JP2002013602A - Belt-type continuously variable transmission, and vehicle provided therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate starting of an engine after stoppage from the 'Hi' state of a velocity ratio by restricting load to be low in starting the engine E, in a forming vehicle having a belt-type continuously variable transmission V on an, with a belt 50 wound around input and output pulleys 10 and 30 to apply tension for applying opening belt thrust to movable sheaves 12 and 32 and closing operation force to the by converting the belt thrust into pressing force to the sheaves 32 and 12 to be reduced sheaves 12 and 32 by the amount. SOLUTION: A clutch 110 is provided between the output pulley 30 and an output shaft 2, and the clutch 110 is drive-connected to an operation lever 102a of a parking brake mechanism 102.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt-type continuously variable transmission arranged on a torque transmission path in a vehicle such as an agricultural work vehicle, and more particularly, to facilitate starting of a driving device such as an engine under a high load. About measures.

[0002]

2. Description of the Related Art As disclosed in, for example, Japanese Patent Application Laid-Open No. 64-3360, a belt-type continuously variable transmission mounted on a vehicle for agricultural work or the like, capable of shifting with a small operating force. It has been known.

In this apparatus, tension is applied to a power transmission belt wound between input and output pulleys to apply a belt thrust to a movable sheave of each pulley in a direction away from a fixed sheave (hereinafter referred to as an opening direction). The belt thrust applied to the movable sheave on the input side is converted into a pressing force in the direction approaching the fixed sheave to the movable sheave on the output side (hereinafter, referred to as a closing direction), while the belt thrust applied to the movable sheave on the output side is When the speed ratio is changed by applying an operating force in the closing direction to each movable sheave, the operating force is converted into the pressing force of the pressing force. It can be reduced by a minute.

[0004]

By the way, in the above-mentioned belt type continuously variable transmission, in order to automatically change the speed ratio according to the load, the output side movable sheave is operated in the closing direction. Is constantly added to urge the speed ratio toward the low speed ratio side (hereinafter referred to as Lo side) where the pitch diameter of the input pulley is small and the pitch diameter of the output pulley is large, and the input rotation is applied to the movable sheave on the input side. It is conceivable to change the speed ratio to a high speed ratio side (hereinafter referred to as Hi side) in which the pitch diameter of the input pulley is large and the pitch diameter of the output pulley is small by applying an operating force in the closing direction according to the speed. Can be

However, when the engine is stopped by applying a sudden brake while the vehicle is running with the speed ratio being Hi, the speed ratio does not return to Lo and remains at Hi. In the case of the related art, there is a disadvantage that a large load is applied to the engine when starting the engine, which makes it difficult to start the engine.

The present invention has been made in view of the above point, and a main object of the present invention is to apply tension to a transmission belt wound between input and output pulleys and apply a tension to a movable sheave of each pulley in an opening direction. To automate the shifting operation in a belt-type continuously variable transmission that applies a belt thrust and converts the belt thrust into a pressing force in the closing direction on each movable sheave so that the operating force can be reduced by the operating force. In addition, by adding a new mechanism, even if the speed ratio is Hi, the load applied to the drive source such as the engine is reduced so that the engine can be easily started.

[0007]

In order to achieve the above object, the present invention provides a clutch between an output pulley and an output shaft, whereby the engine is started at a high speed ratio. In such a case, the transmission of torque between the output pulley and the output shaft is interrupted by the clutch, so that the engine can be easily started by reducing the load applied to the engine while ensuring the shifting operation.

More specifically, according to the first aspect of the present invention, there are provided a fixed sheave and a movable sheave, an input pulley to which a torque is inputted from a driving side, and a fixed sheave and a movable sheave. An output pulley for outputting torque to the driven side, a transmission belt wound between these pulleys, and a tension mechanism for applying tension to the movable belt to apply a belt thrust to each movable sheave in an opening direction. The belt thrust applied to the movable sheave on the input side is converted into a pressing force in the closing direction for the movable sheave on the output side, while the belt thrust applied to the movable sheave on the output side is converted into a pressing force in the closing direction for the movable sheave on the input side. A conversion mechanism that converts the pressure into a pressing force, and a low-speed ratio mechanism that constantly applies an operating force in the closing direction to the movable sheave on the output side so that the speed ratio between both pulleys is urged toward the low-speed ratio side. Input speed ratio in accordance with the rotational speed is a belt type continuously variable transmission is premised that includes a high-speed ratio mechanism to apply the direction of the operating force close to the movable sheave of the input side so as to be changed to the high-speed ratio side.

The output pulley is provided with a clutch for connecting and disconnecting torque transmission from the output pulley to the driven side.

In the above arrangement, when the input rotation speed is low, for example, immediately after the start of the engine, the high-speed ratio-measuring mechanism stops operating. Only the operating force in the closing direction by the low speed ratio mechanism is applied to the movable sheave. Since the belt thrust in the opening direction on the output side is canceled by this operating force, on the input side, the pressing force in the closing direction converted from the belt thrust on the output side is reduced, and the pressing force on the input side is smaller than the pressing force on the input side. Since the belt thrust is relatively large, the movable sheave moves in the opening direction by the belt thrust. Therefore, the pitch diameter of the input pulley becomes smaller. On the other hand, with the movement of the input side movable sheave in the opening direction, the belt thrust applied to the movable sheave in the opening direction decreases on the output side, so that the movable sheave is closed by conversion from the input side belt thrust. It moves in the closing direction by the combined force of the pressing force in the direction and the operating force. Therefore, the pitch diameter of the output pulley increases, and as a result, the speed ratio between the input pulley and the output pulley is changed to Lo.

[0011] When the input rotation speed increases, the operating force in the closing direction is applied to the movable sheave of the input pulley in response to the increase in the input rotation speed. Since the belt thrust in the opening direction on the input side is canceled by this operation force, the pressing force in the closing direction converted from the belt thrust on the input side is reduced on the output side. Then, when the resultant force of the pressing force and the operating force of the low speed ratio mechanism becomes relatively smaller than the belt thrust on the output side, the movable sheave moves in the opening direction by the belt thrust. Therefore, the pitch diameter of the output pulley becomes smaller. On the other hand, as the output side movable sheave moves in the opening direction, on the input side, the belt thrust in the opening direction applied to the movable sheave decreases, and with this reduction in belt thrust, the movable sheave has a lower speed ratio. The belt moves in the closing direction due to the resultant force of the pressing force converted from the belt thrust reduced by the operating force of the mechanism and the operating force of the high-speed rationing mechanism. Therefore, the pitch diameter of the input pulley increases, and as a result, the speed ratio is changed to the Hi side.

In the above operation, when the operation of the drive source is stopped while the speed ratio is Hi, the speed ratio remains in the Hi state. Therefore, if it is attempted to start the drive source in such a state, a high load is applied to the drive source, which makes it difficult to start the drive source.

At this time, the transmission of torque from the output pulley to the driven side can be cut off by the clutch.
Only a low load up to the output pulley is applied to the drive source, so that the drive source can be easily started even when the speed ratio is Hi.

According to a second aspect of the present invention, as a vehicle equipped with the above-described belt-type continuously variable transmission, an engine as a drive source and a torque transmitted from the engine via the belt-type continuously variable transmission are rotated. When the vehicle includes a plurality of traveling wheels including driven wheels to be driven, and a parking brake mechanism for locking at least a part of the traveling wheels to a rotation stop state when traveling is stopped, a belt type When the parking brake mechanism locks the traveling wheel in a rotation stop state, the clutch of the step transmission device interlocks with the operation of the parking brake mechanism to interrupt the transmission of torque from the output pulley to the driving wheel side, while the parking brake mechanism When the mechanism releases the lock of the rotation stop state, the parking is performed so that torque is transmitted from the output pulley to the drive wheel side in conjunction with the operation of the parking brake mechanism. It assumed to be drivingly connected to rake mechanism.

In the above configuration, when stopping the running of the vehicle and stopping the operation of the engine, generally, at least a part of the running wheels is locked in a rotation stopped state by a parking brake mechanism. At this time, the clutch operates in conjunction with the operation of the parking brake mechanism, and the transmission of torque from the output pulley to the drive wheel side in the belt-type continuously variable transmission is cut off. Then, when the vehicle is driven again, generally, first, the engine is started, and then,
The parking brake mechanism releases the lock of the traveling wheels in the rotation stop state, and then the vehicle starts.

Therefore, between the output pulley of the belt-type continuously variable transmission and the drive wheels, when the lock of the rotation stop state by the parking brake mechanism is released, that is, after the engine is started, torque transmission is not performed. Therefore, even if the speed ratio of the belt-type continuously variable transmission is Hi, the engine is started with a low load.

According to a third aspect of the present invention, the vehicle is a farm work vehicle.

In the above configuration, the agricultural work vehicle includes:
A belt-type continuously variable transmission is provided, and the torque transmission between the output pulley and the drive wheel side of the belt-type continuously variable transmission is disconnected and connected by a clutch that operates in conjunction with the operation of a parking brake mechanism. Therefore, the normal operation of the parking brake mechanism facilitates the start of the engine under a high load. Therefore, if a person is accustomed to the operation of the conventional agricultural work vehicle, even if it is an elderly farm worker, there is no burden on the operation.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows an entire configuration of a farm work vehicle such as a combine according to an embodiment of the present invention.
In this agricultural work vehicle, a belt-type continuously variable transmission V is disposed in a torque transmission path between the engine E and the reduction gear R.

The vehicle is provided with four traveling wheels, of which two traveling wheels on the rear side (lower side in FIG. 1) are driven by driving wheels 100 and 1 connected to a reduction gear R.
00 is set. Each driving wheel 100 has the driving wheel 1
A brake 101 for limiting the rotation of the brake pedal 00 is provided continuously. The brake 101 is operated by a brake mechanism including a brake pedal and a hydraulic circuit (not shown). Also works. Specifically, the parking brake mechanism 102 has an operation lever 102a for the vehicle operator to manually operate.
2a is arranged in the driver's seat of the vehicle. By operating the operation lever 102a, the two drive wheels 100, 100 can be locked in a rotation stopped state, or the lock can be released.

As shown in FIG. 2, the engine E and the reduction gear R have an output shaft 1 of the engine E and an input shaft 2 of the reduction gear R parallel to each other and in the same direction (rightward in FIG. 2).
The belt-type continuously variable transmission V transmits the torque generated by the engine E to the reduction gear R, and outputs the output rotation speed of the engine E and the input to the reduction gear R. The ratio of the applied torque to the rotational speed is continuously changed. That is, for the transmission V, the output shaft 1 of the engine E corresponds to the input shaft (hereinafter, referred to as input shaft 1), and the input shaft 2 of the reduction gear R corresponds to the output shaft (hereinafter, referred to as output shaft 2). I do.

As shown in an enlarged view in FIG. 3, a cylindrical auxiliary shaft 3 having both ends opened is coaxially connected to an end of the input shaft 1 of the transmission V. The auxiliary shaft 3 is rotatably and externally fitted to the input shaft 1 at a portion on the engine E side (the left side in the figure), and an open end thereof is locked to a step portion of the input shaft 1. An input pulley 10 is externally fitted on the shaft 3 so as to rotate integrally.

