JP2001343059A - Speed changer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speed changer furnished with a stepless speed variator in which a range of speed ratio is increased and compact in size is attained. SOLUTION: In the speed changer having a stepless speed variator 1 which is able to change continuously a ratio of rotating speed of an input element 2 and an output element 3, an input member 5 for inputting a torque to the stepless speed variator 1, and an output member 14 to which the torque is transmitted from the stepless speed variator, the speed changer comprising: a first changeover driving mechanism (6, 7, 8, P1, S1) which connects the input member 5 selectively to the input element 2 and the output element 3; and a second changeover driving mechanism (11, 12, 13, P2, S2) which connects the output member 14 selectively to the input element 2 and the output element 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission for changing the rotational speed ratio between an input element and an output element, and more particularly to a transmission having a continuously variable transmission.

[0002]

2. Description of the Related Art An example of this type of transmission is disclosed in Japanese Unexamined Patent Publication No.
No. 182,667. The device described in this publication is a transmission for a vehicle, and a forward / reverse switching device including a pair of double pinion type planetary gear mechanisms is connected to an output side of a torque converter. A belt-type continuously variable transmission is connected to the output side. In the continuously variable transmission, the primary pulley on the input side and the secondary pulley on the output side are each configured by a fixed sheave and a movable sheave that can approach and separate from the fixed sheave, and include a primary pulley and a secondary pulley. The movable sheaves move in opposite directions to increase the groove width on one pulley and decrease the groove width on the other pulley, thereby increasing or decreasing the winding radius of the belt wound around each pulley. Thus, the gear ratio is set appropriately.

[0003] Therefore, in the transmission described in the above publication, the belt winding radius is minimized by maximizing the groove width of the primary pulley and the belt winding radius by minimizing the groove width of the secondary pulley. Is maximized, the gear ratio is maximized. From this state, while gradually reducing the groove width of the primary pulley and gradually increasing the groove width of the secondary pulley, the speed ratio gradually decreases, and the groove width of the primary pulley is made the narrowest to reduce the winding radius of the belt. The gear ratio is minimized by maximizing the groove width of the secondary pulley and minimizing the winding radius of the belt.

[0004]

As described above, the speed change ratio of a belt-type continuously variable transmission is determined by the winding radius of the belt around each pulley. Therefore, conventionally, the primary pulley and the secondary pulley are almost equal to each other. The diameter of each pulley is set so that the groove width of each pulley can be changed in any of the enlargement and reduction directions from the state of the gear ratio "1" where the winding radius of the belt is the same. For this reason, the distance between the shafts of the pulleys needs to be at least as small as the outer diameter of the pulley, resulting in a disadvantage that the device must be occupied by a large space.

In the belt-type continuously variable transmission, the width of the settable gear ratio is widened by increasing the difference between the groove widths of the respective pulleys, that is, the difference between the belt winding radii. However, when the groove radius of the belt is reduced by increasing the groove width of the pulley, the curvature of the belt increases, and at the same time, the winding angle of the belt with respect to the pulley decreases, so that the durability of the belt decreases, or Problems such as a reduction in torque transmission efficiency due to slippage of the belt occur. Therefore, there is a restriction in reducing the winding radius of the belt around each pulley,
In order to maintain the gear ratio width (the width of the gear ratio determined by the maximum gear ratio and the minimum gear ratio) to a certain degree or more, each pulley needs to have a large diameter, and the transmission device is accordingly disadvantageously enlarged. Occurs. In other words, it has been difficult to achieve both an increase in the gear ratio width and a reduction in the size of the device.

SUMMARY OF THE INVENTION The present invention has been made in view of the above technical problems, and has as its object to reduce the size of a transmission equipped with a continuously variable transmission and to expand the speed ratio range. It is.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is characterized in that a mechanism for reversing the input and output of torque to and from a continuously variable transmission is provided. More specifically, the invention of claim 1
A continuously variable transmission capable of continuously changing the ratio of the number of revolutions of the input element and the output element, an input member for inputting torque to the continuously variable transmission, and a torque transmitted from the continuously variable transmission. A transmission having an output member to be transmitted, wherein the first switching transmission mechanism selectively connects the input member to the input element and the output element, and the output member includes the input element and the output element. And a second switching transmission mechanism selectively connected to the transmission.

