JPH02253047A - Engine brake control device using look-up clutch - Google Patents

Abstract

PURPOSE:To aim at improving the efficiency of an engine brake and make it possible to adjust the braking state by engaging a lock-up clutch when the output shaft rotating speed of a torque converter exceeds the input shaft rotating speed. CONSTITUTION:A CPU inputs the signals of various sensors 23-26 and switches 27-29 and executes engine brake control when the engine speed NE>=1000 rpm.NE < the turbine rotating speed NT continues for more than the specified time, the throttle opening theta is closed, all the conditions for the 'on' state of an idle switch 28 are satisfied and the present duty ratio of a solenoid valve 37 is 0%. The CPU further switches on a solenoid valve for lock-up relay 36, engages the solenoid valve 37 for lock-up duty control by 10% and engages a lock-up clutch forcibly. The efficiency of an engine brake can be thus improved as well as the braking state of the engine brake can be selected by the stepping-on state of an accelerator pedal.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to an engine brake control device that controls engine braking by operating a lock-up clutch of an electronically controlled automatic transmission installed in a vehicle. Regarding.

(Prior art) In order to realize vehicles with low fuel consumption, lock-up clutches have been used in vehicles equipped with a 1-lux converter to engage and disengage the input and output shafts of the torque converter depending on the driving conditions. Techniques for providing this are known. This type of technology is disclosed in, for example, Japanese Patent Laid-Open No. 56-35858.

(Problems to be Solved by the Invention) In a vehicle equipped with an automatic transmission, a gear position is automatically determined depending on the driving state. When the driver releases the accelerator in an attempt to decelerate the vehicle, engine braking is applied if the vehicle speed is higher than the engine rotation. At this time, if the lock-up clutch is not engaged, the torque converter will slip, and the engine brake will be less effective than when the lock-up clutch is engaged.

Therefore, the technical objective of the present invention is to increase the efficiency of engine braking.

Another technical challenge is to be able to adjust the degree of engine braking according to the driver's will.

[Structure of the invention]

(Means for Solving the Problems) The technical means used in the present invention to solve the above problems is to engage the lock-up clutch when the rotation speed of the output shaft of the torque converter exceeds the input shaft rotation speed. This is what I decided to do.

Further, the lock-up clutch is engaged only when the number of revolutions of the output shaft of the torque converter exceeds the number of revolutions of the input shaft only when the amount of depression of the accelerator pedal is small.

(Operation) According to the above-mentioned technical means, the lock-up clutch is engaged when the rotational speed of the output shaft of the I/L converter hearter exceeds the rotational speed of the input shaft. Therefore, since the output shaft of the engine and the wheel shaft are connected without a torque converter, the engine becomes a load for the rotation of the wheels, and the efficiency of engine braking increases.

Further, since the control can be selected depending on the amount of depression of the accelerator pedal, the driver can select the degree of application of the engine brake.

(Example) Hereinafter, an example using the present invention will be described based on the drawings. In this embodiment, the lock-up clutch is controlled simultaneously within the control circuit of the automatic transmission. The automatic transmission itself uses a 4-speed (with overdrive).

The operation of this automatic transmission will be explained with reference to FIG.

Turbine shaft 6 which is the input shaft of overdrive mechanism 67
0 is connected to the engine via a torque converter. Turbine shaft 60 becomes the output shaft of the torque converter. This turbine shaft 60 is connected to a carrier 69 of a planetary gear system. A planetary pinion 70 rotatably supported by a carrier 69 is an OD planetary gear 61
It is connected to the input shaft 71 of the gear transmission mechanism 68 via. Further, the planetary binion 70 meshes with the sun gear 72. There is an OD between carrier 69 and sun gear 72.
Kufrati CO is located there. A D brake BO is provided between the sun gear 72 and the housing 62. A forward clutch CI is provided between the input shaft 71 and the intermediate shaft 73 of the gear fluid 'a mechanism 68. Further, a direct crank notch C2 is provided between the input shaft 73 and the sun gear shaft 66. A second brake B1 is provided between the sun gear shaft 66 and the housing 62. A planetary pinion 76 rotatably supported by a carrier 74 connected to the output shaft 65 is connected to the intermediate shaft 73 via a gear and the carrier 75. Also,
The planetary binion 76 meshes with the sun gear shaft 66. Planetary pinion 78 meshes with carrier 74 and sun gear shaft 66. planetary binion 7
8 and the housing 62 is provided with an lSt&RCV brake B2.

In this automatic transmission, clutches Co and CI.

C2 and brake BO, B1. The relationship between B2 and the gear position is as shown in the table below.

○: Engaged ×: Disengaged Clutches Co, C1, C2 and brakes BO, B
1 and B2 are controlled in their engagement and release by the hydraulic circuit shown in FIG.

Referring to FIG. 2, hydraulic oil pumped up from the oil reservoir 41 by the hydraulic pump 40 is supplied to the line pressure oil passage 57. The oil pressure (line pressure) in the line pressure oil passage 57 is controlled by the line pressure control solenoid 38 of the throttle valve 43. The pressure is regulated by the operation of the first regulator valve 42. The line pressure control solenoid 38 has a duty ratio controlled. Line pressure control solenoid 38
A pulse signal of a predetermined period is applied to the movable iron core, and the position of the movable iron core is determined according to the ON time of the pulse signal. The movable iron core adjusts the orifice diameter of the throttle valve 43. Since the orifice diameter is changed, the oil passage 58a
The hydraulic pressure can be controlled.

The valve of the regulator valve 42 is driven by the oil pressure in the oil passage 58a, and adjusts the oil pressure in the line pressure oil passage 57.

