JPH039152A - Continuously variable transmission by belt in power-driven mobile agricultural machine - Google Patents

Abstract

PURPOSE:To increase on-ground height of a belt transmission system by providing constitution in such a way as juxtaposing transmission upper and lower position variable V pulleys in both sides of an intermediate sheave, moved normally and reversely in the axial direction, and speed change-transmitting rotation of a drive shaft to a driven shaft through primary and secondary V belts. CONSTITUTION:An intermediate sheave 20 is moved by an operating arm 48 in a direction of narrowing a transmission lower position variable V pulley 31, and a secondary tension arm 43 is press-turned to the outer against a tension ar return spring through a secondary V belt 40, while a primary tension arm 37 is pressed to a primary V belt 36 by resilient force of the return spring and press-adapted to a V groove, in which the effective diameter of a transmission upper position variable V pulley 30 is decreased by moving the intermediate sheave 20 in an opposite direction, thus rotation of a drive shaft 4 is increased and transmitted to a driven shaft 9. When the operating arm 48 is reversely returned, the rotation of the drive shaft 4 is reduced. Disconnected clutch condition appears when the V belt 40 touches a belt receiving part. By the above, on-ground height of a belt transmitting system is increased, and damage of a work machine is reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The application field of the present invention is a belt continuously variable transmission device for a riding mobile agricultural machine, a walking type power mobile agricultural machine, etc.

[Prior art]

In Japanese Utility Model Application Publication No. 62-41955, the belts from the engine to the transmission case are held in a belt transmission system between the engine and the transmission case by an outer pulley member and an inner pulley member, respectively. By moving this split pulley mechanism forward and backward in the belt tensioning direction, one of the two pulley members is moved in the distance direction relative to the other in conjunction with this movement. A transmission structure for an agricultural tractor is disclosed which includes a continuously variable transmission and is further provided with a tension pulley type main clutch mechanism that acts on one of the belts.

[Problem to be solved by the invention]

In the above conventional technology, since a belt continuously variable transmission is provided under the machine frame, this belt continuously variable transmission restricts the height of the work equipment suspended below the belly of the vehicle body. There was a problem with this.

[Means to solve the problem]

This invention takes the following technical means to solve the above problems. That is, an upper transmission variable V-pulley and a lower transmission variable V-pulley are arranged side by side by means of inner and outer split pulleys provided on both sides of an intermediate sheave that is moved forward and backward in the axial direction by an operating arm provided on the machine frame on the transmission shaft. At the same time, a belt control unit is installed on the back of the fender floor of the car body, and the belt holder is configured to freely rotate at the bottom of the lower transmission variable V-pulley. Drive ■ Primary V-belt spanning the pulley and upper variable transmission V-pulley and lower variable transmission ■ Secondary V-belt spanning the pulley and passive V-pulley, speed change to the passive shaft protruding upward on the transmission case side It was configured to transmit.

[Effect]

In this invention, when the operation arm is operated against the return spring force of the arm, the intermediate sheave is moved in the direction of narrowing the lower transmission variable V pulley, increasing the effective diameter of the groove of the lower transmission variable pulley and creating a secondary The V-belt is separated and the secondary tension arm is pressed and rotated outward against the elastic force of the tension arm return spring, and the primary tension arm is pressed against the primary belt by the elastic force of the return spring. By moving the intermediate sheave in the opposite direction, it is brought into pressure contact with the V-groove with a reduced effective diameter of the transmission upper variable V-pulley, and the rotation of the drive shaft is sequentially increased in speed and transmitted to the passive shaft.

Then, when the operating arm is returned to the opposite direction, the intermediate sheave moves in the direction that narrows the transmission upper variable V-pulley, so that the intermediate sheave is moved through the primary V-belt and the primary tension arm is removed against the elastic force of the return spring. The secondary tension arm is pressed against the secondary V-belt by the elastic force of the return spring, and the secondary V-belt is pressed against the V-groove with a reduced effective diameter of the transmission lower variable V-pulley. The rotation of the drive shaft is sequentially decelerated and transmitted to the driven shaft. And the quadratic V
When the belt contacts the belt receiver of the lower transmission variable V-pulley, a clutch disconnection state is established in which the secondary belt idles.

