JP2006070937A - Twin clutch type transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly dispose a bearing for a second input shaft, a minimum diameter gear grouped in a gear set for a shift stage, an oil seal, and a smoothening mechanism so that the wall thickness of the second input shaft can be secured by avoiding that a load resulting from a large torque acts on the second input shaft and the strength of a twin clutch type transmission is affected in the twin clutch type transmission in which the second input shaft formed in a hollow shape is rotatably supported on a first input shaft. <P>SOLUTION: The minimum diameter gear 35 among gears 31, 33, and 35 formed on the outer periphery of the second input shaft 6 is disposed adjacent to a ball bearing 9 for the second input shaft 6. Needle bearings 7 and 8 smoothening the relative rotation of the first input shaft 5 relative to the second input shaft 6 are installed between the rear end inner peripheral surface of the second input shaft 6 and the outer peripheral surface of the first input shaft 5. The oil seal 11 for preventing a lubricating oil from flowing out of the needle bearings 7 and 8 to clutches C1 and C2 is disposed between the inner peripheral surface of the second input shaft 6 and the outer peripheral surface of the first input shaft 5 between the needle bearings 7 and 8 and the minimum diameter gear 35. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention includes an automatic clutch for each gear stage grouped between an engine and a transmission. The automatic clutch engagement / disengagement switching (replacement control) and alternate selection of gear stages between the two gear groups. Thus, the present invention relates to a so-called twin clutch transmission that is useful for automatic shifting.

  As such a twin clutch transmission, conventionally, as described in Patent Document 1, for example, a first input shaft and a second input shaft to which engine rotation is selectively input via individual automatic clutches are provided. The shaft is hollow and rotatably supported on the first input shaft, and the first input shaft projects from the rear end of the second input shaft far from the engine and is supported rotatably on the fixed wall of the transmission case via a bearing. The grouped even-numbered gear group and the reverse-geared gear group are respectively arranged between the protruding rear end portion of the first input shaft and the counter shaft juxtaposed with the first and second input shafts. Provided as appropriate for transmission, and provided with a gear group of the odd-numbered shift stage group divided between the second input shaft and the countershaft as appropriate for transmission, and after shifting according to the selected shift stage. Rolling, a front-engine front-drive vehicle (FF vehicle) twin-clutch transmission for is known that they were taken out from the front end of the counter shaft close to the engine in the radial direction.

  In the above-described twin clutch transmission, in a state in which the gear position in one gear group is selected and the corresponding automatic clutch is engaged, no gear in the other gear group is selected, and when shifting, In the state where the gear position in the other gear group is selected and the corresponding automatic clutch is released, the automatic clutch related to the one gear group is released and the automatic clutch related to the other gear group is engaged. Thus, automatic shift can be performed by so-called clutch changeover control and alternate selection of shift speeds between the two shift speed group, and automatic transmission can be achieved even though it is a manual transmission.

As described above, since the first and second input shafts have a double structure, the needle bearing is rotatable between the inner peripheral surface of the second input shaft and the outer peripheral surface of the first input shaft. It is necessary to provide a smooth mechanism composed of, for example.
By the way, when a dry clutch type is used as the automatic clutch, it is necessary to prevent the lubricating oil from flowing out from the smooth mechanism to the automatic clutch provided at the front ends of the first and second input shafts. . This is because the smooth mechanism is filled with lubricating oil, and if the lubricating oil flows out to the engine side between the inner peripheral surface of the second input shaft and the outer peripheral surface of the first input shaft, and reaches the automatic clutch. This is because inconvenience arises in the engagement of the automatic clutch, and so-called clutch slip occurs, resulting in a problem that engine rotation cannot be completely transmitted.

