JPH0433690Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a depth control device for agricultural tractors.

(b) Prior Art It is known that a back switch is provided in an automatic control device for a work machine of an agricultural tractor to automatically raise the work machine when the tractor moves backward.

For example, there is a technique described in Japanese Utility Model Publication No. 55-5530.

(c) Problems to be solved by the invention The present invention not only uses an electric type as the depth control device, but also incorporates a safety raising device during back-shifting into the depth control device.

In addition, when the gear shift lever is placed in reverse, the rotary automatically and momentarily raises, and even if the operator hastily shifts the gear lever from forward to neutral due to this mistake, the rotary immediately switches to lower. Both of these should be avoided as they may injure assisting personnel in the vicinity of the agricultural tractor.

In this invention, the control valve is turned upward by the rotation of the motor, and then rotated upward, so there is some time for the control valve to move upward, and after a certain period of time, the motor always returns it to neutral. , up to this point is configured so that it is always performed as a series of operations. Therefore, even if the gear shift lever is lowered or set to neutral, the shift from neutral to automatic depth control takes the same amount of time as the motor rotates.

Also, if you set the return switch to turn off immediately when the back switch is activated, and if you want to return to automatic mode again, it will not return unless you press the return switch, which will further increase your safety. It is also possible to do this.

(d) Means for solving the problems The problems to be solved by this invention are as described above.
Next, means for solving the problem will be explained.

By turning the tilling depth setting lever 5, the tilling depth is set using the rotary encoder 22, and the tilling depth sensor 1 is set.
The controller 7 compares and judges the feedback signal from the controller 7 with the set value, and rotates the control motor 9 in forward and reverse directions to rotate one end of the depth control bar 40. In the electric depth control device, the position of the spool 15 after sliding is detected by the valve position detection switch 10 and fed back to the controller 7, when the gear shift lever 8 of the agricultural tractor is in automatic mode. Back switch 19 that operates when the gear is shifted to the reverse position
When the back switch 19 is turned on, the automatic mode is turned off, and the valve position detection switch 1 is turned on.
The control motor 9 is driven until the lift arm 13 is raised sufficiently at the "raise" position for t1 time, the spool 15 is configured to return to neutral after the t1 time elapses, and the back switch is activated. When 19 is activated, it will automatically
A return switch 60 that is turned OFF is provided, and when the return switch 60 is turned ON, the depth control automatic mode is restored.

(e) Embodiment The purpose of the present invention is as described above, and the detailed structure of the present invention will be explained based on the structure of the embodiment shown in the attached drawings.

The configuration of the control device will be explained with reference to the drawing in FIG.

A hydraulic case 6 is mounted on the upper surface of a rear axle case 52 of an agricultural tractor, and a lift arm 13 is driven by a hydraulic cylinder 16 within the hydraulic case 6. Lift link 5 to lift arm 13
3 are connected to move the rotary tiller up and down. The rotary tiller is composed of a tiller claw 17, a rear cover 2, a tiller cover 54, etc., and a tiller depth sensor 1 is provided on the tiller cover 54.

Reference numeral 20 denotes a control panel fixed to the dash board panel surface of the agricultural tractor, and an automatic switch 21 and a return switch 6 are mounted on the control panel 20.
0 is set. Automatic switch 21 is "off"
This is a switch for setting the pulse width to ``large'' or ``small.''

The tilling depth value of the depth control is set by rotating the tilling depth setting lever 5. The tilling depth setting lever 5 has a rotary encoder 22 at its tip as shown in Fig. 3.
The plowing depth is set using voltage converters such as the following. A control motor 9 that determines the plowing depth set value by the plowing depth setting lever 5 and the feedback value from the plowing depth sensor 1 using the controller 7, issues forward/reverse rotation commands to the control motor 9, and rotates the depth control bar 40.
It rotates forward and reverse.

Since the commands sent to the control motor are only forward and reverse rotation commands, the actual position of the spool 15 of the control valve 12 (raised, neutral, or lowered) is detected by the valve position detection switch 10, and the controller 7 It feeds back to the motor and determines whether to continue rotating the motor forward, stopping, or reversing.

