WO2008041620A1

WO2008041620A1 - Clutch control device for power transmission device for vehicle

Info

Publication number: WO2008041620A1
Application number: PCT/JP2007/068907
Authority: WO
Inventors: Yasushi Yamamoto; Hiroyuki Kawanishi
Original assignee: Isuzu Motors Limited
Priority date: 2006-09-29
Filing date: 2007-09-20
Publication date: 2008-04-10
Also published as: JP4179368B2; JP2008082528A

Abstract

A power transmission device for a vehicle, in which a clutch (3) automatically connected to and disconnected from a fluid coupling (2) is placed between an engine (1) and a transmission (4), wherein the power transmission device accurately learns a partial-clutch-engagement start point at which substantial torque transmission starts and controls the clutch by using the learned value. A clutch control device (31) has a learning device having a map for representing characteristics of the speed ratio and amount of torque transmission of the fluid coupling and also having speed ratio detection means. To learn the partial-clutch-engagement start point, the clutch (3) is first disengaged with the output shaft of the clutch (3) stopped while the vehicle is at a standstill, and then the amount of engagement of the clutch is gradually increased. This causes the rotation speed and speed ratio of a turbine (22) of the fluid coupling (2) to decrease gradually. Based on this speed ratio, the amount of torque transmission is calculated by using the map, and the amount of clutch engagement when the amount of torque transmission is at a predetermined value is learned as the partial-clutch-engagement start point. Because the amount of torque transmission itself is calculated, the learning value accurately represents the partial-clutch-engagement start point at which torque transmission starts.

Description

Patent application title: Clutch control device for vehicle power transmission device

The present invention relates to a clutch for a vehicle power transmission device that is provided with a fluid coupling and an automatic clutch between an engine and a transmission, and that is configured such that the clutch is automatically connected / disengaged at the time of shifting to change the gear position of the transmission. The present invention relates to a control device. Background art

As a trend of vehicles in recent years, in order to facilitate vehicle driving or reduce driver fatigue, power transmission devices for vehicles for the purpose of easy drive, represented by so-called AT vehicles, have been spreading. AT vehicles have a power transmission device that combines a torque converter and a planetary gear mechanism, but some of the vehicle power transmission devices for easy drive use a parallel shaft gear mechanism type gear shift similar to a so-called manual vehicle. Some machines combine this with an automatic clutch. This vehicle is not equipped with a clutch petal, and the clutch control device automatically connects and disconnects the clutch in response to a shift command signal for switching the gear position. The shift command signal is output according to the running state of the vehicle from an electronic control device such as a computer. In a vehicle in which the driver switches the gear stage with the shift lever, the clutch is automatically connected and disconnected by a signal when the shift lever is operated.

Recently, in a vehicle equipped with a diesel engine and using a parallel shaft gear mechanism type transmission, a power transmission device has been developed in which a fluid coupling is interposed between the engine and an automatic clutch. When a fluid coupling is interposed, especially in a diesel engine with a large torque in a region where the engine speed is small, it is possible to start using the slip between the fluid coupling pump and the turbine when starting the vehicle. In other words, a delicate clutch operation is not required when starting a manual vehicle, and a smooth start can be easily performed. At the same time, engine torque fluctuations during idling are absorbed, and vibration and noise are reduced. Such a power transmission device with a fluid coupling interposed will be described with reference to the schematic diagram of FIG. A fluid coupling 2 is fastened to the rear of the diesel engine 1, and further via a clutch 3. Thus, a transmission 4 having a parallel shaft gear mechanism is connected. The output shaft 41 of the transmission 4 is provided with a center brake (parking brake) 42 that is operated when the vehicle is stopped in the middle of the force coupling to the propeller shaft that drives the wheels of the vehicle.

In the fluid coupling 2, a pump 21 that is integrated with the output shaft of the diesel engine 1 and a turbine 2 2 that is integrated with the input shaft 31 of the clutch 3 are disposed. The two are basically connected by a lock-up clutch 23 except when the vehicle is started, so that the output shaft of the diesel engine 1 is directly connected to the input shaft 31 of the clutch 3. The speed changer 4 is a normal parallel shaft gear mechanism type transmission in which a transmission sleeve is fitted to a gear spline formed integrally with a gear, and has a well-known sink opening mechanism including a sink opening kniter ring and the like. It is. The transmission 4 is shifted by a shift actuator 61 according to a shift command from the electronic control unit. In a vehicle without such an electronic control unit, the shift is performed by a shift lever operated by a driver.

The clutch 3 in this device is a wet multi-plate clutch, and inside thereof, there are a large number of friction plates spline-fitted to the input shaft 3 2 and a large number of spline-fitted to the output shaft 3 3. The friction plates are alternately arranged. The clutch 3 includes a clutch control device 31. This control device cooperates with the engine control device 1 1 to which the amount of depression of the accelerator petal 62 is input at the time of shifting to change the gear position of the transmission 4. While controlling the amount of clutch 3 connected.

The connection amount of the clutch 3 is controlled by adjusting the hydraulic pressure acting on the biston that presses the friction plate disposed in the clutch 3 according to the duty ratio D of the pulse output from the clutch control device 31. The In the steady state, the clutch 3 is connected with a duty ratio of D = 0% (minimum hydraulic pressure specified value) and disconnected at D = 100% (maximum hydraulic pressure specified value). As the clutch 3, it is also possible to use a dry single plate clutch instead of the wet multi-plate clutch. At this time, the amount of connection is controlled by controlling the actuator that changes the clutch stroke.

The clutch control device 3 1 includes a rotational speed sensor 5 1 for detecting the rotational speed of the input shaft 3 2 of the clutch 3 (the rotational speed of the turbine 2 2 of the fluid coupling 2), and the rotational speed of the output shaft 3 3 of the clutch 3 ( The rotation speed sensor 5 2 for detecting the rotation speed of the input shaft of the transmission 4 and the rotation speed sensor 5 2 for detecting the rotation speed of the output shaft 4 1 of the transmission 4 are transmitted. Used to control connection volume. At the time of shifting, the clutch control device 31 gradually changes the amount of engagement of the clutch 3 in order to avoid a shift shock due to sudden torque transmission and engine stop. For example, when the clutch 3 is connected after the gear, the clutch control device 31 controls the duty ratio so that the connection amount of the clutch 3 is gradually increased. While clutch 3 slips in the so-called half-clutch state, it gradually matches the engine speed with the input shaft speed of transmission 4, and when the clutch is fully engaged (D = 0%), the slip amount becomes zero. The diesel engine 1 is directly connected to the input shaft of the transmission 4.

A shift shock may also occur when the clutch 3 is disengaged at the beginning of a shift. During normal travel, the engine drive torque is transmitted to the vehicle wheels, and the transmission system such as the transmission 4 is twisted by the drive torque, and the reaction torque acts on the vehicle body. The shift shock at the time of disconnection occurs when the drive torque is released with the rapid disconnection of the clutch 3 and the torsion etc. disappears instantaneously. In diesel engines with large engine torque, especially when the vehicle is running at low speed, there is a large shift shock that accompanies disconnection, and it is desirable to implement control that gradually reduces the amount of connection when clutch 3 is disengaged. By the way, in the actual clutch 3, since the transmission torque hardly increases even if the hydraulic pressure is increased from the disconnected state in the connection amount region before reaching the half clutch state, the region is shortened for quick connection / disconnection. Need to pass in time. In addition, there are some individual differences in the wet multi-plate clutch 3 that is actually installed in each vehicle, and even with the same clutch, the secular change occurs, so the connection amount at which the half-clutch state is started depends on the clutch. Change. Therefore, the value of the hydraulic pressure at the start of the half-clutch, in other words, the duty ratio, which is the connection amount at which substantial torque transmission starts, needs to be learned periodically for each vehicle. The clutch control device 31 can execute accurate and quick clutch control by using the half-clutch learning value that is sequentially updated.

The learning of the half-clutch state is generally performed in a vehicle equipped with an automatic clutch. For example, there is a known method of gradually increasing the clutch engagement amount and learning the connection amount at which the transmission input shaft starts rotating. Yes. In addition, a learning method for learning the amount of engagement of the clutch 3 in the half-clutch state in a power transmission device provided with a fluid coupling is described in Japanese Patent Application Laid-Open No. 2000-029525 as an example. Yes. The learning of the half-clutch state disclosed in this publication is performed when the vehicle is stopped. This is done by gearing in the transmission 4 and rotating the diesel engine 1. The wet multi-plate clutch 3 is disengaged, and the lock-up clutch 2 3 of the fluid coupling 2 is also disengaged.

