WO2017122682A1

WO2017122682A1 - Control device for vehicle dual clutch transmission

Info

Publication number: WO2017122682A1
Application number: PCT/JP2017/000636
Authority: WO
Inventors: 俊郎平賀; 将之田中; 秀人万田
Original assignee: アイシン・エーアイ株式会社
Priority date: 2016-01-13
Filing date: 2017-01-11
Publication date: 2017-07-20
Also published as: JPWO2017122682A1; DE112017000355T5; CN107208788A

Abstract

This control device (7) for a vehicle dual clutch transmission (1) has a first input shaft (31), a second input shaft (32), an output shaft (4), a first clutch (21), a second clutch (22), a first speed change mechanism (5), and a second speed change mechanism (6), the control device (7) having: a parallel engagement control unit (71) that maintains the first clutch in an engaged state and switches the second clutch from a disengaged state to a half-engaged state for transmitting a predetermined clutch torque while slipping, when a shift-down speed change is performed to the next shift stage for switching from a first clutch engaged state to a second clutch engaged state while the first speed change mechanism has selected the current shift stage and the second speed change mechanism has selected the next shift stage at which the speed is lower than that at the current shift stage; and a clutch switch control unit (72) that switches the first clutch from the engaged state to the disengaged state after the second clutch has been switched to the half-engaged state. Accordingly, fuel consumption can be enhanced and the comfort of making driving inputs can be maintained.

Description

Control device for dual clutch type transmission for vehicle

The present invention relates to a control device for a dual clutch type transmission for a vehicle provided with two clutches capable of switching between an engagement state and a disengagement state independently.

One type of transmission mounted on a vehicle includes two clutches, two input shafts connected to and disconnected from the engine by each clutch, and a transmission mechanism provided between each input shaft and output shaft. There is a dual clutch transmission. The dual clutch type transmission has an advantage that the speed change operation can be performed promptly without interruption of the torque by performing the torque changeover operation with two clutches. For each clutch, for example, a friction clutch can be used in which a plate having a friction material is driven by a clutch actuator. The transmission mechanism is generally configured with about 4 to 7 shift stages, and any shift stage can be selected by a known synchronization device. Patent Document 1 discloses one technical example of this type of dual clutch transmission.

The shift control device for a dual clutch type transmission for a vehicle according to Patent Document 1 includes means for determining whether the transmission is in a pre-shift state and one of transmitting torque when it is determined that it is in a pre-shift state. Means for making the friction clutch in the state of micro-slip and making the other friction clutch capable of transmitting a small amount of torque. According to this, when carrying out a shift, it is said that the other friction clutch can be promptly shifted to the slip state required at the time of clutch switching.

JP 2007-239909 A

By the way, when fuel cut control of the engine is performed to improve fuel consumption, the engine is reversely driven from the drive wheels via the transmission mechanism and the clutch. When a shift down shift request is generated in such a coasting (inertial running) state, problems may occur if the clutch switching control during engine driving of the related art is performed.

For example, due to a control error at the time of clutch replacement, the clutch torque may be too small relative to the friction torque of the engine. In this case, the engine speed is reduced to the fuel cut return speed or less, fuel supply is resumed, and fuel consumption may be reduced. On the contrary, when the clutch torque becomes excessive with respect to the friction torque of the engine, the engine rotational speed steeply synchronizes with the transmission input rotational speed during the downshift. As a result, since the engine brake acts suddenly, the driver feels a pull-in feeling which is a sudden deceleration feeling of the vehicle, and the comfortable feeling of the driving operation is lost.

The present invention has been made in view of the above-mentioned problems of the background art, and it is possible to provide a control device of a dual clutch type transmission for a vehicle, which can achieve good fuel consumption and can maintain the comfort of driving operation. It is an issue to be solved.

