JPH0454373A - Controller of transmission - Google Patents

Abstract

PURPOSE:To acquire a thorough accelerating force at the time of restarting when a deceleration rate comes to be more than specified in the case when a car speed is high by setting a car speed signal immediately before it as a car speed for gear change control. CONSTITUTION:The title controller judges whether an actual car speed signal Vd by a car speed detection means A is higher than a set car speed value C and in the case when the signal Vd is judged lower than the value C by a first car speed comparing means B, it sets D the signal Vd as a car speed signal Vc for gear change control. In the case when the signal Vd is judged higher than the value C, when a deceleration rate judging means E judges a deceleration rate is lower than a specific value, the signal Vd is set F to the signal Vc, and in the case when the deceleration rate is higher than the specific value, the signal Vc set at the point of time is held G as the car speed signal Vc for gear change control as it is. Actuation of a high speed time car speed signal renewal means F is restarted only in the case when a vitual critical deceleration car speed in the case when it is decelerated at a specific value of the deceleration rate from the signal Vd at the time when the deceleration rate comes to be higher than the specific value is computed H and the signal Vd is judged to become higher than a virtual critical car speed.

Description

[Detailed description of the invention] (b) Industrial application field The present invention relates to a control device for a transmission.

(b) Conventional technology In the case of an electronically controlled transmission, a vehicle speed sensor detects the vehicle speed as an electrical signal, a throttle sensor detects the engine load as an electrical signal, and the two signals are compared to determine the speed change. Control takes place. If a vehicle equipped with such a transmission is traveling at high speed and the vehicle speed sensor fails and future signals are no longer input to the electronic control device, the following problems will occur. That is, since the vehicle speed signal is determined to be O, the electronic control device outputs a shift command signal to bring the transmission into the maximum gear ratio state. Therefore, the transmission that is running in the highest gear, for example, fourth gear, is switched to first gear. This sudden downshift may cause the engine to overrun, the vehicle to spin, etc. In order to prevent such a situation from occurring, Japanese Patent Application Laid-Open No. 59-86741 discloses that when the signal from the vehicle speed sensor is interrupted, the value immediately before the interruption is maintained as the vehicle speed signal for shift control, and The gear position is also shown to be maintained at the state immediately before the interruption. By doing this, it is possible to prevent a sudden downshift from occurring in the event of a failure of the vehicle speed sensor or the like.

(C) Problems to be Solved by the Invention However, in the conventional transmission control device as described above, when the vehicle stops due to sudden braking that locks the wheels while driving, it is difficult to control the driving force when restarting. There is a problem that there is a shortage of. In other words, when sudden braking that causes the wheels to lock is performed, the output from the vehicle speed sensor becomes O, so the same judgment is made as if the vehicle speed sensor had failed, and the vehicle speed signal for control corresponds to the speed of the vehicle while the vehicle is running. The vehicle is held in place, and the gear is also held in the high gear during driving.

If you stop the vehicle in this state, the gear and control vehicle speed signal will be held in the state immediately before braking, and if you try to restart from this state, the vehicle will start in a high gear and accelerate. becomes insufficient. The present invention aims to solve these problems.

(d) Means for Solving the Problems The present invention uses the detected actual vehicle speed signal as it is as a vehicle speed signal for shift control when the vehicle speed is low, and when the vehicle speed is high and the deceleration rate exceeds a predetermined value, immediately before The above problem is solved by using the vehicle speed signal as the vehicle speed signal for speed change control. That is, the transmission control device of the present invention includes a vehicle speed detection means (302) that detects the rotational speed of the output shaft of the transmission or a member that rotates in a predetermined relationship with the output shaft, and an actual vehicle speed detected by the vehicle speed detection means. The first vehicle speed comparison means (step 506) determines whether the signal (Vd) is equal to or higher than the preset vehicle speed value (C), and the first vehicle speed comparison means determines whether the actual vehicle speed signal is smaller than the set vehicle speed value. When the judgment is made, the actual vehicle speed signal is converted into the vehicle speed signal for speed change control (V
c) Low vehicle speed vehicle speed updating means (step 508)
), and deceleration vehicle determining means (step 5
10.512), and high vehicle speed vehicle speed updating means ( step 514), a speed change vehicle speed signal holding means (step 510) which uses the speed change control vehicle speed signal set at that time as the speed change control vehicle speed signal when the deceleration rate is equal to or higher than a predetermined value (step 510); a virtual limit vehicle speed calculation means (step 504) that calculates a virtual limit deceleration vehicle speed when decelerating at the predetermined value of the deceleration rate from the actual vehicle speed signal at the time when the actual vehicle speed signal becomes a predetermined value or more; a second vehicle speed comparison means for comparing the vehicle speed with the limit vehicle speed (
Step 510), only when the second vehicle speed comparing means determines that the actual vehicle speed signal is equal to or higher than the virtual limit vehicle speed, the control vehicle speed signal holding means is deactivated and the high speed vehicle speed signal updating means is restarted. The present invention is characterized in that it has a return means (steps 510, 512, and 514) for causing Note that reference numerals in parentheses indicate corresponding ones in the embodiments described later.