Since the wet multi-plate clutch 3 is disconnected, the turbine 2 2 of the fluid coupling 2 is dragged to the pump 21 even though the vehicle stops and the output shaft 3 3 of the wet multi-plate clutch 3 is stationary. It is rotating at the same rotational speed as the diesel engine 1. As shown in FIG. 5, from this state, the output duty ratio of the clutch control device 31 is decreased and the amount of connection of the wet multi-plate clutch 3 is increased. Since the output shaft 3 3 of the wet multi-plate clutch 3 is stationary, the rotational speed of the turbine 2 2 integrated with the input shaft 3 2 of the wet multi-plate clutch 3 increases as the amount of connection increases and the amount of torque transmission increases. Will decline. Then, the duty ratio when the rotational speed of the turbine 2 2 is reduced by a predetermined value (3,000 rpm in this example) with respect to the rotational speed of the diesel engine 1 (the rotational speed of the pump 21) is calculated as the half-clutch learning value. The duty ratio is stored in the clutch control device 31. In the half-clutch learning method described above, the duty ratio output by the clutch control device 31 is gradually decreased to increase the amount of engagement of the clutch 3, that is, while the braking torque acting on the turbine 22 is gradually increased. The difference between the rotational speed and the rotational speed of the turbine 22 is detected, and the duty ratio when the difference reaches a predetermined value is defined as the half clutch start point. The difference between the two speeds increases as the transmission torque of the clutch 3 increases, but it does not accurately represent the transmission torque because of the difference in the speed. In addition, the rotational speed of the diesel engine 1 changes according to the load torque (transmission torque of the clutch 3), and the change situation also depends on the control method of fuel injection of the engine. For this reason, the predetermined value of the rotational speed difference that determines the half-clutch starting point needs to be changed according to various vehicle engines.

Also, as the clutch 3 connection amount increases and the load torque of the diesel engine 1 increases, its rotational speed decreases, so when learning the half-clutch starting point, increase the engine rotational speed in advance in anticipation of the decrease. I have to leave. If the engine speed is set to a high value, the engine output torque will increase and there is a greater risk that the parked vehicle will start unexpectedly.

An object of the present invention is to solve such a problem when learning a half-clutch state and to learn an accurate half-clutch starting point. Disclosure of the invention In view of the above problems, the present invention provides a vehicular power transmission device including a fluid coupling and a clutch that is automatically connected / disconnected, and uses a map that represents a torque transmission amount of the fluid coupling to provide a half-clutch state. It is to detect accurately. That is, the present invention, as described in claim 1,

“A clutch control device for a vehicle power transmission device in which a fluid coupling and a clutch are arranged between an engine and a transmission.

The pump of the fluid coupling is connected to rotate integrally with the output shaft of the engine, the turbine bin of the fluid coupling is connected to rotate integrally with the input shaft of the clutch, and the output shaft of the clutch is connected to the speed change Connected to the input shaft of the machine,

The clutch control device includes a learning device that learns a connection amount in a half-clutch state, and uses the learned connection amount to control the connection amount of the clutch. The learning device includes the fluid coupling. A detection means for detecting a speed ratio, which is a ratio between the rotational speed of the pump and the rotational speed of the turbine bin, and calculation of a torque transmission amount having a map representing a relationship between the speed ratio and the torque transmission amount of the fluid coupling Means and

After the vehicle is stopped and the output shaft of the clutch is stationary, the speed is detected by the detecting means while gradually increasing the amount of connection after the clutch is cut, and the detected speed ratio is set to the detected speed ratio. Based on the calculation means, the torque transmission amount is calculated,

It is configured to memorize the connection amount when the calculated torque transmission amount reaches a predetermined value as the connection amount in the half-clutch state. ''

The clutch control device is characterized by this. The half-clutch learning device according to the present invention includes a detecting means for detecting a speed ratio which is a ratio of a pump rotation speed and a turbine rotation speed in a fluid coupling, and a relationship between the speed ratio and a torque transmission amount of the fluid coupling. And a calculation means for calculating a torque transmission amount using a map representing. The map is determined according to the characteristics of each fluid coupling. Even if the clutch or engine changes, the characteristics of torque transmission with respect to the speed ratio do not change. Therefore, it is possible to accurately obtain the torque transmission amount corresponding to the speed ratio, and it is possible to calculate the change in the torque transmission amount according to the connection amount regardless of the individual difference or aging of the clutch. In the learning device of the present invention, the map is stored in the memory of the clutch control device, for example.

