchart, FIG. 3 is a flowchart of a specific control program for the downshift process in FIG. 2, FIG. 4 is an overall configuration diagram of the automatic transmission control device according to the second invention, FIG. 5 is a flowchart of a control program executed by the control means of the second invention, and FIG. 6 is a flowchart of a specific control program for the downshift process in FIG. 1 and 4, 8 is a vehicle speed sensor, 9 is a control device, 11 is an accelerator pedal, lla is an accelerator pedal sensor, 12 is a brake pedal, 12a is a brake pedal depression amount sensor, 13 is an exhaust brake lever, 13a indicates an exhaust brake switch, and 14 indicates an exhaust brake. In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] (1) A memory map of the brake pedal depression amount detection means, the vehicle speed detection means, the accelerator pedal depression amount detection means, and the vehicle speed versus the brake pedal depression amount stored in advance when the accelerator pedal depression amount detection means indicates an idle state. 1. An automatic transmission control device comprising: a control device that determines an optimum gear position from the above and controls the speed change. (2) Vehicle speed detection means, accelerator pedal depression detection means, multi-stage exhaust brake switch, and optimum vehicle speed stored in advance for each exhaust brake stage when the accelerator pedal depression detection means indicates an idle state. An automatic transmission control device comprising: a control device that determines a gear stage and controls a shift.