JP2002048213A - Speed change gear equipped with variable speed change mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speed change gear equipped with variable speed change mechanism, capable of improving not only the durability of a variable speed change gear but the transmission efficiency of power. SOLUTION: A variable speed change mechanism 4, capable of continuously changing a variable change gear ratio in a power transmission system from a power source 1 to an output member 8 intervenes in the speed change gear, reduction mechanisms 24, 26, 28 and 29 in which a gear change ratio is determined not less than 1.25 times the maximum change gear ratio and not greater than 2.0 times the variable speed change mechanism 4 are arranged, in parallel with the variable speed change mechanism 4 in the power source 1 and the output member, and further a selecting media 6 and 22 are installed so that the torque is transmitted from the power source 1 to the output member 8 via the decreasing mechanism 24, 26 and 29 on starting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission in which a continuously variable transmission capable of continuously changing a gear ratio is disposed in a power transmission system from a power source to an output member.

[0002]

2. Description of the Related Art As a continuously variable transmission mechanism used in a transmission for a vehicle, a belt type and a traction type (toroidal type) are conventionally known. These continuously variable transmission mechanisms are configured to continuously change the effective diameter of the pulley around which the belt is wound and the effective diameter of the disk with which the power roller contacts, so as to appropriately set the gear ratio.
One example thereof is described in Japanese Patent Application Laid-Open No. H11-182667. The transmission described in this publication is used for switching between forward and backward switching on the input side of a driving pulley (primary pulley) in a belt-type continuously variable transmission mechanism. And a driven pulley (secondary pulley) is connected to an output member via a pair of counter gears.

[0003]

The advantage of using a continuously variable transmission mechanism in a vehicle transmission is that the speed ratio of the power source can be set to an appropriate speed ratio by continuously changing the speed ratio. The point that it can be set to the rotation speed that minimizes fuel consumption is that the speed ratio that can be set by the continuously variable transmission mechanism is not only to improve fuel efficiency, but also to improve the power performance or running performance of the vehicle, Preferably, it can be changed in a wide range to some extent. When increasing the speed ratio width in the continuously variable transmission mechanism, for example, in a belt-type continuously variable transmission mechanism,
The effective diameter of one pulley is made as small as possible, while the effective diameter of the other pulley is made as large as possible.

However, if the effective diameter of any of the pulleys is reduced, the belt-type continuously variable transmission mechanism increases the curvature of the belt, so that the belt stress increases or the belt is repeatedly subjected to large bending. Therefore, if the belt tension is limited in order to prevent the durability from being lowered and to prevent the durability from being lowered, the torque that can be transmitted by the continuously variable transmission mechanism is reduced, and as a result, the torque is increased. There are inconveniences such as the inability to use the vehicle with a displacement. Furthermore, if the effective diameter is reduced, power transmission efficiency may be reduced due to a reduction in the contact range between the belt and the pulley, for example.
Eventually, the effect of improving fuel efficiency may be reduced.

The present invention has been made in view of the technical problem described above, and has improved durability of a continuously variable transmission mechanism.
It is another object of the present invention to provide a transmission capable of improving power transmission efficiency.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention uses a transmission mechanism such as a gear pair as an alternative when the power transmission efficiency of the continuously variable transmission mechanism is poor. Or used together. More specifically, claim 1
The invention relates to a transmission having a continuously variable transmission mechanism in which a continuously variable transmission mechanism capable of continuously changing a transmission ratio is interposed in a transmission system of power from a power source to an output member. Is 1.25 of the maximum speed ratio of the continuously variable transmission mechanism.
A speed reduction mechanism set at a predetermined value of at least twice and at most 2.0 times is arranged in parallel with the continuously variable transmission mechanism between the power source and the output member, and further reduces the speed when the vehicle starts. A transmission, comprising: switching means for setting a torque transmission path so as to transmit torque from the power source to the output member via a mechanism.

Therefore, according to the first aspect of the present invention, at the time of start, torque is transmitted to the output member via the speed reduction mechanism instead of the continuously variable transmission mechanism by the switching means, and thus the vehicle travels while shifting by the speed reduction mechanism. The speed ratio in this case is a predetermined speed ratio that is 1.25 times or more and 2.0 times or less of the maximum speed ratio by the continuously variable transmission mechanism. Therefore, necessary and sufficient start acceleration is obtained, and power transmission is performed. Does not depend on the continuously variable transmission mechanism, so that its transmission efficiency is improved. Further, since the speed ratio of the speed reduction mechanism is 1.25 times or more and 2.0 times or less the maximum speed ratio of the continuously variable transmission mechanism, the torque is transmitted by the continuously variable transmission mechanism instead of the speed reduction mechanism after the vehicle starts. When the torque transmission path is changed in such a manner, the step of the gear ratio does not become particularly large, so that the torque transmission path can be changed without deteriorating the shock.

According to a second aspect of the present invention, in the first aspect of the invention, the switching means reduces the torque transmission amount from 0% to 1%.
A transmission comprising an engagement mechanism that continuously changes between 00%.

Therefore, according to the second aspect of the present invention, the transmission torque gradually changes by operating the switching means at the time of starting or after starting. Therefore, the change of the torque appearing on the output member at the time of changing the torque transmission path at the time of starting or after starting becomes smooth, and as a result, the shock is improved.

