JPH0125532B2 - - Google Patents

Description

[Detailed Description of the Invention] Conventionally, a shear pin was inserted into the transmission part as a safety device when an overload was applied to the grain culm conveyor.
If a torque limiter is installed inside, but a shear pin is inserted, the replacement operation is extremely troublesome and requires a lot of effort and time to return to a state where transmission is possible.Furthermore, torque limiters are not only expensive but also There were drawbacks such as the need for space to install it.

The present invention aims to improve the above-mentioned drawbacks, and includes a chain tensioner with an elastic mechanism for tensioning the main transport chain on the slack side of the drive sprocket that drives the main transport chain, and In a conveyance device configured to drive a sub-conveyance belt by a shaft, the drive sprocket and the drive shaft to which it is attached are divided in a direction perpendicular to the axial direction, and the divided drive sprockets are superimposed so as to be relatively rotatable. When the main transport chain is tensioned by the chain tension member to the extent that it comes off the drive sprocket at the maximum torque that should cut off the transmission, and an overload is applied to the sub-transfer belt, the main transport chain The chain roller is sandwiched between the teeth of the divided drive sprocket.

The embodiment shown in the drawings will be explained below.1
is a threshing device mounted on a machine base having a traveling device 2, in front of which a frame 6 of a reaping device 5 is attached via a mounting frame 4 pivotally supported on a horizontal shaft 3; 5 is the branch 6'...
Cutting blade 7, grain culm lifting frame 8..., raking wheels 9, 9, stock raking chains 10, 10, and stem raking belt 11,
11, etc., and the stem part scraping belt 1
1, 11 and the feed chain 1a of the threshing device 1 is a main conveyor 12 that pinches and conveys the stock side of the grain culm.
A gear case 14 of the shaft 3 near the control section is interlocked with one grain culm lifting frame 8 by a shaft 15.

Further, the main conveyance body 12 has a main conveyance chain 12a.
and a clamping rail 12b installed opposite to the conveyance surface thereof, and the conveyance section and front and rear circulation sections of the main conveyance chain 12a are formed by bending the outer peripheral edge downward to form a U-shaped cross section, and a chain roller is attached to the support frame 16. The supporting frame 16 is attached by stays 16a, 16a to a gearbox 17 which is tiltably attached to the horizontal axis 3 near the feed chain 1a, and the drive which rises from the gearbox 17 A driving sprocket 19 around which the main transport chain 12a is wound around the shaft 18, and a driving sprocket 2 of the lug chain 13a of the sub-transport body 13.
The main transport body 12 and the sub-transport body 13 are connected to a handling depth adjustment lever 23 provided in the control section via a link 22 that is biased upward by a spring 21. The drive sprocket 19 and the drive shaft 18 are each divided into upper and lower parts, and the main sprocket 19a in the lower half of the drive sprocket 19 is fixed to the upper part of the lower half 18a of the drive shaft 18, and the sub sprocket 19b in the upper part is fixed to the upper part of the lower half 18a. The boss portion is fixed to the lower end of the upper half portion 18b of the drive shaft 18, and the upper end of the lower half portion of the drive shaft 18 is rotatable with respect to the sub sprocket 19b.

Further, a tension roller 24 for tensioning the main conveyance chain 12a near the drive sprocket 19 is pivotally supported at the tip of a short arm 24a whose base is rotatably supported on the drive shaft 18. The tip of the arm 25 protruding from the boss portion is connected via a tension splinter 27 to a rod 26 screwed onto the support frame 16 so as to be adjustable in forward and backward movement.

In the above-mentioned device, the grain culm harvested by the reaping device 5 is transferred to the main conveyor 12 and the sub-conveyor 13 and transported later, and in this rearing process, the handling depth is adjusted, and then the grain is removed from the stock. The part is transferred to the feed chain 1a and the clamping rail 1b, and the spike part is inserted into the supply port.

At that time, if the load on the main conveyance body 12 and the sub conveyance body 13 is normal, the tension roller 2
4 is a sprocket 19 that drives the main conveyance chain 12a.
Since the main transport body 12 and the sub-transport body 13 are both rotated normally.

Generally, when a chain is driven by a sprocket, the chain must not come off the sprocket no matter how large the load is, such as when the culm is clogged. Tosin(φ+α−θ)/sin(φ+α)
・ [sinφ/sin(φ+α)] A sufficiently large tension load was applied to the chain to prevent ^K-1 from losing its balance, and a shear pin was inserted or a torque limiter was installed as mentioned above to prevent overload.

