JPH0437367Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention connects and supports an agricultural machine to the traveling machine body through a lifting device so that it can be raised and lowered, and when the machine body is reversed or turned, the agricultural machine is automatically raised in conjunction with this. This invention relates to a lifting device for agricultural machinery. Conventionally, as shown in Japanese Utility Model Application No. 55-34723 and Japanese Utility Model Application No. 55-131608, there has been a technique in which when raising an agricultural machine, the raising is stopped at a halfway position without raising it to the end of the stroke. .

However, since the above-mentioned conventional technology detects the raising position step by step by providing a plurality of switches to stop the agricultural machine, the switch is installed near the hydraulic cylinder or lifting support part that raises the agricultural machine. This poses structural problems such as the waterproofness and vibration resistance of the switch, as well as handling problems such as adjusting the switching timing of the switch. It was something I couldn't get.

However, the present invention is provided with a hydraulic cylinder that raises and lowers the agricultural machine, and a switch that operates the hydraulic cylinder in conjunction with reverse or turning operations to raise the agricultural machine, and also operates the hydraulic cylinder via the switch. The present invention is characterized in that a regulator is provided for changing the control time for raising the agricultural working machine, and the control time for raising the agricultural machine is changed by the regulator according to the output of the switch.

Therefore, there is no need for multiple switches to detect the raised position of the agricultural working machine, making it easier to reduce manufacturing costs and improve control stability compared to conventional methods. It can be set in a stepless manner, and a lifting operation suitable for the work situation and location can be easily obtained.

Hereinafter, one embodiment of the present invention will be described in detail based on the drawings.

Fig. 1 is an overall side view of the present invention, in which a rotary tiller 2 is installed at the rear of a tractor 1, which is a traveling machine, and 3 in the figure is a side view of the tractor 1.
4 is the clutch case, 5 is the transmission case, 6 is the front wheel, 7 is the rear wheel, 8 is the engine installed in the
A PTO shaft 9 is a hydraulic lift, which is a hydraulic lifting device equipped with a lift arm 10 and a lifting lever 11;
2 is a driver's seat, 13 is a steering handle, and the working machine 2 is attached to the rear side of the tractor 1 so that it can be raised and lowered via a three-point linkage mechanism 14 that is a lifting mechanism. The three-point link mechanism 14 includes a top link 15 that connects the rear part of the hydraulic lift 19 and the upper central part of the work machine 2.
and a pair of left and right lower links 16, 1 that connect both sides of the lower part of the transmission case 5 and both sides of the front part of the work machine 2.
6, the pair of left and right lift arms 10, 10 provided on the hydraulic lift 9 and the middle of the left and right lower links 16, 16 are connected by lift rods 17, 17, and the lift arms 10, 10 of the hydraulic lift 9 are connected by lift rods 17, 17.
The working machine 2 is configured to be moved up and down by the vertical swing operation of 10.

In addition, 18 in the figure is the tilling rotary of work machine 2, 1
9 is rotary cover, 20 is main beam, 21
is the tail wheel, and 22 is the depth adjust handle.

FIG. 2 is an explanatory diagram of the control system of the hydraulic switching valve 23, which is interposed between the hydraulic lift 9 and the lifting lever 11 and operates the lift arms 10, 10 to swing up and down, and 24 in the figure is an oil tank. , 25 is a strainer,
26 is a line filter, 27 is a gear pump which is a hydraulic pump, 28 is a main relief valve, 2
9 is a slow return stop valve, 30 is a safety valve, and 31 is a hydraulic cylinder of the hydraulic lift 9. , 32 is an unload valve of the switching valve 23, 33 is a main spool, 24 is a flow control valve, 35 is a load check valve, 36 is a mechanical check valve, 37 is a push bar, 38 is a spool bar, and 38 is a spool bar. 11 is connected to the main spool 33 via an operating shaft 39, and by sliding the main spool 33 via the lever 11, oil is appropriately supplied from the pump 27 to the cylinder 31, or oil in the cylinder 31 is transferred to the tank 24. The structure is such that the working machine 2 is raised and lowered by reflux.

By the way, the relief valve 28 and the switching valve 2
A 3-position 4-port electrohydraulic switching valve 40 for automatic operation is interposed between the switching valve 40 and the switching valve 40.
A 2-position, 3-port pilot control valve 42, which is a select valve connected to the switching valve 40 via a pilot-operated check valve 41, is interposed between the switching valve 23 and the slow return stop valve 29. When one solenoid 43 is excited and the switching valve 40 is switched in the direction of the solid line arrow, the switching valve 2
3, the hydraulic pressure from the pump 27 is supplied to the cylinder 31 via the check valve 41 and the control valve 42 to raise the work implement 2, and at the same time, the solenoid 43 is deenergized and the switching valve 40 is placed in the neutral position. At this time, the pilot pressure of the control valve 42 is maintained by the action of the check valve 41, and a self-holding circuit A is formed between the valve 42 and the cylinder 31, and the working machine 2 while holding the rising
When the other solenoid 44 is energized to switch the switching valve 40 in the direction of the dashed arrow, the pilot pressure causes the check valve 41 to flow backwards, returning the control valve 42 to its original free position.

