JPS6293552A - Transmission control device for automatic transmission - Google Patents

Abstract

PURPOSE:To avoid a speed change shock caused by a rapid increase in engine speed, by maintaining a medium speed position for a predetermined period of time, and thereafter shifting the speed position to a final target speed position to be controlled. CONSTITUTION:When a transmission range is changed from D range to L range, an idling operation of a one-way clutch 21 is hindered, and the establishment of a first speed position in the L range generating an engine brake from a third speed position in the D range is hindered. At this time, a second speed position in the D range or a second speed position in Z range is once established, and thereafter the first speed position in the L range is established. Accordingly, the generation of rapid engine brake may be suppressed, and in association with this, the generation of large speed change shock may be avoided thereby improving the comfortability to drive.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a shift control device for an automatic transmission used in vehicles such as automobiles, and more particularly to an electric T-type shift control device.

One of the shift control devices of a shift control device for an automatic transmission that includes a fluid coupling such as a fluid torque converter and a gear transmission equipped with a plurality of frictional engagement devices for obtaining multiple gear stages. a vehicle speed sensor that detects the vehicle speed, a load sensor that detects the engine load, a storage means that stores a predetermined target gear according to the vehicle speed and the engine load, and a vehicle speed that is detected by the vehicle speed sensor and the load. a calculation means for reading a target gear from the storage means in accordance with the engine load detected by the sensor; and a calculation means for reading the target gear from the storage means, and a friction engagement device for changing the gear to the target gear in accordance with the gear read by the calculation means. BACKGROUND OF THE INVENTION Electronic transmission control devices are known that utilize control means for controlling operation.

In the case where the gear transmission has at least three gears, in the case of a dual gear shift control device, when changing the gear range, that is, when changing a manual shift, the target gear is set at the current gear. The actual gear position may be different by two or more gears, and the gear position may change suddenly by two or more gears. If you shift down two or more gears all at once, especially if it occurs due to a manual shift change from the D range to the engine braking effect generation range such as the L range, the sudden engine braking effect will be very large. Shift shock occurs and ride comfort deteriorates.

In view of the above-mentioned problems with conventional electronic transmission control devices, the present invention prevents the gear from changing two or more gears at once when changing the gear range, and ensures that the gear changes by one gear at a time. This is an improvement that aims to alleviate the shift shock, and also allows the gears to change at once (two or more gears) during shifts where the shift shock is not so large, reducing the number of shifts and speeding up the shift. The purpose of the present invention is to provide an electronic speed change control device that is equipped with the following functions.

According to the present invention, the object of the present invention is to provide a shift control device for an automatic transmission including a gear transmission equipped with one or more frictional engagement devices for obtaining at least three gear stages,
a vehicle speed sensor that detects the vehicle speed; a load sensor that detects the engine load; a storage means that stores a gear position determined in advance according to the second speed and the engine load; and a vehicle speed that is detected by the vehicle speed sensor and the load. calculation means for reading out a target gear from the storage means in accordance with the engine load detected by the sensor; and whether the difference between the target gear read from the storage means and the current actual gear is 2 or more. determining means for determining whether or not the gear shift range has been changed; and determining means for determining whether or not the gear shift range has been changed; When downshifting, the gear changes immediately to the target gear, and when downshifting due to a change in the gear range, the gear changes step by step after a predetermined period of time even if the shift is 2 or more steps. This is achieved by a shift control device for an automatic transmission having a control means for controlling the operation of the one-wheel friction engagement and disengagement.

The present invention will now be described in detail with reference to embodiments with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing one embodiment of an automatic transmission incorporating a speed change control device according to the present invention. The automatic transmission includes a hydraulic torque converter 1 and a gear transmission 2 with three forward speeds and one reverse speed.

The hydrodynamic torque converter 1 is a well-known one that includes a pump 3, a turbine 4, and a stator 5, the pump 3 being connected to an engine crankshaft 6, and the turbine 4 being connected to a turbine shaft 7.
is connected to. The turbine shaft 7 forms the output shaft of the hydraulic torque converter 1, and also serves as the human power shaft of the gear transmission 2.

