JPH056059B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an automatic transmission for a vehicle that can obtain a stronger engine braking force than a normal engine brake during deceleration while the vehicle is running.

(Prior art) In vehicles equipped with conventional electronically controlled automatic transmissions, the amount of depression of the accelerator pedal, vehicle speed, and engine load are detected, and based on these relationships, an electronic control device composed of a microcomputer determines a shift map. The vehicle searches, selects the optimum gear, and controls the transmission to drive. And while running,
When the driver releases the accelerator pedal when engine braking is required, depending on the driving conditions, the engine braking may not be as effective, and the transmission may shift up when the accelerator pedal is released. It may not be effective. In order to solve this problem, we developed a method that automatically shifts down from the highest gear when the brake pedal is pressed, and a timer circuit is installed in the accelerator pedal, so that when the brake pedal is released, the brake pedal is not pressed within a certain period of time. There has been a proposal (Japanese Unexamined Patent Publication No. 56-39349) to perform downshifting by moving the engine forward.

(Problems with the prior art) In this way, in order to apply engine braking, the transmission must be downshifted, but normally the select lever is operated to downshift to apply engine braking. To return to driving, you have to move the select lever again, shift up, and start driving, which takes a lot of effort.

In addition, with the above method of automatically downshifting from the highest gear when the brake pedal is depressed, the shift down occurs every time the brake pedal is depressed, causing inconvenience even when driving without engine braking. . Note that the above-mentioned proposal to provide a timer circuit to the accelerator pedal is for a hydraulic automatic transmission, so the effectiveness of the engine brake is weak, and sufficient braking cannot be achieved with the engine brake alone, so the brake pedal should be used to supplement the braking force. It will be used as

(Object of the Invention) An object of the present invention is to provide an automatic transmission for a vehicle that eliminates the above-mentioned conventional drawbacks and can obtain strong engine braking force in a vehicle equipped with an automatic transmission.

(Summary of the Invention) The present invention provides an automatic transmission for a vehicle that automatically changes gears by an electronic control device that has a built-in shift map that determines the gear position according to the vehicle speed and the amount of depression of the accelerator pedal. The vehicle is equipped with a shift map during engine braking and a shift map during engine braking, and is further provided with an engine brake switch operated by the driver and a switch that detects release of the accelerator pedal, and detects the operation of both switches. The electronic control device is characterized in that the shift map is switched to a shift map during engine braking.

(Example) Next, an example of the present invention will be described in detail using the drawings.

FIG. 1 is a block diagram of an embodiment for realizing the present invention, FIG. 2 is an explanatory diagram of the configuration of the main parts according to the present invention, and FIG. 3 is an explanatory diagram of a shift map in the configuration of FIG. 1.

In the figure, 1 is an engine, which includes a throttle valve 1a for controlling the amount of air or air-fuel mixture, and has a flywheel 1b. Reference numeral 2 denotes a clutch body, which is composed of a friction clutch, and the amount of clutch engagement is controlled by the operation of a clutch actuator 3 via a release lever 2a. Reference numeral 4 designates a hydraulic mechanism, and reference numeral 5 designates a gear shift actuator, both of which are controlled by commands from an electronic control device (described later) to drive a synchronous mesh transmission 6, and drive an input shaft 6a and an output shaft connected to the clutch body 2. 6
The gear shifting operation is performed by changing the state of engagement with b.
Note that 6c is a gear position sensor that detects the gear position of the transmission 6. 7 is a select lever operated by the driver, which selects between "N" range (neutral position) and "N" range.
Range (automatic shift), "1" range (1st speed), "2"
Range (2nd speed), "3" range (1st, 2nd, 3rd speed automatic shifting), and "R" range (reverse) can be selected by the lever position, and a selection signal SP indicates the selected range. is the select sensor 7a
is output by 8a is input shaft 6
8b is a vehicle speed sensor that detects the vehicle speed based on the rotation speed of the output shaft 6b, and 1c detects the rotation speed of the flywheel 1b to detect the rotation speed of the engine 1. This is an engine rotation sensor. Reference numeral 9 denotes an electronic control device composed of a microcomputer, which includes a processor 9a that performs arithmetic processing, a transmission 6, and a clutch body 2.
and a read-only memory (ROM) 9b that stores a control program for controlling the throttle valve 1a, an output port 9c, an input port 9a, a random access memory (RAM) 9e that stores calculation results, etc. and an address data bus (BUS) 9f that connects the address data bus (BUS) 9f. The output port 9c is connected to the clutch actuator 3, the hydraulic mechanism 4, the transmission actuator 5, and the throttle valve 1a, and outputs control signals CDV, PDV, ADV, and SDV for controlling these. In addition, the input port 9d is connected to various sensors 1.
c, 6c, 7a, 8a, 8b and an engine brake circuit (EB circuit), which will be described later, an accelerator pedal,
It is connected to the brake pedal and receives signals from these.

Reference numeral 10 denotes an engine brake switch (EB switch) provided in a place that can be easily operated by the driver, for example, on the steering wheel, and the circuit of the EB switch 10 is turned on by the driver's touch operation. Further, reference numeral 11a designates an accelerator switch provided on the accelerator pedal 11, and is configured so that the circuit is turned on when the accelerator pedal 11 is released, that is, when the amount of depression is zero, and as shown in FIG. 11a in series circuit (EB
circuit) and the processor 9 via the input port 9d.
When the driver stops pressing the accelerator pedal 11 and touches the EB switch 10, an ON signal will reach the processor 9a.

Next, 11b is a potentiometer-type accelerator sensor that detects the amount of depression of the accelerator pedal 11, 12 is a brake pedal, and 12a is a potentiometer-type brake sensor that detects the amount of depression of the brake pedal.

