JP3726934B2 - Continuously variable transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a continuously variable transmission in which a planetary forward / reverse switching device is disposed between a starting device and a continuously variable transmission.
[0002]
[Prior art]
Generally, a continuously variable transmission mounted on a vehicle such as an automobile includes a continuously variable transmission, which is a main transmission mechanism that performs a shift in a running state, and a start that controls power transmission between the engine and the transmission at the time of start. A device and a forward / reverse switching device that reverses the direction of rotation of the driving force transmitted to the transmission to reverse the vehicle are provided.
[0003]
In the case where a planetary gear is used as the forward / reverse switching device, for example, Japanese Patent Publication No. 3-72857 employs a torque converter as a starting device and a planetary forward / reverse switching device that is attached to a turbine runner of the torque converter. An input shaft and a clutch drum constituting a forward clutch of the planetary forward / reverse switching device are spline-engaged between the forward clutch and the hub, and the tip of the input shaft is connected to a stepped portion on the back surface of the pump cover. Further, there is disclosed a technique in which the sun gear of the planetary gear and the hub are spline-engaged with an input shaft that is pivotally supported by the primary pulley of the continuously variable transmission.
[0004]
Further, for example, Japanese Patent Laid-Open No. 58-94667 discloses a forward / reverse switching device in which an end of an output shaft of a forward / reverse switching device that is attached to a primary pulley of a continuously variable transmission is connected to a turbine runner of a torque converter. A technique is disclosed in which the input shaft of the forward / reverse switching device is supported by a pump cover of an oil pump while being inserted and supported in a hollow portion formed at the tip of the input shaft.
[0005]
[Problems to be solved by the invention]
By the way, when the engine and the continuously variable transmission that are assembled together are mounted horizontally in the engine room provided in the front part of the vehicle body, the entire width must naturally be a size that can be stored in the engine room.
[0006]
However, in recent engine rooms, frames that absorb shocks at the time of collision are provided on both sides, and a front tire is provided outside the frame. It is necessary for the frame to have a sufficient cross section to maintain rigidity in order to maintain the steering stability of the vehicle and to ensure the collision safety, and the front tire is used for handling the vehicle. In order to ensure the stability, it is necessary to set a large turning angle.
[0007]
To fully satisfy both the volume of the engine room and the turning angle of the front tire, it is only necessary to increase the size of the vehicle body. The increase in weight, the reduction in maneuverability, and the increase in the efficiency of the drive system are hindered, resulting in poor fuel efficiency.
[0008]
As a result, the volume in the engine room tends to be relatively narrow, and inevitably there is a need to shorten the entire width of the engine and the continuously variable transmission.
[0009]
However, in the continuously variable transmission disclosed in the above Japanese Patent Publication No. 3-72857, the spline engaging portion between the clutch drum of the forward / reverse switching device and the input shaft connected to the turbine runner of the torque converter has a pump cover. And the forward clutch hub, the entire width of the continuously variable transmission becomes longer, and the outer periphery of the intermediate shaft extending from the primary pulley of the continuously variable transmission is Since the sun gear of the forward / reverse switching device and the hub of the forward clutch are spline-engaged, the structure is complicated and it is difficult to accommodate in the engine room which tends to be narrowed recently.
[0010]
On the other hand, in the continuously variable transmission disclosed in JP-A-58-94667, the front end of the output shaft of the forward / reverse switching device is rotated relative to the input shaft of the forward / reverse switching device via a bearing. The structure is complex because the input shaft is supported freely and the input shaft is rotatably supported on the oil pump cover via another bearing, and the overall width of the continuously variable transmission is reduced from the current configuration. It is difficult.
[0011]
On the other hand, as a technique for shortening the overall width of the continuously variable transmission, for example, the pulley ratio of the continuously variable transmission is reduced, the width of the belt wound between both pulleys of the continuously variable transmission is reduced, or each member Although measures such as thinning the wall thickness or reducing the clearance between each member are conceivable, these technologies have poor feasibility because they may reduce the function and durability of the continuously variable transmission. .
[0012]
In view of the above circumstances, the present invention is capable of shortening the entire width without deteriorating durability and function and without complicating the structure, and is easily mounted in an engine room that tends to be narrowed recently. It is an object of the present invention to provide a continuously variable transmission that can perform the above.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, a first continuously variable transmission according to the present invention includes a forward / reverse switching device disposed between a starting device and a continuously variable transmission, and the starting device and the continuously variable transmission during forward traveling. A planetary gear, and a reverse brake for reversing the sun gear of the planetary gear for fixing the ring gear provided on the planetary gear and connecting it to the input shaft of the primary pulley during reverse travel. An input portion provided on a clutch drum of the forward clutch and the forward clutch, with the shaft end portion of the input shaft extending from the primary pulley supported on the outer periphery of the shaft end portion of the output shaft extending from the starting device When the output portion provided on the hub of the output shaft is inserted between the shaft end portion of the output shaft and the shaft end portion of the input shaft, The, the input section connected to the shaft end portion outer periphery of the output shaft, further the output unit, characterized in that connected to the peripheral axial end portion of the input shaft.
