JP2006070929A - Selective engagement type gear mechanism of transmission for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To specify a prescribed engagement position by a simple structure without requiring the need of separately installing a dedicated positioning member in a selective engagement type gear mechanism installed in a transmission having a plurality of gear sets for shifting between an input shaft and a countershaft and drivingly engaging by sliding an idler gear to the prescribed engagement position until engaged with an input/output gear among the gear sets. <P>SOLUTION: A first input shaft 5 is rotatably supported on the rear wall 1b of a transmission case 1 through bearings 10 projectedly from the rear end of a second input shaft 6 positioned apart from an engine, and the gear set GR for reverse shifting is properly installed between the rear end part 5b of the projected first input shaft and the countershaft 15 disposed parallel with the first and second input shafts 5 and 6 so as to be transmitted. A reverse idler gear 25 which is a gear slidably pivoted on the reverse idler shaft 25a among the reverse gear set GR is slid in a direction approaching the rear wall 1b to dampingly abut on the rear wall 1b so as to specify the engagement position for engaging it with a reverse input gear 23 on the first input shaft 5 and a reverse output gear 24 on the countershaft 15. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  INDUSTRIAL APPLICABILITY The present invention is used in a gear set constituting each gear stage of a vehicle transmission, and when driven, an idler gear slides on an idler shaft to a predetermined position so that an input gear on the input side and an output on the output side are output. The present invention relates to a selective meshing gear mechanism that meshes with a gear to drive-couple these input / output gears.

  As a selective meshing gear mechanism of such a vehicle transmission, conventionally, for example, as described in Patent Document 1, a first input shaft and a second input shaft that selectively input engine rotation via individual automatic clutches are used. The second input shaft is hollow and supported rotatably on the first input shaft. The first input shaft protrudes from the rear end of the second input shaft far from the engine and rotates on the fixed wall of the transmission case via a bearing. Between the rear end portion of the projecting first input shaft and the countershaft juxtaposed with the first and second input shafts, the gear sets and the reverse gear stages of the even-numbered speed group are grouped between Each gear set is provided so that it can be transmitted as appropriate, and the gear groups of the odd-numbered shift stage groups that are grouped between the second input shaft and the counter shaft are provided so that they can be transmitted as appropriate. Gears related to the reverse gear of a twin-clutch transmission for a front engine / front wheel drive vehicle (FF vehicle) in which the rotation after shifting according to the speed is extracted radially from the front end of the countershaft close to the engine The set is known.

The reverse idler gear that belongs to the gear set related to the reverse gear of the twin clutch transmission and that reverses the rotation direction of the first input shaft and transmits it to the countershaft is a reverse idler that rotatably supports the reverse idler gear in a normal state. It does not mesh with other gears on the shaft and floats without transmitting any power, but when reverse gear is selected, the reverse idler gear slides on the reverse idler shaft and the input gear and output gear And the first input shaft and the countershaft are coupled to each other, thereby reversing the direction of rotation of the first input shaft and transmitting it to the countershaft.
JP-A-8-320054

  However, the selective meshing gear mechanism for a vehicle transmission described in Patent Document 1 has the following problems. That is, the structure of the gear set related to the reverse gear of the conventional twin clutch transmission is such that the reverse idler gear d belonging to the gear set of the reverse gear is in a normal state (non-reverse) as shown in FIG. Is adjacent to a fixed wall b that forms part of the transmission case a, and does not mesh with any gear and floats on the reverse idler shaft c. When the reverse gear is selected, the reverse idler gear d is slid in the direction of the arrow, and is brought into contact with the dedicated positioning member e to define the meshing position. Therefore, it is necessary to separately provide a dedicated positioning member e, which increases the number of processing steps and the number of parts.

  In order to avoid this, as shown in FIG. 5, it is conceivable that the shape of a part of the transmission case a is a wall-shaped member f such as the positioning member e described above. However, in this case, the shape of the transmission case a becomes complicated and processing becomes difficult. In any case, it requires a man-hour and a complicated configuration of the transmission case, which is a major factor in increasing the cost.

First of all, to explain the premise vehicle transmission,
Between the input shaft driven by the engine and the countershaft that drives the wheels, gear sets corresponding to each gear stage are individually provided,
One end of the input shaft is rotatably supported on a fixed wall of the transmission case via a bearing, and the gear set provided at least in the vicinity of the fixed wall of the gear set includes an input gear on the input shaft side, An output gear on the counter shaft side and an idler gear pivotally supported on an idler shaft are provided, and when the driving force is transmitted, the idler gear slides to a predetermined position and meshes with the input / output gear. Thus, a selective meshing gear set that performs drive transmission is obtained.

