JPH04285355A - Transmission for vehicle - Google Patents

Abstract

PURPOSE:To make a transmission for a vehicle in a compact size, which enables forward-backward switching and staged speed change of plural stages using a belt-type continuously variable gear as a base. CONSTITUTION:A forward-backward switching mechanism 14 is disposed on the back side of a fixed rotor 78 of a drive side variable pulley 72 of a belt type continuously variable gear 16, that is, in a region where a hydraulic cylinder 88 of the driven side variable pulley 74 is positioned. A staged speed change mechanism 18 is disposed on the back side of a fixed rotor 80 of the driven side variable pulley 74, that is, in a region where a hydraulic cylinder 86 of the drive side variable pulley 72 is positioned.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a vehicle transmission.
In particular, the present invention relates to an improvement of a vehicle transmission equipped with a belt-type continuously variable transmission, a forward/reverse switching mechanism, and a stepped transmission mechanism.

0002

[Prior Art] As a transmission for a vehicle, (a) a fixed rotating body fixed to an input shaft, a movable rotating body disposed so as to be movable in the axial direction of the input shaft, and a rear side of the movable rotating body; a drive-side variable pulley provided with a driving means for driving the movable rotating body in the axial direction; a fixed rotating body fixed to the output shaft parallel to the input shaft; and axial movement of the output shaft. a movable rotary body disposed so as to be movable, and a driving means disposed on the back side of the movable rotary body to drive the movable rotary body in the axial direction, the axial arrangement being opposite to the drive side variable pulley. A belt-type continuously variable transmission having variable driven pulleys arranged in the same direction, and a transmission belt wound around the variable driving pulley and the variable driven pulley;
(b) A forward/reverse switching mechanism that switches the direction of rotation is installed in series in the power transmission path from the engine, and a belt-type continuously variable transmission continuously changes the gear ratio, and the forward/reverse switching mechanism allows forward and reverse movement. There are some devices that allow you to switch. One type of vehicle transmission is equipped with an auxiliary transmission that includes the function of the forward/reverse switching mechanism described above that can switch not only the rotational direction but also the rotational speed. There is an enlarged version of this. For example, the transmission described in Japanese Patent Application Laid-Open No. 60-252857 is one such example.

Specifically, as shown in FIG. 12, the power of the engine 210 is transmitted through a fluid coupling with a lock-up clutch 212, a belt-type continuously variable transmission 214, an auxiliary transmission 216, and a reduction gear device 218. , and a differential gear device 220 to the wheels 224 connected to the drive shaft 222.
16 allows switching between forward and backward movement, high speed gear, and low speed gear. The sub-transmission 216 is shown in FIG.
As shown in detail in 3, a first sun gear 228 is arranged to be rotatable about the output shaft 226 and concentrically, and a second sun gear 2 is arranged to be non-rotatable relative to the output shaft 226.
30, a ring gear 232 rotatably disposed concentrically with the output shaft 226; a first planet gear 234 that meshes with the first sun gear 228 and the ring gear 232; a second planet gear that meshes with the second sun gear 230 and the first planet gear 234; 236, first planetary gear 234 and second planetary gear 2
36 rotatably supported, and a carrier 240 connected to the second output shaft 238 in a relatively non-rotatable manner. In addition, the output shaft 226 and the first sun gear 228
A multi-disc high-speed clutch 242 that connects the two in a relatively non-rotatable manner, a band-type low-speed brake 244 that prevents rotation of the first sun gear 228, and a multi-disc reverse brake 246 that prevents rotation of the ring gear 232. The engagement is controlled by hydraulic cylinders 248, 250, and 252, respectively. When the high-speed clutch 242 is engaged, the planetary gear unit is rotated integrally, the second output shaft 238 is rotated integrally in the same direction as the output shaft 226, and the low-speed brake 242 is rotated integrally with the second output shaft 238 in the same direction as the output shaft 226.
44 is engaged and controlled, the rotation of the first sun gear 228 is blocked and the second output shaft 238 changes to the gear ratio γG (=rotational speed of the output shaft 226/rotational speed of the second output shaft 238)=1
+(ZS1/ZS2) to decelerate and rotate in the same direction as the output shaft 226, and when the reverse brake 246 is engaged, the rotation of the ring gear 232 is blocked and the second output shaft 2
38 is rotated in the opposite direction to the output shaft 226, that is, in a direction that causes the vehicle to move backward. The above ZS1 is the number of teeth of the first sun gear 228, and ZS2 is the number of teeth of the second sun gear 230.

0004

[Problems to be Solved by the Invention] However, when a sub-transmission having forward/reverse switching and gear shifting functions is disposed on the input shaft or the output shaft (the output shaft in the conventional example), the sub-transmission The axial dimension of the installed side was relatively long, requiring a large installation space. For this reason, it is desirable to arrange a one-way clutch in order to smoothly switch from a low gear to a high gear, but it is difficult due to space constraints, and as the engine torque increases, the multi-disc clutch It is necessary to increase the number of friction plates in the transmission and brakes, or to widen the tooth width of the gears, but it is difficult to make such design changes in conventional transmissions. In addition, the speed ratio γG of the low speed gear by the Ravigneaux type compound planetary gear device is about 1.7 to 1.8, and the change in engine speed when shifting to the high speed gear with speed ratio γG = 1 is large. Another problem was that the shock was relatively large.

The present invention has been made against the background of the above circumstances, and its object is to provide a vehicle transmission that is based on a belt-type continuously variable transmission and is capable of forward/reverse switching and multi-stage stepped shifting. The device is designed to be compact, and a one-way clutch is installed to facilitate gear changes and easily respond to higher engine torque, while reducing the difference in gear ratios of stepped transmissions. The purpose is to reduce gear shift shock.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the mechanisms for forward/reverse switching and stepped shifting described above should be arranged separately on the driving side and driven side of the belt type continuously variable transmission. Preferably, the present invention provides that the (a) belt-type continuously variable transmission, the (b) forward/reverse switching mechanism, and (c) the stepped transmission mechanism that switches the rotational speed in multiple stages are capable of transmitting power from the engine. The vehicle transmission is arranged in series on a path, and either one of the forward/reverse switching mechanism or the stepped transmission mechanism is arranged on the back side of the fixed rotary body of the drive-side variable pulley, and The other of the forward/reverse switching mechanism and the stepped transmission mechanism is disposed on the back side of the fixed rotating body of the variable driven pulley.

[0007]

[Operation and Effects of the Invention] In such a vehicle transmission, the forward/reverse switching mechanism and the stepped transmission mechanism are provided separately on the driving side and the driven side of the belt-type continuously variable transmission, and each is fixed. Since it is arranged on the back side of the rotating body, in other words in the axial direction where the driving means for the other variable pulley is provided, the axial dimensions of the driving side and driven side of the belt type continuously variable transmission are approximately equal. In addition, they overlap each other in the direction perpendicular to the axis, so that the transmission can be constructed compactly as a whole. This makes it possible to provide a one-way clutch in the stepped transmission mechanism to facilitate gear changes, and also to increase engine torque by increasing the number of friction plates in multi-disc clutches and brakes. This makes it easier to deal with the situation. In addition, since the above-mentioned stepped transmission mechanism does not require forward/reverse switching, by adopting a single pinion type planetary gear device, etc., it is possible to reduce the difference in gear ratio of the stepped transmission and reduce shift shock. can.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIGS. 2 to 4 are cross-sectional views showing a transverse transaxle for a front-wheel drive vehicle equipped with a vehicle transmission, which is an embodiment of the present invention, and FIG. 1 shows a drive force transmission diagram of the transaxle. FIG. 2 is a schematic diagram illustrating the system. Further, FIG. 5 is a diagram showing the positional relationship of each axis of the transaxle, and the above-mentioned FIGS. 2 to 4 show these axes in one plane for easy understanding. Below, Figure 2 is based on Figure 1.
This will be explained with reference to FIGS.

First, the power of the engine 10 is transmitted through a fluid coupling 12 with a lock-up clutch, a forward/reverse switching mechanism 14, and a belt-type continuously variable transmission (hereinafter referred to as CVT) 16.
, a stepped transmission mechanism 18, a reduction gear device 20, and a differential gear device 22, and are transmitted to wheels 26 connected to a drive shaft 24. Fluid coupling 1
2 includes a pump impeller 30 connected to the crankshaft 28 of the engine 10, a turbine impeller 32 rotated by oil from the pump impeller 30, and a turbine impeller 32 connected to the turbine impeller 32 in a relatively non-rotatable manner. A lock-up clutch 38 is provided on the output shaft 34 via a damper 36. lock up clutch 3
8 is activated when, for example, the vehicle speed, the engine rotational speed, or the rotational speed of the turbine wheel 32 exceeds a predetermined value, and connects the crankshaft 28 and the output shaft 34 directly. Further, the pump impeller 30 includes a hydraulic pump 4.
0 (see FIG. 2) is connected to the rotor 42, and an internal gear 44 meshed eccentrically with respect to the rotor 42 is driven to rotate together with the rotor 42, thereby generating hydraulic pressure for operating the hydraulic actuators of each part. can be generated.

The forward/reverse switching mechanism 14 is a double pinion type planetary gear device that is selectively switched to a forward gear or a reverse gear according to the operating position of a shift lever (not shown), and is a double pinion type planetary gear device that connects the fluid cup with the CVT 16 in between. It is arranged on the opposite side from the ring 12. The output shaft 34 of the fluid coupling 12 passes through the shaft center of the CVT 16 and protrudes to the opposite side. A ring gear 52 provided, a pair of planetary gears 54 and 56 that mesh with one and the other of the sun gear 50 and ring gear 52 and mesh with each other, rotatably support the planetary gears 54 and 56, and input the CVT 16. A carrier 60 is connected to the shaft 58 in a relatively non-rotatable manner. A multi-disc forward clutch 62 is provided between the sun gear 50 and the carrier 60, and a multi-disc reverse brake 66 is provided between the ring gear 52 and the housing 64, each with a hydraulic cylinder 63. , 67 (see FIG. 2). When the forward clutch 62 is engaged by the hydraulic cylinder 63 in a state where the reverse brake 66 is released, the output shaft 34 and the carrier 60 are connected so that they cannot rotate relative to each other, and the input shaft 58 rotates integrally with the output shaft 34. When the forward clutch 62 is released and the reverse brake 66 is engaged by the hydraulic cylinder 67, the ring gear 5
2 is prevented from rotating, the carrier 60 and further the input shaft 5
8 is in the opposite direction to the output shaft 34, that is, in the direction of reversing the vehicle. Gear ratio γG1 (=rotational speed of output shaft 34/rotational speed of input shaft 58) = 1 - (number of teeth of ring gear 52 ZR
/number of teeth of sun gear 50 ZS). The input shaft 58 has an insertion hole through which the output shaft 34 is inserted, and the input shaft 58 is arranged to be rotatable relative to the output shaft 34 about a common axis a.

The CVT 16 includes the input shaft 58 and an output shaft 70 rotatably disposed about an axis b parallel to the axis a of the input shaft 58.
8. The output shaft 70 is provided with a variable drive pulley 72 and a variable driven pulley 74, and a transmission belt 76 is wound between the variable pulleys 72 and 74. The variable pulleys 72 and 74 are fixed rotating bodies 78 and 80 fixed to the input shaft 58 and the output shaft 70, respectively, and are provided on the input shaft 58 and the output shaft 70 respectively so as to be movable in the axial direction but not relatively rotatable around the shafts. The movable rotary body 82 and 84 are
and 84 are moved in the axial direction by hydraulic cylinders 86 and 88 as driving means disposed on their rear sides, respectively, thereby changing the V-groove width, that is, the hanging diameter (effective diameter) of the transmission belt 76. , CVT16
The gear ratio γ (=rotational speed of input shaft 58/rotational speed of output shaft 70) is changed. These variable pulleys 72 and 74 have a V groove width independent of relative changes in V groove width.
The fixed rotary bodies 78, 80 and the movable rotary body 82 are oriented in opposite directions in the axial direction so that the centers of the grooves coincide with each other.
84 are arranged to be opposite to each other, and the forward/reverse switching mechanism 14 is located on the back side of the fixed rotating body 78 of the variable drive pulley 72. Further, the hydraulic cylinder 86 is operated exclusively to change the gear ratio γ, and the hydraulic cylinder 88 is operated exclusively to obtain the minimum clamping force within a range that does not cause the transmission belt 76 to slip. The gear ratio γ of the CVT 16 is controlled by an electronic control device (not shown) along a predetermined optimal curve so as to satisfy both fuel efficiency and drivability. The speed is changed to the maximum deceleration side (speed ratio γ maximum side).

The stepped transmission mechanism 18 is constituted by a single pinion type planetary gear device, and is arranged concentrically with the output shaft 70 on the back side of the fixed rotating body 80 of the variable driven pulley 74. This planetary gear device includes a sun gear 90 that is rotatably arranged concentrically with the output shaft 70, a ring gear 92 that is connected to the output shaft 70 in a relatively non-rotatable manner,
It includes a planetary gear 94 that meshes with the sun gear 90 and ring gear 92, and a carrier 98 that rotatably supports the planetary gear 94 and is connected to a second output shaft 96 in a relatively non-rotatable manner. Sun gear 90 above
A multi-disc high-speed clutch 1 is connected between the and carrier 98.
00, and a one-way clutch 102 and a multi-plate low speed brake 104 are provided in series between the sun gear 90 and the housing 64. The engagement of the high-speed clutch 100 and the low-speed brake 104 is controlled by hydraulic cylinders 106 and 108 (see FIG. 3), respectively, and the one-way clutch 102 is engaged and controlled by the low-speed brake 104. In this state, the sun gear 90 is prevented from rotating in the direction opposite to the direction of rotation of the ring gear 92 during forward movement, but rotation in the opposite direction is allowed. Therefore, when the output shaft 70 is rotated in a direction that moves the vehicle forward while the high speed clutch 100 is released and the low speed brake 104 is engaged and controlled by the hydraulic cylinder 108, the carrier 98 and The second output shaft 96 rotates in the same direction as the output shaft 70 due to the action of the one-way clutch 102, so that the gear ratio γG2 (=rotational speed of the output shaft 70/rotational speed of the second output shaft 96)=1+(
Number of teeth of sun gear 90 ZS / Number of teeth of ring gear 92 ZR
), that is, the rotation is reduced at a higher gear (smaller reduction ratio) than when using a Ravigneaux-type compound planetary gear system. Conversely, when the low speed brake 104 is released, the high speed clutch 100 is connected to the hydraulic cylinder 106.
When the engagement is controlled by the sun gear 90 and the carrier 9
8 are connected so that they cannot rotate relative to each other, so that the planetary gear device can be rotated integrally with the second output shaft 96.
is rotated in the same direction as the output shaft 70 at a gear ratio γG2=1. Note that during forward movement, the gears can be switched by controlling engagement of the high speed clutch 100 while keeping the low speed brake 104 engaged.

A first gear 110 is provided on the second output shaft 96, and a second gear 1 is provided on the intermediate shaft 112.
It is meshed with 14. The intermediate shaft 112 is rotatably arranged around an axis c parallel to the axis b of the second output shaft 96, and is connected to the large diameter gear 11 of the differential gear device 22.
6 and a third gear 118 meshed with the third gear 118. Second
The gear 114 has a larger diameter than the first gear 110 and the third gear 1
18 has a smaller diameter than the large diameter gear 116, and these first
The gear 110, the second gear 114, and the third gear 118 constitute the reduction gear device 20.

The differential gear device 22 includes a pair of differential small gears 120 that are rotatably supported around an axis perpendicular to the rotation axis d of the drive shaft 24 and rotate integrally with the large diameter gear 116.
and a pair of large differential gears 122 that mesh with the small differential gear 120 and are connected to the drive shaft 24. Therefore, the power transmitted from the reduction gear device 20 is equally distributed to the left and right drive shafts 24 in the differential gear device 22, and then transmitted to the left and right wheels 26.

