JPH11107784A - Engine braking control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain engine braking force as intended. SOLUTION: This control device has an engine 61, a transmission section 10 actuating gear shifting based on a change-gear ratio every step of gear shifting, a selection means selecting each step of gear shifting, a throttle opening changing means changing the opening of a throttle regardless of accelerator pedal footing, an acceleration detecting means 82 detecting acceleration, a comparison means 83 comparing acceleration with a target value set in advance, and a keeping means 84 which actuates the throttle opening changing means based on the result of comparison made by the comparison means, and keeps acceleration at the target value. In this case, since acceleration can be kept at zero based on the result of comparison made between detected acceleration and the target value, engine braking force as intended can thereby be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle engine brake control device.

[0002]

2. Description of the Related Art Conventionally, in an automatic transmission, rotation generated by an engine is transmitted to a transmission through a torque converter, and the transmission is shifted to drive wheels. . In the transmission, a gear unit including a plurality of gear elements is provided, and a clutch, a friction engagement element such as a brake is disengaged, and the rotation of the gear element is selectively output, whereby
A plurality of gears are achieved.

When a driver operates a shift lever, a parking range (P), a reverse range (R), a neutral range (N), a drive range (D), a second range (S), and a low range (L) are provided. Etc. can be selected. Then, if sufficient engine braking force cannot be obtained even when the driver releases the accelerator pedal while the vehicle is running with the drive selected, by selecting a second range, a low range, etc. The gear is selected so that sufficient engine braking force can be obtained.

[0004]

However, in the above-mentioned conventional automatic transmission, since the speed ratio is set in a step-like manner for each shift speed, the engine braking force changes in a step-like manner, and the driver's desired speed is changed. May not be able to obtain the engine braking force. For example, when turning a curve or running the vehicle on a long downhill, sufficient engine braking force cannot be obtained at the third speed, and an unnecessarily strong engine brake is required at the second speed. Power is gained. In this case, the driver depresses the brake pedal while applying the engine brake at the third speed, or depresses the accelerator pedal while applying the engine brake at the second speed.

[0005] Further, when downshifting is performed in order to apply the engine brake, a shock is generated as the engine braking force changes in a stepwise manner, and the traveling feeling is reduced. The present invention solves the problems of the conventional automatic transmission and provides an engine brake control device for a vehicle that can obtain a desired engine braking force and that does not cause a decrease in running feeling due to a shock. The purpose is to provide.

[0006]

For this purpose, a vehicle engine brake control apparatus according to the present invention receives an engine and rotation generated by the engine.
A transmission that shifts at a speed ratio for each gear stage, a selection unit that selects the gear stage, a throttle opening degree changing unit that changes a throttle opening degree regardless of depression of an accelerator pedal, and an acceleration that detects acceleration Detecting means, comparing means for comparing the acceleration with a preset target value, and holding means for operating the throttle opening changing means based on the comparison result by the comparing means to hold the acceleration at the target value And

According to another aspect of the present invention, there is provided an engine brake control apparatus for a vehicle, an engine, a transmission for receiving a rotation generated by the engine, and performing a shift at a speed ratio for each speed step, Selecting means for selecting
Throttle opening changing means for changing the throttle opening regardless of depression of an accelerator pedal, deceleration operation determining means for determining whether or not a deceleration operation has been performed by the driver; acceleration detection means for detecting acceleration; When it is determined by the operation determining means that a predetermined deceleration operation has been performed, comparing means for comparing the acceleration with a preset target value; and changing the throttle opening based on the comparison result by the comparing means. Holding means for operating the means to hold the acceleration at a target value.

In another aspect of the present invention, the deceleration operation determining means includes an accelerator opening sensor for detecting an amount of depression of an accelerator pedal, and a shift speed selected by the selecting means. Speed detecting means for detecting the shift speed. Then, when at least one of the release of the accelerator pedal, the selection of a gear other than the gear having the smallest gear ratio, and the selection of a range other than the drive range is detected. It is determined that a predetermined deceleration operation has been performed.

In still another embodiment of the present invention, the target values are set for each shift speed.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram of a vehicle engine brake control device according to an embodiment of the present invention. In the figure, reference numeral 61 denotes an engine (E /
G), the rotation generated by the engine 61 is transmitted to the transmission 10, and the transmission 10 shifts at a gear ratio for each gear.

Reference numeral 81 denotes a shift lever as selection means for selecting the gear position and range, 74 denotes an electronic throttle valve as throttle opening changing means for changing the throttle opening regardless of depression of an accelerator pedal (not shown), 82 is an acceleration detecting means for detecting acceleration. Then, the control unit 86 includes the comparing unit 83 and the holding unit 8.
4 and a target value setting means 85.
Compares the acceleration with a target value set in advance by the target value setting means 85 based on the traveling state of the vehicle, the traveling environment, the operation of the driver, and the like. The holding means 84 operates the electronic throttle valve 74 based on the result of the comparison by the comparing means 83, and holds the acceleration at a target value.

