JPH0443832A - Shift shock reducing device for multi-stage transmission - Google Patents

Abstract

PURPOSE:To adapt the device to various variation of friction coefficient of road surface by providing a road surface friction coefficient detecting means to detect friction coefficient of road surface, and an output torque changing means to change output torque of an internal combustion engine based on the output signal of the former. CONSTITUTION:Net torque is calculated based on rotating speed Ne output from a rotating speed detector 3 and intake pipe pressure Ps output from an intake pipe pressure detector 5. Nextly, a shift position signal Sp output from a shift position detector 14 is detected. Driving wheel speed Vw output from a driving wheel speed detector 1 and driven wheel speed Vv output from a driven wheel speed detecter 2 are read. From above-stated respective values, torque and slip ratio of a driving wheel are computed, and then based on them estimated value of road surface friction coefficient is searched from a map. Critical driving force to generate skid and excess driving force are calculated, corresponding mode is decided, according to this either ignition retard or fuel cut is selected, and setting value of a timer is selected.

Description

Detailed Description of the Invention A6 Objective of the Invention (1) Industrial Application Field The present invention relates to a shift shock for a multi-speed transmission that reduces shift shock by controlling the output torque of an internal combustion engine during a gear shift in a multi-speed transmission. Relating to a reduction device.

(2) Prior art The shift shock reduction device for multi-speed transmissions currently in use establishes a new gear stage by detecting the shift timing of the multi-speed transmission and controlling the output torque of the internal combustion engine. The purpose is to reduce the sudden shock caused by gear engagement during boat fishing, and to improve drivability on road conditions with a normal coefficient of friction for boat fishing.

(3) Problems to be solved by the invention By the way, if a gear shift is performed while driving on a road surface with a small coefficient of friction, such as an icy road, the drive wheels may slip and have no positive effect on the running of the vehicle. Therefore, it is necessary to perform different control on a road surface with a low friction coefficient than on a road surface with a normal friction coefficient.

Figure 9A shows an example of control by a conventional shift shock reduction device for normal road surfaces, in which the output torque of the internal combustion engine is controlled to decrease slightly after a time delay from the shift up command signal, and the longitudinal acceleration is reduced. In other words, shift shock is reduced. Furthermore, Fig. 9B shows an example of control by a conventional shift shock reduction device for dealing with roads with low friction coefficients such as icy roads, in which the output torque of the internal combustion engine temporarily decreases to zero immediately after a shift-up command signal. The acceleration is controlled to decrease, and the longitudinal acceleration is reduced.

By the way, as shown in FIG. 10, when a shift shock reduction device designed for normal road surfaces is used on a road surface with a low friction coefficient, there is a possibility that a large slip will occur in the drive wheels.

On the other hand, as shown in Fig. 11, when a shift shock reduction device designed for low friction coefficient road surfaces is used on normal road surfaces,
There is a disadvantage that the acceleration feeling is insufficient.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a shift shock reduction device for a multi-speed transmission that is adaptable to various changes in the road surface friction coefficient.

B0 Structure of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention provides a multi-stage transmission that changes the output torque of an internal combustion engine to reduce shift shock during gear shifting in the multi-stage transmission. A shift shock reduction device comprising a road surface friction coefficient detection means for detecting a road surface friction coefficient, and an output torque changing means for changing an output torque of an internal combustion engine based on an output signal of the road surface friction coefficient detection means. The first characteristic is that it becomes

In addition to the first feature, the present invention has a second feature that the output torque changing means switches the timing of changing the output torque depending on the magnitude of the detected road surface friction coefficient.

In addition to the first feature, the present invention also provides a method for determining the amount of change in the output torque of the internal combustion engine based on the road grip force determined from the driving wheel torque, the amount of change in the driving wheel torque before and after gear shifting, and the coefficient of friction of the road surface. The third feature is that it is determined by

In addition to the third feature, the present invention has a fourth feature that the drive wheel torque is corrected based on at least the amount of change in rotational speed of the internal combustion engine or the amount of change in the speed of the drive wheels.

In addition to the third feature, the present invention has a fifth feature that the amount of change in drive wheel torque before and after the gear soft is determined based on the gear position and the elapsed time from the start of the shift.

