JP6255586B2 - Continuously variable transmission for vehicle - Google Patents

Description

  The present invention relates to a so-called split type continuously variable transmission for a vehicle.

  Conventionally, what is disclosed by the following patent documents 1-3 is provided as what is called a split type continuously variable transmission for vehicles. The high-efficiency continuously variable transmission system for an automobile engine disclosed in Patent Document 1 below includes a planetary gear train, a first drive link having a constant speed ratio, and a second variable speed ratio having a continuously variable speed ratio between an input shaft and an output shaft. It is set as the structure provided with the drive link. In the planetary gear train, the planetary support is coupled to rotate with the first drive link, and the ring gear is coupled to rotate with the output shaft. In addition, the sun wheel of the planetary gear train is coupled to rotate with the second drive link. The engagement state of the first drive link with respect to the input shaft can be switched by a clutch, and the engagement state of the second drive link with respect to the output shaft can be switched by the clutch.

  The continuously variable transmission disclosed in Patent Document 2 below includes a continuously variable transmission mechanism, a planetary gear mechanism, a brake and a clutch for the planetary gear mechanism, and a drive gear provided on the input shaft. A driven gear provided on the planetary gear mechanism side is engaged with a gear serving as an idler.

Japanese National Patent Publication No. 11-504415 JP 59-110594 A

  Here, in the high-efficiency continuously variable transmission system for an automobile engine described in Patent Document 1 described above, a system in which power is transmitted by a chain is employed as the first drive link having a constant speed ratio. In the case of such a system, there arises a problem that the power transmission efficiency is lowered as the chain tension is increased by the centrifugal force.

  In order to solve such a problem, as in the continuously variable transmission of Patent Document 2, when power transmission can be performed by a gear pair including a driving gear and a driven gear, the gear on the power input side and the power output If a gear serving as an idler is not provided between the side gears, an output in the desired rotation direction cannot be obtained. Therefore, in the case of the configuration as disclosed in Patent Document 2, it is necessary to configure a configuration in which gears and the like are arranged on a large number of axes exceeding three axes, and the size of the continuously variable transmission increases accordingly. There is.

  In addition to this, in the case of the configuration as disclosed in Patent Document 2, it is necessary to provide a large-diameter gear on the first axis disposed below in the continuously variable transmission. Therefore, in the configuration of Patent Document 2, the agitation resistance of the lubricating oil accompanying the drive of the gear arranged on the first axis increases, which may cause a problem in terms of improving fuel consumption.

  Therefore, the present invention has an object to provide a continuously variable transmission for a vehicle that can contribute to improvement in fuel consumption by suppressing the agitation resistance of the lubricating oil while reducing the number of shafts to a minimum and making the structure compact. .

A continuously variable transmission for a vehicle according to the present invention provided to solve the above-described problem includes a first power transmission system capable of transmitting rotational power input from a power source side to a continuously variable transmission, A second power transmission system capable of transmitting rotational power input from a power source through a system different from the first power transmission system, and the first power transmission system and / or the second power transmission system. Rotational power transmitted from a power transmission system can be input to a pair of reduction gears, and a first axis located on the output axis of the power source, a second axis parallel to the first axis, and a second axis A primary pulley that constitutes the continuously variable transmission on the first axis, a first planetary gear mechanism capable of transmitting power to the primary pulley, and the second power transmission. The drive gears that make up the system A secondary pulley that constitutes the continuously variable transmission, a driven gear that meshes with the drive gear and constitutes the second power transmission system, and the secondary pulley and the driven gear. A second planetary gear mechanism capable of inputting power and a reduction gear that is one of the reduction gear pairs and that operates in response to an output from the second planetary gear mechanism. A diff ring gear meshing with the reduction gear is disposed on the third axis, the gear being the other of the reduction gear pair, and the drive gear is located on the first planet. A high class gear disposed upstream of the gear mechanism in the power transmission direction and capable of switching a power transmission state to the drive gear on the first axis. And a low clutch capable of switching a power transmission state from the continuously variable transmission to the second planetary gear mechanism on the second axis, and while disengaging the high clutch, By engaging the low clutch, it is possible to operate in a belt drive mode in which power can be input to the reduction gear pair by power transmission by the first power transmission system, while the high clutch is in the engaged state. By disengaging the low clutch, in addition to the first power transmission system, the operation in the torque split drive mode in which power can be input to the reduction gear pair by power transmission by the second power transmission system. The reverse clutch is disengaged when the belt drive mode or the torque split drive mode is selected. The forward brake is engaged ,
The reverse clutch and the forward brake is characterized Rukoto provided in the first planetary gear mechanism, those.

