JP3533865B2 - Vehicle deceleration control method and control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deceleration control method and control device for a vehicle in which the output rotation speed of a multi-cylinder internal combustion engine is reduced by a stepped transmission.

[0002]

2. Description of the Related Art Generally, an automatic transmission of a vehicle is designed to change a gear ratio stepwise or continuously based on an accelerator operation amount or a throttle valve opening and a vehicle speed. However, in the conventional automatic transmission having a stepped gear ratio, the accelerator pedal is downshifted according to the vehicle speed even when the accelerator operation amount or the throttle valve opening is zero. Even if the vehicle is released, if the vehicle speed increases without obtaining sufficient engine braking force, there is a problem that the engine braking force further decreases due to an upshift.

As a countermeasure against this, the actual vehicle speed when the accelerator is turned off is compared with the determination vehicle speed, and when the actual vehicle speed exceeds the determination vehicle speed, the gear ratio of the automatic transmission is increased. A technique of downshifting a gear to increase engine braking force is disclosed in, for example, Japanese Patent Laid-Open No. 5-16.
No. 2570, etc.

[0004]

However, in the above-described automatic transmission that downshifts the transmission gear stage, if the transmission gear stage is lowered by one stage, the engine braking force will change significantly, so that the road gradient will be reduced. It was difficult to obtain the optimum engine braking force.

For example, in the case of an automatic transmission for a vehicle having four shift gears, the gear ratio is 5 at 3rd and 2nd.
It is generally set so that it is different from each other,
According to a simple calculation, the engine braking force increases by 50% when the gear is downshifted from 3rd to 2nd by one step. Therefore, depending on the road surface gradient, the engine braking force may be insufficient at 3rd, but too large at 2nd. In such a case, the shift gear stage may be held at 3rd so that the driver does not feel uncomfortable.

The present invention has been made in view of the above problems of the prior art, and the problem to be solved by the present invention is a cylinder for changing the shift speed and performing fuel cut in a multi-cylinder internal combustion engine. By combining the number and the number, it is possible to finely control the deceleration and to obtain the optimum engine braking force according to the road surface gradient.

[0007]

The present invention adopts the following means in order to solve the above problems. The present invention relates to a vehicle deceleration control method for reducing the output rotational speed of a multi-cylinder internal combustion engine by means of a stepped transmission, and when a vehicle is decelerated, it is desirable.
Based on the deceleration of at least one gear position
The number of cylinders of the internal combustion engine that performs fuel cut is different.
The gear position and the number of cylinders for fuel cut.
One pattern from multiple patterns set by combination
Select, determines the position of the variable <br/> speed of the number of cylinders and a transmission for performing fuel cut, based on the determination, fuel mosquitoes
Of the determined number of cylinders when in the fuel range
To execute the cutout and the control of the gear position.
A deceleration control method for a vehicle, characterized in that the deceleration force of the vehicle is controlled by:

Further, according to the present invention, in a deceleration control device for a vehicle that decelerates an output rotational speed of a multi-cylinder internal combustion engine by means of a stepped transmission, a deceleration traveling detection means for detecting that the vehicle is decelerating. A reference acceleration determining means for determining a reference acceleration of the vehicle during decelerating traveling; an actual acceleration detecting means for detecting an actual acceleration of the vehicle during decelerating traveling;
At this time, the reference acceleration determined by the reference acceleration determining means is compared with the actual acceleration detected by the actual acceleration detecting means, and at least based on the comparison result.
Internal combustion that performs fuel cut for the gear position of 1
The position of the gear and the fuel so that the number of cylinders of the engine is different
Multiple patterns set in combination with the number of cylinders to cut
Select one pattern from chromatography emissions, a reduction level determining means for determining the position of the gear of the air cylinder number and a transmission for performing fuel cut, based on the determination of the reduction level determining means
The cylinder determined as above when in the fuel cut region
A fuel supply control means for executing a certain number of fuel cuts, and a gear position control means for executing a position control of the gear position of the transmission based on the determination of the deceleration level determination means. It is a deceleration control device.

There are various ways of thinking about how to set the reference acceleration. For example, an empirical numerical value that an occupant in a vehicle can feel without feeling uncomfortable is obtained in advance by experiments. It is also possible to adopt this numerical value.

In the vehicle deceleration control device of the present invention, the deceleration traveling detection means detects that the vehicle is decelerating, and the reference acceleration determining means determines the reference acceleration during deceleration traveling and the actual acceleration detecting means. The actual acceleration of the vehicle during deceleration (hereinafter referred to as the actual acceleration) is detected. Then, the deceleration level determining means compares the reference acceleration with the actual acceleration, and based on the comparison result, determines the number of cylinders of the internal combustion engine and the position of the shift stage of the transmission for performing fuel cut. Further, based on the determination of the deceleration level determination means, the fuel supply control means executes the presence / absence of the fuel cut to each cylinder, and the shift speed control means changes the position of the shift speed of the transmission.

Even if the gear positions of the transmission are the same, the magnitude of the firing torque differs depending on how many cylinders of the internal combustion engine the fuel cut is performed, and the magnitude of the firing torque also differs. Causes a difference in the magnitude of engine braking force. The gear position and the number of fuel cut cylinders are controlled so that the engine braking force increases as the deviation between the actual acceleration and the reference acceleration increases and the degree of insufficient engine braking force increases.