Therefore, by changing the on-time of the pulse signal,
Line pressure can be adjusted. The oil pressure in the line pressure oil passage 57 is applied via the first modulator valve 56 to the flatch CO control solenoid valve 30. Clutch 02 control solenoid valve 31. It is supplied to a lock-up relay solenoid valve 36 and a lock-up duty control solenoid valve 37. Further, the oil pressure in the line pressure oil passage 57 is applied to the brake BO control solenoid valve 32 through the second module lake valve 54. Brake B1
Control solenoid valve 33. It is supplied to the solenoid valve 34 for controlling the brake B2. Furthermore, line pressure oil passage 5
7 oil pressure is the lock-up control valve 46. Manual valves 48, 49, 50 and 51 are supplied. Lock-up control valve 46 A lock-up clutch 47° clutch CO, clutch C2, brake B1, and brake BO are connected to the outputs of the manual valves 4B, 49, 51, and 51, respectively. The output of the manual valve 53 is connected to the brake B2 via the valve 52. The valve 52 is connected to a shift valve 55 via a low/reverse prohibition solenoid valve 35. The shift valve 55 moves in response to the operation of the shift lever, and line pressure is applied to the inside of the shift valve 55 when the shift valve 55 is in a position other than the P range. Further, this shift valve 55 applies oil pressure to the clutch C1 when the range is other than the R and PN ranges. Then, oil pressure is supplied to the valve 52 when in the L and 2 ranges, and low and low when in the L and R ranges.
Hydraulic pressure is supplied to the reverse prohibition solenoid valve 35.

With the above configuration, when the clutch CO control solenoid valve 30 is closed, the manual valve 48
Drain the oil from the pipe connected to O. Therefore, clutch CO does not operate. When the solenoid valve 30 is opened, the manual valve 48 opens the line pressure oil line 57 and the clutch CO according to the difference between the oil pressure of the line connected to the clutch CO and the oil pressure of the line connected to the solenoid valve 30.
Connect or cut off conduits connected to therefore,
The hydraulic pressure applied to the clutch CO is adjusted according to the pressure output from the solenoid valve 30. The output pressure of the solenoid valve 30 is adjusted by duty-controlling its energization. In this way, when the flatch CO control solenoid valve 30 is opened, the manual valve 48 moves, pressure is applied to the clutch CO according to the operation of the flatch CO control solenoid valve 30, and the clutch CO
is engaged. Solenoid valve 3 for flatch CO control
If 0 is closed, no oil pressure is applied to the clutch CO, and the clutch CO is released.

Clutch CI is engaged by applying hydraulic pressure when the range is other than R, P, or N, and is released without applying hydraulic pressure when the clutch is in other ranges.

In the clutch C2, similarly to the clutch C1, when the clutch 02 control solenoid valve 31 is opened, the manual valve 49 moves, hydraulic pressure is applied to the clutch C2, and the clutch CO is engaged. The engagement state of the clutch CO can be controlled by the energization state of the solenoid valve 31 for controlling the clutch 02. When the clutch 02 control solenoid valve 31 is closed, no hydraulic pressure is applied to the clutch C2, and the clutch C2 is released. However, when the shift valve 55 is in the 2nd range, hydraulic pressure is supplied to the manual valve 49, and the clutch C2 control solenoid valve 3
The hydraulic pressure to clutch C2 is canted regardless of the movement of clutch C2.

In the brake BO, when the brake BO control solenoid valve 32 is opened, the manual valve 50 moves, and hydraulic pressure is no longer applied to the brake BO, and the brake B
O is released. When the brake BO control solenoid valve 32 is closed, hydraulic pressure is applied to the brake BO, and the brake BO is engaged. Note that while the clutch CO is in operation, hydraulic pressure is applied to the manual valve 51 for controlling the brake B1, and the brake BO is forcibly opened.

In the brake Bl, when the brake B1 control solenoid valve 33 is opened, the manual valve 51 moves, and hydraulic pressure is no longer applied to the brake B1.
l is released. When the brake B1 control solenoid valve 33 is closed, hydraulic pressure is applied to the brake B1, and the brake B1 is engaged. Note that while the clutch C1 is in operation, hydraulic pressure is applied to the manual valve 50 for controlling the brake B1, so that the brake B1 is forcibly opened.

In the brake B2, when the brake B2 control solenoid valve 34 is opened, the manual valve 53 is moved, hydraulic pressure is no longer applied to the brake B2, and the brake B2 is released. When the brake B2 control solenoid valve 34 is closed, hydraulic pressure is applied to the brake B2 via the valve 52, and the brake B2 is engaged. However, R
When the solenoid valve 35 for inhibiting low and reverse is turned on in range and L range, hydraulic pressure is applied to the valve 52, and the supply of hydraulic pressure to the brake B2 is canted, thereby releasing the brake B2.

The second regulator valve 44 is the throttle valve 43
Secondary hydraulic pressure is generated in the oil passage 58b according to the output pressure and line pressure. Secondary hydraulic pressure is applied to lock-up relay valve 45.

The lock-up relay valve 45 is controlled by a lock-up relay solenoid valve 36.

The lock-up relay solenoid valve 36 is a normally open solenoid valve, and when it is off, the oil passage 58
b and the oil passage 58c, and the oil passage 58d and the oil passage 58e. When turned on, the oil passage 58b and the oil passage 58d are connected. The oil passage 58C is connected to the working chamber of the torque converter 59. The oil passage 58d connects the torque converter 59 and the lock-up relay valve 45. The oil passage 58e sends oil from the lock-up relay valve 45 to the cooler 39.

The lock-up duty control solenoid valve 37 is a normally closed solenoid valve and is duty-controlled. When the lock up duty control solenoid valve 37 is off, the connection between the candle control half 46 and the oil 158c and the drain 46a is cut off. When the lock amplifier duty control solenoid valve 37 is duty-controlled, the orifice between the oil passage 58c and the drain 46a is controlled according to the duty ratio, or the orifice between the oil passage 58c and the drain 46a is controlled.
The flow rate of oil discharged to is controlled. When oil flows from the oil passage 58d to the oil passage 58c, the lock-up clutch 47 is activated, directly connecting the output shaft of the engine to the turbine shaft 60, and creating a lock-up state.