(e) Effect Even if the actual vehicle speed signal detected by the vehicle speed detection means rapidly decreases when the vehicle speed is low, this signal is directly used as the vehicle speed signal for shift control. Even in this case, since the vehicle speed is originally low, a sudden downshift will not occur, and problems such as engine overrun and vehicle spin will not occur.

On the other hand, when the actual vehicle speed signal decreases at a rate greater than the predetermined rate at a vehicle speed greater than or equal to a predetermined vehicle speed, the immediately preceding vehicle speed signal for shift control is maintained. This prevents a sudden downshift from occurring due to a failure of the vehicle speed detection means.

(F) Embodiments Hereinafter, embodiments of the present invention will be described with reference to FIGS. 2 to 7 of the accompanying drawings.

FIG. 2 shows a schematic diagram of a power transmission mechanism of an automatic transmission with four forward speeds and one reverse speed with an overdrive. This power transmission mechanism includes an input shaft 13 to which rotational force from an engine output shaft 12 is transmitted via a torque converter 10, an output shaft 14 that transmits driving force to the final drive device, a first planetary gear set 15, and a second planetary gear set. Group 16, reverse clutch 1
8, a high clutch 20, a forward clutch 22, an overrunning clutch 24, a low and reverse brake 26, a band brake 28, a row one-way clutch 29, and a forward one-way clutch 30. Note that the torque converter 10 has a lock-up clutch 11 built therein. The first planetary gear set 15 is composed of a sun gear S1, an internal gear R1, and a carrier PCI that supports a binion gear Pi that meshes with both gears Sl and R1 at the same time.
6 is composed of a sun gear S2, an internal gear R2, and a carrier PC2 that supports a binion gear P2 that meshes with both gears S2 and R2 at the same time. Carrier PCI can be connected to input shaft 13 via high clutch 20, and sun gear S1 is connected to reverse clutch 18.
It can be connected to the input shaft 13 via. carrier PCI
The overrunning clutch 2 is connected via the forward clutch 22 and the forward one-way clutch 30 connected in series thereto, or via the overrunning clutch 2 arranged in parallel to the forward clutch 22 and the forward one-way clutch 30.
It can also be connected to internal gear R2 via 4.

Sun gear S2 is always connected to input shaft 13, and internal gear R1 and carrier PC2 are connected to output shaft 14.
is always connected.

The low and reverse brake 26 can fix the carrier PCI, and the band brake 28 can fix the sun gear Sl. The row one-way clutch 29 is arranged in an orientation that allows forward rotation (rotation in the same direction as the engine output shaft 12) of the carrier PCI, but does not allow reverse rotation (rotation in the opposite direction to the forward rotation).

The power transmission mechanism includes clutches 18, 20, 22 and 2.
4. By operating the brakes 26 and 28 in various combinations, each element (S
L, S2, R1, R2, Pct, and PC2) can be changed, thereby making it possible to variously change the rotational speed of the output shaft 14 relative to the rotational speed of the input shaft 13. By operating the clutches 18, 20, 22 and 24 and the brakes 26 and 28 in combination as shown in FIG. 3, four forward speeds and one reverse speed can be obtained. In addition, in Fig. 3, ○ marks indicate operating clutches and brakes, α1 and α2 are the ratios of the number of teeth of sun gears Sl and S2 to the number of teeth of internal gears R1 and R2, respectively, and the gear ratio is the output This is the ratio of the rotation speed of the input shaft 13 to the rotation speed of the shaft 14.