The normal driving shift map shown in FIG. 3A is a shift map stored in the ROM 9b of the electronic control unit 9, where the horizontal axis shows the vehicle speed, the vertical axis shows the amount of accelerator pedal depression, and , , , at each gear stage. The solid line is the boundary line between the gears when shifting up, and the dotted line is the boundary line between the gears when shifting down. When the vehicle is running, the vehicle speed signal WP generated by the vehicle speed sensor 8b and the accelerator pedal depression amount AP generated by the accelerator sensor 11b are input to the processor 9a. The system is configured to find the optimum gear position based on the driving shift map. Also, the engine brake shift map shown in Figure 3B is the same as the normal driving shift map described above.
9b, and the horizontal and vertical axes as well as ~ are the same as above. When the vehicle is running, when the series circuit (EB circuit) between the EB switch 10 and the accelerator switch 11a is turned on,
The processor 9a immediately performs a downshift from the current gear, switches from the normal running shift map to the engine brake shift map to find the optimum gear, and drives the transmission. Then, when the accelerator pedal 11 is depressed and the accelerator switch 11a is turned off, the vehicle is configured to return to the previous normal driving shift map and determine the gear position.

Next, the operation of this embodiment having such a configuration will be explained.

First, the select lever 7 is operated to the "D" range, and the selection signal SP for the "D" range is sent from the select sensor 7a to the processor 9 via the input port 9d.
When it is input to a, it is stored in the RAM 9e. Next, the processor 9a sends a drive signal to the transmission actuator 5.
ADV is output from the output port 9c, and the transmission 6 is shifted to 1st speed.

When the processor 9a receives the gear signal GP from the gear position sensor 6c, it detects that the transmission 6 has been shifted to the first speed, and stores this in the RAM 9e.

Next, the processor 9a detects the accelerator sensor 11.
In response to the depression amount AP of b, the clutch drive signal CDV
is sent to the clutch actuator 3 to operate the clutch body 2 and start the vehicle.

Then, the vehicle speed signal WP from the vehicle speed sensor 8b
Then, in accordance with the depression amount AP from the accelerator sensor 11b and the selection signal SP from the select lever 7, the optimum gear position is determined from the normal driving shift map, and the gear shifting operation is executed to put the vehicle into a driving state.

Here, if engine braking is required, if the driver stops pressing the accelerator pedal 11 and touches the EB switch 10 to turn it on, the amount of depression of the accelerator pedal 11 is zero, so the accelerator switch 11
Since a is in the ON state, the EB circuit is turned ON. Processor 9a via input port 9d
When the EB circuit is detected to be ON, the normal driving shift map stored in ROM9b immediately switches on the engine brake.
Since the system switches to the shift map and downshifts from the current gear, a sufficient engine braking effect is obtained and braking force is applied to the vehicle.

Next, there is no need for engine braking,
When the accelerator pedal 11 is depressed, the accelerator switch 11a turns OFF, so when the processor 9a detects this OFF, it immediately returns from the engine brake shift map to the previous normal driving shift map stored in the ROM 9b, and changes the current vehicle speed. The transmission 5 is operated to the optimum gear position according to the amount of depression of the accelerator pedal, and the vehicle runs.

Figure 4 is a processing flow diagram related to the EB circuit,
When the EB switch and accelerator switch are both ON (step A), the normal driving shift map is switched to the engine brake shift map (step B). In this state, when the accelerator switch is turned off (step C), the shift map returns to the state before switching in step B, that is, the state of the normal driving shift map.

Although the present invention has been described with reference to one embodiment, it can also be applied to, for example, an ordinary electronically controlled hydraulic automatic transmission, within the scope of the present invention.
Various modifications can be made to the mounting location of the EB switch, such as arranging it on a select lever, console box, etc., and these are not excluded from the scope of the present invention.

(Effects of the Invention) As explained in detail above, the present invention provides an automatic transmission for a vehicle that performs automatic gear shifting operation by an electronic control device, which is provided with an EB switch and an accelerator pedal switch, and these switches are configured as a series circuit to be electronically controlled. A signal is sent by connecting to the device, and the electronic control device switches to the engine brake shift map and operates the transmission based on the signal, so that an engine brake effect with sufficient braking force can be obtained.

Furthermore, since the present invention operates with a direct-coupling automatic transmission rather than a hydraulic automatic transmission, it provides powerful engine braking. Therefore, by taking your foot off the accelerator pedal while driving, you can obtain normal engine braking, but by turning on the EB switch at this time, it becomes stronger engine braking, and by further depressing the brake pedal,
The strongest braking force will be obtained.

In addition, in the present invention, when returning to normal driving after taking your foot off the accelerator pedal and turning on the EB switch to activate strong engine braking,
By simply stepping on the accelerator pedal, the gear position before the use of engine braking is automatically returned, so it is possible to return to normal driving without any trouble.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment according to the present invention, FIG. 2 is an explanatory diagram of the configuration of main parts according to the present invention, FIG. 3 is an explanatory diagram of a shift map in the configuration of FIG. 1, and FIG.
The figure is a processing flow diagram related to the EB circuit. 6...Transmission, 9...Electronic control device, 10...
Engine brake switch, 11... accelerator pedal, 11a... accelerator switch.

Claims (1)

[Scope of Claims] 1. In an automatic transmission for a vehicle that automatically shifts gears using an electronic control device that has a built-in shift map that determines the gear position according to the vehicle speed and the amount of depression of the accelerator pedal, the electronic control device has a shift map that determines the gear position during normal driving. It is equipped with an engine brake switch operated by the driver and a switch that detects release of the accelerator pedal, and when the operation of both switches is detected, the electronic control unit is activated. An automatic transmission for a vehicle characterized by switching a shift map to a shift map during engine braking.