JPS6357958A - Stepless speed changer with belt - Google Patents

Abstract

PURPOSE:To enhance the reliability and durability of a backward motion clutch by suppressing high-speed relative rotation of the backward motion clutch. CONSTITUTION:In advancing, an advance clutch 36 is in connection while a backward motion clutch 52 is disengaged, and the torque on input shaft 26 is transmitted to the output shaft 30 through a belt 34. Here an idler gear 58 of a reverse gear train 48 is held in disengaged position where no meshing is made with the first stage gear 50. Consequently the torque of output shaft 30 is not transmitted to the receipt plate 52b of the backward motion clutch 52. Accordingly in this clutch 52, a driving plate 52a in connection with the input shaft 26 is solely rotated, which should suppress the relative revolving speed between the driving 52a and receipt 52b plates. This will enhance the reliability and durability of backward motion clutch 52.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a belt-type continuously variable transmission that can be used as an automobile transmission, and particularly to a continuously variable transmission that can be switched between forward and reverse modes.

(Prior art) For example, as shown in Japanese Unexamined Patent Publication No. 51-33422, a continuously variable transmission is used for automobiles, in which a driving pulley and a driven pulley with a variable effective pitch diameter are connected by a belt. Attempts are being made to use it as a machine. In that case,
A gear device is required to enable switching of the output rotation direction, that is, switching between forward and backward movement.

However, in conventional belt-type continuously variable transmissions of this type, as shown in the above-mentioned publication, the gear device for forward/reverse switching (the primary reduction gear in the above-mentioned publication) is connected to the drive from the prime mover. It is interposed between the clutch that connects and disconnects the driving force and the drive pulley of the continuously variable transmission, and the direction of manual rotation of the continuously variable transmission is reversed by switching the gear device. However, such a configuration may cause the following problems.

That is, when this belt-type continuously variable transmission device is used in an automobile transmission, it is configured to automatically change gears in a direction in which the speed increases as the vehicle speed increases. Therefore, if such a gear shift is performed when the car is reversing,
The vehicle speed increases against the driver's will, which poses an unfavorable safety problem. For this problem,
This problem can be solved by fixing the reduction ratio of the continuously variable transmission when reversing, but in that case, the speed change control device becomes complicated.

In order to solve the above problems, for example, as shown in Japanese Patent Application Laid-Open No. 60-205059, a drive side pulley with a variable effective pitch diameter and a driven side pulley are connected by a belt. In a transmission using a continuously variable transmission, especially a transmission that can switch between forward and backward movement, power is transmitted through the continuously variable transmission only when moving forward, and when reversing, the power from the prime mover is transferred to the reverse gear. It is proposed to configure the output via columns.

In this case, a forward clutch is placed in front of the stand of the drive pulley on the input shaft, and a reverse clutch is placed in the reverse gear train, so that when the car is moving forward, the forward clutch is connected and the reverse clutch is disengaged. , the driving force of the input shaft is transmitted to the output shaft via the belt, and when the vehicle is moving backward, the forward clutch is disengaged and the reverse clutch is connected, and the driving force of the input shaft is transmitted through the belt. without intervening,
It is conceivable to configure the signal to be transmitted to the output shaft via a reverse gear train.

(Problems to be Solved by the Invention) However, in such a configuration, one gear of the reverse gear train and the reverse clutch device rotate relative to each other at a high rotational speed during forward movement. For this reason, the configuration of the reverse clutch has problems such as poor reliability and durability.

In addition, in the continuously variable transmission disclosed in the above-mentioned patent publication, Hara! The first power transmission path connects the power from IIIm to the human power shaft provided with the drive pulley of the continuously variable transmission from the latch output shaft, and also connects the clutch output shaft to the reverse gear train and the second intermediate shaft. A switching device is provided to selectively connect the second transmission path to the second output gear, and two idle gears are required in the reverse gear train, making the overall structure somewhat complex and large. There's a problem.