The input pulley 10 includes a fixed sheave 11 that cannot move in the axial direction, and a movable sheave 12 as a movable member that is disposed on the engine E side of the fixed sheave 11 and that can move in the axial direction. Consists of The fixed sheave 11 is connected to an end of the auxiliary shaft on the side opposite to the engine E by a bolt 4, while the movable sheave 12 has a long cylindrical boss portion 12a extending toward the engine E. That are disposed at both ends in the axial direction of the boss portion 12a.
The auxiliary shaft 3 is supported movably in the axial direction via two slide members 13. And the movable sheave 12
However, the pitch diameter of the pulley 10 is increased by moving in the closing direction (the right direction in FIG. 3), which is a direction approaching the fixed sheave 11, and conversely, the opening direction (the same direction as separating from the fixed sheave 11). The pitch diameter of the pulley 10 is reduced by moving the movable sheave 12 to the left (in the left direction in the figure).

The input pulley 10 is provided such that the inclination angle of the belt contact surface of the fixed sheave 11 with respect to a plane perpendicular to the axis and the inclination angle of the belt contact surface of the movable sheave 12 are different from each other. Eccentric pulley. In the present embodiment, the inclination angle of the belt contact surface of the fixed sheave 11 is:
The inclination of the movable sheave 12 is smaller than the inclination angle of the belt contact surface.

The movable sheave 1 of the input pulley 10
Reference numeral 2 is such that, when moving in the opening direction, the transmission belt described later can move to an axial position (a position indicated by a solid line in FIG. 3) at which the transmission belt does not contact the fixed sheave 11 and the movable sheave 12. And, between both sheaves 11 and 12,
A cylindrical member 14 having a short shaft length is disposed, and the movable sheave 12 moves to the above-described position, and the transmission belt
The transmission belt is rotatably supported when it comes into non-contact with the transmission belts 1 and 12. Specifically, the cylindrical member 14 is loosely fitted on the auxiliary shaft 3 and has a bearing 15.
Are held rotatably relative to the auxiliary shaft 3 via
A pair of flanges 14 forming an outward flange shape protruding outward in the radial direction is provided around both opening edges of the cylindrical member 14.
a, 14a are provided. These two flanges 14a, 1
The axial dimension between 4a is set to be the same as or slightly larger than the belt width dimension on the inner circumferential side of the belt. The inner diameter of the end of the movable sheave 12 on the side of the fixed sheave 11 at the boss portion 12a is increased to form an annular accommodation space. When the movable sheave 12 moves in the closing direction, The accommodation of the tubular member 14 prevents the tubular member 14 from hindering the movement of the movable sheave 12.

On the other hand, on the end of the output shaft 2, a clutch driving member 111 to be described later is arranged. As shown in FIG. 4, the drive side member 111 has a substantially cylindrical shape, is externally fitted on the output shaft 2, and
An output pulley 30 is rotatably and externally fitted on 11.

The output pulley 30 is connected to the input pulley 10
As in the case of, the fixed sheave 31 that cannot be moved in the axial direction.
And the reduction gear R side of the fixed sheave 31 (the left side in FIG. 4).
Movable sheave 32 which is arranged at
It consists of That is, the axial position of the movable sheave 32 with respect to the fixed sheave 31 is the same as the axial position of the movable sheave 12 with respect to the fixed sheave 11 in the case of the input pulley 10. The fixed sheave 31 is provided with a reduction gear R
Has a short cylindrical boss portion 31a extending toward the opposite side (right side in the figure), and is externally fitted on the end of the drive side member 111 in the boss portion 31a so as to be axially immovable. On the other hand, the movable sheave 32 has a long cylindrical boss portion 32a extending toward the reduction gear R,
The boss 32a is supported by the drive-side member 111 via two slide members 33, 33 disposed at both ends in the axial direction so as to be movable in the axial direction and not to rotate around the axis. This output pulley 30 is also similar to the input pulley 10,
A deflection pulley provided so that the inclination angle of the belt contact surface of the fixed sheave 31 with respect to a plane perpendicular to the axis is different from the inclination angle of the belt contact surface of the movable sheave 32, wherein the belt contact of the fixed sheave 31 Movable sheave 32
Is smaller than the inclination angle of the belt contact surface.

As shown in FIGS. 5 and 6, a transmission belt 50 is wound between the pulleys 10 and 30. In the transmission V, the transmission belt 50 is disposed between the pulleys 10 and 30. When the torque is transmitted via the transmission belt 50, a span (the lower span in the example shown in FIGS. 5 and 6) on the loose side of the transmission belt 50 is pressed in the belt thickness direction to apply tension to the transmission belt 50. Is provided. The tension mechanism 55 is used for the transmission belt 5.
In addition to having a tension pulley 56 that contacts with the tension pulley 56, a support portion that guides and supports the tension pulley 56 movably along the belt pressing direction, and biases the tension pulley 56 toward the belt pressing direction, although not shown. Biasing member. The tensioning mechanism 55 applies tension to the power transmission belt 50 so that the power transmission belt 5
0, the torque between the pulleys 10 and 30 is transmitted, and the movable sheaves 12 and 32 of each of the pulleys 10 and 30 apply a belt thrust in the opening direction (left direction in FIGS. 2 to 4). Is added.

An input cam mechanism 20 (see FIG. 3) is provided between the input pulley 10 and the engine E. The cam mechanism 20 includes a fixed member 21 provided so as not to move in the axial direction with respect to the input pulley 10 and non-rotatable about the axis, and a side of the input pulley 10 with respect to the fixed member 21 (right side in FIG. 3). And the input pulley 10
And a rotating member 22 provided integrally with the movable sheave 12 so as to be movable in the axial direction and relatively rotatable.

