JPS60184753A - Speed control device for automatic transmission for vehicle - Google Patents

Abstract

PURPOSE:To aim at damping a shock upon speed change, by providing such a control device for a vehicle automatic transmission that the occurrence of a slip is determined in accordance with the rotational speeds of front and rear wheels, and the engaging speed of friction members is lowered by means of a speed change shock damping means. CONSTITUTION:A slip determining means 13 determines the presence of a slip in accordance with signals from front and rear wheel speed detecting means 11L, 11R, 12L, 12R. When the occurrence of a slip is detected, a speed change shock damping means 14 lowers the engaging speed of friction members upon speed change by an automatic transmission 4. Accordingly, the rate of variation in torque transmitted to the tiers may be limited upon speed change so that moderate speed change having less shock may be made.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a shift control device that controls the shift position of an automatic transmission for a vehicle, and particularly to a shift control device that controls the shift position of an automatic transmission for a vehicle, and in particular a shift control device that can prevent rotational slip of drive wheels. This invention relates to a speed change control device that performs.

(Prior art) When a slip occurs between the wheels and the road surface while the vehicle is running, the steering control becomes difficult and dangerous.
Various anti-slip measures have been considered. An example of this is the Andes 4-nit brake, which reduces braking force if the wheels slip when the brakes are applied.
In general, as disclosed in Japanese Patent Application Laid-open No. 51-102773, the shift position of the automatic transmission is shifted to a position where engine braking is less likely to be applied during undesired skid operation, preventing slips caused by cone brakes and reducing undesired skids. Proposals have also been made to increase the effectiveness of Kidd devices.

Slip becomes a problem not only when the brakes are applied as described above, but also when the accelerator is pressed on a wet or frozen road, or when shifting gears. When the road surface becomes wet or frozen, the stiffness coefficient between the tire and the road surface decreases, and the tire's grip force decreases, and the driving force that the tire can transmit to the road surface decreases in GJ by the amount of the decrease in grip force. Hereinafter, such a road surface will be referred to as a low μ road. Therefore, in such a state, slippage is likely to occur due to changes in the torque transmitted to the tires when the accelerator is depressed or when changing gears. Accelerator depression can be adjusted according to the driver's will, but in the case of so-called automatic cars equipped with automatic transmissions, the gear shift shock is determined at the time of manufacture, and it can be adjusted freely even if the road surface is slippery. It's not possible. To achieve this, it would be better to create an automatic transmission with less shift shock from the time of manufacture, but in this case, the durability of the frictional engagement members decreases due to increased heat generation in the frictional engagement members that change gears. There is a great risk that it will cause

(Objective of the Invention) The present invention has been made in view of the above circumstances, and is designed to reduce the engagement speed of the frictional engagement member only during gear shifting when slip of the drive wheels is detected, thereby alleviating the gear shifting shock. The object of the present invention is to provide a shift control device for an automatic transmission for a vehicle.

(Structure of the Invention) The speed change control device of the present invention detects the rotational speeds of the front and rear wheels using a rotational speed detection means, compares these using a slip determination means, determines whether slip has occurred based on the difference, and determines whether slip has occurred. When a slip detection signal is detected, a slip detection signal is output to the shift buffer means, and the shift buffer means reduces the engagement speed of the friction member when shifting is performed while receiving this slip detection signal. It is something.

(Effects of the Invention) According to the present invention, when the slip determination means detects slip from the rotation difference between the front and rear wheels and it is determined that the vehicle is traveling on a low μ road, when the gear is changed, the shift buffer means operates to reduce friction. Since the engagement speed of the members is reduced, the rate of change in the torque transmitted to the tires that occurs during gear shifting can be suppressed, allowing for gentle and less shocking gear shifting, which prevents tire slippage and prevents the car from spinning. can be effectively prevented. Further, the transmission control device of the present invention requires only a partial improvement of a conventional automatic transmission, and can be easily used in conventional automatic transmission vehicles.

<Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows the operating system of the speed change control device of the present invention. In this example, the output of the engine 3 is changed speed by the automatic transmission 4, transmitted to the C differential 6 via the propeller shaft 5, and The rear wheel is 2L.