Therefore, as described above, a fine deceleration can be obtained by combining the control of the number of cylinders of the internal combustion engine which performs the fuel cut and the position control of the shift stage of the transmission.

[0013]

DETAILED DESCRIPTION OF THE INVENTION

[First Embodiment] A first embodiment of a vehicle deceleration control device of the present invention will be described below with reference to the drawings of FIGS. 1 to 11. In the first embodiment, the vehicle deceleration control device of the present invention is a four-cylinder gasoline engine and a four-cylinder gasoline engine.
This is a mode applied to a vehicle provided with an automatic transmission having a gear shift stage.

In FIG. 1, the air sucked from the air cleaner 14 has an air flow meter 16, an intake passage 18,
Throttle valve 20, bypass passage 22, surge tank 2
4, the intake manifold 26 is divided into four intake manifolds 26, and is sucked into the combustion chamber 12 of each cylinder from each intake valve 28 of the four cylinders of the gasoline engine (internal combustion engine) 10. A fuel gas injected from a fuel injection valve 30 provided in each interior manifold 26 is mixed with this air.

The air flow meter 16 measures the intake air amount, and outputs a signal representing the intake air amount to the engine control computer 32. The throttle valve 20 continuously changes the amount of air taken into the engine 10, and the slot valve opening θ is controlled according to a slot control signal DTH supplied from the throttle control computer 35. Further, a throttle position sensor 36 is provided in the throttle valve 20, and a throttle valve opening signal S indicating a throttle valve opening θ.
θ is output to the engine control computer 32, the transmission control computer 34, and the throttle control computer 35.

The bypass passage 22 is arranged in parallel with the throttle valve 20, and the bypass passage 22 is provided with an idle speed control valve 38, which is controlled by the computer 32 for controlling the engine. By controlling the opening, the amount of air that bypasses the throttle valve 20 is adjusted and the engine speed during idling is controlled.

The injection timing and the injection amount of the fuel injection valve 30 are also controlled by the engine control computer 32. An intake air temperature sensor 40 that measures the temperature of intake air is provided upstream of the air flow meter 16.
A signal indicating the intake air temperature is sent to the engine control computer 3
Output to 2.

The engine 10 comprises four cylinders, an intake valve 28, an exhaust valve 42, a piston 44 and an ignition plug 46 provided in each cylinder. Spark plug 4
6 generates an ignition spark by a high voltage supplied from an igniter 48 controlled by an engine control computer 32 through a distributor 50, explodes a mixed gas in the fuel chamber 12 to move a piston 44 up and down. To rotate the crankshaft.

The intake valve 28 and the exhaust valve 42 are opened and closed by a cam shaft which is rotationally driven in synchronization with the rotation of the crank shaft, and a variable valve timing (not shown) controlled by the engine control computer 32. The mechanism changes the rotational phase of the cam shaft and the crank shaft to adjust the opening / closing timing.

Exhaust gas burned in the fuel chamber 12 of each cylinder passes through an exhaust manifold 54 from an exhaust valve 42 of each cylinder and then an exhaust pipe 55.
Are discharged into the atmosphere through the exhaust passage 56 and the catalyst device 58.

In FIG. 1, the route from the intake manifold 26 to the exhaust manifold 54 is
One cylinder is shown, and three cylinders are omitted. The engine 10 is provided with a water temperature sensor 60 that measures the engine cooling water temperature, and outputs a signal representing the engine cooling water temperature to the engine control computer 32.

The exhaust pipe 55 is provided with an oxygen sensor 62 for detecting the oxygen concentration in the exhaust gas,
A signal representing the oxygen concentration is output to the engine control computer 32.

The distributor 50 has a rotation angle sensor 5 for generating a pulse in synchronization with the rotation of the crankshaft.
1 is provided, and the pulse signal, that is, the engine rotation speed signal SNE representing the engine rotation speed NE is output to the engine control computer 32 and the transmission control computer 34.

The engine control computer 32, the transmission control computer 34, and the throttle control computer 35 are all CPU, RAM and R.
The OM includes an OM, an input / output interface circuit, an A / D converter, etc., and performs signal processing according to a program stored in advance in the ROM while utilizing the temporary storage function of the RAM.

Transmission control computer 3
In addition to the above signals, a pattern select switch 70
To a pattern signal SP indicating a selection pattern, a brake signal SB indicating that the brake lamp switch 72 is operated by depressing the brake, and a shift permission from the overdrive switch 74 to the 4th shift gear (O / D gear). O / D signal SO, accelerator operation amount sensor 7
The accelerator operation amount signal SAc indicating the operation amount Ac of the accelerator pedal is supplied from 6 and the idle signal SI indicating the idle state (ON) is supplied from the idle switch 86. The accelerator operation amount signal SAc and the idle signal SI are also supplied to the engine control computer 32 and the throttle control computer 35.

The pattern select switch 70 has at least an automatic engine brake pattern for automatically increasing the engine brake on a downhill, and a power pattern for controlling the shift of the automatic transmission 78 by a shift map that emphasizes power performance. Economy patterns such as shift control with shift maps that emphasize fuel efficiency,
The driver selects and operates a favorite driving pattern from a plurality of predetermined driving patterns.

