JP4858052B2 - Shift clutch control device in vehicle power transmission device - Google Patents

Description

  The present invention relates to a shift of a vehicle power transmission device that includes a fluid coupling and an automatic clutch between an engine and a transmission, and that is configured so that the clutch is automatically connected / disengaged at the time of shifting to change the shift stage of the transmission. The present invention relates to an hour clutch control device.

As a trend of vehicles in recent years, in order to facilitate vehicle driving or reduce driver fatigue, vehicle power transmission devices for easy driving, represented by so-called AT vehicles, have been spreading. The AT car has 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 include a parallel shaft gear mechanism type gear shift similar to a so-called manual vehicle. There is a combination of this and an automatic clutch using a machine. This vehicle is not provided 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 in accordance with the running state of the vehicle from an electronic control device such as a computer. In a vehicle in which a driver switches gears with a shift lever, automatic clutch connection / disconnection is performed 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 in which a fluid coupling (fluid coupling) is interposed between the engine and an automatic clutch has been developed. When a fluid coupling is interposed, particularly in a diesel engine having a large torque in a region where the engine speed is small, it is possible to start using the slip between the pump of the fluid coupling and the turbine when starting the vehicle. That is, 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 and the like 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 behind the diesel engine 1, and a transmission 4 having a parallel shaft gear mechanism is connected via a clutch 3. The output shaft 41 of the transmission 4 is coupled to a propeller shaft that drives the wheels of the vehicle, and a center brake (parking brake) 42 that is activated when the vehicle is stopped is provided in the middle.

In the fluid coupling 2, a pump 21 integrated with the output shaft of the diesel engine 1 and a turbine 22 integrated with the input shaft 31 of the clutch 3 are arranged. When the vehicle is running at a low speed when starting, the pump 21 rotates independently of the turbine 22 but is basically connected by a lock-up clutch 23 except when the vehicle is starting. The output shaft is directly connected to the input shaft 31 of the clutch 3. The transmission 4 is a normal parallel shaft gear mechanism type transmission in which a transmission sleeve is meshed with a gear spline formed integrally with a gear, and includes a known synchronization mechanism including a synchronizer ring. The transmission 4 is shifted by the shift actuator 61 in response 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 the driver.

The clutch 3 in this apparatus is a wet multi-plate clutch, and includes a large number of friction plates spline-fitted to the input shaft 32 and a large number of friction splines-fitted to the output shaft 33. The plates are arranged alternately. The clutch 3 includes a clutch control device 31, and this control device cooperates with the engine control device 11 to which the depression amount of the accelerator petal 62 is input at the time of shifting to change the gear stage of the transmission 4. Control of the connection amount of the clutch 3 is executed.

The amount of connection of the clutch 3 is controlled by adjusting the hydraulic pressure acting on the piston that presses the friction plate disposed therein according to the duty ratio D of the pulse output from the clutch control device 31. In the steady state, the clutch 3 is set to be connected at a duty ratio: D = 0% (minimum hydraulic pressure prescribed value) and disconnected at D = 100% (maximum hydraulic pressure prescribed value). As the clutch 3, a dry single plate clutch can be used 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 31 includes a rotational speed sensor 51 for detecting the rotational speed of the input shaft 32 of the clutch 3 (the rotational speed of the turbine 22 of the fluid coupling 2), and the rotational speed of the output shaft 33 of the clutch 3 (input of the transmission 4). Respective rotation speed signals detected by the rotation speed sensor 52 for detecting the rotation speed of the shaft and the rotation speed sensor 53 for detecting the rotation speed of the output shaft 41 of the transmission 4 are transmitted and used for controlling the connection amount. .

At the time of shifting, the clutch control device 31 gradually changes the amount of engagement of the clutch 3 in order to avoid shift shock and engine stop due to sudden torque transmission. For example, when the clutch 3 is connected after the gear-in, the clutch control device 31 controls the duty ratio so that the connection amount of the clutch 3 is gradually increased. The clutch 3 gradually matches the engine speed and the input shaft speed of the transmission 4 while sliding in a so-called half-clutch state, and when the clutch is completely connected (D = 0%), the slip amount becomes zero. The diesel engine 1 is directly connected to the input shaft of the transmission 4. Thus, a clutch control method for gradually increasing the amount of engagement of the clutch 3 while preventing a shift shock or the like is disclosed in, for example, Japanese Patent Laid-Open No. 10-274258 (however, the clutch of this example is a dry single plate). A clutch, and the amount of connection is controlled by changing its stroke).

