JPS602104A - Oil pressure controller in tractor - 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 The present invention provides a hydraulic control device for a tractor that changes the descending speed of a ground working machine such as a rotary tiller in a landing position during work when the running speed of the tractor becomes poor. With the goal.

In general, when the tractor is running at high speed, such as during puddling work, it is better to lower the tractor far away after turning around at the edge of the ridge, in order to improve work efficiency by a factor of 11. Also, even if the rear cover etc. is brought into contact with the ground and plowing work is performed using automatic plowing depth control,
The higher the lowering speed of the hydraulic lifting device, the less undulating the field surface will be and the better the finished product, so it is said that it is desirable to control both "up J" and "down" at approximately the same speed. On the other hand, when working with a rotary tiller, it is recommended to slow down the speed of the implement in order to reduce the shock caused by the rotating tiller claws when landing. is good.

This invention provides a hydraulic control device that is capable of changing the speed of a hydraulic lifting device that suspends a ground-based work machine in accordance with the traveling speed of a tractor to which the work machine is connected. The aim is to provide the following technical measures.

That is, the ground working machine (1) is connected to the rear of the tractor (2) by hydraulic pressure so as to be able to rise and fall freely, and this ground working machine (1)
When the vehicle speed of the tractor (2) that connects and tows the tractor (2) is in a high speed state, the lowering speed of the hydraulic lifting device (3) is increased, and conversely, when the vehicle speed is low, the lowering speed is made slower than in the high speed state. (b) is interposed between the main controller l-0-le)<)rep α side and the cylinder chamber (i) of the hydraulic lifting device (3) (
2) has the configuration of the hydraulic control device.

Since the present invention is configured as described above, it has the following technical effects.

That is, during plowing work, the lowering speed of the work equipment becomes faster, so it is possible to lower the work equipment as soon as the tractor (2) turns and continue the plowing work, and the tractor (2) ) can perform continuous plowing work without having to slow down the travel speed and wait for the work equipment to land, significantly improving work efficiency.

In addition, during rotary tillage work where the vehicle speed is relatively slow, the control pulp (e) is switched so that the lowering speed of the hydraulic lifting device (3) is slow, so the rotary tiller (1) is lowered into hard fields. The shock of landing when the rotary tiller (1) is lowered is reduced, and the rotary tiller (1) Since the fall of the plow due to its own weight is suppressed, the set plowing depth can be maintained at all times, and accurate automatic plowing depth control work can be performed.

A particularly noteworthy feature of the present invention is the automatic plowing depth control operation in which the rear cover etc. are brought into contact with the ground. When plowing work is performed using a tractor (2), the descending speed is relatively delayed due to the faster vehicle speed of the tractor (2), and the field surface is greatly raked (b).However, according to the present invention, the work equipment (1) The speed of the "lower" side of the hydraulic lifting device (3) is changed before landing, and when performing high-speed work like the above-mentioned raking work, the speed of the "lower" side is also fast, so rPJ
The pitch shown in (a) also becomes narrower, which increases the accuracy of the work and significantly improves the finished product.

In the illustrated example, (1) is a rotary tiller connected to the rear of a tractor (2) so that it can be raised and lowered by a hydraulic lifting device (3).
) are the tilling claws (4) and the main cover (
5), main cover (5), rear cover (6) pivoted at the rear
), etc., and the tractor (2) has a lower link (
7), (7), and are connected by a tonoplink (8). (
9) and (9) are lift arms, and (1o and θ@) are lift arms.

Figure 2 is a hydraulic circuit diagram that controls the elevation of this rotary publishing device (1), where (11) is a pump, α-gon is a flow divider valve,
With the Q3id main control pulp, this main control 1 roll valve θ can be switched appropriately with the hydraulic control lever at hand (l→, hydraulic control lever 04) to the upper limit.
position (Fig. 3 f6=) ) and the limit “lower” position (Fig. 3 (
)), the lift arm (9) (9) is moved in proportion to the rotation angle of the operating lever Q4), and the spool (not shown) in the valve 0 [phase] is placed in the neutral position. It is configured to return to and maintain that position. The pressure oil sent through the diversion valve (2) is guided to the proportional control valve OQ through the oil passage o. This proportional control valve αQ is normally closed and has a chamber (16a) that communicates with the tank (mission case) o-no, and opens when the work machine "up" command is received by the rear cover (6) and connects the oil passage 0. Communication room (
161)).

