JP2006153048A - Transmission using multiple clutch device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission provided with a compact parking mechanism capable of holding a parking condition of a vehicle securely by devising a structure of the transmission using a multiple clutch device. <P>SOLUTION: A pair 110 of first backing gears are composed of a gear 122 fixed to an auxiliary shaft 30 and a first backing gear 191 arranged to rotate relatively for a backing shaft 70 and meshing with the gear 122. A pair 140 of fourth gears are composed of a gear 141 arranged to rotate relatively for an output shaft 40 and a gear 142 fixed to the auxiliary shaft 30 and meshing with the gear 141. A second switching mechanism can connect the auxiliary shaft 30 with the output shaft 40 through the pair 140 of fourth gears and release its connection. A parking gear 301 is arranged to rotate relatively for the backing shaft 70 and to prevent its relative rotation for the first backing gear 191. The parking mechanism 300 includes the parking gear 301 to regulate rotation of the parking gear 301 and release its regulation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a transmission, and more particularly to a transmission using a double clutch device, which is equipped with a parking mechanism.

  There is an automatic transmission (AT) as a means for automatically shifting the vehicle. In recent years, for example, a combination of a torque converter, a plurality of planetary gears, and a clutch has become mainstream. The AT eliminates the need for clutch operation by the driver at the start, stop, and shift required for the manual transmission (MT) due to the continuously variable transmission action of the torque converter and automatic switching of the plurality of clutches. On the other hand, since AT uses a torque converter via fluid, the transmission efficiency is inferior to MT that mechanically directly connects the input side and output side to transmit torque. Therefore, the AT has an advantage that the labor of the driver is reduced, but has a disadvantage that the fuel consumption of the vehicle is reduced. Therefore, in order to eliminate the need for clutch operation while ensuring the transmission efficiency of MT, an automatic transmission (AMT) automated based on the structure of MT has been developed.

  The AMT automates the clutch operation of the MT and the gear shifting operation of the transmission, and can eliminate the clutch operation while ensuring the same transmission efficiency as the conventional MT. However, since the AMT releases the clutch connection in the same manner as the MT during the speed change operation, torque transmission is temporarily interrupted. While the torque transmission is interrupted, the vehicle is driven only by inertia without acceleration, so that the so-called torque loss during the shift greatly affects the acceleration of the vehicle and tends to make the driver uncomfortable. On the other hand, in the case of AT, since a plurality of clutches are used, there is no torque interruption at the time of shifting.

  In order to solve the above-described problem of running out of torque, an AMT clutch device employing a double clutch device has been developed. The double clutch device mainly includes an input shaft, a first output shaft, a second output shaft, a first clutch, and a second clutch. The input shaft is for inputting torque from the engine to the double clutch device. The first output shaft is for outputting torque to the transmission side, and is arranged coaxially with the input shaft. The second output shaft is for outputting torque to the transmission side, and is a cylindrical member arranged coaxially on the outer peripheral side of the first output shaft. The first clutch is for transmitting and interrupting torque input to the input shaft to the first output shaft. The second clutch is for transmitting and blocking torque input to the input shaft to the second output shaft, and is disposed on the outer peripheral side of the first clutch (see, for example, Patent Document 1).

In the double clutch device, torque can be alternately transmitted to the first and second output shafts by the first and second clutches in order to prevent torque shortage. The first and second output shafts can be selectively connected to different gear pairs. In this compound clutch device, when the first clutch is connected and torque is transmitted to the first output shaft, the second output shaft is connected to one of the gear pairs and the first clutch is released. At the same time, the second clutch can be connected to transmit torque to the second output shaft. The reverse operation is also possible. Therefore, the AMT that employs this dual clutch device does not cause a torque shortage at the time of shifting, and enables a smooth and lean shifting operation.
JP 2000-352431 A JP 2004-217204 A

  As a transmission device mounted on the AMT described above, for example, the one described in Patent Document 2 can be cited. Since this transmission is capable of six-speed shifting by the counter gear system, six gear pairs that are the same as the number of gears are required for forward movement. In addition, this transmission device requires four switching mechanisms.

  For example, in the case of MT, a parking mechanism for a transmission using such a counter gear is such that a low-speed gear is connected to a member on the engine side during parking, and the rotation of the output shaft is restricted by the rotation prevention force of the engine. A method of maintaining the parking state is employed. However, the rotation prevention force of the engine is inadequate for maintaining the parking state of the vehicle. For example, when the vehicle is parked on a slope, the vehicle may move, which is dangerous. Further, since it is necessary to separate the engine side member and the output shaft when starting the engine, it is necessary to disengage the clutch or set the gear to neutral. When such a parking mechanism is employed in an AMT transmission, the operation of separating the engine and the output shaft is extraneous as compared to the AT, which increases the operation burden on the driver. From the above, it is not so preferable to adopt a method for maintaining the parking state of the vehicle by utilizing the rotation prevention force of the engine for the AMT.

  On the other hand, AT employs a method of mechanically locking the output shaft. Specifically, in a conventional AT parking mechanism, a parking gear is provided on the output shaft to mechanically prevent the parking gear from rotating. However, since the output shaft is the last of the speed change gear and does not have a configuration in which the output shaft is greatly decelerated between the wheels, a large rotation blocking force is required to maintain the parking state. For this reason, the AT parking mechanism needs to withstand a large load, and the parking mechanism itself tends to increase in size. In particular, commercial vehicles require a large-capacity parking mechanism because the total weight of the vehicle is larger than that of passenger cars, and the transmission itself is increased in size. Therefore, it is not preferable to adopt this method for AMT.

  The subject of this invention is providing the transmission which mounts the small parking mechanism which can hold | maintain the parking state of a vehicle reliably by devising the structure of the transmission using a double type clutch apparatus.

  The transmission according to claim 1 is mounted on an automatic transmission having a dual clutch device capable of selectively connecting and disconnecting the first and second clutches, and transmits torque from the engine to the output side. Is. The transmission includes a first input shaft, a second input shaft, a counter shaft, an output shaft, a reverse shaft, a first reverse gear pair, a fourth gear pair, a second switching mechanism, a parking gear. And a parking mechanism. The first input shaft is for inputting torque via the first clutch. The second input shaft is for inputting torque via the second clutch. The sub-axis is arranged in parallel to the first input axis. The output shaft is disposed coaxially with the first input shaft. The reverse shaft is disposed in parallel to the first input shaft. The first reverse gear pair is composed of a fourth gear fixed to the countershaft, and a first reverse gear arranged to be rotatable relative to the reverse shaft and meshing with the fourth gear. The fourth gear pair includes a seventh gear disposed so as to be rotatable relative to the output shaft, and an eighth gear fixed to the sub shaft and meshing with the seventh gear. The second switching mechanism can connect and disconnect the auxiliary shaft and the output shaft via the fourth gear pair. The parking gear is arranged so as to be rotatable relative to the reverse shaft and not rotatable relative to the first reverse gear. The parking mechanism includes a parking gear, and can regulate and release the rotation of the parking gear.

  Since this transmission includes the first reverse gear pair, the parking gear and the countershaft are connected via the reverse gear pair. Further, since the fourth gear pair and the second switching mechanism are provided, the countershaft and the output shaft are connected via the fourth gear pair. That is, the parking gear is connected to the output shaft through the reverse gear pair and the fourth gear pair. The parking gear and the output shaft can be connected with a large reduction ratio by appropriately setting the reduction ratio of each gear pair. As a result, when the rotation of the output shaft is blocked and the vehicle is parked, the rotation blocking force on the parking gear can be reduced, and the parking mechanism can be downsized. Moreover, in this transmission, since the rotation prevention force to the parking gear can be reduced, the parking state of the vehicle can be reliably maintained.

  According to a second aspect of the present invention, the transmission according to the first aspect includes a first gear pair, a second gear pair, a third gear pair, and a first switching mechanism. The first gear pair is composed of a first gear fixed to the second input shaft and a second gear fixed to the countershaft and meshing with the first gear. The second gear pair includes a fourth gear and a third gear that is disposed so as to be rotatable relative to the first input shaft and meshes with the fourth gear. The third gear pair is composed of a fifth gear fixed to the countershaft and a sixth gear meshed with the fifth gear so as to be relatively rotatable with respect to the first input shaft. The first switching mechanism can selectively connect and disconnect the first input shaft and the countershaft via either one of the second and third gear pairs. Further, the second switching mechanism selectively switches and releases the connection between the auxiliary shaft and the output shaft through the fourth gear pair and the connection between the first input shaft and the output shaft without using the fourth gear pair. Is possible.

  In this transmission, since the fourth gear meshes with both the third gear and the first reverse gear, the second gear pair and the first reverse gear pair share the fourth gear. Then, since the parking mechanism can use some of the gears of the transmission mechanism, there is no need to provide a reduction gear as the parking mechanism, and the transmission does not increase in size. Since the parking gear and the output shaft can be connected with a large reduction ratio, the rotation preventing force on the parking gear can be reduced when the rotation of the output shaft is prevented and the vehicle is parked. it can. Thereby, in this transmission, the parking mechanism can be reduced in size, and the parking state of the vehicle can be reliably maintained.

  Further, in this transmission, by changing the connection pattern of the first and second switching mechanisms, for example, the following six types of torque transmission paths from the first and second input shafts to the output shaft can be considered.

1) First input shaft → first switching mechanism → second gear pair → second shaft → second switching mechanism → fourth gear pair → output shaft 2) Second input shaft → first gear pair → second shaft → second switching Mechanism → fourth gear pair → output shaft 3) first input shaft → first switching mechanism → third gear pair → secondary shaft → second switching mechanism → fourth gear pair → output shaft 4) second input shaft → first Gear pair-> secondary shaft-> first switching mechanism-> second gear pair-> first input shaft-> second switching mechanism-> output shaft 5) First input shaft-> second switching mechanism-> output shaft 6) Second input shaft-> second 1 gear pair-> secondary shaft-> 1st switching mechanism-> 3rd gear pair-> 1st input shaft-> 2nd switching mechanism-> output shaft Therefore, the reduction ratio is set appropriately and the operation of the first and second clutches By appropriately switching the first and second switching mechanisms, this transmission can realize a six-speed shift. As compared with the conventional six-speed transmission, the conventional transmission requires six gear pairs and four switching mechanisms as described above, whereas this transmission has three (reverse drive). Only 4) gear pairs and 2 switching mechanisms are required. As a result, this transmission can achieve a six-speed shift with fewer components than in the prior art. As a result, the parking mechanism can be reduced in size and the axial dimension of the transmission mechanism can be shortened as compared with the prior art, so that the transmission can be reduced in size.

  According to a third aspect of the present invention, the transmission according to the first or second aspect further includes a second reverse gear pair and a reverse switching mechanism. The second reverse gear pair is disposed so as to be relatively rotatable with respect to the reverse shaft and disposed so as to be relatively rotatable with respect to the first input shaft and the second reverse gear disposed so as not to be relatively rotatable with respect to the first reverse gear and the parking gear. And a third reverse gear meshing with the second reverse gear. The reverse switching mechanism can connect and disconnect the first input shaft and the first and second reverse gears via the second reverse gear pair.

  Since this transmission includes the second reverse gear pair and the reverse switching mechanism, the parking mechanism can be downsized and the reverse can be achieved. For example, as the torque transmission path from the first input shaft to the output shaft during reverse travel, the following one is conceivable.