This invention was made in view of the above-mentioned problems, and an object of the invention is to improve the reliability and durability of the reverse clutch by suppressing high-speed relative rotation in the reverse clutch, and to simplify the configuration. It is an object of the present invention to provide a belt type continuously variable transmission which can be made smaller by making it more compact.

(Means for Solving the Problems) In order to solve the above-mentioned problems and achieve the purpose, a belt-type continuously variable transmission according to the present invention includes an input shaft that is rotationally driven by a prime mover and a speed reduction mechanism that is connected to the input shaft. The output shaft is wound around the drive pulley and the driven pulley, and the rotation of the input shaft is connected to the output shaft. an endless belt that transmits power to the engine, and a forward clutch that is installed on the human power shaft and that connects and intermits rotation from the prime mover to the drive pulley.
Reverse means is provided between the input shaft and the speed reduction mechanism, and rotates the speed reduction mechanism in a direction opposite to the rotational direction of the output shaft rotated via the belt, bypassing the rotation transmission by the belt. , this reversing means includes a reverse gear train that reverses the rotational direction of the rotational force of the input shaft and transmits it to the reduction mechanism, and a reverse gear train that is arranged on the input shaft closer to the prime mover than the forward clutch. It is characterized by comprising a reverse clutch that connects and disconnects rotation to the first gear in the reverse gear train, and engagement and disengagement means that engages and disengages at least one gear in the reverse gear train with other gears. It is said that

(Function) In the belt type continuously variable transmission configured as above,
During forward movement, the forward clutch is connected, the reverse clutch is disconnected, and the rotational force of the input shaft is transmitted to the output shaft via the belt. Here, since at least one gear of the reverse gear train is disengaged from the other gears by the engagement/disengagement means, the rotational force of the output shaft is not transmitted to the passive plate of the reverse clutch. Therefore, in the reverse clutch, only the drive plate connected to the human power shaft rotates, and the relative rotational speed between the drive plate and the passive plate is kept low. Further, since both the forward clutch and the reverse clutch are arranged in line with the input shaft, the overall configuration is simplified.

(Embodiment) An embodiment of the belt type continuously variable transmission according to the present invention will be described in detail below with reference to the accompanying drawings.

As shown in the first section, the belt type continuously variable transmission 10 has a motor 12 attached to the shaft end of its output shaft 14.
For example, power is inputted through a clutch 16, which is a fluid coupling, and drives the differential gear 18 with continuously variable speed. and reverse gear device 24
These are arranged inside the case 10a.

This continuously variable transmission 20 has an output of the clutch 16 @16a
A human power @ 26 coaxially arranged on the human power shaft 26 , a drive pulley 28 coaxially provided on this human power shaft 26 , and a human power shaft 26
an output shaft 30 arranged parallel to the output shaft 30, a driven pulley 32 provided coaxially with the output shaft 30, and
, 32 and an endless belt 34 extending therebetween. Both of the driving and driven pulleys 28 and 32 are variable effective pitch diameter pulleys.

That is, the driving pulley 28 includes a fixed disk 28a that is integrally formed or fixed to the input shaft 26, and this disk 2.
8a and a movable disk 28b that is slidable in the axial direction. Both disks 28a, 28
The belt 34 is held between the mutually opposing conical surfaces of b. Similarly, the driven pulley 32 also has a fixed disk 3 that is integrally formed or fixed to the output shaft 30.
2a, and a movable disk 32b that is slidable in the axial direction with respect to the disk 32a.

A belt 34 is held between the mutually opposing conical surfaces of both disks 32a and 32b.

And the movable disk 28 in both pulleys 28, 32
Hydraulic chambers 28c and 32c are provided at the backs of a and 32a, respectively.
is provided. Movable disk 2 of drive pulley 28
8b approaches and separates from the fixed disk 28a by the hydraulic pressure introduced into the hydraulic chamber 28c, the clamping position (effective pitch diameter) of the belt 34 changes, and as a result, the driving pulley 28 and the driven pulley 32 The transmission rotation ratio between the two changes. At this time, also in the driven pulley 32, the movable disc 32b is worked by the hydraulic pressure introduced into the hydraulic chamber 32c and the spring 32d installed in the hydraulic chamber 32c, so that the belt 34 is always kept in the required tension state. It is designed to be retained.

