WO2019074085A1

WO2019074085A1 - Dual clutch transmission

Info

Publication number: WO2019074085A1
Application number: PCT/JP2018/038048
Authority: WO
Inventors: 壮史岡本
Original assignee: いすゞ自動車株式会社
Priority date: 2017-10-12
Filing date: 2018-10-12
Publication date: 2019-04-18
Also published as: CN111201390B; CN111201390A; JP2019074103A

Abstract

When a shift is performed from a first prescribed shift stage in which motive power is transmitted to an output shaft from a drive source via a second input shaft, a first countershaft, and a second countershaft, to a second prescribed shift stage in which motive power is transmitted to the output shaft from the drive source via a first input shaft and the second countershaft, this dual clutch transmission sets a state in which the coupling of the first countershaft and the second countershaft is released and motive power is not transmitted from the drive source to the first countershaft, and, when the state is to be changed to a state in which motive power is transmitted from the drive source or the output shaft to the first countershaft, a second clutch is temporarily set in a connected state before the state is changed.

Description

Dual clutch transmission

The present disclosure relates to a dual clutch transmission.

Patent Document 1 discloses a dual clutch transmission in which a dual clutch device having two clutches is provided between an engine and a transmission so that power transmission from the engine to the transmission can be switched to two systems. It is done.

Japanese Patent Publication No. 2010-537144

In the dual clutch transmission as described in Patent Document 1, for example, while traveling in even gear, pre-shifting is performed in odd gear. When pre-shifting is performed, the elements in the transmission path that do not contribute to the power transmission from the engine to the wheels are rotationally driven by the engine, so the oil agitation resistance increases, resulting in deterioration of fuel efficiency.

An object of the present disclosure is to provide a dual clutch transmission that can suppress deterioration in fuel efficiency due to stirring of oil.

A dual clutch type transmission according to an aspect of the present disclosure includes a first input shaft having a first clutch capable of connecting and disconnecting power from a drive source, and a second clutch capable of connecting and disconnecting power from the drive source. A second input shaft coaxial with the first input shaft, a first counter shaft parallel to the first input shaft, and the first counter shaft coaxial with the first input shaft; A second counter shaft selectively coupled to the counter shaft; and an output shaft coaxially disposed with the first input shaft, the second input shaft from the drive source, the first counter shaft, and Power is transmitted from the drive source to the output shaft from the drive source via the first input shaft and the second counter shaft from a first predetermined shift stage where power is transmitted to the output shaft via a second counter shaft When shifting to the second predetermined gear is performed Releasing the coupling between the first counter shaft and the second counter shaft so that power is not transmitted from the drive source to the first counter shaft, and the first counter from the drive source or the output shaft When performing a state change to a state in which power is transmitted to the shaft, prior to the state change, the second clutch is temporarily brought into the connected state.

According to the transmission control device according to the present disclosure, it is possible to suppress the deterioration of fuel consumption due to the stirring of oil.

FIG. 1 is a skeleton diagram showing a dual clutch transmission according to an embodiment. FIG. 2 is a skeleton diagram showing the state immediately after the shift from the eighth gear to the ninth gear. FIG. 3 is a skeleton diagram showing a traveling state at the 9th gear. FIG. 4 is a flowchart showing the processing content of the oil agitation reduction control. FIG. 5 is a skeleton diagram showing a state immediately after shifting from the fourth gear to the fifth gear. FIG. 6 is a skeleton diagram showing a traveling state at the fifth gear.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiment described below is an example, and the present disclosure is not limited to this embodiment.

First, with reference to FIG. 1, the whole structure of the dual clutch type transmission 1 which concerns on embodiment is demonstrated. The left side in FIG. 1 is the front side of the dual clutch transmission 1, and the right side in FIG. 1 is the rear side of the dual clutch transmission 1.

The dual clutch transmission 1 includes a first clutch 10, a second clutch 20, and a transmission unit 30. A drive wheel is coupled to the output side of the transmission unit 30 so as to be able to transmit power via a propeller shaft, a differential and a drive shaft (not shown).

The first clutch 10 is, for example, a hydraulically operated wet multi-plate clutch having a plurality of input side clutch plates 11 and a plurality of output side clutch plates 12. The input clutch plate 11 rotates integrally with the output shaft 2 of the engine (not shown). The output-side clutch plate 12 rotates integrally with the first input shaft 31 of the transmission unit 30.

The first clutch 10 is biased in the disconnecting direction by a return spring (not shown), and the control oil pressure is supplied to the hydraulic fluid chamber of the piston (not shown), whereby the piston moves and the input side clutch plate 11 and the output side clutch plate 12 are brought into pressure contact with each other. With the first clutch 10 engaged, the power of the engine is transmitted to the first input shaft 31. The connection and disconnection of the first clutch 10 is controlled by the controller 40.

The second clutch 20 is provided on the outer peripheral side of the first clutch 10. In the present embodiment, the second clutch 20 is provided on the outer peripheral side of the first clutch 10 as an example, but the arrangement relationship of the first clutch 10 and the second clutch 20 is the same. It is not limited. For example, the second clutch 20 may be disposed on the front side or the rear side of the first clutch 10.