2 [( is driven. Front wheel rotational speed detection means 11L, 11R that detect the rotation of the front wheels IL, IR, and the rear wheels 2L,
rear wheel rotation speed detection means 12L for detecting rotation of 2R;
Slip determination means 13L receives the signal from 12R:
A) IT ＾ζr kIS catfish rotation r: Wb Tom1)
Determine if s gfu11・vpu is ruined. In other words, when there is no slip, the rotational speed of both wheels is equal as long as the outer diameters of the front and rear wheels are the same, but if the rear wheel, which is the driving wheel, slips, the rotational speed of the rear wheel becomes greater, so slipping occurs. can be detected. When the occurrence of a slip is detected, a slip detection signal is output from the slip determination means 13 to the shift buffer means 14, and the shift buffer means 14 that receives the signal outputs a slip detection signal to the shift buffer means 14 when the automatic transmission 4 shifts.
It operates to reduce the engagement speed of the friction member that performs the 4th gear change. A preferred embodiment of the speed change buffering means 14 is one in which the engagement of the friction member is performed by hydraulic pressure, and a line pressure adjustment device for reducing this hydraulic pressure is used as the buffering means.

FIG. 2 shows a cross section of an automatic transmission 4 according to an embodiment of the present invention and a part of the hydraulic control circuit which is an adjustment device.

The automatic transmission 4 includes a torque converter 41 on an engine output shaft 40 that converts and outputs the output of the engine 3 according to the load and speed ratio, and an A-bar arranged in series that changes the output of the torque converter 41. It consists of a drive planetary gear transmission mechanism 42 and a multi-stage gear transmission mechanism 43, and hydraulic pressure is selectively supplied to the hydraulic clutches J5 and brakes in both mechanisms 42 and 43 by a hydraulic control circuit to perform gear changes. It will be done.

The hydraulic control circuit includes a pressure regulating valve 21 and a select valve 22.1-2.
Shift valve 23.2-3 To shift 1 valve 24.3-4 Shift valve 25, first to fourth solenoid valves SL 1 to 81-4, second lock valve 26, cutback valve 27, vacuum throttle valve 28, SLOT]~Le backup valve 29
The valves are arranged as shown in the figure, and receive hydraulic pressure from a hydraulic pump 30 driven by the engine 3, and are operated in conjunction with the driver's shift lever operation. 0 of the fourth solenoid valve 5l-1 to SL4
In response to N-OFF, these valves control the transmission mechanism 42.
．． Hydraulic pressure is selectively supplied to the clutches and brakes at No. 43.

Incidentally, the transmission mechanism 4 is 44.45I.
It is for brake operation within 2°43. Further, the fourth solenoid valve SL4 is used to operate the lock-up mechanism 41a of the torque converter 41, and the fourth solenoid valve SL4 is used for operating the lock-up mechanism 41a of the torque converter 41. SL 2. SL 3 is used for shifting. First to third solenoid 81-1°SL2.
The relationship between the ON-OFF combination of SL3 and the shift position is set as shown in Table 1, for example.

Furthermore, this hydraulic control circuit includes a hydraulic pressure supply line 31a for determining the magnitude of hydraulic pressure to be supplied to a clutch and a brake that act on the lower end of the pressure regulating valve 21 in the figure to change gears;
A line pressure regulating valve 31 is provided in 3Ib. This line pressure regulating valve 31 is operated by a signal from the second AND circuit 35, and the signal from the second AND circuit 35 is
At the time of FF, the normal line pressure determined only by the pressure regulating valve 21 is generated, and the above-mentioned signal is generated.

When the signal is ON, the line pressure of the pressure regulating valve 21 is at the normal oil level.
It operates in such a way that it becomes lower. To explain the light output of this signal, the ON signal is output from the gear change controllers 1 to 32 at the time of gear shifting, and signals are received from the front wheel and rear wheel rotational speed detection means 11 and 12 (JI and rear wheel rotational speed detection means 11 and 12). The determination means outputs a QN signal when a slip is detected.The first AND circuit 33 receives both of these signals.
[Jl] When both of these signals are ON, that is, when a shift is being performed and a slip is detected, an ON signal is output. The output of the first AND circuit 33 is divided into two parts, one directly and the other output to the second ΔN through the timer 34.
+) A person is connected to the circuit 35. Therefore, when an ON signal is output from the first AND circuit, an ON signal is output from the second AND circuit 35 to the line pressure regulating valve 31 for a certain period of time determined by the timer 34.