FIG. 4 shows a hydraulic device that controls the operation of the power transmission mechanism. This hydraulic control device includes a pressure regulator valve 40, a pressure modifier valve 4
2, line pressure solenoid 44, modifier pressure accumulator 46. Pilot valve 48, torque converter relief valve 50, lock-up control valve 52, first shuttle valve 54, lock-up solenoid 56, manual valve 58, first shift valve 60
, second shift valve 62, first shift solenoid 64,
2nd shift solenoid 66, servo charger valve 68.3-2 timing valve 70.4-2 relay valve 72, 4-2 sequence valve 74, first reducing valve 76, second shuttle valve 78, overrunning clutch control valve 80, Overrunning clutch solenoid 82, Overrunning clutch reducing valve 84.1-2 Accumulator 86.2-3 Accumulator 88.3-4
Accumulator 90, N-D accumulator 92, accumulator control valve 94. It has a filter 96, etc., and these are connected to each other as shown in the figure, and the torque converter 10 described above (in addition, the apply chamber 11a and release chamber 11b of the lock-up clutch 11 are formed in this). ), forward clutch 22, high clutch 20. Band brake 28 (note that this includes a 2nd speed apply chamber 28a, 3rd speed release chamber 28b, and 4th speed apply chamber 28c), reverse clutch 18, low and reverse brake 26, and overrunning. It is also connected to the clutch 24 as shown, and further connected to a variable capacity vane type oil pump 34 equipped with a feedback accumulator 32, an oil cooler 36, a front lubrication circuit 37, and a rear lubrication circuit 38 as shown. ing. A detailed explanation of these valves will be omitted.

For parts omitted from explanation, see Japanese Patent Application Laid-Open No. 63-25165.
It is similar to that described in 21.

FIG. 5 shows a control unit 300 that controls the operation of solenoids 44,56,64,66 and 82. The control unit 300 has an input interface 3
11. Reference pulse generator 312, CPU (central processing unit) 313, ROM (read only memory) 314,
It has a RAM (random access memory) 315 and an output interface 316, which are communicated by an address by 319 and a data bus 320.

This control unit 300 includes an engine speed sensor 301, a vehicle speed sensor 302, a throttle opening sensor 303, and a select position switch 304.
, kickdown switch 305, idle switch 30
6. Full throttle switch 307, oil temperature sensor 30
8. Signals from the input shaft rotational speed sensor 309, overdrive switch 310, etc. are input. On the other hand, shift solenoids 64 and 66, overrunning clutch solenoid 82, lock-up solenoid 56
, and a signal is output to the line pressure solenoid 44.

Processing of the vehicle speed signal for speed change control is performed according to the control flow shown in FIG. First, it is determined whether the maximum deceleration vehicle speed Vm is 0 (step 502),
If it is not 0, the maximum deceleration rate R multiplied by time t is subtracted from Vm, and this is set as a new Vm (504). t is the elapsed time from the previous routine to the current routine execution. R is set to the maximum deceleration rate at which the wheels decelerate without locking (
In other words, it is the deceleration rate at which the anti-skid brake device operates). Then, the actual vehicle speed signal Vd becomes the set vehicle speed value C.
(506). Vd is an actual vehicle speed signal detected by vehicle speed sensor 302.

The value of C is relatively low vehicle speed value (e.g. 20 km
/h) is set. If Vd is smaller than C, the actual vehicle speed signal Vd is directly set as the vehicle speed signal Vc for speed change control (508). On the other hand, Vd is C
If the actual vehicle speed signal Vd is larger than the maximum decelerated vehicle speed Vm, it is determined whether the actual vehicle speed signal Vd is larger than the maximum decelerated vehicle speed Vm (step 510).

When Vd is larger than Vm, Vd is the VmO value.
512), and then the vehicle speed signal Vc for speed change control.
The actual vehicle speed signal Vd is set as (514). On the other hand, if Vd is smaller than Vm in step 510,
Returns without changing the setting of the vehicle speed signal Vc for speed change control.

As a result, the following operations are performed by the above control. That is, when the actual vehicle speed signal Vd detected by the vehicle speed sensor 302 is smaller than the set vehicle speed value C, the actual vehicle speed signal Vd is used as it is as the vehicle speed signal Vc for shift control (steps 506-+508). At a vehicle speed lower than the set vehicle speed value C, for example, even if the vehicle speed signal becomes O due to a failure of the vehicle speed sensor 302, the gear is always in first gear, or even if a town shift is performed. Because the vehicle speed is low, engine overrun and vehicle spin do not occur.