FIG. 2 is a conceptual diagram of a vehicle according to an embodiment of the present invention, and FIG. 18 is a diagram showing a range position and a shift position of a shift lever according to the embodiment of the present invention. In the figure, 61 is an engine (E / G), 62 is an automatic transmission (A / T), 53 is an engine control device that controls the engine 61, and 31 is an automatic transmission that controls the automatic transmission 62 Control device, 65 is a differential device,
66 and 67 are rear wheels serving as drive wheels, 71 and 72 are front wheels, 7
3 is a throttle valve which is opened and closed in conjunction with an accelerator pedal (not shown), 74 is an electronic throttle valve,
The electronic throttle valve 74 opens and closes irrespective of the depression of the accelerator pedal in accordance with a control signal from the engine control device 53, and changes the throttle opening. Also,
The automatic transmission control device 31 has control means 86 (FIG. 1), and the operation signal from the holding means 84 is transmitted to the engine control device 5
The electronic throttle valve 74 is opened and closed.

The automatic transmission control device 31 sends a gear shift command to the automatic transmission 62 in accordance with the selected range based on the throttle opening signal from the throttle valve 73 and the vehicle speed from the automatic transmission 62. Send. For this purpose, as shown in FIG. 18, the shift lever 81 is provided with a parking range (P), a reverse range (R), a neutral range (N), a drive range (D) (automatic shift mode and manual shift mode), and a second range ( S) and a low range (L). The automatic transmission control device 31 is configured to be able to select from six positions. The most appropriate speed among the third, second, and first speeds is selected based on the throttle opening and the vehicle speed.

When the second range is selected, the automatic transmission control device 31 selects the most appropriate one of the third, second, and first gears and the low range. Sometimes, the most appropriate one of the second speed and the first speed is selected based on the throttle opening and the vehicle speed, respectively. In the drive range, the driver further slides (shifts) the shift lever 81 to the H-shape to operate the manual shift mode (1s).
t position, 2nd position, 3rd position and 4th position) can be selected, and by selecting each position arbitrarily, the gear position (1
Speed, 2nd speed, 3rd speed, and 4th speed) can be selected.

The automatic transmission 62 achieves the gear position by a shift command from the automatic transmission control device 31 based on the operation of the shift lever 81. FIG. 3 is a schematic diagram of the automatic transmission according to the embodiment of the present invention, and FIG. 4 is a diagram illustrating the operation of the automatic transmission according to the embodiment of the present invention. In FIG. 4, ○ indicates the on state of the first to third solenoid valves S1 to S3, the first clutch C1, the second clutch C2, the third clutch C0, the first brake B1, the second brake B2, Third brake B3 and fourth brake B
0 indicates the engaged state, and X indicates the off state of the first to third solenoids S1 to S3, the first clutch C1, the second clutch
Clutch C2, third clutch C0, first brake B1,
The release state of the second brake B2, the third brake B3, and the fourth brake B0 is shown.

In FIG. 3, automatic transmission 62 receives rotation generated by engine 61 (FIG. 2),
A transmission 10 that shifts at a speed ratio for each gear, and a fluid transmission 11 such as a torque converter, which transmits rotation generated by the engine 61 to the transmission 10 via the fluid transmission 11; The transmission 10 changes the speed and transmits it to the rear wheels 66 and 67.

The fluid transmission device 11 includes a pump impeller 12, a turbine runner 13, a stator 14, and a lock-up clutch 15 for improving power transmission efficiency.
The rotation of the input member 16 is indirectly applied to the input shaft 17 of the transmission 10 by the oil flow (not shown) in the fluid transmission 11 or by locking up the lock-up clutch 15. introduce.

The transmission 10 includes an auxiliary transmission unit 18 and a main transmission unit 19, and the auxiliary transmission unit 18 is an overdrive planetary gear unit 2.
0, the main transmission unit 19 has a front planetary gear unit 21 and a rear planetary gear unit 22. Here, the overdrive planetary gear unit 20 is connected to the input shaft 17 and supports the carrier CR ₁ supporting the pinion P ₁ , the sun gear S ₁ surrounding the input shaft 17, and the input shaft 23 of the main transmission unit 19.
Consisting ring gear R ₁ connected to. Also, between the carrier CR ₁ and the sun gear S _1, the third clutch C0
And the third one-way clutch F0 is, the fourth brake B0 is disposed respectively between the sun gear S ₁ and the case 24.

Next, the front planetary gear unit 2
1 is a carrier CR ₂ connected to the output shaft 25 of the main transmission unit 19 and supporting the pinion P ₂ ;
5 and a rear planetary gear unit 22
Made from the sun gear S ₃ formed integrally with the sun gear S ₂ ring gear R ₂ which, and linked via a first clutch C1 to the input shaft 23. Also, between the input shaft 23 and the sun gear S ₂ is the second clutch C2, the sun gear S
Between the case ₂ and the case 24
The second brake B2 is provided via the brake B1 and the first one-way clutch F1.

