JPH081248B2 - Lockup clutch hydraulic controller - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a lockup clutch hydraulic control device for controlling hydraulic pressure supplied to a lockup clutch.

[Conventional technology]

FIG. 11 shows a conventional lockup clutch control system. In this control system, a lockup clutch 1, a torque converter 2 (hereinafter abbreviated as torque converter),
Transmission tank 3, strainer 4, hydraulic pump 5, main relief valve 6, torque converter relief valve 7, rear brake cooling 8, oil cooler 9, oil filter 10, cooling relief valve 11, lubrication relief valve 12, transmission lubrication unit 13, lock The up-modulation valve 14 and the solenoid valve 15 are provided, and the lock-up modulation valve 14 is operated through the solenoid valve 15 to engage and release the lock-up clutch 1 and gradually increase the hydraulic pressure.

FIG. 12 shows an example of the internal configuration of the conventional modulation valve 14 and solenoid valve 15 according to the present invention, and FIG. 13 shows the characteristics over time of each part during a gear shift.

That is, in this system, the solenoid of the solenoid valve 15 is first locked up “OFF” when shifting.
Signal is sent (time t ₁ ), which results in solenoid valve
15 is opened as shown in Fig. 11, and is set by the main relief valve 6 and the pilot hydraulic pressure is the solenoid valve.
Push the piston 20 of the modulation valve 14 to the left through 15. This piston 20 spools through the piston 21
By pushing 22 to the left, the port D leading to the lockup clutch 1 is closed, and the oil in the lockup clutch 1 is drained.

Then, after a predetermined lockup delay time in which the lockup is kept off, the solenoid valve 15
A lock-up “ON” signal is sent to the solenoid of (time t ₂ ). As a result, the solenoid valve 15 is switched to the closed state, and the hydraulic oil pushing the piston 20 is drained through the solenoid valve 15. Therefore, the working oil pressure pushing the piston 20 becomes Okg / cm ² , and the spool 22 is pushed to the right by the spring 23 and the valve 14 is opened. As a result, the main hydraulic pressure flows from A to C to D and flows into the lockup clutch 1 through the D port, and then the filling time is reached.
After tf, the clutch 1 is filled with oil.

At this time, the oil flowing into the D port passes through the orifice 24 of the spool 22 and the piston 21 moves to the oil chamber 25 between the spool 22.
Flow into the initial pressure P ₀ (= Kx / S ₁ ) due to the balance between the pressure receiving area S ₁ of the piston 21 and the pressing force of the spring 23 (kx, k; spring constant x; initial displacement). (Fig. 13 (c)) After that, the oil that has passed through the drill hole of the valve body 26 passes through the orifice 28 of the cover 27 and pushes the piston 29 to the right, and as the piston 29 strokes to the right, it locks. The hydraulic pressure rises.

On the other hand, the hydraulic pressure in the lockup clutch 1 is almost zero during the filling period tf, and rises to the initial hydraulic pressure Pa at the same time as the filling is completed, and then gradually increases (time t ₃ ). When the piston 29 hits the stopper, the rise in hydraulic pressure stops,
The pressure at that time becomes the set pressure Pb of the lockup valve (time t ₄ ).

The above is the operation of the modulation valve 14 at the time of gear shifting, but as described above, the initial hydraulic pressure Pa obtained by the modulation valve 14 and its gradually increasing characteristic depend on the mounting load Kx of the spring 23, the pressure receiving area S _{1 of the} piston 21, etc. It is fixedly set.

By the way, in this control system, the lockup clutch 1 is soaked in the torque converter 2 and an oil passage 16 (Fig. 11) is shown in the piston back pressure portion of the lockup clutch 1. The internal pressure of torque converter 2
Pt is designed to work. Since the torque converter internal pressure Pt changes due to fluctuations in the engine rotation, a large initial pressure Pa is set in this conventional device, and the clutch pressure is gradually increased from this initial pressure Pa.

[Problems to be solved by the invention]

Therefore, in this conventional device, there are inconveniences such as variations in the clutch engagement timing (filling time) and a large shift shock (see FIG. 13 (f)).

The present invention has been made in view of such a situation,
An object of the present invention is to provide a lockup clutch hydraulic control device that reduces lockup shock and improves acceleration performance.

