JPH02256964A - Slip control device of torque converter - Google Patents

Abstract

PURPOSE:To reconcile the acceleration performance and the fuel consumption by detecting an engine load for its change discriminating by its rate the time of acceleration or steady operation and setting a target slip amount. CONSTITUTION:A load change condition detecting means 28 detects a load, when its change rate increases to not less than a preset value, a target slip amount change means 29, by judging the time of acceleration operation, changes a target slip amount of a control means 27 to an increasing side. Consequently, a torque converter 2 effectively displays its torque magnifying action improving acceleration performance. On the contrary, when the change rate of the engine load is less than the preset value, the target slip amount is held to the preset value by judging the time of steady operation. Accordingly, when this target slip amount is left as set to a small value, a good fuel consumption can be secured.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention provides a torque converter with a lock-up mechanism that directly connects its input and output shafts, and adjusts the rotational speed difference between the input and output shafts of the torque converter to a set value ( The present invention relates to an improvement of a slip control device for a torque converter that controls the fastening force of a lockup mechanism to achieve a target slip ff1).

(Prior Art) Conventionally, as a slip control device of this kind of torque converter, as disclosed in Japanese Patent Laid-Open No. 57-33253, for example, the rotation speed of the input shaft and output shaft of the torque converter is detected, In a given operating range, when the rotational speed difference between the input and output shafts exceeds the target slip amount, the lock-up mechanism's fastening force is controlled to a large extent, while when the rotational speed difference is less than the target slippage amount, the fastening force is reduced. control,
It is known that the rotation speed difference is adjusted to the target slip amount.

(Problem to be Solved by the Invention) By the way, regarding the setting of the target slip amount between the input and output shafts of the torque converter, this is set variably according to the engine rotation speed and the throttle valve l5i1 degree. By setting the slip amount to a large slip amount at a large opening, it is possible to improve acceleration performance by the torque multiplication effect of the torque converter during acceleration with a large throttle valve opening.

However, in this case, if we examine the details in detail, there are cases where the vehicle is accelerating from a small throttle valve opening, and there are cases where the vehicle is running steadily even with a large throttle valve opening. Therefore, in the above idea, when accelerating from a small throttle valve opening, the lock-up machine (14) is close to the directly connected state, and although it is possible to suppress the decrease in fuel efficiency caused by slipping of the torque converter, the torque multiplication effect of the torque converter is effective. On the other hand, during steady driving with a large throttle valve opening, the amount of slip is large, resulting in poor fuel efficiency.

The present invention has been made in view of the above, and its purpose is to achieve both acceleration performance and fuel efficiency by appropriately setting a target slip amount according to driving conditions in a torque converter equipped with a lock-up mechanism. The aim is to achieve this goal.

(Means for Solving the Problems) In order to achieve the above object, the present invention detects changes in engine load, determines acceleration or steady state based on the rate of change, and sets a target slip amount. shall be.

In other words, the specific solution of the present invention, as shown in FIG. 1, includes a lock-up device 5 that directly connects the input and output shafts of the torque converter 2, and a The slip control device for a torque converter is assumed to be provided with a control means 27 for controlling the fastening force of the lockup device 5 so that the rotational speed difference becomes a target slip amount. Then, when the load change state detection means 28 detects the change state of the engine load and the load change rate detected by the load change state detection means 28 is equal to or higher than a set value, the target slip amount of the control means 27 is increased. The structure includes two target slip amount changing means for changing the target slip amount on the side.

(Function) With the above configuration, in the present invention, when the rate of change in engine load exceeds a set value, it is determined that acceleration operation is being performed.
Since the target slip amount is changed to the increasing side, the torque multiplication effect of the torque converter is effectively exerted, and acceleration performance is improved.

On the other hand, if the rate of change in the engine load is less than the set value, it is determined that steady operation is occurring and the target slip amount is maintained at the set value. It is possible to get good fuel efficiency.

(Effects of the Invention) As explained above, according to the torque converter slip control device of the present invention, acceleration or steady state is detected based on a change in engine load, and the target slip amount is determined only when this acceleration is detected. Since it has been changed to the increasing side, it is possible to effectively exert the torque multiplication effect during acceleration operation and improve acceleration performance, and during steady operation, it is possible to suppress the decrease in fuel consumption due to the slippage of the torque converter. It is possible to achieve both improved acceleration and improved fuel efficiency.