Therefore, according to the first aspect of the present invention, a so-called forward transmission state in which the input member and the input element are connected by the first switching transmission mechanism and the output element and the output member are connected by the second switching transmission mechanism. And a so-called reverse transmission state in which the input member and the output element are connected by the first switching transmission mechanism and the input element and the output member are connected by the second switching transmission mechanism. Therefore, the reciprocal of the gear ratio in the forward transmission state in the continuously variable transmission is the gear ratio in the reverse transmission state. for that reason,
In the belt-type continuously variable transmission, by making one of the pulley serving as the input element and the pulley serving as the output element smaller in diameter than the other, even if the distance between the input element and the output element is shortened, Since the gear ratio in the forward transmission state and the gear ratio in the reverse transmission state can be set, the apparatus can be made compact without reducing the gear ratio width. Also, the first
And if any of the second switching transmission mechanisms is a mechanism having a speed ratio other than "1", the overall transmission is constructed by combining the speed ratio of the speed change mechanism and the speed ratio of the continuously variable transmission. Is determined, so that the overall speed ratio of the transmission is diversified, that is, the speed ratio width is increased.

According to a second aspect of the present invention, in the first aspect, one of the first switching transmission mechanism and the second switching transmission mechanism includes a sun gear, a ring gear, and a carrier as rotating elements. A planetary gear mechanism, the sun gear is connected to one of the input element and the output element, and one of the ring gear and the carrier is connected to the other of the input element and the output element, Further, the transmission is characterized in that one of the ring gear and the carrier is connected to the output member.

Therefore, in the second aspect of the invention, in addition to the function of the first aspect, the continuously variable transmission and the planetary gear mechanism are interposed between the input member and the output member in parallel. With this configuration, torque can be transmitted through both of them, and as a result, torque transmission efficiency is improved.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described based on specific examples. FIG. 1 shows an example in which a belt-type continuously variable transmission 1 is used as a continuously variable transmission, and a primary pulley 2 as an input element and a secondary pulley 3 as an output element.
Are arranged with their axes parallel to each other, and a belt 4 is wound around these pulleys 2 and 3.
These pulleys 2 and 3 move the movable sheave arranged opposite to the fixed sheave to change the groove width in the same manner as in the conventional belt-type continuously variable transmission, thereby changing the width of the belt 4.
Is changed by changing the winding radius of the gear.

An input shaft 5, which is an input member, is arranged on the same axis as the primary pulley 2, and a first clutch P1 for selectively connecting the input shaft 5 and the primary pulley 2 is arranged between the input shaft 5 and the primary pulley 2. ing. A drive sprocket 6 is mounted on the input shaft 5, and a driven sprocket 7 paired with the drive sprocket 6 is disposed on the same axis as the secondary pulley 3, and a chain 8 is wound around these sprockets 6, 7. Have been. Further, a second clutch S1 for selectively connecting the driven sprocket 7 and the secondary pulley 3 is disposed between the driven sprocket 7 and the secondary pulley 3.

Accordingly, the input shaft 5 is connected to the primary pulley 2 by engaging the first clutch P1, and the input shaft 5 is connected to the secondary pulley 3 by engaging the second clutch S1. Has become. That is, the clutches P1, S1, the respective sprockets 6, 7, and the chain 8 constitute a first switching transmission mechanism of the present invention. In place of the sprockets 6, 7 and the chain 8, a gear mechanism configured so that the input shaft 5 and the second clutch S1 rotate in the same direction can be used.

The input shaft 5 is connected to an engine 10 as a power source via a damper 9. Note that a torque converter or an input clutch may be arranged between the input shaft 5 and the engine 10. Further, instead of the engine 10, another power source such as a motor or a motor generator can be used.

A chain transmission mechanism having the same configuration as the above-described chain transmission mechanism including the sprockets 6 and 7 and the chain 8 is disposed on the opposite side of the continuously variable transmission 1. That is, the second drive sprocket 11 is arranged on the same axis as the primary pulley 2, the third clutch P2 is arranged between the drive sprocket 11 and the primary pulley 2, and the primary drive pulley 2 and the second drive sprocket 11 Are selectively connected. A second driven sprocket 12 is disposed on the same axis as the secondary pulley 3, and a fourth clutch S2 is disposed between the driven sprocket 12 and the secondary pulley 3, and the second driven sprocket 12
Of the driven sprocket 12 is selectively connected. Then, these second driving sprockets 11
A chain 13 is wound around the second driven sprocket 12 and the second driven sprocket 12. Further, a second driven sprocket 12 is integrally attached to an output shaft 14 which is an output member.