Then, the rear planetary gear unit 22
, The carrier CR ₃ supporting a pinion P _3, consists sun gear S _3, and a ring gear R ₃ connected directly to the output shaft 25, third between the carrier CR ₃ and the case 24
The brake B3 and the second one-way clutch F2 are arranged in parallel. 43 is an input speed sensor, SP1,
SP2 is a vehicle speed sensor.

The first to third solenoid valves S1 to S3 of the automatic transmission 62, the first clutch C1, the second clutch C2, the third clutch C0, the first brake B1, the second brake B2, and the third brake B3. And the fourth brake B0
Are controlled as shown in the operation table of FIG. 4 in each of the drive ranges, the second range, and the low range.

That is, the automatic transmission mode (AUTO.) Of the drive range or the first gear (1.
At the time of ST), only the first solenoid valve S1 is turned on, as a result, the first clutch C1 and the third clutch C0 are engaged, and the second one-way clutch F
The second and third one-way clutches F0 are locked, and the others are released. Therefore, each element of the overdrive planetary gear unit 20 is directly connected integrally via the third clutch C0 and the third one-way clutch F0, and the rotation of the input shaft 17 is directly connected to the input shaft 23 of the main transmission unit 19. Is transmitted.

Further, in the main transmission unit 19, rotation of the input shaft 23 is transmitted to the ring gear R ₂ via the first clutch C1, further carrier CR _2, and the carrier CR ₂ integral with the output shaft 25 Is transmitted. At this time, since it tries to transmit the rotation of the left to the carrier CR ₃ of the rear planetary gear unit 22 via the sun gear S _2, S _3, rotation is prevented by the locking of the second one-way clutch F2, the pinion P ₃ Rotates and transmits rotation to a ring gear R ₃ integral with the output shaft 25.

Further, at the second speed (2ND) in the automatic shift mode of the drive range, only the first solenoid valve S1 and the second solenoid valve S2 are turned on. As a result, the first clutch C1, the third clutch C0, and the second brake B2 are engaged,
One-way clutch F1 and third one-way clutch F
0 is locked and the others are released. Therefore,
The direct drive state of the overdrive planetary gear unit 20 is maintained, and the rotation of the input shaft 17 is transmitted to the input shaft 23 of the main transmission unit 19 as it is. Further, in the main transmission unit 19 is transmitted to the ring gear R ₂ of the front planetary gear unit 21 the rotation of the input shaft 23 through the first clutch C1, the rotation of the left to the sun gear S ₂ via the pinions P ₂ tries to transmit, the sun gear S ₂ is rotation is prevented by the locking of the first one-way clutch F1 due to engagement of the second brake B2. Therefore, the carrier CR is rotated while rotating the pinion P _2.
2 rotates, and the second-speed rotation is transmitted to the output shaft 25 only through the front planetary gear unit 21.

In the automatic shifting mode of the drive range and the third speed (3RD) in the second range, only the second solenoid valve S2 is turned on, and the first clutch C1, the second clutch C2, and the third clutch C3 are turned on. C0 and the second brake B2 are engaged, the third one-way clutch F0 is locked, and the others are released.
Therefore, the overdrive planetary gear unit 2
0 indicates that the direct connection state is maintained, and the main transmission unit 19
Since the components of the front planetary gear unit 21 are integrated by the engagement of the first clutch C1 and the second clutch C2, the rotation of the input shaft 23 is
Is transmitted to

In the fourth speed (4TH), ie, the highest speed, in the automatic shift mode of the drive range,
The first to third solenoid valves S1 to S3 are all turned off, and the first clutch C1, the second clutch C2,
The second brake B2 and the fourth brake B0 are engaged.
The main transmission unit 19 is in a directly connected state as in the case of the third speed, but the overdrive planetary gear unit 20 is configured to release the third clutch C0 and to release the fourth brake B0.
Are switched to be engaged. Therefore, the sun gear S ₁ is locked by the engagement of the fourth brake B 0, the pinion P ₁ rotates and the power is transmitted to the ring gear R ₁ while the carrier CR ₁ rotates, and the input of the main transmission unit 19 in the directly connected state is performed. The overdrive rotation is transmitted to the shaft 23.

On the other hand, during a downshift, the third clutch C0 is engaged and the fourth brake B0 is released in the case of the 4-3 shift, and the second clutch C2 is released in the case of the 3-2 shift. Then, in the case of the 2-1 shift, the second brake B2 is released. Further, at the 1st speed and the 3rd speed in the second range, it is the same as the 1st speed and the 3rd speed in the automatic shift mode of the drive range described above.
Then, during the second speed the first clutch C1, third clutch C0, the first brake B1 and second brake B2 are engaged to lock the sun gear S ₂ of the main transmission unit 19, to generate engine braking force.