With the above configuration, when the lock amplifier duty control solenoid valve 37 is off (duty ratio 0%) and the lock-up relay solenoid valve 36 is off, secondary oil flows into the working chamber of the torque converter 59 through the oil path 58C. and the oil passage 58d and the oil passage 58
It is sent to clarinet 39 via e. In this case, the lock-up clutch is turned off. When the lock-up relay solenoid valve 36 is turned on, secondary oil is sent to the working chamber of the torque converter 59 via the oil passage 58d. At this time, if the lock-up duty control solenoid valve 37 is 100% engaged, the lock-up clutch 47 is engaged. When the lock-up duty control solenoid valve 37 is duty-controlled,
Since the oil in the working chamber of the torque converter 59 is discharged to the drain according to the duty value, the state of engagement of the opening/notch/notch 47 can be changed. When the duty ratio of the lock-up duty control solenoid valve 37 is increased, the amount of oil discharged to the drain is reduced, the pressure in the working chamber of the torque converter 59 is increased, and the engagement ratio of the lock-up clutch 47 is increased. When the duty ratio of the lock amplifier duty control solenoid valve 37 is lowered, the amount of oil discharged to the drain increases, and the pressure in the working chamber of the torque converter 59 decreases.
The lock-up clutch 47 becomes slippery.

The solenoid 38 and the solenoid valves 30 to 37 are driven by an electronic control circuit, which will be described later, and are controlled so that the clutches and brakes have the relationships shown in Table 1 depending on the driving conditions.

FIG. 3 shows an electronic control circuit that drives each solenoid valve in the hydraulic circuit.

An input end of a constant voltage power source 22 is connected to a terminal of a battery 20 mounted on the vehicle via an ignition switch 21. The output terminal of the constant voltage power supply 22 is connected to power terminals VCC and GND of the central processing unit CPU. The constant voltage power supply 22 is for converting the output voltage of the battery 20 into a voltage at which the central processing unit 1-CPU can operate.

Each input terminal of the central processing unit CPU is connected to an engine rotation sensor 23. Turbine rotation sensor 24° output shaft rotation sensor 25. Throttle sensor 26 Neutral start switch 27. An idle switch 28 and a brake switch 29 are connected. In FIG. 3, the input interfaces of each sensor and switch are omitted for simplicity.

The engine rotation sensor 23 is a sensor that detects the rotation speed of the vehicle engine. Since the output shaft of the engine is the same as the input shaft of the torque converter, this sensor also serves as means for detecting the rotational speed of the input shaft of the torque converter. The engine rotation sensor is disposed near the output shaft of the engine and outputs a pulse signal having a frequency corresponding to the engine rotation speed.

In this embodiment, the engine rotation sensor is an electromagnetic pink amplifier type rotation sensor installed opposite the teeth of a ring gear attached to the output shaft of the engine.
Outputs 120 pulses per rotation. This output is sent to the central processing unit CPU.

The turbine rotation sensor 24 is a sensor that detects the rotation speed of the turbine. Since the turbine shaft is the same as the output shaft of the torque converter, this sensor is also a means for detecting the rotational speed of the output shaft of the torque converter. The turbine rotation sensor is disposed near the turbine rotation shaft and outputs a pulse signal having a frequency corresponding to the rotation speed of the turbine. In this embodiment, the turbine rotation sensor is an electromagnetic pickup-type rotation sensor installed opposite the teeth of a gear attached to the turbine shaft 60, and outputs 57 pulses per rotation of the gear. This output is sent to the central processing unit CPU.

The transmission output shaft rotation sensor 25 is a sensor that detects the rotation speed of the output shaft of the automatic transmission. The output shaft rotation sensor is disposed near the output shaft of the automatic transmission, and outputs a pulse signal having a frequency corresponding to the rotation speed of the output shaft of the automatic transmission. In this embodiment, the output shaft rotation sensor is an electromagnetic pickup type rotation sensor installed opposite the teeth of a gear attached to the output shaft, and outputs 18 pulses for one rotation of the gear. This output is sent to the central processing unit CPU. In this embodiment, the output shaft rotation sensor is used to measure the speed of the vehicle.

If the relationship between the output shaft of the automatic transmission and the rotational speed of the wheels and the diameter of the wheels are clearly known, it can be converted to the speed of the vehicle. Instead of this output shaft rotation sensor 25, another type of vehicle speed sensor that detects the speed of the vehicle may be used.

The throttle sensor 26 is a sensor that detects the opening degree of the throttle valve of the engine. The throttle sensor includes a digital 2-mechanical throttle sensor that detects the rotation angle of the throttle valve and divides the opening of the throttle valve, and an A/D converter that converts the rotation angle of the throttle valve into a voltage value. There are analog and electric throttle sensors that divide the opening of the throttle valve. In the present invention, both throttle sensors are provided and used selectively, but in a normal device, only one of them may be used. The throttle sensor outputs a signal obtained by dividing the opening degree of the throttle valve into eight parts from a signal line. Fully closed state is θ0. The fully open state is assumed to be θ7.

The space between θ0 and 07 is assumed to be θ1 to θ6.

The neutral start switch 27 detects the position of the shift lever, and is a D (dry mode) range switch and an L (low) range switch.

It has 2 (second) range switch, 3 (custom) range switch, N (neutral) range switch, R (reverse) range switch, and P (parking) range switch, and has D, L, 23, N, R, and P range switches. Detect each range.

The idle switch 28 is a switch that detects the idle state of the vehicle, and in this embodiment, a switch that is attached to the accelerator pedal and responds when the accelerator pedal is not depressed is used. This switch may be replaced by one that detects the idle state depending on the opening degree of the throttle valve, the pressure of the intake manifold, etc.

The brake switch detects the brake state of the vehicle. This may be a switch attached to the brake pedal or may be one that detects the deceleration of the vehicle.

Clutch 0 is connected to each output terminal of the CPU (central processing unit).
2 control solenoid valve 30. Clutch 02 control solenoid valve 31. Brake B2 control solenoid valve 32. Brake B2 control solenoid valve 33.
Brake B2 control solenoid valve 34. Low/reverse prohibition solenoid valve 35. Solenoid valve for lock-up relay 36. A lock amplifier duty control solenoid valve 37 and a line pressure control solenoid 38 are connected. In FIG. 3, the output interface or drive device for each solenoid is omitted for simplicity.

