JPH09100887A - Belt type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve operability enabling quick speed-change operation by providing a mechanism for giving resistance to the separation movement between a movable sheave and a fixed sheave. SOLUTION: A condition of the lowest speed position is made wherein the movable sheave 27B of a driving spindle 24 is parted to the utmost to the left part of a paper surface from a fixed sheave 27A, and the movable sheave 34 of a driven spindle 32 is neared to the utmost to a fixed sheave 33. From this condition, when a cam body 30 is rotated in a direction orthogonal to the paper surface, a ring member 28 and the sheave 27B of the driving spindle 24 are pushed to near to the fixed sheave 27A side via a tilted cam surface 30a to increase the winding radius of a transmission belt 23 in a drive pulley PK. Following this, the mavable sheave 34 of the driven spindle 32 is parted to the right part of the paper surface from the fixed sheave 33, thereby speed- changeably operating a continuously variable transmission 1 to a high-speed side. Also, a coil spring 47 is provided between a spring receiver 46 and a bearing 29 for supporting the ring member 28, thereby giving movement resistance when the movable sheave 27B is parted to the fixed sheave 27A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission belt in which at least one of a drive pulley and an output pulley around which a transmission belt is wound is a split pulley type, and the pulley is composed of a fixed sheave and a movable sheave. The present invention relates to a belt-type continuously variable transmission used as a transmission such as a combine having a variable diameter.

[0002]

2. Description of the Related Art When a split pulley is constructed, a movable sheave is moved by a cam in order to move the movable sheave away from a fixed sheave to change the transmission diameter of the belt. In other words, when the movable sheave is moved toward the fixed sheave by the cam surface of the cam body, and the cam surface is retracted in the direction away from the movable sheave to loosen the pressure on the movable sheave, the movable sheave is moved. , The movement of the transmission belt toward the smaller side of the transmission belt toward the stable side is moved in the direction away from the fixed sheave, and the cam surface is positioned at the stopped position (for example, Kaihei 7-158707).

[0003]

Although the operating lever is provided as an operating mechanism for switching the working surface of the cam surface with respect to the movable sheave, it may be desired to improve the operability by increasing the speed of gear shifting operation. However, in the case of the above-mentioned configuration, in order to separate the movable sheave, a delicate balance between the moving force of the transmission belt toward the small diameter side and the cam surface that pushes the movable sheave is kept, so a rapid operation was performed. In this case, the movable sheave could not follow the retreat of the cam surface, and the belt sometimes slipped because the sufficient pressing force between the movable sheave and the transmission belt could not be obtained. An object of the present invention is to provide a belt type continuously variable transmission that can improve the operability by increasing the speed of gear shifting operation.

[0004]

According to a first aspect of the invention, at least one of a drive pulley and an output pulley around which a transmission belt is stretched is a split pulley type, and the pulley is a fixed sheave and a movable sheave. And a variable transmission diameter of the transmission belt, the movable sheave of the one pulley is movable in the perspective direction with respect to the fixed sheave by the cam surface of the cam body, and An artificial adjustment operation mechanism for adjusting the relative position of the movable sheave with respect to the fixed sheave is provided by switching the action surface with respect to the movable sheave, and a mechanism for providing resistance to the separation movement of the movable sheave with respect to the fixed sheave is provided. And its effects are as follows.

[Operation] In other words, even if the cam surface is rapidly moved away from the cam surface, the movable sheave is fixed while being kept in contact with the transmission belt due to the resistance of the mechanism that gives resistance to the separation movement. Moves away from the sheave. Therefore, the transmission belt does not slip.

[Effect] As a result, rapid operation is possible, and operability can be improved.

The characteristic configuration according to the invention of claim 2 is
In the invention according to claim 1, the mechanism for applying the resistance is a spring for urging the movable sheave toward the side closer to the fixed sheave, and the function and effect thereof are as follows.

[Operation] That is, since the movable sheave is urged by the spring toward the side closer to the fixed sheave, the movable sheave is always kept in contact with the transmission belt, and the movable sheave is fixed from the low speed state. Even when shifting to a high speed state in which the sheave is brought close to the sheave, the shifting operation can be quickly performed.