  In the present invention, an idler gear which is a gear which is supported on one end of the idler shaft on the fixed wall and is slidably supported on the idler shaft. However, the meshing position for the meshing is defined by sliding in the direction approaching the fixed wall and coming into contact with the fixed wall.

According to the configuration of the present invention, the meshing position of the idler gear is defined by using the fixed wall that supports the idler shaft as shown in FIG. 3 as compared with the selective meshing gear mechanism of the conventional vehicle transmission. As a result, it is not necessary to separately provide a dedicated positioning member for defining the meshing position. Therefore, it is possible to specify the meshing position of the reverse idler gear with a simple configuration by simplifying the shape of the transmission case 1 without providing a separate positioning member, which is advantageous in terms of cost.
Further, since one end of the input shaft is rotatably supported on the fixed wall via a bearing, the position where the large reverse torque acts on the first input shaft is brought close to the support point (bearing) of the fixed wall. be able to. Therefore, the strength of the input shaft is advantageous, and the durability performance of the vehicle transmission is improved.

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 type transmission as a vehicle transmission according to an embodiment of the present invention, and FIG. 2 shows an actual configuration diagram of the twin clutch type transmission. The twin-clutch transmission will have the following useful configuration for front engine and front wheel drive vehicles (FF vehicles).

In the figure, reference numeral 1 denotes a transmission case, and an odd-numbered speed stage (first speed, 1st speed, between a later-described gear transmission mechanism housed in the transmission case 1 and an engine (only the crankshaft 2 is shown in FIG. 2). The automatic clutch C1 for the third speed, the fifth speed, and the reverse) and the automatic clutch C2 for the even 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 speed change 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 is controlled via the odd speed shift clutch C1 and the even speed shift clutch C2. A first input shaft 5 and a second input shaft 6 which are selectively input are provided.
The second input shaft 6 is hollow and is supported on the first input shaft 5. The front input needle bearing 7 and the rear needle bearing 8 are interposed in the annular space between the two 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 on the engine side of the first input shaft 5 and the second input shaft 6 that are rotatably supported by each other 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 is rotatably supported by a ball bearing 9 on the front wall 1a of the transmission case 1, the front needle bearing 7 is disposed in the vicinity thereof, and the rear needle bearing 8 is remote from the engine. The second input shaft 6 is disposed at the rear end.
The first input shaft 5 is protruded from the rear end of the second input shaft 6, and the protruding rear end portion 5 b of the first input shaft 5 is rotatably supported by the ball bearing 10 on the rear wall 1 b of the transmission case 1.

  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 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 force 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.

  The remaining third speed gear set G3 and fifth speed gear set G5 transmit the output of high rotational small torque, and therefore a small force 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 5 b of the first input shaft 5, the reverse output gear 24 rotatably provided on the counter shaft 15, and these gears 23, 24. These gears 23 and 24 are composed of a reverse idler gear 25 that is driven and coupled in the reverse direction, and the reverse idler gear 25 is rotatable by a reverse idler shaft 25a installed between the transmission case front wall 1a and the rear wall 1b. To support. The reverse idler gear 25 is slidable in the axial direction on the reverse idler shaft 25a. In a normal state (when not retracted), as shown 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 output gear 24 does not mesh with the reverse output gear 24, and the reverse idler gear 25 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.
At the center of the reverse idler gear 25, a hollow cylindrical boss 25b protruding in the direction of the arrow shown in FIG. The boss portion 25b is penetrated by the idler shaft 25a, and the reverse idler gear 25 is stabilized so that the posture perpendicular to the idler shaft 25a is maintained. When the vehicle moves backward, the front end of the boss portion 25 abuts against the rear wall 1b, thereby defining the meshing position of the idler gear 25.

  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 arranged 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, a gear set of an even-numbered speed stage (second speed, fourth speed, sixth speed) group, that is, the second gear sequentially from the front side close to the engine, A speed gear set G2, a fourth speed gear set G4, and a sixth speed gear set G6 are provided.
The second speed gear set G2 is disposed at the front end of the second input shaft 6 along the front wall 1a of the transmission case 1, and the sixth speed gear set G6 is disposed at the rear end of the second input shaft 6 to provide the fourth speed. The gear set G4 is arranged 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 gear stage (second speed) gear set G2 is arranged on the side closest to the engine.

  Since the second speed gear set G2 transmits an output of a relatively low rotational large torque, a relatively large force acts on the second input shaft 6 and the countershaft 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 G4 transmits the output of the high rotation small torque, the second input shaft is at these axial positions. 6 and a small force act on 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 bearing. For this reason as well, the fourth speed gear set G4 and the sixth speed gear set G6 are arranged at the rear end of the second input shaft 6.

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 C2 is disengaged while releasing the clutch C1 (so-called pre-shift clutch switching), and an upshift from the third speed to the fourth speed is performed.
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 countershaft 15, and the counter gear 19, and at this time, the reverse idler gear 25 reverses the rotation direction. 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 the present embodiment, a gear set corresponding to each gear stage is provided between the first input shaft 5 driven by the engine crankshaft 2 and the countershaft 15 driving the differential gear device 20. G1, GR, G5, G3 are provided individually,
The first input shaft 5 is rotatably supported on the rear wall 1b of the transmission case 1 via a bearing 10, and the gear set GR provided at least in the vicinity of the rear wall 1b among the gear sets G1, GR, G5, G3 is: A reverse input gear 23 formed integrally with the first input shaft 5, a reverse output gear 24 provided on the countershaft 15, and an idler gear 25 slidably supported on an idler shaft 25a are provided. At the time of selection, the idler gear 25 slides to a predetermined position indicated by a broken line in FIG.
The idler shaft 25a is supported by the rear wall 1b, and the idler gear 25 slides in a direction approaching the rear wall 1b and comes into contact with the rear wall 1b, whereby the meshing position indicated by the broken line in FIG. From the provisions
As shown in FIG. 3, it is possible to define the meshing position of the idler gear 25 using the rear wall 1b, and it is not necessary to separately provide a dedicated positioning member that has been conventionally used. This can be simplified and is advantageous in terms of cost.

  The selective meshing gear set GR of the present invention is not limited to the above-described twin clutch transmission, and can also be applied to a manual shift vehicle transmission having one input shaft that has been widely used in the past. The selective meshing gear set of the present invention can be applied to the above-described reverse shift stage, and can be used for other forward movements by adding one gear on the drive transmission path and converting the rotation direction to forward movement. Of course, the present invention can also be applied to a shift stage.

In this embodiment, a boss portion 25b protruding toward the rear wall 1b is provided at the center of the reverse idler gear 25. The reverse idler shaft 25b is inserted into the boss portion 25b, and the tip of the boss portion 25b is By defining the meshing position for the meshing of the idler gear by contacting the fixed wall,
The reverse gear set GR can be separated from the rear wall 1b by the protruding height of the boss portion 25b. Accordingly, a clearance can be provided between the reverse idler gear 25 excluding the boss portion 25b and the rear wall 1b, and a space for providing parts such as the first speed gear set G1 can be provided in this clearance. There is an advantage.

In this embodiment, since the reverse gear stage GR, which is a low speed gear stage, is the selective meshing gear set of the present invention, the reverse input gear 23 that meshes with the reverse idler gear 25 as shown in FIG. It is provided in the vicinity of 1b, and the reverse gear set GR is disposed at a position close to the ball bearing 10 which is a bearing on the rear wall 1b side, as compared with the conventional twin clutch transmission shown in FIGS. It becomes possible.
Therefore, even if a large reverse torque (for low speed) acts on the first input shaft 5 with the reverse input gear 23, it is advantageous in terms of shaft strength and can reduce the burden on the ball bearing 10 as a bearing. it can.
In the present embodiment, the rear wall 1b rotatably supports the rear end of the countershaft 15 via the roller bearing 17 that is a bearing. Therefore, even if a large reverse torque acts on the countershaft 15, This is advantageous in terms of shaft strength, and can reduce the burden on the roller bearing 17 that is a bearing.

  Further, in this embodiment in which the selective meshing gear set of the present invention is applied to a twin clutch transmission, the clutch C1, C2 is normally released, and the clutch C1 or C2 is engaged by hydraulic pressure during drive transmission. Contrary to the present embodiment, the clutches C1 and C2 are engaged and the coupling sleeves 30a, 37a, and 38a of the synchronous meshing mechanisms 30, 37, and 38 are used in the transmission path that does not transmit the driving force. Of course, it may be of a normally closed type with a neutral position.