Each solenoid valve has a central processing unit CPU.
controlled by The central processing unit CPU has internal memories such as RAM and ROM, a timer, and registers. When the ignition switch is turned on, voltage begins to be supplied to the central processing unit CPU via the constant voltage circuit 22. When voltage is applied to the central processing unit CPU, the central processing unit CPU starts executing processing according to the main routine shown in FIG.

FIG. 4 is a flowchart of the main routine of the central control unit (CPU).

(Main routine) When the central control unit CPU starts, it first sets the input/output direction of each input/output port, initializes each memory, and sets the presence/absence of interrupts (step 7).
0). Then the input/output reading routines are executed,
The states of each sensor and switch connected to the input terminal are read, noise is removed, and data is set according to the state of each sensor and switch (step 71).

Next, a rotational speed calculation processing routine is executed to calculate the vehicle speed, turbine rotational speed, and engine rotational speed (step 72).

The engine rotation speed NH is calculated using the following formula.

Note that since the output from the engine rotation sensor has a high frequency, it is calculated after dividing the frequency by eight.

NE −(nE(i−1)+nEi) / 2nIEi
= (PCEi /TEi) × (8 division / 8
10-')
Time count to the edge of the first pulse exceeding 10 m5 from the previous pulse, PCEi: Number of pulses during TEi, 8X10-”:
This is the minimum unit of detection time (8 μS).

Calculation of the turbine rotation speed NT is performed using the following formula.

Note that since the output from the turbine rotation sensor has a high frequency, the frequency is divided by four before calculation.

NT - (nT(i-1) + nTt) / 2nT
i= (PCTi /TTi) × (4 frequency division / 8 × 10-6) × (60157) where, nTi: Turbine rotation speed due to the current pulse, TTi:
PCTi is the time count until the edge of the first pulse exceeding 10 m5 from the previous pulse, and PCTi is the number of pulses in TTi.

The output shaft rotation speed NO is calculated using the following formula.

NO= (no(i-1) + n0i) / 2nO
i = (PCOi /TOi) X (1/8
The time count until the edge of the first pulse exceeding 10 m5 from the previous pulse is PCOi: the number of pulses during TOi.

Since the gear ratio of the output shaft and the axle and the radius of the wheels are determined in advance, the vehicle speed can be determined from the output shaft rotational speed NO.

After the rotational speed calculation processing routine, a shift determination routine is executed, and a shift determination is made (step 73). Line pressure is also set within the shift determination routine. The line pressure set value is set by the throttle opening and turbine rotation speed. The line pressure solenoid is duty-driven according to this setting. In this routine, it is determined whether or not a shift is to be determined based on a shift diagram created in advance using the throttle opening, vehicle speed, and current shift position.

Next, a speed change processing routine is executed, and a speed change process is performed (step 74). Here, when a shift determination is made, a solenoid valve on the release side and a solenoid valve on the engagement side are set. Next, a lock amplifier control routine is executed and lockup processing is performed (step 75). Finally, an output control routine is executed to perform output control (step 76). Output control includes selecting a power-on upshift, a power-off shift, and a downshift at the start of a shift, determining a shift state during a shift, and outputting a signal to a solenoid valve. Note that a power-on upshift refers to an amplifier shift when the engine driving torque is high, and a power-off shift refers to an amplifier shift when the engine driving torque is low. Since torque fluctuations on the automatic transmission's output shaft increase depending on the state of the engine's drive torque, the shock is reduced by changing the control time.

(Interrupt Routine) The outputs of the output shaft rotation sensor, turbine rotation sensor, and engine rotation sensor are each connected to the interrupt input terminal of the central processing unit CPU, and each time the voltage level of the interrupt terminal changes, the An output shaft rotation sensor interrupt routine, a turbine rotation sensor interrupt routine, and an engine rotation sensor interrupt routine are executed. In the output shaft rotation sensor interrupt routine, first, the time at the time of the interrupt is read from a timer, and then a calculation flag for calculating the output shaft rotation speed is turned on. Therefore, the rotation speed of the output shaft can be calculated by referring to the time read when the calculation flag is on in the main routine or subroutine. In the turbine rotation sensor interrupt routine, first, the time at the time of the interrupt is read from the timer, and then the manual pulse is set to 4.
When the interrupt is counted four times for frequency division, the calculation flag for turbine rotation speed calculation is turned on. In the engine rotation sensor interrupt routine, first the time at the time of the interrupt is read from the timer, and then the human power pulse is set to 8.
When the interrupt is counted 8 times for frequency division, the calculation flag for engine rotation speed calculation is turned on. The turbine rotation speed and the engine rotation speed are also calculated in the same way as the output shaft rotation speed.

The central control unit (UNISO) CPU has regular interrupts that occur every predetermined time period as shown in FIG.

In this embodiment, a scheduled interrupt routine is executed every 4 ms. Here, first, various timers used for control are subtracted.

Here, the timers to be subtracted include, in addition to the timer for shifting, three timers for lock-up control, TLI,
TL2. There is a timer TEGB for TLN and engine brake control. When each timer for lockup control is set to an arbitrary value of 1 or more during execution of the main routine or subroutine, it is decremented by 1 every time the scheduled interrupt routine is executed. However, the value is 1
, it holds 1. Therefore, when the time corresponding to the value initially assigned to each timer has elapsed, the value of the timer becomes 1, indicating that the timer has ended. If each timer is set to 0 during execution of the main routine or subroutine, it will retain the value 0 even if an interrupt occurs. As will be described later, each timer is set to 0 after confirming that the value of each timer has become 1 in the main routine or subroutine. Therefore, if the value of the timer is 2 or more, it means that the timer is running, if it is ■, the timer has ended, and if it is O, it means that the timer has already completed. The timer TEGB for engine brake control is also almost the same as each timer for lockup control, except that 0 is not immediately substituted when the timer ends. This timer means that engine brake control is possible when its value is 1.