[Means for solving problems]

According to the present invention, the oil pressure of the output port for the lockup clutch is applied to one pressure receiving surface of the spool, one end of the spring is brought into contact with the other pressure receiving surface of the spool, and the piston is brought into contact with the other end of the spring. The oil pressure in the oil chamber, which is introduced through the throttle from the oil in the port, acts on the piston, and the first valve that supplies the oil from the pump to the lockup clutch and the first command when the input electric command is turned off. A second valve that closes the first valve to drain the oil of the lockup clutch, and opens the first valve to supply the oil from the pump to the lockup clutch when the input electric command is turned on;
When the input electric command is turned on, the third valve that drains the oil in the oil chamber of the first valve and the electric command that is input to the second valve during shifting are kept on, and The electric command input to the valve No. 3 includes control means for controlling so as to maintain ON only for a preset time so that the electric command is shortened in response to the increase of the engine throttle opening from the start of gear shift. I am trying.

Further, in the present invention, the oil pressure of the output port for the lockup clutch is applied to one pressure receiving surface of the spool,
Abut one end of the spring on the other pressure receiving surface of the spool,
A first valve in which a piston is brought into contact with the other end of the spring, and the oil pressure in the oil chamber, in which the oil in the output port is introduced through a throttle, acts on the piston to supply the oil from the pump to the lockup clutch. When the input electric command is turned off, the first valve is closed to drain the oil of the lock-up clutch, and when the input electric command is turned on, the first valve is opened and the oil from the pump is opened. To a lockup clutch, a third valve for draining oil in the oil chamber of the first valve when an input electric command is turned on, and a second valve for shifting gears. The electric command input to the third valve is kept on, and the electric command input to the third valve is applied to the transmission relative rotation speed (= n3G-n2, n3:
The transmission output shaft rotational speed, n2: transmission input shaft rotational speed, G: transmission gear ratio) are controlled to be kept on until they become substantially zero.

Further, in the present invention, the oil pressure of the output port for the lockup clutch is applied to one pressure receiving surface of the spool, one end of the spring is brought into contact with the other pressure receiving surface of the spool, and the piston is brought into contact with the other end of the spring. When the oil pressure in the oil chamber, which is introduced through the throttle from the oil in the output port, acts on the piston to supply the oil from the pump to the lockup clutch and the input electric command is turned off, A second valve that closes the first valve to drain the oil from the lockup clutch, and a second valve that opens the first valve to supply the oil from the pump to the lockup clutch when an input electrical command turns on; , A third valve that drains oil in the oil chamber of the first valve when an input electric command is turned on, and a second valve when shifting gears. The electric command input to the valve is kept on, and the electric command input to the third valve is the torque converter E value (= n2 / n1, n2: torque converter output shaft speed, n1: torque converter) from the start of gear shifting. A control means for controlling to keep the ON state until the input shaft rotation speed) becomes equal to or less than a set value is provided.

[Action]

At the time of gear shifting, the first means is controlled by the control means.
The valve is opened to supply the oil from the pump to the lockup clutch, and the oil in the oil chamber of the first valve is drained.

As a result, the lockup clutch oil pressure is
Falls to a predetermined hydraulic pressure determined by the initial biasing force for the spring and the pressure receiving area of the other side of the spool,
After that, the electric command input to the third valve is gradually increased from the time when the electric command is turned off.

That is, according to the present invention, the oil pressure of the lockup clutch is not drained during the gear shift, and the oil pressure is reduced to a predetermined non-zero pressure.

〔Example〕

Hereinafter, the present invention will be described in detail according to an embodiment shown in the accompanying drawings.

FIG. 1 shows a lock-up clutch control system according to an embodiment of the present invention. This embodiment system is a system in which a solenoid valve 30 for drain is added to the conventional system shown in FIG. 11, and other components are denoted by the same reference numerals as those in FIG. 11, and duplicated description will be omitted.

The electromagnetic valve 30 is for guiding the oil in the load piston control chamber of the modulation valve 14 to the drain, and is operated by the controller 40. In such a system configuration, the lockup clutch hydraulic pressure is applied to the modulation valve 14 (the first in the claims).
Corresponding to the valve), solenoid valve 15 (corresponding to the second valve in the claims) and electromagnetic valve 30.
(Hereinafter, it is controlled by the action corresponding to the third valve in the claims, which is called a drain valve.

An example of the internal structure of these three valves is shown in FIGS. 2 and 3. In FIG. 2 and FIG. 3, the load piston control chamber 31 that applies hydraulic pressure to the piston 29 of the modulation valve 14 is connected to the drain through the oil passage 32 and the drain valve 30, and the drain valve 30
Depending on whether you want to drain or not.