The above-described human power shaft 26 includes a first portion 26a coupled to the output shaft 16a of the clutch 16, and a second portion 26 to which the drive pulley 28 of the continuously variable transmission 20 is fixed.
It is divided into b. The first portion 26a and the second portion 26b are connected to each other by a forward clutch 36. As shown in the figure, this forward clutch 36 is connected to the fixed disc 28 of the drive pulley 28.
The forward clutch 36 has a structure similar to that of a normal wet-type multi-disc clutch except that a part of the forward clutch 36 is used in common, and a detailed explanation of the forward clutch 36 will be omitted.

Incidentally, this forward clutch 36 is used when the automobile is moving forward.
The first portion 26a and the second portion 26b of the drive shaft 26 are connected so that the output of the prime mover 12 is transmitted to the drive pulley 28. On the other hand, when the vehicle is traveling backwards, the first portion 26
a and the second portion 26b are cut off, so that the output of the original WJ machine 12 is not transmitted to the drive pulley 28.

On the other hand, the output shaft 30 on which the driven pulley 32 of the continuously variable transmission device 20 is provided and the differential device 18 are always connected via the output gear device 22 described above. That is, this output gear device 22 has an intermediate shaft 3 disposed parallel to an output shaft 30.
8, and a pair of intermediate gears 40.4 fixedly attached to or integrally formed with the output shaft 30 and the intermediate shaft 38, respectively, and meshed with each other.
2, and an output gear 44 coaxially formed integrally with or fixed to the intermediate shaft 38. This output gear 44
is meshed with a final gear 46 that drives the differential device 18.

A reverse gear device 24 is provided between the first portion 26a of the input shaft 26 and the output shaft 30.
The reverse gear device 24 is arranged between the reverse gear device 48, the first stage gear 50 of the reverse gear train 48, and the first portion 26a of the input shaft 26. , first stage gear 50 and input shaft 26
and a reverse clutch 52 that connects and connects between the two.

This reverse gear train 48 is provided with an idler gear 58 that is slidably provided along the axial direction on a spline shaft 56 that is arranged parallel to the input shaft 26 and can mesh with the first stage gear 50, and an intermediate shaft 38. A final stage gear 60 is provided coaxially and fixedly provided.

The idler gear 58 described above is rotatably attached to a spline bearing 59 that is slidably attached to the spline shaft 56 along the axial direction. A hydraulic cylinder device 64 for sliding the idler gear 58 along the axial direction is connected to the spline bearing 59.

This hydraulic cylinder device 64 includes a cylinder body 66 that is integrally attached to a case ioa, and a cylinder body 66 that is integrally attached to a case ioa.
A piston 68 that slides inside the cylinder body 66, and a piston rod 70 that supports the piston 68 slidably along the axial direction at one end and has the other end taken out outside the cylinder body 66.
an actuator 72 attached to the outwardly projecting end of the piston rod 70 and connected to the spline bearing 59 so as to allow rotation thereof and to lock the slide in the axial direction; and an actuator 72 disposed within the cylinder body 66 and piston 6
8 and a spring 74 that biases the idler gear 58 in a direction in which the idler gear 58 separates from the first gear 50. A space within the cylinder body 66 on the side where the spring 74 is not provided is connected via a boat 76 to a pressure source (not shown).

The above-described spline shaft 56, spline bearing 59, and hydraulic cylinder device 64 constitute an engagement and disengagement mechanism that engages the idler gear 58 with the first-stage gear 50 in a detachable manner. By configuring the engagement and disengagement mechanism in this manner, when no hydraulic pressure is applied within the cylinder body 66, the idler gear 58 is held in the disengaged position where it does not mesh with the first stage gear 50 by the biasing force of the spring 74.

