JPS599541Y2 - Automatic wheel lifting device for walking rice transplanter - Google Patents

Description

[Detailed description of the invention] The present invention is a walking-type rice transplanter that automatically controls the elevation of the propulsion wheels based on the detection of changes in the attitude of the swinging float relative to the machine body in order to maintain the attitude of the machine body with respect to the field at a substantially constant level. This invention relates to a wheel automatic lifting device.

When controlling the wheel elevation in the above walk-behind rice transplanter,
When the hard ground is deep and the amount of descent of the wheels relative to the aircraft body is large, the rotational resistance of the wheels is large, and the rotational reaction force causes the aircraft body to rotate relative to the wheel axis, causing the swinging float to be pushed into the mud. The float becomes difficult to move and the control sensitivity tends to slow down. Also, when the hard ground is shallow and the amount of descent of the wheels relative to the aircraft body is small, contrary to the above case, the float is pushed into the mud less and moves less. Because of this, unexpected wheel elevation control is performed in response to relatively small bumps on the mud surface, which tends to cause pitching of the aircraft. Due to changes in the planting depth, control delays and aircraft pitching occurred, and the planting depth was still not sufficiently constant.

The purpose of the present invention is to solve the above-mentioned problem based on the height position of the wheel.

The characteristic structure of the present invention is that in the wheel automatic lifting device of the walking type rice transplanter mentioned above, the wheel lifting speed when the amount of descent of the wheels relative to the body of the machine is small is higher than the feed speed when the amount of descent is large. In order to reduce the size of the vehicle, the operating speed of the wheel lifting mechanism is changed according to the alignment of the wheels with respect to the aircraft body.The operation and effects thereof are as follows.

In other words, when the wheels sink significantly, control sensitivity decreases, and the drive reaction force of the wheels is large, the aircraft tends to be in a state where it is difficult to pitch regardless of whether the wheels are raised or lowered.
The wheel lifting speed is increased, and the wheel lifting is carried out in a state that follows the change of the hard surface with a little delay. Also, the wheel sinking is reduced, the control sensitivity is increased, and the wheel drive reaction force is small, which improves longitudinal stability. When the aircraft tends to be unstable due to the aircraft being in a low position, and aircraft pitching tends to occur due to wheel elevation, the wheel elevation speed is reduced to prevent wheel elevation from causing hunting. This is done while ensuring that pitching of the aircraft does not occur as much as possible.

Therefore, when the hard plate is in a deep place and the depth changes, the wheels can be raised and lowered as quickly as possible, and in places where the hard plate is shallow, control notching and aircraft pitching are unlikely to occur even when the wheels are raised and lowered. As a result, the planting depth for the field as a whole can be kept very constant and precise.

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

Figure 1 shows the overall side view of the walking rice transplanter, in which 1 is the engine, 2 is the transmission case, 3, 3 is a pair of left and right main frames, 4 is the planting case, 5 is the seedling stand, 6...・
is a planting device, 7 is a control handle, 8, 8 is a wheel transmission case, 9, 9 is a propulsion wheel, or 10 is a float.

The wheel transmission cases 8, 8 are hydraulically raised and lowered by the following structure.

That is, a swinging arm 11 is pivotally attached to the main frame 3 around a horizontal lateral support a, and a hydraulic cylinder 12 is attached to one end of the swinging arm 11 so as to be able to swing freely. Balance arms 1 are installed at both ends of the support shaft 13, which is horizontally supported on the
4, 14 are provided, and each balance arm 14, 14 and the wheel transmission case 8, 8 are connected via a support rod 16, 16 with a shock absorber 15, 15.

Further, the other end of the swing arm 11 is connected to a hydraulic cylinder 12, and the wheels 9, 9 are raised and lowered simultaneously by the expansion and contraction of this cylinder 12.

The hydraulic cylinders 12 for lifting and lowering the wheels are controlled in the following manner in conjunction with the float 10 in order to keep the body posture substantially constant regardless of changes in the depth of the hard disk.

That is, the float 10 is then supported by the aircraft body so as to be able to swing up and down about the fulcrum R, and the rod 17 extending upward from the front part of the float is connected to the hydraulic cylinder 1.
It is linked to the second control valve 18 via an L-shaped arm 19.

