JPH01283459A - Belt type continuously variable automatic transmission for vehicle - Google Patents

Abstract

PURPOSE:To avoid making the outside dimensions of a device too large by providing a multi-disc type brake along the external surface of the ring gear of a planetary gear device. CONSTITUTION:A V-type endless belt 51 is extended between two variable pulleys 31 and 41 and the radial position thereof in contact with the pulleys 31 and 41 is changed, thereby varying a rotational speed ratio continuously. A reverse and forward selector device 110 is constituted with a multi-disc clutch 11, a multi-disc brake 19 and a planetary gear device 18, and the multi-disc brake 19 is positioned along the external surface of the ring gear 15 of the planetary gear device 18. According to the aforesaid construction, the size of the device in the title can be curtailed by the overlapped amount of the multi-disc brake 19 and the ring gear 15.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is directed to an endless belt having a V-shaped or trapezoidal cross section, which is stretched between two variable pulleys, and which has a radius at which the endless belt contacts each variable pulley. A belt-type continuously variable automatic transmission that continuously changes the rotational speed ratio between the shafts of two variable pulleys by changing the directional position, especially a belt type for vehicles that is applied to automatic transmissions for vehicles. It relates to a continuously variable automatic transmission.

(Prior art) Conventionally, belt-type continuously variable transmissions require a gear mechanism for reversing in order to be used in vehicles, and there is a limit to the diameter of the variable pulley, making it difficult to set a large reduction ratio. Therefore, the reduction ratio between the output shaft and the wheel drive shaft needs to be larger than that of a gear transmission. However, the structure is simpler and smaller than a gear transmission, so it can be It is suitable for integrally incorporating a differential device and a differential device.

This conventional belt-type continuously variable automatic transmission for vehicles has a structure in which an endless belt connects a primary pulley supported on the human power shaft side and a secondary pulley supported on the output side. The primary pulley and secondary boolean each include a fixed flange and a movable flange that moves relative to the fixed flange.

In addition, a forward/reverse switching device is formed by a multi-disc clutch, a planetary gear device, and a multi-disc brake, and the core reverse switching device is connected to the input shaft side or output shaft side of the variable pulley consisting of the primary pulley and secondary pulley. It is arranged to switch the vehicle forward or backward.

By the way, the multi-plate brake of the forward/reverse switching device has a large number of fixed side thin plates fixed to a housing, and a large number of rotating side thin plates fixed to, for example, a ring gear and rotated relative to the fixed side thin plates. The rotating side thin plate can be brought into contact with and separated from the stationary side thin plate by the operation of a hydraulic cylinder, and can be engaged with and disengaged from the stationary side thin plate.

The ring gear has a cylindrical protrusion protruding from a hub portion or the like, and the rotation side thin plate of the multi-disc brake is fixed to the protrusion.

(Problem to be Solved by the Invention) However, in the above-mentioned conventional belt-type continuously variable automatic transmission for vehicles, the thin plate on the rotating side of the multi-disc brake has a cylindrical convex portion that protrudes from the hub portion, etc. Since the rotating side thin plate of the multi-disc brake is fixed to this portion, the axial dimension of the vehicle belt-type continuously variable automatic transmission increases by the size of this overhanging portion.

Furthermore, since the power transmission system becomes longer due to the overhanging portion, the strength of the belt-type continuously variable automatic transmission for a vehicle decreases.

The present invention eliminates the problems of the conventional belt-type continuously variable automatic transmission for vehicles, and prevents the structure for incorporating the multi-plate brake that constitutes the forward/reverse switching device from increasing the overall size of the device. It is an object of the present invention to provide a belt-type continuously variable automatic transmission for a vehicle that is compact, has high strength, and is reliable.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides an endless bell (51) with a figure-7 or trapezoidal cross section between the two variable pulleys (31) and (41). Hand over, the endless bell) (5
By changing the radial position where 1) contacts each of the variable pulleys (31) and (41), the rotational speed ratio between the axes of the two variable pulleys (31) and (41) can be adjusted steplessly. In a belt-type continuously variable automatic transmission for a vehicle, which is equipped with a forward/reverse switching device (110) that switches the vehicle between forward and reverse movement by engaging a multi-disc clutch (11) or a multi-disc brake (19). The forward/reverse switching device (110) is configured to include a multi-disc clutch (11), a multi-disc brake (19), and a planetary gear device (18).

And the ring gear (1 day) of the planetary gear device (1 day)
The multi-plate brake (19) is disposed on the outer periphery of the ring gear (15), and the flange of the ring gear (15) is disposed on the output side of the forward/reverse switching device (110).

