JPS637B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power transmission device for transmitting rotation of a drive shaft to a reaping device in a reaping machine.

Combine harvester reapers need to adjust the reaping height according to the dry and wet conditions of the field. To do this, the upper end of the reaping frame that supports the reaper is pivoted to the threshing machine side, and it is necessary to adjust the reaping height from the operator's seat. The height of the cutting blade provided at the lower end of the cutting blade above the ground can be adjusted by swinging the cutting blade. on the other hand,
The threshing machine side is provided with a reaping drive shaft that is drivingly connected to the engine, and the reaping machine side is provided with a reaping input shaft that is drivingly connected to the reaping drive shaft with a gear or belt. The reaping input shaft is configured to drive each device of the reaping machine. However, the reaping input shaft is generally provided at the free end of the reaping frame, and is displaced by the above-mentioned cutting height adjustment, so even if it is displaced, it will not interfere with the power transmission between it and the reaping drive shaft. The structure is such that there is no

FIG. 1 is a side view of a conventional belt-type power transmission device, and its outline will be explained based on the figure.A reaping frame 1 supporting a reaping machine has a support lever 2 pivotally supported on the threshing machine side. The upper end portion is supported by the threshing machine, and the lower end portion is supported via a connecting rod 4 by a swinging lever 3 which is also pivotally supported on the threshing machine side. And the reaping frame 1 is
The levers 2, 3, 4 are moved by the expansion and contraction of the hydraulic cylinder 5.
At the same time, a link movement is made around the pivots 6 and 7, and as a result, the dividing rod 8 attached to the lower end of the reaping frame 1 moves up and down as shown by the solid line and chain line in the figure, and is attached to the dividing rod. The structure is such that the height of the cutting blade and the grass cutting body above the ground can be adjusted. A reaping input shaft 9 is provided in the center of the reaping frame 1, and is drivingly connected to a reaping drive shaft 11 supported by a bearing 10 on the threshing machine side through a belt 12. As the cutting height is adjusted, it is displaced as shown by the solid line and the chain line. In order to prevent the distance between the two shafts 9 and 11 from changing regardless of this displacement, the movement locus of the reaping input shaft 9 is set to the reaping drive shaft 11 by setting the positions of the pivots 6 and 7 and the lengths of the links. It is constructed to be an approximate circular arc centered at . However, this locus is only an approximate circular arc, and the distance between the shafts 9 and 11 varies slightly, and there is also elongation of the belt, so a tension pulley 13 is provided to absorb this. And this tension pulley 13
is biased toward tensioning the belt 12 by a tension spring 14.

In the conventional power transmission device configured in this way, the tension spring 14 is attached to the tension pulley 13.
Since the support arm 15 is stretched between the support arm 15 and a fixed part on the threshing machine side, the support arm 15 expands and contracts greatly as the support arm 15 swings. Therefore, the tension of the belt 12 fluctuates, and when the tension spring 14 contracts, the belt 12 becomes slack and the conduction force decreases, or the tension force is attenuated due to repeated large expansion and contraction of the tension spring 14. There was a problem.

The present invention has been made in view of the above points, and includes supporting a tension pulley of a reaper drive belt on one of a pair of swinging members whose free ends are biased by a spring member in a direction toward which the tension pulley is attached. By configuring the other swinging member to swing in conjunction with the vertical movement of the reaper and tension the belt while keeping the length of the spring member almost constant regardless of the vertical movement of the reaper, the belt The present invention provides a power transmission device for a reaper that maintains the tension of a spring member constant at all times to equalize the transmitted force and improve the durability of the spring member.

Hereinafter, its configuration and the like will be explained in detail with reference to embodiments shown in the drawings.

2 and 3 show a power transmission device according to the present invention, FIG. 2 is a side view and a sectional view of the vicinity of the drive shaft, and FIG. 3 is a perspective view of the vicinity of the drive shaft.
In these figures, the reaping frame 21 is formed in a dogleg shape, and is supported by a bendable support lever 23 at the center which is swingably supported on a pivot 22 on the threshing machine side. There is. Reaping frame 2
1 is supported via a connecting rod 26 by a swinging lever 25 that is swingably supported on a pivot 24 on the threshing machine side. A rod end of a hydraulic cylinder 27 supported on the threshing machine side is pivotally connected to the swing lever 25, and the reaping frame 21 is moved between the levers 23 and 2 by the expansion and contraction of the hydraulic cylinder 27.
5 and 26 so as to move in a linked manner around pivots 22 and 24. A grass cutting rod 28 extending forward is attached to the lower end of the cutting frame 21, and a cutting device such as a grass cutting body, a pulling device, and a cutting blade (not shown) is attached to this.