[Effects] Therefore, regardless of whether the gear shift operation is performed at high speed or low speed, a rapid gear shift operation can be performed, and the operability can be improved.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a combine transmission as an example of a work vehicle. That is, the power from the engine E is transmitted through the belt transmission mechanism B including a tension clutch (not shown) to the belt type continuously variable transmission 1
The power output from the belt type continuously variable transmission 1 is transmitted to the transmission mechanism in the transmission case 3.

As shown in FIGS. 1 and 2, in the mission case 3, a forward drive shaft 4 and a reverse drive shaft 5 are provided.
Are arranged side by side in parallel, and the mission case 3
1 is arranged so as to be biased to one lateral side on the left side of the drawing in FIG. A forward hydraulic clutch 6 and a forward input gear 7 for transmitting the forward power to the lower transmission side in the transmission case 3 are attached to the forward transmission shaft 4,
The reverse hydraulic clutch 8 and the reverse input gear 9 for transmitting the reverse power to the lower transmission side in the mission case 3,
It is attached to the reverse transmission shaft 5 in a state of being engaged with the forward input gear 7 and constitutes a forward / reverse transmission 26.

At the top of the mission case 3, FIG.
As shown in FIG. 5, the hydraulic plate 10 is connected to the forward and reverse transmission shafts 4 and 5, and the hydraulic oil from the forward / reverse switching valve (V) is transferred to the forward and reverse transmission shafts 4 and 5.
The oil is supplied to the forward hydraulic clutch 6 and the reverse hydraulic clutch 8 via the internal oil passage. Further, as shown in FIG. 1, a pair of gears 11 for a mowing pretreatment unit (not shown) at the front of the combine of the fuselage, a first transmission shaft 12 as a supporting shaft for supporting the pair of gears 11, and an output shaft 13 are provided. And the hydraulic clutch 14 for the pre-cutting section, and the input shaft 15 for inputting the power from the belt type continuously variable transmission 1, the forward transmission shaft 4 and the reverse transmission shaft 4 in the mission case 3.
It is arranged on one side of the mission case 3 on the same side as the forward and reverse transmission shafts 4 and 5 on the upper side of the transmission case 5. Here, the first gear 11a of the gear pair 11, the drive gear 16 provided on the input shaft 15, and the forward input gear 7 are provided.
And the second gear 11b of the gear pair 11 and the input gear 17 of the pre-cutting processing hydraulic clutch 14 are in mesh. And these gear pairs 1
1, the drive gear 16 and the input gear 17 constitute a pre-mowing processing section and a transmission mechanism 18 to the forward / rearward movement transmission shaft. Incidentally, the forward input gear 7, the reverse input gear 9, the input gear 17
Are supported by the shafts 4, 5 and 12 so as to be in a free rotation state when the hydraulic clutches 6, 8 and 14 are off.

Further, as shown in FIG. 1, the outputs of the forward hydraulic clutch 6 and the reverse hydraulic clutch 8 are transmitted to the axles 22 of the crawler traveling devices 21 and 21 via the auxiliary transmission 19 and the side clutches 20 and 20. It is configured to transmit to 22.

Next, the belt type continuously variable transmission 1 will be described. As shown in FIG. 2, a belt type continuously variable transmission 1
Includes a drive pulley PK, a passive pulley PJ, and a transmission belt 23 that extends between these two pulleys, and is mounted inside a transmission case Ca having a half-split structure. Both the drive and passive pulleys PK and PJ have a split pulley structure capable of variably adjusting the belt winding radius, and the belt winding radii of the respective pulleys are linked so as to be reciprocally adjusted in size.

A half case 25 is attached to the drive shaft 24 on the transmission side.
Input pulley 2 to which power is transmitted on the outer side of A
Is fixed, and the drive pulley PK is mounted inside the half case 25A of the drive shaft 24. Drive pulley PK
Is composed of a fixed sheave 27A fixedly attached to the drive shaft 24 and a movable sheave 27B. The movable sheave 27B is opposed to the fixed sheave 27A on the drive shaft 24, and rotates integrally with the drive shaft 24 in the axial direction. It is fitted so that it can move freely.