Next, if the actual vehicle speed signal -%Vd is larger than the set vehicle speed value C, a comparison is made between the actual vehicle speed signal Vd and the maximum deceleration vehicle speed Vm (step 510). This means that That is, since Vm is the value obtained by subtracting the maximum deceleration rate R multiplied by time t from Vm in the previous routine, if the actual vehicle speed signal Vd is greater than this, a normal signal is output from the vehicle speed sensor 302. Also, since it is considered that the wheels are not slipping, the current actual vehicle speed signal Vd is set as the maximum deceleration vehicle speed Vm, and the actual vehicle speed signal Vd is set as the vehicle speed signal Vc for shift control. That is, the signal from the vehicle speed sensor 302 is used as it is to perform gear change control and the like.

On the other hand, when the actual vehicle speed signal Vd is smaller than the maximum deceleration vehicle speed Vm, the vehicle speed signal VC for shift control is not reset, and the previous vehicle speed signal VC for shift control is used as is. If the actual vehicle speed signal d is smaller than the maximum deceleration vehicle speed Vm, it means that the signal from the throttle opening sensor 302 is not output (or the wheels are in a slip state). By using the vehicle speed signal Vc for speed change control in
A sudden town shift is prevented from occurring.

The state in which the vehicle speed signal Vc for speed change control is not reset, that is, is not updated, is canceled when the actual vehicle speed signal Vd becomes larger than the maximum deceleration vehicle speed Vm. The value of Vm is decreased according to the maximum deceleration rate in step 504 (however, if the actual vehicle speed signal Vd becomes larger than this, the wheel slip condition subsides, and the actual vehicle speed signal Vd corresponding to the actual vehicle speed is output. This is because it is determined that the

When the above-mentioned control is illustrated in correspondence with an actual running condition, it is as shown in FIG. 7. That is, the actual speed of the vehicle relative to the road surface is a, -b -c, as shown in Figure 7(a).
It is accelerated between c-d-e-f, and decelerated and stopped between f=g-h-i-j-k. In this case, it is assumed that the actual vehicle speed signal changes as shown in FIG. 7(b).

Between a = b - c - d, the vehicle is in an acceleration state or a constant vehicle speed state, and the actual vehicle speed signal Vd is always larger than the maximum deceleration vehicle speed Vm, so the vehicle speed signal Vc for shift control matches the actual vehicle speed signal Vd. . If the actual vehicle speed signal Vd is not output due to a temporary disconnection between d and c, Vd becomes smaller than Vm and Vc is not updated, and even between 6 and 0, Vc is equal to the VC between c and d. is the same value. When the throttle opening sensor 302 resumes outputting the signal at point e, Vd becomes V
m, and Vd is again set as Vc. Therefore, vehicle speed sensor 302
It will not downshift even if the signal is no longer output. Next, a state in which the anti-skid brake device is activated to decelerate from point f is shown. f-g
During this period, the actual vehicle speed signal Vd decelerates without becoming smaller than the maximum decelerated vehicle speed Vm. Therefore, Vd is directly set to Vc. , when the wheel loses its clipping force at point g and begins to lock, the actual vehicle speed signal Vd
becomes smaller than the maximum decelerated vehicle speed Vm, updating of Vc is interrupted and the value at point g is maintained as the value of Vc.

On the other hand, the maximum deceleration vehicle speed Vm decreases according to the maximum deceleration rate R (.When the anti-skid brake device detects that the wheels are in a locked state and weakens the brake pressure,
The grip of the wheels has been recovered, and the actual vehicle speed signal Vd is increasing (at point h, the actual detected vehicle speed signal Vd reaches the maximum deceleration vehicle speed Vm).
When the speed change control vehicle speed signal Vc is exceeded, updating of the vehicle speed signal Vc for speed change control is restarted, and Vd is set as Vc. Therefore, although the actual vehicle speed signal Vd suddenly decreases and then increases rapidly between gh and gh, this is not reflected in the speed change control vehicle speed signal Vc, so that no unnecessary downshift is performed between gh. In addition, 8
The actual vehicle speed signal Vd suddenly decreases at point 8, but in this case, the vehicle speed at point 8 is less than the set vehicle speed value C, so the vehicle speed signal Vc for shift control also decreases rapidly like Vd. However, in this case, since the vehicle speed is low, a sudden downshift will not occur.