1) First input shaft → reverse switching mechanism → second reverse gear pair → first reverse gear pair → second shaft → second switching mechanism → fourth gear pair → output shaft Therefore, the parking mechanism is a part of the speed change mechanism. Since a gear can be used, it is not necessary to provide a reduction gear as a parking mechanism, and the transmission does not increase in size. Since the parking gear and the output shaft can be connected with a large reduction ratio, the rotation preventing force on the parking gear can be reduced when the rotation of the output shaft is prevented and the vehicle is parked. it can. Thereby, in this transmission, the parking mechanism can be reduced in size, and the parking state of the vehicle can be reliably maintained.

  According to a fourth aspect of the present invention, there is provided the transmission according to the first aspect, wherein the first gear pair, the second gear pair, the third gear pair, the fifth gear pair, the second reverse gear pair, and the first switching mechanism. And a third switching mechanism. The first gear pair is composed of a first gear fixed to the second input shaft and a second gear fixed to the countershaft and meshing with the first gear. The second gear pair includes a fourth gear and a third gear that is disposed so as to be rotatable relative to the first input shaft and meshes with the fourth gear. The third gear pair is composed of a fifth gear fixed to the countershaft and a sixth gear meshed with the fifth gear so as to be relatively rotatable with respect to the first input shaft. The fifth gear pair is composed of a ninth gear fixed to the countershaft and a tenth gear arranged to be rotatable relative to the first input shaft and meshing with the ninth gear. The second reverse gear pair is disposed so as to be relatively rotatable with respect to the first input shaft, relative to the reverse shaft, and not relative to the first reverse gear and the parking gear. And a second reverse gear meshing with the third reverse gear. The first switching mechanism can selectively connect and disconnect the first input shaft and the countershaft via either one of the second and third gear pairs. The third switching mechanism selectively switches between the connection of the first input shaft and the countershaft via the fifth gear pair and the connection of the first input shaft and the reverse shaft via the second reverse gear pair. It is possible to cancel. Further, the second switching mechanism selectively switches and releases the connection between the auxiliary shaft and the output shaft through the fourth gear pair and the connection between the first input shaft and the output shaft without using the fourth gear pair. Is possible.

  In this transmission, since the fourth gear meshes with both the third gear and the first reverse gear, the second gear pair and the first reverse gear pair share the fourth gear. Then, since the parking mechanism can use some of the gears of the transmission mechanism, there is no need to provide a reduction gear as the parking mechanism, and the transmission does not increase in size. Since the parking gear and the output shaft can be connected with a large reduction ratio, the rotation preventing force on the parking gear can be reduced when the rotation of the output shaft is prevented and the vehicle is parked. it can. Thereby, in this transmission, the parking mechanism can be reduced in size, and the parking state of the vehicle can be reliably maintained.

  Moreover, this transmission can change the connection pattern of each switching mechanism, for example, can consider the following eight types of torque transmission paths from the first and second input shafts to the output shaft.

1) First input shaft → first switching mechanism → second gear pair → second shaft → second switching mechanism → fourth gear pair → output shaft 2) First input shaft → third switching mechanism → fifth gear pair → second gear Shaft → second switching mechanism → fourth gear pair → output shaft 3) second input shaft → first gear pair → secondary shaft → second switching mechanism → fourth gear pair → output shaft 4) first input shaft → first 5) 2nd input shaft-> 1st gear pair-> secondary shaft-> 1st switching mechanism-> 3rd gear pair-> 1st switching mechanism-> 3rd gear pair-> secondary shaft-> 2nd switching mechanism-> 4th gear pair-> output shaft Input shaft → second switching mechanism → output shaft 6) First input shaft → second switching mechanism → output shaft 7) Second input shaft → first gear pair → secondary shaft → third switching mechanism → fifth gear pair → second 1 input shaft → second switching mechanism → output shaft 8) second input shaft → first gear pair → secondary shaft → second switching mechanism → second gear pair → first input shaft → second switching mechanism → output shaft Set the gear ratio appropriately and make the first Beauty by appropriately switching the respective switching mechanism in accordance with the operation of the second clutch, the transmission may be realized up to 8-speed. Compared with a conventional eight-speed transmission, the conventional transmission requires eight gear pairs and at least four switching mechanisms, which are the same as the number of gears. Only one gear pair and three switching mechanisms are required. As a result, this transmission can achieve an eight-speed shift with fewer components than in the prior art. As a result, the transmission can reduce the size of the parking mechanism as compared with the conventional one and can reduce the axial dimension of the transmission mechanism such as the gear pair and the switching mechanism. it can.

  According to a fifth aspect of the present invention, in any one of the second to fourth aspects, the number of teeth of the first reverse gear is the same as the number of teeth of the third gear. Further, the reduction ratio from the second input shaft of the first gear pair to the secondary shaft is α1, the reduction ratio from the first input shaft of the second gear pair to the secondary shaft is α2, and from the first input shaft of the third gear pair Α3 <α1 <α2 <α4, where α3 is the reduction ratio to the sub-axis.

  The reduction ratios α1 to α4 of the first to fourth gear pairs are as shown in FIG. Then, when the condition of α3 <α1 <α2 <α4 is satisfied, the connection patterns 1) to 6) in claim 2 correspond to the first speed to the sixth speed. Then, the reduction ratio of the first speed is α2 × α4. On the other hand, in this transmission, since the number of teeth of the first reverse gear is the same as the number of teeth of the third gear, the reduction ratio of the second gear pair and the reduction ratio of the first reverse gear pair are the same. That is, the reduction ratio from the parking gear to the output shaft is α2 × α4, which is equal to that in the first speed. Thereby, in this transmission, the reduction ratio from the parking gear to the output shaft can be reliably increased, and the rotation prevention force to the parking gear can be reduced.

  In addition, by setting α3 <α1 <α2 <α4, this transmission can reliably realize a six-speed shift with fewer gear pairs and a switching mechanism than in the prior art. As a result, the parking mechanism can be miniaturized and the axial dimension of the transmission can be shortened, and the transmission can be miniaturized.

  Further, by setting α2 <α4, the distance between the first input shaft and the auxiliary shaft can be shortened. Since α2 is a reduction ratio from the first input shaft to the counter shaft of the second gear pair, the diameter of the second gear on the counter shaft side is larger than the diameter of the first gear on the first input shaft side. On the other hand, the first gear is disposed so as to be rotatable relative to the first input shaft, and a bearing such as a needle bearing is provided on the inner peripheral side of the first gear. It cannot be made smaller. Therefore, it is difficult to reduce the diameter of the first and second gears.

  On the other hand, since α4 is a reduction ratio from the secondary shaft to the output shaft of the fourth gear pair, the diameter of the fourth gear on the secondary shaft side is smaller than the diameter of the third gear on the output shaft side. The third gear is disposed so as to be rotatable relative to the output shaft, and a bearing such as a needle bearing is provided on the inner peripheral side of the third gear. However, since the fourth gear is fixed to the countershaft, it is easy to reduce the diameter, and the third gear having the bearing can also be reduced in diameter. Therefore, the third and fourth gears can be easily reduced in diameter as compared with the first and second gears.

  As described above, the reduction ratio α2 of the second gear pair, which is difficult to reduce the diameter, is reduced, and the reduction ratio α4 of the fourth gear pair, which is easy to reduce the diameter, is increased, that is, α2 <α4. The diameter of each gear of the four gear pairs can be reduced. As a result, in this transmission, the parking mechanism can be miniaturized and the distance between the first input shaft and the countershaft can be shortened, and the transmission can be miniaturized. And the enlargement of the whole AMT can be prevented.

  According to a sixth aspect of the present invention, in the fourth aspect, the number of teeth of the first reverse gear is the same as the number of teeth of the third gear. Further, the reduction ratio from the second input shaft of the first gear pair to the secondary shaft is α1, the reduction ratio from the first input shaft of the second gear pair to the secondary shaft is α2, and from the first input shaft of the third gear pair When the reduction ratio to the countershaft is α3, the reduction ratio from the countershaft to the output shaft of the fourth gear pair is α4, and the reduction ratio from the first input shaft to the subshaft of the fifth gear pair is α5, α3 <Α1 <α5 <α2 <α4.

  In this transmission, since the condition of α3 <α1 <α5 <α2 <α4 is satisfied, the connection patterns 1) to 6) in claim 4 correspond to the first speed to the sixth speed. Then, since the number of teeth of the first reverse gear is the same as the number of teeth of the third gear, the reduction ratio of the second gear pair and the reduction ratio of the first reverse gear pair are the same. That is, the reduction ratio from the parking gear to the output shaft is α2 × α4, which is equal to that in the first speed. Thereby, in this transmission, the reduction ratio from the parking gear to the output shaft can be reliably increased, and the rotation prevention force to the parking gear can be reduced.

  In addition, by setting α3 <α1 <α5 <α2 <α4, this transmission can be surely realized up to a maximum of eight speeds with fewer gear pairs and switching mechanisms than in the past. As a result, the parking mechanism can be miniaturized and the axial dimension of the transmission can be shortened, and the transmission can be miniaturized.

  Further, by setting α2 <α4, the distance between the first input shaft and the auxiliary shaft can be shortened. Since α2 is a reduction ratio from the first input shaft to the counter shaft of the second gear pair, the diameter of the second gear on the counter shaft side is larger than the diameter of the first gear on the first input shaft side. On the other hand, the first gear is disposed so as to be rotatable relative to the first input shaft, and a bearing such as a needle bearing is provided on the inner peripheral side of the first gear. It cannot be made smaller. Therefore, it is difficult to reduce the diameter of the first and second gears.

  On the other hand, since α4 is a reduction ratio from the secondary shaft to the output shaft of the fourth gear pair, the diameter of the fourth gear on the secondary shaft side is smaller than the diameter of the third gear on the output shaft side. The third gear is disposed so as to be rotatable relative to the output shaft, and a bearing such as a needle bearing is provided on the inner peripheral side of the third gear. However, since the fourth gear is fixed to the countershaft, it is easy to reduce the diameter, and the third gear having the bearing can also be reduced in diameter. Therefore, the third and fourth gears can be easily reduced in diameter as compared with the first and second gears.

  As described above, the reduction ratio α2 of the second gear pair, which is difficult to reduce the diameter, is reduced, and the reduction ratio α4 of the fourth gear pair, which is easy to reduce the diameter, is increased, that is, α2 <α4. The diameter of each gear of the four gear pairs can be reduced. As a result, in this transmission, the parking mechanism can be miniaturized and the distance between the first input shaft and the countershaft can be shortened, and the transmission can be miniaturized. And the enlargement of the whole AMT can be prevented.

  According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the parking mechanism includes a parking cam assembly, a parking rod assembly, and a parking shaft assembly. The parking cam assembly is for restricting the rotation of the parking gear by engaging with the parking gear. The parking rod assembly is for biasing the parking cam assembly against the parking gear. The parking shaft assembly is for driving the parking rod assembly.

  According to an eighth aspect of the present invention, there is provided the transmission according to the seventh aspect, wherein the parking cam assembly is engageable with the parking gear, a support member that rotatably supports the parking cam, and the parking cam as the parking gear. A first elastic member that biases the side and the opposite side. The parking rod assembly is provided with a rod, a tip member provided so as to be movable relative to the rod, and for biasing the parking cam to the parking gear side, and a first member attached to the rod for biasing the tip member. 2 elastic members. Further, the parking shaft assembly includes a shaft body, a lever that is fixed to the shaft body and drives the rod, and a drive lever that rotates the shaft body.

  A transmission according to a ninth aspect is the cylindrical member according to any one of the first to sixth aspects, wherein the second input shaft is coaxially disposed on the outer peripheral side of the first input shaft.