Although not shown, the determination of whether the vehicle has stopped is made during this scheduled interruption. In this embodiment, vehicle stopping speed N5t
The vehicle is stopped when the speed is below 144 rpm (approximately 3 km). Moreover, the input frequency Tstop to the central control unit CPU=23. The vehicle is stopped when there is no pulse for 13 mS or more.

(Lockup Control) FIG. 6 is a flowchart of the lockup control routine.

The timers used during this control include TLI, TL
2. There are four: TLN and TEGB. Timer T
As shown in FIG. 16b, L1 is a timer used to fix the duty ratio of the lock-up clutch at 0% for a predetermined period of time after the lock-up is turned on. Timer TL2 is a timer used to fix the duty ratio of the lock-up clutch at 25% for a predetermined period of time after the end of timer TLI, as shown in FIG. 16b. The timer TLN is a timer for prohibiting the next lockup control for a predetermined period of time after the lockup clutch is turned on. Timer TEGB is
This is a timer for preventing hunting in engine brake control, which will be described later.

Also, the flags used during this control include the speed change control flag FLD and the engine brake control flag FE.
There is GB. The during-speed change control solag FLD is a flag that is set when the lock-up clutch is controlled during a speed change. The engine brake control flag FEGB is a flag that is set when engine brake control is performed.

Furthermore, a counter C5D is used during this control.

Counter C5D takes values from 0 to 5. counter C
The 3D value indicates in which region the current duty value is located in the lock amplifier diagram shown in FIG. 15, which will be described later. When in area 0, the value of counter C5D is O, when in area 1, the value of counter csD is l, when in area 2, the value of counter C5D is 2, and when in area 3, counter C5D If the value of C is 3, if it is in area 4, the counter C
The value of 5D is set to 4. However, − degree counter C3
When the value of D is set to 4, the value of the counter C5D remains 4 until it enters area O. - When the value of degree counter C5D is set to 0, area 1. 2. The value of the counter C5D remains at 4 until it reaches 3 or 4.

Referring to FIG. 6, when the lock amplifier control routine is executed, first, timer TLN ends (TLN=1).
Check if it is running, and if it is finished, timer TL
Complete N (TLN-0) (step 86.87)
.

Next, if timer TLN has not completed, lockup control is skipped and the process returns to the main routine. If the timer TLN has been completed, a shift non-control processing routine or a shift control raw processing routine is selected depending on whether or not a shift is currently being performed (steps 88 to 91).

Next, timer processing is performed to prevent hunting in engine brake control (steps 92 to 97). Timer T Turbine rotation speed N when EGB is completed (TEGB=O)
If T is above the engine speed NB, set the timer TEGB to a predetermined value.

(for example, 0.1 seconds) and start timer T Er;B. Timer TEGB P: Working time (TEGB
= 1) or turbine rotation speed NT is engine rotation speed N
If it exceeds E, timer T EGB is completed.

(Non-shift control raw processing) If the automatic transmission of the vehicle is not changing gears, processing is executed according to the flowchart of FIG.

First, as a process immediately after leaving the shift control, if the flag FLD is set, which is set when lock-up control is performed during the process during the shift control, the flag FLD is set.
is cleared and counter C3D is set to 5 (steps 100 to 102).

Next, it is determined whether lock-up is possible (step 10).
3). Details of this determination are shown in FIG. In the flowchart of FIG. 9, one of the following three options is determined: lock-up change prohibition, lock-up forced off, or lock-up change permission, as shown in the table shown in FIG. 1st
Lock-up is turned off when the switch is in the PR, N, or L ranges. When the counter C3D is 0 at the 1st time or in the P, R, N, and L ranges, the lockup is already off, so in this case, lockup change is prohibited. Also, since O/D is prohibited in the 2nd range, the lockup is also turned off in this case.

Referring again to FIG. 7, if it is determined that lockup change is prohibited, no processing is performed and the process returns to the lockup control routine of FIG. 6. Therefore, the lockup remains as it is.

If it is determined in the lock-up determination that the lock amplifier change is permitted, the current range is determined based on the range, shift position, and throttle opening. The lock-up diagram of this embodiment is as shown in FIG. FIG. 14 is a lock-up diagram for the D range, and similar lock-up diagrams are set for the other ranges. FIG. 15 is an enlarged view of section A in FIG. 14. The lockup diagram shows the area 1. of duty 5DYI%. Duty 5DY2% area 2. Duty 5DY3% Area 3 Duty 10
0% area 4. It consists of region 5, which is within the hysteresis range from on to off and from off to on, and region 0, where the duty is completely 0% (off). 5DYI to 3 are set according to the current shift stage, and the 12th
The table shown in the figure is as follows. In region determination, it is determined in which region of regions 0 to 5 the current vehicle speed is located at the current range shift position and throttle opening. The central processing unit 1-CPU stores vehicle speed data at the time of duty switching in each range, shift, and throttle opening as shown in Figure 13, and the area is determined by comparing the current vehicle speed with this vehicle speed data. do. After determining the range, if the lock-up clutch is in ranges 1 to 4, it is determined that it can be turned on. If the lock-up clutch can be turned on, the number of the searched area is substituted into variable RO (step 124). If the caranta C5D is 5, it means that it has just exited the gear shift process, so step 13
Step 125) of executing the lock-up-on control of steps 7 to 145. If counter C5D is equal to or greater than variable RO, the current duty ratio is larger than the duty ratio to be changed, so lock-up-on processing is not performed and step 1
The process jumps to lockup-off processing after 07 (step 126). If counter C5D is smaller than variable RO, lockup can be changed to a larger duty ratio. At this time, after clearing the engine brake control flag F EGB, if the counter C5D is 0, steps 129 to 136, which is lock-up preliminary control, are executed, and if the counter C5D is other than 0, steps 137 to 145 are executed. Up-on control is executed (steps 127-128).