By configuring as described above, when shifting gears when a slip is detected, the line pressure will be lowered for a certain period of time from the start of gear shifting. As a result, it is possible to reduce the engagement speed of the friction member at A3 during gear shifting, allowing smooth gear shifting. Roughly speaking, after a certain period of time has elapsed from the start of gear shifting and the engagement of the friction member is completed, the line pressure is reduced. Return it to its original position to prevent abnormal slipping of the friction member,
Deterioration of durability can be prevented.

FIG. 3 shows an overall flowchart of the shift control, and as can be seen from this figure, the shift control is first performed from initialization settings. This initialization setting first initializes the baud 1 to l113 of each control valve that switches the hydraulic control circuit of the automatic transmission and the necessary counters, sets the gear shift NfS43 to first gear, and releases the lock-up clutch 41a. Set. After this, various working areas of the multiplex control circuit are initialized to complete the initialization settings.

Next, this flowch! 7 - Subtract 1 from the value of timer T, which is used to set the speed at which the tot is executed, and replace that value with T. For example, if T = 20, this means that the timer will be reset by performing the flow 20 times, and if the timer is reset every second, the main program will be reset 20 times per second. is carried out.

After this, a step of reading the position of the shutoff valve 22, ie, the shift 1 to range, is performed. Next, it is determined whether the read shift range is lunge. When this determination is NO, it is determined whether the shift range is the 2nd range. When this determination is YES, that is, when the shift range is the 2nd range, a signal is generated to control the shift valve so as to release the lockup and shift the gear 'Ii speed mechanism 43 to the 2nd speed. The process then proceeds to step 81. On the other hand, when the determination of the 2nd range is r40, the shift range is the D range, so the shift control line d3 and [cock A shift d3 and [-1 up shift map including the up 1liIJ control line is set.Next, shift 1 to up shift control including shift up determination is performed.This shift up shift control is performed using the up shift control shown in FIG. After that, downshift control according to the shift town shift control subroutine shown in FIG. 7 and lockup control according to the lockup control subroutine shown in FIG. 9 are performed in this order, and the process proceeds to step S1. Also, when it is determined that the shift 1 range is a lunge, first release the lockup, then shift down to 1st gear, and then calculate whether the engine will overrun or not. .

Thereafter, based on this calculation, it is determined whether or not overrun will occur, and if this determination is No, the gear is shifted to the first gear, and if this determination is YES, the gear is shifted to the second gear. After this, proceed to step $1.

In step S1, in order to determine the speed at which this flow 1/-1 is executed, an R delay of a certain time is created, for example, after creating a time delay of 507 rL seconds, the flowchart is re-executed. This time delay in step S1 is related to timer T, for example, timer T
If the initial value of is set to T-20, the time delay of 50 msec is repeated 20 times, resulting in a time delay of 1 second, so the timer F
will be reset every 1 second.

After this, it is determined whether the vehicle is traveling on a low μ road or not, and step 82
Returns to , and this ノ[l- is repeated. The judgment as to whether or not it is low μ road running tJ is made based on the dimension rib routine shown in FIG.
> After reading the driven wheel rotation (Nc), the absolute value of the difference between the two I ND - Ncl and the slip judgment tool il value N +,
compared with IN-NCI? ,・N1, Notogi is low μ
Set the flag to 1, and set IND-Nc l≦NL to low 1
This is to set the flag to 0.

Shift 1 to up shift 11'111 This shift 1 to up shift control first reads out the position of the gear transmission diagram 43 according to the gear stage, as shown in FIG.
Start by determining whether or not the current gear position is 7'I on the right based on the read gear position. Ureru 1, if this judgment is YES, do you have any more shift I up?
:i'', ;Since it is not possible to change the mouth, the upshift control is ended.