Fixed member 21 of input side cam mechanism 20
Has a pair of protruding portions 21a, 21a which are arranged so as to face each other with the axis interposed therebetween and are provided so as to protrude toward the side opposite to the engine E. Each protrusion 21a
Are attached to the protruding ends thereof so as to be rotatable about an axis perpendicular to the axis. The axes of these two engagement rollers 23, 23 coincide with each other.

Rotating member 22 of input side cam mechanism 20
Has a boss 22a whose inner diameter is larger than the outer diameter of the boss 12a of the movable sheave 12, and a bearing 2 is provided between the boss 22a and the boss 12a of the movable sheave 12.
The rotation member 22 is held by the movable sheave 12 so as to move integrally in the axial direction and to be relatively rotatable. An outwardly flanged disk portion 22b is provided around an opening edge of the boss portion 22a of the rotating member 22 on the engine E side so as to protrude outward in the radial direction. At two radially opposite positions on the periphery of the portion 22b, side wall portions 22c each having an arc-shaped cross section are provided so as to protrude toward the engine E side.

Each side wall portion 22c of the rotating member 22 has
Each of the engaging rollers 2 is provided with a slit-shaped groove cam portion 91 which penetrates the side wall portion 22c in the radial direction and spirally extends in the right-hand direction on the side wall portion 22c.
3 is disposed in the groove cam portion 91. The inclined surface of the groove cam portion 91 on the input pulley 10 side (each right side in FIGS. 2 and 3) contacts the engagement roller 23 from the input pulley 10 side and engages the roller 23 so as to roll. The roller has a first cam surface 25. On the other hand, the inclined surface on the engine E side (the left side in each drawing) comes into contact with the engaging roller 23 from the engine E side so that the roller 23 can roll. 2nd to support
A cam surface 90 is provided. The gap between the two cam surfaces 25 and 90, that is, the width of the groove cam portion 91 is larger than the diameter of the engaging roller 23.
Are rotatably arranged in the groove cam portion 91.

Each first cam surface 25 of the rotating member 22 is
When viewed from the engine E side, it is inclined so as to gradually approach the engine E side in the counterclockwise direction. Thus, the engagement roller 23 and the first cam surface 25 apply the belt thrust in the opening direction applied to the movable sheave 12 to the rotating member 2.
2 in a first direction r ₁ (counterclockwise as viewed from the engine E side), while the first direction r ₁
When a rotating force in the second direction r ₂ (clockwise direction viewed from the engine E side) opposite to the above is applied to the rotating member 22,
The rotational power is converted into a pressing force in the closing direction on the movable sheave 12.

Each second cam surface 90 of the rotating member 22 is
When viewed from the side of the input pulley 10, it is inclined so as to gradually approach the input pulley 10 in a counterclockwise direction. Thereby, the engagement roller 23 and the second cam surface 90
When a pressing force in the closing direction is applied to the movable sheave 12, the pressing force is applied to the rotating member 22 in the second direction r _2.
When the rotational force in the first direction r ₁ opposite to the second direction r ₂ is applied to the rotating member 22, the rotational force is moved to the movable sheave 12 in the opening direction. It converts to force.

An output cam mechanism 40 (see FIG. 4) is provided between the output pulley 30 and the speed reducer R. The cam mechanism 40 includes a fixed member 41 provided so as not to be movable in the axial direction with respect to the output pulley 30 and non-rotatable about the axis, and a side of the fixed member 41 opposite to the reduction gear R (see FIG. 4). (A right side), and a rotating member 42 provided integrally with the movable sheave 32 of the output pulley 30 so as to be movable in the axial direction and relatively rotatable.

The fixing member 41 of the output side cam mechanism 40
Are disposed so as to face each other across the axis, and are provided so as to protrude toward the side opposite to the reduction gear R.
It has a pair of protrusions 41a, 41a. An engagement roller 43 is provided at the protruding end of each protruding portion 41a so as to be rotatable around an axis perpendicular to the axis. The axes of the two engagement rollers 43 are made to coincide with each other.

Rotating member 42 of output side cam mechanism 40
Has a cylindrical boss portion 42a whose inner diameter is larger than the outer diameter of the boss portion 32a of the movable sheave 32.
A bearing 44 is interposed between the movable member 2a and the boss portion 32a of the movable sheave 32.
Are held by the movable sheave 32 so as to move integrally in the axial direction and to be relatively rotatable. The boss 42 of the rotating member 42
An outer flange-like disk portion 42b is provided around the opening edge on the reduction gear R side in FIG. 3A so as to protrude outward in the radial direction, and extends radially in the peripheral edge of the disk portion 42b. Two opposing portions have side walls 42 having an arc-shaped cross section.
c is provided so as to project toward the reduction gear R side.

Each of the side wall portions 42c of the rotating member 42 has
Each penetrates the side wall portion 42c in the radial direction and on the side wall portion 42c, as opposed to the case of the input side cam mechanism 20,
Slit-shaped groove cam portion 9 spirally extending in the direction of right-hand thread
2 are provided, and the engagement roller 43 is disposed in the groove cam portion 92. The inclined surface of the groove cam portion 92 on the output pulley 30 side (each right side in FIGS. 2 and 4) is a cam surface that contacts the engaging roller 43 from the output pulley 30 side and rotatably supports the roller 43. 45. Each of these cam surfaces 45 is formed on an inclined surface gradually approaching the reduction gear R in the clockwise direction as viewed from the reduction gear R side, opposite to the case of the first cam surface 25 of the input side cam mechanism 20. Is formed. Thus, the engagement roller 43 and the cam surface 45 apply the belt thrust in the opening direction applied to the movable sheave 32 to the rotating member 42 in the first direction r ₁ (the reduction gear R).
It converted into rotational force in the clockwise direction) as viewed from the side, while the second direction r ₂ (times of watching from the reduction gear R side counterclockwise direction) is a direction opposite its first direction r ₁ When the power is applied to the rotating member 42, the power is applied to the movable sheave 3
The pressing force is converted into a pressing force in the closing direction for 2. In this embodiment, since the inclination directions of the first cam surface 25 and the cam surface 45 in each of the cam mechanisms 20 and 40 are opposite to each other, the appearance (for example, when viewed from the engine E side or the reduction gear R side). ), The first direction r ₁ and the second direction r for the rotating member 42 of the output side cam mechanism 40.
₂ is the same as the second direction r ₂ and the first direction r ₁ for the rotating member 22 of the input side cam mechanism 20, respectively.
In operation, they are in opposite directions.