(18) is a valve exclusively for "up" during automatic tilling depth work, which is activated when the rear cover (6) in the neutral state moves upward, that is, when the tilling depth becomes deeper than the set value.
When the rear force /< -(5) moves upward, the solenoid 09) of this valve α8) turns ON, the valve (+8) opens, and the oil passage αυ and oil passage (C) 4 communicate with each other, resulting in proportional control. Switch valve 0 to the empty (16b) side.

(a) eυ is a control pulp that is turned on and off by a solenoid (c), and the valve (a) is a chamber (20
a) and a room (201)) having a communication boat;
In addition, the valve Cυ is a chamber (2) having a check valve (a)
and a room (20b) with a communicating boat, and these two
Both of the two valves (E) (■)) are in communication with the main control pulp (13) via oil passages (W) (C) under normal conditions.

In addition, the symbol (c) (company) in the figure is the oil path, ■ is the IJ 9-f valve, 0])0→ is the check valve, (to) is the variable throttle, ■
is a hydraulic cylinder constituting the tractor's hydraulic lifting device (3), (to) is a piston rod, and (c) is a lift crank.

Fig. 4' shows the operating principle of the control pulp wire, in which the tachometer (b) is connected to the drive pinion (the final drive part) to detect the traveling speed of the tractor (2).
When the lift arm (9) is lowered and enters the working state (range shown in Fig. 2 (a)), the lift arm switch (g) closes and the traveling speed of the tractor (2) increases. When the speed reaches a low speed range suitable for rotary tillage work, the control section operates and the solenoid (A) of the control valve (A) is activated.

Next, the operation of the upper side will be explained.

When performing rotary tillage work while sensing and detecting changes in plowing depth using the rear cover (6), first push down the hydraulic operating lever α→, and then move the operating lever 0← to the desired depth. (Fig. 3) Tilling work is performed in this state, but when there is no change in the plowing depth, that is, the rear cover (6) is in a neutral state (Fig. 2 (
C)), both control valves 400 are switched to the right chambers (20a and (21a)), so the hydraulic fluid in the hydraulic cylinder is the control valve/rev Q1) check valve. This prevents the rotary tiller (1) from returning to the tank α force, thereby preventing the rotary tiller (1) from descending.

Then, when the rotary tiller (1) descends deeper than the set depth, the tiller cover (6) moves upward (Fig. 2←)
), switch the "upper" exclusive valve α to the operating side and switch the proportional control valve 0 → to the chamber (16b) side. Then, the pressure oil sent from the hydraulic pump (l) through the diversion valve a flows into the hydraulic cylinder (b) chamber through the oil passage aυ→chamber (16t))→oil passage (a) in order, and then flows into the hydraulic cylinder (b) chamber. Push the crank (G) to move the lift arm (9) upward and pull the rotary tiller (1) upward until it returns to its original depth.

Conversely, the tiller cover (6), which reduces the plowing depth, rotates downward (as shown in Figure 2), and at this time, the above-mentioned "upper" exclusive valve α barrel and control valve ■υ are left inactive. Then, only the control bar/rev (A) is energized and operates solenoid (A).

Then, the hydraulic oil in the hydraulic cylinder (b) chamber passes through the throttle (to) → oil path (c) → chamber (20a, ) → chamber (21b) → main control valve 03 in order, and is returned to the tank α force, and is returned to the tank α force, which is used for rotary tilling. The device (1) slowly descends, and when it returns to the original set position, the solenoid (A) of the control valve I2υ is energized, and this control valve 0η is switched from the chamber (21b) to the chamber (21a). This prevents further descent.

Note that an explanation of the action of the purge work will be omitted, but when performing the purge work, since the traveling speed of the tractor (2) is fast, the solenoid (A) of the control valve (E) is not energized, and therefore , this control valve is located in the chamber (20b)
When lowering the working machine, the hydraulic oil that returns to tank o71 is often throttled by this control valve (e).

[Brief explanation of drawings]

The figure shows one embodiment of this invention, and Fig. 1 is an explanation of the side symbols (1) Rotary tillage device (2) Tractor (3) Hydraulic lifting device α■ Main control valve 0 (A) Hydraulic operating lever Patent applicant Name: Iseki Agricultural Machinery Co., Ltd. Representative: Akira Takashi Iseki

Claims (1)

[Claims] A ground work equipment is connected to the rear of the tractor so that it can be raised and lowered by hydraulic pressure, and when the vehicle speed of the l-rafter that connects and tows this ground work equipment is in a high speed state, the speed of the lowering side of the hydraulic lifting device is increased, and conversely, when the vehicle speed is low speed. A hydraulic control device for a tractor, characterized in that a control valve is interposed between the main control valve and the cylinder chamber of the hydraulic lifting device, so that the descending speed is slower in the high speed state than in the high speed state.