JPH02134452A - Engine brake control device of automatic transmission - Google Patents

Abstract

PURPOSE:To have strong braking force by giving a shift-down command only when all of such conditions are met, as an exhaust brake switch is put on the On side, the degree of throttle opening is below the set value, and the car speed is below the set value. CONSTITUTION:An engine brake control means (d) makes shift-down control automatically when engine brake is required, to put the engine brake in effect. Therein a shift-down command is given only when all of such conditions are met, as an exhaust switch (a) to change over an exhaust brake device from ON to OFF and vice versa is put on the ON side, the degree of throttle opening sensed by a throttle opening sensing means (b) is below the set value, the car speed sensed by a car speed sensing means (c) is below the set value. Thus a strong braking force by engine brake can be obtained only when needed, while speed change shocks are prevented at other times.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine brake control device for an automatic transmission in a vehicle equipped with an exhaust brake device.

(Prior Art) Conventionally, as an engine brake control device for an automatic transmission, for example, Japanese Patent Laid-Open No. 59-192620 and Japanese Patent Laid-Open No. 6
A device as described in Japanese Patent No. 0-1447 is known.

The above-mentioned conventional device automatically downshifts and applies engine braking when the brake switch ◯N satisfies the conditions that the throttle is fully open and the vehicle speed is below a set speed.

(Problem to be Solved by the Invention) However, in such a conventional engine brake control device, even in a situation that does not match the driver's will, it is difficult to determine whether the brake switch conditions, throttle conditions, and vehicle speed conditions are satisfied. Because it was designed to automatically downshift, there was a shift shock due to downshifting,
There is a problem in that the driving feeling deteriorates and the driver feels uncomfortable.

For example, even if you press the brake pedal lightly and do not want strong engine braking due to downshifting, as long as the above three conditions are met, the downshift will occur automatically. Accompanying this is a shift shock.

In addition, if the above engine brake control device is applied as is to automatic transmissions of large vehicles such as trucks equipped with exhaust brake devices, as is the case with vehicles such as passenger cars, due to unavoidable circumstances, high vehicle weight Since the inertia of the vehicle is large, the shift shock accompanying the above-mentioned downshift is also large, resulting in a significant deterioration of the driving feeling.

The present invention has been made in view of the above-mentioned problems, and provides an engine brake for an automatic transmission that enables engine braking to be applied only when necessary by using an exhaust switch operation that reflects the driver's will. The subject is the development of a control device.

(Means for Solving the Problems) In order to solve the above problems, the engine brake control device for an automatic transmission according to claim 1, as shown in FIG. 1a, automatically performs downshift control when engine braking is required. In an engine brake control device for an automatic transmission, the engine brake control device for an automatic transmission is configured to use an exhaust switch a to activate or deactivate the exhaust brake device mounted on the vehicle, and a throttle opening controller to detect the throttle opening degree. The speed detection means shifts down only when the following conditions are satisfied: the vehicle speed detection means C detecting the vehicle speed and the exhaust switch a are on the operating side, the throttle opening is less than the set opening, and the vehicle speed is less than the set speed. The engine brake control means d outputs a command.

Further, in the engine brake control device for an automatic transmission according to claim 2, as shown in FIG. The brake control device includes an exhaust switch a that switches between activation and deactivation of the exhaust brake device mounted on the vehicle, a throttle opening detection means that detects the throttle opening, and a vehicle speed detection means C that detects the vehicle speed. and deceleration detection means e for detecting the deceleration of the vehicle.
A shift down command is issued only when exhaust switch a is on the operating side, the throttle opening is less than or equal to the set opening, and the vehicle speed is less than or equal to the deceleration response setting, which is set to a higher value as the vehicle deceleration increases. The engine brake control means f outputs an engine brake control means f.

(for production) The operation of the apparatus according to claim 1 will be explained.

When the exhaust switch a of the exhaust brake device mounted on the vehicle is switched to the non-operating side, engine brake control is performed even when the throttle opening is less than the set opening and the vehicle speed is less than the set speed. A downshift command is not output from the means d.