At the time of the second speed in the low range, the operation is the same as that at the time of the second speed in the second range, but at the time of the first speed, the first clutch C1, the third clutch C0, and the third brake B3 are engaged. lock the carrier CR ₃ of the rear planetary gear unit 22, to generate engine braking force. The operation at the third speed and the fourth speed in the manual shift mode (MANU.) Of the drive range is the operation at the third speed and the fourth speed in the automatic shift mode, and the operation at the second speed in the manual shift mode is the automatic shift. The operation at the second speed in the second range in the mode and the operation at the first speed in the manual shift mode are the same as the operation at the first speed in the low range in the automatic shift mode.

Next, the automatic transmission control device 31 of the present invention will be described. FIG. 5 is a schematic diagram of the automatic transmission control device according to the embodiment of the present invention, FIG. 6 is an input side block diagram of the automatic transmission control device according to the embodiment of the present invention, and FIG.
FIG. 8 is an output side block diagram of the automatic transmission control device according to the embodiment of the present invention, and FIG. 8 is a shift diagram for an automatic transmission mode according to the embodiment of the present invention. In FIG. 8, the horizontal axis represents the rotation speed of the output shaft 25 (FIG. 3) corresponding to the vehicle speed v, and the vertical axis represents the throttle opening.

In the figure, 31 is an automatic transmission control device for controlling an automatic transmission 62, 32 is a CPU, 33 is an RO
M and 34 are RAMs, 35 is an input interface circuit, 3
Reference numeral 6 denotes an input processing circuit which is connected to the input interface circuit 35 and performs input processing of each signal. Reference numeral 37 denotes sensors which are connected to the input processing circuit 36 and output each signal. 38 is an output interface circuit, 39 is connected to the output interface circuit 38, drive circuits for performing output processing of each signal, 40 is connected to the drive circuit 39,
The actuator is driven by the output signal. The automatic transmission control device 31 has a control means 86
(FIG. 1) is provided. The actuator 40 includes first to third solenoids S1 to S3 and linear solenoid valves SLU, SLN, and SLT.

Reference numeral 43 denotes a third gear of the transmission 10 (FIG. 2).
An input speed sensor for detecting the speed of the clutch C0, S
P1 and SP2 are vehicle speed sensors for detecting the number of rotations of the output shaft 25 of the automatic transmission 62. The vehicle speed sensor SP1 is used as a backup when the vehicle speed sensor SP2 breaks down and as a speedometer. . A shift position sensor 44 is provided in the transmission 10 to detect which range the shift lever 81 has selected in the automatic shift mode.
And a shift position sensor as shift speed detecting means for detecting which shift speed the shift lever 81 is selecting in the manual shift mode.

A throttle opening sensor 46 is provided on the engine 61 and detects a throttle opening corresponding to the engine load by a potentiometer (not shown).
A brake switch 47 is provided on a brake pedal (not shown) to detect a brake operation, and a brake switch 48 is provided on the throttle opening sensor 46 so that the throttle opening is 0.
An idling (IDL) switch 49 for detecting the [%] is provided on an accelerator pedal (or a throttle opening sensor 46) (not shown) so that the throttle opening is 1%.
A kick-down (K / D) switch 50 for detecting that a kick-down is requested by setting to 00 [%] is provided in the transmission 10, and an oil temperature for detecting an oil temperature of the transmission 10 is provided. A sensor 51 is an engine speed sensor for detecting the engine speed.

Each of the sensors 37 is connected to a corresponding input processing circuit 36. S1 is a first solenoid valve for shifting, S2 is a second solenoid valve for shifting, S3 is a third solenoid valve for shifting, and the first to third solenoid valves S1 to S3 are ,
By switching on and off a solenoid (not shown), switching is performed in accordance with each gear. And
SLU is a linear solenoid valve for lock-up, S
LN is a linear solenoid valve for back pressure control of an accumulator (not shown), and SLT is a linear solenoid valve for line pressure control. The first to third solenoid valves S1 to S3 and the linear solenoid valves SLU, S
Between the LN, SLT and the output interface circuit 38, a solenoid drive circuit and a monitor circuit of the drive circuits 39 are provided. The solenoid drive circuit,
The monitor circuit generates a voltage or a current for operating the first to third solenoid valves S1 to S3 and the linear solenoid valves SLU, SLN, and SLT.
-Check the operating states of the third solenoid valves S1 to S3 and the linear solenoid valves SLU, SLN, SLT, determine a failure, and perform a self-diagnosis.

Reference numeral 53 denotes an engine control device for controlling the engine 61, and reference numeral 54 denotes a torque reduction for outputting a signal for temporarily reducing the torque generated by the engine 61 in order to reduce a shock during shifting. An input / output processing circuit;
Receives a signal from the torque reduction input / output processing circuit 54 and performs ignition timing delay, fuel cut, and the like. An electronic throttle valve signal output processing circuit 55 outputs a signal for opening and closing the electronic throttle valve 74.

Reference numeral 56 denotes a DG for outputting a self-diagnosis result by an O / D off indicator lamp or the like (not shown) when the transmission device 10, the engine control device 53, etc., fail.
CHECKER 57 is the DG CHECKER 56
A DG input / output processing circuit for outputting a self-diagnosis result to a display device 58 such as a mode selection lamp and an O / D off indicator lamp (not shown) for displaying the state of the transmission 10; Drive circuit for the display.