C) Effect According to the first feature of the present invention having the above configuration, when the road surface friction coefficient is detected by the road surface friction coefficient detection means, the output torque is changed according to the magnitude of the detected road surface friction coefficient. Means adjust output torque of the internal combustion engine. As a result, by maintaining the output torque of the internal combustion engine on a high friction coefficient road surface, it is possible to perform a shift change without reducing acceleration performance, and when the same output torque as on a high friction coefficient road surface is applied, slippage occurs. On a road surface with a low coefficient of friction that is easy to ride, it is possible to prevent re-slip after a shift change by reducing the output torque.

Furthermore, according to the second feature of the present invention, the timing of changing the output torque of the internal combustion engine is changed according to the magnitude of the road surface friction coefficient, so that the output can be reduced early when the amount of reduction in the output torque is large. By doing so, appropriate control becomes possible.

Furthermore, according to the third feature of the present invention, the amount of change in the output torque of the internal combustion engine is determined from the driving wheel torque, the difference between the driving wheel torques before and after the gear shift, and a correction value that depends on the road surface friction coefficient. , the output torque of the internal combustion engine is prevented from being excessively suppressed.

Furthermore, according to the fourth feature of the present invention, since the amount of change in the rotational speed of the internal combustion engine or the amount of change in the speed of the drive wheels is used to calculate the drive wheel torque, the inertia of the drive system is corrected and the drive wheel torque is calculated accurately. The surplus output torque of the internal combustion engine is calculated.

Further, according to the fifth feature of the present invention, when calculating the drive wheel torque change amount, the gear positions before and after the gear shift and the slip state of the torque converter are directly or indirectly taken into consideration, so that regardless of the shift pattern, An appropriate amount of torque change can be calculated.

(3) Examples Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a schematic configuration diagram of a vehicle equipped with this device, and this vehicle has a pair of drive wheels W driven by an internal combustion engine.
r and a pair of driven wheels Wf, and the driving wheel Wr and the driven wheel Wf are respectively provided with a driving wheel speed detector 1 and a driven wheel speed detector 2 for detecting their speeds V, Vv. ing.

The internal combustion engine E has a crankshaft rotational speed Ne
A rotational speed detector 3 consisting of a gear and an electromagnetic pickup is provided in the intake passage 4 and connected to an intake pipe internal pressure detector 5 for detecting the intake pipe internal pressure P and a pulse motor 6. A throttle valve 7 that is driven to open and close is provided. Further, an ignition retard mechanism 9 for adjusting ignition timing is connected to the ignition plug 8 of the internal combustion engine E, and a fuel injection valve 11 equipped with a twin cylinder cut means 10 is provided at the downstream end of the intake passage 4. A shift solenoid valve 13 provided in the transmission 12 is provided with a shift position detector 14 that detects a shift position (and shift timing) and outputs a shift signal S. The driving wheel speed detector 1, the driven wheel speed detector 2, the rotational speed detector 3, and the intake pipe internal pressure detector 5
, pulse motor 6, ignition retard mechanism 9, twin wheel cut means 10, and shift position detector 14 are connected to an electronic control unit U consisting of a microcomputer.

FIG. 2 shows arithmetic processing of detection signals inputted from each of the detectors based on a control program to drive the ignition retard mechanism 9, twin wheel cut means 10, or pulse motor 6 in order to suppress skid of the drive wheels Wr. An electronic control unit U for reducing the output torque of the internal combustion engine E is shown. This electronic control unit U is a central processing unit for performing the above calculation processing! (CPU) 15, a read-only memory (ROM) 16 that stores data such as the control program and various maps, a random access memory (RAM) 17 that temporarily stores the detection signals and calculation results of each of the detectors, and the An input section 18 to which the respective detectors, namely the driving wheel speed detector 1, the driven wheel speed detector 2, the rotational speed detector 3, the intake pipe internal pressure detector 5, and the shift position detector 14 are connected, and the ignition retard mechanism 9. Output section 1 to which the twin cutting means 10 and the pulse motor 6 are connected.
It consists of 9. The electronic control unit U uses the central processing unit 15 to perform arithmetic processing on each detection signal input from the input section 18 and data stored in the read-only memory 16 based on a control program to be described later.
Finally, by driving the ignition retard mechanism 9, the twin wheel cutter IO1, or the pulse motor 6 via the output section 19, the output torque of the internal combustion engine E is controlled to suppress skidding of the drive wheels Wr.

