JPS5911105A - Apparatus for controlling working angle in agricultural 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 working machine such as a rotary tiller installed on the rear working machine mounting device of an agricultural tractor, with respect to the horizontal line.
This is a device that is controlled so that it can be maintained horizontally or at a constant angle, and is used to free float to follow the unevenness of the ground surface in order to maintain a constant cutting height when mowing grass with a mower as a special task. be.

Conventionally, there have been devices that control work equipment in a horizontal position, but the present invention enables angle control to be controlled to a certain angle in addition to this horizontal control, and of course also allows manual control. In addition to these controls, it also enables free float, which allows the oil pressure/linder to freely extend, for working machines such as mowers, which are advantageous in following the unevenness of the ground surface.

In the case of manual operation, the rotary can be moved up to the right or up to the left by pushing the manual lever up or down, and when the manual lever is released, the hydraulic valve becomes neutral at that position.

In addition, in the case of angle control, when the lift lever is moved to the up position, the hydraulic cylinder returns to the standard central position, and when the lift lever is in any other position, it becomes angle control, and when the manual lever is moved up or down, the hydraulic cylinder returns to the standard position in the center. It rises and falls, but then returns to angle control.

In the case of free float, this can only be done when the lift lever is in the downward position; in any other position, the lift lever always moves to the neutral position of the hydraulic cylinder. While operating the manual lever, it will rise and fall, but when released, the hydraulic cylinder will return to neutral.

The present invention enables such control.

The purpose of the present invention is as described above, and the present invention will be described in detail based on the configuration of the embodiment shown in the accompanying drawings.

Fig. 1 is a perspective view of a rotary tiller equipped with a rotary angle control device, a slide control device, and an auto-pitch device, Fig. 2 is a control block diagram of the rotary angle control device, and Fig. 3 is an electric circuit diagram. , Figure 4 is a hydraulic circuit diagram, Figure 5 is a side view of a part of the angle control cylinder, and Figure 6 is a side view of a part of the angle control cylinder.
The figure is an explanatory diagram of the operation of the comparator made by M-C (M-C) in Fig. 3.

In Figure 1, the lower link (2L) of the three-point link type work equipment mounting device installed at the rear of the agricultural tractor (
2R), and a slide frame (4) for a slide rotary device is pivotally connected to the top link (7).

An angle control hydraulic link 241 is interposed on the right side of one of the lift links connecting the lower link and the lift arms (IL) (IR) of the agricultural tractor. The angle of the rotary tiller with respect to the horizontal plane is controlled by expanding and contracting this angle control oil pressure/linder (24). Slide frame of slide rotary device (4)
A top roller (5) slides inside, and moves the sliding beam +9) L, which is also spanned between the slide frame (4), and the slide hydraulic pressure/linder (10) left and right.

The left and right sides of this hydraulic cylinder (10) and the top roller (
The insertion frame of the automatic hitch device (6) is supported by the three points 5) and 5). In the automatic hitch device (6), both the insertion frame and the receiving frame are triangular in shape, and by inserting the insertion frame from below using the force of a hydraulic lift, the insertion frame naturally matches the receiving frame to complete installation.

The rotary tilling device (
A) is added.

This rotary tiller can be easily installed using the automatic hitch device (6), can be slid left and right using the slide rotary device, and can be controlled at a constant angle with respect to the horizontal plane using the angle control device.

(8) is a hydraulic valve for the slide rotary.

The child control diagram will be explained in Fig. 2.

A manual lever (22) is provided on the control panel (191J2) near the Rafter's seat, and a switching switch (22) is provided.
21) in the manual position.
Lifting solenoid (sol-8u) is activated by operating Ri-t22+.
) or lowering solenoid (sol/Sa) is energized, the angle control control valve (28) is moved upward or downward, and can be controlled manually. In addition, an angle setting dial (15) is provided on the operation panel (19), and this dial allows you to set the value of the voltage (V6, 7), which is the reference voltage of the comparator (MC) in Figure 3. By changing the angle using a variable resistor, the rotary tiller can be tilted at a constant angle such as a 15° right tilted state, a horizontal state, or a 15° left tilted state.