〔Example〕

Embodiments of the present invention will be specifically described below based on the drawings.

First, the configuration shown in FIGS. 1 to 3 will be explained.

A prime mover 3 is mounted on the front side of the machine frame 2 of the vehicle body 1 of the lawn tractor so that the drive shaft 4 protrudes below the machine frame 2.
The outside of the prime mover 3 is covered with a bonnet 5, a meter panel 6 is provided on the rear side of the bonnet 5, and a handle column 7 erected on the rear side of the prime mover 3 projects upward from the meter panel 6. A transmission case 8 is located on the rear side of the machine frame 2.
The transmission case 8 is provided with a passive @ 9 that protrudes upward, and on the left and right sides of the transmission case 8, a differential gear (not shown) that is internally installed in the transmission case 8 and receives power from the passive shaft 9 is provided. An interlocking rear axle 10.10 is provided protrudingly. At the intermediate portion between the drive shaft 4 and the driven shaft 9, a bell control unit 13 is attached to a mounting bracket 12 provided on the back side of the fender floor 11 provided on the upper side of the machine frame 2. It is attached so as to protrude between the lower left and right sides of 2. That is, the general structure of this bell converter unit 13 is that an inner split pulley 16 is provided at one end of an outer cylinder 15.
The shaft portion 17 of is fitted and supported via a bearing 18, and this outer n1
On the other end side of 5.

A slanted cam groove 19.19 is formed on a part of the outer periphery, and an intermediate sheave 20 in the form of a solo bread ball is provided at one end, and is internally fitted to the shaft portion 17 of the inner split pulley 16 via a needle bearing 21 as a belt receiving portion. A guide tube 25 is fitted into the outer tube 15 via the bearing 24 with a bearing 23 provided at the end of the inserted shift tube portion 22 and a guide portion 24.24 that engages with the cam groove 19.19. A shift shaft 26 is slidably spline-fitted into the shift cylinder portion 22, and the shift shaft 26 is
The base of 6 is supported by M27 via a bearing (not shown),
An outer split pulley 29 is attached to the lower end of the speed change shaft 26 via a bearing 28. In this embodiment, in the double variable V pulley 14, the outer split pulley 29 and the intermediate sheave 20 transmit the upper variable V-boot IJ 30, and the intermediate sheave 20 and the inner split pulley 16 transmit the lower variable V-boot. Pulley 3
1, and a rotatable belt receiving portion 32 formed by a needle bearing 21 is formed at the bottom of the lower transmission variable V-pulley 31. A drive pulley 33 provided on the drive shaft 4, and a vertical shaft 3 protruding downward from the right side of the machine frame 2 between the drive shaft 4 and the belt control unit 11.
A second V-belt 36 is passed between the primary intermediate V-pulley 35 provided at 4 and the transmission upper variable pulley 30. A tension roller 38 of a pivotally mounted secondary tension arm 37 is provided outside this secondary V-belt 36 so that it can come into contact with it by the elastic force of a return spring (not shown). Then, a secondary belt 40 is passed around the passive V pulley 39 provided on the passive shaft 9 and the transmission lower variable pulley 31, and the arm portion 4 protrudes from the transmission case 8 to the right side.
The tension roller 44 of the secondary tension arm 43, which is pivotally connected to the second V-belt 40 via the vertical shaft 42, is returned to the outer periphery of the secondary V-belt 40 and is provided so as to be able to come into contact with it by the elastic force of a spring (not shown). A base 49 of an operation arm 48 whose upper part protrudes upward from the front and rear elongated holes 47 of the right step 45 is pivoted to a horizontal shaft 46 protruding from the machine frame 2 on the lower side, and an actuation arm 50 provided on this base 49. The intermediate sheave 20 moves upward when the operating arm 48 is stepped onto the rotating arm 51 extending from one guide section 24 of the bellcon unit 13 via an appropriate link mechanism, and when the operation arm 48 is stopped being depressed, the intermediate sheave 20 moves upward. 20 are connected so that they can move upward.