The process by which shift shock is reduced by this device consists of three steps: ■ Estimating the road surface friction coefficient ■ Estimating the surplus driving force during shifting ■ Changing the output torque of the internal combustion engine. Each stage will be explained in sequence below. .

(2) In this embodiment of surface friction-1, the road surface friction coefficient is estimated by map search from the drive wheel torque FDIIV that can be transmitted to the road surface and the tire slip ratio S.

That is, in general, the drive wheel torque F, v that can be transmitted to the road surface
is, F v*v = T QOUT *η, *ηt
* Cuo “η.

dt dt Ctsu, *■, ...
It is expressed as (1).

Here, TQoua; net torque of the internal combustion engine η,; gear ratio ηf; final ratio η9; transmission loss coefficient Ne; internal combustion engine rotational speed ■; driving wheel speed Vv; driven wheel speed CW11 + constant determined by vehicle weight and tire size CR%l; 0 for experimental constant; 1 for experimental constant; experimental constant. In addition, the above constants Cl1o, CRv, Ko
, The value of K+ is the driving wheel speed ■1, the driven wheel speed ■9,
Gear ratio η3, multi-speed 1! i! It can be changed as appropriate depending on 12 types (automatic or manual), atmospheric pressure, torque converter slip rate, etc.

In addition, the tire slip rate S is Vv It is expressed as

Now, the driving wheel torque F DIIV and the slip rate S
There is a relationship between them as shown in FIG. 3, and this relationship changes depending on the magnitude of the road surface g-friction coefficient. Therefore, if the drive wheel torque F□9 and the slip ratio S are calculated, the estimated value μm of the road surface friction coefficient μ can be found from the curve passing through the intersection P (shown by a broken line). Actually, the driving wheel torque is F! The relationship between Im and the slip ratio S is stored in the read-only memory 16 of the electronic control unit U as a map as shown in FIG. 4, and the estimated value p1 of the road surface friction coefficient is retrieved from this map.

As another method for obtaining the estimated value μ8 of the road surface friction coefficient, it is also possible to give the estimated value μ0 in the form of a function, such as p" = f (S, Feat), and calculate it from there. When, the driving wheel torque F□1 is expressed by the above formula (
Instead of calculating from 1), this driving wheel torque F DI
V may be calculated by Femv = Cm * </v (C1; experimental constant).

In addition, as a simple method for calculating the estimated value μ'' of the road surface friction coefficient, as shown in FIG.
Immediately from the Feat value when S < Sh, μ” wKuo *TQoot *ηi *η, *
It is also possible to obtain it as C, , *η-(Kpo i experimental constant).

(2) When the estimated value μm of the road surface friction coefficient at the time of shifting is determined as described above, the magnitude of the surplus driving force when a shift is performed depending on the road surface is estimated.

Shift shifting is caused by the impulse generated when multiple rotating bodies with different inertia rates and angular velocities are coupled within a minute time, and is determined by the type of shift and the rotational speed of the main shaft and countershaft. Ru. Therefore, the driving force FSF□ applied to the driving wheels Wr by shifting is as follows: Fsry = f (K, , NM , N, ,
t).

Here, K1-1i is a constant N, 4 depending on the type of shift (from i stage to j stage); rotation i of the main shaft [ N,: rotation speed t of the counter shaft; time; gear ratio η, and torque converter If the slips of N, and N above are taken into account. The rotational speed Ne of the internal combustion engine E and the driving wheel speed ■1 can be used instead.

Actually, the driving force F, 17 is experimentally determined by the following method. That is, as shown in Table 1, -1 is experimentally determined in advance for the constant according to the type of shift, and -1 is determined in advance according to the rotational speed change dN of the main shaft that is predicted to occur due to the shift. Experimental constant) (predetermine as and create a table, and search from this table -4 and
The driving force F SFT is calculated based on the following equation.

F srt ”' K=-1* Kdy* C3FTC
Csr□: Experimental constant) Table 1 The limit driving force at which skid occurs is determined experimentally by μ* CW * as a function of the estimated value μ° of the road surface friction coefficient.
μ0 (Kμ; Experimental correction formula = f(V,, θμ)) (Cw;
The experimental correction formula is given by f (front and rear weight distribution).