As shown in FIG. 3, reverse and forward detection switches 47 and 48 for detecting reverse and forward running states are installed on the lever guide plate 46 of the main shift lever 45 that performs the gear change operation. 4
When the solenoids 43 and 44 are turned on, the solenoids 43 and 44 are turned on.
It is configured to excite.

FIG. 4 shows this electrical circuit diagram, in which the switches 47 and 48 are connected to the battery 49 via an automatic switch 50, and a lift amount regulator 52 is connected to the drive circuit 51 of the lift operation solenoid 43.
The switch 47 is connected via a timer 53, and when the switch 47 is turned on, the solenoid 43 is energized for a certain period of time set by the regulator 52. As is clear from the above, the switch 47 is provided with a hydraulic cylinder 9 that raises and lowers the agricultural machine 2, and which operates the hydraulic cylinder 9 to raise the agricultural machine 2 in conjunction with reverse or turning operations. A regulator 52 is provided for changing the control time for operating the hydraulic cylinder 9 via the switch 4.
The controller 52 is configured to change the control time for raising the agricultural machine 2 by using the 7 outputs.

In addition, the switch 48 is connected to the drive circuit 54 of the solenoid 44 for canceling the lifting operation via the normally closed timer switch 53b of the timer 53 and the timer 55, and when the solenoid 43 is not energized, the switch 48 is turned on to maintain a constant state. The solenoid 44 is energized for a certain period of time.
Further, a blinking type operating lamp 57 (blinking cycle: 500 milliseconds, duty: 60%) is connected between the switches 47 and 53b via a flip-flop circuit 56, and when the switch 47 is turned on, the lamp 57 is made to blink. , the lamp 57 is turned off even when the switch 48 is turned on.

The present embodiment is configured as described above, and when the work implement 2 is lowered through the switching valve 23 by operating the lift lever 11 during plowing work, the main shift lever 45 is moved to the reverse position. When the switch is switched and the vehicle is driven backward, the switch 47 is turned on, the solenoid 43 is energized for a certain period of time set by the regulator 52, and the switching valve 40 is switched from the neutral position in the direction of the solid arrow in FIG. 2. As a result, the hydraulic pressure from the pump 27 is sent to the control valve 42 via the check valve 41.
In this case, valve 4 is closed by applying pilot pressure.
2 is switched in the direction of the marked arrow, hydraulic pressure is supplied to the cylinder 31, and the working machine 2 is raised.

Next, when the shift lever 45 is returned to the neutral position and the excitation of the solenoid 45 is released, the switching valve 43 is also returned to the neutral position. In this state, the check valve 41 prevents the backflow of hydraulic pressure from the control valve 42, so the control valve 42 maintains its previous operating state and maintains the self-maintenance to maintain the work implement 2 raised between it and the hydraulic cylinder 31. Form circuit A.

When the speed change lever 45 is switched to the forward position again to drive forward, the switch 48 is turned on, the solenoid 44 is energized for a certain period of time, and the switching valve 40 is moved in the direction of the broken line arrow in FIG. Switch. As a result, pilot pressure is applied to the check valve 41, and the oil pressure between it and the control valve 42 is reversed, and the control valve 42 returns to its original neutral state. Then, when the excitation of the solenoid 44 is released and the switching valve 40 is switched to the neutral position again, the pump 2
The hydraulic pressure from 7 is supplied to the manually operated hydraulic pressure switching valve 23, and as a result, the working machine 2 returns to its original lowered state before the switch 47 was operated.

In short, the automatic operation switching valve 40 is operated with priority over the manual operation switching valve 23, and when the control valve 42 is in the neutral position of the switching valve 40 that does not operate, the switching valve 23 is freely operated by the lifting lever 11 and the switching valve 23 is operated freely. Manual elevation control of machine 2 is performed.

As is clear from the above embodiments, the present invention includes a hydraulic cylinder 9 for raising and lowering the agricultural machine 2, and a switch 47 that operates the hydraulic cylinder 9 to raise the agricultural machine 2 in conjunction with a reverse or turning operation.
and a regulator 52 for changing the control time for operating the hydraulic cylinder 9 via the switch 47, and for changing the control time for lifting the agricultural machine 2 by the output of the switch 47. This structure eliminates the need for multiple switches to detect the raised position of the agricultural machine 2, making it easier to reduce manufacturing costs and improve control stability compared to conventional methods. 52 operation, the raising position of the agricultural working machine 2 can be set in a stepless manner, and the raising operation adapted to the working situation and location can be easily obtained.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; Fig. 1 is an overall side view, Fig. 2 is a hydraulic system diagram of the main parts, Fig. 3 is a partial plan view of the main parts, and Fig. 4 is a diagram of the main parts. FIG. DESCRIPTION OF SYMBOLS 1... Traveling machine body, 2... Agricultural working machine, 9... Hydraulic lifting device (hydraulic lift), 52... Lift amount adjustment mechanism (lift amount adjuster).

Claims (1)

[Scope of utility model registration request] It is equipped with a hydraulic cylinder 9 that raises and lowers the agricultural working machine 2, and is provided with a switch 47 that operates the hydraulic cylinder 9 to raise the agricultural working machine 2 in conjunction with reverse or turning operations. A lifting device for an agricultural working machine, characterized in that a regulator 52 is provided to change the control time for operation, and the control time for raising the agricultural working machine 2 is changed by the output of the switch 47. .