Also, when switching the exhaust switch a of the exhaust brake device installed on the vehicle to the operating side,
When the throttle opening is less than or equal to the set opening and the vehicle speed is less than or equal to the set vehicle speed, the engine brake control means d outputs a downshift command.

Therefore, whether or not the driver needs engine braking is determined based on whether or not exhaust switch a is turned on, and when it is not necessary, the driver uses powerful engine braking only when necessary, while preventing gear shock due to downshifting. You get engine braking.

The operation of the apparatus according to claim 2 will be explained.

When the exhaust switch a of the exhaust brake device mounted on the vehicle is switched to the non-operating side, engine brake control is performed even when the throttle opening condition and the vehicle speed condition are satisfied, similarly to the device according to claim 1. A downshift command is not output from the means f. .

Also, when switching the exhaust switch a of the exhaust brake device installed on the vehicle to the operating side,
A shift down command is output from the engine brake control means f when the throttle opening is less than or equal to the set opening and the vehicle speed is less than or equal to the deceleration corresponding set vehicle speed, which is set to a higher value as the deceleration of the vehicle increases. .

Therefore, similarly to the engine brake control device according to claim 1, whether or not the driver needs engine braking is determined based on whether or not the exhaust switch a is turned on, and if it is not necessary, the shift shock caused by downshifting is applied. While preventing this, the engine brake provides powerful braking force only when necessary.

Furthermore, the vehicle speed condition for engine brake control is set to be less than or equal to the set vehicle speed corresponding to deceleration, which is set to a higher value as the deceleration of the vehicle is greater, so the greater the deceleration, the earlier the downshift will start, causing the driver to press the pedal more quickly. The braking effect of the engine brake can be effectively utilized with a quick response without delay during high deceleration such as during brake operation.

(Example) Embodiments of the present invention will be described below based on the drawings.

First, as shown in FIG. 2, an engine brake control device for an automatic transmission according to a first embodiment corresponding to the device according to claim 1 characterized in its configuration has the following features:
This is a device that automatically performs downshift control to apply engine braking when engine braking is required, and is incorporated as a part of various electronically controlled automatic transmission control devices, and serves as control information input means. It includes an exhaust switch 1, a throttle fully closed switch 2, and a vehicle speed sensor 3, an A control unit 4 as a processing means for calculations and judgments, and shift solenoids 5 and 6 as control actuators.

The exhaust switch 1 is a means for switching between activation and deactivation of an exhaust brake device mounted on a vehicle by operating a switch from the driver's seat.

Note that the exhaust brake device is a device that closes the exhaust pipe, causes the engine to work as a compressor, and applies a large braking force to the vehicle.

The throttle fully closed switch 2 is provided in the throttle valve section of the engine 10, and serves both to detect the throttle opening TH and to detect that the throttle opening TH is in the fully closed range THulN, ) is in the total question area THMIN, it outputs an ON signal.

The vehicle speed sensor 3 is provided on the output shaft portion 12 of the automatic transmission 11, and is a means for detecting the vehicle speed V by outputting a signal corresponding to shaft rotation.

The AT control unit 4 has an electronic control circuit configuration centered on a microcomputer, and has a gear shift control program, a lock-up control program, etc., and when the exhaust switch 1 is on the operating side (ON) and the throttle fully closed switch 2 is ON, Moreover, an engine brake control program is incorporated that outputs a downshift command instead of normal gear change control only when all conditions are satisfied that the vehicle speed V is equal to or less than the set vehicle speed V0.

The shift solenoids 5 and 6 are means that operate according to commands from the AT control unit 4 and switch the shift valves in the control valve unit 13 according to the gear shift position 1.

Next, the effect will be explained.

(a) When the exhaust switch is OFF When the exhaust switch 1 of the exhaust brake device mounted on the vehicle is switched to the non-operating side, the throttle opening T)l is less than the set opening and the set vehicle speed V
Even when the condition of 0 or less is satisfied, the AT control unit 4 does not output a downshift command.

That is, in the flowchart showing the flow of the shift control operation in FIG. 3, step 30 → step 31 → step 3
2, and normal shift control is performed according to the shift schedule as shown in the shift characteristic diagram of FIG.