(Example) Hereinafter, an example of the present invention will be described based on the drawings from FIG. 2 onwards.

FIG. 2 shows the structure and hydraulic control circuit of the torque converter section of the automatic transmission. In the figure, 1 is an engine output shaft, 2 is a torque converter that transmits the power of the engine output shaft 1 to a subsequent stage, and the torque converter 2 is connected to the engine output shaft 1 and rotates integrally with a pump 2a. ,
The turbine 21) is disposed facing the pump 2a, and the stator 2C is disposed between the two spaces and performs a torque multiplier action. A transmission gear mechanism (not shown) having, for example, four forward speeds and one reverse speed is connected to the rear end of the converter output shaft 3.

In the torque converter 2, a lock is provided between the turbine 2b and the converter case 4 in front of the turbine 2b as a lock-up device that directly connects the input/output shaft of the torque converter 2, that is, the engine output shaft 1 and the converter output shaft 3. An up clutch 5 is arranged. The lock-up clutch 5 has an engagement-side hydraulic chamber 5 located behind it.
It is urged in the fastening direction (to the right in the figure) by the hydraulic pressure in a, and conversely in the opening direction by the hydraulic pressure in the open-side hydraulic chamber 51 located at the front.

Further, the hydraulic control circuit A has a function of engaging and disengaging the lock-up clutch 5 and controlling the engagement force. In the hydraulic control circuit A, 10 is a lock-up control valve that adjusts the supply of oil to the lock-up clutch 5. The lock-up control valve 10 includes a spool 10a that slides from side to side in the drawing within its internal space, and a spring 10b that urges the spool 10a to the right in the drawing. Also, a line pressure introduction port 10 into which line pressure is introduced.
c, and a line pressure supply port 10d that communicates with the introduction port 10c and supplies line pressure, and the line pressure supply port 10d is communicatively connected to the engagement side hydraulic chamber 5a of the lock-up clutch 5. There is. Furthermore, it has a pressure regulating port 10e and a tank port 10f, which are connected to the opening side hydraulic chamber 5b of the lock-up clutch 5, and the hydraulic pressure P1 of the pressure regulating port hlOc is transmitted to the spool 1 through the hydraulic passage 11.
It is acting on the left end of 0a. Further, oil is supplied to the right end of the sprue 10a in the figure via a pressure passage 12, and a tank 14 is connected to the oil pressure passage 2 via a tank passage 13. In the middle of the tank passage 13, there is a duty solenoid valve S for opening and closing the tank passage 13.
QL is intervening.

The above duty solenoid valve SQL has a duty ratio of 10
When the duty ratio is 0%, the tank passage 13 is always communicated, and when it is 0%, it is always closed. By adjusting the duty rate, the opening rate of the hydraulic passage 12 to the tank 14 is adjusted, and the hydraulic passage 12 is It has a function to adjust the hydraulic pressure PO to the hydraulic pressure according to the duty rate. Therefore, spool 10
a Hydraulic pressure acting on the right end (hydraulic pressure Po of the hydraulic passage 12),
The spool 10a is moved from side to side depending on the magnitude of the oil pressure acting on the left end (hydraulic pressure P1 of 7,', l pressure bow i・10e + biasing force SP of the spring 10b), and the pressure regulation port 10e is connected to the line pressure introduction port 10c. and tank board 1-10 are alternately connected, and finally the oil pressure P1 of the pressure regulating port 10e is
(That is, the opening hydraulic pressure of the lock-up clutch 5) is set as the hydraulic pressure according to the hydraulic pressure Po of the hydraulic passage 12 to adjust the engagement force of the lock-up clutch 5. Therefore, when the duty rate is -1°0%, the action of the release hydraulic pressure is released and the lock-up clutch 5 is fully engaged with the maximum engagement force, and the engagement force gradually decreases as the duty rate gradually decreases. When the duty rate is -0%, the release oil pressure is set to the maximum value and the lock-up clutch 5 is completely opened.

Further, FIG. 3 shows the basic electric circuit By7 configuration for controlling the engagement force of the lock-up clutch 5. As shown in FIG.