Therefore, it is necessary to provide an oil seal between the inner peripheral surface of the second input shaft and the outer peripheral surface of the first input shaft to prevent the lubricating oil from flowing out. Conventionally, for example, those described in Patent Document 2 are known. The oil seal arrangement position described in Patent Document 2 is rotatable between the inner peripheral surface of the outer cylinder shaft corresponding to the second input shaft and the outer peripheral surface of the central shaft corresponding to the first input shaft. An inner bearing is provided. An inner oil seal is provided on the shaft between the inner bearing and the two-line clutch (travel clutch and PTO clutch). The inner oil seal serves to prevent the lubricating oil of the inner bearing from flowing into the clutch case.
JP-A-8-320054 Japanese Utility Model Publication No. 62-34051

  However, the conventional oil seal arrangement position described in Patent Document 2 causes the problems described below. That is, since the axial positions of the bearing supporting the outer cylinder shaft and the inner oil seal overlap, the thickness of the outer cylinder shaft cannot be secured sufficiently. For this reason, if the conventional oil seal placement position is applied, the thickness of the hollow cylindrical second input shaft is reduced, and the shaft strength of the second input shaft that transmits torque from the engine side to the rear end is reduced. Will be disadvantageous. In order to avoid this, if the design thickness of the second input shaft is increased, the wall thickness of the second input shaft will become larger than necessary at some axial positions, and the twin clutch transmission will become larger.・ Invite negative effects such as weight.

  The present invention proposes an appropriate arrangement of the bearing of the second input shaft, the oil seal, and the smooth mechanism so as not to be disadvantageous in terms of strength in view of such circumstances, and the twin clutch transmission is reduced in size and weight. It contributes to the conversion.

First of all, to explain the premise twin clutch transmission,
First, the input shaft includes a first input shaft and a second input shaft for selectively inputting engine rotation via individual clutches, and the front end portion of the second input shaft close to the engine is a fixed wall of the transmission case. The second input shaft is hollow and supported rotatably on the first input shaft through a bearing.

Then, the first input shaft protrudes from the rear end portion of the second input shaft far from the engine, and a group is formed between the protruding first input shaft portion and the counter shaft juxtaposed with the first and second input shafts. The gear group of one of the divided gear groups is provided so that it can be transmitted as appropriate,
Between the second input shaft and the countershaft, gear groups of the other grouped gear group are provided so as to be able to transmit appropriately.

For such a twin clutch transmission, in the present invention, the first input shaft and the second input shaft are provided between the inner peripheral surface at the rear end of the second input shaft far from the engine and the outer peripheral surface of the first input shaft. Provide a smooth mechanism that smoothes the relative rotation of
Between the inner peripheral surface of the second input shaft and the outer peripheral surface of the first input shaft between the axial position of the smooth mechanism and the axial position of the bearing supporting the front end of the second input shaft, An oil seal for preventing the lubricating oil from leaking from the smooth mechanism to the clutch is arranged so that the respective axial positions do not overlap each other.

  According to such a configuration of the present invention, the lubricating oil can be prevented from flowing out from the smooth mechanism to the automatic clutch, and so-called clutch slip can be prevented. Since the oil seal and the smooth mechanism are arranged, the arrangement makes it possible to obtain a layout configuration capable of ensuring the thickness of the second input shaft sufficiently and sufficiently, and the torque from the engine side is rear end. The shaft strength of the second input shaft that is transmitted to can be obtained. Therefore, the twin clutch transmission can be reduced in size and weight.

Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.
FIG. 1 shows a skeleton diagram of a twin-clutch transmission according to an embodiment of the present invention, and FIG. 2 shows an actual configuration diagram of the twin-clutch transmission. The following configuration is useful for front engine / front wheel drive vehicles (FF vehicles).

In the figure, reference numeral 1 denotes a transmission case. Between a gear transmission mechanism (described later) housed in the transmission case 1 and an engine (only the crankshaft 2 is shown in FIG. 2), an odd number is provided as shown in FIG. An automatic clutch C1 for shift speeds (first speed, third speed, fifth speed, reverse) and an automatic clutch C2 for even speed shift speeds (second speed, fourth speed, sixth speed) are interposed,
Both clutches C1 and C2 are coupled to the engine crankshaft 2 through a drive plate 3 under buffering.

The gear transmission mechanism housed in the transmission case 1 will be described below with reference to FIG. 2 as well. This is because the engine rotation from the drive plate 3 via the odd gear clutch C1 and the even gear clutch C2 is explained. The first input shaft 5 and the second input shaft 6 are selectively input.
The second input shaft 6 is hollow and is supported on the first input shaft 5. A front side needle bearing 7 and a rear side needle bearing 8 are interposed in an annular space between the two. These needle bearings 7 and 8 are smooth mechanisms lubricated with lubricating oil, and the inner first input shaft 5 and the outer second input shaft 6 are rotatable concentrically with each other.