The ring member 2 is attached to the boss of the movable sheave 27B.
8 is rotatably fitted over a bearing 29, and the receiving member 2 is attached to a pair of pins 28 a fixed to the ring member 28.
8b is attached, and the ring member 28 is prevented from rotating by entering the recess 25a of the other half case 25B. A cylindrical cam body 30 is externally fitted to the drive shaft 24 via a pair of bearings 31, and a pair of recessed left and right inclined cam surfaces 30a are formed in the cam body 30 to form a pair of ring members. 28 pin 28a roller 28
c enters into the pair of concave portions of the cam body 30.

In the passive shaft 32 on the lower transmission side, a fixed sheave 33 is arranged inside the other half case 25B, and a movable sheave 34 is integrally rotated with the passive shaft 32 while facing the fixed sheave 33. It is fitted so that it can move in the core direction. The movable sheave 34 of the passive shaft 32 is urged toward the fixed sheave 33 side by the spring 35, and the movable sheave 34 is fixed in proportion to the increase in the load on the passive shaft 32 side.
A cam mechanism 36 that pushes to the side is provided.

In the state shown in FIG. 2, the movable sheave 27B of the drive shaft 24 is farthest from the fixed sheave 27A on the left side of the drawing,
The movable sheave 34 of the passive shaft 32 is in the state of the lowest speed closest to the fixed sheave 33. Then, when the cam body 30 is rotated in the direction orthogonal to the paper surface from this state, the ring member 28 and the movable sheave 27B of the drive shaft 24 are pushed toward the fixed sheave 27A side via the inclined cam surface 30a and approached. As the winding radius of the transmission belt 23 around the drive pulley PK increases, the movable sheave 34 of the passive shaft 32 moves away from the fixed sheave 33 to the right in the drawing, and the continuously variable transmission device. 1 is shifted to the high speed side. In the above configuration, the fixed sheave 27A rotatably attached to the drive shaft 24 and the fixed sheave 27A.
Bearing 3 provided between the boss of the cam and the cam body 30
1, a spring bearing 46 is provided toward the movable sheave 27B so as to be loosely fitted to the drive shaft 24, and a coil spring 47 is provided between the spring bearing 46 and the bearing 29 supporting the ring member 28. With this, when the movable sheave 27B moves away from the fixed sheave 27A, a movement resistance can be given. Here, the coil spring 47 is referred to as a mechanism that gives resistance to the separating movement.

Next, the gear shift operation structure of the belt type continuously variable transmission 1 will be described. As shown in FIGS. 2 and 3,
A boss member 37 is fixed to the boss portion of the cam body 30 on the outer side of the half case 25B, and a gear shift lever 38 as a gear shift operation tool is supported by the boss member 37.
A fan-shaped gear 39 is fixed to the fan-shaped gear 39, and a geared motor 40 that rotationally drives the fan-shaped gear 39 is provided. Then, the pin 37b of the arm 37a of the boss member 37 is inserted into the opening 39a of the fan-shaped gear 39, and the shift lever 3
A pair of rubber-like pressure-sensitive sensors 41 as operation direction detection sensors 8 are fixed to the fan-shaped gear 39 so as to sandwich the pin 37b of the arm 37a.

The state shown in FIG. 3 is a state in which the speed change lever 38 is operated to the neutral stop position, and when the speed change lever 38 is operated in the direction along the paper surface to rotate the cam body 30, this operation is performed. As a result, the pin 37b of the arm 37a is pressed by the pressure sensor 41, and the signal from the pressure sensor 41 causes the motor 40 to operate so that the boss member 37 and the fan-shaped gear 39 rotate in the operation direction of the speed change lever 38, The belt-type continuously variable transmission 1 is operated to shift to the high speed side. When the operation of the speed change lever 38 is stopped at a desired operation position, the motor 40 also stops, and the speed change lever 38 and the belt type continuously variable transmission 1 are held by the motor 40 at this operation position.