Between the input-side cam mechanism 20 and the output-side cam mechanism 40, the rotating members 2 of the cam mechanisms 20 and 40 are provided.
A connection mechanism 60 is provided for connecting the two 2, 42 to each other so as to rotate in directions opposite to each other in operation (in the case of the present embodiment, the same direction in appearance). The connecting mechanism 60 is connected to the rotating member 22 of the input side cam mechanism 20.
A rotating lever portion 61 provided so as to protrude outward in the radial direction, and a rotating member 42 of the output side cam mechanism 40.
And a connecting rod 63 for connecting the rotating levers 61 and 62 to each other so as to protrude outward in the radial direction. Specifically, the respective rotating lever portions 61 and 62 are located on the same side with respect to a plane including the input shaft 1 and the output shaft 2 and are arranged substantially parallel to each other. Therefore, each of the rotating lever portions 61 and 62 is configured to rotate in the same direction around each axis in appearance.

That is, the above-mentioned connecting mechanism 60 applies the rotating force of the rotating member 22 of the input cam mechanism 20 in the first direction r ₁ to the second rotating member 42 of the output cam mechanism 40.
The rotational force in the direction r ₂ (r ₁ → r ₂ ) and the rotational force in the second direction r ₂ of the rotating member 22 of the input cam mechanism 20 are applied to the rotating member 42 of the output cam mechanism 40 in the first direction. r
₁ of rotational force (r ₂ → r ₁₎ while converting each output-side cam mechanism first direction r ₁ at the pivot member 42 of the 40
To the rotating force of the input side cam mechanism 20 in the second direction r _{2 with} respect to the rotating member 22 (r ₁ → r ₂ ), and the rotating force of the rotating member 42 of the output side cam mechanism 40 in the second direction r ₂ The turning force is converted into a turning force in the first direction r _{1 with} respect to the rotating member 22 of the input side cam mechanism 20 (r ₂ → r ₁ ).

As described above, the belt thrust in the opening direction applied to the movable sheave on the input side is converted into rotational power in the first direction r ₁ for the rotating member 22 in the input side cam mechanism 20, the rotational force is r _1, is converted in a second direction r ₂ turning force for turning member 42 of the output-side cam mechanism 40 by the connecting mechanism 60, the second direction r ₂ rotating force, an output-side cam mechanism 40 Thus, the pressure is converted into the pressing force in the closing direction on the output side movable sheave 32. On the other hand, belt thrust on the output side, the output-side cam mechanism 40, is converted in a first direction r ₁ rotating force for rotating member 42, the rotational force to the first direction r ₁ is input by the connecting mechanism 60 The rotational force in the second direction r ₂ of the cam mechanism 20 is converted into the rotational force in the second direction r ₂ , and the rotational force in the second direction r ₂ is converted by the input side cam mechanism 20 into a pressing force in the closing direction on the input side movable sheave 12. Will be converted. The conversion mechanism in the present invention is constituted by the input side cam mechanism 20, the output side cam mechanism 40, and the connection mechanism 60.

The connecting mechanism 60 includes the output side cam mechanism 4.
A tension coil spring 70 as a low-speed ratio changing mechanism that constantly applies a rotating force in the second direction r ₂ to the 0 rotating member 42 is continuously provided. Specifically, this tension coil spring 70
The input shaft 1 is interposed between a fixed body such as a housing of the transmission V and the end of the connecting rod 63 of the connecting mechanism 60 on the input shaft 1 side. One side (the upper side in FIGS. 2 to 4 and the left side in FIGS. 5 and 6) is constantly biased. The rotating member 42
For pivoting force second direction r _2, the output-side cam mechanism 40
Is converted into a pressing force in the closing direction against the movable sheave 32. That is, the movable sheave 32 of the output side cam mechanism 40
, A pressing force in the closing direction by the tension coil spring 70 is constantly applied in addition to the pressing force converted from the belt thrust on the input side.

Further, a centrifugal weight mechanism 80 is provided between the fixed member 21 and the rotating member 22 of the input side cam mechanism 20 as a high speed ratioing mechanism. The centrifugal weight mechanism 80 includes a fixed member 81 that is externally fitted on the end of the input-side auxiliary shaft 3 on the engine E side so as not to move in the axial direction and to rotate about the axis.
Of the input pulley 1
And a movable member 82 provided integrally with the 0 movable sheave. The inner peripheral side portion of the fixing member 81 has a planar shape orthogonal to the axis. The portion located on the outer peripheral side is formed in a tapered portion 81a that gradually approaches the movable member 82 toward the outside in the radial direction, and the peripheral edge thereof is located radially outward from the movable member 82. I have. Tapered part 81
The outermost peripheral portion of the fixed member 81, which is a portion located on the outer peripheral side of a, is formed in a cylindrical shape extending toward the input pulley 10 while covering the movable member 82 from the outer peripheral side. On the other hand, the movable member 82 includes a disk-shaped main body, and a boss 82a that is provided so as to protrude from the main body toward the input pulley 10 and is externally fitted on the boss 12a of the movable sheave 12. Having. These fixed member 81 and movable member 82
, A plurality of weight rollers 83 are arranged movably in the radial direction. Then, each weight roller 83 is formed by the centrifugal force generated by the rotation of the input shaft 1 so that the tapered portion 81a of the fixed member 81 and the movable member 82
When moving outwardly in the radial direction between the main sheaves of the movable sheave 12, the weight rollers 83, 83,... Separate the fixed member 81 and the movable member 82 in the axial direction.
, An operating force in the closing direction is applied.

In this embodiment, as shown in FIG. 7, the output pulley 30 is provided so as to be relatively rotatable with respect to the output shaft 2 via the driving member 111 described above. Above, between the output pulley 30 and the output shaft 2, a clutch 110 for disconnecting and connecting the torque transmission between the output pulley 30 and the output shaft 2 is provided.

More specifically, the clutch 110 is connected to the driving member 11 rotatably supported on the output shaft 2.
1 and the drive-side member 111 which is disposed between the drive-side member 111 and the reduction gear R, and is integrally rotatable with the output shaft 2.
And a driven-side member 112 provided so as to be able to be disengaged from the driven member 1.

The main body of the drive-side member 111 is located between the output pulley 30 and the speed reducer R, and has a disk shape that expands outward in the radial direction. The cylindrical boss 111a is provided so as to extend toward the side opposite to the speed reducer R. This boss part 1
11a is loosely fitted on the output shaft 2 with a gap in the radial direction between the output shaft 2 and the boss 31a of the fixed sheave 31 at the end opposite to the speed reducer R. The output shaft 2 is rotatably held on the output shaft 2 via a bearing 113 disposed between the output shaft 2 and a bearing 114 disposed between the output shaft 2 and the output shaft 2 at the end on the reduction gear R side. And is rotatably held on the output shaft 2 via the. The output pulley 30 is placed on the boss 111a.
Are externally fitted integrally with each other. At a plurality of locations in the circumferential direction of the main body, mounting holes 111b penetrating in the axial direction are provided at equal intervals. In each of the mounting holes 111b, a locking claw 111c is directed toward the reduction gear R side. It is inserted and fixed so as to protrude.

On the other hand, the main body of the driven side member 112 is disposed so as to face the main body of the drive side member 111, and the main body of the driven side member 112 has a boss portion 112a extending toward the reduction gear R side. Boss 112a
Are held on the output shaft 2 so as to be movable in the axial direction via slide members 115, 115 arranged on the inner periphery of both ends.
At a plurality of positions in the circumferential direction of the main body, engagement holes 112b into which the respective locking claws 111c of the driving side member 111 can be engaged are provided. A spring stopper 116 is provided on the boss 112a.
Are externally fitted via a bearing 117 so as to be relatively rotatable and move integrally in the axial direction. And the driven side member 1
7 is moved from the position shown by the solid line in FIG.
The output pulley 30 and the output shaft 2 are integrally connected to each other by engaging the locking claws 111c of the driving side member 111 with the driving side members 111, respectively, while the driven side member 112 is positioned at a position indicated by a virtual line in FIG. The output pulley 30 and the output shaft 2 in the coupled state are separated from each other by moving in a direction away from the drive side member 111 (left direction in the same figure) and coming out of the engagement claw 111c from the engagement hole 112b. It has become.

A compression coil spring 118 is contracted between the spring stopper 116 and the speed reducer R, and the driven member 112 is compressed by the spring force of the compression coil spring 118 to expand in the axial direction. The side of the drive side member 111 (FIG. 4)
(Right side of FIG. 7).

As shown in FIG. 1, the clutch 110 is drivingly connected to a parking brake mechanism 102 of the vehicle.
Is locked in the rotation stop state, the driven member 112 is driven against the spring force of the compression coil spring 118 by interlocking with the operation of the parking brake mechanism 102.
When the parking brake mechanism 102 releases the lock of the rotation stop state, the pulling of the driven side member 112 is released in conjunction with the operation of the parking brake mechanism 102. The driven-side member 112 is allowed to move in a direction approaching the driving-side member 111 by the spring force of the compression coil spring 118.

More specifically, the driven side member 112 of the clutch 110 is connected to the operation lever 102a of the parking brake mechanism 102 via, for example, a wire, and is operated so as to lock the drive wheel 100 in a rotation stop state. When the lever 102a is operated, the operation lever 102a
When the operation is performed, the driven side member 112 is pulled in a direction away from the drive side member 111, and when the operation lever 102a is operated so as to return the drive wheel 100 to a rotatable state, the above-mentioned tension is released. I have.

Here, the operation of the belt type continuously variable transmission V in the agricultural vehicle configured as described above will be described.

[0053] First, in the state in which the engine E is stopped, as shown in FIG. 5, in a first direction r ₁ of the side rotational member 22 of the input-side cam mechanism 20 (the left side in the figure), and the output The rotation member 42 of the side cam mechanism 40 is positioned by being pulled by the tension coil spring 70 on the side in the second direction r ₂ (the left side in the drawing), and the speed ratio at this time is determined by the pitch of the input pulley 10. It is in the Lo state where the diameter is the smallest and the pitch diameter of the output pulley 30 is the largest. Further, in addition to the pressing force converted from the belt thrust on the input side, a pressing force by a tension coil spring 70 is applied to the movable sheave 32 on the output side.
The pressing force converted from the output-side belt thrust reduced by the pressing force of the extension coil spring 70 is applied.