Further, according to a third aspect of the present invention, there is provided a continuously variable transmission mechanism in which a continuously variable transmission mechanism capable of continuously changing a transmission ratio is interposed in a power transmission system from a power source to an output member. In the transmission provided, a speed reduction mechanism whose speed ratio is set to a predetermined value larger than the maximum speed ratio of the continuously variable transmission mechanism is provided between the power source and the output member, with respect to the continuously variable transmission mechanism. It is arranged in parallel, and further transmits torque from the power source to the output member via the deceleration mechanism at the time of starting and transmits torque to the output member via the continuously variable transmission mechanism after starting. A transmission provided with switching means for switching a transmission path and gradually increasing the amount of torque transmitted to the continuously variable transmission mechanism.

Therefore, according to the third aspect of the present invention, torque is transmitted to the output member via the speed reduction mechanism at the time of starting, and the speed ratio in that case becomes larger than the maximum speed ratio by the continuously variable transmission mechanism. Therefore, the power transmission efficiency is better than when the continuously variable transmission mechanism is used, and the necessary and sufficient acceleration for starting is obtained. Further, after the start, the switching means operates to transmit torque to the output member via the continuously variable transmission mechanism, and the continuously variable transmission mechanism performs a shift. In the case of the switching of the torque transmission path, the speed ratio of the reduction mechanism is larger than the maximum speed ratio of the continuously variable transmission mechanism, so that a step of the speed ratio occurs. , The change in the torque appearing in the above becomes smooth, and the deterioration of the shock is prevented.

According to a fourth aspect of the present invention, there is provided a continuously variable transmission mechanism in which a continuously variable transmission mechanism capable of continuously changing a transmission ratio is interposed in a power transmission system from a power source to an output member. In the transmission, a plurality of gear pairs having different speed ratios are arranged in parallel with the continuously variable transmission mechanism, and the torque output by the power source is transmitted to one of the plurality of gear pairs and to the continuously variable transmission. The transmission is provided with a distribution mechanism that distributes and transmits the transmission to the transmission mechanism.

Therefore, according to the fourth aspect of the present invention, a gear pair having a speed ratio that matches the speed ratio set by the continuously variable transmission mechanism is selected and torque is transmitted through the distribution mechanism. That is, torque is transmitted from the power source to the output member via the continuously variable transmission mechanism and the gear pair. As a result, the amount of torque transmitted by the continuously variable transmission mechanism is reduced, and accordingly, the power transmission efficiency of the entire transmission is improved.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described based on specific examples. The example shown in FIG. 1 is an example of a transmission in which a starting gear pair is provided in parallel with a continuously variable transmission mechanism. That is, the input shaft 2 is arranged on the same axis as the output shaft of the engine (internal combustion engine) 1 as a power source, and the input shaft 2 and the engine 1 are connected via the damper 3. That is, the output shaft and the input shaft 2 of the engine 1 are configured to always rotate together.

A drive pulley 5 which is one of the rotary members of the continuously variable transmission mechanism 4 is arranged on the same axis as the input shaft 2, and between the drive pulley 5 and the input shaft 2, both are selectively provided. (Hereinafter, tentatively referred to as a direct coupling clutch) 6 is provided. This direct coupling clutch 6
Is a wet type multi-plate clutch, for example, which is configured so that the torque transmission amount can be continuously changed in a range of 0% to 100%. Here,
“Continuous change” includes a step change with a small deviation.

A driven pulley 7, which is the other rotating body in the continuously variable transmission mechanism 4, is arranged in parallel with the drive pulley 5. The output shaft 8 is attached to the driven pulley 7 so as to rotate integrally.

The drive pulley 5 and the driven pulley 7 are provided with a fixed sheave and a movable sheave arranged opposite thereto, similarly to a conventional belt-type continuously variable transmission, and an actuator 9 operated by hydraulic pressure or the like. , 10 move the movable sheave in the axial direction, thereby changing the groove width, that is, the effective diameter around which the belt 11 is wound. In order to match the center positions of the pulleys 5 and 7 in the axial direction when the groove width is changed,
The arrangement relationship between the fixed sheave and the movable sheave is
And the driven pulley 7 are opposite to each other. Accordingly, the actuator 9 of the drive pulley 5 is arranged on the opposite side of the drive pulley 5 from the engine 1,
On the other hand, the actuator 1 in the driven pulley 7
0 is disposed on the engine 1 side with respect to the driven pulley 7.

The output shaft 8 extends toward the actuator 10 of the driven pulley 7, and an output gear 12 is attached to an end thereof. This output gear 12 includes:
The gear 14 attached to the counter shaft 13 is engaged.
Another gear 15 is attached to the counter shaft 13, and the gear 15 meshes with a ring gear 17 of the differential 16. Therefore, the differential 1 is driven via the driven pulley 7 and the output shaft 8 integrated therewith.
The first transmission path is configured to output torque to the output shaft 8 and the output gear 12 through the clutch 6 and the continuously variable transmission mechanism 4.

A description will be given of a second torque transmission path which is in parallel with the first torque transmission path. A double pinion type planetary gear mechanism 18 is provided coaxially with the input shaft 2 between the engine 1 and the direct coupling clutch 6. The planetary gear mechanism 18 includes a sun gear 19, a ring gear 20 disposed concentrically with the sun gear 19, a first pinion gear meshed with the sun gear 19, and the first pinion gear and the ring gear, as in the prior art. And a carrier 21 holding a second pinion gear engaged with the carrier 20 so as to rotate and revolve freely, and a sun gear 19 is provided integrally on the outer periphery of the input shaft 2. Further, a clutch (hereinafter, referred to as a start clutch) 22 for selectively connecting the sun gear 19 and the carrier 21 to integrally rotate the planetary gear mechanism 18 is provided. The starting clutch 22 is, for example, a wet-type multi-plate clutch, which is capable of continuously changing the torque transmission amount between 0% and 100%, similarly to the direct coupling clutch 6 described above. Here, the “continuous change” includes a stepwise change with a small deviation. Further, the start clutch 22 is disposed on the side of the direct coupling clutch 6 with respect to the planetary gear mechanism 18.

Further, a brake (hereinafter, referred to as a reverse brake) 23 for selectively fixing the ring gear 20 is provided. The reverse brake 23 is constituted by a wet-type multi-plate type brake capable of continuously changing the torque transmission amount, similarly to the clutches 6 and 22 described above. Then, a first drive gear 24 forming a first gear pair is connected to the carrier 21. Therefore, the carrier 21 is an output element in the planetary gear mechanism 18. When the torque is input from the sun gear 19 and the ring gear 20 is fixed, the carrier 21 rotates in the opposite direction to the sun gear 19. When the reverse brake 23 is released and the start clutch 22 is engaged, the input shaft 2 is directly connected to the first drive gear 24. Thus, the planetary gear mechanism 18 is used as a mechanism for setting the reverse gear.

An intermediate shaft 25 is arranged in parallel with the input shaft 2 and the output shaft 8, and a first driven gear 26 meshed with the first drive gear 24 is held by the intermediate shaft 25 so as to be relatively rotatable. ing. A two-way clutch 27 is provided between the first driven gear 26 and the intermediate shaft 25. As the two-way clutch 27, various types of conventionally known clutches can be used, and for example, a two-way clutch described in Japanese Patent Application Laid-Open No. 9-25942 can be used. That is, in the two-way clutch 27, an interposed member that performs a wedge action such as a plurality of rolling elements held by a holder is disposed between the inner ring and the outer ring, and the relative position of the interposed member in the circumferential direction is changed. Thereby, torque is transmitted in a direction in which the outer ring rotates forward or backward with respect to the inner ring. In other words, in the direction opposite to the torque transmission direction set by the position of the intervening member, relative rotation between the inner ring and the outer ring occurs, so that torque is not transmitted. The switching of the torque transmission direction in the two-way clutch 27 is performed by rotating the holder circumferentially at a predetermined angle by an actuator (not shown).

The intermediate shaft 25 is connected to the pulleys 5, 7
Between the intermediate shaft 25 and the output shaft 8 by a second pair of gears provided on the outer periphery of the actuator 9 in the drive pulley 5.
Are connected so as to be able to transmit torque. That is, the second drive gear 28 is attached to the shaft end of the intermediate shaft 25, and the second driven gear 29 meshed with the second drive gear 28 is attached to the output shaft 8.

Therefore, the first gear pair consisting of the first drive gear 24 and the first driven gear 26 and the second gear pair consisting of the second drive gear 28 and the second driven gear 29 allow the stepless gearing. A second torque transmission path that is in parallel with the transmission mechanism 4 is formed. The first gear pair and the second gear pair correspond to the speed reduction mechanism of the present invention, and the speed ratio (gear ratio) of each of these gear pairs as a whole is the maximum Gear ratio γ
The predetermined value is set to 1.25 times or more and 2.0 times or less of max. The value is a value corresponding to a torque amplification factor in a torque converter used in a conventional vehicle.

Next, the operation of the above transmission will be described. First, when the engine 1 is started, the clutches 6 and 22 and the reverse brake 23 are released to bring the entire transmission into a neutral state in which torque is not transmitted to the output gear 12 as an output member. When starting in the forward direction after starting the engine 1, the two-way clutch 27 is set to transmit torque in the forward direction.
And the starting clutch 22 is gradually engaged. The starting clutch 22 is constituted by, for example, a wet-type multi-plate clutch, and is configured such that the torque transmission amount gradually increases from 0% to 100%. 2 to the first drive gear 24 via the carrier 21.

Therefore, by engaging the starting clutch 22, the first gear pair consisting of the first drive gear 24 and the driven gear 26 and the second gear pair consisting of the second drive gear 28 and the driven gear 29 are connected. Via this, the output torque of the engine 1 is transmitted to the output shaft 8 and the output gear 12.
Further, a torque is output from this to driving wheels (not shown) via the counter shaft 13 and the differential 16. If the torque is transmitted via the so-called second torque transmission path at the time of starting in this way, the speed ratio set by the second torque transmission path is equal to the maximum speed ratio γmax of the continuously variable transmission mechanism 1. Since the transmission has a predetermined speed ratio of 25 times or more and 2.0 times or less, the same starting acceleration force as when a conventional transmission using both a normal belt-type continuously variable transmission mechanism and a fluid torque converter is used. Can be obtained.

Further, when the forward running is started in this way, the amount of torque transmitted by the starting clutch 22 gradually increases, so that the driving torque increases smoothly and the shock at the time of starting is prevented. .

Once the vehicle has started, the required driving torque becomes relatively small, so that the vehicle is upshifted. In the transmission according to the present invention, the upshift is performed by first engaging the direct coupling clutch 6. In other words, the start clutch 22 is engaged to start the vehicle, and thereafter, when the vehicle speed reaches a predetermined vehicle speed, the direct coupling clutch 6 is gradually engaged. In that case, the continuously variable transmission mechanism 4 is set to the maximum speed ratio γmax.

In this case, the gear ratio of the first gear pair and the second gear pair is the maximum gear ratio γ of the continuously variable transmission mechanism 4.
The drive pulley 5 is rotating at a lower speed than the input shaft 2 because it is 1.25 to 2.0 times max. Therefore, when the direct coupling clutch 6 starts to be engaged, the torque transmission capacity is small, so that the direct coupling clutch 6 is in a slipping state, and the drive pulley 5 and the input shaft 2 are relatively rotating. When the torque transmission amount of the direct coupling clutch 6 gradually increases, torque is transmitted from the input shaft 2 to the output shaft 8 via the continuously variable transmission mechanism 4, and accordingly, the rotation speed of the input shaft 2, that is, the rotation speed of the engine 1 is reduced. The rotation speed of the first drive gear 24 and the driven gear 26 decreases.

The driven gear 26 has a two-way clutch 27
And the rotation speed of the intermediate shaft 25 is maintained at a rotation speed corresponding to the vehicle speed. Therefore, when the rotation speed of the driven gear 26 decreases as the engine rotation speed decreases, Since the relative rotational directions of the inner and outer wheels in the directional clutch 27 are reversed, the transmission of torque by the two-way clutch 27 is interrupted. That is, the connection between the driven gear 26 and the intermediate shaft 25 is released.

In this manner, the torque transmission path from the engine 1 to the output shaft 8 and the output gear 12 is changed from the second torque transmission path including the first and second gear pairs via the continuously variable transmission mechanism 4. 1 is switched to the first torque transmission path. In this case, the speed ratio of the second torque transmission path and the speed ratio set by the continuously variable transmission mechanism 4 are greatly different, but the torque transmission amount of the direct coupling clutch 6 gradually increases, and the two-way Since the clutch 27 is gradually released, a change in torque appearing on the output shaft 8 and the output gear 12, that is, a change in drive torque becomes smooth, and no shock occurs. Therefore, the starting clutch 22 and the direct coupling clutch 6 correspond to the switching means of the present invention.

After the torque transmission path is switched to the path via the continuously variable transmission mechanism 4, the target speed ratio or the target input rotation of the continuously variable transmission mechanism 4 is determined based on the vehicle operating conditions such as the vehicle speed and the required driving amount. Then, the continuously variable transmission mechanism 4 is controlled so as to match the target value. During normal traveling, the speed ratio of the continuously variable transmission mechanism 4 is set to a speed ratio smaller than the maximum speed ratio γmax. Therefore, if the vehicle suddenly stops during traveling for some reason, the speed ratio of the continuously variable transmission mechanism 4 is changed. In some cases, the continuously variable transmission mechanism 4 stops without returning to the maximum speed ratio γmax. However, in the above-described transmission, the starting clutch 22 is gradually engaged from the state in which the clutches 6, 22 and the reverse brake 23 are released when starting for forward traveling, so that the drive pulley 5 is connected to the input shaft 2. The continuously variable transmission mechanism 4 is driven in the disconnected state.
Accordingly, in such a so-called idling state, the gear ratio of the continuously variable transmission mechanism 4 can be returned to the maximum gear ratio γmax by changing the groove width of each of the pulleys 5 and 7.

Next, a description will be given of the case where the vehicle travels in the reverse direction. After the engine 1 is started, the clutches 6 and 22 are released, and the two-way clutch 27 is set to transmit torque in the reverse traveling direction. Reverse clutch 2
3 gradually engage. Thus, in the planetary gear mechanism 18, since the sun gear 19 is an input element and the ring gear 20 is a fixed element, the carrier 21 and the first drive gear 24 connected to the carrier 21 rotate in the reverse direction. Then, torque is transmitted from the second gear pair to the output shaft 8 via the first drive gear 24, the driven gear 26 meshing with the first drive gear 24, and the two-way clutch 27, and the vehicle travels backward. Even in that case, the reverse clutch 23
, The amount of torque transmission gradually increases, so that no shock occurs when the vehicle starts moving backward.

When the vehicle is towed with the engine 1 stopped, torque is input from the differential 16 side. However, since the engine 1 is stopped and no hydraulic pressure is generated, each clutch 6, 22 and the reverse Since the brake 23 is released and the two-way clutch 27 is set to the neutral state in which torque is not transmitted in any direction, torque is not input to the planetary gear mechanism 18 and the planetary gear mechanism 18 is stopped. Can be maintained. That is, it is possible to avoid applying a load to the planetary gear mechanism 18 during towing, so that the traction of the vehicle is improved.

The belt-type continuously variable transmission mechanism 4 requires actuators 9 and 10 for driving the movable sheave, which are projected in the axial direction, and the projection direction is driven by the drive pulley 5 and the driven pulley 5. The direction is opposite to that of the pulley 7. In the example shown in FIG. 1, the actuator 9 of the drive pulley 5 projects on the side opposite to the clutch 6 and the planetary gear mechanism 18. On the other hand, in the transmission shown in FIG. 1, the second gear pair is arranged on the outer peripheral side of the actuator 9, so that a space does not remain on the outer peripheral side of the actuator 9, and that part can be effectively used. By arranging the gear pair by utilizing the transmission, the overall length of the transmission in the axial direction can be reduced. In the configuration shown in FIG. 1, the first gear pair is arranged on the engine 1 side with respect to the planetary gear mechanism 18, so that the driven pulley 7 is connected to the axis 10 while avoiding interference of the driven pulley 7 with the actuator 10. In the direction of the engine 1, the length of the transmission as a whole in the axial direction can be reduced, and the transmission as a whole can be more compact.

The above-mentioned planetary gear mechanism 18 can be provided coaxially with the intermediate shaft 25 instead of being provided coaxially with the input shaft 2. FIG. 2 shows an example of this, and the first
A drive gear 24 is provided so as to rotate integrally with the input shaft 2, whereas a first driven gear 26 is connected to the intermediate shaft 2.
5 so as to rotate integrally therewith. A planetary gear mechanism 18 is arranged concentrically on the shaft end side (the left end side in FIG. 2) of the intermediate shaft 25, and its sun gear 1
9 is integrated with the intermediate shaft 25.

A starting clutch 22 for selectively connecting the intermediate shaft 25 and the carrier 21 is provided, and a reverse brake 2 for selectively stopping rotation of the ring gear 20.
3 is arranged on the outer peripheral side of the ring gear 23. The second drive gear 2 is provided at an intermediate portion of the intermediate shaft 25 in the axial direction.
8 is rotatably fitted, and its second drive gear 28
The two-way clutch 27 described above is disposed between the two-way clutch 27 and the carrier 21. The other configuration is almost the same as the configuration shown in FIG.

Even in the configuration shown in FIG. 2, by engaging the starting clutch 22, the output shaft 8 and the output gear 12 are connected to the output shaft 8 and the output gear 12 via the first gear pair and the second gear pair.
The output torque of the engine 1 can be transmitted to the output shaft 8 and the output gear 12 via the continuously variable transmission mechanism 4 by engaging the direct coupling clutch 6 instead of the starting clutch 22. Can be transmitted. Further, by engaging the reverse brake 23, the carrier 21 rotates in the opposite direction with respect to the intermediate shaft 8, and the reverse gear can be set. In the configuration shown in FIG. 2, the number of components arranged on the same axis as the engine 1 is reduced, so that the axial length in the same axis direction as the engine 1 can be shortened.

When the maximum speed ratio is set by the continuously variable transmission mechanism and when the minimum speed ratio is set, the effective diameter of one of the rotating bodies on the driving side and the driven side becomes smaller. In addition, the effective diameter of the other rotating body increases.
That is, the continuously variable transmission mechanism is operated in a state where the difference between the effective diameters is large. For this reason, the power transmission efficiency is reduced as the speed ratio is increased and, conversely, as the transmission ratio is decreased. In order to improve this, the configuration shown in FIG. 3 is configured to transmit torque by both the continuously variable transmission mechanism and the gear pair regardless of whether the gear ratio is large or small. .

More specifically, in FIG. 3, an input shaft 32 is disposed on the same axis as the engine 31 as a power source, and the engine 31 and the input shaft 32 are connected to each other via a damper 33. Have been. On the same axis as the input shaft 32, a double pinion type planetary gear mechanism 34
, A low speed drive gear 35, a high speed drive gear 36, C
A VT drive gear 37 is provided.

The planetary gear mechanism 34 meshes with a sun gear 38, a ring gear 39 disposed concentrically with the sun gear 38, a first pinion gear meshed with the sun gear 38, and the first pinion gear and the ring gear 39. And a carrier 40 holding the second pinion gear and the carrier so as to rotate and revolve freely. The sun gear 38 is connected to the CVT drive gear 37 so as to rotate integrally. Further, the carrier 40 is connected to the high-speed drive gear 36 so as to rotate integrally therewith.

Further, a forward clutch 41 for selectively connecting the input shaft 32 and the ring gear 39 and a direct connection clutch 42 for selectively connecting the input shaft 32 and the carrier 40 are provided. These clutches 41 and 42 are arranged on the opposite side of the drive gears 35, 36 and 37 with the planetary gear mechanism 34 interposed therebetween. A low-speed clutch 43 for selectively connecting the carrier 40 and the low-speed drive gear 35 is provided.
Is provided. Further, a reverse brake 44 for selectively fixing the ring gear 39 is arranged on the outer peripheral side of the ring gear 39. The reverse brake 44 is constituted by a multi-plate brake or a band brake.