A large-diameter drive pulley 52 is installed on the lower side of the drive shaft 4.
The cutting blade (
(not shown) is driven.Next, the configuration shown in FIGS. 4 to 6 will be described. A bell controller unit 56 connects the double variable V pulley 57 to the machine frame 2 at an intermediate portion between the drive shaft 4 and the passive shaft 9.
It is attached so that it protrudes from the bottom of the. That is, the general structure of this bell converter unit 56 is as follows: A transmission shaft 58 is rotatably provided in the machine frame 2 so as to protrude downward, and an inner split pulley 59 is fixed to one part of the transmission shaft 58, and an outer split pulley 59 is fixed to the bottom end of the transmission shaft 58. An intermediate sheave 61 in the form of a solo pan bead is installed between the pulley 60 and
The outer split pulley 59 and the intermediate sheave 61 are provided so as to be movable downward.
The upper transmission variable V-pulley 62 and the intermediate sheave 18 and the inner split pulley 59 constitute the lower transmission variable pulley 63. A drive V pulley 64 provided on the drive shaft 4; a primary intermediate V pulley 66 provided on a vertical shaft 65 protruding downward from the right side of the machine frame 2 between the drive shaft 4 and the belt control unit 56; A secondary V-belt 67 is passed around the transmission upper variable V-pulley 62, and a secondary tension arm 68 pivotally connected to the vertical shaft 65 is connected between the drive V-pulley 64 and the primary intermediate V-boo+J 66. tension roller 6
9 is provided on the outside of this secondary V-belt 67 so as to be able to come into contact with it. A passive pulley 70 provided at the upper end of the passive shaft 9
and a secondary intermediate V provided on the vertical shaft 71 protruding to the lower right side of the machine frame 2 between the bellcon unit 56 and the passive shaft 9.
A secondary V-belt 73 is passed between the pulley 72 and the lower transmission variable pulley 63, and a tension roller 75 of a secondary tension arm 74 is pivotally connected to the vertical shaft 71.
is provided so as to be able to abut on the outer periphery of the secondary V-belt 73, and a return spring 78 is installed between the arm portion 76 projecting to the right at the pivot point of the secondary tension arm 74 and the right bracket 77 of the machine frame 2. ing. and - next tension arm 6
8 and the arm section 76, there is a - next tension arm 6
A tensile elastic connecting rod 82 is provided by connecting a turn baffle mechanism 79 pivotally connected to the arm 8 and a rear connecting rod 80 pivotally connected to the arm 76 with a connecting spring 81. A base 87 of an operating arm 86 whose upper part projects upward from the front and rear elongated holes 85 of the right step 83 is pivotally attached to a horizontal shaft 84 protruding from the machine frame 2 to the lower side of the right step 83, and a base 87 is provided on the base 87. The secondary tension arm 74 moves clockwise when the operating arm 86 is depressed through a connecting rod 89 in which the operating arm 88 and the arm portion 76 are ball-jointed at both ends. They are connected to rotate counterclockwise. Then, a cutting blade (not shown) is connected to a large-diameter drive V-pulley 90 provided on the lower side of the quick-acting shaft 4 and a passive V-pulley 92 provided to the mower deck 91 via a belt 93 and a work clutch (not shown). It is configured to be driven.