The second clutch 20 is, for example, a hydraulically operated wet multi-plate clutch having a plurality of input side clutch plates 21 and a plurality of output side clutch plates 22. The input clutch plate 21 rotates integrally with the output shaft 2 of the engine. The output side clutch plate 22 rotates integrally with the second input shaft 32 of the transmission unit 30.

The second clutch 20 is biased in the disconnecting direction by a return spring (not shown), and the control oil pressure is supplied to the hydraulic fluid chamber of the piston (not shown), whereby the piston moves and the input side clutch plate 21 and the output side clutch plate 22 are brought into pressure contact with each other. The power of the engine is transmitted to the second input shaft 32 by engaging the second clutch 20. The connection and disconnection of the second clutch 20 is controlled by the control device 40.

The transmission unit 30 includes a first input shaft 31 connected to the output side of the first clutch 10 and a second input shaft 32 connected to the output side of the second clutch 20. The transmission unit 30 further includes a first counter shaft 33 and a second counter shaft 34 disposed in parallel to the first input shaft 31 and the second input shaft 32. The transmission unit 30 further includes an output shaft 35 coaxially disposed with the first input shaft 31 and the second input shaft 32.

The first input shaft 31 is rotatably supported by the second input shaft 32 via a bearing (not shown). A second input gear 52 a functioning as a reverse gear is fixed to an intermediate portion in the front-rear direction of the first input shaft 31.

A first sync hub 61 a of a first sync mechanism 61 (to be described later) is fixed at a stage subsequent to the second input gear 52 a of the first input shaft 31.

A third input gear 53a is provided between the second input gear 52a and the first synchro hub 61a so as to be rotatable relative to the first input shaft 31.

At the rear stage of the first synchro hub 61a, a fourth input gear 54a (corresponding to the "free rotation gear" of the present disclosure) is provided so as to be rotatable relative to the first input shaft 31.

The second input shaft 32 is a hollow shaft through which the first input shaft 31 is inserted, and is rotatably supported by a transmission case (not shown) via a bearing (not shown). A first input gear 51 a is fixed to the rear end of the second input shaft 32. The first input gear 51a is disposed on the front side of the second input gear 52a.

The first counter shaft 33 is rotatably supported by a transmission case (not shown) via a bearing (not shown). A first counter gear 51b, a third sync hub 63a of a third sync mechanism 63 (described later), a sixth counter gear 56b and a seventh counter gear 57b are fixed to the first counter shaft 33 in order from the front side. .

The first counter gear 51b is in constant mesh with the first input gear 51a. A first gear train 51 is formed by the first input gear 51a and the first counter gear 51b.

A second counter gear 52 b is provided between the first counter gear 51 b and the third synchronizing mechanism 63 so as to be rotatable relative to the first counter shaft 33. The second counter gear 52b is constantly meshed with the second input gear 52a via the reverse idler gear 52c. A reverse gear train 52 is configured by the second input gear 52a, the reverse idler gear 52c, and the second counter gear 52b.

The second counter shaft 34 is disposed between the third synchronizing mechanism 63 and the sixth counter gear 56 b. The second counter shaft 34 is a hollow shaft through which the first counter shaft 33 is inserted, and is rotatably supported relative to the first counter shaft 33 via a bearing (not shown). A third counter gear 53 b is fixed to the front of the second counter shaft 34. The third counter gear 53b is in constant mesh with the third input gear 53a. A second gear train 53 is formed by the third input gear 53a and the third counter gear 53b.

A fourth counter gear 54 b (corresponding to the “first counter gear” of the present disclosure) is fixed at a stage subsequent to the third counter gear 53 b in the second counter shaft 34. The fourth counter gear 54b is in constant mesh with the fourth input gear 54a. A third gear train 54 is configured by the fourth input gear 54a and the fourth counter gear 54b. A fifth counter gear 55 b (corresponding to a “second counter gear” in the present disclosure) is fixed to the rear end portion of the second counter shaft 34.

The output shaft 35 is rotatably supported by a transmission case (not shown) via a bearing (not shown). At the front end of the output shaft 35, a second synchro hub 62a of a second synchro mechanism 62 (described later) is fixed. A fourth sync hub 64 a of a fourth sync mechanism 64 (to be described later) is fixed at a stage subsequent to the second sync hub 62 a in the output shaft 35.

A first output gear 55 a (corresponding to the “output gear” in the present disclosure) is provided between the second synchro hub 62 a and the fourth synchro hub 64 a so as to be rotatable relative to the output shaft 35. The first output gear 55a is in constant mesh with the fifth counter gear 55b. A fourth gear train 55 is formed by the first output gear 55a and the fifth counter gear 55b.

A second output gear 56 a is provided rotatably relative to the output shaft 35 between the first output gear 55 a and the fourth synchro hub 64 a. The second output gear 56a is in constant mesh with the sixth counter gear 56b. A fifth gear train 56 is configured by the second output gear 56a and the sixth counter gear 56b.

A third output gear 57 a is provided in the rear stage of the fourth synchro hub 64 a so as to be rotatable relative to the output shaft 35. The third output gear 57a always meshes with the seventh counter gear 57b. A sixth gear train 57 (corresponding to the “fifth gear train” in the present disclosure) is configured by the third output gear 57 a and the seventh counter gear 57 b.