As described above, the front ends of the first input shaft 5 and the second input shaft 6 that are rotatably supported on the engine side pass through the front wall 1a of the transmission case 1 and are coupled to the corresponding clutches C1 and C2.
The outer periphery of the front end of the second input shaft 6 close to the crankshaft 2 of the engine is rotatably supported on the front wall 1a of the transmission case 1 by a ball bearing 9 as a bearing, and the ball bearing 9 is passed through the front wall 1a through 1h. Support with. A second speed input gear 35 described later is formed adjacent to the ball bearing 9 on a second input shaft farther from the ball bearing 9 when viewed from the crankshaft 2 of the engine.

An annular space between the inner peripheral surface of the second input shaft 6 and the outer peripheral surface of the first input shaft 5 that is farther than the ball bearing 9 and closer to the needle bearings 7 and 8 when viewed from the crankshaft 2 of the engine. Is provided with an oil seal 11 for preventing the lubricating oil of the front side needle bearing 7 and the rear side needle bearing 8 from flowing out to the automatic clutches C1 and C2. For this reason, the axial positions of the needle bearings 7 and 8 and the oil seal 11 are on the rear end side with respect to the axial position of the ball bearing 9.
Therefore, the ball bearing 9 and the oil seal 11 do not coincide with each other on the axis of the second input shaft 6, and the wall thickness of the second input shaft 6 that is in close contact with them can be ensured sufficiently.

In this embodiment, since the thickness of the second input shaft 6 is not sacrificed by the root diameter of the second speed input gear 35, the axial direction of the second speed input gear 35 is shown in FIG. An oil seal 11 can be disposed at the position.
On the other hand, although not shown, when the thickness of the second input shaft 6 is sacrificed by the root diameter of the second speed input gear 35, the axial position of the oil seal 11 and the second speed By disposing the input gear 35 in the axial direction so as not to overlap each other, the thickness of the second input shaft 6 can be ensured sufficiently and sufficiently.

The first input shaft 5 is protruded from the rear end of the second input shaft 6, and the rear end portion 5 b of the protruded first input shaft 5 is rotatably supported on the rear wall 1 b of the transmission case 1 by a ball bearing 10. .
A counter shaft 15 is provided in parallel with the first input shaft 5 and the second input shaft 6 and is rotatably supported by the roller bearings 16 and 17 on the front wall 1a and the rear wall 1b of the transmission case 1.

  A counter gear 19 is provided at the front end of the counter shaft 15 so as to be integrally rotatable, and a differential gear device 20 is provided in the same plane perpendicular to the axis. The differential gear device 20 is drivingly coupled to left and right driving wheels (not shown).

  Between the rear end portion 5b of the first input shaft 5 and the countershaft 15, a gear set of an odd-numbered speed stage (first speed, third speed, fifth speed, reverse) group, that is, sequentially from the front side close to the engine The third speed gear set G3, the fifth speed gear set G5, the reverse gear set GR, and the first speed gear set G1 are provided.

  Since the first speed gear set G1 and the reverse gear set GR transmit the output of the low rotation large torque, a large load acts on the first input shaft 5 and the countershaft 15. Therefore, it is advantageous in terms of strength to arrange these gear sets G1 and GR in the vicinity of the ball bearing 10 as a bearing and in the vicinity of the roller bearing 17. Accordingly, the first speed gear set G1 is disposed adjacent to the ball bearing 10 and the roller bearing 17 at the rearmost end of the countershaft 15 and the rear end of the rear end portion 5b, and is disposed on the engine side of the first speed gear set G1. Adjoins the reverse gear set GR.

  Since the remaining third speed gear set G3 and fifth speed gear set G5 transmit the output of high rotational small torque, a small load acts on the first input shaft 5 and the countershaft 15. Therefore, these gear sets G3 and G5 may be arranged on the front side of the rear end portion 5b far from the bearing. Therefore, the fifth speed gear set G5 is disposed adjacent to the front side of the reverse gear set GR, and the third speed gear set G3 is disposed adjacent to the engine side of the fifth speed gear set G5.