On both sides of the planetary gear mechanism 34,
A drive pulley 46 and a driven pulley 47 that constitute the continuously variable transmission mechanism 45 are arranged with their central axes parallel to the input shaft 32. These pulleys 46,
Reference numeral 47 denotes a structure similar to the pulleys 5 and 7 in the above-described continuously variable transmission mechanism 4 shown in FIG. 1 or FIG. 2, and the movable sheave is moved in the axial direction by the actuators 48 and 49, whereby the groove width, ie, the belt The shift is executed by changing the effective diameter around which 50 is wound up or down.

On the shaft on which the driving pulley 46 is mounted,
A CVT driven gear 51 meshing with the CVT drive gear 37 is attached. The gear ratio of these gears 37 and 51 is set to substantially "1", so that the torque of the sun gear 38 is transmitted to the drive pulley 46 as it is.

On the other hand, a low-speed driven gear 53 meshed with the low-speed driving gear 35 is mounted on the output shaft 52 to which the driven pulley 47 is mounted so as to rotate integrally therewith. The high-speed driven gear 54 meshed with the gear is rotatably mounted. And
A high-speed clutch 55 is provided between the high-speed driven gear 54 and the output shaft 52 for selectively connecting them. The gear ratios of the low-speed gears 35 and 53 are as follows: the continuously variable transmission mechanism 45 is set to the maximum transmission ratio γmax, and the ring gear 39 to the sun gear 38 and the continuously variable transmission mechanism 45.
And the gear ratio of the path from the ring gear 39 to the carrier 40 and the low speed gears 35 and 53
Is set to a value that makes the speed ratio of the path reaching the output shaft 52 via the output shaft 52 equal. The gear ratio of the high-speed gears 36 and 54 is from the ring gear 39 to the output shaft 52 via the sun gear 38 and the continuously variable transmission mechanism 45 with the continuously variable transmission mechanism 45 set to the minimum transmission ratio γmin. The speed ratio of the path and the speed ratio of the path from the ring gear 39 to the output shaft 52 via the carrier 40 and the high-speed gears 36 and 54 are set to be equal.

The high-speed clutch 55 may be provided between the carrier 40 and the high-speed drive gear 36, and the high-speed driven gear 54 may be attached to the output shaft 52 so as to rotate integrally therewith. Further, the low-speed drive gear 35 may be connected to the carrier 40 so as to rotate integrally therewith, and the low-speed clutch 43 may be provided between the low-speed driven gear 53 and the output shaft 52.

The engine 31 on the output shaft 52
An output gear 56 is attached to the shaft end on the side of the shaft 57. The output gear 56 is a ring gear 58 of a differential 57.
Is engaged.

In the transmission having the structure shown in FIG. 3, the engine 1 is started in a so-called neutral state in which the forward clutch 41 and the direct connection clutch 42 are released. When starting in the forward direction, the continuously variable transmission mechanism 45 is set to the maximum speed ratio γmax, and the forward clutch 41 is gradually engaged while the low-speed clutch 43 is engaged. Increase the transmission gradually. As a result, the ring gear 39 of the planetary gear mechanism 34 is
, The torque is distributed and transmitted to the carrier 40 and the sun gear 38 according to the gear ratio of the planetary gear mechanism 34 (the ratio between the number of teeth of the sun gear 38 and the number of teeth of the ring gear 39). .

The torque of the sun gear 38 is transmitted to the drive pulley 4 via the CVT drive gear 35 and the CVT driven gear 51.
6 and the belt 50 and the driven pulley 4
7, an output shaft 52 and an output gear 56 which are output members.
Is transmitted to On the other hand, the torque distributed to the carrier 40 is transmitted from the low speed clutch 43 to the low speed gears 3.
5 and 53 to the output shaft 52. Therefore, after the torque of the input shaft 32 is distributed to the carrier 40 and the sun gear 38 by the planetary gear mechanism 34, the torque of the output shaft 5 is transmitted through two paths of the continuously variable transmission mechanism 45 and the low-speed gear pair.
2 where the torques passing through the respective paths are combined. This is the so-called torque split mode. Therefore, even if the gear ratio set by the continuously variable transmission mechanism 45 is the maximum gear ratio γmax, the torque acting on the continuously variable transmission mechanism 45 is about half of the total torque transmitted to the output shaft 52. , The load on the belt 50 is
Is greatly reduced as compared with the case where torque is transmitted alone.

After starting in this manner, the low speed clutch 43 is released and the direct coupling clutch 42 is engaged. Therefore, in the planetary gear mechanism 34,
Since the carrier 40 and the ring gear 39 are connected, the entire planetary gear mechanism 34 rotates integrally. Therefore, the torque transmitted from the input shaft 32 to the ring gear 39 is directly transmitted from the sun gear 38 to the CVT drive gear 3.
7 and the CVT driven gear 51 through the continuously variable transmission mechanism 45
Is transmitted to Then, the continuously variable transmission mechanism 45 is controlled to an appropriate speed ratio according to the driving state of the vehicle, and the torque increased or decreased according to the speed ratio is output to the output shaft 52 and the output gear 56.
Is transmitted to