The transmission unit 30 includes a first synchronizing mechanism 61, a second synchronizing mechanism 62, a third synchronizing mechanism 63, and a fourth synchronizing mechanism 64.

The first synchronization mechanism 61 includes a first synchronization hub 61a, a first synchronization sleeve 61b, a first dog gear 61c, and a second dog gear 61d. The first synchro hub 61a is fixed to the first input shaft 31 as described above.

The first synchro sleeve 61 b is provided to surround the first synchro hub 61 a. The first synchro sleeve 61b has spline internal teeth that engage with the spline external teeth of the first synchro hub 61a. The first synchro sleeve 61b rotates integrally with the first synchro hub 61a, and is movable in the front-rear direction with respect to the first synchro hub 61a.

The first dog gear 61c is provided on the rear side of the third input gear 53a. The second dog gear 61d is provided on the front side of the fourth input gear 54a. Synchronizer rings (not shown) are provided between the first synchro hub 61a and the first dog gear 61c and the second dog gear 61d, respectively. The spline internal teeth of the first synchro sleeve 61b are selectively engageable with the spline external teeth of the first dog gear 61c and the second dog gear 61d.

The first sync mechanism 61 is configured such that the first sync sleeve 61b is moved by a shift fork (not shown) and engaged with the first dog gear 61c or the second dog gear 61d, whereby the first input shaft 31 and the third input gear are engaged. It selectively couples in synchronization with the 53a or the fourth input gear 54a. The operation of the first synchro sleeve 61 b is controlled by the controller 40.

The second synchronization mechanism 62 includes a second synchronization hub 62a, a second synchronization sleeve 62b, a third dog gear 62c, and a fourth dog gear 62d. The second synchro hub 62a is fixed to the output shaft 35 as described above.

The second synchro sleeve 62b is provided so as to surround the second synchro hub 62a. The second synchro sleeve 62b has spline internal teeth that engage with the spline external teeth of the second synchro hub 62a. The second sync sleeve 62b rotates integrally with the second sync hub 62a, and is movable in the front-rear direction with respect to the second sync hub 62a.

The third dog gear 62c is provided on the rear side of the fourth input gear 54a. The fourth dog gear 62d is provided on the front side of the first output gear 55a. Synchronizer rings (not shown) are provided between the second synchro hub 62a and the third dog gear 62c and the fourth dog gear 62d, respectively. The spline internal teeth of the second synchro sleeve 62b are selectively engageable with the spline external teeth of the third dog gear 62c and the fourth dog gear 62d.

The second synchro mechanism 62 moves the second synchro sleeve 62b by a shift fork (not shown) and engages with the third dog gear 62c or the fourth dog gear 62d, whereby the output shaft 35 and the fourth input gear 54a or The first output gear 55a is selectively and synchronously coupled. The operation of the second synchro sleeve 62 b is controlled by the controller 40.

The third synchronization mechanism 63 includes a third synchronization hub 63a, a third synchronization sleeve 63b, a fifth dog gear 63c, and a sixth dog gear 63d. The third synchro hub 63a is fixed to the first counter shaft 33 as described above.

The third synchro sleeve 63b is provided to surround the third synchro hub 63a. The third synchro sleeve 63b has spline internal teeth that engage with the spline external teeth of the third synchro hub 63a. The third sync sleeve 63b is integrally rotated with the third sync hub 63a, and is movable in the front-rear direction with respect to the third sync hub 63a.

The fifth dog gear 63c is provided on the rear side of the second counter gear 52b. The sixth dog gear 63 d is provided at the front end of the second countershaft 34. Synchronizer rings (not shown) are provided between the third synchro hub 63a and the fifth dog gear 63c and the sixth dog gear 63d, respectively. The spline internal teeth of the third synchro sleeve 63b are selectively engageable with the spline external teeth of the fifth dog gear 63c and the sixth dog gear 63d.

In the third synchronization mechanism 63, the third synchronization sleeve 63b is moved by a shift fork (not shown) and engaged with the fifth dog gear 63c or the sixth dog gear 63d, whereby the first counter shaft 33 and the second counter gear are engaged. And 52b or the second counter shaft 34 is selectively synchronized. The operation of the third synchro sleeve 63 b is controlled by the controller 40.

The fourth synchronizing mechanism 64 includes a fourth synchronizing hub 64a, a fourth synchronizing sleeve 64b, a seventh dog gear 64c, and an eighth dog gear 64d. The fourth synchro hub 64a is fixed to the output shaft 35 as described above.

The fourth sync sleeve 64b is provided to surround the fourth sync hub 64a. The fourth synchro sleeve 64b has spline internal teeth that engage with the spline external teeth of the fourth synchro hub 64a. The fourth synchro sleeve 64b rotates integrally with the fourth synchro hub 64a, and is movable in the front-rear direction with respect to the fourth synchro hub 64a.

The seventh dog gear 64c is provided on the rear side of the second output gear 56a. The eighth dog gear 64d is provided on the front side of the third output gear 57a. Synchronizer rings (not shown) are provided between the fourth synchro hub 64a and the seventh dog gear 64c and the eighth dog gear 64d, respectively. The spline internal teeth of the fourth synchro sleeve 64b are selectively engageable with the spline external teeth of the seventh dog gear 64c and the eighth dog gear 64d.