  In the transmission according to the present invention, the structure of the transmission and the parking mechanism using the double clutch device can be reduced by devising the structure.

Embodiments of the present invention will be described with reference to the drawings.
1. Configuration of AMT FIG. 2 shows a configuration diagram of an AMT equipped with a dual clutch device. In FIG. 2, the engine (not shown) is arranged on the left side. The AMT is mainly composed of a double clutch device 1, a transmission device 2, and a casing (not shown), and the operation of each device is automatically performed by hydraulic control or the like. The double clutch device 1 mainly includes an input shaft 5, a first output shaft 50, a second output shaft 60, a first clutch C1, and a second clutch C2. The input shaft 5 is a member to which torque from the engine is input, and is elastically coupled to the flywheel 3 on the engine (not shown) side via the damper mechanism 4 in the rotational direction. The first output shaft 50 is for outputting torque input from the input shaft 5 to the transmission device 2 side. Similar to the first output shaft 50, the second output shaft 60 is for outputting torque input from the input shaft 5 to the transmission 2 side. The first clutch C <b> 1 is for transmitting and interrupting torque between the input shaft 5 and the first output shaft 50. The second clutch C <b> 2 is for transmitting and interrupting torque between the input shaft 5 and the second output shaft 60. With such a configuration, the double clutch device 1 can selectively output the torque to the first output shaft 50 or the second output shaft 60 by selectively operating the first and second clutches C1 and C2. The torque transmitted to the first output shaft 50 or the second output shaft 60 is output from the output shaft 40 after being shifted by the transmission 2. As the transmission 2 of the present invention employed in the AMT described above, the following first and second embodiments can be considered.

2. First Embodiment (1) Structure of Transmission A transmission 2 as a first embodiment of the present invention will be described. The transmission device 2 of the present embodiment is capable of six-speed transmission. FIG. 3 shows a schematic longitudinal sectional view of the transmission as the first embodiment of the present invention. FIG. 3 shows a cross-sectional view passing through the axes of the first input shaft, the counter shaft, and the reverse shaft. As shown in FIG. 3, the transmission 2 includes a first input shaft 10, a second input shaft 20, a countershaft 30, an output shaft 40, a reverse shaft 70, a first gear pair 110, Gear pair 120, third gear pair 130, fourth gear pair 140, first switching mechanism 160, second switching mechanism 170, reverse switching mechanism 180, reverse gear 199, and first reverse gear pair 195 And a second reverse gear pair 190 and a casing (not shown).

  The first input shaft 10 is for receiving torque from the double clutch device 1 and is provided so as not to rotate relative to the first output shaft 50 of the first clutch C1. The second input shaft 20 is for receiving torque from the double clutch device 1 and is provided so as not to rotate relative to the second output shaft 60 of the second clutch C2. In this embodiment, the first and second input shafts 10 and 20 are integrated with the first and second output shafts 50 and 60. The second input shaft 20 is a cylindrical member that is coaxially disposed on the outer peripheral side of the first input shaft 10. The second input shaft 20 is supported by the first bearing 81 so as to be rotatable relative to the casing. A needle bearing 82 is disposed between the first input shaft 10 and the second input shaft 20 in the radial direction. The first input shaft 10 is supported by a needle bearing 82 so as to be rotatable relative to the second input shaft 20. Further, the needle bearing 82 is disposed close to the first bearing 81 in the axial direction. And the 1st input shaft 10 is arrange | positioned so that relative rotation with respect to a casing is possible by the 3rd bearing 83 arrange | positioned at the output shaft 40 side mentioned later. As is clear from these structures, the first input shaft 10 is supported by the first bearing 81, the needle bearing 82, and the third bearing 83 so as to be rotatable relative to the second input shaft 20 and the casing.

  The auxiliary shaft 30 is disposed in parallel to the first input shaft 10. Sixth and seventh bearings 86 and 87 are provided at both ends of the countershaft 30. The countershaft 30 is supported by sixth and seventh bearings 86 and 87 so as to be rotatable relative to the casing. The output shaft 40 is for outputting torque from the transmission 2, and is disposed coaxially with the first input shaft 10. A gear 181 of a reverse switching mechanism 180 described later is provided at the end of the first input shaft 10 on the output shaft 40 side. The gear 181 has a cylindrical portion 181a that protrudes toward the axial output shaft 40, and the end of the output shaft 40 is inserted into the inner peripheral side of the cylindrical portion 181a. A needle bearing 84 is disposed between the output shaft 40 and the cylindrical portion 181a in the radial direction. The output shaft 40 is supported by a needle bearing 84 so as to be rotatable relative to the first input shaft 10. The needle bearing 84 is disposed close to the third bearing 83 in the axial direction. A fifth bearing 85 is provided on the output side of the output shaft 40. As apparent from these structures, the output shaft 40 is supported by the third bearing 83, the needle bearing 84, and the fifth bearing 85 so as to be rotatable relative to the first input shaft 10 and the casing. Further, the reverse shaft 70 is arranged in parallel with the first input shaft 10. The reverse shaft 70 is directly inserted into the casing, and is supported by the fixing member 71 so as not to rotate relative to the casing.

  The first gear pair 110 is for connecting the second input shaft 20 and the countershaft 30, and includes a gear 111 and a gear 112. The gear 111 is integrally formed on the outer peripheral side of the second input shaft 20. The gear 112 is fixed to the countershaft 30. The gear 111 and the gear 112 mesh with each other. The second gear pair 120 is for connecting the first input shaft 10 and the countershaft 30, and includes a gear 121 and a gear 122. The gear 121 is disposed so as to be rotatable relative to the first input shaft 10 by a needle bearing 121a. The gear 122 is formed integrally with the countershaft 30. The gear 121 and the gear 122 mesh with each other. The third gear pair 130 is for connecting the first input shaft 10 and the countershaft 30 and includes a gear 131 and a gear 132. The gear 131 is disposed so as to be rotatable relative to the first input shaft 10 by a needle bearing 131a. The gear 132 is integrally formed on the outer peripheral side of the auxiliary shaft 30. The gear 131 and the gear 132 mesh with each other. The fourth gear pair 140 is for connecting the output shaft 40 and the auxiliary shaft 30, and includes a gear 141 and a gear 142. The gear 141 is disposed so as to be rotatable relative to the output shaft 40 by two needle bearings 141a. The gear 142 is integrally formed on the outer peripheral side of the auxiliary shaft 30. The gear 141 and the gear 142 are meshed with each other. Since the gear 142 is formed integrally with the auxiliary shaft, the diameter of the gear 141 can be minimized and the distance between the shafts can be easily reduced.

  The first switching mechanism 160 is for selectively connecting and disconnecting the first input shaft 10 and the countershaft 30 via either one of the second and third gear pairs. 161, a first switching gear S1, a second switching gear S2, and a first sleeve 162. The switching mechanism 161 is fixed to the outer peripheral side of the first input shaft 10 and is composed of a plurality of members. The switching mechanism 161 has the same configuration as, for example, a conventional synchro mechanism or the like (in FIG. 3, a double sync mechanism), and thus detailed description thereof is omitted. The first switching gear S <b> 1 is provided so as to be rotatable relative to the first input shaft 10 and not rotatable relative to the gear 121. The second switching gear S <b> 2 is provided such that it can rotate relative to the first input shaft 10 and cannot rotate relative to the gear 131. The first sleeve 162 is a cylindrical member disposed on the outer peripheral side of the switching mechanism 161, and the inner peripheral side thereof meshes with the teeth formed on the outer peripheral side of the switching mechanism 161. The first sleeve 162 is movable relative to the first input shaft 10 in the axial direction, thereby connecting and releasing the connection between the switching mechanism 161 and either the first switching gear S1 or the second switching gear S2. Switching is possible. The operation of the first sleeve 162 is automatically performed by hydraulic pressure or the like.

  The second switching mechanism 170 is for selectively connecting and disconnecting either the first input shaft 10 or the countershaft 30 and the output shaft 40, and includes the switching mechanism 171 and the third switching gear S3. And a fourth switching gear S4 and a second sleeve 172. The switching mechanism 171 is fixed to the outer peripheral side of the output shaft 40 and is composed of a plurality of members. Since the switching mechanism 171 has the same configuration as, for example, a conventional synchro mechanism or the like (in FIG. 3, a double sync mechanism), detailed description thereof is omitted. The third switching gear S3 is provided such that it can rotate relative to the output shaft 40 and cannot rotate relative to the gear 141. The fourth switching gear S4 is provided so as not to rotate relative to the first input shaft 10. The second sleeve 172 is a cylindrical member disposed on the outer peripheral side of the switching mechanism 171, and the inner peripheral side thereof meshes with teeth formed on the outer peripheral side of the switching mechanism 171. The second sleeve 172 can be moved relative to the output shaft 40 in the axial direction to switch between connection and release of the switching mechanism 171 with either the third switching gear S3 or the fourth switching gear S4. It is possible. The operation of the second sleeve 172 is automatically performed by hydraulic pressure or the like.

  The reverse gear 199 includes a first reverse gear 191 of the first reverse gear pair 195, a second reverse gear 192 and a third reverse gear 193 of the second reverse gear pair 190, and a parking gear 194. Is disposed on the reverse shaft 70 fixed to the shaft so as to be relatively rotatable via needle bearings 191a and 192a. In this embodiment, the first reverse gear 191, the second reverse gear 192, and the parking gear 301 are formed as an integral member. The first reverse gear pair 195 is for connecting the reverse gear 199 and the countershaft 30, and includes the gear 122 of the second gear pair 120 and the first reverse gear 191. The first reverse gear 191 and the gear 122 mesh with each other. The second reverse gear pair 190 includes a second reverse gear 192 and a third reverse gear 193. The second reverse gear 192 is provided so as not to rotate relative to the first reverse gear 191. The third reverse gear 193 is disposed so as to be rotatable relative to the first input shaft 10 by a needle bearing 193a. The second reverse gear 192 and the third reverse gear 193 are in mesh with each other. The parking gear 301 is included in a parking mechanism 300, which will be described later, and is used to maintain the parking state of the vehicle, and is disposed so as not to rotate relative to the first reverse gear 191 and the second reverse gear 192.

  The reverse switching mechanism 180 is used to connect and disconnect the first input shaft 10 and the reverse shaft 70 via the second reverse gear pair 190. The reverse switch mechanism 180 includes a gear 181, a reverse switching gear S5, And a sleeve 182. The gear 181 is fixed to the outer peripheral side of the first input shaft 10. The reverse switching gear S <b> 5 is disposed so as to be relatively rotatable with respect to the first input shaft 10 and not to be relatively rotatable with respect to the third reverse gear 193. The reverse sleeve 182 is a cylindrical member disposed on the outer peripheral side of the gear 181, and the inner peripheral side thereof meshes with the outer peripheral side of the gear 181. The reverse sleeve 182 is movable relative to the first input shaft 10 in the axial direction, so that the reverse switching gear S5 and the gear 181 can be connected and disconnected. The operation of the reverse sleeve 182 is automatically performed by hydraulic pressure or the like.

(2) Structure of parking mechanism The transmission 2 further includes a parking mechanism 300. FIG. 4 shows a structural diagram of the parking mechanism 300. The parking mechanism 300 includes a parking gear 301, a parking cam assembly 310, a parking rod assembly 320, and a parking shaft assembly 330.

  The parking gear 301 is disposed so as to be rotatable relative to the reverse shaft 70 and not to be rotatable relative to the first reverse gear 191 and the second reverse gear 192. In this embodiment, the parking gear 301 is formed as a member integrated with the first, second and third reverse gears 191 and 192 (see FIG. 2). A plurality of external teeth 301 a extending in the radial direction are formed on the outer peripheral side of the parking gear 301.