  With this configuration, the continuously variable transmission for a vehicle can have a three-axis configuration. As a result, the number of constituent axes can be minimized as compared with the conventional continuously variable transmission, and the vehicle continuously variable transmission can be made more compact.

  In the continuously variable transmission for a vehicle according to the present invention, the drive gear forming the second power transmission system is disposed on the first axis at a position upstream of the first planetary gear mechanism in the power transmission direction. As a result, the speed increasing ratio in the second power transmission mechanism becomes larger than in the case where the drive gear is disposed downstream of the first planetary gear mechanism, and the diameter of the drive gear disposed on the first axis is reduced. be able to. Along with this, the stirring loss of the lubricating oil in the entire first shaft and the second shaft is reduced, and it becomes possible to contribute to improvement in fuel consumption.

  According to the present invention, it is possible to provide a continuously variable transmission for a vehicle that can contribute to improvement in fuel consumption by suppressing the agitation resistance of lubricating oil while reducing the number of shafts to a minimum and reducing the number of shafts. it can.

It is a skeleton figure of the continuously variable transmission for vehicles concerning one embodiment of the present invention.

  Hereinafter, a continuously variable transmission X for a vehicle according to an embodiment of the present invention will be described in detail with reference to the drawings, taking a vehicle equipped with the same as an example. The vehicle shown in FIG. 1 is an FF (front engine / front drive) type vehicle, and includes an engine 1 (power source), a torque converter 2, a first planetary gear mechanism 3, a belt-type continuously variable transmission 4, a second planetary gear. A gear mechanism 5, a power split mechanism 6, a reduction gear pair 7, a differential gear mechanism 8, and the like are mounted. In the following, each part of the vehicle continuously variable transmission X will be described in detail for each part, and then the arrangement of each component and the operation of the vehicle continuously variable transmission X will be described.

≪About Engine 1≫
The engine 1 is, for example, a multi-cylinder gasoline engine, and a crankshaft 11 that is an output shaft is connected to the torque converter 2. The engine 1 functions as a power source that inputs power to the vehicle continuously variable transmission X.

≪About torque converter 2≫
The torque converter 2 includes a pump impeller 21 on the input shaft side, a turbine runner 22 on the output shaft side, a stator 23 that exhibits a torque amplification function, and a one-way clutch 24, and is provided between the pump impeller 21 and the turbine runner 22. The power is transmitted through the fluid.

  The torque converter 2 is provided with a lockup clutch 25 that directly connects the input side and the output side thereof. The lockup clutch 25 has a differential pressure (lockup differential pressure) ΔP between the hydraulic pressure in the engagement side oil chamber 26 and the hydraulic pressure in the release side oil chamber 27 (ΔP = hydraulic pressure in the engagement side oil chamber 26 minus the release side). This is a hydraulic friction clutch that is frictionally engaged with the front cover 2a by the hydraulic pressure in the oil chamber 27, and is engaged or released by controlling the differential pressure ΔP. That is, the lockup clutch 25 is engaged by setting the lockup differential pressure ΔP to a positive value, and the lockup clutch 25 is released by setting the lockup differential pressure ΔP to zero or less. The lockup differential pressure ΔP is controlled by a lockup control valve 82 and the like which will be described later and the control device 8.

  The torque converter 2 is provided with a mechanical oil pump 9 that is connected to and driven by a pump impeller 21. The oil pressure supplied from the oil pump 9 becomes the original pressure of the oil pressure control circuit 20.

≪About the first planetary gear mechanism 3≫
The first planetary gear mechanism 3 includes a first sun gear 31, a first ring gear 32, a first pinion gear 33, a reverse clutch C1, and a forward brake B1. The first planetary gear mechanism 3 is of a single pinion type, for example, and the first sun gear 31 is connected to the turbine shaft 28 and the first ring rear 32 is connected to the input shaft 40. The forward brake B1 is for stopping the rotation of the first carrier 34 that supports the first pinion gear 33 so as to rotate freely around the axis of the first sun gear 31. The reverse clutch C1 is for fastening the first carrier 34 and the first sun gear 31 together in a rotating manner.

  When the reverse clutch C1 is released and the forward brake B1 is engaged, the rotation of the turbine shaft 28 is reversed and decelerated and transmitted to the input shaft 40. On the other hand, when the forward brake B1 is released and the reverse clutch C1 is engaged, the first carrier 34 and the first sun gear 31 of the first planetary gear mechanism 3 rotate integrally, and the turbine shaft 28 and the input shaft 40 Is directly connected. Further, when both the reverse clutch C1 and the forward brake B1 are released, the first planetary gear mechanism 3 cuts off the power to form a neutral state.

≪About belt type continuously variable transmission 4≫
The belt-type continuously variable transmission 4 includes an input-side primary pulley 41, an output-side secondary pulley 42, a metal belt 43 wound between the primary pulley 41 and the secondary pulley 42, and the like. .

  The primary pulley 41 is a variable pulley having a variable effective diameter, and a fixed sheave 411 fixed to the input shaft 40 and a movable sheave 412 disposed on the input shaft 40 in a state in which sliding is possible only in the axial direction. And is mainly composed. Similarly to the primary pulley 41, the secondary pulley 42 is a variable pulley having a variable effective diameter, and a fixed sheave 421 fixed to the output shaft 44 and a state in which the output shaft 44 can slide only in the axial direction. The movable sheave 422 is mainly configured.

  A hydraulic actuator 413 for changing the V groove width between the fixed sheave 411 and the movable sheave 412 is disposed on the movable sheave 412 side of the primary pulley 41. The V groove width is changed by controlling the hydraulic pressure supplied to the hydraulic actuator 413. Similarly, a hydraulic actuator 423 for changing the V groove width between the fixed sheave 421 and the movable sheave 422 is disposed on the movable sheave 422 side of the secondary pulley 42, and is supplied to the hydraulic actuator 423. The V groove width is changed by controlling the hydraulic pressure.

≪About the second planetary gear mechanism 5≫
The second planetary gear mechanism 5 includes a second sun gear 51, a second ring gear 52, a second pinion gear 53, and a low clutch C2. In the second planetary gear mechanism 50, the second sun gear 51 is connected to the output shaft 44, and the second ring gear 52 is connected to the reduction gear 71 that forms the speed reduction gear pair 7. The low clutch C <b> 2 is for fastening the second carrier 54 and the second sun gear 51 connected to the second pinion gear 53 to rotate together. When the low clutch C2 is engaged, the second carrier 54 and the second sun gear 51 of the second planetary gear mechanism 50 rotate together, and the input shaft 40 and the second ring gear 52 are directly connected.

≪About power split mechanism 6≫
The power split mechanism 6 is a power transmission mechanism composed of parallel shaft gears. Specifically, the power split mechanism 6 includes a drive gear 61 disposed on the turbine shaft 28 located on the first axis L1, a driven gear 62 disposed on the output shaft 44 serving as the second axis L2, and a high clutch. C3. The drive gear 61 and the driven gear 62 mesh with each other. By setting the high clutch C3 to the engaged state, power can be transmitted from the turbine shaft 28 to the drive gear 61. The driven gear 62 is connected to the second carrier 54 of the second planetary gear mechanism 5 so as to be able to transmit power. Therefore, by setting the high clutch C3 in the engaged state, the rotational power of the turbine shaft 28 can be input to the second carrier 54 of the second planetary gear mechanism 5 via the drive gear 61 and the driven gear 62.

≪Regarding the arrangement of each component in the vehicle continuously variable transmission X≫
The continuously variable transmission X for a vehicle has a three-axis configuration in which the above-described various components are arranged on three axes including a first axis L1, a second axis L2, and a third axis L3. Specifically, the first axis L1 is an axis located below the other axes L2, L3 in the continuously variable transmission X for a vehicle. On the first axis L1, a primary pulley 41 that constitutes the belt-type continuously variable transmission 4, a first planetary gear mechanism 3, and a drive gear 61 that constitutes a second power transmission system R2 are disposed. The drive gear 61 is disposed on the first axis L1 on the upstream side in the power transmission direction with respect to the first planetary gear mechanism 3, that is, on the engine 1 and torque converter 2 side.

