JPH0432894Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to an elevating device for the ground-contacting part of a working machine or wheels of a working vehicle, especially a planting part of a riding rice transplanter, and more specifically, the elevating and lowering device for the planting part of a riding rice transplanter. Regarding the mechanism.

(b) Prior art In general, the planting section of a riding rice transplanter is raised and lowered by a hydraulic cylinder that is controlled manually or by sensing soil pressure using a float. A compression spring is interposed between them to support the load of the planted part, and is configured to provide a buffer only in the upward direction of the planted part. For this reason, if the earth pressure sensing ability of the float is reduced, the sensing mechanism may resonate, or the vibration of the planter arm may cause a pitting phenomenon in which the lifting device moves violently up and down when the float touches the rice field. Problems may occur, such as making it impossible to control the lift or lowering the seedlings, or causing the seedlings on the seedling stand to fall.

Therefore, a rice transplanter has been proposed in which an oil damper is grounded between the seedling stand and the lifting link to suppress pitting at the planting section.

In addition, as shown in Utility Model Application Publication No. 59-179059,
A cylindrical elastic body made of rubber is slidably fitted onto the rod of the hydraulic cylinder, and a cylindrical case is provided around the outer periphery of the cylindrical elastic body, and the inner peripheral surface of the cylindrical case is used to move the rod. A shock absorbing device has also been devised in which the slope is tapered toward the front, so that as the rod moves, the frictional force generated between the outer circumferential surface of the rod and the inner circumferential surface of the cylindrical elastic body increases. ing.

(c) Problems that the invention aims to solve However, the method using an oil damper requires an expensive oil damper, which increases costs, and also restricts the quick movement of the planting area by sensing the earth pressure of the float. , which obstructs the highly sensitive elevation control of the planting area.

In addition, due to the frictional force of the cylindrical elastic body, the frictional force between the outer circumferential surface of the rod and the inner circumferential surface of the cylindrical elastic body decreases relatively early, which reduces its effectiveness and causes an increase in costs. It's getting old.

(d) Means for solving the problem The purpose of this invention is to solve the above-mentioned problems, and as shown in Figs. Or ground contact part 1 of wheels etc.
is supported on the traveling body through a link 2 so as to be freely movable up and down, and a hydraulic cylinder device 5 is disposed between the link 2 and the traveling body. And the cylinder device 5
An interlocking member 7 connected to the link 2 via a bracket 6 etc. is slidably supported on the piston rod 5a, and retaining rings 9, 9 are fixed to both sides of the interlocking member 7 and the piston rod 5a. Springs 10 and 11 are interposed between them, and of these springs 10 and 11, the spring 11 on the opposite side has a stronger elastic force than the spring 10 on the side where the weight of the ground contact part 1 acts. It is set as follows.

(e) Effect Based on the above configuration, when the cylinder device 5 contracts and touches the ground, the gravity of the grounding part 1 on which the lower spring 10 is acting is suddenly released, the spring 10 expands, and the grounding part 1 Although a pitching phenomenon such as jumping up tends to occur, the upper spring 11 suppresses the jumping up, and based on the difference in elastic force between the two springs 10 and 11, the pitching phenomenon is rapidly attenuated to prevent the pitching phenomenon.

In addition, in a working state in which the grounding part (for example, the planting part) 1 is in contact with the ground, the cylinder device 5 expands and contracts by constantly receiving rising and falling signals from a sensing member such as a bloat. 10 and 11 buffer the sudden movement of the cylinder device 5, and rapidly attenuate based on the difference in elastic force between both springs, stabilizing and restraining the ground contact part 1 in a predetermined working position with a gentle movement. .

(F) Embodiment An embodiment in which the present invention is applied to a riding rice transplanter will be described below with reference to the drawings.

As shown in FIG. 4, the riding rice transplanter 11 has a traveling body 15 supported by front wheels 12 and rear wheels 13, and an engine 16 is mounted on the traveling body 15 in front of the front wheels. At the same time, a driver's seat 19 is disposed such that the seat 17 is located between the front and rear wheels, that is, at the center of gravity of the machine. Further, at the rear of the traveling body 15, a planting section 1 is supported via a link 2 so as to be able to rise and fall freely, and a large number of planters 20..., floats 21 are installed in the planting section 1.
A long seedling stand 22 on which two and a half pine seedlings can be vertically placed is also provided. In addition, the traveling aircraft 1
Front transmission case 23 and link 2 in 5
A hydraulic cylinder device 5 is disposed between a bracket 6 fixedly attached to a hydraulic control valve 25 and a hydraulic cylinder device 5.
Based on the expansion and contraction of the hydraulic cylinder device 5 as shown in FIG. 3, the planting section 1 moves up and down.

The hydraulic control valve 25, as shown in FIG.
The elevator control lever 26 located on the driver's seat 19 is operated at the raised position U, the neutral position N, the lowered position D, and the automatic position A. Specifically, at the raised position U, the pump P is switched to a position where the pressure oil is sent to the hydraulic cylinder 5, and at the neutral position N, it is switched to the hold position. The lowering position D and the automatic position A are linked with automatic detection based on the float 21 moving up and down due to pressure from the field surface, and in the lowering position D, the pressure oil of the hydraulic cylinder device 5 is drained into the tank T. It can be semi-automatic, switched to the position and stopped in the hold position based on the float 21, or it can be fully automatic, including the raised position. Further, the automatic position A is switched to a lower position, a hold position, and a raised position exclusively by automatic sensing from the float 21. In addition,
When the lowering position D is set to semi-automatic, the float 21 presses down on the rice field when the rice transplanter travels on the rice field, leveling out the unevenness of the rice field, and when set to fully automatic, the rice transplanter rotates or travels. This prevents the float from collecting mud when the float is used.