The gear transmission 2 includes an intermediate shaft 8, a sun gear shaft, and an output shaft 10.
It has A clutch 1] is provided between the input shaft 7 and the intermediate shaft 8, and a clutch 2 is provided between the input shaft 7 and the sun gear shaft 9. A brake]-4 for selectively fixing the sun gear shaft 9 to the transmission housing 13 is provided between the sun gear shaft 9 and the transmission housing 13. Further, one clutch element of a one-way clutch 15 is connected to the sun gear shaft 9, and this one-way clutch 15 is selectively fixed to the transmission housing 1 through the transmission housing 13 by a brake 16 using the other clutch element. It looks like this. A sun gear 17 is attached to the sun gear shaft 9,
This sun gear 17 meshes with one planetary binion carried on a carrier]8. A brake 20 is installed between the carrier 18 and the transmission housing 13.
A one-way clutch 21 is provided. The planetary pinion 19 meshes with a ring gear 22, and the ring gear 22 is connected to the output shaft 10.

Further, the sun gear 17 meshes with a planetary pinion 24 carried by another carrier 23.

The carrier 23 is connected to the output shaft 10. The planetary pinion 24 meshes with another ring gear 25, which is connected to the intermediate shaft 8. The clutch] 1.12 and the brake 14, ] 6.20 are each driven by hydraulic pressure, and are engaged or released in combinations shown in Table 1 by the speed change control device, which will be explained in detail below. It is designed to achieve each gear stage of one reverse gear and one reverse gear.

Table 1 In Table 1, ○ indicates clutch or brake engagement, Δ
The mark indicates engagement when the vehicle is being driven from the engine side (released during engine braking), and the mark X indicates the open state. The speed change i1J control device has a hydraulic control device 30 that selectively supplies hydraulic pressure to the clutch or brake, and this hydraulic control device includes a hydraulic pump, a pressure regulator valve, a 1-2 shift valve, and a 2-3 shift valve. The 1-2 shift valve is equipped with a 1-2 shift solenoid 3, which is well known in itself, and includes a valve, a manual valve, etc.
1, the 2-3 shift valve is switched and driven by a 2-3 shift solenoid 32.

The hydraulic control device 30 has a manual valve switching position operated by a manual shift (range) lever and 1-2.
Shift solenoid 31 and 2-3 shift solenoid 32
According to the operation of the clutch or brake, hydraulic pressure is supplied to the clutch or brake in combinations shown in Table 1 to achieve a predetermined gear position.

The operation of the 1-2 shift solenoid 31 and the 2-3 shift solenoid 32 is controlled by a shift control computer 33. Speed change control computer 33
is clearly shown in Figure 2. The computer 33 is supplied with signals generated by the vehicle speed sensor 34, throttle opening sensor 40, and shift range sensor 43, and controls the energization of the solenoids 31 and 32 based on these signals.

The vehicle speed sensor 34 generates a pulse signal with a frequency proportional to the vehicle speed, and this pulse signal is input to the gate counter circuit 35 as a gate signal. The gate counter circuit 35 receives a clock signal from the clock generation circuit 36, counts clock pulses during one cycle of the gate signal, and sends the count result to the input port 37 at a predetermined time via the common bus 38 for central processing. It is designed to output to three units (hereinafter referred to as CPUs).

The throttle opening sensor 40 is configured to generate an analog signal (voltage signal) corresponding to the opening of a throttle valve provided in an intake system of an engine (not shown). An analog signal generated by the throttle opening sensor 40 is input to an A/D converter 41 . The A/D converter 41 receives a clock signal from the clock generation circuit 36, and converts the analog signal into a digital signal based on the clock signal. A digital signal generated by the A/D converter 41 is transmitted from the input port 42 to the common bus 38 at a predetermined time.
The data is input to the CPU 39 via the .

The shift range sensor 43 detects the shift range determined by the driver's intention using the manual shift lever.
, and generates a corresponding signal. This signal is transmitted from the input port 44 to the common bus 38 at a predetermined time.
The data is input to the CPU 39 via the .

The CPU 39 is a well-known device including a general register, an EI arithmetic circuit, a program counter, etc., and includes a memory control unit (memory control unit) that controls the memory (storage) device 45.
A control command signal is output via a control bus 48 to each of a device control unit (DCU) 47 that controls the MCU) 46 and the input ports 37, 42, and 44. Memory device 45 is bidirectional common bus 3
8 is connected to the CPU 39 by read-only memory (ROM) and duplex access memory (RAM).
Contains. The read-only memory stores programming that determines computer routines, target gears that correspond to vehicle speed and engine load for each shift range, and various coefficients for calculations. The [-1+i ia gears stored in the read-only memory are determined so that the ☆ gears are set in the pattern shown in FIGS. 3 to 5. Furthermore, Fig. 3 shows the shift pattern in the D range, Fig. 4 shows the shift pattern in the 2 range, and Fig. 5 shows the shift pattern in the L range. The solid line indicates the shift-up line, and the broken line indicates the shift-down line.

The Dunram access memory temporarily stores signals generated by each of the vehicle speed sensors 3, 4, throttle opening sensor 40, and shift range sensor 43, other output signals, and signals used to save registers. It has become.

The CPU 39 reads the current target gear from the memory device 45 in accordance with the vehicle speed detected by the vehicle speed sensor 34 and the throttle opening detected by the throttle opening sensor 40, and outputs the signal to the output port 49. There is. Signals applied to the four output ports are input to the 1-2 shift solenoid 31 and the 2-3 shift solenoid 32 via an amplifier 50.5 to control energization thereof.

Further, as described above, the CPU 39 determines whether or not the step difference between the target gear position read from the memory device 45 and the current actual gear position is 2 or more, and if the step difference is not 2 or more, the gear position is changed. A control signal is output to the output port 49 so that the gear speed changes immediately to the target gear speed, and when the step difference is 2 or more, the actual gear speed changes one step at a time to the target gear speed after a predetermined period of time. It has become.

Next, the operation of the shift control device for an automatic transmission according to the present invention will be explained with reference to the flowchart shown in FIG. First, the CPU 39 manually inputs vehicle speed, throttle opening, and shift range data from the vehicle speed sensor 34, throttle opening sensor 40, and shift range sensor 43. CPU39
Based on this data, the gear stage St is read out from the plow memory device 45 and the target gear stage is set. Next, the CPU 39 determines whether the current shift range is within the same range. This shift range is N (neutral) range, R (reverse) range.
range, P (parking) range, the target gear St is set to the actual gear S, and a gear setting control signal is output to port 49 so that the gear of the gear transmission η2 becomes the target gear SL. By controlling the energization of the 1-2 and 2-3 shift solenoids 31 and 32 in accordance with this gear setting control signal, the gear transmission 2 is set to its target gear St. .

When the shift range is D range, 2 range, or L range, the CPU 39 determines whether or not to shift up. When the gear position does not change, the computer routine advances to NO in this step and then determines whether it is a downshift, but at this time, the routine advances to NO in this step as well, and the CPU 5t-5r, and the same gear stage setting control signal is outputted continuously. Therefore, sometimes the gear position is not changed.

In the above-mentioned step of determining whether or not to shift up, if the shift is up, the CPU 39 next compares whether the throttle opening degree T is larger or smaller than a predetermined value AI. When the throttle opening degree T is larger than the predetermined value A1, it is immediately set to 5L-5R, and even if the difference between the actual gear S at that time and the target gear is 2 or more, the gear is set to the target gear. Outputs a gear setting control signal so that it changes immediately. As a result, the gear transmission 2 is shifted up by one or two gears. When shifting up under conditions where the throttle opening degree T is greater than or equal to the predetermined value A1, that is, when shifting up with power on, even if two gears are shifted up at once, no large shift shock will occur; Sometimes it is permitted to shift up two gears at once in order to achieve a more responsive gear shift.

In the throttle opening degree comparison step, when the throttle opening degree T is smaller than the predetermined value A1, the CPU 39 determines whether or not the first timer is on. Since the first timer is not on at this time, the CPU 39 next determines whether the difference between the target gear St and the current actual gear Sr is two or more. When this step difference is not 2 or more, the first timer is turned on, and the gear is set to 5L-8r so that the gear changes immediately to the target gear 3t, and the gear changes immediately to the target gear. A control signal for gear position setting 1i is output.

When the difference between the target gear St and the actual gear Sr is 2 or more, the CPU 39 performs the calculation 5t-5r Samurai-1, and then goes to section 1, turns the timer on I1.5t-8r, and selects the gear. Part 11. Actual gear shifting of ν! - Outputs a gear setting control signal so that the gear is shifted up by one step. As a result, Ertun transmission; 14 "2" is the final "1st gear St" at this time, for example, 2nd gear!

Even if the speed is high, the second speed is first set. The first timer is
It maintains the on state for a predetermined time, and turns off after the predetermined time has elapsed.

Since the computer 33 repeats the routine as described above,
In the step of determining whether or not the timer is on in the next routine, the routine proceeds in the yes direction and maintains that gear position until the time determined by the first timer has elapsed. In the routine after the time set by the first timer has elapsed, 11 determines whether the first timer is on or not.
At the next step, the first timer is not on and has returned to the off state, so the routine advances to No, and the difference between the target gear S and the actual gear Sr is 2 again. It is determined whether the above is the case.

If the target gear St is the third gear at this time, the actual gear Sr of the gear transmission 2 is already the second gear, so the step difference is 1, and therefore the CPU 3
9 turns on the first timer, sets SL=Sr, and outputs a gear setting control signal so that the gear becomes the final target gear, that is, the third gear.

As a result, the gear position of the @tun transmission device 2 is shifted up to third speed, and the shift amplifier operation at this time is completed.

That is, when upshifting in a state where the throttle opening degree T is less than the predetermined value A1, for example, during power-off upshifting, the gear position is prevented from changing two gears at once, and at this time, the gear position that is one higher is first shifted. The shift-up is performed, and the gear position, for example, second gear, is maintained until a predetermined time period determined by the first timer started along with this has elapsed, and after that, the shift to third gear, which is the final control target gear, is performed. A gear shift is performed. As a result, after the gears between -1 and μΦ are maintained for a predetermined period of time, the final control is performed to shift to the top position, thereby avoiding a sudden large change in the gear ratio. This prevents the engine speed from dropping suddenly and prevents a large shift shock from occurring due to this.

Furthermore, when the shift is down, the CP XJ 39 determines whether the throttle opening degree T is larger than the predetermined opening degree A2. When the throttle opening degree T is smaller than the predetermined opening degree A2, it is determined whether the downshift is due to a change in the shift range, that is, a change in the manual shift range such as from D range to L lunge.

If the manual shift range is not changed, the shift is immediately changed to 5t-5r, and the gear Sr becomes the 11th gear S.
A gear position setting control signal is output so that the gear position changes to i.

Therefore, at this time, the gear transmission 2 is downshifted by one or two gears.

That is, the gear shift range is D range and the throttle opening is T.
is less than a predetermined value A2. For example, during a power-off downshift, the one-way clutch 21
Because no large shift shock occurs due to the idling action of
At this time, downshifting in two steps is rather permitted in order to reduce the number of gear changes and speed up the gear change.

If the throttle opening degree T is smaller than the predetermined opening degree A and the downshift is due to a change in the gear range, the CPU 3
Step 9 then determines whether or not the third timer is on. At this time, the third timer is not on, so the CPU determines that the difference between the target gear St and the current actual gear Sr is 2.
It is determined whether or not the above is true. When the step difference is 1, the third timer is turned on and the gear position setting control signal is immediately set to 5t-Sr and outputs the gear position setting control signal so that the gear position Sr becomes the target gear position St.

On the other hand, when the step difference between the target gear St and the current actual gear Sr is 2 or more, the calculation S t-3r-1 is performed, and after turning on the second timer, St -3r is set, and the gear is set to St -3r. For example, when in the third gear, a gear setting control signal is output so that the gear is first shifted down to the second gear. As a result, the gear transmission 2
is set to the second speed even if the final target gear St at this time is the -th speed. This state continues while the third timer is on, and when the third timer turns off, the CP
U39 outputs a gear position setting control signal so that the actual gear position becomes the final gear position, that is, the -th gear position. As a result, the gear transmission 2 is downshifted to the first speed.

