JPS62115204A - Working machine lifting and falling apparatus of runniing working vehicle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (a) Industrial Application Field The present invention is directed to a traveling working vehicle equipped with a hydraulic lifting device, in which automatic lifting control of a working machine attached to the working machine so as to be able to move up and down becomes impossible to converge. This solves the problem that occurs when the camera is stuck (the so-called hunting phenomenon).

(B) Conventional technology Traditionally, in traveling work vehicles equipped with hydraulic lifting devices, various types of work equipment are mounted so that they can be raised and lowered by link devices, and the work status is detected by a ground sensor installed on the work equipment side. However, feedback was provided directly or via a wire to the hydraulic directional control valve that operated the hydraulic lifting device, so that the working machine was automatically lowered to the A position so as to be in the optimum position.

(c) Problems to be solved by the invention When the work equipment is raised or lowered using automatic lifting control as described above, the ground sensor may collide with an obstacle, or the machine may suddenly start or stop. If the position of the sensor changes unexpectedly and sends out a false signal, the hydraulic directional control valve will pass through the point where it should have returned to the neutral position and will not switch to the up or down position, which is the opposite of the previous operation. However, once such an erroneous operation occurs, factors such as inertia due to the work equipment's own weight, elastic displacement of the link device, and play in the link are added, causing the work equipment to repeatedly rise and fall, resulting in a problem that makes it impossible to converge. occurs, resulting in an inconsistency of the working surfaces.

In particular, in riding rice transplanters, shock-absorbing springs are installed in series to prevent shocks after the elevating cylinder has finished extending and contracting, so that the vertical movement of the link device by the elevating cylinder is not directly transmitted as a shock to the operator on the seat. Therefore, once such a phenomenon occurs, the planting area will be violently vibrated, causing inconvenience to the planting work.

Below, we will take a riding rice transplanter as an example and look at the causes of non-convergence in automatic lifting control.

In a riding rice transplanter, the ground sensor used to maintain a constant planting depth is a float, the rear end is pivoted, the front end can be rotated widely, and the movement of the rotating part is converted into movement of the control wire. That's what I do. Normally, when the planting part rises and falls and the sensor float has soft land against the planting surface, it is detected through the control 1 gear, or directly from the sensor float to the hydraulic directional control valve. The directional control valve is switched from the lower position to the neutral position, and the elevating and lowering cylinder stops expanding and retracting, and at the same time the planting part stops at that position, and the control is known and converged between 11 and 11.

However, if the front end of the sensor float rides on a protruding object such as a clod of earth, the rear end will drop relatively, causing
The float detects the downward direction and switches the hydraulic directional control valve to the vertical position via the control wire. As a result, even if the sensor float rises to the point where the hydraulic directional control valve is in the neutral position, the planting part will be affected by the inertia force due to its own weight, the elastic displacement of the link device, the backlash of the link, etc., as well as the impact buffer spring. This movement immediately switches the hydraulic directional control valve to the lower position, causing the planting section to descend. When descending, due to the same factors mentioned above, the sensor float continues to descend further than the point at which the hydraulic directional control valve is placed in the neutral position, and sends out a signal to switch the control valve to the raised position. It is.

After that, this repetition continues and convergence becomes impossible.

The present invention aims to solve the conventional problem that the control as described above does not converge.

(d) Means for Solving the Problems The objects of the present invention are as described above. Next, the structure for achieving the objects will be explained.

A working machine is supported on a traveling work vehicle so that it can be raised and lowered freely via a link device by a lifting cylinder provided on the traveling working vehicle, and the lifting cylinder is moved by detecting the amount of vertical movement of the ground sensor of the working equipment. In a configuration that provides feedback to and controls the hydraulic directional control valve, a shock absorber that suppresses the rotational movement of the sensor is interposed between the rotational part of the sensor and the working machine side.

Further, the shock absorber is a shock absorber that slows down only the rotation of the ground sensor in the downward direction.

(e) Embodiments and Functions The object structure of the present invention is as described above. Next, the structure and functions of the embodiment of the riding rice transplanter shown in the attached drawings will be explained.

Figure 1 is an overall side view of the riding rice transplanter, Figure 2 is a partial side view of the lifting cylinder and impact buffer spring installed between the traveling device and the link device, and Figure 3 is a partial side view of the sensor float and side view. FIG. 4 is a side view of a portion of the planting depth adjustment lever; FIG. 5 is a side view of the sensor device portion, which is the main part of the present invention; and FIG. 6 is a connection link structure with the sensor float. A side view, FIG. 7 is a side view showing the link devices of FIGS. 5 and 6 overlappingly, FIG. 8 is a side view of the sensor float in a bad state where the rear end rotates around the front end,
Figure 9 is a side view of the ideal sensor state in which the front end of the sensor float rotates around the rear end, Figure 10 is a side view and control curve of a state where control does not converge, and Figure 11 shows control convergence. FIG. 12 is an enlarged sectional view of the shock absorber.

The overall configuration when the traveling work vehicle is closed to the riding rice transplanter in FIG. 1 will be explained.

A riding rice-transplanting vehicle taA, which is a traveling work vehicle, is supported by front wheels 31 and rear wheels 32 composed of lug wheels, and the wheels are grounded on a tiller C in a paddy field to obtain driving force and supporting force for traveling. -ing There is a planting surface made of muddy soil and muddy water on top of the tiller C, and the planting section B, which is a working machine, is in a soft landing state, which may or may not come into contact with this surface.
It is suspended and supported by a link device 4 from the riding rice transplanter A side. Sensor flow 1-7, which serves as a ground sensor, is in the center, and side floats 8L and 8R are on the left and right.
are arranged, but the planting part is not supported by these three floats; these floats only detect the water landing state, and are actually suspended and supported by the link device 4. .

33 is a seat, and a hydraulic directional control valve is switched by an elevator lever 34 next to the seat 33, and the planting section B is raised and lowered. 5 is a seedling stand, and 6 is a planting claw.

As shown in FIG. 2, an elevating cylinder 1 is interposed between the riding rice transplanter A and the link device 4, and the upper end of the elevating cylinder 1 is connected to the link device 4. In addition, as shown in the embodiment, shock-absorbing springs 2 and 3 are interposed between the lifting cylinder 1 and the link device 4, and since the riding rice transplanter is supported by lug wheels, it is easy to transmit vibrations. , the start and stop of the expansion and contraction of the elevating cylinder 1, and the start and stop of the movement of the J part B (=the start and stop of movement of the J part B are directly transmitted to the operator of the seat 33-■-, which tends to cause discomfort, so shocks are designed to absorb these) Buffer spring 2/3
is interposed.

It is composed of three link devices: a toss printer 4T, and left and right lower links 4L and 4R. Part 3
The planting section 1 is connected by a link device 4 composed of wooden links.
3 is supported.

The present invention will be explained in detail with reference to FIGS. 3 to 7.

In this embodiment, the planting section B is a 6-row rice transplanter, and three floats are arranged in the planting section 13. In other words, this is the main part of the present invention. The sensor float 7 in the center and the left and right side floats 8L and 8R make up the ground sensor.The planting depth adjustment device adjusts the positions of the three floats, the sensor float 7 and the side floats 8L and 8R, with a float pivot. It is configured to move up and down in the same manner with respect to the rod 10. That is, the planting depth adjustment lever 9 is configured to be fixed in multiple stages within the lever guide 35, and the planting depth adjustment lever 9 is By raising the planting part B to a height that the operator can reach and then rotating it, the base 9a of the planting depth adjustment lever 9 is fixed to the float pivot rod 10, so the float pivot can be adjusted. The arm 11 is rotated by the rotation of the support rod 10, and the pivot portions at the rear ends of the sensor float 7 and side floats 8L and 8R are moved up and down. The planting claw 6 driven by the planting drive mission case 37 moves up and down, changing the distance between the float and the planting claw 6, and planting. A depth adjustment is made. As shown in FIG. 3, the arm 1 is
1 has protruding parts 11C, 11L, and IIR, and simultaneously moves the sensor float 7 and the left and right side floats 8L and 8R by two degrees for the planting depth adjustment lever.

In addition, in order to prevent the adjustment of the distance between the planting claw 6 and the float by adjusting the planting depth from affecting the change in the feedback value by the sensor float 7, the feedback control wire 26 is connected to the rotation of the planting depth adjustment lever °9. The inner wires 26a of the two are being adjusted at the same time. In this embodiment, the feedback value from the sensor float 7 is generated by pulling the outer wire 26b of the control wire 26.