By the way, in the actual clutch 3, in the connection amount region before reaching the half clutch state, the transmission torque hardly increases even when the hydraulic pressure is increased from the disconnected state. This is the same not only for wet multi-plate clutches but also for dry single-plate clutches, but it is necessary to pass through the region in a short time for quick connection / disconnection. In addition, there is some individual difference in the clutch 3 that is actually installed in each vehicle, and since the secular change occurs even in the same clutch, the connection amount at which the half-clutch state is started varies depending on the clutch. . Accordingly, it is necessary to periodically learn the value of the hydraulic pressure at the time of starting the half clutch, in other words, the duty ratio that is the connection amount at which substantial torque transmission starts, in each individual 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, a method of learning the connection amount at which the clutch input shaft starts rotating by gradually increasing the clutch connection amount is known. Yes. Moreover, the learning method which learns the connection amount of the half-clutch state of the clutch 3 in the power transmission device provided with the fluid coupling is described in Japanese Patent Application Laid-Open No. 2002-295529 as an example. The learning of the half-clutch state disclosed in this publication is performed by gearing in the transmission 4 and rotating the diesel engine 1 when the vehicle is stopped. The wet multi-plate clutch 3 is disengaged, and the lock-up clutch 23 of the fluid coupling 2 is also disengaged.

Since the wet multi-plate clutch 3 is disengaged, the turbine 22 of the fluid coupling 2 is dragged by the pump 21 even when the vehicle stops and the output shaft 33 of the wet multi-plate clutch 3 is stationary. The engine 1 is rotating at the same rotational speed. As shown in FIG. 7, the output duty ratio of the clutch control device 31 is decreased from this state to increase the amount of connection of the wet multi-plate clutch 3. Since the output shaft 33 of the wet multi-plate clutch 3 is stationary, the rotational speed of the turbine 22 integrated with the input shaft 32 of the wet multi-plate clutch 3 decreases as the connection amount increases and the torque transmission amount increases. Then, the clutch control device 31 uses the duty ratio when the rotational speed of the turbine 22 is reduced by a predetermined value (300 rpm in this example) with respect to the rotational speed of the diesel engine 1 (the rotational speed of the pump 21) as a half-clutch learning value duty ratio. Remember me.
JP-A-10-274258 JP 2002-295529 A

  In clutch control at the time of shifting, the amount of clutch engagement is controlled so as to prevent shift shock or engine stop. At this time, if the change rate of the amount of connection is large, the transmission torque changes rapidly and a shift shock is likely to occur. When the clutch is connected, there is a possibility of causing an engine stop. On the other hand, when the change speed is low, the time for shifting becomes long, which impairs drivability.

The shift shock may occur not only when the clutch is connected after gear-in but also when the clutch 3 is disconnected at the beginning of the 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 rapid disconnection of the clutch 3 and the torsion or the like disappears instantaneously. In a diesel engine having a large engine torque, the shift shock accompanying the disconnection is large when the vehicle is at a low speed such as when starting, and it is desirable to disconnect the clutch 3 while controlling the amount of connection even when the clutch 3 is disconnected.

An object of the present invention is to allow a power transmission device including a fluid coupling to quickly connect and disconnect a clutch at the time of shifting without causing a shift shock or the like. In order to quickly connect and disconnect, it is necessary to pass the connection amount region up to the half-clutch start point within a short time. However, the above-described learning method of the half-clutch start point has the following problem. .

In this method, the engine speed and the rotation of the turbine 22 are increased while gradually decreasing the duty ratio output by the clutch control device 31 and increasing the amount of engagement of the clutch 3, that is, gradually increasing the braking torque acting on the turbine 22. The difference from the number is detected, and the duty ratio when the difference reaches a predetermined value is set as the half clutch start point. The difference between the rotational speeds of the two increases as the transmission torque of the clutch 3 increases. However, the difference in the rotational speeds does not accurately represent the transmission torque. Further, the rotational speed of the diesel engine 1 changes according to the load torque (transmission torque of the clutch 3), and the change state varies depending on the fuel injection control method of the engine. Therefore, the predetermined value of the rotational speed difference that determines the half clutch starting point needs to be changed according to the engines of various vehicles.

Further, when the amount of clutch 3 connected increases and the load torque of the diesel engine 1 increases, the rotation speed decreases. There must be. However, when the engine speed is set to be high, the engine output torque increases, and there is an increased risk that the stopped vehicle will start unexpectedly.
A further object of the present invention is to solve such a problem when learning the half-clutch state and to enable the accurate learning of the half-clutch starting point.