In lock-up preliminary control, the timer T is set at the start of control.
Since both LI and TL2 should be 0, first set the timer TLI to 1 and turn on the output flag SL of the lock-up relay solenoid valve 36. Note that when this flag is on, the lock-up relay solenoid valve 36 is controlled to be on in the output control routine.

Processing is skipped while this timer TLI is being executed.

When the timer TLI ends (TL] = 1), after setting the timer TLI to 0, setting the timer TI, 2, and setting the variable SLD for the output of the solenoid valve 37 for the lock-up duty control 4711 to 25%. do. still,
In the output control routine, the lock-up duty control solenoid valve 37 is controlled by the value assigned to the variable SLD.

In the lock-up-on control (steps 137 to 145), no processing is performed until the timer TL2 ends. When the timer TL2 ends, 0 is assigned to the timer T1.2 to complete the timer TL2. When the timer TL2 is completed or terminated, a variable RO indicating the area to be changed is assigned to the counter C5D. If the assigned value is other than 4, a duty value corresponding to the value of counter C5D is loaded and the duty value is assigned to variable SLD. For example, if the current shift stage is 3rd, the counter C3
If the value of D is 2, the duty value 5DY2=60% of the 3rd and area 2 (see FIG. 12) is read from the memory and set as the variable SLD. If the substituted value is 4, the timer TLN is set to set the variable SLD to 100%, and the lock-up duty control solenoid valve 37
fully turned on.

In the process for lock-up off after step 107, the flag FEGB for engine brake control is set to 1.
When , the lockup off IJ? in steps 111 to 118 is performed. Wholesale is skipped.

If the flag FEGB is 1, lock-up is turned on in engine brake control, which will be described later, so lock-up-off control is not performed. If the flag FBCB is O and the area searched in step 105 is area 0, lock-up is possible, so the number of the area searched, ie, 0, is assigned to variable RO (step 109). After this, when the value of the variable RO is larger than the counter C5D indicating the current area, the process of lowering the duty is not performed and the lock-up-off control is skipped (step 110).

In lock-up-off control, if the value of counter C3D is other than 0, the duty value is loaded and placed in variable SLD (step 113.1.14). This process is
In this embodiment, the variable RO is set to 0 before lock-up-off control.
Since there are no other settings to be made, this is not actually done.

Therefore, it may be deleted. This step is effective when the lockup is not turned off immediately but needs to be fixed at a predetermined duty value. Counter C3Dσ (if direct is 0, timer T1.,
N, turn off the output flag SL of the solenoid valve 36 for the solenoid relay, and set the variable SLD to 0.
%, and clears the flag FLD indicating that lock-up control has been performed in the shift control raw processing.

If the lock amplifier is forcibly turned off in the lock-up judgment described above, this candle asso off control is performed. Since the variable RO is set to 0 in step 104, when the lock-up-off control is executed, the output flag SL of the lock-up relay solenoid valve 36 is turned off, and the variable SL D becomes 0%.

Lock-up-off control is then performed, followed by engine brake control. First, it is determined whether or not engine brake control is possible. The details of this judgment are shown in FIG. ■Engine speed NB≧1100Orp, ■Engine speed NB
<Turbine rotation speed NT, ■Timer TEGB = 1
．． (Engine speed NE <turbine speed NT continues for more than a time TEGB).

■Throttle opening θ-θ0. Engine brake control is executed when all five conditions (Idle switch is on and the accelerator is not depressed) are satisfied and counter C3D=O (current solenoid valve duty ratio is 0%). At this time, the flag FEGB is set and 4 is substituted into the variable RO, and then the daily backup-on control is executed. Therefore, steps 144 and 145 are executed, and the lock-up duty control solenoid valve 37 is completely turned on. During this engine brake control execution (FEGB = 1), if at least one of the previous five conditions is no longer satisfied, a determination is made to stop the control, the flag FIEGB is cleared, and 0 is assigned to the variable RO. After that, execute lock-up-off control. Therefore, in steps 116 and 117, the lock-up duty control solenoid valve 37 is completely turned off. Engine brake control in progress (FEGB=
1) Even if all five conditions from ■ to ■ above are satisfied, the current lock-up state is off (counter C
If G,' is not 3D-0), the brake is on. If at least one of the conditions of the N range or the R range is satisfied, a control stop determination is made. In other cases, no control takes place.

(Shift Control Raw Processing) When the automatic transmission of the vehicle is changing gears, processing is executed according to the flowchart of FIG. 8.

First, if the flag FLD is O and the engine brake control is not being executed (flag FEGB=1), duty value hold control is performed (step 150.
151), if the 7-lag FLD is o and the engine brake control is being executed, the flag FEGB is set to O, the flag SL for the output of the lock-up relay solenoid valve 36 is turned off, and the variable SLD is set to 0. % (steps 152-154).

Duty value hold control is performed when the current lock-up relay solenoid valve 36 is on (SL-ON).
, and the lock amplifier duty control solenoid valve 37 is 100% engaged (SLD=1.00%), and the gear change is other than an amplifier shift to 2nd gear or a downshift to 1st gear. only (step 1)
55-159). For duty value hold control, first,
A duty value is set according to the shift and throttle/nottle opening degree, and the set duty value is substituted into the variable SLD. After that, set the flag FLD and set the counter cso to 1.
(Steps 160 to 162).

Note that the duty value is set based on the table shown in FIG. 17.

When duty value hold control is executed, flag FL
Since D is 1, step 1 is executed after executing duty value hold control and when executing the next shift control raw processing.
63 and subsequent steps are executed. Steps 164 to 175 are lock-up-off control. In step 164, a region is searched similarly to step 105 in the non-shift control process (FIG. 7). Steps 165-175 are the same as steps 108-118 in the non-shift control process (FIG. 7). If the lock-up relay solenoid valve 36 can be turned off, counter C3D is set to O, timer TLN is set, flag SL for the output of the lock-up relay solenoid valve 36 is turned off, variable SLD is set to 0%, and the flag FLD
Clear.