The housing 64 is, for example, an aluminum die-cast product, and as is clear from FIGS. 2 to 4, it has a first case 130, a second case 132, and a third case integrally connected to each other by a number of bolts. Case 13
4, and a cap 136, a first chamber 138 that accommodates the fluid coupling 12, and a CVT
16, a third chamber 142 that accommodates the forward/reverse switching mechanism 14, a fourth chamber 144 that accommodates the stepped transmission mechanism 18, and a reduction gear device 20 and a differential gear device 22. A fifth chamber 146 is provided. The second case 132 also includes the hydraulic cylinders 63 and 67.
, 106, 108, etc., a valve body 148 (see FIG. 2) is fixed with bolts, and a cover 150 is provided to cover the valve body 148. It is permanently installed. An accumulator 152 for suppressing fluctuations in oil pressure is fixed to the valve body 148, and the accumulator 152 is located within the second chamber 140. A pump housing 154 that constitutes the hydraulic pump 40 is also fixed to the second case 132 on the side end surface of the first case 130 .

The clutches 62, 100 and brake 66 of the transaxle configured as described above
, 104 are engaged and controlled as shown in FIG. 6 according to the operation range of the shift lever. Specifically, when the shift lever is operated to the N (neutral) range, the high speed clutch 100 of the stepped transmission mechanism 18 is controlled to be engaged. In the N range, if at least the forward clutch 62 and the reverse brake 66 of the forward/reverse switching mechanism 14 are released, the CVT is transferred from the forward/reverse switching mechanism 14.
Since the power transmission to 16 is cut off, the stepped transmission mechanism 18
Clutch 100 for high speed and brake 10 for low speed
4 may be engaged or disengaged, but in this embodiment, the high speed clutch 100 is engaged in order to smoothly control the switching from the N range to the R (reverse) range or the D (drive) range. It is designed to be controlled in a controlled manner.

When the shift lever is switched from the N range to the R range, the reverse brake 66 of the forward/reverse switching mechanism 14 is controlled to be engaged, so that power is transmitted to the CVT 16 in the direction of reverse rotation, that is, moving the vehicle backward. In addition, the stepped transmission mechanism 18, the reduction gear device 20, and the differential gear device 22 with the high-speed clutch 100 in the engaged state
The signal is transmitted to the wheels 26 via the . At this time, the stepped transmission mechanism 1
8 is maintained at a high speed gear with a gear ratio γG2 of 1, but the forward/reverse switching mechanism 14 and the CVT controlled to the maximum gear ratio
16 and reduction gear device 20, a sufficient reduction ratio can be obtained. Note that the CVT 16 is controlled so that its gear ratio γ is maximized.

Furthermore, when the shift lever is switched from the N range to the D range, the forward clutch 62 of the forward/reverse switching mechanism 14 is engaged and the forward rotation, that is, the power in the direction of moving the vehicle forward, is transmitted to the CVT 16. become,
Further, the stepped transmission mechanism 18, the reduction gear device 20, and the differential gear device 2 with the high-speed clutch 100 in the engaged state
2 to the wheels 26. The stepped transmission mechanism 18 is
At the beginning of switching to the D range, the high speed clutch 100 is engaged and the low speed brake 104 is engaged, as in the case of the N range.
is in the released state, but there is a slight delay from the engagement control of the forward clutch 62 of the forward/reverse switching mechanism 14, that is, the brake of the vehicle is depressed and the vehicle is still in the stopped state.
．． Within a few seconds, the low speed brake 104 is engaged and the high speed clutch 100 is released, and the gear is switched to a low speed gear with a large gear ratio γG2. This reduces the shock when switching from the N range to the D range, and provides a sufficient reduction ratio when the vehicle starts. The CVT 16 is controlled so that the gear ratio γ is the maximum when starting, but while driving, the gear ratio γ is controlled depending on the driving condition such as the throttle valve opening and the vehicle speed.
is changed sequentially.