The learning of the half-clutch state of the present invention is executed while gradually increasing the amount of connection after the clutch is disengaged while the output shaft of the clutch is stationary while the vehicle is stopped. When learning Since the lock-up clutch is disengaged and the braking torque acting on the turbine of the fluid coupling increases as the amount of connection increases, the rotational speed gradually decreases. This point is the same as in the conventional learning shown in Patent Document 1, but the conventional learning method detects that the reduced rotational speed difference has reached a predetermined value and sets it as a half-clutch start point. In the present invention, a speed ratio that is a ratio between the rotational speed of the pump and the rotational speed of the turbine is detected, and the torque transmission amount itself is calculated from the speed ratio using a map to determine the half-clutch starting point. As a result, the half-clutch state can be grasped more accurately, and the characteristics of the torque transmission amount with respect to the speed ratio are uniquely determined according to the fluid coupling. Applicable to all engines. In some cases, the transmission torque at the half-clutch starting point can be easily adjusted according to, for example, the vehicle weight.

Furthermore, the present invention detects a speed ratio that is a ratio between the rotational speed of the pump and the rotational speed of the turbine. Can also be measured. In the conventional learning method, in order to learn with a predetermined value of the difference in the rotational speed, it is necessary to increase the engine speed in advance when learning starts in anticipation of a decrease in the engine speed during learning. . On the other hand, the learning according to the present invention can be executed with the engine speed set to be relatively low, so that it is possible to avoid a situation where the vehicle suddenly starts during learning. Since the learning device of the present invention can accurately grasp the connection amount in the half-clutch state as the torque transmission amount itself, the clutch control device provided with this enables quick clutch engagement / disengagement without a shift shock at the time of shifting. . For example, as in the invention described in claim 2, when the clutch is disconnected at the time of shifting of the transmission, when the connection amount stored as the learning value is reached, control is performed to increase the decrease rate of the connection amount. It is possible to quickly disconnect, and as in the invention described in claim 3 of the claim, when connecting a clutch that is disconnected at the time of shifting of the transmission, the connection amount is reduced until the stored connection amount is reached. Increasing the speed increases the speed of connection. On the other hand, when using the learning value obtained by the conventional learning method, the period during which the operation speed is low had to be set longer in order to avoid shift shock caused by the inaccuracy of the learning value. The present invention can be implemented as a method for learning the amount of connection in the half-clutch state, and in this case, as described in claim 4, “A fluid coupling and a clutch are arranged between the engine and the transmission, the pump of the fluid coupling is connected to rotate integrally with the output shaft of the engine, and the turbine of the fluid coupling is connected to the input of the clutch. A learning method for learning a connection amount of the clutch in a half-clutch state, wherein the clutch is connected to rotate integrally with a shaft, and the output shaft of the clutch is connected to an input shaft of the transmission. Because '

After the vehicle is stopped and the output shaft of the clutch is stationary, the clutch is disconnected, and then the ratio of the rotational speed of the pump in the fluid coupling and the rotational speed of the turbine is increased while gradually increasing the amount of connection. Detects the speed ratio,

The torque transmission amount is calculated using a map representing the relationship between the detected speed ratio and the torque transmission amount of the fluid coupling,

The connection amount when the calculated torque transmission amount reaches a predetermined value is memorized as the connection amount in the half-clutch state. ''

This is a method for learning the amount of connection in the half-clutch state. As described above, when the present invention is implemented as a learning method invention, the above-described effects are similarly achieved.

In the method for learning the amount of connection in the half-clutch state, as described in claim 5, it is preferable that the method is executed in a state where the vehicle is stopped and a braking force is applied to the vehicle. In this way, sudden start of the vehicle can be prevented more reliably. Brief Description of Drawings

FIG. 1 is a schematic diagram of a vehicle power transmission device to which a control device of the present invention is applied.

Fig. 2 shows the characteristics of the torque and speed ratio of the fluid coupling.

FIG. 3 is a flowchart showing the operation of the learning apparatus of the present invention.