On the other hand, the hydraulic cylinder device 5 is shown in FIGS.
As shown in the figure, it has a cylinder portion 5b and a piston rod 5a, and the base end of the cylinder portion 5b is pivotally supported and connected to the front transmission case 23 by a pin 27. Also, the piston rod 5a
A holder 7 constituting an interlocking member is slidably inserted into the holder 7, and a fulcrum pin 30 is implanted in the holder 7 and pivotally supported by a bracket 6 fixed to the upper link 2a. A retaining ring 9 fitted to the stepped portion a of the piston rod 5a
A spring 10 having a large diameter and a relatively small spring constant is compressed between the rod 5a and a spring receiver 29 that slides integrally with the holder 7.
There is a retaining ring 9 fixed to the bolt part b at the tip with a nut 31 and the other side of the holder 7, which has a small diameter and a relatively large spring constant (spring 10).
The spring 11 is compressed (approximately 2.5 times the size of the spring).

Since the present embodiment has the above-described configuration, the raising/lowering control lever 26 is lowered to the lowering position D from a state in which the planting section 1 is in the raised position and the raising/lowering lever 26 is in the neutral position N, in a semi-automatic or fully automatic manner. The planting section 1 is automatically lowered to the working position. At this time, the oil in the hydraulic cylinder device 5 is discharged into the tank T at the position of the control valve 25, and the heavy planting section 1 due to the long seedling stand 22 relatively suddenly lands on the field surface. As a result, the spring 10, which was under a large load, is instantly unloaded and tries to stretch.
This force is suppressed by the upper spring 11,
The planting part 1 is prevented from jumping up. Then, when the planting section 1 is lowered to the working position, the elevation control lever 26 is placed in the automatic position A, and the elevation control lever 26 is automatically controlled by sensing the soil pressure of the float 21, and is interlocked with the elevation control lever 26. The planter clutch is connected and the planter 20 starts the planting operation. At this time, the control valve 25 is switched between positions by the movement of the float 21 to expand and contract the hydraulic cylinder device 5, but the springs 10 and 1
1, the movement in both upward and downward directions is buffered, and the planting part 1 moves up and down smoothly, and since the spring constants of both springs 10 and 11 are different, it quickly damps and stops at an appropriate position. be done.

(G) Effect of the invention As explained above, according to the invention, since the springs 10 and 11 are interposed on both sides of the interlocking member 7, the upper spring 1
1 can effectively suppress the springing up of the ground contact part 1, and can support the ground contact part 1 softly by cushioning movement in both upward and downward directions, while reducing the elastic force of both springs 10 and 11. Since they are different from each other, the movement of the ground contact portion 1 can be rapidly attenuated, and the pitching phenomenon can be prevented. Also, springs 1 are provided on both sides of the interlocking member 7.
Since only 0 and 11 are interposed, there is no need for an oil damper or a cylindrical elastic body, and the structure can be manufactured at low cost with an extremely simple structure.

In addition, since the elastic force of the spring 11 on the rebound side is set to be stronger than that of the spring 10 on the side where the gravity of the grounding part 1 acts, the impactful and large bouncing force when the grounding part 1 touches the ground can be effectively used. It can be held down.

Furthermore, when applied to the riding rice transplanter 11, the sensing force of the float 21 can be set to a small value, automatic lifting control with good responsiveness can be performed, and the sensing force and compression spring can be easily selected. Since the phenomenon is prevented,
Even if weak seedlings are placed on a seedling stand, pine seedlings can be prevented from falling off, and smooth scraping work can be performed.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a lifting device according to the present invention;
FIG. 2 is a sectional view thereof, FIG. 3 is a diagram showing a control valve in a riding rice transplanter to which the present invention is applied, and FIG. 4 is an overall side view showing the riding rice transplanter. 1...Grounding part (planting part), 2...Link, 5...
...Hydraulic cylinder device, 5a...Piston rod,
6...Bracket, 7...Interlocking member (holder),
9... Retaining ring, 10, 11... Spring, 11
...Work vehicle (riding rice transplanter), 21...Float,
25...Control valve, 26...Elevation control lever.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A work vehicle having a ground-contacting part that is supported so as to be raised and lowered via a link on the traveling body, and a hydraulic cylinder device disposed between the traveling body and the link. An interlocking member connected to the link is slidably supported on the piston rod of the cylinder device, and springs are interposed between both sides of the interlocking member and the piston rod, and the elasticity of both springs is A grounding part elevating device for a work vehicle, in which the spring force is set so that the spring on the opposite side of the spring on which the weight of the grounding part acts is stronger than the spring on the opposite side. (2) The planting part elevating device in a riding rice transplanter according to claim 1, wherein the working vehicle is a riding rice transplanter, and the ground contact part is a planting part.