Further, when the gear ratio to be set is reduced to about the minimum gear ratio due to an increase in the vehicle speed or a decrease in the required driving force, the direct coupling clutch 42 is released and the high speed clutch 55 is released. Engaged. As a result, a differential action occurs in the planetary gear mechanism 34 and the torque input to the ring gear 39 is distributed to the carrier 40 and the sun gear 38, while the torque is transmitted to the output shaft 52 via the continuously variable transmission mechanism 45. On the other hand, the torque is transmitted to the output shaft 52 via the high-speed gears 36 and 54, and the torque transmitted by these two systems is combined. Such a torque transmission state is a so-called torque split mode similar to the case where the maximum gear ratio is set. Therefore, the speed ratio set by the continuously variable transmission mechanism 45 is the minimum speed ratio γmin, and the pulleys 46, 47
Even if the motor rotates at a high speed, the torque acting on the continuously variable transmission mechanism 45 is about half of the total torque transmitted to the output shaft 52.
Is greatly reduced as compared with the case where torque is transmitted alone.

When the vehicle travels backward, the direct coupling clutch 42 is engaged with the reverse brake 44 engaged. By doing so, in the planetary gear mechanism 34, torque is input to the carrier 40 while the ring gear 39 is fixed, so that the sun gear 38, which is an output element, rotates in the opposite direction to the ring gear 39, and the torque is transmitted to the CVT drive gear. The transmission is transmitted to the continuously variable transmission mechanism 45 via the CVT driven gear 51 and the CVT driven gear 51, and as a result, the vehicle enters a reverse traveling state.

Therefore, in the transmission having the configuration shown in FIG. 3, when the speed ratio at which the effective diameter of one of the driving pulley 46 and the driven pulley 47 is reduced is set, the transmission from the engine 31 to the output shaft 52 is performed. Part of the torque to be transmitted is transmitted to the output shaft 52 via a low-speed or high-speed gear pair disposed in parallel with the continuously variable transmission mechanism 45. Therefore, when the torque to be transmitted is large or when the continuously variable transmission mechanism 45 rotates at high speed, the torque applied to the belt 50 is reduced, so that the durability of the belt 50 can be improved. Therefore, the above-described planetary gear mechanism 34 corresponds to the distribution mechanism of the present invention.

It should be noted that the other transmission mechanisms arranged in parallel with the continuously variable transmission mechanism 45 are not limited to those transmitting torque when the transmission ratio of the continuously variable transmission mechanism 45 is maximum or minimum. Thus, even when the continuously variable transmission mechanism 45 is set to an intermediate speed ratio, a part of the torque transmitted to the output shaft 52 may be transmitted.

FIG. 4 shows an example in which the planetary gear mechanism of the configuration shown in FIG. 3 is changed to a single pinion type. Since the double pinion type planetary gear mechanism and the single pinion type planetary gear mechanism are functionally the same as those in which the respective carriers and ring gears are replaced, the transmission shown in FIG. A forward clutch 41 is provided therebetween, and a reverse brake 44 is arranged to selectively fix the carrier 40a. On the other hand, the ring gear 39a
It is integrated with the VT drive gear 37. Further, a direct coupling clutch 42 is arranged between the sun gear 38a and the input shaft 32. The other configuration is substantially the same as the configuration shown in FIG. 3 except that the arrangement position is changed according to the change of the planetary gear mechanism to the single pinion type.

The transmission shown in FIG. 4 also has a so-called split mode between the maximum speed ratio at the time of starting and the minimum speed ratio at the time of high-speed running. Is shifted by the continuously variable transmission mechanism 45. In addition, in the transmission having the configuration shown in FIG. 4, when the reverse gear is set, torque is input to the sun gear 38a while the carrier 40a is fixed, and the ring gear 3
9a is rotated in reverse, so that the ring gear 39a
Is greatly reduced with respect to the sun gear 38a. As a result, the overall gear ratio at the reverse speed is lower geared, and the reverse coupling
2 can be changed from the slipping state to the fully engaged state relatively early, the thermal load on the direct coupling clutch 42 can be reduced, and the durability thereof can be improved.

By the way, in the specific example described above, an example is shown in which the present invention is applied to a transmission of a vehicle provided with one kind of power source. However, the present invention is not limited to the specific example. The present invention can also be applied to a transmission in a hybrid vehicle that uses an internal combustion engine and an electric motor as power sources. Further, the continuously variable transmission mechanism in the present invention is not limited to the belt type. Furthermore, the distribution mechanism in the present invention is:
The present invention is not limited to the one configured by the planetary gear mechanism, and may be another configuration that performs a differential action, such as a viscous joint.

[0057]

As described above, according to the first aspect of the present invention, at the time of starting, torque is transmitted to the output member via the reduction mechanism instead of the continuously variable transmission mechanism by the switching means,
Therefore, the vehicle travels while performing a speed change by the speed reduction mechanism, and the speed ratio in this case is a predetermined speed ratio which is 1.25 times or more and 2.0 times or less of the maximum speed ratio by the continuously variable transmission mechanism. Since the starting acceleration is high and the power is not transmitted by the continuously variable transmission mechanism, the transmission efficiency can be improved and the durability of the continuously variable transmission can be improved. Further, since the speed ratio of the speed reduction mechanism is 1.25 times or more and 2.0 times or less the maximum speed ratio of the continuously variable transmission mechanism, the torque is transmitted by the continuously variable transmission mechanism instead of the speed reduction mechanism after the vehicle starts. When the torque transmission path is changed such that the step of the gear ratio does not become particularly large, the torque transmission path can be changed without deteriorating the shock, and the deterioration of the riding comfort can be prevented.