11 is a rack and pinion case in which a rack and pinion device for slowing down the rotation of the control motor 9 is housed.

Reference numeral 19 is a back switch, which is the essential part of the present invention, and is turned on when the gear shift lever 8 is placed in reverse. Reference numeral 18 denotes a position control switch that is turned on when the position control lever 4 is raised to the highest position, such as when going around the edge of the field.

The specific structure around the hydraulic case 6 will be explained based on the drawings of FIGS. 2, 3, and 4. The fixing plate 2 of the control motor 9 is on the left side of the hydraulic case 6.
A pinion rack case 11 including a pinion 23 and a rack 24 is fixed to the control motor fixing plate 25, and a control motor 9 and a valve position detection switch 10 are fixed to the pinion rack case 11.

Further, as shown in FIG. 3, a lever guide plate 46 is provided on the right side of the hydraulic case 6, and the position control lever 4 and plowing depth setting lever 5 are guided by this lever guide plate 46.

A position control lever switch 18 is also provided on the lever guide 46. Further, a rotary encoder 22 for setting the plowing depth is also fixed to the lever guide 46.

The tilling depth setting lever 5 is a rotary encoder 22
The depth control bar 40 and the spool 15 are not directly moved, but are rotated to change the voltage value. On the other hand, the position control lever 4 rotates to move the arm 37 and link 3 in FIG.
6, the right end of the position control bar 35 is rotated to set the position control position. As a result, when pressure oil enters the hydraulic cylinder 16 and the lift arm 13 rotates, the arm 34 in FIG. 4 rotates via the link 45 and arm 44 in FIG. The left end of the control bar 35 moves in the opposite direction to the direction set by the lever, and the return control is stopped until the spool 15 becomes neutral.

The depth control device is configured to electrically set the settings using a rotary encoder 22, compare this with the feedback plowing depth value from the plowing sensor 1, and gradually move the spool 15 in the upward or downward direction using the control motor 9. It is. The rotation of the control motor 9 is the pinion 2
3. The rotation of the rack gear 24 results in the rotation of the arm 42 in the hydraulic case 6 via the arm and link 26, and the rotation of the right end of the depth control bar 40 via the link 41.

Since the left end of the depth control bar 40 is not related to the tillage setting lever 5, it is fixed approximately at the center by the depth control lever 47, and does not rotate in a fixed state during normal control. However, if the control circuit fails electrically, the control motor 9 stops at the raised position of the spool 15, and when the position control lever 4 cannot lower the rotary tiller, the right lever guide 4
Remove the butterfly bolt 57 from the fixed position of the depth control lever 47 left in the spool 15.
At the very least, only the position control can be used by retracting to the lowering side.

By rotating the depth control lever 47, the depth control bar 40 is moved backward in the downward direction via the arm 38 and the link 39. Reference numeral 51 denotes a contact bar, which is provided in the vertical direction so that both the depth control bar 40 and the position control bar 35 can come into contact with the spool 15.

In this configuration, the present invention operates when the gear shift lever 8 enters reverse during automatic depth control, the back switch 19 is activated, the control motor 9 automatically raises the switch, and after a certain period of time has elapsed, the lift arm is raised. The control motor moves so that the spool becomes neutral again.

Then, turn the return switch 60 OFF,
Even if the gear lever is subsequently returned to forward or neutral,
Once reverse is entered during automatic control, the operations up to this point are always performed, and the return switch 60 must be pressed to return to automatic mode again.

To explain this point using the flowcharts in Figures 5 and 6, PCL is the position control lever switch 18, and the automatic mode is set only when the position control lever switch 18 is OFF and the automatic spool is ON. It is composed of

When the position control lever 4 is raised and the position control switch 18 is turned on, the automatic mode is immediately turned off and the control motor 9 stops regardless of the depth control position.

Further, when the automatic switch is turned off, the control motor is configured to rotate until the spool 15 is in the lower position on the control valve 12, and the rotation of the motor 9 is stopped at that position.

Then, only when the position control lever switch 18 is OFF and the automatic switch 21 is ON, when the back switch 19 of the present invention is turned ON, the flow chart toy shown in FIG. 6 is activated.