A control device for a dual clutch type transmission for a vehicle according to the present invention comprises a first input shaft, a second input shaft, an output shaft, and a torque that can be transmitted between an engine crankshaft and the first input shaft. A first clutch that adjusts a first clutch torque that is a maximum value, and a second clutch that adjusts a second clutch torque that is a maximum value of torque that can be transmitted between the crankshaft and the second input shaft; A first transmission mechanism for selecting one gear position among a plurality of gear positions between the first input shaft and the output shaft; and a plurality of gear positions between the second input shaft and the output shaft Control device for a dual clutch type transmission for a vehicle having a second transmission mechanism for selecting one gear position from among the above, wherein the first transmission mechanism selects the current gear position, and the second transmission gear. Select the next gear in which the mechanism is at a lower speed than the current gear When performing a downshift from the joint state in which the first clutch is transmitting torque without slippage to the next gear stage in which the second clutch shifts to the joint state A parallel joint control unit for shifting to a half joint state in which a predetermined clutch torque is transmitted while sliding the second clutch from the disconnected state while maintaining the first clutch in the coupled state; And a clutch shift control unit configured to shift the first clutch from the connection state to the disconnection state after shifting to the connection state.

Furthermore, when performing the downshift to the next gear while the engine is performing fuel cut, the control device preferably executes the parallel joint control unit and the clutch shift control unit. .

According to the control device of the dual clutch type transmission for a vehicle of the present invention, the second clutch is shifted to the half engagement state while maintaining the first clutch in the engagement state at the early stage of the downshift. As a result, it is possible to maintain a state in which the torque that can be transmitted by the two clutches is large with respect to the friction torque of the engine, so the engine rotational speed hardly decreases, and it is hardly necessary to consume fuel and maintain the rotational speed. . Therefore, the fuel consumption can be improved. Further, after the second clutch shifts to the half joint state in the later stage of the rotation synchronization control of the downshift, the first clutch shifts from the joint state to the disconnection state. According to this, the torque for driving the engine from the drive wheel side does not become excessive. Therefore, there is no possibility that the number of revolutions of the engine is drawn in and the engine brake acts excessively, and the comfort of the driving operation can be maintained.

Furthermore, in the mode in which the parallel joint control unit and the clutch shift control unit are executed in the fuel cut state of the engine, the engine speed is hardly reduced during the downshift, so the fuel cut state can be maintained. Therefore, the effect of improving the fuel consumption becomes remarkable.

It is a skeleton diagram showing an example of composition of a dual clutch type transmission for vehicles which a control device of an embodiment controls. It is a figure of the time chart which illustrates control operation of a control device of a dual clutch type transmission of an embodiment typically. FIG. 10 is a diagram of a time chart when the engine speed has sharply decreased in the downshift according to the prior art. FIG. 8 is a diagram of a time chart when the engine rotation speed is drawn in and the driving operation is not comfortable in the downshift according to the prior art.

A control device 7 of a dual clutch type transmission 1 for a vehicle according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is a skeleton diagram showing a configuration example of a dual clutch type transmission 1 for a vehicle controlled by the control device 7 of the embodiment. The dual clutch type transmission 1 for vehicle selects one of the fifth forward gear and the first reverse gear and transmits the output torque of the engine 91 to the differential gear 93. The dual clutch type transmission 1 for a vehicle includes a first input shaft 31, a second input shaft 32, an output shaft 4, a first clutch 21, a second clutch 22, a first transmission mechanism 5, a second transmission mechanism 6, and the like. It is configured.

The first clutch 21 and the second clutch 22 are portions that rotatably connect the first input shaft 31 and the second input shaft 32 to the crankshaft of the engine 91 so as to be able to connect and disconnect. The first clutch 21 and the second clutch 22 can be, for example, friction clutches driven by the first clutch actuator 23 and the second clutch actuator 24, respectively. Moreover, a servomotor, a hydraulic drive mechanism, etc. can be illustrated as

clutch actuators

23 and 24, for example.

In the first clutch 21 and the second clutch 22, the first and

second clutch actuators

23 and 24 operate according to a command from the control device 7 to adjust the friction joint force. Thus, the first clutch torque T1 and the second clutch torque T2, which are the maximum values of the torque that can be transmitted by the first clutch 21 and the second clutch 22, are adjusted independently. The first clutch 21 and the second clutch 22 are in a disconnected state in which torque is not transmitted between input and output, in a semi-connected state in which torque is transmitted while sliding between input and output, and in an engaged state Transition the state.