Further, the multi-plate clutch (19) is disposed close to the input side of the forward/reverse switching device (110), and is directly connected to the input side and the output side.

(Operation and Effect of the Invention) According to the present invention, the forward/reverse switching device (110
), a multi-disc clutch (11), and a multi-disc brake (1
9) and a planetary gear device (18), and the multi-plate brake (19) is disposed on the outer periphery of the ring gear (15) of the planetary gear device (18). Plate brake (19) and ring gear (15)
) can be shortened by the amount that they overlap, and the belt-type continuously variable automatic transmission for vehicles can be made more compact. Furthermore, since the length of the power transmission system can be shortened, the strength of the device is increased and reliability is improved.

In the above description, each element is given a reference numeral for convenience of explanation, but these do not limit the configuration of the present invention.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

Fig. 1 is a schematic diagram of a belt-type continuously variable automatic transmission for a vehicle, Fig. 2 is a schematic diagram showing the rotational connection state between the primary pulley, secondary pulley, and differential gear housing, and Fig. 3 is a schematic diagram of the belt-type continuously variable automatic transmission of the present invention. FIG. 1 is a sectional view of a belt-type continuously variable automatic transmission for a vehicle.

In the figure, a torque converter l includes a pump impeller 2 connected to the output shaft of a prime mover A such as an internal combustion engine, a turbine runner 3 connected to an input shaft 7 to be described later, and a stator 4 supported in a housing 100 by a one-way clutch. configured. Further, the piston 5 is slidable relative to the turbine runner 3 or the input shaft 7, or the input shaft 7
The turbine runner 3 is fixed to the turbine runner 3, which is slidable.

A friction plate 6 provided on the piston 5 faces the casing of the torque converter 1 fixed to the pump fin propeller 2, and the casing and the piston 5 constitute a direct clutch.

The input shaft 7 of the transmission is rotatably supported by a housing 100, one end of which is connected to the turbine runner 3, and the other end rotatably supports an intermediate shaft 8 arranged on the same axis. There is. One end of the intermediate shaft 8 is supported by the input shaft 7 as described above, and the other end is supported by the housing 10.
It is supported by 0.

A clutch drum 9 is concentrically fixed to the end of the input shaft 7, and a clutch hub 10 is concentrically connected to the end of the intermediate shaft 8 on the manpower shaft side by spline engagement. Then, the clutch drum 9 and the clutch hub 1
A multi-disc clutch 11 is disposed between the cylindrical members o, and the multi-disc clutch 11 is actuated by a piston 12 slidably provided on the clutch drum 9 to engage and disengage the input shaft 7 and the intermediate shaft 8. be done. Note that 13 is a cylinder that operates the piston 12.

Incidentally, the intermediate shaft 8 includes a sun gear 14 spline-engaged with the shaft 8, a ring gear 15 rotatable concentrically with the shaft 8, a planetary pinion 16 meshing with the sun gear 14, and the ring gear 15. The planetary pinions 16' that mesh with each other, and the planetary pinions 1
A planetary gear device 18 is provided, which includes a planetary carrier 17 that rotatably supports the gears 6 and 16' in mesh with each other.

The outer periphery of the planetary carrier 17 of the planetary gear device 18 is splined to the clutch drum 9, and the outer periphery of the ring gear 15 and the housing 100 form a cylinder 20.

A piston 21 is slidably housed in the cylinder 20, and the multi-disc brake 19 is actuated to engage and disengage the ring gear 15 from the housing 100.

In the above configuration, when the multi-disc clutch 11 is engaged, the rotation of the input shaft 7 is transmitted to the intermediate shaft 8 and the vehicle moves forward. On the other hand, when the multi-disc clutch 11 is released and the multi-disc brake 19 is engaged, the ring gear 15
is locked to the housing 100, and the rotation of the input shaft 7 is reversed and transmitted to the intermediate shaft 8.

In this way, the multi-disc clutch 11, the planetary gear device 18, and the multi-disc brake 19 arranged from the input shaft 7 side to the intermediate shaft 8 side create a forward/reverse device between the input shaft 7 and the intermediate shaft 8, i.e. A forward/reverse switching device 110 is configured.

In the forward/reverse switching device 110, the rotation of the input shaft 7 is directly transmitted to the output shaft 8 simply by engaging the multi-plate clutch 11 during forward movement, and meshing between the gears of the planetary gear device 18 is not required. Therefore, it is possible not only to reduce noise caused by meshing but also to improve the durability of the planetary gear device 18.