On the other hand, due to the hydraulic pressure acting within the cylinder body 66, the idler gear 58 is slid from the disengaged position against the biasing force of the spring 74, and is brought to the engaged position where it meshes with the first stage gear 50. Note that the hydraulic pressure from the pressure source to the cylinder body 66 is configured to act only when the vehicle is moving backward.

Further, the drive plate 52a of the reverse clutch 52 is connected to the input shaft 2.
The input shaft 26 is attached to the first portion 26a of the input shaft 26 so as to rotate together with the input shaft 26, and is arranged so as to rotate coaxially with the input shaft 26. On the other hand, the passive plate 52b of the reverse clutch 52
is attached to the first stage gear 50 of the reverse gear train 48 so as to rotate integrally therewith.

Such a reverse clutch 52 is configured to disconnect the first gear 50 and the input +i[h26 when the vehicle is moving forward, so that the rotational force of the input shaft 26 is not transmitted to the reverse gear train 48. When going in reverse, first gear 5
0 and the input shaft 26, and the rotational force from the input shaft 26 is transmitted to the output shaft 30 via the reverse gear train 48 with the rotation direction reversed from that during forward movement. .

Note that FIG. 1 shows the belt-type continuously variable transmission 10 in an expanded form for convenience of display on the same plane, and the actual arrangement is as shown in FIG. 2. Therefore, in FIG. 1, the idler gear 58 and the final stage gear 6 are
Although gears 58 and 60 are depicted as not meshing, in reality, both gears 58 and 60 are in mesh.

The operation of the belt type continuously variable transmission 10 configured as above will be described below. First, with reference to FIG. 3, a description will be given of when the automobile moves forward.

First, with the forward clutch 36 connected and the reverse clutch 52 disengaged, the input shaft of the continuously variable transmission 20 is supplied from the first portion 26a of the input shaft 26 via the forward clutch 36. A transmission path leading to a certain second portion 26b is connected.

In this way, the power from the output shaft 14 of the prime mover 12 is transmitted to the clutch 16, the first portion 26a1, and the forward clutch 36.
The signal is then input to the drive pulley 28 of the continuously variable transmission 20 via the second portion 26b. The driven pulley 32 in the continuously variable transmission 20 is driven via the belt 34, and the driven pulley 32 is taken out from the output shaft 30.
Further, the power is manually input from the final gear 46 to the differential gear 18 via a pair of intermediate gears 40 and 42 in the output gear device 22 and the output gear 44.

At this time, if the rotational direction of the output shaft 14 of the prime mover 12 is, for example, direction A (clockwise) as shown in FIG. The pulleys 28 also rotate in the A direction, and the driven pulley 32, the output @30, and one intermediate gear 40 on the output shaft 30 also rotate in the A direction. Further, the other intermediate gear 42 on the intermediate shaft 38 and the output gear 44 each rotate in the B direction (counterclockwise), so that the final gear 46 or the differential gear 18 rotates on the output shaft 1 of the prime mover 12.
It is rotated in the same direction as the rotation direction A of No. 4, that is, in the forward direction.

Further, in this case, since the power passes through the continuously variable transmission 20, the driving pulley 28 in the continuously variable transmission 20
By controlling the effective pitch diameter of the driven pulley 32 variable @IJ, the rotation ratio between both pulleys 28° 32, that is, the differential gear 18 with respect to the rotational speed of the output shaft 14 of the drive m12.
The reduction ratio of the input rotational speed is variably controlled.

Note that when the vehicle moves forward, the hydraulic cylinder device 6
Hydraulic pressure to 4 is not working. Therefore, the piston rod 70 is drawn inward by the biasing force of the spring 74, and the idler gear 58 is held at a disengaged position where it does not mesh with the first stage gear 50. In this way, the rotation of the output shaft 3o is not transmitted to the first stage gear 50, and therefore the passive plate 52b of the reverse clutch 52 connected to the first stage gear 5° is in a state where rotation is stopped. On the other hand, since the drive plate 52a of the reverse clutch 52 is integrally connected to the input shaft 26, it is in a state where it is rotationally driven in accordance with the rotation of the input shaft 26.