The automatic transmission 78 includes a torque converter 110, a first transmission 112, and a second transmission 114, as shown in FIG. 2, for example. The pump impeller of the torque converter 110 is connected to the crankshaft 118 of the engine 10, and the turbine impeller of the torque converter 110 is the input shaft 12.
It is connected to the carrier 122 of the first transmission 112 via 0.

The first transmission 112 includes a sun gear 124, a ring gear 126, and a planetary gear unit rotatably arranged on the carrier 122 and comprising a planetary gear 128 meshed with the sun gear 124 and the ring gear 126. Cage, sun gear 124 and carrier 12
2, a clutch C ₀ and a one-way clutch F ₀ are provided in parallel, and a brake B ₀ is provided between the sun gear 124 and the housing 130.

Since the one-way clutch F ₀ is provided between the sun gear 124 and the carrier 122, the clutch C is used when power is transmitted from the engine 10 side.
_{Even if 0} is released, the one-way clutch F ₀ allows the clutch C _{0 to} be released.
The same operation as when the engagement control is performed can be obtained.

The second transmission 114 is rotatably disposed on the sun gear 132, the pair of ring gears 134 and 136, and the carrier 138 so as to be rotatable on the sun gear 132, the planetary gear 140 meshed with the ring gear 134, and the carrier 142. The planetary gear 14 arranged and meshed with the sun gear 132 and the ring gear 136.
4 which is configured to include a complex type planetary gear set comprising a clutch C ₁ is provided between the ring gear 126 of the ring gear 136 first transmission 112, between the sun gear 132 and ring gear 126 Has a clutch C ₂
The brake B ₁ and the one-way clutch F ₁ and the brake B ₂ arranged in series are arranged in parallel between the sun gear 132 and the housing 130.
A brake B ₃ and a one-way clutch F ₂ are provided in parallel between the valve 38 and the housing 130.

Further, the ring gear 134 and the carrier 14
Reference numeral 2 is integrally connected to the output shaft 146, and the output shaft 146 is connected to the drive wheels via a differential gear device or the like.

The clutches C _{0 to} C ₂ and the brakes B ₀ to
B ₃ (hereinafter, referred to as a clutch C and a brake B unless otherwise specified) is a hydraulic friction engagement device such as a multi-plate clutch or a band brake that is engagement-controlled by a hydraulic actuator. The hydraulic oil is supplied from the hydraulic control circuit 150.

The hydraulic control circuit 150 is provided with a large number of switching valves and the like, and the solenoids S1, S2, and S are operated in accordance with signals from the transmission control computer 34.
By switching the excitation and non-excitation of No. 3 respectively, the hydraulic circuit is switched to selectively control the engagement of the clutch C and the brake B, and as shown in FIG. That shift gear is established.

In FIG. 3, the mark "○" in the column of solenoid means excitation, and the mark "○" in the column of clutch and brake means engagement. Shift position "D", "S",
“L” is the operating range of the driver's shift lever,
In the "D" range, the shift gear stage control is performed in 4 stages from 1st to 4th (O / D), and in the "S" range, the shift gear stage control is performed in 3 stages from 1st to 3rd.
In the "L" range, the speed change gear stage control is performed in two stages, 1st and 2nd.

The gear ratio (rotational speed of the input shaft 120 / rotational speed of the output shaft 146) is the largest at 1st, 2nd, 3
It becomes smaller as it becomes rd and 4th, and the gear ratio of 3rd is 1.0.

In the "D" range, 3rd and 4t
The engine brake acts at h, and the engine brake does not work at 1st and 2nd due to the action of the one-way clutches F ₂ and F ₁ , but is shown in parentheses (1st),
At (2nd), the brakes B ₃ and B ₁ are engaged by exciting the solenoid S3, and the engine brake is activated. 2nd of "S" range
Also, the engine brake operates at the first and second ends of the "L" range.

Although illustration is omitted, when the shift lever is operated to the "R" range, the manual shift valve of the hydraulic control circuit 150 is switched to establish the reverse shift gear.

The automatic transmission 78 is provided with a pair of rotation speed sensors 80 and 82. The rotation speed sensor 80 is the input shaft 120, that is, the torque converter 110.
The rotational speed sensor 82 detects the rotational speed N _T of the turbine impeller, and the rotational speed sensor 82 detects the rotational speed N ₀ of the output shaft 146. The rotational speed signal SN represents the respective rotational speeds N _T and N _{0. The T} and SN ₀ are output to the transmission control computer 34.

Further, the hydraulic control circuit 150 is provided with a neutral start switch 84, and the "D", "S", "L", "R" from the position of the manual shift valve which is switched by operating the shift lever. The shift range signal SR indicating the shift range is output to the transmission control computer 34.

The control computers 32, 34,
Necessary information is exchanged between 35,
The throttle valve opening signal Sθ, the engine rotation speed signal SNE, and the accelerator operation amount signal SAc may be supplied to at least one of the control computers 32, 34 or 35. Also, for example, the steering angle of the steering wheel, the slope of the road surface, the exhaust temperature, etc.
By capturing various other signals that represent the driving status of the car,
It can also be used for engine control, shift control of the automatic transmission 78, and throttle control.