In the fourth synchronizing mechanism 64, the fourth synchronizing sleeve 64b is moved by a shift fork (not shown) and engaged with the seventh dog gear 64c or the eighth dog gear 64d, whereby the output shaft 35 and the second output gear 56a or The third output gear 57a is selectively and synchronously coupled. The operation of the fourth synchro sleeve 64 b is controlled by the controller 40.

Next, the power transmission path of each gear by the dual clutch transmission 1 of the present embodiment will be described. In the following, as an example, a case will be described in which the vehicle is started at the first gear and upshifted to the ninth gear sequentially.

In the first gear, the first clutch 10 is brought into contact, and the first input shaft 31 and the fourth input gear 54 a are coupled by the first synchro mechanism 61, and the third counter shaft 63 is coupled with the first counter shaft 34 by the third synchro mechanism 63. The counter shaft 33 is coupled, and the second output gear 56 a and the output shaft 35 are coupled by the fourth synchronizing mechanism 64.

That is, the power of the engine is: first clutch 10 → first input shaft 31 → first synchro mechanism 61 → third gear train 54 → second counter shaft 34 → third synchro mechanism 63 → first counter shaft 33 → fifth gear The power transmission path of the first gear is established by transmitting the train 56 → the fourth synchronization mechanism 64 → the output shaft 35.

In the second gear, the second clutch 20 is brought into contact, and the second output gear 56a and the output shaft 35 are coupled by the fourth synchronizing mechanism 64.

That is, the power of the engine is transmitted to the second clutch 20 → second input shaft 32 → first gear train 51 → first countershaft 33 → fifth gear train 56 → fourth synchronizing mechanism 64 → output shaft 35 The power transmission path of the second gear is established.

When the second gear is established, pre-shifting to the third gear is performed. Specifically, the coupling between the second counter shaft 34 and the first counter shaft 33 by the third synchronizing mechanism 63 is released, and the first output gear 55 a and the output shaft 35 are coupled by the second synchronizing mechanism 62.

The third gear is realized by disconnecting the second clutch 20 and engaging the first clutch 10 in a state in which the preshift to the third gear is completed in the second gear. In the third gear, the first clutch 10 is brought into contact, and the first input shaft 31 and the fourth input gear 54a are coupled by the first synchro mechanism 61, and the first output gear 55a and the output shaft are formed by the second synchro mechanism 62. And 35 are combined.

That is, the power of the engine is 1st clutch 10 → 1st input shaft 31 → 1st synchro mechanism 61 → 3rd gear train 54 → 2nd counter shaft 34 → 4th gear train 55 → 2nd synchro mechanism 62 → output shaft 35 The power transmission path of the third gear is established.

When the third gear is established, pre-shifting to the fourth gear is performed. Specifically, the coupling between the second output gear 56a and the output shaft 35 by the fourth synchronizing mechanism 64 is released, and the first counter shaft 33 and the second counter shaft 34 are coupled by the third synchronizing mechanism 63.

The fourth gear is realized by disengaging the first clutch 10 and engaging the second clutch 20 in a state in which the preshift to the fourth gear is completed in the third gear. In the fourth gear, the second clutch 20 is brought into contact, and the first output gear 55a and the output shaft 35 are coupled by the second synchro mechanism 62, and the first counter shaft 33 and the second counter shaft by the third synchro mechanism 63. 34 are combined.

That is, the power of the engine is second clutch 20 → second input shaft 32 → first gear train 51 → first counter shaft 33 → third synchro mechanism 63 → second counter shaft 34 → fourth gear train 55 → second synchro By transmitting the mechanism 62 → the output shaft 35, a power transmission path of the fourth gear is established.

When the fourth gear is established, pre-shifting to the fifth gear is performed. Specifically, the connection between the first input shaft 31 and the fourth input gear 54a is released by the first synchronization mechanism 61, and the first input shaft 31 and the third input gear 53a are connected.

The fifth gear is realized by disengaging the second clutch 20 and engaging the first clutch 10 in a state in which the preshift to the fifth gear is completed in the fourth gear. In the fifth gear, the first clutch 10 is brought into contact, and the first input shaft 31 and the third input gear 53a are coupled by the first synchro mechanism 61, and the first output gear 55a and the output shaft are formed by the second synchro mechanism 62. And 35 are combined.

That is, the power of the engine is 1st clutch 10 → 1st input shaft 31 → 1st synchro mechanism 61 → 2nd gear train 53 → 2nd counter shaft 34 → 4th gear train 55 → 2nd synchro mechanism 62 → output shaft 35 The power transmission path of the fifth gear is established.

When the fifth gear is established, pre-shifting to the sixth gear is performed. Specifically, the coupling between the second counter shaft 34 and the first counter shaft 33 by the third synchronizing mechanism 63 is released, and the third output gear 57 a and the output shaft 35 are coupled by the fourth synchronizing mechanism 64.