The first input shaft 31 is rotatably connected to the crankshaft of the engine 91 by the first clutch 21 so as to be able to be connected and disconnected. The first input shaft 31 is rod-shaped. The second input shaft 32 is rotatably connected to the crankshaft of the engine 91 by the second clutch 22 so as to be able to connect and disconnect. The second input shaft 32 has a tubular shape and is disposed coaxially outside of the first input shaft 31. The right end of the first input shaft 31 in the drawing is connected to the output side member of the first clutch 21. The left end of the first input shaft 31 in the figure protrudes through the second input shaft 32 and is supported by a ball bearing 36. The right end of the second input shaft 32 in the drawing is connected to the output side member of the second clutch 22. A central portion in the longitudinal direction of the second input shaft 32 is supported by a ball bearing 37.

The output shaft 4 is disposed parallel to the lower side of the first input shaft 31 and the second input shaft 32 in the drawing. Both ends of the output shaft 4 are supported by

tapered roller bearings

46 and 47. An output gear 48 is fixed near one of the tapered roller bearings 46 of the output shaft 4. The output gear 48 meshes with the differential gear 93. Therefore, the output shaft 4 transmits and outputs torque to the drive wheel via the differential device 93.

The first transmission mechanism 5 is provided between the first input shaft 31 and the output shaft 4. The first transmission mechanism 5 has three

gear sets

51, 53, 55 that constitute odd-numbered shift speeds of first, third and fifth speeds. More specifically, the first speed drive gear 51A is fixedly provided in order from the left side of the first input shaft 31 in the drawing, the third speed drive gear 53A is provided so as to allow free rotation, and the fifth speed drive gear 55A is free. It is provided in a rollable manner. On the other hand, a first speed driven gear 51P is provided rotatably at a location opposite to the output shaft 4, a third speed driven gear 53P is fixed, and a fifth speed driven gear 55P is fixed.

The first speed drive gear 51A and the first speed driven gear 51P are always meshed with each other to form a first speed gear set 51 that constitutes a first speed. When the first-speed driven gear 51P is rotationally connected to the output shaft 4 by the sleeve S1 of the first-speed synchromesh mechanism 81 (synchronization device), the first-speed gear set 51 is meshed and coupled to transmit torque It becomes possible. Similarly, the third speed drive gear 53A and the third speed driven gear 53P are always meshed to form a third speed gear set 53 that constitutes a third speed stage. When the third speed drive gear 53A is rotationally connected to the first input shaft 31 by the sleeve S35 of the third to fifth synchromesh mechanism 82, the third speed gear set 53 is meshed and coupled to transmit torque. It becomes possible.

Further, the fifth speed drive gear 55A and the fifth speed driven gear 55P are constantly meshed to form a fifth speed gear set 55 that constitutes the fifth speed. When the fifth speed drive gear 55A is rotationally connected to the first input shaft 31 by the sleeve S35, the fifth speed gear set 55 is meshed and coupled to enable transmission of torque. Only one of the first speed gear set 51, the third speed gear set 53, and the fifth speed gear set 55 is selectively meshed and coupled by an interlock mechanism (not shown).

The second transmission mechanism 6 is provided between the second input shaft 32 and the output shaft 4. The second transmission mechanism 6 has two gear sets 62 and 64 that constitute the second and fourth even gear stages. More specifically, the fourth speed drive gear 64A and the second speed drive gear 62A are fixed in order from the left side of the second input shaft 32 in the drawing. On the other hand, the fourth speed driven gear 64P and the second speed driven gear 62P are provided at the opposing positions of the output shaft 4 so as to allow free rotation.