Then, the engine control computer 32 causes the intake air amount, the throttle valve opening θ, the engine rotation speed NE, the cooling water temperature of the engine 10, the intake air temperature, the oxygen concentration in the exhaust passage 56, the accelerator operation. Quantity Ac
In accordance with the above, for example, the fuel injection valve 30 is based on a predetermined data map or arithmetic expression so as to reduce fuel consumption and harmful exhaust gas while securing a necessary engine output.
Controls the injection amount and injection timing of the fuel gas, the ignition timing by the igniter 48, the idle speed by the idle speed control valve 38, the opening and closing timing of the intake and exhaust valves 28, 42 by the variable valve timing mechanism, and the like.

Transmission control computer 3
4 is a throttle valve opening θ, an engine speed NE, a selection pattern represented by a pattern signal SP, and a brake signal SB.
The presence / absence of the brake operation represented by, and the O / D represented by the O / D signal SO
The automatic transmission 78 is switched by switching between energized and de-energized states of the solenoids S1, S2 and S3, respectively, based on whether or not shifting to the D speed is possible, the accelerator operation amount Ac, the output shaft rotation speed N ₀ of the automatic transmission 78, and the like. The transmission gear position of is controlled to be switched.

The transmission control computer 34 also switches the lockup clutch of the torque converter 110 between full engagement, a slip state, and an open state by duty-controlling a solenoid (not shown) provided in the hydraulic control circuit 150. It is like this.

Further, the throttle control computer 35
Basically outputs a throttle control signal DTH based on the accelerator operation amount Ac, and controls the throttle valve opening degree θ of the throttle valve 20 according to the accelerator operation amount Ac.

The engine control computer 3 is also provided.
2 and the transmission control computer 34,
When the automatic engine braking pattern is selected by the pattern select switch 70, the engine braking force is automatically controlled so that the optimum engine braking force according to the road surface gradient can be obtained on the downhill. ing.

The control of the engine braking force is realized by a combination of the control of the shift gear stage in the automatic transmission 78 and the control of the fuel cut for each cylinder of the engine 10. Hereinafter, control of the engine braking force will be described with reference to FIGS. 4 to 11.

First, the control (AT control) of the shift gear stage of the automatic transmission 78 will be described with reference to the flowcharts of FIGS. 4 and 5. First, in FIG. 4, step 20
At 1, various parameters (vehicle speed signal, idle switch signal, etc.) necessary for shift gear control are input to the transmission control computer 34.

Next, in step 202, it is judged whether or not the shift range is "D (drive)", and step 2
In 03, it is determined whether the traveling pattern is the "automatic engine braking pattern", in step 204 it is determined whether the idle switch 86 is ON, and in step 205, the current vehicle speed V requires engine braking control. It is determined whether or not the vehicle speed is within a certain vehicle speed range (V ₁ or more and less than V ₂ ).

In the D range, as shown in FIG. 3, the shift control is performed with a total of four shift gear stages of 1st, 2nd, 3rd, and 4th. If even one of the steps 202 to 205 is NO, the flag F1 is set to "0" and the flag F2 is set to "0" in step 206, and the routine proceeds to step 207 to execute normal shift gear control. . On the other hand, the above steps 202 to 205
If all of the determinations of YES are YES, step 208 and subsequent steps for controlling the engine braking force are executed.

When the automatic engine braking control is executed in all the driving patterns, step 202 and step 203 can be omitted.

The normal shift gear control in step 207 is performed when the operation range of the shift lever is the D range.
Basically, the accelerator operation amount Ac (%) and the vehicle speed V (k
m / h), the shift gear of the automatic transmission 78 is switched according to the shift map of FIG. 7. For example, when the current shift gear is 3rd and the accelerator operation amount Ac is about 40%, As indicated by the alternate long and short dash line in 7,
The shift-up vehicle speed Vu is obtained from the "4" shift line, the shift-down vehicle speed Vd is obtained from the "2 ← 3" shift line, and the actual vehicle speed V is compared with the shift-up vehicle speed Vu and the shift-down vehicle speed Vd to shift gears. It is determined whether the automatic transmission 78 is to be performed or not, and the solenoids S1 and S2 are switched between energized and de-energized according to the determination result.
The shift gear stage of is controlled to be switched.

When the operation range of the shift lever is the S range, shifting to the 4th is prohibited, and when the operating range of the shift lever is the L range, shifting to the 3rd and 4th is prohibited. As shown in FIG. 3, the solenoid S3 is excited in the 2nd and L ranges of the S range where engine braking is required.

A plurality of types of shift maps are stored in advance in the ROM of the transmission control computer 32 in accordance with a plurality of travel patterns selectable by the pattern select switch 70.

In step 208, the engine brake level determination process is performed. The engine brake level determination process will be described with reference to the flowchart of FIG. First, the reference acceleration Ab corresponding to the current vehicle speed is shown in FIG.
The map is calculated by an interpolation method or the like with reference to the map shown in (step 2081). Here, the reference acceleration Ab is an acceleration (deceleration) that the driver normally feels as a natural deceleration, and in this embodiment, when the idle switch 86 is ON and the shift gear is 4th coasting on a flat road surface. The acceleration (deceleration) is defined as the reference acceleration Ab.
The map shown in FIG. 8 is created by previously measuring the vehicle speed and the reference acceleration Ab at the vehicle speed, and is stored in the ROM of the transmission control computer 34.

Next, the current actual vehicle acceleration (hereinafter,
Am is called the actual acceleration (step 208)
2). The actual acceleration Am is calculated as the amount of change in vehicle speed over a predetermined time.