The subsequent steps 176 to 186 are non-shift control processing (
Steps 119-123 and Step 1 in Figure 7)
Same as 37-145. It is determined whether or not engine brake control is possible, and if control is possible, flag F
After setting EGB and setting variable RO to 4, timer T
Wait for L2 to end and set variable RO to counter C5D.
Set the value (4) of , set timer TLN,
Let the variable SLD be 100%.

The above lock-up control routine operations are performed in steps 16a to 1.
This will be explained with reference to the time chart shown in Fig. 6h and the lockup diagram shown in Fig. 15.

During non-shift control, the points corresponding to the throttle opening and vehicle speed on the lock amplifier diagram are from area 0 or area 5 to area 4.
When the lock-up duty control solenoid valve 37 is changed from 0% to 100% (see Fig. 16a). Since non-shift control is in progress, non-shift control raw processing (FIG. 7) is executed. When entering the 100% area, first check the lock-up relay solenoid valve 3.
6 is turned on. After that, after time TLI seconds have elapsed, the lock-up duty control solenoid valve 37 is set to 25%.
only engaged. The reason why the lock-up duty control solenoid valve 37 waits for T11 seconds to start engaging is that when the lock-up relay solenoid valve 36 is turned on and the hydraulic pressure flow of the lock-up relay valve 45 is switched, the lock-up duty control solenoid valve 37 waits for T11 seconds. This is because it takes time for the oil pressure to stabilize. In other words, time TL1
can be determined from the time from when the lock-up relay solenoid valve 36 is turned on until the oil pressure in the working chamber in the torque converter stabilizes. When the lock amplifier duty control solenoid valve 37 is engaged by 25%,
Hydraulic pressure is applied to the lock-up clutch in the torque converter. However, at 25%, the 1-tuck-up clutch does not actually act as a clutch. In other words, this value of 25% is a preliminary value for enabling the lock-up clutch to operate immediately, and is a value determined from the ratio immediately before the lock-up clutch actually starts to operate.

When the time TL of 2 seconds has elapsed, the lock-up duty control solenoid valve 37 is engaged to 100%.

During non-shift control, the points corresponding to the throttle opening and vehicle speed on the lock amplifier diagram are from area 0 or area 5 to area 1.
, 2.3 and enters region 4, processing is performed to sequentially change the duty ratio of the solenoid valve for lock-up duty control (see Fig. 16b). Since non-shift control is in progress, non-shift control raw processing (FIG. 7) is executed. When entering region 1, first, the lock-up relay solenoid valve 36 is turned on. Thereafter, after a time TL of 1 second has elapsed until the oil pressure stabilizes, the lockup duty control solenoid valve 37 is engaged by 25% in order to apply preliminary oil pressure for a time of TL 2 seconds. Then, the lock-up duty control solenoid valve 37 is
Engagement is performed by a duty value of 5 DYI set according to the diagram. Thereafter, each time the vehicle enters the next region, the duty ratio of the lock-up duty control solenoid valve 37 is changed to a value corresponding to that region.

When the point corresponding to the throttle opening and vehicle speed on the lock amplifier diagram enters region 0 from region 4 during non-shift control, the duty ratio of the solenoid valve for lock up duty control is changed to 0%. (16th
(see figure c). Since non-shift control is in progress, non-shift control raw processing (FIG. 7) is executed. In this case, when entering area 0,
Immediately turn on the lock-up relay solenoid valve 36 and set the lock-up duty control solenoid valve 37 to 0% (release).

During lock-up duty control during non-shift control, for example, if the point corresponding to the throttle opening and vehicle speed on the lock-up diagram enters region 0 again from region 0 or region 5 through region 1, 2.3. In this case, the duty ratio of the lock amplifier duty control lock/id valve is set to 0% at the time when the range reaches 0. (See Figure 16d).

If a shift other than a 1-2 or 2-1 shift occurs when the lock-up is fully on (duty 100%), the duty ratio of the solenoid valve for lock-up duty control is set to a predetermined value only during the shift. (See Figure 16e). When the shift is started, a shift control process (FIG. 8) is executed. At this time, the duty ratio of the lock-up duty control solenoid valve is changed to a value corresponding to the shift and throttle opening as shown in FIG. When the shift is completed, the non-shift control process (7th
) is executed. Here, since the counter C3D is first set to 5, the lock-up preliminary control is skipped, and the lock-up duty control solenoid valve suddenly becomes duty control for the current area.

When the solenoid is under duty control during non-shifting or shifting, if the engine brake control execution determination is established, the engine brake control is executed (16th step).
(see figure f). However, immediately after the shift starts, it is cleared immediately. During engine brake control, the lock-up relay solenoid valve 36 is turned on, and the lock-up duty control solenoid valve 37 is engaged 100%. When the engine brake control is determined to stop, at that point the lock-up relay solenoid valve 3
6 and release the lock-up duty control solenoid valve 37.

If lock-up-on and lock-up-off decisions occur in extremely short succession, lock-up off is performed after a predetermined time delay (see Figure 16g). When the lock-up duty control solenoid valve 37 is engaged 100% after the lock-up-on determination is made, the timer TLN is started at that point. This timer T
Lock amplifier control is skipped while LN is running. If the area is 0 when timer TLN ends,
The lock amplifier is turned off.

If the lock-up-off judgment is established instantaneously during lock-up (100% engagement), and the lock-up-off judgment is while the timer TLN is being executed, the off processing will not be performed (see Figure 16h). . If the timer TLN ends, the lockup is immediately turned off.

In this embodiment, when the turbine rotation speed NT, which is the rotation speed of the output shaft of the torque converter, exceeds the engine rotation speed NE, which is the rotation speed of the input shaft of the torque converter, the lock-up clutch is forced as engine brake control. It's on.

Therefore, turbine speed NT > engine speed N
In the case of H, torque is transmitted without going through a torque converter. Therefore, engine braking becomes more effective.

Furthermore, in this embodiment, engine brake control is not performed when the throttle opening is not the minimum opening θ0 or when the idle switch is off. Therefore, even if the engine brake is too strong, it is possible to return to the normal engine brake state by pressing the accelerator pedal a little.