The forward/reverse switching device 110 also includes a planetary pinion 16 between the sun gear 14 and the ring gear 15 as described above.
．． Since the double binion type planetary gear device 18 having the gear 16' is used, the output does not change between forward movement and reverse movement.

Further, the multi-disc brake 19 is disposed radially outward of the planetary gear device 18, and the rotating side thin plate of the multi-disc brake 19 is fixed to the outer periphery of the ring gear 15 of the planetary gear device I8. , forward/reverse switching device 1
10 can be rubbed compactly.

Next, a primary pulley 31 is disposed on the intermediate shaft 8 adjacent to the forward/reverse switching device, and forms a variable pulley together with a secondary pulley 41, which will be described later.

The primary pulley 31 includes a fixed flange 32 concentrically integrated with the intermediate shaft 8, and a movable flange 33 concentrically arranged with respect to the intermediate shaft 8 and sliding in the axial direction. It consists of

A cylindrical disk 35 is integrally formed on the movable flange 33 and arranged concentrically with a circumferential ring 37 of a cylinder 36 fixed to the intermediate shaft 8 . A first piston 38 whose inner periphery is fixed to the intermediate shaft 8 and whose outer periphery is fitted to the inner periphery of the cylindrical disk 35 is fitted between the first piston 38 and the peripheral wall 37 of the cylinder 3G. A double piston type fluid pressure servo 40 is constituted by the combined second piston 39.

Here, a wall 111 is provided between the forward/reverse switching device 110 and the primary pulley 31 to separate them.
The intermediate shaft 8 passes through a through hole 117 provided at the center of the wall 111. A recess 112 that opens toward the forward/reverse switching device 110 is formed in the wall III, and at least a part of the elements constituting the core reverse switching device 110, such as the piston 21, is disposed within the recess 112. It is accommodated.

Further, a hair ring 113 is provided in the wall 111 on the axial center side of the through hole 117 .

Therefore, the forward/reverse switching device 1 accommodated in the recess 112
Since at least a portion of the bearing 10 is disposed in a position overlapping the bearing 113 in the axial direction, the axial dimension of the device can be reduced by the overlapping length.

By the way, the primary pulley 31 is directly supported by the housing 100 by a hair ring 113 at one end and by a bearing 114 at the other end. Moreover,
Each hair ring 113 , 114 is placed close to the fixed flange 31 and the movable flange 33 .

On the other hand, an output shaft 25 is provided parallel to the intermediate shaft 8 in order to take out the output after changing the rotational speed ratio via the variable boom. The output shaft 25 is directly supported on the housing 100 by hair rings 115 and 116, similar to the intermediate shaft 8, and bearings 115 and 116 are connected to the fixed flange 42 and the movable flange 4.
It is placed close to 3.

In this way, both the intermediate shaft 8 and the output shaft 25 are firmly supported by the housing 100, so that the rigidity against the stress applied to both shafts 8 and 25 due to the tension of the endless bell 51, which will be described later, is increased. Can keep both shafts 8, 2 at all times
5 can be kept parallel.

The output shaft 25 also includes the primary pulley 3.
Secondary pulley 41 which together with 1 constitutes a variable pulley
A fixed flange 42 is formed integrally with the output shaft 2.
A movable flange 43 disposed concentrically with respect to the output shaft 25 can slide on the output shaft 25 in the axial direction.

Further, a cylindrical disc 45 integrally formed with the movable flange 43
are arranged concentrically with the circumferential ring 47 of the cylinder 46 fixed to the output shaft 25. Then, a first shaft whose inner circumference is fixed to the output shaft 25 and whose outer circumference is fitted to the inner circumference of the cylindrical disk 45 is provided.
a second piston 4 fitted between the first piston 48 and the circumferential member 47 of the cylinder 46;
9 constitute a double piston type fluid pressure servo 50.

A helical spring 44 is provided within the cylinder 46, and provides an elastic force that constantly presses the movable flange 43 toward the fixed flange 42.

51 is the primary pulley 31 and the secondary boot 1
This is an endless belt that is stretched over the opposing conical inclined surfaces of each flange of J41. The endless bell) 51 has a large number of metal blocks 54 arranged in the thickness direction, each having a plurality of slits 53 and 53 formed in the inclined surfaces 52 and 52 that are engaged with the conical inclined surface. ,53
(See, for example, Japanese Patent Laid-Open No. 54-52253). The primary pulley 31. The secondary pulley 41 and the endless belt 51 constitute a belt type continuously variable transmission.