FIG. 8 shows shift lines for shifting up and down. The automatic transmission control device 31 refers to the shift line and selects a speed corresponding to the rotation speed of the output shaft 25 and the throttle opening detected by the vehicle speed sensor SP2. In FIG. 8, 1 → 2, 2 → 3, 3 → 4, 4
← 3, 3 ← 2 and 1 ← 2 are 1-2 shift, 2-
3 shifts, 3-4 shifts, 4-3 shifts, 3-2 shifts and 2-shifts
Represents one shift.

Next, the engine 6 in the vehicle having the above-described configuration will be described.
1 will be described. FIG. 9 is a diagram showing the relationship between the output torque characteristics of the engine and the throttle opening of the electronic throttle valve according to the embodiment of the present invention, and FIG. 10 is a diagram showing the engine braking characteristics according to the embodiment of the present invention. In FIG. 9, the horizontal axis represents the engine speed N.
The _E, the engine torque T _E on the vertical axis, 10,
The horizontal axis of the vehicle speed v, the vertical axis the engine braking force F _B (FIG. 9
It is taken the engine braking force F _B) when the electronic throttle opening is 0% at.

In FIG. 9, α1 to α5 represent the throttle opening of the electronic throttle valve 74 (FIG. 2), and the lines to which the throttle opening α1 to α5, “0%” and “100%” are given are: Each electronic throttle valve 74
When the throttle opening of the throttle valve is set to α1 to α5, the throttle opening of the throttle valve 73 is set to 0% or 1%.
The figure shows the output torque generated by the engine 61 when it is set to 00 [%]. 10, the engine braking force F _B of 1ST first speed, 2ND is a 2nd speed of the engine braking force F _B, 3RD is a 3rd speed of the engine braking force F _B,
4TH is a line representing the fourth speed engine braking force F _B.

When the foot is released from the accelerator pedal (not shown), the throttle opening of the throttle valve 73 becomes 0 [%].
But it becomes, when you try to an engine speed N _E above idle speed in this state, as can be seen from Figure 9, the driving force from the outside to the engine 61, i.e., it is necessary to apply the engine braking force F _B. The engine brake utilizes this characteristic.

By the way, in the automatic transmission 62 having the above-described structure, since the speed ratio is set in a stepwise manner for each gear, the foot is released from the accelerator pedal and the throttle opening is 0%. engine braking force F _B which is generated is uniquely changes stepwise in accordance with the vehicle speed at each shift stage of the 1st to 4th speeds. Therefore, it may not be possible to obtain a desired engine braking force F _B.

Therefore, in this embodiment, the electronic throttle valve 74 is operated with the engine brake applied.
Is controlled, the throttle opening is set to a predetermined opening, and FIG.
The hatched portion of 0 is the engine brake possible range.
In the case of the first speed and the second speed, restrictions are imposed by the engine rotation limit, so that the engine brake possible range is limited. The details will be described later with reference to FIG.

Next, the engine braking force F when the throttle opening of the electronic throttle valve 74 is changed.
The change of _B will be described. FIG. 11 is an operation diagram of the engine brake according to the embodiment of the present invention. Incidentally, in FIG., Each shift speed on the horizontal axis, are taken throttle opening and the engine braking force F _B of the electronic throttle valve 74 (FIG. 2) on the vertical axis.

In [0043] FIG, L1 is a line indicating the engine braking force F _B before adjustment for changes stepwise at each gear position of 1st to 4th speed, L2 is to control the throttle opening of the electronic throttle valve 74 is a line indicating the engine braking force F _B after adjustment according to the present invention obtained by. Therefore, since the gear ratio is controlled steplessly, it is possible to obtain a desired engine braking force F _B.

[0044] In this case, at each shift speed, by controlling the throttle opening of the electronic throttle valve 74, when the smallest engine braking force F _B, and maximum engine braking force F _B at 1 stage above the shift stage Become equal. FIG. 12 is another operation diagram of the engine brake according to the embodiment of the present invention. Incidentally, in FIG., Each shift speed on the horizontal axis, are taken throttle opening and the engine braking force F _B of the electronic throttle valve 74 (FIG. 2) on the vertical axis.

In [0045] FIG, L3 is a line indicating the engine braking force F _B before adjustment for changes stepwise at each gear position of 1st to 4th speed, L4 is possible to control the throttle opening of the electronic throttle valve 74 is a line indicating the engine braking force F _B after adjustment obtained by.
In this case, at each shift speed, the electronic throttle valve 7
By controlling the fourth throttle opening and gradually to reduce the engine braking force F _B, it is possible to achieve engine braking force F _B at the gear position of a plurality of stages higher. Then, only by controlling the throttle opening of the electronic throttle valve 74, a predetermined engine braking force F _B
Therefore, the frequency of the shift can be reduced. Therefore, it is possible not only to prevent the traveling feeling from being reduced due to the occurrence of the shock, but also to improve the durability of the friction engagement elements such as the clutch and the brake necessary for performing the shift.