In the D range, the stepped transmission mechanism 18 is held in the low gear as described above when driving at low speeds, but when driving at medium and high speeds, the engagement of the high speed clutch 100 is controlled so that the gear ratio γG2= 1 high speed gear. At this time, the change in the gear ratio γG2 is smaller than that in a stepped transmission mechanism using a Ravignillo type compound planetary gear system, so the shock during gear shifting is relatively small, and the action of the one-way clutch 102 causes a lower speed shift. The brake 104 may remain in the engaged state, and the gear ratio γG2 can be smoothly switched. This also applies when switching the stepped transmission mechanism 18 from a high gear to a low gear.
In the stepped transmission mechanism 18, only the high speed clutch 100 is engaged or released depending on the running state of the vehicle, and the gear ratio γG is
2 can be switched smoothly. Further, the gear ratio γ of the CVT 16 is also successively changed according to the driving state of the vehicle.

Here, in the transaxle of this embodiment, the forward/reverse switching mechanism 14 and the stepped transmission mechanism 18
are provided separately on the driving side and driven side of the CVT 16, and the other variable pulley 74,
Since the hydraulic cylinders 88 and 86 of the CVT 16 are disposed in the area where the hydraulic cylinders 88 and 86 of the CVT 16 are provided, as is clear from FIGS. They overlap each other in this direction, making the transaxle compact as a whole. Since the compact structure allows space, in this embodiment, the stepped transmission mechanism 18 is provided with a one-way clutch 102.
The gear ratio γG2 can be changed smoothly, and in response to the increase in torque of the engine 10,
It is also possible to easily increase the number of friction plates in the clutches 62, 100 and brakes 66, 104, or to increase the tooth width of the planetary gear device.

Further, since the forward/reverse switching mechanism 14 and the stepped transmission mechanism 18 are arranged separately, and a single pinion type planetary gear device is adopted as the stepped transmission mechanism 18, a Ravigneau type compound planetary gear This has the advantage that the difference in gear ratio between gears can be set smaller than that of conventional gear shift systems, and the shock during gear shifting can be reduced.

Furthermore, in this embodiment, the high-speed clutch 100 of the stepped transmission mechanism 18 is engaged in the N range, and the reverse brake 66 or Forward brake 6
2, the switching control is performed smoothly, and since the gear ratio γG2 of the stepped transmission mechanism 18 is 1 at the beginning of switching to the D range, the gear ratio γG2
This has the advantage that the shock at the time of switching is reduced compared to the case of immediately switching to a low speed gear with a large speed.

Next, another embodiment of the present invention will be described. In the following embodiments, parts substantially common to those in the first embodiment are designated by the same reference numerals and detailed explanations will be omitted.

FIGS. 7 to 10 are diagrams corresponding to FIGS. 1 to 4, respectively, and although there are slight differences in the number of friction plates of the clutch and brake, the diameter of the gears, etc., there is no substantial difference. This is done by a stepped transmission mechanism 160 disposed on the back side of the fixed rotating body 80 of the driven variable pulley 74. Like the stepped transmission mechanism 18, this stepped transmission mechanism 160 includes a sun gear 90, a ring gear 92, a planetary gear 94,
A multi-plate high-speed clutch 162 is provided between the sun gear 90 and the carrier 98 and between the sun gear 90 and the housing 64, respectively. , a low speed brake 164 are provided, and the engagement of these high speed clutch 162 and low speed brake 164 is controlled by hydraulic cylinders 166 and 168 (see FIG. 9), respectively. Also provided between sun gear 90 and housing 64 is a one-way clutch 170 that prevents sun gear 90 from rotating in a direction opposite to the rotational direction of ring gear 92 during forward movement, but allows rotation in the opposite direction. . Therefore, when the output shaft 70 is rotated in the direction of moving the vehicle forward with both the high speed clutch 162 and the low speed brake 164 released, the carrier 98 and the second output shaft 96 are connected to the one-way clutch 170. Due to this action, the output shaft 70 is rotated at a reduced speed in the same direction as the rotational direction of the output shaft 70. In addition, the hydraulic cylinder 168
Even when the low speed brake 164 is engaged, the gear ratio γG2 remains the same, and the low speed brake 170
The engagement is controlled when engine braking is required and when the one-way clutch 170 is not functioning and the vehicle is traveling in reverse. In addition, when the low speed brake 164 is released, the output shaft 70
is rotationally driven in the direction of moving the vehicle forward, the high-speed clutch 16 is operated by the hydraulic cylinder 166.
2 is engaged, the sun gear 90 and the carrier 98 are connected so that they cannot rotate relative to each other, so that the planetary gear device is rotated integrally, and the second output shaft 96 has a gear ratio γG2=1. It is rotated in the same direction as the output shaft 70.