That is, when the shift range is changed from the D range to the L range, the idling action of the one-way clutch 21 is prevented, and the L range first gear, which produces an engine braking effect, is prevented from being suddenly established than the D range third gear. At this time, the second speed of the D range or the second speed of the second range is established, and then the second speed of the L range is established. This suppresses the occurrence of a sudden engine braking effect, avoids the occurrence of a large shift shock associated with this, and improves ride comfort.

When the throttle opening degree T is larger than the predetermined opening degree A2, CP
U39 then determines whether the second timer is on. At this time, the second timer is not on, so C
The PU determines whether the difference between the target gear St and the current actual gear Sr is two or more. This step is 1
When this happens, the second timer is turned on to immediately set the gear to 5t-Sr, and a gear setting control signal is outputted so that the gear Sr becomes the target gear St.

On the other hand, when the gear step difference is 2 or more, St −
After performing the calculation 3r-1 and turning on the second timer, set St = Sr, and set the gear so that the gear is downshifted by one step, for example, when the gear is in third gear, it is first shifted down to second gear. Outputs a control signal. As a result, the gear transmission 2 shifts to the final target gear position St at this time.
is set to the second speed even if it is the -th speed. This state continues while the second timer is on, and when the second timer turns off, the CPU 39 sends a gear setting control signal so that the actual gear becomes the final target gear, that is, the -th gear. Output. As a result, the gear transmission 2 is downshifted to the -th speed.

That is, during a power-on shift down, that is, a kick down, in which the throttle opening degree T is greater than or equal to the predetermined value A2, the gear stage is set to 2nd gear - regardless of whether the shift is due to a change in the gear range or not. sudden change or avoidance,
At this time, a downshift is first performed to a gear position one step lower, and the gear position, for example, second gear, is shifted down until a predetermined time period determined by the second timer started along with this has elapsed. After this, a shift to the -th gear, which is the final control target stage, is performed. This means -mouth.

By shifting to the final control gear after the intermediate gear is maintained for a predetermined period of time, a sudden large change in the gear ratio is avoided and the engine speed increases rapidly. This prevents large frictional forces from momentarily acting on the frictional elements of the frictional engagement device for speed change control, ensuring its durability, and also prevents the engine from overrunning. Avoided.

In addition, the time period during which the gear is held in the intermediate gear to prevent the gear from changing to two gears all at once is determined by the shift door.

They may be different when shifting down and when shifting down.

In the above-mentioned embodiment, the target gear position is stored in the storage device according to the vehicle speed and the throttle opening, but the present invention is not limited to this. It may be a tube negative pressure, as long as it indicates the engine load.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited to the above-mentioned embodiments, and various other embodiments are possible within the scope of the present invention. This will be obvious to those skilled in the art.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of an automatic transmission incorporating a shift control device according to the present invention, FIG. 2 is a block diagram showing one embodiment of a shift control computer, and FIGS. FIG. 5 is a diagram showing a shift pattern in each shift range, and FIG. 6 is a flowchart 1 for explaining the operation of the shift control device according to the present invention.

Claims (1)

[Claims] A speed change control device for an automatic transmission including a gear transmission equipped with a plurality of frictional engagement devices for obtaining at least three gears, including a vehicle speed sensor that detects vehicle speed and a load sensor that detects engine load. a storage means that stores a predetermined target gear according to the vehicle speed and the engine load, and a storage means that stores the target gear from the storage means according to the vehicle speed detected by the vehicle speed sensor and the engine load detected by the load sensor. a calculating means for reading; a determining means for determining whether the difference between the target gear position read from the storage means and the current actual gear position is two or more; and determining means for determining whether the gear range has been changed. a discriminating means for discriminating, and a shift range so that the gear immediately changes to the target gear when the step difference is not 2 or more, or when the throttle opening is less than a predetermined value and a downshift is not caused by a change in the gear range. and a control means for controlling the operation of the frictional engagement device so that the gear speed changes step by step after a predetermined time even if the step difference is two or more during a downshift caused by a change in the speed change. Control device.