  The first speed gear set G1 includes a first speed input gear 21 formed integrally with the rear end portion 5b of the first input shaft 5 and a first speed output gear 22 rotatably provided on the countershaft 15. It is configured by meshing.

  The reverse gear set GR is meshed with the reverse input gear 23 formed integrally with the rear end portion 5b of the first input shaft 5, the reverse output gear 24 provided rotatably on the counter shaft 15, and the gears 23, 24. The reverse idler gear 25 is configured by a reverse idler shaft 25a constructed between a transmission case front wall 1a and a rear wall 1b. Support for rotation. The reverse idler gear 25 is slidable in the axial direction on the reverse idler shaft 25a. In a normal state (when not retracted), the reverse idler gear 25 is located on the engine side as indicated by a broken line in FIG. 1 and a solid line in FIG. It does not mesh with the reverse input gear 23. Further, the reverse idler gear 25 does not mesh with the reverse output gear 24, and is in a floating state without meshing with any gear. On the other hand, at the time of retreating, it slides on the reverse idler shaft 25a in the direction of the arrow shown in FIG. 1 and is adjacent to the rear wall 1b. At this position, the reverse idler gear 25 meshes with the reverse input gear 23 as indicated by a solid line in FIG. 1 and a broken line in FIG. It also meshes with the reverse output gear 24.

  The fifth speed gear set G5 meshes a fifth speed input gear 26 formed integrally with the rear end portion 5b of the first input shaft 5 and a fifth speed output gear 27 provided rotatably on the countershaft 15. Let me configure.

  The third speed gear set G3 includes a third speed input gear 28 formed integrally with the rear end portion 5b of the first input shaft 5 and a third speed output gear 29 provided by being coupled to the countershaft 15 by mutual driving. It is configured by meshing.

The countershaft 15 is further provided with a synchronous meshing mechanism 30 disposed between the first speed output gear 22 and the fifth speed output gear 27,
When the coupling sleeve 30a is moved leftward from the neutral position shown in FIG. 2 and meshed with the clutch gear 30b, the first speed output gear 22 is drivingly coupled to the counter shaft 15 so that the first speed can be selected as will be described later. Shall
When the coupling sleeve 30a is moved rightward from the neutral position shown in FIG. 2 and meshed with the clutch gear 30c, the fifth speed output gear 27 is drivingly coupled to the countershaft 15 so that the fifth speed can be selected as will be described later. And
The left and right rows of the coupling sleeve 30a are performed by engaging a shift fork (not shown) with an outer circumferential groove 30g provided on the outer circumference of the coupling sleeve 30a.

Further, gear teeth are implanted on the outer periphery of the coupling sleeve 30a to form the reverse output gear 24. When the reverse idler gear 25 is meshed with the reverse output gear 24 as described above at the neutral position shown in FIG. 2 that does not mesh with any of the clutch gears 30b, 30c, the reverse output gear 24 is drivingly coupled to the countershaft 15 and will be described later. As you can see, you can choose to move backwards.
As shown in FIG. 2, the gear teeth of the reverse output gear 24 are planted by being arranged closer to the rear wall 1b than the outer peripheral groove 30g provided on the outer periphery of the coupling sleeve 30a.

Between the hollow second input shaft 6 and the countershaft 15, there is a gear set of the even-numbered speed (second speed, fourth speed, sixth speed) group, that is, from the front side close to the countershaft 2 of the engine. A second speed gear set G2, a fourth speed gear set G4, and a sixth speed gear set G6 are sequentially provided.
The second speed gear set G2 is arranged at the front end of the second input shaft 6 along the front wall 1a of the transmission case 1, the sixth speed gear set G6 is arranged at the rear end of the second input shaft 6, and the fourth The speed gear set G4 is disposed at the center between both ends of the second input shaft 4.