The clutches 62, 162 and brakes 66, 164 of this embodiment are engaged and controlled as shown in FIG. 11 in accordance with the operating range of the shift lever. Specifically, when the shift lever is operated to the N range, the low speed brake 164 of the stepped transmission mechanism 160 is controlled to be engaged. In the N range, if at least the forward clutch 62 and the reverse brake 66 of the forward/reverse switching mechanism 14 are released, the CVT is transferred from the forward/reverse switching mechanism 14.
Since the power transmission to 16 is cut off, the stepped transmission mechanism 16
0 high speed clutch 162 and low speed brake 1
The operating state of the brake 64 can be either engaged or disengaged, but in this embodiment, the low speed brake 164 is controlled to be engaged in order to smoothly control the switching from the N range to the R range or the D range. It has become.

When the shift lever is switched from the N range to the R range, the reverse brake 66 of the forward/reverse switching mechanism 14 is controlled to be engaged, so that power is transmitted to the CVT 16 in the direction of reverse rotation, that is, moving the vehicle backward. Then, the stepped transmission mechanism 160, the reduction gear device 20, and the differential gear device 2 with the low speed brake 164 in the engaged state
2 to the wheels 26. At this time, the stepped transmission mechanism 160 is maintained at the low speed gear, so that a sufficient reduction ratio can be obtained. Further, when the shift lever is switched from the N range to the D range, the forward clutch 62 of the forward/reverse switching mechanism 14 is engaged and controlled, and the stepped transmission mechanism 160 is engaged.
The low speed brake 164 is released, and forward rotation, that is, power in the direction of moving the vehicle forward, is transmitted to the CVT 16, and further, the stepped transmission mechanism 160 and the reduction gear device 2
0, and is transmitted to the wheels 26 via the differential gear 22. The stepped transmission mechanism 160 transmits power by decelerating at a large gear ratio due to the action of the one-way clutch 170. However, since the low-speed brake 164 can remain engaged, the forward clutch 62 Even if the timing between the engagement control and the release of the low speed brake 164 is different, the N
Switching from range to D range is performed smoothly. The low-speed gear brake 164 is engaged and controlled in a driving state where engine braking is required, but is normally released. When the vehicle enters a medium-high speed running state, the high-speed gear clutch 162 is engaged and controlled to set the gear ratio γG2= 1 high speed gear. Switching between high and low gears is
This is done smoothly by engaging and disengaging only the high-speed clutch 162.

In this embodiment as well, the axial dimensions of the driving side and the driven side of the CVT 16 are approximately equal and overlap each other in the direction perpendicular to the axis, and the transaxle is constructed compactly as a whole. By providing the one-way clutch 170 in the transmission mechanism 160, it is possible to smoothly switch the transmission ratio γG2, and it is also possible to easily cope with the increase in torque of the engine 10.
The same effects as in the first embodiment can be obtained. In addition, since a single pinion type planetary gear unit is adopted as the stepped transmission mechanism 160, the difference in gear ratio between gears can be made smaller compared to when a Ravigneau type compound planetary gear unit is used. This is also similar to the first embodiment in that the shock is reduced.

Although one embodiment of the present invention has been described above in detail based on the drawings, the present invention can also be implemented in other embodiments.

For example, in the embodiment described above, the forward/reverse switching mechanism 14 and the stepped transmission mechanisms 18 and 160 are configured with a planetary gear device, but other forward/reverse switching mechanisms such as a counter gear system or stepped transmission mechanisms may be used. can also be adopted. By adopting a Lavignillo type compound planetary gear device as the forward/reverse switching mechanism, it has a stepped transmission function, and the number of gears is 3.
It is also possible to use the above stepped transmission mechanism.