  Further, on a second axis L2 that is substantially parallel to the first axis L1, a secondary pulley 42 that constitutes the belt-type continuously variable transmission 4, a driven gear 62 that constitutes the second power transmission system R2, A two planetary gear mechanism 5 and a reduction gear 71 that constitutes one of the reduction gear pair 7 are arranged. A diff ring gear 72 that forms the other of the reduction gear pair 7 is disposed on the third axis L3.

≪About power transmission system≫
In the continuously variable transmission X for a vehicle, a power transmission system including two systems, a first power transmission system R1 and a second power transmission system R2, is provided. In the vehicle continuously variable transmission X, power is transmitted to the reduction gear pair 7 and the differential gear mechanism 8 via the first power transmission system R1 and the second power transmission system R2, and left and right drive wheels (not shown). .) Can be activated.

The first power transmission system R1 outputs the output of the engine 1 from the torque converter 2 via the first planetary gear mechanism 3, the belt-type continuously variable transmission 4, the second planetary gear mechanism 5, and the differential gear pair 7 and the differential. This is a power transmission system for transmitting to the gear mechanism 8. The second power transmission system R2 transmits the power output from the engine 1 via the torque converter 2 via the power split mechanism 6 without passing through the first planetary gear mechanism 3 and the continuously variable transmission 4. 5 is a system different from the first system in which power is transmitted via the reduction gear pair 7 and the differential gear mechanism 8.

≪About operation mode in continuously variable transmission X for vehicles≫
The continuously variable transmission X for a vehicle has a belt drive mode and a torque split drive mode as operation modes for moving the vehicle forward. The continuously variable transmission X for a vehicle has a reverse drive mode as an operation mode for moving the vehicle backward. In the continuously variable transmission X for a vehicle, each operation mode is switched by switching the engagement state of the reverse clutch C1, the forward brake B1, the low clutch C2, and the high clutch C3 as shown in the engagement table shown in Table 1. Can be switched.

  Specifically, the belt drive mode is an operation mode in which power is input to the reduction gear pair 7 and the vehicle is advanced by power transmission by the first power transmission system R1. When the belt drive mode is selected, the reverse clutch C1 is disengaged and the forward brake B1 is engaged. Thereby, the rotation of the turbine shaft 28 is reversed and decelerated and transmitted to the input shaft 40.

  In the belt drive mode, the high clutch C3 is disengaged and the low clutch C2 is engaged. Thereby, the power transmission to the second power transmission system R2 is interrupted, and the second ring gear 52 of the second planetary gear mechanism 5 and the input shaft 40 are directly connected. Therefore, when the belt drive mode is selected, the power output from the engine 1 is input to the second planetary gear mechanism 5 via the first planetary gear mechanism 3 and the belt-type continuously variable transmission 4, and the second planetary gear mechanism 5 It is output to the reduction gear pair 7 side in the ring gear 52.

  On the other hand, in the torque split drive mode, the power generated in the engine 1 is transmitted to the second power transmission system R2 in addition to the first power transmission system R1, and is input to the second planetary gear mechanism 5 to input the vehicle. This is an operation mode for moving forward. When the torque split drive mode is selected, the reverse clutch C1 is disengaged and the forward brake B1 is engaged as in the belt drive mode described above. Thereby, the rotation of the turbine shaft 28 is reversed and decelerated and transmitted to the input shaft 40.

  In the torque split drive mode, the high clutch C3 is engaged and the low clutch C2 is disengaged, contrary to the case of the belt drive mode described above. As a result, the power transmitted through the first power transmission system R1 is input to the second sun gear 51 from the input shaft 40, and the power transmitted through the second power transmission system R2 is input to the second pinion gear 53. Is input. Therefore, when the torque split drive mode is selected, the power output from the engine 1 is distributed not only to the first power transmission system R1 but also to the second power transmission system R2. The power distributed to the second power transmission system R2 is input to the second planetary gear mechanism 5 via the power split mechanism 6, that is, the drive gear 61 and the driven gear 62. In this way, the second planetary gear mechanism 5 operates by receiving the power input from the first power transmission system R1 and the second power transmission system R2, and moves forward to the reduction gear pair 7 via the second ring gear 52. It is output as power for use.