The sixth gear is realized by disengaging the first clutch 10 and engaging the second clutch 20 in a state where the preshift to the sixth gear is completed at the fifth gear. In the sixth gear, the second clutch 20 is brought into contact, and the third output gear 57 a and the output shaft 35 are coupled by the fourth synchronizing mechanism 64.

That is, the power of the engine is transmitted to the second clutch 20 → second input shaft 32 → first gear train 51 → first countershaft 33 → sixth gear train 57 → fourth synchronizing mechanism 64 → output shaft 35 The power transmission path of the sixth gear is established.

When the sixth gear is established, pre-shifting to the seventh gear is performed. Specifically, the first synchronization mechanism 61 releases the connection between the first input shaft 31 and the third input gear 53a, and the first input shaft 31 and the fourth input gear 54a are connected to each other. The connection between the first output gear 55a and the output shaft 35 is released by 62, and the fourth input gear 54a and the output shaft 35 are connected.

The seventh gear is realized by disengaging the second clutch 20 and engaging the first clutch 10 in a state where pre-shifting to the seventh gear is completed in the sixth gear. In the seventh gear, the first clutch 10 is brought into contact, and the first input shaft 31 and the fourth input gear 54 a are coupled by the first synchro mechanism 61, and the fourth input gear 54 a and the output shaft by the second synchro mechanism 62. And 35 are combined.

That is, the power of the engine is transmitted to the first clutch 10 → the first input shaft 31 → the first synchro mechanism 61 → the fourth input gear 54 a → the second synchro mechanism 62 → the output shaft 35, whereby the power of the seventh gear is achieved. A transmission path is established. The 7th gear is a direct connection gear.

When the seventh gear is established, pre-shifting to the eighth gear is performed. Specifically, the coupling between the third output gear 57a and the output shaft 35 by the fourth synchronizing mechanism 64 is released, and the first countershaft 33 and the second countershaft 34 are coupled by the third synchronizing mechanism 63.

The eighth gear is realized by disengaging the first clutch 10 and engaging the second clutch 20 in a state where the preshift to the eighth gear is completed in the seventh gear. In the eighth gear, the second clutch 20 is brought into contact, and the fourth synchronizer 62 couples the fourth input gear 54a to the output shaft 35, and the third synchro mechanism 63 couples the first counter shaft 33 to the second counter shaft. 34 are combined.

That is, the power of the engine is second clutch 20 → second input shaft 32 → first gear train 51 → first counter shaft 33 → third synchronizing mechanism 63 → second counter shaft 34 → third gear train 54 → second synchro By transmitting the mechanism 62 → the output shaft 35, a power transmission path of the eighth gear is established.

When the eighth gear is established, pre-shifting to the ninth gear is performed. Specifically, the connection between the first input shaft 31 and the fourth input gear 54a is released by the first synchronization mechanism 61, and the first input shaft 31 and the third input gear 53a are connected.

The ninth gear is realized by disengaging the second clutch 20 and engaging the first clutch 10 in a state in which the preshift to the ninth gear is completed in the eighth gear. In the ninth gear, the first clutch 10 is brought into contact, and the first input shaft 31 and the third input gear 53a are coupled by the first synchro mechanism 61, and the fourth input gear 54a and the output shaft are formed by the second synchro mechanism 62. And 35 are combined.

That is, the power of the engine is 1st clutch 10 → 1st input shaft 31 → 1st synchro mechanism 61 → 2nd gear train 53 → 2nd counter shaft 34 → 3rd gear train 54 → 2nd synchro mechanism 62 → output shaft 35 Thus, the power transmission path of the ninth gear is established.

Next, an outline of the oil agitation reduction control performed in the ninth gear in the dual clutch transmission 1 according to the present embodiment will be described in detail with reference to FIGS. 2 and 3. FIG. 2 shows a state immediately after the upshift from the eighth gear to the ninth gear is performed.

In FIGS. 2 and 3, thick lines indicate power transmission paths contributing to power transmission from the engine to the output shaft 35. The solid line does not contribute to the power transmission from the engine to the output shaft 35, but indicates that rotational power from the engine is transmitted. The broken line indicates that rotational power from the engine is not transmitted.

As shown in FIG. 2, immediately after the upshift from the eighth gear to the ninth gear is performed, the third synchronizing mechanism 63 is in a state in which the first counter shaft 33 and the second counter shaft 34 are coupled.

Therefore, rotational power from the engine is also transmitted to the first countershaft 33 via the first input shaft 31, the third input gear 53a and the second countershaft 34. Thus, the first counter gear 51b, the sixth counter gear 56b and the seventh counter gear 57b fixed to the first counter shaft 33 are rotationally driven by the engine. Therefore, the agitation resistance of the lubricating oil in the transmission case is increased by the rotation of the first counter gear 51b, the sixth counter gear 56b and the seventh counter gear 57b, resulting in deterioration of the fuel efficiency.

In the present embodiment, the following operation is performed to prevent the first counter shaft 33 from being rotationally driven by the engine after the shift from the eighth gear to the ninth gear.

Specifically, after the upshift from the eighth gear to the ninth gear is performed, in the state of the ninth gear, coupling of the first counter shaft 33 and the second counter shaft 34 is performed by the third synchronizing mechanism 63. Release (see Figure 3). This can prevent the rotational power from the engine from being transmitted to the first countershaft 33. Therefore, the deterioration of the fuel consumption by stirring of lubricating oil can be suppressed.