Therefore, the output shaft 14 is connected to the primary pulley 2 by engaging the third clutch P2, and the output shaft 14 is connected to the secondary pulley 3 by engaging the fourth clutch S2. Has become. That is, each of these clutches P2, S2
And each sprocket 11, 12 and the chain 13
This constitutes a second switching transmission mechanism of the present invention. Instead of the sprockets 11 and 12 and the chain 13, a gear mechanism configured so that the output shaft 14 and the third clutch P2 rotate in the same direction can be used.

The speed ratios (gear ratios) of the respective chain transmission mechanisms are set to the same value. Further, the gear ratio is specifically set to “1”, but is not limited to this. For example, it may be a value equal to any of the speed ratios that can be set in the continuously variable transmission 1.

A counter shaft 15 is provided in parallel with the output shaft 14.
Are arranged, and a counter gear pair 16 and a reverse gear pair 1 for transmitting torque between these shafts 14 and 15 are provided.
7 are provided. That is, the counter drive gear 18 and the reverse drive gear 19 are rotatably mounted on the output shaft 14, and a shift mechanism 20 for selectively connecting these gears 18, 19 and the output shaft 14 is provided. . The counter drive gear 18 meshes with a counter driven gear 21 attached to the counter shaft 15. Further, the reverse drive gear 19 meshes with the idle gear 22 and the idle gear 22
Are engaged with the reverse driven gear 23 attached to the counter shaft 15. The output gear 24 attached to the counter shaft 15 meshes with the ring gear 26 of the differential gear 25. The differential gear 25 transmits torque to left and right wheels (not shown).

Therefore, by connecting the output shaft 14 to the counter drive gear 18 by the shift mechanism 20, the wheels rotate in the forward direction, and the shift mechanism 20
By connecting the output shaft 14 to the reverse drive gear 19, the wheels rotate in the reverse direction.

Next, the operation of the thus configured transmission will be described. The transmission and the engine 10 can be mounted on a vehicle, and the torque is output from the engine 10 to the input shaft 5 in a state where there is a request for increasing the driving force such as depressing an accelerator pedal (not shown).
In this state, when the first clutch P1 is engaged and the input shaft 5 is connected to the primary pulley 2, torque is input to the primary pulley 2 to rotate it, and further, torque is transmitted to the secondary pulley 3 via the belt 4. This rotates. Then, by engaging the fourth clutch S2, torque is transmitted from the secondary pulley 3 to the output shaft 14, and the output shaft 14 rotates. In this case, the second and third clutches S1, P2 are released.

In this state, the groove width of the primary pulley 2 is maximized to minimize the winding radius of the belt 4, and the groove width of the secondary pulley 3 is minimized to maximize the winding radius of the belt 4. The gear ratio γ becomes the largest. That is, the speed ratio γmax on the lowest speed side is obtained. This state is shown as Mode I in the chart of FIG.

From the state of the maximum transmission ratio γmax, the groove width of the primary pulley 2 is gradually narrowed to increase the winding radius of the belt 4, and the groove width of the secondary pulley 3 is gradually widened to increase the winding radius of the belt 4. When it is reduced, the gear ratio γ becomes smaller and gradually approaches “1”. And
When the winding radius of the belt 4 on each of the pulleys 2 and 3 becomes equal, the speed ratio γ becomes “1”. This state is shown in FIG.
As mode II. In this state, the input shaft 5
And each pulley 2, 3 and the output shaft 14 rotate at the same speed. That is, the driving sprockets 6, 11 and the driven sprockets 8, 1 in each of the chain transmission mechanisms described above.
2 rotates at the same speed, and the entire rotating element from the input shaft 5 to the output shaft 14 rotates integrally. Therefore,
By setting the gear ratio of each chain transmission mechanism to "1", the second and third clutches S1 and P2 which have been maintained in the disengaged state are engaged, and the primary pulley 2 is moved to the third position. The output shaft 14 can be connected via the clutch P2 and the chain 13, and the secondary pulley 3 can be connected to the input shaft 5 via the second clutch S1 and the chain 8.

Next, when the first clutch P1 and the fourth clutch S2 are released, the primary pulley 2 is connected to the output shaft 14, and the secondary pulley 3 is connected to the input shaft 5, so that the continuously variable transmission 1 Is reversed from the initial state. Therefore, since the secondary pulley 3 is on the driving side and the primary pulley 2 is on the driven side, the secondary pulley 3
When the groove width of the belt 4 is gradually reduced by narrowing the groove width as originally set, the winding radius of the belt 4 is gradually increased, and at the same time, the groove width of the primary pulley 2 is widened and the winding radius of the belt 4 is gradually reduced. The ratio γ gradually decreases. In other words, the speed ratio is on the high speed side. If the groove width of the secondary pulley 3 is made the smallest and the winding radius of the belt 4 is maximized, and the groove width of the primary pulley 2 is made the largest and the winding radius of the belt 4 is minimized, the gear ratio becomes the most. Become smaller. That is, the speed ratio γmin on the highest speed side is set. This state is shown as mode III in FIG.

Accordingly, in the transmission shown in FIG. 1, the winding radius of the belt 4 of the primary pulley 2 is minimized at the maximum speed ratio γmax, and the belts of the pulleys 2 and 3 are directly connected at the speed ratio γ of “1”. 4, the outer diameter of the primary pulley 2 may be smaller than the outer diameter of the secondary pulley 3, since the winding radius of the belt 4 of the primary pulley 2 is minimized at the minimum speed ratio γmin. Therefore, the distance between the center axes of the pulleys 2 and 3, that is, the distance between the shafts is shorter than when the outer diameters of the pulleys are equal. Further, the reciprocal of the maximum speed ratio γmax becomes the minimum speed ratio γmin, and the speed can be changed during that period, so that the speed ratio width does not become narrow.

Since the input / output relationship with respect to the continuously variable transmission 1 can be reversed as described above, the secondary pulley 3 may have a small diameter in place of the primary pulley 2 having a small diameter, as in the above example. The distance between the shafts can be reduced without reducing the gear ratio width.

In the transmission shown in FIG. 1, a transmission ratio in a so-called forward transmission state in which torque is transmitted from the primary pulley 2 to the secondary pulley 3 and a torque is transmitted from the secondary pulley 3 to the primary pulley 2. The so-called reverse transmission state gear ratio has a reciprocal relationship to each other. Therefore, if the vehicle suddenly stops while traveling at the minimum speed ratio (speed ratio on the highest speed side) γmin, each of the clutches P1, P2, S1,.
If the input / output relationship to the continuously variable transmission 1 is reversed by reversing the engaged / disengaged state of S2, the gear ratio becomes the maximum gear ratio (the gear ratio on the lowest speed side) γmax. Start can be performed smoothly. In other words, the shift response at the time of re-acceleration after the sudden stop is improved.

By setting the gear ratio of the chain transmission mechanism on the input shaft 5 side and the chain transmission mechanism on the output shaft 14 side to be the same, these chain transmission mechanisms can have the same configuration. It is possible to reduce the cost by sharing the same.

In the example shown in FIG. 1 described above, the gear ratios of the first and second switching transmission mechanisms are both set to "1", but if the gear ratio is set to a value smaller than "1" as an example, Thus, the transmission ratio width of the entire transmission can be further increased. In the case of such a configuration, the gear ratio of the continuously variable transmission 1 is matched with the gear ratio of each switching transmission mechanism, and in that state, the input / output relationship with the continuously variable transmission 1 is reversed. The gear ratio of 1 will be changed.

Next, another embodiment of the present invention will be described with reference to FIG. In the example shown in FIG. 3, one of the two switching transmission mechanisms for inverting the input / output relationship with the continuously variable transmission 31 is provided with a planetary gear mechanism in one of the switching transmission mechanisms. In other words, the continuously variable transmission 31 is similar to the continuously variable transmission 1 shown in FIG.
The belt 34 is wound around the second pulley 2 and the secondary pulley 33, and the groove width of the pulleys 32, 33 is changed, so that the winding radius of the belt 34 is changed, so that the gear ratio is steplessly changed. It is configured as follows. The primary pulley 32 corresponds to an input element in the present invention. An input shaft 35 is disposed on the same axis as the primary pulley 32, and a first clutch Cd1 is disposed between the input shaft 35 and the primary pulley 32. , The input shaft 35 and the primary pulley 32 are selectively connected.

A drive sprocket 36 is mounted on the input shaft 35. A driven sprocket 37, which forms a pair with the drive sprocket 36, is arranged on the same axis as the secondary pulley 33, and a chain 38 is connected to these sprockets 36 and 37. Is wrapped around. The number of teeth of the driven sprocket 37 is set smaller than the number of teeth of the drive sprocket 36 in this chain transmission mechanism, and its speed ratio (gear ratio) i1
Is set equal to the minimum speed ratio (speed ratio on the highest speed side) γmin that can be set in the continuously variable transmission 31.

A second clutch Ch1 is disposed between the driven sprocket 37 and the secondary pulley 33, and the second clutch Ch1 is used to selectively connect the secondary pulley 33 and the driven sprocket 37. It is configured.

Further, an engine 39 is disposed on the opposite side of the input shaft 35 from the primary pulley 32,
An input shaft 35 is connected to an output shaft of the engine 39 via a damper 40. Therefore, the chain transmission mechanism including the drive sprocket 36 and the driven sprocket 37 and the chain 38 wound around the drive sprocket 36 and the first and second clutches Cd1 and Ch1
This is the first switching transmission mechanism in the present invention.

A single pinion type planetary gear mechanism 41 is disposed between the primary pulley 32 and the secondary pulley 33. This planetary gear mechanism 41
A rotating element includes a sun gear 42, a ring gear 43 arranged concentrically with respect to the sun gear 42, and a carrier 44 rotatably and revolvingly holding a pinion gear meshing with the sun gear 42 and the ring gear 43. A sun gear shaft 43 is integrally attached to the sun gear 42. This sun gear shaft 4
Numeral 3 is arranged in parallel with the primary pulley 32, one end of which extends in a direction opposite to the engine 39 with respect to the primary pulley 32, and a driven gear 46 is integrally attached to the end. The drive gear 47 meshing with the driven gear 46
Are arranged on the same axis as the primary pulley 32, and a third clutch Ch2 is arranged between the drive gear 47 and the primary pulley 32.
That is, the primary pulley 32 and the drive gear 4
2 is selectively connected by a third clutch Ch2.

On the other hand, a hollow shaft-shaped ring gear shaft 48 integrated with the ring gear 43 is rotatably fitted on the outer peripheral side of the sun gear shaft 45, and a drive gear 49 integrated with the ring gear shaft 48 is driven by a driven gear 49. 50 are engaged. Further, the driven gear 50 is arranged on the same axis as the secondary pulley 33 and is connected to the secondary pulley 33 so as to rotate integrally therewith.

The sun gear 4 in the planetary gear mechanism 41
The fourth clutch Cd2 is disposed between the second gear 2 and the ring gear 43. When the fourth clutch Cd2 is engaged, the two rotating elements of the planetary gear mechanism 41 are integrated and the entire planetary gear mechanism 41 Are designed to rotate together. The carrier 4 in the planetary gear mechanism 41
An output gear 51 is integrally attached to the gear 4, and the output gear 51 meshes with a ring gear 53 attached to a differential gear 52. Therefore, this output gear 51 is the output member in the present invention.

Therefore, between the output gear 51 and the primary pulley 32, the planetary gear mechanism 41 having the fourth clutch Cd2, a gear pair including a pair of gears 46 and 47, and the third clutch Ch2 are arranged. And the output gear 51
The planetary gear mechanism 41 and a gear pair including a pair of gears 49 and 50 are disposed between the planetary gear mechanism 41 and the secondary pulley 33. Therefore, the planetary gear mechanism 41, the two gear pairs, and the clutches Ch2 and Cd2 constitute a second switching transmission mechanism in the present invention.

The gear ratio i2 of the gear pair consisting of the pair of gears 46 and 47 is the same as the gear ratio of the gear pair consisting of the other pair of gears 49 and 50 and the minimum transmission set by the continuously variable transmission 31. It is set to a value equal to the product of γmin.

A mechanism for setting the reverse state will be described. A reverse drive sprocket 55 is mounted integrally with a drive sprocket 47 in a gear pair between the primary pulley 32 and the sun gear shaft 45. A reverse driven gear 57 to which torque is transmitted by a chain 56 wound around the drive sprocket 55 is rotatably fitted on the outer peripheral side of the sun gear shaft 45. A reverse clutch Rev is provided between the reverse driven gear 57 and the ring gear shaft 48. The primary pulley 32 and the ring gear 41 are connected by engaging the reverse clutch Rev and the third clutch Ch2. It has become so.

The differential gear 52 is
It is arranged on the outer peripheral side of the input shaft 35 or on the outer peripheral side of the first drive sprocket 36. Therefore, it is possible to arrange the differential gear 52 such that the lengths of the drive shafts (not shown) for the left and right wheels are made as equal as possible.

Next, the operation of the transmission shown in FIG. 3 will be described. In the transmission shown in FIG.
Is connected to the primary pulley 32 and the secondary pulley 33 is connected to an output gear 51 which is an output member, a so-called forward transmission state. The input shaft 35 is connected to the secondary pulley 33, while the primary pulley 32 is connected to the output gear 51. In addition to being able to set the so-called reverse transmission state, the CVT mode in which the continuously variable transmission 31 changes the speed by incorporating the planetary gear mechanism 41 in the second switching transmission mechanism of the present invention, A split mode in which the speed is changed by the planetary gear mechanism 41 in addition to the step transmission 31 is possible. Hereinafter, each mode will be described.