Next, the operating structure of the belt type continuously variable transmission 1, the forward and reverse hydraulic clutches 6 and 8 will be described. 4 and 5, the hydraulic oil of the pump 48 is supplied to the forward and reverse hydraulic clutches 6 and 8 via the forward / reverse switching valve V as a control valve, and the lever guide 43 is provided to the shift lever 38. Provided on the lever guide 43 are a neutral path 43N, a forward path 43F and a reverse path 43 corresponding to the neutral stop position N of the speed change lever 38.
It is configured with R. The fan-shaped gear 39 on the speed change lever 38 side and the forward / reverse switching valve V are linked via a push-pull wire 44 as a linking mechanism and an interchange mechanism 45.

With the above structure, as shown in FIG. 5, when the speed change lever 38 is operated to the center of the neutral path 43N (neutral stop position N) of the lever guide 43, the continuously variable transmission 1
Is operated to the lowest speed position as shown in FIG. Then, in this state, the forward / reverse switching valve V is operated to the neutral stop position N to move the forward and reverse hydraulic clutches 6, 8.
The aircraft will stop when you turn off. From this state, the transmission lever 38 is moved to the forward path 43F in the neutral path 43N.
Side, and start operating along the forward path 43F,
The pin 37b is pressed by the pressure-sensitive sensor 41, and the motor 40 moves the fan-shaped gear 39 counterclockwise in FIG. 2 based on the detection of the pressure-sensitive sensor 41. The advance switching valve V is switched from the neutral stop position to the forward position.

As a result, the forward hydraulic clutch 6 is engaged and operated, the continuously variable transmission 1 is operated from the lowest speed position to the high speed side, and the machine body advances. Then, the shift lever 41
When the operation of is stopped at the desired operation position, the motor 40 also stops, and the speed change lever 38 and the continuously variable transmission 1 are held at this operation position by the motor 40. The operation of the speed change lever 38 is absorbed by the accommodation mechanism 45. Contrary to the above state, when the gear shift lever 38 is operated to the reverse side route 43R side from the state shown in FIG. 4, the machine body moves backward.

[Other Embodiments] (1) As the mechanism 47 for giving resistance to the moving movement of the movable sheave 27B with respect to the fixed sheave 27A, a member having a large resistance or a sliding surface of the movable sheave 27B is used. You may take measures such as sticking. (2) As the mechanism 47, a sponge, a soft resin, or the like may be formed into a cylindrical shape, and may be mounted at the position where the spring is mounted instead. (3) As the spring for the mechanism 47, a leaf spring or a disc spring may be used instead of the coil spring.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a traveling transmission system of a combine.

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

FIG. 3 is a side view showing an operation structure for a belt type continuously variable transmission.

FIG. 4 is a configuration diagram showing a linkage between a shift operation tool and a forward / reverse switching valve.

FIG. 5 is a plan view showing a lever guide for an operating tool for a belt type continuously variable transmission.

[Explanation of symbols]

 23 Transmission belt 27A Fixed sheave 27B Movable sheave 30 Cam body 30a Cam surface 47 Mechanism for giving resistance PK Drive pulley PJ Movable pulley

Claims (2)

[Claims] 1. A split pulley type at least one of a drive pulley (PK) and an output pulley (PJ) around which a transmission belt (23) is stretched, and the pulley (PK or PJ) is a fixed sheave (27A). The movable sheave (27B) is configured so that the transmission diameter of the transmission belt (23) can be varied, and the movable sheave (27) of the one pulley (PK or PJ) is configured.
B) is movable in the perspective direction with respect to the fixed sheave (27A) by the cam surface (30a) of the cam body (30), and the action surface of the cam surface (30a) with respect to the movable sheave (27B) is switched. , The movable sheave (27B)
An artificial adjustment operation mechanism (38) for adjusting the relative position of the movable sheave (27A) with respect to the fixed sheave (27A) is provided, and a mechanism (47) for giving a resistance to the moving movement of the movable sheave (27B) with respect to the fixed sheave (27A) is provided. Belt type continuously variable transmission. 2. The belt type continuously variable transmission according to claim 1, wherein the resistance applying mechanism (47) is a spring for urging the movable sheave (27B) toward a side closer to the fixed sheave (27A). .