By the way, a differential gear housing 28 houses a differential gear device including a wheel drive shaft 27.27' for transmitting power to the left and right wheels, and a bevel gear fixed to the wheel drive shaft 27.27'.
However, the wheel drive shafts 27 and 27' are rotatably supported by the housing 100 so as to be parallel to the output shaft 25. A sprocket wheel 26 is provided on the output shaft 25, and a chain 61 is stretched between the sprocket wheel 26 and a sprocket wheel 29 provided on the outer periphery of the differential gear housing 28. , the rotation of the output shaft 25 is transmitted to the wheel drive shaft 27.27'.

The sprocket wheel 26 of the output shaft 25 may be fixed directly to the output shaft 25, but in the illustrated embodiment, it rotates concentrically with the output shaft 25.

That is, a reduction gear is provided by a sun gear 55 fixed to the output shaft 25, a planetary carrier 58 which rotatably supports a ring gear 57 and a planetary binion 56 which mesh with the cough sun gear 55 and which are fixed to the housing 100 at a position concentric with the sun gear 55. A device 118 is configured. The planetary carrier 58 is connected to the sprocket wheel 26 to decelerate the rotation of the output shaft 25 and transmit it to the sprocket wheel 26.

On the other hand, in order to lock the power transmission system when parking the vehicle, the fixed flange 42 of the secondary pulley 41
An engagement claw 120 for parking is provided on the outer peripheral edge of the vehicle. Since the engaging claw 120 is disposed in front of the reduction gear device 118 in the power transmission system, the torque reversely transmitted from the tire to the engaging claw 120 can be reduced. Further, the reduction gear device 118 is arranged behind the forward/reverse switching device 110 in the power transmission system. Therefore, even though the engaging pawl 120 is locked, the torque from the tires causes the forward/reverse switching device 110 to
This eliminates the problem of not being able to park completely due to misalignment of the internal gears.

Note that grooves in the axial direction are formed so as to face each other on the outer wall of the intermediate shaft 8 and the inner wall of the shaft of the movable flange 33 of the primary pulley 31, and a plurality of spheres 62, 62 are formed in the grooves.
...is pinched. Similarly, grooves in the axial direction are formed facing each other on the outer wall of the output shaft 25 and the inner wall of the shaft of the movable flange 43 of the secondary pulley 41, and a plurality of spheres 63, 63, . . .・is pinched. Due to the engagement of these grooves and the spheres 62.63, the movable flange 33.43 is rotated integrally with the shaft 8.25 and is supported by the spheres 62.63, reducing the sliding resistance in the axial direction. It will be done.

Further, a governor valve 101 is provided at one end of the output shaft 25, and is adjusted so that a factor proportional to the running speed of the output shaft 25, that is, the wheels, is added to the fluid pressure generated by the oil pump 102.

In the vehicle belt-type continuously variable automatic transmission configured as described above, when the manual valve (not shown) is operated to the forward position, the line pressure adjusted by the throttle valve (not shown) and the governor valve 101 is adjusted. is introduced into the cylinder ] 3, the multi-disc clutch 11 is engaged, and the input shaft 7 and intermediate shaft 8 are coupled.

At this time, the line pressure is applied to the shaft hole 103 of the intermediate shaft 8.
, the line pressure is introduced into the cylinder chamber of the fluid pressure servo 4o through the oil hole 104 and the oil hole 105 drilled in the shaft cylinder portion of the movable flange 33, while the line pressure is introduced into the shaft hole 106 of the output shaft 25, the oil hole 107, and When the movable flange 43 is introduced into the cylinder chamber of the fluid pressure servo 50 through the oil hole 108 formed in the axial cylinder portion, the movable flanges 33.43 of the primary pulley 31 and the secondary pulley 41 are connected to the fixed flange 33. 43 is pressed toward the fixed flange 32.42, its conical inclined surface pinches the inclined surface 52 of the endless belt 51, and the rotation of the intermediate shaft 80 is transmitted to the output shaft 25 via the endless belt 51. .

When the pressure of the working fluid acting on the fluid pressure servo 40 of the primary pulley 31 is to be made higher than the pressure of the working fluid acting on the fluid pressure servo 50 of the secondary pulley 41, the primary boo IJ31 is engaged. As the effective driving radius of the endless belt 51 gradually increases, the effective driving radius of the endless belt 51 that engages with the secondary pulley 41 gradually decreases, and the belt type transmission increases the speed of the output shaft 25 steplessly. It turns out.