The fourth speed drive gear 64A and the fourth speed driven gear 64P are constantly meshed to form a fourth speed gear set 64 which constitutes a fourth speed. When the fourth-speed driven gear 64P is rotationally connected to the output shaft 4 by the sleeve S24 of the second-fourth synchromesh mechanism 83, the fourth-speed gear set 64 is meshed and capable of transmitting torque Become. Similarly, the second speed drive gear 62A and the second speed driven gear 62P are always meshed to form a second speed gear set 62 that constitutes a second speed stage. When the second-speed driven gear 62P is rotationally connected to the output shaft 4 by the sleeve S24, the second-speed gear set 62 is meshed and can transmit torque. Only one of the fourth speed gear set 64 and the second speed gear set 62 is selectively meshed and coupled.

The "first" and "second" attached to the first clutch 21, the second clutch 22, the first input shaft 31, the second input shaft 32, the first transmission mechanism 5, and the second transmission mechanism 6 It is a convenient article that distinguishes two torque transmission paths. Therefore, "first" and "second" may be interchanged. That is, the first transmission mechanism 5 may constitute an even gear stage, and the second transmission mechanism 6 may constitute an odd gear stage. Further, although not shown in FIG. 1, the configuration of a conventional gear set can be appropriately used for the reverse gear.

The control device 7 is a part that controls the first clutch 21, the second clutch 22, the first transmission mechanism 5, and the second transmission mechanism 6. That is, the control device 7 acquires various information such as the operating state of the engine 91 and the vehicle speed, and determines the presence or absence of requests for upshift, downshift, and preshift shift using known shift diagrams. The controller 7 controls the first clutch actuator 23 and the second clutch actuator 24 in association with the three synchromesh mechanisms (81, 82, 83) when an operation based on the determination result is required. The control device 7 can be configured using an electronic control unit (ECU) which has a CPU and operates with software. The control device 7 can also be configured such that a plurality of electronic control units (ECUs) cooperate with each other to perform cooperative control.

The control device 7 of the embodiment performs the downshifting from the current gear position to the next gear position on the low speed side while the engine 91 is performing fuel cut. At this time, the control device 7 executes the parallel joint control unit 71 and the clutch shift control unit 72. Further, the clutch shift control unit 72 includes a rotational speed deviation torque difference storage unit 76 and a constant torque control unit 77. The parallel joint control unit 71, the clutch shift control unit 72, the rotational speed deviation torque difference storage unit 76, and the constant torque control unit 77 are realized by software. These detailed functions and operations will be described later.

Next, the control operation of the control device 7 will be described. FIG. 2 is a time chart diagram schematically illustrating the control operation of the control device 7 of the dual clutch transmission 1 for a vehicle according to the embodiment. The waveforms shown in FIG. 2 are, from top to bottom, the acceleration a of the vehicle, the first clutch torque T1 (shown by a solid line) of the first clutch 21 and the second clutch torque T2 (shown by a broken line) of the second clutch, Crankshaft torque TE 91 (corresponding to friction torque of engine and represented by a negative value), first rotation number N1 of first input shaft 31 (shown by solid line) and second rotation number N2 of second input shaft (broken line) And the engine rotational speed NE of the engine 91 (indicated by an alternate long and short dash line).

Before time t1 in FIG. 2, the engine speed NE matches the first speed N1 and is larger than the fuel cut return speed Nf. The fuel cut return rotational speed Nf is a threshold value for determining to restart the fuel supply when the engine speed NE is lowered. Therefore, the engine 91 is controlled to the fuel cut state. The vehicle is coasting at the current gear. At this time, the current transmission gear position is selected in the first transmission mechanism 5, and the first clutch 21 is in the connected state. On the other hand, in the second transmission mechanism 6, the next gear position lower than the current gear position is selected by the pre-rail shift operation, and the second clutch 22 is in the disconnected state. The acceleration a is a negative value, and the vehicle is decelerated gradually. The first rotation speed N1 and the second rotation speed N2 also gradually decrease in proportion to the vehicle speed. Since a downshift request has occurred at time t1, the controller 7 performs downshift from the current gear position to the next gear position.