In view of the above problems, the present invention provides a vehicle power transmission device including a fluid coupling and a clutch that is automatically connected and disconnected, and a torque transmission state of the clutch using a map that represents a torque transmission amount of the fluid coupling. Is detected accurately, and the change rate of the connection amount is determined based on this. That is, the present invention
“A clutch control device of a vehicle power transmission device in which a fluid coupling and a clutch are disposed between an engine and a transmission, wherein a pump of the fluid coupling is coupled to rotate integrally with an output shaft of the engine, A turbine of a fluid coupling is connected to rotate integrally with an input shaft of the clutch, and an output shaft of the clutch is connected to an input shaft of the transmission;
In the clutch control device for controlling the connection amount of the clutch at the time of shifting and performing the connection / disconnection thereof,
The clutch control device includes a detecting unit that detects a speed ratio that is a ratio of a rotation speed of a pump and a rotation speed of a turbine in the fluid coupling, and a map that represents a relationship between the speed ratio and a torque transmission amount of the fluid coupling. And a torque transmission amount calculation means having
When the shift is performed with the pump and the turbine disconnected, and the clutch is in a half-clutch state, the torque transmission amount obtained by the detection means and the calculation means becomes smaller. Increase the rate of change of clutch engagement. "
The clutch control device is characterized by this.

In the latch control device having the map representing the torque transmission amount of the fluid coupling, a half-clutch learning device using the map can be provided. The learning device according to claim 2, wherein the detecting means gradually increases the amount of connection after the clutch is disengaged in a state where the vehicle is stopped and the output shaft of the clutch is stationary. In addition to detecting the speed ratio, the calculation means calculates the torque transmission amount based on the detected speed ratio, and the connection amount when the calculated torque transmission amount reaches a predetermined value is defined as the connection amount in the half-clutch state. Configured to remember.

In the case where the learning device according to claim 2 is provided, as described in claim 3, when the clutch is disengaged at the time of shifting of the transmission, the clutch control device is more than the connection amount stored by the learning device. It is possible to control to decrease the connection rate decrease rate in a certain range on the connection side, and to increase the connection rate decrease rate when the stored connection amount is reached. According to a third aspect of the present invention, when the clutch disconnected at the time of shifting of the transmission is connected, the increasing speed of the connection amount until the clutch control device reaches the connection amount stored by the learning device. When the stored connection amount is reached, control can be performed to decrease the increase rate of the connection amount.

The clutch control device according to the present invention includes a 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 in the fluid coupling, and a map representing the relationship between the speed ratio and the torque transmission amount of the fluid coupling. And calculating means for calculating the torque transmission amount. The map is stored in the memory of the clutch control device, for example, and is determined according to the characteristics of the individual fluid couplings. Even if the clutch or engine changes, the characteristics of the torque transmission amount with respect to the speed ratio do not change. In such a vehicle power transmission device, the torque transmission amount of the fluid coupling is equal to the transmission torque of the clutch. Therefore, when the fluid coupling pump and the turbine (clutch input shaft) are disconnected when the vehicle starts, the transmission torque of the clutch can be detected by detecting the speed ratio between the two.

The clutch control device determines the change rate of the connection amount according to the value of the clutch transmission torque itself thus detected. In other words, since the changing speed of the connection amount is controlled by the state of the transmission torque that changes every moment when the clutch is engaged / disengaged, the changing speed can be set to a speed as high as possible without causing a shift shock or the like. Is executed. In particular, since the vehicle is traveling at a low speed at the time of starting, the influence of the shift shock on the drivability is great. However, in the present invention, accurate clutch control without the shift shock is executed at this time, and a smooth driving can be achieved. .

  As in the second aspect of the invention, if a map representing the relationship between the speed ratio and the torque transmission amount of the fluid coupling is used for learning the half clutch state, the torque transmission amount corresponding to the speed ratio can be accurately obtained. Thus, it is possible to calculate a change in torque transmission amount according to the amount of connection regardless of individual differences or aging of the clutch. In other words, in the conventional learning method disclosed in Patent Document 1, it is detected that the difference between the reduced rotational speeds has reached a predetermined value and set as a half-clutch starting point, whereas in the present invention, the rotational speed of the pump and the turbine A speed ratio, which is a ratio to the rotational speed of, is detected, and a torque transmission amount itself is calculated from the speed ratio using a map to determine a half clutch start point. As a result, the half-clutch state can be captured more accurately, and the characteristic of torque transmission with respect to the speed ratio is uniquely determined according to the fluid coupling. Can be applied in common. In some cases, the transmission torque at the half-clutch starting point can be easily adjusted according to the vehicle weight, for example.