10,000, if the above judgment is NO, the throttle opening is read by the throttle opening sensor, and for example, in the upshift map shown in FIG. Turbine speed: Read lSP (MAR). That is, in FIG. 6, the turbine rotational speed corresponding to the throttle 611 degree is read on the shift 1 to up shift line M'fu (solid line). Next, the actual turbine rotation speed: TSP is detected by the turbine rotation speed sensor and compared with the turbine rotation speed: 1-8P (MAP) on the map.

When TSP≦TSP (MAP), that is, when the actual turbine rotation speed is on the lower side (left side) than the shift-up shift line Mfu (solid line) in Fig. 6, the
Set the second upshift line Mfu' (broken line) to be (MAP) x O, 8, and set TSP (MAR) x 0.
8 and TSP. -r S P > T
When S P (MAP) xo, a, 4, that is, the second shift 1-
-T to the higher rotation side from the up-shift line Mfu' (broken line)
When SP is positioned, shift 1 to up shift control is completed.

When SP≦I'S'P (MAR,)
(Shift 1 - map shift control is completed. This flag 1 is set when an upshift is executed.
, to remember the upshift state C
be.

1-' S l) > -T-S P (M A R), that is, in FIG.
When there is 1' S I) on the higher rotation side, 9"
It is determined whether l=1 or not, and when flag 1=1, it indicates that an upshift has already been performed, and the upshift speed change control is ended as it is. When flag 1 = 0, after setting the flag to 1 - 1, it is determined whether the low μ flag is -1, and the low μ flag is set to 1.
When the flag is -1, the line pressure regulating valve is turned ON to avoid a drop in line pressure, and the line pressure drop flag is set to 1. When the low μ flag is O, the line pressure ([(lower flag is 0
Keep it as it is, and keep the line pressure as it is. In either case (both in the case of the low μ flag -1 and in the case of the low μ flag -0), a one-stage upshift is performed and a lock-up release timer is set. After this, it is determined whether the line pressure -F1 flag is 1 or not, and if it is 1, the line pressure drop flag is set to O after a certain period of time and this flow is #3.
If the result is O, this flow ends as it is.

As described above, the shift-up transmission control 611 /J<
When the winter is over, the shift town change shown in Figure 7 will take place.
m fl+' control is executed.

Shift-down speed change control This shift-down speed change control starts by first reading the gear position, that is, the position of the gear transmission mechanism 43, and determining whether or not the gear is currently in the first gear based on the read gear position. be) This judgment is Y[
In the case of ES, no further downshifts can be performed, so the downshift control is terminated to shift 1.

On the other hand, if the determination as to whether or not it is in the first gear is NO, the throttle angle is read by the throttle distance 111[-t], and for example, in the downshift map shown in FIG. Read the corresponding turbine speed: TSP (MAP).

Furthermore, in Fig. 8, the downshift shift line M [(1
Read the tartine rotation speed corresponding to the above throttle opening on the (solid line). Next, the actual turbine rotation speed: 1 SP is detected by the turbine rotation speed range, and the turbine rotation speed on the map is:, -rSP(M A 1).
) and compare.

When i S l-'≧-T-8P (MAP), that is, when J5 is in Fig. 8 and the actual turbine rotation speed is on the side (right side) of the downshift shift line Mt'd (solid line) Sets the second downshift line M[d' (dashed line) that becomes l'sP (MAP) x 1.25, and T S
Compare P(MAR) x 1.25 and TSP. l-
When Sp < -rsp (MAR) Zuru. T S )) ≧ TSP (MAP) X 1
．． 25] 14, that is, when the second shift 1 to G is located on the higher rotation side than the shift line Mjd' (broken line), the shift town shift control is terminated as flag 2-0. Flag 2 is set to 1 to 1 when a downshift is executed, and is used to store the downshift state.

When TSP<TS'P (MAR), 1 is J3 in Figure 8, and T is on the lower rotation side than the downshift gear FAMfd.
When SP is present, it is determined whether flag 2-1 is present or not, and when flag 2=1, it indicates that a downshift has already been performed, and the shift town speed change control is terminated.