Next, the operation of the embodiment of this invention will be explained. When mowing work is performed in a lawn garden, when the prime mover 3 is started, the drive shaft 4 is driven. No. 13 intermediate sheave 20 is moved downward and the clutch is disengaged,
The rotation of the drive V pulley 33 is transmitted to the upper variable transmission pulley 30 of the belt converter unit 13 via the secondary V belt 36, but the rotation of the drive V pulley 33 is transmitted to the lower transmission variable
2 is idling and the clutch is in a disengaged state, so no rotational power is transmitted to the secondary belt 40. Further, since the working clutch is disengaged, the rotation of the large-diameter driving V-pulley 52 is not transmitted to the passive V-pulley 54, and by connecting the working clutch and rotating the cutting blade, the operating arm 48
As the user depresses the button, the actuating arm 50 also rotates, and the rotating arm 51 is rotated forward via the link mechanism, so that the guide portion 24 of the bell-con unit 13 moves into the cam groove 1.
9.19 and move the intermediate sheave 20 upward, the transmission upper variable V pulley 30 sequentially reduces the V groove effective diameter, and conversely, the transmission lower variable V pulley 30 gradually decreases the effective diameter of the V groove.
Since the effective diameter of the V groove of the pulley 29 gradually increases, the secondary V
The belt 40 increases the tension and rotates the secondary tension arm 43 in a clockwise direction, that is, pushes it outward against the elastic force. The secondary tension arm 37 is rotated counterclockwise by the elastic force and applies tension to the loose secondary V-belt 36. Due to this series of actions, the rotation speed of the passive V-pulley 3 is increased sequentially.
9 to the transmission case 8 via the passive shaft 9, the vehicle body 1 runs from low speed to high speed and performs grass cutting work. When the mowing work is completed and the operation arm 48 is stopped being depressed, the intermediate sheave 20 of the bell converter unit 13 is moved downward by the elastic force of the return spring of the operation arm 48, and the transmission upper variable V pulley 30 is moved downward. In addition to increasing the V-groove effective diameter, the
The groove effective diameter is made smaller, and as a result, the secondary tension arm 37 is pushed by the tension of the secondary belt 36 and rotated clockwise, and the secondary tension arm 43
are simultaneously moved counterclockwise by the elastic force of the return spring, and the secondary V-bell 1-40 comes into contact with the belt receiving portion 32 at the bottom of the lower variable transmission V31, resulting in a clutch disengaged state.

〔effect〕

In short, this invention uses inner and outer split pulleys provided on both sides of an intermediate sheave, which is moved forward and backward in the axial direction by an operating arm provided on the machine frame on the transmission shaft, to control the transmission upper variable V-pulley and the transmission lower variable V-pulley. In addition to being installed in parallel, a belt control unit with a freely rotatable belt holder at the bottom of the pulley is installed on the back of the fender floor of the vehicle body, and a drive shaft protrudes from the prime mover side mounted on the machine frame. - Drives the rotation of the Since the transmission is configured so that variable speed is transmitted to the passive shaft that protrudes from the belt, the belt control unit can be installed at a high position, and the ground clearance of the belt transmission system is increased. Therefore, the work equipment can be raised high when not working. Even when traveling on an uneven road surface, the working machine is less likely to be damaged by foreign objects on the road surface, making it safer.

[Brief explanation of drawings]

1 to 3 show one embodiment of this invention,
Figure 1 is a plan view of the main parts in the clutch disengaged state, Figure 2
FIG. 3 is a side view of the main parts in the clutch disengaged state, FIG. 3 is a cross-sectional schematic diagram showing the belt control unit in a low speed state, and FIGS. 4 to 6 show an embodiment of the invention related to the above embodiment. FIG. 4 is a plan view showing the operation of the belt transmission system when the belt controller unit is in a clutch disengaged state, FIG. 5 is a plan view showing the operation of the belt transmission system when the belt controller unit is in a high speed state, and FIG. 6 is an overall side view. Explanation of main symbols 1... Vehicle body 2... Machine frame 3... Prime mover 4...
・Drive shaft 8...Transmission case 9...Passive shaft 11.
...Fender floor 13...Belcon unit
16...Inner split pulley 20...Intermediate sheave 26
... Speed change shaft 29 ... Outer split pulley 30 ... Transmission upper variable V pulley 31 ... Transmission lower variable V pulley
32... Belt receiving part 33... Drive V pulley 36.
...-Next V-belt 39...Passive V-pulley 40...
・Secondary V-belt 48...Operation arm

Claims (1)

[Claims] An upper transmission variable V pulley and a lower transmission variable V pulley are arranged side by side by means of inner and outer split pulleys provided on both sides of an intermediate sheave that moves forward and backward in the axial direction by an operating arm provided on the machine frame on the speed change shaft, A belt control unit, which has a freely rotatable belt receiver at the bottom of the transmission lower variable V-pulley, is attached to the back of the fender floor of the car body, and the rotation of the drive shaft protruding from the prime mover mounted on the machine frame is connected to the drive V-pulley. The speed change is transmitted to the passive shaft protruding upward on the transmission case side through the primary V belt that spans the transmission upper variable V pulley and the secondary V belt that spans the transmission lower variable V pulley and the passive V pulley. A belt continuously variable transmission device for a power mobile agricultural machine, characterized by the following features: