WO2017141937A1

WO2017141937A1 - Control device for dual-clutch transmission

Info

Publication number: WO2017141937A1
Application number: PCT/JP2017/005419
Authority: WO
Inventors: 智啓下沢
Original assignee: いすゞ自動車株式会社
Priority date: 2016-02-18
Filing date: 2017-02-15
Publication date: 2017-08-24
Also published as: CN108700187A; PH12018501714A1; JP2017145922A

Abstract

The invention is provided with: a clutch control unit 83 that, when a downshift instruction is detected by a transmission control device 80 and in the event that an accelerator is off, the gear position on a gear shift destination clutch side is lower than on a gear shift source clutch side, and the clutch that engages with an engine 10 can be switched from the gear shift source clutch to the gear shift destination clutch, controls the engagement force of both clutches such that the engine rotational speed is equal to or less than the rotational speed of a gear shift source input shaft, and performs control such that the gear shift source clutch is changed to a disengaged state and the gear shift destination clutch is changed to a half-clutch state; and a synchronization control unit 84 that, when the rotational speed of a gear shift source input shaft is equal to or less than a maximum allowable rotational speed, increases the engine rotational speed so as to match the rotational speed of a gear shift destination input shaft. After the engine rotational speed and the rotational speed of the gear shift destination input shaft are made to match, the clutch control unit 83 configures the gear shift destination clutch to be controlled in a connected state.

Description

Control device for dual clutch transmission

The present disclosure relates to a control device for a dual clutch transmission in which a clutch device including two clutches is provided between an engine and a transmission mechanism.

2. Description of the Related Art Conventionally, there is known a dual clutch transmission that includes two clutches capable of connecting / disconnecting power transmission from an engine and is capable of switching a driving force transmission path from the engine to a transmission mechanism to a system via any one of the clutches. .

In a dual clutch transmission, for example, a driver manually operates an operation lever to designate a gear position and a shift up / shift down, thereby operating an actuator according to the designation, switching a clutch, A device that controls engagement / disengagement of gears in a transmission mechanism is known.

As a technique related to downshifting in a dual clutch transmission, a technique is known in which the shift speed is changed quickly by pre-shifting to a shift speed that reflects the intention of the driver to switch the shift speed (for example, Patent Documents). 1).

Japanese Unexamined Patent Publication No. 2010-38229

For example, in a dual clutch transmission in which the driver can specify a shift, if the shift is immediately executed in response to the driver's shift specification, the engine may be damaged. For example, if the driver has designated downshifting and immediately tries to shift to a low gear, the engine speed may exceed the allowable upper engine speed (allowable upper engine speed). .

Therefore, in a dual clutch transmission, if the driver gives an instruction to shift down, the engine shifts after waiting until the engine speed falls within the allowable upper limit speed even if the shift down is executed. Had to run.

In this way, even if the downshift is executed, if the engine speed is kept within the allowable upper limit number of revolutions and then the speed change is executed, the driver shifts in order to obtain a strong engine brake deceleration. Even if down is designated, a state in which the downshift is not actually performed occurs, and a deceleration desired by the driver cannot be obtained.

Therefore, an object of the present disclosure is to provide a technique capable of obtaining appropriate deceleration at an early stage when the driver designates downshifting.

In order to achieve the above-described object, a control device for a dual clutch transmission according to an aspect of the present disclosure includes a clutch device including two clutches between an engine and a transmission mechanism, and the output of the transmission mechanism from the engine. A control system for a dual clutch transmission capable of switching a driving force transmission path to a vehicle drive system connected to a shaft between paths via respective clutches, and whether or not there has been a downshift instruction from the driver A shift down instruction detecting means for detecting the engine and when the downshift instruction is detected, the accelerator is in an off state and is connected to a transmission source clutch that is a clutch engaging the engine and the transmission mechanism. The speed stage of the speed change mechanism connected to the speed change destination clutch, which is a clutch different from the speed change source clutch, is lower than the speed change speed of the speed change mechanism. The clutch switching determining means for determining whether or not the clutch that engages the engine and the transmission mechanism can be switched from the transmission source clutch to the transmission destination clutch, and the clutch switching determination means in an accelerator-off state. In addition, the speed of the speed change mechanism connected to the speed change destination clutch is lower than the speed change speed of the speed change mechanism connected to the speed change source clutch. When it is determined that the clutch to be engaged can be switched from the transmission source clutch to the transmission destination clutch, the transmission source input shaft that is the input shaft of the transmission mechanism whose engine speed is connected to the transmission source clutch The transmission source clutch is changed from the engaged state to the disengaged state while controlling the fastening force of the transmission source clutch and the transmission destination clutch so that the rotation speed is less than The engine switching control means for executing the control for changing the front clutch from the disengaged state to the half-clutch state, and the rotational speed of the speed change destination input shaft that is the input shaft of the speed change mechanism connected to the speed change destination clutch The engine rotation synchronization determination means for determining whether or not the rotation speed is equal to or less than the rotation speed, and when it is determined that the rotation speed of the shift destination input shaft is equal to or lower than the allowable upper limit rotation speed, Engine rotation synchronization control means for increasing the engine speed so as to coincide with the engine speed, synchronization completion determining means for determining whether the engine speed and the speed of the shift destination input shaft coincide with each other, engine speed and speed change After it is determined that the rotational speed of the front input shaft matches, a shift end control means for controlling the shift destination clutch to the engaged state is provided.

In the control apparatus for a dual clutch transmission, the clutch switching control means is a sum of a transmission torque between the engine and the transmission mechanism by the transmission source clutch and a transmission torque between the engine and the transmission mechanism by the transmission destination clutch. The engagement force of the shift source clutch and the shift destination clutch may be controlled so that is less than or equal to the deceleration torque by the engine.

Further, in the control apparatus for the dual clutch transmission, the engine rotation synchronization determination means includes the rotation speed of the output shaft of the speed change mechanism detected by the output shaft rotation speed sensor, and between the shift destination input shaft and the output shaft. The rotational speed of the shift destination input shaft may be calculated based on the gear ratio.

Further, in the control apparatus for the dual clutch transmission, the shift end control means may be configured such that the shift destination clutch is operated after a predetermined time elapses after it is determined that the engine speed and the speed of the shift destination input shaft match. You may make it start the control which makes a contact state.

According to the present disclosure, when the driver designates downshifting, appropriate deceleration can be obtained early.

It is a typical lineblock diagram showing a dual clutch type transmission provided with a dual clutch device concerning one embodiment of this indication. 5 is a flowchart of a shift control process according to an embodiment of the present disclosure. (A) is a figure which shows the change to the torque from the transmission source input shaft to an engine in the transmission control process, the torque from a transmission destination input shaft to an engine, and the torque by an engine, (b) is a transmission source input shaft, It is a figure which shows the change of a speed-change destination input shaft and an engine speed.

Hereinafter, a shift control device that is an example of a control device for a dual clutch transmission according to an embodiment of the present disclosure will be described with reference to the accompanying drawings. The same parts are denoted by the same reference numerals, and their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

FIG. 1 is a schematic configuration diagram illustrating a dual clutch transmission including a dual clutch device according to an embodiment of the present disclosure.

The dual clutch transmission 1 provided in the vehicle is connected to an output shaft 11 of an engine 10 which is an example of a drive source.

The dual clutch transmission 1 includes a dual clutch device 20 having a first clutch 21 and a second clutch 22, a speed change mechanism 30, a speed change control device 80 as an example of a control device, an engine speed sensor 91, a vehicle speed. A sensor 92 (also referred to as an output shaft rotational speed sensor), an accelerator opening sensor 93, and a shift position sensor 95 are provided.

The first clutch 21 is, for example, a wet multi-plate clutch, and includes a clutch hub 23 that rotates integrally with the output shaft 11 of the engine 10, and a first clutch drum 24 that rotates integrally with the first input shaft 31 of the transmission mechanism 30. A plurality of first clutch plates 25, a first space 21A around the plurality of first clutch plates 25, a first piston 26 press-contacting the first clutch plates 25, and a first hydraulic chamber 26A. ing.

When the first piston 26 strokes to the output side (right direction in FIG. 1) due to the pressure of hydraulic oil (hydraulic pressure) supplied to the first hydraulic chamber 26A, the first clutch plate 25 is pressed against the first clutch 21. Thus, a connection state for transmitting torque is established. On the other hand, when the operating hydraulic pressure in the first hydraulic chamber 26A is released, the first piston 26 is stroked to the input side (left direction in FIG. 1) by the urging force of a spring (not shown), and the first clutch 21 transmits power. It becomes the cutting state (cutting state) which interrupts. In the following description, the state in which torque is transmitted via the first clutch plate 25 while the clutch hub 23 and the first clutch drum 24 rotate at different rotational speeds is referred to as a half-clutch state of the first clutch 21. In other words, a state in which the clutch hub 23 and the first clutch drum 24 rotate integrally with the same rotation speed and torque is transmitted through the first clutch plate 25 is referred to as a contact state of the first clutch 21. Hydraulic fluid is supplied to the first space 21A in order to discharge frictional heat and the like generated in the first clutch plate 25.

The second clutch 22 is, for example, a wet multi-plate clutch, and includes a clutch hub 23, a second clutch drum 27 that rotates integrally with the second input shaft 32 of the transmission mechanism 30, and a plurality of second clutch plates 28. A second space 22A around the plurality of second clutch plates 28, a second piston 29 press-contacting the second clutch plates 28, and a second hydraulic chamber 29A are provided.

In the second clutch 22, when the second piston 29 is stroked to the output side (right direction in FIG. 1) by the hydraulic pressure supplied to the second hydraulic chamber 29 </ b> A, the second clutch plate 28 is pressed to transmit torque. Connection state. On the other hand, when the operating hydraulic pressure is released, the second piston 29 is stroked to the input side (left direction in FIG. 1) by the urging force of a spring (not shown), and the second clutch 22 is in a disconnected state in which torque transmission is interrupted ( Disconnected state). In the following description, the state in which the torque is transmitted via the second clutch plate 28 while the clutch hub 23 and the second clutch drum 27 rotate at different rotational speeds is referred to as the half-clutch state of the second clutch 22. In other words, the state in which the clutch hub 23 and the second clutch drum 27 rotate together at the same rotation speed and torque is transmitted through the second clutch plate 28 is referred to as a contact state of the second clutch 22. Hydraulic fluid is supplied to the second space 22A in order to discharge frictional heat and the like generated in the second clutch plate 28.

The transmission mechanism 30 includes a sub-transmission unit 40 disposed on the input side and a main transmission unit 50 disposed on the output side. The transmission mechanism 30 includes a first input shaft 31 and a second input shaft 32 provided in the sub-transmission unit 40, an output shaft 33 provided in the main transmission unit 50, and parallel to these shafts 31 to 33. The counter shaft 34 is provided. The first input shaft 31 is inserted into a hollow shaft that penetrates the second input shaft 32 in the axial direction so as to be relatively rotatable. A propeller shaft (vehicle drive system) connected to a vehicle drive wheel (not shown) via a differential device or the like is connected to the output end of the output shaft 33.

The auxiliary transmission unit 40 is provided with a first splitter gear pair 41 and a second splitter gear pair 42. The first splitter gear pair 41 includes a first input main gear 43 fixed to the first input shaft 31, and a first input sub gear 44 fixed to the sub shaft 34 and constantly meshing with the first input main gear 43. It has. The second splitter gear pair 42 includes a second input main gear 45 fixed to the second input shaft 32, and a second input sub gear 46 fixed to the sub shaft 34 and constantly meshing with the second input main gear 45. It has. Therefore, the sub shaft 34, the first input shaft 31, and the second input shaft 32 are always coupled. In the present embodiment, the gear ratio of the first splitter gear pair 41 is smaller than that of the second splitter gear pair 42. That is, the first splitter gear pair 41 side is a high-speed gear stage. Therefore, in the auxiliary transmission unit 40, when the driving force is transmitted via the first splitter gear pair 41 (when the first clutch 21 is connected), the auxiliary transmission unit 40 can be set to the high speed side, and the second splitter gear. When the driving force is transmitted via the pair 42 (when the second clutch 22 is connected), the speed can be reduced. Here, the case through the first splitter gear pair 41 is referred to as an H (high speed side) stage, and the case through the second splitter gear pair 42 is referred to as an L (low speed side) stage.

The main transmission unit 50 is provided with a first output gear pair 51, a second output gear pair 61, a third output gear pair 71, a first sync mechanism 55, and a second sync mechanism 56. The first output gear pair 51 includes a third-speed sub-gear 52 fixed to the sub-shaft 34 and a third-speed main gear 53 that is rotatably provided on the output shaft 33 and always meshes with the third-speed sub-gear 52. I have. The second output gear pair 61 includes a second-speed sub-gear 62 fixed to the sub-shaft 34 and a second-speed main gear 63 that is provided on the output shaft 33 so as to be relatively rotatable and always meshes with the second-speed sub-gear 62. I have. The third output gear pair 71 includes a first-speed sub-gear 72 fixed to the sub-shaft 34, and a first-speed main gear 73 that is rotatably provided on the output shaft 33 and always meshes with the first-speed sub-gear 72. I have.

The first sync mechanism 55 and the second sync mechanism 56 are known structures, and each includes a sleeve, a dog clutch, etc. (not shown). The first sync mechanism 55 can bring the output shaft 33 and the third-speed main gear 53 into an engaged state (gear-in). When the output shaft 33 and the third speed main gear 53 are engaged, the output shaft 33 rotates at a speed corresponding to the third speed (3H speed) of the H stage on the H-stage side path of the sub-transmission unit 40. With respect to the L-stage side path of the transmission unit 40, the output shaft 33 rotates at a speed equivalent to the L-speed 3rd speed (3L speed).

The second synchronization mechanism 56 can bring the output shaft 33 and the second speed main gear 63 into an engaged state, and can bring the output shaft 33 and the first speed main gear 73 into an engaged state. When the output shaft 33 and the second speed main gear 63 are brought into an engaged state, the output shaft 33 rotates at a speed equivalent to the second speed (2H speed) of the H stage with respect to the H-stage side path of the auxiliary transmission unit 40. For the path on the L-stage side of the transmission unit 40, the output shaft 33 rotates at a speed equivalent to the L-stage 2nd speed (2L speed). Further, when the output shaft 33 and the first-speed main gear 73 are engaged, the output shaft 33 rotates in the H-stage path of the sub-transmission unit 40 corresponding to the first H-speed (1H-speed). For the path where the sub-transmission unit 40 is in the L stage, the output shaft 33 rotates at a speed corresponding to the first speed (1L speed) in the L stage.

In the transmission mechanism 30, the auxiliary transmission unit 40 and the main transmission unit 50 can be switched to 1L speed, 1H speed, 2L speed, 2H speed, 3L speed, and 3H speed. In the speed change mechanism 30, the speed is 1L speed, 1H speed, 2L speed, 2H speed, 3L speed, and 3H speed in order from the low speed stage. In addition, when each gear stage is indicated by a series of numbers, it is 1st, 2nd, 3rd, 4th, 5th, and 6th, respectively. The operations of the first sync mechanism 55 and the second sync mechanism 56 are controlled by a shift control unit 82, which will be described later, depending on the accelerator opening detected by the accelerator opening sensor 93, the speed detected by the vehicle speed sensor 92, and the like. The output shaft 33 and the output main gears (53, 63, 73) are selectively engaged (gear-in) or non-engaged according to the designation of a shift by an operation lever 94 described later by the driver. Switch to state (neutral state). The number of output gear pairs (51, 61, 71) and the synchro mechanisms (55, 56), the arrangement pattern, and the like are not limited to the illustrated examples, and may be changed as appropriate without departing from the spirit of the present disclosure. Is possible.

In the speed change mechanism 30, at the time of shifting between 1L speed and 1H speed, between 2L speed and 2H speed, between 3L speed and 3H speed (shift up and shift down), the speed is changed only by switching the clutch. When shifting between 1H speed and 2L speed and between 2H speed and 3L speed (shift up and shift down), it is necessary to perform clutch switching and gear change.

The engine speed sensor 91 detects the speed of the engine 10 (engine speed) and outputs it to the shift control device 80. The vehicle speed sensor 92 detects the rotational speed of the output shaft 33 (output shaft rotational speed) and outputs it to the transmission control device 80. The vehicle speed can be specified from the output shaft rotation speed. Further, the rotational speed of the first input shaft 31 (first input shaft rotational speed) is specified by multiplying the output shaft rotational speed by the gear ratio between the output shaft 33 and the first input shaft 31. be able to. Further, the rotational speed of the second input shaft 32 (second input shaft rotational speed) is specified by multiplying the output shaft rotational speed by the gear ratio between the output shaft 33 and the second input shaft 32. be able to. The accelerator opening sensor 93 detects the accelerator opening and outputs it to the shift control device 80. The shift position sensor 95 detects the position designated (selected) by the operation lever 94 and outputs it to the shift control device 80. With the operation lever 94, for example, a P (parking) range that is selected when the vehicle is stopped, an N (neutral) range that is selected when the vehicle is temporarily stopped, a D (drive) range that is selected when automatic shifting is performed, and a gear shift. Select the M (manual) range to be selected when performing the above operation, plus (+) to specify upshifting in the M range, minus (-) to specify downshifting in the M range, etc. Can do.

The transmission control device 80 includes a control unit 81, a transmission shifter 85, a first clutch hydraulic oil adjustment unit 86, and a second clutch hydraulic oil adjustment unit 87.

The control unit 81 performs various controls of the engine 10, the first clutch hydraulic oil adjustment unit 86, the second clutch hydraulic oil adjustment unit 87, the shift shifter 85, and the like. A known CPU, ROM, RAM, input port, output It is configured with ports and the like. In order to perform these various controls, sensor values of various sensors (91 to 93, 95) are input to the control unit 81.

The control unit 81 also includes a shift control unit 82 as an example of a downshift instruction detection unit, a clutch control unit 83 as an example of a clutch switch determination unit, a clutch switch control unit, and a shift end control unit, and engine rotation synchronization. The determination unit, the engine rotation synchronization control unit, and the synchronization control unit 84 as an example of the synchronization completion determination unit are included as some functional elements. In the present embodiment, these functional elements are described as being included in the control unit 81 that is an integral piece of hardware. However, any one of these functional elements may be provided in separate hardware.

When the designated position of the operation lever 94 transmitted from the shift position sensor 95 is in the D range, the shift control unit 82 uses information such as the accelerator opening from the accelerator opening sensor 93 and the vehicle speed from the vehicle speed sensor 92. Based on this, it is determined whether or not a shift is necessary. If a shift is necessary, a necessary shift (shift destination) is specified. Further, the shift control unit 82 determines whether the required shift is a shift with only clutch switching or a shift accompanied by a gear change (gear shift) in switching the clutch. The shift control unit 82 instructs the clutch control unit 83 to switch the clutch to be engaged in the case of shifting only by clutch switching. Further, the shift control unit 82 instructs the shift shifter 85 to change the gear when the shift is accompanied by a gear change.

In addition, the shift control unit 82 receives a shift down instruction (in this embodiment, an operation to move the operation lever 94 negative in the M range) from the driver according to the designated position of the operation lever 94 transmitted from the shift position sensor 95. It is determined whether or not it has been detected. When a downshift instruction is detected, the shift control unit 82 notifies the clutch control unit 83 to that effect.

The clutch control unit 83 is in an accelerator-off state (the accelerator opening detected by the accelerator opening sensor 93 is 0) when receiving a notification from the shift control unit 82 that a downshift instruction has been detected, It is connected to a shift destination clutch, which is a clutch different from the shift source clutch, than the shift speed of the shift mechanism 30 connected to the shift source clutch, which is a clutch engaging the engine 10 and the transmission mechanism 30. It is determined whether or not the shift speed of the shift mechanism 30 is lower and the clutch that engages the engine 10 and the shift mechanism 30 can be switched from the shift source clutch to the shift destination clutch.

Here, the accelerator-off state is determined in order to determine that the engine 10 is not in a situation where the rotational speed increases due to the supply of fuel. If the accelerator 10 is in the accelerator-off state, the engine rotational speed is determined at this time. Is the rotation speed (shift source input shaft rotation speed) of the input shaft (shift source input shaft) connected to the shift source clutch and the rotation speed (shift destination) of the input shaft (shift destination input shaft) connected to the shift destination clutch. It is guaranteed that the rotation speed is less than the input shaft speed. In addition, it is determined that the speed of the speed change mechanism 30 connected to the speed change destination clutch is lower than the speed change speed of the speed change mechanism 30 connected to the speed change source clutch. This is to determine that the low speed stage can be quickly achieved only by switching the clutch. Further, it is determined whether or not the clutch that engages the engine 10 and the speed change mechanism 30 can be switched from the speed change source clutch to the speed change destination clutch. This is to determine that the clutch can be switched immediately, not in a situation where the clutch switching is prohibited.

In the present embodiment, when the transmission source clutch is the first clutch 21 and the transmission destination clutch is the second clutch 22, the transmission mechanism 30 is connected to the second clutch 22 that is the transmission destination clutch. The shift speed of the existing transmission mechanism 30 is lower. More specifically, when the shift stage on the first clutch 21 side is 3H, 2H, and 1H, it is guaranteed that the shift stage on the second clutch 22 side is 3L, 2L, and 1L, respectively. For this reason, the clutch control unit 83 determines whether or not the shift speed is 3H, 2H, or 1H, thereby connecting to the shift destination clutch rather than the shift speed of the transmission mechanism 30 connected to the shift source clutch. It can be determined that the gear position of the transmission mechanism 30 that is being used is a lower gear position.

The clutch control unit 83 is in an accelerator-off state, and the speed of the speed change mechanism 30 connected to the speed change destination clutch is higher than the speed change speed of the speed change mechanism 30 connected to the speed change source clutch. If it is determined that the clutch that engages the engine 10 and the speed change mechanism 30 can be switched from the speed change source clutch to the speed change destination clutch, the engine speed is input to the speed change source. While controlling the engagement force of the transmission source clutch and the transmission destination clutch so that the shaft rotational speed is less than the shaft rotation speed, the transmission source clutch is changed from the engaged state to the disconnected state and the transmission destination clutch is changed from the disconnected state to the half-clutch state As described above, the control signal is output to the first clutch hydraulic oil adjusting unit 86 and / or the second clutch hydraulic oil adjusting unit 87.

Here, a specific example will be described in which the engagement force of the shift source clutch and the shift destination clutch is controlled so that the engine speed is equal to or lower than the shift source input shaft speed.

The engine speed acceleration (engine speed acceleration) ω ^· _e is expressed by the relational expression shown in Expression (1).

^{_{_{_{Iω · e = T e + T}}}} H + T L ··· (1)
Here, I is a moment of inertia of the engine 10, T _e is the torque (engine torque) engine 10 occurs, T _H is the torque (transmission source input that is transmitted from the transmission source clutch to the engine 10 _TL is torque transmitted from the shift destination clutch to the engine 10 (shift destination input shaft transmission torque). The engine torque _Te , the shift source input shaft transmission torque _TH, and the shift destination input shaft transmission torque _TL are positive torques in the direction acting in the direction in which the engine 10 is rotated. When the accelerator is off, the engine torque _Te is a negative torque that acts in a direction that suppresses the rotation of the engine 10 due to the friction of the engine 10, that is, a torque that acts as an engine brake that decelerates the vehicle.

In order for the engine speed to be equal to or less than the speed change source input shaft speed, it is necessary to maintain or increase the decrease speed of the engine speed. That is, it is necessary to maintain the engine speed acceleration ω ^· _e at 0 or less.

In the equation (1), when the engine speed acceleration ω ^· _e = 0, the equation shown in the equation (2) is obtained.

-T _e = T _H + T _L (2)
According to equation (2), the absolute value of the engine torque T _e is a negative torque when the accelerator pedal, a speed change based on the input shaft transmits torque T _H, the absolute total torque and the transmission destination input shaft transmits torque T _L the same as the value, i.e., by the total torque to counteract the engine torque T _e, it can be seen that the engine speed acceleration ω ^· _{e =} 0. When engine speed acceleration ω ^· _e <0, it is only necessary to satisfy −T _e ≧ T _H + T _L.

In the present embodiment, the clutch control unit 83 is configured such that the engine torque _Te , the transmission source input shaft transmission torque _TH, and the transmission destination input shaft transmission torque _TL satisfy the expression (2). to, i.e., a transmission source input shaft transmits torque T _H, the total torque of the transmission destination input shaft transmits torque T _L is, the engine torque T _e while maintaining as the same value in the reverse direction, shift from input Control is performed such that the shaft transmission torque _TH is decreased and the shift destination input shaft transmission torque _TL is increased.

Specifically, the clutch controller 83, the shift in order to reduce the original input shaft transmits torque T _H, to determine the hydraulic pressure supplied to the hydraulic chamber of the gear shift based on the clutch to reduce engagement force of the shift based on the clutch In addition, in order to increase the shift destination input shaft transmission torque _TL , the operating hydraulic pressure supplied to the hydraulic chamber of the shift destination clutch is determined, and a control signal (control current) for supplying the determined operating hydraulic pressure is determined. It outputs to the 1 clutch hydraulic oil adjustment part 86 and the 2nd clutch hydraulic oil adjustment part 87. Note that transmission torque (shift source input shaft transmission torque _TH and shift destination input shaft transmission torque T _L ) by the first clutch 21 and the second clutch 22 and hydraulic pressure to the hydraulic chambers (26A, 29A) of each clutch. Can be grasped in advance by performing measurement using a clutch device having the same or similar configuration.

In this way, when the shift source input shaft transmission torque T _H is decreased and the shift destination input shaft transmission torque _TL is controlled to increase, the transmission destination input shaft transmission torque T _H is reduced by the reduced torque. The torque _TL will increase. Here, the speed change destination input shaft side is a low speed stage, and the speed change destination input shaft side has a higher gear ratio than the speed change source input shaft side, so even if the torque amount is the same on the input shaft side, As the torque amount on the side, the shift destination input shaft side is larger. That is, even a weight torque is canceled by the engine torque T _e is the same, who if through the transmission destination input shaft side becomes large as a torque to brake the vehicle. Therefore, when the clutch switching control is started, the torque for braking the vehicle gradually increases. For this reason, it is possible to increase the torque for braking the vehicle at an early stage after detecting the driver's downshift instruction, and to decelerate the vehicle strongly.

In addition, the clutch control unit 83 operates the first clutch so that the shift destination clutch is brought into a contact state when receiving a notification from the synchronization control unit 84 that the engine speed and the shift destination input shaft rotation speed coincide with each other. A control signal is output to the oil adjustment unit 86 or the second clutch hydraulic oil adjustment unit 87.

Further, the clutch control unit 83 outputs a control signal to the first clutch hydraulic oil adjustment unit 86 and / or the second clutch hydraulic oil adjustment unit 87 based on an instruction from the transmission control unit 82.

The synchronization control unit 84 determines whether or not the speed change destination input shaft rotational speed is equal to or lower than the allowable upper limit speed of the engine 10 after the clutch control unit 83 performs the clutch switching, and performs the speed change destination input shaft rotation. When it is determined that the number is equal to or lower than the allowable upper limit rotational speed, the engine 10 is controlled to increase the engine rotational speed so as to coincide with the shift destination input shaft rotational speed.

Further, the synchronization control unit 84 determines whether or not the engine speed and the speed-destination input shaft speed match, and if it determines that the engine speed and the speed-destination input shaft speed match, This is notified to the clutch control unit 83.

The shift shifter 85 operates the first sync mechanism 55 and the second sync mechanism 56 in accordance with an instruction from the shift control unit 82 to release the engagement state between the output shaft 33 and the output main gear (53, 63, 73). (Gear out) or engage (gear in) the output shaft 33 and the output main gear (53, 63, 73).

The first clutch hydraulic oil adjustment unit 86 includes, for example, a linear solenoid valve, and adjusts hydraulic oil from a hydraulic supply source (not shown) according to a control signal (control current) supplied from the clutch control unit 83. Then, the amount and pressure of the hydraulic oil supplied to the first hydraulic chamber 26A are adjusted.

The second clutch hydraulic oil adjustment unit 87 includes, for example, a linear solenoid valve, and adjusts hydraulic oil from a hydraulic supply source (not shown) according to a control signal (control current) supplied from the clutch control unit 83. Then, the amount and pressure of hydraulic fluid supplied to the second hydraulic chamber 29A are adjusted.

Next, the shift control process by the shift control device 80 will be described.

FIG. 2 is a flowchart of a shift control process according to an embodiment of the present disclosure.

The shift control process is executed when the vehicle is running.

The shift control unit 82 determines whether or not there is a downshift instruction for the operation lever 94 by the driver based on the sensor value of the shift position sensor 95 (step S11). As a result, when there is no downshift instruction (step S11: NO), the shift control unit 82 executes step S11 again.

On the other hand, when there is a downshift instruction (step S11: YES), the clutch control unit 83 determines whether or not the sensor value by the accelerator opening detection sensor 93 indicates accelerator off (step S12). Then, it is determined whether or not it is possible to shift to a low speed only by switching the clutch (step S13). The determination as to whether or not it is possible to shift to a low speed only by switching the clutch is made, for example, based on the speed of the speed change mechanism 30 connected to the speed change source clutch that is the clutch engaging the engine 10 and the speed change mechanism 30. A clutch that engages the engine 10 and the transmission mechanism 30 has a lower shift stage of the transmission mechanism 30 that is connected to a destination clutch that is a clutch different from the transmission source clutch. Further, it may be determined whether or not the shift source clutch can be switched to the shift destination clutch.

As a result, when the accelerator is not turned off (step S12: NO), or when it is not possible to shift to a low speed only by clutch switching (step S13: NO), a normal shift-down process (normal shift-down process) Is executed (step S14), and the shift control unit 82 advances the process to step S11.

On the other hand, if the accelerator is off (step S12: YES) and the gear can be shifted to a low speed only by clutch switching (step S13: YES), the clutch control unit 83 performs clutch switching control. Execute (Step S15). That is, the clutch control unit 83 changes the transmission source clutch from the engaged state to the disconnected state while controlling the fastening force of the transmission source clutch and the transmission destination clutch so that the engine speed is equal to or lower than the transmission source input shaft rotation speed. At the same time, a control signal is output to the first clutch hydraulic oil adjusting unit 86 and / or the second clutch hydraulic oil adjusting unit 87 so as to change the shift destination clutch from the disengaged state to the half clutch state.

Next, the synchronization control unit 84 determines whether or not engine rotation synchronization is possible (step S16). Specifically, the synchronization control unit 84 determines whether or not the speed change destination input shaft speed is equal to or lower than the allowable upper limit speed of the engine 10.

As a result, when the speed-destination input shaft rotation speed is not less than the allowable upper limit rotation speed and engine rotation synchronization is not possible (step S16: NO), the synchronization control unit 84 executes step S16 again. On the other hand, when the speed change destination input shaft speed is equal to or lower than the allowable upper limit speed and the engine speed can be synchronized (step S16: YES), the synchronization control unit 84 sets the engine speed to the speed change destination input shaft speed. It raises so that it may correspond (step S17).

Next, the synchronization control unit 84 determines whether or not the engine speed matches the speed change destination input shaft speed (step S18). As a result, when the engine speed does not match the speed change destination input shaft speed (step S18: NO), the synchronization control unit 84 executes step S18 again.

On the other hand, when it is determined that the engine speed and the speed change destination input shaft speed match (step S18: YES), the synchronization control unit 84 notifies the clutch control unit 83 to that effect and has received the notification. The clutch control unit 83 outputs a control signal to the first clutch hydraulic oil adjusting unit 86 or the second clutch hydraulic oil adjusting unit 87 to control the shift destination clutch to be in an engaged state (step S19), and processing To step S11.

Next, changes in various states in the shift control process for performing clutch switching control of the dual clutch transmission 1 according to the present embodiment will be described.

FIG. 3A is a diagram showing torque from the shift source input shaft to the engine, torque from the shift destination input shaft to the engine, and torque change by the engine in the shift control process, and FIG. It is a figure which shows the change of the rotation speed of an original input shaft, a gear shift destination input shaft, and an engine.

Here, in the speed change mechanism 30, the output shaft 33 and the second-speed main gear 63 are engaged by the second sync mechanism 56, and the path between the first input shaft 31 and the output shaft 33 is 2H. The speed state is set, and the path between the second output shaft 32 and the output shaft 33 is set to the 2L speed state. Further, the first clutch 21 connected to the transmission source input shaft (here, the first input shaft 31) is in the engaged state, and the second clutch connected to the transmission destination input shaft (here, the second input shaft 32). Assume that the clutch 22 is disengaged, and at time T0, the driver turns off the accelerator and starts deceleration by engine braking.

At time T0 which is the accelerator-off, as shown in FIG. 3 (a), a negative torque which the engine torque T _e is applied in a direction to stop the engine rotation, commensurate with the speed change based on the input shaft transmits torque T _H It is like that.

In this state, as shown in FIG. 3B, the speed change source input shaft rotation speed and the engine rotation speed gradually decrease at the same rotation speed.

Thereafter, at time T1, it is assumed that the driver operates the operation lever 94 to give a downshift instruction in order to perform a stronger deceleration.

When it is detected at time T1 that the driver has issued a downshift instruction, if a predetermined condition (steps S12 and S13 in FIG. 2) is satisfied, clutch switching control (step S15) is started. The Rukoto.

In the clutch changeover control, transmission original clutch, so gradually controlled to the cross-sectional state from contact state, as shown in (a) of FIG. 3, the transmission source input shaft transmits torque T _H is gradually decreased On the other hand, since the shift destination clutch is gradually controlled from the disengaged state to the half clutch state, the shift destination input shaft torque _TL gradually increases. At this time, a transmission source input shaft transmits torque T _H, the total torque of the transmission destination input shaft transmits torque T _L is, as to be canceled by the engine torque T _e, to reduce the transmission source input shaft transmits torque T _H Then, control is performed to increase the shift destination input shaft transmission torque _TL . At the time T2 when the clutch switching control ends, the transmission source input shaft transmission torque T _H becomes 0, and the transmission destination input shaft torque T _L is the transmission source input shaft transmission torque T _H before the start of the clutch switching control (time T1). And the same torque.

At the time T2 from the time point T1, the speed change input shaft transmits torque T _L increases to be canceled by the engine torque T _e. This shift destination input shaft transmission torque _TL is a torque having a value obtained by multiplying the value of the shift destination input shaft transmission torque _TL by the gear ratio between the shift destination input shaft and the output shaft 33 around the output shaft 33. It corresponds to. Here, the shift speed between the shift destination input shaft (second input shaft 32) and the output shaft 33 is lower than the shift speed between the shift source input shaft (first input shaft 31) and the output shaft 33. Therefore, the gear ratio between the shift destination input shaft and the output shaft is larger than the gear ratio between the shift source input shaft and the output shaft. For this reason, when the shift destination input shaft transmission torque _TL increases, the torque acting in the direction of decreasing the rotation speed of the output shaft 33 around the output shaft 33 increases, and the vehicle is decelerated more strongly.

As a result, as shown in FIG. 3B, the gradients of decrease in the transmission source input shaft rotational speed, the transmission destination input shaft rotational speed, and the engine rotational speed increase from time T1 to time T2. After time T2, the slope is the same as that at time T2.

Here, at the time point T2, the speed change destination input shaft speed is higher than the allowable upper limit speed of the engine. For this reason, the shift destination clutch cannot be brought into the engaged state at time T2.

Thereafter, when time elapses and time T3 is reached, as shown in FIG. 3B, the speed change destination input shaft rotational speed matches the allowable upper limit rotational speed of the engine 10. Thereafter, even if the shift destination clutch is in the engaged state, the rotational speed of the engine 10 does not exceed the allowable upper limit rotational speed. In the present embodiment, when it is detected that the shift destination input shaft rotation speed and the allowable upper limit rotation speed of the engine 10 coincide with each other, as shown in FIG. Increase to match the number of revolutions. At this time, as shown in FIG. 3B, the engine torque _Te is zero.

Thereafter, when the engine speed coincides with the speed change destination input shaft speed at the time T4, the clutch control unit 83 controls the speed change destination clutch to be in an engaged state. As a result, the vehicle is decelerated due to the friction of the engine 10 at the shift speed (low speed) at the shift destination in a state where the engine speed is higher. Here, in a state where the engine speed is higher, the friction of the engine 10 becomes larger, so the effect of deceleration of the vehicle is high.

As described above, according to the speed change control device 80 according to the present embodiment, when the driver gives a downshift instruction, the accelerator mechanism is off and the speed change mechanism 30 connected to the speed change source clutch is connected. The speed of the speed change mechanism 30 connected to the speed change destination clutch is lower than the speed change speed, and the clutch that engages the engine 10 and the speed change mechanism 30 is shifted from the speed change source clutch. When it is determined that it is possible to switch to the front clutch, the transmission source clutch is engaged while controlling the fastening force of the transmission source clutch and the transmission destination clutch so that the engine speed is equal to or lower than the transmission source input shaft rotation speed. From the disengaged state to the half-clutch state. To, can be decelerated more strongly the vehicle at an early stage. Therefore, a desired deceleration feeling can be given to the driver at an early stage.

Further, when it is determined that the speed change destination input shaft speed is equal to or lower than the allowable upper limit speed of the engine 10, the engine speed is increased so as to coincide with the speed change destination input shaft speed, Since the shift destination clutch is connected when the shift destination input shaft rotation speed matches, the engine rotation speed can be appropriately prevented from exceeding the allowable upper limit rotation speed, and at lower shift speeds. The engine 10 can be decelerated.

It should be noted that the present disclosure is not limited to the above-described embodiment, and can be appropriately modified and implemented without departing from the spirit of the present disclosure.

For example, in the above-described embodiment, when it is determined that the engine speed and the speed-destination input shaft speed match, control for immediately bringing the speed-change destination clutch into contact is started. Without being limited thereto, after the predetermined time has elapsed after it is determined that the engine speed and the speed change destination input shaft speed match, the control to start the speed change destination clutch is started after maintaining the half clutch state. It may be. By doing so, it is possible to make the shift destination clutch slightly slipped (that is, the micro-slip state), and to reduce the shock that occurs when the clutch is subsequently engaged.

In the above embodiment, the input shaft is based on the rotation speed of the output shaft 33 detected by the vehicle speed sensor 92 and the gear ratio between the output shaft 33 and the input shaft (31, 32) in the speed change mechanism 30. However, the present disclosure is not limited to this, and includes a sensor that detects the rotational speed of the first input shaft 31 and a sensor that detects the rotational speed of the second input shaft 32. The rotational speed of the input shaft may be specified by the sensor value.

Further, in the above embodiment, the operation lever 94 is configured to designate the minus or plus of the M range when manually shifting by the driver. However, the present disclosure is not limited to this, and for example, the operation lever 94 94 may be configured such that each gear position can be directly designated. In this case, it is possible to specify that the downshift is specified when the speed after the speed change is lower than the speed before the speed change.

Moreover, in the said embodiment, although it was set as the dual clutch type transmission 1 which has the subtransmission part 40, this indication is not restricted to this, It has two input shafts and one output shaft, One input shaft And the output shaft between the other input shaft and the output shaft can be set to a state of a speed step that is lower than the speed step. The present disclosure can be applied even to a dual clutch transmission that does not include the auxiliary transmission unit 40.

This application is based on a Japanese patent application (Japanese Patent Application No. 2016-029161) filed on February 18, 2016, the contents of which are incorporated herein by reference.

The control device for the dual clutch transmission of the present disclosure is useful in that appropriate deceleration can be obtained at an early stage when the driver designates downshifting.

DESCRIPTION OF SYMBOLS 1 Dual clutch type transmission 10 Engine 11 Output shaft 20 Dual clutch apparatus 21 1st clutch 22 2nd clutch 26,29 Piston 26A 1st hydraulic chamber 29A 2nd hydraulic chamber 30 Transmission mechanism 31 1st input shaft 32 2nd input shaft 33 Output shaft 34 Sub shaft 40 Sub transmission unit 41 First splitter gear pair 42 Second splitter gear pair 50 Main transmission unit 51 First output gear pair 52 Third speed sub gear 53 Third speed main gear 55 First sync mechanism 56 Second Synchro mechanism 61 2nd output gear pair 62 2nd speed sub gear 63 2nd speed main gear 71 3rd output gear pair 72 1st speed sub gear 73 1st speed main gear 80 Transmission control device 81 Control unit 82 Transmission control section 83 Clutch control section 84 Synchronous control unit 85 Shift shifter 86 First clutch hydraulic oil adjustment unit 87 Second clutch hydraulic oil adjustment unit 91 Engine speed sensor 92 Vehicle speed sensor 93 Accelerator opening sensor 94 Operation lever 95 Shift position sensor

Claims

A clutch device including two clutches is provided between the engine and the transmission mechanism, and the driving force transmission path from the engine to the vehicle drive system connected to the output shaft of the transmission mechanism is between the paths via the respective clutches. A dual clutch transmission control device that can be switched with
Downshift instruction detecting means for detecting whether or not there has been a downshift instruction from the driver;
When the downshift instruction is detected, the accelerator is in an off state, and the shift speed of the speed change mechanism connected to the speed change source clutch, which is the clutch engaging the engine and the speed change mechanism, A clutch that engages the engine and the speed change mechanism with a speed lower than that of the speed change mechanism connected to a speed change destination clutch that is a clutch different from the speed change source clutch. Clutch switching determination means for determining whether or not switching from the shift source clutch to the shift destination clutch is possible,
The shift state of the speed change mechanism connected to the shift destination clutch is higher than the speed change state of the speed change mechanism connected to the speed change source clutch in the accelerator off state by the clutch switching determination means. Is determined to be low and the clutch that engages the engine and the speed change mechanism is determined to be switchable from the speed change source clutch to the speed change destination clutch. While controlling the fastening force of the shift source clutch and the shift destination clutch so that the number is equal to or less than the rotation speed of the shift source input shaft that is the input shaft of the transmission mechanism connected to the shift source clutch. Clutch switching control means for changing the original clutch from the engaged state to the disengaged state and executing control for changing the shift destination clutch from the disengaged state to the half-clutch state ,
Engine rotation synchronization determination means for determining whether or not the rotation speed of a shift destination input shaft that is an input shaft of the transmission mechanism connected to the shift destination clutch is equal to or lower than an allowable upper limit rotation speed of the engine;
Engine rotation synchronization control means for increasing the engine speed so as to coincide with the speed of the shift destination input shaft when it is determined that the speed of the shift destination input shaft is equal to or lower than the allowable upper limit speed. When,
Synchronization completion determination means for determining whether or not the rotational speed of the engine and the rotational speed of the shift destination input shaft match.
A control apparatus for a dual clutch transmission, comprising: a shift end control means for controlling the shift destination clutch to a contact state after it is determined that the rotation speed of the engine and the rotation speed of the shift destination input shaft match. .
The clutch switching control means is configured such that a sum of a transmission torque between the engine and the transmission mechanism by the transmission source clutch and a transmission torque between the engine and the transmission mechanism by the transmission destination clutch is determined by the engine. The control apparatus for a dual clutch transmission according to claim 1, wherein the engagement force of the shift source clutch and the shift destination clutch is controlled so as to be equal to or less than a deceleration torque.
The engine rotation synchronization determination means is configured to change the speed based on the rotation speed of the output shaft of the transmission mechanism detected by the output shaft rotation speed sensor and the gear ratio between the shift destination input shaft and the output shaft. The control apparatus for a dual clutch transmission according to claim 1 or 2, wherein the rotational speed of the front input shaft is calculated.
The shift end control means starts control for bringing the shift destination clutch into an engaged state after a predetermined time has elapsed since it was determined that the engine speed and the speed of the shift destination input shaft coincided with each other. The control apparatus for a dual clutch transmission according to any one of claims 1 to 3.