Next, the actual control contents will be described.
In the automatic transmission 62 having the above configuration, for example,
When the vehicle is traveling in the second gear,
Speed v ₁Engine braking force F at_BControl
The principle of this will be described. FIG. 13 shows an embodiment of the present invention.
Characteristics of Engine and Electronic Throttle Valve Throttle
4 shows an engine characteristic map showing a relationship with a throttle opening.
FIGS. 14A and 14B show the engine shake in the embodiment of the present invention.
The relationship between the braking force and the throttle opening of the electronic throttle valve
FIG. In FIG. 13, the horizontal axis represents the vehicle speed v,
The vertical axis shows the driving force F _FAnd engine braking force F_BFigure 1
In 4, the horizontal axis indicates the throttle opening and the vertical axis indicates the engine
Braking force F_BIs taken.

First, the CPU 32 (FIG. 5) determines whether or not a deceleration operation has been performed by deceleration operation determination means (not shown). For this purpose, the deceleration operation determining means determines whether or not the accelerator pedal (not shown) is released, that is, whether or not the accelerator is off, based on the depression amount of the accelerator pedal detected by the accelerator opening sensor (not shown). When the accelerator is off, the deceleration operation determining means determines whether or not a gear other than the highest gear having the smallest gear ratio is selected in the manual gear shift mode, that is, whether the gear is the first gear, the second gear, or the third gear. It is determined whether or not the current gear is selected. The deceleration operation determining means can determine whether a second range, a low range, or the like other than the drive range has been selected.

[0048] Then, the deceleration operation determination means, the driver, or releases the accelerator pedal, the first speed, when to select a gear of the second speed or the third speed, the predetermined engine braking force F _B Determine if it has occurred. Here, when turning a curve, the time to drive the vehicle at the third speed in a long downhill, but it is impossible to obtain a sufficient engine braking force F _B at the third speed gear stage, requires more than a two-speed gear stage description will be given of a case where thus obtained a strong engine brake F _B to.

Firstly, the CPU32 is the acceleration of the vehicle by the acceleration detecting means 82 (FIG. _{1) β β = {N O} (t) -N O (t-Δt)} / Δt N O (t): at the timing t The rotational speed of the output shaft 25 of the automatic transmission 62 is detected, and the comparing means 83 compares the acceleration β with 0 as a target value to determine whether or not the acceleration β is β> 0. Note that the acceleration β can be detected by an acceleration sensor (not shown).

In this case, the third speed is selected.
Therefore, sufficient engine braking force F _BCan get
Instead, the acceleration β becomes larger than zero. Therefore, the driver
Waits for the second gear to be selected. And driving
If the driver selects the second gear, the second gear is required
Since the stronger engine brake is applied,
The acceleration β becomes 0 or less. Therefore, the CPU 32
Controls the throttle opening of the electronic throttle valve 74
The engine braking force F_BWeakens and slows down
Weaken.

For example, when the engine brake is applied at the second speed, the engine 61 is driven with the characteristics shown in FIG. Note that an engine characteristic map as shown in FIG. 13 is stored in advance in a storage device (not shown) for each shift speed. That is, release the foot from the accelerator pedal, it becomes the throttle valve 73 throttle opening 0% (Figure 2), an engine braking force F _B is applied to the engine 61 as a negative driving force F _F. Incidentally, the engine braking force F _B is reduced and the vehicle speed v becomes lower.

[0052] Then, open the electronic throttle valve 74 in a state of releasing the foot from the accelerator pedal, in accordance with the throttle opening increases the α5 from [alpha] 1, the engine braking force F _B as shown in FIG. 14 is reduced. Also,
When traveling downhill, it becomes the equivalent drive force F _F is generated in accordance with the inclination of the road increases as r ₃ from r _1, the driving force F _F is increased.

[0053] Then, for example, release the foot from the accelerator pedal when the vehicle is traveling the road gradient r ₂ in the second speed gear stage at a vehicle speed v _1, the value of the driving force F _F together with becomes F _F2 , the value of the engine braking force F _B becomes F _B0. Therefore, the vehicle is decelerated by the difference between the value F _B0 and _{F F2 (F B0 -F F2)} . Therefore, when the throttle opening of the electronic throttle valve 74 to the alpha 4, and is equal driving force F _F and the engine braking force F _B, the difference (F _B0 -
F _F2 ) can be set to zero.

That is, the holding means 84 of the CPU 32
Referring to the engine characteristic map which is set for each shift speed, it calculates a throttle opening degree of the drive force F _F and the engine braking force F _B and are equal such an electronic throttle valve 74, the acceleration beta is, beta = 0 Is determined. In practice, it is determined whether β ≒ 0.

[0055] Thus, the driving force F _F and the engine electronic throttle valve 7 as the braking force and F _B equals
Calculating a fourth throttle opening, since the acceleration β is adapted to hold the 0, the desired engine braking force F _B
Can be obtained. Further, when the engine brake is applied, the gear ratio does not change stepwise, so that a shock does not occur and the running feeling does not deteriorate.

The threshold value of the acceleration β for making this determination is set in consideration of the vehicle standard, sensor accuracy, test evaluation, and the like. In the present embodiment, it is determined whether the acceleration β is greater than 0, and the throttle opening of the electronic throttle valve 74 is controlled to maintain the acceleration β at 0. It is determined whether the value is larger than the value β ₀ and the electronic throttle valve 74 is determined.
By controlling the throttle opening, the acceleration β can be held at the target value β ₀ . The acceleration β and the target value β
₀ may be set based on the running state of the vehicle, the running environment, the operation of the driver, and the like.

The target value β ₀ can be set differently for each shift speed. Further, the target value β ₀ can be set by the driver operating an operation key, an operation switch or the like. The target value β ₀ is set by the target value setting means 85. Next, the flowchart will be described.

FIG. 15 is a first flowchart showing the operation of the automatic transmission control device according to the embodiment of the present invention, and FIG. 16 is a second flowchart showing the operation of the automatic transmission control device according to the embodiment of the present invention. FIG. 17 is a third flowchart showing the operation of the automatic transmission control device according to the embodiment of the present invention. Step S1 When starting the program, initial settings are made for all conditions. Step S2 Based on signals from the input speed sensor 43 (FIG. 6) and the vehicle speed sensors SP1 and SP2, the current speed of the input shaft 17 and output shaft 25 of the transmission 10 (FIG. 3) is calculated. Step S3: A range is detected based on a signal from the shift position sensor 44. At the same time, a failure of the neutral start switch (N.S.S.W.) is determined. Step S4: The throttle opening is detected based on the signal from the throttle opening sensor 46. Step S5: The oil temperature of the transmission 10 is detected based on the signal from the oil temperature sensor 50. Step S6: The gear position is detected based on the signal from the shift position sensor 45.

In this case, the shift position sensor 45
Has a manual shift switch at each shift position. Step S7: It is determined whether any one of the manual shift switches is turned on. If any one of the means shift switches is turned on, step S
On the other hand, if none of the means shift switches is on, the process proceeds to step S8. Step S8: It is determined whether or not the manual shift mode flag is turned on. If the manual shift mode flag is on, the process proceeds to step S16; otherwise, the process proceeds to step S9. Step S9 The automatic shift data D is set to the shift point data MSL in the shift diagram for the automatic shift mode shown in FIG. Step S10 Automatic shift data D is added to the lockup point data MSLP of the lockup diagram for the automatic shift mode.
Is set. Step S11 A shift (A / T shift) determination and a lock-up (L-up) determination in the automatic shift mode are performed based on the automatic shift data D read in steps S9 and S10 and the various running conditions calculated previously. Step S12 The timing determination of the shift determination and the lockup determination performed in step S11 is performed. Step S13: The manual shift mode flag is turned on to set the manual shift mode. Step S14: Reset the value of the timer (not shown) for returning to the automatic transmission mode. Step S15: Perform a manual shift (M / T) map selection process, select a shift diagram and a lockup diagram for the manual shift mode, and set the manual shift data in the shift point data MSL and the lockup point data MSLP. . Step S16 automatic shift mode returning timer to determine whether the time t that counts is longer than the set value t _1. To step S17 if the time t is longer than the set value t _1, when the time t is set t ₁ following the process proceeds to step S15. Step S17: Turn off the manual shift mode flag. Step S18 A shift (M / T shift) determination and a lock-up determination in the manual shift mode are performed based on the manual shift data read in step S15 and the various running conditions calculated previously. Step S19 The timing determination of the shift determination and the lockup determination performed in step S18 is performed. Step S20 The third solenoid valve S3 (FIG. 7) for shifting is controlled in order to make the engine brake effective, based on the shift position detected based on the signal from the shift position sensor 45, the speed corresponding to the output request, and the like. A determination process is performed. Step S21 Steps S11, S12, S18 to S
A shift output or an engine brake output is generated according to the determination at 20 and the first to third solenoid valves S1
変 速 S3 is activated to start shifting or apply engine braking. Step S22 At the time of shift shifting in the manual shift mode, a process of determining whether to temporarily increase the line pressure to reduce the time lag is performed. Step S23 As a result of the determination processing in step S22, the linear solenoid valve SLT for line pressure control is controlled. Step S24: In order to prevent a shock during a shift shift, it is determined whether to control the back pressure of the accumulator for the manual shift or the back pressure of the accumulator for the automatic shift. Perform control processing. Step S25 Linear solenoid valves SLU, SL
N, SLT is controlled. Step S26: It is determined whether or not the accelerator is off. If the accelerator is off, the process proceeds to step S27,
If the ask cell is not off, the process returns to step S2. Step S27: The selected gear is 1st, 2nd or 3rd
Determine if it is fast. If the gear is 1st, 2nd or 3rd, the process proceeds to step S28. If it is not 1st, 2nd or 3rd, the process returns to step S2. Step S28: It is determined whether the acceleration β is larger than 0. If the acceleration β is greater than 0, the process returns to step S2, and if the acceleration β is 0 or less, the process proceeds to step S29. Step S29: Control the throttle opening of the electronic throttle valve 74. Step S30: It is determined whether or not the acceleration β is substantially zero. If the acceleration β is almost 0, step S2
If the acceleration β is not substantially zero, the process returns to step S29.