Next, the acceleration difference ΔA between the actual acceleration Am and the reference acceleration Ab is calculated (step 2083). The larger the acceleration difference ΔA, the larger the downward gradient.
Therefore, an engine braking level (hereinafter, simply referred to as a level) is determined in step 2084 and subsequent steps from the magnitude of the acceleration difference ΔA so that a larger engine braking force can be obtained as the acceleration difference ΔA increases.

In this embodiment, five threshold values k2, k3, k4, k5, k6 are set for the acceleration difference ΔA, and the engine brake level is divided into six stages. Step 20
At 84, it is determined whether the acceleration difference ΔA calculated at step 2083 is greater than or equal to the threshold value k6.
When it is determined that A is the threshold value k6 or more, it is determined to be level 6 (L6).

When it is determined that the acceleration difference ΔA is smaller than the threshold value k6, it is determined whether or not it is the threshold value k5 or more (step 2085), and when it is determined that it is the threshold value k5 or more. It is determined to be level 5 (L5).

When it is determined that the acceleration difference ΔA is smaller than the threshold value k5, it is determined whether or not it is the threshold value k4 or more (step 2086), and when it is determined that it is the threshold value k4 or more. It is determined to be level 4 (L4).

When it is judged that the acceleration difference ΔA is smaller than the threshold value k4, it is judged whether or not it is the threshold value k3 or more (step 2087), and when it is judged that it is the threshold value k3 or more. It is determined to be level 3 (L3).

When it is judged that the acceleration difference ΔA is smaller than the threshold value k3, it is judged whether or not it is the threshold value k2 or more (step 2088), and when it is judged that it is the threshold value k2 or more. Level 2 (L2) is determined and threshold value k2
If it is determined to be smaller than the above, it is determined to be level 1 (L1).

As shown in FIG. 9, each threshold value k2,
An ON value (kn _ON ) and an OFF value (kn _OFF ) are provided for k3, k4, k5, and k6 to provide hysteresis to prevent frequent level changes.

After performing the level determination processing in this way, the routine proceeds to step 209 in FIG. 4 to determine whether the engine brake level is level 1. When it is determined that the level is 1, the routine proceeds to step 206, the flag F1 is set to "0", the flag F2 is set to "0", and the routine proceeds to step 207 to control the normal shift gear stage.

If it is determined in step 209 that the engine brake level is not level 1, the process proceeds to step 210 and it is determined whether or not it is level 2. Level 2
If it is determined that the flag F1 is "1", the flag F1 is set to "1", the flag F2 is set to "0", and the process proceeds to step 212 to shift the automatic transmission 78 to the 4th gear position. Ban. Prohibition of shifting to 4th is achieved by maintaining the shift gear position at 3rd even when it is determined in the shift map of FIG. 7 that it is in the 4th region.

If it is determined in step 210 that the engine brake level is not level 2, the process proceeds to step 213, where it is determined whether it is level 3. Level 3
If it is determined that the flag F1 is “0”, the flag F1 is set to “0”, the flag F2 is set to “0”, and the process proceeds to step 212 to shift the automatic transmission 78 to the 4th gear. Ban.

If it is determined in step 213 that the engine brake level is not level 3, the process proceeds to step 215 to determine whether it is level 4. Level 4
If it is determined that the flag F1 is set to "0", the flag F1 is set to "0", the flag F2 is set to "1", and the process proceeds to step 217, where the shift gears of the automatic transmission 78 are changed to 4th and 3rd. Prohibit shifting. The prohibition of shifting to 4th and 3rd is 4t in the shift map of FIG.
Even if it is determined to be in the h and 3rd regions, it is achieved by maintaining the shift gear at 2nd.

If it is determined in step 215 that the engine brake level is not level 4, the process proceeds to step 218 and it is determined whether or not it is level 5. Level 5
If it is determined that the flag F1 is “1”, the flag F1 is set to “1”, the flag F2 is set to “0”, and the process proceeds to step 217, where the shift gears of the automatic transmission 78 are changed to 4th and 3rd. Prohibit shifting.

If it is determined in step 218 that the engine brake level is not level 5, the process proceeds to step 220, the flag F1 is set to "0", the flag F2 is set to "0", and the process proceeds to step 217 to further determine the automatic transmission. Prohibit shifting of 78 gears to 4th and 3rd.

After steps 212 and 217, the routine proceeds to step 221, where it is judged whether or not the current gear position is 2nd. If it is judged that it is 2nd, the solenoid S3 is excited in step 222. . As a result, (2nd) shown in the column of D range in FIG. 3 is achieved,
The engine brake can be applied even when the gear position is 2nd. The above is the control of the shift gear stage of the automatic transmission 78.

Next, regarding the fuel cut control for each cylinder of the engine 10, the fuel injection control (EF
This will be described with reference to the flowchart of (I control). First,
In FIG. 6, various parameters required for fuel injection control in step 301 (engine speed, intake air amount, etc.)
Is input to the engine control computer 32.

Next, the fuel injection amount TAU required for each cylinder is calculated from the engine speed NE and the intake air amount Q (step 302). The fuel injection amount TAU is calculated by Equation 1.