The sixth speed gear set G6 includes a sixth speed input gear 31 integrally formed on the outer periphery of the second input shaft 6 and a sixth speed output gear 32 that is rotatably provided on the countershaft 15 and meshes with each other. Constitute.
The fourth speed gear set G4 includes a fourth speed input gear 33 integrally formed on the outer periphery of the second input shaft 6 and a fourth speed output gear 34 that is rotatably provided on the countershaft 15 and meshes with each other. Constitute.
The second speed gear set G2 is formed by meshing a second speed input gear 35 integrally formed on the outer periphery of the second input shaft 6 with a second speed output gear 36 rotatably provided on the countershaft 15. Constitute.

  Here, the reason why the gear sets G2, G4, G6 of the even-numbered speed stage (second speed, fourth speed, sixth speed) group provided between the second input shaft 6 and the counter shaft 15 are arranged as described above. That is, the reason why the second speed gear set G2, the fourth speed gear set G4, and the sixth speed gear set G6 are sequentially arranged from the front side close to the engine will be described.

In arranging the gear sets G2, G4, and G6 of these even gear stages (2nd speed, 4th speed, 6th speed) group,
The requirement that the rear needle bearing 8 among the needle bearings 7 and 8 interposed between the first and second input shafts 5 and 6 should be positioned near the rear end of the second input shaft 6 in relation to the bearing span, And, in view of the requirement that the countershaft 15 should have a shape with a maximum diameter at the front end and a diameter gradually decreasing toward the rear end in terms of strength and gear assembly,
First, the input gear 31, 33, 35 formed on the second input shaft 6 has a large outer diameter and can provide a bearing housing space for the needle bearing 8 between the first input shaft 5 and the second input shaft 6. Gears 31 and 33 are selected, and the gear set G6 of the high speed stage (sixth speed) among the speed stages (sixth speed and fourth speed) is arranged on the side far from the engine, and the low speed stage (fourth speed) ) Gear set G4 on the side closer to the engine,
The remaining second speed input gear 35 having the smallest outer diameter is disposed adjacent to the ball bearing 9 as described above, and the gear set G2 of the second gear stage related thereto is disposed on the side closest to the engine.

  Since the second speed gear set G2 transmits the output of the low rotation large torque, a large load acts on the second input shaft 6 and the counter shaft 15. Therefore, it is advantageous in terms of strength to dispose the gear set G2 in the vicinity of the ball bearing 9 as a bearing and in the vicinity of the roller bearing 16. For this reason, the second speed gear set G2 is disposed adjacent to the ball bearing 9 and the roller bearing 16 at the front end of the second input shaft 6 and the front end of the countershaft 15 closest to the engine.

Further, since the remaining fourth speed gear set G4 transmits the output of the middle rotating torque, and the sixth speed gear set G6 transmits the output of the high rotation small torque, the second input is at these axial positions. A small load acts on the shaft 6 and the countershaft 15. Therefore, these gear sets G4 and G6 may be disposed on the rear side of the second input shaft 6 far from the ball bearing 9 as a bearing. For this reason, it is reasonable to dispose the fourth speed gear set G4 and the sixth speed gear set G6 at the rear end of the second input shaft 6.
Furthermore, the outer diameter of the second input shaft 6 can be made larger as long as it does not interfere with other members on the rear end side from the axial position of the second speed input gear 35 having a small diameter, Even when the oil seal 11 and the oil seal 11 are disposed, the thickness of the second input shaft 6 can be secured.

The countershaft 15 is further provided with a synchronous meshing mechanism 37 disposed between the third speed output gear 29 and the sixth speed output gear 32,
When the coupling sleeve 37a is moved leftward from the illustrated neutral position and meshed with the clutch gear 37b, the third speed output gear 29 is drivingly coupled to the countershaft 15 so that the third speed can be selected as will be described later. ,
When the coupling sleeve 37a is moved rightward from the illustrated neutral position and meshed with the clutch gear 37c, the sixth speed output gear 32 is drivingly coupled to the counter shaft 15 so that the sixth speed can be selected as will be described later. .

The countershaft 15 is provided with a synchronous meshing mechanism 38 disposed between the fourth speed output gear 34 and the second speed output gear 36,
When the coupling sleeve 38a is moved leftward from the illustrated neutral position and meshed with the clutch gear 38b, the fourth speed output gear 34 is drivingly coupled to the counter shaft 15 so that the fourth speed can be selected as will be described later. ,
When the coupling sleeve 38a is moved rightward from the illustrated neutral position and meshed with the clutch gear 38c, the second speed output gear 36 is drivingly coupled to the counter shaft 15 so that the second speed can be selected as will be described later. .