[0018]
The second continuously variable transmission is characterized in that, in the first continuously variable transmission, the sun gear of the planetary gear is integrally formed on the outer periphery of the shaft end portion of the input shaft.
[0022]
In the first continuously variable transmission, between the shaft end portion of the output shaft extending from the starting device and the input shaft extending from the primary pulley of the continuously variable transmission supported on the outer periphery of the shaft end portion. The input portion provided on the clutch drum of the forward clutch and the output portion provided on the hub of the forward clutch are inserted, the input portion is connected to the shaft end portion of the output shaft, and the output portion is further connected to the input shaft. The width of the forward / reverse switching device is shortened by connecting to the shaft end portion.
[0024]
In the second continuously variable transmission, in the first continuously variable transmission, the sun gear of the planetary gear constituting the forward / reverse switching device is integrally formed on the outer periphery of the shaft end portion of the input shaft, thereby reducing the number of parts, The entire size of the continuously variable transmission is reduced.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 and 2 show a first embodiment of the present invention.
Reference numeral 1 in FIG. 1 denotes a continuously variable transmission, which includes a starting device 2, a front / rear switching device 3, and a continuously variable transmission 4, and an engine A is connected to the input side of the continuously variable transmission 1.
[0026]
The starting device 2 is provided with a clutch fixing plate 5 connected to the crankshaft A1 of the engine A. A torque converter case 6 for fixing the clutch fixing plate 5 is connected to a pump impeller 7a of the torque converter 7. Has been. Further, a torque converter output shaft 8 extending from a turbine runner 7b provided on the pump impeller 7a faces the forward / reverse switching device 3.
[0027]
Further, the torque converter case 6 is provided with a lock-up clutch 6a connected to the turbine runner 7b. When the lock-up clutch 6a is engaged with the torque converter case 6, the driving force of the engine A does not pass through the torque converter 7 but passes through the turbine runner 7b to a pulley input shaft 13a of the continuously variable transmission 4 described later. Directly transmitted.
[0028]
The stator 7c of the torque converter 7 is connected to a stator shaft 7e fixed directly or indirectly to the main body case 2a of the starting device 2 via a one-way clutch 7d. Reference numeral 9 denotes an oil pump that is rotationally driven by the pump impeller 7a.
[0029]
The forward / reverse switching device 3 is provided with a forward clutch 10, a planetary gear 11, and a reverse brake 12, and a torque converter output shaft 8 extending from the turbine runner 7 b of the torque converter 7 is provided in the forward clutch 10. The hub 10b of the forward clutch 10 is connected to a pulley input shaft 13a extending from a primary pulley 13 provided in the continuously variable transmission 4, and is further connected to the clutch drum 10a. The sun gear 11a of the planetary gear 11 is integrally formed with the shaft end portion 13c of the pulley input shaft 13a.
[0030]
A pinion gear 11c that connects the sun gear 11a and the ring gear 11b of the planetary gear 11 is connected to the clutch drum 10a of the forward clutch 10 through a carrier 11d. Further, a reverse brake cylinder 12a provided in the reverse brake 12 is connected to the main body case 3a of the forward / reverse switching device 3 so as to be able to advance and retreat in a state where the rotation direction is restricted. When the rotation of the ring gear 11b of the planetary gear 11 is stopped via the reverse brake 12 by the operation of the reverse brake cylinder 12a, the pinion gear 11c is rotated and the pulley input shaft 13a is reversely rotated in a decelerated state via the sun gear 11a. Drive.
[0031]
The primary pulley 13 of the continuously variable transmission 4 and a secondary pulley 14 provided opposite to the primary pulley 13 are connected via a belt 15, and a pulley output shaft 14 a that supports the secondary pulley 14. Is connected via a reduction gear group 15a of the final reduction gear 15 to a differential device 15b that is attached to the drive shaft 16 of the front wheel or the rear wheel.
[0032]
The continuously variable transmission 4 has a pulley groove width set by a primary hydraulic pressure supplied to a primary hydraulic chamber 13 b provided in the primary pulley 13. Further, a secondary hydraulic pressure supplied to a secondary hydraulic chamber 14 b provided in the secondary pulley 14 applies a tension necessary for torque transmission to the secondary pulley 14. The primary hydraulic pressure and the secondary hydraulic pressure are set based on an engine operating state or the like in a transmission control unit (TCU) (not shown), and the groove widths of the pulleys 13 and 14 are set in an inversely proportional state in the continuously variable transmission 4. A desired reduction ratio is obtained.