  The parking cam assembly 310 is for restricting the rotation of the parking gear 301, and includes a parking cam 311, a lever support member 312, and a spring 313. The parking cam 311 includes a cam portion 311a, a claw portion 311b, and a lever portion 311c. The cam portion 311a is a portion with which a parking rod assembly 320 described later is engaged. The cam portion 311a is engaged with a spring 313 described later. The claw portion 311b is a portion that engages with the external teeth 301a of the parking gear 301, and protrudes from the cam portion 311a toward the parking gear 301 side. The lever portion 311c is provided with the aforementioned cam portion 311a at one end portion. The lever support member 312 is fixed inside the casing 6. The other end of the lever portion 311c is connected to the lever support member 312 by a pin 312a. Thereby, the parking cam 311 is supported so as to be rotatable with respect to the casing 6. The spring 313 is attached to the pin 312a with a part thereof engaged with the tip of the cam portion 311a. The spring 313 urges the parking cam 311 in a direction away from the parking gear 301 (lower side in FIG. 4).

  The parking rod assembly 320 includes a rod 321, a tip member 322, and a spring 323. The rod 321 is for pushing up the parking cam 311 to the parking gear 301 side (upper side in FIG. 4), and is formed by bending, for example, round steel or the like into an L shape. The front end member 322 is a member provided at the end of the rod 321 on the parking cam 311 side, and includes a front end member main body 322a, two rollers 322b, and a guide portion 322c. The tip member main body 322a is fitted with a rod 321 and is movable relative to the rod 321 in the axial direction. The two rollers 322b are provided adjacent to the tip member main body 322a so as to be relatively rotatable. The two rollers 322b are in contact with each other and rotate in opposite directions. The roller 322b is disposed so as to be movable in the left-right direction in FIG. 4 while being sandwiched between the cam portion 311a of the parking cam 311 and the base 6a fixed to the casing 6. The pedestal 6a has a regulating member 6c for regulating the movement of the cam portion 311a to the lower side in FIG. 4 within a certain range. The guide portion 322c is a cylindrical portion that protrudes from the tip member main body 322a along the outer peripheral side of the rod 321 and stabilizes the axial movement of the tip member main body 322a. The spring 323 is inserted into the rod 321 and is disposed in a compressed state between the guide portion 322 c and a retaining ring 321 a provided on the rod 321.

  The parking shaft assembly 330 includes a shaft 331, a drive lever 332, and a nut 333. The shaft 331 includes a shaft main body 331a and a lever 331b. The shaft main body 331 a is provided so as to be rotatable relative to the casing 6, and one end portion projects to the outside of the casing 6. The lever 331b is for connecting the shaft body 331a and the rod 321 and has, for example, a plate shape and an L shape. One end of the lever 331b is fixed so as not to rotate relative to the shaft body 331a. The rod 321 is connected to the other end of the lever 331b by, for example, a pin or the like so as to be relatively movable within a certain range in the vertical direction of FIG. The drive lever 332 is for rotating the shaft main body 331a, and is fixed to the end of the shaft main body 331a by a nut 333 so as not to be relatively rotatable.

  With the configuration described above, the parking rod assembly 320 is moved in the left-right direction in FIG. 4 by the parking shaft assembly 330, and the parking cam assembly 310 can be rotated in the up-down direction in FIG. It has become. The pawl portion 311 b of the parking cam assembly 310 is engaged with the external teeth 301 a of the parking gear 301, so that the parking state of the vehicle can be maintained via the parking gear 301.

(3) Operation of Transmission Device Next, the operation of the transmission device 2 will be described with reference to FIGS. Here, the operation at the time of shifting up from the first speed to the sixth speed and the operation at the time of reverse travel will be described. FIG. 5A is a configuration diagram of the transmission as the first embodiment of the present invention, and FIG. 5B is a schematic diagram of the torque transmission path of the transmission according to the first embodiment of the present invention. In FIG. 5B, each axis is indicated by a dotted line, and a torque transmission path at each shift speed is indicated by a solid line. And the clutch which act | operates is shown by "C1" or "C2" on the left side of FIG.5 (b). FIG. 6 shows the engagement element control and the reduction ratio at each gear stage of the transmission as the first embodiment of the present invention. In FIG. 6, the clutches and the switching gears connected at the respective speeds are indicated by “◯”, and the switching gears connected in preparation for upshifting and downshifting are indicated by “(◯)”. Further, on the right side of FIG. 6, the reduction gear ratio of the entire transmission device 2, the step of the reduction gear ratio of each gear, and the entire range are shown. Furthermore, the reduction ratio of each gear is shown on the lower side of FIG.

Here, the reduction ratio of each gear pair will be described. The reduction ratio generally means a value obtained by dividing the number of teeth of the driven gear by the number of teeth of the driving gear. However, in this embodiment, each gear pair is switched between the driven side and the driving side. Here, for the sake of convenience, the gears on the first input shaft 10 and the second input shaft 20 side are referred to as drive-side gears. Further, regarding the fourth gear pair 140, since the driving side and the driven side are not interchanged, the gear on the output shaft 40 side is the driven side gear. Further, regarding the first reverse gear pair 195, the first reverse gear 191 is used as a driving gear. In this embodiment, each reduction ratio is set as follows (see FIG. 6).
First gear pair 110 (gear 111 → gear 112): α1 = 1.38
Second gear pair 120 (gear 121 → gear 122): α2 = 1.85
Third gear pair 130 (gear 131 → gear 132): α3 = 0.87
Fourth gear pair 140 (gear 142 → gear 141): α4 = 2.87
First reverse gear pair 195 (first reverse gear 191 → gear 122): αb1 = 1.85
Second reverse gear pair 190 (third reverse gear 193 → second reverse gear 192): αb2 = 1.14
<Stop to forward 1st speed>
When the vehicle is stopped, the first clutch C1 and the second clutch C2 are disconnected. In this state, as shown in FIG. 6, the switching mechanism 161 and the first switching gear S <b> 1 are connected by the first sleeve 162 of the first switching mechanism 160 and switched by the second sleeve 172 of the second switching mechanism 170. The mechanism 171 and the third switching gear S3 are connected. Then, the first clutch C1 is gradually connected. As a result, as shown in FIG. 5, the torque input to the first input shaft 10 via the first clutch C <b> 1 is output to the output shaft 40 via the second gear pair 120, the countershaft 30 and the fourth gear pair 140. The vehicle travels at the first speed. In this case, the overall reduction ratio α0 of the transmission 2 is α0 = α2 × α4 = 1.85 × 2.87 = 5.31.

<Forward first speed to forward second speed>
As shown in FIG. 6, when traveling in the first speed, the first clutch C1 is disconnected and the second clutch C2 is connected. At this time, similarly to the first speed, the connection between the switching mechanism 171 and the third switching gear S3 is maintained by the second sleeve 172 of the second switching mechanism 170. As a result, as shown in FIG. 5, the torque input to the second input shaft 20 via the second clutch C2 is output to the output shaft 40 via the first gear pair 110, the countershaft 30, and the fourth gear pair 140. The vehicle travels at the second speed. In this case, the reduction ratio α0 of the entire transmission device 2 is α0 = α1 × α4 = 1.38 × 2.87 = 3.96.

<Forward second speed to Forward third speed>
As shown in FIG. 6, during the second speed traveling, the switching mechanism 161 and the second switching gear S <b> 2 are connected by the first sleeve 162 of the first switching mechanism 160. Then, the connection of the second clutch C2 is released and the first clutch C1 is connected. At this time, similarly to the second speed, the connection between the switching mechanism 171 and the third switching gear S3 is maintained by the second sleeve 172 of the second switching mechanism 170. As a result, as shown in FIG. 5, the torque input to the first input shaft 10 via the first clutch C1 is output to the output shaft 40 via the third gear pair 130, the countershaft 30, and the fourth gear pair 140. The vehicle travels at the third speed. In this case, the reduction ratio α0 of the entire transmission device 2 is α0 = α3 × α4 = 0.87 × 2.87 = 2.50.

<Forward 3rd speed-Forward 4th speed>
As shown in FIG. 6, when traveling in the third speed, the first clutch C1 is disengaged, and the connecting portion in the second switching mechanism 170 is switched from the third switching gear S3 to the fourth switching gear S4. Thereafter, the second clutch C2 is connected. At this time, similarly to the third speed, the connection between the switching mechanism 161 and the second switching gear S2 is maintained by the first sleeve 162 of the first switching mechanism 160. As a result, as shown in FIG. 5, the torque input to the second input shaft 20 via the second clutch C <b> 2 is applied to the first gear pair 110, the countershaft 30, the third gear pair 130, and the first input shaft 10. And the vehicle travels at the fourth speed. In this case, the reduction ratio α0 of the entire transmission device 2 is α0 = α1 / α3 = 1.38 / 0.87 = 1.58.

<Forward 4th speed-Forward 5th speed>
As shown in FIG. 6, during the fourth speed traveling, the second clutch C2 is disengaged and the first clutch C1 is engaged. At this time, similarly to the fourth speed, the connection between the switching mechanism 171 and the fourth switching gear S4 is maintained by the second sleeve 172 of the second switching mechanism 170. Thus, as shown in FIG. 5, the torque input to the first input shaft 10 via the first clutch C1 is transmitted to the output shaft 40 via the second switching mechanism 170, and the vehicle is in the fifth speed. Run. In this case, the speed reduction ratio α0 of the entire transmission device 2 is α0 = 1.00.

<Forward fifth speed to forward sixth speed>
As shown in FIG. 6, during the fifth speed travel, the switching mechanism 161 and the first switching gear S <b> 1 are connected by the first sleeve 162 of the first switching mechanism 160. Then, the first clutch C1 is released and the second clutch C2 is connected. At this time, as in the fifth speed, the connection of the fourth switching gear S4 of the second switching mechanism 170 is maintained. As a result, as shown in FIG. 5, the torque input to the second input shaft 20 via the second clutch C <b> 2 is output to the output shaft 40 via the first gear pair 110, the countershaft 30 and the second gear pair 120. The vehicle travels at the sixth speed. In this case, the speed reduction ratio α0 of the entire transmission device 2 is α0 = α1 / α2 = 1.38 / 1.85 = 0.74.

<Stop-reverse>
When the vehicle is stopped, the first clutch C1 and the second clutch C2 are disconnected. In this state, as shown in FIG. 6, the gear 181 and the reverse switching gear S5 are connected by the reverse sleeve 182 of the reverse switching mechanism 180, and the switching mechanism 171 and the second switching gear 170 are connected by the second sleeve 172 of the second switching mechanism 170. The three switching gear S3 is connected. Then, the first clutch C1 is gradually connected. As a result, as shown in FIG. 5, the torque input to the first input shaft 10 via the first clutch C1 is the first input shaft 10, the second reverse gear pair 190, the first reverse gear pair 195, The vehicle is transmitted to the output shaft 40 via the shaft 30 and the fourth gear pair 140, and the vehicle moves backward. In this case, the reduction gear ratio α0 of the entire transmission device 2 is α0 = αb2 × αb1 × α3 = 1.14 × 1.85 × 2.87 = 6.05.

  As described above, the speed change device 2 can realize a forward six-speed shift with only four gear pairs and two switching mechanisms. The transmission device 2 also includes a reverse gear.