On the other hand, a bearing 29 is provided on the threshing machine side, which is a driving part, and a drive shaft 30 driven by an engine is supported on this bearing. Further, a reaping gear box 31 is provided in the center of the reaping frame 21, and a reaping input shaft 32 is pivotally supported on the input side of the reaping gearbox 31, and the output side thereof is connected to the above-mentioned devices and a drive mechanism (not shown). connected by. A belt 35 is stretched between a drive pulley 33 pivotally attached to the drive shaft 30 and an input pulley 34 pivotally attached to the reaping input shaft 32. Note that the reaping input shaft 32, which is displaced with the link movement of the reaping frame 21, is connected to the pivots 22, 24.
The position of the levers 23, 25, and 26 are set such that they are displaced on an approximate circular arc trajectory centered on the drive shaft 30.

A tension arm 36 serving as one of the swinging members is swingably fitted to the outer periphery of the boss of the bearing 29, and a tension pulley 37 is pivotally attached to the free end of the tension arm 36. . Also, bearing 2
A spring lever 38 as the other swinging member is fitted adjacent to the tension arm 36 on the outer periphery of the boss 9, and the pair of swinging members 3
A tension spring 39 is stretched between 6 and 38 to bias the free ends of each other in a direction toward each other. Furthermore, a roller 40 is provided at the free end of the spring-loaded lever 38.
is pivotally attached to the reaping frame 21, and an arm 41, which is formed into a rod shape and serves as an engaging member that engages with the rollers 40, is fixed to the reaping frame 21. and,
This arm 41 is displaced while constantly engaging with the rollers 40 along with the link movement of the reaping frame 21,
The length of the tension spring 39 is held substantially constant, and the tension arm 36 is made to swing following the length of the tension spring 39.

In the reaper equipped with the power transmission device configured as described above, the cutting height is adjusted by operating the hydraulic cylinder 27 from the operator's seat. That is, if it is desired to mow a high part of the grain culm, for example, the hydraulic cylinder 27 located at the solid line position in the figure is extended as shown by the chain line. Then,
The reaping frame 21 moves together with the levers 23, 25, 26 in a linked manner around the pivots 22, 24, and the entire reaper including the dividing rod 28 integrated therewith and the reaping device (not shown) rises to the position shown by the chain line. . As a result, the reaping input shaft 32 moves along an approximate circular arc trajectory centered on the drive shaft 30, so that the length of the belt 35 hardly changes.

As is clear from the solid line position in FIG. 2a, the tension arm 36 and the spring loaded lever 38
The spring-loaded lever 38 is biased by the tension spring 39 in the direction of bringing the free ends closer together.
The roller 40 is pressed against the arm 41, and the tension pulley 37 of the tension arm 36 is pressed against the belt 35 to apply tension to it. When the reaping frame 21 moves in this state, the arm 41 pushes up the rollers 40 and swings the spring-loaded lever 38, so the tension arm 36 follows and swings via the tension spring 39. , while applying a constant tension to the belt 35 at all times. Further, the length of the tension spring 39 does not change during the cutting height adjustment and before and after the adjustment.

As is clear from the above description, in the present invention, in a power transmission device for a reaper, one of a pair of swinging members is biased by a spring member in a direction in which the tension pulley of the reaper drive belt is brought closer to each other. By configuring the other swinging member to swing in conjunction with the vertical movement of the reaper, the length of the spring member is always maintained almost constant regardless of the vertical movement of the reaper. Since the belt can be tensioned, the tension between the belt and the spring member can be maintained constant, the transmission force can be made uniform, and the durability of the spring member can be significantly improved.

[Brief explanation of the drawing]

Fig. 1 is a side view of a conventional power transmission device for a reaper, Figs. 2 and 3 show a power transmission device for a reaper according to the present invention, and Fig. 2 is a side view and a cross section near the drive shaft. 3 are perspective views of the vicinity of the drive shaft. 30... Drive shaft, 32... Reaping input shaft, 35...
...Belt, 36...Tension arm, 37...
Tension pulley, 38...Spring lever, 3
9... tension spring, 40... roller, 41... arm.

Claims (1)

[Claims] 1. In a reaping machine equipped with a reaping input shaft that is displaced in an approximate circular arc trajectory centered on the drive shaft as the reaper moves up and down, and in which the two shafts are drivingly connected by a belt, tension pulleys relative to the belt are mutually connected by a spring member. It is supported by one of a pair of swinging members biased in the direction of bringing the free ends closer together, is displaced in conjunction with the vertical movement of the reaper, and is constantly engaged with the other swinging member. A power transmission device for a reaper, characterized in that an engaging member is provided for swinging one of the swinging members in the tensioning direction of the belt via the spring member.