When a downshift request is generated, the parallel connection control unit 71 of the control device 7 slides the second clutch 22 from the disconnected state while maintaining the first clutch 21 in the connected state, while the predetermined clutch torque T2 d is It shifts to the half joint state to transmit. Specifically, the parallel engagement control unit 71 slightly reduces the first clutch torque T11 to a first clutch torque T12 while maintaining the first clutch 21 in the engaged state at time t2, and performs the torque changing operation. Prepare. Parallel joint control unit 71 maintains first clutch torque T12 until time t4 thereafter. Further, the parallel engagement control unit 71 causes the second clutch 22 to be disengaged from the disengaging state at time t3 to gradually increase the second clutch torque T23, and a partial engagement state of the predetermined clutch torque T2d by time t4. Migrate to

Here, the predetermined clutch torque T2d shown in FIG. 2 is preset within a range in which the engine speed NE does not deviate from the first speed N1. Specifically, the predetermined clutch torque T2d is set to less than the first clutch torque T12 at which the first clutch 21 maintains the engaged state. The predetermined clutch torque T2d is set to exceed the absolute value of the crankshaft torque TE in the fuel cut state. The predetermined clutch torque T2d is preferably set based on the value of a torque characteristic map preset for each model of the engine 91, taking into consideration individual differences in friction torque and the like. By gradually increasing the second clutch torque T23 of the second clutch 22 to a predetermined clutch torque T2d while maintaining the first clutch torque T12 in the connection state of the first clutch, the engine rotational speed NE is set to the first rotational speed Maintaining N1 can prevent a significant drop.

From time t4, the clutch shift control unit 72 operates to perform rotation synchronization control. The clutch shift control unit 72 disconnects the first clutch 21 to shift to the disconnected state while maintaining the predetermined clutch torque T2 d in the half engagement state of the second clutch 22, and finally, the engine rotational speed NE is Synchronize with 2 revolutions N2. More specifically, the rotational speed deviation torque difference storage unit 76 of the clutch transfer control unit 72 performs the disconnection operation of the first clutch 21 while maintaining the predetermined clutch torque T2d of the second clutch 22 after time t4. Then, the rotational speed deviation torque difference storage unit 76 detects the rotational speed deviation timing at which the engine rotational speed NE starts to separate from the first rotational speed N1.

Specifically, the rotational speed deviation torque difference storage unit 76 compares the engine rotational speed NE with the first rotational speed N1 to calculate the difference for each predetermined control cycle after time t4. When the difference becomes equal to or greater than the predetermined value, the rotational speed deviation torque difference storage unit 76 determines that the rotational speed deviation timing at which the engine rotational speed NE starts to separate from the first rotational speed N1. In the example of FIG. 2, time t5 is the rotational speed deviation timing, and a small first clutch torque T15 remains.

The rotation speed deviation torque difference storage unit 76 stores the clutch torque difference at the time when the rotation speed deviation timing is detected as the rotation speed deviation torque difference Teff. The clutch torque difference means a value obtained by subtracting the first clutch torque from the second clutch torque. Therefore, the rotational speed deviation torque difference Teff is a value obtained by subtracting the first clutch torque T15 from the predetermined clutch torque T2d at time t5.

The constant torque control unit 77 operates from time t5. The constant torque control unit 77 sets a target clutch torque difference based on the rotational speed deviation torque difference Teff. In the present embodiment, the constant torque control unit 77 sets the rotational speed deviation torque difference Teff as the target clutch torque difference. The constant torque control unit 77 adjusts the second clutch torque T25 while disconnecting the first clutch 21 so that the clutch torque difference becomes equal to the target clutch torque difference after time t5. Thus, when the first clutch torque T15 is decreasing, the clutch torque difference is maintained at the rotational speed deviation torque difference Teff. In the example of FIG. 2, after time t5, the second clutch torque T25 and the first clutch torque T15 gradually decrease with the same inclination. When the first clutch torque T15 disappears at time t6, the constant torque control unit 77 keeps the second clutch torque T26 constant.

Here, the second clutch torque T2 is a torque that attempts to increase the engine speed NE and synchronize with the second speed N2. On the other hand, the first clutch torque T1 is a torque for maintaining the engine speed NE at the first speed N1. That is, in the second clutch torque T2 and the first clutch torque T1, the rotational directions acting on the crankshaft are reversed. For this reason, by maintaining the clutch torque difference at the constant rotational speed deviation torque difference Teff, the balance between the clutch torque difference and the crankshaft torque TE is maintained. Therefore, engine speed NE is kept constant after time t5.