In the figure, reference numeral 20 denotes a CPU that controls disconnection, connection, and engagement force of the lock-up clutch 5;
20 includes a vehicle speed sensor 21 that detects the vehicle speed, an opening sensor 22 that detects the opening of the engine throttle valve, a gear position sensor 23 that detects the current gear position, and an engine rotation sensor 23 that detects the engine speed. Detection signals from a number sensor 24 and a turbine rotation speed sensor'+125 that detects the turbine rotation speed are input.

Next, the disengagement, connection, and engagement force control of the lock-up clutch 5 will be explained based on the control flow shown in FIG. 4.

After starting, the vehicle speed V1, throttle valve opening temperature θ, engine rotation speed Ne, turbine rotation speed Nt, and gear position G are read from each of the above-mentioned sensors in step S1, and then step S2
The difference between the engine speed Nc and the line speed Nt, that is, the actual slip between the input and output shafts of the torque converter 2 mN5
(Ns-INe-Ntl) is calculated. Furthermore, in step s3, the target slip mNO is set based on the target slip amount setting flow shown in FIG. 6, and then in step S4, the deviation ΔN (ΔN-N5- No) is calculated.

Thereafter, in step S5, a slip is performed to control the engagement force of the lock-up clutch 5 within the operating range determined by the vehicle speed and the throttle valve opening as shown in FIG. Determine whether it is an area or not. and,
If it is not in the slip region, the current slip amount deviation ΔN is replaced with the previous value ΔN' in step S6, and then in step S7 it is determined whether or not it is in the lock-up region in which the lock-up clutch 5 is fully engaged in the operating region shown in FIG. determine whether
If it is in the lock-up region, the duty D is set to the maximum value Dra x in step s8 to bring the lock-up clutch 5 into a fully engaged state, whereas if it is not in the lock-up region (that is, the torque converter shown in (if the lock-up clutch 5 is in the range), the duty D is set to the minimum value Dmjn in step S9, and the lock-up clutch 5 is controlled to a completely open state.

On the other hand, if it is in the slip region in step S5, the engagement force of the lock-up clutch 5 is controlled and the duty ratio is calculated in step SIO.
Proceed to the following.

That is, if it is in the slip region, step 5lf
Slip with l1. Feedback 1 in l control: After determining the control parameters A and B for calculating the control amount U, the deviations ΔN and ΔN' between the previous and current slips 11 and the control parameter A are determined in step Sl+.

The feedback control ff1U is calculated using the following formula % formula % based on Additionally correct the duty D°.

After that, in step SI3, the current slip amount deviation ΔN is replaced with the previous value ΔN', and then in step SI3
At step 4, a control signal (duty lead signal) is output to the duty solenoid valve SQL, and the process returns to step S1.

Next, the target slip amount setting flow shown in FIG. 6 will be explained.

First, in step SS+, the rate of change ΔTH (ΔTH-THj-Tlli-1) of the throttle valve opening is calculated from the difference between the current and previous values THi, T)Ii-1 of the throttle valve opening.

After that, in step SS2, the rate of change ΔTll of the throttle valve opening is compared with a set value C, which is a positive value corresponding to 1ll during acceleration operation, and when ΔTH>C, the change rate ΔTll is compared with the set value C, which is a positive value corresponding to 1ll during acceleration operation, and step S
After setting a timer to change the target slip amount to the increasing side for a predetermined time T in step S3, the seventh slip amount is set in step SS4.
As shown in the target slip amount map in the figure, a target slip amount during acceleration operation is set according to the engine speed and throttle valve opening at that time. Here, the target slip amount map in FIG. 7 is 15 or, p, Ill for a small throttle valve opening, 25 or, p, m for a medium throttle valve opening, and 400 or, p, m for a large throttle valve opening in the slip region.
r, p, and In, respectively.

In step SS2, if the acceleration operation with ΔTH>C continues, the above operation is repeated, while when ΔTll≦C, the fastening force is maintained at the target slip mNo during the acceleration operation for the predetermined time T. In order to control the time, the timer time is grasped in step Sss, and before the timer time elapses when T≠0, the timer time is counted in step SSs, and then the timer time is determined in step Ss.
At step a, the target slip amount is set based on the target slip amount map shown in FIG. 7 according to the engine speed and throttle valve opening at that time, and the process returns.