The adjustment of the inner wire 26a by the planting depth adjustment lever 9 is performed as follows. In other words, as shown in Figure 5, Flow! - An arm 12 is fixed to the pivot rod 10, a link 14 is connected to the tip of the arm 12, and the link 1
One side of the adjustment arm 15 is connected to the tip of the adjustment arm 4.

The adjustment arm 15 is loosely fitted to a shaft 30 that is loosely fitted to a pivot bracket 16, and the pivot bracket 16 is fixed to a planting drive transmission case 37.

The other end of the adjustment arm 15 is provided with a buffer spring 27,
The tips of the inner wires 262 are connected. In this configuration, the pivot bracket 16 is in a fixed state 1 and does not move, and eventually, along with the rotation of the planting depth adjustment lever 9, the adjustment arm 15 rotates about the shaft 30, and the tip position of the inner wire 26a is adjusted. In other words, it is necessary to adjust the A guide rod 28 and a guide pin 29 are provided to prevent the outer wire receiver 22 from escaping when the adjustment arm 15 rotates.

The configuration of the feedback value correction device based on the planting depth adjustment has been described above. Next, the process of creating the feedhack value of the outer wire 26b based on the vertical movement of the sensor float 7 will be described.

The +lK branch 7a at the rear end of the sensor float 7 is fixed to an arm 11 protruding from a float pivot 10, and the front end of the sensor float 7 moves up and down around the pivot 7a to connect the outer part of the control wire 26. wire 26
This is to move b by two degrees. Outer wire 26b
generates a feedback value by pulling the outer wire receiver 22.

As shown in FIGS. 5, 6, and 7, an arm 18 is protruded from the front end of the sensor float 7.
The tip of Arno 19 is pivotally connected to the upper end of the . The rear end of the arm 19 is fixed to a rotation shaft 21 that is loosely fitted and supported by the fixed pivot bracket 16, and the rotation shaft 21 is also loosely supported by the pivot bracket 16. The sensor arm 17 that pulls the outer wire 261) is fixed at the left end. With this configuration, when the front end of the sensor arm I:j-l.7 moves up and down around the pivot 7a, the sensor arm 17 rotates up and down via the arm 18, arm 19, and rotation shaft 21, and the outer The outer wire receiver 22 of the wire 26b is pulled. As a result, the inner wire 268
The relative position of the outer wire 26b changes, and this becomes the feedback value that rotates the arm that switches the hydraulic directional control valve.

Conventionally, this was the only configuration, so for example, when the planting section B is lowered, the sensor float 7 makes a soft landing on the planting surface and moves upward at the same time, switching the hydraulic directional control valve from lowering to neutral. Even if the lifting cylinder 1 stops, the planting part B still descends due to the contraction of the shock buffer spring 2, so the sensor float 7 further rotates upward, and the hydraulic directional control valve immediately changes from neutral to upward. After switching, the planting part B rose again and the sensor float 7 was lowered, and this repetition delayed the convergence of control.

If this state occurs, for example, when a clod of soil is clamped below the front end of the sensor float 7, as in the state shown in FIGS. 8 and 10, the range of vertical movement of the front end of the sensor float 7 becomes small, and the sensor The sensor flow 1 is adjusted to the extent that the hydraulic directional control valve is switched by rotating the front end of the float 7.
If the planting section at the rear of -7 does not move up and down, the hydraulic directional control valve will no longer be switched, and eventually planting section B will rotate greatly to rotate the rear end of Senna float 7. It is.

This rotation gives the shock buffer springs 2 and 3 enough inertia to expand and contract, and the shock buffer springs 2 and 3 will remain forever.
Combined with the large expansion and contraction of 3, the damping coefficient of the control was not kept below 1, resulting in a situation where the control did not converge.

In contrast, in the present invention, a shock absorber 25 is interposed between the adjustment arm 15 and the sensor arm 17.

In this embodiment, the shock absorber 25 is constituted by a hydraulic shock absorber. The buffer device 25 does not function as a buffer device when the sensor float 7 rotates upward, and on the contrary, it does not slowly move the sensor float 7 until the sensor float 7 rotates in the downward direction. It works in the direction of descending. In this way, by using the buffer bag N25 that acts only in one direction, when the planting part B rapidly falls, the buffer device 25 cannot contract rapidly and becomes a rigid body, which prevents the sensor float 7 from being supported. section and shock absorber 25
This allows you to avoid destroying the connection links. The delay in the descending speed of the sensor float 7 due to the buffer device 25 is caused by the planting section 13 once falling to the planting surface, and the front end of the sensor float 7 being pushed up by the planting surface at a normal speed. When the hydraulic directional control valve switches again to the upward direction and the planting section B rises, this time the shock absorber 2
Due to the action of 5, the sensor float 7 does not descend immediately,
- The hydraulic directional control valve is configured so that it is not switched to the lower position, the reaction speed is slowed so that the switching is delayed, and the control is converged at the neutral position.

When the buffer device 25 lowers the planting part B from the raised state to accompany it to the edge of the field after the rotation is completed, the buffer device 25 will be used to loosen the buffer while the planting part B is raised and lowered in both directions. Although it is a fast descent, it is set at such a speed that it descends completely, so it does not affect the lifting and lowering operations at the edge of the field. Further, since the raising and lowering of the planting part B at the edge of the field is independently operated by the raising/lowering lever 34 and switching the hydraulic directional control valve, the shock absorber 25 does not work and have no adverse effect.

The shock absorber 25 begins to exert its influence only when the planting section B is lowered to the top of the planting surface and then raised again. As described above, in the automatic control using the sensor float 7, the switching of the hydraulic directional control valve is delayed by one tempo, so that the control can be converged.

It should be noted that such a shock absorbing device 25 can be applied not only to the above-mentioned riding rice transplanter but also to, for example, a tractor in which the rear cover of a rotary tiller is used as a sensor.

In FIG. 12, details of the shock absorber 25 are shown. The shock absorber 25 is composed of a piston rod 25d and a piston 25b, and the piston 25b has a throttle hole 25a through which hydraulic oil passes when descending, and a check valve 25C that opens when ascending to accelerate the ascending speed. There is.

(F) Effects of the Invention Since the present invention is constructed as described above, it has the following effects.

First, in conventional traveling work vehicles, when certain conditions are met by the ground sensor, the automatic lifting control of the work equipment does not converge and the work equipment continues to swing up and down with a certain amplitude. However, the non-convergence of the control could be resolved by interposing the shock absorber 25 to slow down the movement of the ground sensor in the downward direction. Therefore, the work surface becomes uniform.

Second, by using the shock absorber 25 that acts in one direction, when the work equipment falls rapidly, the shock absorber 25 cannot contract rapidly and becomes rigid, causing the support part of the sensor and This makes it possible to avoid destroying the connection link of the buffer device 25.

[Brief explanation of drawings]

Figure 1 is an overall side view of the riding rice transplanter, Figure 2 is a partial side view of the lifting cylinder and impact buffer spring installed between the traveling device and the link device, and Figure 3 is a partial side view of the sensor float and side view. FIG. 4 is a side view of a portion of the planting depth adjustment lever, FIG. 5 is a side view of the sensor device which is the main part of the present invention, and FIG. 6 is a connection link structure with the sensor float. A side view, FIG. 7 is a side view showing the link devices of FIGS. 5 and 6 overlappingly, FIG. 8 is a side view of the sensor float in a bad state where the rear end rotates around the front end,
Figure 9 is a side view of the ideal sensor state in which the front end of the sensor float rotates around the rear end, Figure 10 is a side view and control curve of a state where control does not converge, and Figure 11 shows control convergence. FIG. 12 is an enlarged sectional view of the shock absorber. A...Travel device B...Planting section C...Plowing plate D...Planting surface 1...Elevating cylinder 2.3...Shock buffer spring 4...Link device 7 ...Sensor float 8L, 8R ...Side float 9 ...Depth adjustment lever 10 ...Float pivot 25 ...Buffer device

Claims (2)

[Claims] (1) A work machine is supported on a traveling work vehicle so that it can be raised and lowered vertically via a link device by a lift cylinder provided on the side of the travel work vehicle, and the amount of vertical movement of a ground sensor of the work machine is detected, In the configuration in which the lifting cylinder is controlled by feedback to the hydraulic directional control valve, a shock absorber for suppressing rotational movement of the sensor is interposed between the rotational part of the sensor and the working machine side. Work equipment lifting device for work vehicles. (2) A work equipment lifting device for a traveling work vehicle, characterized in that the shock absorber according to claim 1 is a shock absorber that slows down only the rotation of the ground sensor in the downward direction.