FIG. 4 shows an example of the overall configuration of a transmission system incorporating the lockup control system.

In FIG. 4, the output of the engine 50 is transmitted via a torque converter (torque converter) 2 to a gear type transmission.
The output of the transmission 60 is transmitted to the drive wheels 64 via the final reduction gear 63. A lockup clutch 1 that directly connects the input and output shafts of the torque converter 2 is interposed.

The engine 50 is provided with an engine speed sensor 51 which outputs a number of signals corresponding to the number of revolutions n ₁ , and the transmission 60 is provided with a number of signals corresponding to the number of revolutions n ₂ and n ₃ of its input shaft and output shaft. Output rotation sensors 52 and 53 are provided respectively, and the outputs of these sensors are output to the controller 40.
Is added to

The throttle amount sensor 70 detects the depression amount of the throttle pedal and inputs a signal S indicating the depression amount to the controller 40. The load sensor 71 detects the vehicle weight I (vehicle body weight + load weight) and inputs this detected amount to the controller 40. The shift selector 72 inputs a signal indicating the shift position (R, N, D, 1 ...) Selected by the shift lever to the controller 40. The transmission 60 has a plurality of shift clutches, and the required clutch corresponding to the speed stage is selectively engaged by the hydraulic pressure supplied from the clutch hydraulic pressure supply device 62. The internal configuration of the clutch hydraulic pressure supply device 61 that applies hydraulic pressure to the lockup clutch 1 is as shown in FIGS. 1 to 3.

In such a configuration, the fifth
The lockup clutch 1 is engaged as in the time chart shown in the figure.

In FIG. 5, (a) shows the command voltage of the controller 40 to the solenoid valve 15, (b) shows the engine speed, and (c) shows the lock-up clutch hydraulic pressure. The controller 40 keeps the drain valve 30 in the off state (the state shown in FIG. 1), and therefore the modulation valve 14
Operates in the same manner as the conventional configuration.

In this state, when the output of the engine speed sensor 51 becomes equal to or higher than the predetermined lockup minimum speed nc (Fig. 5 (b)), the controller 40 turns on the command voltage to the solenoid valve 15 to turn on the solenoid valve 14. Open and supply pressure oil to the lockup clutch 1. The lock-up clutch 1 is filled with oil after the filling time tf has elapsed, and then the clutch oil gradually increases. Since this operation is the same as the conventional one, the details are omitted.

Next, the operation at the time of shifting will be described with reference to the time chart of FIG.

In FIG. 6, (a) is a command voltage of the controller 40 for the solenoid valve 15, (b) is a command voltage for the drain valve 30, (c) is a hydraulic pressure PL of the piston chamber 31,
(D) is the valve outlet hydraulic pressure P of the modulation valve 14.
v and (e) show the lockup clutch hydraulic pressure, (f) shows the stroke of the piston 29, and (g) shows the output shaft torque of the transmission.

When the engine speed n ₁ is equal to or higher than the lockup minimum speed, the controller 40 sets the command voltage to the solenoid valve 15 to the “ON” state as shown in FIG. 6A before shifting. When a gear shift is instructed in this state (time t ₁ ), the controller 40 maintains the command voltage for the solenoid valve 15 in the “ON” state (FIG. 6 (a)) and sets the command voltage for the drain valve 30 to “ "ON" (Fig. 6 (b)). Then, the controller 40 sets the drain valve 30 to “O” during the lockup delay time T _I.
The “N” state is maintained, and the command voltage for the drain valve 30 is set to 0 after the delay time has elapsed (time t ₂ ). As a result, the drain valve 30 is switched to the drain side, and the pressure oil in the load piston control chamber 31 is rapidly drained via the oil passage 32. Therefore, the load piston 29 moves from the position shown in FIG. 3 to the position shown in FIG.
It is returned to the position at the time of installation of 23 (Fig. 6 (f), time
t ₁ , which results in the outlet hydraulic pressure Pv of the modulation valve 14
Falls to the initial pressure Po (= Kx / S ₁ , K; spring constant, x; initial displacement, S ₁ ; pressure receiving area of piston 21) as shown in Fig. 6 (d), and during the lockup delay time. Is this initial pressure
Po is retained. Therefore, the lockup clutch hydraulic pressure is also the valve outlet hydraulic pressure Pv as shown in FIG. 6 (e).
Changes almost the same as.