In the above state, when the engine E is started and torque is input to the input shaft 1, the torque is transmitted to the output shaft 2 via the input pulley 10, the transmission belt 50 and the output pulley 30 in this order. Is done. When the input rotation speed increases, the weight rollers 83, 83,...
Since the movable member moves toward the outside in the radial direction between the first tapered portion 81a and the main body of the movable member 82, an operating force in the closing direction is applied to the movable sheave 12. This operating force increases as the input rotation speed increases.

Then, the belt thrust on the input side is canceled by the above-mentioned operating force.
The pressing force in the closing direction which is converted from the belt thrust and is applied to the movable sheave 32 is reduced. When the resultant force of the pressing force and the pressing force by the tension coil spring 70 becomes smaller than the belt thrust on the output side, the movable sheave 32
The movable sheave 32 moves in the opening direction due to the belt thrust. Therefore, as shown in FIG.
Has a smaller pitch diameter. On the other hand, as the diameter of the output pulley 30 is reduced, on the input side, the belt thrust in the opening direction with respect to the movable sheave 12 is reduced, so that the input pulley 10 is reduced by the pressing force of the tension coil spring 70 on the output side. The input pulley 10 is moved in the closing direction by the combined force of the pressing force converted from the thrust and the operation force, and the diameter of the input pulley 10 is reduced. As a result, the speed ratio between the pulleys 10 and 30 changes to the Hi side. That is, as shown in FIG.
The rotating member 42 of the output side cam mechanism 40 is in the first direction r ₁ (clockwise direction in the figure), and the rotating member 22 of the input side cam mechanism 20 is in the second direction r ₂ (clockwise direction in the figure). Each rotates.

In the above state, when the input rotational speed decreases, the operating force of the centrifugal weight mechanism 80 in the closing direction on the movable sheave 12 decreases, and the movable sheave 12 moves in the opening direction by the thrust of the belt. , The diameter of the input pulley 10 is reduced. On the other hand, as the operating force of the centrifugal weight mechanism 80 decreases, the output side cam mechanism 40
In this case, the pressing force in the closing direction by the tension coil spring 70 is restored by an amount corresponding to the decrease in the operating force.
Move in the closing direction by the pressing force and the pressing force converted from the input-side belt thrust.
Increases in diameter. As a result, the speed ratio between the pulleys 10 and 30 changes to the Lo side again (see FIG. 5).

In the above operation, when the operation of the engine E is stopped in a state where the speed ratio is Hi, for example, due to sudden braking, the speed ratio remains in the Hi state. Therefore,
If an attempt is made to start the engine E in such a state, a high load will be applied to the engine E.
When the vehicle is run again, it becomes difficult to start the engine E.

At this time, the operation lever 102a of the parking brake mechanism 102 is manually operated to lock the drive wheel 100 in the rotation stop state, so that the operation lever 102
The clutch 110 is operated in conjunction with the operation of a, and the output pulley 30 and the output shaft 2 in the connected state are disconnected. As a result, only a low load up to the output pulley 30 is applied to the engine E at the time of starting, so that the engine E can be easily started despite the state in which the speed ratio is Hi. Then, when the engine E is started,
The input pulley 10 rotates and the transmission belt 50
The speed ratio is changed to the Lo side by the tension coil spring 70 because the speed ratio is shifted between 0 and 30. Next, when the operation lever 102a of the parking brake mechanism 102 is manually operated so that the lock of the rotation stop state of the driving wheel 100 is released, the clutch 110 is operated in conjunction with the operation of the operation lever 102a. Since the pulley 30 and the output shaft 2 are integrally connected to rotate, the vehicle travels by increasing the rotation speed of the engine E thereafter.

Therefore, according to the present embodiment, the tension is applied to the transmission belt 50 wound between the input and output pulleys 10 and 30 by the tension mechanism 55 to apply the tension to the movable sheaves 12 and 32 of the pulleys 10 and 30. While applying a belt thrust in the opening direction and supporting each movable sheave 32, 12 with a pressing force in the closing direction converted from the belt thrust applied to each movable sheave 12, 32, the tension coil spring 7 is used.
A belt-type continuously variable transmission in which the operating force in the closing direction is constantly applied to the output-side movable sheave 32 by 0, while the centrifugal weight mechanism 80 applies the operating force in the closing direction to the input-side movable sheave 12 in accordance with the input rotation speed. In the agricultural work vehicle equipped with the device V, the clutch 110 is provided between the output pulley 30 and the output shaft 2 of the belt-type continuously variable transmission V, so that the engine is started when the speed ratio is Hi. Load can be kept low, so that the speed ratio is H
The engine E after stopping the engine E in the state of i
Can be easily started.

The clutch 110 is drivingly connected to the operation lever 102a of the parking brake mechanism 102, and the clutch 110 is operated in conjunction with the manual operation of the operation lever 102a. The clutch 110 can be operated by a normal operation performed on the operation lever 102a, and a special operation by the vehicle operator for operating the clutch 110 can be eliminated.

In the above embodiment, the input pulley 10
And the output pulley 30 uses an eccentric pulley, and the transmission belt 50 uses an eccentric belt. However, the pulleys having the same inclination angle of the belt contact surface are used, and the inclination angles of both side surfaces of the belt are mutually different. Equal V-belts may be used. However, in this case, the positions of the fixed sheave and the movable sheave in the axial direction are opposite to each other on the input side and the output side.

In the above-described embodiment, the tension coil spring 70 is used as the low-speed ratio-setting mechanism, and the centrifugal weight mechanism 80 is used as the high-speed ratio-setting mechanism. Is not particularly limited, and any low speed ratioing mechanism may be used as long as it can apply a pressing force in the closing direction to the movable sheave 32 on the output side. As a result, any mechanism can be used as long as an operation force in the closing direction can be applied to the input-side movable sheave 12 in accordance with the input rotation speed.