After time t5, the engine speed NE leaves the first speed N1 and approaches the second speed N2. This makes it possible to reliably prevent a sharp increase or decrease in the engine speed NE. At time t8, the engine speed NE synchronizes with the second speed N2. Then, the constant torque control unit 77 increases the second clutch torque T26 to the maximum second clutch torque T28, and ends the downshift.

The constant torque control unit 77 may use another method of adding the rotational speed deviation torque difference Teff and a positive value or negative value offset torque determined according to the next gear to be a target clutch torque difference. You can also. The aim is to reduce the driver's discomfort due to the rapid increase in engine braking at the low speed, in consideration of the fact that the engine braking is more effective at the low speed. On the contrary, there is also an aim of setting the target clutch torque difference to be large and completing the downshifting at an early stage when the engine braking effect is low and the driver's discomfort is small at high speed.

In order to realize the above aim, for example, the constant torque control unit 77 can use offset torque with a negative value when the next shift speed is a low speed (such as the first speed) that is lower than a predetermined speed. When a negative offset torque is used, from time t5 in FIG. 2, the engine speed NE is synchronized with the second speed N2 while decreasing at a constant negative slope. Also, for example, when the next shift speed is a high speed gear exceeding a predetermined speed (such as one low speed side of the highest speed speed), the constant torque control unit 77 can use the offset torque of a positive value. When a positive offset torque is used, from time t5 in FIG. 2, the engine speed NE is synchronized with the second speed N2 while increasing with a positive constant gradient.

However, the driver's sense of incongruity is determined by evaluating the shift feeling in the entire vehicle while considering the gear ratio of each shift speed. Therefore, setting of offset torque other than that described above is also conceivable. For example, depending on the combination of vehicle type and gear position, the offset torque may be zero or a negative value, and may not be a positive value.

Next, a control device for down-shifting according to the prior art will be described. FIG. 3 is a diagram of a time chart when the engine speed NE sharply decreases in the downshifting according to the prior art. Further, FIG. 4 is a diagram of a time chart when the engine speed NE is drawn in and the comfort of the driving operation is impaired in the downshift in the prior art.

In the prior art, as shown by the thin broken line in FIG. 3, the first clutch torque T1 and the second clutch torque T2 are multiplied from time t31 while keeping the total sum constant. However, there may be cases where there is a control error between the first clutch torque T1 and the second clutch torque T2, and the actual sum becomes smaller as shown by the thick solid line and the thick broken line. In this case, the engine speed NE may sharply decrease from the first speed N1 after time t31, and may decrease to the fuel cut return speed Nf or less at time t32. Then, the fuel supply is resumed, the engine 91 is started, and the fuel consumption is reduced.

In addition, after time t35 after torque replacement, as indicated by a thick broken line in FIG. 4, the second clutch torque T2 may be excessively controlled. In this case, the engine rotational speed NE sharply increases from the first rotational speed N1 after time t35 and approaches the second rotational speed N2. Then, the engine brake acts excessively to impair the driving comfort.

As compared with the above-described prior art, in the present embodiment, while maintaining the first clutch torque T12 in the connection state of the first clutch 21, the second clutch 22 is in the half connection state to generate the predetermined clutch torque T2d. . Therefore, the total torque does not run short, and the reduction of the engine speed NE can be reliably prevented. Further, in the present embodiment, the engine rotational speed NE is synchronized with the second rotational speed N2 in a state in which the clutch torque difference is maintained at the constant rotational speed deviation torque difference Teff. Therefore, a sharp increase in engine speed NE can be reliably prevented.