FIG. 4 is a diagram showing a control mode of the clutch connection amount according to the present invention.

FIG. 5 is a diagram showing a conventional half-clutch learning value determination method. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a clutch control device for a vehicle power transmission device embodying the present invention will be described with reference to the drawings. Devices constituting the vehicle power transmission device to which the present invention is applied are shown in FIG. This is not a different device. That is, in the vehicle power transmission device, the fluid coupling 2 is fastened to the rear of the diesel engine 1 and is a clutch that automatically connects and disconnects. A transmission 4 having a parallel shaft gear mechanism is connected via a plate wet clutch 3. The pump 2 1 and the turbine 2 2 of the fluid coupling 2 are fastened by the lock-up clutch 2 3 except when both vehicles start, and the output shaft of the diesel engine 1 is directly connected to the input shaft of the wet multi-plate clutch 3. It will be in the state.

The wet multi-plate clutch 3 includes a clutch control device 31, and the clutch control device 31 performs connection / disconnection while controlling the amount of connection of the wet multi-plate clutch 3 when the transmission 4 is shifted. Like the conventional clutch control device, the clutch control device 31 outputs a duty ratio: D, which is a command value for the amount of connection, and acts on the piston that presses the friction plate of the wet multi-plate clutch 3 accordingly. The amount of connection of the wet multi-plate clutch 3 is controlled by changing the hydraulic pressure. In addition, the clutch control device 31 includes a rotation speed signal of the pump 21 (engine speed signal from the engine control device 11) and a rotation speed signal of the turbine 22 (clutch input shaft from the rotation speed sensor 51). 3 Rotational speed signal (2) is input. In the clutch control device 31 of the present invention, a map indicating the characteristics of the speed ratio e of the fluid coupling 2 (ratio of the rotational speed of the turbine 22 to the rotational speed of the pump 21) and the torque transmission amount is stored as a memory. It is stored. This characteristic is known as the coefficient τ representing the specific input torque, and is determined according to the individual fluid coupling, and as shown in Fig. 2, it increases as the speed ratio decreases. The torque transmission amount of the fluid coupling is obtained from the following equation after the torque coefficient.

Torque transmission amount = CX x X (Pump 2 1 speed) ² : C is a constant

The clutch control device 31 of the present invention includes the above map and also includes means for detecting a speed ratio e from the input rotation speed signal of the pump 21 and the rotation speed signal of the turbine 22, A half-clutch learning device is configured. Here, the learning procedure of the half clutch start point in the learning device of the present invention and the operation of the vehicle power transmission device at the time of learning will be described with reference to the flowchart of FIG.

When you reach the B temple period to learn, you can determine in step 1 whether or not the vehicle is stopped, and if it is stopped, in step 2 whether or not the braking force is acting on the vehicle \ Determine whether the foot brake or parking brake (center brake) is operated. Further, in step 3, it is determined whether the driver is depressing the accelerator pedal, that is, whether the diesel engine 1 is in an idle state. These judgments are learning This is done to ensure the safety of the vehicle inside and to prevent unexpected start. When it is confirmed that the vehicle is stopped, the brake is operated, and the engine is in an idle state, the conditions for executing the learning are in place and learning of the half-clutch starting point is started. In this learning, first, the duty ratio output from the clutch control device 31 is set to 100%, and the wet multi-plate clutch 3 is disconnected (S 4). At the same time, the state of the transmission 4 is detected. When the transmission 4 is in the neutral position, the transmission actuator 61 is operated to engage one of the gears of the transmission, for example, the fifth gear, and the transmission Set 4 to the gear-in state (S 5). As a result, the output shaft 4 of the transmission 4 1 is connected to the input shaft 33 integrated with the output shaft of the wet multi-plate clutch 3. Further, when the lock-up clutch 23 of the fluid coupling 2 is connected, it is disconnected so that the pump 21 and the turbine 22 of the fluid coupling 2 can freely rotate (S6). Next, the duty ratio output from the clutch control device 31 is decreased by a small amount, for example, by 1% (S 6), and the connection amount of the wet multi-plate clutch 3 is increased. When the wet multi-plate clutch 3 is completely disconnected, the braking torque does not substantially act on the turbine 22 integrated with the input shaft 3 2. At this time, the turbine 22 of the fluid coupling has almost the same rotational speed as the pump 21, and its speed ratio e is 1. By the way, the output shaft 33 of the wet multi-plate clutch 3 is connected to the output shaft 41 of the transmission 4, and remains stationary while the vehicle is stopped. Therefore, if the connection amount of the wet multi-plate clutch 3 is increased, a braking torque force equal to the transmission torque at the connection amount is generated in the input shaft 3 2, that is, the turbine 2 2 of the fluid coupling, and the rotation speed and speed of the turbine 2 2 of the fluid coupling 2 The ratio e decreases. In other words, the transmission torque of the wet multi-plate clutch 3 is equal to the torque transmission amount of the fluid coupling 2 when the speed ratio e decreases.