By the way, when shifting to the eighth gear is performed due to a decrease in vehicle speed or the like during traveling at such a ninth gear, the first counter shaft 33 and the second counter shaft 34 can be When rejoining, the following problems may occur.

That is, while the second counter shaft 34 is rotating at high speed, the rotational speed of the first counter shaft 33 is low. Therefore, if it is attempted to couple the first countershaft 33 and the second countershaft 34 by the third synchronizing mechanism 63 as it is, there is a possibility that an excessive load may be applied to the third synchronizing mechanism 63.

Therefore, in the present embodiment, in order to prevent an excessive load from being applied to the third synchronizing mechanism 63, prior to the reconnection of the first counter shaft 33 and the second counter shaft 34 by the third synchronizing mechanism 63, the following will be described. Operation is performed.

Specifically, before the third synchro sleeve 63b is engaged with the sixth dog gear 63d, the second clutch 20 is temporarily engaged.

As a result, the power of the engine is transmitted to the first countershaft 33 via the second input shaft 32, and the rotational speed of the first countershaft 33 is increased. Then, when the rotational speed of the first counter shaft 33 is sufficiently increased, the engaged second clutch 20 is disconnected, and the third synchro sleeve 63b is engaged with the sixth dog gear 63d. Thereby, the load applied to the third synchronizing mechanism 63 can be reduced.

Next, the processing contents of the oil agitation reduction control will be described with reference to the flowchart of FIG. 4. Such oil agitation reduction control is started when a shift from the eighth gear to the ninth gear is performed.

First, in step S1, the control device 40 determines whether or not pre-shifting is unnecessary. This determination is made, for example, based on the vehicle speed and the like. Also, for example, this determination may be made by determining whether there is a possibility of shifting to the eighth gear.

If it is determined in step S1 that pre-shifting is not unnecessary (step S1: NO), the process of step S1 is repeated. On the other hand, if it is determined in step S1 that pre-shifting is unnecessary (step S1: YES), the process proceeds to step S2.

In step S2, the control device 40 performs gear removal in the third synchronizing mechanism 63. Specifically, the engagement state between the third synchro sleeve 63b and the sixth dog gear 63d is released.

In step S3 following step S2, control device 40 determines whether or not pre-shifting is necessary. This determination is performed based on the vehicle speed or the like, for example, as in the above-described step S1.

If it is determined in step S3 that pre-shifting is not necessary (step S3: NO), the process of step S3 is repeated. On the other hand, if it is determined in step S3 that pre-shifting is necessary (step S3: YES), the process proceeds to step S4.

In step S4, the control device 40 determines whether the rotational speed difference between the first countershaft 33 and the second countershaft 34 is less than or equal to a predetermined threshold. This determination is made, for example, by detecting the number of rotations of the first countershaft 33 and the number of rotations of the second countershaft 34 with a rotation number sensor (not shown) and directly determining the number of rotations. In this case, the above-described threshold value may be stored in advance in the control device 40 as a rotational speed difference that does not apply an excessive load to the third synchronizing mechanism 63 by an experiment or the like.

Further, the determination in step S4 may be made by measuring an elapsed time after gear removal in the third synchronizing mechanism 63. In this case, an elapsed time until the above-mentioned rotational speed difference exceeds a predetermined threshold may be determined by experiment.

If it is determined in step S4 that the rotational speed difference between the first countershaft 33 and the second countershaft 34 is less than or equal to the predetermined threshold (step S4: YES), the process proceeds to step S8 (described later). On the other hand, if it is determined in step S4 that the rotational speed difference between the first countershaft 33 and the second countershaft 34 is not less than or equal to the predetermined threshold (step S4: NO), the process proceeds to step S5.

At step S5, the control device 40 engages the second clutch 20. Specifically, the second clutch 20 is fully engaged. The second clutch 20 may be slip engaged. When the second clutch 20 is engaged in step S5, the process proceeds to step S6.

In step S6, the control device 40 determines whether the rotational speed difference between the first countershaft 33 and the second countershaft 34 is equal to or less than a threshold. This determination is made, for example, by detecting the number of rotations of the first countershaft 33 and the number of rotations of the second countershaft 34 with a rotation number sensor (not shown) and directly determining the number of rotations. When the second clutch 20 is completely engaged, the engagement time required to bring the second clutch 20 into the full engagement state from the disengaged state is determined in advance by experiment. You may make it judge simply by whether it is not.

If it is determined in step S6 that the rotational speed difference between the first countershaft 33 and the second countershaft 34 is not less than or equal to a predetermined threshold (step S6: NO), the process of step S6 is repeated. On the other hand, when it is determined in step S6 that the rotational speed difference between the first countershaft 33 and the second countershaft 34 is less than or equal to the predetermined threshold (step S6: YES), the process proceeds to step S7.

At step S7, the control device 40 releases the engagement of the second clutch 20. Then, the process proceeds to step S8.

In step S8, the control device 40 causes the third synchronization mechanism 63 to engage the gear. Specifically, the third synchro sleeve 63b and the sixth dog gear 63d are engaged.