[0060]

As described above in detail, according to the present invention, in a vehicle engine brake control system, an engine and a rotation ratio generated by the engine are used to change the gear ratio of each gear. A transmission for shifting gears with
Selecting means for selecting the gear position, throttle opening changing means for changing the throttle opening regardless of depression of an accelerator pedal, acceleration detecting means for detecting acceleration, and the acceleration and a preset target value. A comparison means for comparing, and a holding means for operating the throttle opening changing means based on a result of the comparison by the comparison means and holding the acceleration at a target value.

In this case, the acceleration detected by the acceleration detecting means is compared with the target value, and the acceleration can be held at 0 by operating the throttle opening changing means based on the comparison result. Therefore, a desired engine braking force can be obtained. Further, when the engine brake is applied, the engine braking force does not change stepwise, so that a shock does not occur and the running feeling does not deteriorate.

[Brief description of the drawings]

FIG. 1 is a block diagram of a vehicle engine brake control device according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram of a vehicle according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of an automatic transmission according to an embodiment of the present invention.

FIG. 4 is a diagram showing an operation of the automatic transmission according to the embodiment of the present invention.

FIG. 5 is a schematic diagram of an automatic transmission control device according to an embodiment of the present invention.

FIG. 6 is an input side block diagram of the automatic transmission control device according to the embodiment of the present invention.

FIG. 7 is an output side block diagram of the automatic transmission control device according to the embodiment of the present invention.

FIG. 8 is a shift diagram for an automatic shift mode in the embodiment of the present invention.

FIG. 9 is a relationship diagram between an output torque characteristic of an engine and a throttle opening of an electronic throttle valve according to the embodiment of the present invention.

FIG. 10 is a diagram showing engine brake characteristics according to the embodiment of the present invention.

FIG. 11 is an operation diagram of an engine brake according to the embodiment of the present invention.

FIG. 12 is another operation diagram of the engine brake according to the embodiment of the present invention.

FIG. 13 is a diagram showing an engine characteristic map showing a relationship between engine characteristics and a throttle opening of an electronic throttle valve in the embodiment of the present invention.

FIG. 14 is a diagram illustrating a relationship between an engine braking force and a throttle opening of an electronic throttle valve according to the embodiment of the present invention.

FIG. 15 is a first flowchart showing an operation of the automatic transmission control device in the embodiment of the present invention.

FIG. 16 is a second flowchart showing the operation of the automatic transmission control device in the embodiment of the present invention.

FIG. 17 is a third flowchart showing the operation of the automatic transmission control device in the embodiment of the present invention.

FIG. 18 is a diagram showing a range position and a shift position of a shift lever according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Transmission 31 Automatic transmission control device 45 Shift position sensor 61 Engine 74 Electronic throttle valve 81 Shift lever 82 Acceleration detection means 83 Comparison means 84 Holding means

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02D 41/12 310 F02D 41/12 310 (72) Inventor Keiichi Kimura 2-19-12 Sotokanda, Chiyoda-ku Tokyo Within Equos Research

Claims (4)

[Claims] 1. An engine, a transmission device that receives a rotation generated by the engine and performs a shift at a speed ratio for each speed stage, a selection unit for selecting the speed stage, and depression of an accelerator pedal. Throttle opening changing means for changing the throttle opening regardless of acceleration, acceleration detecting means for detecting acceleration, comparing means for comparing the acceleration with a preset target value, and based on a comparison result by the comparing means. Holding means for activating the throttle opening changing means and holding the acceleration at a target value. 2. An engine, a transmission for receiving a rotation generated by the engine, and performing a shift at a speed ratio for each speed, a selecting means for selecting the speed, and depressing an accelerator pedal. Throttle opening changing means for changing the throttle opening regardless of the speed, and deceleration operation determining means for determining whether the driver has performed a deceleration operation,
Acceleration detecting means for detecting acceleration; comparing means for comparing the acceleration with a preset target value when the predetermined deceleration operation is determined by the deceleration operation determining means; And a holding means for activating the throttle opening changing means based on the comparison result and holding the acceleration at a target value. 3. The deceleration operation determining means includes an accelerator opening sensor for detecting an amount of depression of an accelerator pedal, and a shift speed detecting means for detecting a shift speed selected by the selecting means. A predetermined deceleration operation is performed when at least one of release, a gear other than the gear with the smallest gear ratio is selected, and a range other than the drive range is selected. 3. The engine brake control device for a vehicle according to claim 2, wherein it is determined that the vehicle has been hit. 4. The engine brake control device for a vehicle according to claim 1, wherein each of the target values is set for each shift speed.