The rotation of the output shaft 25 is transmitted to the sprocket wheel 26 at a predetermined reduction ratio by a reduction gear device composed of a sun gear 55, a planetary pinion 56, a plastic carrier 58, and a ring gear 57, and is further transmitted to the sprocket wheel 26 at a predetermined reduction ratio.
1. It is transmitted to the left and right wheel drive shafts 27 and 27' via the sprocket wheel 29 and the differential gear housing 28.

Here, when the manual valve is operated to the reverse position, line pressure is sent to the cylinder 20 and the piston 21
activates the multi-plate brake 19. As a result, the ring gear 15 is locked to the housing 100, and the intermediate shaft 8 is
The input shaft 7 is reversely rotated at a predetermined reduction ratio through the planetary gear device.

Then, the same line pressure as above acts on the primary pulley 31 and the fluid pressure servo 40.50 of the secondary boot 1, and the wheel drive shaft 27.27' is rotationally driven in the reverse direction.

Next, when the manual valve is operated to the neutral position, the cylinder 13.20 and the line brake of the fluid pressure servo 40 are drained, so the elastic force of the helical spring 44 in the fluid pressure servo 50 of the secondary pulley 41 is The movable flange 43 is pressed close to the fixed flange 41. At this time, the locking position of the endless belt 51 that engages with the secondary boob 1741 is pushed out in the radial direction, so that the output shaft 2 with respect to the intermediate shaft 8 while the vehicle is stopped is
The deceleration rate of 5 is the largest.

In the vehicle belt-type continuously variable automatic transmission having the above configuration, as shown in FIG.
7.27' are made parallel, and the drive is transmitted between both wheels by the chain 61, so compared to the case where the drive is transmitted by gears, the deceleration rate between the output shaft 25 and the wheel drive shaft 27, 27' can be set arbitrarily. You can choose.

Further, the power transmission path can be made short and lightweight, and the working fluid can be supplied to the fluid pressure servo 50 of the output shaft 25 from the end of the output shaft 25. , the degree of freedom in arranging the wheel drive shaft 27 is increased.

Note that the present invention is not limited to the above embodiments,
Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

For example, in the present invention, any fluid coupling such as a full can coupling can be used in addition to the illustrated torque converter.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the belt-type continuously variable automatic transmission for vehicles of the present invention, FIG. 2 is a schematic diagram of the power transmission system, and FIG. 3 is a sectional view of the belt-type continuously variable automatic transmission for vehicles of the present invention. It is. A... Prime mover, 1... Torque converter, 7...
Input shaft, 8... intermediate shaft, 11... multi-plate clutch,
14...Sun gear, 15...Ring gear, 16...
・Planetary pinion, 18... Planetary gear device, 19... Multi-plate brake, 25... Output shaft, 26
．． 29...Sprocket wheel, 27°27'...
・Wheel drive shaft, 28...Differential gear housing, 31...Primary pulley, 32.42...Fixed flange, 33
．． 43... Movable flange, 40.50... Fluid pressure servo, 41... Secondary pulley, 44... Spring, 51... Endless belt, 61... Chain,
110... Forward/forward switching device, 111... Wall, 1.1
2... recess, 113-116... bearing, 11
7...Through hole. Patent applicant: Aisin AW Co., Ltd. Agent: Patent attorney: Makoto Kawai (1 other person)

Claims (4)

[Claims] (1) By extending an endless belt with a V-shaped or trapezoidal cross section between two variable pulleys and changing the radial position where the endless belt contacts each variable pulley,
For vehicles equipped with a forward/reverse switching device that continuously changes the rotational speed ratio between the shafts of two variable pulleys and engages a multi-disc clutch or multi-disc brake to switch the vehicle between forward and reverse motion. In the belt-type continuously variable automatic transmission, the forward/reverse switching device includes a multi-disc clutch, a multi-disc brake, and a planetary gear device, and the multi-disc brake is disposed on the outer periphery of a ring gear of the planetary gear device. A belt-type continuously variable automatic transmission for vehicles, which is characterized by the following: (2) The belt-type stepless automatic vehicle according to claim 1, wherein the multi-disc clutch is directly connected to the input side and output side of the forward/reverse switching device without intervening a planetary gear device. gearbox. (3) The belt-type continuously variable automatic transmission for a vehicle according to claim 1 or 2, wherein the multi-plate clutch is disposed on the input side of the forward/reverse switching device. (4) The belt-type continuously variable automatic transmission for a vehicle according to claim 1, wherein the flange of the ring gear is disposed on the output side of the forward/reverse switching device.