As described above, according to the present embodiment, when the shift from the eighth gear to the ninth gear is performed, the connection between the first counter shaft 33 and the second counter shaft 34 is performed by the third synchronizing mechanism 63. To release. This can prevent the rotational power from the engine from being transmitted to the first countershaft 33. Therefore, the deterioration of the fuel consumption by stirring of lubricating oil can be suppressed.

Further, according to the present embodiment, when the first countershaft 33 and the second countershaft 34 are rejoined by the third synchronizing mechanism 63, the second clutch 20 is temporarily engaged. Therefore, the load applied to the third synchronizing mechanism 63 can be reduced.

Furthermore, according to the present embodiment, when the rotational speed difference between the first countershaft 33 and the second countershaft 34 exceeds the predetermined threshold, the second clutch 20 is temporarily engaged. In other words, when the relative rotational speed between the first countershaft 33 and the second countershaft 34 is small and is less than or equal to the predetermined threshold, the third sync is generated without temporarily engaging the second clutch 20. Gear engagement in the mechanism 63 is performed. Therefore, in a situation where the load applied to the third synchronizing mechanism 63 is not so large, the time required for the pre-shift can be shortened.

(Modification)
In the above-described embodiment, the case where the shift from the eighth gear to the ninth gear is performed is described as an example, but the present invention is not limited to this. For example, even when the shift from the fourth gear to the fifth gear is performed, similar effects can be obtained by the same control. Hereinafter, the case where the shift from the fourth gear to the fifth gear is performed will be described in detail.

FIG. 5 shows a state immediately after the upshift from the fourth gear to the fifth gear is performed. As shown in FIG. 5, immediately after the upshift from the fourth gear to the fifth gear is performed, the third synchronizing mechanism 63 is in a state in which the first counter shaft 33 and the second counter shaft 34 are coupled.

In this example, the following operation is performed to prevent the first counter shaft 33 from being rotationally driven by the engine after the shift from the fourth gear to the fifth gear.

Specifically, after the upshift from the 4th gear position to the 5th gear position is performed, in the state of the 5th gear position, coupling of the first counter shaft 33 and the second counter shaft 34 by the third synchro mechanism 63 is performed. Release (see FIG. 6). This can prevent the rotational power from the engine from being transmitted to the first countershaft 33. Therefore, the deterioration of the fuel consumption by stirring of lubricating oil can be suppressed.

By the way, when shifting to the fourth gear is performed due to a decrease in the vehicle speed or the like while traveling at the fifth gear, the first counter shaft 33 and the second counter shaft 34 are re-operated by the third synchro mechanism 63. Although it will combine, in this case, the problem shown below may arise.

Therefore, in the present embodiment, in order to prevent an excessive load from being applied to the third synchronizing mechanism 63, prior to the reconnection of the first counter shaft 33 and the second counter shaft 34 by the third synchronizing mechanism 63, The action is taken.

When shifting to the sixth gear is performed due to an increase in the vehicle speed or the like while traveling at a state where the first countershaft 33 and the second countershaft 34 are disengaged in the fifth gear, the fourth synchro mechanism Although the third output gear 57a and the output shaft 35 are coupled by 64, in this case, the following problems may occur.

That is, while the output shaft 35 is rotating at high speed, the rotational speed of the third output gear 57a is low. Therefore, if it is attempted to couple the third output gear 57a and the output shaft 35 by the fourth synchronizing mechanism 64 as it is, there is a possibility that an excessive load may be applied to the fourth synchronizing mechanism 64.

Therefore, in the present embodiment, in order to prevent an excessive load from being applied to the fourth synchronizing mechanism 64, the following operation is performed prior to the connection of the third output gear 57a and the output shaft 35 by the fourth synchronizing mechanism 64. It will be.

Specifically, before the fourth synchro sleeve 64b is engaged with the eighth dog gear 64d, the second clutch 20 is temporarily engaged.

Thus, the power of the engine is transmitted to the third output gear 57a via the second input shaft 32, the first gear train 51, the first countershaft 33 and the seventh counter gear 57b, and the rotational speed of the third output gear 57a Will rise. Then, when the rotational speed of the third output gear 57a is sufficiently increased, the engaged second clutch 20 is disconnected, and the fourth synchro sleeve 64b is engaged with the eighth dog gear 64d. Thereby, the load applied to the fourth synchronizing mechanism 64 can be reduced.

(Another example of load reduction control of synchro mechanism)
By the way, for example, when performing the preshift to the fourth gear immediately after the downshift from the sixth gear to the fifth gear, the fourth synchro mechanism 64 couples the third output gear 57a to the output shaft 35. Then, the first counter shaft 33 and the second counter shaft 34 are coupled by the third synchronizing mechanism 63. In this case, the following problems may occur.

That is, by releasing the connection between the third output gear 57a and the output shaft 35 by the fourth synchronizing mechanism 64, the first counter shaft 33 is separated from the engine, and the rotational power from the engine is transmitted to the first counter shaft 33. It will not be done. Therefore, the rotation speed of the first counter shaft 33 lower than the rotation speed of the second counter shaft 34 is further reduced by the stirring resistance of the lubricating oil in the transmission case. In this state, if the first counter shaft 33 and the second counter shaft 34 are to be coupled by the third synchronizing mechanism 63 as it is, there is a possibility that the third synchronizing mechanism 63 may be overloaded.