The angle sensor (S) is provided on a part of the rotary tiller or a part of the slide frame, and is a proportional sensor that oscillates a voltage in proportion to the angle. A voltage corresponding to the angle signal sensed here is sent to the terminal (8) of the comparator (M, C) in FIG.

The detailed contents of the control, which is composed of a comparator (MC), transistors, diodes, variable resistors, etc., are shown in dotted lines in FIG. Then, as shown in Fig. 2, press the manual reno < - t22+, selector switch (2]) on the operation panel toward this control section (C).
, a signal from the angle setting dial (15) is sent. Similarly, signals from lift lever position detection switches (Ld) (Lu) provided on the lift lever (two-force guide plate) are also transmitted.

Signals are also sent from four sui-sochi provided to sense the movement state of the angle control hydraulic cylinder (24). They are shown in Figure 5.
), lower limit switch (MfEd), upper position stop detection switch (Ca), lower position stop detection switch (cb
).

The control unit (C) judges the signals from these switches, etc., and selects the angle control hydraulic pressure valve 28+ raising solenoid (S01/su) and lowering solenoid (SO
I/sd) or free float hydraulic valve 9)
(Sol・ff) is excited to control the pressure oil.

The hydraulic circuit will be explained with reference to FIG.

Pump attached to the engine of an agricultural tractor (25)
lift arm (IL) (IR) for controlling work equipment.
) Hydraulic pressure for rotation/Pressure oil is sent to the cylinder (31), but the pressure oil is divided by the flow divider (26) (26+) and used for slide rotary and angle control.

(30) is a hydraulic control valve that controls hydraulic pressure for rotation of the hydraulic lift arm (LL) (IR)/pressure oil to the cylinder (31), and is operated by the lift lever (27) in Fig. 2. It will be done. The movement of this lift lever (27) and angle control are linked in various ways. Next, a flow divider (32) separates the hydraulic control valve (8) for the slide rotary and the hydraulic valve (28) for the angle control device. (9
) is the piston that also serves as the sliding beam in Fig. 1, (10
) is the oil pressure/linder.

Hydraulic valve for angle control (28) K raising solenoid (Sol/Su) and lowering solenoid 1 (sol-sd)
are provided, and by their excitation, pressure oil enters the upper chamber (24u) of the angle control hydraulic cylinder (24), or
It will be decided whether or not to join the royal family (24d). Once in the lower room (2
The reason why the pressure oil that entered the hydraulic valve (4d) leaks out from the hydraulic valve (that cut to the lowered position) into the transmission case, which is the hydraulic oil tank, is due to the equipment of the rotary device.
Since this will result in a fall in the I-C, a four-clause check valve is provided to prevent the fall. The check valve (
33) is a special check valve that stops when the pressure rYII to the upper chamber (24u) exceeds a certain pressure.

- is a free float hydraulic valve, and when the solenoid (eol・ff) of this hydraulic valve is excited, the angle 15 is suppressed oil; the upper chamber (24u) of the cylinder 124J
, the lower chamber (24a) vi directly communicates with the drain, and the piston t17+ can move upward according to the unevenness of the ground surface L')k, resulting in a tree-float shape. . However, since there is a check valve 1" of +1iJ-ilB, the check valve will not open unless the upper chamber pressure r"+pressure B rises, lc, which causes the free float to f(1-)r': In addition, a bypass circuit 1 containing an aperture box is installed to enable tree floating,
Since the pressure oil in the lower chamber C (24d) leaks through the throttle and the intermediary in both manual and automatic gauges, it is constructed to prevent shock and drop.

In addition, in the conventional angle control device, the angle control oil pressure/linder t
When 24+ expanded and contracted to the lower limit or upper limit, the pressure oil was not sent to the flow divider +321 (2G+'s flow divider relief valve continued to blow, so the oil temperature rose and the relief valve chattered). The upper limit switch (MSu) and lower limit switch (MS
d), and when the upper and lower limits are reached, the solenoid (sol
・It is configured to cancel su) and (sol-sd) and return to neutrality.