Since the learning device of the present invention can accurately grasp the amount of engagement 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 of claim 3, when the clutch is disengaged at the time of shifting of the transmission, if the connection amount stored as the learning value is reached, control is performed so as to increase the rate of decrease of the connection amount, thereby enabling quick disconnection. Further, as in the invention of claim 4, when the clutch disconnected at the time of shifting of the transmission is connected, it is possible to make a quick connection by increasing the increasing speed of the connection amount until the stored connection amount is reached. become. On the other hand, when using a learning value obtained by a conventional learning method, a period during which the operation speed is low has to be set longer in order to avoid a shift shock due to inaccuracy of the learning value.

  Hereinafter, a clutch control device for a vehicle power transmission device embodying the present invention will be described with reference to the drawings. The equipment constituting the vehicle power transmission device to which the present invention is applied is a conventional device shown in FIG. It is not exceptionally different. That is, in the vehicle power transmission device, the fluid coupling 2 is fastened to the rear of the diesel engine 1, and the transmission 4 having a parallel shaft gear mechanism is connected via a multi-plate wet clutch 3 that is a clutch that automatically connects and disconnects. Are connected. When the vehicle starts, a smooth start is performed using slippage between the pump 21 of the fluid coupling 2 and the turbine 22, and then the lockup clutch 23 is engaged, and the output shaft of the diesel engine 1 is input to the wet multi-plate clutch 3. It is in a state of being directly connected to the shaft.

The wet multi-plate clutch 3 includes a clutch control device 31, and the clutch control device 31 is connected and disconnected while controlling the amount of connection of the wet multi-plate clutch 3 at the time of shifting of the transmission 4. Similar to the conventional clutch control device, the clutch control device 31 outputs a duty ratio: D, which is a command value for the connection amount, and according to this, the hydraulic pressure acting on the piston that presses the friction plate of the wet multi-plate clutch 3. Is changed, the amount of connection of the wet multi-plate clutch 3 is controlled. The clutch control device 31 includes a rotation speed signal of the pump 21 (engine rotation speed signal from the engine control device 11) and a rotation speed signal of the turbine 22 (rotation speed signal of the clutch input shaft 32 from the rotation speed sensor 51). Is entered.

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. This characteristic is known as a coefficient τ representing a specific input torque, is determined according to each fluid coupling, and increases as the speed ratio decreases, as shown in FIG. The torque transmission amount of the fluid coupling is obtained from the torque coefficient τ by the following equation.
Torque transmission amount = C x τ x (rotation speed of pump 21) ² : C is a constant

The clutch control device 31 of the present invention includes the above map and also includes means for detecting the speed ratio e from the input rotation speed signal of the pump 21 and the rotation speed signal of the turbine 22. Used for clutch control and learning of the half-clutch state.

Here, first, the operation of the clutch control device 31 of the present invention at the time of shifting will be described with reference to the flowchart of FIG. However, this flowchart shows control of the duty ratio in the range of the half-clutch state, and the duty ratio changes abruptly as described later outside this range.
When the vehicle 21 is running while the pump 21 of the fluid coupling 2 and the turbine 22 are separated from each other, when a gear shift command signal is input to the clutch control device 31 from the vehicle control device or the gear shift lever, in step 1 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. In step 2, 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-described equation. Since the torque transmission amount of the fluid coupling 2 is equal to the transmission torque of the wet multi-plate clutch 3, the transmission torque of the wet multi-plate clutch 3 is calculated as a result.

  In step 3, the rate of decrease in the connection amount (increase rate in the duty ratio) is determined according to the calculated transmission torque of the wet multi-plate clutch 3. The change rate of the optimum connection amount with respect to the torque transmission amount is obtained by experiments or the like, and is stored in the memory of the clutch control device 31 as a map as shown in FIG. The clutch control device 31 changes the amount of connection while controlling the duty ratio output to the wet multi-plate clutch 3 so that the determined change speed is obtained (S4).