In step 8, every time the amount of connection of the wet multi-plate clutch 3 is increased, the speed ratio e is detected using the input rotation speed signal of the pump 21 and the rotation speed signal of the turbine 22. Then, in step 9, the torque coefficient τ at the speed ratio e is obtained from the map stored in the memory of the clutch control device 31, and the torque transmission amount of the fluid coupling 2 is calculated by the above formula. As a result, the transmission torque of the wet multi-plate clutch 3 is calculated.

In Step 10, it is determined whether or not the calculated torque transmission amount is a force that has reached a predetermined value of the torque transmission amount corresponding to the half clutch starting point. When the predetermined value is reached, the clutch control device 31 stores the duty ratio at that time as the duty ratio of the half clutch start point, updates the existing learning value, and stores it in the memory (S ll). The torque transmission amount corresponding to the half-clutch starting point is determined in advance by experiments or the like according to each vehicle on which such a power transmission device is mounted. It has been. In some cases, the clutch control device 31 can be configured so that the predetermined value of the torque transmission amount can be changed. FIG. 4 shows a control mode of the engagement amount of the clutch 3 at the time of shifting by the clutch control device 31 of the present invention. The solid line in the figure shows the change in the connection amount when the clutch 3 is first disengaged during gear shifting.

During normal driving of the vehicle, the clutch control device 31 outputs a pulse with a duty ratio of 0%, and the clutch 3 is in a fully connected state. When a shift command is input from an electronic control device such as a computer mounted on the vehicle to the clutch control device 31, the clutch control device 31 increases the output duty ratio to 100% and disconnects the clutch 3. To do. In this case, the duty ratio is first increased rapidly to obtain the connection amount at point A in the figure. Point A is the connection amount at which the clutch 3 is substantially completely connected, that is, the connection amount at which slip does not occur between the input and output shafts of the clutch 3, and is the connection amount at the end of the half-clutch state. After the connection amount reaches point A, the clutch control device 31 reduces the increased acceleration of the output duty ratio and gradually decreases the connection amount. As a result, the torsion accumulated in the power transmission system is not released instantaneously, and the shift shock associated with the disengagement of the clutch 3 is avoided.

When the duty ratio output by the clutch control device 3 1 increases and the connection amount decreases to point B, that is, the connection amount of the half clutch start point learned by the learning device of the present invention, the clutch control device 3 1 increases the increasing rate of the duty ratio again to reach 100%. The half-clutch starting point obtained by the learning device of the present invention is equal to the transmission torque itself of the clutch 3, and the amount of connection is rapidly decreased immediately after reaching the point B, which is an accurate value. However, there is no shift shock. On the other hand, with the conventional clutch control device, the reliability of the learned value is not sufficient, and as shown by the two-dot chain line in the figure, the range where the rate of decrease in the connection amount is low is set long so as to reliably avoid the shift shock Therefore, the time required for cutting could not be shortened.

The broken line in the figure shows the change in the connection amount when the clutch 3 is connected after gear-in. Even at this time, the clutch control device 31 controls the change rate of the output duty ratio in a manner almost similar to that at the time of disconnection. The connection amount of clutch 3 is rapidly increased up to point B and gradually increased between point B and point A, thereby preventing shift shock and the like and achieving quick connection. The above control of the amount of connection of the clutch 3 at the time of shifting is such that the rate of change of the amount of connection from the start point B to the complete contact point A of the half-clutch is a moderate constant speed. On the other hand, it is also possible to control so that the change rate of the connection amount between point B and point A is changed according to the torque transmission amount. For example, the torque transmission amount of the power transmission system has a characteristic that increases as the difference between the rotational speed of the turbine 2 2 of the fluid coupling 2 and the rotational speed of the pump 21 increases. The difference may be detected, and if the speed difference is large, control may be performed to reduce the change rate of the clutch 3 engagement amount. In this case, fine control of the amount of connection in the half-clutch region is possible, and a quicker shift without shifting shock is achieved.