The valve 18 is a three-position switching valve, and when the spool 20 is pushed forward, the cylinder 12 is extended and the transmission case 8 is lowered, and conversely, when the spool 20 is pulled out rearward, the cylinder 12 is is shortened, the transmission case 8 is raised, and the cylinder 12 is hydraulically locked at the spool neutral position.

Therefore, while driving with the aircraft in the normal position,
When the hard G becomes locally deep, is there a car here? 9 falls and the aircraft sinks, so the float 10 that floats on the mud surface rises and swings relative to the aircraft, the spool 20 of the vibrator 18 is pushed forward, the wheels 9 are controlled to descend, and the aircraft floats. When the wheel returns to its original position, the valve 18 becomes neutral and the wheel lift is stopped.

Conversely, when the hard plate G becomes shallow, the wheels 9 ride on it and lift the aircraft, so the float 10 swings downward against the aircraft due to its own weight, the spool 20 is pulled out, and the aircraft returns to its original state. The wheels 9 are controlled to rise until they return to the posture.

The automatic wheel lifting device of the present invention operates as described above, and is configured so that the wheel lifting speed changes depending on the depth of the hard disk.

In other words, the hydraulic cylinder 12 receives pressure oil from a constant discharge pump (for example, a gear pump) driven by the mounted engine 1, and operates in a linear manner at a constant speed.
Each pivot point a, b, C...f in the wheel lifting mechanism (second
(see figure), when the amount of descent of the wheels 90 relative to the aircraft body is small (asada time), the amount of elevation of the wheels 9 relative to the unit expansion/contraction amount of the cylinder 12, that is, the wheel elevation speed, is set such that the amount of descent of the wheels 9 relative to the aircraft body is large. Toki (Toki Fukada)
The wheel lifting speed is set to be smaller than the wheel lifting speed.

FIG. 3 is a graph showing the relationship between the actual cylinder extension amount and the lifting speed of the wheel center position in the vertical direction. The lifting speed is lower than the lifting speed when the amount of extension is large and the amount of wheel descent is large.

Therefore, when working in Fukada where the amount of descent of the wheels 9 is large,
Sensitive control with little delay is performed at a high wheel lifting speed, and stable control with little lifting overrun is performed at a small wheel lifting speed at Asada where the amount of descent of the wheels 9 is small.

In the embodiment, a case has been shown in which the wheel lifting speed is changed as described above with respect to the constant speed operation of the hydraulic cylinder 12 by appropriately setting the link structure for wheel lifting.
Based on the height detection, the discharge amount per unit time from the hydraulic pump is changed to change the operating speed of the hydraulic cylinder 12, and the operating speed of the drive mechanism itself is changed to perform the same operation. It is also possible to have it done.

Also, based on the height detection of the wheel 9, the linkage mechanism between the float 10 and the valve 18 is adjusted automatically to increase the control sensitivity at Fukada, when the wheel descends a large amount, and at the Asada, when the wheel descends a small amount. It is also conceivable to further add a compensating means to the present invention to reduce the control sensitivity.

[Brief explanation of the drawing]

The drawings show an embodiment of the wheel automatic lifting device for a walk-behind rice transplanter according to the present invention. Figure 1 is an overall side view, Figure 2 is a side view of the main part, and Figure 3 is a diagram showing the cylinder extension amount and wheel lifting speed. It is a graph showing a relationship. 9... Propulsion vehicle, 10... Flow I...
12...Hydraulic Shinonda.

Claims (1)

[Scope of utility model registration request] In order to maintain a nearly constant attitude of the aircraft relative to the field scene,
In an automatic wheel lifting device for a walk-behind rice transplanter that automatically lifts and lowers the propulsion wheels 9 based on the detection of a change in attitude relative to the machine body in the swing flow} 10, the wheel lift speed when the amount of descent of the wheels 9 relative to the machine body is small is A wheel lifting device for a walk-behind rice transplanter, characterized in that the operating speed of the wheel lifting mechanism is changed in accordance with the position of the wheels with respect to the machine body so that the speed is lower than the speed when the amount of descent is large. .