First, the CVT mode will be described.
The CVT mode is a mode in which torque is transmitted via the continuously variable transmission 31, and thus the speed is changed by the continuously variable transmission 31, and as shown in FIG. 35 is connected to the primary pulley 32, and the fourth clutch Cd2 is engaged so that the entire planetary gear mechanism 41 is integrated. That is, the output torque of the engine 39 is transmitted from the input shaft 35 to the continuously variable transmission 31 and amplified according to the speed ratio.
The gears are transmitted to a sprocket 51 which outputs the gears via a gear 50. At this time, the gears are shifted by a pair of gears 49 and 50, further transmitted from the output gear 51 to a differential gear 52, and then transmitted to left and right wheels (not shown). You.

In the above-mentioned CVT mode, the groove width of the primary pulley 32 is gradually narrowed to increase the winding radius of the belt 34 while the secondary pulley 3
By gradually increasing the groove width of No. 3 and reducing the winding radius of the belt 34, the speed ratio γ gradually decreases.
Then, while minimizing the groove width of the primary pulley 32 and maximizing the winding radius of the belt 34,
If the groove width of the secondary pulley 33 is maximized and the winding radius of the belt 34 is minimized, the secondary pulley 33 rotates at the highest speed with respect to the primary pulley 32. That is, the speed ratio γ is the minimum speed ratio γ
min.

FIG. 5 is a collinear diagram showing the process of such a shift. That is, since the planetary gear mechanism 41 is entirely integrated, the sun gear (S) 4
2 and ring gear (R) 43 and carrier (C)
44 are rotating at the same speed, the rotation speeds thereof are the same, and the speed ratio of the continuously variable transmission 31 is the maximum speed ratio γmax.
From to the minimum gear ratio γmin,
Sun gear 42, ring gear 43 and carrier 4
4 gradually increases. Therefore, as shown by the thick line in FIG. 5, the rotation speed of these rotating elements is represented by a horizontal straight line, and this gradually moves upward.

The speed ratio γ of the continuously variable transmission 31 is set to the minimum speed ratio γ.
By inverting the input / output relationship with respect to the continuously variable transmission 31 in a state where the speed has been changed to min, the split mode is established, and further gear shifting is performed. That is, as shown in FIG. 4, the first and fourth clutches Cd1 and Cd2 are released, and the second and third clutches Ch1 and Ch2 are engaged. In the split mode, the input shaft 35 is connected to the secondary pulley 33 via a chain transmission mechanism, while the primary pulley 32 is connected to the planetary gear mechanism 41 and the output gear 51 via the third clutch Ch2 and a pair of gears 47 and 46. Linked to

In this case, since the gear ratio i1 in the chain transmission mechanism including the drive sprocket 36, the driven sprocket 37 and the chain 38 is set equal to the minimum speed ratio γmin in the continuously variable transmission 31, the first clutch Cd1 is engaged. By engaging the second clutch Ch1 in the engaged state and then releasing the first clutch Cd1, the connection state of the input shaft 35 to the continuously variable transmission 31 can be switched. Such switching of the clutch disengagement state is similar to the switching of the third clutch Ch2 and the fourth clutch Cd2. When the clutches Ch2 and Cd2 are both engaged, the fourth clutch Cd2 is switched. The connection relation of the output gear 51 to the continuously variable transmission 31 can be reversed by releasing the connection.

In the split mode, the torque of the input shaft 35 is input to the secondary pulley 33 via the chain transmission mechanism and the second clutch Ch1, and further from there, the planetary gear mechanism 4 via a pair of gears 49 and 50.
The power is transmitted to one ring gear 43. Torque is transmitted from the secondary pulley 33 to the primary pulley 32 by the belt 34, and further from the primary pulley 32 to the sun gear shaft 45 and the sun gear 4 via the third clutch Ch2 and the pair of gears 46 and 47.
2, torque is transmitted. That is, the planetary gear mechanism 41
Are transmitted to the sun gear 42 and the ring gear 43, and these torques are combined and output from the carrier 44 to the output gear 51.

If the speed ratio set by the continuously variable transmission 31 is the minimum speed ratio γmin described above, the sun gear 42 and the ring gear 43 are the same since the speed ratio and the speed ratio by the chain transmission mechanism are the same. Therefore, the carrier 44 and the output gear 51 rotate at the same speed as the sun gear 42 and the ring gear 43. In this state, when the speed ratio γ of the continuously variable transmission 31 is changed to a speed ratio on the low vehicle speed side, the output rotational speed is further increased. That is, while gradually increasing the groove width of the primary pulley 32 to decrease the winding radius of the belt 34, and gradually decreasing the groove width of the secondary pulley 33 to gradually increase the winding radius of the belt 34,
The speed ratio of the continuously variable transmission 31 gradually increases.