The control operation state will be explained using the electric circuit shown in FIG.

First, when the selector switch I21) is set to manual, the ground of the comparator terminals (4, 1+12) is connected, and the output terminal +2+
+14+ is the sensor (S) as shown in the comparator output table in Figure 6.
) becomes (H) (H) in all states regardless of the input,
Neither the solenoid (sol-su) nor the solenoid (sol-sd) is energized and maintains a neutral state. In this manual state, manual lever c2
When 2) is turned on, the switch (Hu) closes, the transistor (Trz) closes, and the solenoid (sol/s) closes.
A current flows through u) and it is excited, and the angle control hydraulic valve (2
8) moves in the upward direction and the rotary rises. but,
When the manual lever 122+ is released, the lever returns to neutral due to its spring force, and the current to the solenoid (sol-su) is stopped again and the hydraulic valve (28) also becomes neutral.

Similarly, when the manual lever @ is put in the downward direction, the switch (2) is closed by (Hd), current flows to the solenoid (sol, sd) by the transistor (Tr4), the hydraulic valve moves in the downward direction, and the same as in the upward direction. Manual lever (2
If you change it back to 2+, it becomes neutral.

Next, selector switch c! Set 1) to 1 angle (K), close it, and match it with the angle you want using the angle setting dial (15). The changeover switch (21) can be cut off from the ground state, so if you close the up (Hu) or down (Hd) switch with the manual lever (22), the terminals +21 +141 will be grounded only while you press them, just like when you use the manual lever (22).
The output is (H) (H), but the switch (Hu) (H
Since the interlocking switch in d) turns the circuit to (L), the raising solenoid (sol-su) or (sol-sd) is energized by the transistor (Trz) (Tr4), and the manual operation goes up or down. When the lever (2) is released, the terminal t41 (12) is grounded, so the angle control is performed in response to the input from the sensor (S).

Also, in this angle control state, if the lift lever @ is moved to the up position and the switch (Lu) is closed, the terminal +4) (121
- is grounded and output terminal! 21 (14) is (H)(
H), so the transistor (Trt) (Tr3) remains open.

When either the upper position stop detection switch (cb) or the lower position stop detection switch (Ca) is closed, that is, when there is no piston in the center, the solenoid (Sol/su) or ( S01.ed) is activated, and the hydraulic cylinder is operated to the position where both central switches (Cb) (C, a) are open, that is, to the state shown in FIG. 5, where it becomes neutral. When the lift lever is in the raised position (
Angle control is performed by input from the angle sensor (S) at locations other than when the angle sensor (S) is closed.

Next, let me explain the case of free float.

When the selector switch ) is set to free float (F), the terminals t41t121 of the comparator (MC) are grounded, and the output terminals [2+ +141 become (H) and (H), and neither solenoid is excited. However, from the other interlocking switch to the relay (R) open/close switch (a) (b)
Since either the lower position stop detection switch (cb) or the upper position stop detection switch (Ca) is closed, the solenoid (sol-su) or (sol
-sd) is energized to move to the center state of the 7 cylinder shown in Fig. 5, and the oil pressure/cylinder is controlled to be in the center.

The lift lever (2) can create a free float state.
This is only when the switch (Lcl) is closed by entering the lowered position, and in this case, when (Ld) in Fig. 3 is closed, the relay (R) is activated, and the open/close switches (a) and (b) are closed.
is reversed and switch (a) closes (sol-ff)
is excited, the free float solenoid valve (29) is opened for the first time, and the royal line (24u) and royal house (24a) of the hydraulic 7 cylinder (24) communicate with each other, creating a free float state. From this, no matter how much the selector switch is set to free float (F), unless the lift lever □□□ is in the lowered position, it will not become free flow 1.