Therefore, a skid will occur when the sum of the [currently outputted driving force] and the [driving force applied by shifting] exceeds the limit driving force at which the E-skid occurs.

Therefore, surplus driving force P1. . , P I sKb = T Q(JUT *η, *ηt
* Cwo ”η.

Cl1v* Vv +F srr + Kμ*Cw*μ
``-(3), the larger this surplus driving force P1.. is, the more likely skids will occur.

■ Torque ・ Now, when the surplus driving force PISKD is determined as described above, based on Table 2, the above P1. . P corresponding to the value of
l,...PI, to torque adjustment mode A, B,...
is determined. As is clear from Table 2, PlsxoO
In the mode where the value is small, the output torque is reduced by ignition retard, Pl.

In a mode in which the value of is large, the output torque is reduced by the twin cut. Then, in the case of ignition retard, the amount of retardation is determined, and in the case of twin cut, the number of cylinders is determined in more detail, and as shown in Figure 6, the reduction of output torque starts from the moment of shift. A time period of 11 seconds and a time period of 12 seconds during which the output torque reduction continues are determined. Thus, the output torque is optimally controlled while taking into consideration the estimated value μm of the road surface friction coefficient, and skids of the drive wheels can be effectively avoided.

Further, as a simple method shown in Table 3, considerable effects can be obtained even if the output torque is controlled by determining only the magnitude relationship between the estimated value μ8 of the road surface friction coefficient and the reference value μ3°.

Table 2 Furthermore, as a more precise method, if control is performed based on a time schedule as shown in FIG. 7, the output torque can be controlled even more precisely.

If you want more precision, change F srt to Fsvr
= fsrt (t) Table 3 t,; Shift start Lf ; Optimal output torque adjustment by variation as shift end it u OP
□(1) can be determined and the output torque reduction reduction can be changed accordingly.

So far, the reduction of soft shock in the case of soft up has been described, but the same applies to downshift.

Next, the operation of the embodiment of the present invention will be explained based on the flowchart of FIG.

In step S1, a net torque T of the internal combustion engine E is determined based on the rotational speed Ne of the internal combustion engine E outputted by the rotational speed detector 3 and the intake pipe internal pressure Pm outputted by the intake pipe internal pressure detector 5.
Qout is calculated and stored in the random access memory 17. Then, in step S2, the shift position signal S output from the shift position detector 14 by the operation of the shift solenoid valve 13 is detected. Then step S
3, the gear ratio ηi of the gear position is determined based on the shift position signal Sv, and the gear ratio ηi of the gear position is determined based on the shift position signal Sv.
At the same time, in step S4, the shift position signal S? The final ratio η1, transmission loss coefficient η1, and experimental constant Cwll are read from the read-only memory 16 based on is determined, and in step S7, 0 is selected as the experimental constant serving as the coefficient. Subsequently, in step S8, the driving wheel speed ■ outputted by the driving wheel speed detector 1
In step S9, differential calculation is performed to obtain 9-, and in step 310, the driven wheel speed ■, which is output by the driven wheel speed detector 2, is read in.Next, in step Sll, the 9□ is Experimental constants serving as coefficients are determined from the driving wheel speed V@, and in the following step S12, C and w are determined from the driven wheel speed VW. Then, in step S13, the drive wheel torque F□1 is calculated based on equation (1) from each of the above numerical values, and in step S14, the slip ratio S is calculated based on equation (2). In step S15, an estimated value μm of the road surface friction coefficient is retrieved from a map (see FIG. 4) stored in the read-only memory 16 based on the drive wheel torque FDII and the slip ratio S.

After the estimated value μm of the road surface friction coefficient is obtained in this way, when it is detected in step S16 that a shift has been performed from the shift position signal Sr, μ is determined in step S17.
Further, in step 31B, the experimental constant 08 is selected, and in step S19, μ is set to the limit driving force at which skid occurs.
*C@*μ0 is calculated. Then, in step S20, surplus driving force PI is calculated based on equation (3). is calculated, and its size is PI in step S21. ...After being compared with PIJ, the corresponding modes A and B are selected in step S22.
... is determined (see Table 2), so step S
In step S23, either ignition retard or twin cut is selected depending on the mode, and step S2
4, the timer set value T,,T, is selected.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above, and various small design changes can be made without departing from the scope of the invention described in the claims. Is possible.