Further, in the above embodiment, the case of the agricultural work vehicle is described, but the belt-type continuously variable transmission according to the present invention can be mounted on various vehicles.

[0064]

As described above, according to the first aspect of the present invention, tension is applied to the belt wound between the input and output pulleys to apply a belt thrust in the opening direction to the movable sheave of each pulley. At the same time, while supporting each movable sheave with the pressing force in the closing direction converted from the belt thrust applied to each movable sheave, the operating force in the closing direction is always applied to the output side movable sheave by the low speed ratio mechanism, while the high speed ratio mechanism In the belt-type continuously variable transmission that applies an operating force in the closing direction to the input-side movable sheave in accordance with the input rotation speed, a clutch that connects and disconnects torque transmission to the driven side from the output pulley is continuously provided. Therefore, the load at the time of starting the drive source can be suppressed low, so that the drive source can be easily started after the drive source is stopped in a state where the speed ratio is Hi. It made.

According to the second aspect of the present invention, as a vehicle having the above-mentioned belt-type continuously variable transmission, a clutch is drivingly connected to a parking brake mechanism, and the clutch is operated in conjunction with the operation of the parking brake mechanism. With this configuration, the clutch can be operated by the normal operation performed on the parking brake mechanism, and a special operation by the vehicle operator for operating the clutch can be eliminated.

According to the third aspect of the present invention, the vehicle is
Since the vehicle is an agricultural work vehicle such as a combine, it is possible to suppress an increase in the operational burden required by the agricultural worker.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing an agricultural work vehicle according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a belt-type continuously variable transmission.

FIG. 3 is an enlarged sectional view showing an input side portion of the belt-type continuously variable transmission.

FIG. 4 is an enlarged sectional view showing an output side portion of the belt-type continuously variable transmission.

FIG. 5 is a schematic diagram showing the belt-type continuously variable transmission when the speed ratio is Lo, as viewed from the engine and the reduction gear side.

FIG. 6 is a diagram corresponding to FIG. 5 showing the belt-type continuously variable transmission when the speed ratio is Hi.

FIG. 7 is a diagram corresponding to FIG. 4, showing a state in which an output pulley and an output shaft are separated by a clutch.

[Explanation of symbols]

 Reference Signs List 1 input shaft 2 output shaft 10 input pulley 11 fixed sheave 12 movable sheave 20 input side cam mechanism (conversion mechanism) 30 output pulley 31 fixed sheave 32 movable sheave 40 output side cam mechanism (conversion mechanism) 50 transmission belt 60 interlocking mechanism (conversion) Mechanism) 70 tension coil spring (low-speed ratio-setting mechanism) 80 centrifugal weight mechanism (high-speed ratio-setting mechanism) 100 drive wheel (running wheel) 102 parking brake mechanism 110 clutch E engine (drive source) V belt-type continuously variable transmission

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroyuki Shimotsu 3-2-15 Meiwadori, Hyogo-ku, Kobe-shi, Hyogo F-term in Bando Chemical Co., Ltd. (Reference) 2B076 AA03 DA02 DB06 DB09 EC19 ED16 3D039 AA02 AA04 AB11 AC04 AC34 AD23 3J050 AA02 AB07 AB10 BA03 BB08 CA02 CC05 CC08 DA06 3J056 AA02 AA62 BB44 BE30 DA02 DA07 DA13 GA01 GA24

Claims (3)

[Claims] 1. A fixed sheave provided so as to be immovable in the axial direction, and a movable sheave provided in the axial direction with respect to the fixed sheave so as to reduce the pitch diameter by moving in a direction away from the fixed sheave. On the other hand, an input pulley that has a movable sheave that increases the pitch diameter by moving in a direction approaching the fixed sheave, and that receives a torque from the driving side, and a fixed sheave that is immovably provided in the axial direction, The fixed sheave is provided so as to be movable toward and away from the fixed sheave. The pitch diameter is reduced by moving in a direction away from the fixed sheave, while the pitch diameter is increased by moving in a direction approaching the fixed sheave. An output pulley having a movable sheave for outputting torque to a driven side, a transmission belt wound around the input / output pulley so as to be able to rotate, and a transmission bell And a tension mechanism for applying a tension so as to apply a belt thrust in an opening direction to each movable sheave of the input / output pulley, and a closing direction of the output pulley with respect to the movable sheave of the output pulley. A conversion mechanism that converts the belt thrust applied to the movable sheave of the output pulley into a pressing force in the closing direction of the input pulley with respect to the movable sheave; A belt-type continuously variable transmission, comprising: a low-speed ratio-mechanism that constantly applies an operating force; and a high-speed ratio-mechanism that applies an operating force in the closing direction to the movable sheave of the input pulley in accordance with an increase in the input rotation speed. A belt-type continuously variable transmission, wherein a clutch for connecting / disconnecting torque transmission from the output pulley to the driven side is connected to the output pulley. apparatus. 2. A vehicle equipped with the belt-type continuously variable transmission according to claim 1, wherein the vehicle is rotationally driven by an engine and a torque transmitted from the engine via the belt-type continuously variable transmission. A plurality of traveling wheels including drive wheels; and a parking brake mechanism for locking at least a part of the traveling wheels of the plurality of traveling wheels in a rotation stop state when traveling is stopped. The clutch of the step-variable transmission device is configured to interrupt transmission of torque from an output pulley to a driving wheel side in conjunction with the operation when the parking brake mechanism performs an operation of locking a traveling wheel to a rotation stop state, When the mechanism performs the operation of releasing the lock of the rotation stop state, the parking brake mechanism is configured to transmit torque from the output pulley to the drive wheel side in conjunction with the operation. Vehicle, characterized in that it is pivotal coupling. 3. The vehicle according to claim 2, wherein the vehicle is a farm work vehicle.