The control device 7 of the dual clutch type transmission 1 for a vehicle according to the embodiment includes the first input shaft 31, the second input shaft 32, the output shaft 4, and between the crankshaft of the engine 91 and the first input shaft 31. The first clutch 21 that adjusts the first clutch torque T1, which is the maximum value of torque that can be transmitted by the second clutch, and the second clutch torque T2, which is the maximum value of torque that can be transmitted between the crankshaft and the second input shaft 32 , The first transmission mechanism 5 for selecting one shift speed among the plurality of shift speeds between the first input shaft 31 and the output shaft 4, the second input shaft 32 and the output A control device 7 of a dual clutch type transmission 1 for a vehicle having a second transmission mechanism 6 for selecting one shift speed from among a plurality of shift speeds with a shaft 4, the first transmission mechanism 5 Selects the current gear position, and the second transmission mechanism 6 Shifting down to the next gear position where the second clutch 22 shifts to the joint state from the joint state where the first clutch 21 that is the low speed step is selected and torque transmission is performed without slippage of the first clutch 21 When shifting is performed, the parallel joint control unit 71 shifts to a half joint state in which the predetermined clutch torque T2d is transmitted while sliding the second clutch 22 from the disconnected state while maintaining the first clutch 21 in the connected state. And a clutch shift control unit 72 configured to shift the first clutch 21 from the joint state to the disengaged state after the second clutch 22 shifts to the half joint state.

According to this, in the first half of the downshift, the second clutch 22 is shifted to the half joint state while the first clutch 21 is maintained in the joint state. As a result, it is possible to maintain a state in which the torque that can be transmitted by the two clutches is large relative to the friction torque of the engine, so the rotational speed of the engine 91 hardly decreases, and it is almost necessary to consume fuel and maintain the rotational speed. Absent. Therefore, the fuel consumption can be improved. Further, after the second clutch 22 shifts to the half joint state in the latter stage of the rotation synchronization control of the downshift, the first clutch 21 shifts from the joint state to the disconnection state. According to this, the torque for driving the engine 91 from the drive wheel side does not become excessive. Therefore, there is no possibility that the engine speed NE will be pulled in and the engine brake will act excessively, and the comfort of the driving operation can be maintained.

Furthermore, when the downshifting to the next gear position is performed while the engine 91 is performing fuel cut, the control device 7 executes the parallel joint control unit 71 and the clutch shift control unit 72.

According to this, since the engine speed NE hardly decreases in the middle of the downshift, the fuel cut state can be maintained. Therefore, the effect of improving the fuel consumption becomes remarkable.

Further, the predetermined clutch torque T2d is preset in a range in which the rotational speed of the crankshaft (engine rotational speed NE) does not deviate from the rotational speed of the first input shaft 31 (first rotational speed N1). According to this, while maintaining the first clutch torque T12 in the connection state of the first clutch 21, the second clutch 22 generates the predetermined clutch torque T2d, and the engine rotational speed NE is set to the first input shaft 31 One rotation speed N1 can be maintained. Therefore, the reduction of the engine speed NE can be reliably prevented, and the effect of maintaining the fuel efficiency favorably becomes remarkable.

Further, the predetermined clutch torque T2d is set to be less than the first clutch torque T12 at which the first clutch 21 maintains the engaged state and to exceed the absolute value of the crankshaft torque TE. According to this, in the first half of the downshift, it is ensured that the engine speed NE does not deviate from the first speed N1.

Furthermore, while the clutch transfer control unit 72 maintains the second clutch 22 in the partially engaged state while disconnecting the first clutch 21, the rotational speed of the crankshaft (the engine speed NE) is the first input shaft 31. A clutch torque difference which is a difference between the first clutch torque T1 and the second clutch torque T2 by detecting a rotational speed deviation timing (time t5) starting to separate from the rotational speed of the clutch The target clutch torque difference is set based on the rotational speed deviation torque difference storage unit 76 that stores the torque difference as the rotational speed deviation torque difference Teff, and the clutch torque difference matches the target clutch torque difference. And a constant torque control unit 77 that adjusts the second clutch torque T2 while the first clutch 21 is disconnected.

According to this, since the clutch torque difference is controlled to coincide with the target clutch torque difference after the rotation speed deviation timing, the change of the engine rotation speed NE can be suppressed. Therefore, there is no possibility that the engine brake acts excessively, and the comfort of the driving operation can be maintained.