In addition, if a vehicle without an anti-skid brake device brakes suddenly and stops with the tires locked, the actual vehicle speed signal before the sudden deceleration starts until the actual vehicle speed signal reaches the set vehicle speed value C. Vd is held as the vehicle speed signal Vc for shift control, but when the actual vehicle speed signal Vd becomes smaller than the set vehicle speed value C, updating of the signal is restarted, and the actual vehicle speed signal Vd is set as the vehicle speed signal Vc for shift control,
A downshift will occur. Therefore, when the vehicle stops, a downshift is performed and the first speed is reached. When restarting, acceleration will be performed from the first gear state, and sufficient driving force can be obtained.
You can accelerate normally. In this way, when the vehicle suddenly brakes and comes to a stop, the vehicle will not be held in the high speed gear.

Although this embodiment has been described with respect to an automatic transmission with four forward speeds, the present invention can also be applied to a continuously variable transmission.

(g) As described in detail, according to the present invention, when the actual vehicle speed signal is smaller than the set vehicle speed value.

Shift control is performed using the actual vehicle speed signal, and if the actual vehicle speed signal is larger than the set vehicle speed value and the deceleration of the actual vehicle speed signal is larger than a predetermined value, the actual vehicle speed immediately before sudden deceleration starts. Since the signal is now used for gear change control, it prevents downshifting and sudden engine braking due to a malfunction of the vehicle speed sensor while driving, and also prevents the wheels from being locked. If you restart your vehicle after a sudden stop, you can start shifting from 1st gear and obtain sufficient acceleration.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the relationship between the constituent elements of the present invention, Fig. 2 is a skeleton diagram of an automatic transmission, Fig. 3 is a diagram showing the combination of elements operating at each gear stage, and Fig. 4 is a hydraulic circuit. 5 is a diagram showing a control unit, FIG. 6 is a diagram showing a control flow, and FIG. 7 is a diagram showing changes in each vehicle speed signal over time. Patent applicant Jatco Co., Ltd. Agent Patent attorney Toshiyuki Miyauchi

Claims (1)

[Scope of Claims] In a control device for a transmission that controls a shift using a vehicle speed signal for shift control as one input signal, the vehicle speed detects the rotation speed of the output shaft of the transmission or a member that rotates in a predetermined relationship with the output shaft of the transmission. a detection means; a first vehicle speed comparison means for determining whether the actual vehicle speed signal detected by the vehicle speed detection means is greater than or equal to a preset vehicle speed value; A low vehicle speed vehicle speed updating means sets the actual vehicle speed signal as a vehicle speed signal for speed change control when the actual vehicle speed signal is determined to be smaller than the set vehicle speed value, and a first vehicle speed comparison means sets the actual vehicle speed signal to the vehicle speed signal for speed change control when the first vehicle speed comparing means determines that the actual vehicle speed signal is equal to or higher than the set vehicle speed value. A deceleration rate determining means for determining whether the deceleration rate decreases by a predetermined ratio or more, and an actual vehicle speed signal detected by the vehicle speed detecting means for use in shift control when the deceleration rate determining means determines that the deceleration rate is smaller than the predetermined value. High vehicle speed update means for setting the vehicle speed signal, and vehicle speed signal holding means for changing the speed change control vehicle speed signal that is set at that time as the speed change control vehicle speed signal when the deceleration rate is equal to or higher than a predetermined value. and a virtual limit vehicle speed calculation means for calculating a virtual limit deceleration vehicle speed when decelerating at the predetermined value of the deceleration rate from the actual vehicle speed signal at the time when the deceleration rate becomes equal to or higher than the predetermined value; A second vehicle speed comparison means compares the vehicle speed with the limit vehicle speed, and only when the second vehicle speed comparison means determines that the actual vehicle speed signal is equal to or higher than the virtual limit vehicle speed, the operation of the control vehicle speed signal holding means is canceled and the control vehicle speed signal holding means is activated. A control device for a transmission, comprising: a return means for restarting operation of a vehicle speed signal updating means.