In this embodiment, if the lock-up clutch is directly connected when the engine speed NE is low, there is a possibility that the engine will stop, so the engine brake control is not performed when NE<11000 rpm.

Furthermore, for safety, if the brake is stepped on during engine brake control, the engine brake control is canceled. The same applies when the N range or R range is entered during engine brake control. This allows the lock-up to be released immediately when the brakes are applied suddenly, preventing the engine from stalling.

〔Effect of the invention〕

As explained above, in the present invention, the input shaft rotation speed detection means (engine rotation sensor 23) detects the rotation speed of the input shaft of the torque converter, and the output shaft rotation speed detecting means (engine rotation sensor 23) that detects the rotation speed of the output shaft of the torque converter. number detection means (turbine rotation sensor 24), and means for engaging the front bar 10 pull-up clutch when the rotation speed of the output shaft exceeds the rotation speed of the input shaft (detected in step 201 and in step 1).
45), the efficiency of engine braking increases. Therefore, when decelerating slowly, there is no need to step on the brakes, the number of times the brakes are used is reduced, and the failure rate of the brakes is reduced.

In addition, since the engine brake control is enabled or disabled depending on the degree of depression of the accelerator pedal (step 203 or step 204), the driver can now select the degree to which the engine brake is applied. Therefore, if the driver does not want to strongly apply the engine brake, the engine brake control described above will not be applied as long as the driver lightly depresses the accelerator, allowing control to suit the driver's feeling.

[Brief explanation of drawings]

FIG. 1 shows an automatic transmission of an electronically controlled automatic transmission which is an embodiment of the present invention. FIG. 2 shows a hydraulic circuit for driving the automatic transmission of FIG. FIG. 3 shows an electronic control circuit that controls the hydraulic circuit of FIG. FIG. 4 is a flowchart of the main routine of the CPU of the electronic control circuit of FIG. FIG. 5 is a flowchart of a regular interrupt routine of the CPU of the electronic control circuit of FIG. FIG. 6 is a detailed flowchart of the lockup control routine of FIG. 7 and 8 are detailed flowcharts of the non-shift control processing routine and the shift control processing routine of FIG. 6, respectively. 9 and 10 are detailed flowcharts of the lock amplifier determination and engine brake control determination routines of FIG. 7 or 8, respectively. FIG. 11 is a table showing the lock-up judgment criteria of this embodiment. FIG. 12 and FIG. 17 are tables for determining the duty ratio of the lock amplifier of this embodiment. FIG. 13 is a table showing vehicle speeds indicating lock-up lines in this embodiment. FIGS. 14 and 15 are lock amplifier diagrams of this embodiment. 16a, 16b, 16c, 16d, 16e, 16f, 16g, and 16h are time charts showing the operation of this embodiment. 21... Ignition switch, 23... Engine rotation sensor, 24... Turbine rotation sensor, 25... Output shaft rotation sensor, 26... Throttle sensor, 27... Neutral start switch, 28...
...Idle switch, 29...Brake switch, 30...Solenoid valve for clutch 02 control 31.
... Solenoid valve 32 for clutch 02 control ... Solenoid valve 33 for brake 82 control ... Solenoid valve 34 for brake B1 control ... Solenoid valve 35 for brake 82 control ... Solenoid valve for low and reverse prohibition, Solenoid valve 3637 for lock-up relay...
Solenoid valve for lock-up duty control, 38... Solenoid for line pressure control, 39... Cooler/hydraulic pump, - Oil reservoir, - Second regulator valve, Throttle valve, - Second regulator valve , ・Lock amplifier relay valve, ・Rosoku asop control hull, ・Lock asop crunch, 9.50 and 51... 40 ・ ・ 41 ・ ・ 42 ・ ・ 43 ・ ・ 44 ・ ・ 45 ・ ・ 46 ・ ・ 47 ・・Lube, 52, 53, 54, 55, 56, 57, 58a. Oil passage, 59...Torque converter, 60...Turbine shaft, ・Valve, ・Manual valve, ・Second modulator valve, ・Shift, ・←, ・First modulator valve, ・Line pressure oil passage, 58b, 58c, 58d 58e --- Manual ha 61... OD planetary gear, 62... Housing, 65... Output shaft, 66... Sun gear shaft, 67... Overdrive mechanism, 68...・Gear transmission mechanism, 69...Carrier, 70...Planetary pinion, 71...Input shaft, 72...Sun gear, 73...Intermediate shaft, 74.75...Carrier, 76.78・...Planetary Binion, NE...
Engine rotation speed, NT... Turbine rotation speed, NO... Output shaft rotation speed, θ... Throttle opening degree, SL, FLD, FEGB... Flag, T
1.1. T1.2. TLN TEGB ...Timer C5D...Counter, SLD...Variable, ...○D brake, -Second brake, -1st and Rev brake, -OD clutch, -Forward clutch, -Direct clutch, ...Central processing unit. O BO・ B 1 ・ B 2 ・ ・ CO・ C1・ ・ C2・ CPU ・

Claims (2)

[Claims] (1) In a vehicle having a lock-up clutch that engages and disengages between a torque converter and an input/output shaft of the torque converter, the input shaft rotation speed detection means detects the rotation speed of the input shaft of the torque converter; Output shaft rotation speed detection means for detecting the rotation speed of an output shaft of a torque converter; and means for engaging the lock-up clutch when the rotation speed of the output shaft exceeds the rotation speed of the input shaft. Engine brake control device using a lock-up clutch. (2) In a vehicle having a lock-up clutch that engages and disengages between a torque converter and an input/output shaft of the torque converter, an input shaft rotation speed detection means for detecting the rotation speed of the input shaft of the torque converter; Output shaft rotation speed detection means for detecting the rotation speed of an output shaft of a torque converter; depression amount detection means for detecting the degree of depression of an accelerator pedal; and when the depression amount is small, the rotation speed of the output shaft is equal to the input An engine brake control device using a lockup clutch, comprising: means for engaging the lockup clutch when the rotational speed exceeds the rotational speed of a shaft.