The optimum value of the change rate of the connection amount of the wet multi-plate clutch 3 varies depending on the amount of the transmission torque, and as shown in FIG. . In the control device of the present invention, for example, 10 msec. Each time the routine of the flowchart is repeated, the speed ratio is detected and the amount of transmission torque is calculated, and the speed of change at that time is determined. As the connection amount decreases, the speed ratio decreases and the torque coefficient τ moves like points A, B, and C in FIG. 2, and the calculated change speed increases. For this reason, the time required for disconnecting the wet multi-plate clutch 3 at the time of shifting is shortened. This control ends when the output duty ratio reaches a predetermined value that is a learned value of the half clutch start point (S5).
Such control of the connection amount is not only performed at the time of disconnection, but also when the wet multi-plate clutch 3 is connected after the gear-in of the transmission is completed, the connection rate increase rate (duty ratio) corresponding to the amount of transmission torque is similarly applied. In this case, the reduction speed is controlled.

Next, the learning procedure of the half-clutch start point and the operation of the vehicle power transmission device at the time of learning in the learning device of the present invention using the map representing the relationship between the speed ratio and the torque transmission amount of the fluid coupling are shown in FIG. This will be described with reference to the flowchart of FIG.
When the time to learn is reached, it is determined in step SX1 whether or not the vehicle is stopped. If the vehicle is stopped, whether or not the braking force is applied to the vehicle in step SX2, that is, step brake Alternatively, it is determined whether the parking brake (center brake) is operated. Further, in step SX3, it is determined whether or not the driver has depressed the accelerator pedal, that is, whether or not the diesel engine 1 is in an idle state. These determinations are made to ensure the safety of the vehicle that is being learned and to prevent an unexpected start. When it is confirmed that the vehicle is stopped and the brake is operated and the engine is in an idle state, the condition for executing the learning is set, 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 (SX4). At the same time, the state of the transmission 4 is detected. When the transmission 4 is neutral, the transmission actuator 61 is operated to mesh any gear of the transmission, for example, the fifth gear, and the transmission 4 is geared in. (SX5). As a result, the output shaft 41 of the transmission 4 is connected to the input shaft 33 integrated with the output shaft of the wet multi-plate clutch 3. 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 rotate independently (SX6).

In this state, the duty ratio output from the clutch control device 31 is decreased by a small amount, for example, by 1% (SX7), 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 32. At this time, the turbine 22 of the fluid coupling has substantially the same rotational speed as the pump 21 and the 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 is kept stationary while the vehicle is stopped. Therefore, when the connection amount of the wet multi-plate clutch 3 is increased, a braking torque equal to the transmission torque at the connection amount is generated in the input shaft 32, that is, the turbine 22 of the fluid coupling, and the rotational speed and speed ratio e of the turbine 22 of the fluid coupling. Will decline.

In step SX8, every time the connection amount of the wet multi-plate clutch 3 is increased, the input rotation speed signal of the pump 21 and the rotation speed signal of the turbine 22 are used in the same manner as in the control of the change rate of the connection amount described above. To detect the speed ratio e. In step SX9, 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-described equation. As a result, the transmission torque of the wet multi-plate clutch 3 is calculated.

In step SX10, it is determined whether or not the calculated torque transmission amount has reached a predetermined value of the torque transmission amount corresponding to the half clutch start 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 (SX11). 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.

FIG. 6 shows a control mode of the amount of engagement of the clutch 3 at the time of shifting while the vehicle is started by the clutch control device 31 of the present invention. The solid line in the figure shows the change in the amount of connection (duty ratio) when the clutch 3 is first disengaged during gear shifting.
When the vehicle is traveling, 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 gear shift command is input to the clutch control device 31 from an electronic control device such as a computer mounted on the vehicle, the clutch control device 31 increases the output duty ratio to 100% and disconnects the clutch 3. At this time, the duty ratio is first increased rapidly to obtain the connection amount at point Q in the figure. The point Q is a connection amount at which the clutch 3 is substantially completely connected, that is, a connection amount at which slip does not occur between the input and output shafts of the clutch 3, and is a connection amount at the end of the half-clutch state.

After the connection amount reaches Q point, the clutch control device 31 determines the increasing rate of the duty ratio to be output according to the flowchart of FIG. 3 and gradually decreases the connection amount. Since the transmission torque is still large at the initial stage of cutting, the increase speed is small, and the speed is increased as the transmission torque becomes small. As a result, the torsion accumulated in the power transmission system is not instantaneously released, and the shift shock accompanying the disconnection of the clutch 3 is avoided.