Further, the constant torque control unit 77 sets the rotational speed deviation torque difference Teff as the target clutch torque difference. According to this, it is possible to keep the engine rotational speed NE constant by keeping the clutch torque difference acting on the crankshaft constant and balancing it with the crankshaft torque TE. Therefore, engine braking does not occur, and the comfort of the driving operation can be reliably maintained.

Further, the constant torque control unit 77 may add the rotational speed deviation torque difference Teff and the positive or negative offset torque determined according to the next gear to obtain the target clutch torque difference. According to this, it is possible to perform control suitable for each of the plurality of shift speeds that are different in the degree of effectiveness of the engine brake.

The present invention can also be applied when the fuel cut control of the engine 91 is not performed. The present invention is capable of various other applications and modifications.

1: Dual clutch type transmission for vehicle 21: First clutch 22: Second clutch 31: First input shaft 32: Second input shaft 4: Output shaft 5: First transmission mechanism 6: Second transmission mechanism 7: Control Device 71: parallel joint control unit: 72: clutch shift control unit 76: rotational speed deviation torque difference storage unit 77: constant torque control unit 91: engine

Claims

A first clutch that adjusts a first clutch torque which is a maximum value of torque that can be transmitted between a first input shaft, a second input shaft, an output shaft, and a crankshaft of the engine and the first input shaft; A second clutch that adjusts a second clutch torque that is a maximum value of torque that can be transmitted between the crankshaft and the second input shaft; and a plurality of the clutches between the first input shaft and the output shaft A first transmission mechanism for selecting one gear position among gear positions, and a second transmission mechanism for selecting one gear position among a plurality of gear positions between the second input shaft and the output shaft; A control device for a dual clutch type transmission for a vehicle,
The first transmission mechanism selects the current gear position, and the second transmission mechanism selects the next gear position that is a lower speed than the current gear position, and the torque transmission is performed without the first clutch slipping When performing the downshifting to the next gear stage in which the second clutch shifts to the engaged state from the engaged state,
A parallel joint control unit configured to shift to a half joint state in which a predetermined clutch torque is transmitted while sliding the second clutch from a disconnected state while maintaining the first clutch in the connected state;
A clutch shift control unit that shifts the first clutch from the joint state to the disengaged state after the second clutch shifts to the partially engaged state;
Control device for a dual clutch type transmission for a vehicle having:
2. The vehicle dual system according to claim 1, wherein the parallel joint control unit and the clutch shift control unit are executed when the downshifting to the next gear is performed with the engine performing fuel cut. Control device for clutch type transmission.
The control device of a dual clutch type transmission for a vehicle according to claim 1 or 2, wherein the predetermined clutch torque is preset within a range in which the rotational speed of the crankshaft does not deviate from the rotational speed of the first input shaft.
The predetermined clutch torque is set to be less than a first clutch torque at which the first clutch maintains the engagement state and to exceed an absolute value of torque of the crankshaft. The control device for a dual clutch type transmission for a vehicle according to one aspect.
The clutch shift control unit
While the second clutch is maintained in the semi-connected state, disconnection of the first clutch is detected, and a rotational speed deviation timing at which the rotational speed of the crankshaft starts to separate from the rotational speed of the first input shaft is detected. A clutch torque difference which is a value obtained by subtracting the first clutch torque from the second clutch torque, and stores the clutch torque difference at the time of detecting the rotation number deviation timing as the rotation number deviation torque difference. A difference storage unit,
A constant torque that sets a target clutch torque difference based on the rotational speed difference torque difference, and adjusts the second clutch torque while disconnecting the first clutch such that the clutch torque difference matches the target clutch torque difference. A control unit,
The control device for a dual clutch type transmission for a vehicle according to any one of claims 1 to 4, including
The control device for a dual clutch type transmission for a vehicle according to claim 5, wherein the constant torque control unit sets the rotational speed deviation torque difference as the target clutch torque difference.
6. The target clutch torque difference according to claim 5, wherein the constant torque control unit adds the rotational speed deviation torque difference and an offset torque of a positive value or a negative value determined according to the next gear to obtain the target clutch torque difference. Control device of dual clutch type transmission for vehicles.