[0033]
By the way, as shown in FIG. 2, the shaft end portion 8 a of the torque converter output shaft 8 extending from the turbine runner 7 b of the torque converter 7 is connected to the shaft end portion 13 c of the pulley input shaft 13 a extending from the primary pulley 13. It is inserted and supported so as to be relatively rotatable. The base of the pulley input shaft 13 a is supported by the main body case 3 a of the forward / reverse switching device 3 through a bearing 17. The outer diameter of the sun gear 11a is slightly smaller than the base portion supported by the bearing 17 of the pulley input shaft 13a. The pulley input shaft 13a can be easily pressed into the bearing 17.
[0034]
Further, a concentric recess 10c is formed in the clutch drum 10a, and this recess 10c is formed on the outer periphery of the pump cover 3b of the oil pump 9 formed integrally with the body case 2a of the starting device 2 via a seal member. An input portion 10d that is rotatably supported and formed at the center of rotation of the clutch drum 10a is interposed between both shaft end portions 8a and 13c of the torque converter output shaft 8 and the pulley input shaft 13a. In addition, it is spline-engaged with the shaft end 8a of the torque converter output shaft 8.
[0035]
Further, an output portion 10e formed in the direction of the rotation center of the hub 10b is engaged with a spline formed on the shaft end portion 13c of the pulley input shaft 13a.
[0036]
Next, the operation of the present embodiment having the above configuration will be described.
During forward travel, the forward clutch 10 is in the coupled state and the reverse brake 12 is in the released state. As a result, the driving force from the turbine runner 7b of the torque converter 7 is input to the forward clutch 10 of the forward / reverse switching device 3 that is splined to the shaft end 8a of the torque converter output shaft 8 extending from the turbine runner 7b. Then, the pulley input shaft 13a of the primary pulley 13 provided in the continuously variable transmission 4 that is spline-engaged with the output portion 10e of the hub 10b of the forward clutch 10 is forwardly rotated.
[0037]
On the other hand, during reverse travel, the reverse brake 12 is in the engaged state, and the forward clutch 10 is in the released state. As a result, when the reverse brake 12 is engaged, the ring gear 11b of the planetary gear 11 is fixed, and the driving force transmitted from the torque converter output shaft 8 to the clutch drum 10a is connected to the planetary gear 10a. 11 is transmitted to the carrier 11d, the pinion gear 11c supported by the carrier 11d is rotated because the ring gear 11 is fixed, and the pulley input shaft 13a is decelerated via the sun gear 11a and reversely rotated. Let
[0038]
When both the forward clutch 10 and the reverse brake 12 are in the released state, the planetary gear 11 is in a neutral state in which it idles.
[0039]
When the lock-up clutch 6a is engaged, the clutch shaft A1 of the engine A is directly connected to the torque converter output shaft 8 via the fixed plate 5, the lock-up clutch 6a, and the turbine runner 7b of the torque converter 7 to be in the lock-up state. Become.
[0040]
In the present embodiment, the input portion 10d of the clutch drum 10a and the output portion 10e of the hub 10b are disposed at positions where they substantially overlap in the axial direction, so that the width of the forward / reverse switching device 3 is increased by this overlap. The overall width W of the continuously variable transmission 1 can be shortened accordingly, and the integrated continuously variable transmission 1 and the engine A can be combined with a recent engine room that tends to be narrowed. It becomes possible to mount it without difficulty in the horizontal position.
[0041]
Furthermore, since the pulley input shaft 13a is directly supported by the main body case 3a via the bearing 17, the support accuracy of the primary pulley 13 is high and high rigidity can be obtained. Furthermore, since the outer diameter of the sun gear 11a is slightly smaller than the base portion supported by the bearing 17 of the pulley input shaft 13a, the pulley input shaft 13a is damaged to the bearing 17 and the sun gear 11a is damaged. And can be easily press-fitted.
[0042]
FIG. 3 shows a second embodiment of the present invention.
In this embodiment, a sun gear 11a formed integrally with a shaft end portion 13c of a pulley input shaft 13a is engaged with a pinion gear 11c of a planetary gear 11 and an output portion 10e of a hub 10b provided on a forward clutch 10. In the first embodiment described above, the output portion 10e of the hub 10b is engaged with a spline separately formed on the shaft end portion 13c of the pulley input shaft 13a. However, in the present embodiment, the sun gear 11a is connected to the hub. By meshing the output portion 10e of 10b, the structure is further simplified, and the manufacturing becomes easier.