However, in this embodiment, the tension roller 24
The tension spring 27 that presses against the main transfer chain 12a is set so that the maximum tension To of the main transfer chain 12a is 2 to 3 times the tensile force TO ₁ under normal load. When the main conveyance chain 12a approaches the main conveyance chain 12a, that is, when the shear pin breaks in the conventional transmission device, or when the torque limiter operates and the transmission is cut off, the engagement balance according to the above formula is broken and the main conveyance chain 12a
comes off the main drive sprocket 19a and stops. At this time, the sub-drive sprocket 19b also stops.

Furthermore, if the sub-transport body 13 is overloaded due to clogging, etc., a large braking force is applied to the sub-drive sprocket 19b, which tries to stop with the chain roller a biting in, so both sprockets 19
The tooth surfaces of the chain rollers a and 19b raise the chain roller a so that it appears to be sticking out, and the main conveyance chain 12a finally rides over the teeth of the main drive sprocket 19a, causing the main drive sprocket 19a to idle.

When an experiment was conducted using the above-mentioned apparatus using a main drive sprocket 19a and a sub-drive sprocket 19b having the same tooth profile, the idling torque ratio between the two was about 6:1.

In other words, the sub-transport body 13 idles when a relatively small overload is applied.

However, the normal torques of both carriers 12 and 13 are often relatively close to each other. For example, in the embodiment described above, the typical torque ratio is approximately 3:1.

In such a case, when the tooth profiles of both drive sprockets 19a and 19b were made different as shown in FIG. 5, the torque ratio during idling became approximately 3:1.

That is, the surface of the teeth of the main drive sprocket 19a in the rotational direction is made a gentle slope to make it easier for the chain roller a to float up, and the tension spring 27 is increased accordingly.
Main conveyor chain 1 with increased tension and predetermined torque.
When the tension spring 2a is released, the surface (rear surface) of the teeth of the sub-drive sprocket 19b that pushes up the chain roller a becomes steeper than the front surface of the teeth of the main drive sprocket 19a.
As the tension of No. 7 was increased, the chain roller a became more difficult to lift, and the aforementioned torque ratio of 3:1 was obtained.

In addition, when using the drive sprocket as a torque limiter by idling the drive sprocket in this way, it is desirable that the winding angle of the chain with respect to the drive sprocket is as shown in Figure 7b, and Tk must be extremely large as shown in Figure 7a, and c Then, if Tk is extremely small,
(for example, less than the chain's own weight).

Since the present invention is constructed as described above, even if a torque limiter or shear pin is not used, if an overload is applied to the main conveyor or the sub-transfer body, the drive sprocket will idle and power transmission will be cut off. Damage or deformation of the device and other members can be prevented.

In addition, since there is no need for a torque limiter, manufacturing costs can be significantly reduced, and there is no need to interfere with conveyance.Also, there is no need for operations such as replacing shear pins, which can cause overloads, such as clogging of conveyed objects. You can start it immediately as long as you don't have to worry about it.

[Brief explanation of drawings]

The drawings show one embodiment of the invention,
Fig. 1 is a side view of the combine, Fig. 2 is a plan view of the conveying device, Fig. 3 is a sectional view of the same, Fig. 4 is a sectional view of the main part, and Fig. 5 a and b are the main parts of other examples. plan view of
FIG. 6 is a plan view showing the meshing of the chain and sprocket, and FIGS. 7 a, b, and c are plan views showing the winding pattern of the chain. 12a...Main conveyance chain, 19...Drive sprocket, 24...Tension roller, 27...
tension spring.

Claims (1)

[Claims] 1. A chain tensioner with a spring for tensioning the main transport chain is provided on the slack side of a drive sprocket that drives the main transport chain, and the sub-transport belt is driven by the shaft of the drive sprocket. In the conveying device configured, the drive sprocket and the drive shaft to which it is attached are divided in a direction perpendicular to the axial direction, and the drive shafts are separately divided with the divided drive sprockets overlapping each other so as to be relatively rotatable. When the main conveyance chain is tensioned by the chain tension member to the extent that it comes off the drive sprocket at the maximum torque that should cut off the transmission, and an overload is applied to the sub conveyance belt, the chain roller of the main conveyance chain will be separated from the divided drive sprocket. A grain culm conveying device characterized in that it is configured to be pinched by teeth. 2. The grain culm conveying device according to claim 1, wherein the divided drive sprockets have different tooth profiles.