Next, the operation of the twin clutch transmission according to the above embodiment will be described.
The clutches C1 and C2 of this embodiment are normally open types, and both the clutches C1 and C2 are released in the neutral (N) range and parking (P) range where power transmission is not desired.
In the D range where forward power transmission is desired and the R range where reverse power transmission is desired, the coupling sleeves 30a, 37a, 38a of the synchronous mesh mechanisms 30, 37, 38, the reverse idler gear 25 and the clutch C1 are as follows. , C2 can be used to select each forward gear and reverse gear.

When the first speed is desired in the D range, with the clutch C1 released, the coupling sleeve 30a of the synchronous mesh mechanism 30 is moved left to drive-couple the gear 22 to the countershaft 15, and then the clutch C1 is engaged.
As a result, the engine rotation from the clutch C1 is output to the differential gear device 20 via the first input shaft 5, the first speed gear set G1, the countershaft 15, and the counter gear 19 to transmit power at the first speed. Can do.
When the selection of the first speed is for starting, it is a matter of course that the engagement progress control of the clutch C1 is performed for that purpose.

During the upshift from the first speed to the second speed, with the clutch C2 disengaged, the coupling sleeve 38a of the synchronous meshing mechanism 38 is moved to the right to drive-couple the gear 36 to the countershaft 15, and then the gear shift is scheduled. Be prepared for the second speed. Then, the clutch C2 is disengaged while releasing the clutch C1 (so-called pre-shift clutch switching) to perform an upshift from the first speed to the second speed.
Such pre-shifting has an advantage that the torque output to the differential gear device 20 during the upshift operation is interrupted, that is, there is no torque interruption during the so-called shift operation. After completion of the upshift, the coupling sleeve 30a of the synchronous meshing mechanism 30 is returned to the neutral position, and the gear 22 is disconnected from the countershaft 15.
As a result, the engine rotation from the clutch C2 is output to the differential gear device 20 via the second input shaft 6, the second speed gear set G2, the countershaft 15, and the counter gear 19 to transmit power at the second speed. Can do.

During the upshift from the second speed to the third speed, with the clutch C1 disengaged, the coupling sleeve 37a of the synchronous meshing mechanism 37 is moved left to drive-couple the gear 29 to the countershaft 15, and then the speed change is scheduled. Be prepared for the third speed. Then, by engaging the clutch C1 while releasing the clutch C2 (so-called pre-shift clutch switching), an upshift from the second speed to the third speed is performed.
After completion of the upshift, the coupling sleeve 38a of the synchronous meshing mechanism 38 is returned to the neutral position, and the gear 36 is separated from the countershaft 15.
As a result, the engine rotation from the clutch C1 is output to the differential gear device 20 via the first input shaft 5, the third speed gear set G3, the countershaft 15, and the counter gear 19 to transmit power at the third speed. Can do.

During the upshift from the third speed to the fourth speed, with the clutch C2 disengaged, the coupling sleeve 38a of the synchronous meshing mechanism 38 is moved to the left to drive-couple the gear 34 to the countershaft 15, and then the speed change is scheduled. Prepare for the 4th speed. Then, the clutch C1 is released and the clutch C2 is engaged (change of clutch by so-called pre-shift), thereby performing an upshift from the third speed to the fourth speed.
After completion of the upshift, the coupling sleeve 37a of the synchronous meshing mechanism 37 is returned to the neutral position, and the gear 29 is separated from the countershaft 15.
As a result, the engine rotation from the clutch C2 is output to the differential gear device 20 via the second input shaft 6, the fourth speed gear set G4, the countershaft 15, and the counter gear 19, and power is transmitted at the fourth speed. Can do.