In this case, since the torque of the input shaft 35 is transmitted to the secondary pulley 33, the secondary pulley 33 is an input-side member and the primary pulley 32 is an output-side member. By increasing (substantially lowering the speed ratio), the rotation speed of the primary pulley 32, which is the output side member, gradually increases. Therefore, the planetary gear mechanism 41
In, the rotation speed of the sun gear 42 gradually increases.
Therefore, as shown in the alignment chart of FIG. 5, the line indicating the rotational speed of each rotary element is shown as an inclined line rising to the left, which is higher on the sun gear 42 side. Is further increased than the rotation speed in the CVT mode described above.

As described above, in the split mode, the input / output relationship with the continuously variable transmission 31 is reversed, and the speed is increased by the planetary gear mechanism 41, thereby further reducing the speed ratio and increasing the speed. it can.
In this case, the sun gear 4 is provided for the carrier 44 as an output member and the output gear 51 integrated therewith.
The torque is transmitted from the gear 2 and the ring gear 43, and the torques are combined and output. Transmission of torque to the ring gear 43 is performed via a chain transmission mechanism and a pair of gears 49 and 50, whereas transmission of torque to the sun gear 42 is performed via the continuously variable transmission 31. Since a part of the output torque is transmitted without passing through the continuously variable transmission 31, the torque transmission efficiency of the entire transmission is improved.

Here, the reverse mode for setting the reverse speed will be described. In the reverse mode, as shown in FIG. 4, the first and fourth clutches Cd1, Cd2, the second clutch Ch1, and the reverse clutch Rev are engaged. Is set. Accordingly, the torque of the input shaft 35 is transmitted to the reverse drive sprocket 55 via the first and third clutches Cd1 and Ch2, and is transmitted to the reverse clutch Rev via the chain 56 and the reverse driven sprocket 57. Is transmitted to the planetary gear mechanism 41 via the ring gear shaft 48.

The planetary gear mechanism 41 includes a fourth clutch C
Since d2 is engaged and the whole is integrated, the torque of the ring gear shaft 48 is transmitted as it is to the output gear 51 via the carrier 44, from which the differential gear 52
Is output to In this case, the transmission of torque to the ring gear shaft 48 is performed by the reverse drive sprocket 55, the reverse driven sprocket 57, and the chain 5
6, the rotation direction of the ring gear 43 in the planetary gear mechanism 41 is opposite to the rotation direction in the CVT mode or the split mode described above, and as a result, the reverse gear is set.

As described above, in the transmission shown in FIG. 3 described above, since one of the switching transmission mechanisms includes the planetary gear mechanism 41, the transmission ratio width is wider than the transmission ratio width of the continuously variable transmission 31. In the state where the gear ratio on the high-speed side is set, torque transmission via the continuously variable transmission 31 and torque transmission without this occur, and the torques are combined. Output is performed, the torque transmission efficiency is improved. Therefore, as shown in FIG. 3, it is possible to obtain a transmission that can be put to practical use without disposing a transmission device such as a torque converter having a torque amplifying action on the output side of the engine 39.

FIGS. 6, 7 and 8 show other examples of the same functions as those of the transmission shown in FIG. That is, in the example shown in FIG. 6, the fourth clutch Cd2 that integrates the entire planetary gear mechanism 41 is
It is arranged between the ring gear 43 and the carrier 44, and the other configuration is the same as the configuration shown in FIG. The fourth clutch Cd2 is connected to the carrier 44 and the sun gear 4
2 can also be provided.

In the example shown in FIG. 7, the fourth clutch Cd2
Is replaced with a one-way clutch instead of a non-directional clutch such as a multi-plate clutch or a dog clutch, and the other configuration is the same as the configuration shown in FIG. 3 or FIG. The one-way clutch Cd2 shown in FIG. 7 is set to be engaged in a state where torque is transmitted from the engine 39 to the output gear 51. 6 and 7 can operate in the same manner as the transmission shown in FIG. 3 described above.

The example shown in FIG. 8 is obtained by changing the arrangement of the components of the apparatus shown in FIG. That is, the reverse drive sprocket 55 is attached to the input shaft 35, and therefore, a chain transmission mechanism including the reverse drive sprocket 55 is disposed between the input shaft 35 and the second clutch Ch1, and the planetary gear mechanism 41 Are disposed on the pair of gears 46 and 47 sides. Accordingly, the differential gear 52 is disposed on the opposite side of the continuously variable transmission 31 from the engine 39.