When the lockup delay time has elapsed, the controller 40 sets the command voltage to the drain valve 30 to 0 and closes the drain valve 30 (time t ₂ ). As a result, the oil that has entered the load piston control chamber 31 through the orifice 28 is blocked in the control chamber 31, thereby pushing the load piston 29 to the right, and as shown in FIG. As 29 strokes to the right, the lockup clutch hydraulic pressure gradually increases. Then the piston 29
The hydraulic pressure stops increasing at the point when hits the stopper, and this hydraulic pressure value is maintained thereafter.

That is, in this system, the pressure oil of the lockup clutch at the time of shifting is not completely drained, but the clutch oil pressure is decreased to the initial pressure Po which is higher than the torque converter internal pressure Pt. As a result, the lock-up clutch hydraulic pressure can build up the initial hydraulic pressure value corresponding to the hydraulic pressure when the filling is completed in a timely manner, improving the acceleration performance, and as shown in FIG. It is possible to reduce the shock at the time of the event.

The reason why the lockup is released at the time of shifting is to reduce the load of the shift clutch, but according to the control of this system, by reducing the transmission torque of the lockup clutch 1 (sliding the lockup clutch 1). ,
The clutch heat load is shared by the shift clutch and the lockup clutch.

The timing (time t ₂ ) at which the lock-up clutch hydraulic pressure is gradually increased can be determined by the following three methods.

(A) Interval time setting The optimum lock-up delay time T _I is obtained in advance by using various gears and engine power (throttle opening) as parameters by simulation, actual vehicle test, etc., and as shown in FIG. It is stored in the memory in the controller 40 by the map method. When shifting, the lockup delay time T _I corresponding to the output of the throttle amount sensor 70 and the current shift stage is read from this memory, and hydraulic buildup is started when this lockup delay time T _I has elapsed. To do so.

The: (b) the clutch relative rotational speed from the output n ₂ and n ₃ of the clutch relative rotational speed sensitive transmission input shaft rotation sensor 52 and the output shaft rotation sensor 53 (gear ratio _{= n 3 · G-n 2} G) When the calculated value becomes zero or a value close to zero as shown in FIG. 8, the build-up is started.

(C) Torque converter E value sensitive type From the output of the engine speed sensor 51 and the transmission input shaft sensor 22 (or the output shaft sensor 53), the torque converter E is detected.
The value (= n ₂ / n ₁ ) is calculated, and when the E value exceeds a certain set value E ₁ as shown in FIG. 9, the buildup is started.

Of the above three methods, (a) is the simplest and most practical. Further, although (b) and (c) require a rotation sensor, (b) is an advantageous method for improving the acceleration performance, and (c) is an advantageous method for reducing shift shock.

Further, the build-up rate at the time of gradually increasing the hydraulic pressure may be changed according to the throttle opening, the vehicle weight (vehicle body weight + load capacity), and the gear ratio of the transmission. Such variable control of the build-up rate can be easily realized by duty-controlling the voltage command applied to the drain valve 30 as shown in FIG. In Figure 10, 0%, 50%, 100
% Decorate ratio was shown.

The shift shock is evaluated by the jerk value expressed by the following equation.

J: Jerk value α: Vehicle acceleration K: Conversion coefficient (known) G: Reduction ratio constant I: Vehicle weight (vehicle weight + load weight) μ: Clutch disc friction coefficient (known) P: Clutch hydraulic pressure J is the target It is a shock and is a value determined by the degree of load. (The smaller the light load is, the larger the heavy load is better.) Although the load applied to the vehicle body cannot be measured here, the target jerk value J is determined by the throttle opening because the load is proportional to the power of the engine. be able to.

That is, the controller 40 measures the throttle opening S, the vehicle weight 1 and the gear ratio, calculates the optimum build-up rate dp / dt based on the measured values, and drains it with a duty ratio that realizes the calculated dp / dt. Control the voltage command of the valve 30.