Further, in this embodiment in which the selective meshing gear set of the present invention is applied to a twin clutch transmission, a reverse gear gear is formed on the outer periphery of the coupling sleeve 30a of the synchronous meshing mechanism 30 to form a reverse output gear 24. Since the gear teeth are arranged on the rear wall 1b side from the outer peripheral groove 30g for engaging the shift fork for engaging the coupling sleeve 30a,
The reverse output gear 24 can be arranged so as to be close to the rear wall 1b, and the gear set GR of the reverse gear stage can be arranged at a position close to the roller bearing 17 that is a bearing on the rear wall 1b side.
Therefore, even if a large reverse torque is applied to the countershaft 15 by the reverse output gear 24, it is advantageous in terms of shaft strength, and the burden on the roller bearing 17 that is a bearing can be reduced.

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. It is a vertical side view which shows typically the position of the reverse idler gear of the twin clutch transmission. It is a vertical side view which shows typically the position of the reverse idler gear of the conventional twin clutch transmission. It is a vertical side view which shows typically the position of the reverse idler gear of the conventional twin clutch transmission.

Explanation of symbols

1 Transmission case
1a Transmission case front wall
1b Rear wall of transmission case 2 Engine crankshaft
C1 Odd-speed clutch
C2 Even gear stage clutch 3 Drive plate 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
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
G5 5th gear set
G6 6th gear set
23 Reverse input gear
24 Reverse output gear
25 Reverse idler gear
25a Reverse idler shaft
30, 37, 38 Synchronous meshing mechanism

Claims (5)

Between the input shaft driven by the engine and the countershaft that drives the wheels, gear sets corresponding to each gear stage are individually provided,
The input shaft is rotatably supported on a fixed wall of a transmission case via a bearing, and the gear set provided at least near the fixed wall of the gear set includes an input gear on the input shaft side, and the counter An output gear on the shaft side and an idler gear pivotally supported on the idler shaft are provided. When driving force is transmitted, the idler gear slides to a predetermined position and engages with the input / output gear. In a vehicle transmission that is a selective meshing gear set that performs transmission,
The idler shaft is supported by the fixed wall, the idler gear slides in a direction approaching the fixed wall, and comes into contact with the fixed wall, thereby defining a meshing position for the meshing of the idler gear. A selectively meshing gear mechanism for a vehicle transmission. The selective meshing gear mechanism of the vehicle transmission according to claim 1,
The idler gear is provided with a boss portion that protrudes toward the fixed wall, and a tip position of the boss portion abuts against the fixed wall to define a meshing position for the meshing of the idler gear. A selective meshing gear mechanism for a vehicle transmission. The selective meshing gear mechanism for a vehicle transmission according to claim 2,
A selective meshing gear mechanism for a vehicle transmission, wherein the selective meshing gear set is a low speed gear. The selective meshing gear mechanism for a vehicle transmission according to claim 3,
The vehicle transmission includes a first input shaft and a second input shaft that selectively input engine rotation via individual clutches as the input shaft, and the second input shaft is hollow and is on the first input shaft. Supported rotatably,
The first input shaft protrudes 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 rear end of the protruding first input shaft, Between the counter shaft juxtaposed to the second input shaft, the gear groups of one of the gear groups that are grouped are provided so as to be able to transmit appropriately, respectively, and the gear sets of the reverse gear are provided to be able to transmit appropriately,
A twin-clutch transmission in which a 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 as appropriate,
The reverse gear stage gear set is a selectively meshing gear set, and a reverse idler gear, which is a gear that is slidably supported on a reverse idler shaft, slides in a direction approaching the fixed wall. A selective meshing gear mechanism for a vehicle transmission, wherein the meshing position for the meshing of the reverse idler gear is defined by moving and contacting the fixed wall. The selective meshing gear mechanism for a vehicle transmission according to claim 4,
The counter shaft is rotatably supported on the fixed wall via a bearing,
Of the synchronous meshing mechanism that enables transmission of the gear group of the shift speed group selectively, the reverse is provided on the outer periphery of the coupling sleeve of the synchronous meshing mechanism that is on the counter shaft and is aligned with the gear set of the reverse speed gear stage. Forming gear teeth for the output gear that can mesh with the idler gear;
A selective meshing gear mechanism for a vehicle transmission, characterized in that the gear teeth are arranged on the fixed wall side from an outer peripheral groove for engaging a shift fork for engaging the coupling sleeve.

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