(4) Setting of reduction ratio The setting value of the reduction ratio described above is provided with a certain limit in order to shorten the inter-axis distance between the first input shaft 10 and the auxiliary shaft 30. Specifically, it is necessary to satisfy α2 <α4 and 0.7 <α3 <1.0. The reason is as follows.

1) For α2 <α4 As shown in FIG. 6, the reduction ratio decreases in order from the first speed to the sixth speed. Therefore, α3 × α4 <α1 × α4 <α2 × α4 is established from the relationship of the reduction ratio from the first speed to the third speed. As a result, in order for the transmission 2 to realize a six-speed shift, a relationship of at least α3 <α1 <α2 is required. α4 is not particularly limited. On the other hand, the inter-axis distance is determined by the gear diameter of the gear pair having the maximum reduction ratio. Accordingly, the inter-axis distance is determined by the magnitude relationship between the reduction ratios α2 and α4.

  Since α2 is a reduction ratio of the second gear pair 120 from the first input shaft 10 to the countershaft 30, the diameter of the gear 122 on the countershaft 30 side is larger than the diameter of the gear 121 on the first input shaft 10 side. Become. On the other hand, the gear 121 is disposed so as to be rotatable relative to the first input shaft 10, and the needle bearing 121 a is provided on the inner peripheral side of the gear 121, so that the diameter of the gear 121 can be made too small. Can not. Therefore, it is difficult to reduce the diameter of the gear 121 and the gear 122.

  On the other hand, since α4 is a reduction ratio from the countershaft 30 to the output shaft 40 of the fourth gear pair 140, the diameter of the gear 142 on the countershaft 30 side is smaller than the diameter of the gear 141 on the output shaft 40 side. . The gear 141 is disposed so as to be rotatable relative to the output shaft 40, and a needle bearing 141 a is provided on the inner peripheral side of the gear 141. However, since the gear 142 is fixed to the countershaft 30, the diameter can be easily reduced, and the gear 141 having the needle bearing 141a can also be reduced in diameter. Therefore, the gear 141 and the gear 142 can be easily reduced in diameter compared to the gear 121 and the gear 122.

  As described above, the reduction ratio α2 of the second gear pair 120 that is difficult to reduce in diameter is reduced, and the reduction ratio α4 of the fourth gear pair 140 that is easy to reduce in diameter is increased, that is, α2 <α4. And the diameter reduction of each gear of the 4th gear pair 120 and 140 is realizable. As a result, in the transmission 2, the distance between the shafts can be shortened, and the transmission 2 can be downsized. And the enlargement of the whole AMT can be prevented.

2) About 0.7 <α3 <1.0 As shown in FIG. 6, since the reduction ratio of the fifth speed is 1.0, it is practical to set the reduction ratio of the fourth speed to about 1.5. It is. Then, α1 / α3 = 1.5. When α3 = 1, α1 = 1.5, and α2 is larger than 1.5. If α2 is increased, the distance between the first input shaft 10 and the auxiliary shaft 30 becomes longer as described above, which is not preferable. Therefore, the distance between the axes can be shortened by reducing α3 to a small speed increase, that is, 0.7 <α3 <1.0 so that α1 and α2 do not increase, and the transmission 2 can be reduced in size. be able to. And the enlargement of the whole AMT can be prevented.

(5) Step of reduction ratio The step of the reduction ratio of MT is generally the largest between the first speed and the second speed, and gradually decreases as the speed increases. However, as shown in FIG. 5, in this transmission 2, the step (1.34) of the reduction ratio from the first speed to the second speed and from the fifth speed to the sixth speed is the step (1) between the other speed stages. .58) is smaller. Assuming that the 6-speed forward transmission 2 corresponds to a conventional MT forward 5-speed transmission, the first to third speeds of the transmission 2 are the first to third speeds of the conventional transmission. It is thought that it corresponds to the 2nd speed from the 1st speed. As a result, the transmission 2 can increase the number of low speed stages by one as compared with the conventional forward five-speed transmission. Therefore, the speed change device 2 can increase the first speed at the low speed stage and reduce the step of the reduction ratio from the first speed to the second speed. As described above, the engine speed is kept low and the fuel efficiency is improved. Can be made. Moreover, since the number of gear pairs and switching mechanisms is not increased as compared with the conventional forward five-speed transmission, the transmission is not increased in size. Further, when the first speed is increased at the low speed stage of MT, the burden of the speed change operation by the driver increases. However, when the speed change operation is automated as in the case of the speed change device 2, such a problem does not occur.

  In addition, since the traction force of the first speed is the largest compared to the other speed stages and the acceleration at the time of starting is smaller than the other speed stages, the first speed changes from the first speed to the second speed as in the conventional MT transmission. If this step is large, the difference in acceleration between the first speed and the second speed becomes large, and the driver is likely to feel uncomfortable. However, in this transmission 2, as described above, since the first speed is increased at the low speed and the step is made smaller, the difference in acceleration is smaller than in the prior art, and it is difficult to give such a sense of incongruity to the driver. Further, if the speed is increased by 1 at the low speed stage of MT, the burden of the speed change operation by the driver increases. However, when the speed change operation is automated as in the case of the speed change device 2, such a problem does not occur. Therefore, it can be said that the transmission 2 is particularly effective as an AMT transmission using the double clutch device 1.

  In addition, since the transmission 2 can reduce the step of the reduction ratio from the first forward speed to the second speed, the second speed before the first clutch C1 finishes sliding at the first forward speed. The two-clutch C2 can be slid to start. Thereby, in this transmission 2, it is possible to reduce facing wear by sharing the load at the time of starting with the first and second clutches C1 and C2.

(6) Operation of Parking Mechanism The operation of the parking mechanism 300 will be described. FIG. 7 shows a structural diagram of the parking mechanism 300 when the parking mechanism 300 is not operated. First, the operation from when the parking mechanism 300 is activated to when it is not activated (from the state of FIG. 4 to the state of FIG. 7) will be described.

  The parking brake lever operated by the driver is connected to the drive lever 332 of the parking shaft assembly 330 by an intermediate member (not shown) such as a wire. In the state of FIG. 4, when the driver sets the parking brake lever to the parking release position, the shaft 331 rotates via the intermediate member and the drive lever 332 (not shown). When the shaft 331 rotates, the parking rod assembly 320 moves to the left in FIG. 4 via the lever 331b. Then, the roller 322b of the tip member 322 moves while rolling between the cam portion 311a of the parking cam 311 and the base 6a. At this time, since the parking cam 311 is biased downward in FIG. 4 by the spring 313, the roller 322b is sandwiched with a certain amount of force in the vertical direction, but the two rollers 322b rotate in opposite directions. Therefore, a large resistance does not occur. When the driver finishes operating the parking brake lever, the roller 322b stops while being sandwiched between the inclined surface 311e of the cam portion 311a and the inclined surface 6d of the base 6a. And the parking mechanism 300 will be in the state shown in FIG. In this state, the cam portion 311a is stopped in contact with the regulating member 6c of the pedestal 6a. Therefore, the claw portion 311b and the external teeth 301a are not engaged, and the vehicle is released from the parking state and the vehicle can run.

  Next, an operation from when the parking mechanism 300 is not operated to when it is operated (from the state of FIG. 7 to the state of FIG. 4) will be described. In the state of FIG. 7, when the driver operates the parking brake lever to the parking position, the shaft 331 rotates via the intermediate member and the drive lever 332 (not shown). When the shaft 331 rotates, the parking rod assembly 320 moves to the right in FIG. 7 via the lever 331b. Then, since the roller 322b pushes the inclined surface 311e of the cam portion 311a obliquely upward, the cam portion 311a is pushed up to the parking gear 301 side (upper side in FIG. 7). Then, the roller 322b enters between the cam portion 311a and the base 6a. At this time, the parking cam 311 is biased downward by the spring 313, but the two rollers 322b enter between the two members while rotating in opposite directions, so that no large resistance is generated. When the driver finishes operating the parking brake lever, the roller 322b stops while being sandwiched between the contact surface 311d of the cam portion 311a and the contact surface 6b of the base 6a. And the parking mechanism 300 will be in the state shown in FIG. 4, and the nail | claw part 311b and the external tooth 301a will engage. Thereby, since the rotation of the parking gear 301 is regulated, the parking state of the vehicle is maintained.

  A case where the claw portion 311b and the external teeth 301a do not mesh is also conceivable. Specifically, when the claw portion 311b and the external tooth 301a do not mesh with each other, the tip of the claw portion 311b and the tip of the external tooth 301a come into contact with each other, so that the cam portion 311a can be pushed up only halfway. In this case, the tip member 322 stops moving to the right in FIG. However, since the tip member 322 and the rod 321 can move relative to each other in the axial direction, even if the movement of the tip member 322 stops, the rod 321 moves to the right in FIG. Stop. In this state, the cam portion 311a is urged upward by the elastic force of the spring 323 via the roller 322b. Therefore, even if the vehicle moves during parking, the parking gear 301 is slightly rotated and the claw portion 311b and the external teeth 301a are engaged with each other, and a state as shown in FIG. Thereby, even if the position of the nail | claw part 311b and the external tooth 301a has shifted | deviated, the parking state of a vehicle can be hold | maintained reliably.

  Here, a fastening element and a reduction ratio when the parking mechanism 300 is operated will be described. The fastening elements and the reduction gear ratio when the parking mechanism 300 is operated are shown in FIG. 5B and FIG. As shown by “P” in FIG. 5B, when the parking mechanism 300 is operated, the fourth gear pair 140 and the output shaft are connected by the third switching gear S3 of the second switching mechanism 170. The parking gear 301 and the countershaft 30 are connected via the first reverse gear pair 195. Further, the sub shaft 30 and the output shaft 40 are connected by the fourth gear pair 140 and the second switching mechanism 170. That is, the parking gear 301 is connected to the output shaft 40 via the first reverse gear pair 195 and the fourth gear pair 140. In this state, when the parking mechanism 300 is operated as described above to prevent the parking gear 301 from rotating, the rotation of the wheel is performed via the first reverse gear pair 195, the countershaft 30, the fourth gear pair 140, and the output shaft. Is prevented and the parking state of the vehicle is maintained. As indicated by “P” in FIG. 6, the reduction ratio from the parking gear 301 to the output shaft at this time is such that the reduction ratio of the first reverse gear pair 195 is αb1 = 1.85, and the reduction ratio of the fourth gear pair. Since the ratio is α4 = 2.87, αb1 × α4 = 1.85 × 2.87 = 5.3. As a result, when the rotation of the output shaft 40 is blocked, the rotation blocking force to the parking gear 301 can be reduced. Thereby, in this transmission 2, the parking mechanism 300 can be made smaller than before, and the parking state of the vehicle can be held more reliably than before.

3. Second Embodiment (1) Structure of Transmission A transmission 2 as a second embodiment of the present invention will be described. The transmission 2 of the first embodiment is a six-speed shift, but the transmission 2 of the second embodiment is capable of a seven-speed shift. FIG. 8 shows a schematic longitudinal sectional view of a transmission as a second embodiment of the present invention. FIG. 8 shows a cross-sectional view passing through the axes of the first input shaft, the counter shaft, and the reverse shaft. As shown in FIG. 8, the transmission 2 includes a first input shaft 10, a second input shaft 20, a countershaft 30, an output shaft 40, a reverse shaft 70, a first gear pair 210, Gear pair 220, third gear pair 230, fourth gear pair 240, fifth gear pair 250, first switching mechanism 260, second switching mechanism 270, third switching mechanism 280, reverse gear 299 And a first reverse gear pair 295, a second reverse gear pair 290, and a casing (not shown).