In this way, in this embodiment, for the latch 52 for backward movement during forward movement, the relative rotational speed between the driving plate 52a and the passive plate 52b is defined only by the rotational speed of the driving plate 52a. , the rotational speed of the driving plate 52a is never set higher than that of the driving plate 52a.

On the other hand, when the vehicle is traveling backwards, the forward clutch 36 is disconnected and the reverse clutch 52 is disconnected, as shown in FIG.
is connected, and hydraulic pressure acts on the hydraulic cylinder device 64. In this way, the first portion 2 of the input shaft 26
6a and the second portion 26b is cut off, and on the other hand, the first gear 50 of the reverse gear train 48 and the idler gear 58 mesh with each other, so that the first portion 26a of the input shaft 26
is connected to the intermediate shaft 38 via a reverse clutch 52.

Therefore, the power input from the output shaft 14 of the prime mover 12 via the clutch 16 is transferred from the first portion 26a to the final gear via the reverse clutch 52, the first gear 50, the idler gear 58, and the final gear 60. 46.

At this time, as shown in FIG. 4, the output shaft 14 of the prime mover 12
With respect to the rotation of the first stage gear 50 on the first portion 26a in the input direction, the idler gear 58 rotates in the B direction and the final stage gear 60 rotates in the A direction, so that the final gear 46 rotates in the B direction, that is, The output shaft 14 of the prime mover 12 is rotated in a direction opposite to the rotational direction A, resulting in a reverse traveling state.

With the above configuration, by simply switching the forward clutch 36 and the reverse clutch 52, the forward drive system via the continuously variable transmission 20 and the reverse drive system via the reverse gear device 24 can be switched. It becomes easy to do.

Further, according to the above configuration, when the vehicle is traveling backwards, the power taken out from the output shaft 14 of the prime mover 12 is transmitted to the differential device 18 via the reverse gear device 24 without passing through the continuously variable transmission device 20. It will be transmitted. Therefore, the differential 18 for the rotational speed of the output shaft 14 of the prime mover 12
The reduction ratio of the input rotational speed is always constant.

Furthermore, when the automobile is moving forward, the drive plate 52a of the reverse clutch 52 is rotated in accordance with the rotation of the input shaft 26 while the passive plate 52b remains stopped. Therefore, the relative speed between the driving plate 52a and the passive plate 52b is
b is held low compared to the case where it is rotationally driven. Therefore, it is no longer necessary to set the gap between the driving plate 52a and the passive plate 52b extremely accurately in preparation for high rotation, and the work efficiency is improved.

Further, since the forward clutch 36 and the reverse clutch 52 are arranged side by side on the input shaft 26, the configuration of the belt type continuously variable transmission 1o can be simplified.

It goes without saying that this invention is not limited to the configuration of the above-described embodiment, and can be modified in various ways without departing from the gist of the invention.