When upshifting from the fourth speed to the fifth speed, with the clutch C1 disengaged, the coupling sleeve 30a of the synchronous meshing mechanism 30 is moved to the right to drive-couple the gear 27 to the countershaft 15, and then the gear shift is scheduled. Be prepared for the fifth speed. Then, by engaging the clutch C1 while releasing the clutch C2 (so-called pre-shift clutch switching), an upshift from the fourth speed to the fifth speed is performed.
After completion of the upshift, the coupling sleeve 38a of the synchronous meshing mechanism 38 is returned to the neutral position, and the gear 34 is separated from the countershaft 15.
As a result, the engine rotation from the clutch C1 is output to the differential gear device 20 through the first input shaft 5, the fifth speed gear set G5, the countershaft 15, and the counter gear 19 to transmit power at the fifth speed. Can do.

When upshifting from the fifth speed to the sixth speed, with the clutch C2 disengaged, the coupling sleeve 37a of the synchronous meshing mechanism 37 is moved to the right to drive-couple the gear 32 to the countershaft 15, and then the speed change is scheduled. Prepare for the 6th speed. Then, by engaging the clutch C2 while releasing the clutch C1 (so-called pre-shift clutch switching), an upshift from the fifth speed to the sixth speed is performed.
After completion of the upshift, the coupling sleeve 30a of the synchronous meshing mechanism 30 is returned to the neutral position, and the gear 27 is separated from the countershaft 15.
As a result, the engine rotation from the clutch C2 is output to the differential gear device 20 via the second input shaft 6, the sixth speed gear set G6, the countershaft 15, and the counter gear 19 to transmit power at the sixth speed. Can do.

  In addition, when downshifting from the sixth speed to the first speed in sequence, a predetermined downshift can be performed by performing the control opposite to the above upshift, and output to the differential gear device 20 during the downshift operation. This has the advantage that there is no torque interruption during the so-called shift operation.

In the R range where reverse power transmission is desired, with the clutch C1 released, the reverse idler gear 25 is moved left to drive-couple the gear 24 to the first input shaft 5, and then the clutch C1 is engaged.
As a result, the engine rotation from the clutch C1 is output to the differential gear device 20 via the first input shaft 5, the reverse gear set GR, the counter shaft 15, and the counter gear 19, and at this time, the rotation direction is reversed by the reverse gear set GR. Therefore, power transmission at the reverse gear position can be performed.
It should be noted that when starting at the reverse gear, the clutch C1 engagement progress control is performed for that purpose.

By the way, in the twin clutch transmission of this embodiment, relative rotation of the first input shaft 5 and the second input shaft 6 is performed in the annular space between the rear end portion of the second input shaft 6 and the first input shaft 5. Smooth needle bearings 7 and 8 are provided, and the second input shaft 6 is positioned between the axial positions of the needle bearings 7 and 8 and the axial position of the ball bearing 9 that supports the front end of the second input shaft 6. Between the inner peripheral surface and the outer peripheral surface of the first input shaft 5, an oil seal 11 for preventing the lubricant oil from flowing out from the needle bearings 7, 8 to the clutches C1, C2 is arranged.
And in the arrangement of the oil seal 11, since the axial position of the ball bearing 9 and the axial position of the oil seal 11 are arranged so as not to overlap each other,
The lubricating oil can be prevented from flowing into the automatic clutches C1 and C2, the fastening of these automatic clutches C1 and C2 can be ensured, and so-called clutch slippage can be prevented,
It becomes possible to ensure the necessary and sufficient thickness so that the thickness of the second input shaft 6 in the vicinity of the roll bearing 9 and the oil seal 11 does not become thin.

  Therefore, the arrangement relationship between the ball bearing 9, the oil seal 11, and the needle bearings 7 and 8 is such that the shaft strength of the second input shaft 6 that transmits torque to the rear end portion far from the engine can be secured at the front end portion. Can be suitably realized to contribute to the reduction in size and weight of the transmission.

Further, among the gears 31, 33, 35 formed on the outer periphery of the second input shaft 6, the gear 35 having the smallest diameter is disposed adjacent to the ball bearing 9 which is the bearing of the second input shaft 6.
The load derived from the large torque transmitted by the smallest diameter gear 35 acts on the middle of the second input shaft, which is disadvantageous with respect to the shaft strength, and a load is also imposed on the bearing of the second input shaft. It can be avoided. Therefore, the second input shaft 6 can be made more advantageous in terms of strength.
In the present embodiment, the minimum diameter gear 35 is disposed adjacent to the ball bearing 9, but it is needless to say that the same effect can be obtained even if it is disposed adjacently without being adjacent.