  The first input shaft 10 is for receiving torque from the double clutch device 1 and is provided so as not to rotate relative to the first output shaft 50 of the first clutch C1. The second input shaft 20 is for receiving torque from the double clutch device 1 and is provided so as not to rotate relative to the second output shaft 60 of the second clutch C2. In this embodiment, the first and second input shafts 10 and 20 are integrated with the first and second output shafts 50 and 60. The second input shaft 20 is a cylindrical member that is coaxially disposed on the outer peripheral side of the first input shaft 10. The second input shaft 20 is supported by the first bearing 81 so as to be rotatable relative to the casing. A needle bearing 82 is disposed between the first input shaft 10 and the second input shaft 20 in the radial direction. The first input shaft 10 is supported by a needle bearing 82 so as to be rotatable relative to the second input shaft 20. The needle bearing 82 is disposed close to the first bearing 81 in the axial direction. The first input shaft 10 is disposed so as to be relatively rotatable with respect to the casing by a third bearing 83 disposed on the output shaft 40 side described later. As is clear from these structures, the first input shaft 10 is supported by the first bearing 81, the needle bearing 82, and the third bearing 83 so as to be rotatable relative to the second input shaft 20 and the casing.

  The auxiliary shaft 30 is disposed in parallel to the first input shaft 10. Sixth and seventh bearings 86 and 87 are provided at both ends of the countershaft 30. The countershaft 30 is supported by sixth and seventh bearings 86 and 87 so as to be rotatable relative to the casing. The output shaft 40 is for outputting torque from the transmission 2, and is disposed coaxially with the first input shaft 10. A cylindrical portion 253 is provided at the end of the first input shaft 10 on the output shaft 40 side, and protrudes toward the output shaft 40 side. An end portion of the output shaft 40 is inserted into the inner peripheral side of the cylindrical portion 253. A needle bearing 84 is disposed between the output shaft 40 and the cylindrical portion 253 in the radial direction. The output shaft 40 is supported by a needle bearing 84 so as to be rotatable relative to the first input shaft 10. The needle bearing 84 is disposed close to the third bearing 83 in the axial direction. A fifth bearing 85 is provided on the output side of the output shaft 40. As apparent from these structures, the output shaft 40 is supported by the third bearing 83, the needle bearing 84, and the fifth bearing 85 so as to be rotatable relative to the first input shaft 10 and the casing. Further, the reverse shaft 70 is arranged in parallel with the first input shaft 10. The reverse shaft 70 is directly inserted into the casing, and is supported by the fixing member 71 so as not to rotate relative to the casing.

  The first gear pair 210 is for connecting the second input shaft 20 and the countershaft 30 and includes a gear 211 and a gear 212. The gear 211 is integrally formed on the outer peripheral side of the second input shaft 20. The gear 212 is fixed to the countershaft 30. The gear 211 and the gear 212 are meshed with each other. The second gear pair 220 is for connecting the first input shaft 10 and the countershaft 30 and includes a gear 221 and a gear 222. The gear 221 is disposed so as to be rotatable relative to the first input shaft 10 by a needle bearing 221a. The gear 222 is formed integrally with the countershaft 30. The gear 221 and the gear 222 are meshed with each other. The third gear pair 230 is for connecting the first input shaft 10 and the countershaft 30 and includes a gear 231 and a gear 232. The gear 231 is disposed so as to be rotatable relative to the first input shaft 10 by a needle bearing 231a. The gear 232 is integrally formed on the outer peripheral side of the auxiliary shaft 30. The gear 231 and the gear 232 mesh with each other. The fourth gear pair 240 is for connecting the output shaft 40 and the auxiliary shaft 30, and includes a gear 241 and a gear 242. The gear 241 is disposed so as to be rotatable relative to the output shaft 40 by two needle bearings 241a. The gear 242 is integrally formed on the outer peripheral side of the auxiliary shaft 30. The gear 241 and the gear 242 mesh with each other. The fifth gear pair 250 is for connecting the first input shaft 10 and the countershaft 30 and includes a gear 251 and a gear 252. The gear 251 is disposed so as to be rotatable relative to the first input shaft 10 by a needle bearing 251a. The gear 232 is integrally formed on the outer peripheral side of the auxiliary shaft 30. The gear 231 and the gear 232 mesh with each other.

  The first switching mechanism 260 is for selectively connecting and disconnecting the first input shaft 10 and the countershaft 30 with two different reduction ratios. The switching mechanism 261, the first switching gear S1, The second switching gear S2 and the first sleeve 262 are included. The switching mechanism 261 is fixed to the outer peripheral side of the first input shaft 10 and is composed of a plurality of members. Since the switching mechanism 261 has the same configuration as, for example, a conventional synchronization mechanism or the like (in FIG. 8, a double synchronization mechanism), detailed description thereof is omitted. The first switching gear S <b> 1 is provided so as to be relatively rotatable with respect to the first input shaft 10 and not rotatable relative to the gear 221. The second switching gear S <b> 2 is provided such that it can rotate relative to the first input shaft 10 and cannot rotate relative to the gear 231. The first sleeve 262 is a cylindrical member disposed on the outer peripheral side of the switching mechanism 261, and the inner peripheral side thereof meshes with teeth formed on the outer peripheral side of the switching mechanism 261. The first sleeve 262 is movable relative to the first input shaft 10 in the axial direction, thereby connecting and releasing the connection between the switching mechanism 261 and one of the first switching gear S1 and the second switching gear S2. Switching is possible. The operation of the first sleeve 262 is automatically performed by hydraulic pressure or the like.

  The second switching mechanism 270 is for selectively connecting and disconnecting either the first input shaft 10 or the counter shaft 30 and the output shaft 40, and includes the switching mechanism 271 and the third switching gear S3. And a fourth switching gear S4 and a second sleeve 272. The switching mechanism 271 is fixed to the outer peripheral side of the output shaft 40 and is composed of a plurality of members. Since the switching mechanism 271 has the same configuration as, for example, a conventional synchro mechanism or the like (in FIG. 8, a double synchro mechanism), detailed description thereof is omitted. The third switching gear S3 is provided such that it can rotate relative to the output shaft 40 and cannot rotate relative to the gear 241. The fourth switching gear S4 is provided so as not to rotate relative to the first input shaft 10. The second sleeve 272 is a cylindrical member disposed on the outer peripheral side of the switching mechanism 271, and the inner peripheral side thereof meshes with teeth formed on the outer peripheral side of the switching mechanism 271. The second sleeve 272 is movable relative to the output shaft 40 in the axial direction, thereby switching between connection and release of either the third switching gear S3 or the fourth switching gear S4 and the switching mechanism 271. It is possible. The operation of the second sleeve 272 is automatically performed by hydraulic pressure or the like.

  The reverse gear 299 includes a first reverse gear 291 of the first reverse gear pair 295, a second reverse gear 292 and a third reverse gear 293 of the second reverse gear pair 290, and a parking gear 294. Is disposed on the reverse shaft 70 fixed to the shaft so as to be relatively rotatable via needle bearings 291a and 292a. In this embodiment, the first reverse gear 291, the second reverse gear 292, and the parking gear 294 are formed as an integral member. The first reverse gear pair 295 is for connecting the reverse gear 299 and the countershaft 30 and includes the gear 222 of the second gear pair 220 and the first reverse gear 291. The first reverse gear 291 and the gear 222 mesh with each other. The second reverse gear pair 290 includes a second reverse gear 292 and a third reverse gear 293. The second reverse gear 292 is provided so as not to rotate relative to the first reverse gear 291. The third reverse gear 293 is disposed so as to be rotatable relative to the first input shaft 10 by a needle bearing 293a. The second reverse gear 292 and the third reverse gear 293 mesh with each other. The parking gear 301 is included in the parking mechanism 300 and is used for maintaining the stop state of the vehicle. The parking gear 301 can be rotated relative to the reverse shaft 70 and can move relative to the first reverse gear 291 and the second reverse gear 292. It is arranged so that it cannot rotate relative to it.

  The third switching mechanism 280 is for enabling connection and disconnection of either the reverse gear 299 or the countershaft 30 and the first input shaft 10, and includes a switching mechanism 281 and a fifth switching gear S5. The sixth switching gear S6 and the third sleeve 282 are configured. The switching mechanism 281 is fixed to the outer peripheral side of the first input shaft 10 and is composed of a plurality of members. Since the switching mechanism 281 has the same configuration as, for example, a conventional synchro mechanism or the like, detailed description thereof is omitted. The fifth switching gear S5 is disposed so as to be relatively rotatable with respect to the first input shaft 10 and not to be relatively rotatable with respect to the third reverse gear 293. The sixth switching gear S <b> 6 is disposed so as to be rotatable relative to the first input shaft 10 and not rotatable relative to the gear 251. The third sleeve 282 is a cylindrical member disposed on the outer peripheral side of the switching mechanism 281, and the inner peripheral side thereof meshes with the teeth formed on the outer peripheral side of the switching mechanism 281. The third sleeve 282 is movable relative to the output shaft 40 in the axial direction, thereby switching between connection and disconnection of one of the fifth switching gear S5 and the sixth switching gear S6 and the switching mechanism 281. It is possible. The operation of the third sleeve 282 is automatically performed by hydraulic pressure or the like.

(2) Structure of parking mechanism Since the parking mechanism of the transmission of the second embodiment has the same structure as the parking mechanism 300 of the first embodiment, detailed description of the structure is omitted.

(3) Operation of Transmission Device Next, the operation of the transmission device 2 will be described with reference to FIGS. 9 and 10. Here, the operation at the time of shifting up from the first speed to the seventh speed (including the first 'speed) and the operation at the time of reverse travel will be described. FIG. 9A is a configuration diagram of the transmission as the first embodiment of the present invention, FIG. 9B is a schematic diagram of the torque transmission path of the transmission according to the first embodiment of the present invention, and FIG. The control of the fastening element and the reduction ratio in each gear stage of the transmission as the first embodiment of the invention are shown. In FIG. 9B, each axis is indicated by a dotted line, and a torque transmission path at each shift speed is indicated by a solid line. And the clutch which act | operates is shown by "C1" or "C2" on the left side of FIG.9 (b). In FIG. 10, the clutches and the switching gears connected at each gear are indicated by “◯”, and the switching gears connected in preparation for upshifting and downshifting are indicated by “(◯)”. Further, on the right side of FIG. 10, the reduction gear ratio of the entire transmission device 2, the step of the reduction gear ratio of each gear stage, and the entire range are shown. Furthermore, the reduction ratio of each gear pair is shown on the lower side of FIG.

Here, the reduction ratio of each gear pair will be described. The reduction ratio generally means a value obtained by dividing the number of teeth of the driven gear by the number of teeth of the driving gear. However, in this embodiment, each gear pair is switched between the driven side and the driving side. Here, for the sake of convenience, the gears on the first input shaft 10 and the second input shaft 20 side are referred to as drive-side gears. Further, regarding the fourth gear pair 240, since the drive side and the driven side are not interchanged, the gear on the output shaft 40 side is the driven side gear. As for the first reverse gear pair 295, the first reverse gear 291 is used as a drive-side gear. In this embodiment, each reduction ratio is set as follows (see FIG. 10).
First gear pair 210 (gear 211 → gear 212): α1 = 1.19
Second gear pair 220 (gear 221 → gear 222): α2 = 1.85
Third gear pair 230 (gear 231 → gear 232): α3 = 0.84
Fourth gear pair 240 (gear 242 → gear 241): α4 = 2.41
Fifth gear pair 250 (gear 251 → gear 252): α5 = 1.52
First reverse gear pair 295 (first reverse gear 291 → gear 222): αb1 = 1.85
Second reverse gear pair 290 (third reverse gear 293 → second reverse gear 292): αb2 = 1.14
<Stop to forward 1st speed>
When the vehicle is stopped, the first clutch C1 and the second clutch C2 are disconnected. In this state, as shown in FIG. 10, the switching mechanism 261 and the first switching gear S <b> 1 are connected by the first sleeve 262 of the first switching mechanism 260 and switched by the second sleeve 272 of the second switching mechanism 270. The mechanism 271 and the third switching gear S3 are connected. Then, the first clutch C1 is gradually connected. As a result, as shown in FIG. 9, the torque input to the first input shaft 10 via the first clutch C <b> 1 is output to the output shaft 40 via the second gear pair 220, the countershaft 30 and the fourth gear pair 240. The vehicle travels at the first speed. In this case, the reduction ratio α0 of the entire transmission device 2 is α0 = α2 × α4 = 1.85 × 2.41 = 4.46.