In the example shown in FIG. 8, a chain transmission mechanism for setting the reverse gear is provided from the input shaft 35 to the ring gear shaft 4.
8, the fourth clutch Cd2 and the reverse clutch Rev may be engaged in the reverse mode in which the reverse gear is set. Other configurations and functions are the same as those in the above-described examples.

In the specific example described above, the configuration using the planetary gear mechanism 41 is such that the output member is incorporated in the second switching transmission mechanism that is connected to the continuously variable transmission 31 by switching. The present invention is not limited to this, and a planetary gear mechanism may be incorporated in the first switching transmission mechanism that switches and transmits the input member to the continuously variable transmission 31. The planetary gear mechanism is not limited to a single pinion type, but may be a double pinion type. When a double pinion type planetary gear mechanism is used, the connection relationship between the rotary element and another rotary member is changed based on a normal design method. Further, the continuously variable transmission used in the present invention is not limited to a belt type, but may be a toroidal type (traction type).

[0058]

As described above, according to the first aspect of the invention, the input member and the input element of the continuously variable transmission are connected by the first switching transmission mechanism, and the second switching transmission mechanism is connected by the second switching transmission mechanism. A so-called forward transmission state in which an output element and an output member of a continuously variable transmission are connected; an input member and the output element connected by a first switching transmission mechanism; and the input element is connected by a second switching transmission mechanism. And a so-called reverse transmission state in which the output member is connected, so that the reciprocal of the gear ratio in the forward transmission state in the continuously variable transmission is represented by:
The gear ratio can be set in the reverse transmission state. Therefore, in a belt-type continuously variable transmission, the distance between the input element and the output element is reduced by making one of the pulley serving as the input element and the pulley serving as the output element smaller in diameter than the other. Also, since the gear ratio in the forward transmission state and the gear ratio in the reverse transmission state can be set, the apparatus can be made compact without reducing the gear ratio width. If any of the first and second switching transmission mechanisms has a speed ratio other than “1”, a combination of the speed ratio of the speed change mechanism and the speed ratio of the continuously variable transmission is used. Since the overall speed ratio of the transmission is determined, the overall speed ratio of the transmission can be diversified, that is, the speed ratio width can be increased.

According to the second aspect of the present invention, in addition to the effects obtained by the first aspect of the present invention, the continuously variable transmission and the planetary gear mechanism are arranged in parallel between the input member and the output member. As a result, the torque can be transmitted through both of them, and as a result, the torque transmission efficiency 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 table collectively showing modes set in the transmission shown in FIG.

FIG. 3 is a skeleton diagram showing another transmission according to the present invention.

FIG. 4 is a table collectively showing each mode set in the transmission shown in FIG. 3 and an operation state of each clutch.

5 is an alignment chart showing an operation state of a planetary gear mechanism in each mode set by the transmission shown in FIG. 3;

FIG. 6 is a skeleton diagram showing still another transmission according to the present invention.

FIG. 7 is a skeleton diagram showing still another transmission according to the present invention.

FIG. 8 is a skeleton diagram showing still another transmission according to the present invention.

[Explanation of symbols]

1,31: continuously variable transmission, 2,32: primary pulley, 3,33: secondary pulley, 4,34
... Belt, 5,35 ... Input shaft, 6,11,36 ... Drive sprocket, 7,12,37 ... Driven sprocket, 8,13,38 ... Chain, 14 ... Output shaft, 41 ... Planetary gear mechanism, 42 ... Sun gear , 43
... Ring gear, 44 ... Carrier, 46,50 ... Driven gear, 47,49 ... Drive gear, 51 ... Output gear.

Claims (2)

[Claims] A continuously variable transmission capable of continuously changing the ratio of the number of revolutions of an input element to an output element; an input member for inputting torque to the continuously variable transmission; A transmission including an output member to which torque is transmitted from a transmission, a first switching transmission mechanism that selectively connects the input member to the input element and the output element, and a transmission mechanism that connects the output member to the input element. And a second switching transmission mechanism selectively connected to the output element and the output element. 2. One of the first switching transmission mechanism and the second switching transmission mechanism includes a planetary gear mechanism including a sun gear, a ring gear, and a carrier as rotating elements, and the sun gear includes the input element and the sun gear. One of the ring gear and the carrier is connected to the other of the input element and the output element, and the other one of the ring gear and the carrier is connected to the output member. The transmission according to claim 1, wherein the transmission is configured to be connected.