Further, in the above embodiment, the forward/reverse switching mechanism 14 is provided on the drive side of the CVT 16, and the stepped transmission mechanisms 18, 160 are provided on the driven side, but the stepped transmission mechanism 18 is provided on the drive side. , 160 is disposed on the driven side to provide a forward/reverse switching mechanism 1.
It is also possible to arrange 4.

Furthermore, in the above embodiment, the forward/reverse switching mechanism 14 is disposed on the opposite side of the fluid coupling 12 across the variable drive pulley 72 of the CVT 16, but it is possible to reverse the direction of the variable drive pulley 72. A forward/reverse switching mechanism 14 may also be provided between the drive side variable pulley 72 and the fluid coupling 12. In that case, the direction of the driven variable pulley 74 and the positions of the stepped transmission mechanisms 18 and 160 will also be reversed.

Furthermore, the stepped transmission mechanism 18, 1 of the embodiment described above
60 is provided with one-way clutches 102, 170, but such one-way clutches are not necessarily essential for carrying out the present invention.

Furthermore, it is of course possible to use a torque converter in place of the fluid coupling 12.

Further, in the above embodiment, the present invention is applied to a transverse transaxle for a front-wheel drive vehicle, but the present invention can be similarly applied to a transmission for other vehicles.

Although no other examples are given, the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram illustrating a transaxle drive force transmission system to which the present invention is applied.

2 is a partial cross-sectional view showing the configuration of the embodiment of FIG. 1 together with FIGS. 3 and 4; FIG.

FIG. 3 is a partial cross-sectional view showing the configuration of the embodiment of FIG. 1 together with FIGS. 2 and 4;

4 is a partial sectional view showing the configuration of the embodiment of FIG. 1 together with FIGS. 2 and 3; FIG.

FIG. 5 is a side view showing the positional relationship of each axis in the embodiment of FIG. 1;

6 is a diagram illustrating the operation of a clutch and a brake in the embodiment of FIG. 1. FIG.

FIG. 7 is a schematic diagram illustrating a driving force transmission system in another embodiment of the present invention.

8 is a partial sectional view showing the configuration of the embodiment of FIG. 7 together with FIGS. 9 and 10. FIG.

9 is a partial sectional view showing the configuration of the embodiment of FIG. 7 together with FIGS. 8 and 10. FIG.

10 is a partial sectional view showing the configuration of the embodiment of FIG. 7 together with FIGS. 8 and 9; FIG.

11 is a diagram illustrating the operation of a clutch and a brake in the embodiment of FIG. 7. FIG.

FIG. 12 is a schematic diagram illustrating an example of a conventional vehicle transmission.

13 is a sectional view showing the configuration of the sub-transmission in the conventional example shown in FIG. 12. FIG.

[Explanation of symbols]

10: Engine 14: Forward/forward switching mechanism 16: Belt type continuously variable transmission 18, 160: Stepped transmission mechanism 58: Input shaft 70: Output shaft 72: Drive side variable pulley 74: Driven variable pulley 76: Transmission belt 78, 80: Fixed rotating body 82, 84: Movable rotating body

Claims (1)

[Claims] 1. A fixed rotating body fixed to an input shaft, a movable rotating body disposed so as to be movable in the axial direction of the input shaft, and a movable rotating body disposed on the back side of the movable rotating body. a drive-side variable pulley equipped with a drive means for driving in the axial direction;
A fixed rotating body fixed to an output shaft parallel to the input shaft, a movable rotating body disposed so as to be movable in the axial direction of the output shaft, and a movable rotating body disposed on the back side of the movable rotating body. a driven variable pulley that is arranged in an opposite axial direction to the driving variable pulley, and a driven variable pulley that is wound around the driving variable pulley and the driven variable pulley. A belt-type continuously variable transmission having a transmission belt, a forward/reverse switching mechanism for switching the direction of rotation, and a stepped transmission mechanism for switching the rotational speed in multiple stages are installed in series in the power transmission path from the engine. A vehicle transmission device, wherein either the forward/reverse switching mechanism or the stepped transmission mechanism is disposed on the back side of the fixed rotating body of the drive-side variable pulley, and the forward/reverse switching mechanism and the stepped transmission A vehicle transmission, wherein the other mechanism is disposed on the back side of the fixed rotating body of the variable driven pulley.