On the other hand, if the timer time has elapsed in step SSS or in the case of steady operation, the target slip ff1No is set to the target slip amount (for example, 70r, p, m) for steady operation in step SS7, and the return is made. do.

Therefore, in the control flow of FIG. 4 above, step S+
, S2, S4, S5.5IO-314 and steps SS2 and sss of the target slip amount setting flow in FIG.
, SS7, the rotational speed difference (Ne - Nt>
A control means 27 is configured to control the engagement force of the lock-up clutch 5 so that the slip becomes the set target slip ff1 (70r, p, m). In addition, step SSI of the setting flow shown in FIG. 6 constitutes a load change state detection means 28 that detects the change state of the engine load based on the rate of change ΔTII of the throttle valve opening, and According to steps S52 to SSG,
When the load change rate ΔTl+ detected by the load change state detection means 28 is equal to or higher than the set value C, the target slip mNo of the control means 27 is set to the increasing side based on the target slip amount map for acceleration operation shown in FIG. Two target slip amount changing means are configured to change the target slip amount.

Therefore, in the above embodiment, as shown in FIG. 8, during acceleration operation in which the throttle valve opening increases from a small value, the rate of change Δ of the throttle valve opening during a unit time Δ is
When Tl+ becomes ΔTl1i>C, the target slip ff1
No. is increased from 7 Or, p, m during steady operation to, for example, 25 Or, p, river according to the throttle valve opening at that time. Furthermore, when the rate of change ΔTll of the throttle valve opening becomes ΔTl1j>C within the timer time T, the target slip fjA N O further increases from 25Or, p, +++ to 40o.
r, p, m, and then 400. while maintaining ΔTl1k>C. The settings of r, p, Im are retained and ΔT
If IIQ<C, the timer returns to 70r and pl during steady operation when the timer time T elapses. Furthermore, although not shown, if ΔTll>C before the timer time T elapses, the drifting slip No. 1 during acceleration operation is maintained during the timer time T, and when the slip area is removed, the lock-up clutch 5 The fastening force control is canceled.

Here, in the slip region, during acceleration operation with △Tll>C, the target slip faNo is 70r for steady operation.
, p, m to 150r, p, m, for acceleration operation in FIG.
Since the torque is increased to 25o, p, m or 40or, p, +n, the large throttle valve opening strongly exerts the torque multiplication effect of the torque converter 2 during acceleration operation, improving acceleration performance. .

On the other hand, in the slip region, during steady operation with △Tll≦C, the target slip amount NO is 7°r,p for steady operation.
, m is held small, so the lock-up clutch 5
The power loss caused by the slippage of the i-lux converter 2 is reduced accordingly, leading to an improvement in fuel efficiency.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of the present invention. 2 to 8 show an embodiment of the present invention, FIG. 2 is a hydraulic circuit diagram for operating a lock-up clutch, FIG. 3 is a control block diagram thereof, and FIG. 4 is a flowchart showing its specific control. Figure 5 is an explanatory diagram of each area of lock-up clutch disengagement, connection, and engagement force control, Figure 6 is a diagram showing the setting flow of the target slip amount, and Figure 7 is an illustration of the engine rotation speed and FIG. 8 is an operation explanatory diagram showing a map of target slip 2 relative to the throttle valve opening. 2... Torque converter, 5... Lock-up clutch (lock-up device), 20... CPU, 22 Opening degree sensor, 27... Control means, 28... Load change state detection means, 29...・Target slip-ro change means. Patent applicant: Japan Automatic Transmission Co., Ltd. Patent applicant: Mazda Motor Corporation. Be

Claims (1)

[Claims] (1) A lockup device that directly connects the input and output shafts of the torque converter, and controls the fastening force of the lockup device so that the rotational speed difference between the input and output shafts of the torque converter becomes the target slip amount in the set operating range. A slip control device for a torque converter, comprising: a load change state detection means for detecting a change state of engine load; A slip control device for a torque converter, comprising: target slip amount changing means for changing the target slip amount of the control means to an increasing side.