According to the invention of claim 2, according to claim 1,
In addition to the same effect as the invention, the transmission torque gradually changes when the switching means operates at the start or after the start, so that the change in the torque appearing on the output member at the time of start or at the time of changing the torque transmission path after the start is changed. As a result, it is possible to prevent an excessive shock and improve riding comfort.

Further, according to the third aspect of the present invention, torque is transmitted to the output member via the speed reduction mechanism at the time of starting, and the speed ratio in that case becomes larger than the maximum speed ratio by the continuously variable transmission mechanism. The transmission efficiency can be improved as compared with the case where the continuously variable transmission mechanism is used, the durability of the continuously variable transmission can be improved, and the necessary and sufficient acceleration for starting can be obtained. Further, after the vehicle starts moving, the switching means operates to transmit torque to the output member via the continuously variable transmission mechanism, and the continuously variable transmission mechanism shifts the speed. In this case, the speed ratio of the reduction mechanism is changed to the continuously variable transmission mechanism. , A step in the gear ratio occurs, but the amount of torque transmitted by the switching means gradually changes, so that the change in torque appearing on the output member becomes smooth,
The deterioration of the shock can be prevented.

According to the fourth aspect of the present invention, a gear pair having a speed ratio matching the speed ratio set by the continuously variable transmission mechanism is selected, and torque is transmitted via the distribution mechanism and the gear pair. As a result, both the continuously variable transmission mechanism and its gear pair are responsible for transmitting torque, and as a result, the amount of torque transmitted by the continuously variable transmission mechanism is reduced. Accordingly, the power transmission efficiency of the transmission as a whole is correspondingly reduced. Can be improved.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram showing an example of a transmission according to the present invention.

FIG. 2 is a skeleton diagram showing another example in which the arrangement is changed.

FIG. 3 is a skeleton diagram showing still another example of the present invention.

4 is a skeleton diagram showing an example in which the planetary gear mechanism in the example shown in FIG. 3 is changed to a single pinion type.

[Explanation of symbols]

1,31 ... engine, 2,32 ... input shaft, 4,45
... continuously variable transmission mechanism, 5, 46 ... drive pulley, 6, 4
2 ... direct-coupled clutch 7 ... driven pulley 8, 52 ...
Output shaft, 12, 56 ... output gear, 18, 34 ... planetary gear mechanism, 19, 38 ... sun gear, 20, 39 ... ring gear, 21, 40 ... carrier, 22 ... starting clutch, 24 ... first drive gear, 26 ... First driven gear,
27: two-way clutch, 28: second drive gear, 2
9: second driven gear, 41: forward clutch, 43:
Low speed clutch, 51: CVT driven gear, 53: Low speed driven gear, 54: High speed driven gear, 55: High speed clutch.

Claims (4)

[Claims] 1. A transmission provided with a continuously variable transmission mechanism in which a continuously variable transmission mechanism capable of continuously changing a transmission ratio is interposed in a power transmission system from a power source to an output member. A speed reduction mechanism whose ratio is set to a predetermined value not less than 1.25 times and not more than 2.0 times the maximum speed ratio of the continuously variable transmission mechanism is provided between the power source and the output member. Switching means arranged in parallel with the speed change mechanism, and further provided with a switching means for setting a torque transmission path so as to transmit torque from the power source to the output member via the speed reduction mechanism at the time of starting. A transmission equipped with a continuously variable transmission mechanism. 2. The method according to claim 1, wherein the switching means sets the torque transmission amount to 0%.
The transmission having the continuously variable transmission mechanism according to claim 1, comprising an engagement mechanism that changes continuously between the range and 100%. 3. A transmission provided with a continuously variable transmission mechanism in which a continuously variable transmission mechanism capable of continuously changing a transmission ratio is interposed in a transmission system of power from a power source to an output member. A speed reduction mechanism whose ratio is set to a predetermined value larger than the maximum speed ratio of the continuously variable transmission mechanism is disposed between the power source and the output member in parallel with the continuously variable transmission mechanism, and At the same time, the torque transmission path is switched so that torque is transmitted from the power source to the output member via the speed reduction mechanism, and torque is transmitted to the output member via the continuously variable transmission mechanism after the vehicle starts. A transmission provided with a continuously variable transmission mechanism, wherein a switching means for gradually increasing the amount of torque transmitted to the step transmission mechanism is provided. 4. A transmission provided with a continuously variable transmission mechanism in which a continuously variable transmission mechanism capable of continuously changing a transmission ratio is interposed in a power transmission system from a power source to an output member. A plurality of gear pairs having different ratios are arranged in parallel with the continuously variable transmission mechanism, and the torque output by the power source is distributed to one of the plurality of gear pairs and the continuously variable transmission mechanism. A transmission provided with a continuously variable transmission mechanism, wherein a transmission mechanism for transmitting the transmission is provided.