Even if the manual lever is moved when the selector switch (2I) is in the free float position, it will only move up or down while the manual lever is moved. However, when the manual lever is returned, the cylinder returns to the center.

To summarize these relationships:

When you change the selector switch to "angle control" and lower the lift, the rotary will tilt to the angle set with the angle setting dial. In order to keep the rotary at the set angle,
This set angle is compared with the signal from the angle sensor, and the solenoid valve is controlled to raise or lower the cylinder.

When the lift is raised, the cylinder returns to the center position and the rotary is in its standard position (left and right lift rods are the same length).

Furthermore, even during angle control, the rotary can be raised or lowered by pressing the manual lever. When you release the lever, it returns to angle control.

By switching to "manual" and moving the manual lever up or down, the rotary can be turned upward to the right or downward to the right 9. When you release the lever, it will stop at that position. When the lift lever is placed in the up position, the 7linder returns to the center.

When switching to "free float" and lowering the lift lever to the -F lowering end, the hydraulic valve 08) becomes free float.

If the lift lever is in any other position, the cylinder will return to the center and the rotary will be in its standard position.

By turning the knob on the variable resistor for adjusting the sensitivity, the sixth
Voltage (v9) to terminal (9) that determines the width from the midpoint to the lower and upper ends of the pulse diagram in the figure, that is, the window value.
can be made larger or smaller, and if the width of 8+v9, which is the sum of the input voltages (v8) and (V9), becomes narrower, the sensitivity becomes more sensitive, and if it becomes wider, the sensitivity becomes less sensitive.

Also, the reference voltage VE has a value of VE-V6.7,
By adjusting the value of V6.7 with the knob of the angle setting variable resistor (15), VE = V6.7 changes,
The angle can be freely set such as 15 degrees to the right and 15 degrees to the left from the horizontal. (16) is a variable resistor for adjustment when an offset value occurs.

In conventional horizontal control devices, the angle sensor was an ON-OFF type sensor that generated a signal when the mercury surface was tilted above a certain level, so the angle could not be controlled without tilting the angle sensor itself. The sensor in this example is a proportional sensing type sensor that emits a voltage value according to the angle of inclination, so the angle can be set by changing the reference voltage VE of the comparator, and by changing the window value. This made it possible to adjust the sensing.

As described above, the present invention provides a configuration in which the left and right inclination angle of the work implement installed in the work implement mounting device of an agricultural tractor is controlled by hydraulic pressure, cylinders, etc. In addition to automatic angle control and manual angle control, the work implement is Since we have also installed Free Flow i control that freely follows the surface, it can be used for tilling sloped land, burying soil, etc., whereas conventional horizontal control of work equipment was only useful for tilling rice fields. This makes it possible to perform free float control of lifting and mower operations, making it a work machine control device that can be used over a wide range of areas.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a rotary tiller equipped with a rotary angle control device, slide control device, auto-pitch device, etc., Figure 2 is a control block diagram of the rotary angle control device, and Figure 3 is an electric circuit diagram. , Figure 4 is a hydraulic circuit diagram, Figure 5 is a side view of a part of the angle control cylinder, and Figure 6 is a side view of a part of the angle control cylinder.
This figure is an explanatory diagram of the operation of the comparator shown in FIG. 3. (Hei... Angle setting dial (variable resistor for angle setting)
(21)... Selector switch (2-way/manual lever (
24) Hydraulic valve for angle control 7 cylinder (28) Hydraulic valve for angle control (29+) Hydraulic valve for free float Applicant Yanmar Diesel Co., Ltd. Yanmar Agricultural Machinery Co., Ltd. Agent Patent attorney Toshikazu Yano

Claims (1)

[Claims] In a configuration where the left and right inclination angle of the work equipment installed on the work equipment mounting device of an agricultural tractor is controlled by a hydraulic cylinder, etc., the work equipment can freely follow the ground surface in addition to automatic angle control and manual angle control. A working machine angle control device for an agricultural tractor, characterized in that it is also equipped with free float control.