That is, when the back switch 19 is turned ON, the automatic mode is turned off and the control motor 9 is driven until the valve position detection switch 10 is set to the "up" position, and the lift arm 1 is moved to the "up" position.
The control motor is stopped for t1 time until the spool 3 has risen sufficiently, and after t1 time, the control motor is rotated in the reverse direction so that the spool 15 returns to neutral, and when the spool 15 reaches neutral, the control motor 9 is turned off.

In this way, even when the gear shift lever goes into reverse, it does not shift immediately like a solenoid valve, but instead shifts by the rotation of the motor 9, so it can be shifted at a single timing, and there is no harm to nearby work assistants. . This one-time timing is shorter than the time it takes for the buried rotary tiller to be compressed and destroyed by the backward movement, so the rotary begins to be raised before the rotary tiller is destroyed.

Then, after climbing up, control valve 12
The spool 15 is always returned to the neutral position once before returning to the automatic circuit.

Although these safety devices are sufficient, the fifth
The flowcharts shown in FIGS. 6 and 6 are configured so that a command to turn off the return switch 60 is issued in addition to this, and in order to enter the automatic mode again, this return switch 60 must be pressed before the automatic mode can be activated. That's what I'm doing.

If you turn on the return switch 60 like this,
Even if the operator panics and returns the gear shift lever to forward or neutral, the work equipment will not descend, which will definitely lead to personal injury.

When the back switch is OFF, the automatic control after that is based on the set plowing depth value V _S , the feedback plowing depth value V ₁ , the adjacent area (V _S + V _D = V _H ), and the dead zone (V _L =
By comparing V _S −V _DZ ), C, D, H, F, and B are controlled.

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

First, even when the gear shift lever 8 goes into reverse, it does not switch immediately like a solenoid valve, but the control valve 12 switches via the depth control bar 40 due to the rotation of the control motor 9, so the shift lever 8 is shifted in one timing. This prevents injury to nearby work assistants.

Second, after ascending, control valve 12
Since the spool 15 is always returned once to the neutral position and then returned to the automatic circuit, it can be raised reliably.

Thirdly, it is turned on by operating the back switch 19.
Since a return switch 6 is provided, even if the gear shift lever 8 is set to forward or neutral again, the control motor 9 will rotate again and the work equipment will not be lowered automatically, thereby preventing personal accidents. This is possible.

[Brief explanation of the drawing]

Fig. 1 is a control block diagram of the depth control device of the invention, Fig. 2 is a left side view of the hydraulic case showing the control motor section, Fig. 3 is a right side view of the hydraulic case showing the control lever section, and Fig. 3 is a right side view of the hydraulic case showing the control lever section. FIG. 4 is a bottom view of the hydraulic case showing the control lever part, and FIGS. 5 and 6 are part of a control flowchart of the depth control provided with a return switch. 1...Plowing depth sensor, 8...Speed lever, 9...
...Control motor, 10...Valve position detection switch, 12...Control valve, 19
...back switch, 15...spool.

Claims (1)

[Scope of utility model registration request] By turning the tilling depth setting lever 5, the tilling depth is set using the rotary encoder 22, and the tilling depth sensor 1 is set.
The controller 7 compares and judges the feedback signal from the controller 7 with the set value, and rotates the control motor 9 in forward and reverse directions to rotate one end of the depth control bar 40. In the electric depth control device, the position of the spool 15 after sliding is detected by the valve position detection switch 10 and fed back to the controller 7, when the gear shift lever 8 of the agricultural tractor is in automatic mode. Back switch 19 that operates when the gear is shifted to the reverse position
When the back switch 19 is turned on, the automatic mode is turned off, and the valve position detection switch 1 is turned on.
The control motor 9 is driven until the lift arm 13 is raised sufficiently at the "raise" position for t1 time, the spool 15 is configured to return to neutral after the t1 time elapses, and the back switch is activated. When 19 is activated, it will automatically
A depth control device for an agricultural tractor, characterized in that a return switch 60 is provided which turns off, and when the return switch 60 is turned on, the automatic mode of the depth control is restored.