〔The invention's effect〕

As described above, according to the present invention, the valve for discharging the pressure oil in the predetermined oil chamber in the modulation valve to the drain is provided, the lockup hydraulic pressure is lowered to the predetermined pressure during the gear shift, and this hydraulic pressure is maintained for a certain time. Since the amount is gradually increased afterward, the filling time required to fill the lock-up clutch is eliminated, and as a result, the shock at the end of filling is reduced and the acceleration at the time of shifting can be improved.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram showing an embodiment of the present invention, FIGS. 2 and 3 are diagrams showing an internal configuration example of each valve in the embodiment, and FIG. 4 is an overall configuration example of a transmission system. Block diagram, FIG. 5 is a time chart for explaining an operation example at the time of starting and running, FIG. 6 is a time chart for explaining an operation example at the time of shifting, and FIG. 7 determines a build-up start timing. FIG. 8 and FIG. 9 are time charts for explaining another method for determining the build-up start timing, and FIG. 10 is a hydraulic pressure gradual increase by duty control. FIG. 11 is a hydraulic circuit diagram showing an example of a conventional device, FIG. 12 is a diagram showing an internal configuration example of each valve of the conventional device, and FIG. 13 is an operation of the conventional device. Explain the example Is Muchato. 1 ... Lockup clutch, 2 ... Torque converter, 3
… Transmission tank, 4… strainer, 5… hydraulic pump, 6,7,11,12… relief valve, 8… rear brake cooling, 9… oil cooler, 10… oil filter, 14… lockup modulation valve, 15… solenoid Valve, 20,21 ... Piston, 22 ... Spool, 23
… Spring, 24… Orifice, 25… Oil chamber, 26… Valve body, 28… Orifice, 29… Load piston, 30… Drain valve, 31… Load piston control chamber, 40… Controller, 50… Engine, 51, 52, 53 ... Rotation sensor, 60
… Transmission, 70… Throttle amount sensor, 71…
Weight sensor, 72 ... Shift lever

Claims (3)

[Claims] 1. A hydraulic pressure of an output port for a lockup clutch is applied to one pressure receiving surface of a spool, one end of a spring is brought into contact with the other pressure receiving surface of the spool, and a piston is brought into contact with the other end of the spring. When the oil pressure in the oil chamber, which is introduced from the oil in the output port through the throttle, acts on the piston to supply the oil from the pump to the lock-up clutch, and the electric command to be input turns off, A second valve that closes the first valve to drain the oil from the lockup clutch, and a second valve that opens the first valve to supply the oil from the pump to the lockup clutch when an input electrical command turns on; A third valve for draining oil in the oil chamber of the first valve when an input electric command is turned on, and a second valve for shifting gears The electric command to be input is kept on, and the electric command to be inputted to the third valve is kept on only for a preset time so as to be shortened from the start of gear shift as the engine throttle opening increases. A lock-up clutch hydraulic control device comprising: control means for controlling so as to control. 2. A hydraulic pressure of an output port for a lock-up clutch is applied to one pressure receiving surface of a spool, one end of a spring is brought into contact with the other pressure receiving surface of the spool, and a piston is brought into contact with the other end of the spring. When the oil pressure in the oil chamber, which is introduced from the oil in the output port through the throttle, acts on the piston to supply the oil from the pump to the lock-up clutch, and the electric command to be input turns off, A second valve that closes the first valve to drain the oil from the lockup clutch, and a second valve that opens the first valve to supply the oil from the pump to the lockup clutch when an input electrical command turns on; A third valve for draining oil in the oil chamber of the first valve when an input electric command is turned on, and a second valve for shifting gears Maintaining the electric command is turned to enter, said third electrical command to be input to the valve transmission relative rotational speed from the time of the shift start (= n3G-n2, n
(3: Transmission output shaft speed, n2: Transmission input shaft speed, G: Transmission gear ratio) Control means for controlling to keep ON until it becomes approximately zero, and lock-up clutch hydraulic control equipped with apparatus. 3. A hydraulic pressure of an output port for a lockup clutch is applied to one pressure receiving surface of a spool, one end of a spring is brought into contact with the other pressure receiving surface of the spool, and a piston is brought into contact with the other end of the spring. When the oil pressure in the oil chamber, which is introduced from the oil in the output port through the throttle, acts on the piston to supply the oil from the pump to the lock-up clutch, and the electric command to be input turns off, A second valve that closes the first valve to drain the oil from the lockup clutch, and a second valve that opens the first valve to supply the oil from the pump to the lockup clutch when an input electrical command turns on; , A third valve for draining oil in the oil chamber of the first valve when an input electric command is turned on, and a second valve for shifting the gear The electric command to be applied remains on, and the electric command to be input to the third valve is the torque converter E value (= n2 / n1, n2: torque converter output shaft speed, n1: torque converter input shaft) from the start of gear shifting. A lock-up clutch hydraulic control device comprising: control means for controlling to keep ON until the rotational speed falls below a set value.