  When the reverse drive mode is selected, unlike the belt drive mode and torque split drive mode described above, the reverse clutch C1 is engaged and the forward brake B1 is disengaged. . Thereby, the rotation of the turbine shaft 28 is transmitted to the input shaft 40 in the normal rotation state. In the reverse drive mode, the high clutch C3 is disengaged and the low clutch C2 is engaged. Thereby, the power transmission to the second power transmission system R2 is interrupted, and the second ring gear 52 of the second planetary gear mechanism 5 and the input shaft 40 are directly connected. Accordingly, in the reverse drive mode, the power output from the engine 1 is input to the second planetary gear mechanism 5, and is output to the reduction gear pair 7 side as rotational power in the direction opposite to the forward direction in the second ring gear 52. The

  As described above, the vehicle continuously variable transmission X has a three-axis configuration including the first axis L1, the second axis L2, and the third axis L3. Therefore, the continuously variable transmission X for a vehicle can have a more compact configuration than the continuously variable transmission having a shaft configuration of four or more shafts exemplified in the prior art.

  In the vehicle continuously variable transmission X described above, the drive gear 61 forming the second power transmission system R2 is disposed on the first axis L1 at a position upstream of the first planetary gear mechanism 3 in the power transmission direction. Has been. As a result, the speed increasing ratio in the second power transmission mechanism becomes larger than in the case where the drive gear 61 is disposed downstream of the first planetary gear mechanism 3, and the drive gear 61 disposed on the first axis L1. Can be reduced in diameter. Along with this, the stirring loss of the lubricating oil in the entire first shaft and the second shaft is reduced, and it becomes possible to contribute to improvement in fuel consumption.

  The continuously variable transmission for a vehicle according to the present invention can be applied to all vehicles equipped with a so-called split type continuously variable transmission, and particularly to all vehicles that require a compact vehicle configuration such as a light vehicle or a compact car. It can be suitably used.

DESCRIPTION OF SYMBOLS 1 Engine 3 1st planetary gear mechanism 4 Belt type continuously variable transmission 5 2nd planetary gear mechanism 7 Reduction gear pair 41 Primary pulley 42 Secondary pulley 61 Drive gear 62 Driven gear 71 Reduction gear 72 Defring gear L1 1st axis L2 2nd Axis L3 Third axis R1 First power transmission system R2 Second power transmission system C2 Low clutch C3 High clutch

Claims (1)

A first power transmission system capable of transmitting the rotational power input from the power source side to the continuously variable transmission;
A second power transmission system capable of transmitting the rotational power input from the power source in a system different from the first power transmission system;
The rotational power transmitted from the first power transmission system and / or the second power transmission system can be input to the reduction gear pair,
A first axis located on the output axis of the power source;
A second axis and a third axis parallel to the first axis;
On the first axis,
A primary pulley constituting the continuously variable transmission;
A first planetary gear mechanism capable of transmitting power to the primary pulley;
A drive gear constituting the second power transmission system is disposed;
On the second axis,
A secondary pulley constituting the continuously variable transmission;
A driven gear that meshes with the drive gear and constitutes the second power transmission system;
A second planetary gear mechanism capable of inputting power through the secondary pulley and the driven gear;
A reduction gear that is configured to receive an output from the second planetary gear mechanism and is a gear that forms one of the pair of reduction gears;
On the third axis,
A gear that forms the other of the pair of reduction gears, and a diffring gear meshed with the reduction gear is disposed,
The drive gear is arranged at a position upstream of the first planetary gear mechanism in the power transmission direction on the first axis;
A high clutch capable of switching a power transmission state to the drive gear on the first axis;
A low clutch capable of switching a power transmission state from the continuously variable transmission to the second planetary gear mechanism on the second axis;
By engaging the low clutch while disengaging the high clutch, it is possible to operate in a belt drive mode in which power can be input to the reduction gear pair by power transmission by the first power transmission system. And
By making the high clutch engaged and disengaging the low clutch, power can be input to the reduction gear pair by power transmission by the second power transmission system in addition to the first power transmission system. It is possible to operate in the torque split drive mode,
When the belt drive mode or the torque split drive mode is selected, the reverse clutch is disengaged and the forward brake is engaged .
The reverse clutch and the forward brake is characterized Rukoto provided in the first planetary gear mechanism, a continuously variable transmission for a vehicle.