[0072]

## EQU1 ## TAU = k × Q / NE × FAF × kh In this equation 1, k, FAF, and kh are correction coefficients.

Next, the routine proceeds to step 303, where it is judged if it is in the fuel cut region or not. That is, it is determined whether the idle switch 86 is ON and the engine speed NE is higher than the fuel cut speed NEc. When both of these conditions are satisfied, the fuel cut region is set, and when both conditions are not satisfied, the fuel cut region is not set.

When it is determined that the fuel cut region is not within the fuel cut region, the routine proceeds to step 304, where the fuel injection amount TAU calculated at step 302 is used as the fuel injection amount TAUi for all cylinders (i = 1, 2, 3, 4). To be adopted as. As a result, the fuel of the fuel injection amount TAU calculated in step 302 is injected into all the cylinders from the first cylinder to the fourth cylinder.

On the other hand, if it is determined in step 303 that the area is the fuel cut area, step 30
In step 5, it is determined whether the flag F1 is "1". If it is determined that the flag F1 is "1", step 3
Proceeding to 06, the fuel injection amount TAU1 calculated in step 302 is adopted as the fuel injection amount TAU1 for the first cylinder, and the fuel injection amounts TAU2, TAU3, TAU4 for the three cylinders from the second cylinder to the fourth cylinder are adopted. "0" is adopted for. As a result, the fuel of the fuel injection amount TAU calculated in step 302 is supplied to the first cylinder, and the second cylinder and the third cylinder
Fuel is not supplied to the cylinder and the fourth cylinder, and fuel is not supplied.

If it is determined in step 305 that the flag F1 is not "1", the flow advances to step 307 to determine whether the flag F2 is "1". When it is determined that the flag F2 is "1", step 30
8, the fuel injection amount TAU calculated in step 302 is adopted as the fuel injection amounts TAU1 and TAU2 for the first cylinder and the second cylinder, and the fuel injection for the two cylinders, the third cylinder and the fourth cylinder, is performed. "0" is used for the quantities TAU3 and TAU4. As a result, the fuel of the fuel injection amount TAU calculated in step 302 is supplied to the first cylinder and the second cylinder, and the fuel is not supplied to the third cylinder and the fourth cylinder due to the fuel cut.

When it is determined in step 307 that the flag F2 is not "1", the fuel injection amount TAU is set to 0 (step 309), and the fuel injection amount TAUi (i = 1, 2, 3) for all cylinders is set. , 4) (step 304). As a result, all the cylinders from the first cylinder to the fourth cylinder are fuel cut and fuel is not supplied.

FIG. 10 shows a summary of the correspondence relationship between the speed change gear and the number of fuel cut cylinders at each level when the speed change gear control and the fuel cut control are performed as described above.

That is, at level 1 (L1), the shift gear is 4th and four cylinders (all cylinders) are fuel cut, and at level 2 (L2), shifting to 4th is prohibited and the shift gear is 3rd. Three cylinders are fuel cut, and at level 3 (L3), shifting to 4th is prohibited, the gear position is 3rd, and four cylinders (all cylinders) are fuel cut, and level 4 (L4).
Then, shifting to 4th and 3rd is prohibited, the shift gear is 2nd, and two cylinders are fuel cut,
At level 5 (L5), shifting to 4th and 3rd is prohibited, the shift gear is 2nd, and three cylinders are fuel cut, and at level 6 (L6), 4th and 3rd.
The shift to d is prohibited and the shift gear is 2nd and 4
Two cylinders (all cylinders) are fuel cut.

Even if the transmission gears of the automatic transmission 78 are at the same position, the magnitude of the firing torque varies depending on the number of cylinders for which fuel cut is performed. Make a difference in the magnitude of force.

As a result, the engine braking force has two levels of large and small even if the transmission gear stage is the same 3rd, and the engine braking force has three stages of large, medium and small even if the transmission gear stage is the same 2nd. Has 6 levels.

FIG. 11 shows an example of the measurement result of the vehicle deceleration for each level under a certain constant vehicle speed in this embodiment. The vehicle deceleration is obviously controlled in 6 stages. I understand that The broken line in the figure indicates the vehicle deceleration in the conventional engine braking force control, and shows the case where the engine braking force is controlled only by changing the shift gears by performing fuel cut for all cylinders. With this conventional control method, the vehicle deceleration is 3
It is a stage.

Therefore, when the engine braking force is controlled as in this embodiment, the engine braking force can be controlled more finely than in the conventional case, and the optimum engine braking force for the road gradient can be obtained.

When the engine braking force is controlled in this manner, the acceleration difference ΔA is large on a downhill with a large gradient, so that, for example, level 5 (L5) is selected and a relatively large engine braking force is obtained. Due to this action, the acceleration of the vehicle is reduced, and as a result, the acceleration difference ΔA is reduced, but it is maintained at level 5 unless the threshold value k5 _OFF is decreased. Then, the acceleration difference Δ
When A becomes smaller than the threshold value k5 _OFF , level 4 (L
4), the engine braking force decreases. On the contrary, when the acceleration difference ΔA becomes more than k6 _OFF , level 6 (L
After shifting to 6), the engine braking force becomes even greater.

In this embodiment, the number of fuel cut cylinders in the low speed gear stage is greater than that in the high speed gear stage. Specifically, 3rd
The number of fuel cut cylinders is divided into two stages (L2, L3) in the shift gear stage of No. 2 and the number of fuel cut cylinders is divided into three stages in the second shift gear stage (L4, L5, L).
6). This is for the following reason.