For example, in the embodiment, the reduction in the output torque of the internal combustion engine E is controlled by the fuel injection amount and the ignition retard amount, but in addition to this, control of the throttle valve 7 may also be used. Moreover, instead of detecting the shift position and shift timing from the drive signal of the shift solenoid valve 13, the drive signal of the shift hydraulic valve,
2 input shaft and output shaft rotation speed ratio, or multi-stage transmission 1
It can be detected from the rotational speed ratio of the main shaft and countershaft.

C1 Effects of the Invention As described above, according to the first feature of the present invention, the output torque of the internal combustion engine is adjusted according to the magnitude of the detected road surface friction coefficient. By maintaining the output torque of , it is possible to perform a shift change without affecting acceleration performance.In addition, on a low friction coefficient road surface where the same output torque as on a high friction coefficient road surface tends to cause slipping, the output torque can be changed without affecting acceleration. By reducing this, re-slip after a shift change can be prevented.

Furthermore, according to the second feature of the present invention, the timing of changing the output torque is switched depending on the magnitude of the road surface friction coefficient. Control becomes possible.

According to the third feature of the present invention, the amount of change in the output torque of the internal combustion engine is determined from the driving wheel torque, the difference between the driving wheel torques before and after the gear shift, and a correction value that depends on the road surface friction coefficient. Excessive suppression of the output torque of the internal combustion engine is prevented.

Furthermore, according to the fourth feature of the present invention, the amount of change in the rotational speed of the internal combustion engine or the amount of change in the speed of the drive wheels is used to calculate the drive wheel torque, so the inertia of the drive system is corrected and accurate An output torque surplus of the internal combustion engine is calculated.

Further, according to the fifth feature of the present invention, when calculating the drive wheel torque change amount, the gear positions before and after the gear shift and the slip state of the torque converter are directly or indirectly taken into consideration, so that regardless of the shift pattern, An appropriate amount of torque change can be calculated.

[Brief explanation of the drawings] Fig. 1 is a schematic configuration diagram of a vehicle equipped with this device, Fig. 2 is a block diagram of its electronic control unit, and Fig. 3 is a diagram of drive wheel torque F□ν and slip ratio S. Graph showing relationships, 4th
The figure is a map for determining the estimated value μ° of the road surface friction coefficient, Figure 5 is a graph explaining a simple method for determining the estimated value μm, Figure 6 is an explanatory diagram of the time schedule for output torque reduction, and Figure 7 is a diagram for explaining the time schedule for reducing the output torque. An explanatory diagram of another time schedule for output torque reduction, FIG. 8 is a flowchart executed in the electronic control unit, FIGS. 9A and 9B are explanatory diagrams of a conventional shift shock reduction method, and FIGS. 10 and 1L. is an explanatory diagram of its effect. E...Internal combustion engine, Wr...Drive wheel, 12...Multi-speed transmission Figure 1 Patent applicant Honda Motor Co., Ltd.

Claims (5)

[Claims] (1) A shift shock reduction device for a multi-stage transmission that changes the output torque of an internal combustion engine to reduce shift shock during gear shifting in a multi-stage transmission, comprising road surface friction coefficient detection means for detecting a road surface friction coefficient; A shift shock reduction device for a multi-speed transmission, comprising output torque changing means for changing the output torque of an internal combustion engine based on the output signal of the road surface friction coefficient detecting means. (2) The shift shock reduction device for a multi-stage transmission according to claim (1), wherein the output torque changing means switches the change timing of the output torque according to the magnitude of the detected road surface friction coefficient. (3) The output torque change amount of the internal combustion engine is determined based on the driving wheel torque, the amount of change in the driving wheel torque before and after the gear shift, and the road surface grip force determined from the friction coefficient of the road surface. Shift shock reduction device for multi-speed transmissions. (4) The shift shock reduction device for a multi-speed transmission according to claim (3), wherein the drive wheel torque is corrected based on at least an amount of change in the rotational speed of the internal combustion engine or an amount of change in the speed of the drive wheels. (5) The shift shock reduction device for a multi-speed transmission according to claim (3), wherein the drive wheel torque change amount before and after the gear shift is determined based on the gear position and the elapsed time from the start of the shift.