When flag 2 = 0, after setting flag 2 = 1, it is determined whether the low μ flag is -1, and if the low μ flag is -1, the line pressure regulating valve is set to Q or N to lower the line pressure. Set the line pressure drop flag to 1. When the low μ flag is -O, the line pressure drop flag is kept at O, and the line pressure is also kept as is. In either case (low μ flag −1),
(Also in the case of low μ flag -O) After this, a one-stage downshift is performed and a [1] pull-up release timer is set.

After this, it is determined whether the line pressure drop flag is 1 or not, and if it is 1, the line pressure drop flag is set to O after a certain period of time and this flow is ended, and if it is 0, this flow is ended as is. .

When the downshift control is completed as described above, the lockup control shown in FIG. 9 is executed next.

[] The lock-up control of Tsukunontsubu reads the lock-up release timer, and when the lock-up release timer is operating (0, 1, - if the determination of whether the timer = 0 or not is No), the lock-up is released, 1 to end this -No1-1-, conversely, the judgment whether or not timer O is Y IE
When S, the preset lock-up
1. This lock-up OFF map MolrFt,l is shown by the broken line in Fig. 10, and is determined by the turbine rotation speed of the 1 to 1 torque converter and the opening degree of the 1 to 1 torque converter. determined.

Read the reading between the slots 1 and 1, and read the text between the slots 1 and 1, and read the text corresponding to the slots 1 and 1.
:l:Matsupu M. 11.1.・ Turbine rotation speed TS
Read P(M△[]). Next, the actual turbine rotation speed TSP/! : Read and compare with 1-mentioned TSP (MAP).

When rSP≧−I SP (MAR), lockup is released and this flow ends. On the other hand, T S P <
For TSP (MAP), select the U-tuck-up ON map MON, which is set to a higher rotation than the OFF map MOFF, and select this ON map M. Read the turbine rotation speed TSP' (MAP) for the above throttle opening on N,
Compare this with the actual turbine rotation speed - ISP. -r
When sp≦TSI]' (MAP), the lockup is activated to end this flow, and TSP>TSP' (MA
If R), the flow is immediately ended.

As explained above, in the present invention, it is only necessary to add a line impression cylinder 1 device to a conventional automatic transmission, and to partially change the control system 11.The present invention has a simple structure and is capable of driving the transmission when changing gears. By suppressing force changes, it is possible to suppress slips.

[Brief explanation of drawings]

Fig. 1 shows the operating system of the control device of the present invention. Fig. 2 is a sectional view J5 and a hydraulic control circuit diagram of an automatic transmission according to an embodiment of the present invention. Fig. 3 is an overall flowchart of shift control. , Figure 4 shows low μ
Flowchart 1-1 for road driving determination FIG. 5 is a flowchart 1 to 1 of shift-up speed change control, FIG. 6 is a graph showing a shift-up speed change map, FIG. 7 is a flowchart of shift-town speed change control, and FIG. The figure is a graph showing a shift-down speed change map, Figure 9 is a flowchart of lock-up control, and Figure 10 is a graph showing a shift-down shift map.
1 is a graph showing a one-size-fits-all map. 3... Engine 4... Automatic transmission 6... Differential 13... Slip determination means 21... Pressure regulation valve
22... Select valve 30... Oil FF pump 31 River line pressure regulating valve Figure III Figure 10

Claims (1)

[Claims] 1) A rotational speed detection means for detecting the rotational speed of each of the front wheels and the rear wheels, and comparing both rotational speeds 1k detected by this rotational speed detection means and detecting the occurrence of slip from the difference. a slip determining means that detects and outputs a slip detection signal; an automatic transmission in which a power transmission path is switched to multiple stages by a friction member; and an automatic transmission that receives the slip detection signal and outputs a slip detection signal; A speed change control device for an automatic transmission for a vehicle, comprising a speed change buffer means for reducing speed. 2> The automatic transmission for a vehicle according to claim 1, wherein the engagement of the friction member is performed by hydraulic pressure, and the shift buffer means is a line adjustment device that reduces the hydraulic pressure. transmission control device.