(Effects of the Invention) As detailed above, the belt type continuously variable transmission according to the present invention has an input shaft rotationally driven by a prime mover, an output shaft connected to a reduction mechanism, a human power shaft and an output shaft. A driving pulley and a driven pulley with variable effective pitch diameters are provided on each side, an endless belt is wound around the driving pulley and the driven pulley and transmits the rotation of the human-powered shaft to the output shaft, and A forward clutch is provided between the human power shaft and the speed reduction mechanism, and the forward clutch is provided to intermittent rotation from the prime mover to the drive pulley, bypassing the rotation transmission by the belt,
Reverse means rotates the speed reduction mechanism in a direction opposite to the rotation direction of the output shaft rotated via the belt, and this reverse means reverses the rotation direction of the rotational force of the input shaft and transmits it to the speed reduction mechanism. a reverse gear train that is arranged on the input shaft closer to the prime mover than the forward clutch, and a reverse clutch that is arranged on the input shaft closer to the prime mover than the forward clutch and that connects and intermits rotation to the output shaft from the first stage gear of the reverse gear train; The present invention is characterized by comprising a means for engaging and disengaging at least one gear with respect to another gear in a freely engageable and disengageable manner. Therefore, according to the present invention, by suppressing high-speed relative rotation in the reverse clutch during forward movement, the reliability and durability of the reverse clutch can be improved, and the device can be downsized by simplifying the configuration. A belt-type continuously variable transmission capable of this will be used.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view showing an embodiment of the belt type continuously variable transmission according to the present invention in an unfolded state, FIG. 2 is a longitudinal sectional side view showing the configuration of a reverse gear train and an output gear device, and FIG. 3 4 is a block diagram schematically showing the connection state of the belt-type continuously variable transmission when the vehicle is moving forward, and FIG. 4 is a block diagram schematically showing the connection state of the belt-type continuously variable transmission when the vehicle is moving backward. It is. In the figure, 10... Belt type continuously variable transmission, 10a... Case, 12... Prime mover, 14... Output shaft, 16...
・Clutch, 18...Differential device, 20...Continuously variable transmission device, 22...Output gear device, 24...Reverse gear device, 26...Input shaft, 28...Drive side pulley ,
30... Output shaft, 32... Driven side pulley, 34...
・Belt, 36...Forward clutch, 38...Intermediate shaft, 40.42...Intermediate gear, 44...Output gear,
46... Final gear, 48... Reverse gear train, 50... First stage gear, 52... Reverse clutch,
56... Spline shaft, 58... Idler gear, 5
9...Spline bearing, 60...Final stage gear, 6
4... Hydraulic cylinder device, 66... Cylinder body,
68... Piston, 70... Piston rod, 72
. . . actuator, 74 . . . spring, 76 . . . boat. Patent Applicant: Mazda Motor Corporation Agent, Patent Attorney: Yasunori Otsuka Figure 2

Claims (4)

[Claims] (1) An input shaft rotationally driven by a prime mover, an output shaft connected to a speed reduction mechanism, a drive-side pulley and a driven-side pulley with variable effective pitch diameters provided on the input shaft and output shaft, respectively, and the drive-side An endless belt that is wrapped around the pulley and the driven pulley and transmits the rotation of the input shaft to the output shaft, a forward clutch that is installed on the input shaft and that connects and disconnects the rotation from the prime mover to the drive pulley, and the input shaft. and a reversing means provided between the deceleration mechanism and the deceleration mechanism, which bypasses the rotational transmission by the belt and rotates the deceleration mechanism in a direction opposite to the rotational direction of the output shaft rotated via the belt. The reverse means includes a reverse gear train that reverses the rotational direction of the rotational force of the input shaft and transmits it to the reduction mechanism, and a reverse gear train that is arranged on the input shaft closer to the prime mover than the forward clutch. The present invention is characterized by comprising a reverse clutch that connects and disconnects rotation to the first gear, and engagement and disengagement means that engages and disengages at least one gear in the reverse gear train with other gears. Belt type continuously variable transmission. (2) The engaging and disengaging means includes a bearing means that supports the at least one gear rotatably and slidably along the rotation axis, and an engagement position that is connected to this gear and meshes with another gear. 2. The belt type continuously variable transmission according to claim 1, further comprising a sliding means for sliding said at least one gear between a disengagement position spaced apart from other gears. (3) The belt type continuously variable transmission according to claim 2, wherein the bearing means includes a spline bearing mechanism, and the slide means includes a hydraulic cylinder. (4) The first stage gear of the reverse gear train is fixed coaxially with a passive plate of the reverse clutch, and the at least one gear is removably engaged with the first stage gear. A belt type continuously variable transmission according to claim 2.