In this embodiment, since the thickness of the second input shaft 6 is not sacrificed by the root diameter of the second speed input gear 35, the axial direction of the second speed input gear 35 is shown in FIG. The position and the axial direction position of the oil seal 11 are arranged to overlap each other.
On the other hand, although not shown, the thickness of the second input shaft 6 is sacrificed by the root diameter of the second speed input gear 35, or the shaft strength of the second input shaft 6 is to be secured sufficiently. Under the design philosophy, the axial position of the oil seal 11 and the axial position of the second speed input gear 35 are shifted from each other without overlapping each other, so that the ball bearing 9 and the minimum diameter gear 35 are arranged. In addition, the oil seal 11 and the needle bearings 7 and 8 can be arranged so that their axial positions do not overlap each other.
As a result, the thickness of the second input shaft 6 can be sufficiently secured, and the second input shaft 6 that transmits torque to the rear end portion far from the engine can be made more advantageous in terms of strength.

  The twin-clutch transmission of this embodiment is a normally open type in which the clutches C1 and C2 are normally disengaged and the clutch C1 or C2 is engaged by hydraulic pressure during drive transmission. In the normal state, the clutches C1 and C2 are engaged, and the transmission path that does not transmit the driving force is a normally closed type that has the coupling sleeves 30a, 37a, and 38a of the synchronous mesh mechanisms 30, 37, and 38 in a neutral position. Of course.

1 is a schematic diagram showing a twin clutch transmission according to an embodiment of the present invention. It is an expanded sectional view showing the actual composition of the twin clutch type transmission.

Explanation of symbols

1 Transmission case
1a Front case of transmission case 2 Engine crankshaft
C1 Odd-speed clutch
C2 Even-speed clutch 5 First input shaft
5b 1st input shaft rear end 6 2nd input shaft 7 Front needle bearing 8 Rear needle bearing
9, 10 Ball bearing
11 Oil seal
15 Counter shaft
16, 17 Roller bearing (bearing)
19 Counter gear
20 Differential gear unit
GR reverse gear set
G1 1st gear set
G2 2nd gear set
G3 3rd speed gear set
G4 4th gear set
G6 6th gear set
23 Reverse input gear
24 Reverse output gear
35 Small-diameter gear belonging to the 2nd speed gear set

Claims (3)

A first input shaft and a second input shaft that selectively input engine rotation via individual clutches are provided, and the front end portion of the second input shaft close to the engine is rotatable on a fixed wall of the transmission case via a bearing. And the second input shaft is hollow and is rotatably supported on the first input shaft,
The first input shaft is protruded from the rear end portion of the second input shaft far from the engine, and the first input shaft portion is grouped between the protruding first input shaft portion and the counter shaft juxtaposed with the first and second input shafts. Each gear group gear set is provided so that it can be transmitted as appropriate,
In the twin-clutch transmission in which the gear group of the other gear group grouped between the second input shaft and the counter shaft is provided so as to be able to transmit appropriately, respectively,
A smooth mechanism is provided between the inner peripheral surface at the rear end portion of the second input shaft far from the engine and the outer peripheral surface of the first input shaft to smoothly rotate the first input shaft and the second input shaft.
Between the inner peripheral surface of the second input shaft and the outer peripheral surface of the first input shaft between the axial position of the smooth mechanism and the axial position of the bearing supporting the front end of the second input shaft, A twin-clutch transmission characterized in that oil seals for preventing the lubricating oil from flowing out from the smooth mechanism to the clutch are arranged so that their axial positions do not overlap each other. In the twin clutch transmission according to claim 1,
The smallest diameter gear among the gears belonging to the gear group of the other gear group and provided on the outer periphery of the second input shaft is disposed in the vicinity of the bearing that supports the front end portion of the second input shaft. Twin clutch transmission. In the twin clutch transmission according to claim 2,
The bearing for supporting the front end portion of the second input shaft, the smallest diameter gear, the oil seal, and the smooth mechanism are arranged so that their axial positions do not overlap each other. Twin clutch transmission.

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