Further, when the vehicle speed is very low (for example, 1 O KmZ h or less) at the start of the vehicle, the difference between the rotational speed of the turbine 22 and the rotational speed of the pump 21 is approximately inversely proportional to the vehicle speed. Therefore, it is possible to detect the vehicle speed instead of detecting the rotational speed difference between the two and change the change rate of the connection amount between point B and point A according to the vehicle speed. Industrial applicability

As described above in detail, the present invention is a vehicle power transmission device that includes a clutch that is automatically connected to and disconnected from a fluid coupling between an engine and a transmission, and represents a torque transmission amount of the fluid coupling. The half-clutch state is accurately detected using the loop. Therefore, it is clear that the present invention can be used for a vehicle power transmission device having a fluid coupling and an automatic clutch. The present invention is not limited to the wet multi-plate clutch as in the above-described embodiment, and a dry single-plate clutch is used. The present invention can also be applied to a vehicle power transmission device that controls a provided clutch stroke. It is also obvious that the present invention can be applied to a vehicle in which a driver operates a shift lever to change speed.

Claims

A clutch control device for a vehicle power transmission device in which a fluid coupling and a clutch are arranged between an engine and a transmission,

The pump of the fluid coupling is connected to rotate integrally with the output shaft of the engine, the turbine of the fluid coupling is connected to rotate integrally with the input shaft of the clutch, and the output shaft of the clutch is connected to the transmission. Connected to the input shaft, and

The clutch control device includes a learning device that learns a connection amount in a half-clutch state, and uses the learned connection amount to control the connection amount of the clutch. The learning device includes the fluid coupling. Detecting means for detecting a speed ratio, which is a ratio between the rotational speed of the pump and the rotational speed of the turbine bin, and a torque transmission amount having a map representing a relationship between the speed ratio and the torque transmission amount of the fluid coupling. Computing means,

After the vehicle is stopped and the output shaft of the clutch is stopped, the clutch is disconnected, and then the speed ratio is detected by the detecting means while gradually increasing the connection amount, and the detected speed is detected. The torque transmission amount is calculated by the calculation means based on the ratio, and the connection amount when the calculated torque transmission amount reaches a predetermined value is stored as the connection amount in the half-clutch state. A clutch control device.

When the clutch is disengaged during the shift of the transmission, the clutch control device reduces the rate of decrease in the connection amount within a certain range on the connection side from the connection amount stored by the learning device, and the stored connection amount. The clutch control device for a power transmission device for a vehicle according to item 1, wherein the rate of decrease in the connection amount is increased when the value reaches the value.

When connecting a clutch that has been disconnected at the time of shifting the transmission, the clutch control device increases the increased acceleration of the connection amount until the connection amount stored by the learning device is reached, and the stored connection amount is reached. The clutch control device for a vehicle power transmission device according to claim 1 or 2, wherein the connection speed is increased at a reduced time.

A fluid coupling and a clutch are arranged between the engine and the transmission, a pump of the fluid coupling is connected to rotate integrally with an output shaft of the engine, and a turbine of the fluid coupling is connected to an input shaft of the clutch And a learning method for learning a connection amount of the clutch in a half-clutch state in a vehicle power transmission device in which the output shaft of the clutch is connected to the input shaft of the transmission. There, While the vehicle is stopped and the output shaft of the clutch is stationary, after the clutch is disconnected, the ratio of the rotational speed of the pump in the fluid coupling and the rotational speed of the turbine is gradually increased while increasing the connection amount. Detects the speed ratio,

Calculate the torque transmission amount using a map representing the relationship between the detected speed ratio and the torque transmission amount of the fluid coupling,

A method of learning a connection amount in a half-clutch state, wherein the connection amount when the calculated torque transmission amount reaches a predetermined value is stored as a connection amount in a half-clutch state.

5. The learning method according to item 4, wherein the connection amount learning in the half-clutch state is performed in a state where the vehicle is stopped and the force and the braking force are applied to the vehicle.