<Forward first speed to forward second speed>
As shown in FIG. 10, during traveling in the first speed, the first clutch C1 is disconnected and the second clutch C2 is connected. At this time, similarly to the first speed, the connection between the switching mechanism 271 and the third switching gear S3 is maintained by the second sleeve 272 of the second switching mechanism 270. As a result, as shown in FIG. 9, the torque input to the second input shaft 20 via the second clutch C2 is output to the output shaft 40 via the first gear pair 210, the countershaft 30, and the fourth gear pair 240. The vehicle travels at the second speed. In this case, the speed reduction ratio α0 of the entire transmission device 2 is α0 = α1 × α4 = 1.19 × 2.41 = 2.88.

<Forward second speed to Forward third speed>
As shown in FIG. 10, during the second speed traveling, the switching mechanism 261 and the second switching gear S2 are connected by the first sleeve 262 of the first switching mechanism 260. Then, the connection of the second clutch C2 is released and the first clutch C1 is connected. At this time, similarly to the second speed, the connection between the switching mechanism 271 and the third switching gear S3 is maintained by the second sleeve 272 of the second switching mechanism 270. As a result, as shown in FIG. 9, the torque input to the first input shaft 10 via the first clutch C <b> 1 is output to the output shaft 40 via the third gear pair 230, the countershaft 30 and the fourth gear pair 240. The vehicle travels at the third speed. In this case, the speed reduction ratio α0 of the entire transmission device 2 is α0 = α3 × α4 = 0.84 × 2.41 = 2.02.

<Forward 3rd speed-Forward 4th speed>
As shown in FIG. 10, at the time of the third speed traveling, the first clutch C1 is disengaged and the connecting portion in the second switching mechanism 270 is switched from the third switching gear S3 to the fourth switching gear S4. Thereafter, the second clutch C2 is connected. At this time, similarly to the third speed, the connection between the switching mechanism 261 and the second switching gear S2 is maintained by the first sleeve 262 of the first switching mechanism 260. As a result, as shown in FIG. 9, the torque input to the second input shaft 20 via the second clutch C <b> 2 is applied to the first gear pair 210, the countershaft 30, the third gear pair 230, and the first input shaft 10. And the vehicle travels at the fourth speed. In this case, the speed reduction ratio α0 of the entire transmission device 2 is α0 = α1 / α3 = 1.19 / 0.84 = 1.42.

<Forward 4th speed-Forward 5th speed>
As shown in FIG. 10, during the fourth speed travel, the second clutch C2 is disengaged and the first clutch C1 is engaged. At this time, similarly to the fourth speed, the connection between the switching mechanism 271 and the fourth switching gear S4 is maintained by the second sleeve 272 of the second switching mechanism 270. Accordingly, as shown in FIG. 9, the torque input to the first input shaft 10 via the first clutch C1 is transmitted to the output shaft 40 via the second switching mechanism 270, and the vehicle is in the fifth speed. Run. In this case, the speed reduction ratio α0 of the entire transmission device 2 is α0 = 1.00.

<Forward fifth speed to forward sixth speed>
As shown in FIG. 10, the gear 251 and the sixth switching gear S6 are connected by the third sleeve 282 of the third switching mechanism 280 during the fifth speed travel. Then, the first clutch C1 is released and the second clutch C2 is connected. At this time, as in the fifth speed, the connection of the fourth switching gear S4 of the second switching mechanism 270 is maintained. As a result, as shown in FIG. 9, the torque input to the second input shaft 20 via the second clutch C <b> 2 is output to the output shaft 40 via the first gear pair 210, the countershaft 30 and the fifth gear pair 250. The vehicle travels at the sixth speed. In this case, the overall reduction gear ratio α0 of the transmission 2 is α0 = α1 / α2 = 1.19 / 1.52 = 0.78.

<6th forward speed to 7th forward speed>
As shown in FIG. 10, the second clutch C2 is disengaged during the sixth speed travel. Thereafter, the connection by the third switching mechanism 280 is released, and the switching mechanism 261 and the first switching gear S1 are connected by the first sleeve 262 of the first switching mechanism 260. Then, the second clutch C2 is connected again. At this time, similarly to the sixth speed, the connection of the fourth switching gear S4 of the second switching mechanism 270 is maintained. As a result, as shown in FIG. 9, the torque input to the second input shaft 20 via the second clutch C <b> 2 is output to the output shaft 40 via the first gear pair 210, the countershaft 30 and the second gear pair 220. The vehicle travels at the seventh speed. In this case, the speed reduction ratio α0 of the entire transmission device 2 is α0 = α1 / α2 = 1.19 / 1.85 = 0.64.
<Stop to forward 1st speed>
In the transmission device 2 in this embodiment, in addition to the above-described seventh forward speed, one more gear position (first forward speed) can be provided between the first speed and the second speed. Specifically, when the vehicle is stopped, as shown in FIG. 10, the first clutch C1 is released and the first switching gear S1 of the first switching mechanism 260 is released. Then, the third switching gear S3 of the second switching mechanism 270 and the sixth switching gear S6 of the third switching mechanism 280 are connected, and the first clutch C1 is gradually connected. As a result, as shown in FIG. 4B, the torque input to the first input shaft 10 via the first clutch C1 is transmitted via the fifth gear pair 250, the countershaft 30, and the fourth gear pair 240. The vehicle is transmitted to the output shaft 40 and travels at the first speed. In this case, the speed reduction ratio α0 of the entire transmission device 2 is α0 = α5 × α4 = 1.52 × 2.41 = 3.66.

<Stop-reverse 1>
When the vehicle is stopped, the first clutch C1 and the second clutch C2 are disconnected. In this state, as shown in FIG. 10, the switching mechanism 281 and the fifth switching gear S5 are connected by the third sleeve 282 of the third switching mechanism 280, and the switching is performed by the second sleeve 272 of the second switching mechanism 270. The mechanism 271 and the third switching gear S3 are connected. Then, the first clutch C1 is gradually connected. As a result, as shown in FIG. 9, the torque input to the first input shaft 10 via the first clutch C1 is the first input shaft 10, the second reverse gear pair 290, the first reverse gear pair 295, The vehicle is transmitted to the output shaft 40 via the shaft 30 and the fourth gear pair 240, and the vehicle moves backward. In this case, the reduction gear ratio α0 of the entire transmission device 2 is α0 = αb2 × αb1 × α4 = 1.14 × 1.85 × 2.41 = 0.09.

  As described above, the speed change device 2 can realize the maximum forward eight-speed shift with only five gear pairs and three switching mechanisms. The transmission device 2 also includes a reverse gear.

(4) Setting of reduction ratio The setting value of the reduction ratio described above is provided with a certain limit in order to shorten the inter-axis distance between the first input shaft 10 and the auxiliary shaft 30. Specifically, it is necessary to satisfy α2 <α4 and 0.7 <α3 <1.0. The reason is as follows.

1) For α2 <α4 As shown in FIG. 10, the reduction ratio decreases in order from the first speed to the seventh speed. Further, the reduction ratio of the first 'speed is smaller than the first speed and larger than the second speed. Therefore, α3 × α4 <α1 × α4 <α5 × α4 <α2 × α4 is established based on the relationship between the reduction ratios of the first speed and the first 'speed to the third speed. Thus, in order for the transmission device 2 to achieve the eight-speed shift, a relationship of at least α3 <α1 <α5 <α2 is required. α4 is not particularly limited. On the other hand, the inter-axis distance is determined by the gear diameter of the gear pair having the maximum reduction ratio. Accordingly, the inter-axis distance is determined by the magnitude relationship between the reduction ratios α2 and α4.

  Since α2 is a reduction ratio of the second gear pair 220 from the first input shaft 10 to the countershaft 30, the diameter of the gear 222 on the countershaft 30 side is larger than the diameter of the gear 221 on the first input shaft 10 side. Become. On the other hand, the gear 221 is disposed so as to be rotatable relative to the first input shaft 10, and the needle bearing 221 a is provided on the inner peripheral side of the gear 221, so that the diameter of the gear 221 can be made too small. Can not. Therefore, it is difficult to reduce the diameter of the gear 221 and the gear 222.

  On the other hand, α4 is a reduction ratio from the countershaft 30 to the output shaft 40 of the fourth gear pair 240, so the diameter of the gear 242 on the countershaft 30 side is smaller than the diameter of the gear 241 on the output shaft 40 side. . The gear 241 is disposed so as to be rotatable relative to the output shaft 40, and a needle bearing 241 a is provided on the inner peripheral side of the gear 241. However, since the gear 242 is fixed to the countershaft 30, the diameter can be easily reduced, and the gear 241 having the needle bearing 241a can also be reduced in diameter. Therefore, the gear 241 and the gear 242 can be easily reduced in diameter as compared with the gear 221 and the gear 222.

  As described above, the reduction ratio α2 of the second gear pair 220 that is difficult to reduce in diameter is reduced, and the reduction ratio α4 of the fourth gear pair 240 that is easy to reduce in diameter is increased, that is, α2 <α4. And the diameter reduction of each gear of the 4th gear pair 220 and 240 is realizable. As a result, in the transmission 2, the distance between the shafts can be shortened, and the transmission 2 can be downsized. And the enlargement of the whole AMT can be prevented.

2) Regarding 0.7 <α3 <1.0 As shown in FIG. 10, the fourth embodiment has a larger number of gears than the first embodiment, and the fifth gear reduction ratio is 1.0. It is practical to set the speed reduction ratio to about 1.4. Then, α1 / α3 = 1.4. When α3 = 1, α1 = 1.4, and α2 is larger than 1.4. If α2 is increased, the distance between the first input shaft 10 and the auxiliary shaft 30 becomes longer as described above, which is not preferable. Therefore, the distance between the axes can be shortened by reducing α3 to a small speed increase, that is, 0.7 <α3 <1.0 so that α1 and α2 do not increase, and the transmission 2 can be reduced in size. be able to. And the enlargement of the whole AMT can be prevented.

(5) Step of reduction ratio If the reduction ratio as shown in FIG. 10 is set, the step of the reduction ratio in the high speed range can be reduced. Specifically, the steps from the fifth speed to the sixth speed and from the sixth speed to the seventh speed are 1.28 and 1.22, respectively. Since the traction force becomes small in the high speed region, it is preferable that the step of the reduction ratio is small, and the preferable step in the high speed region is 1.2 to 1.3. Therefore, an ideal reduction ratio step can be obtained by setting the reduction ratio.