(b) When the exhaust switch is ON When the exhaust switch 1 of the exhaust brake device mounted on the vehicle is switched to the operating side, the throttle opening TH is below the full open range THu+h, and the vehicle speed V is below the set vehicle speed V0. When the conditions are satisfied, A
A shift down command is output from the T control unit 4.

That is, the flow of the shift control operation in the engine brake mode is as follows in FIG. 3: Step 30 → Step 31 → Step 33 → Step 34 → Step 35, and the engine brake control operation as shown in the shift characteristic diagram of FIG. Shift control is performed to downshift from 4th gear to 2nd gear or from 3rd gear to 2nd gear in accordance with the brake mode shift schedule.

As explained above, in the engine brake control device of the first embodiment, depending on whether the exhaust switch 1 is turned on or not, it is possible to determine whether the driver requires strong braking force in addition to the engine braking caused by downshifting. The driver's intention is determined, and engine braking provides powerful braking force only when necessary, while preventing shift shock caused by downshifting when unnecessary.

Next, a second embodiment corresponding to the engine brake control device for an automatic transmission according to the second aspect of the present invention shown in FIGS. 6 to 8 will be described.

The configuration of this second embodiment is similar in appearance to the device of the first embodiment shown in FIG.

However, in the AT control unit 4 of the second embodiment,
The vehicle speed signal from the vehicle speed sensor 3 is differentiated to determine the vehicle deceleration Δ
When the deceleration ΔV of the vehicle is less than or equal to the set deceleration ΔV1, the set vehicle speed is set to vl on the low vehicle speed side, and when the deceleration ΔV of the vehicle exceeds the set deceleration ΔV, the set vehicle speed is set to high vl. It has a deceleration compatible setting vehicle speed selection section which is set to V2 on the vehicle speed side.

Next, the effect will be explained.

(B) When the exhaust switch is OFF When the exhaust switch 1 of the exhaust brake device installed on the vehicle is switched to the non-1'''F drive side, the throttle opening condition and vehicle speed condition are changed as in the first embodiment. Regardless of the above, the AT control unit 4 does not output a downshift command.

That is, in the flow chart showing the flow of the speed change control operation in FIG. 6, step 60 → step 61 - step 6
2, and normal shift control is performed according to the shift schedule as shown in the shift characteristic diagram of FIG.

(b) When the exhaust switch is ON When the exhaust switch 1 of the exhaust brake device mounted on the vehicle is switched to the operating side, the throttle opening TH is below the fully closed range TH,□, and the vehicle speed V is the set vehicle speed. When the condition of V1 or V2 or less is satisfied, a shift down command is output from the AT control unit 4.

That is, the flow of the shift control operation in the engine brake mode during low deceleration that satisfies ΔV≦ΔV1 is as follows in FIG. 6: Step 60 - Step 61 → Step 63 →
The flow proceeds from step 64 to step 65 to step 67, and the shift control is performed to downshift from 4th gear to 2nd gear or from 3rd gear to 2nd gear according to the engine brake mode shift schedule as shown in the shift characteristic diagram in FIG. It is done.

Furthermore, the flow of the shift control operation in the engine brake mode during high deceleration that satisfies ΔV>ΔV1 is shown in FIG. 6 as follows: Step 60→Step 61→Step 63→
The flow proceeds from step 64 to step 66 to step 67, and the shift control is performed to downshift from 4th gear to 2nd gear or from 3rd gear to 2nd gear according to the engine brake mode shift schedule as shown in the shift characteristic diagram of FIG. It is done.

As explained above, in the engine brake control device of the second embodiment, similarly to the device of the first embodiment, the driver can apply powerful engine braking by downshifting depending on whether or not the exhaust switch 1 is turned ON. The system determines whether a strong braking force is required, and uses engine braking to provide strong braking force only when necessary, while preventing shift shocks caused by downshifting when unnecessary.