When the fuel cut is not performed, 4th
The difference between the vehicle decelerations of 2nd and 3rd is larger than the difference between the vehicle decelerations of 3rd and 3rd. Further, the influence on the vehicle deceleration by the presence or absence of the fuel cut is larger than that on the vehicle deceleration by the presence or absence of the fuel cut at 3rd. From this, it is possible to reduce the vehicle deceleration difference between each level by increasing the number of cases depending on the number of fuel cut cylinders at the low speed gear stage than at the high speed gear stage, and as a result, It is possible to reduce the discomfort felt by the driver when changing the level.

In the first embodiment, the deceleration running detection means is constructed by including the portion for executing step 204 of the series of signal processing by the transmission control computer 34 and the idle switch 86. The portion that executes step 2081 constitutes the reference acceleration determining means, and the portion that executes step 2082 constitutes the actual acceleration detecting means.

Further, in the first embodiment,
Of the series of signal processing by the transmission control computer 34, the steps 206, 207, 208
The deceleration level determining means is configured by the parts that execute steps 3 to 2088 and 210 to 217.

Further, in the first embodiment, the fuel supply control means is constituted by the portion that executes steps 301 to 309 of the series of signal processing by the engine control computer 32.

Further, in the first embodiment,
Of the series of signal processing by the transmission control computer 34, the steps 207, 212, 217 are performed.
The shift control means is constituted by the hydraulic control circuit 150 controlled by.

[Other Embodiments] In the above-described embodiment, the shift to 4th is prohibited in step 212 and the shift to 4th and 3rd is prohibited in step 217 in FIG. Therefore, for example, the engine brake level is determined to be level 2 or level 3 and step 212
Even if the shift to the 4th gear is prohibited and the engine brake is applied at the 3rd gear, the gear position is changed to 2 as the vehicle speed decreases.
In some cases, the relationship between the shift gear and the number of fuel cut cylinders may deviate from the relationship shown in FIG. Therefore, when it is desired to more accurately control the correspondence relationship between the gear shift stage at the engine brake level and the number of fuel cut cylinders, the gear shift stage is held at 3rd in step 212 and is held at 2nd in step 217. You may. Speed change gear 3r
The d-hold is achieved by exciting the solenoid S2 of the automatic transmission 78 and deactivating the solenoids S1 and S3, and the 2nd hold is achieved by the solenoids S1, S2 and S.
It can be achieved by exciting all three.

Although the above-described embodiment is an example in which the present invention is applied to a 4-cylinder engine, the present invention is a 6-cylinder engine or an 8-cylinder engine.
It is also applicable to multi-cylinder engines such as cylinder engines,
In that case, the deceleration of the vehicle can be divided into smaller parts and controlled, so that a more optimal engine braking force can be obtained. In addition, in the above-described embodiment, 1st
Although the engine brake is not used in the shift gear position of 1), it is also possible to use the engine brake in the first gear and combine it with the fuel cut control.

Further, the above-described embodiment is an example in which the present invention is applied to a 4-speed automatic transmission, but the present invention is not limited to 4-speed, but is applied to a 5-speed automatic transmission, for example. It is also possible.

Further, in the above-described embodiment, the engine braking force is automatically controlled when the automatic engine braking pattern is selected by the pattern select switch 70, but other running patterns such as the power pattern are selected. In this case, the engine braking force can be automatically controlled, or the engine braking force can be automatically controlled regardless of the type of the traveling pattern. It is of course possible to provide a switch for controlling the engine brake independently of the pattern select switch 70.

Further, although the engine control computer 32, the transmission control computer 34, and the throttle control computer 35 are separately configured in the above-described embodiment, they may be configured by a single computer. It is possible.

[0096]

As described above, according to the vehicle deceleration control method of the present invention, a desired deceleration is achieved when the vehicle is decelerated.
Based on the degree, at least one gear position
ー Change the number of cylinders of the internal combustion engine
Combination of speed position and number of cylinders for fuel cut
Select one pattern from the multiple patterns set by
Te, determines the position of the gear of the number of cylinders and a transmission for performing fuel cut, based on the determination, a fuel cut territory
When the fuel consumption is within the range,
And the position control of the gear position
By controlling the deceleration force of the vehicle, each cylinder of the internal combustion engine
Control of fuel supply to the vehicle and position control of the gear position of the transmission
In addition, the deceleration of the vehicle can be finely controlled.
As a result, the optimum engine braking force for the road surface gradient can be obtained.

Further, according to the vehicle deceleration control device of the present invention, the deceleration traveling detection means for detecting that the vehicle is decelerating, and the reference acceleration determining means for determining the reference acceleration during deceleration traveling, The actual acceleration detecting means for detecting the actual acceleration of the vehicle during deceleration traveling and the reference acceleration determined by the reference acceleration determining means during deceleration traveling are compared with the actual acceleration detected by the actual acceleration detecting means. and, based on the comparison result, at least one gear
Number of cylinders of internal combustion engine that performs fuel cut for position
Position and fuel cut so that
1 of the multiple patterns that are set in combination with the number of cylinders
Select pattern, a deceleration level determining means for determining the position of the gear of the air cylinder number and a transmission for performing fuel cut, the fuel on the basis of the determination of the reduction level determining means
When in the cut region, the fuel of the determined number of cylinders is
The fuel supply control means for executing the L-cut, and the position of the gear position of the transmission based on the determination of the deceleration level determination means.
By providing the shift speed control means for executing the control, it is possible to finely control the deceleration of the vehicle by combining the fuel supply control to each cylinder of the internal combustion engine and the position control of the shift speed of the transmission. As a result, the excellent effect that the optimum engine braking force for the road surface gradient can be obtained is exhibited.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine, an automatic transmission and the like including a vehicle deceleration control device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of the automatic transmission shown in FIG.