Therefore, in the present embodiment, in order to prevent an excessive load from being applied to the third synchronizing mechanism 63, the fourth synchronizing mechanism 64 releases the connection between the third output gear 57a and the output shaft 35, and then the third synchronizing mechanism Prior to coupling the first counter shaft 33 and the second counter shaft 34 according to 63, the following operation is performed.

Specifically, after disengaging the fourth synchro sleeve 64b and the eighth dog gear 64d, the second clutch 20 is temporarily engaged before the third synchro sleeve 63b is engaged with the sixth dog gear 63d. Match.

As a result, the power of the engine is transmitted to the first countershaft 33 via the second input shaft 32, and the rotational speed of the first countershaft 33 is increased. Then, when the rotational speed of the first counter shaft 33 is sufficiently increased, the engaged second clutch 20 is disconnected, and the third synchro sleeve 63b is engaged with the sixth dog gear 63d.

Thereby, the load applied to the third synchronizing mechanism 63 can be reduced. Such load reduction control of the synchronization mechanism is not limited to the pre-shift to the fourth gear immediately after the down shift from the sixth gear to the fifth gear, and is applicable.

This application is based on the Japanese Patent Application (Japanese Patent Application No. 2017-198763) filed on October 12, 2017, the contents of which are incorporated herein by reference.

The dual clutch transmission of the present disclosure can suppress the deterioration of fuel efficiency due to the stirring of oil, and has great industrial applicability.

Reference Signs List 1 dual clutch type transmission 2 output shaft 10 first clutch 11 input clutch plate 12 output clutch plate 20 second clutch 21 input clutch plate 22 output clutch plate 30 transmission unit 31 first input shaft 32 second input shaft 33 first counter shaft 34 second counter shaft 35 output shaft 40 control device 51 first gear train 51 a first input gear 51 b first counter gear 52 reverse gear train 52 a second input gear 52 b second counter gear 52 c reverse idler gear 53 2nd gear train 53a 3rd input gear 53b 3rd counter gear 54 3rd gear train 54a 4th input gear 54b 4th counter gear 55 4th gear train 55a 1st output gear 55b 5th counter gear 56 5th gear train 56a Second output gear 56b Sixth counter gear 57 Sixth gear train 57a Third output Gear 57b seventh counter gear 61 first synchronizing mechanism 61a first synchro hub 61b first synchronizer sleeve 61c first Dogugiya 61d second Dogugiya 62 second synchronizing mechanism
62a second sync hub 62b second sync sleeve 62c third dog gear 62d fourth dog gear 63 third sync mechanism 63a third sync hub 63b third sync sleeve 63c fifth dog gear 63d sixth dog gear 64 fourth sync mechanism 64a fourth sync Hub 64b 4th synchro sleeve 64c 7th dog gear 64d 8th dog gear

Claims

A first input shaft having a first clutch capable of connecting and disconnecting power from a driving source, and a second clutch capable of connecting and disconnecting power from the driving source, the first input shaft being coaxial with the first input shaft; Two input shafts, a first counter shaft parallel to the first input shaft, and a second counter shaft coaxially arranged to the first counter shaft and selectively coupled to the first counter shaft An output shaft coaxially arranged with the first input shaft,
From the drive source to the first input shaft and the first input gear, from the first predetermined shift stage where power transmission is performed from the drive source to the output shaft via the second input shaft, the first counter shaft and the second counter shaft When a shift to a second predetermined shift stage is performed where power is transmitted to the output shaft via the second counter shaft, the coupling between the first counter shaft and the second counter shaft is released. While the power is not transmitted from the drive source to the first counter shaft,
When performing a state change to a state where power is transmitted from the drive source or the output shaft to the first counter shaft, the second clutch is temporarily connected prior to the state change.
Dual clutch transmission.
In the case where the relative rotational speed between the first countershaft and the second countershaft exceeds a predetermined threshold value after releasing the coupling between the first countershaft and the second countershaft, Temporarily connect the second clutch,
The dual clutch transmission according to claim 1.
A first gear train for transmitting power between the second input shaft and the first counter shaft;
A second gear train selectively transmitting power between the first input shaft and the second counter shaft;
A third gear train having an idle gear connectable to the first input shaft and the output shaft, and a first counter gear fixed to the second counter shaft;
A fourth gear train having a second counter gear fixed to the second counter shaft and an output gear connectable to the output shaft;
And a fifth gear train for selectively transmitting power between the first countershaft and the output shaft.
The dual clutch transmission according to claim 1.
In the first predetermined gear, power is transmitted from the drive source to the output shaft via the first gear train and the third gear train.
In the second predetermined gear, power is transmitted from the drive source to the output shaft through the second gear train and the third gear train.
The dual clutch transmission according to claim 3.
In the first predetermined gear, power is transmitted from the drive source to the output shaft via the first gear train and the fourth gear train.
In the second predetermined gear, power is transmitted from the drive source to the output shaft via the second gear train and the fourth gear train.
The dual clutch transmission according to claim 3.