[0043]
FIG. 4 shows a third embodiment of the present invention.
In the present embodiment, the output portion 10e of the hub 10b provided in the forward clutch 10 is formed in a boss shape so as to face the inner periphery of the shaft end portion 13c of the pulley input shaft 13a, and the shaft end portion 13c The spline is engaged with the inner periphery.
[0044]
According to the present embodiment, the input portion 10d of the clutch drum 10a, the output portion 10e of the hub 10b, and the sun gear 11a are arranged so as to substantially overlap in the coaxial direction, so the first and second embodiments described above. As compared with this, the width direction of the forward / reverse switching device 3 can be further shortened.
[0045]
FIG. 5 shows a fourth embodiment of the present invention.
In the present embodiment, the torque converter output shaft 8 is supported on the inner periphery of the pump cover 3b of the oil pump 3 through an oil bushing 18 so as to be rotatable. The torque converter output shaft 8 is attached to the pump cover 3b. Since it is supported, it is not necessary to support the shaft end portion 8a of the torque converter output shaft 8 on the pulley input shaft 13a, and accordingly, the shaft length of the torque converter output shaft 8 can be shortened. Since the shaft 8 can be supported with a relatively wide width with respect to the inner periphery of the pump cover 3b, durability is improved. Further, the depth of the hole for loosely inserting the shaft end portion 8a of the torque converter output shaft 8 formed in the front end surface of the pulley input shaft 13a can be reduced.
[0046]
Reference numeral 8b denotes a hydraulic circuit drilled in the torque converter output shaft 8, and the oil bushing 18 has an oil hole 18a communicating with the hydraulic circuit 8b.
[0050]
【The invention's effect】
According to the first aspect of the present invention, the forward movement is performed between the shaft end portion of the output shaft extending from the starting device and the input shaft extending from the primary pulley of the continuously variable transmission supported on the outer periphery of the shaft end portion. The input portion provided on the clutch drum of the clutch and the output portion provided on the hub of the forward clutch are inserted, the input portion is connected to the shaft end of the output shaft, and the output portion is connected to the input shaft. Since it is connected to the shaft end portion, the input portion of the clutch drum and the output portion of the hub are disposed at a position that substantially overlaps the axial direction of the both shaft end portions. The overall width of the continuously variable transmission can be reduced, and the integrated continuously variable transmission and the engine can be placed horizontally in a recent engine room that tends to be narrowed. Can be installed without difficulty That.
[0052]
The invention according to claim 2 is the invention according to claim 1 , wherein the sun gear of the planetary gear constituting the forward / reverse switching device is integrally formed on the outer periphery of the shaft end portion of the input shaft, thereby reducing the number of parts. Miniaturization of the entire transmission can be realized.
[Brief description of the drawings]
FIG. 1 is a schematic view of a continuously variable transmission according to a first embodiment. FIG. 2 is a cross-sectional view of the main part of the forward / reverse switching device. FIG. FIG. 4 is a cross-sectional view of an essential part of a forward / reverse switching device according to a third embodiment. FIG. 5 is a cross-sectional view of an essential part of a forward / reverse switching device according to a fourth embodiment.
A ... Engine 1 ... Continuously variable transmission 2 ... Starting device 3 ... Forward / reverse switching device 3b ... Case body (pump cover)
4 ... continuously variable transmission 8 ... torque converter output shafts 8a, 13c ... shaft end 10 ... forward clutch 10a ... clutch drum 10d ... input part 10e ... output part 11 ... planetary gear 11a ... sun gear 11b ... ring gear 12 ... reverse brake 13 ... primary Pulley 13a ... pulley input shaft 13b ... primary hydraulic chamber

Claims (2)

To the forward / reverse switching device arranged between the starting device and the continuously variable transmission,
The planetary gear that fixes the forward clutch that couples the starting device and the primary pulley of the continuously variable transmission during forward travel, the planetary gear, and the ring gear provided to the planetary gear during reverse travel and couples it to the input shaft of the primary pulley In a continuously variable transmission equipped with a reverse brake that reverses the sun gear,
The shaft end portion of the input shaft extending from the primary pulley is pivotally supported on the outer periphery of the shaft end portion of the output shaft extending from the starting device,
An input portion provided on the clutch drum of the forward clutch and an output portion provided on the hub of the forward clutch are inserted between the shaft end portion of the output shaft and the shaft end portion of the input shaft,
Connecting the input unit to the outer periphery of the shaft end of the output shaft;
Further, the continuously variable transmission is characterized in that the output unit is connected to the inner periphery of the shaft end of the input shaft. Continuously variable transmission device according to claim 1, wherein the sun gear of the planetary gear is integrally formed on the shaft end portion outer periphery of the input shaft.

Images