FIG. 3 is a diagram showing a shift gear stage of the automatic transmission shown in FIG. 2, excitation of a solenoid for establishing the shift gear stage, and engagement operation of a clutch and a brake.

FIG. 4 is a flowchart illustrating an operation of the deceleration control device shown in FIG. 1 together with FIGS. 5 and 6.

FIG. 5 is a flowchart illustrating the operation of the deceleration control device shown in FIG. 1 together with FIGS. 4 and 6.

FIG. 6 is a flowchart illustrating the operation of the deceleration control device shown in FIG. 1 together with FIGS. 4 and 5.

7 is an example of a shift map for switching the shift gears of the automatic transmission shown in FIG.

8 is an example of a reference acceleration map used to determine a reference acceleration in step 2081 of FIG.

9 is a diagram showing hysteresis of threshold values of the reference acceleration map shown in FIG.

FIG. 10 is a diagram showing the relationship between the shift gear stage and the number of fuel cut cylinders at each engine brake level when the vehicle deceleration control is executed according to the flowcharts of FIGS. 4 to 6;

11 is an example of measurement results of vehicle deceleration at each engine braking level when vehicle deceleration control is executed according to the flowcharts of FIGS. 4 to 6. FIG.

[Explanation of symbols]

10 Gasoline engine (internal combustion engine) 32 Engine control computer 34 Transmission Control Computer 35 Throttle control computer 78 automatic transmission 86 Idle switch (deceleration running detection means)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI F02D 29/00 F02D 29/00 H 29/02 341 29/02 341 41/02 330 41/02 330C 41/12 330 41/12 330J F16H 61/18 F16H 61/18 // F16H 59:48 59:48 (72) Inventor Kenji Matsuo 1 Toyota-cho, Toyota-shi, Aichi Prefecture Toyota Motor Corporation (56) Reference JP-A-8-254139 (JP, A) JP 5-79364 (JP, A) JP 4-345541 (JP, A) JP 10-95251 (JP, A) JP 6-219191 (JP, A) Kaihei 6-26373 (JP, A) JP 6-87355 (JP, A) JP 60-222650 (JP, A) JP 7-81463 (JP, A) (58) Fields investigated ( Int.Cl. ⁷ , DB name) F02D 29/00 F02D 17/02 B60K 41/00 F02D 41/00-45/00 F16 H

Claims (4)

(57) [Claims] 1. A deceleration control method for a vehicle that reduces an output rotation speed of the stepped transmission for an internal combustion engine of a multi-cylinder, during deceleration traveling of the vehicle, based on the desired deceleration, less the
Even if the fuel cut is performed for the gear position of 1
The gear position and fuel are adjusted so that the number of cylinders of the combustion engine is different.
Of multiple cylinders that are set in combination with the number of cylinders
The pattern of 1 from the turn is selected to determine the number of cylinders to be subjected to fuel cut and the position of the gear position of the transmission , and based on the above determination, when in the fuel cut region
Execution of fuel cut and shift of the determined number of cylinders
The vehicle deceleration force can be
Controlling deceleration control method for a vehicle, characterized by. 2. In the pattern, the gear position is a high speed gear position.
If the number of cylinders for fuel cut is different
Number of patterns when gear speed is lower than the number of patterns
Is set in more, the claim 1 characterized in that
A deceleration control method for the vehicle described. 3. A deceleration control device for a vehicle which decelerates the output rotational speed of a multi-cylinder internal combustion engine by means of a stepped transmission, and deceleration traveling detection means for detecting that the vehicle is decelerating. Reference acceleration determining means for determining the reference acceleration of the vehicle at the time of deceleration, actual acceleration detecting means for detecting the actual acceleration of the vehicle during deceleration traveling, and reference acceleration determined by the reference acceleration determining means during deceleration traveling The actual acceleration detected by the actual acceleration detecting means is compared, and based on the comparison result, at least one shift speed position is set for the fuel economy.
The gear position so that the number of cylinders of the internal combustion engine
Setting and the number of cylinders for fuel cut.
Select one pattern from a plurality of patterns, a reduction level determining means for determining the position of the gear of the air cylinder number and a transmission for performing fuel cut, the fuel cut based on the determination of the reduction level determining means
Number of cylinders that have been pre-Symbol determined when in bets area of the fuel
A deceleration control device for a vehicle, comprising: a fuel supply control means for executing a cut; and a shift speed control means for executing a position control of a shift speed of a transmission based on the determination of the deceleration level determination means. . 4. The position of the shift speed is a high speed gear in the pattern.
If the number of cylinders for fuel cut is different
Number of patterns when gear speed is lower than the number of patterns
Is set more, the claim 3 is characterized in that
The vehicle deceleration control device described.