  Further, the forward transmission 8 speed transmission device 2 of the present embodiment has a smaller reduction gear ratio step by increasing the number of shift stages than in the first embodiment. When considering the forward 8-speed transmission 2 of the present embodiment as opposed to a general MT forward 6-speed transmission, the number of high-speed stages is one stage compared to the conventional forward 6-speed transmission. Can be increased. Therefore, the transmission 2 can increase the number of steps at a high speed to reduce the step of the reduction ratio, and can obtain a step of an ideal reduction ratio compared to the conventional art. Moreover, since the number of gear pairs and switching mechanisms is not increased as compared with the conventional forward 6-speed transmission, the transmission is not increased in size. Furthermore, if the speed is increased by 1 at the high speed stage of MT, the burden of the speed change operation by the driver increases. Therefore, it can be said that the transmission 2 is particularly effective as an AMT transmission using the double clutch device 1.

  In the transmission 2, the first speed and the first 'speed can be selected in the reverse speed. Since the speed reduction ratio of the first speed is the maximum, if the first speed is selected at the time of start, a strong start is possible. In addition, the reduction ratio of the 1 'speed is smaller than the reduction ratio of the 1st speed, and the step from the 1' speed to the 2nd speed is smaller than the step from the 1st speed to the 2nd speed. If 1 'speed is selected, smooth start is possible with emphasis on fuel consumption. In addition, by sliding the second clutch C2 before the first clutch C1 finishes sliding at the first speed, the load at the time of starting is shared by the first and second clutches C1 and C2, thereby reducing facing wear. can do.

(6) Operation of parking mechanism The parking mechanism of the transmission 2 of the second embodiment has the same structure as the parking mechanism 300 of the first embodiment, and a detailed description of the operation is omitted.

  Here, a fastening element and a reduction ratio when the parking mechanism 300 is operated will be described. The fastening elements and the reduction ratio when the parking mechanism 300 is operated are shown in FIG. 9B and FIG. As shown by “P” in FIG. 9B, the fourth gear pair 240 and the output shaft 40 are connected by the second switching mechanism 270 when the parking mechanism 300 is operated. The parking gear 301 and the countershaft 30 are connected via the first reverse gear pair 295. The countershaft 30 and the output shaft 40 are connected by the fourth gear pair 240 and the second switching mechanism 270. That is, the parking gear 301 is connected to the output shaft 40 via the first reverse gear pair 295 and the fourth gear pair 240. In this state, when the parking mechanism 300 is operated to prevent the parking gear 301 from rotating as described above, the rotation of the wheel is performed via the first reverse gear pair 295, the countershaft 30, the fourth gear pair 240, and the output shaft. Is prevented and the parking state of the vehicle is maintained. Further, as indicated by “P” in FIG. 9, the reduction ratio from the parking gear 301 to the output shaft at this time is that the reduction ratio of the first reverse gear pair 295 is αb1 = 1.85, and the reduction ratio of the fourth gear pair. Since the ratio is α4 = 2.41, αb1 × α4 = 1.85 × 2.41 = 4.46. As a result, when the rotation of the output shaft 40 is blocked, the rotation blocking force to the parking gear 301 can be reduced. Thereby, in this transmission 2, the parking mechanism 300 can be made smaller than before, and the parking state of the vehicle can be held more reliably than before.

4). Other Embodiments The present invention is not limited to the above-described embodiments, and various modifications or corrections can be made without departing from the scope of the present invention.

(1) Reduction ratio In the above-described embodiment, the reduction ratio is exemplified, but the reduction ratio is not limited thereto, and other reduction ratios may be used as long as the above-described conditions are satisfied. .

(2) Speed change operation In the above-described embodiment, the operation of the speed change device 2 has been described. However, this does not limit the speed change operation of the speed change device 2. Therefore, the speed change device 2 can change speed by a speed change operation other than the above-described operation.

(3) Switching mechanism In the above-mentioned embodiment, although arrangement of each switching mechanism is illustrated, it is not limited to those arrangements. The axial arrangement of the switching mechanism may be switched, or the fixed side and the relative rotation side of the gear may be switched.

(4) Structure of parking mechanism In the above-described embodiment, the structure of the parking mechanism 80 is shown, but it is not limited to this structure. Other structures can be used as long as the rotation of the parking gear 301 can be restricted.

An example of the transmission pattern and reduction ratio of this invention. The block diagram of AMT carrying a double type clutch apparatus. 1 is a schematic longitudinal sectional view of a transmission as a first embodiment of the present invention. FIG. 3 is a structural diagram of the parking mechanism as the first embodiment of the present invention (when the parking mechanism is activated). The block diagram of the transmission as 1st Embodiment of this invention, and the schematic diagram of the torque transmission path | route of a transmission. The control of the fastening element and reduction ratio in each gear stage of the transmission as the first embodiment of the present invention. 1 is a structural diagram of a parking mechanism as a first embodiment of the present invention (when a parking mechanism is not operated). The longitudinal cross-sectional schematic of the transmission as 2nd Embodiment of this invention. The block diagram of the transmission as 2nd Embodiment of this invention, and the schematic diagram of the torque transmission path | route of a transmission. The control and reduction ratio of the fastening element in each gear stage of the transmission as the second embodiment of the present invention.

Explanation of symbols

1 Double clutch device 2 Transmission device 3 Flywheel 4 Damper mechanism 5 Input shaft 10 First input shaft 20 Second input shaft 30 Sub shaft 40 Output shaft 50 First output shaft 60 Second output shaft 70 Reverse shaft 110, 210 First Gear pair 120, 220 Second gear pair 130, 230 Third gear pair 140, 240 Fourth gear pair 250 Fifth gear pair 160, 260 First switching mechanism 170, 270 Second switching mechanism 180 Reverse switching mechanism 280 Third switching Mechanism 195, 295 First reverse gear pair 190, 290 Second reverse gear pair 300 Parking mechanism 301 Parking gear (parking gear)
310 parking cam assembly 320 parking rod assembly 330 parking shaft assembly C1 first clutch C2 second clutch S1 first switching gear S2 second switching gear S3 third switching gear S4 fourth switching gear S5 fifth switching gear S6 6 switching gears

Claims (9)

A transmission that is mounted on an automatic transmission including a dual clutch device that can selectively connect and disconnect the first and second clutches, and that transmits torque from the engine to the output side,
A first input shaft to which torque is input via the first clutch;
A second input shaft to which torque is input via the second clutch;
A counter shaft arranged in parallel to the first input shaft;
An output shaft disposed coaxially with respect to the first input shaft;
A reverse shaft disposed in parallel to the first input shaft;
A first reverse gear pair comprising a fourth gear fixed to the countershaft, and a first reverse gear arranged to be rotatable relative to the reverse shaft and meshing with the fourth gear;
A fourth gear pair composed of a seventh gear disposed so as to be rotatable relative to the output shaft, and an eighth gear fixed to the auxiliary shaft and meshing with the seventh gear;
A second switching mechanism capable of connecting and disconnecting the auxiliary shaft and the output shaft via the fourth gear pair;
A parking gear disposed so as to be rotatable relative to the reverse shaft and not rotatable relative to the first reverse gear;
A transmission including the parking gear, and a parking mechanism capable of restricting and releasing the rotation of the parking gear. A first gear pair composed of a first gear fixed to the second input shaft and a second gear fixed to the countershaft and meshing with the first gear;
A second gear pair constituted by the fourth gear and a third gear which is arranged to be rotatable relative to the first input shaft and meshes with the fourth gear;
A third gear pair comprising a fifth gear fixed to the countershaft, and a sixth gear arranged to be rotatable relative to the first input shaft and meshing with the fifth gear;
A first switching mechanism capable of selectively connecting and disconnecting the first input shaft and the auxiliary shaft via any one of the second and third gear pairs;
The second switching mechanism selects a connection between the auxiliary shaft and the output shaft via the fourth gear pair and a connection between the first input shaft and the output shaft not via the fourth gear pair. Can be switched and released automatically,
The transmission according to claim 1. A second reverse gear disposed relative to the reverse shaft and non-rotatable relative to the first reverse gear and the parking gear; and a second reverse gear disposed relative to the first input shaft. A second reverse gear pair composed of a third reverse gear meshing with the reverse gear;
A reverse switching mechanism capable of connecting and disconnecting the first input shaft and the first and second reverse gears via the second reverse gear pair;
The transmission according to claim 1 or 2. A first gear pair composed of a first gear fixed to the second input shaft and a second gear fixed to the countershaft and meshing with the first gear;
A second gear pair constituted by the fourth gear and a third gear which is arranged to be rotatable relative to the first input shaft and meshes with the fourth gear;
A third gear pair comprising a fifth gear fixed to the countershaft, and a sixth gear arranged to be rotatable relative to the first input shaft and meshing with the fifth gear;
A fifth gear pair composed of a ninth gear fixed to the countershaft and a tenth gear arranged to rotate relative to the first input shaft and meshing with the ninth gear;
A third reverse gear arranged to be rotatable relative to the first input shaft; and a third reverse gear arranged to be rotatable relative to the reverse shaft and not rotatable relative to the first reverse gear and the parking gear. A second reverse gear pair composed of a second reverse gear meshing with the reverse gear;
A first switching mechanism capable of selectively connecting and disconnecting the first input shaft and the auxiliary shaft via one of the second and third gear pairs; the first input shaft and the auxiliary shaft; And a third switching mechanism capable of selectively switching and releasing the connection through the fifth gear pair and the connection between the first input shaft and the reverse shaft through the second reverse gear pair. ,
The second switching mechanism selects a connection between the auxiliary shaft and the output shaft via the fourth gear pair and a connection between the first input shaft and the output shaft not via the fourth gear pair. Can be switched and released automatically,
The transmission according to claim 1. The number of teeth of the first reverse gear is the same as the number of teeth of the third gear,
A reduction ratio of the first gear pair from the second input shaft to the countershaft is α1,
A reduction ratio of the second gear pair from the first input shaft to the sub shaft is α2,
Α3 <α1 <α2 <α4, where α3 is a reduction ratio from the first input shaft to the sub shaft of the third gear pair,
The transmission according to any one of claims 2 to 4. The number of teeth of the first reverse gear is the same as the number of teeth of the third gear,
A reduction ratio of the first gear pair from the second input shaft to the countershaft is α1,
A reduction ratio of the second gear pair from the first input shaft to the sub shaft is α2,
A reduction ratio of the third gear pair from the first input shaft to the sub shaft is α3,
A reduction ratio from the secondary shaft to the output shaft of the fourth gear pair is α4,
Α3 <α1 <α5 <α2 <α4, where α5 is a reduction ratio from the first input shaft to the sub shaft of the fifth gear pair,
The transmission according to claim 4. The parking mechanism is
A parking cam assembly for restricting rotation of the parking gear by engaging with the parking gear;
A parking rod assembly for biasing the parking cam assembly against the parking gear;
A parking shaft assembly for driving the parking rod assembly;
The transmission according to any one of claims 1 to 6. The parking cam assembly includes a parking cam that can be engaged with the parking gear, a support member that rotatably supports the parking cam, and a biasing member that biases the parking cam to the side opposite to the parking gear side. 1 elastic member,
The parking rod assembly includes a rod, a tip member provided so as to be relatively movable with respect to the rod, and biasing the parking cam toward the parking gear, and biasing the tip member attached to the rod A second elastic member for
The parking shaft assembly includes a shaft main body, a lever fixed to the shaft main body for driving the rod, and a drive lever for rotating the shaft main body.
The transmission according to claim 7. The second input shaft is a cylindrical member disposed coaxially on the outer peripheral side of the first input shaft.
The transmission according to any one of claims 1 to 6.

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