When the duty ratio output by the clutch control device 31 increases and the connection amount decreases to the R point, that is, the connection amount of the half-clutch start point learned by the learning device of the present invention, the clutch control device 31 returns to the duty cycle again. The rate of increase of the ratio is increased to reach 100%. Since the half-clutch starting point obtained by the learning device of the present invention is an accurate value equal to the transmission torque itself of the clutch 3, even if the connection amount is rapidly decreased immediately after reaching the R point, a shift shock occurs. Absent. On the other hand, in the conventional clutch control device, the reliability of the learning value is not sufficient, and as shown by the two-dot chain line in the figure, the range in which the reduction rate of the connection amount is low is set long so as to reliably avoid the shift shock Thus, the time required for cutting could not be shortened.

The broken line in the figure shows the change in the amount of connection 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 the clutch 3 is rapidly increased up to the R point and gradually increased between the R point and the Q point, thereby preventing a shift shock and the like and achieving a quick connection.

As described above in detail, the present invention provides a vehicle power transmission apparatus including a fluid coupling and a clutch that is automatically connected / disconnected between an engine and a transmission, and a torque transmission amount of the fluid coupling at the time of shifting. Is used to control the amount of clutch engagement, and to accurately detect the half-clutch state. Therefore, the present invention is not limited to the wet multi-plate clutch as in the above-described embodiments, but can be applied to a vehicle power transmission device that includes a dry single-plate clutch and controls the clutch stroke. It is obvious that the present invention can also be applied to a vehicle in which the driver operates the speed change lever to change speed.

It is the schematic of the power transmission device for vehicles to which the control device of the present invention is applied. It is a figure which shows the characteristic of the torque and speed ratio of a fluid coupling. It is a flowchart which shows an action | operation to the clutch control apparatus of this invention. It is a figure which shows the relationship between the torque transmission amount of a clutch, and a connection amount change speed. It is a flowchart which shows the action | operation of the half-clutch learning apparatus of this invention. It is a figure which shows the control aspect of the clutch connection amount by this invention. It is a figure which shows the determination method of the conventional half clutch learning value.

Explanation of symbols

1 Diesel engine 2 Fluid coupling (fluid coupling)
21 Pump 22 Turbine 3 clutch (wet multi-plate clutch)
31 Clutch control device 4 Transmission

Claims (4)

A clutch control device (31) of a vehicle power transmission device in which a fluid coupling (2) and a clutch (3) are arranged between an engine (1) and a transmission (4), wherein the fluid coupling (2) A pump (21) is connected to rotate integrally with an output shaft of the engine (1), and a turbine (22) of the fluid coupling (2) is connected to rotate integrally with an input shaft of the clutch (3). The output shaft of the clutch (3) is connected to the input shaft of the transmission (4);
In the clutch control device (31) for controlling the amount of connection of the clutch (3) and performing connection / disconnection at the time of shifting,
The clutch control device (31) includes a detecting means for detecting a speed ratio which is a ratio between the rotational speed of the pump (21) and the rotational speed of the turbine (22) in the fluid coupling (2), the speed ratio and the A torque transmission amount calculating means having a map representing a relationship with the torque transmission amount of the fluid coupling,
When shifting is performed with the pump (21) and the turbine (22) disconnected, and when the clutch (3) is in a half-clutch state, it is obtained by the detection means and the calculation means. A clutch control device that increases the change rate of the connection amount of the clutch (3) as the torque transmission amount decreases. The clutch control device (31) has a learning device for learning the connection amount in the half-clutch state, and controls the connection amount of the clutch (3) using the learned connection amount;
The learning device is configured to detect the speed ratio by the detecting means while gradually increasing the amount of connection after the clutch (3) is disconnected while the vehicle is stopped and the output shaft of the clutch (3) is stationary. And calculating the torque transmission amount by the calculation means based on the detected speed ratio,
The clutch control device for a vehicle power transmission device according to claim 1, configured to store a connection amount when the calculated torque transmission amount reaches a predetermined value as a connection amount in a half-clutch state. When the clutch (3) is disengaged at the time of shifting of the transmission (4), the clutch control device (31) sets 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. The clutch control device for a vehicle power transmission device according to claim 2, wherein the clutch control device reduces the connection amount and increases the decrease rate of the connection amount when the stored connection amount is reached. When the clutch (3) disconnected at the time of shifting of the transmission (4) is connected, the clutch control device (31) increases the increasing rate of the connection amount until it reaches the connection amount stored by the learning device. 4. The clutch control device for a vehicle power transmission device according to claim 2, wherein when the stored connection amount is reached, the increase rate of the connection amount is decreased.

Images