Furthermore, the vehicle speed condition for engine brake control is set to a higher value as the deceleration ΔV of the vehicle is larger, such as a set vehicle speed ΔV1 corresponding to deceleration. Since the condition is ΔV2 or less, when the deceleration is small, the start time of downshifting is delayed, and the deceleration of the vehicle is prevented from increasing suddenly during low deceleration such as when applying the brakes only by the pedal track. In addition, when the deceleration is large, the downshift starts early, and the braking effect of the engine brake can be effectively utilized with a quick response without delay during high deceleration, such as when the brake is operated by suddenly pressing the pedal.

Although the embodiment has been described above based on the drawings, the specific configuration is not limited to this embodiment, and the present invention may be modified without departing from the gist of the present invention. Included in invention. For example, in the second embodiment, in order to make the set vehicle speed correspond to the vehicle deceleration, an example was shown in which the set vehicle speed is selected in two stages: rapid deceleration and slow deceleration. The vehicle speed may be set in multiple stages of 3 or more or in a stepless manner.

(Effects of the Invention) As described above, in the engine brake control device for an automatic transmission according to claim 1, when the exhaust switch is on the operating side and the throttle opening is equal to or less than the set opening,
In addition, we have installed an engine brake control means that outputs a downshift command only when all conditions are met: the vehicle speed is below the set speed, so the driver can apply engine braking by downshifting depending on whether or not the exhaust switch is operated, creating a powerful braking force. The driver's intention is determined whether or not the engine brake is needed, and when it is not needed, the engine brake can provide strong braking force only when it is needed, while preventing gear change shock due to downshifting.

Further, in the engine brake control device for an automatic transmission according to claim 2, the exhaust switch is on the operating side;
Engine brake control means outputs a downshift command only when the throttle opening is below a set opening and the vehicle speed is below a deceleration corresponding set vehicle speed, which is set to a higher value as the deceleration of the vehicle increases. As a result, in addition to the above effects, the downshift starts earlier when the deceleration is large, and engine braking is effectively applied with a quick response without delay during high decelerations such as when applying the brake by suddenly pressing the pedal. effect can be used.

[Brief explanation of the drawing]

1a and 1b are claims-corresponding views showing the engine brake control device for an automatic transmission according to the present invention, and FIG.
An overall schematic diagram of the automatic transmission according to the embodiment without showing the engine brake control device, FIG. 3 is a flowchart showing the flow of the shift control operation in the AT control unit of the device of the first embodiment, and FIG. 4 is a normal shift control. FIG. 5 is a shift schedule characteristic diagram for shift control in engine brake mode, FIG. 6 is a flowchart showing the flow of shift control operation in the AT control unit of the second embodiment device, and FIG. 8 is a shift schedule characteristic diagram for shift control in the slow deceleration engine brake mode, and FIG. 8 is a shift schedule characteristic diagram for shift control in the rapid deceleration engine brake mode. a...Exhaust switch b...Throttle opening detection means C...Vehicle speed detection means d...Engine brake control means e...Deceleration detection means f...Engine brake control means

Claims (1)

[Scope of Claims] 1) An engine brake control device for an automatic transmission that automatically performs downshift control to apply engine braking when engine braking is required, which controls the operation and operation of an exhaust brake device mounted on a vehicle.
An exhaust switch that switches between inactivation and inactivation by a switch operation, a throttle opening detection means that detects the throttle opening, and a vehicle speed detection means that detects the vehicle speed. An engine brake control device for an automatic transmission, further comprising: engine brake control means for outputting a downshift command only when all conditions of the vehicle speed being less than or equal to a set vehicle speed are satisfied. 2) In an engine brake control device for an automatic transmission that automatically controls downshifts to apply engine braking when engine braking is required, the system controls the operation and operation of the exhaust braking device installed on the vehicle.
An exhaust switch that can be switched to non-operation by a switch operation, a throttle opening detection means that detects the throttle opening, a vehicle speed detection means that detects vehicle speed, a deceleration detection means that detects vehicle deceleration, and an exhaust switch that is activated. On the side, the engine brake outputs a shift down command only when the throttle opening is below the set opening and the vehicle speed is below the deceleration response setting, which is set to a higher value as the vehicle deceleration increases. An engine brake control device for an automatic transmission, comprising a control means.